Development of Blood Capillary Glass Electrodes for Use in Medical Electronics

Abstract

Blood capillary glass electrode, a recent development in medical electronics is used in conjunction with anaesthesia monitoring equipment to observe and record the hydrogen ion concentration of blood, particularly when the patient undergoes a surgical operation. With a view to develop the electrode, a systematic investigation was undertaken using the glasses from the following systems (i) Na2O—CaO—SiO2, (ii)Li2O—CaO—SiO2, (iii) Li2O—La2O3—Cs2O—SiO, (iv) Li2O—La2O3—BaO—CeO2—SiO2. The glasses were melted and capillary tubes were drawn. Keeping in view the monitoring system in medical electronics, an arrangement was set up for ascertaining the suitability of the capillary fibres made out of the glass for pH measurement.It was found that only glass no. (iii) responded to the activity of hydrogen ions and produced slope values very close to the ideal Nurnst value at room temperature when the measured emf data were plotted against the corresponding pH showing thereby that the remaining three glasses were not su...