Design and optimisation of soft robotic actuators for augmented lung-ventilation

Pulmonary rehabilitation through invasive ventilation involves the insertion of an endotracheal tube into the trachea of a sedated patient to control breathing via a ventilating machine. Invasive ventilation offers benefits such as greater control over oxygen supply, higher efficiency in supporting patient respiration, and the ability to manage airway secretions. However, this method also poses treatment challenges like ventilator-induced pneumonia, airway injury, long recovery times, and ventilator dependence. Here, we explore an alternative invasive ventilation technique using soft robotic actuators to mimic the biological function of the diaphragm for augmenting and assisting ventilation. We investigated two actuator geometries, each at two locations superior to the diaphragm. These actuators were tested on a bespoke ex vivo testbed that accurately simulated key diaphragmatic characteristics throughout the respiratory cycle. From this, we have been able to drive intrathoracic pressures greater than the 5 cmH${}_2$O required for ventilation in a human male. Additionally, by optimising the placement and geometry of these soft robotic actuators we have been able to generate maximum intrathoracic pressures of (6.81 ± 0.39) cmH${}_2$O.