A novel integrated mechanomyogram-vocalization access solution

作者：Alves Natasha; Falk Tiago H; Chau Tom^*

来源：Medical Engineering & Physics, 2010, 32(8): 940-944.

DOI：10.1016/j.medengphy.2010.06.003

• Rehabilitation engineering
• Signal processing
• Access technology
• Mechanomyogram
• Eyebrow switch
• Non-verbal vocalizations
• Multiple switches
• Disability
• Muscle activity
• Silent speech interfaces

We introduce a novel dual-switch control paradigm based on the simultaneous measurement of frontalis muscle mechanomyography (MMG) and vocalizations (humming) using a single contact microphone attached to the forehead. Vibrations of the face and skull during vocalization are manifested as periodic high-frequency components in the microphone signal recorded at the forehead. The presence of these periodic components is detected by a normalized cross-correlation function, while muscle contractions are detected using a continuous wavelet transform method. The dual-switch provides two independent binary control signals. Eleven participants, including one individual with severe physical disabilities, participated in a cued activation task in which the dual-switch exhibited sensitivities and specificities of 96.8 +/- 3% and 98.4 +/- 1%, respectively for vocalizations, and 99.7 +/- 0.5% and 99.2 +/- 0.5%, respectively for muscle contractions. Since skin vibrations due to voiced sounds and muscle contractions have non-overlapping dominant bandwidths, the performance of the MMG switch was not affected by vocalizations. This new integrated MMG-vocalization access solution affords the user two binary switches from a single access site, and may thus augment access alternatives for certain individuals with severe physical disabilities. 2010 IPEM. Published by Elsevier Ltd.

• 出版日期2010-10