Controlling Prosthetic Limbs With Your Mind

by Gabrielle DeMarco on February 16, 2012

In the short video above an adorable little monkey is eating marshmallows. What is exceptional about this little monkey is not his love of sticky sweets, but the way he is grabbing them. This particular monkey has tiny, freckle-sized sensors in its brain. The electrical signals from these sensors are allowing the monkey to control a robotic arm with enough precision to grab a small marshmallow and put it in its eager mouth. The technology, created by scientists at the University of Pittsburgh, is a neuroprosthesis.

Obviously the development of reliable and safe neuroprostheses would be revolution in healthcare. Imagine having the ability to replace missing or nonfunctional arms or legs. This little monkey makes that future seems so close. Unfortunately, there are multiple obstacles to the use of such advanced neuroprosthetic devices. The good news is the scientists and engineers at Rensselaer are working as I write to help overcome these obstacles.

Led by mathematician Kristin Bennett and industrial and systems engineer Mark Embrechts, researchers here at Rensselaer are coming together with scientists, engineers, and doctors from across the country to develop better and longer-lasting neuroprosthetic implants.

A big problem these researchers are looking to surmount is reliability. To date, neuroprosthetic implants of this level of sophistication (a level high enough to accurately manipulate something as complex as a hand) typically don’t last for more than a few months. The body starts to reject them, the signals from the electrodes in the implants within the brain stop working, and eventually the implants become useless, uber-sophisticated hunks of metal in your brain.  And as Embrechts accurately put it, “No one wants to have brain surgery every few months to replace the device.” Instead, you want a prosthesis that last upwards of twenty years or even a lifetime.

In order to make longer lasting devices, researchers need to understand exactly what is happening in the brain that stops the devices from working. This is where Bennett, Embrechts, and their teams come in to help.

Both of the researchers specialize in making sense of large streams of data. In this case, they will analyze data being produced by partnering universities and companies testing the performance of neuroprosthetic implants. With their analysis, they will seek to determine what happens in the brain in response to the device, what researchers could do to fix this response, and how failure of device can be predicted. The ultimate aim is to greatly increase the life of these products.

Their work is part of a very large, multi-university, multi-disciplinary project being funded by the Defense Advanced Research Projects Agency (DARPA). The project includes more than half a million dollars in research funding to Rensselaer over the next three years.