A new fibre optic pulse oximeter probe for monitoring splanchnic organ arterial blood oxygen saturation

Abstract

A new, continuous method of monitoring splanchnic organ oxygen saturation (SpO(2)) would make the early detection of inadequate tissue oxygenation feasible, reducing the risk of hypoperfusion, severe ischaemia, and, ultimately, death. In an attempt to provide such a device, a new fibre optic based reflectance pulse oximeter probe and processing system were developed followed by an in vivo evaluation of the technology on seventeen patients undergoing elective laparotomy. Photoplethysmographic (PPG) signals of good quality and high signal-to-noise ratio were obtained from the small bowel, large bowel, liver and stomach. Simultaneous peripheral PPG signals from the finger were also obtained for comparison purposes. Analysis of the amplitudes of all acquired PPG signals indicated much larger amplitudes for those signals obtained from splanchnic organs than those obtained from the finger. Estimated SpO(2) values for splanchnic organs showed good agreement with those obtained from the finger fibre optic probe and those obtained from a commercial device. These preliminary results suggest that a miniaturized 'indwelling' fibre optic sensor may be a suitable method for pre-operative and post-operative evaluation of splanchnic organ SpO(2) and their health.

Optical Fibre-Based Pulse Oximetry Sensor with Contact Force Detection

“…Transmission mode is limited to extremities such as the finger, toe or earlobe whereas reflectance mode provides greater flexibility of body site. Unobtrusive wearable reflectance pulse oximetry has attracted a lot of research attention [ 7 ] with optical fibres providing a convenient method of delivering light to and from the body [ 8 , 9 ]. This is useful in magnetic resonance imaging (MRI) where metallic parts should be avoided [ 10 ].…”