Calibration of a wearable glucose sensor

Area of Science:

• Biomedical Engineering
• Analytical Chemistry
• Diabetes Technology

Background:

• Traditional glucose sensors with immobilized glucose-oxidase face challenges in accurate calibration.
• Poor correlation between in vitro and in vivo electrode sensitivity hinders reliable glucose monitoring.
• Existing methods require improved accuracy and consistency for clinical application.

Purpose of the Study:

• To develop and evaluate a novel glucose sensor system overcoming calibration difficulties.
• To assess the in vivo performance of a microdialysis-based sensor with dissolved glucose-oxidase.
• To compare sensor performance in healthy volunteers and type 1 diabetic patients.

Main Methods:

• Development of a microdialysis system employing an external oxygen electrode and dissolved glucose-oxidase.
• Subcutaneous implantation of a hollow fiber in 12 healthy and 12 type 1 diabetic subjects.
• In vivo two-point calibration using clamped blood glucose levels.

Main Results:

• High correlation (r = 0.949) observed between in vivo and in vitro calibration factors.
• The sensor measured 43 +/- 9% of the blood glucose value in subcutaneous tissue.
• No significant differences in sensor performance were found between healthy and diabetic groups.

Conclusions:

• The developed microdialysis-based glucose sensor offers improved in vivo calibration accuracy.
• This system demonstrates reliable glucose measurement in subcutaneous tissue for both healthy and diabetic individuals.
• The dynamic selection approach with dissolved enzyme overcomes limitations of immobilized enzymes.