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

PI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，以重新训练受损的运动功能，并培训患有创伤性脑损伤(TBI)的退伍军人(医务人员)的新的精细运动技能。以前的触觉模拟设计方法通常侧重于相对于现实的呈现的完整性。然而，模拟器可能用于许多不同的任务，因此完备性可能不能确保其有用性。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，在触觉模拟设计中考虑关键应用，如运动技能训练，将从人类表现的角度促进有效的设计。因此，他们提出了一种面向认知的触觉模拟设计和评估方法。在这个项目中，PI将通过设计和制作用于绘图和手术任务的先进VR触觉模拟器的原型来测试他们的想法。模拟将根据用于虚拟对象建模的(医疗)数据源的类型和分辨率、用于运动技能和脑功能评估的视觉和力呈现的类型以及模拟的图形和触觉渲染的方法来定义。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，包括虚拟触觉辅助工具(例如，力的边界和潜力)和康复试验中的力分级。最后，他们将使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业神经心理学家和外科医生就精神运动任务表现和外科手术进行，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，开发具有有效人机接口的基于触觉的运动技能培训工作站，以及使用基于GPU的图形和平滑粒子流体动力学(SPH)模型优化视觉和触觉表示，以减少力反馈的触觉对象渲染中的CPU开销。模拟设计还将反映基线运动性能以及VR绘图和手术模拟器练习的结果。这项测试之后，将对运动任务中的受试者进行功能磁共振成像，以检查参与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设备，并在不同的过程中逐渐减少相对于标称力的力反馈。治疗后将进行运动和模拟器测试，以及后续的功能磁共振扫描。运动恢复和脑区神经成像介导的运动表现将为模拟设计的有效性和康复效果提供证据。PI的假设是，与以保真度为中心的设计方法相比，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。他们还期待触觉模拟器的经验将改善精细的运动控制和运动规划(Prxis)，在绘图模拟设备上的经验将推广到手术模拟设备上的性能改善，以及参与运动控制的区域的脑血流将增加。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，从更好地理解VR触觉模拟的最佳计算建模方面。它还将促进基于计算机的治疗方法的最先进水平，通过触觉模拟发展运动技能，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的本质的理解。将确定改善现有基于VR的康复策略，以治疗脑外伤患者的运动和实践障碍；将确定可能对各种脑损伤患者(例如，中风患者)产生影响的康复治疗方案。

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).