A novel portable device and validation procedure for transcutaneous electrical nerve stimulation

Area of Science:

• Biomedical Engineering
• Neuroprosthetics
• Rehabilitation Technology

Background:

• Upper limb myoelectric prosthesis adoption is hindered by the absence of closed-loop control systems.
• Restoring sensory feedback via the afferent nerve channel remains a significant challenge for prosthetic integration.
• Transcutaneous electrical nerve stimulation (TENS) shows promise for somatotopic sensory feedback but is limited by current device constraints.

Purpose of the Study:

• To introduce a novel, wearable transcutaneous electrical nerve stimulation (TENS) device specifically designed for sensory feedback in prosthetic applications.
• To address the limitations of existing TENS devices, including bulkiness, power source issues, and restricted waveform customization.

Main Methods:

• Development and characterization of a compact, wearable TENS device (46g, 62x49x20 mm).
• Benchtop testing to evaluate charge-balanced stimulation wave delivery across a skin-like resistive load.
• Preliminary user study with 10 healthy participants comparing the novel device against a reference stimulator for elicited sensations (quality, intensity, area).

Main Results:

• The novel wearable TENS device successfully delivered charge-balanced stimulation waves.
• The device elicited sensations of tingling and vibration with intensities comparable to a reference stimulator.
• User feedback indicated similar qualities and intensities of sensation between the proposed device and the reference.

Conclusions:

• The developed wearable TENS device is suitable for sensory feedback applications in upper limb prosthetics.
• This technology has the potential to overcome limitations of current TENS systems, facilitating closed-loop control.
• Further research and validation are warranted to fully integrate this device into practical prosthetic systems.