Quantitative classification of pediatric swallowing through accelerometry.
BACKGROUND
Dysphagia or swallowing disorder negatively impacts a child's health and development. The gold standard of dysphagia detection is videofluoroscopy which exposes the child to ionizing radiation, and requires specialized clinical expertise and expensive institutionally-based equipment, precluding day-to-day and repeated assessment of fluctuating swallowing function. Swallowing accelerometry is the non-invasive measurement of cervical vibrations during swallowing and may provide a portable and cost-effective bedside alternative. In particular, dual-axis swallowing accelerometry has demonstrated screening potential in older persons with neurogenic dysphagia, but the technique has not been evaluated in the pediatric population.


METHODS
In this study, dual-axis accelerometric signals were collected simultaneous to videofluoroscopic records from 29 pediatric participants (age 6.8 ± 4.8 years; 20 males) previously diagnosed with neurogenic dysphagia. Participants swallowed 3-5 sips of barium-coated boluses of different consistencies (normally, from thick puree to thin liquid) by spoon or bottle. Videofluoroscopic records were reviewed retrospectively by a clinical expert to extract swallow timings and ratings. The dual-axis acceleration signals corresponding to each identified swallow were pre-processed, segmented and trimmed prior to feature extraction from time, frequency, time-frequency and information theoretic domains. Feature space dimensionality was reduced via principal components.


RESULTS
Using 8-fold cross-validation, 16-17 dimensions and a support vector machine classifier with an RBF kernel, an adjusted accuracy of 89.6% ± 0.9 was achieved for the discrimination between swallows with and with out airway entry.


CONCLUSIONS
Our results suggest that dual-axis accelerometry has merit in the non-invasive detection of unsafe swallows in children and deserves further consideration as a pediatric medical device.
Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada. celeste.merey@utoronto.ca
Celeste
C
Merey
Azadeh
A
Kushki
Ervin
E
Sejdić
Glenn
G
Berall
Tom
T
Chau
D000054:Acceleration; D000465:Algorithms; D001466:Barium Sulfate; D002648:Child; D003287:Contrast Media; D003413:Cricoid Cartilage / Q000503:physiopathology; D003625:Data Collection; D003627:Data Interpretation, Statistical; D003679:Deglutition / Q000502:physiology*; D003680:Deglutition Disorders / Q000175:diagnosis* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D005260:Female; D005471:Fluoroscopy; D019416:Head Movements; D006801:Humans; D008297:Male; D025341:Principal Component Analysis; D015203:Reproducibility of Results; D060388:Support Vector Machine; D014732:Vibration
D003287:Contrast Media; D001466:Barium Sulfate