In the future, infra-red light may enable assessment of blood chemistry without needing to take a sample.
Space medicine has many potential spin-offs for health on the ground. One of the latest, described by the National Space Biomedical Research Institute, is needle-free blood tests. The space researchers want to take blood samples in space, for medical research. For this purpose, they are looking at near infrared light, which can penetrate the skin and gain chemical information about blood and tissues.
We already use near infrared, in the pulse oximeter. This measures how much oxygen there is in the blood, by placing a sensor on the finger or ear. It's a standard piece of equipment in the intensive care unit. But we could do far more with near infrared. The researchers are currently looking at how to take account of different skin colours and levels of body fat in interpreting the result. They think the first applications of near infrared will be for seriously ill people, where multiple samples are needed and perhaps in researching the science of sport. But one day we may all be able to use the needle-free approach for routine blood tests.