From cosmetics to melanin detection, an analytical model of how light interacts with skin opens a pathway to simplifying the design of low cost sensors designed to detect a wide range of skin constituents. Niloy Choudhury explains the work behind our recent whitepaper.

Light-tissue interaction model: A tool for consumer health device development


How you look is a complex interaction between the light that falls on your skin and how it interacts with different skin constituents. If you measure the reflected spectrum of skin, and you have a model of skin, you can use that mode; to analyse the reflected spectrum and predict different skin constituents that make up your skin.

Skin is a very complex structure, but you can use a simplified multi-layer model of skin and use that simplified model to come up with an analytical model of skin. At Cambridge Consultants we have developed a model of skin based on Monte Carlo Simulation. And using that model we can measure the reflected spectrum of skin and predict different skin constituents. This has many applications from the cosmetics industry to the medical industry where for example you have to measure blood profusion or oxygenation, which can be indications of different diseases, or the effect of medication.

Another advantage of having a skin model and having a good knowledge of how light interacts with skin is that is enables you to design low cost sensors that measure specific skin constituents. For example if you want to measure melanin concentration we can now use our model to come up with a sensor that is most sensitive to melanin, while the cross-talk from other constituents is minimum.

An example of a project like this is Skintuition which we have developed, it enables you to do foundation matching under different lighting conditions. We have also worked on other skin applications, for example Reflexion that measures the glossiness of your skin, by measuring how light is scattered from your skin.

At Cambridge Consultants we’re working hard to develop low cost sensors that hep you to move measurement from a lab setting to a consumer’s home environment, so that consumers can get the personalised experience that they’ve come to expect in today’s world.

Niloy Choudhury

Niloy is an expert in the design of biomedical instrumentation, optical coherence tomography and spectroscopy, with almost two decades of scientific, industrial and academic experience, and expertise in telecom optical components, biomedical imaging and industrial sensors.