The Future of BMI

Utah's electrode array

One of the next challenges in the field of BMI prosthetics is making them feel like normal limbs. A normal limb has a sense of touch and proprioception, the process by which sensory feedback to the brain transmits the location and position of the body's muscles, allowing us to be aware of the arm’s position without having to look. This is accomplished by an array of receptors in the muscles and joints, as well as mechanical receptors in the skin, that enable us to know when we are touching an object. The next generation of prosthetic arms will have proprioception and “feeling,” generating feedback pulses to the brain or to nerve endings that will result in their bearers having an almost natural feel to their bionic limb.

It seems that today, more than ever, BMIs that can operate bionic prosthetics are within our grasp. The Defense Advanced Research Project Agency (DARPA) set an ambitious goal of releasing a fully functioning bionic arm for Food and Drug Administration (FDA) approval by 2009. This arm will have far more degrees of freedom than any other available prosthetic, and in 2011 DARPA is planning to release a prosthetic that has nearly all the motion ability and dexterity of a normal limb, including touch and proprioception. Theoretically, an amputee using this arm will be able to play the piano.

Normann artificial vision

A future type of BMI for patients with paralyzed limbs or spinal cord injuries will send efferent motor impulses directly to the muscles of the limb. Unlike the situation of amputees, in spinal cord injuries, the muscles are functional but nerve impulses aren’t able to get there. A muscle-stimulating BMI will be able to bypass the severed point and directly innervate the muscle through small electric currents. Robotic arms and hands approaching the agility and sensitivity of the human hand already exist and have been covered recently by TFOT.

BMI technologies are not only confined to prosthetic and paralyzed limbs. In the future, BMIs may allow blind people to see using an artificial picture-capturing device, much like a camera. Several methods for visual prosthetics have already been used successfully with patients. These methods use a computer chip implanted on the retina that is fed by a miniature camera on a patient's glasses. The chip stimulates the optic nerves, transmitting a picture to the brain. Devices used today allow patients to see vague shapes or distinguish light from dark, but future devices, such as the Cortical Visual Prosthesis being developed allow improved synthetic vision.

Professor Eilon Vaadia

The John A. Moran Eye Center at the University of Utah has developed a chip , but it could also be applied to other BMI applications. The chip contains an array of electrodes that can be individually stimulated, are small enough to be inserted into brain tissue without much damage, and at the same time are strong enough to withstand the insertion procedure. Some of these implants have been successfully implanted in blind people with positive results. Future generations of these types of devices will lead to improved resolution, and ultimately restoration of sight to the blind.

What we are witnessing today is only the tip of the iceberg of the great potential BMIs hold for medical, military, recreation, and other purposes in the future. BMI research is on the threshold where science meets science fiction. There will surely be exciting news emerging from this field in the very near future.