A Wireless, Low-Power, and Miniaturized EIT System for Remote and Long-Term Monitoring of Lung Ventilation in the Isolation Ward of ICU

作者：Lin Yang, Meng Dai, Hang Wang, Xinsheng Cao, Shiqin Li, Feng Fu, Junying Xia, Zhanqi Zhao · 发表于：IEEE Transactions on Instrumentation and Measurement · 年份：2021 · DOI：10.1109/tim.2021.3085970 · 被引用次数：23 · 研究领域：Electrical and Bioimpedance Tomography、Non-Invasive Vital Sign Monitoring、Microwave Imaging and Scattering Analysis

Individualized lung-protective ventilation strategy is essential for patients with COVID-19. In this study, a wireless, low-power, and miniaturized electrical impedance tomography (EIT) system was developed for remote and long-term monitoring of lung ventilation for patients with COVID-19 in the isolation ward of ICU. A new strategy of combining filtering and improved voltage-controlled current was employed to design the current source for a simplified system structure, and a new differential receiver circuit consisting of a buffer amplification and a differential amplification was proposed to design the voltage measurement unit for high precision. Moreover, a Bluetooth interface was adopted for wireless data transmission, and components characterized by low power consumption were selected to minimize the system power consumption. The proposed EIT system occupies a total size of$6.5\times 4.5\times0.6$cm3and can work stably within 25 m from the wireless terminal installed with host EIT software. The system has a signal-to-noise of 70 dB at 50 kHz, stability of 0.1% relative change, and power consumption of 114 mW, as tested with a resistor phantom. Furthermore, a comparison between the proposed system and a commercial ICU EIT device was conducted on nine healthy volunteers for ventilation monitoring. The correlation between lung volume and relative impedance changes was higher than 0.9 for both EIT systems ($p < 0.001$). The analysis of the corresponding EIT images reveale...