A general framework for automatic closed-loop control of bladder voiding induced by intraspinal microstimulation in...

Area of Science:

• Neuroscience
• Biomedical Engineering
• Rehabilitation Medicine

Background:

• Spinal cord injury and neurological disorders often impair bladder voiding function due to dyssynergic urethral sphincter contraction.
• Restoring bladder function is crucial for improving the quality of life for affected individuals.

Purpose of the Study:

• To introduce and evaluate a closed-loop intraspinal microstimulation (ISMS) system for efficient bladder voiding.
• To develop a neuroprosthesis that restores natural bladder function without invasive surgical procedures like rhizotomy or neurotomy.

Main Methods:

• Utilized asynchronous two-electrode ISMS with combined pulse-amplitude and pulse-frequency modulation.
• Intermittently stimulated electrodes implanted in the S2 lateral ventral horn (to excite bladder motoneurons) and S1 dorsal gray commissure (to inhibit urethral sphincter motoneurons).
• The closed-loop system aimed to reduce the net electric field and maximize selective neural stimulation.

Main Results:

• Achieved a high voiding efficiency ranging from 77.2% to 100%.
• The average voiding efficiency was recorded at 91.28 ± 8.4%.
• Demonstrated effective bladder voiding without requiring rhizotomy, neurotomy, or high-frequency blocking.

Conclusions:

• The proposed closed-loop ISMS system is a promising approach for restoring bladder function.
• This technology represents a significant step towards developing natural and robust motor neuroprosthesis devices.
• The method offers an efficient and selective way to manage voiding dysfunction in neurological conditions.