scholarly journals MRI–Compatible Fluid-Powered Medical Devices

2013 ◽  
Vol 135 (06) ◽  
pp. S13-S16 ◽  
Author(s):  
Jun Ueda ◽  
David B. Comber ◽  
Jonathon Slightam ◽  
Melih Turkseven ◽  
Vito Gervasi ◽  
...  

This article introduces recent developments and challenges related to magnetic resonance imaging (MRI)-compatible medical devices. Recent advances in fluid-powered medical devices are described, including a needle steering robot for neurosurgery and a haptic device for hemiplegia rehabilitation. Recent three-dimensional printing technologies for fabricating integrated fluid-powered robots are also reported. The use of additive manufacturing conjoined with modern digital imaging techniques allow for the customization of components, a trait that is generally needed in medical implants and devices. Furthermore, the materials that are available in additive processes allow for direct end-use production of customized components and devices. In addition, the polymer-based materials have an inherently low permeability, allowing for use in an MRI environment while not causing imaging interference. Presently, selective laser sintering (SLS), stereolithography, and extrusion processes illustrate and suggest that they offer the greatest promise in MRI compatible end-use components. Future work is aimed at using Additive Manufacturing (AM) to develop inherently safe, compact, MRI compatible medical devices.

2016 ◽  
Vol 49 (5) ◽  
pp. 281-287 ◽  
Author(s):  
Heron Werner Júnior ◽  
Jorge Lopes dos Santos ◽  
Simone Belmonte ◽  
Gerson Ribeiro ◽  
Pedro Daltro ◽  
...  

Abstract Objective: To generate physical models of fetuses from images obtained with three-dimensional ultrasound (3D-US), magnetic resonance imaging (MRI), and, occasionally, computed tomography (CT), in order to guide additive manufacturing technology. Materials and Methods: We used 3D-US images of 31 pregnant women, including 5 who were carrying twins. If abnormalities were detected by 3D-US, both MRI and in some cases CT scans were then immediately performed. The images were then exported to a workstation in DICOM format. A single observer performed slice-by-slice manual segmentation using a digital high resolution screen. Virtual 3D models were obtained from software that converts medical images into numerical models. Those models were then generated in physical form through the use of additive manufacturing techniques. Results: Physical models based upon 3D-US, MRI, and CT images were successfully generated. The postnatal appearance of either the aborted fetus or the neonate closely resembled the physical models, particularly in cases of malformations. Conclusion: The combined use of 3D-US, MRI, and CT could help improve our understanding of fetal anatomy. These three screening modalities can be used for educational purposes and as tools to enable parents to visualize their unborn baby. The images can be segmented and then applied, separately or jointly, in order to construct virtual and physical 3D models.


2013 ◽  
Vol 315 ◽  
pp. 63-67 ◽  
Author(s):  
Muhammad Fahad ◽  
Neil Hopkinson

Rapid prototyping refers to building three dimensional parts in a tool-less, layer by layer manner using the CAD geometry of the part. Additive Manufacturing (AM) is the name given to the application of rapid prototyping technologies to produce functional, end use items. Since AM is relatively new area of manufacturing processes, various processes are being developed and analyzed for their performance (mainly speed and accuracy). This paper deals with the design of a new benchmark part to analyze the flatness of parts produced on High Speed Sintering (HSS) which is a novel Additive Manufacturing process and is currently being developed at Loughborough University. The designed benchmark part comprised of various features such as cubes, holes, cylinders, spheres and cones on a flat base and the build material used for these parts was nylon 12 powder. Flatness and curvature of the base of these parts were measured using a coordinate measuring machine (CMM) and the results are discussed in relation to the operating parameters of the process.The result show changes in the flatness of part with the depth of part in the bed which is attributed to the thermal gradient within the build envelope during build.


3D Printing ◽  
2017 ◽  
pp. 154-171 ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi

Laser additive manufacturing is an advanced manufacturing process for making prototypes as well as functional parts directly from the three dimensional (3D) Computer-Aided Design (CAD) model of the part and the parts are built up adding materials layer after layer, until the part is competed. Of all the additive manufacturing process, laser additive manufacturing is more favoured because of the advantages that laser offers. Laser is characterized by collimated linear beam that can be accurately controlled. This chapter brings to light, the various laser additive manufacturing technologies such as: - selective laser sintering and melting, stereolithography and laser metal deposition. Each of these laser additive manufacturing technologies are described with their merits and demerits as well as their areas of applications. Properties of some of the parts produced through these processes are also reviewed in this chapter.


2019 ◽  
Vol 23 (03) ◽  
pp. 227-251 ◽  
Author(s):  
Florian Schmaranzer ◽  
Luis Cerezal ◽  
Eva Llopis

AbstractOver the last 2 decades, the definition of pathomechanical concepts that link osseous deformities to chondrolabral damage and expose young and active patients to the risk of early osteoarthritis has led to a tremendous increase in the number of joint-preserving surgeries performed. The rise in arthroscopic procedures has led to an increasing demand for comprehensive preoperative magnetic resonance imaging (MRI) assessment of the hip joint. This includes conventional MRI for the assessment of extra-articular and periarticular pathologies such as greater trochanteric pain, deep gluteal pain syndrome, and sports injuries. Magnetic resonance arthrography with or without traction is reserved for the accurate evaluation of deformities associated with impingement and hip instability and for detecting the resulting intra-articular lesions. This article summarizes the current standard imaging techniques that the radiologist should know. It also explores the potential of computer-assisted analysis of three-dimensional MRI for virtual impingement simulation and volumetric analysis of cartilage composition and geometry.


2005 ◽  
Vol 15 (S3) ◽  
pp. 61-67 ◽  
Author(s):  
Laura Socci ◽  
Francesca Gervaso ◽  
Francesco Migliavacca ◽  
Giancarlo Pennati ◽  
Gabriele Dubini ◽  
...  

The recent developments in imaging techniques have created new opportunities to give an accurate description of the three-dimensional morphology of vessels. Such three-dimensional reconstruction of anatomical structures from medical images has achieved importance in several applications, such as the reconstruction of human bones, spine portions, and vascular districts.


2019 ◽  
Vol 26 (1) ◽  
pp. 58-70
Author(s):  
Yu YUN ◽  
Tingchun SHI ◽  
Yonghui MA ◽  
Fangfang SUN ◽  
Jinde PAN ◽  
...  

Additive manufacturing is a rapid manufacturing based on discrete accumulation to achieve prototypes or parts of products. Inorganic non-metallic materials, as one of the three major materials, have incomparable application prospect in medical, aerospace, automotive, construction, arts and crafts, as well as many other fields. In order to rapidly create devices with arbitrarily complex shapes, additive manufacturing of inorganic non-metallic materials is becoming a hot spot of current research. In view of the technical types, materials and other aspects, this article introduced research status and development of additive manufacturing in inorganic non-metallic materials at home and abroad. Several common inorganic non-metallic materials are compared and analyzed, such as Al2O3, Si3N4 SiO2, ZrO2, etc. The forming characteristics and the problems of several popular ceramic materials and sand–casting materials are illustrated with emphases. The key problems existed in additive manufacturing forming process of inorganic non-metallic material are pointed out and urgent to be solved at present. Furthermore, the impacts of the material handling process, three dimensional printing (3DP), Selective Laser Sintering(SLS), Selective Laser Melting (SLM) three-dimensional forming processes and post treatment process on the quality and performance of the forming parts are analyzed. Finally, the prospects in SLS of the gem material are put forward.


2018 ◽  
Vol 19 (9) ◽  
pp. 2684 ◽  
Author(s):  
Amir Zadpoor

There has been a growing interest in metallic biomaterials during the last five years, as recent developments in additive manufacturing (=3D printing), surface bio-functionalization techniques, infection prevention strategies, biodegradable metallic biomaterials, and composite biomaterials have provided many possibilities to develop biomaterials and medical devices with unprecedented combinations of favorable properties and advanced functionalities. Moreover, development of biomaterials is no longer separated from the other branches of biomedical engineering, particularly tissue biomechanics, musculoskeletal dynamics, and image processing aspects of skeletal radiology. In this editorial, I will discuss all the above-mentioned topics, as they constitute some of the most important trends of research on metallic biomaterials. This editorial will, therefore, serve as a foreword to the papers appearing in a special issue covering the current trends in metallic biomaterials.


2019 ◽  
Vol 12 ◽  
pp. 175628641984059 ◽  
Author(s):  
Marcello Moccia ◽  
Serena Ruggieri ◽  
Antonio Ianniello ◽  
Ahmed Toosy ◽  
Carlo Pozzilli ◽  
...  

The spinal cord is frequently affected in multiple sclerosis (MS), causing motor, sensory and autonomic dysfunction. A number of pathological abnormalities, including demyelination and neuroaxonal loss, occur in the MS spinal cord and are studied in vivo with magnetic resonance imaging (MRI). The aim of this review is to summarise and discuss recent advances in spinal cord MRI. Advances in conventional spinal cord MRI include improved identification of MS lesions, recommended spinal cord MRI protocols, enhanced recognition of MRI lesion characteristics that allow MS to be distinguished from other myelopathies, evidence for the role of spinal cord lesions in predicting prognosis and monitoring disease course, and novel post-processing methods to obtain lesion probability maps. The rate of spinal cord atrophy is greater than that of brain atrophy (−1.78% versus −0.5% per year), and reflects neuroaxonal loss in an eloquent site of the central nervous system, suggesting that it can become an important outcome measure in clinical trials, especially in progressive MS. Recent developments allow the calculation of spinal cord atrophy from brain volumetric scans and evaluation of its progression over time with registration-based techniques. Fully automated analysis methods, including segmentation of grey matter and intramedullary lesions, will facilitate the use of spinal cord atrophy in trial designs and observational studies. Advances in quantitative imaging techniques to evaluate neuroaxonal integrity, myelin content, metabolic changes, and functional connectivity, have provided new insights into the mechanisms of damage in MS. Future directions of research and the possible impact of 7T scanners on spinal cord imaging will be discussed.


2021 ◽  
Vol 15 ◽  
Author(s):  
Paulla Vieira Rodrigues ◽  
Katiane Tostes ◽  
Beatriz Pelegrini Bosque ◽  
João Vitor Pereira de Godoy ◽  
Dionisio Pedro Amorim Neto ◽  
...  

The assessment of three-dimensional (3D) brain cytoarchitecture at a cellular resolution remains a great challenge in the field of neuroscience and constant development of imaging techniques has become crucial, particularly when it comes to offering direct and clear obtention of data from macro to nano scales. Magnetic resonance imaging (MRI) and electron or optical microscopy, although valuable, still face some issues such as the lack of contrast and extensive sample preparation protocols. In this context, x-ray microtomography (μCT) has become a promising non-destructive tool for imaging a broad range of samples, from dense materials to soft biological specimens. It is a new supplemental method to be explored for deciphering the cytoarchitecture and connectivity of the brain. This review aims to bring together published works using x-ray μCT in neurobiology in order to discuss the achievements made so far and the future of this technique for neuroscience.


2021 ◽  
Vol 25 (03) ◽  
pp. 418-424
Author(s):  
Blake C. Jones ◽  
Shivani Ahlawat ◽  
Laura M. Fayad

AbstractAdvances in magnetic resonance imaging (MRI) technology now enable the feasible three-dimensional (3D) acquisition of images. With respect to the imaging of musculoskeletal (MSK) tumors, literature is beginning to accumulate on the use of 3D MRI acquisition for tumor detection and characterization. The benefits of 3D MRI, including general advantages, such as decreased acquisition time, isotropic resolution, and increased image quality, are not only inherently useful for tumor imaging, but they also contribute to the feasibility of more specialized tumor-imaging techniques, such as whole-body MRI, and are reviewed here. Disadvantages of 3D acquisition, such as motion artifact and equipment requirements, do exist and are also discussed. Although further study is needed, 3D MRI acquisition will likely prove increasingly useful in the evaluation of patients with tumors of the MSK system.


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