基于ADS1298設計的8路24位精度心電圖(ECG)前端技術

ADS1298集成了心電圖(ECG)前端的8路24位精度delta-sigma (ΔΣ)模/數(shù)轉換器,具有同時取樣和內置的可編增益放大器(PGA),基準電壓和振蕩器,包含了醫(yī)療心電圖(ECG)和腦電圖(EEG)所有的功能.本文介紹了ADS1298主要特性和優(yōu)勢,功能方框圖,以及每路輸入復接器方框圖,單電源連接框圖, 雙電源連接框圖與心電圖(ECG)總體方框圖.

8-Channel, 24-Bit Analog-To-Digital Converter With Integrated ECG Front End

The ADS1294/6/8 are a family of multichannel, simultaneous sampling, 24-bit, delta-sigma (ΔΣ) analog-to-digital converters (ADCs) with a built-in programmable gain amplifier (PGA), internal reference, and an onboard oscillator. The ADS1294/6/8 incorporate all of the features that are commonly required in medical electrocardiogram (ECG) and electroencephalogram (EEG) applications.

ADS1298主要特性和優(yōu)勢:

Simplifies design and saves board space, using up to 95 percent fewer components, by integrating all common features required for ECG and EEG front ends, including the following:

eight low-noise programmable gain amplifiers (PGAs).

eight high-resolution, simultaneous sampling analog-to-digital converters (ADCs).

integrated amplifier for right-leg drive.

integrated amplifiers for Wilson Central Terminal (WCT) and Goldberger Terminals (GCT).

digital pace detection capability.

continuous lead-off detection.

onboard oscillator and reference for smaller footprint and low-power applications.

Power consumption of 1 mW/channel results in up to 95 percent less power use than discrete implementations, increasing equipment portability and improving patient mobility.

The ADS1298’s 4-uVpp (typical) input-referred noise is far superior to the limits set in IEC60601-2-27/51, for more accurate measurements in portable equipment and high channel-density, high-end ECG and EEG equipment.

Complementing the analog front end’s leading power consumption is the low-power TMS320C5505 DSP family. At less than 0.15-mW/MHz power consumption, the TMS320C5505 maximizes battery life for portable patient monitoring applications. Together with TI’s full portfolio of analog signal chain and power management solutions, these devices offer customers a complete signal chain for ECG and EEG applications to speed their time to market.

ADS1298應用:

Medical Instrumentation (ECG and EEG) including:

C Patient monitoring; Holter, event, stress, and vital signs ECG, AED, telemedicine,
fetal ECG

C Bispectral index (BIS), Evoked audio potential (EAP), Sleep study monitor

High-Precision, Simultaneous, Multichannel Signal Acquisition


圖1.ADS1298功能方框圖

圖2.ADS1298每路輸入復接器方框圖

a)標準配置 b) DAISY_IN 配置