Biomedical sensor using thick film technology for transcutaneous oxygen measurement

• Published in: Medical engineering & physics Vol. 29; no. 3; pp. 291 - 297
• Main Authors: Lam, Yu-Zhi, Atkinson, John K.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.04.2007
• Subjects: Biosensing Techniques - economics; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Blood Gas Monitoring, Transcutaneous - economics; Blood Gas Monitoring, Transcutaneous - instrumentation; Blood Gas Monitoring, Transcutaneous - methods; Electrodes; Electrolytes - chemistry; Equipment Design; Fluorocarbon Polymers - chemistry; Hot Temperature; Humans; Monitoring, Physiologic; Nitrates - chemistry; Oxygen - analysis; Oxygen - metabolism; Polyelectrolyte; Potassium Compounds - chemistry; Radiology; Reproducibility of Results; Screen-printed; Sensitivity and Specificity; Silver - chemistry; Silver Compounds - chemistry; Transcutaneous oxygen; Polyelectrolyte; Screen-printed; Transcutaneous oxygen
• DOI: 10.1016/j.medengphy.2006.03.010
• ISSN: 1350-4533

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 °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 μA/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.