ABSTRACT
SIGNIFICANCE: Oxygenation is one of the skin tissue physiological properties to follow for patient care management. Furthermore, long-term monitoring of such parameters is needed at the patient bed as well as outside the hospital. Diffuse reflectance spectroscopy has been widely used for this purpose. AIM: The aim of the study is to propose a low-cost system for the long-term measurement of skin physiological parameters in contact. APPROACH: We have developed a low-cost, wearable, CMOS-based device. We propose an original method for processing diffuse reflectance data to calculate the tissue oxygen saturation (StO2). RESULTS: We tested the device for the assessment of tissue oxygenation during a first-in-human clinical trial that took place at the Grenoble University Hospital France. CONCLUSIONS: The results of this clinical trial show a good accordance between our sensor and commercial devices used a reference.
Subject(s)
Wearable Electronic Devices , Humans , Skin/diagnostic imaging , Spectrum AnalysisABSTRACT
Spatially resolved diffuse reflectance spectroscopy (srDRS) is a well-established technique for noninvasive, in vivo characterization of tissue optical properties toward diagnostic applications. srDRS has a potential for depth-resolved analysis of tissue, which is desired in various clinical situations. However, current fiber-based and photodiode-based systems have difficulties achieving this goal due to challenges in sampling the reflectance with a high enough resolution. We introduce a compact, low-cost architecture for srDRS based on the use of a multipixel imaging sensor and light-emitting diodes to achieve lensless diffuse reflectance imaging in contact with the tissue with high spatial resolution. For proof-of-concept, a prototype device, involving a commercially available complementary metal-oxide semiconductor coupled with a fiber-optic plate, was fabricated. Diffuse reflectance profiles were acquired at 645 nm at source-to-detector separations ranging from 480 µm to 4 mm with a resolution of 16.7 µm. Absorption coefficients (µa) and reduced scattering coefficients (µs') of homogeneous tissue-mimicking phantoms were measured with 4.2 ± 3.5 % and 7.0 ± 4.6 % error, respectively. The results obtained confirm the potential of our approach for quantitative characterization of tissue optical properties in contact imaging modality. This study is a first step toward the development of low-cost, wearable devices for skin condition diagnosis in vivo.
