Tiny sensor tracks blood flow during major heart surgeries

A miniscule fiber-optic sensor could outperform more traditional methods for monitoring blood flow during prolonged and intensive surgical CV procedures, even in the smallest and youngest heart patients, researchers at Flinders University in Australia report.

The micro-medical device is still a proof-of-concept prototype, according to research published in the Journal of Biophotonics, but the university’s team, led by strategic professor John Arkwright, is hoping the project will be picked up for further development. Right now, the continuous cardiac flow monitoring probe is a simple design that can be inserted through a keyhole aperture in a patient’s skin to monitor blood flow through their aorta.

The device would theoretically be placed in a patient’s femoral artery, the authors said, and is so small it can even measure slight changes in blood flow in infants’ tiny vessels. It passed initial testing in a heart-lung machine, and Arkwright et al. think it could be a lower-cost alternative for more closely monitoring blood flow during cardiac surgery.

“The minimally invasive device is suitable for neonates right through to adults,” Arkwright said in a statement. “It’s a far more representative measurement compared to traditional blood flow monitoring, and without life-threatening delays in the period ‘snapshot’ provided by current blood flow practices using ultrasound or thermo-dilution.”

With traditional methods, blood flow is assessed every half hour or so. Arkwright and colleagues’ prototype, on the other hand, is capable of giving readouts similar to a pulsating heartbeat response on a laptop or nearby screen—all in real time.

The team said more research is required to determine how the sensor will behave under more physiological conditions and to ensure it’s a safe way to monitor flow during major surgery.