articles+ search results

mandibular reconstruction, rapid prototyping, stereolithographic model, Dentistry, RK1-715, Surgery, and RD1-811

This article documents four mandibular reconstructions performed using free fibula flaps. CT scan DICOM (Digital Imaging and COmmunication in Medicine) files were obtained in order to print stereolithographic models of the mandible, and in one case cutting guides for fibular osteotomies. One case study details the treatment a cancer recurrence on a right emimandibulectomy. Because of a lack of access to previous CT scans, the left part of the mandible was mirrored to obtain an accurate 3D model. In one case, due to the young age of the woman, a double barrel fibula flap was used. All cases resulted in satisfactory chewing function and aesthetic outcome, with no flap failures. The report concludes that Virtual Planning and Rapid Prototyping are helpful as they reduce costs and intraoperative times while simultaneously improving surgical precision.

laser forming, rapid prototyping, self-folding origami, metal bending, Technology, Electrical engineering. Electronics. Nuclear engineering, and TK1-9971

Lasers can be used to bend 2D metal sheets into complex 3D objects in a process called ‘laser forming.’ Laser forming bends metal sheets by locally heating the sheets to generate plastic strains and is an established metal bending technology in the shipbuilding industry. Recent studies have investigated the laser forming of thin metal parts as a complementary rapid prototyping technology to metal 3D printing. This review discusses the laser forming process, beginning with the mechanisms before covering various design considerations. Laser forming for the rapid manufacturing of metal parts is then reviewed, including the recent advances in process planning, before highlighting promising future research directions.

rapid prototyping, stl, additive technology, subtractive technology, 3d printing, desktop milling, verification, simulation, Engineering (General). Civil engineering (General), TA1-2040, Mechanics of engineering. Applied mechanics, and TA349-359

This paper describes methodology for application of a rapid prototyping using subtractive, additive and formative technology based on STL files. Rapid prototyping technology includes using of a digital information chain CAD/CAM/CNC to a level which allows the successful realization of the physical models based on new technologies by adding, subtracting and molding material. The paper discusses about the usual technologies for rapid prototyping, for which a generalized methodology for their application has been proposed. The possibilities for program verification prior to the realization of the model were also shown. The methodology is verified on real examples of making selected parts. Used technologies are subtracting and adding material layers, layer by layer, and mold making (by adding material) for molding the silicone model.

CO2 laser, rapid prototyping, microneedle, multicellular tumor spheroids, microwells, hanging drops, Biology (General), and QH301-705.5

CO2 laser manufacturing has served as an enabling and reliable tool for rapid and cost-effective microfabrication over the past few decades. While a wide range of industrial and biological applications have been studied, the choice of materials fabricated across various laser parameters and systems is often confounded by their complex combinations. We herein presented a unified procedure performed using percussion CO2 laser drilling with a range of laser parameters, substrate materials and various generated microstructures, enabling a variety of downstream tissue/cellular-based applications. Emphasis is placed on delineating the laser drilling effect on different biocompatible materials and proof-of-concept utilities. First, a polydimethylsiloxane (PDMS) microneedle (MN) array mold is fabricated to generate dissolvable polyvinylpyrrolidone/polyvinyl alcohol (PVP/PVA) MNs for transdermal drug delivery. Second, polystyrene (PS) microwells are optimized in a compact array for the formation of size-controlled multicellular tumor spheroids (MCTSs). Third, coverglass is perforated to form a microaperture that can be used to trap/position cells/spheroids. Fourth, the creation of through-holes in PS is validated as an accessible method to create channels that facilitate medium exchange in hanging drop arrays and as a conducive tool for the growth and drug screenings of MCTSs.

Rapid Prototyping, surgery planning, fractures, Information technology, T58.5-58.64, Electronic computers. Computer science, and QA75.5-76.95

Orthopaedic trauma surgery is a complex surgical speciality in which anatomy, physiology and physics are mixed. Proper diagnosing and based on that planning and performing surgery is of crucial matter. This article presents usefulness of 3D reconstruction in diagnostics and surgical planning. It focuses on utility of computed tomography reconstruction in trauma surgery. Moreover, two cases in which this technique was used is described. Complex 3D reconstruction proved its usefulness and in future it may become a modality of choice for planning complex trauma procedures in which standard implants and approaches are insufficient.

BLE, Embedded System, Internet of Things, MQTT, Rapid Prototyping, STM32 ODE, Computer software, and QA76.75-76.765

The Internet of Things (IoT) is characterized by many technologies, standards, tools and devices for a wide range of application fields and often, for the end-users (makers and developers), is hard to orientate in an equally wide range of offers from various manufacturers. In recent years, the Bluetooth Low Energy (BLE) communication protocol is achieving a large portion of the market, thanks to its low-power and low-cost orientation and its pervasiveness in mobile devices, like smartphones. For these reasons, BLE is increasingly used in IoT-oriented Wireless Personal Area Networks (WPAN), where a small set of devices arranged in star topology network and connected to a smartphone and a Wi-Fi gateway, can cover a large number of monitoring and controlling use case scenarios. This work presents the ST’s STM32 Open Development Environment (ODE), a complete suite of hardware and software tools representing a reference point for end-users willing to create BLE-based star topology networks for a wide range of applications. Through a simple use case in a smart home context, it is shown how all provided tools can be used to fast prototype applications addressing all user requirements.

translaminar facet screw, rapid prototyping, guide template system, screw trajectory, tail angle, submergence angle, Computer applications to medicine. Medical informatics, R858-859.7, Surgery, and RD1-811

It is technically demanding and requires rich experience to insert the translaminar facet screw(TFS) via the paramedian mini-incision approach. It seems that it is easy to place the TFS using computer-assisted design and rapid prototyping(RP) techniques. However, the accuracy and safety of these techniques is still unknown. The aim of this study is to assess the accuracy and safety of translaminar facet screw placement in multilevel unilateral transforaminal lumbar interbody fusion using a rapid prototyping drill guide template system. A patient-matched rapid prototyping translaminar facet screw guide was examined in fourteen cadaveric lumbar spine specimens. A three-dimensional (3D) preoperative screw trajectory was constructed using spinal computed tomography scans, from which individualized guides were developed for the placement of translaminar facet screws. Following bone tunnel establishment, the 3D positioning of the entry point and trajectory of the screws was compared to the preoperative plan as found in the Mimics software.Among 60 trajectories eligible for assessment, no cases of clinically significant laminar perforation were found. The mean deviation between the planned and the actual starting points on spinous process was 1.22 mm. The mean tail and submergence angle deviation was found to be 0.68°and 1.46°, respectively. Among all the deviations, none were found to have any statistical significance. These results indicate that translaminar facet screw placement using the guide system is both accurate and safe.

tooth contact analysis, eccentric cycloid gear engagement, rapid prototyping, Industrial safety. Industrial accident prevention, and T55-55.3

This paper presents a mathematical model and tooth contact analysis of eccentric cycloid gear mesh. Numerical simulations aimed at generating contact pattern for a sample gear pair were performed. Contact pattern was also determined for gear wheels made by additive fabrication from transparent light-activated resin.

virtual prototyping, computer graphics, orthopaedics, virtual bones, rapid prototyping, Engineering (General). Civil engineering (General), TA1-2040, Mechanics of engineering. Applied mechanics, and TA349-359

The paper presents some methods used to analyze human bone joints. First, there were defined the 'hard' parts as the main bone components and 'soft' parts as ligaments or menisci using CT images. These components are imported into a parameterized environment assembly module and a biomechanical model of human walking is being obtained, which is exported to a kinematic simulation environment and finite element analysis, where first the kinematic parameters are defined. With these defined parameters, the kinematic and dynamic simulation of the subsystems for classical, normal motion can be switched. Following the interpretation of the results, the initial parameters of the biomechanical subsystems may be modified. In the next phase, the components of the subsystems are divided successively and the finite element structure is obtained for the entire biomechanical system of the joints that participate in human locomotion.

thermal insulation, rapid prototyping, heat transfer, thermal barrier, thermal conductivity, Mechanical engineering and machinery, and TJ1-1570

Nowadays, 3-D printing technology is very often applied in industry due to design cycles shortening and surface quality improvement when comparing to conventional manufacturing technologies. In order to adapt 3-D printed materials as thermal barriers, it is necessary to determine its thermophysical properties. As far as thermal insulation is concerned, the lowest thermal conductivity is required and therefore the crucial parameter of the material is the porosity. This paper presents the results of experimental investigation of effective thermal conductivity of thermal barriers with variable porosity fabricated by the fused filament fabrication technology. Also the numerical study was presented. The commercial code - COMSOL multiphysics was used to model the coupled heat transfer. The model was than validated by comparing the numerical and experimental results. For each sample the density and thermal conductivity were determined experimentally. The influence of the size and shape of the cell on the formation of free convection was investigated in particular. The effect of the conduction and radiation on temperature and velocity profiles within the enclosure has been analyzed. In addition, the dominant heat transfer mechanisms as a function of density have been identified.

rapid tooling, rapid prototyping, 3d printing, 3d printed molds, fiber-reinforced polymers (frps), biomedical devices, articular splints, computer-aided design (cad), Technology, Electrical engineering. Electronics. Nuclear engineering, TK1-9971, Engineering (General). Civil engineering (General), TA1-2040, Microscopy, QH201-278.5, Descriptive and experimental mechanics, and QC120-168.85

Advances in additive manufacturing technologies and composite materials are starting to be combined into synergic procedures that may impact the biomedical field by helping to achieve personalized and high-performance solutions for low-resource settings. In this article, we illustrate the benefits of 3D-printed rapid molds, upon which composite fibers can be laminated in a direct and resource-efficient way, for the personalized development of articular splints. The rapid mold concept presented in this work allows for a flexible lamination and curing process, even compatible with autoclaves. We demonstrate the procedure by completely developing an autoclave-cured carbon fiber−epoxy composite ankle immobilizing, supporting, or protecting splint. These medical devices may support patients in their recovery of articular injuries and for promoting a more personalized medical care employing high-performance materials, whose mechanical response is analyzed and compared to that of commercial devices. In fact, this personalization is fundamental for enhanced ergonomics, comfort during rehabilitation, and overall aesthetics. The proposed design and manufacturing strategies may support the low-cost and user-centered development of a wide set of biomedical devices and help to delocalize the supply chain for involving local populations in the development of medical technology.

Prostheses, Rapid Prototyping, Prosthesis Design, 3D Printing, Three Dimensional Printing, Transtibial, Socket Strength, Transtibial Socket, Thermoplastic, Lamination, Rapid Additive Manufacturing, Lower-limb Prostheses, Medical technology, R855-855.5, Orthopedic surgery, and RD701-811

BACKGROUND: Rapid Prototyping is becoming an accessible manufacturing method but before clinical adoption can occur, the safety of treatments needs to be established. Previous studies have evaluated the static strength of traditional sockets using ultimate strength testing protocols outlined by the International Organization for Standardization (ISO). OBJECTIVE: To carry out a pilot test in which 3D printed sockets will be compared to traditionally fabricated sockets, by applying a static ultimate strength test. METHODOLOGY: 36 sockets were made from a mold of a transtibial socket shape,18 for cushion liners with a distal socket attachment block and 18 for locking liners with a distal 4-hole pattern. Of the 18 sockets, 6 were thermoplastic, 6 laminated composites & 6 3D printed Polylactic Acid. Sockets were aligned in standard bench alignment and placed in a testing jig that applied forces simulating individuals of different weight putting force through the socket both early and late in the stance phase. Ultimate strength tests were conducted in these conditions. If a setup passed the ultimate strength test, load was applied until failure. FINDINGS: All sockets made for cushion liners passed the strength tests, however failure levels and methods varied. For early stance, thermoplastic sockets yielded, laminated sockets cracked posteriorly, and 3D printed socket broke circumferen-tially. For late stance, 2/3 of the sockets failed at the pylon. Sockets made for locking liners passed the ultimate strength tests early in stance phase, however, none of the sockets passed for forces late in stance phase, all broke around the lock mechanism. CONCLUSION: Thermoplastic, laminated and 3D printed sockets made for cushion liners passed the ultimate strength test protocol outlined by the ISO for forces applied statically in gait. This provides initial evidence that 3D printed sockets are statically safe to use on patients and quantifies the static strength of laminated and thermoplastic sockets. However, all set-ups of sockets made for locking liners failed at terminal stance. While further work is needed, this suggests that the distal reinforcement for thermoplastic, laminated and 3D printed sockets with distal cylindrical locks may need to be reconsidered. Article PDF Link: https://jps.library.utoronto.ca/index.php/cpoj/article/view/31008/24937 LAYMAN’S ABSTRACT 3D printing is a new manufacturing method that could be used to make prosthetic sockets (the part of the prosthesis connected to the individual). However, very little is known about the strength of 3D printed sockets and if they are safe to use. As Prosthetists are responsible for providing patients with safe treatments, the strength of 3D printed sockets needs to be established before they can be used in clinical practice. The strength of sockets made using current manufacturing methods was compared to those made using 3D printing. Strength was tested using the static portion of the ISO standard most applicable for this situation which outlines the forces a socket must take at 2 points in walking–when the foot is placed on the ground (early stance) and when the foot pushed off the ground (late stance). Sockets made for two prosthetic designs (cushion and locking) were tested to determine if one is safer than the other. All sockets made for cushion liners passed the standard for forces applied statically. However, different materials failed in different ways. At early stance, thermoplastic sockets yielded, laminated composite sockets cracked and 3D printed sockets broke circumferentially. At late stance other components failed 2/3 of the time before the sockets were affected. This provides initial evidence that sockets made for cushion liners are statically safe to use on patients. Sockets made for locking liners failed around the end, showing that 3D printing should not be used to create sockets with the design tested in this study. How to Cite: Pousett B, Lizcano A, Raschke S.U. An investigation of the structural strength of transtibial sockets fabricated using conventional methods and rapid prototyping techniques. Canadian Prosthetics & Orthotics Journal. 2019; Volume2, Issue1, No.2. DOI: https://doi.org/10.33137/cpoj.v2i1.31008