Mechanical Design of a Low Cost Transhumeral Prosthesis

Author(s):  
Luis Arturo Gómez Malagón ◽  
João Luiz Vilar Dias
Keyword(s):  
Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Conghui Liang ◽  
Hao Gu ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone

SUMMARYA mechanical design and dynamics walking simulation of a novel tripod walking robot are presented in this paper. The tripod walking robot consists of three 1-degree-of-freedom (DOF) Chebyshev–Pantograph leg mechanisms with linkage architecture. A balancing mechanism is mounted on the body of the tripod walking robot to adjust its center of gravity (COG) during walking for balancing purpose. A statically stable tripod walking gait is performed by synchronizing the motions of the three leg mechanisms and the balancing mechanism. A three-dimensional model has been elaborated in SolidWorks® engineering software environment for a characterization of a feasible mechanical design. Dynamics simulation has been carried out in the MSC.ADAMS® environment with the aim to characterize and to evaluate the dynamic walking performances of the proposed design with low-cost easy-operation features. Simulation results show that the proposed tripod walking robot with proper input torques, gives limited reaction forces at the linkage joints, and a practical feasible walking ability on a flatten ground.


2020 ◽  
Vol 2 (2) ◽  
pp. 280-293
Author(s):  
Mathew G. Pelletier ◽  
Greg A. Holt ◽  
John D. Wanjura

The removal of plastic contamination in cotton lint is an issue of top priority to the U.S. cotton industry. One of the main sources of plastic contamination showing up in marketable cotton bales, at the U.S. Department of Agriculture’s classing office, is plastic from the module wrap used to wrap cotton modules produced by the new John Deere round module harvesters. Despite diligent efforts by cotton ginning personnel to remove all plastic encountered during unwrapping of the seed cotton modules, plastic still finds a way into the cotton gin’s processing system. To help mitigate plastic contamination at the gin; an inspection system was developed that utilized low-cost color cameras to see plastic on the module feeder’s dispersing cylinders, that are normally hidden from view by the incoming feed of cotton modules. This technical note presents the design of an automated intelligent machine-vision guided cotton module-feeder inspection system. The system includes a machine-learning program that automatically detects plastic contamination in order to alert the cotton gin personnel as to the presence of plastic contamination on the module feeder’s dispersing cylinders. The system was tested throughout the entire 2019 cotton ginning season at two commercial cotton gins and at one gin in the 2018 ginning season. This note describes the over-all system and mechanical design and provides an over-view and coverage of key relevant issues. Included as an attachment to this technical note are all the mechanical engineering design files as well as the bill-of-materials part source list. A discussion of the observational impact the system had on reduction of plastic contamination is also addressed.


2006 ◽  
Vol 1 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Rahul D. Sathe ◽  
David N. Ku

Over 7 million Americans suffer from chronic venous insufficiency (CVI), a disease that affects the venous system of the lower extremities. Problems associated with CVI include ulcerations, bleeding, swelling, and varicose veins, as well as deep vein thrombosis and pulmonary embolism. The presence of CVI is the result of incompetent, or malfunctioning, one-way vein valves in leg veins. There are few effective clinical therapies for treating CVI and there are currently no prosthetic vein valves commercially available. The purpose of this study was to define clinically relevant design requirements, develop functional tests for assessing a prosthetic vein valve, and design and fabricate a functional prosthetic vein valve for eventual clinical use. Engineering design methods were used to develop the valve, building a product based on well-defined consumer needs and design specifications. Emphasis was placed on creating a valve with potential clinical functionality. This clinical functionality was distilled into three major design criteria: that the valve (1) withstand backpressure of 300mmHg with less than 1.0mL∕min of leakage; (2) open with distal pressure gradients less than 5mmHg; and (3) meet criteria 1 and 2 after 500,000cycles of opening and closing. Hydrostatic testing was conducted to measure the opening pressure and reflux leak rate of the valve. Cyclic life functionality was assessed using a cyclic flow loop simulating physiologic conditions of cyclic flow and pressure found in leg veins. The valve opened with a pressure of 2.6mmHg±0.7mmHg, which matches physiologic vein valve function. The valve also withstood 300mmHg of backpressure with less than 0.5mL∕min of leakage, and maintained this performance even after 508,000cycles of opening and closing in simulated physiologic conditions. The valve’s burst pressure was a minimum of 530mmHg±10mmHg, six times greater than physiologic pressure natural vein valves experience. The valve continued to function well in an environment of vein-like tube expansion. The newly designed bi-leaflet prosthetic valve is comprised of a flexible, biocompatible material. Bench test results have shown that the valve is hydrodynamically functional and meets the mechanical design criteria for backpressure competency and opening pressure after 500,000cycles. Finally, the valve can be manufactured easily with low cost.


Author(s):  
ELIEL EDUARDO MONTIJO-VALENZUELA ◽  
SAUL DANIEL DURAN-JIMENEZ ◽  
LUIS ALBERTO ALTAMIRANO-RÍOS ◽  
JOSÉ ISAEL PÉREZ-GÓMEZ ◽  
OSCAR SALMÓN-AROCHI

The objective of this research is to manufacture a prototype of a teaching die for the specialty of precision mechanical design in mechatronic engineering, in order to achieve the skills required in unit two, regarding dies. The methodology used consists of five stages: 1. Definition of the preliminary conditions. 2. Theoretical calculations for die design. 3. Design, modeling and assembly using computer-aided software (CAD) of the parts that make up the die. 4. Validation with simulation of finite element analysis (AEF). 5. Manufacture of parts and physical assembly of the die. A functional prototype was obtained with which the teacher and student can perform calculations, designs and CAD models, AEF analysis of the static and fatigue type, manufacture of rapid prototypes using 3D printing, the identification of the parts that make up a die and their functioning. The advantage of this prototype, compared to metal die-cutting machines, is its low cost of production and manufacturing, it does not require expensive and specialized machinery for manufacturing, specific designs can be made by the students and its subsequent manufacture within the laboratories of the Technological Institute of Hermosillo.


2021 ◽  
pp. 1-36
Author(s):  
Shubhdildeep S. Sohal ◽  
Bijo Sebastian ◽  
Pinhas Ben-Tzvi

Abstract This paper presents a self-reconfigurable modular robot with an integrated 2-DOF active docking mechanism. Active docking in modular robotic systems has received a lot of interest recently as it allows small versatile robotic systems to coalesce and achieve the structural benefits of large systems. This feature enables reconfigurable modular robotic systems to bridge the gap between small agile systems and larger robotic systems. The proposed self-reconfigurable mobile robot design exhibits dual mobility using a tracked drive mechanism for longitudinal locomotion and a wheeled drive mechanism for lateral locomotion. The 2-DOF docking interface allows for efficient docking while tolerating misalignments. To aid autonomous docking, visual marker-based tracking is used to detect and re-position the source robot relative to the target robot. The tracked features are then used in Image-Based Visual Servoing to bring the robots close enough for the docking procedure. The hybrid-tracking algorithm allows eliminating external pixelated noise in the image plane resulting in higher tracking accuracy along with faster frame update on a low-cost onboard computational device. This paper presents the overall mechanical design and the integration details of the modular robotic module with the docking mechanism. An overview of the autonomous tracking and docking algorithm is presented along-with a proof-of-concept real world demonstration of the autonomous docking and self-reconfigurability. Experimental results to validate the robustness of the proposed tracking method, as well as the reliability of the autonomous docking procedure, are also presented.


2015 ◽  
Vol 17 (1) ◽  
pp. 79-90 ◽  
Author(s):  
Juan Francisco Ayala Lozano ◽  
Guillermo Urriolagoitia Sosa ◽  
Beatriz Romero Ángeles ◽  
Christopher René Torres San-Miguel ◽  
Luis Antonio Aguilar-Pérez ◽  
...  

<strong>Título en ingles: Mechanical design of an exoskeleton for upper limb rehabilitation</strong><p><strong>Título corto: Diseño mecánico de un exoesqueleto</strong></p><p><strong>Resumen:</strong> El ritmo de vida actual, tanto sociocultural como tecnológico, ha desembocado en un aumento de enfermedades y padecimientos que afectan las capacidades físico-motrices de los individuos. Esto ha originado el desarrollo de prototipos para auxiliar al paciente a recuperar la movilidad y la fortaleza de las extremidades superiores afectadas. El presente trabajo aborda el diseño de una estructura mecánica de un exoesqueleto con 4 grados de libertad para miembro superior. La cual tiene como principales atributos la capacidad de ajustarse a la antropometría del paciente mexicano (longitud del brazo, extensión del antebrazo, condiciones geométricas de la espalda y altura del paciente). Se aplicó el método <em>BLITZ QFD</em> para obtener el diseño conceptual óptimo y establecer adecuadamente las condiciones de carga de servicio. Por lo que, se definieron 5 casos de estudio cuasi-estáticos e implantaron condiciones para rehabilitación de los pacientes. Asimismo, mediante el Método de Elemento Finito (MEF) se analizaron los esfuerzos y deformaciones a los que la estructura está sometida durante la aplicación de los agentes externos de servicio. Los resultados presentados en éste trabajo exhiben una nueva propuesta para la rehabilitación de pacientes con problemas de movilidad en miembro superior. Donde el equipo propuesto permite la rehabilitación del miembro superior apoyado en 4 grados de libertad (tres grados de libertad en el hombro y uno en el codo), el cual es adecuado para realizar terapias activas y pasivas. Asimismo, es un dispositivo que está al alcance de un mayor porcentaje de la población por su bajo costo y fácil desarrollo en la fabricación.</p><p><strong>Palabras clave:</strong> MEF, Blitz QFD, exoesqueletos, diseño mecánico.</p><p><strong>Abstract</strong>: The pace of modern life, both socio-cultural and technologically, has led to an increase of diseases and conditions that affect the physical-motor capabilities of persons. This increase has originated the development of prototypes to help patients to regain mobility and strength of the affected upper limb. This work, deals with the mechanical structure design of an exoskeleton with 4 degrees freedom for upper limb. Which has the capacity to adjust to the Mexican patient anthropometry (arm length, forearm extension, geometry conditions of the back and the patient’s height) BLITZ QFD method was applied to establish the conceptual design and loading service conditions on the structure.  So, 5 quasi-static cases of study were defined and conditions for patient rehabilitation were subjected. Also by applying the finite element method the structure was analyzed due to service loading. The results presented in this work, show a new method for patient rehabilitation with mobility deficiencies in the upper limb. The proposed new design allows the rehabilitation of the upper limb under 4 degrees of freedom (tree degrees of freedom at shoulder and one at the elbow), which is perfect to perform active and passive therapy. Additionally, it is an equipment of low cost, which can be affordable to almost all the country population.</p><p><strong>Key words:</strong> FEM, Blitz QFD, exoskeletons, mechanical design<strong>.</strong></p><p><strong>Recibido:</strong> agosto 20 de 2014   <strong>Aprobado:</strong> marzo 26 de 2015</p>


2017 ◽  
Author(s):  
Nathaniel Boisjolie-Gair ◽  
Jeremy Straub

Author(s):  
Maria Augusta de Menezes Lourenço ◽  
Fabrício Silva ◽  
Ludmila Silva ◽  
Jony Eckert ◽  
Franco Giuseppe Dedini

2017 ◽  
Vol 2017 (1) ◽  
pp. 000604-000607
Author(s):  
Nolan Grant ◽  
Mahdi Haghzadeh ◽  
Alkim Akyurtlu

Abstract This work presents design and fabrication processes for creating statically gain-reconfigurable conformal patch array antennas. In our previous work, a fully printable and conformal antenna array on a flexible substrate with a new Left-Handed Transmission Line (LHTL) phase shifter based on a Barium Strontium Titanate (BST)/polymer composite was computationally studied for radiation pattern correction and beam steering applications. In this work, additive manufacturing techniques were used to experimentally demonstrate the phase compensation needed to improve the degraded performance of the conformal arrays. An Aerosol Jet direct-write printer was used to print several patch antenna arrays and was tested in an anechoic chamber to establish baseline gain metrics. Once a baseline is established, a high dielectric constant material (BST nano-ink) was dispensed onto the IDCs in several configurations, to provide the necessary phase compensation. The antennas were retested and the changes in their gain profiles were investigated. The findings of this work and the proposed method allow for gain compensation of curved conformal antennas and post-production modification of the radiation pattern of antenna arrays. This work has potential applications in the automotive industry due to the low cost of production and the ability to be integrated onto curved conformal surfaces without interfering with super structure or other mechanical design related criteria.


2021 ◽  
Vol 13 (2) ◽  
Author(s):  
Haosen Yang ◽  
Guowu Wei ◽  
Lei Ren ◽  
Zhihui Qian ◽  
Kunyang Wang ◽  
...  

Abstract This paper presents the design, analysis, and development of an anthropomorphic robotic hand coined MCR-hand II. This hand takes the advantages of both the tendon-driven and linkage-driven systems, leading to a compact mechanical structure that aims to imitate the mobility of a human hand. Based on the investigation of the human hand anatomical structure and the related existing robotic hands, mechanical design of the MCR-hand II is presented. Then, using D-H convention, kinematics of this hand is formulated and illustrated with numerical simulations. Furthermore, fingertip force is deduced and analyzed, and mechatronic system integration and control strategy are addressed. Subsequently, a prototype of the proposed robotic hand is developed, integrated with low-level control system, and following which empirical study is carried out, which demonstrates that the proposed hand is capable of implementing the grasp and manipulation of most of the objects used in daily life. In addition, the three widely used tools, i.e., the Kapandji score test, Cutkosky taxonomy, and Kamakura taxonomy, are used to evaluate the performance of the hand, which evidences that the MCR-hand II possesses high dexterity and excellent grasping capability; object manipulation performance is also demonstrated. This paper hence presents the design and development of a type of novel tendon–linkage-integrated anthropomorphic robotic hand, laying broader background for the development of low-cost robotic hands for both industrial and prosthetic use.


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