Are measurements in interstitial fluid... the future of sensing?

Interstitial fluid is a thin layer of fluid which surrounds the body’s cells and makes almost 40% of the water in our body. It is similar to composition as plasma, meaning it contains most proteins that are commonly found in blood. Therefore, interstitial fluid has become useful in the monitoring of glucose levels in people with diabetes. However, I will discuss in this video how this can be expanded to other markers and I expect many more sensors based on measurements in interstitial fluid.

Closed loop drug delivery:
Continuous glucose monitors (CGM) are machines which measure the glucose level within interstitial fluid. These sensors can be left there for a number of days (typically 7-14 days) since interstitial fluid can be accessed in a non-invasive (without pain) manner. The sensor is then able to read the glucose level within the surrounding interstitial fluid and send these readings to a display once every few minutes. A formula is applied to convert glucose levels in interstitial fluid to that of blood. This can be used for monitoring purposes but, if connected to an insulin pump, it can lead to a closed loop drug delivery system. These closed loop drug delivery systems have made a significant impact in the life of patients; in the future, there might be more closed loop systems that come on the market based on monitoring of biomarkers in interstitial fluid.