A high voltage, constant current stimulator for electrocutaneous stimulation through small electrodes.

Area of Science:

• Biomedical Engineering
• Neuroscience
• Electrical Engineering

Background:

• Transcutaneous electrical stimulation is crucial for sensory feedback.
• Existing devices often lack the high voltage compliance needed for fingertip tactile stimulation.
• Accurate and safe stimulation parameters are essential for clinical applications.

Purpose of the Study:

• To design and develop a high-voltage stimulator for transcutaneous tactile fiber stimulation.
• To achieve high compliance voltage and precise current control for fingertip stimulation.
• To address power supply challenges and ensure safety for hospital environments.

Main Methods:

• Utilized an improved Howland current pump topology for the output stage.
• Employed commercially available high-voltage operational amplifiers to reach ~800 V compliance.
• Implemented an optically coupled input stage for computer control and safety compliance.

Main Results:

• Achieved output current accuracy better than +/- 5% from 1 to 25 mA for pulses >= 30 microseconds.
• Demonstrated a rise time of less than 1 microsecond for square pulses.
• Successfully addressed high-voltage, common-mode, and latch-up power supply issues.

Conclusions:

• The developed high-voltage stimulator effectively enables transcutaneous tactile stimulation of the fingertip.
• The design offers precise current control, fast response times, and high voltage compliance.
• The stimulator meets safety standards for hospital use and can be adapted for biphasic stimulation.