Numerical Optimisation of a NIRS Device for Monitoring Tissue Oxygen Saturation.

The present work aims to develop a wearable, textile-integrated NIRS-based tissue oxygen saturation (StO) monitor for alerting mobility-restricted individuals - such as paraplegics - of critical tissue oxygen de-saturation in the regions such as the sacrum and the ischial tuberosity; these regions are proven to be extremely susceptible to the development of pressure injuries (PI).Using a combination of numerical methods including finite element analysis, image reconstruction, stochastic gradient descent with momentum (SGDm) and genetic algorithms, a methodology was developed to define the optimal combination of wavelengths and source-detector geometry needed for measuring the StO in tissue up to depths of 3 cm. The sensor design was optimised to account for physiologically relevant adipose tissue thicknesses (ATT) between 1 mm and 5 mm.

Feasibility to Measure Tissue Oxygen Saturation Using Textile-Integrated Polymer Optical Fibers.

Tissue oxygen saturation (StO) is a crucial factor in the aetiology of pressure injury (PI), since hypoxia leads to necrotization. Pressure on the tissue occludes blood circulation and reduces the StO, resulting in hypoxia. PI causes severe suffering, heals slowly and is expensive to treat.