The Research On Electrical Stimulation And Inhibition Mechanism On Urinary System

After spinal cord injury(SCI),the bladder cannot store well at the same time incontinence occurs frequently because of bladder detrusor overactivity. Due to the detrusor sphincter dyssynergia(DSD),the bladder exhibits a large residual urine volume. Most patients need urethral catheterization to empty the bladder. However, urethral catheterization and large residual urine volumes can cause bladder infections. High bladder pressure leads to many urinary system diseases. So the optimal management of bladder function after spinal cord injury is a challenging task because it requires two functions as follows:the first function is inhibition of detursor overactivity during urine storage,and the other one is induction of a large amplitude bladder contraction to empty bladder.To solve these problems above, these jobs were in this research:1. Testing whether an implantable wireless-controlled stimulator can complete these functions:1) making the EUS relax by blocking the pudendal nerve with high-frequency biphasic stimulation.2) inducing a large amplitude and maintained bladder contraction.3) inhibition of bladder reflex during urine storage.2. Research on the effect of non-symmetric waveform on nerve conduction block induced by high-frequency biphasic stimulation is investigated using a lumped circuit model of the unmyelinated axon based on Hodgkin-Huxley equations.3. Research the recovery course of nerve conduction during post-stimulation period.It is revealed in the result that:1. The controlled, implantable stimulator can function as it was expected: inhibiting the overactivity bladder and inducing large amplitude bladder contraction.2. The mechanism of blocking the propagation of action potential along the axon induced by high-frequency biphasic stimulation with non-symmetric waveform is different from that with symmetric waveform. The mechanism underlying the non-symmetric waveform blocking is due to the inactivation induced by high-frequency biphasic stimulation with non-symmetric waveform.3. The post-stimulation block induced by high-frequency biphasic stimulation can recover. The recovery duration depends on the intensity and duration of stimulation, not depends on the frequency of stimulation.