IDBR: Hardware and Software Development for 3D Visualization of Rapid Skeletal Motion in Vertebrate Animals

该奖项是对脊椎动物快速骨骼运动三维可视化仪器的开发。它的两个主要组成部分是(1)高速双平面X射线透视系统和(2)通过将3D CT骨骼模型与2D X射线图像对齐来实现精确的3D骨骼动画的自动化软件。这一结果将比目前可用于脊椎动物功能形态和生物力学研究的技术有实质性的进步。其目标是使动态3D骨骼成像成为一种负担得起的广泛可用的技术。这种高速、双面X射线和3D可视化软件的新组合被命名为“CTX成像”。脊椎动物功能形态是生物生物学的一个活跃和发展的分支领域，研究解剖形态和生物力学功能之间的力学和进化关系。例如，长腱在袋鼠跳跃中作为弹簧的作用，嘴的大小和形状对鱼类吸食的影响，以及在鸟类飞行中的功能，都是在过去20年里被功能形态学家解释的。功能形态学的新发现一直是由新技术的引入推动的，如高速相机、肌电图像仪、测力板和数字粒子图像测速仪。动物的自然运动几乎总是以3D方式发生，而且通常非常快。在3D中量化骨骼的快速运动将是将形态与功能联系起来的一项强大的技术，但功能形态学家还没有在3D中测量骨骼运动的技术。蒙皮上外部标记的移动通常用作骨骼运动的代理，但蒙皮通常是松散的，标记不能很好地跟踪骨骼。对一次CT扫描和两次X光电影进行CTX分析，将产生骨骼元素在太空中移动的高精度3D动画。这些将不仅仅是棒状图形--每根骨骼的完整3D形态将呈现出来，并通过这种技术精确地进行动画制作。双平面X射线成像和CTX分析将使研究骨骼运动学的一些方面成为可能，而这些方面是其他技术基本上无法获得的，例如骨骼的长轴旋转，小动物细小骨骼的假定弯曲，以及关节关节表面的相对3D运动。CTX将为肌肉骨骼模型的输入提供更准确的数据，如逆动力学和神经控制模型的关节角度。这是一项跨学科的建议，结合了两位在动物运动的动态X射线成像方面拥有丰富经验的功能形态学家(Braind和Gatesy)和一位专门构建加速科学的计算工具的计算机科学家(Laidlaw)的专业知识，其中特别强调科学可视化工具。脊椎动物快速骨骼运动的三维可视化将有可能与该奖项下开发的仪器一起开发。该仪器使CTX成像成为可能，将为脊椎动物功能形态的研究开辟新的领域，如三维关节生物力学的比较研究。与CTX一起开发的动画将是强大的科学工具，但它们也将是可访问和吸引普通公众的。只要有可能，这些动画将被用来增加对基础研究的欣赏。

This award is for the development of instrumentation for 3D visualization of rapid skeletal motion in vertebrates. Its two primary components are (1) a high-speed, biplane X-ray fluoroscopy system and (2) automated software for precise, 3D skeletal animation by aligning 3D CT bone models with pairs of 2D X-ray images. The result will be a substantial advance over technology that is currently available for research in vertebrate functional morphology and biomechanics. The objective is to make dynamic 3D skeletal imaging an affordable and widely available technique. The new combination of high-speed, biplane X-ray and 3D visualization software is named "CTX imaging." Vertebrate functional morphology is an active and growing subfield of organismal biology in which the mechanical and evolutionary relationships between anatomical form and biomechanical function are investigated. For example, the action of long tendons as springs in kangaroo hopping, the effect of mouth size and shape on suction feeding in fish, and the function of the "wishbone" in bird flight have all been explained in the past two decades by functional morphologists. New discoveries in functional morphology have consistently been driven by the introduction of new technologies, such as high-speed cameras, electromyography, force plates and digital particle image velocimetry. Natural movements in animals almost always occur in 3D and often are very fast. Quantification of rapid skeletal movement in 3D would be a powerful technique for relating form to function, but functional morphologists have had no technique for measuring bone movements in 3D. The movement of external markers on the skin is generally used as a proxy for skeletal movement, but skin is often loose and the markers do not track the skeleton well. CTX analysis of a CT scan plus two X-ray movies will produce a highly accurate 3D animation of skeletal elements moving in space. These will be more than stick figures -- the complete 3D morphology of each bone will be present and animated precisely with this technique. Biplane X-ray imaging and CTX analysis will make it possible to study aspects of skeletal kinematics that are largely inaccessible with other techniques, such as long axis rotation of bones, putative bending of fine bones in small animals, and the relative 3D motions of the articular surfaces of joints. CTX will provide more accurate data for input into musculoskeletal models, such as joint angles for inverse dynamics and neural control models. This is an interdisciplinary proposal combining the expertise of two functional morphologists (Brainerd and Gatesy) who have extensive experience with dynamic X-ray imaging of animal movement and a computer scientist (Laidlaw) who specializes in building computational tools for accelerating science, with particular emphasis on scientific visualization tools.Three-dimensional visualization of rapid skeletal motion in vertebrates will be possible with instrumentation to be developed under this award. CTX imaging, made possible with this instrumentation, will open up new areas of research in vertebrate functional morphology, such as the comparative study of 3D joint biomechanics. The animations developed with CTX will be powerful scientific tools, but they will also be accessible and appealing to the general public. These animations will be used to increase appreciation for basic research whenever possible.