A Simple Method For Producing A Pacemaker With Low Cost That Works In Modes: VOO, AOO Yousef Darabimoghadam Kermanshah University of Medical sciences Kermanshah, Iran Email: pacmyodaraby@yahoo.com Sina Darabimoghadam Department of Electrical and Computer Isfahan University of Technology Isfahan, Iran Email: sinad1367@yahoo.com Abstract—This paper presents a method for designing and producing a temporary cardiac pacemaker device to cure cardiac arrhythmia. To produce this device Schmitt Trigger Circuit was used to control rate, Op-Amp comparator circuit to regulate pulse width, monostable to regulate pace refractory period and sense refractory period, and it is worthy to mention hat pacemaker works in VOO and AOO. Parameters of this device were measured by employing Sigmapace1000. I. INTRODUCTION The purpose of this paper is a method for producing a temporary external pacemaker with low cost. First we studied the physiology of cardiac and heart arrhythmia and then we studied different type of temporary external pacemaker. Components used in this project are exciting in Iran. Technical data were measured by Sigmapace1000 (external pacemaker analyzer) and compared with pacemaker PAC101H. A. Temporary External Pacemaker The cardiac pacemaker is an electric stimulator that produces periodic electric pulses conducted to electrodes located on the surface of heart (epicardium), within the heart muscle (myocardium), or within the cavity of the heart or the lining of the heart (endocardium) [1]. These devices provide essential support following cardiac surgery and after some myocardial infraction, allowing time for the recovery of the natural heart pacemaker own pacing function [2]. For the patient who develops atrial flutter following open heart surgery, use of the temporary external pacemaker to perform rapid atrial pacing to restore sinus rhythm [3]. B. Pacing mode The North American society of pacing and Electrophysiology and British Pacing and Electrophysiology Group (NASPE/BPEG) Generic code (the NBG Code), the antibradycardia pacing mode code currently in use, was published in 1987 after being adopted by NASPE and BPEG [4]. Position I indicates the chambers being paced, atrium (A), ventricle (V), both (D, dual), or none (O). Position II gives the location where the pacemaker senses native cardiac electrical activity (A,V, D, or O). Position III indicates the pacemaker’s response to sensing-triggering (T), inhibition (I), both (D), or none (O) [5]. C. Capture threshold The capture threshold is the minimum pacemaker output current required to stimulate myocardium. To capture is done both of the mechanical (heart beat) and electric (wave QRS) [6]. Stimulating nerves were the initial research on stimulation pulse energy, but the results obtained have been shown generally to hold when stimulating or pacing cardiac tissue. The energy used should be the minimum possible to induce stimulation reliably, which is controlled by varying the pulse width. Early work on nerve stimulation showed that no matter how wide the pulse width was, a minimum pulse voltage existed, called the rheobase voltage. The lowest energy required is found at about twice this voltage, with a lower pulse width. The greater voltage required results in increased energy requirements to induce pacing If the pulse width is reduced. The pulse width for minimum energy is called the chronaxie time, shown in Fig. 1. The pulse energy is not for providing pumping energy. The energy levels that Figure 1. Pulse energy as a function of pulse width. are only to initiate cardiac depolarization are low and on the order of only a few microjoules [2]. The pulse width is fixed at around 1.5 ms in many temporary external