Compliant Mechanism as a Motion-Preserving Artificial Spinal Disc: A Novel Concept

2020 ◽  
Vol 3 (3) ◽  
Author(s):  
Or David ◽  
Moshe Shoham
Keyword(s):  
Compliant Mechanism ◽  
Three Dimensional ◽  
Joint Motion ◽  
Facet Joints ◽  
Artificial Disc ◽  
Screw Axis ◽  
Natural Motion ◽  
Spinal Disc ◽  
Novel Concept ◽  
Artificial Intervertebral Disc

Abstract Investigations of spinal disc replacement options have been conducted for several decades but, as yet, the suggested solutions have not been proven to correctly preserve the natural joint motion. This paper focuses on a new structure of an artificial intervertebral disc joint that closely supports a close-to-natural three-dimensional motion of two adjacent vertebrae. The disc design is based on a passive parallel mechanism, with different stiffnesses for each link. Optimization of the artificial disc dimensions and link stiffnesses enabled convergence of the finite screw axis (FSA) of the artificial disc joint with that of a natural disc. As a result, the natural motion of the spine vertebrae was maintained and the loads on the facet joints minimized. The mechanism design was optimized, built, tested, and proven to be a feasible artificial disc with natural motion preservation characteristics.

Spontaneous craniocervical osseous fusion caused by cervical dystonia

2001 ◽  
Vol 95 (1) ◽  
pp. 115-118 ◽  
Author(s):  
Ralf Weigel ◽  
Michael Rittmann ◽  
Joachim K. Krauss
Keyword(s):  
Cervical Dystonia ◽  
Three Dimensional ◽  
Sternocleidomastoid Muscle ◽  
Facet Joints ◽  
Content Type ◽  
History Of ◽  
Posterior Neck ◽  
Atlantoaxial Rotatory Fixation ◽  
The Right ◽  
Rotatory Fixation

✓ The authors report on a 31-year-old man with spontaneous craniocervical osseous fusion secondary to cervical dystonia (CD). After an 8-year history of severe CD, the patient developed a fixed rotation of his head to the right. Three-dimensional computerized tomography reconstructions revealed rotation and fixation of the occiput and C-1 relative to C-2, which was similar to that seen in atlantoaxial rotatory fixation. There was abnormal ossification of the odontoid facet joints and ligaments. Additional ossification was observed in the cervical soft tissue bridging the lateral mass of C-1 and the occiput. The patient underwent partial myectomy of the dystonic left sternocleidomastoid muscle and selective posterior ramisectomy of the right posterior neck muscles; postoperatively he experienced relief of his neck pain. In patients with CD refractory to conservative treatment, the appropriate timing of surgical treatment is important.

scholarly journals Physiological in vitro sacroiliac joint motion: a study on three‐dimensional posterior pelvic ring kinematics

2018 ◽  
Vol 234 (3) ◽  
pp. 346-358 ◽  
Author(s):  
Niels Hammer ◽  
Mario Scholze ◽  
Thomas Kibsgård ◽  
Stefan Klima ◽  
Stefan Schleifenbaum ◽  
...  
Keyword(s):  
Sacroiliac Joint ◽  
Pelvic Ring ◽  
Three Dimensional ◽  
Joint Motion ◽  
Posterior Pelvic Ring

Novel Concept of the Three-Dimensional Vertical FG nand Flash Memory Using the Separated-Sidewall Control Gate

2012 ◽  
Vol 59 (8) ◽  
pp. 2078-2084 ◽  
Author(s):  
Moon-Sik Seo ◽  
Bong-Hoon Lee ◽  
Sung-Kye Park ◽  
Tetsuo Endoh
Keyword(s):  
Flash Memory ◽  
Three Dimensional ◽  
Nand Flash ◽  
Nand Flash Memory ◽  
Novel Concept

Low-volume-change, dendrite-free lithium metal anodes enabled by lithophilic 3D matrix with LiF-enriched surface

2019 ◽  
Vol 7 (11) ◽  
pp. 6090-6098 ◽  
Author(s):  
Yangyang Feng ◽  
Chaofan Zhang ◽  
Bing Li ◽  
Shizhao Xiong ◽  
Jiangxuan Song
Keyword(s):  
Synergistic Effect ◽  
Volume Change ◽  
Three Dimensional ◽  
Lithium Metal ◽  
Metal Anode ◽  
3D Matrix ◽  
Lithium Metal Anodes ◽  
Li Metal Anode ◽  
Low Volume ◽  
Novel Concept

We report a novel concept for a stable Li metal anode via the synergistic effect of a three-dimensional skeleton and stable artificial SEI.

Two polymorphs of 2-ethyl-3-hydroxy-6-methylpyridinium hydrogenN-acetyl-L-glutamate from powder diffraction data

2013 ◽  
Vol 69 (12) ◽  
pp. 1549-1552 ◽  
Author(s):  
Vladimir V. Chernyshev ◽  
Sergey Y. Efimov ◽  
Ksenia A. Paseshnichenko ◽  
Andrey A. Shiryaev
Keyword(s):  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Powder Diffraction ◽  
Diffraction Data ◽  
Crystal Packing ◽  
Three Dimensional ◽  
Powder Diffraction Data ◽  
Screw Axis ◽  
Dimensional Network ◽  
Polymorphic Modifications

The title salt, C8H12NO+·C7H10NO5−, crystallizes in two polymorphic modifications,viz.monoclinic (M) and orthorhombic (O). The crystal structures of both polymorphic modifications have been established from laboratory powder diffraction data. The crystal packing motifs in the two polymorphs are different, but the conformations of the anions are generally similar. InM, the anions are linked by pairs of hydrogen bonds of the N—H...O and O—H...O types into chains along theb-axis direction, and neighbouring molecules within the chain are related by the 21screw axis. The cations link these chainsviaO—H...O and N—H...O hydrogen bonds into layers parallel to (001). InO, the anions are linked by O—H...O hydrogen bonds into helices along [001], and neighbouring molecules within the helix are related by the 21screw axis. The neighbouring helical turns are linked by N—H...O hydrogen bonds. The cations link the helicesviaO—H...O and N—H...O hydrogen bonds, thus forming a three-dimensional network.

A novel three-dimensional elliptical vibration cutting device based on the freedom and constraint topologies theory

2018 ◽  
Vol 233 (3) ◽  
pp. 675-685 ◽  
Author(s):  
Sheng Lin ◽  
Xi Kong ◽  
Chun Wang ◽  
Yun Zhai ◽  
Liang Yang
Keyword(s):  
Design Theory ◽  
Compliant Mechanism ◽  
Three Dimensional ◽  
Cutting Speed ◽  
Elliptical Vibration Cutting ◽  
Vibration Cutting ◽  
Elliptical Vibration ◽  
The Common ◽  
Constraint Topologies ◽  
The Relationship

Aiming at the issue of the lack of the design theory for the three-dimensional elliptical vibration cutting device, a compliant mechanism with two rotations and one translation is synthesized based on the theory of freedom and constraint topologies. And a three-dimensional elliptical vibration cutting device is proposed on the basis of the compliant mechanism. The relationship between the critical speed and the length of the tool bar is analyzed. Simulation is conducted to analyze the influence of parameters on the output ellipse. Experiments are conducted to verify the validity of the elliptical vibration cutting device. The relationship between the roughness and the cutting speed is obtained. Experiments with different driving frequencies are conducted without the change of other parameters. Results show that the proposed compliant mechanism is feasible for the elliptical vibration cutting device. Compared with the common cutting, the new elliptical vibration cutting device has a better performance in the processing effect. This provides an important reference for design of the elliptical vibration cutting device.

A Computational Design Framework for a Rapid Solid Freeform Fabrication Process

2000 ◽  
Author(s):  
Deepesh Khandelwal ◽  
T. Kesavadas
Keyword(s):  
Solid Freeform Fabrication ◽  
Optimization Technique ◽  
Three Dimensional ◽  
Computational Design ◽  
Freeform Fabrication ◽  
3D Cad ◽  
Build Time ◽  
Cad Models ◽  
Efficient Machine ◽  
Novel Concept

Abstract Solid Freeform Fabrication (SFF) techniques in recent years have shown tremendous promise in reducing the design time of products. This technique enables designers to get three-dimensional physical prototypes from 3D CAD models. Although SFF has gained popularity, the manufacturing time and cost have limited its use to small and medium sized parts. In this paper we have proposed a novel concept for rapidly building SFF parts by inserting prefabricated inserts into the fabricated part. A computational algorithm was developed for determining ideal placement of inserts/cores in the CAD model of the part being prototyped using a heuristic optimization technique called Simulated Annealing. This approach will also allow the designers to build multi-material prototypes using the Rapid Prototyping (RP) technique. By using cheaper pre-fabricates instead of costly photopolymers, the production cost of the SFFs can be reduced. Additionally it will also reduce build time, resulting in efficient machine utilization.

Spark plug reliability improvement with regard to ceramic insulator form factor

2020 ◽  
pp. 095440702094662
Author(s):  
Bernard Fryskowski
Keyword(s):  
Form Factor ◽  
Surface Resistance ◽  
Design Method ◽  
Three Dimensional ◽  
Fuel Mixture ◽  
Spark Plug ◽  
Ceramic Insulators ◽  
Spherical Polynomial ◽  
Novel Concept ◽  
High Degree

Ceramic insulators for spark plugs are important components responsible for the dielectric barrier to generate high-voltage pulses required to ignite the air–fuel mixture and for providing mechanical support to the center electrode. To ensure a high degree of reliability, many manufacturers apply corrugation patterns to the glazed upper part of an insulator to prevent flashover and parasitic discharges as well as to reduce the leakage current. The corrugation pattern design based mostly on simple cylindrical and conical shapes has changed very little over the years. This gives rise to the question whether an application of more sophisticated curves such as spherical, polynomial, or exponential can improve the surface resistance of a ribbed spark plug insulator. Quantitative analysis based on form factor and leakage distance calculations was used as a design method to optimize the shape of the spark plug insulator and its pollution performance. Furthermore, a novel concept of concave insulator corrugation patterns formed by quadratic and exponential functions was proposed and discussed as an alternative solution suitable for practical application. It was found that insulator ribs completed with supplementary concave corrugation ensure a longer leakage distance than conventional patterns. According to the results of calculations and measurements performed on three-dimensional printed samples, it was stated that the novel concave corrugation patterns can significantly increase the surface resistance of spark plug insulators.

scholarly journals Novel 3D printing concept for the fabrication of time-controlled drug delivery systems

2018 ◽  
Vol 4 (1) ◽  
pp. 141-144 ◽  
Author(s):  
Jan Konasch ◽  
Alexander Riess ◽  
Michael Teske ◽  
Natalia Rekowska ◽  
Natalia Rekowska ◽  
...  
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Inkjet Printing ◽  
Drug Delivery Systems ◽  
Three Dimensional ◽  
Delivery Systems ◽  
Glycol Diacrylate ◽  
Pharmaceutical Ingredients ◽  
Poly Ethylene ◽  
Novel Concept

AbstractThree-dimensional (3D) printing has become a popular technique in many areas. One emerging field is the use of 3D printing for the development of 3D drug delivery systems (DDS) and drug-loaded medical devices. This article describes a novel concept for the fabrication of timecontrolled drug delivery systems based on stereolithography combined with inkjet printing. An inkjet printhead and an UV-LED light source have been integrated into an existing stereolithography system. Inkjet printing is used to selectively incorporate active pharmaceutical ingredients (API) during a stereolithographic 3D printing process. In an initial experimental study, poly (ethylene glycol) diacrylate (PEGDA) was used as polymer whereas 2-Hydroxy-4´-(2- hydroxyethoxy)-2-methylpropiophenone (Irgacure 2959) and Lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) were used as photoinitiators. Basic structures could be manufactured successfully by the new hybrid 3D printing system.

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