strength-duration curve


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curve

 [kerv]
a line that is not straight, or that describes part of a circle, especially a line representing varying values in a graph.
dose-effect curve (dose-response curve) a graphic representation of the effect caused by an agent (such as a drug or radiation) plotted against the dose, showing the relationship of the effect to changes in the dose.
growth curve the curve obtained by plotting increase in size or numbers against the elapsed time.
oxyhemoglobin dissociation curve a graphic curve representing the normal variation in the amount of oxygen that combines with hemoglobin as a function of the partial pressures of oxygen and carbon dioxide. The curve is said to shift to the right when less than a normal amount of oxygen is taken up by the blood at a given Po2, and to shift to the left when more than a normal amount is taken up. Factors influencing the shape of the curve include changes in the blood pH, Pco2, and temperature; the presence of carbon monoxide; alterations in the constituents of the erythrocytes; and certain disease states.
pulse curve sphygmogram.
Spee curve (curve of Spee) the anatomic curvature of the occlusal alignment of teeth, beginning at the tip of the lower canine, following the buccal cusps of the premolars and molars, and continuing to the anterior border of the ramus.
strength-duration curve a graphic representation of the relationship between the intensity of an electric stimulus at the motor point of a muscle and the length of time it must flow to elicit a minimal contraction; see also chronaxie and rheobase. In cardiac pacing it is useful in determining characteristics of a particular pacing electrode and determining the most efficient selection of pacing parameters for an appropriate safety margin.
survival curve a graph of the probability of survival versus time, commonly used to present the results of clinical trials, e.g., a graph of the fraction of patients surviving (until death, relapse, or some other defined endpoint) at each time after a certain therapeutic procedure.

strength-·du·ra·tion curve

a graph relating the intensity of an electrical stimulus to the length of time it must flow to be effective. See: chronaxie, rheobase.
References in periodicals archive ?
There was sufficient variability between different sessions with the same subject to necessitate recalculating the strength-duration curve at each session, but it was found that 5 points with 2 responses at each point would sufficiently represent the curve.
The protocol for obtaining the strength-duration curves was modified partway through testing in response to observations that many of the trials contained data points primarily in the linear portion of the strength-duration curve, near the rheobase voltage.
Strength-duration curves were found using the reduced number of points suggested to decrease collection time.