School of Biomedical Engineering, Science and Health Systems, Drexel University.
Bioengineering Department, Temple University;
J Vis Exp. 2024 Jan 12(203). doi: 10.3791/65924.
Peripheral nerves undergo physiological and non-physiological stretch during development, normal joint movement, injury, and more recently while undergoing surgical repair. Understanding the biomechanical response of peripheral nerves to stretch is critical to the understanding of their response to different loading conditions and thus, to optimizing treatment strategies and surgical interventions. This protocol describes in detail the calibration process of the stereo-imaging camera system via direct linear transformation and the tracking of the three-dimensional in-situ tissue displacement of peripheral nerves during stretch, obtained from three-dimensional coordinates of the video files captured by the calibrated stereo-imaging camera system. From the obtained three-dimensional coordinates, the nerve length, change in the nerve length, and percent strain with respect to time can be calculated for a stretched peripheral nerve. Using a stereo-imaging camera system provides a non-invasive method for capturing three-dimensional displacements of peripheral nerves when stretched. Direct linear transformation enables three-dimensional reconstructions of peripheral nerve length during stretch to measure strain. Currently, no methodology exists to study the in-situ strain of stretched peripheral nerves using a stereo-imaging camera system calibrated via direct linear transformation. Capturing the in-situ strain of peripheral nerves when stretched can not only aid clinicians in understanding underlying injury mechanisms of nerve damage when overstretched but also help optimize treatment strategies that rely on stretch-induced interventions. The methodology described in the paper has the potential to enhance our understanding of peripheral nerve biomechanics in response to stretch to improve patient outcomes in the field of nerve injury management and rehabilitation.
外周神经在发育、正常关节运动、损伤以及最近的手术修复过程中会经历生理和非生理的拉伸。了解外周神经对拉伸的生物力学反应对于理解它们对外界不同加载条件的反应至关重要，从而优化治疗策略和手术干预。本方案详细描述了通过直接线性变换对立体成像相机系统进行校准的过程，以及在拉伸过程中跟踪外周神经的三维原位组织位移，该位移是通过校准的立体成像相机系统捕获的视频文件的三维坐标获得的。从获得的三维坐标中，可以计算出拉伸的外周神经的神经长度、神经长度的变化以及相对于时间的应变百分比。使用立体成像相机系统为捕获拉伸时的外周神经三维位移提供了一种非侵入性的方法。直接线性变换可以实现拉伸过程中周围神经长度的三维重建，以测量应变。目前，尚无使用通过直接线性变换校准的立体成像相机系统来研究拉伸的周围神经原位应变的方法。捕获拉伸时的周围神经原位应变不仅可以帮助临床医生了解神经过度拉伸时的潜在损伤机制，还可以帮助优化依赖于拉伸诱导干预的治疗策略。本文所述的方法有可能提高我们对外周神经对拉伸的生物力学反应的理解，从而改善神经损伤管理和康复领域的患者预后。
