这项研究得到了美国国立卫生研究院 Eunice Kennedy Shriver 国家儿童健康与人类发展研究所的资助，奖号为 R15HD093024 和 R01HD104910A 以及 NSF CAREER 奖1752513号。

使用 DLT 校准立体成像对周围神经进行生物力学分析

<ol>
	<li>Bueno, F. R., Shah, S. B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Implications+of+tensile+loading+for+the+tissue+engineering+of+nerves.">Implications of tensile loading for the tissue engineering of nerves.</a> Tissue Engineering Part B: Reviews. 14 (3), 219-233 (2008).</li><li>Grewal, R., Xu, J., Sotereanos, D. G., Woo, S. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+properties+of+peripheral+nerves.">Biomechanical properties of peripheral nerves.</a> Hand Clinics. 12 (2), 195-204 (1996).</li><li>Papagiannis, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+behavior+and+viscoelastic+properties+of+peripheral+nerves+subjected+to+tensile+stress:+common+injuries+and+current+repair+techniques.">Biomechanical behavior and viscoelastic properties of peripheral nerves subjected to tensile stress: common injuries and current repair techniques.</a> Critical Reviews in Physical and Rehabilitation Medicine. 32 (3), 155-168 (2020).</li><li>Castaldo, J., Ochoa, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+injury+of+peripheral+nerves.+Fine+structure+and+dysfunction.">Mechanical injury of peripheral nerves. Fine structure and dysfunction.</a> Clinics in Plastic Surgery. 11 (1), 9-16 (1984).</li><li>Singh, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Extent+of+impaired+axoplasmic+transport+and+neurofilament+compaction+in+traumatically+injured+axon+at+various+strains+and+strain+rates.">Extent of impaired axoplasmic transport and neurofilament compaction in traumatically injured axon at various strains and strain rates.</a> Brain Injury. 31 (10), 1387-1395 (2017).</li><li>Singh, A., Kallakuri, S., Chen, C., Cavanaugh, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+functional+changes+in+nerve+roots+due+to+tension+at+various+strains+and+strain+rates:+an+in-vivo+study.">Structural and functional changes in nerve roots due to tension at various strains and strain rates: an in-vivo study.</a> Journal of Neurotrauma. 26 (4), 627-640 (2009).</li><li>Singh, A., Lu, Y., Chen, C., Kallakuri, S., Cavanaugh, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+model+of+traumatic+axonal+injury+to+determine+the+effects+of+strain+and+displacement+rates.">A new model of traumatic axonal injury to determine the effects of strain and displacement rates.</a> Stapp Car Crash Journal. 50, 601 (2006).</li><li>Singh, A., Lu, Y., Chen, C., Cavanaugh, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+properties+of+spinal+nerve+roots+subjected+to+tension+at+different+strain+rates.">Mechanical properties of spinal nerve roots subjected to tension at different strain rates.</a> Journal of Biomechanics. 39 (9), 1669-1676 (2006).</li><li>Singh, A., Shaji, S., Delivoria-Papadopoulos, M., Balasubramanian, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Biomechanical+responses+of+neonatal+brachial+plexus+to+mechanical+stretch.">Biomechanical responses of neonatal brachial plexus to mechanical stretch.</a> Journal of Brachial Plexus and Peripheral Nerve Injury. 13 (01), e8-e14 (2018).</li><li>Zapa&#322;owicz, K., Radek, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+properties+of+the+human+brachial+plexus.">Mechanical properties of the human brachial plexus.</a> Neurologia I Neurochirurgia Polska. 34, 89-93 (2000).</li><li>Zapa&#322;owicz, K., Radek, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Annales Academiae Medicae Stetinensis. 51 (2), 11-14 (2005).</li><li>Zapa&#322;owicz, K., Radek, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+distribution+of+brachial+plexus+lesions+after+experimental+traction:+a+cadaveric+study.">The distribution of brachial plexus lesions after experimental traction: a cadaveric study.</a> Journal of Neurosurgery: Spine. 29 (6), 704-710 (2018).</li><li>Kawai, H., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stretching+of+the+brachial+plexus+in+rabbits.">Stretching of the brachial plexus in rabbits.</a> Acta Orthopaedica Scandinavica. 60 (6), 635-638 (1989).</li><li>Marani, E., Van Leeuwen, J., Spoor, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+tensile+testing+machine+applied+in+the+study+of+human+nerve+rupture:+a+preliminary+study.">The tensile testing machine applied in the study of human nerve rupture: a preliminary study.</a> Clinical Neurology and Neurosurgery. 95, 33-35 (1993).</li><li>Lee, S. K., Wolfe, S. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Peripheral+nerve+injury+and+repair.">Peripheral nerve injury and repair.</a> JAAOS-Journal of the American Academy of Orthopaedic Surgeons. 8 (4), 243-252 (2000).</li><li>Rickett, T., Connell, S., Bastijanic, J., Hegde, S., Shi, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Functional+and+mechanical+evaluation+of+nerve+stretch+injury.">Functional and mechanical evaluation of nerve stretch injury.</a> Journal of Medical Systems. 35, 787-793 (2011).</li><li>Topp, K. S., Boyd, B. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+and+biomechanics+of+peripheral+nerves:+nerve+responses+to+physical+stresses+and+implications+for+physical+therapist+practice.">Structure and biomechanics of peripheral nerves: nerve responses to physical stresses and implications for physical therapist practice.</a> Physical Therapy. 86 (1), 92-109 (2006).</li><li>Lu, Y., Chen, C., Kallakuri, S., Patwardhan, A., Cavanaugh, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+an+in+vivo+method+to+investigate+biomechanical+and+neurophysiological+properties+of+spine+facet+joint+capsules.">Development of an in vivo method to investigate biomechanical and neurophysiological properties of spine facet joint capsules.</a> European Spine Journal. 14 (6), 565-572 (2005).</li><li>Kallakuri, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tensile+stretching+of+cervical+facet+joint+capsule+and+related+axonal+changes.">Tensile stretching of cervical facet joint capsule and related axonal changes.</a> European Spine Journal. 17 (4), 556-563 (2008).</li><li>Abdel-Aziz, Y. I., Karara, H. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Direct+linear+transformation+from+comparator+coordinates+into+object+space+coordinates+in+close-range+photogrammetry.">Direct linear transformation from comparator coordinates into object space coordinates in close-range photogrammetry.</a> Photogrammetric Engineering &amp; Remote Sensing. 81 (2), 103-107 (2015).</li><li>Pourcelot, P., Audigi&#233;, F., Degueurce, C., Geiger, D., Denoix, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+method+to+synchronise+cameras+using+the+direct+linear+transformation+technique.">A method to synchronise cameras using the direct linear transformation technique.</a> Journal of Biomechanics. 33 (12), 1751-1754 (2000).</li><li>Hedrick, T. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Software+techniques+for+two-+and+three-dimensional+kinematic+measurements+of+biological+and+biomimetic+systems.">Software techniques for two- and three-dimensional kinematic measurements of biological and biomimetic systems.</a> Bioinspiration &amp; Biomimetics. 3 (3), 034001 (2008).</li><li>Chen, L., Armstrong, C. W., Raftopoulos, D. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+investigation+on+the+accuracy+of+three-dimensional+space+reconstruction+using+the+direct+linear+transformation+technique.">An investigation on the accuracy of three-dimensional space reconstruction using the direct linear transformation technique.</a> Journal of Biomechanics. 27 (4), 493-500 (1994).</li><li>Singh, A., Magee, R., Balasubramanian, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+for+in+vivo+biomechanical+testing+on+brachial+plexus+in+neonatal+piglets.">Methods for in vivo biomechanical testing on brachial plexus in neonatal piglets.</a> Journal of Visualized Experiments. (154), e59860 (2019).</li><li>Black, J., Ellis, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multi+camera+image+tracking.">Multi camera image tracking.</a> Image and Vision Computing. 24 (11), 1256-1267 (2006).</li><li>Cardenas-Garcia, J. F., Yao, H. G., Zheng, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=3D+reconstruction+of+objects+using+stereo+imaging.">3D reconstruction of objects using stereo imaging.</a> Optics and Lasers in Engineering. 22 (3), 193-213 (1995).</li><li>Mahan, M. A., Yeoh, S., Monson, K., Light, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+stretch+injury+to+peripheral+nerves:+biomechanical+results.">Rapid stretch injury to peripheral nerves: biomechanical results.</a> Neurosurgery. 85 (1), E137-E144 (2019).</li><li>Rydevik, B. L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+in+vitro+mechanical+and+histological+study+of+acute+stretching+on+rabbit+tibial+nerve.">An in vitro mechanical and histological study of acute stretching on rabbit tibial nerve.</a> Journal of Orthopaedic Research. 8 (5), 694-701 (1990).</li><li>Mahan, M. A., Warner, W. S., Yeoh, S., Light, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid-stretch+injury+to+peripheral+nerves:+implications+from+an+animal+model.">Rapid-stretch injury to peripheral nerves: implications from an animal model.</a> Journal of Neurosurgery. 133 (5), 1537-1547 (2019).</li><li>Singh, A., Ferry, D., Balasubramanian, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Efficacy+of+clinical+simulation+based+training+in+biomedical+engineering+education.">Efficacy of clinical simulation based training in biomedical engineering education.</a> Journal of Biomechanical Engineering. 141 (12), 121011-121017 (2019).</li></ol>

作者没有需要披露的利益冲突。

报告因牵拉损伤而导致周围神经 （PN） 生物力学特性的研究各不相同，这种变化可归因于测试方法，例如测试设备和伸长率分析 5,6,7,8,9,10,11,12,13,14,16,24 <sup class...

周围神经 （PN） 在发育、生长、正常关节运动、损伤和手术1 过程中经历拉伸。PN 表现出粘弹性，可在正常运动期间保护神经 2,3 并维持其神经纤维的结构健康2。因为 PN 对机械拉伸的反应已被证明取决于神经纤维损伤的类型4、对相邻结缔组织的损伤 2,4 和测试方法（即负荷速率或方向）5,6,7,8,9,10,11,12,13,14，必须区分 PNs 在正常运动范围内和非生理范围内在慢拉伸和快速拉伸速率下的生物力学反应。这可以进一步理解响应拉伸的 PN 损伤机制，并有助于及时和优化干预 1,4,15,16。物理治疗越来越倾向于根据神经生理学和生物力学之间的关系来评估和干预17。通过了解各种施加负载下 PN 生物力学的差异，物理治疗师可以更好地准备修改当前的干预措施17。
响应拉伸的 PN 的可用生物力学数据仍然可变，可归因于测试设备和程序以及伸长数据分析的差异 5,6,7,8,9,10,11,12,13,14,16。此外，在目前可用的文献中，测量三维 （3D） 原位神经位移仍然描述不佳。以前的研究使用立体成像技术来最大限度地提高小关节囊组织移位的 3D 重建的准确性18,19。直接线性变换 （DLT） 技术能够将两个或多个二维 （2D） 视图转换为 3D 真实世界坐标（即以毫米为单位）20,21,22。DLT 为立体成像相机系统提供了一种高精度校准方法，因为它能够精确重建 3D 位置，考虑镜头畸变、相机参数和图像坐标，并允许立体成像相机设置的灵活性 20,21,22。使用 DLT 校准的立体成像摄像系统的研究通常用于研究运动和步态分析22,23。该协议旨在提供一种详细的方法，以使用 DLT 校准的立体成像相机系统和开源跟踪软件22 来确定不同拉伸程度的 PN 的原位应变。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Clear Acrylic Plexiglass Square Sheet</td>
			<td>W W Grainger Inc</td>
			<td>BULKPSACR9</td>
			<td>Construct three-dimensional control volume</td>
		</tr>
		<tr>
			<td>Stereo-imaging camera system - ZED Mini Stereo Camera</td>
			<td>StereoLabs Inc.</td>
			<td>N/A</td>
			<td>N/A</td>
		</tr>
		<tr>
			<td>Imaging Software - ZED SDK</td>
			<td>StereoLabs Inc.</td>
			<td>N/A</td>
			<td>N/A</td>
		</tr>
		<tr>
			<td>Maintence Software - CUDA 12</td>
			<td>StereoLabs Inc.</td>
			<td>N/A</td>
			<td>Download to run ZED SDK&#160;</td>
		</tr>
		<tr>
			<td>Camera stand - Cast Iron Triangular Support Stand with Rod</td>
			<td>Telrose VWR Choice</td>
			<td>76293-346</td>
			<td>N/A</td>
		</tr>
		<tr>
			<td>MicroSribe G2 Digitizer with Immersion Foot Pedal</td>
			<td>SUMMIT Technology Group</td>
			<td>N/A</td>
			<td>N/A</td>
		</tr>
		<tr>
			<td>Proramming Software - MATLAB&#160;</td>
			<td>Mathworks</td>
			<td>N/A</td>
			<td>version 2019A or newer</td>
		</tr>
		<tr>
			<td>DLTcal5.m</td>
			<td>Hedrick lab</td>
			<td>N/A</td>
			<td>Open Source</td>
		</tr>
		<tr>
			<td>DLTdv7.m</td>
			<td>Hedrick lab</td>
			<td>N/A</td>
			<td>Open Source</td>
		</tr>
	</tbody>
</table>

direct linear transformation for the measurement of in-situ peripheral nerve strain during stretching

周围神经在发育、正常关节运动、损伤以及最近接受手术修复时经历生理和非生理拉伸。了解周围神经对拉伸的生物力学反应对于了解它们对不同负荷条件的反应至关重要，因此，对于优化治疗策略和手术干预至关重要。该协议详细描述了立体成像相机系统的校准过程，通过直接线性变换和跟踪拉伸过程中周围神经的三维 原位 组织位移，从校准的立体成像相机系统捕获的视频文件的三维坐标中获得。
根据获得的三维坐标，可以计算出拉伸的周围神经的神经长度、神经长度的变化和随时间的变化百分比应变。使用立体成像摄像头系统提供了一种非侵入性方法，用于捕获拉伸时周围神经的三维位移。直接线性变换可以在拉伸过程中对周围神经长度进行三维重建，以测量应变。目前，还没有使用通过直接线性变换校准的立体成像相机系统研究拉伸周围神经的 原位 应变的方法。捕获拉伸时周围神经的 原位 应变不仅可以帮助临床医生了解过度拉伸时神经损伤的潜在损伤机制，还有助于优化依赖于拉伸诱导干预的治疗策略。论文中描述的方法有可能增强我们对响应拉伸的周围神经生物力学的理解，从而改善神经损伤管理和康复领域的患者预后。

Peripheral nerves (PNs) undergo stretch during development, growth, normal joint movement, injury, and surgery1. PNs display viscoelastic properties to protect the nerve during regular movements2,3 and maintain the structural health of its nerve fibers2. Because PN response to mechanical stretch has been shown to depend on the type of nerve fiber damage4, injuries to adjacent connective tissues2,4, and testing approaches (i.e., loading rate or direction)5,6,7,8,9,10,11,12,13,14, it is essential to distinguish the biomechanical responses of PNs during normal range of motion versus non-physiological range at both slow- and rapid-stretch rates. This can further the understanding of the PN injury mechanism in response to stretch and aid in timely and optimized intervention1,4,15,16. There has been a growing trend in physical therapy to evaluate and intervene based on the relationship between nerve physiology and biomechanics17. By understanding the differences in PN biomechanics at various applied loads, physical therapists can be better prepared to modify current interventions17.
Available biomechanical data of PNs in response to stretch remains variable and can be attributed to testing equipment and procedures and differences in elongation data analysis5,6,7,8,9,10,11,12,13,14,16. Furthermore, measuring three-dimensional (3D) in-situ nerve displacement remains poorly described in the currently available literature. Previous studies have used stereo-imaging techniques to maximize the accuracy of 3D reconstruction of tissue displacement of facet joint capsules18,19. The direct linear transformation (DLT) technique enables the conversion of two or more two-dimensional (2D) views to 3D real-world coordinates (i.e., in mm)20,21,22. DLT provides a high-accuracy calibration method for stereo-imaging camera systems because it enables precise reconstruction of 3D positions, accounting for lens distortion, camera parameters, and image coordinates, and permits flexibility in stereo-imaging camera setup20,21,22. Studies using DLT-calibrated stereo-imaging camera systems are typically used to study locomotion and gait analysis22,23. This protocol aims to offer a detailed methodology to determine the in-situ strain of PNs at varying degrees of stretch using a DLT-calibrated stereo-imaging camera system and an open-source tracking software22.

立体成像系统 DLT 校准，用于捕获拉伸周围神经的 3D 原位位移

直接线性变换，用于拉伸过程中原 位 周围神经应变的测量

使用所描述的方法，可以获得各种输出文件。DLTdv7.m *_xyzpts.csv（补充文件 12）包含每个时间范围内每个跟踪点的 （x， y， z） 坐标（以毫米为单位），进一步用于计算拉伸 PN 的长度、长度变化和应变。拉伸 PN 的代表性长度-时间、长度-时间变化和应变-时间图如图 10 所示。拉伸的 PN 有一个插入标记、沿其长度的四个标记和一个由六段组成的夹标记。通过量化拉...

Read this Scientific Article Protocol about Direct Linear Transformation for the Measurement of In-Situ Peripheral Nerve Strain During Stretching at JoVE.com

该协议实现了一个立体成像相机系统，该系统使用直接线性变换进行校准，以捕获拉伸周围神经的三维 原位 位移。通过捕获这些位移，可以确定在不同程度的拉伸下诱导的应变，从而通知拉伸损伤阈值，从而推进拉伸依赖性神经修复的科学。

Peripheral nerves undergo physiological and non-physiological stretch during development, normal joint movement, injury, and more recently while ...

首先，获取三张透明的亚克力有机玻璃方片。在每张图纸上，创建一个网格并标记至少 10 个点，确保在 x、y 和 z 坐标平面上跨 3D 控制体积至少有 30 个点。将纸张堆叠在不同的高度，以捕获预期录制的最大高度。使用配备脚踏板的数字化器，数字化 3D 控制体积上的所有点。建立 3D 控制立方体的原点并定义正 x 和 y 方向以获得 x、y 和 z 坐标。在数字化器软件界面上，分别设置参考系上的原点和正 x 轴和 y 轴。打开一个新的 Excel 工作表以保存控制卷的 x、y 和 z 坐标。然后在数字化器软件界面上，将格式字符串设置为 Excel，以将坐标存储在 3D 控制卷上。当使用数字化仪和脚踏板对 x、y 和 z 坐标进行数字化时，它们将被记录到打开的 Excel 工作表上。要记录它们，请打开 Excel 工作表并将坐标另存为 csv 文件。

direct-linear-transformation-for-measurement-situ-peripheral-nerve

Research

JoVE Journal

Bioengineering

Direct Linear Transformation for the Measurement of In-Situ Peripheral Nerve Strain During Stretching

272 次观看.  Drexel University. 首先，获取三张透明的亚克力有机玻璃方片。在每张图纸上，创建一个网格并标记至少 10 个点，确保在 x、y 和 z 坐标平面上跨 3D 控制体积至少有 30 个点。将纸张堆叠在不同的高度，以捕获预期录制的最大高度。使用配备脚踏板的数字化器，数字化 3D 控制体积上的所有点。建立 3D 控制立方体的原点并定义正 x 和 y 方向以获得 x、y 和 z 坐标。在数字化器软件界面上，分...

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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.

This protocol implements a stereo-imaging camera system calibrated using direct linear transformation to capture three-dimensional in-situ displacements of stretched peripheral nerves. By capturing these displacements, strain induced at varying degrees of stretch can be determined informing the stretch injury thresholds that can advance the science of stretch-dependent nerve repair.