Flexible Prosthetic Vein Valve

2006 ◽  
Vol 1 (2) ◽  
pp. 105-112 ◽  
Author(s):  
Rahul D. Sathe ◽  
David N. Ku
Keyword(s):  
Mechanical Design ◽  
Varicose Veins ◽  
Low Cost ◽  
Bench Test ◽  
Design Criteria ◽  
Flow Loop ◽  
Opening Pressure ◽  
Vein Thrombosis ◽  
Cyclic Flow ◽  
Opening And Closing

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.

Mechanical Design of a Low Cost Transhumeral Prosthesis

2017 ◽  
Author(s):  
Luis Arturo Gómez Malagón ◽  
João Luiz Vilar Dias
Keyword(s):  
Mechanical Design ◽  
Low Cost

Leech Therapy - A unique treatment in Ayurveda

2019 ◽  
Vol 4 (02) ◽  
Author(s):  
Prasadshakti G. Gannur
Keyword(s):  
Blood Circulation ◽  
Skin Diseases ◽  
Varicose Veins ◽  
Blood Stream ◽  
Blood Capillaries ◽  
Analgesic Property ◽  
Vein Thrombosis ◽  
Leech Therapy ◽  
Medicinal Leeches ◽  
Deep Vein

As mentioned in Ayurveda, Rakta itself is life for human being. If it get vitiated (impure) by means of unhealthy food habits and seasonal change is going to induce many disease. There is a unique worm - Leech which is used therapeutically to treat certain diseases induced by impure blood. Medicinal leeches are used for therapeutic purpose; these will suck only impure blood and relieve the symptoms. While sucking leaches leave saliva into the blood stream, which contain many medicinal properties. Out of which Hirudin is the main content which is having very effective anti-coagulant and analgesic property, because of this analgesic property, the process of sucking is painless. Leaches are mainly used in skin diseases as acne, Kusta, Visarpa, recurrent abscess along with these certain diseases which involve impairment of the blood circulation such as varicose veins deep vein thrombosis non healing ulcers and necrosis are also get benefited by leech therapy which improve the blood circulation by stimulating blood capillaries. Hence in this paper the uses of leech therapy are mentioned for the society to get benefited.

Design and operation of a tripod walking robot via dynamics simulation

Robotica ◽  
2010 ◽  
Vol 29 (5) ◽  
pp. 733-743 ◽  
Author(s):  
Conghui Liang ◽  
Hao Gu ◽  
Marco Ceccarelli ◽  
Giuseppe Carbone
Keyword(s):  
Mechanical Design ◽  
Low Cost ◽  
Three Dimensional ◽  
The Body ◽  
Dynamics Simulation ◽  
Walking Ability ◽  
Walking Robot ◽  
Three Dimensional Model ◽  
Software Environment ◽  
Leg Mechanisms

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.

Thermo-Mechanical Design of Brazed Plate-Fins Heat Exchanger Based on Finite Element Modeling Using Homogenization Techniques

2009 ◽  
Author(s):  
Johan Dib ◽  
Ivan Lewon ◽  
Boris Martin
Keyword(s):  
Finite Element ◽  
Heat Exchanger ◽  
Heat Exchangers ◽  
Mechanical Design ◽  
Periodic Structures ◽  
Software Tool ◽  
Design Criteria ◽  
Base Metals ◽  
The Core ◽  
Aluminum Base

Using classical Finite Element (FE) tools to model heat exchangers emphasizes the need to elaborate specific methods to reduce the size of the numerical problem. Among these methods, homogenization techniques can be adapted and used for Brazed Aluminum Plate-Fins Heat Exchangers (BAHX) including layers of periodic structures. Actually the core is formed by stacking single layers consisting of periodic corrugated fins, side-bar and parting sheets which are all made of aluminum base metals, and brazed in a furnace. So in this paper a global methodology of BAHX modeling and design is presented. It integrates homogenization techniques to perform FE calculation and localization techniques to allow applying the appropriate design criteria. Finally, to validate this methodology, results are then compared on a basic heat exchanger modeled both by classical FE tools and a dedicated software tool encapsulating both homogenization and localization techniques.

scholarly journals A Cotton Module Feeder Plastic Contamination Inspection System

2020 ◽  
Vol 2 (2) ◽  
pp. 280-293
Author(s):  
Mathew G. Pelletier ◽  
Greg A. Holt ◽  
John D. Wanjura
Keyword(s):  
Mechanical Design ◽  
Low Cost ◽  
Processing System ◽  
Technical Note ◽  
Inspection System ◽  
Learning Program ◽  
Cotton Lint ◽  
Cotton Industry ◽  
Bill Of Materials ◽  
The U.S

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.

Design of a Teaching Robot with Three Degrees of Freedom

2012 ◽  
Vol 619 ◽  
pp. 325-328
Author(s):  
You Jun Huang ◽  
Ze Lun Li ◽  
Zhi Cheng Huang
Keyword(s):  
Degrees Of Freedom ◽  
Low Cost ◽  
Degree Of Freedom ◽  
Good Repeatability ◽  
Main Components ◽  
Opening And Closing ◽  
Three Degree Of Freedom ◽  
Three Degrees Of Freedom ◽  
Application Prospects

A teaching robot with three degree of freedom is designed. The three degrees of freedom are: waist rotation, lifting and stretching of the arm and opening and closing of the gripper. The designs of the main components are: a mobile chassis, parallel rails, horizontal rails and manipulator. The teaching robot designed has the features of low cost, easy to regulation, good repeatability and it has good promotion and application prospects in the field of teaching.

scholarly journals MANUFACTURE OF A DIE PROTOTYPE FOR DIDACTIC PURPOSES IN MECHATRONIC ENGINEERING

2020 ◽  
pp. 1-40
Author(s):  
ELIEL EDUARDO MONTIJO-VALENZUELA ◽  
SAUL DANIEL DURAN-JIMENEZ ◽  
LUIS ALBERTO ALTAMIRANO-RÍOS ◽  
JOSÉ ISAEL PÉREZ-GÓMEZ ◽  
OSCAR SALMÓN-AROCHI
Keyword(s):  
Mechanical Design ◽  
Theoretical Calculations ◽  
Low Cost ◽  
Die Design ◽  
Element Analysis ◽  
Technological Institute ◽  
Computer Aided ◽  
Cad Models ◽  
Functional Prototype ◽  
Definition Of

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.

scholarly journals Difficulties of differential diagnosis of portal hypertension: case report

2021 ◽  
pp. 92-101
Author(s):  
T. V. Penkina ◽  
O. E. Berezutskaya ◽  
D. T. Dicheva ◽  
E. V. Partsvania-Vinogradova ◽  
V. S. Larina ◽  
...  
Keyword(s):  
Differential Diagnosis ◽  
Portal Hypertension ◽  
Portal Vein ◽  
Portal Vein Thrombosis ◽  
Clinical Case ◽  
Clinical Symptoms ◽  
Varicose Veins ◽  
Small Diameter ◽  
Magnetic Resonance Tomography ◽  
Vein Thrombosis

In the article we analysed the difficulties of differential diagnosis of portal hypertension, considers a clinical case that illustrates the presented theoretical material. In the presented clinical observation, the patient’s disease was manifested by bleeding from the varicose veins of the esophagus. In most cases, portal hypertension syndrome in practicing clinicians is associated with liver cirrhosis, however, it is necessary to remember about the possibility of developing subhepatic portal hypertension, in particular as a result of the formation of portal vein thrombosis. If there are signs of portal hypertension, it is necessary to specify the level of obstruction to blood flow, that is, the form of portal hypertension (subhepatic, hepatic, suprahepatic). Often, portal vein thrombosis can be formed due to undiagnosed blood diseases that occur without any clinical symptoms. The provided clinical example demonstrates a case of portal hypertension in the outcome of a chronic form of myeloproliferative syndrome. Portal cavernoma is quite rare and it is formed due to multiple small-diameter venous structures that gradually replace the occluded vessel with a system of collaterals proximal and distal to the portal vein thrombosis site. In the formation of the diagnosis the main are radiation research methods, but the conclusions should be considered only in conjunction with the clinical evidence. The clinical case is interesting because a large cavernoma of the portal vein in a patient with subhepatic portal hypertension was regarded as a «solid formation» according to magnetic resonance tomography. According to the literature data, cavernous transformation has an external similarity to the tumor process, which expands the range of differential diagnosis and requires the exclusion of oncological formations. 

scholarly journals Application of analytic hierarchy process to evaluate design criteria for humane trap cage.

2020 ◽  
Vol 4 (2) ◽  
pp. 30-35
Author(s):  
Sivajothi Paramasivam ◽  
Hari Krishnan Munisamy ◽  
Santhansamy Rayappan
Keyword(s):  
Analytic Hierarchy Process ◽  
Low Cost ◽  
Quality Criteria ◽  
Design Criteria ◽  
Animal Population ◽  
Chronic Infections ◽  
Analytic Hierarchy ◽  
The Public ◽  
Hierarchy Process ◽  
Selection Of

Atrocities against stray animal’s especially large number of scavenging street dogs have increased at an alarming rate nationwide. Relevant authorities, in view of controlling stray animal population and curb chronic infections mulled cracking down on stray dogs using inhumane methods such as usage of tranquilizers or forcefully capturing. Thus, causing injuries, trauma and potentially death to these captured strays. Even though statistics about the number of violent incidents against strays remains unknown but animal welfare groups report constant complaints regarding animal cruelty. Animal activists mooted a request to design and built a modernize efficient yet low cost trap cage with a provision of technology which are normally ignored by many quarters; as a vehicle to educate the public on humane and compassionate ways to treat stray animals.   The design of the cage involves consists of 3 parts, which was electronics hardware, communication system and critically the structure hardware whereby to withstand the possible aggressiveness of the animal. The objective of this paper is to present and apply the techniques of the analytic hierarchy process (AHP) in the prioritization and selection of design criteria of the trap cage. The finding shows that out of 5 design criteria, quality criteria is the most important criteria in designing of a humane trap cage issue. This is followed by innovativeness, cost, safety and aesthetics factors.

Autonomous Docking of Hybrid-Wheeled Modular Robots with an Integrated Active Genderless Docking Mechanism

2021 ◽  
pp. 1-36
Author(s):  
Shubhdildeep S. Sohal ◽  
Bijo Sebastian ◽  
Pinhas Ben-Tzvi
Keyword(s):  
Visual Servoing ◽  
Mechanical Design ◽  
Low Cost ◽  
Image Plane ◽  
Robotic Systems ◽  
Modular Robots ◽  
Tracking Accuracy ◽  
Drive Mechanism ◽  
Docking Mechanism ◽  
Autonomous Docking

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.

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