Wearable High Voltage Compliant Current Stimulator for Restoring Sensory Feedback

Area of Science:

• Biomedical Engineering
• Neuroprosthetics
• Wearable Technology

Background:

• Transcutaneous Electrical Nerve Stimulation (TENS) shows potential for restoring tactile sensations in amputees.
• Current TENS applications are limited by bulky, non-portable laboratory equipment.
• Need for adaptable, wearable instrumentation for reliable sensory stimulation exists.

Purpose of the Study:

• To develop a low-cost, wearable, high-voltage compliant current stimulator for TENS.
• To enable portable and reliable sensory feedback for amputees in daily life.
• To create a multi-channel TENS device using COTS components.

Main Methods:

• Designed a microcontroller-based system with a digital-to-analog controlled voltage-current converter.
• Implemented a four-channel, high-voltage compliant current stimulator.
• Utilized Components-Off-The-Shelf (COTS) for a low-cost, compact PCB (115.9 mm × 61 mm, 52 g).

Main Results:

• The stimulator delivers up to 25 mA into loads up to 3.6 kΩ.
• High-voltage compliance allows stimulation of loads >10 kΩ with 5 mA, adapting to impedance variations.
• Functionality confirmed on resistive loads and skin-like RC circuits; amplitude modulation demonstrated.

Conclusions:

• The developed wearable TENS device offers a portable and adaptable solution for sensory feedback in amputees.
• This COTS-based system addresses the limitations of current TENS instrumentation for daily use.
• The device shows promise for improving the quality of life for individuals with limb amputation.