The Miniaturization of Glass Electrodes.

The miniaturization of cation sensitive glass electrodes (Eisenman, 1962) is part of a programme designed to monitor continuously the plasma cationic concentrations in human extracorporeal circulations and in the physiologically normal animal. The investigation of diurnal and metabolic changes in plasma cationic parameters using flame photometry on samples from animals submitted to open operations leaves much to be desired. An implanted miniature glass electrode from which long-term readings could be obtained appeared to be the ideal for the investigation of such variations. The model seen in Fig. 1 consists of a high density