EAGER: COLLABORATIVE RESEARCH: A New Integrated Quantitative Metrics Approach for Identifying Coordinated Gaits in Swimming Animals

动物游泳表现的定量评估对于了解水生物种在其环境中竞争和承受变化的能力至关重要。彻底了解游泳性能需要量化推进器的运动和由此产生的流体流动。对于使用推进器的无数水生动物来说，同时量化由各种推进器产生的流体流动的能力受到当前仅在两个维度上测量流量的方法学方法的限制。在这个项目中，研究人员提出了一种新的3D方法来研究游泳动物。他们将重点研究鱿鱼（射流和鳍）的两个独立但协调的推进系统，具体如下：(1)收集乌贼游动时（鳍和鳍同时）产生的完整流体流动（尾迹）的三维数据和游动运动的三维运动学数据；(2)应用新的数学工具，根据物理特征定量区分流体动力模式和运动学模式（即步态）；(3)评估与步骤2中确定的步态相关的推进性能（即推力和效率）。这种定量方法将阐明驱动动力和支持推进器的肌肉骨骼系统的结构、力学和动力学的选择压力。这项研究为任何游泳者或飞行者的步态识别提供了一个通用的框架，特别是那些使用多个推进器的人，因此可能会改变目前研究运动的方法。在生物学领域之外，这种定量的3D方法可以为生物动力推进系统的工程师提供一个有价值的框架，他们可能会在紧凑的设计中寻求类似于大自然提供的改进的推进性能。最后，该项目的跨学科合作性质将使具有不同生理学、生物力学和工程学背景的本科生和研究生能够互动并获得尖端技术的培训。

Quantitative assessment of animal swimming performance is essential to gaining an understanding the ability of aquatic species to compete in and withstand changes in their environment. A thorough understanding of swimming performance requires quantifying both the motion of the propulsors and the resulting fluid flow. For the myriad aquatic animals that use them, the ability to quantify simultaneously fluid flows produced by their various propulsors is constrained by the current methodological approaches that measure flow in only two dimensions. In this project, the investigators propose a novel 3D approach for studying swimming animals. They will focus on the two separate, but coordinated, propulsive systems of squid (jets and fins) as follows: (1) collect 3D data of the complete fluid flow (wake) generated by swimming squid (both fin and jet wakes simultaneously) and 3D kinematic data of the swimming motion; (2) apply new mathematical tools to quantitatively distinguish between hydrodynamic and kinematic patterns (i.e., gaits) based on their physical features; and (3) evaluate the propulsive performance (i.e., thrust and efficiency) associated with gaits identified in step 2. This quantitative approach will illuminate the selective pressures driving the structure, mechanics, and dynamics of the musculoskeletal system that powers and supports the propulsors. This research holds great promise for developing a universal framework for gait identification in any swimmer or flyer, especially those employing multiple propulsors, and thus may potentially transform current methods for studying locomotion. Beyond the field of biology, this quantitative, 3D approach could provide a valuable framework for engineers of bioinspired propulsion systems, who may be seeking improved propulsive performance in compact designs similar to what nature offers. Finally, the collaborative interdisciplinary nature of this project will allow undergraduate and graduate students with diverse backgrounds in physiology, biomechanics, and engineering to interact and acquire training in cutting edge technologies.