A tiny wireless optical sensor developed by Oak Ridge National Laboratory tells doctors in minutes, rather than hours, if an organ is getting enough blood flow after transplant or reconstructive surgery. Conventional methods for assessing circulation involve invasive procedures or extensive lab tests. In some cases, by the time doctors realize there isn't enough blood flowing to an organ or tissue, there has already been irreversible damage. "Our goal is to offer a technique that gives the physician a very early indication of whether the surgery is successful," says ORNL's Nance Ericson, engineering science and technology division.

The tiny implantable sensor would work with microinstrumentation being developed by Ericson by transmitting data to a nearby receiver. The unit assesses tissue circulation using optical sensors.

Modeling, post processing, and sensor-optimization work is taking place at Texas A&M's Department of Biomedical Engineering. ORNL researchers are providing engineering, signal processing, system design, radio-frequency telemetry design, and fabrication and microfabrication techniques. ORNL researchers are working to miniaturize the sensors and their electronics so that surgeons have no problem implanting them in a precise area. Other areas of emphasis include optimizing biosensors, designing low-power, highly miniaturized signal processing and telemetry electronics, and developing encapsulation techniques.