The evaluation of laryngeal movement during swallowing using a laryngeal motion measurement system with photoelectric distance sensors

Abstract

We measured and analyzed laryngeal movement during swallowing using a laryngeal motion measurement system (Nodomiru OE-NDMR01) with a 16-photoelectric-distance-sensor array to investigate its usefulness in the evaluation of the swallowing function. Four healthy adult males and two healthy adult females were tested, and clear laryngeal motion curves were obtained in all cases. The obtained data were analyzed, and the following indices were proposed for the swallowing function evaluation: 1) maximum laryngeal elevation distance, 2) peak laryngeal elevation and descent velocity, 3) laryngeal elevation time, and 4) laryngeal elevation arrival time. This system has some points that need to be improved, such as the difficulty of measurement when the laryngeal prominence is unclear, the need for the neck to be extended for measurement, the inability of the laryngeal prominence to be accurately detected at the laryngeal elevation position in some cases, the difficulty of displaying the absolute coordinates, and the inability to simply compare the data with VF data. However, because it is noninvasive, relatively inexpensive, radiation-free, and easy to use, this approach appears useful for elucidating the mechanism underlying swallowing, screening for dysphagia, and promoting swallowing rehabilitation.