Bioelectronics Section, Department of Electrical Engineering, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (Cinvestav), Mexico City 07360, Mexico.
Instrumentation, Sensors and Interfaces Group, Universitat Politècnica de Catalunya (Barcelona Tech), 08860 Barcelona, Spain.
Sensors (Basel). 2023 Oct 8;23(19):8303. doi: 10.3390/s23198303.
A low-power long-term ambulatory ECG monitor was developed for the acquisition, storage and processing of three simultaneous leads DI, aVF and V2 with a beat-to-beat heart rate measurement in real time. It provides long-term continuous ECG recordings until 84 h. The monitor uses a QRS complex detection algorithm based on the continuous wavelet transform with splines, which automatically selects the scale for the analysis of ECG records with different sampling frequencies. It includes a lead-off detection to continuously monitor the electrode connections and a real-time system of visual and acoustic alarms to alert users of abnormal conditions in its operation. The monitor presented is based in an ADS1294 analogue front end with four channels, 24-bit analog-to-digital converters and programmable gain amplifiers, a low-power dual-core ESP32 microcontroller, a microSD memory for data storage in a range of 4 GB to 32 GB and a 1.4 in thin-film transistor liquid crystal display (LCD) variant with a resolution of 128 × 128 pixels. It has programmable sampling rates of 250, 500 and 1000 Hz; a bandwidth of 0 Hz to 50% of the selected sampling rate; a CMRR of -105 dB; an input margin of ±2.4 V; a resolution of 286 nV; and a current consumption of 50 mA for an average battery life of 84 h. The ambulatory ECG monitor was evaluated with the commercial data-acquisition system BIOPAC MP36 and its module for ECG LABEL SS2LB, simultaneously comparing the morphologies of two ECG records and obtaining a correlation of 91.78%. For the QRS detection in real time, the implemented algorithm had an error less than 5%. The developed ambulatory ECG monitor can be used for the analysis of the dynamics of the heart rate variability in long-term ECG records and for the development of one's own databases of ECG recordings of normal subjects and patients with cardiovascular and noncardiovascular diseases.
开发了一种低功耗、长期动态心电图监测仪，用于采集、存储和处理三个同步导联 DI、aVF 和 V2，并实时进行心率测量。它可以提供长达 84 小时的连续心电图记录。该监测仪使用基于样条连续小波变换的 QRS 复合检测算法，可自动选择用于分析不同采样频率心电图记录的比例。它包括导联脱落检测，以连续监测电极连接，以及实时视觉和声音报警系统，以提醒用户其运行中的异常情况。所提出的监测仪基于具有四个通道、24 位模数转换器和可编程增益放大器的 ADS1294 模拟前端、低功耗双核 ESP32 微控制器、用于在 4GB 到 32GB 范围内存储数据的 microSD 存储器，以及分辨率为 128×128 像素的 1.4 英寸薄膜晶体管液晶显示器 (LCD) 变体。它具有可编程采样率为 250、500 和 1000Hz；带宽为所选采样率的 0Hz 至 50%；CMRR 为-105dB；输入余量为±2.4V；分辨率为 286nV；平均电池寿命为 84 小时，电流消耗为 50mA。该动态心电图监测仪与商业数据采集系统 BIOPAC MP36 及其 ECG LABEL SS2LB 模块进行了评估，同时比较了两个心电图记录的形态，并获得了 91.78%的相关性。对于实时的 QRS 检测，实现的算法误差小于 5%。所开发的动态心电图监测仪可用于分析长期心电图记录中心率变异性的动态，并用于开发正常受试者和心血管及非心血管疾病患者的心电图记录的自有数据库。
