A team of researchers from the Massachusetts Institute of Technology (MIT) that has worked in collaboration with scientists from Brigham and Women’s Hospital in Boston has developed a new way of feeding and communicating with devices implanted in the human body, which represents an important advance in the field of medicine, since, among the applications of said devices, there would be the administration of drugs, the monitoring of patients with conditions within the body or treating diseases by stimulating the brain with electricity or light.
The implants work with radiofrequency waves, which can pass safely through human tissues. Researchers have already carried out tests on animals, and have found that waves can feed devices located 10 centimeters deep in the tissue and from a distance of about one meter.
“Although these small implantable devices do not have batteries, we can now communicate with them from a distance outside the body,” says Fadel Adib, assistant professor in the MIT Media Lab and lead author of the study. study. This will be presented in August, within the framework of the Sigcomm annual congress (according to its acronym in English), organized by the ACM (Association of Computational Machinery) and which focuses on Data Communication.
The size of a grain of rice
Because the devices would not require a battery, they could be manufactured in a tiny format. In fact, when they conducted the study, these scientists tested a prototype the size of a grain of rice, but they explain that they could make them even smaller.
“Having the ability to communicate with these systems without the need to integrate a battery would imply a significant advance.” These devices could be compatible with, for example, helping in the administration of a drug, “says Giovanni Traverso, another of the authors of the study. study and assistant professor at Brigham and Women’s Hospital, Harvard Medical School.
Medical devices susceptible to being ingested or implanted in the body can offer new and advanced physicians mechanisms to perform their diagnoses, monitor and treat many diseases. Giovanni Traverso’s laboratory is now working on a variety of edible systems that can be used to administer drugs, monitor vital signs and detect movement of the gastrointestinal tract.
It would also have its applications in the electrodes that are implanted in the brain to administer an electric current and treat, for example, epilepsyor Parkinson’s disease. These electrodes, which are used for a technique known as deep brain stimulation, are controlled by a device similar to a pacemaker that is placed under the skin and could be eliminated if wireless communication was used. These future wireless implants could also help deliver light to stimulate or inhibit neuronal activity through optogenetics, which has not yet been adapted for use in humans, but which could be useful in treating numerous neurological disorders.
Today, implantable medical devices, such as pacemakers, carry their own batteries, which occupy most of the space of the device and offer a limited lifespan. Fadel Adib, who is betting that there will be much smaller devices without a battery, has been exploring the possibility of wirelessly feeding implantable devices with radio waves emitted by antennas outside the body.
Until now, this has been difficult to achieve because radio waves tend to dissipate as they pass through the body, so they end up being too weak to supply enough energy. To overcome this important obstacle, researchers who have participated in this study have devised a system that they have called “In Vivo Networking” (IVN), which is based on a series of antennas that emit radio waves of slightly different frequencies . As the radio waves travel, they overlap and combine in different ways; At certain points, where the high points of the waves overlap, they can provide enough energy to power an implanted sensor.
“We choose frequencies that are slightly different from each other and, in doing so, we know that at some point in time these will reach their maximum at the same time, and when they do, they are able to exceed the threshold of energy needed to power the device”, clarifies Adib.
With the new system, researchers do not need to know the exact location of the sensors in the body, since the energy is transmitted over a large area , which also means that they can power multiple devices at the same time. At the same time that the sensors receive a burst of power, they also receive a signal that tells them to transmit information to the antenna. Also, this signal could be used to stimulate, for example, the release of a drug or a pulse of light, the researchers comment.