Recognizing that providing a more intuitive experience with robotic prostheses would improve their utility in performing everyday tasks, researchers designed an advanced control system for the benefit of upper limb amputees. The Muscle Activity Sensor Strip Impact team at Simon Fraser University, British Columbia, Canada, is testing its control sensor system with a robotic arm developed by UK-based Steeper Prosthetics.

New sensors improve movement and control of this advanced prosthetic arm. Image source: Dale NortheyNew sensors improve movement and control of this advanced prosthetic arm. Image source: Dale NortheyAn armband of pressure sensors inserted in the prosthetic socket tracks movements in the user’s remaining muscles as a bottle is grasped or other intuitive actions are performed. Computer algorithms analyze sensor data to decode the wearer’s intentions and move the prosthesis.

The researchers are working with paralympic skier Danny Letain, who lost his left arm below the elbow 35 years ago and who has been using a body-powered prosthesis with a pincer-like split hook and a series of straps to mechanically maneuver the artificial limb.

The hook is durable and quick to respond, but controlling it with straps is not natural, says Letain. Yet with the university team’s new control system, Letain already has a variety of different grip patterns that he says work “well beyond” what he could achieve with prosthetic devices.

The prototype is being fine-tuned for the cyborg Olympics, or the inaugural Cybathlon event to be held by the Swiss Federal Institute of Technology in Zurich in October 2016. The competition is organized for people with disabilities who use robotic technology and is expected to stimulate relevant technological innovation (see video).

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