Intragastric pH measurement using a novel disposable sensor.

An unique disposable pH sensor molded into the end of a nasogastric tube was tested in twelve healthy human volunteers. A Spearman's rank correlation coefficient (rs) of 0.90 was observed for the sensor and an indwelling miniature glass membrane electrode. The sensor did not correlate as well with aspirated stomach fluid (rs = 0.68). No sensor calibration was necessary and the sensors measured +/- 0.1 pH in laboratory pH buffers before and after the clinical study. Both bare and shielded disposable sensors closely agreed with a shielded miniature glass electrode.