The investigation of a non-invasive oximeter and the further development of an extracorporeal oximeter

A literature search revealed that existing non-invasive oximeters are difficult to calibrate and therefore have not been widely accepting as useful instruments in clinical situations. The development of a non-invasive oximeter which could be easily calibrated would he a significant contribution.

The first half of this thesis concerns the investigation of a reflectance type non-invasive oximeter. In this investigation a noninvasive transducer was designed and tested. The transducer design was deemed unworkable because it did not respond to changes in the per cent of the hemoglobin saturated with oxygen of blood under the skin.

The second half of this thesis deals with the further development of an existing extracorporeal oximeter. The existing oximeter was designed to continuously monitor the per cent of the hemoglobin saturated with oxygen of blood entering and leaving a membrane-type oxygenator. The oximeter was redesigned to improve the transducer, power supply, analog-to-digital converter, and calibration procedure. A detailed description of the new oximeter design is presented along with data obtained from testing the new oximeter.