Fig. 3
Simulating an unfused tetanic signal using a twitch model and a spike train. A A twitch (blue line) is generated by its five parameters (black dashed lines) of the model are the half-contraction time Thc (ms), the contraction time Tc (ms), the half-relaxation time Thr (ms), the twitch duration Ttw (ms), and the maximal amplitude Amax (arbitrary unit, a.u.). B Generated twitches using the twitch model in A by randomly sampling their parameters from a uniform distribution. C Time instants (spikes, black vertical lines) for each twitch were simulated using a Gaussian renewal process. The unfused tetanus was obtained by summating the twitches in B at their respective time instants with added normally distributed noise to achieve a certain signal-to-noise (SNR) level. Note that the unfused tetanic signal has been differentiated with respect to time, providing unfused tetanus concerning the rate of change (e.g., yank or velocity instead of force or displacement)