Diabetes is a growing medical problem in the world today that typically requires control of the blood glucose level of afflicted patients. Blood glucose concentration can be detected by using glucose oxidase to convert glucose in a blood sample into gluconic acid. The pH of this sample can be detected through the use of a pH indicator liquid whose colour change can be detected through an apparatus detecting the luminosity of light passed through the sample. This device would output a voltage based upon the luminosity detected. It can be more inexpensively created through the use of a carefully chosen LED and Photodiode connected with a multi-mode optical fibre. Detection can also be taken a step further by providing a rough calculation of the amount of insulin the patient should inject to normalize his/her blood glucose concentration levels. Use of a general pH indicator such as bromocresol purple would allow for the device to be expanded for the detection of other chemicals in the bloodstream. The proposed device would be an inexpensive, variable optical fibre glucose biosensor with post-processing elements to calculate suggested insulin dosage. The theory behind this device, hardware design, experimental results and efficacy are outlined below.
Lim, Edwin, "Design of an Optical Fibre Glucose Biosensor" (2010). EE 4BI6 Electrical Engineering Biomedical Capstones. Paper 41.