Approximate identification and digital simulation of the respiration-heartrate system

This paper considers the problem of determining a digital computer model for the heart rate system that includes nonrespiratory as well as respiratory effects on the heart rate. A sampled-data model is shown to be exact in certain cases and can be used with some errors for other cases. Several methods are developed for finding the model transfer function parameters as well as the parameters of a signal added to the system output. Linear and nonlinear models are considered.