Regaining Control

By Rebecca Yerworth

Just before Christmas, the second year Biomedical Engineering students spent a week in the lab designing and building a device to replace a computer mouse for a hypothetical client who had no hand. The devices picked up electrical activity in the muscle of the arm and translated these into cursor movements and clicks – or at least that was the theory.

The students’ knowledge of electronics, anatomy and problem solving were all put to the test as they built and tested their circuits. They discovered the delights of bread-boarding moderately complex circuits – and the importance of keeping your ‘spaghetti’ colour coded! Of equal importance was realising that some muscle groups are easier to control independently that others – and that what most of us do routinely, without consciously thinking about it, takes a lot more physical and mental effort when being relearnt.

All the groups successfully detected and recorded electrical activity from muscles. Detecting muscle activity from multiple muscle groups with a sufficiently clear signal to control a mouse pointer is much more challenging, but everyone managed this, at least intermittently. In amongst the hard work, it was good to see the moments of fun and hear the cries of delight as the first hand-free mouse clicks appeared.