HCC: Medium: Haptic Simulation Design for Motor Rehabilitation and Skill Training

该项目旨在设计和研究基于虚拟现实的触觉模拟的新功能和策略，以重新训练创伤性脑损伤（TBI）的退伍军人（医务人员）受损的运动功能和训练新的精细运动技能。以前的触觉模拟设计方法通常侧重于相对于现实的呈现完整性。然而，模拟器可能用于许多不同的任务，因此完整性可能无法确保有用性。pi认为，模拟对用户的作用及其所需的功能是更重要的设计问题，并且在触觉模拟设计中考虑运动技能训练等关键应用将从人类表现的角度促进有效的设计。因此，他们提出了一种以认知为导向的触觉模拟设计和评估方法。在这个项目中，pi将通过为绘图和手术任务设计和制作先进的VR触觉模拟器来测试他们的想法。模拟将根据用于虚拟对象建模的（医学）数据源的类型和分辨率、用于运动技能和大脑功能评估的视觉和力表示类型以及模拟的图形和触觉渲染方法来定义。通过模拟的人为因素实验，pi还将评估运动发展的干预策略，包括虚拟触觉辅助（例如，力边界和电位）和康复试验中的力毕业。最后，他们将利用行为指数和先进的磁共振成像（fMRI）来验证触觉模拟对神经认知和运动表现的影响。认知任务分析将与专家神经心理学家和外科医生进行精神运动任务表现和外科手术，以告知模拟设计过程。仿真设计操作将包括通过使用图形方法逼近点云数据来减少源数据，开发具有有效人机界面的基于触觉的运动技能训练工作站，以及使用基于gpu的图形和平滑粒子流体动力学（SPH）模型来优化视觉和触觉表示，以减少CPU开销触觉对象渲染与力反馈。模拟设计也将反映基线运动性能和VR绘图和手术模拟器实践的结果。在此测试之后，将对执行运动任务的受试者进行功能磁共振成像，以检查调节运动控制的大脑区域的激活情况。随后，将使用触觉模拟器进行一系列运动训练。受试者将接触到模拟设计参数的各种设置，以及虚拟触觉辅助和力反馈的逐渐减少，相对于名义力，跨会话。治疗后的运动和模拟器测试，以及后续的功能磁共振成像扫描，将进行。运动恢复和调节运动表现的脑区神经成像将为模拟设计的有效性和康复效果提供证据。pi假设，基于运动技能训练需求和人类表现指标的触觉模拟设计经验将加速技能发展，相对于以保真度为中心的设计方法。他们还期望触觉模拟器的经验将改善精细运动控制和运动规划（实践），在绘图模拟设备上的经验将推广到在手术模拟设备上的改进，并且脑血流量将增加调节运动控制的区域。更广泛的影响：这项工作将有助于计算机图形学和触觉渲染的设计，更好地理解VR触觉仿真的最佳计算建模。它还将推动以触觉模拟为基础的运动技能发展的计算机治疗方法的发展，并增强我们对控制运动输出的大脑行为关系和运动康复后神经恢复本质的理解。将确定现有的基于vr的脑外伤患者运动和实践障碍康复策略的改进；将确定康复治疗方案，这可能对患有脑损伤的各种人群（例如中风患者）有影响。

The PI seeks to design and investigate novel features and strategies for use of virtual reality based haptic simulations to retrain impaired motor functions and train new fine motor skills in veterans (medics) with traumatic brain injury (TBI). Previous approaches to haptic simulation design have typically focused on completeness of presentation relative to reality. However, simulators may be used for many different tasks, so completeness may not ensure usefulness. The PIs argue that the role of the simulation for a user and its required functionality are the more important design questions, and that consideration of critical applications like motor skill training in haptic simulation design will promote effective design from a human performance perspective. Thus, they propose a cognitive-oriented approach to haptic simulation design and evaluation. In this project, the PIs will test their ideas by designing and prototyping advanced VR haptic simulators for drawing and surgical tasks. The simulations will be defined in terms of the type and resolution of (medical) data sources used for virtual object modeling, the type of visual and force presentation for motor skill and brain function assessment, and the approach to graphic and haptic rendering of the simulation. Through human factors experimentation with the simulations, the PIs will also assess interventional strategies for motor development, including virtual haptic aids (e.g., force boundaries and potentials) and force graduation across rehabilitation trials. Finally, they will validate the effect of the haptic simulations on neurocognitive and motor performance using behavioral indices and advanced magnetic resonance imaging (fMRI). Cognitive tasks analyses will be conducted with expert neuropsychologists and surgeons on psychomotor task performance and surgical operations to inform the simulation design process. Simulation design manipulations will include source data reduction through approximation of point-cloud data using graphical methods, development of a haptic-based motor skill training workstation with an effective human-computer interface, and optimization of visual and haptic representation using GPU-based graphics and a smoothed particle hydrodynamics (SPH) model for reduction of CPU overhead in haptic object rendering with force feedback. The simulation design will also reflect results on baseline motor performance and VR drawing and surgical simulator practice. This testing will be followed by fMRI of subjects in motor tasks in order to examine activation of brain regions mediating motor control. Subsequently, a series of motor training sessions will be conducted using the haptic simulators. Subjects will be exposed to the various settings of the simulation design parameters along with the virtual haptic aids and gradual reduction of force feedback, relative to nominal forces, across sessions. Post-therapy motor and simulator tests, as well as follow-up fMRI scanning, will be conducted. Motor recovery and neuroimaging of brain regions mediating motor performance will provide evidence of the effectiveness of the simulation design and rehabilitation efficacy. The PIs' hypothesize that experience with a haptic simulation design based on motor skill training demands and human performance metrics will accelerate skill development relative to a fidelity-centered approach to design. They also expect that haptic-simulator experience will improve fine motor control and motor planning (praxis), that experience on the drawing-simulation device will generalize to improved performance on the surgical-simulation device, and that brain blood flow will increase in regions mediating motor control.Broader Impacts: This work will make contributions to the design of computer graphics and haptic rendering, in terms of better understanding of optimal computational modeling for VR haptic simulation. It will also advance the state of the art in computer-based therapeutic approaches to motor skill development with haptic simulation, and enhance our understanding of brain-behavior relationships governing motor output and the nature of neural recovery following motor rehabilitation. Improvements in existing VR-based rehabilitation strategies for motor and praxis impairment in individuals suffering from TBI will be identified; rehabilitation treatment regimens will be identified that may have implications for various populations suffering from brain injuries (e.g., stroke patients).