Microchip implanted in spine stimulates paralysed limb muscles
01 Dec 2010
A new type of microchip that can be implanted into the spine
to stimulate muscles of people with paraplegia has been developed by a
team of engineers from the UK, Germany and Ireland.
It is the first 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
The Engineering and Physical Sciences Research Council (EPSRC)
project is led by Professor Andreas Demosthenous from University
College London and includes engineers from Freiburg University and
the Tyndall Institute in Cork.
The microchips 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
The spinal implant microchip
Although electrical stimulation of leg muscles has been used for
some time, it is usually done by attaching electrodes to the outside
of the legs and then connecting the electrodes to an external
stimulator. This is too time consuming to be used every day so few
people with spinal cord injury continue with this method despite the
clear health benefits.
At the moment electrical stimulation of nerve roots in the spinal
canal can be carried out using implanted electrodes and an implanted
stimulator connected by a cable. This latest research is the first
to combine the electrodes and muscle stimulator in one unit so that
more nerves can be stimulated and better function achieved.
“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 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
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.
Universities and Science Minister David Willetts, said: “The
Active Book is a good example of how UK scientists and engineers are
translating research into innovations that deliver real benefits for
society. This tiny implant has the potential to make a real
difference to the lives and long-term health of people with
paraplegia in the UK and around the world.”
The Active Book will be made available for pilot studies in 2011.