Evaluating Head Impact Intensities and Accelerations Using Flexible Wearable Sensors for Traumatic Brain Injury Assessment

In response to the significant health threat posed by Traumatic Brain Injury (TBI) resulting from sudden collisions on the head, there is an urgent need for timely assessment and evaluation. With the wide applications of wearable devices in health monitoring, here we report a flexible and wearable smart headband based on a polyvinylidene fluoride (PVDF) sensor to evaluate the impact force and acceleration for TBI assessment. Based on the electromechanical coupling characteristics of PVDF, a lumped parameters model of an equivalent circuit was obtained by a system identification method, which accurately transforms the output signal of the PVDF sensor to the impact force for TBI assessment of focal brain damage. Besides, a drop tower was used to impose different impact intensity levels on a dummy head wearing the smart headband; the results (MSE<0.018) of transformed impact force show the universal applicability of the model. Moreover, the correlation analysis results show that the impact force has a positive correlation (R>85%) with impact acceleration at the head center of gravity, which enables the TBI assessment of diffuse brain damage. This smart headband can be used for real-time monitoring of human head impact and has excellent potential for application in medical and sports devices.