Pforzheim, Germany
Pforzheim, Germany

Time filter

Source Type

Schweizer S.,University of Basel | Schuster T.,University of Basel | Junginger M.,University of Potsdam | Junginger M.,Max Planck Institute of Colloids and Interfaces | And 4 more authors.
Macromolecular Materials and Engineering | Year: 2010

The report shows that simple LbL deposition of positively charged chitosan and negatively charged heparin can be used to efficiently modify the native surface of both NiTi and Ti without any previous treatments. Moreover, mineralization of the polymer multilayers with calcium phosphate leads to surfaces with low contact angles around 70 and 20° for NiTi and Ti, respectively. This suggests that a polymer multilayer/calcium phosphate hybrid coating could be useful for making NiTi or Ti implants that are at the same time antibacterial (via the chitosan), suppress blood clot formation (via the heparin), and favor fast endothelialization (via the improved surface hydrophilicity compared to the respective neat material). © 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.


Feth N.,Admedes Schuessler GmbH | Strobel M.,Admedes Schuessler GmbH
Conference on Lasers and Electro-Optics Europe - Technical Digest | Year: 2014

We give an overview of the application of ultra-short pulse (USP) lasers in the fabrication of miniaturized medical implants and devices like stents. Furthermore, we estimate the economic requirements to be fulfilled by USP lasers. © 2014 Optical Society of America.


Wohlschlogel M.,Admedes Schuessler GmbH | Steegmuller R.,Admedes Schuessler GmbH | Schuler A.,Admedes Schuessler GmbH
Journal of biomedical materials research. Part B, Applied biomaterials | Year: 2012

The electrochemical properties of electropolished Nitinol vascular implants manufactured in a serial-production manner starting with laser cutting of tubing and ending with electropolishing and final inspection were analyzed and evaluated over a time period of 1 year. Potentiodynamic polarization tests in phosphate-buffered saline were conducted on over 1250 Nitinol implants covering the entire serial production range at ADMEDES Schuessler GmbH - from tiny stents for neurovascular applications up to large heart valve frames. Breakdown potentials were evaluated and correlated to product group, properties of the semifinished material and raw material supplier. Results of this study give clear indications for the interrelation between material quality and the event of electrochemical breakdown in a potentiodynamic polarization test. Copyright © 2012 Wiley Periodicals, Inc.


Siekmeyer G.,Admedes Schuessler GmbH | Schussler A.,Admedes Schuessler GmbH | De Miranda R.L.,Acquandas GmbH | De Miranda R.L.,University of Kiel | Quandt E.,University of Kiel
Journal of Materials Engineering and Performance | Year: 2014

Self-expanding vascular implants are typically manufactured from Nitinol tubing, using laser cutting, shape setting, and electropolishing processes. The mechanical and fatigue behavior of those devices are affected by the raw material and its processing such as the melting process and subsequent warm and cold forming processes. Current trends focus on the use of raw material with fewer inclusions to improve the fatigue performance. Further device miniaturization and higher fatigue life requirements will drive the need toward smaller inclusions and new manufacturing methods. As published previously, the high-cycle fatigue region of medical devices from standard processed Nitinol is usually about 0.4-0.5% half-alternating strain. However, these results highly depend on the ingot and semi-finished materials, the applied manufacturing processes, the final dimensions of test samples, and applied test methods. Fabrication by sputter deposition is favorable, because it allows the manufacturing of micro-patterned Nitinol thin-film devices without small burrs, heat-affected zones, microcracks, or any contamination with carbides, as well as the fabrication of complex components e.g., 3D geometries. Today, however, there is limited data available on the fatigue behavior for real stent devices based on such sputter-deposited Nitinol. A detailed study (e.g., using metallographic methods, corrosion, tensile, and fatigue testing) was conducted for the first time in order to characterize the micro-patterned Nitinol thin-film material. © 2014 ASM International.


Wohlschlogel M.,Admedes Schuessler GmbH | Steegmuller R.,Admedes Schuessler GmbH | Schussler A.,Admedes Schuessler GmbH
Journal of Materials Engineering and Performance | Year: 2014

Nonmetallic inclusions in Nitinol, such as carbides (TiC) and intermetallic oxides (Ti4Ni2O x ), are known to be triggers for fatigue failure of Nitinol medical devices. These mechanically brittle inclusions are introduced during the melting process. As a result of hot and cold working in the production of Nitinol tubing inclusions are fractionalized due to the mechanical deformation imposed. While the role of inclusions regarding Nitinol fatigue performance has been studied extensively in the past, their effect on Nitinol corrosion behavior was investigated in only a limited number of studies. The focus of the present work was to understand the effect of inclusion size and distribution on the corrosion behavior of medical-device grade Nitinol tubing made from three different ingot sources during different manufacturing stages: (i) for the initial stage (hollow: round bar with centric hole), (ii) after hot drawing, and (iii) after the final drawing step (final tubing dimensions: outer diameter 0.3 mm, wall thickness 0.1 mm). For one ingot source, two different material qualities were investigated. Potentiodynamic polarization tests were performed for electropolished samples of the above-mentioned stages. Results indicate that inclusion size rather than inclusion quantity affects the susceptibility of electropolished Nitinol to pitting corrosion. © 2014 ASM International.


Rahim M.,Ruhr University Bochum | Frenzel J.,Ruhr University Bochum | Frotscher M.,Ruhr University Bochum | Frotscher M.,Cortronik GmbH | And 5 more authors.
Acta Materialia | Year: 2013

In the present work we show how different oxygen (O) and carbon (C) levels affect fatigue lives of pseudoelastic NiTi shape memory alloys. We compare three alloys, one with an ultrahigh purity and two which contain the maximum accepted levels of C and O. We use bending rotation fatigue (up to cycle numbers >108) and scanning electron microscopy (for investigating microstructural details of crack initiation and growth) to study fatigue behavior. High cycle fatigue (HCF) life is governed by the number of cycles required for crack initiation. In the low cycle fatigue (LCF) regime, the high-purity alloy outperforms the materials with higher number densities of carbides and oxides. In the HCF regime, on the other hand, the high-purity and C-containing alloys show higher fatigue lives than the alloy with oxide particles. There is high experimental scatter in the HCF regime where fatigue cracks preferentially nucleate at particle/void assemblies (PVAs) which form during processing. Cyclic crack growth follows the Paris law and does not depend on impurity levels. The results presented in the present work contribute to a better understanding of structural fatigue of pseudoelastic NiTi shape memory alloys. © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.


Patent
Admedes Schuessler GmbH | Date: 2013-08-16

A method for production of a body implant (1), having the steps: generating a braiding (10) from a first fiber material (12); executing a first heat treatment on the braiding (10); removing part of the fibers of the first fiber material (12), and replacing by a second fiber material (14) or reinsertion of the first fiber material (12) after the execution of a further processing step on the removal part of the fibers of the first fiber material (12).


The invention relates to a method for producing a body implant comprising the steps of: providing a wire; producing predetermined cuts of the cross section of the wire by means of an ultrashort pulse laser in order to produce a predetermined shape of the body implant. This method can be used to produce, for example, a body implant, an assembly consisting of a guide wire and a body implant, or a medical instrument having a guide wire.


PubMed | Acquandas GmbH, University of Kiel and Admedes Schuessler GmbH
Type: Journal Article | Journal: Journal of biomedical materials research. Part B, Applied biomaterials | Year: 2016

Corrosion behavior and microcleanliness of medical-device grade Nitinol tubing (Nix Ti1- x , x = 0.51; outer diameter 7 mm, wall thickness 0.5 mm), drawn from various ingot qualities, are compared to the characteristics of sputtered Nitinol film material (Nix Ti1- x , x=0.51; thickness 50 m). Electropolished tubing half-shell samples are tested versus as-received sputtered film samples. Inclusion size distributions are assessed using quantitative metallography and corrosion behavior is investigated by potentiodynamic polarization testing in phosphate-buffered saline at body temperature. For the sputtered film samples, the surface chemistry is additionally analyzed employing Auger Electron Spectroscopy (AES) composition-depth profiling. Results show that the fraction of breakdowns in the potentiodynamic polarization test correlates with number and size of the inclusions in the material. For the sputtered Nitinol film material no inclusions were detectable by light microscopy on the one hand and no breakdowns were found in the potentiodynamic polarization test on the other hand. As for electropolished Nitinol, the sputtered Nitinol film material reveals Nickel depletion and an Oxygen-to-Titanium intensity ratio of 2:1 in the surface oxide layer, as measured by AES. 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1176-1181, 2016.


Euroflex, Germany, announces that its parent company, G. Rau Group, has acquired the remaining shares of Admedes Schuessler GmbH from the co-founder Dr. Andreas Schüssler, making the G. Rau Group the sole owner. Up to now, G. Rau has been the majority shareholder of Admedes, a component supplier for the medical industry. Admedes management will be taken over by Dr. Axel Pfrommer (CEO) and Frank Nauheimer (CFO). Thus the management will be run now by an experienced executive team. Both managers have the full confidence of the G.Rau shareholders. Dr. Andreas Schüssler will stay connected with Admedes as the Chairman of the Technology Advisory Board, and Admedes will stay independent as a subsidiary company within the G. Rau Group. But from now on, there will be a well positioned group of companies with a stable financial background standing by side by side.

Loading Admedes Schuessler GmbH collaborators
Loading Admedes Schuessler GmbH collaborators