Non-Contact Cell Concentration Detector

Many medical screening devices require a different number of cells depending on their concentration in the specimen. Being able to detect the concentration of relevant cells before the test without disrupting the specimen will increase the speed at which the screening device can operate.

This design consists of an LED light source that illuminates the contents of the vial and a photodiode detector that detects the optical power emitted from the cells.

Autofluorescence, whereby biological molecules absorb light at one wavelength and emit it at another, differentiate diagnostically relevant cells from other contents. Optical filters tune the emission spectrum of the light source and the responsivity of the detector so only the relevant cells fluoresce and emit light in the wavelength band to which the detector responds. A Raspberry Pi microcontroller converts the voltage response from the detector to concentration and displays it on a screen.