(1301) Evaluation of Vital Signs Measured by Wristband-Type Sensors in the Intensive Care Unit

Introduction: Activation of the rapid response system depends on changes in vital signs or scores based on vital signs. However, bedside monitors are not feasible for all hospitalized patients. A wearable device was recently utilized to capture changes in vital signs. This study investigated the accuracy of a prototype wristband-type sensor developed by Nihon Kohden for detecting changes in vital signs before a sudden deterioration. The wristband sensor measured photoplethysmography (PPG), acceleration, skin temperature, and heat flux. Heart rate (HR), respiratory rate (RR), and blood pressure (BP) were calculated by PPG signal analysis. Body temperature (BT) was estimated from skin temperature and heat flux.

Methods: Among the patients admitted to the intensive care unit with bedside monitors between March 2020 and June 2023, this study recruited those who agreed to wear the wristband sensor. HR, RR, BP, and BT values measured by the wristband sensor were compared with those measured by the bedside monitor.

Results: This study included 90 patients (47 postoperative, 12 sepsis, 11 stroke, and 20 others). Among them, 29 were on mechanical ventilation. The mean patient age was 69.5±15.0 years; 55 patients were male. The mean HR measured by the wristband sensor differed from that on the bedside monitor by 0.46±3.78 beats/min (n=30). The mean RR measured by the wristband sensor differed by 0.15±2.40 breaths/min (n=10) from the capnometry measurements and 1.58±7.58 breaths/min (n=21) from impedance measurements on the bedside monitor during mechanical ventilation and spontaneous breathing, respectively. The mean BT measured by the wristband sensor differed by 0.93±1.08°C (n=23) from that measured on the bedside monitor. Although BP measurements were also analyzed, no consistent trend was observed.

Conclusions: Although the wristband sensor accurately measured the HR, RR during ventilation, and BT, the RR measured during spontaneous breathing differed more from that measured by the bedside monitor. The wristband sensor enables continuous monitoring of HR, RR, and BT and may enable early detection of a ward patient's condition deterioration.