A small pH sensor catheter of the endoscope for acidity test of gullet and stomach

Ji Hyoung Roh, Kyu Sik Shin, Nam Kyu Cho, Don Haeng Lee, Byung-Moo Moon, Dae Sung Lee

Research output: Contribution to journalArticle

3 Citations (Scopus)


The detection of pH in the gullet and stomach is highly significant for the diagnosis of gastroesophageal reflux disease (GERD), particularly with the use of a pH sensor in vivo. Most conventional pH sensors are used singly and could not be inserted in the endoscope's working channel. Because the ion sensitivity field-effect transistor (ISFET) chip has become very small, we have made the pH sensor smaller than a conventional glass pH sensor, and have used it. In this paper, we introduce a small in vivo pH sensor catheter of 2.7 mm diameter and 8 mm length, which can be put in the endoscopy's working channel of 3 mm diameter. The catheter was evaluated in buffer solution (pH 2-12) and its sensitivity was 43 mV/pH. It was confirmed that the catheter properly functioned during an animal experiment.

Original languageEnglish
Pages (from-to)417-424
Number of pages8
JournalSensors and Materials
Issue number8
Publication statusPublished - 2008 Dec 1



  • Endoscope
  • Gastroesophageal reflux disease (GERD)
  • pH

ASJC Scopus subject areas

  • Instrumentation
  • Materials Science(all)

Cite this

Roh, J. H., Shin, K. S., Cho, N. K., Lee, D. H., Moon, B-M., & Lee, D. S. (2008). A small pH sensor catheter of the endoscope for acidity test of gullet and stomach. Sensors and Materials, 20(8), 417-424.