Researchers Discuss Artificial Retina Development

 Bionic Eye

Recently, a team from Lawrence Livermore National labs describes how the nervous system works and how neurons communicate then discusses the first long-term retinal prosthesis that can function for years inside the harsh biological environment of the eye.

Millions of people worldwide suffer from ocular diseases that degrade the retina, the light-processing component of the eye, causing blindness.

Now, a team from Lawrence Livermore National labs describes how the nervous system works and how neurons communicate then discusses the first long-term retinal prosthesis that can function for years inside the harsh biological environment of the eye.

For researchers such as Satinderpall Pannu of Livermore’s Engineering Directorate, integrating nanometer-size devices with biological systems and studying the interface between them is a daily reality. 

In 2009, he and his team set the stage for a new generation of neural implants with the design and fabrication of an artificial retina. The device, a fully implantable neural prosthetic actually restores a sense of vision to people who have lost their sight because of ocular disease. Pannu and his team have continued to enhance the technology, which promises to dramatically improve the lives of patients with debilitating conditions caused by injury or neurological disease.

Sat Pannu - Image Source: BizJournal

The device works with a miniature camera, which sits inside a pair of sunglassew and sends images wirelessly to a microprocessor worn on a patient’s belt. There it is converted to an electronic signal that is sent to a receiver on the eye, which sends the signal via a thin cable to a nano-fabricated, watch-battery-size microelectrode array that is surgically tacked onto the retina. The array then emits pulses to the optic nerve, which sends a signal to the brain for processing.

The camera allows patients to zoom in and adjust the contrast of an image, describes Pannu.  

Keys to the success of this new class of implants are advances made at Livermore in the area of nano- and microfabrication techniques and in the use of novel materials that make the devices both biocompatible and fully implantable for long-term use. 

Also the implants promise to do more than just stimulate neural tissue. They will record electrical and even chemical signals for the first time, creating a feedback mechanism that allows the stimulation to be fine-tuned for each patient. “These devices are a real game changer,” Pannu says. “Once we understand what fully implantable prosthetics can do, the floodgates to innovation are open.”

Neural implants, or prosthetics, are a class of devices that communicate with the nervous system. An electronics package in each device activates an array of tiny electrodes that interface directly with healthy neurons in the body. Signals produced by the electrodes bypass damaged areas of the brain or part of the nervous system to restore function, block pain, or prevent seizures. Someday, these devices may even be used to treat depression and other ailments.

Since the late 1990s, implants for the brain and spinal cord have been developed with varying degrees of success. Some help prevent seizures in patients with epilepsy and Parkinson’s disease. Spine implants are being used for pain control, and other devices stimulate peripheral nerves and muscles. 

Although these devices have dramatically improved many people’s lives, they are limited in terms of performance compared to the promise held by technologies now under development. Except for the artificial retina, today’s implants operate with a handful of electrodes and an electronics package the size of a deck of cards, which causes significant complications during and after surgery. 

However, the researchers still take great satisfaction from knowing they are making a difference in people’s lives, and—perhaps even more importantly—they are giving many patients a precious gift: hope. “We get e-mails from parents whose children have retinitis pigmentosa,” Pannu says. “They know their kids will go blind because no therapies are available to help them. They’re desperate. The artificial retina offers hope that there will be a better future for their children.”



SOURCE  UCTV

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