Engineers from the University of California, San Diego and startup Nanovision Bioscience Inc. have recently created a new type of retinal prosthesis. This breakthrough was possible thanks to advancements in both nanotechnology and wireless electronics.
“We want to create a new class of devices with drastically improved capabilities to help people with impaired vision,” says Gabriel A. Silva, professor in bioengineering and ophthalmology at UC San Diego and one of the original founders of Nanovision.
The first essential technological component is an array of silicon nanowires. As these rows sense light, they activate the retina via electric stimulation. The nanowires also allow for a high degree of resolution, closely mimicking the compressed spacing of photoreceptors in the human retina.
Additionally, a wireless device serves as another critical design element. At incredibly fast speed and low energy, this component can transmit power and data to the nanowire arrays over a single wireless connection.
Surprisingly, this retinal prototype does not require a remote vision sensor to record visual data and convert the gathered information into signals. The nanowires are responsible for directly stimulating the eye, since they mimic the light-sensing cones and rods found inside the retina.
As stated above, the wireless power is extremely energy efficient, minimizing energy loss during the stimulation process and data transmission. This is due to its ability to recycle the circulating electrostatic energy. The team states that about 90 percent of the transmitted energy is directly used for neural activation.
Scientists recently tested this prosthesis, implanting the device beneath a rat’s degenerated retina. The damaged eye recorded extracellular neural action potential. Following up on these promising results, the researchers hope to transition this technology towards clinical trials, helping those who suffer from severe retinal degeneration.
The details of this research were published in the latest issue of Journal of Neural Engineering.