HemoCleanse, Inc. - Comment

Progress towards a reliable system for measuring blood glucose on a nearly continuous basis has been very slow. The major problem with subcutaneously implanted electrochemical glucose sensors is that as fibrin and fibrous tissue surround the sensor, the mass transfer coefficient between blood and the sensor continuously changes. This causes changes in the relationship between glucose diffusion to the sensor and blood glucose level, thus continuously changing the calibration of the sensor. Some years ago I decided that the solution to this problem is to use ultrafiltration instead of diffusion to convect the glucose. By placing ultrafiltration fibers under the skin and applying a negative pressure, an ultrafiltrate is created to convect fluid from capillary blood, through the SQ tissue and into the fibers. Ultrafiltration of fluid brings with it all of the chemical components of the fluid, up to the pore size of the membranes and tissues (over 20,000 m.w.). Using this approach we demonstrated that the filtrate glucose contained essentially the same glucose concentration as blood for periods up to one month, accounting for the time delay of fluid passage from the blood to the testing point (see attached article). Further work by Dr. Korf in the Netherlands confirmed the same phenomenon (see attached abstract). So I see a fairly simple solution to glucose measurement in hospitalized patients. Use a specialized needle to implant a few ultrafiltration membranes under the skin. Attach a negative pressure vacuum source, and use an existing electrochemical glucose sensor to measure the glucose. This will certainly work in the hospital and in fact would work to provide glucose measurement in ambulatory patients for months with the same sensor, and without need for recalibration.