5-Channel ECG AFE with Respiration, Pacemaker Detection and Lead-Off/Quality Detection

The ADAS1021 is a highly integrated, analog front end (AFE) designed for measurement of patient biopotential information. The primary measurement performed is electrocardiogram (ECG) activity, where the ADAS1021 employs dedicated Σ-Δ analog-to-digital converters (ADCs) per channel to acquire and digitize on a lead basis. The signal acquisition is architected to support low noise, diagnostic level measurement in the presence of a variety of interferers.

The ADAS1021 also includes three dedicated successive approximation register (SAR) ADCs to digitize the high frequency pacemaker content that is analyzed by the on-chip pacemaker detection algorithm.

A dedicated and flexible impedance measurement block captures impedance variation during patient respiration and is available on multiple leads.

The ADAS1021 has a number of complementary features supporting ECG measurement: driven reference for common-mode rejection and lead-off detection that identifies if an electrode connection is degrading or has fallen off. The product also includes a shield drive amplifier to bias the shield of the cable.

Applications

* Portable and line powered ECG monitor and diagnostic measurement

* Battery powered ECG equipment

* 5 ECG acquisition channels and 1 driven reference

* Flexible front-end arrangement allows right arm electrode or WCT referenced

* Dedicated per channel Σ-Δ ADC

* 50 mV typical calibration signal for gain correction

* Digital 50 Hz or 60 Hz mains power line filtering

* Flexible pacemaker detection capability

* Digital detection algorithm on selectable 3 of 5 ECG channels

* Programmable threshold levels

* Dedicated high sample rate SAR ADCs

* Lead-off or lead fail detection

* DC lead-off detection on ECG and RLDOUT

* Programmable polarity, current, and threshold levels

* AC lead quality measurement

* Programmable polarity, current

* Reference electrode drive

* Flexible redirection to other electrodes if RLD lead failure