Prosthetic Eyes and Ears Soon Will Equal Human Capabilities

Progress in the medical field (with hefty contributions from computer science), has rapidly been marching towards capability pairing of the key human senses: sight and hearing.

Image Credit: Sheila Nirenberg

Sheila Nirenberg of Weill Cornell Medical College has demonstrated a novel approach that appears to improve on previous labors by fashioning a device that mimics the brain’s innate software. Replacing retinal circuits by processing light received and then outputting a code.  The code is then relayed internally to the processing centers in the brain to construct a conscious image.

Previous technology, including work done by NASA,  produced simpler images. (The pictures above show natural vision on the left, an old-style artificial retinal image on the right and different stages of processing Nirenberg’s coded images in the two middle pictures.) Nirenberg and her student, Chethan Pandarinath, hail from the neural coding field, which brings a new way of approaching the problem. The standard focus has been on improving prosthetics by increasing the number of electrical nerve stimulators that are placed in the patient’s retina. Nirenberg’s group has been focusing on how to turn the stimulators on and off in the right pattern, so that the retina sends normal signals to the brain. Their device mimics the retina’s software to replicate the signalling used to produce an image in the brain.

At TEDMED, Sheila Nirenberg shows a bold way to create sight in people with certain kinds of blindness: by hooking into the optic nerve and sending signals from a camera direct to the brain.

One of the key findings by scientists, like  Nirenberg  is that the neural connections and systems used for the ocular prosthetic can be directly used for other senses.  That is to say the brains neural networks have the same essential connection patterns for every sense.  We should therefore see improvements in all areas of bionic sensing at nearly the same time.  

Other work relating to robotics and prosthetics may soon yield devices that actually allow the user to feel through the prosthetic. A new study was conducted with two arm amputees who had undergone a surgery called targeted reinnervation, in which the remaining nerve ends from the severed arm were rerouted to an area on the arm above the site of amputation. This patch of skin serves as a proxy — touching different parts of the area makes the amputee feel as though distinct parts of his or her missing arm were being touched.

The question, of course, is once human levels are reached with our bionic and prosthetic devices, how long before the capabilities of our devices start to exceed human levels?