Feasibility study of early pressure injury detection using single-chamber and dual-cavity optical sensor
En Chuang, Shao-Hung Lu, Wen-Chi Lin, Shi-Yi Wu, Mei-Fen Chen, Wen-Chen Lin, Cheng-Lun Tsai, Kang-Ping LinAbstract
Objective
To develop and evaluate a single-chamber dual-channel optical probe leveraging near-infrared spectroscopy (NIRS) for the objective assessment of pressure-modulated tissue response, with emphasis on subcutaneous microvascular-related optical changes.
Methods
A single-chamber and dual-cavity optical probe was designed using a quantitative approach inspired by the blanching test principle. The probe simulated two conditions: pressure and non-pressure, using 740 nm and 850 nm near-infrared LEDs as light sources. The optical properties of skin tissues were evaluated in these conditions to analyze localized blood flow changes. The study recruited healthy participants and individuals with pressure injuries, targeting high-risk anatomical sites to compare reflectance intensity differences across the two wavelengths.
Results
Data from 398 measurement points demonstrated significant differences in NIRS reflectance between healthy and pressure injury tissues. In healthy tissues, reflectance at 740 nm and 850 nm increased under pressure due to effective blood displacement, indicating normal vascular function. Conversely, pressure injury sites exhibited reduced reflectance changes and higher hemoglobin absorption, particularly at 850 nm, reflecting impaired blood perfusion. Variance analysis confirmed significantly lower reflectance variation in pressure injury tissues compared to healthy tissues (p < 0.001), highlighting restricted blood flow dynamics.
Conclusion
This pilot study demonstrates the feasibility of NIRS-based optical probing for assessing pressure-modulated tissue response at high-risk anatomical sites. These preliminary findings support further validation in larger and more rigorously designed clinical studies.