The effects of head movement on dual-axis cervical accelerometry signals
1 Bloorview Research Institute, Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
2 Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
3 Division of Gerontology, Beth Israel Deaconess Medical Center, Boston, MA, USA
4 Harvard Medical School, Harvard University, Boston, MA, USA
5 Toronto Rehabilitation Institute, Toronto, Ontario, Canada
6 Department of Speech-Language Pathology, University of Toronto, Toronto, Ontario, Canada
BMC Research Notes 2010, 3:269 doi:10.1186/1756-0500-3-269Published: 26 October 2010
Head motions can severely affect dual-axis cervical acceloremetry signals. A complete understanding of the effects of head motion is required before a robust accelerometry-based medical device can be developed. In this paper, we examine the spectral characteristics of dual-axis cervical accelerometry signals in the absence of swallowing but in the presence of head motions.
Data from 50 healthy adults were collected while participants performed five different head motions. Three different spectral features were extracted from each recording: peak frequency, spectral centroid and bandwidth. Statistical analyses showed that peak frequencies are independent of the type of head motion, participant gender and age. However, spectral centroids are statistically different between the anterior-posterior (A-P) and superior-inferior (S-I) directions and between different motion. Additionally, statistically different bandwidths are observed for head tilts down and back between the A-P and the S-I directions.
These differences indicate that head motions induce additional non-dominant spectral components in dual-axis cervical recordings. The results presented here suggest that head motion ought to be considered in the development of medical devices based on dual-axis cervical accelerometery signals.