In vivo glucose monitoring using dual-wavelength polarimetry to overcome corneal birefringence in the presence of motion.
OBJECTIVE
Over the past 35 years considerable research has been performed toward the investigation of noninvasive and minimally invasive glucose monitoring techniques. Optical polarimetry is one noninvasive technique that has shown promise as a means to ascertain blood glucose levels through measuring the glucose concentrations in the anterior chamber of the eye. However, one of the key limitations to the use of optical polarimetry as a means to noninvasively measure glucose levels is the presence of sample noise caused by motion-induced time-varying corneal birefringence.


METHODS
In this article our group presents, for the first time, results that show dual-wavelength polarimetry can be used to accurately detect glucose concentrations in the presence of motion-induced birefringence in vivo using New Zealand White rabbits.


RESULTS
In total, nine animal studies (three New Zealand White rabbits across three separate days) were conducted. Using the dual-wavelength optical polarimetric approach, in vivo, an overall mean average relative difference of 4.49% (11.66 mg/dL) was achieved with 100% Zone A+B hits on a Clarke error grid, including 100% falling in Zone A.


CONCLUSIONS
The results indicate that dual-wavelength polarimetry can effectively be used to significantly reduce the noise due to time-varying corneal birefringence in vivo, allowing the accurate measurement of glucose concentration in the aqueous humor of the eye and correlating that with blood glucose.
Department of Biomedical Engineering, Texas A&M University, College Station, Texas 77843-3120, USA. cpirnst@tamu.edu
Casey W
CW
Pirnstill
Bilal H
BH
Malik
Vincent C
VC
Gresham
Gerard L
GL
Coté
D000818:Animals; D000867:Anterior Chamber / Q000378:metabolism*; D001082:Aqueous Humor / Q000378:metabolism*; D001718:Birefringence; D001786:Blood Glucose / Q000378:metabolism*; D003315:Cornea / Q000378:metabolism*; D008991:Monitoring, Physiologic; D009068:Movement; D011817:Rabbits; D057109:Scanning Laser Polarimetry / Q000295:instrumentation* / Q000379:methods
D001786:Blood Glucose