Design and Testing of a Respiratory Simulator for the Optimization of Soft Robotic Assistive Breathing Devices

Abstract

Diaphragm dysfunction can lead to respiratory difficulties and failure, requiring interventions like positive pressure ventilation that forces air into the lungs. Such interventions can interfere or hinder a patient’s quality of life, making activities like speech and swallowing extremely difficult. Surgically implanted soft robotic actuators have been explored to mechanically support diaphragmatic motion in a patient that has lost function of such an important muscle. Optimizing these actuators before surgery is paramount and requires “in situ” testing that may take months in between porcine terminal studies, let alone human testing. This thesis works towards developing a bench top model that can recreate the physiological biomechanics of the respiratory system to effectively test and optimize the design of diaphragmatic assist devices before implantation in specimen.

Through the product development cycle undertaken in this thesis, a respiratory simulator was fabricated, assembled, and tested in order to facilitate the optimization of soft robotic pneumatic actuators. We find that the simulator is capable of recreating and maintaining physiological pressures in the major cavities of the body, with active diaphragmatic motion. We demonstrate the effectiveness of the modular design, allowing for rapid testing of different types of diaphragmatic assist actuators, patient conditions and breathing patterns. Through testing of the assist devices, we demonstrate their ability to recreate physiologically relevant pressure drops.

This respiratory simulator lays the groundwork for the rapid development of implantable assistive breathing devices that serve as a new ventilation option that will liberate the airways and not sacrifice quality of life.