Electromagnetic Phenomena: Characteristics of ELECTRICITY and magnetism such as charged particles and the properties and behavior of charged particles, and other phenomena related to or associated with electromagnetism.Electromagnetic Fields: Fields representing the joint interplay of electric and magnetic forces.Electromagnetic Radiation: Waves of oscillating electric and MAGNETIC FIELDS which move at right angles to each other and outward from the source.Magnetic Field Therapy: The magnetic stimulation of specific target tissues or areas of the body for therapeutic purposes via the application of magnetic fields generated by MAGNETS or ELECTROMAGNETS.Radiation, Nonionizing: ELECTROMAGNETIC RADIATION or sonic radiation (SOUND WAVES) which does not produce IONS in matter through which it passes. The wavelengths of non-ionizing electromagentic radiation are generally longer than those of far ultraviolet radiation and range through the longest RADIO WAVES.Radio Waves: Electromagnetic waves with frequencies between about 3 kilohertz (very low frequency - VLF) and 300,000 megahertz (extremely high frequency - EHF). They are used in television and radio broadcasting, land and satellite communications systems, radionavigation, radiolocation, and DIATHERMY. The highest frequency radio waves are MICROWAVES.Microwaves: That portion of the electromagnetic spectrum from the UHF (ultrahigh frequency) radio waves and extending into the INFRARED RAYS frequencies.Cellular Phone: Analog or digital communications device in which the user has a wireless connection from a telephone to a nearby transmitter. It is termed cellular because the service area is divided into multiple "cells." As the user moves from one cell area to another, the call is transferred to the local transmitter.Radiation: Emission or propagation of acoustic waves (SOUND), ELECTROMAGNETIC ENERGY waves (such as LIGHT; RADIO WAVES; GAMMA RAYS; or X-RAYS), or a stream of subatomic particles (such as ELECTRONS; NEUTRONS; PROTONS; or ALPHA PARTICLES).Equipment Design: Methods of creating machines and devices.Radar: A system using beamed and reflected radio signals to and from an object in such a way that range, bearing, and other characteristics of the object may be determined.Magnetics: The study of MAGNETIC PHENOMENA.Electricity: The physical effects involving the presence of electric charges at rest and in motion.Terahertz Radiation: Non-ionizing electromagnetic energy in the frequency range of 100 gigahertz to 10 terahertz which spans from the mid-INFRARED RAYS frequency to the high-frequency edge of the MICROWAVES band.Equipment and Supplies, Hospital: Any materials used in providing care specifically in the hospital.Equipment Failure: Failure of equipment to perform to standard. The failure may be due to defects or improper use.