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Monocrystalline antimony electrodes have been shown to be suitable for the in vivo determination of pH in blood, tissue and in the upper gastro-intestinal canal. Thanks to their small dimensions it has been possible to mount them into conventional manometry catheters for oesophageal investigation. The monocrystalline antimony pH electrode has several advantages over the conventional pH glass electrode; better accuracy, shorter rise time, smaller dimensions. The monocrystalline antimony electrode has been used for long-term registration of gastro-oesophageal reflux, for the oesophageal acid clearing test and for identification of the pH gradient zone between the gastric and oesophageal mucosa. Its use in combination with pressure sensors has added a new dimension to the diagnosis of functional disorders in the gastro-oesophageal region. [ABSTRACT FROM AUTHOR]

Rapid determinations of bloodgas parameters are desirable in today's clinical care. This calls for continuous in vivo measurements with miniaturised electrodes. In this study we have replaced the commonly used glass pH sensor in a pCO-electrode of the conventional type with a monocrystalline antimony electrode. The disadvantages of the glass electrode, such as instability and fragility when miniaturised, are of minor importance for an antimony electrode. The results, which confirm that the antimony pCO-electrode does not need frequent calibration, have been obtained using macroscale electrodes. However, the favourable characteristics of the antimony electrode are known to be maintained even after miniaturisation. Therefore, it seems possible that in the future we shall be able to measure bloodgas parameters such as pCO in vivo with reasonable accuracy. [ABSTRACT FROM AUTHOR]

A combined pH- and pressure-measurement device for oesophageal investigations has been designed using monocrystalline antimony pH electrodes and perfused polyvinyl catheters. The combined device facilitates pressure measurements simultaneously with pH recording, both distal and proximal to the pH electrode. The device is easier to pass through the nose to the oesophagus than the conventional glass pH electrode. pH and pressure measurements in the oesophagus are therefore simplified and valuable information about the function of the region of the lower oesophageal sphincter is added owing to the simultaneous recording of the two parameters. [ABSTRACT FROM AUTHOR]

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In 24 h pH monitoring, the evaluation is dependent on the absolute accuracy of the pH measurements. Several sources of error exist, such as the chemical composition of calibration buffers and reference electrode gel and the effect of temperature on both the pH and the reference electrodes. We investigated the magnitude of these errors for the monocrystalline antimony electrode. Similar analysis applies to other types of pH electrodes. The errors we found are important when choosing a calibration procedure. We recommend a calibration procedure in which the pH and reference electrodes are both put in a beaker with the calibration buffers prior to and after the 24 h measurements. The calibration buffers and the electrode gel should have a specially selected ion composition where, for example, the Cl-ion concentration is critical. Corrections for differences in temperature between the calibration and the in situ measurements must be added. The pH measurements can be checked by performing in situ calibration. [ABSTRACT FROM AUTHOR]