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.

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Osseointegrated transfemoral implants have been introduced as an alternative to conventional, socket-based prostheses for above knee amputees. This method is showing great promise; however, the frequency of device failure is of concern. As a means to understand some of these failures, this study investigates the mechanical behaviour of three osseointegrated transfemoral implant systems; an in-house prototype design and two assemblies comprised of implant-grade parts provided by Integrum AB, Sweden. A series of mechanical tests were administered to evaluate the effects of tightening specifications and connection geometry on the material response, and mechanical behaviour of the assemblies. The tests included torque-elongation measurements, torque to failure tests, and strain analyses during loading. This research was carried out in an attempt to better understand the behaviour of components under loading, in order to optimize the assembly specifications and improve the useful life of the system. The results obtained confirm that the Integrum assemblies exhibit improved performance when tightened to a level beyond the current specified tightening torque of 12 Nm. Increased tightening torque provides an improved connection between components, leading to increased torque retention, decreased peak tensile strain values and a more gradual, primarily compressive distribution of strains throughout the assembly. / Thesis (Master, Mechanical and Materials Engineering) -- Queen's University, 2009-09-29 12:14:18.438

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