Dimensional Printing Research Articles

Novel morphological classification of left atrial appendage using 3-dimensional printer -rock, paper and scissors-

Abstract Background The WATCHMAN device was developed as a permanent implantable device to seal off the LAA to prevent cardiogenic embolism. It has been used in Japan since September 2019 only for patients who are at the high risk of bleeding events. It is known that the LAA diameter of Asians is larger than that of non-Asians. Furthermore, the LAA of the Japanese are more complicated, compared to the Western. Whereas the four classifications from previous reports are widely used in the world, the classification differs with different physicians in the real-world practice. Purpose We aimed to identify the relationship between morphological features of LAA and clinical events such as ischemic stroke in Japanese patients. Methods All LAAC cases in our institution performed between February 2020 and December 2023 were retrospectively analyzed. The three-dimensional printing of LAA was generated from cardiovascular computed tomography imaging data. The shapes of the LAA were classified into 3 morphological types: (1) The LAA with bi lobe was defined as "Scissors" type; (2) The one with complicated peripheral branches was "Paper" type; (3) The simple one was "Rock" type. We examined the between the risk of cardioembolic stroke and the morphological features of the LAA. The left atrial appendage was classified by two cardiologists, and when they made different choices, we used the operator's choice. Results The cohort consisted of 116 patients, excluding 22 patients without CT scans. Of those, 30 (26%), 38 (33%) and 48 (41%) patients were divided into the Rock, Scissors and Paper types, respectively. All groups were identically matched for comorbidities. Table shows the patient characteristics and the results of univariate and multivariate analysis. There were 51 (44%) patients who had a history of cardioembolic stroke (18% vs. 30% vs. 53%; Rock vs. Scissors vs. Paper types, p-value = 0.05). In the multivariate analysis, the Paper type is the potential risk factor of cardioembolic stroke (p-value = 0.01). In addition, of those, 36 (31%), 32 (28%), 28 (24%) and 20 (17%) patients were divided into the Chicken wing, Cactus, Cauliflower and Windsock types, respectively. The four types were not associated with prior cardioembolic stroke events (18% vs. 25% vs. 55%; Chicken wing vs. Cactus vs. Cauliflower vs. Windsock types, p-value = 0.83). The match rate of cardiologists’ choice was 86.2% for the new classification and 44.8% for the classical classification. Conclusions The morphological features of LAA by three-dimensional printing was significantly related to cardioembolic stroke in this population. Patients with Paper type LAA were significantly more likely to have had a history of cardioembolic stroke. These results could have a relevant impact on the antithrombotic management of patients who are at the high risk of embolic and bleeding events and, moreover, LAAC could be the best option for these patients.

3-Dimensional Printing in Healthcare: Manufacturing Techniques and Applications

3D printing and additive manufacturing are interchangeable terms. Additive manufacturing builds models layer by layer using a variety of laser-based or sophisticated printing processes. While this was one of the earliest techniques for 3D printing, the field now widely uses a number of other patented methods. The objective is to analyze the success rate of 3D printing in healthcare. The medical industry has found 3D printing to be highly beneficial in recent years. The application of 3D printing technology allows for greater customization of the therapeutic process, which enhances treatment safety, accuracy, and precision. On the other hand, the disclosure of new materials for 3D printing occurs frequently. For some producers, the right materials might just be a few months or years away. However, printing certain materials may be difficult or impossible. Excellent results are not always possible with 3D printers. We can conclude that 3D printing represents one of the most advanced techniques in healthcare.

Versatility of patient specific implants in reconstruction of maxillofacial defect: a case report of central giant cell granuloma

Reconstructing maxillofacial defects is challenging due to its complex anatomy and cosmetic and functional effects on patients. From a functional and esthetic view, it is imperative for surgeons to accurately restore the defect in a way that will ensure patient satisfaction and well-being. Here, a case of large lytic lesion of anterior mandible, causing extensive bony resorption, in a young female patient is reported. Incisional biopsy was performed and the histopathological features were suggestive of Central giant cell granuloma (CGCG). Surgical treatment by en-bloc resection of the lesion was done. Several reconstruction options are available in the literature are available for the residual bony defect including iliac crest graft, costochondral graft, submental island flaps and more. However, the advent of additive manufacturing, 3–dimensional (3D) printing, and the recent advances in those technologies has positively influenced the biomedical field, leading to the utilization of patient-specific implants (PSIs) in the surgical repair of maxillofacial defects. This report highlights the advantages of using Patient Specific Implant and describes our experience with it.

A Comparative Study of Traditional and Computer-aided Surgical Simulation Guides in Orthognathic Correction of Bimaxillary Protrusion.

To compare the efficacy of traditional occlusal guides with computer-aided surgical simulation (CASS) guides in enhancing postoperative outcomes for patients with bimaxillary protrusion. This retrospective study evaluated 34 patients undergoing anterior maxillary and mandibular subapical osteotomy at the Plastic Surgery Hospital of the Chinese Academy of Medical Sciences. Fourteen patients were treated using traditional occlusal guides, whereas 20 patients were treated with CASS guides (median age 28.6 years, median follow-up 259 days). Pre and postoperative cephalometric indicators were measured using cephalometric software. Data analysis was conducted using SPSS 14.0, with significant differences determined at P < 0.05. All 34 patients experienced primary healing without complications. Follow-up indicated significant improvements in key cephalometric measurements in the CASS group compared with the traditional group, including mandibular position (SNB angle, P < 0.001), jaw relationship (ANB angle, P < 0.001), facial angle (FH-NPo, P = 0.002), and condyle-to-sella distance (Co-S, P = 0.024). The CASS group also showed better aesthetic outcomes, with significant reductions in overjet (P = 0.012), overbite (P = 0.001), and improved alignment of upper and lower incisors (U1-L1 angle, P = 0.031). CASS-guided surgery offers a superior alternative to traditional methods for treating bimaxillary protrusion, providing more precise and aesthetically pleasing results. This study highlights the significant advantages of using advanced digital simulation and 3-dimensional printing technologies in orthognathic surgery.

Influence of printing orientation on power-law hardening and ductile damage parameters for 3D-printed SS316L steel: experimental and FEA approach

In the present investigation, the selective laser melting (SLM) technique has been utilized for the 3-dimensional printing (tensile test specimens) of SS316L steel powder at 00 (horizontal) and 900 (vertical) angles. Further, an experimental and finite element analysis approach has been made to analyse the effect of printed orientation or direction on the Hollomon power law parameters (strain hardening exponent (n) and strength coefficient (K)) and ductile damage parameters (fracture strain (εf), stress triaxiality (η) and strain rate ( ε ̇ )). The influence of printing orientation on plastic deformation behavior has also been analysed. The results revealed that 00 angle 3D-printed specimens exhibited 11.05%, 21.97% and 9.50% more yield strength, tensile strength and elongation than 900 angle 3D-printed tensile test specimens. Further, the strain hardening exponent (n) and strength coefficient (K) (Hollomon power law hardening model parameters) for 00 angle 3D-printed specimens are 35.80% and 32.47% more than the 900 angle 3D-printed tensile test specimens respectively. The fracture strain for 00 angle 3D-printed specimens is 37.82% less than the 900 angle 3D-printed tensile test specimens. The percentage difference between FEA and experimental results is less than 5% which shows the good prediction capability of estimated Hollomon power law parameters and ductile damage model parameters with developed FEA model for 00 and 900 3D printed specimens.

An experimental analysis of mechanical properties for a dissimilar pattern structure in the 3-D printing of a PLA5F filament using the Taguchi method

Abstract Many automobile components and machine parts can be fabricated using the Fused Deposition Modeling (FDM) process with materials such as Polylactic Acid (PLA), Acrylonitrile Butadiene Styrene (ABS), Polyethylene Terephthalate Glycol (PET-G), and polymeric composite materials (e.g., PLA with carbon fiber, PLA with glass fiber). In this study, a new polymeric composite material was fabricated using Polylactic Acid and natural flax fiber was analysed for tensile stress, elongation, and impact load resistance using Taguchi Analysis. This analysis optimized the printing parameters, including layer thickness (0.15, 0.25, 0.35 mm), nozzle movement speed (80, 100, 120 mm s−1), filling structure (Lines - a, Triangular - b, and Octet - c), and occupancy rate (20%, 40%, 60%). The American Society for Testing and Materials (ASTM) standards for tensile strength (ASTM D638) and impact strength (ASTM D256) were used for evaluation. As a result, layer thickness was found to be the most effective variable for improving tensile characteristics, compared to extruder temperature, occupancy rate, or filling structure pattern. Mechanical properties including a layer thickness of 0.25 mm, an occupancy ratio of 20% for the bottom of the 2nd layer and 40% for the top of the 4th layer, triangular and octet filling structures, a nozzle speed of 100 mm s−1, and an extruder temperature of 200 °C are considered the most appropriate parameters for producing automotive parts in Three Dimensional (3D) Printing. Due to its tensile properties and impact strength resistance, these settings can be utilized in potential application in a wide variety of machine parts and vehicle components.

How environmentally friendly is the disposal of clear aligners? A gas chromatography-mass spectrometry study

Used clear aligner trays are often indiscriminately disposed of with general plastic waste and incinerated. This study aimed to analyze the smoke composition from incinerating 2 common aligner materials: glycol-modified polyethylene terephthalate (PET-G) and polyurethane. Each of the 2 materials in triplets was thermoformed. The thermoformed trays were shredded and subjected individually to open-fire combustion, ignited using a methane torch, in a specially designed combustion chamber. The resultant smoke was collected and analyzed using gas chromatography-mass spectrometry to study its in-depth composition. A total of 20 peaks, corresponding to 20 compounds, were identified from each of the 2 material samples. O-xylene (21.06%) showed the maximum concentration in the PET-G sample, whereas 1,4-dimethyl-1,3-cyclohexadiene in polyurethane (18.88%). The first peak in the PET-G sample corresponded to benzene with a relative concentration of 5.18%. Four compounds were common to both samples: 1,4-dimethyl-1,3-cyclohexadiene; 1,3-cyclohexadiene, 2,3-dimethyl-; 1-hydroxymethly-4-methylenecyclohexane; and cyclohexanemethanol, 4-methylene-. Benzene, a group 1 carcinogen, was identified in the PET-G smoke sample, whereas tetrahydrofuran, a suspected carcinogen, was found in the polyurethane sample. Some compounds were hazardous, whereas most were skin, eye, and respiratory irritants. Possible mitigation strategies include proper case selection, efficient manufacturing, direct 3-dimensional printing, and developing biodegradable materials. Clinicians can set up 'used aligner collection points' to ensure responsible disposal. Proper disposal guidelines and stringent regulations are the need of the hour.

Current developments and advancements of 3-dimensional printing in personalized medication and drug screening.

3-Dimensional printing (3DP) is an additive manufacturing (AM) technique that is expanding quickly because of its low cost and excellent efficiency. The 3D printing industry grew by 19.5 % in 2021 in spite of the COVID-19 epidemic, and by 2026, the worldwide market is expected to be valued up to 37.2 billion US dollars. Science Direct, Scopus, MEDLINE, EMBASE, PubMed, DOAJ, and other academic databases provide evidence of the increased interest in 3DP technology and innovative drug delivery approaches in recent times. In this review four main 3DP technologies that are appropriate for pharmaceutical applications: extrusion-based, powder-based, liquid-based, and sheet lamination-based systems are discussed. This study is focused on certain 3DP technologies that may be used to create dosage forms, pharmaceutical goods, and other items with broad regulatory acceptance and technological viability for use in commercial manufacturing. It also discusses pharmaceutical applications of 3DP in drug delivery and drug screening. The pharmaceutical sector has seen the prospect of 3D printing in risk assessment, medical personalisation, and the manufacture of complicated dose formulas at a reasonable cost. AM has great promise to revolutionise the manufacturing and use of medicines, especially in the field of personalized medicine. The need to understand more about the potential applications of 3DP in medical and pharmacological contexts has grown over time.

Effect of aging on dimensional accuracy and color stability of CAD-CAM milled and 3D-printed denture base resins: a comparative in-vitro study

BackgroundThere is a lack of studies comparing the dimensional accuracy and color stability of denture base resins made using computer-aided design and computer-aided manufacturing (CAD-CAM) milling, 3-dimensional (3D) printing, and conventional denture processing techniques. This makes it challenging to determine the best method to fabricate complete dentures. The objective of this in vitro investigation was to assess and contrast the color stability and dimensional accuracy of denture base resins that were 3D printed and CAD-CAM milled, both before and after aging by thermocycling using digital surface matching technology and a benchtop laser scanner without using a spray, to optimize adaptation of the denture base and cast to minimize any imperfections and to evaluate the impact of the denture cleansing solution on the stability of color.MethodsEvaluation of the dimensional accuracy (n = 27) was completed on a sectional maxillary stone cast using a digital 3D-surface matching software before and after 5000 thermocycles. A spectrophotometer was used to measure the color change (△E00) of all disc specimens (N = 54) before and after 500 thermocycles and immersion in denture cleansing solution for 30 cycles (3 min each) daily for 6 days. The Kruskal Wallis test, Dunn’s post hoc test, Tukey’s test with Bonferroni adjustment, one sample t test and independent t test were used to statistically analyze the data (α < 0.05).ResultsThermocycling decreased the dimensional accuracy of the heat polymerized group at all 5 locations and the 3D-printed group at locations 1, 3 and 5 (P > .05), while it had no significant difference on the CAD-CAM milled group at all locations (P < .05). The color change (△E00) was lowest in the CAD-CAM milled group, moderate in the heat-polymerized group and highest in the 3D-printed group. After immersion in denture cleanser, the color change (△E00) was significantly higher in the 3 groups compared with after thermocycling (P > .001).ConclusionsCAD-CAM milled resins had the highest dimensional accuracy and the best color stability, conventional heat polymerized acrylic resins showed moderate change in dimensional accuracy and color stability, while the 3D- printed resin had the lowest dimensional accuracy and color stability after aging by thermocycling.

A Path towards SDGs: Investigation of the Challenges in Adopting 3D Concrete Printing in India

In recent years, three dimensional concrete printing (3DCP) has gained traction as a promising technology to mitigate the carbon footprint associated with construction industry. However, despite its environmental benefits, studies frequently overlook its impact on social sustainability and its overall influence on project success. This research investigates how strategic decisions by firms shape the tradeoffs between economic, environmental, and social sustainability in the context of 3DCP adoption. Through interviews with 20 Indian industry leaders, it was found that companies primarily invest in 3DCP for automation and skilled workforce development, rather than solely for environmental reasons. The lack of incentives for sustainable practices in government procurement regulations emerges as a significant barrier to the widespread adoption of 3DCP. Our study identifies five key strategies firms employ to promote sustainability through 3DCP and proposes actionable measures for government intervention to stimulate its advancement. Addressing these issues is crucial for realizing the full societal and environmental benefits of 3DCP technology.

Mechanism for airborne ozone decomposition on X-MIL-53(Fe) (X = H, NH2, NO2)

Ground−level ozone (O3) pollution poses a significant threat to both ecosystem sustainability and human health. The catalytic decomposition of O3 presents as a promising technology to address the issues of O3 pollution. This study undertook the synthesis of various functionalized metal−organic framework (MOF) catalysts (i.e., X-MIL-53(Fe) (X = H, NH2, NO3)) to delve into the influence of ligand functional groups on skeletal structure and catalytic efficacy, particularly focusing on unraveling the mechanism of O3 catalytic decomposition under humid conditions. NH2-MIL-53(Fe) catalyst achieved complete O3 decomposition under ambient temperature and high humidity conditions (RH=75 %), exhibiting a reaction rates (mol·m−2·s−1) 129 and 10.5 times greater than that of MIL-53(Fe) and NO2-MIL-53(Fe). The NH2 group promotes electron flow within the backbone towards the hydroxyl group (OH) linked to Fe atom. In humid O3, H2O molecules augment the interaction between O3 and NH2-MIL-53(Fe), and OH is converted to·O2− after deprotonation, promoting O3 decomposition. Additionally, leveraging three−dimensional (3D) printing technology, a monolithic catalyst for O3 decomposition was prepared for application. This study not only advances understanding of the mechanisms underlying O3 decomposition but also offers practical solutions for addressing O3 pollution at humid conditions.

Innovative External Cranial Devices for Protecting a Craniectomy Site: A Scoping Review on Noninvasive Approaches for Patients Awaiting Cranioplasty.

Decompressive craniectomy (DC) is a commonly performed procedure to alleviate high intracranial pressure. To enhance patient quality of life and minimize complications after DC in patients awaiting cranioplasty (CP), multidisciplinary teams have designed and implemented external protective prototypes, including 3-dimensional printing and plaster models, whenever feasible. The aim of this scoping review was to assess the evidence available on innovative external cranial devices that protect the craniectomy site for patients who have undergone DC while awaiting CP in high-income countries and low- and middle-income countries. This scoping review was conducted following the methodology outlined by the Joanna Briggs Institute. Searches were performed in databases such as MEDLINE, Embase, Web of Science, Scielo, Scopus, and World Health Organization Global Health Index Medicus. Patent documents were also searched in Espacenet, Google Patents, and World Intellectual Property Organization. This scoping review included external protective devices for adult patients who underwent DC and CP, while invasive devices were excluded. A total of 9 documents described external cranial devices, with 7 of them led by researchers from high-income countries, including the United States (n = 4), Singapore (n = 1), the United Kingdom (n = 1), and Hong Kong SAR, China (n = 1). Among these devices, 77.7% (n = 7) were created using 3-dimensional printing, while 22.3% (n = 2) were developed through plaster hand modeling. The individual study results were summarized. Sustainable Development Goal (SDG) 3, SDG 9, and SDG 10 play a crucial role in the advancement of innovative strategies to ensure access to essential neurosurgical care, reduce global disparities in treatment outcomes, mitigate postoperative complications, and provide life-saving interventions. This scoping review provides fundamental evidence for multidisciplinary teams involved in designing noninvasive innovations to minimize the risks associated with post-DC complications. It is anticipated that more cost-effective models, particularly in low- and middle-income countries, can be implemented based on the findings of this review.

Transapical Transcatheter Aortic Valve Replacement Under 3-Dimensional Guidance to Treat Pure Aortic Regurgitation in Patients with a Large Aortic Annulus.

Transcatheter aortic valve replacement (TAVR) is a challenge for patients with aortic regurgitation (AR) and a large annulus. Our goal was to evaluate the clinical outcomes and predictors of transapical TAVR in AR patients with a large annulus and noncalcification and the feasibility and safety of 3-dimensional printing (3DP) in the preprocedural simulation. Patients with a large annulus (diameter >29 mm) were enrolled and divided into the simulation (n = 43) and the nonsimulation group (n = 82). Surgeons used the specific 3DP model of the simulation group to simulate the main steps before the procedure and to refit the transcatheter heart valve (THV) according to the simulated results. The average annular diameter of the overall cohort was 29.8 ± 0.7 mm. Compared with the nonsimulation group, the simulation group used a higher proportion of extra oversizing for THVs (97.6% vs. 85.4%, p = 0.013), and the coaxiality performance was better (9.7 ± 3.9° vs. 12.7 ± 3.8°, p < 0.001). Both THV displacement and ≥ mild paravalvular leakage (PVL) occurred only in the nonsimulation group (9.8% vs. 0, p < 0.001; 9.8% vs. 0, p < 0.001). Multivariate regression analysis showed that extra oversizing, coaxial angle and annulus diameter were independent predictors of THV displacement and ≥ mild PVL, respectively. Based on 3DP guidance, transapical TAVR using extra oversizing was safe and feasible for patients with noncalcified AR with a large annulus. Extra oversizing and coaxial angle were predictors of postprocedural THV displacement and ≥ mild PVL in such patients.

Nondestructive testing techniques for investigating mechanical property and porosity disparities in extrusion 3D printed concrete

ABSTRACT Three Dimensional Concrete printing (3DCP) stands at the forefront of modern construction methodologies, also named additive manufacturing, offering unparalleled time, cost, and labour savings compared to conventional approaches. The evaluation of fresh state parameters like extrudability and buildability through a specialised concrete extruder, combined with a methodical layer-by-layer deposition, ensures structural stability by precisely strengthening each layer. Mechanical strength evaluations highlight the printed material’s anisotropic nature, revealing extreme reductions of Fy = 27.94%, Fx = 19.07%, and Fy = 16.33% in compression, flexural, and split tensile strengths, respectively, compared to cast specimens. This emphasises the importance of direction-specific mechanical testing in understanding material behaviour completely. Non-destructive testing (NDT) methods, like Ultrasonic Pulse Velocity (UPV) testing, are crucial for the qualitative assessment of the integrity and mechanical strength of concrete structures, including both printed and cast specimens, by establishing a strong correlation with compressive strength without causing any damage. Limited research indicates that the microstructure of the material plays a significant role in its mechanical strength, particularly in printed specimens. This claim is reinforced by mercury intrusion porosimetry (MIP) results, which reveal that printed specimens have slightly higher overall porosity, concentrated between 1 µm and 0.1 µm, while cast specimens show higher porosity in pores smaller than 0.1 µm.

Training the Next Generation of Transplant Surgeons With a 3-Dimensional Trainer: A Pilot Study.

In the United States, no published guidelines promote exposure to technical variants (ie, living donor or split liver) during transplant fellowship. Simulation with hands-on liver models may improve training in transplantation. This pilot study addressed 3 overall goals (material and model creation tools, recruitment rates and assessment of workload, and protocol adherence). A patient-specific hands-on liver model was constructed from clinical imaging, and it needed to be resilient and realistic. Multiple types of materials were tested between January 2020 and August 2022. Participants were recruited stepwise. A left lateral segmentectomy simulation was conducted between August 2022 and December 2022 to assess protocol adherence. Digital anatomy 3-dimensional printing was considered the best option for the hands-on liver model. The recruitment rate was 100% and 47% for junior attendings and surgical residents, respectively. Ten participants were included and completed all the required surveys. Seven (70%) and 6 (60%) participants "agreed" that the overall quality of the model and the material were acceptable for surgical simulation. Five participants (50%) "agreed" that the training improved their surgical skills. Nine participants (90%) "strongly agreed" that similar sessions should be included in surgical training programs. Three-dimensional hands-on liver models have the advantage of tactile feedback and were rated favorably as a potential training tool. Study enrollment for further studies is possible with the support of leadership. Rigorous multicenter designs should be developed to measure the actual impact of 3-dimensional hands-on liver models on surgical training.

Multifunctional hernia repair biopatch: Development, characterization, in vitro and in vivo evaluation

Incisional hernia, a prevalent postoperative complication, is characterized by the protrusion of organs or tissues through damaged abdominal wall. Predisposing factors for hernias include obesity, wound infections, immunosuppression, and comorbidities. However, hernia patches currently in use, including the commercial polypropylene (PP) patch, still have limitations in providing the mechanical and biological properties necessary for abdominal wall regeneration. In this study, three dimensional (3D) printing and coaxial electrospinning methods were combined to create a multifunctional double layered hernia repair biopatch to overcome these limitations. The double-layer design of the biopatch serves a multifunctional role in addressing incisional hernia models, with 3D printed ciprofloxacin (CIP) loaded polycaprolactone (PCL)/gelatin (Ge) scaffold (3DCIP) layer and coaxially electrospun PCL/Ge/κ-carrageenan (κ-C) nanofiber (NF) layers. While 3DCIP layers provides temporary mechanical reinforcement to the damaged abdominal wall, prevention of adhesions to internal organs, and reduction of surgical site infections, NF layer serves as tissue regeneration and fast wound healing. The developed multifunctional hernia biopatches underwent comprehensive physical and chemical characterization, followed by in vitro and in vivo evaluations. These evaluations included comparisons with a commercial PP patch, which was used as the control in the experiments. The study successfully fabricated multifunctional hernia biopatches with excellent antibacterial properties, high mechanical robustness, and strong biocompatibility.

Individualized Design Application of 3-Dimensional Printing Navigational Template for Pedicle Screw Installation: A Training Case Report.

BACKGROUND The proper installation for pedicle screws by the traditional method of surgeons dependent on experience is not guaranteed, and educational solutions have progressed from chalkboards to electronic teaching platforms. We designed a case of 3-dimensional printing drill guide template as a surgical application, which can accurately navigate implantation of pedicle screws, and assessed its effect for simulative training. MATERIAL AND METHODS We randomly selected a set of computed tomography data for spondylolisthesis. A navigational template of pedicles and screws was designed by software Mimics and Pro-E, where trajectories of directions and angles guiding the nail way were manipulated for screwing based on anatomy, and its solid model was fabricated by a BT600 3D printer. The screws were integrated and installed to observe their stability. RESULTS The navigational model and custom spine implants were examined to be compatibly immobilized, because they are tolerant to radiation and stable against hydrolysis. The screw size and template were fit accurately to the vertebrae intraosseously, because the pilot holes were drilled and the trajectories were guided by cannulas with visible routes. During the surgical workflow, the patient reported appreciation and showed substantial compliance, while having few complications with this approach. Compared with fluoroscopy-assisted or free-hand techniques, the effect of simulative training during processing was excellent. CONCLUSIONS The surgical biomodel is practical for the procedural accuracy of surgical guides or as an educational drill. This fostering a style of "practice substituting for teaching" sets a paragon of keeping up with time and is worthy of recommendation.

Progress in organ 3D bioprinting.

Three dimensional (3D) printing is a hot topic in today’s scientific, technological and commercial areas. It is recognized as the main field which promotes “the Third Industrial Revolution”. Recently, human organ 3D bioprinting has been put forward into equity market as a concept stock and attracted a lot of attention. A large number of outstanding scientists have flung themselves into this field and made some remarkable headways. Nevertheless, organ 3D bioprinting is a sophisticated manufacture procedure which needs profound scientific/technological backgrounds/knowledges to accomplish. Especially, large organ 3D bioprinting encounters enormous difficulties and challenges. One of them is to build implantable branched vascular networks in a predefined 3D construct. At present, organ 3D bioprinting still in its infancy and a great deal of work needs to be done. Here we briefly overview some of the achievements of 3D bioprinting technologies in large organ, such as the bone, liver, heart, cartilage and skin, manufacturing.

Demographics, Utilization, Workflow, and Outcomes Based on Observational Data From the RSNA-ACR 3D Printing Registry

PurposeThe aim of this study was to report data from the first 3 years of operation of the RSNA-ACR 3D Printing Registry. MethodsData from June 2020 to June 2023 were extracted, including demographics, indications, workflow, and user assessments. Clinical indications were stratified by 12 organ systems. Imaging modalities, printing technologies, and numbers of parts per case were assessed. Effort data were analyzed, dividing staff members into provider and nonprovider categories. The opinions of clinical users were evaluated using a Likert scale questionnaire, and estimates of procedure time saved were collected. ResultsA total of 20 sites and 2,637 cases were included, consisting of 1,863 anatomic models and 774 anatomic guides. Mean patient ages for models and guides were 42.4 ± 24.5 years and 56.3 ± 18.5 years, respectively. Cardiac models were the most common type of model (27.2%), and neurologic guides were the most common type of guide (42.4%). Material jetting, vat photopolymerization, and material extrusion were the most common printing technologies used overall (85.6% of all cases). On average, providers spent 92.4 min and nonproviders spent 335.0 min per case. Providers spent most time on consultation (33.6 min), while nonproviders focused most on segmentation (148.0 min). Confidence in treatment plans increased after using 3-D printing (P < .001). Estimated procedure time savings for 155 cases was 40.5 ± 26.1 min. ConclusionsThree-dimensional printing is performed at health care facilities for many clinical indications. The registry provides insight into the technologies and workflows used to create anatomic models and guides, and the data show clinical benefits from 3-D printing.

Enhancing electromagnetic shielding property and absorption coefficients via constructing electromagnetic rings in janus composites

Polymer based electromagnetic wave (EMW) shielding materials with high conductivity have excellent electromagnetic shielding properties, but also exhibit high reflection of EMWs, resulting in inevitable secondary electromagnetic pollution. EMW shielding materials with low reflection have extensive potential applications in the next generation of anti-EMW equipment. Herein, a production strategy combining three dimensional (3D) printing technology and solution casting method was proposed to prepare polylactic acid (PLA)@multi-walled carbon nanotubes (MWCNT)/polydimethylsiloxane (PDMS)@carbonyl iron powder (CIP) absorptive electromagnetic shielding Janus composites with a ring-shaped electromagnetic synergistic structure (spiral rings or concentric circular rings). By utilizing PLA and MWCNTs as primary components, a 3D integrated framework that combines a highly conductive reflector and a ring inductance structure can achieve significant EMW shielding performance with low reflection. With PDMS as a matrix and magnetic CIP as functional fillers, a strong magnetic permeability network is provided around the ring inductance frame. The magnetic loss resulting from electromagnetic cooperative ring structure further enhances microwave absorption capacity. The composite materials, benefiting from the synergistic interaction between the electromagnetic rings and the reflector, demonstrate excellent impedance matching and efficient EMW shielding capabilities. Specifically, the PLA@MWCNT/PDMS@CIP Janus composites with ring structure exhibit a notable EMW shielding effectiveness (SE) of 31 dB and a reflection coefficient as minimal as 0.3. Therefore, this study presents a powerful approach to the development of low-reflective materials with high EMW SE, promising potential applications in the next-generation intelligent electronic devices.