sentences:  Although both sphincter and detrusor muscles are stimulated at the same time, the slower contraction kinetics of the bladder wall (smooth muscle tissue) compared to the sphincter (striated muscle tissue) mean that voiding occurs between the stimulation pulses, rather than during them.This device is implanted over the sacral anterior root of the spinal cord; controlled by an external transmitter, it delivers intermittent stimulation which improves the ability to empty the bladder.It may also assist in defecation and also may enable male patients to have a sustained full erection.