EXPERIMENTAL EVALUATION OF 2 NEW SENSORS FOR RESPIRATORY RATE MONITORING

Visual observation was chosen as the reference method for measuring th e respiratory rate in ten healthy volunteers. The new fibre-optic and acoustic sensors were simultaneously compared with capnography and tra nsthoracic impedance plethysmography during normoventilation in the re spiratory rate range of 6-24 breaths per minute and at a fixed respira tory rate of 13 breaths per minute. In addition a simulation of centra l apnoea was performed. All the measurements were recorded on an analo gue tape recorder and a strip-chart recorder and analysed off line. Th e analyses of the recordings were performed by a person who was unable to see the monitoring systems. There was no discrepency in the result s of these methods. Each of the methods responded rapidly to an apnoei c event. The new fibre-optic and acoustic sensors correlate well with more traditional methods such as capnography and transthoracic impedan ce plethysmography for respiratory rate monitoring.