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Amudhan K, Vasanthanathan A, Thilak JAJ. Computational assessment of carbon fabric reinforced polymer made prosthetic knee: Mechanics, finite element simulations and experimental evaluation. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2024; 40:e3827. [PMID: 38623951 DOI: 10.1002/cnm.3827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 03/04/2024] [Accepted: 04/05/2024] [Indexed: 04/17/2024]
Abstract
A prosthetic knee is designed to replace the functionality of an anatomical knee in transfemoral amputees. The purpose of a prosthetic knee is to restore mobility and compensate amputees for their impairment. In the present research numerical modelling and simulation of a carbon fabric reinforced polymer made polycentric prosthetic knee with four-bar mechanism was performed. Virtual prototyping with computer-aided design and computer-aided engineering software ensured geometric and structural stability of the knee design. The linkage mechanism, instantaneous centre's location and trajectory were investigated using multibody dynamics and analytical formulations. Computational simulations with a non-linear finite element model were employed with joints, contact formulations and an orthotropic material model to predict the displacement, stress formulated and life of the knee prosthesis under static and cyclic loading conditions. Finite element analysis assessed the strength and durability of knee in accordance to standards. Maximum Principal stress of 155 MPa and life expectancy of 3.1 × 106 cycles were determined for the composite knee through numerical simulations ensuring a safe design. Experimental testing was also conducted as per standards and the percentage error was estimated to be 2.52%, thereby establishing the validity of the finite element model deployed. This type of simulation-based approach can be implemented to efficiently and affordably design and prototype a prosthetic knee with desired functioning criteria.
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Affiliation(s)
- Kannan Amudhan
- Department of Mechanical Engineering, Mepco Schlenk Engineering College, Sivakasi, India
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Turner AT, Halsne EG, Caputo JM, Curran CS, Hansen AH, Hafner BJ, Morgenroth DC. Prosthetic forefoot and heel stiffness across consecutive foot stiffness categories and sizes. PLoS One 2022; 17:e0268136. [PMID: 35536854 PMCID: PMC9089881 DOI: 10.1371/journal.pone.0268136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 03/24/2022] [Indexed: 11/18/2022] Open
Abstract
Prosthetic foot stiffness plays a key role in the functional mobility of lower limb prosthesis users. However, limited objective data exists to guide selection of the optimal prosthetic foot stiffness category for a given individual. Clinicians often must rely solely on manufacturer recommendations, which are typically based on the intended user’s weight and general activity level. Availability of comparable forefoot and heel stiffness data would allow for a better understanding of differences between different commercial prosthetic feet, and also between feet of different stiffness categories and foot sizes. Therefore, this study compared forefoot and heel linear stiffness properties across manufacturer-designated stiffness categories and foot sizes. Mechanical testing was completed for five types of commercial prosthetic feet across a range of stiffness categories and three foot-sizes. Data were collected for 56 prosthetic feet, in total. Testing at two discrete angles was conducted to isolate loading of the heel and forefoot components, respectively. Each prosthetic foot was loaded for six cycles while force and displacement data were collected. Forefoot and heel measured stiffness were both significantly associated with stiffness category (p = .001). There was no evidence that the relationships between stiffness category and measured stiffness differed by foot size (stiffness category by size interaction p = .80). However, there were inconsistencies between the expected and measured stiffness changes across stiffness categories (i.e., magnitude of stiffness changes varied substantially between consecutive stiffness categories of the same feet). While statistical results support that, on average, measured stiffness is positively correlated with stiffness category, force-displacement data suggest substantial variation in measured stiffness across consecutive categories. Published objective mechanical property data for commercial prosthetic feet would likely therefore be helpful to clinicians during prescription.
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Affiliation(s)
- Anne T. Turner
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, Washington, United States of America
- Elson S. Floyd College of Medicine, Washington State University, Spokane, Washington, United States of America
| | - Elizabeth G. Halsne
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, Washington, United States of America
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, United States of America
| | - Joshua M. Caputo
- Human Motion Technologies LLC d/b/a Humotech, Pittsburgh, Pennsylvania, United States of America
| | - Carl S. Curran
- Human Motion Technologies LLC d/b/a Humotech, Pittsburgh, Pennsylvania, United States of America
| | - Andrew H. Hansen
- Minneapolis VA Health Care System, Minneapolis, Minnesota, United States of America
- University of Minnesota, Minneapolis, Minnesota, United States of America
| | - Brian J. Hafner
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, United States of America
| | - David C. Morgenroth
- VA RR&D Center for Limb Loss and Mobility (CLiMB), VA Puget Sound Health Care System, Seattle, Washington, United States of America
- Department of Rehabilitation Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
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Bartlett HL, King ST, Goldfarb M, Lawson BE. Model Based Design of a Low Cost and Compliant Low Profile Prosthetic Foot. J Biomech Eng 2022; 144:1119454. [PMID: 34505139 DOI: 10.1115/1.4052369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Indexed: 11/08/2022]
Abstract
This paper describes the design of a simple and low-cost compliant low-profile prosthetic foot based on a cantilevered beam of uniform strength. The prosthetic foot is developed such that the maximum stress experienced by the beam is distributed approximately evenly across the length of the beam. Due to this stress distribution, the prosthetic foot exhibits compliant behavior not achievable through standard design approaches (e.g., designs based on simple cantilevered beams). Additionally, due to its simplicity and use of flat structural members, the foot can be manufactured at low cost. An analytical model of the compliant behavior of the beam is developed that facilitates rapid design changes to vary foot size and stiffness. A characteristic prototype was designed and constructed to be used in both a benchtop quasi-static loading test as well as a dynamic walking test for validation. The model predicted the rotational stiffness of the prototype with 5% error. Furthermore, the prototype foot was tested alongside two commercially available prosthetic feet (a low profile foot and an energy storage and release foot) in level walking experiments with a single study participant. The prototype foot displayed the lowest stiffness of the three feet (6.0, 7.1, and 10.4 Nm/deg for the prototype foot, the commercial low profile foot, and the energy storage and release foot, respectively). This foot design approach and accompanying model may allow for compliant feet to be developed for individuals with long residual limbs.
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Affiliation(s)
| | - Shane T King
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37212
| | - Michael Goldfarb
- Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37212
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Amudhan K, Vasanthanathan A, Anish Jafrin Thilak J. An insight into Transfemoral Prostheses: Materials, modelling, simulation, fabrication, testing, clinical evaluation and performance perspectives. Expert Rev Med Devices 2022; 19:123-140. [PMID: 35142577 DOI: 10.1080/17434440.2022.2039624] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
INTRODUCTION A Transfemoral prosthesis restores any limb amputated above the knee. Designing and developing a transfemoral prosthesis that is consistent with human performance is a tough task. While prosthetic components are widely available in the market, ongoing research is being conducted to develop parts that would restore the lost capability, taking into account numerous social, economic and technological considerations. AREAS COVERED The present paper provides a comprehensive review about the mechanical aspects and performance of transfemoral prosthesis in recent years based on the research findings on materials, manufacturing methods and evaluations for suitability of the prostheses. The fundamental terminologies as well as technical advancements are covered in order to impart a better knowledge in the area of Lower Limb prostheses. This review also provides a concise description on the role of computers, advanced software packages, sensors and other hardware components for the design, fabrication and testing of transfemoral prosthetic devices in the current environment. EXPERT OPINION The current state of lower limb prostheses and future research opportunities are summarised to address upcoming challenges. Based on survey of various research works, adapting modern technology may aid in the development of functional and cost-efficient prosthetic components with superior safety, comfort and quality.
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Affiliation(s)
- K Amudhan
- Department of Mechanical Engineering, Mepco Schlenk Engineering College,626005, Tamilnadu, India
| | - A Vasanthanathan
- Department of Mechanical Engineering, Mepco Schlenk Engineering College,626005, Tamilnadu, India
| | - J Anish Jafrin Thilak
- Department of Mechanical Engineering, Mepco Schlenk Engineering College,626005, Tamilnadu, India
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Abstract
In the original edition of Prosthetics and Orthotics International, Dr Sidney Fishman identified what he anticipated as foundational educational needs for the emerging field of clinical prosthetics and orthotics. Within the broader construct of the physical sciences, this included mathematics, physics, chemistry, biomechanics, and material sciences. The clinical application of these disciplines to expanding the collective understanding within the field is described, including the biomechanics of able-bodied and prosthetic gait, the material science of socket construction, the physics of suspension and load distribution, and the engineering of prosthetic components to mimic human biomechanics. Additional applications of the physical sciences to upper limb prosthetics and lower limb orthotics are also described. In contemplating the continued growth and maturation of the field in the years to come, mechatronics and statistics are suggested as future areas where clinical proficiency will be required.
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Affiliation(s)
- Phillip M Stevens
- Department of Clinical and Scientific Affairs, Hanger Clinic, Salt Lake City, UT, USA.,Division of Physical Medicine and Rehabilitation, University of Utah Healthcare, Salt Lake City, UT, USA
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Ernst M, Altenburg B, Schmalz T. Characterizing adaptations of prosthetic feet in the frontal plane. Prosthet Orthot Int 2020; 44:225-233. [PMID: 32493118 DOI: 10.1177/0309364620917838] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Energy-storage and return feet incorporate various design features including split toes. As a potential improvement, an energy-storage and return foot with a dedicated ankle joint was recently introduced allowing for easily accessible inversion/eversion movement. However, the adaptability of energy-storage and return feet to uneven ground and the effects on biomechanical and clinical parameters have not been investigated in detail. OBJECTIVES To investigate the design-related ability of prosthetic feet to adapt to cross slopes and derive a theoretical model. STUDY DESIGN Mechanical testing and characterization. METHODS Mechanical adaptation to cross slopes was investigated for six prosthetic feet measured by a motion capture system. A theoretical model linking the measured data with adaptations is proposed. RESULTS The type and degree of adaptation depends on the foot design, for example, stiffness, split toe or continuous carbon forefoot, and additional ankle joint. The model used shows high correlations with the measured data for all feet. CONCLUSIONS The ability of prosthetic feet to adapt to uneven ground is design-dependent. The split-toe feet adapted better to cross slopes than those with continuous carbon forefeet. Joints enhance this further by allowing for additional inversion and eversion. The influence on biomechanical and clinical parameters should be assessed in future studies. CLINICAL RELEVANCE Knowing foot-specific ability to adapt to uneven ground may help in selecting an appropriate prosthetic foot for persons with a lower limb amputation. Faster and more comprehensive adaptations to uneven ground may lower the need for compensations and therefore increase user safety.
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Affiliation(s)
- Michael Ernst
- Research Biomechanics, Clinical Research and Services, Ottobock SE & Co. KGaA, Göttingen, Germany
| | - Björn Altenburg
- Research Biomechanics, Clinical Research and Services, Ottobock SE & Co. KGaA, Göttingen, Germany
| | - Thomas Schmalz
- Research Biomechanics, Clinical Research and Services, Ottobock SE & Co. KGaA, Göttingen, Germany
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Evaluation of Gait Variable Change over Time as Transtibial Amputees Adapt to a New Prosthesis Foot. BIOMED RESEARCH INTERNATIONAL 2019; 2019:9252368. [PMID: 31236415 PMCID: PMC6545810 DOI: 10.1155/2019/9252368] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 04/03/2019] [Accepted: 04/22/2019] [Indexed: 11/18/2022]
Abstract
A variety of prescribed accommodation periods have been used in published prosthesis intervention studies that have examined biomechanical outcomes. Few investigators included repeated measurements in their study design, leaving questions as to how measured outcomes change as amputees acclimate to a new prosthesis. This paper is the product of our investigation as to whether measured gait variables were affected by the duration of accommodation period, and to assess the relationship between measured outcomes and the subjective perception of the participants. A sample of transtibial amputees were recruited for this study. Gait data was collected by wearable sensor repeatedly, starting immediately after fitting the interventional foot and extending over a subsequent four days. Participants indicated their perceived accommodation quality on a visual analog scale (VAS). A total of twelve commonly used spatiotemporal gait parameters were analyzed. Friedman tests were used to determine overall differences across time points in both early (one hour) and late (day two through five) accommodation phases, for each gait variable. Statistically significant changes across the early phase were found for variables gait speed χ2(2)=8.000, p=0.018, cadence χ2(2)=7.185, p=0.028, and double support time on the sound side χ2(2)=8.615, p=0.013. Across days two through five, no gait variable significantly changed. VAS scores correlated strongly with step count (r=1.000, p<0.001) and cadence (r=0.857, p=0.014). Longer accommodation periods resulted in less deviations of gait variables for the clinical assessment in the process of prosthetic rehabilitation. Trying out prosthetic interventions for less than one hour has yielded unreliable outcomes.
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Womac ND, Neptune RR, Klute GK. Stiffness and energy storage characteristics of energy storage and return prosthetic feet. Prosthet Orthot Int 2019; 43:266-275. [PMID: 30688551 DOI: 10.1177/0309364618823127] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Mechanical properties of prosthetic feet can significantly influence amputee gait, but how they vary with respect to limb loading and orientation is infrequently reported. OBJECTIVE The objective of this study is to measure stiffness and energy storage characteristics of prosthetic feet across limb loading and a range of orientations experienced in typical gait. STUDY DESIGN This study included mechanical testing. METHODS Force-displacement data were collected at combinations of 15 sagittal and 5 coronal orientations and used to calculate stiffness and energy storage across prosthetic feet, stiffness categories, and heel wedge conditions. RESULTS Stiffness and energy storage were highly non-linear in both the sagittal and coronal planes. Across all prosthetic feet, stiffness decreased with greater heel, forefoot, medial, and lateral orientations, while energy storage increased with forefoot, medial, and lateral loading orientations. Stiffness category was proportional to stiffness and inversely proportional to energy storage. Heel wedge effects were prosthetic foot dependent. CONCLUSION Orientation, manufacturer, stiffness category, and heel wedge inclusion greatly influenced stiffness and energy storage characteristics. CLINICAL RELEVANCE These results and an available graphical user interface tool may help improve clinical prescriptions by providing prosthetists with quantitative measures to compare prosthetic feet.
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Affiliation(s)
| | | | - Glenn K Klute
- 2 Center for Limb Loss and MoBility, VA Puget Sound Health Care System, Seattle, WA, USA.,3 University of Washington, Seattle, WA, USA
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Webber CM, Kaufman K. Instantaneous stiffness and hysteresis of dynamic elastic response prosthetic feet. Prosthet Orthot Int 2017; 41:463-468. [PMID: 28008788 DOI: 10.1177/0309364616683980] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND Dynamic elastic response prosthetic feet are designed to mimic the functional characteristics of the native foot/ankle joint. Numerous designs of dynamic elastic response feet exist which make the prescription process difficult, especially because of the lack of empirical evidence describing the objective performance characteristics of the feet. OBJECTIVES To quantify the mechanical properties of available dynamic elastic response prosthetic feet, specifically the stiffness and hysteresis. STUDY DESIGN Mechanical testing of dynamic elastic response prosthetic feet. METHODS Static Proof Testing in accordance with ISO 10328 was conducted on seven dynamic elastic response prosthetic feet. Load-displacement data were used to calculate the instantaneous stiffness in both the heel and forefoot regions, as well as hysteresis associated with each foot. RESULTS Heel stiffness was greater than forefoot stiffness for all feet. The heel of the glass composite prosthetic foot was stiffer than the carbon fiber feet and it exhibited less hysteresis. Two different carbon fiber feet had the stiffest forefoot regions. CONCLUSION Mechanical testing is a reproducible method that can be used to provide objective evidence about dynamic elastic response prosthetic foot performance and aid in the prescription process. Clinical relevance The quantitative stiffness and hysteresis data from this study can be used by prosthetists to aid the prescription process and make it more objective.
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Sadeghi-Demneh E, Forghany S, Onmanee P, Trinler U, Dillon MP, Baker R. The influence of standards and clinical guidelines on prosthetic and orthotic service quality: a scoping review. Disabil Rehabil 2017. [PMID: 28631506 DOI: 10.1080/09638288.2017.1335802] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
OBJECTIVES Standards and guidelines are an integral part of prosthetic and orthotic service delivery in the developed world underpinned by an assumption that they lead to improved services. Implementing them has a cost, however, and that cost needs to be justified, particularly in resource-limited environments. This scoping review thus asks the question, "What is the evidence of the impact of standards and guidelines on service delivery outcomes in prosthetics and orthotics?" MATERIALS AND METHODS A structured search of three electronic databases (Medline, Scopus and Web of Science) followed by manual searching of title, abstract and full text, yielded 29 articles. RESULTS Four categories of papers were identified: Descriptions and Commentaries (17 papers), Guideline Development (7), Guideline Testing (2) and Standards implementation (3). No articles were explicitly designed to assess the impact of standards and guidelines on service delivery outcomes in prosthetics and orthotics. DISCUSSION AND CONCLUSION Studies tended to be commentaries on or descriptions of guideline development, testing or implementation of standards. The literature is not sufficiently well developed to warrant the cost and effort of a systematic review. Future primary research should seek to demonstrate whether and how guidelines and standards improve the outcomes for people that require prostheses, orthoses and other assistive devices. Implications for Rehabilitation International Standards and Clinical Guidelines are now an integral part of clinical service provision in prosthetics and orthotics in the developed world. Complying with standards and guidelines has a cost and, particularly in resource-limited environments, it should be possible to justify this in terms of the resulting benefits. This scoping review concludes that there have been no previous studies designed to directly quantify the effects of implementing standards and guidelines on service delivery.
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Affiliation(s)
- Ebrahim Sadeghi-Demneh
- a Musculoskeletal Research Center , Isfahan University of Medical Sciences , Isfahan , Iran
| | - Saeed Forghany
- a Musculoskeletal Research Center , Isfahan University of Medical Sciences , Isfahan , Iran.,b Health Sciences Research Centre, University of Salford , Greater Manchester , UK
| | - Pornsuree Onmanee
- b Health Sciences Research Centre, University of Salford , Greater Manchester , UK
| | - Ursula Trinler
- b Health Sciences Research Centre, University of Salford , Greater Manchester , UK
| | - Michael P Dillon
- c School of Allied Health, College of Science, Health and Engineering , La Trobe University , Melbourne , Australia.,d Royal Melbourne Hospital , Victoria , Australia
| | - Richard Baker
- b Health Sciences Research Centre, University of Salford , Greater Manchester , UK
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CANNELLA FERDINANDO, GARINEI ALBERTO, D'IMPERIO MARIAPAOLA, ROSSI GIANLUCA. A NOVEL METHOD FOR THE DESIGN OF PROSTHESES BASED ON THERMOELASTIC STRESS ANALYSIS AND FINITE ELEMENT ANALYSIS. J MECH MED BIOL 2014. [DOI: 10.1142/s021951941450064x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
This work is about a prosthesis destined for the people of Senegal and the victims of mines that have been spread throughout countries involved in war. The purpose of this study is to design a new, low-cost prosthesis using the materials produced in Senegal: teak wood and iron (AISI 304). In order to optimize the design of the new prosthesis, a methodology was developed to evaluate stress patterns for different configurations. A commercial CAD and ANSYS Workbench were used to define prosthesis geometry and to perform Finite Element Analysis. Load and constraints were defined according to Regulation ISO10328-2006, and stress distribution was estimated using the FE model. Fatigue due to the cycling load was also taken into account. The two materials currently used in western countries, titanium and steel (AISI 1020), were compared to iron and teak in order to determine the prosthesis' lifespan based on the differences in structural behaviors. An experimental, non-contact measurement technique based on the Thermoelastic principle is proposed here to validate the FE model. This technique permits the evaluation of superficial stress patterns on the prosthesis subjected to a cyclic load. A loading rig was built to test the prosthesis, and experimental and FEM results were compared to allow qualitative mechanical assessment of the new prosthesis. The finding of this work was that the prosthesis can indeed be built using autochthonous materials such as teak and iron. Moreover, the methodology proposed can be used for the performance prediction and design of new prostheses using materials that are typically expensive or difficult to test (such as wood), allowing for optimization of the geometry based on stress distribution, an increase in reliability and a decrease in costs.
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Affiliation(s)
| | - ALBERTO GARINEI
- DMII, Università degli Studi Guglielmo Marconi, Roma 00193, Italy
| | | | - GIANLUCA ROSSI
- DII, Università degli Studi di Perugia, Perugia 06125, Italy
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