Optical fibre catheter photoplethysmograph

A fibre optic system for monitoring arterial oxygen saturation of internal tissue sites utilising the principle of reflectance pulse oximetry is being developed. It was shown that it is possible to obtain a stable photoplethysmograph (PPG) signal from the fingertip using a twin optical fibre catheter. The results of experiments to optimise the detection of PPG signals using optical fibres are presented. Possible applications of this method include measuring SpO2 in the oesophagus, trachea, large intestine, brain tissue and spinal cord