ADI低成本无线ECG Holter监视器解决方案

ADI公司的低成本无线ECG Holter监视器解决方案主要采用12位精密模拟微控制器ADuC7022, 高性能ISM频段FSK/ASK收发器 ADF7022, 低成本仪表放大器AD623, 微功耗精密CMOS运算放大器AD8500和低功耗JFET放大器AD8641等器件.本文介绍了典型的单通道心电图方框图, 低功耗低成本无线ECG Holter 监视器方框图以及主要器件的主要特性和应用电路.
The ECG signal is characterized by six peaks and valleys labeled with successive letters of the alphabet P, Q, R, S, T, and U.

图1.心电图(ECG)的信号波形

图2. 典型的单通道心电图方框图
Awireless Holter monitor–small enough to fit on the back side of an electrode–provides more accurate signals than traditional designs because noise and interference are greatly reduced. The circuit is inexpensive and capable of providing diagnostic-quality 1-lead ECG traces. A driven leg eliminates the need for a 60 Hz notch filter. Depending on the frequency band used, the transceiver (the ADF702x is shown below) and its surrounding circuitry will change. Patient comfort and privacy is greatly improved because all circuitry can be worn under clothing.

图3.低功耗低成本无线ECG Holter 监视器方框图(1)

图4.低功耗低成本无线ECG Holter 监视器方框图(2):ADuC7022替代AD7466+MCU
主要元件性能介绍:
ADUC7022: Precision Analog Microcontroller, 12-Bit Analog I/O, ARM7TDMI® MCU
The ADuC7019/20/21/22/24/25/26/27/28 are fully integrated, 1 MSPS, 12-bit data acquisition systems incorporating high performance multichannel ADCs, 16-bit/32-bit MCUs, and Flash/EE memory on a single chip.
The ADC consists of up to 12 single-ended inputs. An additional four inputs are available but are multiplexed with the four DAC output pins. The four DAC outputs are only available on certain models (ADuC7020 and ADuC7026). However, in many cases where the DAC outputs are not present, these pins can still be used as additional ADC inputs, giving a maximum of 16 ADC input channels. The ADC can operate in single-ended or differential input modes. The ADC input volta...