Phd Ceremony T.A. van Kalkeren: Hands-free voice restoration. Clinical aspects of the development of a hands-free speech valve and its fixation for laryngectomy patients

Patients with advanced-stage laryngeal carcinoma are deprived of their vocal folds as a result of the removal of their larynx. The trachea now ends at an artificially created opening in the neck. Patients are still able to speak when the tracheostoma is occluded. The shunt valve allows air to be forced into the esophagus. This air induces vibration of the esophagus and thus aids voice production and speech. However, this means of speech requires the patient to use his/her hand to occlude the opening in the neck. This means of voice initiation requires the patient to use a finger to occlude the tracheostoma, which is not very natural. To tackle this problem, hands-free speech valve’s are available. However these devices are not widely used. We have looked into why this is the case. First of all, the application on the skin around the neck opening is a problem. The adhesive patches, onto which the valves and filters are fixed, do not fit well. The shape of the neck opening was measured in a worldwide study. They proved not to be flat, (as the patches assume), but funnel shaped. Using these new data, new, contoured, patches were designed. In addition, most speech valves have characteristics which cause high air pressures during speech. This causes early detachment of the patches facilitating the speech valve. To tackle this problem, a new hands-free speech valve has been designed based on a different operating principle. This speech valve was successfully tested by patients.