Multimaterial and Multiscale Rapid Prototyping of Patient-Specific Scaffold

2016 ◽  
Vol 100 ◽  
pp. 151-158
Author(s):  
Aurora de Acutis ◽  
Carmelo de Maria ◽  
Giovanni Vozzi
Keyword(s):  
Rapid Prototyping ◽  
Building Materials ◽  
Bone Defects ◽  
Patient Specific ◽  
3D Printer ◽  
Multi Scale ◽  
Full Control ◽  
Engineered Tissue ◽  
The Common ◽  
Design Proposal

The majority of strategies used in tissue engineering (TE) employ a scaffold, which is used to guide .the proliferation, the migration and the adhesione of cell in 3D to pruduce an engineered tissue. A new trend in scaffolds’s fabrication is represented by the hybrid Rapid Prototyping technologies. This is a new multimaterial and multiscale fabrication approach which combine the common RP technologies with other micro/nanofabrication techiques to fabricate scaffold that mimick the hetereogenty and hierarchical structure typical of the native extracellular matrix. In this new contest our work present: 1) an innovative device for the fabrication of multi material scaffolds based on an open source FDM 3D printer suitably modified to integrate a multi nozzle deposition tool 2) a design proposal for a multi material and multi scale machine to allow a full control over the modulation of the building materials and of the topography in a scaffold 3) and lastly a CAD workflow to guide the fabrication of RP patient specific scaffolds. Multifunctional hydrogel-based scaffold are fabricated as a demonstration of the validity of the proposed devices. Starting from a clinical case we print a patient-specific scaffold with the aim to recover bone defects at mandibular level as a validation of the proposed CAD process.

scholarly journals Additive Manufacturing of β-Tricalcium Phosphate Components via Fused Deposition of Ceramics (FDC)

Materials ◽  
2020 ◽  
Vol 14 (1) ◽  
pp. 156
Author(s):  
Steffen Esslinger ◽  
Axel Grebhardt ◽  
Jonas Jaeger ◽  
Frank Kern ◽  
Andreas Killinger ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Critical Size ◽  
Bone Defects ◽  
Healthcare Systems ◽  
The Body ◽  
Patient Specific ◽  
Poly Lactic Acid ◽  
Fused Deposition ◽  
Poly Ethylene ◽  
Fused Deposition Of Ceramics

Bone defects introduced by accidents or diseases are very painful for the patient and their treatment leads to high expenses for the healthcare systems. When a bone defect reaches a critical size, the body is not able to restore this defect by itself. In this case a bone graft is required, either an autologous one taken from the patient or an artificial one made of a bioceramic material such as calcium phosphate. In this study β-tricalcium phosphate (β-TCP) was dispersed in a polymer matrix containing poly(lactic acid) (PLA) and poly(ethylene glycole) (PEG). These compounds were extruded to filaments, which were used for 3D printing of cylindrical scaffolds via Fused Deposition of Ceramics (FDC) technique. After shaping, the printed parts were debindered and sintered. The components combined macro- and micropores with a pore size of 1 mm and 0.01 mm, respectively, which are considered beneficial for bone healing. The compressive strength of sintered cylindrical scaffolds exceeded 72 MPa at an open porosity of 35%. The FDC approach seems promising for manufacturing patient specific bioceramic bone grafts.

Developments in the Field of Rapid Prototype Production

2008 ◽  
Vol 589 ◽  
pp. 421-425 ◽  
Author(s):  
Norbert Krisztián Kovács ◽  
József Gábor Kovács
Keyword(s):  
Mechanical Strength ◽  
Porous Structure ◽  
Epoxy Resin ◽  
Rapid Prototype ◽  
Post Treatment ◽  
3D Printer ◽  
Infiltration Depth ◽  
3D Printed ◽  
The Common ◽  
Polymer Engineering

Characteristics of 3D printed specimens are porous structure and low mechanical strength. Due to porous structure post treatment is possible, and in most cases infiltration with an epoxy resin, wax or cyanoacrylate material takes place. As a result of post treatment, the mechanical strength can be increased by 100%, although this is strongly influenced by the infiltration depth that depends on the porous structure and the resin viscosity. In the framework of the common research of the Department of Polymer Engineering, BME and Varinex Zrt. the applicability of a 3D printer is examined in the field of direct tool making. As the first step, the resin uptake ability of specimens prepared with a Z810 3D printer is examined.

scholarly journals DCPNet: A Densely Connected Pyramid Network for Monocular Depth Estimation

Sensors ◽  
2021 ◽  
Vol 21 (20) ◽  
pp. 6780
Author(s):  
Zhitong Lai ◽  
Rui Tian ◽  
Zhiguo Wu ◽  
Nannan Ding ◽  
Linjian Sun ◽  
...  
Keyword(s):  
Multiple Scales ◽  
Feature Fusion ◽  
State Of The Art ◽  
Depth Estimation ◽  
Multi Scale ◽  
Pyramid Structure ◽  
Benchmark Datasets ◽  
The Common ◽  
Monocular Depth ◽  
Multiple Stages

Pyramid architecture is a useful strategy to fuse multi-scale features in deep monocular depth estimation approaches. However, most pyramid networks fuse features only within the adjacent stages in a pyramid structure. To take full advantage of the pyramid structure, inspired by the success of DenseNet, this paper presents DCPNet, a densely connected pyramid network that fuses multi-scale features from multiple stages of the pyramid structure. DCPNet not only performs feature fusion between the adjacent stages, but also non-adjacent stages. To fuse these features, we design a simple and effective dense connection module (DCM). In addition, we offer a new consideration of the common upscale operation in our approach. We believe DCPNet offers a more efficient way to fuse features from multiple scales in a pyramid-like network. We perform extensive experiments using both outdoor and indoor benchmark datasets (i.e., the KITTI and the NYU Depth V2 datasets) and DCPNet achieves the state-of-the-art results.

scholarly journals Early Outcomes of Patient-Specific Modular Cones for Substitution of Methaphysial and Diaphysial Bone Defects in Revision Knee Arthroplasty

2019 ◽  
Vol 25 (2) ◽  
pp. 9-18 ◽  
Author(s):  
A. A. Cherny ◽  
A. N. Kovalenko ◽  
S. S. Bilyk ◽  
A. O. Denisov ◽  
A. V. Kazemirskiy ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Scoring Systems ◽  
Bone Defects ◽  
Patient Specific ◽  
Implant Fixation ◽  
Diaphyseal Bone ◽  
Custom Made ◽  
The Stability ◽  
Valid Solution

The aim of this study was the assessment of early outcomes of patient-specific three-dimensional titanium cones with specified porosity parameters to compensate for extensive metaphysical-diaphyseal bone defects in RTKA.Materials and Methods. Since 2017 till 2019 30 patient-specific titanium cones (12 femoral and 18 tibial) implanted during 26 RTKAS. Clinical outcomes evaluated using KSS, WOMAC and fjS-12 scoring systems on average 10 (2–18) months after surgery. At the same time the stability of implant fixation analyzed using frontal, lateral and axial knee roentgenograms.Results. During all procedures there were no technical difficulties in positioning and implantation of custom-made titanium cones. At the time of preparation of the publication, none of the patients had indications for further surgical intervention, as well as intra- and postoperative complications. Six months after surgery all scores improved significantly: KSS from 23 (2–42, SD 19.96) to 66.5 (62–78, SD 7.68), WOMAC from 59 (56–96, SD 28.31) to 32.25 (19–46, SD 11.76), the index FJS-12 was 29.16 points (0–68.75, SD 30.19). The average scores continued to improve up to 18 months: KSS — 97.5 (88–108, SD 9.14), WOMAC — 16.5 (9–24, SD 6.45), FJS-12 — 45.85 (25–75, SD 22.03). No radiolucent lines were noticed during this period of observation.Conclusion. The original additive technology of designing and producing patient-specific titanium cones for compensation of extensive metaphyseal-diaphyseal bone defects in RTKA is a valid solution at least in the short term. A longer follow-up period is required to assess its medium-and long-term reliability compared to existing alternative surgical solutions.

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.

A discussion on building technology in the 1980s - The contribution of the materials scientist

1972 ◽  
Vol 272 (1229) ◽  
pp. 585-593 ◽  
Keyword(s):  
Building Materials ◽  
Materials Science ◽  
Surface Coatings ◽  
Glass Technology ◽  
Teaching And Research ◽  
Building Technology ◽  
Recent Innovation ◽  
Conservative Attitude ◽  
The Common ◽  
Cement And Concrete

Some examples are given of recent innovation in building materials which show that the common impression that there is little innovation is false. There has been, however, a conservative attitude, and design has to some extent been hampered by the need to choose materials from the existing catalogue. The pace of innovation is likely to be accelerated in the future by two trends: specification by performance and the emergence of teaching and research in materials science. Current research and applications in the fields of cement and concrete, glass technology, metals, plastics and surface coatings are mentioned by way of illustration and an estimate of future progress is made.

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