###### Abstract  
Despite the recent development of wearable cardiopulmonary monitoring devices and their necessity in clinical settings, the evidence regarding their application in real-world intensive care units (ICUs) is limited. These devices have notable problems, such as inefficient manufacturing and cumbersome hardware for medical staff and patients. In this study, we propose a simplified cardiopulmonary monitoring system and present a protocol for a single-center prospective study to evaluate the efficacy of the proposed system compared with those from the conventional monitoring system. The system was designed to continuously measure electrocardiogram, respiration rate, and oxygen saturation in a stand-alone device with an intuitive data visualization platform and automatic data collection. The accuracy of the data measured from the proposed device will be pre-validated by comparing them with those from the reference device. Medical staff from the St. Vincent's Hospital ICU will complete a five-point Likert-type scale questionnaire regarding their experience with conventional ICU monitoring systems. The result will be compared with the second questionnaire conducted after deploying the system. Since this is a study proposal paper, we do not have any data on this study yet. However, compared with the conventional patient monitoring system, the proposed device should be a promising method to relieve medical staff fatigue and that of the patients who must wear and attach the monitoring device for a long time. Keywords:critical care; electrocardiography; ambulatory; oxygen saturation; wearable medical device design +
Footnote †: journal: MedicalDespite the benefits of cardiopulmonary monitoring, the complexity of the currently available clinical devices poses a critical limitation. Currently, separate individual sensors are required for acquiring each signal, leading to complex cabling between each sensor and signal acquisition electronics. Moreover, all current systems require a power line for operation, further complicating the arrangement of cables and power lines from other devices, such as ventilator monitors and infusion pumps. Due to this complexity of setup, the differences in experience between users may cause a difference in the quality of the acquired data [13; 14; 15]. So far, several previous researchers have proposed to improve wearable cardiopulmonary monitoring devices. For example, the wearable device with flexible electrodes, which consist of porous graphene [16], nanowires [17], and nanofiber [18], achieved high permeability to enhance their long-term usage and signal-to-noise ratio without any obstructive cables. However, the manufacturing of the devices needs high-cost materials and a low-throughput process. Some devices are still bulky and have poor portability [19; 20], so they are unsuitable for full-day or bedside monitoring. Moreover, to enhance the ease of wear and device integrity, the T-shirt-type wearable sensor arrays [21; 22] also emerged to improve the comfort of wear and device integration. Nevertheless, synchronizing the signal from each sensor and parallel usage of other life support equipment has remained an unresolved problem. Although such recent developments in material and device integration technology have created a new era for wearable and flexible healthcare sensors that include cardiopulmonary monitoring devices [10; 12; 23; 24; 25; 26; 27; 28; 29; 30; 31], more practical and simplified devices with evidence regarding their use in the real-world intensive care unit (ICU) are needed. Herein, we propose a simplified cardiopulmonary monitoring system with a user-friendly interface (UI) and wireless data transmission. Unlike existing monitoring devices, the proposed system removes obstructive cables. The relocation and arrangement of cables are often cumbersome during patient transport and urgent treatments in ICUs, endangering the critical care environment [22; 32].