Effectiveness of the smart-ring based chest compression depth feedback system

Introduction We developed a smart-ring for feedback of chest compression depth (CCD). To accuracy and clinical usefulness, we conducted a manikin simulation study. Material & Method Smart-ring has an inertial measurement unit (IMU) sensor to measure the CC depth. The experiments included 4 levels of CC depth and 3 CC directions to assess the accuracy. And, adult CPR simulation experiment of randomized crossover study was conducted to verify the effectiveness. The control performed CC without the feedback, and the feedback group performed CC using a device with the feedback. The result was set to the CC depth and the accuracy of the CC depth. Result In the accuracy experiments, the mean SD of errors for each CC depth level was determined: 1.99 (1.10) mm for 50-60 mm. When the CC direction was 30°oblique, the mean SD of the errors was 1.36 (1.09) mm. In the adult CPR simulation, CC depth was 50.5 (6.1) and 44.4 (9.4) mm, the accuracy of depth was 62.7 (38.7) and 35.9 (39.2) % in the feedback group (n = 20) and the control (n = 20) (p <0.001, p <0.001). When two minutes of CC were divided into four sections (30 sec) and the changes in the outcome were compared, the feedback group showed a slight decrease in CC depth over time, but the CC depth was maintained at the recommended depth (52.0 ? 50.7 ? 50.0-49.8 mm). Conclusion We predicted that the real-time feedback provided by a smart ring might help to maintain adequate CC depth during CPR.