Modular-Hybrid Wearable Cardiopulmonary Monitoring Sensor for Unobstructive Critical Care: With a Demonstration in Practice

Continuous cardiopulmonary monitoring is essential for improving treatment outcomes because it enables early detection of associated diseases and the monitoring of disease status while allowing medical personnel to intervene quickly and appropriately. However, conventional cardiopulmonary monitoring systems have unresolved problems, such as bulky and cumbersome monitoring devices with numerous cables and a lack of integrity between multiple stand-alone monitoring devices. These limitations increase the complexity of the clinical environment and lead to medical staff fatigue, which in turn affects the safety and quality of patient care. Here, we propose a modular hybrid electronic system that integrates all wireless communication and biosignal sensing functions into a single device. The importance of the proposed system is also evident in the fabrication and integration of the proposed multimodal, flexible, and disposable sensor, which consists of a laser-induced graphene (LIG)-based respiratory sensor, flexible Cu electrocardiogram (ECG) electrodes, and a dual-wavelength photoplethysmography (PPG) sensor. Several experiments were conducted to ensure the quality of the proposed system. The respiratory sensor fabricated by laser irradiation showed excellent sensitivity (1.59 kΩ · kPa^-1) in the ultralow-pressure range, and the results of the laboratory experiment showed a high correlation between the ECG signal of the proposed system and that of the reference device (R = 0.99). Moreover, in our pilot study conducted in an intensive care unit (ICU), the proposed system effectively detected cardiac arrhythmias, and the system was also used for postoperative follow-up monitoring. The proposed system is a promising candidate for accurate and unobstructed critical care and post-discharge monitoring.