In order to explore the dose effect of high frequency nanosecond pulse bursts on muscle contraction

we investigated the effect of 10 unipolar high frequency nanosecond pulse bursts with different electric field intensities（1 kV/cm

4 kV/cm and 8 kV/cm）

intra-burst frequencies（10 kHz

100 kHz and 1 MHz） and intra-burst number of pulses（1

10 and 100） on rabbit muscle contraction in vivo. High frequency nanosecond pulse bursts with different parameters were delivered to the surface skin of rabbit thighs biceps through plate electrode

and the intensity of muscle contraction was assessed using the acceleration signal measured by a three-axis acceleration sensor attached on the surface skin of the muscle. The results of time and frequency domain analysis of synthetic acceleration module value signal show that the peak value of the signal increases as the value of any of the three parameters increases

however

the spectral distributions of the signals are similar

mainly distributing below 60 Hz. The multivariate nonlinear regression analysis of the experimental results reveals that the peak value of the signal can be expressed as a function of the three parameters

which indicate that when the frequency of the applied pulse burst is relatively low

appropriate increase in the intra-burst number of pulses will not strengthen muscle contraction too much. However

the intra-burst number of pulses should be minimized to limit strength of muscle contraction as much as possible when the frequency within the applied pulse burst is relatively high.