Design and testing of a cardiac monitor for home care

The aim of this paper is to discuss the design and testing of a new battery-powered cardiac monitor for Homecare. The device is able to acquire two ECG channels; these signals can be processed, stored and transmitted through a Bluetooth´s communication channel. The monitor is based on the MSP430F5438 microcontroller from Texas Instruments and includes a graphic LCD, a simple keypad, a two-channel ECG amplifier, and two NiMH batteries. The ECG is displayed in real time with the heart rate; QRS complexes are detected to compute heart rate. The QRS complex detection is based on an energy function. A new element was introduced in the ECG acquisition; an ECG channel can be acquired by holding with hands the device because its case has two embedded electrodes. On the other hand, the two ECG channels can be acquired by connecting the appropriated patient cable to the monitor. The method developed for QRS complex detection has been tested with twelve ECG strips from MIT-BIH annotated ECG database; 98.05% of the QRS complexes were detected and false positives were not present.