Stanford Engineers Develop Wearable to Monitor Tumors

The process of developing new cancer therapies is slow as technologies for measuring tumor regression while undergoing drug treatments can take weeks. Engineers from Stanford University have designed a wearable device that can measure those changes in real-time and beam the results to a smartphone or other mobile device. The battery-operated device is sensitive down to one-hundredth of a millimeter and represents a new, fast, inexpensive way to test the efficiency of cancer drugs.

Known as FAST (Flexible Autonomous Sensor measuring Tumors), the device was created using a stretchable, flexible polymer skin embedded with gold circuitry. The sensor is connected to a small backpack-like harness with a development board that handles information processing and wireless capabilities. Monitoring is done using that gold circuitry, which, when stretched, develops small cracks that change the material's electrical conductivity. Stretch the material, and the number of cracks increases, causing the resistance in the sensor to increase as well. When the material contracts, the cracks come back into contact, and conductivity improves.

The research team had concerns that the stretchable polymer might cause inaccurate readings as the material could provide undo stress on the tumors themselves, essentially squeezing them when contracting. They mitigated that risk by developing the material to be as pliant as human skin, thus maintaining accurate measurements.

"It is a deceptively simple design," explains Alex Abramson, post-doctorate grad. "But these inherent advantages should be very interesting to the pharmaceutical and oncological communities. FAST could significantly expedite, automate, and lower the cost of the process of screening cancer therapies."

The prospect of monitoring tumor growth in real-time could go a long way to developing new cancer treatments quickly and efficiently.