New implant helps stroke patients

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Researchers in Wiltshire have helped develop a device that could help stroke patients walk more easily.

It helps patients with dropped foot - the inability to lift the foot due to muscle weakness or paralysis.

Originally Salisbury District Hospital team used electrical impulses via sticky pad electrodes to stimulate the muscle and lift the foot.

The unit, used by about 1,600 people, had limitations. The new STIMuSTEP is implanted which avoids the problems.

Research physiotherapist, Ingrid Wilkinson, said dropped foot normally meant patients' toes rubbed along the ground, which made walking difficult and increased the risk of falls.

Initially the team developed the Odstock Dropped Foot Stimulator (ODFS) which applies small, controlled electrical impulses to stimulate the nerves of the affected muscle, causing the muscle to contract and the foot to lift.

The stimulation is applied via self adhesive patches (electrodes) worn on the leg.

A foot switch triggers the stimulation in time with the person's step.

'Positioning problems'

Ingrid Wilkinson said: "Unfortunately some of these people experience difficulty positioning the electrodes or skin irritation.

"So, we worked with Finetech Medical Ltd and the University of Twente, (in the) Netherlands to develop the STIMuSTEP," Ms Wilkinson added.

"A short operation places the small implant module under the skin on the nerve.

"Once healed, the external transmitter and footswitch is set up and the system can be used."

There have been 21 operations in the UK so far and a recent controlled trial of STIMuSTEP has also shown an increase in walking speed when compared to conventional splints.

It provides the same functionality as the ODFS but reduces the need to place electrodes daily.

It is implanted under general anaesthetic in a day surgery procedure lasting about an hour.