PITA Fiscal Year 2009 Projects - Biomedical and Health Engineering

Dense Capillary Network Bloodstream Sensor

Principal Investigators: Dr. Alan Rosenbloom, Dr. Phil Campbell, Gregory Fisher

Making long-term measurements in the bloodstream is difficult. No sensor can be implanted inside of a blood vessel because of risks such as infection, clotting, vessel blockage etc. Sensors exposed to blood tend to be overgrown by cells with subsequent failure (or you could say loss of function). This project uses a unique approach to making indirect measurements from the blood. Using tissue engineering techniques, one can construct a tissue – sensor interface wherein substances in the blood can diffuse freely into implanted sensors. This approach circumvents the difficulties with placing foreign material within blood vessels while allowing access to small molecules that circulate within the bloodstream. When fully developed, sensors that read the bloodstream via capillaries may be capable of fully automated, closed-loop control of insulin dosing. This will mimic an “artificial pancreas” and free diabetes patients from finger sticks and injections. At the same time, blood sugar control will be much more accurate, 24 hours per day. The complications of diabetes due to fluctuations in blood glucose may be significantly lessened by continuous and accurate insulin dosing. This technology can be added to existing sensors. This will make implementation easier. It will also be capable of continuously measuring blood hormones, metabolites and drug levels, allowing more precise monitoring of other disease conditions in addition to diabetes. For example, monitoring of blood urea nitrogen and creatinine could be used to follow kidney function.