3D printing parameters
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This paper presents a complex and extensive experimental evaluation of fine particle emissions released by an FDM 3D printer for four of the most common printing materials (ABS, PLA, PET-G, and TPU). These thermoplastic filaments were examined at three printing temperatures within their recommended range. In addition, these measurements were extended using various types of printing nozzles, which influenced the emissions considerably. This research is based on more than a hundred individual measurements for which a standardized printing method was developed. The study presents information about differences between particular printing conditions in terms of the amount of fine particles emitted as well as the particle size distributions during printing periods. This expands existing knowledge about the emission of ultrafine particles during 3D printing, and it can help reduce the emissions of these devices to achieve cleaner and safer 3D printer operations.
BACKGROUND: The presented study investigates the application of bi-arterial 3D printed models to guide transseptal puncture (TSP) in left atrial appendage closure (LAAC). AIMS: The objectives are to (1) test the feasibility of 3D printing (3DP) for TSP guidance, (2) analyse the distribution of the optimal TSP locations, and (3) define a CT-derived 2D parameter suitable for predicting the optimal TSP locations. METHODS: Preprocedural planning included multiplanar CT reconstruction, 3D segmentation, and 3DP. TSP was preprocedurally simulated in vitro at six defined sites. Based on the position of the sheath, TSP sites were classified as optimal, suboptimal, or nonoptimal. The aim was to target the TSP in the recommended position during the procedure. Procedure progress was assessed post hoc by the operator. RESULTS: Of 68 screened patients, 60 patients in five centers (mean age of 74.68 ± 7.64 years, 71.66% males) were prospectively analyzed (3DP failed in one case, and seven patients did not finally undergo the procedure). In 55 patients (91.66%), TSP was performed in the optimal location as recommended by the 3DP. The optimal locations for TSP were postero-inferior in 45.3%, mid-inferior in 45.3%, and antero-inferior in 37.7%, with a mean number of optimal segments of 1.34 ± 0.51 per patient. When the optimal TSP location was achieved, the procedure was considered difficult in only two (3.6%) patients (but in both due to complicated LAA anatomy). Comparing anterior versus posterior TSP in 2D CCT, two parameters differed significantly: (1) the angle supplementary to the LAA ostium and the interatrial septum angle (160.83° ± 9.42° vs. 146.49° ± 8.67°; p = 0.001), and (2) the angle between the LAA ostium and the mitral annulus (95.02° ± 3.73° vs. 107.38° ± 6.76°; p < 0.001), both in the sagittal plane. CONCLUSIONS: In vitro TSP simulation accurately determined the optimal TSP locations for LAAC and facilitated the procedure. More than one-third of the optimal TSP sites were anterior.
- MeSH
- 3D tisk MeSH
- fibrilace síní * terapie chirurgie MeSH
- lidé MeSH
- počítačová rentgenová tomografie MeSH
- punkce metody MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- síňové ouško * diagnostické zobrazování chirurgie MeSH
- výsledek terapie MeSH
- Check Tag
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
OBJECTIVE: Precise control over the ultrasound field parameters experienced by biological samples during sonication experiments in vitro may be quite challenging. The main goal of this work was to outline an approach to construction of sonication test cells that would minimize the interaction between the test cells and ultrasound. METHODS: Optimal dimensions of the test cell were determined through measurements conducted in a water sonication tank using 3D-printed test objects. The offset of local acoustic intensity variability inside the sonication test cell was set to value of ±50% of the reference value (i.e., local acoustic intensity measured at last axial maximum in the free-field condition). The cytotoxicity of several materials used for 3D printing was determined using the MTT (3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide) assay. RESULTS: The sonication test cells were 3D printed from polylactic acid material, which was not toxic to the cells. Silicone membrane HT-6240, which was used to construct the bottom of the test cell, was found to reduce ultrasound energy minimally. Final ultrasound profiles inside the sonication test cells indicated the desired variability of local acoustic intensity. The cell viability in our sonication test cell was comparable to that of commercial culture plates with bottoms constructed with silicone membrane. CONCLUSION: An approach to construction of sonication test cells minimizing the interaction of the test cell and ultrasound has been outlined.
Due to a broad spectrum of endodontic rotary instruments on the market and no standardised protocol for comparing their mechanical properties, it can be challenging for clinician to choose proper instruments. In vitro studies using resin blocks with artificial canals can offer many valuable information because of their uniformity compared to studies performed on extracted teeth. To improve precision and reproducibility of artificial canals, 3D printing was used in this study to manufacture endodontic test block samples. 20 commercially available endodontic blocks Endo-Training-Bloc-J by Dentsply Sirona were tested. The mean values of the measured parameters were used for a 3D CAD model of their replicas. 20 copies of the endodontic training blocks were printed from acrylic resin (VeroClear-RGD810, Stratasys, Eden Prairie, USA) using the 3D printer Objet30 Pro (Stratasys, Eden Prairie, USA). The key dimensions of the commercial blocks and the 3D printed blocks were measured under and compared using t - test and Levene's test for equality of variances. The profiles of the 3D printed artificial canals showed significantly lower dimensional variability when compared with the commercial blocks. 3D polyjet printing proved to be a precise and reproducible method for production of blocks for testing endodontic rotary instruments.
- MeSH
- 3D tisk MeSH
- endometrióza * MeSH
- extrakce zubů MeSH
- lidé MeSH
- reprodukovatelnost výsledků MeSH
- výzkumný projekt * MeSH
- Check Tag
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Akutní hypoxemické respirační selhání (které se vyskytuje i při závažném průběhu onemocnění COVID-19) vyžaduje kyslí kovou léčbu. Invazivita a intenzita zvolené terapie odpovídá stavu pacienta a dostupným technickým prostředkům. Pokud dojde k náhlému výskytu velikého počtu nemocných s hypoxickým selháním, může být dostupná materiální a/nebo lidská kapacita pro poskytování účinné kyslíkové terapie přetížena. Cílem našeho experimentu bylo otestovat funkčnost Venturiho trysky Corovalve, kterou jsme navrhli a vytiskli na 3D tis kárně. Trysku jsme vřadili do jednoduchého systému, který jsme zkompletovali z dílů běžně dostupných v České republice. Toto zařízení jsme odzkoušeli ve statickém testu a v dynamickém testu sami na sobě a změřili jeho základní parametry. V provedeném experimentu generovalo naše zařízení při spontánní ventilaci pozitivní hodnotu středního tlaku v dýchacích cestách. Při vyšších průtocích byl systém schopný udržet mírný pozitivní tlak i během inspiria, můžeme tedy mluvit o systému, který za určitých podmínek umožňuje spontánní ventilaci při kontinuálním přetlaku. Nejefektivnějším nastavením během spontánní ventilace byl příkon kyslíku 15 l/min v kombinaci s nastavením PEEP ventilu na 10–15 cm H2O. Při těchto parametrech byl generován střední tlak v dýchacích cestách 9–12 cm H2O při výsledné koncentraci kyslíku ve vdechované směsi 41–42 %. Výsledky našeho experimentu dokládají, že s pomocí trysky Corovalve vytištěné na 3D tiskárně je možné sestrojit jedno duché zařízení umožňující aplikaci kyslíku přetlakem EPAP/CPAP. Jedná se o metodu ekonomickou a jednoduše provedi telnou, a proto s poměrně zajímavým potenciálem. Při dostatečném počtu 3D vytištěných trysek by mohla být nasazena rychle a v masovém měřítku.
Acute hypoxemic respiratory failure (which occures also with severe course of COVID-19) requires oxygen therapy. The in vasiveness and intensity of chosen therapy corresponds with patient's condition and technical means available. If a large number of patients with hypoxic failure suddenly occur, the available equipment and/or human capacity to provide effective oxygen therapy may be greatly strained. The goal of our experiment was to test functionality of a simple device equipped with a Venturi nozzle Corovalve which we designed and printed on a 3D printer. We incorporated the nozzle into a system assembled from parts commonly available in the Czech Republic. We put this device through a static test and a dynamic test performed on ourselves and measured its basic parameters. In our experiment during spontaneous ventilation the device was able to generate positive mean airway pressure. At higher flow rates, the system was able to maintain a slightly positive pressure even during the inspiration, so we can talk about a system that allows, under certain circumstances, spontaneous ventilation at continuous positive airway pressure. The most effective from setting tested was oxygen input of 15 L/min combined with PEEP valve set to 10–15 cm H 2 O. Mean airway pressure ranged at 9–12 cm H 2 O and oxygen concentration in the inspiration mixture was 40–42%. We therefore conclude that our nozzle Corovalve printed on a 3D printer can be used in a simple device allowing positive pressure oxygen application during spontaneous ventilation EPAP/CPAP. It is economical and easy to provide method and therefore of a rather interesting potential. With a sufficient number of 3D printed nozzles it could be deployed quickly and on a mass scale.
PURPOSE: Endoscopically assisted sagittal strip craniotomy with subsequent cranial orthosis is a frequently used surgical approach for non-syndromic sagittal synostosis. Originally, this technique involved a wide sagittal strip craniectomy with bilateral wedge osteotomies. More recent studies suggest omitting wedge osteotomies, achieving similar outcomes. The controversy surrounding wedge osteotomies and our efforts to refine our technique led us to create models and evaluate the mechanical impact of wedge osteotomies. METHODS: We conducted a 3D-print study involving preoperative CT scans of non-syndromic scaphocephaly patients undergoing minimally invasive-assisted remodelation (MEAR) surgery. The sagittal strip collected during surgery underwent thickness measurement, along with a 3-point bending test. These results were used to determine printing parameters for accurately replicating the skull model. Model testing simulated gravitational forces during the postoperative course and assessed lateral expansion under various wedge osteotomy conditions. RESULTS: The median sagittal strip thickness was 2.00 mm (range 1.35-3.46 mm) and significantly positively correlated (p = 0.037) with the median force (21.05 N) of the 3-point bending test. Model testing involving 40 models demonstrated that biparietal wedge osteotomies significantly reduced the force required for lateral bone shift, with a trend up to 5-cm-long cuts (p = 0.007). Additional cuts beyond this length or adding the occipital cut did not provide further significant advantage (p = 0.1643; p = 9.6381). CONCLUSION: Biparietal wedge osteotomies reduce the force needed for lateral expansion, provide circumstances for accelerated head shape correction, and potentially reduce the duration of cranial orthosis therapy.
- MeSH
- 3D tisk * MeSH
- anatomické modely MeSH
- endoskopie metody MeSH
- kojenec MeSH
- kraniosynostózy * chirurgie MeSH
- kraniotomie metody MeSH
- lidé MeSH
- osteotomie * metody MeSH
- počítačová rentgenová tomografie MeSH
- Check Tag
- kojenec MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
Currently, due to the relatively high number of active users with amputation of the lower limbs, it is important to increase user comfort, innovate and optimize the connection between the residual limb and the prosthesis, i.e. the prosthetic socket. The purpose of this work is to combine the potential and advantages of both conventional and innovative (modern) production processes for the design and fabrication of personalized hybrid sockets to optimize production, comfort, and patient safety. The socket was designed and constructed for a highly active user (Functional Classification Level 4) to ensure comfort and safety during high-stress sports activities (skiing). Unlike traditional plastering, a 3D scanner was used to take measurement data. The 3D model of the stump was edited in a software environment instead of laborious and lengthy processing of the plaster positive. Subsequently, a matrix of the prosthetic socket was made from PETG material using FFF 3D printing, which was laminated to increase strength. 3D printed samples of PETG material were tested for tension and pressure according to the relevant standard (EN ISO 527-2: 1996). The last phase was static and dynamic testing of the hybrid socket. No deviations were recorded in the monitored parameters, both at a slow (1.0 km/h) and at a standard (2.5 km/h) walking speed. Once the socket integrity has been assessed, a greater dynamic load was initiated in the form of activities with higher dynamic levels (lateral leaning on the knee and jumps). According to the test results, there has been no change in the shape or integrity of the socket, and the subjective point of view of the volunteer rated the hybrid prosthetic socket as comfortable.
Additive Manufacturing (AM) is a name of a group of technologies that build 3D objects by adding layer-upon-layer of material. There are many technologies, including Rapid Prototyping (RP), Direct Digital Manufacturing (DDM), layered manufacturing and additive fabrication. Many types of materials can be used for AM technology. Biodegradable polymers such as polylactic acid (PLA) and polyhydroxybutyrate (PHB), are currently the subject of intensive research in the field of additive manufacturing and regenerative medicine. A number of biodegradable and bioresorbable materials, as well as scaffold designs, have been experimentally and clinically studied in many research facilities around the world. For effective using of bioprinting technologies in tissue and biomedical engineering, the knowledge of material and technological parameters in the process of printing is necessary. In this study the 3D printer Bioplotter EnvisionTEC (the printer with ability to print different materials from hydrogel to plastic materials) was used. Scaffolds for the purpose of the experiment were prepared via extrusion-based bioprinting. Experimental part of this study was focused on defining the influence of printing parameters and technological pre-processing of the material on quality and mechanical and geometrical properties of printed parts. Testing of printed samples showed high influence of pre-processing of material, mainly drying process, on mechanical and geometric quality of samples. Drying of material before printing process makes the material more stable and allows it to maintain defined material properties for a longer time than non-dried material. Time of heating of the material in printing cartridge has also high impact on material behaviour. Test results showed that if the time of heating of the material in the high temperature cartridge exceeds defined time limit, the material starts to degrade and is no more usable.
- MeSH
- 3D tisk * MeSH
- biokompatibilní materiály * chemie MeSH
- biomedicínské technologie MeSH
- kyselina polyglykolová chemie MeSH
- lidé MeSH
- polymery * MeSH
- pružnost MeSH
- testování materiálů MeSH
- tkáňové inženýrství * MeSH
- tkáňové podpůrné struktury MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- práce podpořená grantem MeSH
Orodispersible films are an innovative dosage form. Their main advantages are the application comfort and the possibility of personalization. This work aimed to evaluate the influence of different drying times on the properties of orodispersible films of various thicknesses, prepared in two different semisolid extrusion 3D printing setups. In the first experiment, drying times were dependent on the overall print time of each batch. In the second setup, the drying time was set equal according to the longest one. The evaluated parameters were films' weight uniformity, thickness, moisture content, surface pH, disintegration time, hardness, and tensile strength. Upon statistical comparison, significant differences in the moisture content were found, subsequently affecting the disintegration time. Moreover, statistically significant differences in films' mechanical properties (hardness, tensile strength) were also described, proving that moisture content simultaneously affects film plasticity and related properties. In conclusion, a mutual comparison of the manufactured orodispersible films showed that the drying time affects their physical and mechanical properties. The in-process drying setup was proved to be sufficient while allowing quicker manufacturing.
- Publikační typ
- časopisecké články MeSH
BACKGROUND: Color stability is a crucial performance parameter for dental restorations, and limited research exists on how surface preparation methods affect it. The purpose of this study was to test the color stability of three resins intended for 3D printing, which can be used to make dentures or crowns in A2 and A3 colors. MATERIALS AND METHODS: Samples were prepared in the form of incisors; the first group was not subjected to any treatment after curing and washing with alcohol, the second was covered with light-curing varnish, and the third was polished in a standard way. Then, the samples were placed in solutions of coffee, red wine, and distilled water and stored in the laboratory. After 14, 30, and 60 days, color changes were measured (presented as Delta E) compared to material stored in the dark. RESULTS: The greatest changes were observed for samples that were not polished, then were placed in red wine dilutions (ΔE = 18.19 ± 0.16). Regarding the samples covered with varnish, during storage, some parts detached, and the dyes penetrated inside. CONCLUSIONS: 3D-printed material should be polished as thoroughly as possible to limit the adhesion of dyes from food to their surface. Applying varnish may be a temporary solution.
- Publikační typ
- časopisecké články MeSH
