Engineering Minute

Engineering Minute – Biodegradable Blood Flow Sensor

Researchers at Stanford University have developed a sensor that allows doctors to monitor the success of blood vessel surgery. The sensor is compact, biodegradable, wireless, and battery-free providing a minimally invasive way to monitor blood flow through an artery and warn the patient's doctor if there is a blockage. The results of their research was recently published in the journal Nature Biomedical Engineering

 

Artist’s depiction of the biodegradable pressure sensor wrapped around a blood vessel with the antenna off to the side (layers separated to show details of the antenna’s structure).
Artist’s depiction of the biodegradable pressure sensor wrapped around a blood vessel with the antenna off to the side (layers separated to show details of the antenna’s structure). Credit: University of Stanford

“Measurement of blood flow is critical in many medical specialties, so a wireless biodegradable sensor could impact multiple fields including vascular, transplant, reconstructive and cardiac surgery,” said Paige Fox, assistant professor of surgery and co-senior author of the paper. “As we attempt to care for patients throughout the Bay Area, Central Valley, California and beyond, this is a technology that will allow us to extend our care without requiring face-to-face visits or tests.”

 

From the Stanford University article: "The sensor wraps snugly around the healing vessel, where blood pulsing past pushes on its inner surface. As the shape of that surface changes, it alters the sensor’s capacity to store electric charge, which doctors can detect remotely from a device located near the skin but outside the body. That device solicits a reading by pinging the antenna of the sensor, similar to an ID card scanner. In the future, this device could come in the form of a stick-on patch or be integrated into other technology, like a wearable device or smartphone.

The researchers first tested the sensor in an artificial setting where they pumped air through an artery-sized tube to mimic pulsing blood flow. Surgeon Yukitoshi Kaizawa, a former postdoctoral scholar at Stanford and co-author of the paper, also implanted the sensor around an artery in a rat. Even at such a small scale, the sensor successfully reported blood flow to the wireless reader. At this point, they were only interested in detecting complete blockages, but they did see indications that future versions of this sensor could identify finer fluctuations of blood flow."

 

Read more about the biodegradable blood flow sensor at Stanford University