Excellent project. Has started working on similar. Just few thoughts. Since the amount of samples per logg is on range of 9000 shall be more convenient to show not only mean but also statistical error and gauss distribution on display? Once someone pay 50 or 200 usd for device and PC power is there thinking adding two more set to measure BG like Acetone air measurement with MQ138 and classical pin with blood sample will cover two alternative and classical control. Also have seen commercial BG that take measurement on soft tissue on the ears (no bean), what if you try there and compare corelation? For classic BG, HX711 can do the jobb slow but economical. Display is there all can be done inside PC and show results no need to external PC ot Matlab.
I am looking into making an improved version with more "intelligent" circuits. It will be more expensive, but I think the data is provides should be more useful (faster logging with more sensors). It will involve a PCB with some very small components, so it will take longer for me to get started also.
Yes it is, this first example works like that. The leds shine light through the finger and as the heart beats, different amounts of blood are present while light is shingling through. So when you measure how much light was received you can see the heart beat. The amount of sugar in the blood will also alter the amount of ir light that goes through, so I am trying to see if I can see that. The amount of blood sugar can also affect the heart beat itself, and the shape of the wave it produces. I have not made any algorithms for that yet, but it is another approach that may help. This very first sensor is very much like a finger tip oxygen sensor you would buy at the store, but in future revisions I would like to try some different LEDs.
