| continuous spectrum | A spectrum in which there are no absorption bands or lines. (05 Mar 2000) |
|---|---|
| continuous spinal anaesthesia | Insertion of a catheter into the spinal subarachnoid space and leaving it in situ to permit serial intermittent injection of local anaesthetic solution for prolonged spinal anaesthesia. Synonym: fractional spinal anaesthesia. (05 Mar 2000) |
| continuous suture | An uninterrupted series of stitches using one suture; the stitching is fastened at each end by a knot. Synonym: spiral suture, uninterrupted suture. (05 Mar 2000) |
| continuous time model | <epidemiology> A model in which the system changes continuously over time. Derivatives (e.g. DY/dt ) are the mathematical formalism for describing such continuous change. The differential equation which embodies a model provides the values of these derivatives at any particular time point; calculus or a computer can then be used to move the state of the model forwards in time. Continuous models have the advantage over discrete time models in that they are more amenable to algebraic manipulation, although they are slightly harder to implement on a computer. The same as a differential equation model. (05 Dec 1998) |
| continuous tremor | A tremor that is constant, whether the subject is at rest or moving. Synonym: continuous tremor. (05 Mar 2000) |
| continuous variable | A variable that may take on any value in an interval or intervals (its domain). (05 Mar 2000) |
| Abbe test plate | <equipment> A long, wedge-shaped coverslip about 0.20 mm thick at one end and 0.10 to 0.12 mm at the other end coated chemically with a silver film on which are ruled horizontal lines. at each variation in thickness of 0.01 mm there are vertical lines. By means of oblique illumination and by focusing on different portions of the plate, it is possible to determine the optimum coverslip thickness for any objective and also, for microscopes with drawtubes, the tube length for best objective performance. The approximate freedom from spherical and chromatic aberrations can also be estimated. Small isolated bits of silver near the edges of the lines form good objects for the star test (05 Aug 1998) |
| acetone test | A test for ketonuria; the suspected urine is shaken up with a few drops of sodium nitroprusside, and strong ammonia water is then gently poured over the mixture; if acetone is present, a magenta ring forms at the line of contact; tablets containing sodium nitroprusside and alkali are now more commonly used. (05 Mar 2000) |
| achievement test | A standardised test used to measure acquired learning, e.g., competence in a specific subject area such as reading or arithmetic, in contrast to an intelligence test which is a useful index of potential ability or learning. (05 Mar 2000) |
| acidified serum test | Lysis of the patient's red cells in acidified fresh serum, specific for paroxysmal nocturnal haemoglobinuria. Synonym: Ham's test. (05 Mar 2000) |
| acid loading test | <nephrology> This is a test used in the diagnosis of renal tubular acidosis. The patient takes ammonium chloride capsules for 3 days to acidify the blood (lower blood pH). A sample of the urine and the blood is then collected and the results are interpreted. (27 Sep 1997) |
| acid perfusion test | <gastroenterology, investigation> A test used to diagnosis gastrooesophageal reflux disease. This investigation requires that the patient swallow 3 tiny tubes into the stomach. A mixture of hydrochloric acid (like stomach acid) and saline are alternatively injected into the tubes. The patient then reports any symptoms they may have. Some patients may vomit. (13 Nov 1997) |
| acid phosphatase test for semen | A screening test for semen by determining acid phosphatase content; because seminal fluid contains high concentrations of acid phosphatase, while other body fluids and extraneous foreign materials have very low concentrations, high values of acid phosphatase on vaginal aspirate or lavage, or on wash fluid from stains, render positive identification of semen, even if the male is aspermic. (05 Mar 2000) |
| acid reflux test | A test to detect gastroesophageal reflux by monitoring oesophageal pH by an electrode in the distal oesophagus either basally or after acid is instilled into the stomach. (05 Mar 2000) |
| ACTH stimulation test | A test for adrenal cortical function; ACTH administered by continuous intravenous infusion, or intramuscularly, evokes an increase in plasma cortisol in normal persons; in adrenal cortical insufficiency, the expected increase in plasma cortisol is limited or nonexistent. (05 Mar 2000) |