| residual volume | The volume of air remaining in the lungs at the end of a maximal expiration. Common abbreviation is rv. (12 Dec 1998) |
|---|---|
| volume | 1. A roll; a scroll; a written document rolled up for keeping or for use, after the manner of the ancients. "The papyrus, and afterward the parchment, was joined together [by the ancients] to form one sheet, and then rolled upon a staff into a volume (volumen)." (Encyc. Brit) 2. Hence, a collection of printed sheets bound together, whether containing a single work, or a part of a work, or more than one work; a book; a tome; especially, that part of an extended work which is bound up together in one cover; as, a work in four volumes. "An odd volume of a set of books bears not the value of its proportion to the set." (Franklin) 4. Anything of a rounded or swelling form resembling a roll; a turn; a convolution; a coil. "So glides some trodden serpent on the grass, And long behind wounded volume trails." (Dryden) "Undulating billows rolling their silver volumes." (W. Irving) 4. Dimensions; compass; space occupied, as measured by cubic units, that is, cubic inches, feet, yards, etc.; mass; bulk; as, the volume of an elephant's body; a volume of gas. 5. Amount, fullness, quantity, or calibre of voice or tone. <chemistry> Atomic volume, Molecular volume, the ratio of the atomic and molecular weights divided respectively by the specific gravity of the substance in question. <physics> Specific volume, the quotient obtained by dividing unity by the specific gravity; the reciprocal of the specific gravity. It is equal (when the specific gravity is referred to water at 4 deg C. As a standard) to the number of cubic centimeters occupied by one gram of the substance. Origin: F, from L. Volumen a roll of writing, a book, volume, from volvere, volutum, to roll. See Voluble. Source: Websters Dictionary (01 Mar 1998) |
| volume averaging | In computed tomography or magnetic resonance imaging, the effect of expressing the average density of a voxel as a pixel in the image; the greater the slice thickness, the more averaging is necessary, with loss in density resolution. (05 Mar 2000) |
| volume-controlled respirator | A respirator that provides a predetermined volume of gases during inhalation, with the pressure required to move that volume remaining variable, depending upon resistance. (05 Mar 2000) |
| volume element | See: voxel. (05 Mar 2000) |
| volume index | An indication of the relative size (e.g., volume) of erythrocytes, calculated as follows: haematocrit value, expressed as per cent of normal ÷ red blood cell count, expressed as per cent of normal = volume index. (05 Mar 2000) |
| volume loading rate | The rate of raw materials put into a fermenter or aerobic digester, expressed in terms of material weight per unit volume per unit time. (09 Oct 1997) |
| volume substitute | Infusion of cell-free or volume-expanding fluids such as dextran for replacement of fluid lost from the circulation as part of the prevention or treatment of circulatory shock. (05 Mar 2000) |
| volume unit | A unit of a logarithmic scale for expressing the power level of a complex audio-frequency electrical signal, such as that transmitting music or speech; the power in volume unit's equals the decibels of power above a reference level of one milliwatt, as measured with an appropriate meter. (05 Mar 2000) |
| respiratory minute volume | The minute volume of breathing; the product of tidal volume times the respiratory frequency. See: pulmonary ventilation. (05 Mar 2000) |
| resting tidal volume | The tidal volume under normal conditions, i.e., in the absence of exercise or other conditions that stimulate breathing. (05 Mar 2000) |
| right ventricular volume overload | <radiology> Atrial septal defect, partial/total APVR, tricuspid insufficiency, pulmonary insufficiency, congenital/aquired absence of pericardium, Ebstein anomaly (not truly RV) (12 Dec 1998) |
| minute volume | The volume of any gas or fluid moved per minute; e.g., cardiac output or the respiratory minute volume. (05 Mar 2000) |
| closing volume | The lung volume at which the dependent lung zones cease to ventilate presumably as a result of airway closure. (12 Dec 1998) |
| plasma volume | Volume of plasma in the circulation. It is usually measured by indicator dilution techniques. (12 Dec 1998) |