Little Chip Packs Big Wallop in Portable Devices

Author: 
Bob Michaels
Ensuring 95% fewer components on PCBs and consuming 95% less power than discrete devices, TI’s analog front ends are suitable for portable ECG and EEG systems.

Texas Instruments (TI) is rolling out a family of fully integrated analog front ends (AFEs) that the company says are just what the doctor ordered. Featuring eight channels, the 24-bit ADS192x family has 95% fewer components on PCBs and consumes 95% less power than discrete devices. Because of these features, the AFE is an attractive option for designers of portable ECG and EEG systems.

Integrating all of the features commonly found in typical ECG front ends, TI’s AFEs have ultralow power levels and provide a scalable platform approach for designing three-, five-, seven-, and 12-lead ECG systems. “Now, ECG machine vendors have a drop in device size that will let them shrink their design cycle, allowing faster time to market on next-generation ECG and EEG systems,” remarks Aimee J. Kalnoskas, TI’s analog communications program manager.

Available in a single 8 × 8-mm ball-grid array package, the AFEs perform all of the functions of typical ECG analog front-end systems that are currently performed by discrete off-the-shelf catalog components. They incorporate low-power instrumentation amplifiers, operational amplifiers, and analog-to-digital convertors, while including critical ECG functions such as leadoff detection, Wilson center terminal derivation, pace detection, and right-leg drive. The chips also implement true simultaneous sampling with dedicated 24-bit high-resolution analog-to-digital conversion for each channel.

Compliant with IEC and AAMI critical specifications, the AFEs are suitable for a range of applications besides ECGs and EEGs, including patient-monitoring systems, bedside monitors, Holter monitors, event monitors, automated external defibrillators, telemedicine, stress ECGs, and sleep-study monitors. The channels in the ADS129x family can also be used for measuring vital signs such as oxygen saturation of arterial blood, blood pressure, and temperature.

Until now, high power consumption and bulky designs limited the portability of ECG and EEG equipment, Kalnoskas says. But with the emergence of TI’s new family of ADEs, it’s a new ballgame. “The ADS129x’s level of integration, its compact size, and its low power levels enable breakthrough portable applications that would be impossible with discrete devices.”


Texas Instruments
Dallas
www.ti.com