In Body Sensors To Track Tumors Or Dispense Drugs

The ReMix system is being described as an in body GPS of sorts, pinpointing the exact location of ingestible implants inside of the body using low power wireless signals, animal testing has demonstrated tracking within centimeter level accuracy, researchers say similar implants may one day be used to deliver drugs to specific regions within the body.

Testing of the ReMix system was conducted by implanting a smaller marker in animal tissues, tracking its movement was done using wireless device reflecting radio signals at the subject and special algorithm to pinpoint marker exact location, using wireless technology previously demonstrated to detect movement, heart rate, and breathing. Markers don’t need to transmit any signal within the body, rather reflect signals transmitted by devices from outside the body without need for battery or any other external source of energy.

Challenges facing wireless signals in this manner include the many competing reflections bouncing off the body, signals reflect of human skin 100 million times more powerful than signal of the metal marker itself. The team designed an approach to overcome this challenge that separates interfering skin signals from the ones trying to be measured using small diode semiconductor devices that mix signal together to filter out skin related signals.

Potential application for ReMix is in proton therapy in treating cancer with bombarding tumors with beams of magnet controlled protons, an approach that allows doctors to prescribe higher doses of radiation but requires extremely high degree of precision, limiting it to certain cancers. Success of this treatment relies on an unreliable source: tumors not moving during radiation process, should the tumor move healthy areas could be exposed. With the small ReMix marker location of the tumor could be determined in real time enabling a pause of treatment or better steering of the beam into the right location to deal with movement; once ReMix margin of error has become close enough to use in clinical settings of a couple millimeters level of accuracy.

The team hopes to combine wireless data with medical information such as MRI scans to improve accuracy. Reassessment of algorithm is ongoing and various trade offs needed to account for complexity of different individual’s bodies. These systems can encourage more applications of the technology, making them more in demand, which could mean more proton therapy centers and lower prices.