The Zeeman Heartbeat Model uses work in Catastrophe Theory to create a simulation of the heartbeat cycle.  The heart is represented as a blue circle in phase space and travels from diastole to systole which are represented as the green circles.  Cardiac muscle fiber length (x) is represented on the y-axis and electrochemical activity (b) is represented on the x-axis.  The model calculates the heart rate (in beats per minute) and a variable called gamma which is intrinsic to the pacemaker.

The model allows the user to adjust several variables, including muscle tension and the location of diastole and systole, to see how the heart rate is affected.  Adjust tension by moving the slider at the top of the display or by manually entering a number into the field.  Adjust the location of diastole and systole by either dragging them or entering values into the fields at the bottom of the display.

The Zeeman Heartbeat Model was developed as a final project in a sophomore-level Computational Physics course (Phy 200) using the Easy Java JavaScript Simulation (EjsS) modeling tool.  It is distributed as a ready-to-run (compiled) Java archive.   Double clicking the jar file will run the program if Java is installed.  You can modify this simulation if you have EJS installed by right-clicking within the map and selecting "Open Ejs Model" from the pop-up menu item.

Please note that this resource requires at least version 1.6 of Java (JRE).