One layer at a time: the use of 3D printing in the fabrication of cadmium-free electron field shaping devices

2020 ◽  
pp. 1-6
Author(s):  
Michael J. Moore ◽  
Ronald Snelgrove ◽  
Johnson Darko ◽  
Ernest K. Osei
Keyword(s):  
3D Printing ◽  
Acrylonitrile Butadiene Styrene ◽  
Intensity Modulation ◽  
Field Size ◽  
Planning System ◽  
Treatment Planning System ◽  
Electron Field ◽  
3D Printed ◽  
3D Printing Technique ◽  
Butadiene Styrene

Abstract Introduction: Electron blocks are typically composed of a low melting point alloy (LMPA), which is poured into an insert frame containing a manually placed Styrofoam aperture negative used to define the desired field shape. Current implementations of the block fabrication process involve numerous steps which are subjective and prone to user error. Occasionally, bowing of the sides of the insert frame is observed, resulting in premature frame decommissioning. Recent works have investigated the feasibility of utilising 3D printing technology to replace the conventional electron block fabrication workflow; however, these approaches involved long print times, were not compatible with commonly used cadmium-free LMPAs, and did not address the problem of insert frame bowing. In this work, we sought to develop a new 3D printing technique that would remedy these issues. Materials and Methods: Electron cutout negatives and alignment jigs were printed using Acrylonitrile Butadiene Styrene, which does not warp at the high temperatures associated with molten cadmium-free alloys. The accuracy of the field shape produced by electron blocks fabricated using the 3D printed negatives was assessed using Gafchromic film and beam profiler measurements. As a proof-of-concept, electron blocks with off-axis apertures, as well as complex multi-aperture blocks to be used for passive electron beam intensity modulation, were also created. Results: Film and profiler measurements of field size were in excellent agreement with the values calculated using the Eclipse treatment planning system, showing less than a 1% difference in line profile full-width at half-maximum. The multi-aperture electron blocks produced fields with intensity modulation ≤3.2% of the theoretically predicted value. Use of the 3D printed alignment jig – which has contours designed to match those of the insert frame – was found to reduce the amount of frame bowing by factors of 1.8 and 2.1 in the lateral and superior–inferior directions, respectively. Conclusions: The 3D printed ABS negatives generated with our technique maintain their spatial accuracy even at the higher temperatures associated with cadmium-free LMPA. The negatives typically take between 1 and 2 hours to print and have a material cost of approximately $2 per patient.

scholarly journals The Effect of Disinfectants Absorption and Medical Decontamination on the Mechanical Performance of 3D-Printed ABS Parts

Polymers ◽  
2021 ◽  
Vol 13 (23) ◽  
pp. 4249
Author(s):  
Diana Popescu ◽  
Florin Baciu ◽  
Catalin Gheorghe Amza ◽  
Cosmin Mihai Cotrut ◽  
Rodica Marinescu
Keyword(s):  
3D Printing ◽  
Medical Devices ◽  
Mechanical Performance ◽  
Acrylonitrile Butadiene Styrene ◽  
Extrusion Process ◽  
Air Gaps ◽  
Safety Issues ◽  
Gas Plasma ◽  
3D Printed ◽  
Butadiene Styrene

Producing parts by 3D printing based on the material extrusion process determines the formation of air gaps within layers even at full infill density, while external pores can appear between adjacent layers making prints permeable. For the 3D-printed medical devices, this open porosity leads to the infiltration of disinfectant solutions and body fluids, which might pose safety issues. In this context, this research purpose is threefold. It investigates which 3D printing parameter settings are able to block or reduce permeation, and it experimentally analyzes if the disinfectants and the medical decontamination procedure degrade the mechanical properties of 3D-printed parts. Then, it studies acetone surface treatment as a solution to avoid disinfectants infiltration. The absorption tests results indicate the necessity of applying post-processing operations for the reusable 3D-printed medical devices as no manufacturing settings can ensure enough protection against fluid intake. However, some parameter settings were proven to enhance the sealing, in this sense the layer thickness being the most important factor. The experimental outcomes also show a decrease in the mechanical performance of 3D-printed ABS (acrylonitrile butadiene styrene) instruments treated by acetone cold vapors and then medical decontaminated (disinfected, cleaned, and sterilized by hydrogen peroxide gas plasma sterilization) in comparison to the control prints. These results should be acknowledged when designing and 3D printing medical instruments.

scholarly journals Tribological Behaviour Comparison of ABS Polymer Manufactured Using Turning and 3D Printing

2019 ◽  
Vol 4 (1) ◽  
pp. 46-57
Author(s):  
Sharba Muammel M Hanon ◽  
M. Kovács ◽  
László Zsidai
Keyword(s):  
3D Printing ◽  
Acrylonitrile Butadiene Styrene ◽  
3D Printer ◽  
Dynamic Friction ◽  
Tribological Behaviour ◽  
Friction Factors ◽  
Subtractive Manufacturing ◽  
3D Printed ◽  
The Difference ◽  
Butadiene Styrene

Additive and subtractive manufacturing of Acrylonitrile Butadiene Styrene (ABS) were employed for fabricating samples. The Additive manufacturing was represented through 3D printing, whereas subtractive manufacturing carried out by Turning. Some developments have been applied for enhancing the performance of the 3D printer. Tribological measurements of the turned and 3D printed specimens have been achieved. Studying the difference between static and dynamic friction factors and the examination of wear values were included. A comparison of the tribological behaviour of the turned and 3D printed ABS polymer has been investigated.

scholarly journals Design and FDM/FFF Implementation of a Compact Omnidirectional Wheel for a Mobile Robot and Assessment of ABS and PLA Printing Materials

Robotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 43
Author(s):  
Elena Rubies ◽  
Jordi Palacín
Keyword(s):  
Mechanical Properties ◽  
3D Printing ◽  
Mobile Robots ◽  
Ball Bearing ◽  
Mechanical Design ◽  
Acrylonitrile Butadiene Styrene ◽  
Small Series ◽  
3D Printed ◽  
Oriented Parallel ◽  
Butadiene Styrene

This paper proposes the design and 3D printing of a compact omnidirectional wheel optimized to create a small series of three-wheeled omnidirectional mobile robots. The omnidirectional wheel proposed is based on the use of free-rotating passive wheels aligned transversally to the center of the main wheel and with a constant separation gap. This paper compares a three inner-passive wheels design based on mass-produced parts and 3D printed elements. The inner passive wheel that better combines weight, cost, and friction is implemented with a metallic ball bearing fitted inside a 3D printed U-grooved ring that holds a soft toric joint. The proposed design has been implemented using acrylonitrile butadiene styrene (ABS) and tough polylactic acid (PLA) as 3D printing materials in order to empirically compare the deformation of the weakest parts of the mechanical design. The conclusion is that the most critical parts of the omnidirectional wheel are less prone to deformation and show better mechanical properties if they are printed horizontally (with the axes that hold the passive wheels oriented parallel to the build surface), with an infill density of 100% and using tough PLA rather than ABS as a 3D printing material.

scholarly journals Optical fibre based real-time measurements during an LDR prostate brachytherapy implant simulation: using a 3D printed anthropomorphic phantom

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
P. Woulfe ◽  
F. J. Sullivan ◽  
L. Byrne ◽  
A. J. Doyle ◽  
W. Kam ◽  
...  
Keyword(s):  
Optical Fibre ◽  
Planning System ◽  
Treatment Planning System ◽  
Prostate Brachytherapy ◽  
Anthropomorphic Phantom ◽  
Optical Fibre Sensor ◽  
Ldr Brachytherapy ◽  
3D Printed ◽  
Average Activity ◽  
Iodine 125

AbstractAn optical fibre sensor based on radioluminescence, using the scintillation material terbium doped gadolinium oxysulphide (Gd2O2S:Tb) is evaluated, using a 3D printed anthropomorphic phantom for applications in low dose-rate (LDR) prostate brachytherapy. The scintillation material is embedded in a 700 µm diameter cavity within a 1 mm plastic optical fibre that is fixed within a brachytherapy needle. The high spatial resolution dosimeter is used to measure the dose contribution from Iodine-125 (I-125) seeds. Initially, the effects of sterilisation on the sensors (1) repeatability, (2) response as a function of angle, and (3) response as a function of distance, are evaluated in a custom polymethyl methacrylate phantom. Results obtained in this study demonstrate that the output response of the sensor, pre- and post-sterilisation are within the acceptable measurement uncertainty ranging from a maximum standard deviation of 4.7% pre and 5.5% post respectively, indicating that the low temperature sterilisation process does not damage the sensor or reduce performance. Subsequently, an LDR brachytherapy plan reconstructed using the VariSeed treatment planning system, in an anthropomorphic 3D printed training phantom, was used to assess the suitability of the sensor for applications in LDR brachytherapy. This phantom was printed based on patient anatomy, with the volume and dimensions of the prostate designed to represent that of the patient. I-125 brachytherapy seeds, with an average activity of 0.410 mCi, were implanted into the prostate phantom under trans-rectal ultrasound guidance; following the same techniques as employed in clinical practice by an experienced radiation oncologist. This work has demonstrated that this sensor is capable of accurately identifying when radioactive I-125 sources are introduced into the prostate via a brachytherapy needle.

scholarly journals Essential work of fracture assessment of acrylonitrile butadiene styrene (ABS) processed via fused filament fabrication additive manufacturing

2021 ◽  
Author(s):  
Pawan Verma ◽  
Jabir Ubaid ◽  
Andreas Schiffer ◽  
Atul Jain ◽  
Emilio Martínez-Pañeda ◽  
...  
Keyword(s):  
Acrylonitrile Butadiene Styrene ◽  
Essential Work ◽  
Fused Filament Fabrication ◽  
Essential Work Of Fracture ◽  
Fracture Properties ◽  
Raster Angle ◽  
3D Printed ◽  
Printing Direction ◽  
Work Of Fracture ◽  
Butadiene Styrene

AbstractExperiments and finite element (FE) calculations were performed to study the raster angle–dependent fracture behaviour of acrylonitrile butadiene styrene (ABS) thermoplastic processed via fused filament fabrication (FFF) additive manufacturing (AM). The fracture properties of 3D-printed ABS were characterized based on the concept of essential work of fracture (EWF), utilizing double-edge-notched tension (DENT) specimens considering rectilinear infill patterns with different raster angles (0°, 90° and + 45/− 45°). The measurements showed that the resistance to fracture initiation of 3D-printed ABS specimens is substantially higher for the printing direction perpendicular to the crack plane (0° raster angle) as compared to that of the samples wherein the printing direction is parallel to the crack (90° raster angle), reporting EWF values of 7.24 kJ m−2 and 3.61 kJ m−2, respectively. A relatively high EWF value was also reported for the specimens with + 45/− 45° raster angle (7.40 kJ m−2). Strain field analysis performed via digital image correlation showed that connected plastic zones existed in the ligaments of the DENT specimens prior to the onset of fracture, and this was corroborated by SEM fractography which showed that fracture proceeded by a ductile mechanism involving void growth and coalescence followed by drawing and ductile tearing of fibrils. It was further shown that the raster angle–dependent strength and fracture properties of 3D-printed ABS can be predicted with an acceptable accuracy by a relatively simple FE model considering the anisotropic elasticity and failure properties of FFF specimens. The findings of this study offer guidelines for fracture-resistant design of AM-enabled thermoplastics. Graphical abstract

scholarly journals Quality Assurance of Dose Distribution of Photon Beam Planning by Anisotropic Analytical Algorithm (AAA)

2013 ◽  
Vol 4 (1) ◽  
pp. 43-49
Author(s):  
M Jahangir Alam ◽  
Syed Md Akram Hussain ◽  
Kamila Afroj ◽  
Shyam Kishore Shrivastava
Keyword(s):  
Quality Assurance ◽  
Treatment Planning ◽  
Dose Distribution ◽  
Maximum Dose ◽  
Photon Beam ◽  
Field Size ◽  
Planning System ◽  
Treatment Planning System ◽  
Anisotropic Analytical Algorithm ◽  
Analytical Algorithm

A three dimensional treatment planning system has been installed in the Oncology Center, Bangladesh. This system is based on the Anisotropic Analytical Algorithm (AAA). The aim of this study is to verify the validity of photon dose distribution which is calculated by this treatment planning system by comparing it with measured photon beam data in real water phantom. To do this verification, a quality assurance program, consisting of six tests, was performed. In this program, both the calculated output factors and dose at different conditions were compared with the measurement. As a result of that comparison, we found that the calculated output factor was in excellent agreement with the measured factors. Doses at depths beyond the depth of maximum dose calculated on-axis or off-axis in both the fields or penumbra region were found in good agreement with the measured dose under all conditions of energy, SSD and field size, for open and wedged fields. In the build up region, calculated and measured doses only agree (with a difference 2.0%) for field sizes > 5 × 5 cm2 up to 25 × 25 cm2. For smaller fields, the difference was higher than 2.0% because of the difficulty in dosimetry in that region. Dose calculation using treatment planning system based on the Anisotropic Analytical Algorithm (AAA) is accurate enough for clinical use except when calculating dose at depths above maximum dose for small field size.DOI: http://dx.doi.org/10.3329/bjmp.v4i1.14686 Bangladesh Journal of Medical Physics Vol.4 No.1 2011 43-49

scholarly journals Electromechanical Assessment and Induced Temperature Measurement of Carbon Fiber Tows under Tensile Condition

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4234
Author(s):  
Samir Mekid ◽  
Hammam Daraghma ◽  
Salem Bashmal
Keyword(s):  
Carbon Fiber ◽  
3D Printing ◽  
Tensile Test ◽  
Thermal Characteristics ◽  
Acrylonitrile Butadiene Styrene ◽  
Break Point ◽  
Host Material ◽  
Special Focus ◽  
Host Materials ◽  
Butadiene Styrene

The paper presents an investigation and analysis of the electromechanical and thermal characteristics of the carbon fiber alone as single tow and embedded in host materials such as polymer e.g., acrylonitrile butadiene styrene (ABS) using 3D printing. While carbon fibers can partially reinforce the structure, they can act as sensors to monitor the structural health of the host material. The piezo-resistive behavior was examined without any pretreatment of the carbon fiber under tensile test in both cases. Special focus on the filaments clamping types and their effects was observed. An auxetic behavior was exhibited; otherwise, the free part shows elastic and yielding ranges with break point at high resistance. An induced temperature of the carbon fiber was measured during the tensile test to show low variation. The carbon fiber can provide strength contribution to the host material depending on the percentage of filling the material in 3D printing. The relative variation of the electrical resistance increases by 400% while embedded in the host material, but decreases as the tows filament density increases from 1 to 12 K.

scholarly journals Does vaporized hydrogen peroxide sterilization affect the geometrical properties of anatomic models and guides 3D printed from computed tomography images?

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Mauricio Toro ◽  
Aura Cardona ◽  
Daniel Restrepo ◽  
Laura Buitrago
Keyword(s):  
Computed Tomography ◽  
Hydrogen Peroxide ◽  
Dimensional Stability ◽  
Acrylonitrile Butadiene Styrene ◽  
Dimensional Error ◽  
Material Extrusion ◽  
Anatomic Models ◽  
3D Printed ◽  
Mean Differences ◽  
Butadiene Styrene

Abstract Background Material extrusion is used to 3D print anatomic models and guides. Sterilization is required if a 3D printed part touches the patient during an intervention. Vaporized Hydrogen Peroxide (VHP) is one method of sterilization. There are four factors to consider when sterilizing an anatomic model or guide: sterility, biocompatibility, mechanical properties, and geometric fidelity. This project focuses on geometric fidelity for material extrusion of one polymer acrylonitrile butadiene styrene (ABS) using VHP. Methods De-identified computed tomography (CT) image data from 16 patients was segmented using Mimics Innovation Suite (Materialise NV, Leuven, Belgium). Eight patients had maxillary and mandibular defects depicted with the anatomic models, and eight had mandibular defects for the anatomic guides. Anatomic models and guides designed from the surfaces of CT scan reconstruction and segementation were 3D printed in medical-grade acrylonitrile butadiene styrene (ABS) material extrusion. The 16 parts underwent low-temperature sterilization with VHP. The dimensional error was estimated after sterilization by comparing scanned images of the 3D printed parts. Results The average of the estimated mean differences between the printed pieces before and after sterilization were − 0,011 ± 0,252 mm (95%CI − 0,011; − 0,010) for the models and 0,003 ± 0,057 mm (95%CI 0,002; 0,003) for the guides. Regarding the dimensional error of the sterilized parts compared to the original design, the estimated mean differences were − 0,082 ± 0,626 mm (95%CI − 0,083; − 0,081) for the models and 0,126 ± 0,205 mm (95%CI 0,126, 0,127) for the guides. Conclusion This project tested and verified dimensional stability, one of the four prerequisites for introducing vaporized hydrogen peroxide into 3D printing of anatomic models and guides; the 3D printed parts maintained dimensional stability after sterilization.

scholarly journals Development of 3D Printed Symbrachydactyly Prosthetic Hand

2019 ◽  
Vol 9 (1) ◽  
pp. 5943-5947
Keyword(s):  
3D Printing ◽  
Minimum Cost ◽  
Acrylonitrile Butadiene Styrene ◽  
Design Stage ◽  
Patient Specific ◽  
Prosthetic Hand ◽  
Simple Task ◽  
3D Printed ◽  
Electrical Component ◽  
Hand Geometry

Symbrachydactyly is a genetical problem occurred to newborn where the newborn experienced underdeveloped or shorten fingers. This condition will limit their normal as even a simple task of holding an item or pushing a button. A device is needed to help them gain a better life. The aim of this project is to fabricate a customized prosthesis hand using 3D printing technology at minimum cost. The proposed prosthetic was not embedded with any electrical component. The patient can only use the wrist to control the prosthetic part which is the prosthetic fingers. The prosthetic hand was also being developed with the patient specific features, which the initial design stage was adapted from a person’s hand geometry using a 3D scanner. Next the model of the prosthesis was analyzed computationally to predict the performance of the product. Different material properties are considered in the analysis to present Polylactic Acid (PLA) and Acrylonitrile Butadiene Styrene (ABS) materials. Then, the prosthesis was fabricated using the 3D printing. The results suggested that PLA material indicated better findings and further be fabricated.

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