The cost of a personal electrocardiogram (ECG) monitor can be reduced through use of new technologies which incorporate microcontroller and digital signal processing into one device.

A personal ECG monitor is a device capable of saving human life. However, its high price limits wider use. A low-cost, single-chip solution can help overcome this obstacle.

Block Diagram at In-depth tab describes control and digital processing aspects of a proposed solution. The ECG signal is collected by probes located on skin near the heart. The signal is then amplified and read by an analog-to digital-converter (ADC). The quality of the ECG signal depends on the probe's location. This influence can be compensated by using multiple probes in different positions. The number of available ADC channels limits the number of probes. The ADC on the DSP56F803 has two channels, each multiplexed to four pins, so a total of eight probes can be connected. One ADC pin is connected to a phone line via a subscriber line interface circuit (SLIC). The remaining seven pins can be connected to probes. Three probes are considered a common set. Two samples will be taken sequentially, a third will be sampled consecutively. The ADC's maximum sampling is 800KHz, and the common sampling frequency of an ECG signal is 500Hz, so there is ample reserve to perform time-multiplexed sampling. The ADC resolution is 12-bit, also enough for this purpose. Learn more about Double-Buffering for Storage and Processing