Sensor Validation: Smart IoT enabled Head Kinematics Monitoring device

Brain injury is more sensitive to the shear force that is produced due to rotational motion of the head. Therefore, angular kinematic plays an important role in assessing head injury. The purpose of our study is to evaluate the accuracy of Micro-Electro-Mechanical Systems (MEMS) based low-cost motion processing unit (MPU 9250, InvenSense) as a research device for measuring the angular kinematic against the high- rate tri-axial angular rate gyroscope (ARS3 PRO, Diversified Technical System (DTS)). The manuscript discusses about a development of low- cost wireless angular rate sensor where micro-SD module is used for data acquisition. To evaluate the accuracy of angular kinematic of low-cost sensor, laboratory impact testing was performed on the surrogate head that was mounted on the hybrid-III neck and subjected to the impact loading using a linear impactor system. The study was performed at two different impact velocities of 3 m/s and 5 m/s where the value of peak angular velocity and temporal time response of both the gyroscopes were statistically compared. The statistically comparison was performed on the raw temporal time response data of low-cost sensor against the high-rate sensor. Where, the linear regression model revealed that the low-rate sensor underestimated the peak angular velocity with respect to high-rate sensor. The Bland-Altman analysis found a non-significant bias between the high-rate and low-rate sensor which represents a reasonable agreement between them. The shapes of angular velocity time-series traces for each impact were compared using the principal component analysis (PCA). Which represents the similarities and dissimilarities between their time series traces. The results from the comparative analysis study indicates the positive correlation between the low-cost and high-cost gyroscope.