Engineers have developed a new type of microchip muscle stimulator implant that will enable people with paraplegia to exercise their paralysed leg muscles. It is the first time that researchers have developed a device of this kind that is small enough to be implanted into the spinal canal and incorporates the electrodes and muscle stimulator in one unit. The implant is the size of a child’s fingernail. There have been other devices that use electrodes in the spinal canal but the muscle stimulators are implanted in the abdomen in the front.
The Engineering and Physical Sciences Research Council (EPSRC) project is being led by Professor Andreas Demosthenous from University College London. It includes engineers from Freiburg University and the Tyndall Institute in Cork.
“The work has the potential to stimulate more muscle groups than is currently possible with existing technology because a number of these devices can be implanted into the spinal canal”, said Professor Andreas Demosthenous. “Stimulation of more muscle groups means users can perform enough movement to carry out controlled exercise such as cycling or rowing.”
The devices could also be used for a wide range of restorative functions such as stimulating bladder muscles to help overcome incontinence and stimulating nerves to improve bowel capacity and suppress spasms.
The research team has overcome previous limitations by micro-packaging everything into one tiny unit. Latest laser processing technology has been used to cut tiny electrodes from platinum foil. These are then folded into a 3D shape (which looks like the pages of a book, earning the device the name of the Active Book). The pages close in around the nerve roots. They are micro-welded to a silicon chip which is hermetically sealed to protect against water penetration, which can lead to corrosion of the electronics
The University College London is doing pioneering work with prosthetics They are attaching directly to the bone and are working to mind controlled prosthetics.