First-in-man demonstration of a fully implanted myoelectric sensors system to control an advanced electromechanical prosthetic hand

Abstract

Background Advanced motorized prosthetic devices are currently controlled by EMG signals generated by residual muscles and recorded by surface electrodes on the skin. These surface recordings are often inconsistent and unreliable, leading to high prosthetic abandonment rates for individuals with upper limb amputation. Surface electrodes are limited because of poor skin contact, socket rotation, residual limb sweating, and their ability to only record signals from superficial muscles, whose function frequently does not relate to the intended prosthetic function. More sophisticated prosthetic devices require a stable and reliable interface between the user and robotic hand to improve upper limb prosthetic function. New Method Implantable Myoelectric Sensors (IMES®) are small electrodes intended to detect and wirelessly transmit EMG signals to an electromechanical prosthetic hand via an electromagnetic coil built into the prosthetic socket. This system is designed to simultaneously capture EMG signals from multiple residual limb muscles, allowing the natural control of multiple degrees of freedom simultaneously. Results We report the status of the first FDA-approved clinical trial of the IMES® System. This study is currently in progress, limiting reporting to only preliminary results. Comparison with Existing Methods Our first subject has reported the ability to accomplish a greater variety and complexity of tasks in his everyday life compared to what could be achieved with his previous myoelectric prosthesis. Conclusion The interim results of this study indicate the feasibility of utilizing IMES® technology to reliably sense and wirelessly transmit EMG signals from residual muscles to intuitively control a three degree-of-freedom prosthetic arm.

Novel postural control algorithm for control of multifunctional myoelectric prosthetic hands

“…TMR has shown great success for high-level upper-limb amputees [9]. Studies have successfully simulated IMES in human subjects using fine-wire intramuscular electrodes [11], and the technique has recently been implemented in humans for the first time [12].…”

At-Home Computer-Aided Myoelectric Training System for Wrist Prosthesis

“…Users can easily change, or create the gestures that they want to include only by simply changing the values of five variables; enable[0], enable [1], enable [2], enable [3], and enable [4]. These five variables correspond to the direction of the thumb, index, middle, ring, and pinkie, respectively.…”

“…1964) to commercialize the first myoelectric-controlled prosthetic limb [1]. Since then, there have been several studies focusing on the control techniques, for example, using toe gesture sensors [2], targeted muscle reinnervation (TMR) [3], and fully implanted myoelectric sensors [4]. The majority of these works involve commercial robotic/prosthetic hands.…”

Introductory Chapter: Toward Near-Natural Assistive Devices

“…A few drawbacks to muscle-based control technology, however, are its generally high cost [7] as well as repeatability and reliability issues in surface EMG signals [36], making this input method difficult to use in prosthetic control. Implanted EMG sensors are a promising technology that can provide high-quality signals; however, they are costly, invasive, and only in the primary stages of human use [33]. Myoelectric control also relies on undamaged neuromuscular pathways being accessible to present the EMG signal [7].…”