New adjustable flow resistance design for mechanical lung simulator xPulm

Abstract

Abstract Active mechanical lung simulators provide a possibility to mimic physiological and pathological breathing patterns. These models should therefore be flexible in the simulation of compliance or flow resistances to cover the widest possible range of interesting applications. The simulation of airway stenosis, an important aspect of respiratory simulation, should cover a larger parameter space in the mechanical lung simulator xPulm than is possible with conventional components. Therefore, a flexibly adjustable airway resistance model was developed. A prototype with iris diaphragm was designed and realized. Prototype was 3D– printed using a high-temperature polylactic acid (PLA) material. The prototype has a modular design and it can be selected according to the simulation requirements of three different types of blades. This way, the application provides a maximum of flexibility to the user. Measurements with the prototype are presented using four measurement setups. To evaluate the prototype, two measurement setups were used without additional equipment. In two further setups, the interaction with the xPulm simulator was evaluated. The quality of the realized stenoses was assessed by means of measurements of the flow and the associated pressure gradient. These measurements showed that the prototype is functional and provides the desired flexibility in use. In addition, it could be shown that the material used to date for blades is inadequate for more intensive operations and that changes to the measurement settings must be made for use in the lung model.