Engineers have invented a vibrating "pill" that tricks the stomach
The new oral capsule activates when dipped in gastric juice and vibrates to create an illusory stretching of the stomach. Measuring 31 by 10 millimeters, the device has a tiny motor and a silver-oxide battery.
Specialists from the Massachusetts Institute of Technology together with gastroenterologists from Brigham and Women's Hospital at Harvard Medical School in the United States have developed a new promising device for getting rid of extra pounds - a vibrating capsule that, when placed in the stomach, modulates its stretch receptors and creates the illusion of satiety. An article about it is published in the journal Science Advances.
The obesity epidemic is one of the major problems of modern public health. Nearly 42% of the adult population of the United States suffer from excessive deposition of fat in the body. In Russia, 3.5 million people are obese, a number that has increased by 36% since 2009.
Since patients are often too difficult to change their lifestyle, and the possibilities of pharmacological therapy are limited, there is a need for alternative methods of fighting excess weight. The authors of the new study proposed their own design - a vibrating bioelectronic swallowable stimulator VIBES measuring 31 by 10 millimeters with a tiny motor and battery.
The idea is that this safe and easy-to-use ingestible device performs mechanical stimulation, causes an illusory stretching of the stomach and helps to achieve a feeling of satiety even before eating. The stomach stretches during a meal, acting on nerve endings in the walls of the organ that send signals to the brain that the person is full.
"VIBES is designed to be taken orally, maintain contact with the gastric mucosa, activate when immersed in gastric juice, vibrate with an amplitude sufficient to stimulate the intraganglionic laminar endings of the stomach for a given period of time, and pass safely through the gastrointestinal tract," the developers said.
Their capsule has a gelatin membrane that dissolves 4.3 ± 1.2 minutes after immersion in gastric juice, releasing a spring-loaded pin that closes the circuit to activate vibration. Since swallowing the tablet and passing it through the esophagus usually takes a maximum of one minute, VIBES is guaranteed to reach the stomach before activation. The offset shaft motor is housed in a special housing that provides a displacement amplitude of two to four millimeters when powered by a 1.55-watt, 80 milliamp-hour silver-oxide battery.
The researchers tested the device by immersing it in gastric juice: the VIBES vibrated for an average of 38.3 ± 1.83 minutes. This time range was found to be acceptable, as a meal typically takes 20 to 30 minutes, and the initial agitation of stomach contents occurs in about an hour. To ensure that the vibrocapsule had no vulnerable materials, two such devices were lowered into artificial gastric juice (pH 1.2) for 24 h and into artificial intestinal fluid for 10 days at 37 degrees Celsius. In the end, there were no changes in the outer body of the capsules and inside them, VIBES were able to successfully activate after the incubation period.
The effectiveness of the development was tested on pigs (weight - 50-80 kilograms, age - four to six months), as the anatomy of their stomach is similar to the human stomach. Animals were injected with vibrocapsules, and then measured the electrical activity of part of the vagus nerve. The result was that the vibrations of the device caused an effect that resembled the expansion of the stomach with air. After four days, VIBES was excreted from the body.
The device caused changes in hormone levels in the pigs, just like eating, including an increase in insulin levels and a decrease in the peptide hormone ghrelin, which is produced by an "empty" stomach and small intestine and causes hunger. In addition, the subjects ate about 40% less than the control group that didn't get VIBES and were less active after eating. The researchers did not record side effects like vomiting or diarrhea.
They plan to improve the development and study its effect on the body in more detail. In particular, it has not yet been possible to confirm that the vibrocapsule will help to lose weight, because the pigs involved in the tests were young and continued to grow. Probably, the next stage will be tests on dogs, and then, if funding is found, in two or three years it will be possible to test VIBES on humans.
Clinical psychologist Tom Hildebrandt reminded that the developers will have to answer some other questions. For example, how will a person feel the vibrating capsule inside himself? In addition, the nerve endings of the stomach wall in obese patients may be less sensitive to stretching. Consequently, there is no guarantee that they will respond to vibration stimulation in the same way as people without the condition.