Obesity

Incredible battery-free implant battles obesity by suppressing appetite

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Graduate student Guang Yao (left) and Xudong Wang (right) hold a small implantable device that helped rats lose 40 percent of their body weight
Sam Million-Weaver
Graduate student Guang Yao (left) and Xudong Wang (right) hold a small implantable device that helped rats lose 40 percent of their body weight
Sam Million-Weaver
Graduate student Guang Yao (seated) uses a microscope to inspect the nanogenerators in the implantable weight-loss device
Sam Million-Weaver

A remarkable new implantable device developed by engineers at University of Wisconsin–Madison promises a new way to battle obesity. By gently stimulating a nerve that links the stomach to the brain, the device tricks your brain into thinking you're full.

The most common current surgical procedure to treat severe obesity involves bariatric procedures such as gastric bypass. These procedures are generally quite effective but they are also dangerously invasive and come with a swathe of challenging side effects. A newer strategy that has arisen over the past few years is called vagus nerve stimulation (VNS).

The vagus nerve is a large conduit that communicates signals between the brain and the body. It has been discovered that this communication pathway is one of the ways the stomach signals to the brain that it is full and our appetite should be suppressed so we stop eating. Experiments have shown that artificially stimulating the vagus nerve can reduce feelings of hunger, essentially making the brain think the stomach is full.

In 2015 the FDA approved the first obesity-controlling device of its kind, a pacemaker-like system that disrupts these vagal nerve communications to help suppress a person's appetite. This device, called "Maestro" was somewhat effective, but it's also incredibly bulky, difficult to operate, and needs to be frequently connected to external batteries to be recharged.

Graduate student Guang Yao (seated) uses a microscope to inspect the nanogenerators in the implantable weight-loss device
Sam Million-Weaver

The newly developed VNS device offers a truly impressive leap forward over the "Maestro." It is tiny, battery-free and generates its electrical stimulations in response to real-time stomach movements. The device is powered by the undulations of the walls of the stomach, meaning it not only needs no battery but it only activates its stimulation in response to the peristalsis of the stomach when a person begins eating.

"The pulses correlate with the stomach's motions, enhancing a natural response to help control food intake," says Xudong Wang, one of the authors on the study. "It's automatically responsive to our body function, producing stimulation when needed. Our body knows best."

The device has not been tested in humans at this point, however, the researchers recently completed animal testing and the results were incredibly promising. In a rat model the device resulted in a rapid 35 percent weight loss in the first 18 days of activity. For the remaining 75 days of the experiment the animals sustained that average weight loss, and once the devices were removed they immediately returned to normal eating patterns and weight levels.

The next steps for the researchers involve further refining the implantable device, perhaps to add some kind of shutter switch that allows the system to be easily turned on or off. Larger animal tests will also be conducted before moving into human trials, but the team is optimistic this system will present a huge leap forward in obesity-prevention technology.

"Our expectation is that the device will be more effective and convenient to use than other technologies," adds Wang.

The new research was published in the journal Nature Communications.

Source: University of Wisconsin–Madison

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6 comments
guzmanchinky
My father in law weighs 266. He's 5-6 He already has high blood pressure and borderline diabetes. This device could save more lives than any other out there.
RobertTaylor
Everybody has high blood pressure and borderline diabetes according to doctors and pharmaceutical companies because some lost tribe somewhere has low blood pressure and they are starving so they have low blood sugar.. That is how doctors and pharmaceutical companies make money.
EZ
The obvious question here is: Why does the Vagas Nerve need external stimulation to signal the brain? Could there be something going on somewhere that's preventing normal activity?
chinamike
This quote: "These procedures are generally quite effective but they are also dangerously invasive and come with a swathe of challenging side effects." I can speak with authority on exactly how people can suffer from the so called 'side effects'.
I am currently living with my friend's family as he slowly dies from liver cancer. He is a U.S. army vet from the Vietnam era. After he left service, he developed an eating disorder. Over a period of several years, he ballooned to nearly 400 lbs. Doctors told him that if he didn't change his diet and lifestyle, he would die at a young age.
Eventually he conceded to having gastric bypass surgery. The surgeon at the V.A. hospital botched the job. To perform the surgery, a small length of small intestines is removed and used to actually bypass a large portion of the stomach, essentially making it smaller. the problem with the surgery was, the opening part of the small intestine to the stomach was incorrectly sutured, causing the opening to be no larger than the end of a no. 2 pencil eraser.
He went to another doctor a few years later, but the doctor said that there could be nothing done to correct it. My friend did lose the weight of course, but he now had to eat tiny three to four bite portions for his entire meal for the rest of his life. It was terrible to see this man eat like a bird, while myself and his friends simply ate whatever we wanted in any amounts.
ljaques
Fasttrack that suckah! It will start saving lives a month after it debuts.
Mzungu_Mkubwa
I am convinced by personal experience that there are serious "defects" (for lack of a better word) in our diet in the U.S. The food we consume is the cause of so many unhealthy effects. @guzmanchinky: there *are* effective dietary solutions that will resolve many of these problems, but what is required is the decision by the sufferer to make the change. I personally made this decision for myself about 4 months ago, chose to make the changes necessary, found a health coach and am down nearly 40 pounds and feeling completely better - and going for more! The success key for me was to identify and engage with a good supportive community who came along side me in this battle. Remaining a victim to this health tragedy isn't the only path, y'all! ☻