Loss of speech is one important factor which contributes to a decrease of life quality for patients who undergo larynx removal following for example advanced laryngeal cancer. Several devices such as the electrolarynx and the tracheo-esophageal valve prosthesis (without oscillation) have been commercialized in order to restore speech. However, such voice restoration prosthesis are still limited for certain patients. The development of a new device using a valve of variable resistance entrained by a linear electromechanical transducer was investigated as a way to produce speech for patients with total laryngectomy (ablation of vocal folds). The concept was to undertake the design of a varying air flow resistance valve, built around existing Blom-Singer valves. The oscillating valve features a spherical head making it possible to block the opening in the wall between the trachea and the esophagus in a sinusoidal periodic fashion. A physical model of the vocal tract was built and used for preliminary in-vitro verification studies. The relationship between pressure and flow rate through the valve was determined from pressure measurements. The orifice discharge coefficient of the orifice was then calculated and the parameters of a variable resistor model were identified. Radiated sound pressure produced from the change in flow rate at the valve orifice was then compared to the original voice output to assess the accuracy of the design prototype. Results showed that the forced oscillating valve prosthesis model has lower power efficiency but can produce better sound quality than the electrolarynx.
| Identifer | oai:union.ndltd.org:LACETR/oai:collectionscanada.gc.ca:QMM.115998 |
| Date | January 2009 |
| Creators | Khoueir, Raja. |
| Publisher | McGill University |
| Source Sets | Library and Archives Canada ETDs Repository / Centre d'archives des thèses électroniques de Bibliothèque et Archives Canada |
| Language | English |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Format | application/pdf |
| Coverage | Master of Engineering (Department of Biomedical Engineering Dept.) |
| Rights | All items in eScholarship@McGill are protected by copyright with all rights reserved unless otherwise indicated. |
| Relation | alephsysno: 003133281, proquestno: AAIMR66931, Theses scanned by UMI/ProQuest. |
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