A Healthy Vision


An epiretinal prosthesis. Image: Second Sight

When Wentai Liu, a professor of bioengineering and electrical engineering at UCLA, was approached by two eye surgeons about helping those with retinal issues, he says there was just one issue: He hadn’t done a great deal of work in biology. But taking on the challenge, he had the chance to be a part of a team of medical professionals and engineers who wanted to make a difference.

Seeing the Opportunity

“I was a professor of electrical engineering [at North Carolina State University] in 1988 and they wanted to design a device that could transfuse light into a chemical signal or electrical signal,” he says. “It was the thought of creating an implantable device to help eyesight. I remember going through a handbook about the eye of more than one thousand pages and trying to understand it better. There was a lot to learn.”

The external equipment includes glasses connected to a video processing unit. Image: Second Sight

The original idea was to put a camera inside the eye but, as technology improved, a video camera outside the eye seemed a more viable option, he says. Just roughly one centimeter in width, it would be mounted to an eyeglass frame.

“The camera sent a video signal to a processor that’s worn at the waist to do further camera processing and creates an electrical signal and becomes electrical stimulation,” he says. “The signal goes to another electronic driver (a computer chip) and it tries to drive a coil because you can’t put a wire through an eye wall. You’re transmitting data wirelessly.”

One of the challenges was to try and make it effective yet not make it too cumbersome for the individual. Available now as Argus II, it received approval from the Federal Drug Administration and now is offered to the public through Second Sight Medical Products, Inc., based in Sylmar, CA.  

A surgery is involved to make it work. It’s an epiretinal prosthesis that’s put in and on the eye, according to the product’s site. It defines an epiretinal prosthesis as “an implant that is placed on top of the retina versus a ‘subretinal’ that sits underneath the retina.” The external equipment has a video processing unit, glasses, and a cable.

It’s presently offered with a 60-pixel microchip but Liu and others at UCLA are working on 1024 to 4096. “We’re making progress but hope to make more strides,” he says. Nonetheless, the project’s results earned grants that have totaled more than $100 million.

Liu credits the persistence of so many involved to get the product to market, looking back at the odyssey that began more than a quarter century ago. “You have to keep at it because results for so many inventions can take a long time and adjustment,” he says. “The mix of medical and technology isn’t always easy.”

Still, he’s found the experience well worth it.

“To help people see better is a huge inspiration to me and has provided more meaning to my work,” he says. “Vision is something you may not think about until it’s gone.”

Eric Butterman is an independent writer.

Learn more about emerging medical technologies at ASME 2015 4th Global Congress on NanoEngineering for Medicine and Biology

The mix of medical and technology isn’t always easy.

Prof. When Wentai Liu, UCLA


March 2015

by Eric Butterman, ASME.org