| flow-over vaporiser | A device for vaporization of a liquid anaesthetic by causing gases to pass over the anaesthetic or over material saturated with the anaesthetic. (05 Mar 2000) |
|---|---|
| flow rate | The amount of water that moves through an area (usually pipe) in a given period of time. (05 Dec 1998) |
| flow void | In magnetic resonance imaging, the absence of signal from blood whose activated protons leave a region before their magnetization is measured. See: signal void. (05 Mar 2000) |
| flow-volume curve | The graph produced by plotting the instantaneous flow of respiratory gas against the simultaneous lung volume, usually during maximal forced expiration. (05 Mar 2000) |
| laminar air flow unit | An air-filtering system used at some transplant facilities to remove particulate matter and fungi from the air. (16 Dec 1997) |
| laminar flow | The relative motion of elements of a fluid along smooth parallel paths, which occurs at lower values of Reynolds number. (05 Mar 2000) |
| forced expiratory flow | Expiratory flow during measurement of forced vital capacity; subscripts specify the exact parameter measured, e.g., peak instantaneous flow, the instantaneous flow at some specified point on the curve of volume expired versus time, or on the flow-volume curve, the mean flow between two expired volumes. (05 Mar 2000) |
| forced expiratory flow rates | Measurements of rates of airflow during a forced vital capacity determination. (12 Dec 1998) |
| Francke's needle | A small lancet-shaped spring-activated needle, used to evacuate a small effusion of blood. (05 Mar 2000) |
| Frazier's needle | A needle for draining lateral ventricles of brain. (05 Mar 2000) |
| frozen-in flow law | <radiobiology> In a perfect conductor, the total magnetic flux through any surface is a constant. In a plasma which is nearly perfectly conducting, the relevant surfaces move with the plasma, the result is that the plasma is tied to the magnetic field, and the field is tied to the plasma. Motion of the plasma thus deforms the magnetic field, and vice versa. The magnetic flux is said to be frozen into the plasma. (09 Oct 1997) |
| low flow principle | A principle based on the observation that animals can survive prolonged vena caval occlusion without sequelae: if blood from the azygos vein alone is permitted to enter the heart, patients are perfused during cardiac and pulmonary bypass at flows much less than the normal resting cardiac output. Synonym: low flow principle. (05 Mar 2000) |
| lumbar puncture needle | A needle, provided with a stylet, for entering the spinal canal or cisterna magna, with a bore of at least 1 mm and 40 mm or more in length. (05 Mar 2000) |
| Amberg's lateral sinus line | A line dividing the angle formed by the anterior edge of the mastoid process and the temporal line. (05 Mar 2000) |
| amyotrophic lateral sclerosis | A serious neurologic disease that results from the progressive degeneration of the motor neurons. (27 Sep 1997) |