Artificial Prosthetic Tongue

Curney, Xavier; Holod, Ace; Singh, Nadia

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Artificial Prosthetic Tongue

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Oral cancer can result in the loss of a patients’ tongue through total glossectomy, the surgical removal of all or parts of the tongue. Patients that lose their tongue have difficulty with speech, deglutition and mastication. Current tongue prosthesis lack the ability to move for mastication and deglutition and are mainly for cosmetic purposes. The goal of this project was to investigate and develop a self-contained prosthetic tongue that could aid in deglutition by moving bolus from the front of the mouth to the back of the mouth. Previous iterations of the project used pneumatic and electromagnetic actuation techniques for the silicone tongue prosthetic. While both methods showed promise, they had multiple issues. Pneumatic methods involving air pumps are challenging to miniaturize while still achieving the necessary actuation. The electromagnetic actuation technique using magnets and solenoids results in a miniature system but the amount of actuation produced to move the bolus is insufficient. Multiple bolus and actuation testing were carried out on electromagnetic and pneumatic powered silicone tongues to verify these problems. Additional research was done to explore alternative designs and it was determined that a linkage system mounted into a silicone cast might be the most efficient method to move the bolus from the front to the back of the mouth. The development of this new prosthetic tongue design entailed creating silicone molds, printing linkage systems and jaws, and developing new circuits. The circuit used a TinyDuino and MOSFET. A force sensor was used to trigger actuation of the tongue when bolus was placed on it. Two micro-servo motors were also used to actuate the linkage system. A functional mandibular Hawley retainer was added to hold the tongue to increase ease of use. The initial prosthetic tongue prototype was tested on actuation height, bolus movement and functionality within an anatomically sized, resin-printed jaw set. Redesigns to the circuit and linkage system were done based on initial testing results as a major problem was the bolus getting stuck on the upper palette. The final circuit design contained an EMG sensor to trigger actuation and a single servo motor with a gear system to actuate the tongue. Kinematic analysis and finite element analysis on the finalized linkage system were carried out. The prosthetic tongue succeeded in moving bolus from the front of the mouth to the back when lying at an 5 degree angle and actuating between 1.8 - 2.31cm. The paper will describe the development process, challenges and future work.

This report represents the work of one or more WPI undergraduate students submitted to the faculty as evidence of completion of a degree requirement. WPI routinely publishes these reports on its website without editorial or peer review.

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