Observed Phenomena during the Development of an Adhesion Test for Coated Medical Devices

2015 ◽  
Vol 812 ◽  
pp. 381-386
Author(s):  
Torda László Sélley ◽  
Anna Kertész ◽  
Eszter Bognár
Keyword(s):  
Stainless Steel ◽  
Medical Devices ◽  
Polymer Coatings ◽  
Adhesion Test ◽  
Adhesive Properties ◽  
Coating Solution ◽  
Steel Sheets ◽  
Polymer Adhesion ◽  
Important Quality

Devices used in the field of medical technology require high biocompatibility. Medical devices that are made from stainless steel have good biocompatible properties, but polymer coatings can radically improve it. One of the most important quality of the coating is adhesion, and this was our rationale for developing a polymer adhesion testing protocol. In our research, two biocompatible polymers were compared, polyurethane (PUR) and poly-(DL-lactic-co-glycolic acid) (PDLG). Surface-treated stainless steel sheets were used as carrier for polymer layers. The adhesive properties of different layers were compared. Adhesion of the coatings was characterised by concentration of coating solution and surface roughness of the carriers, and some phenomena were observed.

Technology of Pulse Electrochemical Polishing of Stainless Steel

2010 ◽  
Vol 44-47 ◽  
pp. 3031-3035
Author(s):  
Zhi Yu Zhao ◽  
Guang Tao Zhou ◽  
Su Zhi Zhang ◽  
Bi Bo Xia
Keyword(s):  
Surface Roughness ◽  
Stainless Steel ◽  
Process Parameters ◽  
Pulse Frequency ◽  
Optimal Parameters ◽  
Electrochemical Polishing ◽  
High Quality ◽  
Important Method ◽  
Steel Sheets

Pulse electrochemical polishing is an important method to improve the surface quality of metal sheet. The reasonable control of process parameters is the key to obtain high-quality polishing. In this paper mechanism of pulse electrochemical polishing of stainless steel were studied using the stainless steel sheets of SUS201, SUS202, and SUS304. The influence of the current density, pulse frequency, duty cycle, and other factors on surface roughness were examined, and the optimal parameters was determined. The research results have directional meaning to the scale polishing of stainless steel-based in manufacturing enterprise.

DRUG REGULATORY PROCEDURES IN TANZANIA: A GLIMPSE

2015 ◽  
Vol 3 (2) ◽  
pp. 1-7 ◽  
Author(s):  
Achin Jain ◽  
M P Venkatesh M P ◽  
Pramod T.M. Kumar
Keyword(s):  
Quality Control ◽  
Medical Devices ◽  
Emerging Market ◽  
Well Being ◽  
New Drugs ◽  
Regulatory Body ◽  
Herbal Drugs ◽  
Drug Products ◽  
Set Up

In Tanzania, Tanzania Food and Drugs Authority (TFDA), is a regulatory body responsible for controlling the quality,safety and effectiveness of food, drugs, herbal drugs, cosmetics and medical devices. The Authority has been ensuringsafety, efficacy and quality of medicines by quality control tests; in addition to other quality assessment mechanisms.The guidelines laid by TFDA have also emanated from commitment to democracy and gives strong emphasis to thefulfilment of the needs of the less privileged rural population.Tanzania is an emerging market; the pharmaceutical market is valued at over US$250 million, and is growing at anannual rate of around 16.5% and is expected to reach approximately US$550 billion in 2020. Currently, the market ishighly dependent on imports, which account for around 75% of the total pharmaceutical market.The procedures and approval requirements of new drugs, variations, import, export and disposal have been set up bythe TFDA, which help in maintaining quality of the drug products that are imported as well being produced locally 

scholarly journals Analysis of Acoustic Emission (AE) Signals for Quality Monitoring of Laser Lap Microwelding

2021 ◽  
Vol 11 (15) ◽  
pp. 7045
Author(s):  
Ming-Chyuan Lu ◽  
Shean-Juinn Chiou ◽  
Bo-Si Kuo ◽  
Ming-Zong Chen
Keyword(s):  
Stainless Steel ◽  
Acoustic Emission ◽  
Frequency Domain ◽  
Monitoring System ◽  
Welding Quality ◽  
Steel Sheets ◽  
Signal Features ◽  
Ae Signal ◽  
Laser Microwelding ◽  
Ae Signals

In this study, the correlation between welding quality and features of acoustic emission (AE) signals collected during laser microwelding of stainless-steel sheets was analyzed. The performance of selected AE features for detecting low joint bonding strength was tested using a developed monitoring system. To obtain the AE signal for analysis and develop the monitoring system, lap welding experiments were conducted on a laser microwelding platform with an attached AE sensor. A gap between the two layers of stainless-steel sheets was simulated using clamp force, a pressing bar, and a thin piece of paper. After the collection of raw signals from the AE sensor, the correlations of welding quality with the time and frequency domain features of the AE signals were analyzed by segmenting the signals into ten 1 ms intervals. After selection of appropriate AE signal features based on a scatter index, a hidden Markov model (HMM) classifier was employed to evaluate the performance of the selected features. Three AE signal features, namely the root mean square (RMS) of the AE signal, gradient of the first 1 ms of AE signals, and 300 kHz frequency feature, were closely related to the quality variation caused by the gap between the two layers of stainless-steel sheets. Classification accuracy of 100% was obtained using the HMM classifier with the gradient of the signal from the first 1 ms interval and with the combination of the 300 kHz frequency domain signal and the RMS of the signal from the first 1 ms interval.

scholarly journals Metal artefact reduction of different alloys with dual energy computed tomography (DECT)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Anand John Vellarackal ◽  
Achim Hermann Kaim
Keyword(s):  
Stainless Steel ◽  
Image Quality ◽  
Femoral Stem ◽  
Dual Energy ◽  
Dual Energy Ct ◽  
Bony Tissue ◽  
Stem Image ◽  
Metal Artefact ◽  
Artefact Reduction

AbstractTo evaluate the influence of dual-energy CT (DECT) and Virtual monochromatic spectral (VMS) imaging on: (1) the artefact size of geometrically identical orthopaedic implants consisting of three different compositions and (2) the image quality of the surrounding bone, three similar phantoms—each featuring one femoral stem composed of either titanium, chrome-cobalt or stainless steel surrounded by five calcium pellets (200 mg hydroxyapatite/calcium carbonate) to simulate bony tissue and one reference pellet located away from the femoral stem—were built. DECT with two sequential scans (80 kVp and 140 kVp; scan-to-scan technique) was performed, and VMS images were calculated between 40 and 190 keV. The artefact sizes were measured volumetrically by semiautomatic selection of regions of interest (ROIs), considering the VMS energies and the polychromatic spectres. Moreover, density and image noise within the pellets were measured. All three phantoms exhibit artefact size reduction as energy increases from 40 to 190 keV. Titanium exhibited a stronger reduction than chrome-cobalt and stainless steel. The artefacts were dependent on the diameter of the stem. Image quality increases with higher energies on VMS with a better depiction of surrounding structures. Monoenergetic energies 70 keV and 140 keV demonstrate superior image quality to those produced by spectral energies 80 kVp and 140 kVp.

scholarly journals Experimental Investigation on Micro Deep Drawing of Stainless Steel Foils with Different Microstructural Characteristics

2021 ◽  
Vol 34 (1) ◽  
Author(s):  
Jingwei Zhao ◽  
Tao Wang ◽  
Fanghui Jia ◽  
Zhou Li ◽  
Cunlong Zhou ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Deep Drawing ◽  
Annealing Temperature ◽  
Localized Deformation ◽  
Microstructural Characteristics ◽  
Height Profile ◽  
Annealing Temperatures ◽  
Micro Deep Drawing ◽  
Profile Distribution

AbstractIn the present work, austenitic stainless steel (ASS) 304 foils with a thickness of 50 µm were first annealed at temperatures ranging from 700 to 1100 ℃ for 1 h to obtain different microstructural characteristics. Then the effects of microstructural characteristics on the formability of ASS 304 foils and the quality of drawn cups using micro deep drawing (MDD) were studied, and the mechanism involved was discussed. The results show that the as-received ASS 304 foil has a poor formability and cannot be used to form a cup using MDD. Serious wrinkling problem occurs on the drawn cup, and the height profile distribution on the mouth and the symmetry of the drawn cup is quite non-uniform when the annealing temperature is 700 ℃. At annealing temperatures of 900 and 950 ℃, the drawn cups are both characterized with very few wrinkles, and the distribution of height profile, symmetry and mouth thickness are uniform on the mouths of the drawn cups. The wrinkling becomes increasingly significant with a further increase of annealing temperature from 950 to 1100 ℃. The optimal annealing temperatures obtained in this study are 900 and 950 ℃ for reducing the generation of wrinkling, and therefore improving the quality of drawn cups. With non-optimized microstructure, the distribution of the compressive stress in the circumferential direction of the drawn foils becomes inhomogeneous, which is thought to be the cause of the occurrence of localized deformation till wrinkling during MDD.

scholarly journals High-quality percussion drilling with ultrashort laser pulses

2021 ◽  
Vol 127 (9) ◽  
Author(s):  
A. Feuer ◽  
R. Weber ◽  
R. Feuer ◽  
D. Brinkmeier ◽  
T. Graf
Keyword(s):  
Stainless Steel ◽  
Laser Fluence ◽  
Ablation Threshold ◽  
Laser Pulses ◽  
Ultrashort Laser Pulses ◽  
High Quality ◽  
Edge Quality ◽  
Ultrashort Laser ◽  
Percussion Drilling

AbstractThe influence of the laser fluence on the quality of percussion-drilled holes was investigated both experimentally and by an analytical model. The study reveals that the edge quality of the drilled microholes depends on the laser fluence reaching the rear exit of the hole and changes with the number of pulses applied after breakthrough. The minimum fluence that must reach the hole’s exit in order to obtain high-quality microholes in stainless steel was experimentally found to be 2.8 times the ablation threshold.

scholarly journals Investigation of Cutting Quality of Remote DOE Laser Cutting in 0.5 mm Stainless Steel

2017 ◽  
Vol 89 ◽  
pp. 164-171
Author(s):  
Sigurd Lazic Villumsen ◽  
Morten Kristiansen
Keyword(s):  
Stainless Steel ◽  
Laser Cutting

scholarly journals Outcomes of Peer Review for Radiotherapy Treatment Plans With Palliative Intent

2018 ◽  
Vol 14 (12) ◽  
pp. e794-e800
Author(s):  
Dina Thompson ◽  
Kimberly Cox ◽  
James Loudon ◽  
Ivan Yeung ◽  
Woodrow Wells
Keyword(s):  
Peer Review ◽  
Treatment Plan ◽  
Palliative Radiotherapy ◽  
Cancer Center ◽  
Palliative Intent ◽  
Treatment Plans ◽  
Important Quality ◽  
Radiation Medicine ◽  
Radiotherapy Treatment

Purpose: Peer review of a proposed treatment plan is increasingly recognized as an important quality activity in radiation medicine. Although peer review has been emphasized in the curative setting, applying peer review for treatment plans that have palliative intent is receiving increased attention. This study reports peer review outcomes for a regional cancer center that applied routine interprofessional peer review as a standard practice for palliative radiotherapy. Methods and Materials: Peer review outcomes for palliative radiotherapy plans were recorded prospectively for patients who began radiotherapy between October 1, 2015, and September 30, 2017. Recommended and implemented changes were recorded. The content of detailed discussions was recorded to gain insight into the complexities of palliative treatment plans considered during peer review. Results: Peer review outcomes were reviewed for 1,413 treatment plans with palliative intent. The proportions of detailed discussions and changes recommended were found to be 139 (9.8%) and 29 (2.1%), respectively. The content of detailed discussions and changes recommended was categorized. Major changes represented 75.9% of recommended changes, of which 84.2% were implemented clinically. Conclusion: Many complexities exist that are specific to palliative radiotherapy. Interprofessional peer review provides a forum for these complexities to be openly discussed and is an important activity to optimize the quality of care for patients with treatment plans that have palliative intent.

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