Implantable Device Aids Weight Loss

“The pulses correlate with the stomach’s motions, enhancing a natural response to help control food intake,” says Xudong Wang, a UW–Madison professor of materials science and engineering.

Unlike gastric bypass, which permanently alters the capacity of the stomach, the effects of the new devices also are reversible. When Wang and his collaborators removed the devices after 12 weeks, the study’s rats resumed their normal eating patterns and weight bounced right back on.

Wang’s device has several advantages over an existing unit that stimulates the vagus nerve for weight loss. That existing unit, “Maestro,” approved by the Food and Drug Administration in 2015, administers high-frequency zaps to the vagus nerve to shut down all communication between the brain and stomach. It requires a complicated control unit and bulky batteries which frequently must be recharged.

That ongoing maintenance can be a big barrier to use, says Dr. Luke Funk, a surgery professor in UW–Madison’s Division of Minimally Invasive, Foregut and Bariatric Surgery who was not involved in the research. “One potential advantage of the new device over existing vagus nerve stimulators is that it does not require external battery charging, which is a significant advantage when you consider the inconvenience that patients experience when having to charge a battery multiple times a week for an hour or so,” he says.

In fact, Wang’s device contains no batteries, no electronics, and no complicated wiring. It relies instead on the undulations of the stomach walls to power its internal generators.

That means the device only stimulates the vagus nerve when the stomach moves.

“It’s automatically responsive to our body function, producing stimulation when needed,” says Wang. “Our body knows best.”