Pharyngeal pH Testing Explained

1/15/18 10:09 AM / by Kathy Bach


The Dx–pH Measurement System is a revolutionary device that comfortably measures pH in the upper airway or esophagus. Prior to Restech’s introduction, it was difficult to detect reflux in the upper airway because previously available pH monitors were limited to measuring liquid reflux in the esophagus. Restech’s patented technology is the only commercial device available that is capable of measuring both liquid and aerosolized pH levels.

Gastric reflux in the upper airway, or laryngopharyngeal reflux (LPR), commonly takes an aerosolized form that cannot be measured using conventional technology. The miniaturized pH sensor at the tip of the Dx–pH Probe measures pH in the upper airway, making the Dx–pH System a valuable tool in determining the existence of LPR and its relationship to various patient symptoms.

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The Dx–pH Measurement System is a simple tool for 24 to 48 hour ambulatory oropharyngeal pH testing. Guided by a blinking light-emitting diode (LED) in the probe tip, the physician visually positions the probe just behind the uvula in the oropharynx. Once placed, the single-channel Dx–pH Probe takes a pH reading twice per second and sends the data wirelessly from the attached Dx–Transmitter to the Dx–Recorder. Throughout the study, the patient inputs clinically relevant information (e.g. meals, symptoms, sleep) with the press of a button. Upon completion of the study, the pH data and patient information is downloaded from the SD memory card into the Dx–pH DataView software to be viewed, graphed, and printed.

The Restech sensor has been independently tested through the range of pH 1–13 for responsiveness and accuracy. Restech reliably reads both acidic and alkaline pH levels through both ends of this range with accuracy within 0.1 pH at any point over 24 hours. Unlike conventional pH probes, there is no drift in Restech’s reading.  


The information provided by the Dx–pH Measurement System is important in determining the impact of laryngopharyngeal reflux (LPR) on a patient’s symptoms. This test provides a graphical representation of the pH activity over a 24 or 48-hour study. The data obtained is valuable as it relays information about the patient’s LPR patterns in a clear fashion.

When assessing patients for potential bile reflux and alkaline exposure, Restech uniquely measures real time alkaline pH. Acid reflux, weakly acid gastroesophageal reflux (WAGR), and alkaline reflux are also accurately measured with Restech.

Some ask "How is this is better than laryngoscopy?" With laryngoscopy, the physician can evaluate the severity of tissue damage but cannot determine whether it is the result of LPR, vocal strain, coughing, or another source.

The Restech pH system can integrate seamlessly into your practice flow. Download our sample flow chart to see how this could be a game-changer to your diagnostic process for reflux. 


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Topics: pH monitoring

Kathy Bach

Written by Kathy Bach

Kathy Bach is the Clinical Support Manager at Restech. Her role encompasses clinical & technical support, clinical training, and content generation for clinical and marketing projects. She graduated from UC Berkeley with a BA in Integrative Biology and has experience performing biological research and working closely with physicians in the clinical setting and operating room.

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We're here to answer your questions about reflux. More specifically, diagnostic and therapeutic approaches to laryngopharyngeal reflux (LPR). Restech's pH system provides real-time pH data to help you develop the most targeted reflux treatment plan possible.


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