A human pilot study of a fully-implantable continuous glucose sensor has demonstrated high accuracy performance for the first time for an implanted biosensor, according to research soon to be presented at the European Association for the Study of Diabetes meeting in Lisbon, Portugal, on September 16.
The research, undertaken by Sensors for Medicine and Science, Inc., showed high level of glucose accuracy, with 77.6% and 19.2% of the data in the A and B zones of the Clark Error Grid, respectively.
The mean absolute relative difference was 12.2%. The results also support the sensor goal of achieving implant time greater than six months.
“We are pleased to report these findings as a first step to realising a viable long-life implanted sensor to help millions of people with diabetes manage their glucose better,” said Tim Goodnow, Ph.D., CEO and President.
“While still early, the pilot study showed comparable performance as current continuous glucose devices.”
The SMSI system includes a miniaturised sensor and reader. The sensor is implanted into the subcutaneous space in the wrist and is inductively powered and remotely interrogated, requiring no battery and no wires connecting the sensor to an external wristwatch-based reader. After implantation, the sensor functions noninvasively, automatically, and continuously.
In the study, nine subjects with Type 1 diabetes were implanted with a sensor in each wrist for approximately 29 days.
Performance was evaluated by comparing 3,000 sensor values with paired YSI blood glucose values.
In a Clarke Error Grid (CEG) analysis, 96.8% of the values fell in zones A or B.
The CEG compares readings between a lab reference and a glucose monitoring device and assigned into one 5 clinical zones: A, B, C, D, or E.
Zone A values are clinically accurate and most consistent with the lab reference value. B values are clinically acceptable. C, D, and E values are progressively less accurate.
“Based on the promising results obtained, we plan to initiate more clinical trials in the very near future, including pursuing collaboration on artificial pancreas research,” said Dr. Goodnow.