Postinspiratory activity of costal and crural diaphragm. (17/3102)

Because the first stage of expiration or "postinspiration" is an active neurorespiratory event, we expect some persistence of diaphragm electromyogram (EMG) after the cessation of inspiratory airflow, as postinspiratory inspiratory activity (PIIA). The costal and crural segments of the mammalian diaphragm have different mechanical and proprioceptive characteristics, so postinspiratory activity of these two portions may be different. In six canines, we implanted chronically EMG electrodes and sonomicrometer transducers and then sampled EMG activity and length of costal and crural diaphragm segments at 4 kHz, 10.2 days after implantation during wakeful, resting breathing. Costal and crural EMG were reviewed on-screen, and duration of PIIA was calculated for each breath. Crural PIIA was present in nearly every breath, with mean duration 16% of expiratory time, compared with costal PIIA with duration -2. 6% of expiratory time (P < 0.002). A linear regression model of crural centroid frequency vs. length, which was computed during the active shortening of inspiration, did not accurately predict crural EMG centroid frequency values at equivalent length during the controlled relaxation of postinspiration. This difference in activation of crural diaphragm in inspiration and postinspiration is consistent with a different pattern of motor unit recruitment during PIIA.  (+info)

Acceptability of computerized self-report of alcohol habits: a patient perspective. (18/3102)

The acceptability of computerized assessment of alcohol habits was explored in 57 consecutive out-patients over a 6-month period. Altogether, 46 men and 11 women agreed to complete a paper and pencil questionnaire exploring their opinion about computerized assessment. The study focused on the patients' acceptance of computerized testing and also on whether some sub-groups had reservations. The participants indicated that they had no general anxiety towards computers and did not mind being assessed by their use. Nearly half of the men were not convinced of the usefulness of computers as a means of asking about alcohol habits. The same level of confidence was recorded with regard to whether doctors would make better assessments using computers. Around one-quarter of both men and women were worried that computers might cause doctors to spend less time with the patients and that staff might lose the personal contact with patients. Because of the small sample size, we conclude tentatively that a computerized lifestyle test appears to be an acceptable method both to men and women with different educational backgrounds. However, two important issues need to be further addressed, namely concerns about confidentiality and loss of personal contact.  (+info)

Characterization of color CRT display systems for monochrome applications. (19/3102)

Soft-copy presentation of medical images is becoming more and more important as medical imaging is strongly moving toward digital technology, and health care facilities are converting to filmless hospital and radiological information management. Although most medical images are monochrome, frequently they are displayed on color CRTs, particularly if general-purpose workstations or PCs are used for medical viewing. In the present report, general measurement and modeling procedures for the characterization of color CRT monitors for monochrome presentation are introduced. The contributions from the three color channels (red, green, and blue) are weighted according to the spectral sensitivity of the human eye for photopic viewing. The luminance behavior and the resolution capabilities of color CRT monitors are analyzed with the help of photometer and charge-coupled device (CCD) camera measurements. For the evaluation of spatial resolution, a two-dimensional Fourier analysis of special test images containing white noise (broadband response) is employed. A stage model for a color CRT monitor is developed to discuss the effects of scanning and dot sampling. Furthermore, display intrinsic veiling glare and reflectivity of typical color CRT monitors are measured and compared with those of monochrome CRT monitors. The developed methods and models allow one to describe the image quality aspects of color monitors if they are applied for medical monochrome image presentation. Particularly, because of the reduced luminance and dynamic range of color monitors, the calibration and control of their luminance curves is a very important task. For present color CRT monitors, 1,280 x 1,024 turns out to be an intrinsic limit for the displayable matrix of medical images.  (+info)

Clinical care and the factory floor. (20/3102)

The purpose of this article is to provide the author's perspective on whether it is likely or feasible that those working in the health care domain will adapt and use lessons learned by those in the industrial domain. This article provides some historical perspective on the changes brought about in the industrial domain through the introduction of new technologies, including information technologies. The author discusses how industrialization catalyzed changes in health care delivery that paralleled but lagged behind those of the broader U.S. economy. The article concludes that there is ample reason for those interested in improving the quality and effectiveness of health informatics to systematically evaluate information technology strategies used in the industrial domain. Finally, it outlines some challenges for health informaticians and a number of factors that should be considered in adapting lessons from industry to the health care domain.  (+info)

Information technology outside health care: what does it matter to us? (21/3102)

Non-health-care uses of information technology (IT) provide important lessons for health care informatics that are often overlooked because of the focus on the ways in which health care is different from other domains. Eight examples of IT use outside health care provide a context in which to examine the content and potential relevance of these lessons. Drawn from personal experience, five books, and two interviews, the examples deal with the role of leadership, academia, the private sector, the government, and individuals working in large organizations. The interviews focus on the need to manage technologic change. The lessons shed light on how to manage complexity, create and deploy standards, empower individuals, and overcome the occasional "wrongness" of conventional wisdom. One conclusion is that any health care informatics self-examination should be outward-looking and focus on the role of health care IT in the larger context of the evolving uses of IT in all domains.  (+info)

A new computer-based evaporimeter system for rapid and precise measurements of water diffusion through stratum corneum in vitro. (22/3102)

It is important to have reliable methods for evaluation of skin barrier function when questions such as barrier perturbing effects of different agents and occlusive effects of different formulations are to be elucidated. A wealth of clinical work relates to measurements of transepidermal water loss in vivo, a method much affected by ambient air relative humidity, temperature, skin irritation processes, psychologic status of the subject, etc., factors that cause the method to suffer from low precision (i.e., high random error). Relating to these obstacles, we have developed a closed in vitro system for measurements of water diffusion rate through pieces of isolated stratum corneum at steady-state conditions, where the relative humidity and temperature is held constant and data can be collected continuously. Our evaporimeter-based in vitro system has a more than 3-fold higher precision (lower random error) ( approximately 10%) than measurements of transepidermal water loss in vivo ( approximately 35%). The results of our study show that: (i) the corneocyte envelopes contribute to the barrier capacity of stratum corneum; (ii) removal of the lipid intercellular matrix results in approximately a 3-fold increase in the water diffusion rate through the isolated stratum corneum (n = 20; p < 0.05), not a 100-fold as has previously been suggested; (iii) exposure to sodium dodecyl sulfate in water does neither alter the water diffusion rate (n = 10; p > 0.05) nor the water holding capacity (n = 10; p > 0.05) of stratum corneum; (iv) exposure to 1 M CaCl2 in water yields an increased water diffusion rate through stratum corneum (n = 10; p < 0.05); and (v) when applied to the stratum corneum in excess concentrations, the penetration enhancer Azone has occlusive effects on water diffusion through the stratum corneum (n = 6; p < 0.05).  (+info)

Mapping the network for planning: a correlational PET activation study with the Tower of London task. (23/3102)

We used the Tower of London task (TOL) and H(2)(15)O-PET to map the network of brain structures involved in planning. Six healthy right-handed subjects had 12 measurements of relative regional cerebral blood flow (rrCBF) during six conditions, each performed twice. There was one rest condition, and five sets of TOL problems at different complexity levels, performed on a touch-sensitive computer monitor with the right arm. Complexity was defined as the number of moves required to solve each problem. Activation was analysed in two ways: a category analysis comparing levels of rrCBF during rest and task was done to identify all structures involved in performance of the TOL; and a correlation analysis was carried out to delineate a subset of structures where the levels of rrCBF correlated with task complexity. Activated brain areas in which rrCBF increases did not correlate with complexity could be grouped into: (i) regions belonging to the dorsal stream of visual input processing, namely visual cortical areas 17, 18 and 19, and posterior parietal cortical areas 7 and 40; and (ii) regions involved in the execution and sequencing of arm movements (right cerebellum, left primary motor cortex and supplementary motor area). Brain regions where levels of rrCBF correlated with task complexity included lateral premotor cortex (area 6), rostral anterior cingulate cortex (areas 32 and 24), dorsolateral prefrontal cortex (areas 9 and 46) bilaterally, and right dorsal caudate nucleus. We propose that dorsolateral prefrontal, lateral premotor, anterior cingulate and caudate areas form a network for the planning of movement that interacts with brain areas primarily involved in visual processing and movement execution.  (+info)

Publication of survey results of assessment of state health agencies' readiness for 2000. (24/3102)

Following publication of the results of a CDC assessment of the readiness for the year 2000 (Y2K) of state health agencies, CDC conducted a follow-up survey during June-August 1999 in which 47 states and the District of Columbia-covering 98.7% of the U.S. population-responded. Overall, responding states are 99% complete with Y2K assessment and 90% complete with Y2K readiness. Additional information from the states and trends from the initial to the follow-up survey identify no significant Y2K readiness vulnerabilities in critical public health functions. Complete results of this survey are available on the World-Wide Web at http://www.cdc.gov/y2k/y2kssurvey.htm++ + and from the Information Resources Management Office, CDC, Mailstop D45, 1600 Clifton Rd., N.E., Atlanta, GA 30333. CDC continues to work with states on Y2K readiness, including identifying and communicating Y2K issues that may occur during the transition to 2000.  (+info)