Simulation of spontaneous respiration nonlinear model driven by muscle pressure

The spontaneous respiratory simulation is one main task of medical patient simulator. Based on the principle of breath, muscle pressure as source power is input into the breath system. Breath system is simulated as two lumped compartments, airway resistance and compliance. The output of the breath system is the flow of respiratory. Compared to the former method that two fixed parameters (R and C) are used as linear coefficient, we avoided the oversimplifications inherent in previous models, namely linear treatment of the breathing mechanics. Nonlinear resistance is used in this model. In order to complete the complicated model and control actuator simultaneous, LabVIEW and simulink program are used both, simulation interface toolkits (SIT) being the bridge between the two different languages. The simulated flow wave is more similar to the real breathing in that the expiratory flow is smoother than in the linear model. The parameters of R and C can be adjusted by knob in LabVIEW. And the controlling peripheral apparatus task can also be accomplished by LabVIEW DAQ card.