Transcatheter aortic valve implantation (TAVI) has become a key treatment for severe aortic stenosis, especially for patients unsuitable for surgery. Since its introduction in 2002, TAVI has advanced significantly due to improvements in imaging, operator skills, and device engineering. Despite these innovations, challenges in device sizing and positioning remain, complicating outcome predictions.
View Article and Find Full Text PDFTo address the noise issue in fiber optic monitoring signals in frozen soil areas, this study employs wavelet denoising techniques to process the fiber optic signals. Since existing parameter choices for wavelets are typically based on conventional environments, selecting suitable parameters for frozen soil regions becomes crucial. In this work, an index library is constructed based on commonly used wavelet basis functions in civil engineering.
View Article and Find Full Text PDFAdditive manufacturing (AM) technology has paved the way for manufacturing personalised stents. However, there is a notable gap in comprehensive microstructure analyses and in vitro evaluations of the AM CoCr stents using advanced methodologies. To address this gap, this study focuses on investigating the microstructure and in vitro performance of personalised CoCr stents manufactured through micro-laser powder bed fusion (μ-LPBF).
View Article and Find Full Text PDFZhongguo Yi Liao Qi Xie Za Zhi
September 2023
Traditional Chinese medicine fumigation device is the carrier of traditional Chinese medicine fumigation treatment. In recent years, with the rapid development of new technology and new materials, the development of fumigation device changes with each passing day, and a variety of new products continue to emerge. However, at present, the lack of corresponding evaluation norms, resulting in some difficulties in the registration, marketing, quality control, evaluation scale and other aspects of the product.
View Article and Find Full Text PDFRecently, additive manufacturing (AM) has been investigated as an innovative method to manufacture stents due to its capability in producing complex and customized structures. In this paper, the cardiovascular stents of M-type and N-type with inverse unequal height strut structure and N-type with equal height strut structure were designed and manufactured by Selective Laser Melting (SLM). Following surface polishing, balloon expansion, plane compression and three-point bending experiments were carried out to evaluate the mechanical performance of the stent.
View Article and Find Full Text PDFBackground: Despite optimizations of coronary stenting technology, a residual risk of in-stent restenosis (ISR) remains. Vessel wall injury has important impact on the development of ISR. While injury can be assessed in histology, there is no injury score available to be used in clinical practice.
View Article and Find Full Text PDFSheng Wu Yi Xue Gong Cheng Xue Za Zhi
June 2023
The interventional therapy of vascular stent implantation is a popular treatment method for cardiovascular stenosis and blockage. However, traditional stent manufacturing methods such as laser cutting are complex and cannot easily manufacture complex structures such as bifurcated stents, while three-dimensional (3D) printing technology provides a new method for manufacturing stents with complex structure and personalized designs. In this paper, a cardiovascular stent was designed, and printed using selective laser melting technology and 316L stainless steel powder of 0-10 µm size.
View Article and Find Full Text PDFAdditive manufacturing of fiber-reinforced polymers is one of the latest technical developments in composites manufacturing. However, there is a severe shortage of research into continuous fiber-reinforced polymers manufactured through stereolithography. For the first time, this article investigates the fracture properties of continuous carbon fiber-reinforced polymer produced by three-dimensional stereolithography printing.
View Article and Find Full Text PDFAdditive manufacturing (AM) is an emerging method for the fabrication of stents, which is cost-saving and capable of producing personalised stent designs. However, poor surface finish and dimension discrepancy in the manufactured stents can significantly affect not only their own mechanical behavior but also mechanical response of arteries. This study investigates the effects of surface irregularities and dimension discrepancy of a 316L stainless steel stent, manufactured using laser powder bed fusion (LPBF), on its biomechanical performance, in comparison with the original design and a commercial stent.
View Article and Find Full Text PDFBiomech Model Mechanobiol
February 2023
Balloon pre-dilation is usually performed before implantation of a nitinol stent in a femoropopliteal artery in a case of severe blockage or calcified plaque. However, its effect on performance of the nitinol stent in a diseased femoropopliteal artery has not been studied yet. This study compares the outcomes of stenting with pre-dilation and without it by modelling the entire processes of stent deployment.
View Article and Find Full Text PDFIn this paper, an improved phase generated carrier (PGC) demodulation algorithm based on frequency mixing and division difference is proposed. The effects of phase modulation depth variation and light intensity disturbance of the light source on the demodulated phase signal are investigated theoretically and experimentally. Compared to the traditional PGC differential-cross-multiplying (PGC-DCM) and PGC arctangent (PGC-Arctan) demodulation algorithms, the ameliorated demodulation algorithm eliminates the harmonic distortion of the demodulated signal by extracting the carrier modulation depth through frequency mixing.
View Article and Find Full Text PDFTo explore the adoption of plan-do-check-action (PDCA) circulation combined with accelerated rehabilitation nursing based on gemstone spectral imaging computed tomography (GSICT) in the prevention and control of hospital infection in the elderly patients undergoing the elective orthopedic surgery, 80 elderly patients who underwent the elective orthopedic surgery in the hospital were selected. Then, according to the randomized controlled principle, these 80 patients were divided into control group (40 cases) with conventional nursing and observation group (40 cases) with accelerated rehabilitation surgical nursing combined with PDCA circulation. All the patients underwent the GSICT examination without any contraindicators.
View Article and Find Full Text PDFUnlabelled: The purpose of this study is to develop personalised nitinol stents for arteries with one and two opposite focal plaques. Novel designs are evaluated through comparison with a commercial stent design, in terms of lumen gain and shape as well as stress levels in the media layer after stenting.
Methods: Personalised stents are developed for arteries with one and two opposite focal plaques, based on medical imaging of patients and computer simulations.
Mater Sci Eng C Mater Biol Appl
November 2021
Background/motivation: Percutaneous femoropopliteal artery intervention moves towards personalised therapy, which requires design of unique lesion-specific stents. However, to date, not much progress has been made in the development of personalised stents.
Objective: This paper aims to design personalised nitinol stents for femoropopliteal arteries based on medical imaging of patients and advanced computational mechanics, which is the first attempt to the authors' best knowledge.
Biomech Model Mechanobiol
October 2020
Development and application of advanced mechanical models of soft tissues and their growth represent one of the main directions in modern mechanics of solids. Such models are increasingly used to deal with complex biomedical problems. Prediction of in-stent restenosis for patients treated with coronary stents remains a highly challenging task.
View Article and Find Full Text PDFInt J Oral Maxillofac Implants
March 2019
Purpose: To investigate the optimal degree of convergence of the abutment with which the bond strength achieved by the pre-bonding method is comparable with that in direct bonding with a conventional degree of convergence.
Materials And Methods: Abutments with 5.5-mm diameter, 5-mm height, 0.
Twin-roll casting AZ31 Mg alloy sheets have been fabricated by normal unidirectional-rolling, head-to-tail rolling, and clock-rolling, respectively. It has been demonstrated that head-to-tail rolling is the most effective to refine the microstructure and weaken the basal texture among the three rolling routes. Excellent integrated tensile properties can be obtained by the head-to-tail rolling.
View Article and Find Full Text PDFA novel absorbable scaffold composed of chitosan and gelatin was fabricated by freezing and lyophilizing methods, resulting in an asymmetric structure. This bilaminar texture is suitable for preparing a bilayer skin substitute. The methods employed to confirm the applicability of this chitosan-gelatin scaffold as an ideal skin substitute were a water uptake ability test, in vitro fibroblast proliferation, and scaffold tests in which fibroblasts were co-cultured with keratinocytes.
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