A Spectral Filter Array Camera for Clinical Monitoring and Diagnosis: Proof of Concept for Skin Oxygenation Imaging

The emerging technology of spectral filter array (SFA) cameras has great potential forclinical applications, due to its unique capability for real time spectral imaging, at a reasonable cost.This makes such cameras particularly suitable for quantification of dynamic processes such as skinoxygenation. Skin oxygenation measurements are useful for burn wound healing assessment and asan indicator of patient complications in the operating room. Due to their unique design, in which allpixels of the image sensor are equipped with different optical filters, SFA cameras require specificimage processing steps to obtain meaningful high quality spectral image data. These steps includespatial rearrangement, SFA interpolations and spectral correction. In this paper the feasibility ofa commercially available SFA camera for clinical applications is tested. A suitable general imageprocessing pipeline is proposed. As a ’proof of concept’ a complete system for spatial dynamicskin oxygenation measurements is developed and evaluated. In a study including 58 volunteers,oxygenation changes during upper arm occlusion were measured with the proposed SFA system andcompared with a validated clinical device for localized oxygenation measurements. The comparisonof the clinical standard measurements and SFA results show a good correlation for the relativeoxygenation changes. This proposed processing pipeline for SFA cameras shows to be effective forrelative oxygenation change imaging. It can be implemented in real time and developed further forabsolute spatial oxygenation measurements.