scholarly journals Accuracy Verification of an Anatomical Model Manufactured Using Low-Cost Additive Production

2021 ◽  
Vol 11 (2) ◽  
pp. 594
Author(s):  
Teodor Tóth ◽  
Patrik Varga ◽  
Branko Štefanovič ◽  
Lucia Bednarčíková ◽  
Marek Schnitzer ◽  
...  
Keyword(s):  
Surface Coverage ◽  
Reference Model ◽  
Low Cost ◽  
Cervical Vertebra ◽  
3D Printer ◽  
3D Scanner ◽  
Entire Surface ◽  
Additive Production ◽  
The Third ◽  
And Training

The paper deals with the separation of the third cervical vertebra using the software VGStudio MAX, Mimics, and inVesalius. During the separation, various parameters of the threshold were used to determine the effect. The comparison of models from Mimics and inVesalius to VGStudio MAX showed that the cumulative variance distribution for 95% surface coverage is less than 0.935 mm. When comparing medically oriented software, Mimics and inVesalius, the deviation was less than 0.356 mm. The model was made of polylactic acid (PLA) material on a low-cost 3D printer, Prusa i3 MK2.5 MMU1. The printed model was scanned by four scanners: Artec Eva, 3Shape D700, Steinbichler Comet L3D, and Creaform EXAscan. The outputs from the scanners were compared to the reference model (standard tessellation language (STL) model for 3D printing) as well as to the scanner with the best accuracy (3Shape). Compared to the publications below, the analysis of deviations was evaluated on the entire surface of the model and not on selected dimensions. The cumulative variance distribution for comparing the output from the 3D scanner with the reference model, as well as comparing the scanners, shows that the deviation for 95% of the surface coverage is at the level of 0.300 mm. Since the model of the vertebra is planned for education and training, the used software and technologies are suitable for use in the design and the production process.

Simple, Fast, and Low Cost Fabrication Methods of Microchannels for Manipulation of Living Cells

2013 ◽  
Author(s):  
Anas Alazzam ◽  
Bashar El-Khasawneh ◽  
Mohammad Abutayeh
Keyword(s):  
Microfluidic Device ◽  
Glass Substrate ◽  
Low Cost ◽  
Living Cells ◽  
Numerical Control ◽  
Adhesive Tape ◽  
3D Printer ◽  
Cnc Machine ◽  
Advantages And Disadvantages ◽  
The Third

This work details simple non-cleanroom fabrication techniques to build hermetic microchannels using laboratory available material and equipment. Four different methods are presented for fast fabrication of microchannels at low cost. The microchannels are to be used for the manipulation of living cells. These methods of fabrication of microfluidics devices have previously been used and documented as reactors, fluid mixer, and for fluids transportation and inspection. In this work, all methods were used for manipulation of living cells. Each method, its advantages and disadvantages for this particular application are reported. The microfluidic device built using the first method includes a polymer-based part and a glass substrate with a layer of patterned electrodes. The Polymer-based microchannel is made outside the cleanroom facility using a simple mold made from adhesive tape. Moreover, the fabrication of a non-polymer microchannel made from double-sided tape is described. The microchannel height is about 50 μm while the width varies between 100 μm to a few hundred microns. The third method of fabrication is made by a 3D printer. The master molds for the polymer-based microfluidic device are fabricated by 3D printing of biocompatible material on glass substrate. The fourth method is a simple embossing of a male die in plastic or polymer substrate. A computer numerical control (CNC) machine was used to fabricate the embossing mold in stainless steel, brass, and aluminum. Microchannels were created by stamping the mold in a Cyclic Olefin Copolymer (COC) substrate.

The Recreation and Evaluation of a Human Hand Using Low-Cost Reverse Engineering and 3D Printing Systems

2016 ◽  
Author(s):  
C. Jacobsen ◽  
E. Ashe ◽  
R. Noorani
Keyword(s):  
Reverse Engineering ◽  
Low Cost ◽  
Three Dimensional ◽  
Human Hand ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
3D Scanner ◽  
Joint System ◽  
The Third ◽  
Motion System

The primary goal of this research was to evaluate the effectiveness of a low-cost reverse engineering system to recreate a physical, three-dimensional model of a human hand. In order to achieve the goal of this research, three key objectives were fulfilled: (1) the first objective was to recreate the physical model of the human hand using a low-cost experimental setup (<$5000), (2) the second objective was to assess the ability of the reverse engineered hand to perform common tasks of everyday life, and (3) the third objective was to investigate the potential biomedical applications of the reverse engineered human hand. A chosen test subject had his or her hand molded and cast into a plaster three-dimensional model that could be held steady and scanned very precisely by a NextEngine Desktop 3D Scanner. Other methods could have been employed to achieve the scanned model, but given the experimental setup and timeline a casted model was assumed to be the most appropriate method to achieve the best results. The plaster casting of the subject’s hand was scanned several times using different orientations of the model relative to the stationary 3D scanner. From these scans, a computer CAD model of the human hand was generated, modified, and 3D printed using a Makerbot Replicator 2. The printed model was evaluated by its ability to perform common every-day tasks such as picking up a cup/bottle, holding a pen/pencil, or opening/closing around an object. Several iterations of the printed human hand were evaluated in order to determine the best design for the fingers’ joints and cable-driven motion system. The first iteration of the printed hand featured a snap-in joint system. This joint design suffered from requiring a large number of individual pieces and poor tolerances of the Makerbot printer. The second iteration featured a press fit style joint system. This system was hindered by tolerances similar to the first iteration as well as plastic deformation of the printed material due to inadequate elasticity. The third and final iteration of the joint system featured a single printed assembly for which the entire prosthetic could be printed at one time. It was expected that the hand would be able to translate the rotational movement of an individual’s wrist to tension the cables of the motion system thereby closing the fingers into a first. This movement will allow the user to close the prosthetic hand around everyday objects and pick them up with relative ease. Although the possibilities of reverse engineering and 3D printing systems have greatly expanded as a result of greater affordability and increased accuracy, their applications in the biomedical field have yet to be fully explored.

Effect of Computerized Auditory Training on Speech Perception of Adults With Hearing Impairment

2013 ◽  
Vol 20 (3) ◽  
pp. 91-106 ◽  
Author(s):  
Rachel Pizarek ◽  
Valeriy Shafiro ◽  
Patricia McCarthy
Keyword(s):  
Hearing Loss ◽  
Speech Perception ◽  
Literature Review ◽  
Low Cost ◽  
Experimental Designs ◽  
Auditory Training ◽  
Hearing Impairments ◽  
Communicative Disorders ◽  
And Training

Computerized auditory training (CAT) is a convenient, low-cost approach to improving communication of individuals with hearing loss or other communicative disorders. A number of CAT programs are being marketed to patients and audiologists. The present literature review is an examination of evidence for the effectiveness of CAT in improving speech perception in adults with hearing impairments. Six current CAT programs, used in 9 published studies, were reviewed. In all 9 studies, some benefit of CAT for speech perception was demonstrated. Although these results are encouraging, the overall quality of available evidence remains low, and many programs currently on the market have not yet been evaluated. Thus, caution is needed when selecting CAT programs for specific patients. It is hoped that future researchers will (a) examine a greater number of CAT programs using more rigorous experimental designs, (b) determine which program features and training regimens are most effective, and (c) indicate which patients may benefit from CAT the most.

scholarly journals Barriers to training in laparoscopic surgery in low- and middle-income countries: A systematic review

2021 ◽  
pp. 004947552199818
Author(s):  
Ellen Wilkinson ◽  
Noel Aruparayil ◽  
J Gnanaraj ◽  
Julia Brown ◽  
David Jayne
Keyword(s):  
Laparoscopic Surgery ◽  
Low Cost ◽  
Surgical Care ◽  
Successful Implementation ◽  
Middle Income ◽  
Middle Income Countries ◽  
Technological Advances ◽  
Local Access ◽  
And Training ◽  
Low And Middle Income

Laparoscopic surgery has the potential to improve care in resource-deprived low- and-middle-income countries (LMICs). This study aims to analyse the barriers to training in laparoscopic surgery in LMICs. Medline, Embase, Global Health and Web of Science were searched using ‘LMIC’, ‘Laparoscopy’ and ‘Training’. Two researchers screened results with mutual agreement. Included papers were in English, focused on abdominal laparoscopy and training in LMICs. PRISMA guidelines were followed; 2992 records were screened, and 86 full-text articles reviewed to give 26 key papers. Thematic grouping identified seven key barriers: funding; availability and maintenance of equipment; local access to experienced laparoscopic trainers; stakeholder dynamics; lack of knowledge on effective training curricula; surgical departmental structure and practical opportunities for trainees. In low-resource settings, technological advances may offer low-cost solutions in the successful implementation of laparoscopic training and improve access to surgical care.

scholarly journals Low-Cost Customized Cranioplasty with Polymethyl Methacrylate Using 3D Printer Generated Mold: An Institutional Experience and Review of Literature

2021 ◽  
Author(s):  
Ankit Chaudhary ◽  
Virendra Deo Sinha ◽  
Sanjeev Chopra ◽  
Jitendra Shekhawat ◽  
Gaurav Jain
Keyword(s):  
Polymethyl Methacrylate ◽  
Bone Fractures ◽  
Low Cost ◽  
Operating Time ◽  
Three Dimensional ◽  
Wound Dehiscence ◽  
3D Printer ◽  
Skull Defects ◽  
Aesthetic Appearance ◽  
The Mean

Abstract Background Cranioplasty is performed to repair skull defects and to restore normal skull anatomy. Optimal reconstruction remains a topic of debate. Autologous bone flap is the standard option but it may not be available due to traumatic bone fractures, bone infection, and resorption. The authors present their experience with prefabrication of precise and low-cost polymethyl methacrylate (PMMA) mold using three-dimensional (3D) digital printing. Methods A total of 30 patients underwent cranioplasty between March 2017 and September 2019 at Sawai Man Singh Medical College Jaipur, India. Preoperative data included diagnosis for which decompressive craniectomy was done and Glasgow coma scale score. Intraoperative data included operating time. Postoperative data included cosmetic outcome in the form of cranial contour and margins, complications such as infection, seroma, implant failure, wound dehiscence, and hematoma. Results Patient age at cranioplasty ranged from 12 to 63 years with a mean age of 36.7 years. The mean operating time was 151.6 minutes (range 130–190 minutes). The mean follow-up period was 8 months (range 6–13 months). Postoperative wound dehiscence developed in one case (3.3%). Cranial contour and approximation of the margins were excellent and aesthetic appearance improved in all patients. Conclusion Low-cost PMMA implant made by digital 3D printer mold is associated with reconstruction of the deformed skull contour giving satisfactory results to the patient and his family members, at a low cost compared with other commercially available implants. This technique could be a breakthrough in cranioplasty.

Performance of Low-Cost 3D Printer in Medical Application

2021 ◽  
Author(s):  
Nor Aiman Sukindar ◽  
Azib Azhari Awang Dahan ◽  
Sharifah Imihezri Syed Shaharuddin ◽  
Nor Farah Huda Abd Halim
Keyword(s):  
Low Cost ◽  
Medical Application ◽  
Fused Deposition Modelling ◽  
3D Printer ◽  
Layer By Layer ◽  
Total Deformation ◽  
Element Analysis ◽  
Porosity Level ◽  
Fused Deposition ◽  
Printing Parameters

Abstract Fused Deposition Modelling (FDM) is an additive manufacturing (AM) process that produces a physical object directly from a CAD design using layer-by-layer deposition of the filament material that is extruded via a nozzle. In industry, FDM has become one of the most used AM processes for the production of low batch quantity and functional prototypes, due to its safety, efficiency, reliability, low cost, and ability to process manufacturing-grade engineering thermoplastic. Recently, the market is flooded with the availability of low-cost printers produced by numerous companies. This research aims to investigate the effect of different porosity levels on a scaffold structure produced using a low-cost 3D printer. Comparisons of these porous structures were made in terms of Von-Mises strain, total deformation, as well as compressive stress. Various porosity levels were created by varying printing parameters, including layer height, infill density, and shell thickness by slicing the initial solid CAD file using Repetier Host 3D printing software. Finite Element Analysis (FEA) simulation was then performed on the created scaffold structures by using Ansys Workbench 19.2. The simulation result indicates that the greater porosity level will result in higher total deformation of the structure. Meanwhile, the compression test shows that the minimum strength value obtained was favourable at 22 MPa and had exceeded that of the trabecular femur (15 MPa). However, its porosity level (maximum at 52%) was still below that of the minimum threshold of porosity level of 70 percent. However, the printing parameters currently used can be adjusted in the future. Therefore, it was deduced that the low-cost 3D printer offers promising potential to fabricate different porosity structures with multiple outcomes.

Ultrastructural changes in the avian vitelline membrane during embryonic development

Development ◽  
1969 ◽  
Vol 21 (3) ◽  
pp. 467-484
Author(s):  
Cynthia Jensen
Keyword(s):  
Embryonic Development ◽  
Mechanical Strength ◽  
Dual Role ◽  
Early Embryonic Development ◽  
Ultrastructural Changes ◽  
Vitelline Membrane ◽  
Entire Surface ◽  
Animal Pole ◽  
The Third ◽  
Vegetal Pole

The vitelline (yolk) membrane of the avian egg plays a dual role during early embryonic development; it encloses the yolk and provides a substratum for expansion of the embryo (Fig. 1). Expansion appears to be dependent upon the movement of cells at the edge of the blastoderm which is intimately associated with the inner layer of the vitelline membrane (New, 1959; Bellairs, 1963). The blastoderm (embryonic plus extraembryonic cells) has almost covered the entire surface of the yolk by the third and fourth days of incubation, and when this stage has been reached the vitelline membrane ruptures over the embryo and slips toward the vegetal pole. Rupture of the membrane during development appears to be the consequence of a decrease in its mechanical strength (Moran, 1936), which changes most rapidly at the animal pole (over the embryo).

scholarly journals Full in-Office Guided Surgery with Open Selective Tooth-Supported Templates: A Prospective Clinical Study on 20 Patients

2018 ◽  
Vol 15 (11) ◽  
pp. 2361 ◽  
Author(s):  
Francesco Mangano ◽  
Uli Hauschild ◽  
Oleg Admakin
Keyword(s):  
Clinical Study ◽  
Low Cost ◽  
Prospective Clinical Study ◽  
3D Printer ◽  
Guided Surgery ◽  
Operative Complications ◽  
Edentulous Patients ◽  
One Year ◽  
Single Crowns ◽  
Surgical Templates

Background: Guided implant surgery appears to have several benefits, such as the possibility of inserting flapless implants in a prosthetically driven manner, avoiding dangerous anatomical structures. However, to date, only a few surgeons routinely use guided surgery in partially edentulous patients. Aim: To present the results obtained with tooth-supported surgical templates characterized by an innovative open design with selective support, and manufactured via a full in-office procedure with a low-cost desktop 3D printer. Methods: Over a two-year period (2016–2018), all partially edentulous patients with one to three missing teeth (in maxilla and/or mandible), referred to a private dental practice for restoration with dental implants, were considered for inclusion in this prospective clinical study. An intraoral scanner (CS 3600®, Carestream Dental) and cone beam computed tomography (CS 9300®, Carestream Dental) were used to acquire the 3D information on the patients. Guided surgery software (SMOP®, Swissmeda) was used to plan the surgeries and to design open, selective, tooth-supported templates that were fabricated with a stereolithographic (SLA) desktop 3D printer (XFAB2000®, DWS). Guided implant surgeries were performed and patients were followed for a period of one year. The study outcomes were fit and stability of surgical templates, duration (time) of surgery, intra and post-operative complications, and implant stability and survival. Results: Twenty (20) partially edentulous patients (9 males, 11 females; mean age 54.4 ± 9.4 years) were included in the study; 28 open, selective, tooth-supported templates were designed with the aim of inserting 38 implants. Among the surgical templates, 24 had optimal fit and stability, three had optimal fit and sufficient stability, and only one had inadequate fit and unsatisfactory stability and was therefore not suitable for clinical use. The average time of the intervention was 15.7 ± 5.2 min per template. No intra-operative complications were reported, but one implant was not stable at placement and had to be removed. In total, 36 implants were restored with 10 two-unit fixed partial prostheses and 16 single crowns. All implants were successfully functioning at one year, even if, in two single crowns, minor prosthetic complications (abutment screw loosening) occurred. Conclusions: Full in-office guided surgery with open, selective, tooth-supported templates seem to represent a clinically predictable surgical procedure to restore partially edentulous patients. Further studies are needed to confirm these positive outcomes.

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