Pacemaker control of heart rate variability: A cyber physical system perspective

Cardiac diseases, like those related to abnormal heart rate activity, have an enormous economic and psychological impact worldwide. The approaches used to control the behavior of modern pacemakers ignore the fractal nature of heart rate activity. The purpose of this article is to present a Cyber Physical System approach to pacemaker design that exploits precisely the fractal properties of heart rate activity in order to design the pacemaker controller. Towards this end, we solve a finite horizon optimal control problem based on the heartbeat time series and show that this control problem can be converted into a system of linear equations. We also compare and contrast the performance of the fractal optimal control problem under six different cost functions. Finally, to get an idea of hardware complexity, we implement the fractal optimal controller on a Virtex4 FPGA and report some preliminary results in terms of area overhead.