This Tiny Device Can Be Implanted in the Brain to Measure Tissue Oxygen Levels

The oxygen levels of body tissues are critical for biological functions, and improper levels can either be the cause, or a symptom, of various health problems. To better understand those cause and effect relationships, researchers need a way to accurately measure tissue oxygen levels within living patients. Doctors would also benefit from being able to monitor those levels. That’s why an international team of researchers have developed a small device that can be implanted into living tissue, including the brain, and wirelessly transmit that data.

The device is just one square centimeter in size — about the size of a fingernail — and weighs a mere 80 milligrams. It doesn’t contain any dangerous power sources, and can be implanted directly into the tissue that needs to be monitored. Once it has been implanted, it can be powered by infrared radiation from an external source in the lab. When powered, it measures the oxygenation of tissue with a sensor probe by monitoring how much light from a red and a green LED is able to pass through the tissue.

During the process, when it is receiving power and monitoring oxygen levels, it also transmits that data wirelessly via infrared radiation to a receiver connected to a computer. The data can then be collected and analyzed, enabling new kinds of research. The team first tested the device by implanting it in artificial tissue. When that was successful, they implanted devices into the skulls of mice. That test was also a success and didn’t harm the mice, meaning this device will likely move onto further trials in living animals and eventually people.