Development of a system to monitor laryngeal movement during swallowing using a bend sensor.
BACKGROUND
Swallowing dysfunction (also known as dysphagia), which results in a deterioration of nutritional intake, slows rehabilitation and causes aspiration pneumonia, is very common following neurological impairments. Although videofluorographic (VF) examination is widely used for detecting aspiration, an objective and non-invasive method for assessing swallowing function has yet to be established because of a lack of adequate devices and protocols. In this paper, a bend sensor whose resistance is altered by bending was introduced to monitor swallowing-related laryngeal movement.


METHODS
Six healthy male volunteers were recruited in the present study. Specific time points on the signal waveform produced by the bend sensor were defined to describe laryngeal movement by differential analysis. Additionally, the physiological significance of the obtained waveform was confirmed by analyzing the sequential correlations between the signal waveform from the bend sensor and hyoid bone kinetics simultaneously recorded by VF.


RESULTS
Seven time points were successfully defined on the signal waveform to reference laryngeal movement. Each time point was well correlated with certain VF events, with evidence of no significant time lags, and there were positive correlations between waveform time points and matched VF events. Furthermore, obvious similarities were noticed between the duration of each phase on the signal waveform and the duration of the matched hyoid bone activity.


CONCLUSIONS
The present monitoring system using a bend sensor might be useful for observing the temporal aspects of laryngeal movement during swallowing, and it was well coordinated with hyoid bone movement.
Department of General Dentistry & Emergency, School of Stomatology, The Fourth Military Medical University, Xi'an, China.
Qiang
Q
Li
Kazuhiro
K
Hori
Yoshitomo
Y
Minagi
Takahiro
T
Ono
Yong-Jin
YJ
Chen
Jyugo
J
Kondo
Shigehiro
S
Fujiwara
Kenichi
K
Tamine
Hirokazu
H
Hayashi
Makoto
M
Inoue
Yoshinobu
Y
Maeda
D000328:Adult; D001696:Biomechanical Phenomena; D003679:Deglutition / Q000502:physiology*; D019719:Diagnostic Equipment; D006801:Humans; D006928:Hyoid Bone / Q000502:physiology; D007830:Larynx / Q000502:physiology*; D008297:Male; D009068:Movement; D055815:Young Adult