Magnetoelastic sensors as a new tool for laryngeal research

Conclusions. The use of custom-built magnetoelastic sensors designed for insertion in the larynx to measure the force of transverse deformation of the thyroarytenoid and cricothyroid muscles was examined. Objectives. The availability of sensors that transduce deformation force into an electrical current (measurable in millivolts) suggested that such sensors could be used to study muscle function in the canine larynx. This study aimed to obtain information about the force exercised by larynx muscles on the sensor in an experiment in vivo. Materials and methods. The results of six surgical interventions in three dogs using four magnetoelastic sensors are described. The sensor and insertion technique were atraumatic. One dog underwent surgery four times to study the morbidity, reliability and reproducibility of the technique. An electromyographic recording was made at the same time that sensor response was registered to compare results with a standardized technique. Results. We obtained 584 regular responses: 256 deglutitions (150 thyroarytenoid and 106 cricothyroid recordings) and 328 phonations (223 thyroarytenoid and 105 cricothyroid recordings). No signs of injury or functional deficit were observed after any intervention. In the dog that underwent four interventions, results were consistent after each intervention.