ABSTRACT

Electrocardiograph machine is a standard equipment used to monitor heart signals, especially for early detection of heart attacks in humans. This ECG machine can be used to monitor heart examination not only in hospitals, but also at home. As medical technology developed, particularly heart signals monitoring equipment with the development of microcontroller technology, so the design innovation of ECG machine needs to be developed through researches. In this research, the researcher designed telemetry- based ECG machine with ATMEGA microcontroller technology. The design of this research started by recording heart signals, creating bio amplifier circuit, transmitter and receiver Xbee-based circuit that results can be displayed through internet which can be seen in personal computer (PC). The research design used Quasi Experimental Design, i.e. Time-Series Design. The free variables of this research are ECG phantom or human, and the dependent variable is ECG machine. The design of telemetry-based ECG machine is created though the following stages: a) designing ECG bio amplifier circuit; b) designing microcontroller circuit and PC display circuit; c) designing heart sounds amplifier; d) designing Xbee module (transmitter and receiver) to process ECG signal by multipoint to point; e) designing data acquisition program, data storing, ECG digital signal filter and analog to PC data plotting; f) measuring heart signal response in heart signal monitoring equipment (ECG machine); g) testing the output calibration circuit. The results and analysis of the research of BPM measurement using phantom with 5% tolerance show  that: a) the measurement of  60 BPM with speed 25 mm/s in ECG 1, the error number is -0,001666667-0,003333333 and  uncertainty (UA) 0,0465059520,067523505; b) the measurement of  60 BPM with speed 25 mm/s in ECG 2, the error number is: -0,001666667 and  uncertainty (UA): 4,65060E-02; c) the measurement of  60 BPM with speed 25 mm/s in ECG 3 the error number is: -0,001666667 and  uncertainty (UA): 0,039727347; The result of data analysis of three heart beat monitoring equipments, especially heart rate, is under the tolerance number allowed, i.e. less than 5%. Thus, the equipment is feasible. However, if this equipment is used to count heart beats, it needs heart rate count restrictions in 1 (one) period so the detection of heart beats reaches normal number. If it is observed based on sensitivity analysis results, ECG 1 equipment shows Error 0,3333 and Uncertainty (Ua) 0,223606798, ECG 2 equipment shows Error : 0,3333  and Uncertainty (Ua) : 0,223607 and ECG 3 equipment shows Error : 0  and Uncertainty (Ua) : 0. This means that three equipments are feasible, because it is under the tolerance allowed, i.e. 2%. The picture of heart output signal that consists of 12 records sent via internet which is shown in PC, the results are good although the parameter is different like speed 25 and 50 mm/s. The research conclusions are: 1) the result of ATMEGA microcontroller listing program design can be used to run telemetry-based ECG program module by displaying heart beat numbers, beep per R signal and ECG signal; 2) the result of telemetry-based ECG design is feasible since the design of bio amplifier circuit that is combined with tapping selection and filter circuit can be used to process heart signal; 3) the design of 1 mV circuit produces the frequency from differentiator 10.17 Hz, but there is still noise after passing microcontroller circuit and displayed in PC; 4) the design of microcontroller circuit can process heart signal from bio amplifier circuit which result can be transmitted into PC and web with URL tekmed.penelitian.poltekkesdepkes-sby.ac.id, with display like heart beat followed by sound, heart signal from three ECG equipments alternately; 5) the design of software is used to run signal receiver program from tapping until transmitted to internet multipoint to point.

 

Keywords: heart signal monitoring, ECG, telemedicine