| A wave | The initial negative deflection in the electroretinogram, presumably reflecting retinal photoreceptor activity, an atrial deflection in an electrocardiogram recorded from within the atrium of the heart, the first positive deflection of the atrial and venous pulses due to atrial systole. (05 Mar 2000) |
|---|---|
| beta wave | <neurology> Brain waves in the electroencephalogram which have a frequency of 18 to 30 per second. They are typical during periods of intense activity of the nervous system, and occur principally in the parietal and frontal regions. (12 Dec 1998) |
| brain wave | Colloquialism for electroencephalogram. (05 Mar 2000) |
| brain wave complex | A specific combination of fast and slow electroencephalographic activity that recurs frequently enough to be identified as a discrete phenomenon. (05 Mar 2000) |
| brain wave cycle | The complete upward and downward excursion of a single wave, complex, or impulse as seen on an electroencephalogram. (05 Mar 2000) |
| brain wave test | <investigation> A diagnostic test which measures the electrical activity of the brain (brain waves) using high sensitive recording equipment attached to the scalp by fine electrodes. Commonly employed in the evaluation of neurological disease (for example seizures, epilepsy, etc.). Acronym: EEG (13 Nov 1997) |
| cannon wave | An exaggerated A wave in the jugular pulse caused by right atrial contraction occurring after ventricular contraction has closed the tricuspid valve, as in ventricular premature beats and in complete A-V block. (05 Mar 2000) |
| radio wave | <physics> Electromagnetic radiation with wavelengths of 300 millimetres or longer (even up to several kilometres). Radiation of this type is used to broadcast radio and television signals, and has frequencies up to thousands of megahertz (or one gigahertz). (09 Oct 1997) |
| recoil wave | The second rise in the tracing of a dicrotic pulse. Synonym: recoil wave. (05 Mar 2000) |
| V wave | <cardiology, physiology> A large pressure wave visible in recordings from either atrium or its incoming veins, normally produced by venous return but becoming very large when blood regurgitates through the A-V valve beyond the chamber from which the recording is made. (05 Mar 2000) |
| retrograde P wave | The P wave pattern in the electrocardiogram representing retrograde depolarisation of the atria, the impulse spreading from the A-V junction or the lower atrium upward. (05 Mar 2000) |
| percussion wave | The main positive wave of an arterial pulse tracing. (05 Mar 2000) |
| R wave | The first positive (upward) deflection of the QRS complex in the electrocardiogram; successive upward deflections within the same QRS complex are labelled R', R'', etc. (05 Mar 2000) |
| wave | 1. An advancing ridge or swell on the surface of a liquid, as of the sea, resulting from the oscillatory motion of the particles composing it when disturbed by any force their position of rest; an undulation. "The wave behind impels the wave before." (Pope) 2. <physics> A vibration propagated from particle to particle through a body or elastic medium, as in the transmission of sound; an assemblage of vibrating molecules in all phases of a vibration, with no phase repeated; a wave of vibration; an undulation. See Undulation. 3. Water; a body of water. "Deep drank Lord Marmion of the wave." "Build a ship to save thee from the flood, I 'll furnish thee with fresh wave, bread, and wine." (Chapman) 4. Unevenness; inequality of surface. 5. A waving or undulating motion; a signal made with the hand, a flag, etc. 6. The undulating line or streak of luster on cloth watered, or calendered, or on damask steel. 7. A swelling or excitement of thought, feeling, or energy; a tide; as, waves of enthusiasm. <physics> Wave front See Undulatory theory, under Undulatory. Origin: From Wave,; not the same word as OE. Wawe, waghe, a wave, which is akin to E. Wag to move. See Wave. Source: Websters Dictionary (01 Mar 1998) |
| wave analyzer | An apparatus that assesses a complex mixture of wave forms by separating out their component frequencies and displaying their distribution. (05 Mar 2000) |