A low-cost Holter monitor design equipped with external memory and Bluetooth connection

Monitoring the heart activity is critical for a patient with heart disease. Twenty-hour detecting of the ECG signal will help the clinician to diagnose the hearth. This device is usually called a Holter monitor. However, the price of this device is very expensive, therefore the development of a Holter is required. The purpose of this study is to develop a portable and low-cost Holter system to record the ECG signal in twenty-four hours. The mainboard is composed of a pre-amplifier, bandpass filter, notch filter, summing amplifier, Arduino microcontroller, SD Card Memory, and a Bluetooth transmitter. ECG signal is collected from the body based on the standard measurement of LEAD II. The ECG signal is sampled with a frequency sampling of 200 Hz. To record the raw data of the ECG signal, the SD Card Memory was used to save the data for further data analysis. Calibration was conducted by using an ECG phantom. The calibration was performed in order to make this design to be a standard ECG machine. The design was also equipped with a Bluetooth transmitter to transmit the data to the computer. The total price to develop this device is 460,000 IDR. After the evaluation, the BPM error of this Holter is ±0.0273% and the Holter able to operate in 24 hours. The developed ECG Holter is portable in dimension and low cost to be fabricated for mass production to help people with heart disease.