Blood glucose concentration measurement is essential for the diagnosis and treatment of diabetes. However, conventional glucose measurement methods are invasive and not suitable for real-time monitoring. This study demonstrated a noninvasive blood glucose measurement method using optical coherence tomography to image human lip in vivo. Optical coherence tomography (OCT) is a noninvasive and depth-resolved technique capable of acquiring tissue structure images in real time. Human lip has very thin skin and is full of blood vessels, which is appropriate for noninvasive glucose measurement. To verify the feasibility of OCT for glucose concentration monitoring, two groups of OCT imaging data were obtained from human lips of normal people. In one group, OCT images of lip were acquired from people on an empty stomach. In the other group, the same sites of lip were observed by OCT 2 hours after breakfast. Evident differences were found from two groups of OCT images that correspond to preprandial glucose and 2- hour postprandial glucose, respectively. The relationship between OCT image and blood glucose concentration was investigated. The result indicates that OCT possesses considerable prospects in terms of noninvasive blood glucose measurement.
Optical coherence tomography (OCT) is a non-invasive imaging technique that provides real-time two- and three-dimensional images of scattering tissues with micrometer resolution. Scattering coefficient is estimated based on the slope of OCT dependent of depth. However, stability of the OCT signal slope is dependent on tissue heterogeneity. Our work is to provide a method of combining post-processing Fourier filtration with automatic identification of fitting range to reduce the effect of tissue heterogeneity on scattering coefficient, and used for noninvasive monitoring of glucose concentration in lip. Axial and lateral resolutions of OCT are 20 μm and 15 μm respectively. OCT images were obtained from lip before breakfast and after breakfast respectively. Results demonstrate that the method improve the stability and the precision of measurement of scattering coefficient of lip. There are obviously different in scattering coefficient of tissue between preprandial glucose and 2-hours postprandial glucose. These pilot studies show that OCT scattering coefficient extraction of lip may be considered as a significant diagnostic marker. OCT has potential to monitor glucose-induced changes in lip in vivo.