Refinement of a medical product to minimize the gag reflex

The gag reflex is a physiologic protective reflex that aims to protect the pharynx and throat from foreign bodies. Touching the nerve endings in the soft palate, pharynx and pharyngeal part of the tongue can elicit gag reflex. Gagging is a common problem during oral medical examinations as it leads to distress of the patient and may even make the medical procedure impossible [1]. Salt on the tip of the tongue is sometimes used in dental applications to inhibit gag reflex during interventions [1], an effect that may be mediated by blockage of the gagging impulse transmission [2]. More precisely, according to Friedmann and Weintraub, gag reflex is extinguished by a superimposed simultaneous stimulation of the chorda tympani branches to the taste buds [3].

As part of an earlier project, Cordula Dürr and her team developed an initial concept and prototypes for gag reflex blockage to be used during a standard throat swab procedure to increase the yield of the test. The objective of this semester project is to refine the product design and production, evaluate its commercial potential and, if deemed suited, lay the ground work and plan a subsequent clinical study.

Project Information

Student: Cordula Dürr, ETH Zürich
Project type: Semester project
Project start: September 2018
Project end: January 2019
Supervisor: Dr. Diane de Zélicourt,


  1. Stefos, S., Zoidis, P. & Nimmo, A. Managing Gag Reflex during Removable Partial Denture Treatment: A Review and a Clinical Report: Managing Gag Reflex during RPD Treatment. J. Prosthodont. (2018). doi:10.1111/jopr.12957
  2. Yasmen Taha AL-Alousi, Zainab Salih & Wasmaa Sadiq Mahmood. Evaluation of the effect of (salt and sugar) on gagging reflex. Karbala J. Med. 2, 1430–1437 (2012).
  3. Friedman, M. H. & Weintraub, M. I. Temporary elimination of gag reflex for dental procedures. J. Prosthet. Dent. 73, 319 (1995).

To improve patient sample collection