A 15-channel 30-V Neural Stimulator for Spinal Cord Repair

Area of Science:

• Biomedical Engineering
• Neuroscience
• Rehabilitation Technology

Background:

• Spinal cord injuries often result in impaired locomotion.
• Restoring motor function requires precise neural stimulation.
• Existing stimulators may lack the required performance for effective rehabilitation.

Purpose of the Study:

• To present a novel 15-channel, 30-V implantable current stimulator.
• To achieve performance specifications comparable to benchtop instrumentation for enhanced locomotion control.
• To develop an effective device for restoring motor function after spinal cord injuries.

Main Methods:

• Design and implementation of a 15-channel current stimulator.
• Integration of high-linearity and high-precision current delivery circuits.
• Development of an Analog-to-Digital Converter (ADC)-based active charge balancing scheme.
• Utilization of a digital Proportional-Integral (PI) controller in firmware.

Main Results:

• The stimulator achieved performance comparable to desktop instrumentation.
• High linearity, precision, and minimal channel-to-channel mismatch were demonstrated.
• A fast settling time of 0.3 microseconds was recorded.
• The ADC-based charge balancing scheme with a digital PI controller was successfully implemented.

Conclusions:

• The developed implantable current stimulator is suitable for restoring locomotion control.
• The device's performance meets the stringent requirements for neural stimulation.
• This technology holds promise for improving rehabilitation outcomes in spinal cord injury patients.