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In-Vitro Drug Delivery and Corrosion Study of Polymer Coated Nitinol StentsTan, Aoyong 28 April 2021 (has links)
No description available.
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Development of an Intervertebral Cage Using Additive Manufacturingwith Embedded NiTi Hinges for a Minimally Invasive DeploymentAnderson, Walter 25 November 2013 (has links)
No description available.
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Development of a Data Transformation Method for a Customized Stent usingAdditive ManufacturingTepe, Julius January 2018 (has links)
Conventionally manufactured stents are available in uniform sizes and straight forms. These standard products are not suitable for all patients and research indicates that this is the reason for migration of stents in the vessel, and tubular structure in general, after deployment. The occurrence of migration makes readmission into hospital and the removal of the deployed stent necessary. This thesis develops a method which results in patient-customized stents which can be manufactured through additive manufacturing. These individualized stents intent to offer the same advantages of conventional stents while mitigating the disadvantages. The work’s core part is thedesign of a stent based on the geometric information through a medical scan. It converts the relevant areas from the medical scan data which is in the DICOM format to the STL file format. After cleaning and further processing, the shape will be the base for the design process of a stent using CAD software. Additionally, it also gives insight into the subjacent technologies such as medical scanning, additive manufacturing, choice of material and necessary further processing steps. A process chain from scanning, data transformation, 3D printing and post processing is described.The developed method delivers a reliable model and results in a fully individualized stent. In the current stage, it involves manual work since the representation of data in the steps is different. Further suggestions for steps to automate the process and an estimation of economic efficiency is given. / Det finns konventionellt tillverkade stenter i likformiga storlekar och raka former. Dem här standardprodukter är inte lämpliga för alla patienter och forskning tyder på att detta är orsaken till migrationen av stenter i blodkärl efter placering. Förekomsten av migration skapa återtagande på sjukhus och avlägsnande av den placerade stenten är nödvändig. Den här avhandlingen utvecklar en metod som resulterar i patient anpassade stenter som kan varatillverkad genom additiv tillverkning. Dessa individualiserade stenter avser att erbjuda samma fördelar som konventionella stenter och mildra nackdelarna. Arbetets kärna är designen av en stent baserad på den geometriska informationen baserande på en medicinsk bildteknik. Det omvandlar relevanta kroppsdelar från det medicinska bildteknik som finns i DICOM-formatet till STLfilformatet. Efter rengöring och vidare bearbetning kommer formen att vara basen för stentens designprocess med CAD-mjukvara. Dessutom ger den också inblick i de underliggande teknikerna som medicinsk bildteknik, tillsatsframställning, materialval och nödvändig vidarebehandling steg. En processkedja från skanning, datatransformation, 3D-utskrift och efterbehandling är beskrivits.Den utvecklade metoden ger en tillförlitlig modell och resulterar i en helt individualiserad stent. I det aktuellt stadium, innebär det manuellt arbete eftersom representationen av data i stegen är annorlunda. Ytterligare förslag till åtgärder för att automatisera processen och en uppskattning av ekonomisk effektivitet är given.
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Design and Analysis of Two Compliant Mechanism Designs for Use in Minimally Invasive Surgical InstrumentsDearden, Jason Lon 01 June 2016 (has links)
Minimally invasive surgery (MIS) has several advantages over traditional methods. Scaling MIS instruments to smaller sizes and increasing their performance will enable surgeons to offer new procedures to a wider range of patients. In this work, two compliant mechanism-based minimally invasive surgical instrument wrist or gripper mechanisms are designed and analyzed.The cylindrical cross-axis flexural pivot (CCAFP) is a single-degree-of-freedom wrist mechanism that could be combined with existing gripper mechanisms to create a multi-degree-of freedom instrument. The simplicity of the CCAFP mechanism facilitates analysis and implementation. The flexures of the CCAFP are integral with the instrument shaft, enabling accessories to be passed through the lumen. The CCAFP is analyzed and determined to be a viable wrist mechanism for MIS instruments based on research results. A finite element (FE) model of the mechanism is created to analyze the force-deflection and strain-deflection relationships. Experimental results are used to verify the FE model. A 3 mm design is created that could undergo an angular deflection of +/- 90 degrees. The addition of cam surfaces to help guide the flexures and limit the maximum stress during deflection is explored. These cam surfaces can be integral to the instrument shaft along with the flexures. A 2 degree-of-freedom (DoF) CCAFP with intersecting axes of rotation is also introduced. The inverted L-Arm gripper compliant mechanism has 2 DoF, one wrist and one gripping. Three challenges associated with using compliant mechanisms in MIS instruments are considered: inadequate performance in compression, large flexure deformations, and a highly variable mechanical advantage. These challenges were resolved in the L-Arm design by inverting the flexures, tailoring flexure geometry and employing nitinol, and integrating pulleys into each jaw of the mechanism. The L-Arm was prototyped at several sizes to demonstrate functionality and scalability. A finite element model of the L-Arm flexure was created to determine the strain-deflection relationship. A fatigue test was completed to characterize nitinol for use in compliant mechanism MIS instruments.These concepts demonstrate the ability of compliant mechanisms to overcome the design and manufacturing challenges associated with MIS instruments at the 3 mm scale. The models and principles included in this work could be used in the application of compliant mechanisms to design new MIS instruments as well as in other areas that employ compliant mechanisms in a cylindrical form factor.
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Tension and Flex Fatigue Behavior of Small Diameter Wires for Biomedical ApplicationsBenini, Brian J. 17 May 2010 (has links)
No description available.
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Design and Testing of a Minimally Invasive Blood Clot Removal Device Constructed With Elements of Superelastic NitinolPuffer, Andrew James January 2014 (has links)
No description available.
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Variable Stiffness and Active Damping Technique for Turbomachinery using Shape Memory AlloysWischt, Rachel Jeanne January 2015 (has links)
No description available.
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Joining of Shape-Memory NiTi Torque Tubes to Structural MaterialsFox, Gordon R. 19 June 2012 (has links)
No description available.
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PRESTRESSING OF SIMPLY SUPPORTED CONCRETE BEAM WITH NITINOL SHAPE MEMORY ALLOYKotamala, Sreenath 25 August 2004 (has links)
No description available.
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Finite Element Analysis of Shape Memory Alloy Biomedical DevicesTabesh, Majid 14 June 2010 (has links)
No description available.
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