Measurement of the amount of air that the lungs may contain at various points in the respiratory cycle.
Measurement of the volume of gas in the lungs, including that which is trapped in poorly communicating air spaces. It is of particular use in chronic obstructive pulmonary disease and emphysema. (Segen, Dictionary of Modern Medicine, 1992)
Either of the pair of organs occupying the cavity of the thorax that effect the aeration of the blood.
Method for determining the circulating blood volume by introducing a known quantity of foreign substance into the blood and determining its concentration some minutes later when thorough mixing has occurred. From these two values the blood volume can be calculated by dividing the quantity of injected material by its concentration in the blood at the time of uniform mixing. Generally expressed as cubic centimeters or liters per kilogram of body weight.
The process of generating three-dimensional images by electronic, photographic, or other methods. For example, three-dimensional images can be generated by assembling multiple tomographic images with the aid of a computer, while photographic 3-D images (HOLOGRAPHY) can be made by exposing film to the interference pattern created when two laser light sources shine on an object.
The volume of air remaining in the LUNGS at the end of a normal, quiet expiration. It is the sum of the RESIDUAL VOLUME and the EXPIRATORY RESERVE VOLUME. Common abbreviation is FRC.
The statistical reproducibility of measurements (often in a clinical context), including the testing of instrumentation or techniques to obtain reproducible results. The concept includes reproducibility of physiological measurements, which may be used to develop rules to assess probability or prognosis, or response to a stimulus; reproducibility of occurrence of a condition; and reproducibility of experimental results.
Volume of circulating BLOOD. It is the sum of the PLASMA VOLUME and ERYTHROCYTE VOLUME.
The volume of air contained in the lungs at the end of a maximal inspiration. It is the equivalent to each of the following sums: VITAL CAPACITY plus RESIDUAL VOLUME; INSPIRATORY CAPACITY plus FUNCTIONAL RESIDUAL CAPACITY; TIDAL VOLUME plus INSPIRATORY RESERVE VOLUME plus functional residual capacity; or tidal volume plus inspiratory reserve volume plus EXPIRATORY RESERVE VOLUME plus residual volume.
The failure by the observer to measure or identify a phenomenon accurately, which results in an error. Sources for this may be due to the observer's missing an abnormality, or to faulty technique resulting in incorrect test measurement, or to misinterpretation of the data. Two varieties are inter-observer variation (the amount observers vary from one another when reporting on the same material) and intra-observer variation (the amount one observer varies between observations when reporting more than once on the same material).
Enlargement of air spaces distal to the TERMINAL BRONCHIOLES where gas-exchange normally takes place. This is usually due to destruction of the alveolar wall. Pulmonary emphysema can be classified by the location and distribution of the lesions.
The physical or mechanical action of the LUNGS; DIAPHRAGM; RIBS; and CHEST WALL during respiration. It includes airflow, lung volume, neural and reflex controls, mechanoreceptors, breathing patterns, etc.
The capability of the LUNGS to distend under pressure as measured by pulmonary volume change per unit pressure change. While not a complete description of the pressure-volume properties of the lung, it is nevertheless useful in practice as a measure of the comparative stiffness of the lung. (From Best & Taylor's Physiological Basis of Medical Practice, 12th ed, p562)
The volume of air remaining in the LUNGS at the end of a maximal expiration. Common abbreviation is RV.
A technique of inputting two-dimensional images into a computer and then enhancing or analyzing the imagery into a form that is more useful to the human observer.
Pathological processes involving any part of the LUNG.
The excision of lung tissue including partial or total lung lobectomy.
The visualization of tissues during pregnancy through recording of the echoes of ultrasonic waves directed into the body. The procedure may be applied with reference to the mother or the fetus and with reference to organs or the detection of maternal or fetal disease.
Non-invasive method of demonstrating internal anatomy based on the principle that atomic nuclei in a strong magnetic field absorb pulses of radiofrequency energy and emit them as radiowaves which can be reconstructed into computerized images. The concept includes proton spin tomographic techniques.
The measurement of an organ in volume, mass, or heaviness.
Tomography using x-ray transmission and a computer algorithm to reconstruct the image.
Volume of circulating ERYTHROCYTES . It is usually measured by RADIOISOTOPE DILUTION TECHNIQUE.
Recession of the eyeball into the orbit.
Measurement of the various processes involved in the act of respiration: inspiration, expiration, oxygen and carbon dioxide exchange, lung volume and compliance, etc.
Volume of PLASMA in the circulation. It is usually measured by INDICATOR DILUTION TECHNIQUES.
Binary classification measures to assess test results. Sensitivity or recall rate is the proportion of true positives. Specificity is the probability of correctly determining the absence of a condition. (From Last, Dictionary of Epidemiology, 2d ed)
The volume of the HEART, usually relating to the volume of BLOOD contained within it at various periods of the cardiac cycle. The amount of blood ejected from a ventricle at each beat is STROKE VOLUME.
The volume of air that is exhaled by a maximal expiration following a maximal inspiration.
Fractures of the bones in the orbit, which include parts of the frontal, ethmoidal, lacrimal, and sphenoid bones and the maxilla and zygoma.
Tumors or cancer of the LUNG.
Normal human serum albumin mildly iodinated with radioactive iodine (131-I) which has a half-life of 8 days, and emits beta and gamma rays. It is used as a diagnostic aid in blood volume determination. (from Merck Index, 11th ed)
The volume of air inspired or expired during each normal, quiet respiratory cycle. Common abbreviations are TV or V with subscript T.
Measure of the maximum amount of air that can be expelled in a given number of seconds during a FORCED VITAL CAPACITY determination . It is usually given as FEV followed by a subscript indicating the number of seconds over which the measurement is made, although it is sometimes given as a percentage of forced vital capacity.
Methods developed to aid in the interpretation of ultrasound, radiographic images, etc., for diagnosis of disease.
Helium. A noble gas with the atomic symbol He, atomic number 2, and atomic weight 4.003. It is a colorless, odorless, tasteless gas that is not combustible and does not support combustion. It was first detected in the sun and is now obtained from natural gas. Medically it is used as a diluent for other gases, being especially useful with oxygen in the treatment of certain cases of respiratory obstruction, and as a vehicle for general anesthetics. (Dorland, 27th ed)
The visualization of deep structures of the body by recording the reflections or echoes of ultrasonic pulses directed into the tissues. Use of ultrasound for imaging or diagnostic purposes employs frequencies ranging from 1.6 to 10 megahertz.
Damage to any compartment of the lung caused by physical, chemical, or biological agents which characteristically elicit inflammatory reaction. These inflammatory reactions can either be acute and dominated by NEUTROPHILS, or chronic and dominated by LYMPHOCYTES and MACROPHAGES.
The range or frequency distribution of a measurement in a population (of organisms, organs or things) that has not been selected for the presence of disease or abnormality.
Computer systems or networks designed to provide radiographic interpretive information.
The age of the conceptus, beginning from the time of FERTILIZATION. In clinical obstetrics, the gestational age is often estimated as the time from the last day of the last MENSTRUATION which is about 2 weeks before OVULATION and fertilization.
Observation of a population for a sufficient number of persons over a sufficient number of years to generate incidence or mortality rates subsequent to the selection of the study group.
The amount of BLOOD pumped out of the HEART per beat, not to be confused with cardiac output (volume/time). It is calculated as the difference between the end-diastolic volume and the end-systolic volume.
Physiologically, the opposition to flow of air caused by the forces of friction. As a part of pulmonary function testing, it is the ratio of driving pressure to the rate of air flow.
The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed.). This does not include tissue respiration (= OXYGEN CONSUMPTION) or cell respiration (= CELL RESPIRATION).
The musculofibrous partition that separates the THORACIC CAVITY from the ABDOMINAL CAVITY. Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION.
The amount of a gas taken up, by the pulmonary capillary blood from the alveolar gas, per minute per unit of average pressure of the gradient of the gas across the BLOOD-AIR BARRIER.
The act of BREATHING in.
A pathological accumulation of air in tissues or organs.
The extra volume of air that can be expired with maximum effort beyond the level reached at the end of a normal, quiet expiration. Common abbreviation is ERV.
The exchange of OXYGEN and CARBON DIOXIDE between alveolar air and pulmonary capillary blood that occurs across the BLOOD-AIR BARRIER.
A vertical distance measured from a known level on the surface of a planet or other celestial body.
An autonomous region located in central Asia, within China.
The force per unit area that the air exerts on any surface in contact with it. Primarily used for articles pertaining to air pressure within a closed environment.
Works containing information articles on subjects in every field of knowledge, usually arranged in alphabetical order, or a similar work limited to a special field or subject. (From The ALA Glossary of Library and Information Science, 1983)
I'm sorry for any confusion, but "Colorado" is a place, specifically a state in the United States, and does not have a medical definition. If you have any questions about medical conditions or terminology, I would be happy to help with those!
Multiple symptoms associated with reduced oxygen at high ALTITUDE.

Double-blind intervention trial on modulation of ozone effects on pulmonary function by antioxidant supplements. (1/1040)

The aim of this study was to investigate whether the acute effects of ozone on lung function could be modulated by antioxidant vitamin supplementation in a placebo-controlled study. Lung function was measured in Dutch bicyclists (n = 38) before and after each training session on a number of occasions (n = 380) during the summer of 1996. The vitamin group (n = 20) received 100 mg of vitamin E and 500 mg of vitamin C daily for 15 weeks. The average ozone concentration during exercise was 77 microg/m3 (range, 14-186 microg/m3). After exclusion of subjects with insufficient compliance from the analysis, a difference in ozone exposure of 100 microg/m3 decreased forced expiratory volume in 1 second (FEV1) 95 ml (95% confidence interval (CI) -265 to -53) in the placebo group and 1 ml (95% CI -94 to 132) in the vitamin group; for forced vital capacity, the change was -125 ml (95% CI -384 to -36) in the placebo group and -42 ml (95% CI -130 to 35) in the vitamin group. The differences in ozone effect on lung function between the groups were statistically significant. The results suggest that supplementation with the antioxidant vitamins C and E confers partial protection against the acute effects of ozone on FEV1 and forced vital capacity in cyclists.  (+info)

Evaluation of pulmonary volumetric morphometry at the light and electron microscopy level in several species of passerine birds. (2/1040)

The lungs of 3 small passerine species, having similar body mass but different diurnal activity patterns, were analysed morphometrically to assess the relationship between diurnal activity and pulmonary volumetry at the light and electron microscope levels. The percentage volumes of the major lung and exchange tissue components of the 3 species--an aerial insectivore, a foliage gleaner/nectarivore and a ground forager--were strikingly similar, and consistent with literature values for other passerine species. The only significant difference found was exchange tissue plasma volume and pulmonary haematocrit, with the ground-foraging, low activity Malurus splendens having significantly lower values than the other 2 species. This may indicate that cardiovascular parameters are more important determinants of metabolic activity in small passerines than aspects of pulmonary anatomy.  (+info)

Expiratory and inspiratory chest computed tomography and pulmonary function tests in cigarette smokers. (3/1040)

This study evaluated small airway dysfunction and emphysematous destruction of lung parenchyma in cigarette smokers, using chest expiratory high-resolution computed tomography (HRCT) and pulmonary function tests (PFT). The degree of emphysematous destruction was classified by visual scoring (VS) and the average HRCT number at full expiration/full inspiration (E/I ratio) calculated in 63 male smokers and 10 male nonsmokers (group A). The Brinkman smoking index (BI), defined as cigarettes x day(-1) x yrs, was estimated. Sixty-three smokers were divided into three groups by PFT: group B1 (n=7), with normal PFT; group B2 (n=21), with diffusing capacity of the lung for carbon monoxide (DL,CO) > or = 80% predicted, forced expiratory volume in one second (FEV1) < 80% pred and/or residual volume (RV) > 120% pred; and group B3 (n=35), with DL,CO < 80% pred, FEV1 < 80% pred and/or RV > 120% pred. Heavy smokers (BI > or = 600) (n=48) showed a significant increase in emphysema by both VS and E/I. E/I was significantly elevated in both group B2 (mean+/-SD 0.95+/-0.05) and B3 (0.96+/-0.06) compared with group B1 (0.89+/-0.03). VS could not differentiate group B2 (3.9+/-5.0) from B1 (1.1+/-1.6). These findings suggest that the expiration/inspiration ratio reflects hyperinflation and airway obstruction, regardless of the functional characteristics of emphysema, in cigarette smokers.  (+info)

Human lung volumes and the mechanisms that set them. (4/1040)

Definitions of human lung volumes and the mechanisms that set them are reviewed in the context of pulmonary function testing, with attention to the distinction between functional residual capacity (FRC) and the static relaxation volume of the respiratory system, and to the circumstances in which FRC and residual volume are set by dynamic rather than by static mechanisms. Related terms, conventions, and issues are addressed, including some common semantic and conceptual difficulties, with attention to "gas trapping", "hyperinflation", and "restriction".  (+info)

Compliance and stability of the bronchial wall in a model of allergen-induced lung inflammation. (5/1040)

Airway wall remodeling in response to inflammation might alter load on airway smooth muscle and/or change airway wall stability. We therefore determined airway wall compliance and closing pressures in an animal model. Weanling pigs were sensitized to ovalbumin (OVA; ip and sc, n = 6) and were subsequently challenged three times with OVA aerosol. Control pigs received 0.9% NaCl (n = 4) in place of OVA aerosol. Bronchoconstriction in vivo was assessed from lung resistance and dynamic compliance. Semistatic airway compliance was recorded ex vivo in isolated segments of bronchus, after the final OVA aerosol or 0.9% NaCl challenge. Internally or externally applied pressure needed to close bronchial segments was determined in the absence or presence of carbachol (1 microM). Sensitized pig lungs exhibited immediate bronchoconstriction to OVA aerosol and also peribronchial accumulations of monocytes and granulocytes. Compliance was reduced in sensitized bronchi in vitro (P < 0.01), and closing pressures were increased (P < 0.05). In the presence of carbachol, closing pressures of control and sensitized bronchi were not different. We conclude that sensitization and/or inflammation increases airway load and airway stability.  (+info)

System identification of closed-loop cardiovascular control mechanisms: diabetic autonomic neuropathy. (6/1040)

We applied cardiovascular system identification (CSI) to characterize closed-loop cardiovascular regulation in patients with diabetic autonomic neuropathy (DAN). The CSI method quantitatively analyzes beat-to-beat fluctuations in noninvasively measured heart rate, arterial blood pressure (ABP), and instantaneous lung volume (ILV) to characterize four physiological coupling mechanisms, two of which are autonomically mediated (the heart rate baroreflex and the coupling of respiration, measured in terms of ILV, to heart rate) and two of which are mechanically mediated (the coupling of ventricular contraction to the generation of the ABP wavelet and the coupling of respiration to ABP). We studied 37 control and 60 diabetic subjects who were classified as having minimal, moderate, or severe DAN on the basis of standard autonomic tests. The autonomically mediated couplings progressively decreased with increasing severity of DAN, whereas the mechanically mediated couplings were essentially unchanged. CSI identified differences between the minimal DAN and control groups, which were indistinguishable based on the standard autonomic tests. CSI may provide a powerful tool for assessing DAN.  (+info)

Thoracic gas volume in early childhood. (7/1040)

A total body plethysmograph is descirbed which was used to study thoracic gas volume (TGV) in infants and young children from birth to 2 1/2 years, and was suitable for use even in very sick babies. Normal TGV values were obtained in 42 studies of 35 healthy infants and young children, and 16 children with abnormal lung volume are described. TGV correlated well with length, weight, chest circumference, and age in the healthy infants. A low TGV was found in children with respiratory difficulties after cardiac and thoracic surgery, in respiratory distress syndrome of the newborn, and in association with pulmonary infection and chest cage abnormalities. Abnormally high TGV was most frequently seen in infants with small airways disease.  (+info)

Comparison of two new methods for the measurement of lung volumes with two standard methods. (8/1040)

BACKGROUND: The two most commonly used methods for the measurement of lung volumes are helium dilution and body plethysmography. Two methods have been developed which are both easier and less time consuming to perform. Mathematical modelling uses complex calculations from the flow-volume loop to derive total lung capacity (TLC), and the nitrogen balance technique uses nitrogen from the atmosphere to calculate lung volume in a similar way to helium dilution. This study was designed to compare the two new methods with the two standard methods. METHODS: Sixty one subjects were studied, 23 with normal lung function, 17 with restrictive airway disease, and 21 with obstructive ventilatory defects. Each subject underwent repeated measurements of TLC by each of the four methods in random order. Reproducible values were obtained for each method according to BTS/ARTP guidelines. Bland-Altman plots were constructed for comparisons between the methods and paired t tests were used to assess differences in means. RESULTS: Bland-Altman plots showed that the differences between body plethysmography and helium dilution fell into clinically acceptable ranges (agreement limits +/-0.9 l). The agreement between mathematical modelling or the nitrogen balance technique and helium dilution or body plethysmography was poor (+/-1.8-3.4 l), especially for subjects with airflow obstruction. CONCLUSIONS: Neither of the new methods agrees sufficiently with standard methods to be useful in a clinical setting.  (+info)

Lung volume measurements are clinical tests that determine the amount of air inhaled, exhaled, and present in the lungs at different times during the breathing cycle. These measurements include:

1. Tidal Volume (TV): The amount of air inhaled or exhaled during normal breathing, usually around 500 mL in resting adults.
2. Inspiratory Reserve Volume (IRV): The additional air that can be inhaled after a normal inspiration, approximately 3,000 mL in adults.
3. Expiratory Reserve Volume (ERV): The extra air that can be exhaled after a normal expiration, about 1,000-1,200 mL in adults.
4. Residual Volume (RV): The air remaining in the lungs after a maximal exhalation, approximately 1,100-1,500 mL in adults.
5. Total Lung Capacity (TLC): The total amount of air the lungs can hold at full inflation, calculated as TV + IRV + ERV + RV, around 6,000 mL in adults.
6. Functional Residual Capacity (FRC): The volume of air remaining in the lungs after a normal expiration, equal to ERV + RV, about 2,100-2,700 mL in adults.
7. Inspiratory Capacity (IC): The maximum amount of air that can be inhaled after a normal expiration, equal to TV + IRV, around 3,500 mL in adults.
8. Vital Capacity (VC): The total volume of air that can be exhaled after a maximal inspiration, calculated as IC + ERV, approximately 4,200-5,600 mL in adults.

These measurements help assess lung function and identify various respiratory disorders such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

Whole-body plethysmography is a non-invasive medical technique used to measure changes in the volume of air in the lungs and chest during breathing. It is often utilized in the diagnosis and assessment of various respiratory disorders such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

During whole-body plethysmography, the patient enters a sealed, clear chamber, usually in a standing or sitting position. The patient is instructed to breathe normally while the machine measures changes in pressure within the chamber as the chest and abdomen move during respiration. These measurements are then used to calculate lung volume, airflow, and other respiratory parameters.

This technique provides valuable information about the functional status of the lungs and can help healthcare providers make informed decisions regarding diagnosis, treatment planning, and disease monitoring.

A lung is a pair of spongy, elastic organs in the chest that work together to enable breathing. They are responsible for taking in oxygen and expelling carbon dioxide through the process of respiration. The left lung has two lobes, while the right lung has three lobes. The lungs are protected by the ribcage and are covered by a double-layered membrane called the pleura. The trachea divides into two bronchi, which further divide into smaller bronchioles, leading to millions of tiny air sacs called alveoli, where the exchange of gases occurs.

Blood volume determination is a medical procedure that involves measuring the total amount of blood present in an individual's circulatory system. This measurement is typically expressed in milliliters (mL) or liters (L) and provides important information about the person's overall cardiovascular health and fluid status.

There are several methods for determining blood volume, including:

1. Direct measurement: This involves withdrawing a known volume of blood from the body, labeling the red blood cells with a radioactive or dye marker, reinfusing the cells back into the body, and then measuring the amount of marked cells that appear in subsequent blood samples over time.
2. Indirect measurement: This method uses formulas based on the person's height, weight, sex, and other factors to estimate their blood volume. One common indirect method is the "hemodynamic" calculation, which takes into account the individual's heart rate, stroke volume (the amount of blood pumped by the heart with each beat), and the concentration of hemoglobin in their red blood cells.
3. Bioimpedance analysis: This non-invasive technique uses electrical signals to measure the body's fluid volumes, including blood volume. By analyzing changes in the body's electrical conductivity in response to a small current, bioimpedance analysis can provide an estimate of blood volume.

Accurate determination of blood volume is important for assessing various medical conditions, such as heart failure, shock, anemia, and dehydration. It can also help guide treatment decisions, including the need for fluid replacement or blood transfusions.

Three-dimensional (3D) imaging in medicine refers to the use of technologies and techniques that generate a 3D representation of internal body structures, organs, or tissues. This is achieved by acquiring and processing data from various imaging modalities such as X-ray computed tomography (CT), magnetic resonance imaging (MRI), ultrasound, or confocal microscopy. The resulting 3D images offer a more detailed visualization of the anatomy and pathology compared to traditional 2D imaging techniques, allowing for improved diagnostic accuracy, surgical planning, and minimally invasive interventions.

In 3D imaging, specialized software is used to reconstruct the acquired data into a volumetric model, which can be manipulated and viewed from different angles and perspectives. This enables healthcare professionals to better understand complex anatomical relationships, detect abnormalities, assess disease progression, and monitor treatment response. Common applications of 3D imaging include neuroimaging, orthopedic surgery planning, cancer staging, dental and maxillofacial reconstruction, and interventional radiology procedures.

Functional Residual Capacity (FRC) is the volume of air that remains in the lungs after normal expiration during quiet breathing. It represents the sum of the residual volume (RV) and the expiratory reserve volume (ERV). The FRC is approximately 2.5-3.5 liters in a healthy adult. This volume of air serves to keep the alveoli open and maintain oxygenation during periods of quiet breathing, as well as providing a reservoir for additional ventilation during increased activity or exercise.

Reproducibility of results in a medical context refers to the ability to obtain consistent and comparable findings when a particular experiment or study is repeated, either by the same researcher or by different researchers, following the same experimental protocol. It is an essential principle in scientific research that helps to ensure the validity and reliability of research findings.

In medical research, reproducibility of results is crucial for establishing the effectiveness and safety of new treatments, interventions, or diagnostic tools. It involves conducting well-designed studies with adequate sample sizes, appropriate statistical analyses, and transparent reporting of methods and findings to allow other researchers to replicate the study and confirm or refute the results.

The lack of reproducibility in medical research has become a significant concern in recent years, as several high-profile studies have failed to produce consistent findings when replicated by other researchers. This has led to increased scrutiny of research practices and a call for greater transparency, rigor, and standardization in the conduct and reporting of medical research.

Blood volume refers to the total amount of blood present in an individual's circulatory system at any given time. It is the combined volume of both the plasma (the liquid component of blood) and the formed elements (such as red and white blood cells and platelets) in the blood. In a healthy adult human, the average blood volume is approximately 5 liters (or about 1 gallon). However, blood volume can vary depending on several factors, including age, sex, body weight, and overall health status.

Blood volume plays a critical role in maintaining proper cardiovascular function, as it affects blood pressure, heart rate, and the delivery of oxygen and nutrients to tissues throughout the body. Changes in blood volume can have significant impacts on an individual's health and may be associated with various medical conditions, such as dehydration, hemorrhage, heart failure, and liver disease. Accurate measurement of blood volume is essential for diagnosing and managing these conditions, as well as for guiding treatment decisions in clinical settings.

Total Lung Capacity (TLC) is the maximum volume of air that can be contained within the lungs at the end of a maximal inspiration. It includes all of the following lung volumes: tidal volume, inspiratory reserve volume, expiratory reserve volume, and residual volume. TLC can be measured directly using gas dilution techniques or indirectly by adding residual volume to vital capacity. Factors that affect TLC include age, sex, height, and lung health status.

Observer variation, also known as inter-observer variability or measurement agreement, refers to the difference in observations or measurements made by different observers or raters when evaluating the same subject or phenomenon. It is a common issue in various fields such as medicine, research, and quality control, where subjective assessments are involved.

In medical terms, observer variation can occur in various contexts, including:

1. Diagnostic tests: Different radiologists may interpret the same X-ray or MRI scan differently, leading to variations in diagnosis.
2. Clinical trials: Different researchers may have different interpretations of clinical outcomes or adverse events, affecting the consistency and reliability of trial results.
3. Medical records: Different healthcare providers may document medical histories, physical examinations, or treatment plans differently, leading to inconsistencies in patient care.
4. Pathology: Different pathologists may have varying interpretations of tissue samples or laboratory tests, affecting diagnostic accuracy.

Observer variation can be minimized through various methods, such as standardized assessment tools, training and calibration of observers, and statistical analysis of inter-rater reliability.

Pulmonary emphysema is a chronic respiratory disease characterized by abnormal, permanent enlargement of the airspaces distal to the terminal bronchioles, accompanied by destruction of their walls and without obvious fibrosis. This results in loss of elastic recoil, which leads to trappling of air within the lungs and difficulty exhaling. It is often caused by cigarette smoking or long-term exposure to harmful pollutants. The disease is part of a group of conditions known as chronic obstructive pulmonary disease (COPD), which also includes chronic bronchitis.

Respiratory mechanics refers to the biomechanical properties and processes that involve the movement of air through the respiratory system during breathing. It encompasses the mechanical behavior of the lungs, chest wall, and the muscles of respiration, including the diaphragm and intercostal muscles.

Respiratory mechanics includes several key components:

1. **Compliance**: The ability of the lungs and chest wall to expand and recoil during breathing. High compliance means that the structures can easily expand and recoil, while low compliance indicates greater resistance to expansion and recoil.
2. **Resistance**: The opposition to airflow within the respiratory system, primarily due to the friction between the air and the airway walls. Airway resistance is influenced by factors such as airway diameter, length, and the viscosity of the air.
3. **Lung volumes and capacities**: These are the amounts of air present in the lungs during different phases of the breathing cycle. They include tidal volume (the amount of air inspired or expired during normal breathing), inspiratory reserve volume (additional air that can be inspired beyond the tidal volume), expiratory reserve volume (additional air that can be exhaled beyond the tidal volume), and residual volume (the air remaining in the lungs after a forced maximum exhalation).
4. **Work of breathing**: The energy required to overcome the resistance and elastic forces during breathing. This work is primarily performed by the respiratory muscles, which contract to generate negative intrathoracic pressure and expand the chest wall, allowing air to flow into the lungs.
5. **Pressure-volume relationships**: These describe how changes in lung volume are associated with changes in pressure within the respiratory system. Important pressure components include alveolar pressure (the pressure inside the alveoli), pleural pressure (the pressure between the lungs and the chest wall), and transpulmonary pressure (the difference between alveolar and pleural pressures).

Understanding respiratory mechanics is crucial for diagnosing and managing various respiratory disorders, such as chronic obstructive pulmonary disease (COPD), asthma, and restrictive lung diseases.

Lung compliance is a measure of the ease with which the lungs expand and is defined as the change in lung volume for a given change in transpulmonary pressure. It is often expressed in units of liters per centimeter of water (L/cm H2O). A higher compliance indicates that the lungs are more easily distensible, while a lower compliance suggests that the lungs are stiffer and require more force to expand. Lung compliance can be affected by various conditions such as pulmonary fibrosis, pneumonia, acute respiratory distress syndrome (ARDS), and chronic obstructive pulmonary disease (COPD).

Residual Volume (RV) is the amount of air that remains in the lungs after a forced exhale, also known as the "expiratory reserve volume." It is the lowest lung volume that can be reached during a forced exhalation and cannot be completely emptied due to the presence of alveoli that are too small or too far from the airways. This volume is important for maintaining the structural integrity of the lungs and preventing their collapse. Any additional air that enters the lungs after this point will increase the total lung capacity. The normal residual volume for an average adult human is typically around 1 to 1.5 liters.

Computer-assisted image processing is a medical term that refers to the use of computer systems and specialized software to improve, analyze, and interpret medical images obtained through various imaging techniques such as X-ray, CT (computed tomography), MRI (magnetic resonance imaging), ultrasound, and others.

The process typically involves several steps, including image acquisition, enhancement, segmentation, restoration, and analysis. Image processing algorithms can be used to enhance the quality of medical images by adjusting contrast, brightness, and sharpness, as well as removing noise and artifacts that may interfere with accurate diagnosis. Segmentation techniques can be used to isolate specific regions or structures of interest within an image, allowing for more detailed analysis.

Computer-assisted image processing has numerous applications in medical imaging, including detection and characterization of lesions, tumors, and other abnormalities; assessment of organ function and morphology; and guidance of interventional procedures such as biopsies and surgeries. By automating and standardizing image analysis tasks, computer-assisted image processing can help to improve diagnostic accuracy, efficiency, and consistency, while reducing the potential for human error.

Lung diseases refer to a broad category of disorders that affect the lungs and other structures within the respiratory system. These diseases can impair lung function, leading to symptoms such as coughing, shortness of breath, chest pain, and wheezing. They can be categorized into several types based on the underlying cause and nature of the disease process. Some common examples include:

1. Obstructive lung diseases: These are characterized by narrowing or blockage of the airways, making it difficult to breathe out. Examples include chronic obstructive pulmonary disease (COPD), asthma, bronchiectasis, and cystic fibrosis.
2. Restrictive lung diseases: These involve stiffening or scarring of the lungs, which reduces their ability to expand and take in air. Examples include idiopathic pulmonary fibrosis, sarcoidosis, and asbestosis.
3. Infectious lung diseases: These are caused by bacteria, viruses, fungi, or parasites that infect the lungs. Examples include pneumonia, tuberculosis, and influenza.
4. Vascular lung diseases: These affect the blood vessels in the lungs, impairing oxygen exchange. Examples include pulmonary embolism, pulmonary hypertension, and chronic thromboembolic pulmonary hypertension (CTEPH).
5. Neoplastic lung diseases: These involve abnormal growth of cells within the lungs, leading to cancer. Examples include small cell lung cancer, non-small cell lung cancer, and mesothelioma.
6. Other lung diseases: These include interstitial lung diseases, pleural effusions, and rare disorders such as pulmonary alveolar proteinosis and lymphangioleiomyomatosis (LAM).

It is important to note that this list is not exhaustive, and there are many other conditions that can affect the lungs. Proper diagnosis and treatment of lung diseases require consultation with a healthcare professional, such as a pulmonologist or respiratory therapist.

A pneumonectomy is a surgical procedure in which an entire lung is removed. This type of surgery is typically performed as a treatment for certain types of lung cancer, although it may also be used to treat other conditions such as severe damage or infection in the lung that does not respond to other treatments. The surgery requires general anesthesia and can be quite complex, with potential risks including bleeding, infection, pneumonia, and air leaks. Recovery from a pneumonectomy can take several weeks, and patients may require ongoing rehabilitation to regain strength and mobility.

Prenatal ultrasonography, also known as obstetric ultrasound, is a medical diagnostic procedure that uses high-frequency sound waves to create images of the developing fetus, placenta, and amniotic fluid inside the uterus. It is a non-invasive and painless test that is widely used during pregnancy to monitor the growth and development of the fetus, detect any potential abnormalities or complications, and determine the due date.

During the procedure, a transducer (a small handheld device) is placed on the mother's abdomen and moved around to capture images from different angles. The sound waves travel through the mother's body and bounce back off the fetus, producing echoes that are then converted into electrical signals and displayed as images on a screen.

Prenatal ultrasonography can be performed at various stages of pregnancy, including early pregnancy to confirm the pregnancy and detect the number of fetuses, mid-pregnancy to assess the growth and development of the fetus, and late pregnancy to evaluate the position of the fetus and determine if it is head down or breech. It can also be used to guide invasive procedures such as amniocentesis or chorionic villus sampling.

Overall, prenatal ultrasonography is a valuable tool in modern obstetrics that helps ensure the health and well-being of both the mother and the developing fetus.

Medical Definition:

Magnetic Resonance Imaging (MRI) is a non-invasive diagnostic imaging technique that uses a strong magnetic field and radio waves to create detailed cross-sectional or three-dimensional images of the internal structures of the body. The patient lies within a large, cylindrical magnet, and the scanner detects changes in the direction of the magnetic field caused by protons in the body. These changes are then converted into detailed images that help medical professionals to diagnose and monitor various medical conditions, such as tumors, injuries, or diseases affecting the brain, spinal cord, heart, blood vessels, joints, and other internal organs. MRI does not use radiation like computed tomography (CT) scans.

Organ size refers to the volume or physical measurement of an organ in the body of an individual. It can be described in terms of length, width, and height or by using specialized techniques such as imaging studies (like CT scans or MRIs) to determine the volume. The size of an organ can vary depending on factors such as age, sex, body size, and overall health status. Changes in organ size may indicate various medical conditions, including growths, inflammation, or atrophy.

X-ray computed tomography (CT or CAT scan) is a medical imaging method that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional (tomographic) images (virtual "slices") of the body. These cross-sectional images can then be used to display detailed internal views of organs, bones, and soft tissues in the body.

The term "computed tomography" is used instead of "CT scan" or "CAT scan" because the machines take a series of X-ray measurements from different angles around the body and then use a computer to process these data to create detailed images of internal structures within the body.

CT scanning is a noninvasive, painless medical test that helps physicians diagnose and treat medical conditions. CT imaging provides detailed information about many types of tissue including lung, bone, soft tissue and blood vessels. CT examinations can be performed on every part of the body for a variety of reasons including diagnosis, surgical planning, and monitoring of therapeutic responses.

In computed tomography (CT), an X-ray source and detector rotate around the patient, measuring the X-ray attenuation at many different angles. A computer uses this data to construct a cross-sectional image by the process of reconstruction. This technique is called "tomography". The term "computed" refers to the use of a computer to reconstruct the images.

CT has become an important tool in medical imaging and diagnosis, allowing radiologists and other physicians to view detailed internal images of the body. It can help identify many different medical conditions including cancer, heart disease, lung nodules, liver tumors, and internal injuries from trauma. CT is also commonly used for guiding biopsies and other minimally invasive procedures.

In summary, X-ray computed tomography (CT or CAT scan) is a medical imaging technique that uses computer-processed combinations of many X-ray images taken from different angles to produce cross-sectional images of the body. It provides detailed internal views of organs, bones, and soft tissues in the body, allowing physicians to diagnose and treat medical conditions.

Erythrocyte volume, also known as red cell volume or hematocrit, is the proportion of whole blood that is made up of erythrocytes or red blood cells. It is typically expressed as a percentage and can be measured using a centrifuge to separate the components of a blood sample by density.

The erythrocyte volume is an important clinical parameter because it can provide information about a person's health status, such as their hydration level, altitude acclimatization, and the presence of certain medical conditions like anemia or polycythemia. Changes in erythrocyte volume can also have significant effects on the body's oxygen-carrying capacity and overall cardiovascular function.

Enophthalmos is a medical term that refers to the abnormal positioning of the eyeball within its socket, resulting in a posterior or backward displacement of the eye. This condition can occur due to various reasons such as trauma, surgical procedures, or diseases that affect the orbital tissues, including cancer, inflammation, or infection. Enophthalmos may lead to cosmetic concerns and visual disturbances, depending on its severity. A thorough examination by an ophthalmologist or an oculoplastic surgeon is necessary for accurate diagnosis and management of this condition.

Respiratory Function Tests (RFTs) are a group of medical tests that measure how well your lungs take in and exhale air, and how well they transfer oxygen and carbon dioxide into and out of your blood. They can help diagnose certain lung disorders, measure the severity of lung disease, and monitor response to treatment.

RFTs include several types of tests, such as:

1. Spirometry: This test measures how much air you can exhale and how quickly you can do it. It's often used to diagnose and monitor conditions like asthma, chronic obstructive pulmonary disease (COPD), and other lung diseases.
2. Lung volume testing: This test measures the total amount of air in your lungs. It can help diagnose restrictive lung diseases, such as pulmonary fibrosis or sarcoidosis.
3. Diffusion capacity testing: This test measures how well oxygen moves from your lungs into your bloodstream. It's often used to diagnose and monitor conditions like pulmonary fibrosis, interstitial lung disease, and other lung diseases that affect the ability of the lungs to transfer oxygen to the blood.
4. Bronchoprovocation testing: This test involves inhaling a substance that can cause your airways to narrow, such as methacholine or histamine. It's often used to diagnose and monitor asthma.
5. Exercise stress testing: This test measures how well your lungs and heart work together during exercise. It's often used to diagnose lung or heart disease.

Overall, Respiratory Function Tests are an important tool for diagnosing and managing a wide range of lung conditions.

Plasma volume refers to the total amount of plasma present in an individual's circulatory system. Plasma is the fluid component of blood, in which cells and chemical components are suspended. It is composed mainly of water, along with various dissolved substances such as nutrients, waste products, hormones, gases, and proteins.

Plasma volume is a crucial factor in maintaining proper blood flow, regulating body temperature, and facilitating the transportation of oxygen, carbon dioxide, and other essential components throughout the body. The average plasma volume for an adult human is approximately 3 liters, but it can vary depending on factors like age, sex, body weight, and overall health status.

Changes in plasma volume can have significant effects on an individual's cardiovascular function and fluid balance. For example, dehydration or blood loss can lead to a decrease in plasma volume, while conditions such as heart failure or liver cirrhosis may result in increased plasma volume due to fluid retention. Accurate measurement of plasma volume is essential for diagnosing various medical conditions and monitoring the effectiveness of treatments.

Sensitivity and specificity are statistical measures used to describe the performance of a diagnostic test or screening tool in identifying true positive and true negative results.

* Sensitivity refers to the proportion of people who have a particular condition (true positives) who are correctly identified by the test. It is also known as the "true positive rate" or "recall." A highly sensitive test will identify most or all of the people with the condition, but may also produce more false positives.
* Specificity refers to the proportion of people who do not have a particular condition (true negatives) who are correctly identified by the test. It is also known as the "true negative rate." A highly specific test will identify most or all of the people without the condition, but may also produce more false negatives.

In medical testing, both sensitivity and specificity are important considerations when evaluating a diagnostic test. High sensitivity is desirable for screening tests that aim to identify as many cases of a condition as possible, while high specificity is desirable for confirmatory tests that aim to rule out the condition in people who do not have it.

It's worth noting that sensitivity and specificity are often influenced by factors such as the prevalence of the condition in the population being tested, the threshold used to define a positive result, and the reliability and validity of the test itself. Therefore, it's important to consider these factors when interpreting the results of a diagnostic test.

Cardiac volume refers to the amount of blood contained within the heart chambers at any given point in time. It is a measure of the volume of blood that is being moved by the heart during each cardiac cycle, which includes both systole (contraction) and diastole (relaxation) phases.

There are several types of cardiac volumes that are commonly measured or estimated using medical imaging techniques such as echocardiography or cardiac magnetic resonance imaging (MRI). These include:

1. End-diastolic volume (EDV): This is the volume of blood in the heart chambers at the end of diastole, when the heart chambers are fully filled with blood.
2. End-systolic volume (ESV): This is the volume of blood in the heart chambers at the end of systole, when the heart chambers have contracted and ejected most of the blood.
3. Stroke volume (SV): This is the difference between the EDV and ESV, and represents the amount of blood that is pumped out of the heart with each beat.
4. Cardiac output (CO): This is the product of the stroke volume and heart rate, and represents the total amount of blood that is pumped by the heart in one minute.

Abnormalities in cardiac volumes can indicate various heart conditions such as heart failure, valvular heart disease, or cardiomyopathy.

Vital capacity (VC) is a term used in pulmonary function tests to describe the maximum volume of air that can be exhaled after taking a deep breath. It is the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume. In other words, it's the total amount of air you can forcibly exhale after inhaling as deeply as possible. Vital capacity is an important measurement in assessing lung function and can be reduced in conditions such as chronic obstructive pulmonary disease (COPD), asthma, and other respiratory disorders.

Orbital fractures refer to breaks in the bones that make up the eye socket, also known as the orbit. These bones include the maxilla, zygoma, frontal bone, and palatine bone. Orbital fractures can occur due to trauma, such as a blunt force injury or a penetrating wound.

There are several types of orbital fractures, including:

1. Blowout fracture: This occurs when the thin bone of the orbital floor is broken, often due to a direct blow to the eye. The force of the impact can cause the eyeball to move backward, breaking the bone and sometimes trapping the muscle that moves the eye (the inferior rectus).
2. Blow-in fracture: This type of fracture involves the breakage of the orbital roof, which is the bone that forms the upper boundary of the orbit. It typically occurs due to high-impact trauma, such as a car accident or a fall from a significant height.
3. Direct fracture: A direct fracture happens when there is a break in one or more of the bones that form the walls of the orbit. This type of fracture can result from a variety of traumas, including motor vehicle accidents, sports injuries, and assaults.
4. Indirect fracture: An indirect fracture occurs when the force of an injury is transmitted to the orbit through tissues surrounding it, causing the bone to break. The most common type of indirect orbital fracture is a blowout fracture.

Orbital fractures can cause various symptoms, including pain, swelling, bruising, and double vision. In some cases, the fracture may also lead to enophthalmos (sinking of the eye into the orbit) or telecanthus (increased distance between the inner corners of the eyes). Imaging tests, such as CT scans, are often used to diagnose orbital fractures and determine the best course of treatment. Treatment may include observation, pain management, and in some cases, surgery to repair the fracture and restore normal function.

Lung neoplasms refer to abnormal growths or tumors in the lung tissue. These tumors can be benign (non-cancerous) or malignant (cancerous). Malignant lung neoplasms are further classified into two main types: small cell lung carcinoma and non-small cell lung carcinoma. Lung neoplasms can cause symptoms such as cough, chest pain, shortness of breath, and weight loss. They are often caused by smoking or exposure to secondhand smoke, but can also occur due to genetic factors, radiation exposure, and other environmental carcinogens. Early detection and treatment of lung neoplasms is crucial for improving outcomes and survival rates.

Radio-iodinated serum albumin refers to human serum albumin that has been chemically bonded with radioactive iodine isotopes, typically I-125 or I-131. This results in a radiolabeled protein that can be used in medical imaging and research to track the distribution and movement of the protein in the body.

In human physiology, serum albumin is the most abundant protein in plasma, synthesized by the liver, and it plays a crucial role in maintaining oncotic pressure and transporting various molecules in the bloodstream. Radio-iodination of serum albumin allows for non-invasive monitoring of its behavior in vivo, which can be useful in evaluating conditions such as protein losing enteropathies, nephrotic syndrome, or liver dysfunction.

It is essential to handle and dispose of radio-iodinated serum albumin with proper radiation safety protocols due to its radioactive nature.

Tidal volume (Vt) is the amount of air that moves into or out of the lungs during normal, resting breathing. It is the difference between the volume of air in the lungs at the end of a normal expiration and the volume at the end of a normal inspiration. In other words, it's the volume of each breath you take when you are not making any effort to breathe more deeply.

The average tidal volume for an adult human is around 500 milliliters (ml) per breath, but this can vary depending on factors such as age, sex, size, and fitness level. During exercise or other activities that require increased oxygen intake, tidal volume may increase to meet the body's demands for more oxygen.

Tidal volume is an important concept in respiratory physiology and clinical medicine, as it can be used to assess lung function and diagnose respiratory disorders such as chronic obstructive pulmonary disease (COPD) or asthma.

Forced Expiratory Volume (FEV) is a medical term used to describe the volume of air that can be forcefully exhaled from the lungs in one second. It is often measured during pulmonary function testing to assess lung function and diagnose conditions such as chronic obstructive pulmonary disease (COPD) or asthma.

FEV is typically expressed as a percentage of the Forced Vital Capacity (FVC), which is the total volume of air that can be exhaled from the lungs after taking a deep breath in. The ratio of FEV to FVC is used to determine whether there is obstruction in the airways, with a lower ratio indicating more severe obstruction.

There are different types of FEV measurements, including FEV1 (the volume of air exhaled in one second), FEV25-75 (the average volume of air exhaled during the middle 50% of the FVC maneuver), and FEV0.5 (the volume of air exhaled in half a second). These measurements can provide additional information about lung function and help guide treatment decisions.

Computer-assisted image interpretation is the use of computer algorithms and software to assist healthcare professionals in analyzing and interpreting medical images. These systems use various techniques such as pattern recognition, machine learning, and artificial intelligence to help identify and highlight abnormalities or patterns within imaging data, such as X-rays, CT scans, MRI, and ultrasound images. The goal is to increase the accuracy, consistency, and efficiency of image interpretation, while also reducing the potential for human error. It's important to note that these systems are intended to assist healthcare professionals in their decision making process and not to replace them.

Helium is not a medical term, but it's a chemical element with symbol He and atomic number 2. It's a colorless, odorless, tasteless, non-toxic, inert, monatomic gas that heads the noble gases section of the periodic table. In medicine, helium is sometimes used in medical settings for its unique properties, such as being less dense than air, which can help improve the delivery of oxygen to patients with respiratory conditions. For example, heliox, a mixture of helium and oxygen, may be used to reduce the work of breathing in patients with conditions like chronic obstructive pulmonary disease (COPD) or asthma. Additionally, helium is also used in cryogenic medical equipment and in magnetic resonance imaging (MRI) machines to cool the superconducting magnets.

Ultrasonography, also known as sonography, is a diagnostic medical procedure that uses high-frequency sound waves (ultrasound) to produce dynamic images of organs, tissues, or blood flow inside the body. These images are captured in real-time and can be used to assess the size, shape, and structure of various internal structures, as well as detect any abnormalities such as tumors, cysts, or inflammation.

During an ultrasonography procedure, a small handheld device called a transducer is placed on the patient's skin, which emits and receives sound waves. The transducer sends high-frequency sound waves into the body, and these waves bounce back off internal structures and are recorded by the transducer. The recorded data is then processed and transformed into visual images that can be interpreted by a medical professional.

Ultrasonography is a non-invasive, painless, and safe procedure that does not use radiation like other imaging techniques such as CT scans or X-rays. It is commonly used to diagnose and monitor conditions in various parts of the body, including the abdomen, pelvis, heart, blood vessels, and musculoskeletal system.

Lung injury, also known as pulmonary injury, refers to damage or harm caused to the lung tissue, blood vessels, or air sacs (alveoli) in the lungs. This can result from various causes such as infection, trauma, exposure to harmful substances, or systemic diseases. Common types of lung injuries include acute respiratory distress syndrome (ARDS), pneumonia, and chemical pneumonitis. Symptoms may include difficulty breathing, cough, chest pain, and decreased oxygen levels in the blood. Treatment depends on the underlying cause and may include medications, oxygen therapy, or mechanical ventilation.

Reference values, also known as reference ranges or reference intervals, are the set of values that are considered normal or typical for a particular population or group of people. These values are often used in laboratory tests to help interpret test results and determine whether a patient's value falls within the expected range.

The process of establishing reference values typically involves measuring a particular biomarker or parameter in a large, healthy population and then calculating the mean and standard deviation of the measurements. Based on these statistics, a range is established that includes a certain percentage of the population (often 95%) and excludes extreme outliers.

It's important to note that reference values can vary depending on factors such as age, sex, race, and other demographic characteristics. Therefore, it's essential to use reference values that are specific to the relevant population when interpreting laboratory test results. Additionally, reference values may change over time due to advances in measurement technology or changes in the population being studied.

Computer-assisted radiographic image interpretation is the use of computer algorithms and software to assist and enhance the interpretation and analysis of medical images produced by radiography, such as X-rays, CT scans, and MRI scans. The computer-assisted system can help identify and highlight certain features or anomalies in the image, such as tumors, fractures, or other abnormalities, which may be difficult for the human eye to detect. This technology can improve the accuracy and speed of diagnosis, and may also reduce the risk of human error. It's important to note that the final interpretation and diagnosis is always made by a qualified healthcare professional, such as a radiologist, who takes into account the computer-assisted analysis in conjunction with their clinical expertise and knowledge.

Gestational age is the length of time that has passed since the first day of the last menstrual period (LMP) in pregnant women. It is the standard unit used to estimate the age of a pregnancy and is typically expressed in weeks. This measure is used because the exact date of conception is often not known, but the start of the last menstrual period is usually easier to recall.

It's important to note that since ovulation typically occurs around two weeks after the start of the LMP, gestational age is approximately two weeks longer than fetal age, which is the actual time elapsed since conception. Medical professionals use both gestational and fetal age to track the development and growth of the fetus during pregnancy.

Prospective studies, also known as longitudinal studies, are a type of cohort study in which data is collected forward in time, following a group of individuals who share a common characteristic or exposure over a period of time. The researchers clearly define the study population and exposure of interest at the beginning of the study and follow up with the participants to determine the outcomes that develop over time. This type of study design allows for the investigation of causal relationships between exposures and outcomes, as well as the identification of risk factors and the estimation of disease incidence rates. Prospective studies are particularly useful in epidemiology and medical research when studying diseases with long latency periods or rare outcomes.

Stroke volume is a term used in cardiovascular physiology and medicine. It refers to the amount of blood that is pumped out of the left ventricle of the heart during each contraction (systole). Specifically, it is the difference between the volume of blood in the left ventricle at the end of diastole (when the ventricle is filled with blood) and the volume at the end of systole (when the ventricle has contracted and ejected its contents into the aorta).

Stroke volume is an important measure of heart function, as it reflects the ability of the heart to pump blood effectively to the rest of the body. A low stroke volume may indicate that the heart is not pumping efficiently, while a high stroke volume may suggest that the heart is working too hard. Stroke volume can be affected by various factors, including heart disease, high blood pressure, and physical fitness level.

The formula for calculating stroke volume is:

Stroke Volume = End-Diastolic Volume - End-Systolic Volume

Where end-diastolic volume (EDV) is the volume of blood in the left ventricle at the end of diastole, and end-systolic volume (ESV) is the volume of blood in the left ventricle at the end of systole.

Airway resistance is a measure of the opposition to airflow during breathing, which is caused by the friction between the air and the walls of the respiratory tract. It is an important parameter in respiratory physiology because it can affect the work of breathing and gas exchange.

Airway resistance is usually expressed in units of cm H2O/L/s or Pa·s/m, and it can be measured during spontaneous breathing or during forced expiratory maneuvers, such as those used in pulmonary function testing. Increased airway resistance can result from a variety of conditions, including asthma, chronic obstructive pulmonary disease (COPD), bronchitis, and bronchiectasis. Decreased airway resistance can be seen in conditions such as emphysema or after a successful bronchodilator treatment.

Medical Definition of Respiration:

Respiration, in physiology, is the process by which an organism takes in oxygen and gives out carbon dioxide. It's also known as breathing. This process is essential for most forms of life because it provides the necessary oxygen for cellular respiration, where the cells convert biochemical energy from nutrients into adenosine triphosphate (ATP), and releases waste products, primarily carbon dioxide.

In humans and other mammals, respiration is a two-stage process:

1. Breathing (or external respiration): This involves the exchange of gases with the environment. Air enters the lungs through the mouth or nose, then passes through the pharynx, larynx, trachea, and bronchi, finally reaching the alveoli where the actual gas exchange occurs. Oxygen from the inhaled air diffuses into the blood, while carbon dioxide, a waste product of metabolism, diffuses from the blood into the alveoli to be exhaled.

2. Cellular respiration (or internal respiration): This is the process by which cells convert glucose and other nutrients into ATP, water, and carbon dioxide in the presence of oxygen. The carbon dioxide produced during this process then diffuses out of the cells and into the bloodstream to be exhaled during breathing.

In summary, respiration is a vital physiological function that enables organisms to obtain the necessary oxygen for cellular metabolism while eliminating waste products like carbon dioxide.

A diaphragm is a thin, dome-shaped muscle that separates the chest cavity from the abdominal cavity. It plays a vital role in the process of breathing as it contracts and flattens to draw air into the lungs (inhalation) and relaxes and returns to its domed shape to expel air out of the lungs (exhalation).

In addition, a diaphragm is also a type of barrier method of birth control. It is a flexible dome-shaped device made of silicone that fits over the cervix inside the vagina. When used correctly and consistently, it prevents sperm from entering the uterus and fertilizing an egg, thereby preventing pregnancy.

Pulmonary diffusing capacity, also known as pulmonary diffusion capacity, is a measure of the ability of the lungs to transfer gas from the alveoli to the bloodstream. It is often used to assess the severity of lung diseases such as chronic obstructive pulmonary disease (COPD) and pulmonary fibrosis.

The most common measurement of pulmonary diffusing capacity is the diffusing capacity for carbon monoxide (DLCO), which reflects the transfer of carbon monoxide from the alveoli to the red blood cells in the capillaries. The DLCO is measured during a spirometry test, which involves breathing in a small amount of carbon monoxide and then measuring how much of it is exhaled.

A reduced DLCO may indicate a problem with the lung's ability to transfer oxygen to the blood, which can be caused by a variety of factors including damage to the alveoli or capillaries, thickening of the alveolar membrane, or a decrease in the surface area available for gas exchange.

It is important to note that other factors such as hemoglobin concentration, carboxyhemoglobin level, and lung volume can also affect the DLCO value, so these should be taken into account when interpreting the results of a diffusing capacity test.

Inhalation is the act or process of breathing in where air or other gases are drawn into the lungs. It's also known as inspiration. This process involves several muscles, including the diaphragm and intercostal muscles between the ribs, working together to expand the chest cavity and decrease the pressure within the thorax, which then causes air to flow into the lungs.

In a medical context, inhalation can also refer to the administration of medications or therapeutic gases through the respiratory tract, typically using an inhaler or nebulizer. This route of administration allows for direct delivery of the medication to the lungs, where it can be quickly absorbed into the bloodstream and exert its effects.

Emphysema is a chronic respiratory disease characterized by abnormal, permanent enlargement of the airspaces called alveoli in the lungs, accompanied by destruction of their walls. This results in loss of elasticity and decreased gas exchange efficiency, causing shortness of breath and coughing. It is often caused by smoking or exposure to harmful pollutants. The damage to the lungs is irreversible, but quitting smoking and using medications can help alleviate symptoms and slow disease progression.

Expiratory Reserve Volume (ERV) is the maximum amount of air that can be exhaled forcefully after a normal tidal exhalation. It is the difference between the functional residual capacity (FRC) and the residual volume (RV). In other words, ERV is the extra volume of air that can be exhaled from the lungs after a normal breath out, when one tries to empty the lungs as much as possible. This volume is an important parameter in pulmonary function tests and helps assess lung health and disease. A decreased ERV may indicate restrictive lung diseases such as pulmonary fibrosis or neuromuscular disorders affecting respiratory muscles.

Pulmonary gas exchange is the process by which oxygen (O2) from inhaled air is transferred to the blood, and carbon dioxide (CO2), a waste product of metabolism, is removed from the blood and exhaled. This process occurs in the lungs, primarily in the alveoli, where the thin walls of the alveoli and capillaries allow for the rapid diffusion of gases between them. The partial pressure gradient between the alveolar air and the blood in the pulmonary capillaries drives this diffusion process. Oxygen-rich blood is then transported to the body's tissues, while CO2-rich blood returns to the lungs to be exhaled.

Altitude is the height above a given level, especially mean sea level. In medical terms, altitude often refers to high altitude, which is generally considered to be 1500 meters (about 5000 feet) or more above sea level. At high altitudes, the air pressure is lower and there is less oxygen available, which can lead to altitude sickness in some people. Symptoms of altitude sickness can include headache, dizziness, shortness of breath, and fatigue. It's important for people who are traveling to high altitudes to allow themselves time to adjust to the lower oxygen levels and to watch for signs of altitude sickness.

I'm sorry for any confusion, but "Tibet" is not a medical term. It is a region in Asia that is currently under the political control of China, although it has a distinct cultural and historical heritage. Tibet is geographically located in the Tibetan Plateau, which is the highest region on Earth, with an average elevation of over 14,000 feet (4,267 meters) above sea level.

If you have any questions about medical terminology or health-related topics, I would be happy to try and help answer them for you!

Air pressure, also known as atmospheric pressure, is the force exerted by the weight of air in the atmosphere on a surface. It is measured in units such as pounds per square inch (psi), hectopascals (hPa), or inches of mercury (inHg). The standard atmospheric pressure at sea level is defined as 101,325 Pa (14.7 psi/1013 hPa/29.92 inHg). Changes in air pressure can be used to predict weather patterns and are an important factor in the study of aerodynamics and respiratory physiology.

An encyclopedia is a comprehensive reference work containing articles on various topics, usually arranged in alphabetical order. In the context of medicine, a medical encyclopedia is a collection of articles that provide information about a wide range of medical topics, including diseases and conditions, treatments, tests, procedures, and anatomy and physiology. Medical encyclopedias may be published in print or electronic formats and are often used as a starting point for researching medical topics. They can provide reliable and accurate information on medical subjects, making them useful resources for healthcare professionals, students, and patients alike. Some well-known examples of medical encyclopedias include the Merck Manual and the Stedman's Medical Dictionary.

I believe you are looking for a medical condition or term related to the state of Colorado, but there is no specific medical definition for "Colorado." However, Colorado is known for its high altitude and lower oxygen levels, which can sometimes affect visitors who are not acclimated to the elevation. This can result in symptoms such as shortness of breath, fatigue, and headaches, a condition sometimes referred to as "altitude sickness" or "mountain sickness." But again, this is not a medical definition for Colorado itself.

Altitude sickness, also known as mountain sickness or hypobaropathy, is a condition that can occur when you travel to high altitudes (usually above 8000 feet or 2400 meters) too quickly. At high altitudes, the air pressure is lower and there is less oxygen available for your body to use. This can lead to various symptoms such as:

1. Headache
2. Dizziness or lightheadedness
3. Shortness of breath
4. Rapid heart rate
5. Nausea or vomiting
6. Fatigue or weakness
7. Insomnia
8. Swelling of the hands, feet, and face
9. Confusion or difficulty with coordination

There are three types of altitude sickness: acute mountain sickness (AMS), high-altitude pulmonary edema (HAPE), and high-altitude cerebral edema (HACE). AMS is the mildest form, while HAPE and HACE can be life-threatening.

Preventive measures include gradual ascent to allow your body time to adjust to the altitude, staying hydrated, avoiding alcohol and heavy meals, and taking it easy during the first few days at high altitudes. If symptoms persist or worsen, immediate medical attention is necessary.

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"Lung volume in mechanically ventilated patients: measurement by simplified helium dilution compared to quantitative CT scan". ... when the lung volume equals FRC), if the patient is initially connected to the spirometer at a different lung volume (like TLC ... total gas volume (FRC + volume of spirometer) V1 = volume of gas in spirometer C1 = initial (known) helium concentration C2 = ... The helium dilution technique is the way of measuring the functional residual capacity of the lungs (the volume left in the ...
Work has been done to correlate survival rates to ultrasound measurements of the lung volume as compared to the baby's head ... Pulmonary hypoplasia or decreased lung volume is directly related to the abdominal organs presence in the chest cavity which ... The first condition is a restriction of blood flow through the lungs thought to be caused by defects in the lung. ... This figure known as the lung-to-head ratio (LHR). Still, LHR remains an inconsistent measure of survival. Outcomes of CDH are ...
This type of spirometer gives a more accurate measurement for the components of lung volumes as compared to other conventional ... Measurements of lung function can vary both within and among groups of people, individuals, and spirometer devices. Lung ... 1813, Kentish, E. used a simple "Pulmometer" to study the effect of diseases on pulmonary lung volume. He used an inverted ... A spirometer is an apparatus for measuring the volume of air inspired and expired by the lungs. A spirometer measures ...
Measurement of lung volumes in real time, using optical plethysmography: Postgraduate Course: WS1 Educational Workshop: ... The thoracic volume is calculated from the volume beneath the reconstructed virtual surface and can be plotted in real time. ... Optical measurement of the change in trunk volume with breathing. Peacock A, Gourlay A, Denison D.Bull Eur Physiopathol Respir ... The technique used the distortion with movement of a structured pattern of light to calculate a volume or change in volume of a ...
Lung compliance is defined as the volume change per unit of pressure change across the lung. Measurements of lung volume ... the surface tension varies according to the volume of air in the lungs, which protects them from atelectasis at low volumes and ... The lung's compliance, and ventilation decrease when lung tissue becomes diseased and fibrotic. As the alveoli increase in size ... extracted from calf lung lavage fluid Poractant alfa (Curosurf) - extracted from material derived from minced pig lung ...
... lung compliance MeSH E01.370.386.700.485 - lung volume measurements MeSH E01.370.386.700.485.750 - total lung capacity MeSH ... expiratory reserve volume MeSH E01.370.386.700.485.750.275.650 - residual volume MeSH E01.370.386.700.485.750.900 - vital ... inspiratory reserve volume MeSH E01.370.386.700.485.750.900.350.750 - tidal volume MeSH E01.370.386.700.615 - plethysmography, ... maximal expiratory flow-volume curves MeSH E01.370.386.700.660.225.510 - maximal midexpiratory flow rate MeSH E01.370.386.700. ...
... therefore specific airway resistance attempts to correct for differences in lung volume at which different measurements of ... Due to the elastic nature of the tissue that supports the small airways airway resistance changes with lung volume. It is not ... Similarly to specific airway resistance, specific airway conductance attempts to correct for differences in lung volume. ... Where V is the lung volume at which RAW was measured. Also called volumic airway resistance. ...
This was followed in 1916 by a study of pulmonary statics, with measurements of pressure in the airways at various lung volumes ... In 1915 he published an analysis of the flow of air in the human lung and its relationship to pressure, based on detailed ... Lung Cellular and Molecular Physiology. 317 (6): L785-L790. doi:10.1152/ajplung.00250.2019. PMID 31577160. Roy J. Shephard ( ...
249590087 Standardisation of the measurement of lung volumes J. Wanger, J. L. Clausen, A. Coates, O. F. Pedersen, V. Brusasco, ... American Review of Respiratory Disease, Volume 123, pp.659-664, 1981. P.H. Quanjer. "Lung Volumes and Forced Ventilatory Flows ... Functional residual capacity (FRC) is the volume of air present in the lungs at the end of passive expiration. At FRC, the ... FRC is the sum of expiratory reserve volume (ERV) and residual volume (RV) and measures approximately 3000 mL in a 70 kg, ...
Measurement of static lung volumes using body plethysmography or other techniques typically reveals reduced lung volumes ( ... Plain chest X-rays are unfortunately not diagnostic but may reveal decreased lung volumes, typically with prominent reticular ... The tissue in the lungs becomes thick and stiff, which affects the tissue that surrounds the air sacs in the lungs. Symptoms ... It is a type of chronic scarring lung disease characterized by a progressive and irreversible decline in lung function. ...
... which allowed the measurement of vital capacity of the lungs. However, his spirometer could only measure volume, not airflow. ... Some people may benefit from long-term oxygen therapy, lung volume reduction and lung transplantation. In those who have ... Lung bulla as seen on chest X-ray in a person with severe COPD A severe case of bullous emphysema Axial CT image of the lung of ... There are a number of procedures to reduce the volume of a lung in cases of severe emphysema with hyperinflation. For severe ...
Static lung compliance is the change in volume for any given applied pressure. Dynamic lung compliance is the compliance of the ... In clinical practice it is separated into two different measurements, static compliance and dynamic compliance. ... Compliance is highest at moderate lung volumes, and much lower at volumes which are very low or very high. The compliance of ... Lung compliance, or pulmonary compliance, is a measure of the lung's ability to stretch and expand (distensibility of elastic ...
Conversion Calculator for Units of Volume A Dictionary of Units of Measurement Measurements (Articles with short description, ... Previously there was a roughly 730 mL limit to glass-blown bottles because that was the limit of a glassblower's lungs. The ... Alcohol measurements are units of measurement for determining amounts of beverage alcohol. The following table lists common ... "When is a Cup Not a Cup?" (PDF). Ragged Soldier Sutlery and Vintage Volumes. Retrieved 4 September 2016. "How Many Shots in a ...
Diagnostic measurements that may be relevant include: Lung volumes, including lung capacity, airway resistance, respiratory ... Because the lungs develop late in pregnancy, premature infants frequently possess underdeveloped lungs. To improve blood ... A productive cough and fever may be present with lung infection, and leg edema may suggest heart failure. Lung auscultation can ... forced oscillation technique for calculating the volume, pressure, and air flow in the lungs, bronchodilator responsiveness, ...
The measurement of Stroke Volume Variation (SVV), which predicts volume responsiveness is intrinsic to all arterial waveform ... intrathoracic blood volume and extravascular lung water. Transpulmonary thermodilution allows for less invasive Q calibration ... 2D measurement of the aortic valve diameter is one source of noise; others are beat-to-beat variation in stroke volume and ... MRI flow measurements have been shown to be highly accurate compared to measurements made with a beaker and timer, and less ...
The lungs expand and contract during the breathing cycle, drawing air in and out of the lungs. The volume of air moved in or ... and total lung capacity of about 6 liters) can therefore also not be measured by spirometry. Their measurement requires special ... If the volume of the lungs were to be instantaneously doubled at the beginning of inhalation, the air pressure inside the lungs ... 3): Not all the air in the lungs can be expelled during maximally forced exhalation(ERV). This is the residual volume(volume of ...
The plethysmography technique applies Boyle's law and uses measurements of volume and pressure changes to determine total lung ... There are four lung volumes and four lung capacities. A lung's capacity consists of two or more lung volumes. The lung volumes ... expiratory reserve volume (ERV), and residual volume (RV). The four lung capacities are total lung capacity (TLC), inspiratory ... Changes in lung volumes and capacities from normal are generally consistent with the pattern of lung impairment. Spirometry is ...
The recorded lung volumes and air flow rates are used to distinguish between restrictive disease (in which the lung volumes are ... an apparatus for assessing the mechanical properties of the lungs via measurements of forced exhalation and forced inhalation ... in which the lung volume is normal but the air flow rate is impeded; e.g., emphysema).)[citation needed] The 1851 invention by ... Vital signs are the four signs that can give an immediate measurement of the body's overall functioning and health status. They ...
Calculating compliance on minute volume (VE: ΔV is always defined by tidal volume (VT), but ΔP is different for the measurement ... 2011). "PEEP-induced changes in lung volume in acute respiratory distress syndrome. Two methods to estimate alveolar ... Lung compliance Chest wall compliance Airway resistance Lung compliance is influenced by a variety of primary abnormalities of ... Alterations in airway resistance, lung compliance and chest wall compliance influence Cdyn. C s t a t = V T P p l a t − P E E P ...
Lung volumes and lung capacities refer to the volume of air associated with different phases of the respiratory cycle. Lung ... In combination with other physiological measurements, the vital capacity can help make a diagnosis of underlying lung disease. ... It is equal to the sum of inspiratory reserve volume, tidal volume, and expiratory reserve volume. It is approximately equal to ... whereas lung capacities are inferred from volumes. The vital capacity can be used to help differentiate causes of lung disease ...
... whereas Eulerian methods assign a velocity to a volume of the measurement domain at a given time. A classic example of the ... Duke University (2022-07-27). "4DX Functional Lung Imaging in the Diagnosis of Chronic Lung Allograft Dysfunction After Lung ... and was found to be a sensitive indicator of regional lung disease. Velocimetry was also expanded to 3D regional measurements ... "Altered Lung Motion is a Sensitive Indicator of Regional Lung Disease". Annals of Biomedical Engineering. 40 (5): 1160-1169. ...
EIT lung imaging can resolve the changes in the regional distribution of lung volumes between e.g. dependent and non-dependent ... Thus, EIT measurements may be used to guide specific ventilator settings to maintain lung protective ventilation for each ... Time difference EIT can resolve the changes in the distribution of lung volumes between dependent and non-dependent lung ... In addition to visual information (e.g. regional distribution of tidal volume), EIT measurements provide raw data sets that can ...
Lung volume at any given pressure during inhalation is less than the lung volume at any given pressure during exhalation. ... Measurement of transpulmonary pressure assists in spirometry in availing for calculation of static lung compliance. John B. ... For a given lung volume, the transpulmonary pressure is equal and opposite to the elastic recoil pressure of the lung. The ... Since atmospheric pressure is relatively constant, pressure in the lungs must be higher or lower than atmospheric pressure for ...
... blood pressure measurement (using the sphygmomanometer), change in body volumes (using plethysmograph), audiometry, eye ... the auscultation of heart sounds and lung sounds (using the stethoscope), temperature examination (using thermometers), ...
Variable volume component in a rebreather to take up and release gas during a breathing cycle Cryogenic rebreather - Rebreather ... Lung gas and blood oxygen concentration sufficient to support consciousness only at depth Life support technician - A member of ... Measurement and requirements of function of breathing regulators British commando frogmen - Special Boat Service, whose members ... Relationship between volume and temperature of a gas at constant pressure Checklist - Aide-memoire to ensure consistency and ...
Brazilians use it internally to treat diseases of the lungs. It was formerly an ingredient of ointments and plasters, but at ... Illustration from Natürliche Pflanzenfamilien, Volume 3, 3 (1891). Tree in Mococa, Brazil Groom, A. (2012). "Hymenaea courbaril ... approximate measurements of hardness. For comparison, Douglas fir measures 660 lbf (2,900 N), white oak 1,360 lbf (6,000 N), ... long volume value, Wikipedia articles incorporating a citation from The American Cyclopaedia, Wikipedia articles incorporating ...
Cysts Condyle Volumes Carotid artery segmentation Diffusion MRI Analysis Target definition for cancer radiotherapy lung cancer ... Safi, Ali-Farid (2018). "Does volumetric measurement serve as an imaging biomarker for tumor aggressiveness of ameloblastomas ... The main features of the program are Image navigation three orthogonal cut planes through the image volume are shown at all ... Human brain tumors (e.g., Meningioma) Kauke, Martin Kauke and Ali-Farid Safi (January 2019). "Image segmentation-based volume ...
... lungs round the clock. At this time, Carl-Gunnar Engström had developed one of the first artificial positive-pressure volume- ... Arterial line to directly monitor blood pressure and obtain arterial blood gas measurements Blood draws or venipucture to ... fluids or total parenteral nutrition Bronchoscopy to look at lungs and airways and sample fluid within the lungs Pulmonary ... Volume 148, Issue 11. pp. 801-809. "Physician burnout: It's not you, it's your medical specialty". American Medical Association ...
  • Measurements of absolute lung volumes, residual volume (RV), functional residual capacity (FRC) and total lung capacity (TLC) are technically more challenging, which limits their use in clinical practice. (
  • Determination of the residual volume is more difficult as it is impossible to "completely" breathe out. (
  • Therefore, measurement of the residual volume has to be done via indirect methods such as radiographic planimetry, body plethysmography, closed circuit dilution (including the helium dilution technique) and nitrogen washout. (
  • Standard errors in prediction equations for residual volume have been measured at 579 ml for men and 355 ml for women, while the use of 0.24*FVC gave a standard error of 318 ml. (
  • These studies lack data on residual volume (RV) and therefore functional residual capacity (FRC), which are essential parameters for assessing obstructive and restrictive respiratory diseases. (
  • We measured or derived functional residual capacity, residual volume (RV), vital capacity (VC), and total lung capacity by helium dilution. (
  • It measures the forced vital capacity (FVC), the forced exhaled volume in 1 second (FEV1), total lung capacity, and residual volume. (
  • Mechanisms determining residual volume of the lungs in normal subjects. (
  • Reference values for residual volume, functional residual capacity and total lung capacity. (
  • The present document integrates and consolidates the recommendations of the current American Thoracic Society (ATS)/European Respiratory Society Task Force on pulmonary function standards, and the recommendations from an earlier National Heart, Lung, and Blood Institute (NHLBI) workshop convened by the ATS. (
  • This document updates the 2005 European Respiratory Society (ERS) and American Thoracic Society (ATS) technical standard for the measurement of lung volumes. (
  • Chief Editor James Chalmers and European Respiratory Society President Monika Gappa discuss awareness of child health and its importance for adult lung health. (
  • The researchers looked at spirometry and lung volume measurements and assessed how many were deemed to have breathing impairments under the race-based algorithm as compared to under a new algorithm. (
  • A short history of spirometry and lung function tests . (
  • By measuring how much air you exhale, and how quickly you exhale, spirometry can evaluate a broad range of lung diseases. (
  • Some lung diseases (such as emphysema, asthma, chronic bronchitis, and infections) can make the lungs contain too much air and take longer to empty. (
  • These lung diseases are called obstructive lung disorders. (
  • Other lung diseases make the lungs scarred and smaller so that they contain too little air and are poor at transferring oxygen into the blood. (
  • Muscular weakness can also cause abnormal test results, even if the lungs are normal, that is similar to the diseases that cause smaller lungs. (
  • The interstitial lung diseases (ILDs) are a diverse group of chronic lung conditions characterised by dyspnoea on exertion and poor health related quality of life. (
  • A pulmonologist is a medical doctor specializing in diagnosing and treating respiratory diseases and conditions affecting the lungs and respiratory system. (
  • Diseases such as bronchiolitis obliterans with organizing pneumonia, interstitial lung disease,or neuromuscular limitation, present with restrictive patterns on spirometry. (
  • Other types of respiratory diseases potentially impacted by workplace exposures include chronic obstructive pulmonary disease (or COPD), hypersensitivity pneumonitis, silicosis, lung cancer, and bronchiolitis obliterans. (
  • Those diseases have been characterized as irritant-induced asthma, chronic nonspecific bronchitis, chronic bronchiolitis/small airway disease, and aggravated preexistent chronic obstructive lung disease (most frequently chronic obstructive pulmonary disease, but also asthma), with the expected overlapping features among them. (
  • Longitudinal studies suggest that both the incidence and the associated functional decline of these predominantly obstructive lung diseases stabilized several years ago, but longer follow-up is clearly necessary. (
  • 3.8 million premature deaths annually from noncommunicable diseases including stroke, ischaemic heart disease, chronic obstructive pulmonary disease (COPD) and lung cancer are attributed to exposure to household air pollution. (
  • By reducing air pollution levels, countries can reduce the burden of disease from stroke, heart disease, lung cancer, and both chronic and acute respiratory diseases, including asthma. (
  • In selected cases where the test results are inconclusive or require clarification, complete pulmonary function testing, arterial blood gas measurement, echocardiography and standard exercise treadmill testing or complete cardiopulmonary exercise testing may be useful. (
  • 1999). Before initiating corticosteroid therapy, a baseline chest radiograph, high resolution CT, complete pulmonary function tests (including lung volumes, spirometry, and diffusing capacity), and exercise testing, with arterial blood gas measurements, should be performed. (
  • Pulmonary function tests are a group of tests that measure breathing and how well the lungs are functioning. (
  • Static lung volumes and capacities based on a volume-time spirogram of an inspiratory vital capacity (IVC). (
  • Lung volumes and lung capacities refer to the volume of air in the lungs at different phases of the respiratory cycle. (
  • The assessment of a lung disorder often involves testing how much air the lungs can hold (lung volume) as well as how much and how quickly air can be exhaled (airflow). (
  • Airflow measurements are made with a spirometer, which consists of a mouthpiece and tubing connected to a recording device. (
  • The high-accuracy of lung volume and airflow rate measurements is ensured by high-quality sensors and electronic components used in the spirometer, the individual calibration of each device on a special stand and the use of built-in temperature, atmospheric pressure, and humidity sensors to correct the measured flow and volume values automatically (bringing to BTPS standard). (
  • If an individual has asthma, their doctor may use a measurement of airflow called diurnal variability to assess the condition. (
  • In the presence of airflow limitation, the patient exhales air slowly, while the total volume of air exhaled is generally not affected. (
  • Current guidelines for exercise prescription in chronic lung disease are based on evidence from studies of patients with COPD 7 where respiratory mechanics and peripheral muscle dysfunction are major limitations to exercise capacity. (
  • In mice, fibroblast growth factor (FGF)10 is essential for lung morphogenesis, and in humans, polymorphisms in the human FGF10 gene correlate with an increased susceptibility to develop COPD. (
  • Methods We analysed FGF10 signalling in human lung sections and isolated cells from healthy donor, smoker and COPD lungs. (
  • Results We found impaired FGF10 expression in human lung alveolar walls and in primary interstitial COPD lung fibroblasts. (
  • Using reference equations for predicting normal values appropriate for a particular racial or ethnic group is an integral part of assessing lung function. (
  • of assessing lung function. (
  • Consensus statement on measurements of lung volumes in humans , 2003, 189 pp. (
  • Accurate and reproducible results were obtained in lung model tests during ventilation with air, N2O in O2, and halothane in O2. (
  • Tidal volume increases by 30-40%, from 0.5 to 0.7 litres, and minute ventilation by 30-40% giving an increase in pulmonary ventilation. (
  • Background Effective lung protective ventilation requires reliable, real-time estimation of lung volume at the bedside. (
  • Lung protective ventilation strategies require reliable estimation of lung volume at the bedside. (
  • Differences in incidence of chronic bronchitis and lung ventilation in he workers are not considered to be significant, smoking found to be significantly related to respiratory symptoms in the workers. (
  • During this time three additional subjects had to be switched to nasal mask intermittent positive pressure ventilation delivered by traditional volume cycled home ventilator (volume controlled NIPPV). (
  • The Bod Pod underwent another significant upgrade with the release of the Bod Pod GS-X. This model featured an improved ventilation system, enhanced temperature control, and increased measurement precision. (
  • One important explanation for the detrimental effects of conventional mechanical ventilation is the biotrauma hypothesis that ventilation may trigger proinflammatory responses that subsequently cause lung injury. (
  • Our findings demonstrate a sharp distinction between ventilation with 24 cm H 2 O that was well tolerated and ventilation with 27 cm H 2 O that was lethal for most animals due to catastrophic lung failure. (
  • The expiratory reserve volume (ERV) is the volume of gas that can be maximally exhaled from the end-expiratory level during tidal breathing ( i.e. from the FRC). (
  • The tidal volume, vital capacity, inspiratory capacity and expiratory reserve volume can be measured directly with a spirometer. (
  • Lung mechanics, expressed by forced vital capacity and forced expiratory volume measurements, are slightly lower for the exposed workers than for the control group. (
  • Doctors use a measurement called the percent predicted passive expiratory volume or forced expiratory volume to classify the exacerbation as mild, moderate, severe, or life threatening. (
  • This is defined in spirometry as a reduction in the ratio of the expiratory volume measured in the 1st second of a forceful exhalation (FEV1) to the total volume of air exhaled in the forced expiration (FVC), the FVC being an estimate of the individual's effective lung volume. (
  • Testing at baseline and 1 hour after overhaul included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), serum Clara cell protein (CC16), and serum surfactant-associated protein A (SP-A). Overhaul increased CC16 in both groups, indicating increased alveolarcapillary membrane permeability. (
  • Lung volumes derived from computed tomography (CT) scans can include estimates of abnormal lung tissue volumes, in addition to normal lung tissue volumes and the volume of gas within the lungs. (
  • To review the evidence on screening for lung cancer with low-dose computed tomography (LDCT) to inform the US Preventive Services Task Force (USPSTF). (
  • The role of lung volume measurements in the assessment of disease severity, functional disability, course of disease and response to treatment remains to be determined in infants, as well as in children and adults. (
  • The NCCN advises that patients are not eligible for lung cancer screening if they have symptoms of lung cancer, a past history of lung cancer, or functional status and/or comorbidity that would prohibit curative intent treatment. (
  • Specific changes in lung volumes also occur during pregnancy. (
  • Objective To determine the ability of lung ultrasound (LUS) of the dependent region to detect real-time changes in lung volume, identify opening and closing pressures of the lung, and detect pulmonary hysteresis. (
  • Conclusion LUS was able to detect large changes in total and regional lung volume in real time and correctly identified opening and closing pressures but lacked the precision to detect small changes in lung volume. (
  • The objective of the study was to determine the sensitivity of these techniques in detecting small changes in lung water. (
  • Bronchopulmonary dysplasia (BPD) is a multifactorial chronic lung disease that contributes to disruption of pulmonary development. (
  • Neonatal chronic lung disease, also known as bron- sidual volume7-24. (
  • As with chronic lung disease of other etiologies, one should evaluate for bacterial respiratory infections and should treat infections promptly with antibiotics when indicated, especially for those on immunosuppressive therapy. (
  • Objectives An increase in lung nodule volume on serial CT may represent true growth or measurement variation. (
  • Contrast-enhanced volume ratio was calculated as the ratio between contrast-enhanced and unenhanced nodule volume. (
  • to our knowledge, only one other study has evaluated lung nodule volume variability before and after contrast medium injection [ 12 ], but none has determined the influence of different CT scan delays on volumetric variation. (
  • Image shows lung nodule volume (cubic millimeters) and density (Hounsfield units) of unenhanced (0 second) and contrast-enhanced CT scans performed at 30, 60, 120, 180, and 300 seconds, calculated with LungCARE software (Siemens Healthcare). (
  • Medical History and Physical Examination for Lung Disorders A doctor first asks the person about symptoms. (
  • In respiratory physiology and sleep sciences, you'll perform a wide range of routine and highly complex diagnostic tests to assess all aspects of lung function and assess sleep disorders by using a variety of non-invasive sleep measuring systems. (
  • ABSTRACT There is insufficient information about reference values for pulmonary volumes for Iranian populations. (
  • Nevertheless, in particular circumstances, measurements of lung volume are strictly necessary for a correct physiological diagnosis 1 . (
  • This study, published in JAMA Network Open, offers one of the first real-world examples of how the issue may affect diagnosis and care for lung patients, said Dr. Darshali Vyas, a pulmonary care doctor at Massachusetts General Hospital. (
  • To reduce intra- and interobserver variability of manual measurements [ 1 , 2 ], some authors [ 3 , 4 ] recommend automated volume calculation as a reliable tool to evaluate potential nodule variation that, in clinical practice, could drastically influence the diagnosis and eventual therapeutic choices. (
  • The guideline set of more than 275 recommendations includes an executive summary of current recommendations for diagnosis and treatment, along with additional recommendations for screening, chemoprevention and treatment of tobacco use in patients with lung cancer. (
  • These results suggest that (1) tests of small airway function, such as RV and delta N2, are more sensitive than radiographic techniques to small increases in lung water, (2) there is some protection of the lung to increases in extracellular fluid volume. (
  • In respiratory physiology , you'll work with patients who have lung, chest wall, airway or blood oxygenation problems to understand the causes of their disorder and the response to and monitoring of treatment. (
  • The COSMED body box provides "gold standard" measurement of lung volumes (TGV), airway resistance (RAW), and spirometry. (
  • As investigators struggled with this challenge, two main phenomena resulted in the evolution of the current paradigm of fetal intervention for CDH: (1) the advent of minimally invasive surgical procedures and (2) recognition of a condition called congenital high airway obstruction syndrome (CHAOS), in which fetuses whose airways were occluded either by a tumor or an atresia developed oversized lungs. (
  • It helps indicate whether a patient has restrictions and needs further testing or care for things like asthma, chronic obstructive pulmonary disorder or lung scarring due to air pollutant exposure. (
  • This involves evaluating lung function and oxygen levels during physical activity, which can help diagnose exercise-induced asthma or other respiratory conditions. (
  • In one imaging exam, DDR helps clinicians assess lung function, track lung movement to detect asymmetry (latent, paradoxical, limited or no movement), and differentiate asthma, obstruction, restriction or mixed conditions. (
  • Often, the tests are repeated after a person takes a drug that opens the airways of the lungs (bronchodilator). (
  • It involves inserting a thin, flexible tube into the airways to examine the lungs and collect tissue samples for analysis. (
  • The rate and pattern of breathing are also influenced by signals from neural receptors in the lung parenchyma, large and small airways, respiratory muscles and chest wall. (
  • Initial studies demonstrated that manipulation of mechanical forces involved in lung development, namely the lung fluid production that distends the airways, could be applicable in the treatment of CDH. (
  • in order to meet this requirement, the thoracic diaphragm has a tendency to lower to a greater extent during inhalation, which in turn causes an increase in lung volume. (
  • Contraction of the diaphragm increases the volume of the thoracic cavity aiding INHALATION. (
  • The act of breathing with the LUNGS, consisting of INHALATION, or the taking into the lungs of the ambient air, and of EXHALATION, or the expelling of the modified air which contains more CARBON DIOXIDE than the air taken in (Blakiston's Gould Medical Dictionary, 4th ed. (
  • They may include spirometry, lung volume measurements, and diffusion capacity measurements. (
  • Lung volume can also be measured when you breathe nitrogen or helium gas through a tube for a certain period of time. (
  • In this study we examined the effect of a 15% increase in extracellular fluid volume on lung density, lung volumes, nitrogen washout, chest radiographs and computerized tomographic (CT) scans of the thorax in 5 volunteers. (
  • Single-breath nitrogen washout was used to measure closing volume and the slope of phase III nitrogen washout (delta N2). (
  • Inspired and expired lung volumes measured by spirometry are useful for detecting, characterising and quantifying the severity of lung disease. (
  • Chest X-rays, CT scans, and MRI scans to diagnose lung conditions and evaluate the severity of respiratory problems. (
  • Specific morbidities in survivors include neurodevelopmental, nutritional, sensorineural hearing, and pulmonary function deficiencies, all of which are most likely attributable to the severity of lung hypoplasia and pulmonary hypertension that accompany CDH. (
  • Other tests used for restrictive lung patterns along with spirometry are helium lung volumes and diffusing capacity of carbon monoxide. (
  • TLC: total lung capacity. (
  • The maximum volume of gas that can be inspired from FRC is referred to as the inspiratory capacity (IC). (
  • The vital capacity (VC) is the volume change at the mouth between the positions of full inspiration and complete expiration. (
  • The average total lung capacity of an adult human male is about 6 litres of air. (
  • Lung volumes vary with different people as follows: A person who is born and lives at sea level will develop a slightly smaller lung capacity than a person who spends their life at a high altitude. (
  • US swimmer Michael Phelps is also said to have a lung capacity of around 12 litres. (
  • Pulmonary function tests measure the lungs' capacity to hold air, to move air in and out, and to absorb oxygen. (
  • The syringe volume approximately equals to the average vital lung capacity of a human. (
  • Objectives: To analyze the effect of monthly intravenous CYC on pulmonary function tests including forced vital capacity (FVC) and diffusing lung capacity (DLCO), as well as Rodnan skin score (mRSS), during long-term follow-up. (
  • Terminology for measurements of ventilatory capacity: a report to the Thoracic Society. (
  • An open circuit tracer gas washout method for measurement of lung volume in patients during anesthesia and intensive care is described and tested. (
  • NEW YORK (AP) - Racial bias built into a common medical test for lung function is likely leading to fewer Black patients getting care for breathing problems, a study published Thursday suggests. (
  • One example beyond lung function is a heart failure risk-scoring system that categorizes Black patients as being at lower risk and less likely to need referral for special cardiac care. (
  • Algorithms that adjust for race raise the threshold for diagnosing a problem in Black patients and may make them less likely to get started on certain medications or to be referred for medical procedures or even lung transplants, Vyas said. (
  • While physicians also look at symptoms, lab work, X-rays and family histories of breathing problems, the pulmonary function testing can be an important part of diagnoses, "especially when patients are borderline," said Dr. Albert Rizzo, the chief medical officer at the American Lung Association. (
  • But the organization also put a call out for more research, including into the best way to modify software and whether making a change might inadvertently lead to overdiagnosis of lung problems in some patients. (
  • Racial bias built into a common medical test for lung function is likely leading to fewer Black patients getting care for breathing problems, researchers said in a study published in JAMA Network Open on Thursday, June 1, 2023. (
  • Patients with evidence of early lung damage are treated with 40 mg of prednisone on a daily or alternate day regimen for 6 months. (
  • None of the guidelines recommend using chest radiography or sputum cytology to screen asymptomatic patients for lung cancer. (
  • In June 2022, two cases of Legionnaires disease were reported in patients, each of whom had received a lung transplant from the same donor, who had drowned in a river. (
  • In July 2022, the Pennsylvania Department of Health received two reports of laboratory-confirmed Legionnaires disease in patients who had recently received lung transplants from the same donor at a single Pennsylvania hospital. (
  • Further investigation confirmed that each of the two patients had undergone transplantation of a single lung from the same donor before disease onset. (
  • Methods LUS was performed on preterm lambs (n=20) during in vivo mapping of the pressure-volume relationship of the respiratory system using the super-syringe method. (
  • Online calculators are available that can compute predicted lung volumes, and other spirometric parameters based on a patient's age, height, weight, and ethnic origin for many reference sources. (
  • There are several diagnostic methods that a pulmonologist may use to evaluate a patient's lung function and diagnose respiratory problems. (
  • In the United States it is less expensive and easier to institute than volume controlled NIPPV and may be as efficacious as this mode if close surveillance and regular reevaluation of the patient's status is maintained. (
  • DDR may overcome the limitations of pulmonary function tests, spirometers and static X-ray images that cannot identify differences between the left and right lung. (
  • Reference values for lung function tests: I. Static volumes. (
  • In contrast to the relative simplicity of spirometric volumes, a variety of disparate techniques have been developed for the measurement of absolute lung volumes. (
  • In contrast, lung volumes derived from conventional chest radiographs are usually based on the volumes within the outlines of the thoracic cage, and include the volume of tissue (normal and abnormal), as well as the lung gas volume. (
  • The purpose of this study was to assess the effects of IV contrast medium and different CT scan delays on volumetric measurements of pulmonary nodule. (
  • Automated volumes of 35 pulmonary nodules were calculated with two dedicated software packages (designated as software A and software B) for each unenhanced and contrast-enhanced CT scan at 30-, 60-, 120-, 180-, and 300-second delays (injection protocol, 2 mL/s and 2 mL/kg). (
  • Differences between unenhanced and contrast-enhanced volumes were analyzed by Wilcoxon's signed rank test. (
  • 0.05) for all the timing delays except at 30 seconds for software A, and no significant differences were found among volumes measured with both software programs at different contrast-enhanced delays. (
  • We recommend comparing volume of pulmonary nodules obtained from CT examinations only if they are all performed with or without contrast material, whereas nodule volumes obtained by use of enhanced CT performed with different scan delays are comparable. (
  • As an example, lung nodules may be initially detected on CT examinations performed without contrast medium, but follow-up CT studies might require contrast medium. (
  • In this study, we evaluated the variation of automated volume measurements of lung nodules during dynamic multiphase contrast-enhanced CT, using two different commercially available software packages. (
  • Thus, the aim of this study was to assess the effects of IV contrast material and different CT scan delays on automated volume measurement of pulmonary nodules and to determinate whether different software packages provide different contrast-enhanced measurements. (
  • In contrast to most occupationally related lung disease, the early detection of CBD is useful for several reasons. (
  • The thoracic gas volume (TGV or V TG ) is the absolute volume of gas in the thorax at any point in time and any level of alveolar pressure. (
  • Earlier this year, the American Thoracic Society, which represents lung-care doctors, issued a statement recommending replacement of race-focused adjustments. (
  • In thoracic and pulmonary imaging, DDR provides a full view of chest, lung and organ movement during the respiratory cycle. (
  • Spirometry (meaning the measuring of breath ) is the most common of the Pulmonary Function Tests (PFTs), measuring lung function, specifically the measurement of the amount (volume) and/or speed (flow) of air that can be inhaled and exhaled. (
  • For centuries, some doctors and others have held beliefs that there are natural racial differences in health, including one that Black people's lungs were innately worse than those of white people. (
  • Background Large lung nodules (≥15 mm) have the highest risk of malignancy, and may exhibit important differences in phenotypic or clinical characteristics to their smaller counterparts. (
  • The scores were compared with total and regional lung volumes, and differences in LUS scores between pressure increments were calculated. (
  • RV refers to the volume of gas remaining in the lung after maximal exhalation (regardless of the lung volume at which exhalation was started). (
  • Sometimes, the test will be preceded by a period of quiet breathing in and out from the sensor (tidal volume), or the rapid breath in (forced inspiratory part) will come before the forced exhalation. (
  • The volume of gas inhaled or exhaled during the respiratory cycle is called the tidal volume (TV or V T ). (
  • the tidal volume is the volume of air that is inhaled or exhaled in only a single such breath. (
  • Restrictive lung problems include extrapulmonary causes such as obesity, spine or chest wall deformities, and intrinsic pulmonary pathology such as interstitial fibrosis, pneumoconiosis, granulomatous disease or collagen vascular disease. (
  • It represents the point where elastic recoil force of the lung is in equilibrium with the elastic recoil of the chest wall, i.e. where the alveolar pressure equilibrates with atmospheric pressure. (
  • The term "lung volume" usually refers to the volume of gas within the lungs, as measured by body plethysmography, gas dilution or washout. (
  • Abnormal results usually mean that you may have chest or lung disease. (
  • Interstitial lung disease (ILD) is characterised by exertional dyspnoea, exercise limitation and reduced quality of life. (
  • Alpha1-antitrypsin deficiency (AATD, AAT deficiency) is an inherited condition that increases the risk of lung and liver disease. (
  • Background: Scleroderma lung disease (ILD-SSc) is treated mainly with cyclophosphamide (CYC). (
  • It remains unknown if a similar interaction exists in non-IPF interstitial lung disease (ILD). (
  • Spirometry is one of two NHANES 2007-8 components on respiratory health sponsored by the National Heart, Lung, and Blood Institute of the National Institute of Health, the Centers for Disease Control and Prevention, National Institute for Health Statistics and the National Institute for Occupational Safety and Health (NIOSH). (
  • The first Legionnaires disease case was identified in a woman aged 70-79 years (patient A) who received a right lung transplant in May 2022. (
  • CT follow-up of lung nodules is commonly used to assess potential growth of undetermined lesions and to evaluate therapeutic response of pulmonary metastases. (
  • Introduction Suspicious lung nodules on CT are typically investigated with a ¹⁸F-FDG PET-CT scan and a Herder score is calculated to guide management. (

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