US Patent 4,808,183
United States Patent and Trademark Office
University of Iowa Research Foundation (Iowa City, IA, US)
The voice button prosthesis of the present invention is used for a patient having his larynx removed and having the upper end of his trachea opening through a stoma to the atmosphere. A small opening or fistula is surgically made in the rear of the trachea and in the forward wall of the esophagus so as to provide communication between the interior of the trachea and the interior of the esophagus. The prosthesis comprises an elongated tube adapted to be inserted into the fistual. The tube has a pair of spaced apart flanges adapted to engage the opposite ends of the fistula so as to hold the tube in place. A one way valve is provided in the rearward end of the tube for permitting air to pass from the trachea into the esophagus, and for preventing fluid from passing from the esophagus into the trachea.
Panje, William R. Voice button prosthesis and method for installing same. US Patent 4,808,183 filed June 03, 1980 and issued February 28, 1989. https://ir.uiowa.edu/patents/64