Control systems are largely prevalent across both mechanical and physiological systems. In this report, we aim to study the intersection of the two by modelling and simulating the control system of a pacemaker regulated functioning heart. The model uses some basic assumptions and has been simplified to a closed loop feedback system which contains a PID controller. The controller tuning was done using Simulink (MATLAB) to obtain a quick rise time, low offset, reduced oscillations and low overshoot. Additionally, an accelerometer was used to simulate a load on the heart that would increase the set point above 60 bpm, such as engaging in physical activity. It was found that the modeled pacemaker system was able to successfully adjust heart rate to these changes in set points.
Heart is one of the most important organs of a human body which need to work continuously and steadily for a living organism’s metabolism to function properly. Therefore, individuals susceptible to abnormal heart rhythms require additional systems to help their heart function normally. One such device used is an artificial pacemaker. The pacemaker senses abnormal heart rhythms (bradycardia or tachycardia) and emits electrical impulses to stimulate the heart muscles accordingly and maintain a normal heart rhythm. The pacemaker performs two main functions: sensing and pacing. A combination of accelerometer, minute ventilation and cardiac contractility sensor enables the pacemaker to provide an immediate response to any physical activity and detect the metabolic need. The electrodes are also able to sense contraction force of the ventricle’s chambers and predict how fast the heart needs to contract to maintain the cardiac output. The pacing action of the pacemaker is performed by electrodes attached to the ventricles or the atria of the patient.
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