New Paper: Design of Wireless Intra-operative pressure sensitive reticulated head (WIPOX2)
We developed and validated a first-generation compact handheld device for real-time wireless monitoring of tissue oxygen saturation during surgical procedures termed wireless intra-operative pulse oximetry (WiPOX). Based on clinical experience gained in our trials [1,9], we present here the design of a second generation WiPOX that includes a reticulated pressure-sensitive head serving two related functions. First, the often-restricted and sensitive environment in which the device is employed constrains both the angle of approach and visibility, necessitating a self-correcting reticulated swiveling head that acts to improve the contact angle between the sensor head and the tissue. Second, because the devices are hand-held, the pressure on the tissue (often a membrane) is determined by the operator; too little pressure produces poor signal to noise ratio (SNR) while too much pressure can occlude blood flow, also reducing SNR and possibly yielding erroneously low oxygenation measurements. To address this, our sensor head includes a novel mounting for multiple “balloon” style pressure sensors that provide feedback on tissue contact pressure and contact angle. The reticulated head and pressure sensor features function in tandem to improve tissue contact and ensure reliable measurements.