Glucose Monitoring in Individuals With Diabetes Using a Long-Term Implanted Sensor/Telemetry System and Model

Glucose Monitoring in Individuals With Diabetes Using a Long-Term Implanted Sensor/Telemetry System and Model

Glucose Monitoring in Individuals With Diabetes Using a Long-Term Implanted Sensor/Telemetry System and Model 170 177 IEEE Transactions on Biomedical Engineering (TBME)

 

Glucose Monitoring in Individuals With Diabetes Using a Long-Term Implanted Sensor/Telemetry System and Model

Diabetes is a disease that is growing worldwide.  Glucose control is central to all therapies for diabetes and achieving control requires monitoring glucose concentration. We have developed a fully implanted sensor/telemetry system consisting of two electrochemical oxygen sensors, one with a membrane of immobilized glucose oxidase and the other an oxygen reference electrode, and a battery-operated telemetry system that transmits glucose values to an external receiver every two minutes, with the circuitry and battery housed in a hermetically sealed titanium container. We described studies in which sensors were implanted in five individuals with diabetes using a simple outpatient procedure, and operated for up to six months. The studies consisted of recordings of monthly in-clinic glucose excursions compared to reference blood glucose values, and long-term at-home recordings of spontaneous glucose excursions compared to reference finger-stick values. We included a glucose mass transfer model that relates sensor signals to reference blood glucose values, and estimated all model parameters. The goal was to determine if long-term glucose monitoring in humans is feasible with this sensor.  Clinical trials are currently underway with a smaller second-generation implant employing the same sensing mechanism and similar design, but having only a fraction of the volume of the present device.

The results: 1) Sensor responses showed a strong association with reference glucose values, as characterized by goodness-of-fit, MARD, and regression coefficients; 2) Sensor calibration varied randomly at an average rate of 2.6%/week, and recalibration was carried out monthly; 3) The permeability to glucose of the tissues adjacent to the implant was comparable to the permeability in solutions; and 4) The results demonstrate the feasibility of long-term, continuous monitoring of glucose in humans.  With further development, this system may lead to a new era of glucose monitoring in diabetes.

Joseph Y. Lucisano

Joseph Y. Lucisano (M’95) received the B.S. degree in bioengineering from the University of California San Diego (UCSD), La Jolla, CA, USA, in 1981, the M.S. degree in aeronautics/ astronautics from Stanford University, Stanford, CA, in 1982, and the Ph.D. degree in bioengineering from UCSD in 1987. From 1988 to 1994, hewas a Research Scientist and Research Program Manager with Alfred E. Mann Foundation, Sylmar, CA. From 1994 to 1998, he was a Principal Sensor Engineer and Program Director, Glucose Systems with Via Medical Corporation, San Diego, CA. In 1998, he cofounded GlySens Incorporated, San Diego, and served as a President and CEO until 2015. Since 2015, he has been with GlySens Incorporated’s as a Chief Technology Officer. His research interests include medical devices, implantable and ex-vivo biosensors, biomaterials, tissue–device interfaces, and signal processing algorithms. Dr. Lucisano is a Member of the American Chemical Society and the American Diabetes Association and is a Founding Member of the Board of Trustees of the Jacobs School of Engineering Department of Bioengineering, University of California San Diego.

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