Smart Headband for Jaw Rehabilitation Following Reconstruction

  • Author / Creator
    Natamai Vasudevan, Pradipika
  • Head and neck cancer is a devastating disease resulting in difficulties in mastication (chewing) and deglutition (swallowing) even after treatment. Jaw reconstruction together with oral prostheses can restore anatomical structures. Without embedded sensory function in the prosthesis, however, patients will still suffer from a loss of sensation of force and texture during mastication. As a result, the patients often exert excessive pressure and difficulties in swallowing that leads to further injuries and complications. Various technologies for biofeedback have been explored over the previous years; they show that tactile stimulation can be an effective sensory substitute. Here, the overall objective of the project is to realize a sensory system that consists of a jaw prosthesis with an embedded array of pressure sensors and a smart garment with an array of piezoelectric actuators for providing biofeedback signals regarding chewing. The specific objective of the current thesis is to develop the smart garment.
    The piezoelectric actuators were selected based on our hypothesis that they can deliver precise feedback about the food texture compared to other types of actuators such as linear resonant actuators (a.k.a., coin vibration motors). Using the laser Doppler vibrometer (LDV) as the characterization tool, we confirmed that the piezoelectric actuators delivered the texture signals with high fidelity. The LDV measurements were performed by passing a sinusoidal signal in the range of 100-300 Hz (the optimal frequency range at which low amplitude vibrations become perceivable) as well as texture signals. The results from the LDV showed that these piezoelectric discs are able to vibrate in accordance with the input signals provided to them. In addition, it was observed that they are able to deliver different types of signals with different input intensities superimposed onto the background vibration in the sinusoidal waveform. These results were used for designing perception tests for assessing the psychophysics of human participants (i.e., establishing the relationship between the tactile stimuli and the level of perception of the subject).
    A smart headband structure was designed with three piezoelectric disks to deliver the food texture signals and a pressure sensor to control the headband tightness. The structure is robust, washable after removing the Velcroed actuators and sensor, and is able to provide the right amount of pressure for stimulation. Food texture signal tests were conducted on the author and her three supervisors using the smart headband. The results showed that the textures were correctly identified above chance. The perception tests were also able to provide important information about the just noticeable difference and spatial differentiation. The sensitivity of the skin towards the actuator was also studied. Overall, our smart headband design can be useful in providing feedback as well as comfort to patients having experienced jaw reconstruction.

  • Subjects / Keywords
  • Graduation date
    Fall 2021
  • Type of Item
  • Degree
    Master of Science
  • DOI
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.