双调制多波长旋光法检测人工前房内葡萄糖的浓度

Dual-Modulation Multi-Wavelength Polarimetry for Monitoring Glucose Concentration in Anterior Chamber of Eye Phantoms

光学旋光法是一种无创血糖检测技术,通过测量眼前房水内葡萄糖浓度来确定体内血糖浓度水平。人眼运动引起的实时变化的双折射是实现旋光法无创血糖测量的主要限制因素之一。设计了实时、闭环、双调制多波长偏振系统来测量人工前房内的葡萄糖浓度,人工前房由离体角膜固定在人工眼房上构成。采用眼耦合装置使光直线穿过眼前房从而避免了空气与角膜之间折射率不匹配引起的光线弯曲。存在运动引起的双折射时,采用双波长旋光系统测量眼模型内的葡萄糖浓度,两次预测葡萄糖浓度的标准差分别为18.9mg/dL和15.2mg/dL,表明该系统具有降低活体角膜实变双折射的潜力,有利于实现与血糖浓度相关的眼前房水内葡萄糖浓度的精确测量。

Optical polarimetry is a noninvasive glucose monitoring technique which can be potentially used to ascertain blood glucose levels through measuring the aqueous humor glucose levels in the anterior chamber of the eye.One major limitation of the polarimetric approach as a means to noninvasively measure glucose levels is timevariant corneal birefringence caused by motion artifact.We design a real-time,closed-loop,dual-modulation,multiwavelength polarimetric system for glucose measurement by using an isolated human cornea ex vivo clamped on an artificial anterior chamber.Eye coupling devices are utilized to prevent bending of the light through the anterior chamber due to index mismatch between air and aqueous humor barrier.The polarimetric setup for glucose measurement ex vivo is presented and the system predicts the glucose concentration with standard error of18.9mg/dL and 15.2 mg/dL in the presence of birefringence with motion at two runs.The results indicate that polarimetry can effectively be used to minimize the effect of corneal birefringence in vivo,and helps to accurately measure glucose concentration in the aqueous humor of the eye that is correlated with blood glucose levels.