next up previous

Exercise 4.9: The human heart.

A simple model of the human heart beat gives

where is the displacement from equilibrium of the muscle fiber, is the concentration of a chemical control, and A are positive constants. Assume , A = 3.

a) Calculate and for starting with , . Use ``xmgr'' to plot the output in the phase plane (x along the horizontal axis, c on the vertical). What does the period appear to be?
b) Repeat with , .