title: Biomedical sensor using thick film technology for transcutaneous oxygen measurement.
abstract: Transcutaneous blood gas monitoring is a non-invasive measurement technique for obtaining fast and relatively accurate responses to determine the respiratory conditions of patients. In this investigation, a screen-printed, disposable, transcutaneous oxygen sensor based on the working principle of amperometry, incorporates an integral heating element to enhance transcutaneous diffusion of blood gases typically at 44 degrees C. A Clark cell configuration is employed with gold working and counter electrodes and a silver/silver chloride reference electrode. Two different types of electrolytes namely potassium nitrate gel and polyelectrolyte (Nafion) have been studied under laboratory test conditions. A fully computer-controlled gas testing rig has been constructed to automate the varying of oxygen levels. Linear relationships have been established with an averaged sensitivity level of 0.029 microA/mmHg. In addition, a brief pilot clinical trial involving a fully grown human subject has been carried out alongside a commercial transcutaneous blood gas analyser. The investigations have shown that although the measured signals are weaker than those obtained from the laboratory test, the thick film sensor displays a repeatable and linear relationship when correlating with the commercial system. This study has greatly contributed towards the understanding for the suitability of the materials in achieving a viable, low-cost biomedical sensor.
authors.affiliation: School of Engineering Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, United Kingdom. LL2004@alumni.soton.ac.uk
authors.forename: Yu-Zhi
authors.initials: YZ
authors.lastname: Lam
authors.forename: John K
authors.initials: JK
authors.lastname: Atkinson
mesh_terms: D015374:Biosensing Techniques / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D001785:Blood Gas Monitoring, Transcutaneous / Q000191:economics / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D004573:Electrolytes / Q000737:chemistry*; D004867:Equipment Design; D005465:Fluorocarbon Polymers / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D008991:Monitoring, Physiologic; D009566:Nitrates / Q000737:chemistry; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D017680:Potassium Compounds / Q000737:chemistry; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012834:Silver / Q000737:chemistry; D018030:Silver Compounds / Q000737:chemistry
chemical_list: D004573:Electrolytes; D005465:Fluorocarbon Polymers; D009566:Nitrates; D017680:Potassium Compounds; D018030:Silver Compounds; C040402:perfluorosulfonic acid; D012834:Silver; C037548:silver chloride; C023844:potassium nitrate; D010100:Oxygen