新型心电信号检测带通滤波器的设计

Design of novel band-pass filter for ECG processing

提出了一种新型的用于心电信号检测的带通滤波器。心电信号是常见的生物电信号,低频达到0.1 Hz,高频分量超过100 Hz,其检测电路中需要一个0.1—100 Hz的带通滤波器。由于0.1 Hz的低截止频率和片上电容、电阻值的限制,采用传统滤波器设计方法很难达到设计要求。为寻找结构简单而性能达标的滤波器结构,引入了电流舵技术,用低通滤波器和高通滤波器串联的方式,使用不超过10 kΩ的电阻和不超过6 p F的电容就可以实现低达0.026 7 Hz的截止频率。该滤波器在SMIC 0.18μm工艺下进行设计与仿真,经过仿真验证,该滤波器在1.8V工作电源的情况下获得了0.026 7 202 Hz的通频带,低于168μV的输入参考噪声;0.1—100 Hz频带内相移小于±30°,带内波动小于1 d B,滤波器整体功耗为311 n W。该滤波器结构简单,所需电阻电容值小,具有低噪声、低功耗的特点。

A novel band-pass filter for electrocardiogram（ ECG） processing is presented. ECG is one of the most common bioelectrical signals,whose frequency varies from as low as 0. 1 Hz to higher than 100 Hz. A 0. 1—100 Hz band-pass filter is needed in ECG detection circuit. Due to the lower cut off frequency of 0. 1 Hz and the limitation of implementing large resistors or capacitors on the chip,traditional design methods cannot meet the design requirement. With the introduction of current steering technique,a band pass filter consists of a low pass filter in series with a high pass filter is implemented with resistors no larger than 10 kΩ and capacitors no larger than 6 p F and achieve a high pass cut off frequency of 0. 026 7 Hz.This filter is designed and simulated using SMIC 0. 18 μm technology. The simulation results show that under the supply of1. 8 V,a pass band of 0. 026 7 202 Hz is achieved. As for noise performance,the input referred noise is no higher than168 μV. In the 0. 1 100 Hz band,a ripple less than 1 d B and a phase shifting less than ± 30° are achieved. The total power dissipation is 311 n W. This band- pass filter is featured with simple structure,low resistor and capacitor requirement,low power and low noise.