scholarly journals P.120 Rapid intraoperative reconstruction of cranial implants for craniotomy procedures: a feasibility study

2019 ◽  
Vol 46 (s1) ◽  
pp. S45
Author(s):  
K Beaulieu ◽  
M Kunz ◽  
R Alkins
Keyword(s):  
Imaging Modality ◽  
Bone Flap ◽  
Patient Specific ◽  
Great Promise ◽  
Surface Model ◽  
Bone Implants ◽  
Scanning Time ◽  
Rapid Generation ◽  
Cranial Implants ◽  
Cost Efficient

Background: The aim of this study was to investigate intraoperative methods to generate patient-specific PMMA bone implants during a craniotomy. The proposed methods combine a cost-efficient, and non-invasive structured light scanner (SLS) as an imaging modality and a prototype printer for rapid generation of implant molds. Methods: This simulation study was performed using retrospective data from three craniotomy patients. The extracted bone flap and the cranial defect were scanned using a SLS, which generates a 3D surface model of an object by projecting a series of light-patterns on it. Prototype printed implant models were generated using two different techniques. The molds were then used to shape PMMA bone implants. These implants were evaluated regarding their accuracy to reconstruct the natural skull anatomy and compared to freehand formed implants. Results: The patient-specific bone implants reconstructed the preoperative anatomy with an average RMS error of 1.37mm (StDev 0.27), compared to an error of 1.5mm (StDev 0.43) for the freehand shaped implants. On average the intraoperative scanning time was 4.7min. The average time to generate and print the implant molds was 204 min. Conclusions: Results of this study have shown great promise for the proposed method to be used for patient-specific bone flap reconstruction during craniotomies.

Technical report: Rapid intraoperative reconstruction of cranial implants using additively manufactured moulds

2020 ◽  
Vol 234 (9) ◽  
pp. 1011-1017
Author(s):  
Katherine Beaulieu ◽  
Ryan Alkins ◽  
Randy E Ellis ◽  
Manuela Kunz
Keyword(s):  
Rapid Prototyping ◽  
Ad Hoc ◽  
Patient Specific ◽  
Bone Implants ◽  
Reconstruction Accuracy ◽  
Skull Reconstruction ◽  
Technical Report ◽  
Custom Software ◽  
Cranial Implants ◽  
Gain Access

During craniotomies, a portion of the calvarium or skull is removed to gain access to the intracranial space. When it is not possible to re-implant the flap, surgeons may repair the defect intraoperatively or at a later date. With larger defects being more difficult to repair intraoperatively, we investigated a method for the creation of patient-specific moulds for ad hoc bone flap reconstruction using rapid prototyping. Patient-specific moulds were created based on light scanned models of the defect, using custom software and rapid prototyping. Polymethylmethacrylate bone implants were created for three retrospective craniotomy cases and evaluated based on original flap and skull reconstruction accuracy. Bone implants created using our moulding method reconstruct the original flap and skull with an average reconstruction accuracy of 0.82 and 1.3 mm, respectively. Average skull reconstruction accuracy obtained by surgeons performing freehand implant reconstruction was 1.49 mm. Time needed to generate moulds was between 2 h and 45 min and 6 h and 20 min. Improvements to current printing technology will make this procedure technically feasible for future cranial procedures.

scholarly journals 3D MODELLING AND RAPID PROTOTYPING FOR CARDIOVASCULAR SURGICAL PLANNING – TWO CASE STUDIES

2016 ◽  
Vol XLI-B5 ◽  
pp. 887-893 ◽  
Author(s):  
E. Nocerino ◽  
F. Remondino ◽  
F. Uccheddu ◽  
M. Gallo ◽  
G. Gerosa
Keyword(s):  
3D Printing ◽  
Rapid Prototyping ◽  
Case Studies ◽  
Surgical Planning ◽  
Heart Diseases ◽  
Coronary Vessels ◽  
3D Modelling ◽  
Patient Specific ◽  
Surface Model ◽  
Medical Imagery

In the last years, cardiovascular diagnosis, surgical planning and intervention have taken advantages from 3D modelling and rapid prototyping techniques. The starting data for the whole process is represented by medical imagery, in particular, but not exclusively, computed tomography (CT) or multi-slice CT (MCT) and magnetic resonance imaging (MRI). On the medical imagery, regions of interest, i.e. heart chambers, valves, aorta, coronary vessels, etc., are segmented and converted into 3D models, which can be finally converted in physical replicas through 3D printing procedure. In this work, an overview on modern approaches for automatic and semiautomatic segmentation of medical imagery for 3D surface model generation is provided. The issue of accuracy check of surface models is also addressed, together with the critical aspects of converting digital models into physical replicas through 3D printing techniques. A patient-specific 3D modelling and printing procedure (Figure 1), for surgical planning in case of complex heart diseases was developed. The procedure was applied to two case studies, for which MCT scans of the chest are available. In the article, a detailed description on the implemented patient-specific modelling procedure is provided, along with a general discussion on the potentiality and future developments of personalized 3D modelling and printing for surgical planning and surgeons practice.

Direct Laser Fabrication of Compositionally Complex Materials

2020 ◽  
pp. 147-163
Author(s):  
Jithin Joseph
Keyword(s):  
Additive Manufacturing ◽  
Great Promise ◽  
Filler Materials ◽  
Chemical Homogeneity ◽  
Laser Fabrication ◽  
Direct Laser ◽  
Direct Laser Fabrication ◽  
Aerospace Medical ◽  
Complex Engineering ◽  
Cost Efficient

Additive manufacturing (AM) opens up the possibility of a direct build-up of components with sophisticated internal features or overhangs that are difficult to manufacture by a single conventional method. As a cost-efficient, tool-free, and digital approach to manufacturing components with complex geometries, AM of metals offers many critical benefits to various sectors such as aerospace, medical, automotive, and energy compared to conventional manufacturing processes. Direct laser fabrication (DLF) uses pre-alloyed powder mix or in-situ alloying of the elemental powders for metal additive manufacturing with excellent chemical homogeneity. It, therefore, shows great promise to enable the production of complex engineering components. This technique allows the highest build rates of the AM techniques with no restrictions on deposit size/shape and the fabrication of graded and hybrid materials by simultaneously feeding different filler materials. The advantages and disadvantages of DLF on the fabrication of compositionally complex metallic alloys are discussed in the chapter.

scholarly journals “Betwixt Mine Eye and Heart a League Is Took”: The Progress of Induced Pluripotent Stem-Cell-Based Models of Dystrophin-Associated Cardiomyopathy

2020 ◽  
Vol 21 (19) ◽  
pp. 6997 ◽  
Author(s):  
Davide Rovina ◽  
Elisa Castiglioni ◽  
Francesco Niro ◽  
Sara Mallia ◽  
Giulio Pompilio ◽  
...  
Keyword(s):  
Stem Cell ◽  
Muscular Dystrophy ◽  
Pluripotent Stem Cell ◽  
Disease Modeling ◽  
Disease Model ◽  
Induced Pluripotent Stem Cell ◽  
Patient Specific ◽  
Great Promise ◽  
Cord Injury ◽  
Induced Pluripotent

The ultimate goal of precision disease modeling is to artificially recreate the disease of affected people in a highly controllable and adaptable external environment. This field has rapidly advanced which is evident from the application of patient-specific pluripotent stem-cell-derived precision therapies in numerous clinical trials aimed at a diverse set of diseases such as macular degeneration, heart disease, spinal cord injury, graft-versus-host disease, and muscular dystrophy. Despite the existence of semi-adequate treatments for tempering skeletal muscle degeneration in dystrophic patients, nonischemic cardiomyopathy remains one of the primary causes of death. Therefore, cardiovascular cells derived from muscular dystrophy patients’ induced pluripotent stem cells are well suited to mimic dystrophin-associated cardiomyopathy and hold great promise for the development of future fully effective therapies. The purpose of this article is to convey the realities of employing precision disease models of dystrophin-associated cardiomyopathy. This is achieved by discussing, as suggested in the title echoing William Shakespeare’s words, the settlements (or “leagues”) made by researchers to manage the constraints (“betwixt mine eye and heart”) distancing them from achieving a perfect precision disease model.

scholarly journals Accuracy Assessment of Molded, Patient-Specific Polymethylmethacrylate Craniofacial Implants Compared to Their 3D Printed Originals

2020 ◽  
Vol 9 (3) ◽  
pp. 832 ◽  
Author(s):  
Dave Chamo ◽  
Bilal Msallem ◽  
Neha Sharma ◽  
Soheila Aghlmandi ◽  
Christoph Kunz ◽  
...  
Keyword(s):  
Computer Aided Design ◽  
Accuracy Assessment ◽  
Three Dimensional ◽  
Production Costs ◽  
Patient Specific ◽  
Patient Specific Implants ◽  
3D Printed ◽  
Cost Efficient ◽  
Craniofacial Implants ◽  
Aided Design

The use of patient-specific implants (PSIs) in craniofacial surgery is often limited due to a lack of expertise and/or production costs. Therefore, a simple and cost-efficient template-based fabrication workflow has been developed to overcome these disadvantages. The aim of this study is to assess the accuracy of PSIs made from their original templates. For a representative cranial defect (CRD) and a temporo-orbital defect (TOD), ten PSIs were made from polymethylmethacrylate (PMMA) using computer-aided design (CAD) and three-dimensional (3D) printing technology. These customized implants were measured and compared with their original 3D printed templates. The implants for the CRD revealed a root mean square (RMS) value ranging from 1.128 to 0.469 mm with a median RMS (Q1 to Q3) of 0.574 (0.528 to 0.701) mm. Those for the TOD revealed an RMS value ranging from 1.079 to 0.630 mm with a median RMS (Q1 to Q3) of 0.843 (0.635 to 0.943) mm. This study demonstrates that a highly precise duplication of PSIs can be achieved using this template-molding workflow. Thus, virtually planned implants can be accurately transferred into haptic PSIs. This workflow appears to offer a sophisticated solution for craniofacial reconstruction and continues to prove itself in daily clinical practice.

Construction of Analysis-Suitable Vascular Models Using Axis-Aligned Polycubes

2019 ◽  
Vol 141 (6) ◽  
Author(s):  
Adam R. Updegrove ◽  
Shawn C. Shadden ◽  
Nathan M. Wilson
Keyword(s):  
Medical Image ◽  
Geometric Model ◽  
Image Data ◽  
Boundary Representation ◽  
Patient Specific ◽  
Surface Model ◽  
Suitable Model ◽  
Computational Domain ◽  
Discrete Surface ◽  
Medical Image Data

Image-based modeling is an active and growing area of biomedical research that utilizes medical imaging to create patient-specific simulations of physiological function. Under this paradigm, anatomical structures are segmented from a volumetric image, creating a geometric model that serves as a computational domain for physics-based modeling. A common application is the segmentation of cardiovascular structures to numerically model blood flow or tissue mechanics. The segmentation of medical image data typically results in a discrete boundary representation (surface mesh) of the segmented structure. However, it is often desirable to have an analytic representation of the model, which facilitates systematic manipulation. For example, the model then becomes easier to union with a medical device, or the geometry can be virtually altered to test or optimize a surgery. Furthermore, to employ increasingly popular isogeometric analysis (IGA) methods, the parameterization must be analysis suitable. Converting a discrete surface model to an analysis-suitable model remains a challenge, especially for complex branched structures commonly encountered in cardiovascular modeling. To address this challenge, we present a framework to convert discrete surface models of vascular geometries derived from medical image data into analysis-suitable nonuniform rational B-splines (NURBS) representation. This is achieved by decomposing the vascular geometry into a polycube structure that can be used to form a globally valid parameterization. We provide several practical examples and demonstrate the accuracy of the methods by quantifying the fidelity of the parameterization with respect to the input geometry.

A self-templating method for metal–organic frameworks to construct multi-shelled bimetallic phosphide hollow microspheres as highly efficient electrocatalysts for hydrogen evolution reaction

2019 ◽  
Vol 7 (14) ◽  
pp. 8602-8608 ◽  
Author(s):  
Yunmei Du ◽  
Mingjuan Zhang ◽  
Zuochao Wang ◽  
Yanru Liu ◽  
Yongjun Liu ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Metal Organic Frameworks ◽  
Environmentally Friendly ◽  
Hollow Microspheres ◽  
Great Promise ◽  
Templating Method ◽  
Energy Technologies ◽  
Metal Organic ◽  
Cost Efficient

Hydrogen evolution reaction (HER) via electrocatalysis using cost-efficient bimetallic phosphide as electrocatalyst holds a great promise for environmentally friendly energy technologies.

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