Wireless system can power devices inside our body

Scientists have developed a new way to power the devices implanted deep within the human body and wirelessly communicate with them, paving the way for new ways to deliver drugs, monitor internal conditions, and treat diseases.

The implants are powered by radio frequency waves, which can safely pass through human tissues. In animal tests, researchers showed that the waves can power devices located 10 centimeters deep in tissue, from a distance of one metre.

"Even though these tiny implantable devices have no batteries, we can now communicate with them from a distance outside the body. This opens up entirely new types of medical applications," said Fadel Adib, an assistant professor at Massachusetts Institute of Technology in the US.

Since they do not require a battery, the devices can be tiny. In this study, the researchers tested a prototype about the size of a grain of rice, but they anticipate that it could be made even smaller.

"Having the capacity to communicate with these systems without the need for a battery would be a significant advance. These devices could be compatible with sensing conditions as well as aiding in the delivery of a drug," said Giovanni Traverso, an assistant professor at Brigham and Women's Hospital (BWH) in the US.

Medical devices that can be ingested or implanted in the body could offer doctors new ways to diagnose, monitor, and treat many diseases. Researchers are now working on a variety of ingestible systems that can be used to deliver drugs, monitor vital signs, and detect movement of the GI tract.

In the brain, implantable electrodes that deliver an electrical current are used for a technique known as deep brain stimulation, which is often used to treat Parkinson's disease or epilepsy.

These electrodes are now controlled by a pacemaker-like device implanted under the skin, which could be eliminated if wireless power is used. Wireless brain implants could also help deliver light to stimulate or inhibit neuron activity through optogenetics, which so far has not been adapted for use in humans but could be useful for treating many neurological disorders.

Currently, implantable medical devices, such as pacemakers, carry their own batteries, which occupy most of the space on the device and offer a limited lifespan.

Researchers have been exploring the possibility of wirelessly powering implantable devices with radio waves emitted by antennas outside the body.

With the new system called "In Vivo Networking" (IVN), the researchers do not need to know the exact location of the sensors in the body, as the power is transmitted over a large area.

In tests in pigs, the researchers showed they could send power from up to a metre outside the body, to a sensor that was 10 centimeters deep in the body. If the sensors are located very close to the skin's surface, they can be powered from up to 38 metres away.

The researchers are now working on making the power delivery more efficient and transferring it over greater distances.

This technology also has the potential to improve RFID applications in other areas such as inventory control, retail analytics, and "smart" environments, allowing for longer-distance object tracking and communication, researchers said.