Evaluation of the Laryngeal Adductor Reflex with a Mechatronic Micro-droplet Laryngoscope

• Applicants: Dr.-Ing. Lüder Alexander Kahrs; Professor Dr. Martin Ptok
• Subject Area: Automation, Mechatronics, Control Systems, Intelligent Technical Systems, Robotics ; Otolaryngology, Phoniatrics and Audiology
• Term: from 2016 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 314572885

The proposed research deals with endoscopic, mechatronic microdroplet dispension for (1) controlled triggering of the laryngeal adductor reflex (LAR, a reflexive glottic closure mechanism ) and (2) image-based qualitative and quantitative measurement of the laryngeal adductor reflex (LAR). Even though LAR plays an imminent role in protecting the lower airways, little is known regarding its basic principles. A reason for this might be, that up to date no practical and safe device exists for the controlled reflex triggering. The Department of Phoniatrics and Pediatric Audiology, Hannover Medical School has recently developed a first prototype that demonstrates benefits of fluid-based reflex stimulation. Disadvantages of the actual prototype have been related to non-reliable reflex stimulation within the subject group (less than 50%) due to multifactorial reasons. This project aims to show that optimized methods for microdroplet dispension will enable valid and reliable reflex characterization and mapping. Based on these methods our hypothesis is that fundamental new research in laryngology and neurolaryngology can be conducted (e.g. reflex fatigue or spatial reflex maps). Technical development is necessary to overcome current limitations and will result in an endoscopic, mechatronic microdroplet dispenser for image-based measurement of LAR that allows precise targeting of the droplets on the endolaryngeal structures. The work program includes: 1) Design with regard to anatomical constraints. Based on clinical data, dimensions and contours of components entering the patients oral cavity and pharynx will be optimized. 2) Investigation on fluid transport and dispension. 3) Reproducible experimental setup and methods as well as characterization of usable parameters. 4) Computer-aided stimulation of LAR by image processing (e.g. triangulation) and target visualization (augmented reality). 5) Finally, new methods and a new prototype will be evaluated in parts and holistic in a neurolaryngological context (informed consent subject trials). The expected outcome of this project is groundbreaking research and knowledge generation in the field of the laryngeal adductor reflex. Additionally, we expect a new method that is feasible for a reliable clinical diagnosis of dysphagia. This also provides the basis for further exploitation in the field of phoniatrics as well as the care of impaired patients, i.e. after stroke.

• DFG Programme: Research Grants
• Co-Investigator: Professor Dr.-Ing. Tobias Johannes Ortmaier