PSI - Issue 37

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2019) 000 – 000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 37 (2022) 139–144

© 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira Abstract Introduction of 3D printing nto man facturi g f prosthetic sockets raised question of structural integrity of such products. Prosthetic ockets, as cu tom zed produ ts, cannot be directly included in a standardized testing protocol like oth r major pa ts of he prosthesis; this makes thei mechanical assessment challenging. In this study, a prototy e t sting rig was developed according t BS EN ISO 10328, able to r c ea e the l ading conditions of the early stance of the mputee gait o a paediatric transfemoral socke . A variety of bove-kne prosthetic socke d signs were 3D prin ed in PLA and carbon-fiber-reinforced nylon. Th sockets were tested unde static compr ssive load sing the developed rig together with a silic ne-rubb r ph ntom limb with mechanical prop rties similar o those of the human tissue. New load requirements were calculated for th ca e of a 14-year-old mal weighting in the 98 th p rc ntile. Af er nitial design improvements, the 3D printed sockets were able to sustain loads up to five times the weight of the user without failing. © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND lic nse (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira 1. Introduction To ensure that a prosthesis is acceptable for use, all its components must comply with minimum specific loa ing apacity requirement detailed in the BS EN ISO 10328-2006 (ISOTC168 2006). Due to unique indivi ual characte istics (McCaslin et al. 2007) linked to specific limb shape, prosthetic sockets cannot be directly inclu ed in a standardized testing protocol like the rest major parts of t e prosthesis. Still, these standards wer widely used s a referen e in previous studie (Golovin et al. 2020; McGrath et al. 2017). Following th se guideline , conventionally manufactured sockets were statically tested in the past for both below- and above-knee applications, and significant ICSI 2021 The 4th International Conference on Structural Integrity Structural integrity of 3D-printed prosthetic sockets: An experimental study for paediatric above-knee applications Theodoros Marinopoulos a , Simin Li a , Vadim V. Silberschmidt a,b a Wolfson School of Mechanical, Electrical and Manufacturing Engineering, Loughborough University, Leicestershire, LE11 3TU, UK b Laboratory of Mechanics of Biocompatible Materials and Devices, Perm National Research Polytechnic University, Perm 614990, Russia Abstract Introduction of 3D printing into manufacturing of prosthetic sockets raised a question of structural integrity of such products. Prosthetic sockets, as customized products, cannot be directly included in a standardized testing protocol like other major parts of the prosthesis; this makes their mechanical assessment challenging. In this study, a prototype testing rig was developed according to BS EN ISO 10328, able to recreate the loading conditions of the early stance of the amputee gait on a paediatric transfemoral socket. A variety of above-knee prosthetic socket designs were 3D printed in PLA and carbon-fiber-reinforced nylon. The sockets were tested under static compressive load using the developed rig together with a silicone-rubber phantom limb with mechanical properties similar to those of the human tissue. New load requirements were calculated for the case of a 14-year-old male weighting in the 98 th percentile. After initial design improvements, the 3D printed sockets were able to sustain loads up to five times the weight of the user without failing. ICSI 2021 The 4th International Conference on Structural Integrity Structural integrity of 3D-printed prosthetic sockets: An experimental study for paediatric above-knee applications Theodoros Marinopoulos a , Simin Li a , Vadim V. Silberschmidt a,b a W lfs n School of Mechanical, Elec rical and M nufacturing Engineering, Loughboroug Univ rsity, Leicestershir , LE1 3TU, UK b Laboratory of Mechanics of Biocompatible Materials and Devices, Perm National Research Polytechnic University, Perm 614990, Russia Keywords: Structural integrity; Prosthetic socket testing; Additive Manufacturing; lower-limb; ISO standards Keywords: Structural integrity; Prosthetic socket testing; Additive Manufacturing; lower-limb; ISO standards 1. Introduction To ensure that a prosthesis is acceptable for use, all its components must comply with minimum specific loading capacity requirements detailed in the BS EN ISO 10328-2006 (ISOTC168 2006). Due to unique individual characteristics (McCaslin et al. 2007) linked to specific limb shape, prosthetic sockets cannot be directly included in a standardized testing protocol like the rest major parts of the prosthesis. Still, these standards were widely used as a reference in previous studies (Golovin et al. 2020; McGrath et al. 2017). Following these guidelines, conventionally manufactured sockets were statically tested in the past for both below- and above-knee applications, and significant

2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira 2452-3216 © 2022 The Authors. Published by ELSEVIER B.V. This is an ope acces article under the CC BY-NC-ND lic nse (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira

2452-3216 © 2022 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of Pedro Miguel Guimaraes Pires Moreira 10.1016/j.prostr.2022.01.069