Clin Exp Otorhinolaryngol.  2019 Nov;12(4):420-426. 10.21053/ceo.2019.00423.

Development of a Novel Intraoperative Neuromonitoring System Using an Accelerometer Sensor in Thyroid Surgery: A Porcine Model Study

  • 1Department of Otolaryngology-Head and Neck Surgery, Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University College of Medicine, Yangsan, Korea.
  • 2Department of Otolaryngology-Head and Neck Surgery, Medical Research Institute, Pusan National University Hospital, Pusan National University College of Medicine, Busan, Korea.
  • 3Department of Biomedical Engineering, Pusan National University Hospital, Busan, Korea.


The sensitivity and positive predictive value of widely used intraoperative neuromonitoring (IONM) using electromyography (EMG) of the vocalis muscle in thyroid surgery are controversial. Thus, we developed a novel IONM system with an accelerometer sensor that uses the piezoelectric effect instead of EMG to detect laryngeal twitching. The objective of this study was to evaluate the feasibility and safety of this novel IONM system during thyroid surgery in a porcine model.
We developed an accelerometer sensor that uses the piezoelectric effect to measure laryngeal twitching in three dimensions. This novel accelerometer sensor was placed in the anterior neck skin (transcutaneous) or postcricoid area. Stimulus thresholds, amplitude, and latency of laryngeal twitching measured using the accelerometer sensor were compared to those measured through EMG of the vocalis muscle.
The amplitudes of the accelerometer sensor at the anterior neck and postcricoid area were significantly lower than those of EMG because of differences in the measurement method used to evaluate laryngeal movement. However, no significant differences in stimulus thresholds between the EMG endotracheal tube and transcutaneous or postcricoid accelerometer sensors were observed.
Accelerometer sensors located at the anterior neck or postcricoid area were able to identify laryngeal twitching. The stimulus intensity measured with these sensors was equivalent to that from conventional vocalis EMG. Our novel IONM system with an accelerometer sensor that checks changes in surface acceleration can be an alternative to EMG of the vocalis muscle for IONM in the future.


Neuromonitoring; Accelerometer Sensor; Electromyography; Recurrent Laryngeal Nerve; Thyroidectomy

MeSH Terms

Laryngeal Muscles
Recurrent Laryngeal Nerve
Thyroid Gland*


  • Fig. 1. (A) Photograph of a transcutaneous accelerometer sensor. (B) Surgical field of dissection on the pig, demonstrating the accelerometer sensor attached to the anterior neck skin. (C) Illustration of surgical field with the transcutaneous accelerometer sensor.

  • Fig. 2. (A) Photograph of a postcricoid accelerometer sensor. (B) Intraoperative endoscopic view of larynx on the pig, demonstrating the accelerometer sensor attached postcricoid area. (C) Illustration of the postcricoid accelerometer sensor placement.

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Application of Novel Intraoperative Neuromonitoring System Using an Endotracheal Tube With Pressure Sensor During Thyroid Surgery: A Porcine Model Study
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Clin Exp Otorhinolaryngol. 2020;13(3):291-298.    doi: 10.21053/ceo.2019.01249.

Intraoperative Neuromonitoring System Using Needle and Skin Electrode during Thyroid Surgery
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Int J Thyroidol. 2022;15(1):17-22.    doi: 10.11106/ijt.2022.15.1.17.


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