Date of Award
Master of Science (MS)
Damage to the spinal cord causes long-lasting loss of motor and sensory function, and currently, there is no ‘cure’ for paralysis. However, even people with severe spinal cord injuries (SCI) have some residual mobility. Studies have shown that transcutaneous electrical spinal cord stimulation (tSCS) combined with functional training targeting residual mobility can further improve the motor function of individuals with SCI. In this study, we present a technical framework that aims to enhance rehabilitation outcomes by targeting residual mobility through a motor training-based approach. Our technical framework centers around a non-invasive body-machine interface (BoMI) that relies on the use of several inertial measurement units (IMUs) to capture the residual mobility of the participant’s body and translate it into the ability to control a two-dimensional (2D) cursor on a computer screen. Participants can manipulate this 2D computer cursor by using their residual body movements to complete a series of self-developed tasks for functional motor training, such as center-out reaching tasks and 2D video games. Additionally, tSCS electrodes were placed at designated spinal segments during the motor training and attempted to produce neuromodulatory effects that facilitate leg and trunk movement and performance of BoMI control.
Subsequently, our work aimed to investigate the effect of using non-invasive tSCS and immersive 2D video games on participants’ performance of motor control and learning rate through the above training framework. Participants' performance was recorded and quantified using four assessment metrics based on different center-out reaching tasks. Therefore, a multi-day experiment recruiting both unimpaired control participants and people with SCI was conducted to investigate the effect of training with tSCS and 2D video games on the performance of center-out reaching tasks.
Our findings revealed that the BoMI performance of the unimpaired control group improved after training with center-out reaching tasks, and the final performance and learning rate were unrelated to the application of tSCS. However, the effect of tSCS on individuals with SCI varied from person to person. Specifically, we found that tSCS had a clear facilitation effect on the BoMI performance, resulting in a better final performance and a significant learning rate for SCI participant BMS002 but not for SCI participant BMS001. Moreover, our results showed that training with reaching tasks and video games resulted in similar final BoMI performance within the unimpaired control group, but training with reaching tasks generated a better learning rate. Regarding participants with SCI, training with video games led to a significant learning rate in BMS001 and a non-significant learning rate in BMS002. In addition, we observed that there was no significant difference between the final performance after training with reaching task and video games in both unimpaired control and SCI participants.
In conclusion, our results suggest that functional training with tSCS could be an effective approach to enhancing motor function and learning rate for individuals with SCI. Also, video games could be considered as a promising training strategy, equivalent to traditional center-out reaching tasks.
Dennis L. Barbour, Jonathan R. Silva