Powering an ECG Front End in Battery Powered Patient Monitoring Applications (CN0308)
This circuit is a highly integrated electrocardiogram (ECG) front end for use in battery powered patient monitoring applications.
Figure 1 shows a top level diagram of the physical connections in a typical 5-lead (four limb and one precordial chest lead) ECG measurement system, including features such as respiration and pace detection. The configuration is typical for portable telemetry ECG measurements or a minimum lead set from a line powered bedside instrument.
An ECG signal has a small amplitude of typically around 1 mV when measured on the surface of the skin. Important information about the health or other characteristics of the patient is stored within that small signal; therefore, requiring measurement sensitivity in the μV level. At the system level, various medical standards call for a maximum of 30 μV p-p noise; however, designers typically target less than this. As a result, when designing a solution suitable for system level requirements, all noise sources must be considered.
The noise performance of the ADAS1000 is specified across various different operating conditions. The power supply must be designed to ensure that it does not degrade the overall performance. Selection of the ADP151 linear regulator was based on its ultralow noise performance (9 μV rms typical, 10 Hz to 100 kHz), coupled with the power supply rejection of the ADAS1000, ensures that the noise of the ADP151 does not degrade the overall noise performance.
Figure 1. Simplified Block Diagram Showing the ADAS1000 as Used in a Typical 4-Electrode + RLD or 5-Lead Configuration (All Connections and Decoupling Not Shown)
Схемы и диаграммы
Быстро получите общее представление о схемотехнике решения
Печатные платы и ПО
Ускорьте разработку по готовому дизайну