Pulse Medical Instruments

After agreeing to participate, and signing an informed consent form, the operation of the pupillometer, FIT 2000 (Pulse Medical Instruments [PMI], Rockville, MD), was explained and demonstrated to the research volunteers. They were allowed to practice the test sequence in the presence of the administrator until they obtained a successful test sequence. This single exposure was the only supervised orientation the participants received. 

The modern era of telecommunications has begun to depend on bundles of optical fibers—thin, flexible tubes of glass and plastic—to send information over long-distance telephone networks. Also used in medical instruments to examine various body cavities, such as the bladder and intestines, a fiber-optics system converts electricity to pulses of light that carry the data—much more of it, in fact, than ordinary wires, which have to use pulses of electricity-... 

The maximal current per pulse is limited [27] in our system to 0.3 A= /o.Asperthel985ANSIstandard, Section 3.2.2.2 of the Association for Advancement of Medical Instrumentation and the American National Standard Institute [30], stimulation should be limited to below 10 mA average current. Hence, stimuli of... 

Flhre-opdc systems use optical fibres to transmit information, in the form of coded pulses or fragmented images (using bundles of fibres), from a source to a receiver. They are also used in medical instruments (fihrescopes) to examine internal body cavities, such as the stomach and bladder. 

Lack of advances in optics has hampered improvements in microscopic imaging. Development of adaptable, inexpensive fiber optics to transmit high-energy femtosecond pulses from mode-locked lasers, custom phase plates, and miniature laser beam scanners for endoscopic microscopy instruments offer the potential for enormous advances in laser scanning microscopy for various applications, including medical diagnostics and surgery. 

There is a class of physically small, benchtop NMR instruments available, useful for dedicated quantitative analysis. These instruments are pulsed, time-domain NMRs (TD-NMRs). TD-NMR is also called relaxometry. TD-NMR does not deal with spectroscopy or magnetic resonance (MR) images. The TD-NMR instrument is usually a small benchtop or handheld, low-resolution and low-field analyzer designed to detect hydrogen or fluorine nuclei. TD-NMR analysis is quantitative and rapid (normally within seconds or minutes). It is also nondestructive and noninvasive. Thanks to these advantages and its ease of use, it is widely used for routine analysis in agriculture, food science, polymer, chemical, petroleum, and pharmaceutical and medical industries. 

The frequency of radiation used in NMR depends on the field strength of the magnet used in the instrument. Frequencies range from 60 to 600 MHz for commercial instruments. Modern NMR equipment uses RF pulses in Fourier transform systems. There are no known safety concerns associated with these frequencies of radiation. However NMR magnetic fields can have adverse effects on pacemakers and other medical devices (see below under magnetic fields). 

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