Although sacral anterior root neuromodulation (SARN) has proven to be effective in patients with neurogenic bladder, it is not widely accepted due to the need to conduct a dorsal rhizotomy, and commercially available SARN devices are not usually equipped with a closed-loop controller for the automatic regulation of bladder functions. Therefore, there is still a need for a more effective electrical neuromodulation scheme to restore bladder function. Intravesical pressure (IVP) is the major biosignal that reflects the state of bladder conditions. The present study develops a closed-loop control strategy for improving bladder emptying and verifies its performance using animal experiments. Two channel outputs of electrical currents triggered by IVP-feedback signals were set to automatically regulate a rat's pudendal nerve for selective nerve stimulation and blocking. Under this experimental design, a series of in vivo animal experiments were conducted on anesthetized rats, including the computational characterization of biosignals, the development of an intermittent high-frequency blocking current waveform for blocking the nerve, and verification of the control strategy. Results show that the IVP-feedback control strategy for dual-channel pudendal neuromodulation performed well in animal experiments and could be utilized to selectively stimulate and block the pudendal nerve to augment bladder contraction and restore external urethral sphincter bursting activity to improve bladder emptying. This study demonstrates the feasibility of the IVP-based feedback-control strategy with animal experiments. The results could provide a basis for developing a sophisticated neural prosthesis for restoring bladder function in clinical use or for neurophysiological study.
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