Every year, heart disease is becoming the major cause of death. Therefore, the need arises tornfind advanced approaches to keep the patients safety. Implantable cardiac pacemakers are anrnelectronic device that can track and boost the heart rate and manage rhythm disorders.rnThis thesis presents nonlinear control of heartbeat model. Because of certain severe cardiacrnarrhythmias display nonlinear feature which is usually correlated with unpredictable andrnoscillatory behavior, a nonlinear technique is used to model heart electrical activity. Zeemanâ€™srnheartbeat model was used to generate ECG signals. Existing model of heartbeat was analyzedrnand revised by integrating the control input to add the control mechanisms as a pacemaker.rnIn this study, sliding mode control (SMC) is applied to heartbeat model in order to track andrngenerate real ECG signal. Fuzzy logic algorithm was also used with SMC to reduce chatteringrnhappened due to high frequency oscillations around the sliding surface that will shorten the lifernspan of pacemaker. Therefore, a fuzzy sliding mode controller (FSMC) for cardiac pacemakerrnbased on ECG signal reference tracking system was designed. In addition, since the heartbeatrnpacemaker is disturbed by the brain signal and sensor output delay, the robustness of the systemrnto disturbance, parameter variations and possible time delay on the feedback system werernanalyzed.rnThe effectiveness of the proposed method was verified through simulation studies using Matlab/rnSimulink software. The proposed control law has shown satisfactory performance in terms ofrntracking ECG signal of the actual data, obtained from the MIT- Bostonâ€™s Beth Israel Hospitalrn(BIH), and the physioNet database by eliminating chattering compared with the use of SMCrncontroller. In addition, the result of root mean square error was reduced by 0.00005 % and totalrnharmonic distortion analyzed from FFT window was reduced by 121.35 % when FSMC wasrnapplied to the system compared with SMC. The control strategy was also found to be robustrnwith respect to external disturbances, parameter variations and random feedback delay.rnTherefore, control algorithm will be applied in dual sensor cardiac pacemakers for clinical use.