頸護具被廣泛應用於醫療及運動中，過去市售頸護具大多以成人的平均尺寸進行設計，此種單一尺寸的護具往往無法符合於所有人的頸部體表幾何。3D列印客製化頸護具可解決頸護具尺寸不符合使用者身形的問題，雖然市售上有許多建模軟體可設計頸護具數位模型，但設計者需從無到有設計頸護具數位模型，除了設計過程繁瑣之外，也易因人為因素使設計頸護具的外形上有所偏差，造成頸護具的支撐效果有限。
本研究開發一套電腦輔助軟體，根據復健科及骨科醫學專家知識建立頸護具設計標準，並將設計準則整合至軟體中，以半自動化方法建立框架式頸護具數位模型，提供一致的頸護具設計標準作業流程，並以力學分析軟體模擬頸護具的受力情況，找出符合安全性的頸護具厚度參數。本研究招募15名受試者，以人體試驗驗證客製化與市售頸護具的功效，固定性實驗結果顯示客製化頸護具的固定性較優，舒適度實驗顯示客製化頸護具與市售頸護具沒有顯著差異，但壓力感測實驗結果顯示客製化頸護具在左右顳骨乳突處有較大的壓力，故本研究針對實驗結果於軟體中調整頸護具設計方法，可以快速因應使用者需求作調整，兼顧客製化與設計彈性。

Cervical orthosis is widely used in medical and sports. In the past, most of the commercially available cervical orthoses were designed to suit average-sized adults. Such single-size orthoses are often not suitable for everyone's neck. 3D-printed customized cervical orthosis can solve the problem where the size of the cervical orthosis does not fit the patient's neck shape. Although there are many commercial modeling software that can design cervical orthosis, the designer has to design the model from scratch. In addition to the cumbersome design process, it is also prone to deviations on the shape of the designed cervical orthosis due to human factors, resulting in a limited supporting effect.
This study developed a computer-aided software to establish the design standards for cervical orthosis based on the knowledge of rehabilitation and orthopedic medicine expertise. The software integrates the design criteria of a cervical orthosis to a semi-automated method to generate a digital model of the cervical orthosis, thus provides a consistent standard operating procedure for cervical orthosis design. The strength of the cervical orthosis was analyzed on a mechanical analysis software to find its minimum thickness in order to meet the safety requirements. In this study, 15 subjects were recruited to verify the efficacy of customized and commercial cervical orthoses. The results from the fixation experiment showed that the customized cervical orthosis provides better immobility. The comfort test showed that there is no significant difference between the customized cervical orthosis and the commercial cervical orthosis. However, the pressure measurement experiment results showed that the customized cervical orthosis exerts greater pressure at the left and right mastoid processes. This study adjusted the design method of the cervical orthosis in the software according to the experimental results to meet the user’s requirements while combining customization and design flexibility.

[1] Tyson, S., Sadeghi-Demneh, E., and Nester, C., "A systematic review and meta-analysis of the effect of an ankle-foot orthosis on gait biomechanics after stroke," Clinical Rehabilitation, Vol.27, No.10, pp.879-891, 2013.
[2] Kuo, Y. R., Fang, J. J., Wu, C. T., Lin, R. M., Su, P. F., and Lin, C. L., "Analysis of a customized cervical collar to improve neck posture during smartphone usage: a comparative study in healthy subjects," European Spine Journal, Vol.28, No.8, pp.1793-1803, 2019.
[3] Schouten, H., Nieuwenhuis, M., and Van Zuijlen, P., "A review on static splinting therapy to prevent burn scar contracture: do clinical and experimental data warrant its clinical application?," Burns, Vol.38, No.1, pp.19-25, 2012.
[4] Schneider, J. C., Holavanahalli, R., Helm, P., Goldstein, R., and Kowalske, K., "Contractures in burn injury: defining the problem," Journal of burn care & research, Vol.27, No.4, pp.508-514, 2006.
[5] Oosterwijk, A. M., Mouton, L. J., Schouten, H., Disseldorp, L. M., van der Schans, C. P., and Nieuwenhuis, M. K., "Prevalence of scar contractures after burn: a systematic review," Burns, Vol.43, No.1, pp.41-49, 2017.
[6] Visscher, D. O., te Slaa, S., Jaspers, M. E., van de Hulsbeek, M., Borst, J., Wolff, J., Forouzanfar, T., and van Zuijlen, P. P., "3D printing of patient-specific neck splints for the treatment of post-burn neck contractures," Burns & trauma, Vol.6, No.1, 2018.
[7] Le Vay, D., The history of orthopaedics: An account of the study and practice of orthopaedics from the earliest times to the modern era, Parthenon Publishing, 1990.
[8] Robotti, E., "The treatment of burns: an historical perspective with emphasis on the hand," Hand clinics, Vol.6, No.2, pp.163-190, 1990.
[9] Jones, W. H. S., Potter, P., Withington, E. T., and Smith, W. D., Hippocrates, Harvard University Press, 1923.
[10] Fess, E. E., "A history of splinting: to understand the present, view the past," Journal of Hand Therapy, Vol.15, No.2, pp.97-132, 2002.
[11] Wu, K. K., Techniques in surgical casting and splinting, in Techniques in Surgical Casting and Splinting. 1987. p. 269-269.
[12] Colditz, J. C., "Plaster of Paris: the forgotten hand splinting material," Journal of Hand Therapy, Vol.15, No.2, pp.144-157, 2002.
[13] Davids, J. R., Frick, S. L., Skewes, E., and Blackhurst, D. W., "Skin surface pressure beneath an above-the-knee cast: plaster casts compared with fiberglass casts," JBJS, Vol.79, No.4, pp.565-569, 1997.
[14] Buonamici, F., Furferi, R., Governi, L., Lazzeri, S., McGreevy, K. S., Servi, M., Talanti, E., Uccheddu, F., and Volpe, Y., "A CAD-based procedure for designing 3D printable arm-wrist-hand cast," Comput.-Aided Des. Appl, Vol.16, No.1, pp.25-34, 2019.
[15] Bracci, R., Maccaroni, E., and Cascinu, S., "Bioresorbable airway splint created with a three-dimensional printer," New England Journal of Medicine, Vol.368, pp.2043-2045, 2013.
[16] Sutherland, I. E., "Sketchpad a man-machine graphical communication system," Simulation, Vol.2, No.5, pp.3-20, 1964.
[17] Li, J. and Tanaka, H., "Rapid customization system for 3D-printed splint using programmable modeling technique–a practical approach," 3D printing in medicine, Vol.4, No.1, p.5, 2018.
[18] Li, J. and Tanaka, H., "Feasibility study applying a parametric model as the design generator for 3D–printed orthosis for fracture immobilization," 3D printing in medicine, Vol.4, No.1, pp.1-15, 2018.
[19] Hale, L., Linley, E., and Kalaskar, D. M., "A digital workflow for design and fabrication of bespoke orthoses using 3D scanning and 3D printing, a patient-based case study," Scientific Reports, Vol.10, No.1, pp.1-7, 2020.
[20] Buonamici, F., Furferi, R., Governi, L., Lazzeri, S., McGreevy, K. S., Servi, M., Talanti, E., Uccheddu, F., and Volpe, Y., "A practical methodology for computer-aided design of custom 3D printable casts for wrist fractures," The Visual Computer, Vol.36, No.2, pp.375-390, 2020.
[21] Maillot, J., Yahia, H., and Verroust, A., "Interactive texture mapping," in Proceedings of the 20th annual conference on Computer graphics and interactive techniques, pp.27-34, 1993.
[22] Eck, M., DeRose, T., Duchamp, T., Hoppe, H., Lounsbery, M., and Stuetzle, W., "Multiresolution analysis of arbitrary meshes," pp.173-182, 1995.
[23] Floater, M. S., "Parametrization and smooth approximation of surface triangulations," Computer aided geometric design, Vol.14, No.3, pp.231-250, 1997.
[24] Floater, M. S., "Mean value coordinates," Computer aided geometric design, Vol.20, No.1, pp.19-27, 2003.
[25] Sheffer, A. and de Sturler, E., "Parameterization of faceted surfaces for meshing using angle-based flattening," Engineering with computers, Vol.17, No.3, pp.326-337, 2001.
[26] Sheffer, A., Lévy, B., Mogilnitsky, M., and Bogomyakov, A., "ABF++: fast and robust angle based flattening," ACM Transactions on Graphics (TOG), Vol.24, No.2, pp.311-330, 2005.
[27] Floyd, R. W., "Algorithm 97: shortest path," Communications of the ACM, Vol.5, No.6, p.345, 1962.
[28] Dijkstra, E. W., "A note on two problems in connexion with graphs," Numerische mathematik, Vol.1, No.1, pp.269-271, 1959.
[29] Lanthier, M., Maheshwari, A., and Sack, J.-R., "Approximating weighted shortest paths on polyhedral surfaces," pp.274-283, 1997.
[30] Kanai, T. and Suzuki, H., "Approximate shortest path on a polyhedral surface and its applications," Computer-Aided Design, Vol.33, No.11, pp.801-811, 2001.
[31] Mitchell, J. S. B., Mount, D. M., and Papadimitriou, C. H., "The discrete geodesic problem," SIAM Journal on Computing, Vol.16, No.4, pp.647-668, 1987.
[32] Surazhsky, V., Surazhsky, T., Kirsanov, D., Gortler, S. J., and Hoppe, H., "Fast exact and approximate geodesics on meshes," ACM Transactions on Graphics (TOG), Vol.24, No.3, pp.553-560, 2005.
[33] Bommes, D. and Kobbelt, L., "Accurate Computation of Geodesic Distance Fields for Polygonal Curves on Triangle Meshes," pp.151-160, 2007.
[34] Chen, J. and Han, Y., "Shortest paths on a polyhedron, Part I: Computing shortest paths," International Journal of Computational Geometry & Applications, Vol.6, No.02, pp.127-144, 1996.
[35] Sethian, J. A., "A fast marching level set method for monotonically advancing fronts," Proceedings of the National Academy of Sciences, Vol.93, No.4, pp.1591-1595, 1996.
[36] Sethian, J. A., "Fast marching methods," SIAM review, Vol.41, No.2, pp.199-235, 1999.
[37] Kimmel, R. and Sethian, J. A., "Computing geodesic paths on manifolds," Proceedings of the National Academy of Sciences, Vol.95, No.15, pp.8431-8435, 1998.
[38] Qu, X. and Stucker, B., "A 3D surface offset method for STL‐format models," Rapid prototyping journal, 2003.
[39] Koc, B. and Lee, Y. S., "Non-uniform offsetting and hollowing objects by using biarcs fitting for rapid prototyping processes," Computers in Industry, Vol.47, No.1, pp.1-23, 2002.
[40] Kim, S.-J., Lee, D. Y., and Yang, M. Y., "Offset triangular mesh using the multiple normal vectors of a vertex," Computer-Aided Design and Applications, Vol.1, No.1-4, pp.285-291, 2004.
[41] Pavić, D. and Kobbelt, L., "High‐resolution volumetric computation of offset surfaces with feature preservation," pp.165-174, 2008.
[42] Wang, C. C. L. and Manocha, D., "GPU-based offset surface computation using point samples," Computer-Aided Design, Vol.45, No.2, pp.321-330, 2013.
[43] Gao, F., "Effectiveness of Adjustable Cervical Orthoses and Modular Cervical Thoracic Orthoses in Restricting Neck Motion," Spine, Vol.40, No.19, pp.E1046-E1051, 2015.
[44] Hart, D. L., Johnson, R. M., Simmons, E. F., and Owen, J., "Review of cervical orthoses," Physical therapy, Vol.58, No.7, pp.857-860, 1978.
[45] Island Artificial Limb & Brace, I., "CERVICAL - Inland Artificial Limb & Brace," 2019, <https://inlandlimbandbrace.com/cervical/>, accessed on 14th Jun, 2020.
[46] Chan, R. C., Schweigel, J. F., and Thompson, G. B., "Halo-thoracic brace immobilization in 188 patients with acute cervical spine injuries," Journal of neurosurgery, Vol.58, No.4, pp.508-515, 1983.
[47] "CTO (Cervical Thoracic Orthosis) | Optec," <http://www.optecusa.com/product/cto-cervical-thoracic-orthosis>, accessed on 7th May, 2020.
[48] Beavis, A., "Cervical orthoses," Prosthetics and orthotics international, Vol.13, No.1, pp.6-13, 1989.
[49] Marieb, E. N., Mallatt, J., and Wilhelm, P. B., Human anatomy, Pearson Benhamin Cummings, 2008.
[50] Vasavada, A. N., Li, S., and Delp, S. L., "Three-dimensional isometric strength of neck muscles in humans," Spine, Vol.26, No.17, pp.1904-1909, 2001.
[51] Harms-Ringdahl, K., Ekholm, J., SCHÜLDT, K., NÉMETH, G., and ARBORELIUS, U. P., "Load moments and myoelectric activity when the cervical spine is held in full flexion and extension," Ergonomics, Vol.29, No.12, pp.1539-1552, 1986.
[52] Chen, C. D., Chen, C. H., Lin, C. L., Lin, C. K., Wang, C. T., Lin, R. M., and Fang, J. J., "Developments, mechanical property measurements and strength evaluations of the wrist braces for the wrist fracture patients," Journal of Mechanics in Medicine and Biology, Vol.19, No.02, 2019.
[53] "The Computational Geometry Algorithms Library," <https://www.cgal.org/>, accessed on 24th August, 2020.
[54] "Vista® Cervical Collar," <https://www.aspenmp.com/vistar-cervical-collar.html>, accessed on 7th May, 2020.
[55] "Pacific Adjustable Collar - Becker Orthopedic," <https://www.beckerorthopedic.com/Product/PrefabricatedOrthoses/Cervical/C-14>, accessed on 2nd July, 2020.
[56] "Military Disablity ratings for Spine conditions," <http://www.militarydisabilitymadeeasy.com/thespine.html>, accessed on 2nd July, 2020.
[57] "CROM 3 | Inclino & Goniometers | Measurement - PhysioSupplies," <https://www.physiosupplies.eu/measurement/inclino-goniometers/crom-3>, accessed on 2nd July, 2020.
[58] Stekelenburg, A., Oomens, C., and Bader, D., Compression-induced tissue damage: animal models, in Pressure ulcer research. 2005, Springer. p. 187-204.
[59] "Small Force Sensing Resistor | FlexiForce A201 Sensor | Tekscan," <https://www.tekscan.com/products-solutions/force-sensors/a201>, accessed on 2nd July, 2020.
[60] Worsley, P. R., Stanger, N. D., Horrell, A. K., and Bader, D. L., "Investigating the effects of cervical collar design and fit on the biomechanical and biomarker reaction at the skin," Medical Devices (Auckland, NZ), Vol.11, p.87, 2018.