How can our brains control prostheses?

Scientists are exploiting ways to connect the human brain to modern prostheses (such as artificial limbs) or via computers to expand our functionality. It’s hoped patients will be the ones to benefit, particularly those who have lost limbs in accidents or at war.

Motor prostheses interpret the natural signals sent from the brain. The electrical signals sent are detected using microelectrodes, which can be implanted underneath the skin or even buried into nerves. The brain signals for each particular movement are unique and slightly different, and the aim is to detect these individually to allow patients the ability to perform fine movements. However, the science is still developing to more accurately recognise these signals, and the perfect prosthesis does not yet exist.

The initial technology was developed with monkeys, and has come a long way since. There has been a massive push in this technology in recent years, as military funding starts to finance research to improve injured soldiers’ quality of life. The initial crude devices are now being replaced with technologically cutting-edge equipment. The most modern devices use hundreds of sensors to determine the precise movements the brain is commanding, and transmits them to some of the most complex and sophisticated prostheses ever.

That said, this technology is still a work-in-progress. Movements are still limited and require refinement. Work is also needed to improve feedback to the patient from the prosthesis (much like you can feel what you’re touching with your fingers), so that movements can become even more realistic. As both the life span and quality of the microprocessors improve, the motion and functionality of prostheses will become ever-more reliable and lifelike.