The chip Ada Poon has invented is as tiny as a grain of rice, but someday, the engineer believes, it could do big things - like transform the way illnesses are treated.Poon and a team of Stanford University researchers have invented a system that wirelessly beams power to tiny implants located deep inside the body, using as much energy as a cell phone.
Although they're years from human tests, the scientists believe they are helping to open the door to a future when doctors treat diseases and pain with electronics, instead of drugs or bulky devices.
Their work is part of the burgeoning field known as bioelectronics or "electroceuticals," which is rooted in the fact that the body's organs and functions are regulated through circuits of neurons that communicate in tiny electrical impulses. A growing number of researchers believe that by accurately mapping the neural patterns of diseases, they could stimulate or block the malfunctioning pathways with tiny electrodes and restore a patient's health.
GlaxoSmithKline is betting on this field. Last year, the British pharmaceutical giant started a $50 million venture capital fund to invest in companies that are developing new technologies in bioelectronics. The journey to get a product on the market could be as long as one or two decades, said Kris Famm, who leads bioelectronics research and development for GlaxoSmithKline.
But "we believe this can be paradigm-shifting," he said, and "can be a whole new class of medicines."Team members John Ho (left), Yugi Tanabe and Alex Yeh work with an optical power measurement device that they built in the research laboratoryTeam members John Ho (left), Yugi Tanabe and Alex Yeh work with an optical power measurement device that they built in the research laboratory
Poon's lab has sought to create a smaller, more efficient pacemaker for the heart. Pacemakers and other existing medical devices are relatively large because of their batteries, or they must be located right under the skin because they have to be recharged from the outside. Those requirements limit the areas in the body where they can be placed, the researchers explained in the Proceedings of the National Academy of Sciences.
In contrast, "we can make the devices very small and go very deep into the body," said Poon, an assistant professor of electrical engineering.
She has developed a tiny microimplant that can be powered or recharged wirelessly by holding a cell phone-like battery above the chip.
Held in the air, the power source does not do anything - but it reacts differently with tissue. Held over skin, it transports electromagnetic waves more than 2 inches into the body. These waves travel farther than the "near-field" waves used in electric toothbrushes or hearing implants.
So far, Poon's group has seen promising results in experiments involving rabbits with a surgically installed chip.
"Just receiving power, it converts it into electrical pulses that regulate the rhythm of the heart," said John Ho, a graduate student at Stanford and co-first author of the recent paper.
The team is confident that its invention is safe. An independent laboratory that tests cell phones found that the system was well within human safety guidelines.
Poon's "potentially quite important" invention could pave the way to replacing conventional medical devices with bulky batteries, said Bill Newsome, director of the Stanford Neurosciences Institute, who is not involved in Poon's research.
"People have wondered for a long time, how can we take devices down to micro-scale - a millimeter or under?" Newsome said. "There's a problem getting power to any device that small because traditional ... methods can't get enough power."
So Poon "is solving a major engineering problem," he said, suggesting that the work could be turned into a powerful alternative to deep-brain stimulation, in which a medical device sends electrical impulses to parts of the brain to treat disorders such as Parkinson's disease. "This is a real innovation in powering devices inside the body."
Poon believes her invention could someday be designed to influence neurosignals in ways that could treat afflictions such as chronic pain, Alzheimer's and urinary incontinence, all of which signal malfunctions in the central nervous system. The engineer has started a company, Vivonda Medical.
Famm of GlaxoSmithKline said Poon's work is encouraging, although he noted that the energy reported to be generated outside the body seemed to dissipate as it made its way through the skin.
So far, GlaxoSmithKline and other venture capital firms have invested $27 million in SetPoint Medical in Southern California, a bioelectronics company working on new ways to treat inflammatory diseases.
SetPoint is developing a tiny, implantable, wirelessly charged device that stimulates a nerve to activate a natural bodily reflex that counters inflammation. Currently, the device is undergoing in clinical trials with rheumatoid-arthritis patients, the world's first clinical trial of its kind.
It's too early to tell how the tests will go, but to Famm, the possibilities are endless.
"We think there is a vast opportunity for precision moderation on peripheral nerves that control our lungs and spleen and pancreas and kidney and liver and gastrointestinal tract," he said. "That's what's we're going after."
Stephanie M. Lee is a San Francisco Chronicle staff writer