Noninvasive blood glucose monitoring using the optical signal of pulsatile microcirculation: a pilot study in subjects with diabetes.
OBJECTIVE
The objective of this study was to determine the conditions for optimizing measurements obtained with a noninvasive blood glucose monitor using the optical signal of pulsatile microcirculation (OSPM) in both prediabetic and diabetic subjects receiving medication.


METHODS
Eighteen subjects (3 prediabetic, 15 diabetic) aged 61.8 [15.9] years (mean [S.D.]) were studied. OSPM was the pulsatile component (P) of the signal obtained and analyzed by a blood glucose monitor. The measurement was calibrated to the fingerstick meter for each subject for personal calibration. Data were obtained from all subjects using both meters.


RESULTS
A total of 179 data pairs were measured and analyzed. The validity of the position of the tested finger was assessed using the position criterion, which resulted in the removal of 38 data pairs. The criterion for the intensity of the P signal was satisfied by 141 data pairs, with nonconforming data (with a much lower P signal) mainly occurring below 26 degrees C. A total of 113 data points passed both criteria, and 100% of them fell within Zones A and B of the Clarke error grid. Data in Zones A and B exhibited a linear relationship (r=.81; slope=0.82; intercept=28.0) between noninvasive and fingerstick measurements.


CONCLUSIONS
Environmental temperature has the greatest influence on the capability of the OSPM technique to monitoring blood glucose concentration, which is subject dependent. The position of the tested finger is the second major factor, hence a carefully designed finger adaptor is essential.
Chen
Chung-Sen
CS
Taipei City Hospital, Zhongxiao Branch, Taipei 115, Taiwan.
Wang
Kuang-Kuo
KK
Jan
Ming-Yie
MY
Hsu
Wei-Chen
WC
Li
Sai-Ping
SP
Wang-Lin
Yuh-Ying
YY
Bau
Jian-Guo
JG
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015190:Blood Glucose Self-Monitoring / Q000295:instrumentation / Q000379:methods*; D003920:Diabetes Mellitus / Q000097:blood*; D005260:Female; D005385:Fingers / Q000098:blood supply; D006801:Humans; D008297:Male; D008833:Microcirculation; D008875:Middle Aged; D055095:Optics and Photonics; D010865:Pilot Projects; D011673:Pulsatile Flow; D012680:Sensitivity and Specificity