Title :
Prediction of neural excitation during magnetic stimulation using passive cable models
Author :
Hsu, Kai-Hsiung ; Durand, Dominique M.
Author_Institution :
Dept. of Biomed. Eng., Case Western Reserve Univ., Cleveland, OH, USA
fDate :
4/1/2000 12:00:00 AM
Abstract :
A method for predicting neural excitation during magnetic stimulation using passive cable models has been developed. This method uses the information of the threshold capacitor voltage for magnetic stimulation coils to determine the equivalent excitation thresholds for the passive transient (PT) and passive steady-state (PSS) cable models as well as for the activating function. The threshold values for the PT, PSS models, and the activating function vary only with the pulsewidth of the stimulus for a variety of coils at different locations and orientations. Furthermore, the excitation threshold for the PSS model is also independent of axon diameter and best fitted to a simple mathematical function. By comparing the transmembrane potential of the PSS model with the corresponding threshold, the prediction of excitation during magnetic stimulation can be made. Similarly, it is also possible to predict excitation using the PT model and the activating function with the corresponding thresholds provided. By taking advantage of the weighted pulsewidth, this method can even predict the excitation for stimuli with various waveforms, greatly simplifying the determination of neural excitation for magnetic stimulation
Keywords :
biomagnetism; neurophysiology; physiological models; axon diameter; equivalent excitation thresholds; magnetic stimulation; neural excitation prediction; passive cable models; simple mathematical function; stimulus pulsewidth; threshold capacitor voltage; transmembrane potential; Biomedical engineering; Capacitors; Coils; Equations; Magnetic stimulation; Mathematical model; Nerve fibers; Neural engineering; Predictive models; Space vector pulse width modulation;
Journal_Title :
Biomedical Engineering, IEEE Transactions on