The in-body GPS system is based on a wireless technology that MIT previously developed to detect heart rate, breathing and movement.
Medicine has come a long way, but it’s still not quite possible to see inside a living person without invasive measures. When it comes to a tumor, knowing exactly where it is at all times could be lifesaving. A team of scientists at MIT are developing a way to make that happen.
Led by Professor Dina Katabi at MIT’s Computer Science and Artificial Intelligence Laboratory (CSAIL), the team announced the development of a GPS system that could track the inner workings of a body. ReMix is a method that uses low-power wireless signals on implants introduced into the body, which allows their exact location to be found, even as they move.
The team first needed to develop a wireless system that worked without the use of batteries or other power sources. Their tracker reflects transmitted signals from outside the body rather than producing its own signals. This posed additional challenges due to numerous reflections bouncing off a body. They were able to design a diode that separates unwanted signals and lets them measure the ones they want.
During testing, the group implanted a small marker in animal tissues and used their wireless system to track the implant’s movement. They then developed an algorithm that uses the signal to give the marker’s exact location, within a centimeter of accuracy.
Their successful testing has the potential to open many doors in helping patients, particularly people with tumors. These implants could work as tiny tracking devices that monitor the movement of shifting tumors. In particular, the team sees it could be advantageous for proton therapy, an approach that directs magnet-controlled proto beams onto tumors.
This treatment requires precision, which is exactly what the team hopes ReMix will eventually provide. If a tumor is moving during treatment, it could expose healthy areas to radiation. If the team is able to get ReMix even more accurate, within millimeters, it could allow doctors to know exactly where the tumor was at all times and adjust treatment accordingly.
While ReMix isn’t quite ready for clinical testing, its researchers continue their work to improve it.
“We want a model that’s technically feasible, while still complex enough to accurately represent the human body,” said MIT PhD student Deepak Vasisht, lead author of the new paper. “If we want to use this technology on actual cancer patients one day, it will have to come from better modeling a person’s physical structure.”