| pulmonary ventilation | The process of exchange of air between the lungs and the ambient air. Pulmonary ventilation is a measure of the rate of ventilation expressed usually in liters per minute. (12 Dec 1998) |
|---|---|
| spontaneous intermittent mandatory ventilation | Intermittent mandatory ventilation spontaneously initiated by the patient, to increase tidal volume, and subsequently synchronised with patient's respiratory cycle. Synonym: synchronised intermittent mandatory ventilation. (05 Mar 2000) |
| synchronised intermittent mandatory ventilation | Intermittent mandatory ventilation spontaneously initiated by the patient, to increase tidal volume, and subsequently synchronised with patient's respiratory cycle. Synonym: synchronised intermittent mandatory ventilation. (05 Mar 2000) |
| intermittent mandatory ventilation | Mechanical application of positive pressure at a predetermined frequency to the airway to increase tidal volume. (05 Mar 2000) |
| intermittent positive-pressure ventilation | Application of positive pressure to the inspiratory phase when the patient has an artificial airway in place and is connected to a ventilator. See: controlled mechanical ventilation (12 Dec 1998) |
| lung ventilation agents | <radiology> Xe-133, most commonly used, Xe-127, t = 36.4 days; photons @ 172, 203, 375 keV, can image V after Q, Kr-81m, very expensive, t = 13 sec; photon 190 keV, can repeat V in each projection, Tc-99m DTPA aerosol, can image V in mult. Projections, image Q after V, 1 mCi most likely to be 50-75 mrad to lung, V/Q imaging (12 Dec 1998) |
| bounce frequency | <physics> The average frequency of oscillation of a particle trapped in a magnetic mirror as it bounces back and forth between its turning points in regions of high magnetic field. (See also trapped particle, turning points, banana orbit). (09 Oct 1997) |
| radio frequency current drive | <radiobiology> Plasma waves in the radio-frequency range can be used to push plasma particles in such a way that current forms in the plasma, this is a method of non-inductive current drive which would allow for steady-state fusion reactors to operate. (09 Oct 1997) |
| radio frequency heating | <radiobiology> Process for heating the plasma by transferring energy to ions or electrons using waves generated by an external oscillator at an appropriate frequency. (This is similar to how a microwave oven heats food.) There are various types: See: ECRH, ICRH, and Lower Hybrid. (09 Oct 1997) |
| radio frequency or radiofrequency | <physics> Term used to describe electromagnetic radiation with frequencies less than infrared, but greater than audio frequencies, i.e., greater than about 15,000 Hz. Wavelengths are therefore less than about 20,000 km and greater than about 0.01 mm. (These numbers are not precise.) (09 Oct 1997) |
| gene frequency | The relative occurence (expressed as a percentage) of a gene in a given population. (09 Oct 1997) |
| recombination frequency | The frequency at which crossingover occurs between two chromosomal loci--the probability that twoloci will become unlinked during meiosis. (09 Oct 1997) |
| resonant frequency | The frequency at which individual magnetic nuclei absorb or emit radiofrequency energy in magnetic resonance studies. Synonym: resonance. (05 Mar 2000) |
| respiratory frequency | The number of breaths per minute. (05 Mar 2000) |
| collision frequency | <chemistry> The rate at which chemical species collide, used in theories of chemical kinetics. Also, the frequency with which gaseous molecules collide. (09 Oct 1997) |