Valencia, CA: ? The Alfred Mann Foundation (AMF) today announced the first subject, a U.S. Marine, SSgt James Sides, as a recipient of its highly anticipated IMES System (implantable myoelectric sensor) ? an experimental system that holds the promise of being the first minimally invasive, intuitive, multi-channel control system for prosthetics intended for long term use.
The IMES System is currently being studied under the Investigational Device Exemption (IDE) regulations of the U.S. Food and Drug Administration (FDA). AMF?s ongoing trial with injured veterans at the Walter Reed National Medical Military Center anticipates subjects intuitively operating three different prosthetic movements simultaneously: opening and closing the hand, rotating the wrist, and moving the thumb. Combining these three movements enables several grasps that are invaluable for performing everyday tasks.
The IMES System takes advantage of electro-chemical signals that occur when a muscle contracts. The IMES implants, which are small capsules about 16mm long and 2mm wide, are placed into the residual muscles of an amputated limb, where they detect contractions that are used to elicit specific movements in the part of the limb that is no longer there.
These signals are captured and wirelessly transmitted from the implanted sensor to a decoder box, which serves as an electronic brain. The IMES System bridges the brain to the artificial limb, enabling the signals sent from the brain to the remaining portions of the amputated muscles to intuitively control the prosthesis without the need for invasive brain or muscle reinnervation surgery.
The IMES system is designed currently to provide up to three distinct movements (or degrees of freedom) that can occur simultaneously. Future systems are targeting up to 13 simultaneous degrees of freedom and the ability to combine pre-programmed patterned movements that will potentially enable advanced prosthetic devices to achieve performances that in many instances will be as fluid and effective as an intact limb.
The IMES system is intended to address many of the shortcomings of current myoelectric control systems which are limited in function because the muscle signals are detected by electrodes placed on the surface of the skin ? sweat, movement between the electrode and the skin, and limited access to only large muscles close to the surface of the skin. These limitations make control non-intuitive, inconsistent, and unreliable.
“I am deeply committed to improving the health and well-being of my patients,? said Retired Army Colonel Paul F. Pasquina, M.D., Principle Investigator and Chair of the Department of Physical Medicine & Rehabilitation at the Uniformed Services University and former Chief of Orthopaedics & Rehabilitation at Walter Reed National Military Medical Center.
?I was thrilled with the idea of collaborating with AMF and leading the IMES project. It holds great promise for future of amputees, and overcomes several of the flaws that exist with the other ?thought-controlled? systems available today. I couldn?t be happier with how quickly our first subject has adapted.?
“This is exciting and promising work, and the AMF team of IMES investigators are confident that this technology will result in a new and improved class of prosthetic devices for both upper and lower limb amputees,” stated David Hankin, Chief Executive Officer of the Alfred Mann Foundation.?
Pasquina Hand or Modular Prosthetic Limb (MPL)
The Modular Prosthetic Limb (MPL) was developed as part of a four-year program by the Johns Hopkins Applied Physics Laboratory, along with Walter Reed National Military Medical Center and the Uniformed Services University of the Health Sciences. The brain-controlled prosthetic has nearly as much dexterity as a natural limb, and allows independent movement of fingers.