What is strength duration curve?
The strength-duration curve is a plot of the threshold current (I) versus pulse duration (d) required to stimulate excitable tissue. As mentioned, the two important points on the curve are rheobase (b) and chronaxie (c), which correlates to twice the rheobase (2b).
What is strength duration curve in electrotherapy?
Strength duration curve is a graph between electrical stimuli of different intensities and recording the time needed by each stimulus to start the response. S-D curve should be plotted after 20th day of injury/lesion.
What is the concept of chronaxie in strength duration curve?
In a strength–duration curve, the rheobase current is the minimal amount of intensity needed to obtain an effect, whereas the chronaxie represents the pulse width needed to obtain a response using twice the rheobase current (Rizzone et al., 2001; Volkmann et al., 2002).
What is the difference between threshold and rheobase?
The threshold , or minimal stimulus , is defined as “the electrical stimulus whose strength (or voltage) is sufficient to excite the tissue. Rheobase is defined as “the minimum strength (voltage) of stimulus which can excite the tissue”.
What is the significance of chronaxie time?
Significance. The main value of chronaxie is comparing excitability across different experiments and measurements using the same standard, thus making data comparisons easier. Electrical stimulation based on chronaxie could regulate myoD gene expression in denervated muscle fibers.
What is SD curve?
Strength duration curve is a graph between electrical stimuli of different intensities and recording the time needed by each stimulus to start the response. S-D curve should be plotted after 20th day of injury/lesion.
What is difference between rheobase and chronaxie?
Rheobase is measured as the threshold stimulus current for an active response with a long-duration pulse and chronaxie is the pulse width at twice the rheobase threshold current19).
What is chronaxie and Rio Base?
Chronaxie is the minimum time required for an electric current double the strength of the rheobase to stimulate a muscle or a neuron. Rheobase is the lowest intensity with indefinite pulse duration which just stimulated muscles or nerves.
Is rheobase and threshold the same?
What is difference between chronaxie and rheobase?
What is chronaxie time?
What is the essential feature of the strength duration curve?
The shape of the curve is the essential feature. When all the nerve fibers supplying the muscles are intact, the strength duration curve has a shape characteristic of normally innervated muscles as shown in the figure.
What is the S-D curve in SDC strength duration?
SDC Strength duration curve is a graph between electrical stimuli of different intensities and recording the time needed by each stimulus to start the response. S-D curve should be plotted after 20th day of injury/lesion.
Is extracellular stimulation strength–duration relationship similar to classical intracellular stimulation?
The strength–duration relationship for extracellular stimulation is often assumed to be similar to the classical intracellular stimulation model, with a slope asymptotically approaching 1/τ at pulse durations shorter than chronaxy.
How does stimulus duration affect threshold strength?
This suggests that a graph of threshold stimulus strength versus stimulus duration should show a decline to near zero as stimulus duration is increased. In other words, the stimulus strength required to reach threshold should decrease during more prolonged stimulation.