Monitoring Muscle Tissue for Signs of Circulatory Shock

At the University of Massachusetts Medical School, researchers are developing a device that can noninvasively detect signs of peripheral hypoperfusion, presumably offering in the future a new method to diagnose and monitor the circulatory shock.
MIT Technology Review explains:

Traditionally, patients in critical condition are continuously monitored for changes in blood pressure, heart rate, and pulse oxygen saturation. But the body has mechanisms to compensate for massive blood loss and systemic infection, keeping those parameters steady even while the patient’s status deteriorates. “When the blood pressure starts to drop, it’s too late,” says spectroscopist Babs Soller, who developed the new device along with colleagues at the UMass Medical School. “The patient is already going into shock.” The new device instead measures the levels of oxygen, pH, and hematocrit–the proportion of red blood cells in the blood–in a patient’s muscle tissue.
Soller’s device beams near-infrared light through the skin over an arm or leg muscle, where it travels through fat and reflects off muscle tissue and back to the monitor. Based on the spectrum of the reflected light, computer algorithms determine the oxygen, pH, and hematocrit levels. Unlike similar infrared biomeasurement devices, the new monitor automatically compensates for differences in skin color and fat thickness between patients to optimize the results.

Full story from MIT Technology Review…