Battery-Free Implantable Weight Loss Device

The journal Nature Communications has published a paper describing a small device that tricks the brain into believing the stomach is full after a small amount of food is eaten. The device has been tested in rats and must now be proven to work in humans before it can be sold to treat obesity. The device shown in panel d below is small and simple but ingenious.

The device is placed on the stomach and two gold-tipped wires are placed near the nerve that communicates stomach food status information to the brain (the vagus nerve). When the stomach churns in response to food, the device generates small electrical pulses that mimic the nerve's food status signals to the brain. Stomach churn causes the device to flex and that natural movement is the energy source for the electrical signal. Stomach movements are shown in panel a below and a trace of the resulting electrical signal is shown in panel b.

Since this has only been tested in rats, clinical trials will be necessary to demonstrate the device, or a variant of it, will be effective in fooling the human brain and lead to weight loss. Typically for drugs that are successful in mouse or rat testing, the chance of the drug ever receiving regulatory approval for marketing is about 0.1% or less. Most drugs that are reasonably effective in animals do not even make it into human testing for various reasons, e.g., toxicity, unknown mechanism of action and thus no obvious way to get regulatory approval, high cost of clinical trials, sometimes hundreds of millions, etc.

The odds of clinical success here are probably much higher, maybe about 40-50%, because (i) electrical signals are not drugs that have to act on a target molecule(s) which may or may not work the same way in humans as in animals, and (ii) similar but bigger, battery powered devices have been effective enough for marketing approval for treating obesity.

B&B orig: 12/20/18