Author(s): Raghu Gopal
Researchers at the Massachusetts Institute of Technology (MIT) have developed a wireless "in-body GPS" system that's capable of accurately pinpointing the location of ingestible implants and tracking tumours inside the body. A study detailing the team's findings is being presented this week at the Sigcomm 2018 conference in Budapest, Hungary.
The study was carried out in collaboration with researchers from Massachusetts General Hospital and a team from MIT's Computer Science and Artificial Intelligence Laboratory, led by professor Dina Katabi.
Dubbed ReMix, the system comprises an external device that emits wireless signals, and a special algorithm that uses those signals to find the exact location of a marker inside a person's body. The marker simply reflects the signals that the device transmits at the body.
One of the biggest challenges in using wireless signals in this way is that there are many competing reflections bouncing off a person's body. In fact, reflected signals off the skin are still 100 million times more powerful than those of the marker. To tackle this problem, the researchers applied a complex series of algorithms to the backscatter signals to filter out the interfering frequencies and locate the marker.
ReMix could find an important role in proton therapy, being used to target a tumour with a magnet-controlled beam of protons. Proton therapy is currently only viable for certain types of cancer that don't move. The new system is intended to allow the proton beam to be precisely steered in real time, protecting healthy tissue and also making the treatment more widely available to fight cancer. Other applications could be to deliver drugs to specific parts of the body.
Researchers clarify that ReMix isn't yet precise enough to be used in clinical settings. At present the system can detect the location of a microchip with an accuracy of 1.4 centimetres. However, by honing its technique, the team hopes that ReMix will eventually be accurate within millimetres to be considered in medical environments.