Design of Amplifier for Wearable Human ECG Sensor with Low Power and Low Noise

Abstract

Electrocardiograph (ECG) data is an important index to determine the human heart state, which helps diagnose heart disease in an early stage. Since the ECG signal is instantaneous, it is important to make the ECG signal collector wearable and have good battery life. The wearable ECG devices need to have certain properties like interference suppression ability of acquired signal, low power consumption, low noise, and high integration, putting forward crucial requirements for the design of the amplifier. To meet the properties, the front-end analog processing circuit with interface input buffer stage structure and post-amp structure was proposed here, which has the characteristics of small size, low power consumption, low input referred noise, fair common-mode rejection ratio, and high input impedance. Besides, as one of the industrial-grade circuit simulation software, LTspice was used to design the circuit structure and analyze the corresponding performance. According to the circuit design and simulation testing, it turned out that the circuit in this work can be quite simple, and all the performance indexes met the practical demands. The frequency range was 0.1Hz∼100Hz, the voltage was 1.2V, the differential gain was 40.37dB, the total integrated input-referred noise was 3.48uVrms, and the total power consumption was 1.75uW. In summary, our data indicate that the ECG device we design is small enough to be wearable and has low power consumption.

Progress in Data Acquisition of Wearable Sensors

“…However, from the overall perspective of the sensing device, such improvement is relatively small. Taking the studies mentioned above as examples [ 143 , 144 ], they can bring microwatt levels of power reduction, while the power consumption of portable sensors is often at the milliwatt level. Alternatively, enhancing the power supply can solve the energy problem including using batteries with a high energy density [ 145 ] and fast charging capability [ 146 , 147 ], as well as applying self-powered designs that sensors obtain energy from the behavior of wearer [ 148 , 149 ], body temperature [ 150 , 151 ], body fluids [ 152 ], friction[ 153 ], raindrop [ 154 ], and sunlight [ 155 ].…”

Design an amplifier to record electrodardiogram(ECG) signals

“…It is known that this 50 Hz noise is a common-mode noise, so to reduce it to observe the ECG signal clearly, subtraction can be applied here [6]. By applying subtraction to V1 and V2, an ECG signal without noise in Figure 5 can be gotten.…”

A 0.8 V, 14.76 nVrms, Multiplexer-Based AFE for Wearable Devices Using 45 nm CMOS Techniques

“…Biomedical devices can be categorized as wearable and implantable therapeutic devices [10]. A WMD is a self-contained, non-invasive object that carries out a specific therapeutic or diagnostic purpose [11]. More research on WMDs was conducted between 2003 and 2023, and our literature analysis shows that this sector is proliferating.…”