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YAG Laser
Published in Anita Prasad, Laser Techniques in Ophthalmology, 2022
PCO development is influenced by age, pre-existing inflammation, and history of trauma. Cataract surgery can be difficult in such patients, with increased risk of retained SLM, iris adhesions, capsular pigment migration, and persistent inflammation.
Complex Light Beams
Published in Lingyan Shi, Robert R. Alfano, Deep Imaging in Tissue and Biomedical Materials, 2017
The spiral patterns encoded onto the SLM have the same shortcomings of the spiral phase plate. The alternative is to generate the modes on diffraction. To resolve the problem of efficiency, the pattern of the grating is blazed, and to resolve the problem of mode purity, the grating is amplitude modulated [13]. An example of such a pattern is shown in Fig. 2.15d for the case of ℓ = 1. In this case, Eq. 2.59 was used, modulo-2π, and multiplied by a modulation factor related to the shape of the mode. The combination of amplitude phase modulation allows one to engineer a pure mode. The SLM has other advantages: the phase can also be manipulated to include deliberate mode superpositions and to simulate other optical elements such as lenses and astigmatic elements [34].
Understanding the Role of Existing Technology in the Fight Against COVID-19
Published in Ram Shringar Raw, Vishal Jain, Sanjoy Das, Meenakshi Sharma, Pandemic Detection and Analysis Through Smart Computing Technologies, 2022
Many companies adopted 3DPT to supply equipment to the hospitals during COVID-19. A brief understanding of the different techniques and materials used for 3DPT is essential to appreciate its use in the present circumstances and future occurrences. The 3DPT can be classified into four techniques: Fused Deposition Modeling (FDM): In this technique, the material is melted and directly deposited layer-by-layer based on the 3D diagram provided through CAD. This is the most famous and simple technique. The preferable materials are polymers [62].Selective Laser Sintering/Melting (SLS/SLM): In this process, thin layers of closely packed fine powder is fused together by irradiating it with laser. This process is continued until the required 3D object is made. SLS can be used for materials ranging from metals, alloys, and polymers, while SLM is preferably used for metals and alloys [47].Stereolithography (SLA): In this method, an electron beam or LTV light is used to induce a chain reaction in the layer of resin or monomer material. This results into the production of a polymer, which after being partly solidified is used for assembling subsequent layers [63].Digital Light Processing (DLP): This process uses projected light to initiate polymerization of the material to form pre-designed structures [63]. The materials of choice include photosensitive resins, ceramic filled materials, and metals.
Design approaches and challenges for biodegradable bone implants: a review
Published in Expert Review of Medical Devices, 2021
Additive manufacturing has emerged as one of the most revolutionary technologies, which offers a wide range of vastly differing applications including those in the medical field. Selective laser melting (SLM) is one such technology and ranks amongst the most important and useful technologies for different kinds of medical devices. This technique makes it possible to directly develop a manufacturing part having any complex geometry by laser melting a finely milled, mixed, and mechanically alloyed metallic powder. Mostly, SLM is used for lower melting point metals to form a new metallurgical solid by varying laser controlling parameters [103–106]. Biodegradable Mg-alloy (AZ61) has been SLMed to result in dual alloying, which offers improved corrosion resistance, biocompatibility, and superior mechanical properties [107]. It is also advantageous for lower degradable metallic biomaterials such as iron-based bio-composite alloys to improve the biodegradation rate for better usability as a biodegradable bone implant [108]. Apart from these, SLM can improve higher melting point NB alloys to promote their toughness and wear for joint replacement applications [109].
Structure and properties of a personalized bio-fixed implant prepared with selective laser melting
Published in Computer Methods in Biomechanics and Biomedical Engineering, 2019
Guoqing Zhang, Junxin Li, Jin Li, Xiaoyu Zhou, Anmin Wang
The advent of additive manufacturing technology (AM) provides the feasibility for the direct manufacture of this personalized implant. Additive manufacturing (AM) technology is a technology which carries out hierarchy slicing over 3D model through the special software to acquire the cross-section data, and then imports the rapid prototyping equipment, to manufacture entity parts by adopting the method of layer-by-layer material accumulation. Due to the adoption of method of layer-by-layer accumulation, AM technology can almost complete arbitrary geometry parts manufacturing, holding the advantages of enabling to manufacture single piece, small-lot and complex geometry structure and compact processing and finishing structure (Jian-Hua et al. 2005). Selective Laser Melting (SLM for short) is a kind of additive manufacturing technology based on Laser Melting metal powder (Xiao et al. 2012; Su et al. 2013).
How does the surface treatment change the cytocompatibility of implants made by selective laser melting?
Published in Expert Review of Medical Devices, 2018
Lucie Matouskova, Michal Ackermann, Jana Horakova, Lukas Capek, Petr Henys, Jiri Safka
Additive manufacturing (AM) is currently considered to be a leading technology in the field of biomedical engineering. Historically, AM covered a range of different technologies such as stereolithography, fused deposition modelling, multi-jet modelling, 3D printing and selective laser sintering [1,2]. Selective laser melting (SLM) is an AM method that enables the construction of metal objects directly from 3D computer-aided (CAD) data by means of selectively melting fine layers of metal powder using a laser beam. The main advantage of SLM technology is its ability to produce complex geometry in a short period of time with minimum wasted material. This technique, which is used extensively in the field of biomedical engineering, enables the production of patient-specific implants via a minimum of fabrication stages [3–7]. Moreover, various metal powders can be used provided they fulfil the relevant biocompatibility requirements.