Department of Rehabilitation, Eniwa Hospital, Eniwa-shi, Japan.
Graduate School, Yamagata Prefectural University of Health Sciences, Yamagata-shi, Japan.
Biomed Mater Eng. 2024;35(5):439-450. doi: 10.3233/BME-240031.
Inertial measurement unit (IMU)-based motion sensors are affordable, and their use is appropriate for rehabilitation. However, regarding the accuracy of estimated angle information obtained from this sensor, it is reported that it is likely affected by velocity.
The present study investigated the reliability and validity of the angle information obtained using IMU-based sensors compared with a three-dimensional (3D) motion analyzer.
The Euler angle obtained using the 3D motion analyzer and the angle obtained using the IMU-based sensor (IMU angle) were compared. Reliability was assessed by comparing the Bland-Altman analysis, intra-class correlation coefficient (ICC) (1,1), and cross-correlation function. The root mean square (RMS) error, ICC (2,1), and cross-correlation function were used to compare data on the Euler and IMU angles to evaluate the validity.
Regarding reliability, the Bland-Atman analysis indicated no fixed or proportional bias in the angle measurements. The measurement errors ranged from 0.2° to 3.2°. In the validity, the RMS error ranged from 0.3° to 2.2°. The ICCs (2,1) were 0.9. The cross-correlation functions were >0.9, which indicated a high degree of agreement.
The IMU-based sensor had a high reliability and validity. The IMU angle may be used in rehabilitation.
基于惯性测量单元（IMU）的运动传感器价格实惠，其应用适用于康复治疗。然而，关于从该传感器获得的估计角度信息的准确性，据报道，它可能容易受到速度的影响。
本研究旨在调查基于 IMU 的传感器获得的角度信息与三维（3D）运动分析器相比的可靠性和有效性。
将 3D 运动分析器获得的欧拉角与基于 IMU 的传感器（IMU 角度）获得的角度进行比较。通过 Bland-Altman 分析、组内相关系数（ICC）（1,1）和互相关函数来评估可靠性。使用均方根（RMS）误差、ICC（2,1）和互相关函数来比较欧拉角和 IMU 角的数据，以评估有效性。
在可靠性方面，Bland-Atman 分析表明角度测量没有固定或比例偏差。测量误差范围为 0.2°至 3.2°。在有效性方面，RMS 误差范围为 0.3°至 2.2°。ICC（2,1）为 0.9。互相关函数>0.9，表明具有高度一致性。
基于 IMU 的传感器具有较高的可靠性和有效性。IMU 角度可用于康复治疗。
