articles+ search results

Collaborative and adaptive cyber Défense strategies, Healthcare networks, Cyber security edge computing, Cyber Défense strategies, Internet of Things, Computer applications to medicine. Medical informatics, and R858-859.7

The Internet of Things (IoT) is a massive network connecting various devices and computer systems. This technology makes prototyping and distributing cutting-edge software and services easier. Through specifically created healthcare networks, the IoT makes it simple to link digital and tangible devices. Disputes continue to arise in the industry due to the absence of uniformity and the rapid growth of products, services, and methods. This study seeks to provide a birds-eye perspective of the technologies and protocols that support the IoT’s foundation. We start by introducing an elaborate process to examine the function of healthcare networks in creating and disseminating IoT-based software and some solutions to the current problems. We then discuss and formulate future challenges and the unanswered concerns surrounding the IoT’s support for healthcare networks. The primary focus of this research is to dissect the IoT, or horizontal network, into its constituent parts. These elements are essential for creating secure and robust mobile applications.

Phonon anisotropy, Heating effects, Temperature definition, Graphene, Monte Carlo method, Boltzmann equations, Engineering (General). Civil engineering (General), and TA1-2040

The effect of inclusion of the planar phonon anisotropy on thermo-electrical behavior of graphene is analyzed. Charge transport is simulated by means of Direct Simulation Monte Carlo technique coupled with numerical solution of the phonon Boltzmann equations based on deterministic methods.The definition of the crystal lattice local equilibrium temperature is investigated as well and the results furnish possible alternative approaches to identify it starting from measurements of electric current density, with relevant experimental advantages, which could help to overcome the present difficulties regarding thermal investigation of graphene.Positive implications are expected for many applications, as the field of electronic devices, which needs a coherent tool for simulation of charge and hot phonon transport; the correct definition of the local equilibrium temperature is in turn fundamental for the study, design and prototyping of cooling mechanisms for graphene-based devices.

Humans, Magnetic Resonance Imaging methods, Magnetic Resonance Spectroscopy, Phantoms, Imaging, Acceleration, Reproducibility of Results, Heart diagnostic imaging, Image Interpretation, Computer-Assisted methods, and Myocardium

Purpose: Enabling fast and accessible myocardial T 1 mapping is crucial for extending its clinical application. We introduce Open-MOLLI-SMS combining simultaneous multi-slice (SMS) with auto-calibration and variable-rate selective excitation (VERSE)-multiband pulses to obtain all slices in a fast single-shot T 1 mapping sequence.
Methods: Open-MOLLI-SMS was developed by integrating SMS with the open-source method Open-MOLLI previously implemented in Pulseq. Three methods were integrated for Open-MOLLI-SMS: (1) auto-calibration blip patterns to ensure consistency between the data and coil information; (2) a blipped-balanced SSFP (bSSFP) readout to induce controlled aliasing in parallel imaging shifts without disturbing the bSSFP frequency response; and (3) a VERSE-multiband pulse for minimizing the achievable TR and the specific absortion rate (SAR) impact of SMS. Two (SMS2) or three (SMS3) slices were excited simultaneously and encoded with an in-plane acceleration factor of 2. Experiments were performed in the International Society for Magnetic Resonance in Medicine/National Institute of Standards and Technology phantom and five healthy volunteers.
Results: Phantom results show accurate T 1 estimates for reference values between 400 to 2200 ms. Artifacts were visible for Open-MOLLI-SMS3 but not replicated in vivo. In vivo Open-MOLLI-SMS (T 1 SMS2  = 993 ± 10 ms; T 1 SMS3  = 1031 ± 17 ms) provided similar values to mean T 1 single-band Open-MOLLI estimates (T 1 Open-MOLLI  = 1005 ± 47 ms). Open-MOLLI-SMS2 provided the closest estimates to the reference.
Conclusion: This proof-of-principle implementation study demonstrates the feasibility of speeding up T 1 -mapping acquisitions and increasing coverage by combining auto-calibration strategies with a blipped-bSFFP readout and VERSE multiband RF excitation pulses. The proposed methodology was built on the Open-MOLLI mapping sequence, which provides a fast means for prototyping and enables open-source sharing of the method.
(© 2023 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals LLC on behalf of International Society for Magnetic Resonance in Medicine.)

Animals, Bayes Theorem, Uncertainty, and Anthozoa

Emerging diseases can have devastating consequences for wildlife and require a rapid response. A critical first step towards developing appropriate management is identifying the etiology of the disease, which can be difficult to determine, particularly early in emergence. Gathering and synthesizing existing information about potential disease causes, by leveraging expert knowledge or relevant existing studies, provides a principled approach to quickly inform decision-making and management efforts. Additionally, updating the current state of knowledge as more information becomes available over time can reduce scientific uncertainty and lead to substantial improvement in the decision-making process and the application of management actions that incorporate and adapt to newly acquired scientific understanding. Here we present a rapid prototyping method for quantifying belief weights for competing hypotheses about the etiology of disease using a combination of formal expert elicitation and Bayesian hierarchical modeling. We illustrate the application of this approach for investigating the etiology of stony coral tissue loss disease (SCTLD) and discuss the opportunities and challenges of this approach for addressing emergent diseases. Lastly, we detail how our work may apply to other pressing management or conservation problems that require quick responses. We found the rapid prototyping methods to be an efficient and rapid means to narrow down the number of potential hypotheses, synthesize current understanding, and help prioritize future studies and experiments. This approach is rapid by providing a snapshot assessment of the current state of knowledge. It can also be updated periodically (e.g., annually) to assess changes in belief weights over time as scientific understanding increases. Synthesis and applications: The rapid prototyping approaches demonstrated here can be used to combine knowledge from multiple experts and/or studies to help with fast decision-making needed for urgent conservation issues including emerging diseases and other management problems that require rapid responses. These approaches can also be used to adjust belief weights over time as studies and expert knowledge accumulate and can be a helpful tool for adapting management decisions.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)

Objectives: Thus far, the findings of numerous studies conducted on the accuracy of three-dimensional (3D) printed dental models are conflicting. Therefore, the aim of the network meta-analysis (NMA) is to determine the accuracy of 3D printed dental models compared with digital reference models.
Data: Studies comparing the accuracy of 3D printed full-arch dental models manufactured using different printing techniques to initial STL files were included.
Sources: This study was registered in PROSPERO (CRD42021285863). An electronic search was performed across four databases in November 2021, and search was restricted to the English language.
Study Selection: A systematic search was conducted based on a prespecified search query. 16,303 articles were pooled after the removal of the duplicates. Following study selection and data extraction, 11 eligible studies were included in the NMA in 6 subgroups. The outcomes were specified as trueness and precision and expressed as root mean square (RMS) and absolute mean deviation values. Seven printing technologies were analyzed: stereolithography (SLA), digital light processing (DLP), fused deposition modeling/fused filament fabrication (FDM/FFF), MultiJet, PolyJet, continuous liquid interface production (CLIP), and LCD technology. The QUADAS-2 and GRADE were used to evaluate the risk of bias and certainty of evidence.
Conclusions: SLA, DLP, and PolyJet technologies were the most accurate in producing full-arch dental models.
Clinical Significance: The findings of the NMA suggest that SLA, DLP, and PolyJet technologies are sufficiently accurate for full-arch dental model production for prosthodontic purposes. In contrast, FDM/FFF, CLIP, and LCD technologies are less suitable for manufacturing dental models.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Humans, Models, Psychological, and Text Messaging

In an experiment so-termed sociotechnical prototypes based on either a graphical or a textual representation of an envisioned work system were evaluated with regard to their ability to communicate a design vision to people involved in a participatory design process. Results of the study reveal, in line with hypotheses, that the graphical prototype, in contrast to the textual one, was significantly better accepted as well as faster explored and evaluated. Moreover, results support the hypothesis that the graphical sociotechnical prototype helps to build up a more accurate mental representation of the system with regard to its elements (e.g. job roles, tasks). However, no positive effect on the mental representation of the system in terms of the relations between its elements (e.g. which role performs which task?) was found. Finally, practical implications and perspectives for further development of the sociotechnical prototyping approach to envision future work systems are discussed.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)

Fluoroscopy methods, Neural Networks, Computer, Area Under Curve, Deglutition, and Deep Learning

Objectives: A videofluoroscopic swallowing study (VFSS) is conducted to detect aspiration. However, aspiration occurs within a short time and is difficult to detect. If deep learning can detect aspirations with high accuracy, clinicians can focus on the diagnosis of the detected aspirations. Whether VFSS aspirations can be classified using rapid-prototyping deep-learning tools was studied.
Methods: VFSS videos were separated into individual image frames. A region of interest was defined on the pharynx. Three convolutional neural networks (CNNs), namely a Simple-Layer CNN, Multiple-Layer CNN, and Modified LeNet, were designed for the classification. The performance results of the CNNs were compared in terms of the areas under their receiver-operating characteristic curves (AUCs).
Results: A total of 18,333 images obtained through data augmentation were selected for the evaluation. The different CNNs yielded sensitivities of 78.8%-87.6%, specificities of 91.9%-98.1%, and overall accuracies of 85.8%-91.7%. The AUC of 0.974 obtained for the Simple-Layer CNN and Modified LeNet was significantly higher than that obtained for the Multiple-Layer CNN (AUC of 0.936) (p < 0.001).
Conclusions: The results of this study show that deep learning has potential for detecting aspiration with high accuracy.
(© 2023. The Author(s) under exclusive licence to Japanese Society for Oral and Maxillofacial Radiology.)

Wireframe structures, Path planning, Additive manufacturing, Deformation processing, Industrial engineering. Management engineering, and T55.4-60.8

This paper presents a computer numerical control (CNC) deformation process, termed Bend-Forming, for fabricating 3D wireframe structures. The process relies on the combination of CNC wire bending with mechanical joints to construct reticulated structures from wire feedstock. A key component of the process is a path planning framework which uses Euler paths and geometrical computations to derive fabrication instructions for arbitrary 3D wireframe geometries. We demonstrate the process by fabricating exemplary structures on the order of 1 m, including reticulated columns, shells, and trusses, with rapid build times compared to other additive manufacturing techniques. The structures fabricated herein contain defects which result in residual stress and imperfect geometries. To determine the tolerances needed to fabricate accurate structures, we develop a model of error stack-up for Bend-Forming, using fabrication defects in feed length, bend and rotate angle, and strut curvature. We find that for tetrahedral trusses fabricated with Bend-Forming, defects in feed length and strut curvature have a large effect on the surface precision and stiffness of the truss, respectively, and are thus important tolerances to control to achieve structural performance metrics. Overall, Bend-Forming is a versatile and low-power process that is well suited for a wide-range of applications, from rapid prototyping of wireframe structures to in-space manufacturing.

Directed energy deposition, entropy, grain refinement, alloy design, Industrial engineering. Management engineering, and T55.4-60.8

Additive manufacturing (AM) is a tool for rapid prototyping with complex geometry. However, the cyclic heating and cooling in laser melting processes often cause large columnar grains that dominate the as-printed microstructure, resulting in a strong texture and anisotropic properties that limit the application of AM. In this work, we apply powder-based directed energy deposition to discover new alloys using mixtures of Inconel 718 (IN718) and Stainless Steel 316L (SS316L). We discovered that the 77 wt.% IN718 alloy mixture, with the highest configurational entropy, demonstrated an intriguingly fine grain structure in the as-built condition and after homogenization at 1180°C. Residual stress from the laser melting process was identified as the primary cause of the observed grain refinement phenomenon. Although, a quantitative analysis of the changes in grain size after homogenization in the alloy mixtures of IN718 and SS316L requires further research. The discovery of this unique microstructural behavior shows how in-situ mixing of commercially available powders can be used to develop next-generation feedstock materials for AM and improve the understanding of fundamental process-microstructure-property relationships.

Despite being researched for decades, shape-shifting molecular crystals have yet to claim their spot as an actuating materials class among the primary functional materials. While the process for developing and commercializing materials can be lengthy, it inevitably starts with building an extensive knowledge base, which for molecular crystal actuators remains scattered and disjointed. Using machine learning for the first time, we identify inherent features and structure-function relationships that fundamentally impact the mechanical response of molecular crystal actuators. Our model can factor in different crystal properties in tandem and decipher their intersectional and combined effects on each actuation performance. This analysis is an open invitation to utilize interdisciplinary expertise in translating the current basic research on molecular crystal actuators into technology-based development that promotes large-scale experimentation and prototyping.

In recent years biomedical scientific community has been working towards the development of high-throughput devices that allow a reliable, rapid and parallel detection of several strains of virus or microparticles simultaneously. One of the complexities of this problem lies on the rapid prototyping of new devices and wireless rapid detection of small particles and virus alike. By reducing the complexity of microfluidics microfabrication and using economic materials along with makerspace tools (Kundu et al. 2018) it is possible to provide an affordable solution to both the problems of high-throughput devices and detection technologies. We present the development of a wireless, standalone device and disposable microfluidics chips that rapidly generate parallel readouts for selected, possible virus variants from a nasal or saliva sample, based on motorized and non-motorized microbeads detection, and imaging processing of the motion tracks of these beads in micrometers. Microbeads and SARS-CoV-2 COVID-19 Delta variant were tested as proof-of-concept for testing the microfluidic cartridges and wireless imaging module. The Microbead Assay (MA) system kit consists of a Wi-Fi readout module, a microfluidic chip, and a sample collection/processing sub-system. Here, we focus on the fabrication and characterization of the microfluidic chip to multiplex various micrometer-sized beads for economic, disposable, and simultaneous detection of up to six different viruses, microparticles or variants in a single test, and data collection using a commercially available, Wi-Fi-capable, and camera integrated device (Fig. 1).
(© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

This study aims to describe the prototype development and testing of a serious game designed for Brazilian children with diabetes. Following an approach of user-centered design, the researchers assessed game's preferences and diabetes learning needs to develop a Paper Prototype. The gameplay strategies included diabetes pathophysiology, self-care tasks, glycemic management, and food group learning. Diabetes and technology experts (n = 12) tested the prototype during audio-recorded sessions. Next, they answered a survey to evaluate the content, organization, presentation, and educational game aspects. The prototype showed a high content validity ratio (0.80), with three items not achieving the critical values (0.66). Experts recommended improving the game content and food illustrations. This evaluation contributed to the medium-fidelity prototype version, which after testing with diabetes experts (n = 12) achieved high content validity values (0.88). One item did not meet the critical values. Experts suggested increasing the options of outdoor activities and meals. Researchers also observed and video-recorded children with diabetes (n = 5) playing the game with satisfactory interaction. They considered the game enjoyable. The interdisciplinary team plays an important role guiding the designers in the use of theories and real needs of children. Prototypes are a low-cost usability and a successful method for evaluating games.
(Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.)

Scaffolds are implants commonly used to deliver cells, drugs, and genes into the body. Their regular porous structure ensures the proper support for cell attachment, proliferation, differentiated function, and migration. Techniques to fabricate a scaffold include leaching, freeze-drying, supercritical fluid technology, thermally induced phase separation, rapid prototyping, powder compaction, sol-gel, and melt molding. Gene delivery from the scaffold represents a versatile approach to influence the environment for managing cell function. Scaffolds can be used for various tissue engineering purposes, e.g. bone formation, periodontal regeneration, cartilage development, artificial corneas, heart valves, tendon repair, or ligament replacement. Moreover, they are also instrumental in cancer therapy, inflammation, diabetes, heart disease, and wound dressings. Scaffolds provide a platform to extend the delivery of drugs and genetic materials at a controlled timeframe, besides potentially being used to prevent infection upon surgery and other chronic diseases, provided that they can be formulated with specific medicines. This review discusses the need to design advanced functional scaffolds with the potential for modified drug delivery and tissue engineering in a synergistic approach. Special attention is given to works published in 2023 to generate the bibliometric map.
Competing Interests: Declaration of Competing Interest The authors declare no conflict of interest.
(Copyright © 2023. Published by Elsevier B.V.)

Humans, Lignin, Alginates pharmacology, Alginates chemistry, Calcium Phosphates pharmacology, Calcium Phosphates chemistry, Bone Regeneration, Osteogenesis, Printing, Three-Dimensional, Tissue Scaffolds chemistry, and Tissue Engineering methods

The bone is a connective, vascularized, and mineralized tissue that confers protection to organs, and participates in the support and locomotion of the human body, maintenance of homeostasis, as well as in hematopoiesis. However, throughout the lifetime, bone defects may arise due to traumas (mechanical fractures), diseases, and/or aging, which when too extensive compromise the ability of the bone to self-regenerate. To surpass such clinical situation, different therapeutic approaches have been pursued. Rapid prototyping techniques using composite materials (consisting of ceramics and polymers) have been used to produce customized 3D structures with osteoinductive and osteoconductive properties. In order to reinforce the mechanical and osteogenic properties of these 3D structures, herein, a new 3D scaffold was produced through the layer-by-layer deposition of a tricalcium phosphate (TCP), sodium alginate (SA), and lignin (LG) mixture using the Fab@Home 3D-Plotter. Three different TCP/LG/SA formulations, LG/SA ratio 1:3, 1:2, or 1:1, were produced and subsequently evaluated to determine their suitability for bone regeneration. The physicochemical assays demonstrated that the LG inclusion improved the mechanical resistance of the scaffolds, particularly in the 1:2 ratio, since a 15 % increase in the mechanical strength was observed. Moreover, all TCP/LG/SA formulations showed an enhanced wettability and maintained their capacity to promote the osteoblasts' adhesion and proliferation as well as their bioactivity (formation of hydroxyapatite crystals). Such results support the LG inclusion and application in the development of 3D scaffolds aimed for bone regeneration.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 The Author(s). Published by Elsevier B.V. All rights reserved.)

Stress, Mechanical, Bioreactors, Polyesters, Tissue Engineering methods, and Mechanotransduction, Cellular physiology

Objective: Tissue engineering (TE) is the study and development of biological substitutes to restore, maintain or improve tissue function. Tissue engineered constructs (TECs) still present differences in mechanical and biological properties compared to native tissue. Mechanotransduction is the process through which mechanical stimulation triggers proliferation, apoptosis, and extracellular matrix synthesis, among other cell activities. Regarding that aspect, the effect of in vitro stimulations such as compression, stretching, bending or fluid shear stress loading modalities have been extensively studied. A fluid flow used to produce contactless mechanical stimulation induced by an air pulse could be easily achieved in vivo without altering the tissue integrity.
Methods: A new air-pulse device for contactless and controlled mechanical simulation of a TECs was developed and validated in this study conducted in the following three phases: 1) conception of the controlled air-pulse device combined with a 3D printed bioreactor; 2) experimental and numerical mechanical characterization of the air-pulse impact by digital image correlation; and 3) achieving sterility and noncytotoxicity of the air-pulse and of the 3D printed bioreactor using a novel dedicated sterilization process.
Results: We demonstrated that the treated PLA (polylactic acid) was noncytotoxic and did not influence cell proliferation. An ethanol/autoclaved sterilization protocol for 3D printed objects in PLA has been developed in this study, enabling the use of 3D printing in cell culture. A numerical twin of the device was developed and experimentally characterized by digital image correlation. It showed a coefficient of determination R 2  = 0.98 between the numerical and averaged experimental surface displacement profiles of the TEC substitute.
Conclusion: The results of the study assessed the noncytotoxicity of PLA for prototyping by 3D printing the homemade bioreactor. A novel sterilization process for PLA was developed in this study based on a thermochemical process. A numerical twin using fluid-structure interaction method has been developed to investigate the micromechanical effects of air pulses inside the TEC, which cannot all be measured experimentally, for instance, wave propagation generated during the air-pulse impact. The device could be used to study the cell response to contactless cyclic mechanical stimulation, particularly in TEC with fibroblasts, stromal cells and mesenchymal stem cells, which have been shown to be sensitive to the frequency and strain level at the air-liquid interface.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier B.V. All rights reserved.)

Biotechnology, Microtechnology, Printing, Three-Dimensional, Microfluidics methods, and Cell Culture Techniques

Rapid prototyping of microfluidic chips is a key enabler for controlled biotechnology applications in microspaces, as it allows for the efficient design and production of microfluidic systems. With rapid prototyping, researchers and engineers can quickly create and test new microfluidic chip designs, which can then be optimized for specific applications in biotechnology. One of the key advantages of microfluidic chips for biotechnology is the ability to manipulate and control biological samples in a microspace, which enables precise and controlled experiments under well-defined conditions. This is particularly useful for applications such as cell culture, drug discovery, and diagnostic assays, where precise control over the biological environment is crucial for obtaining accurate results. Established methods, for example, soft lithography, 3D printing, injection molding, as well as other recently highlighted innovative approaches, will be compared and challenges as well as limitations will be discussed. It will be shown that rapid prototyping of microfluidic chips enables the use of advanced materials and technologies, such as smart materials and digital sensors, which can further enhance the capabilities of microfluidic systems for biotechnology applications. Overall, rapid prototyping of microfluidic chips is an important enabling technology for controlled biotechnology applications in microspaces, as well as for upscaling it into macroscopic bioreactors, and its continued development and improvement will play a critical role in advancing the field. The review will highlight recent trends in terms of materials and competing approaches and shed light on current challenges on the way toward integrated microtechnologies. Also, the possibility to easy and direct implementation of novel functions (membranes, functionalization of interfaces, etc.) is discussed.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)

Humans, Software, Pharmacists, Vancomycin, and Drug Monitoring

Background: Different software applications have been developed to support health care professionals in individualized drug dosing. However, their translation into clinical practice is limited, partly because of poor usability and integration into workflow, which can be attributed to the limited involvement of health care professionals in the development and implementation of drug dosing software. This study applied codesign principles to inform the design of a drug dosing software to address barriers in therapeutic drug monitoring using vancomycin as an example.
Methods: Three workshops (face-to-face and online) were conducted by design researchers with pharmacists and prescribers. User journey storyboards, user personas, and prototyping tools were used to explore existing barriers to practice and opportunities for innovation through drug dosing software design. A prototype of the software interface was developed for further evaluation.
Results: Health care professionals (11 hospital pharmacists and 6 prescribers) with ≥2 years of clinical experience were recruited. Confidence and software usability emerged as the main themes. Participants identified a lack of confidence in vancomycin dosing and pharmacokinetic understanding and difficulty in accessing practice guidelines as key barriers that could be addressed through software implementation. Accessibility to information (eg, guidelines and pharmacokinetic resources) and information presentation (eg, graphical) within the dosing software were dependent on the needs and experience of the user. A software prototype with a speedometer-dial visual to convey optimal doses was well received by participants.
Conclusions: The perspectives of health care professionals highlight the need for drug dosing software to be user centered and adaptable to the needs and workflow of end users. Continuous engagement with stakeholders on tool usability, training, and education is needed to promote the implementation in practice.
Competing Interests: The authors declare no conflict of interest.
(Copyright © 2022 Wolters Kluwer Health, Inc. All rights reserved.)

Microactuators can autonomously convert external energy into specific mechanical motions. With the feature sizes varying from the micrometer to millimeter scale, microactuators offer many operation and control possibilities for miniaturized devices. In recent years, advanced microfluidic techniques have revolutionized the fabrication, actuation, and functionalization of microactuators. Microfluidics can not only facilitate fabrication with continuously changing materials but also deliver various signals to stimulate the microactuators as desired, and consequently improve microfluidic chips with multiple functions. Herein, this cross-field that systematically correlates microactuator properties and microfluidic functions is comprehensively reviewed. The fabrication strategies are classified into two types according to the flow state of the microfluids: stop-flow and continuous-flow prototyping. The working mechanism of microactuators in microfluidic chips is discussed in detail. Finally, the applications of microactuator-enriched functional chips, which include tunable imaging devices, micromanipulation tools, micromotors, and microsensors, are summarized. The existing challenges and future perspectives are also discussed. It is believed that with the rapid progress of this cutting-edge field, intelligent microsystems may realize high-throughput manipulation, characterization, and analysis of tiny objects and find broad applications in various fields, such as tissue engineering, micro/nanorobotics, and analytical devices.
(© 2023 Wiley-VCH GmbH.)

Microplasma UV lamps have recently emerged as viable excimer-based sources of UV radiation, garnering significant attention during the recent COVID-19 pandemic for their use in disinfection applications because of their ability to emit human-safe far-UVC (200-240 nm) spectrums. An accurate model to simulate the radiation profile of microplasma UV lamps is of paramount importance to develop efficient microplasma lamp-implemented systems. We developed a 3D numerical model of microplasma UV lamps using the ray optics method. The simulation results for lamp irradiance and fluence rate were experimentally validated with standard optical radiometry and actinometry measurements, respectively. To improve the optical efficiency of microplasma lamps, an in-depth analysis of radiation behavior inside the standard commercially available lamp was performed using the geometrical optics method, and several potential scenarios were explored. A 2D modeling of an individual microcavity indicated that the current common lamp design can be significantly improved by preventing radiation loss, and small modifications in optical design can greatly increase the energy performance of the system. Based on the findings of this study, several virtual design concepts were proposed, and their performances were numerically compared with that of the original design of commercial microplasma lamps. The developed model can potentially be integrated with hydrodynamic and kinetic models for the virtual prototyping of complex photoreactors operating with UV microplasma lamps.
Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(© 2023 Elsevier Ltd. All rights reserved.)

Ex vivo hemocompatibility testing is a vital element of preclinical assessment for blood-contacting medical devices. Current approaches are resource intensive; thus, we investigated the feasibility of accelerating hemocompatibility testing by standardizing the number of pump exposures in loops of various sizes. Three identical blood loops were constructed, each with a custom-molded reservoir able to facilitate large-volume expansion. Using the HVAD rotary blood pump operating at 5 L·min-1 and 100 mmHg, three test volumes (80, 160, and 320 ml) were circulated for 4000 pump exposures. Blood sampling was performed at individualized intervals every one-sixth of total duration for the assessment of hemolysis and von Willebrand Factor (vWF) degradation. While steady increases in hemolysis (~24 mg·dl-1) were identified in all tests at completion, loop volume was not a primary discriminator. The normalized index of hemolysis did not vary significantly between loops (4.2-4.9 mg·100 L-1). vWF degradation progressively occurred with duration of testing to a similar extent under all conditions. These data support an accelerated approach to preclinical assessment of ex vivo blood damage. Adopting this approach enables: enhanced efficiency for rapid prototyping; reduced ex vivo blood aging, and; greater utility of blood, which is presently limited if 450 ml loops are desired.
Competing Interests: Disclosure: The authors have no conflicts of interest to report.
(Copyright © ASAIO 2023.)

3D printing, Zinc submicron particles, Osteoinductivity, Anti-inflammatory, Bone defect repair, Materials of engineering and construction. Mechanics of materials, TA401-492, Biology (General), and QH301-705.5

Long-term nonunion of bone defects has always been a major problem in orthopedic treatment. Artificial bone graft materials such as Poly (lactic-co-glycolic acid)/β-tricalcium phosphate (PLGA/β-TCP) scaffolds are expected to solve this problem due to their suitable degradation rate and good osteoconductivity. However, insufficient mechanical properties, lack of osteoinductivity and infections after implanted limit its large-scale clinical application. Hence, we proposed a novel bone repair bioscaffold by adding zinc submicron particles to PLGA/β-TCP using low temperature rapid prototyping 3D printing technology. We first screened the scaffolds with 1 wt% Zn that had good biocompatibility and could stably release a safe dose of zinc ions within 16 weeks to ensure long-term non-toxicity. As designed, the scaffold had a multi-level porous structure of biomimetic cancellous bone, and the Young's modulus (63.41 ± 1.89 MPa) and compressive strength (2.887 ± 0.025 MPa) of the scaffold were close to those of cancellous bone. In addition, after a series of in vitro and in vivo experiments, the scaffolds proved to have no adverse effects on the viability of BMSCs and promoted their adhesion and osteogenic differentiation, as well as exhibiting higher osteogenic and anti-inflammatory properties than PLGA/β-TCP scaffold without zinc particles. We also found that this osteogenic and anti-inflammatory effect might be related to Wnt/β-catenin, P38 MAPK and NFkB pathways. This study lay a foundation for the follow-up study of bone regeneration mechanism of Zn-containing biomaterials. We envision that this scaffold may become a new strategy for clinical treatment of bone defects.

3D Bioprinting, Bioink, Printability, FDM, Carboxy methyl cellulose, Medical technology, and R855-855.5

Three dimensional (3D) bioprinting is a rapid prototyping technology that can be used to accurately position living cells and biomaterials called bioink, to fabricate functional living tissue constructs or organs. The bioink are deposited in 3D in a layer-by-layer manner using a bioprinter. However, commercially available 3D bioprinters are expensive, limiting the widespread adoption of this technology in low-resource laboratories. To overcome this limitation the conventional Filament Deposition Modelling (FDM) 3D printer can be modified to a 3D bioprinter by replacing the print head unit. During the makeover, The device has to perform in its most efficient capacity in synergy with the bioink used. Hence it is essential to check the bio-printabililty of bioink in the modified FDM printer. In this study we created certain specific G-codes for the evaluation of hybrid bioinks and authenticated the printability. This study focuses on quantifying the printability of a hybrid hydrogel composed of sodium salt carboxymethyl cellulose (CMC) and gelatin using a 3D bioprinter based on the RepRap prototyper. The 3D design and slicing parameters were generated using opensource software and manually edited for printability evaluation. The results of these experiments indicate the importance of printability evaluation of custom bioprinters and provide some key aspects of how to modify CAD design parameters for printability evaluation. This approach can also be adopted to evaluate the printability of other hydrogels for bio-printing. The codes are created to evaluate the printability of bioink using FDM modified bioprinters. The printability evaluation is limited to high viscous bioink for extrusion bioprinting. A user friendly, simple G-Codes and methodology for evaluation of printability of bioink using FDM modified bioprinters. To authors knowledge, this is the first report on 3D printability evaluation of bioink using FDM modified bioprinters. The study also fulfills an identified need to study printability of bioink in biofabrication by additive manufacturing.

Power electronics, Inverters, Rapid control prototyping, Experimental setups, Science (General), and Q1-390

A flexible power electronic converter embedding a rapid control prototyping platform suitable to be applied in research test setups and teaching laboratories is proposed and described in this paper. The electronic system is composed of three subsystems, namely, i) three half-bridge power boards, ii) a dc-link capacitor bank with a half-bridge power module for active dc-link control, iii) an interfacing board, called motherboard, to couple the power modules with a control unit, iv) a digital control unit with rapid control prototyping functionalities for controlling power electronic circuits. Power modules integrate sensors with related conditioning circuits, driving circuits for power switches, and protection circuits. Conversion circuits exploit GaN electronic switches for optimal performance. The architecture and implementation of the system are described in detail in this manuscript. Main applications are in the implementation of conversion circuits for supplying arbitrary ac or dc voltages or currents, testing of new control algorithms for power electronic converters, testing of systems of electronic converters in, for example, smart nanogrids or renewable energy applications, training of undergraduate and graduate students.

Superhydrophobic, Reentrant structures, Wenzel state, Cassie-Baxter state, Two-photon polymerization, 3D printing, Electronics, TK7800-8360, Technology (General), and T1-995

In this work, we fabricate a hexagonal array of pillars where each pillar has a “micro-hoodoo” shape, i.e., a reentrant cross section. The shape of the pillars makes them more resilient towards total wetting, i.e., transition from a Cassie-Baxter non-wetting state to a Wenzel wetting state. We show the single-step fabrication of 4 × 4 mm2 arrays by two-photon polymerization direct laser writing of the polydimethylsiloxane (PDMS)-derived commercial resin IP-PDMS. The use of a hydrophobic resin for rapid prototyping of reentrant structures enables the fabrication of surfaces patterns displaying superhydrophobic behavior despite the use of relatively simple structures, i.e. with a single reentrant surface. By changing the size of the micro-hoodoos and the packing density of the arrays, we map wetting behaviors ranging from the pinning of water droplets in Wenzel state to non-wetting Cassie-Baxter states. The measured contact angles follow quite well the theoretical results obtained by minimizing Gibbs free energy using the Wenzel, Cassie-Baxter and partial wetting theories. Among the tested micropatterns, five exhibited superhydrophobic properties, with a static contact angle with water as high as 158.1° ± 7.1°. This is the first demonstration of superhydrophobic surfaces produced by two-photon polymerization direct laser writing of PDMS in a single-step process.

Additive manufacturing, Two-photon, Direct laser writing, Photolithography, 3D microscopy, SU-8, Electronics, TK7800-8360, Technology (General), and T1-995

Multifocus gratings (MFGs) enable microscopes and other imaging systems to record entire Z-stacks of images in a single camera exposure. The exact grating shape depends on microscope parameters like wavelength and magnification and defines the multiplexing onto a grid of MxN Z-slices. To facilitate the swift production and alteration of MFGs for a system and application at hand, we have developed a fabrication protocol that allows manufacturing of 1xN MFGs within hours and without the requirement of clean room facilities or hazardous etching steps. Our approach uses photolithography with a custom-built stage-scanning direct laser writing (DLW) system. By writing MFG grating lines into spin-coated negative tone SU-8 photoresist, polymerized parts are crafted onto the substrate and thus directly become a part of the grating structure. We provide software to generate the required MFG grating line paths, details of the DLW system and fully characterize a manufactured MFG. Our produced MFG is 5.4 mm in diameter and manages to record an image volume with a Z-span of over 600 μm without spherical aberrations or noticeable loss of resolution.

Medicine

Background In the COVID-19 pandemic, ventilators vital to keeping infected patients alive, were in short supply globally. Our aim was to rapidly prototype and implement production of basic ventilators to serve the local and regional needs in this emergency situation. Methods We adopted a supply-to-design approach, estimating the potential demand for ventilator units and sourcing for common off-the-shelf components available in the estimated quantities, to assemble ventilator units which met the essential requirements for clinical use. We determined the minimum requirements of a basic ventilator based on published specifications and clinician input. Building the ventilator involved interdisciplinary collaboration (between clinicians, industry, hospital innovation engineers and government partners), prototyping and repeated iterations, bench testing, animal testing, regulatory processes, ISO13485 quality management processes, licensing and user acceptability testing. Results We prototyped a limited feature ventilator to supplement hospital ventilators which could be manufactured in sufficient numbers within a short span of time from easily available component parts. Developed with close attention to clinician user input with compliance to ISO standards and quality management processes where possible, this ventilator system was composed of coupled resuscitation bags, motor systems, and pressure and flow sensors capable of delivering ventilator breaths within safe and clinically important targets. This system is functional on ambient air with or without low pressure oxygen supplementation. User feedback cited size, alarms and intuitiveness of controls as potential areas for improvement. Conclusions Further modification based on user acceptability testing results are needed to refine the usability of this limited feature ventilator.

pathogens, uv-c radiation, disinfection, additive manufacturing, rapid prototyping, Machine design and drawing, TJ227-240, Engineering machinery, tools, and implements, and TA213-215

This manuscript aims to familiarise readers with the development of a device for the construction of a mobile disinfection chamber for small communication devices and small objects. The conceptual design and the material of the new device play essential roles in the design process of a new device. The manuscript presents concepts based primarily on previous experience and different perspectives. The concept design is created in the 3D modelling program CREO Parametric 8.0. A multi-criteria team evaluation determined the most suitable version of the idea. For dimensioning and shape adaptation of the device was used EinScan SP device (3D scanning method). The article's aim was also to establish a suitable way of producing a prototype using tribological research in available production methods and materials within rapid prototyping. Using the ALICONA Infinite Focus G5 device, experimentally investigated the parameters characterising the surface of the parts. The end of the manuscript focused on the mechanical structure and subjecting them to FEM analysis in the program ANSYS Workbench. The design of the concept disinfection device was also for extreme cases of use. Within this issue was optimising shapes, wall thicknesses, reinforcement design and other necessary modifications using the FEM analysis. From the results, the most suitable material to produce a more significant number of parts may not be the most suitable material to create prototype devices. Tools such as 3D scanning, rapid prototyping, and FEM analysis can "significantly" help reduce mistakes before testing the device.

jaw defect, functional reconstruction, digital technology, computer-aided design, 3d printing, personalized surgical instruments, preoperative virtual surgery, immediate implantation, and Medicine

With the development of computer-aided surgery and rapid prototyping via 3D printing technology, digital surgery has rapidly advanced in clinical practice, especially in the field of oral and maxillofacial surgery. 3D printing technology has been applied to the functional restoration and reconstruction of the jawbone. Before surgery, a 3D digital model is constructed through software to plan the scope of the osteotomy, shape the bone graft and plan the placement of the implant. Additionally, 3D models of personalized surgical instrument guides are printed prior to surgery. With these 3D-printed models and guides, accurate excision of the jaw tumor, accurate placement of the grafted bone and precise placement of implants can be achieved during surgery. Postoperative evaluation of accuracy and function shows that 3D printing technology can aid in achieving the biomechanical goals of simultaneous implant placement in jaw reconstruction, and in combination with dental implant restoration, the technology can improve patients' postoperative occlusal and masticatory functions. Nevertheless, 3D printing technology still has limitations, such as time-consuming preparation before surgery. In the future, further development of 3D printing technology, optimization of surgical plans, and alternative biological materials are needed. Based on domestic and foreign literature and our research results, we have reviewed the process and clinical application prospects of jaw reconstruction via 3D printing technology to provide a reference for oral and maxillofacial surgeons.

Humans, Hand, Public Health, Family Characteristics, Hand Disinfection methods, Soaps, and Health Behavior

Handwashing with soap is a widely advocated public health measure, but seldom practiced, partly because it is often difficult (especially outside of rich Western country contexts) to make both soap and water readily available in relevant situations. This study used both Behaviour Centred Design and Human Centred Design to guide development of a novel hand cleansing technology appropriate for the context of post-toilet hand cleansing in resource-poor societies. Extensive prototyping and field testing resulted in the pilot production of 'tab' soap, a small but durable single-use, decomposable substrate embedded with soap. It can be produced in dispenser roll or tear-off formats. With this affordable solution, one may use soap without worrying about contamination pretty much anytime and anywhere. A small-scale field test showed that all poor households in rural and peri-urban areas in Tanzania included in the proof-of-concept study (N = 12 households) would use the product reliably over the medium term. Tab soap awaits full-scale production and marketing but could make hand cleansing a more popular practice around the world.
Competing Interests: The authors have an interest in the innovation becoming available at scale and are working to develop partnerships, apply for grants and otherwise support such progress though no financial gain is expected. While a product is in development, there are currently no patents associated with this research to declare. This does not alter our adherence to PLOS ONE policies on sharing data and materials.
(Copyright: © 2023 Brial et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Fast imaging methods are needed to promote widespread clinical adoption of Ultrasound Tomography (UST), and more widely available UST hardware could support the experimental validation of new measurement configurations. In this work, an open-source 256-element transducer ring array was developed (morganjroberts.github.io/open-UST) and manufactured using rapid prototyping, for only £2k. Novel manufacturing techniques were used, resulting in a 1.17° mean beam axis skew angle, a 104 μm mean element position error, and a ±13.6 μm deviation in matching layer thickness. The nominal acoustic performance was measured using hydrophone scans and watershot data, and the 61.2 dB SNR, 55.4° opening angle, 10.2 mm beamwidth and 54% transmit-receive bandwidth (-12 dB), were found to be similar to existing systems, and compatible with state of the art full-waveform-inversion image reconstruction methods. The inter-element variation in acoustic performance was typically <10% without using normalisation, meaning that the elements can be modelled identically during image reconstruction, removing the need for individual source definitions based on hydrophone measurements. Finally, data from a phantom experiment was successfully reconstructed. These results demonstrate that the open-UST system is accessible for users, and suitable for UST imaging research.

Humans, Child, User-Centered Design, Indonesia, Mobile Applications, Telemedicine methods, and Leukemia

Background: A mobile health (mHealth) application can encourage parents and pediatric patients to be involved in caring for their child's health condition by providing the ability to identify and actively manage chemotherapy-related symptoms in their child. Several monitoring systems available today are diverse in features and system basis. This study aimed to develop and trial the Chemo Assist for Children (CAC) mHealth application for symptom management in children with acute lymphoblastic leukemia (ALL).
Methods: In this study, the development of the CAC application went through multiple phases and methods. Study phases included: (1) development of the application's feature based on the need assessment, (2) creation of content of application based on literature review, (3) develop prototyping of CAC, (4) expert review and feedback on the application content, (5) usability testing by targeted end-user.
Results: Based on need assessment, it was determined that parents with leukemia children were interested in symptom management of chemotherapy and preferred mobile applications. Therefore, a mHealth application was designed to include features to identify symptoms and provide recommendation strategies to manage the symptom. Usability evaluation by end-user revealed that mHealth is a valid, accessible, and appropriate application for users.
Conclusions: The CAC mHealth application developed can meet the needs of technology users to identify symptoms and manage chemotherapy-related symptoms in children with ALL. The CAC mHealth application can accommodate data not recorded at out-of-hospital care, increase the independence of symptom management, and improve communication between parents of children with ALL and health workers.
(© 2023. The Author(s).)

Background: Fatigue is an important symptom for many patients, including patients with kidney disease. Cognitive biases, such as attentional bias and self-identity bias, are thought to influence fatigue. Cognitive bias modification (CBM) training is a promising technique to counter fatigue.
Objective: We aimed to evaluate a CBM training among patients with kidney disease and health care professionals (HCPs) and assess acceptability and applicability in the clinical setting using an iterative design process to evaluate expectations and experiences with the training.
Methods: This was a longitudinal, qualitative, and multiple stakeholder-perspective usability study in which we interviewed end users and HCPs during the prototyping phase and after the end of training. We conducted semistructured interviews with 29 patients and 16 HCPs. The interviews were transcribed and analyzed thematically. Next to a general evaluation of the training, the acceptability of the training was evaluated using the Theoretical Framework of Acceptability, and applicability was assessed by evaluating obstacles and solutions for implementation in the kidney care setting.
Results: Generally, participants were positive about the training and its applicability. The biggest negatives were doubts about effectiveness and annoyance about the repetitive character of CBM. Acceptability was judged with a mixed evaluation, with a negative evaluation of perceived effectiveness; mixed results for burden, intervention coherence, and self-efficacy; and positive results for affective attitude, ethicality, and opportunity costs. Barriers for applicability were patients' varying computer skills, subjectivity of fatigue, and integration with regular treatment (eg, the role of HCPs). Possible solutions included assigning representatives among nurses, offering training on an app, and providing assistance via a help desk. The iterative design process, including repeated waves of testing user expectations and experiences, yielded complementary data.
Conclusions: To the best of our knowledge, this study is the first to introduce a CBM training targeting fatigue. Furthermore, this study provides one of the first user evaluations of a CBM training, both among patients with kidney disease and their care providers. Overall, the training was evaluated positively, although acceptability showed mixed results. Applicability was positive although barriers were identified. The proposed solutions require further testing, preferably following the same frameworks, as the iteration in this study contributed positively to the quality of the training. Therefore, future research should follow the same frameworks and consider stakeholders and end users in eHealth intervention design.
(©Jody Geerts, Marcel Pieterse, Goos Laverman, Femke Waanders, Nicole Oosterom, Jacqueline Slegten, Elske Salemink, Christina Bode. Originally published in JMIR Formative Research (https://formative.jmir.org), 29.05.2023.)

Female, Humans, Spectroscopy, Fourier Transform Infrared, Fluorouracil, Polyesters, and Uterine Cervical Neoplasms drug therapy

Solid lipid nanoparticles (SLNs) are used extensively to achieve site-specific drug delivery with improved bioavailability and reduced toxicity. This work focused on a new approach to provide site-specific stimuli-responsive delivery of SLNs loaded within thermo-sonic nano-organogel (TNO) variants to deliver the model chemotherapeutic agent 5-FU in treating cervical cancer. Pharmaceutically stable nanospherical SLNs comprising poly-L-lactic acid (PLA), palmitic acid (PA), and polyvinyl alcohol (PVA) were prepared and incorporated into TNO variants augmented by external thermal and ultrasound stimuli for release of 5-FU in the cervix. Results revealed that rate-modulated 5-FU release was achieved from SLNs (particle size =450.9 nm; PDI =0.541; zeta potential =-23.2 mV; %DL =33%) within an organogel upon exposure to either a single (thermo-) and/or both (thermo-sonic) stimuli. 5FU was released from all TNO variants with an initial burst on day 1 followed by sustained release over 14 days. TNO 1 provided desirable release over 15 days (44.29% vs. 67.13% under single (T) or combined (TU) stimuli, respectively). Release rates were primarily influenced by the SLN:TO ratio in tandem with biodegradation and hydrodynamic influx. Biodegradation by day 7 revealed that variant TNO 1 (1:5) released 5FU (46.8%) analogous to its initial mass than the other TNO variants (i.e., ratios of 2:5 and 3:5). FT-IR spectra revealed assimilation of the system components and corroborative with the DSC and XRD analysis (i.e., in ratios of PA:PLA 1:1 and 2:1). In conclusion, the TNO variants produced may be used as a potential stimuli-responsive platform for the site-specific delivery of chemotherapeutic agents such as 5-FU to treat cervical cancer.
(© 2023. The Author(s).)

The aim of this study was to introduce a new computer guided technique for debulking and contouring the craniofacial fibrous dysplasia involving the fronto-orbital and fronto-cranial regions. Computer-guided contouring was performed using a modified patient-specific surgical depth guide for six patients with craniofacial fibrous dysplasia involving the fronto-orbital and fronto-cranial regions. Virtual planning was performed to determine the desired amount of bone removal and construct the patient-specific surgical depth guide. Then, the guide was printed using rapid prototyping. In the surgical theatre, the guide was seated in position. Implant drills were inserted through the created depth holes according to the planned fixed depth to create depth holes. Finally, the bone in between the created holes was removed using cutting discs, bone chisels and surgical burs. Satisfaction with facial aesthetics was evaluated by the patients using a Likert scale, and by the surgeons using the Whitaker rating scale. The surgical procedures were uneventful for all the patients. All the patients were satisfied with the post-operative facial esthetics and categorized as category I Whitaker rating scale. Patient-specific surgical guide technique for recontouring of fronto-orbital and fronto-cranial fibrous dysplasia can be considered an accurate substitution technique that overcomes the drawbacks of the unpredictable conventional one. Further investigations are required.
Competing Interests: Declaration of competing interest None.
(Copyright © 2023 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

The transition of additive manufacturing (AM) from a technique for rapid prototyping to one for manufacturing of near net or net components has been led by the development of methods that can repeatedly fabricate quality parts. High-speed laser sintering and the recently developed multi-jet fusion (MJF) processes have seen quick adoption from industry due to their ability to produce high-quality components relatively quickly. However, the recommended refresh ratios of new powder led to notable amounts of used powder being discarded. In this research, polyamide-11 powder, typically used in AM, was thermally aged to investigate its properties at extreme levels of reuse. The powder was exposed to 180 °C in air for up to 168 h and its chemical, morphological, thermal, rheological, and mechanical properties were examined. To decouple the thermo-oxidative aging phenomena from AM process related effects, such as porosity, rheological and mechanical properties characterisation was performed on compression-moulded specimens. It was found that exposure notably affected the properties of both the powder and the derived compression-moulded specimens within the first 24 h of exposure; however, consecutive exposure did not have a significant effect.

Three-dimensional (3D) printing is one of the promising technologies for the fabrication of microstructures due to its versatility, ease of fabrication, and low cost. However, the direct use of 3D-printed microstructure as a microchannel is still limited due to its surface property, biocompatibility, and transmittance. As an alternative, rapid prototyping of poly(dimethylsiloxane) (PDMS) from 3D-printed microstructures ensures both biocompatibility and efficient fabrication. We employed 3D-printed molds fabricated using horizontal and vertical arrangement methods with different slice thicknesses in a digital light projection (DLP)-based 3D printing process to replicate PDMS microchannels. The replicated PDMS structures were investigated to compare their optical transmittances and surface roughness. Interestingly, the optical transmittance of PDMS from the 3D-printed mold was significantly increased via bonding two single PDMS layers. To evaluate the applicability of the replicated PDMS devices from the 3D-printed mold, we performed droplet generation in the PDMS microchannels, comparing the same device from a conventional Si-wafer mold. This study provides a fundamental understanding of prototyping microstructures from the DLP-based 3D-printed mold.
Competing Interests: The authors declare no competing financial interest.
(© 2023 The Authors. Published by American Chemical Society.)

Objective: The objective of this paper is to describe the techniques and process of developing and testing a take-home surgical anastomosis simulation model.
Design: Through an iterative process, a simulation model was customized and designed to target specific skill development and performance objectives that focused on anastomotic techniques in thoracic surgery and consist of 3D printed and silicone molded components. Various manufacturing techniques such as silicone dip spin coating and injection molding have been described in this paper and explored as part of the research and development process. The final prototype is a low-cost, take-home model with reusable and replaceable components.
Setting: The study took place at a single-center quaternary care university-affiliated hospital.
Participants: The participants included in the model testing were 10 senior thoracic surgery trainees who completed an in-person training session held during an annual hands- on thoracic surgery simulation course. Feedback was then collected in the form of an evaluation of the model from participants.
Results: All 10 participants had an opportunity to test the model and complete at least 1 pulmonary artery and bronchial anastomosis. The overall experience was rated highly, with minor feedback provided regarding the set- up and fidelity of the materials used for the anastomoses. Overall, the trainees agreed that the model was suitable for teaching advanced anastomotic techniques and expressed an interest in being able to use this model to practice skill development.
Conclusions: Developed simulation model can be easily reduced, with customized components that accurately simulate real-life vascular and bronchial components suitable for training of anastomoses technique amongst senior thoracic surgery trainees.
(Copyright © 2023. Published by Elsevier Inc.)

Six acrylamide resins, derived from l-phenylalanine and l-leucine, are designed for application in digital light processing (DLP) printers to obtain biodegradable thermoset polymers. The acrylamide copolymers are prepared under light irradiation at 405 nm and thermal post-curing processes. Low molecular weight poly(ethylene glycol)diacrylate (PEGDA) and N,N-dimethylacrylamide (DMAM), both liquid resins, are used as co-monomers and diluents for the amino acid-derived acrylamide solubilization. The presence of two phenylalanine units and two ester groups in the acrylamide monomer accuses a fast degradation rate in hydrolytic medium in 90 days. The residual products leached in the aqueous media prove to be non-cytotoxic, when 3D-printed samples are cultured with osteoblast cells (MG63), which represents an advantage for the safe disposal of printer waste materials. The scaled-up pieces derived from l-phenylalanine and diethylene glycol, as amino acid-derived acrylamide (named compound C), PEGDA and DMAM, present high dimensional stability after DLP printing of complex structures used as testing samples. Layers of 50 µm of thickness are well cohesive having isotropic behavior, as demonstrated with tensile-strain measurements performed in X-Y-Z (plane) directions. The compound C, which contains phenylalanine amino acid, reveals a promising potential to replace non-biodegradable acrylate polymers used in prototyping systems.
(© 2023 Wiley-VCH GmbH.)

Humans, Porosity, Electrodes, and Graphite

Flexible pressure sensors are widely applied in tactile perception, fingerprint recognition, medical monitoring, human-machine interfaces, and the Internet of Things. Among them, flexible capacitive pressure sensors have the advantages of low energy consumption, slight signal drift, and high response repeatability. However, current research on flexible capacitive pressure sensors focuses on optimizing the dielectric layer for improved sensitivity and pressure response range. Moreover, complicated and time-consuming fabrication methods are commonly applied to generate microstructure dielectric layers. Here, we propose a rapid and straightforward fabrication approach to prototyping flexible capacitive pressure sensors based on porous electrodes. Laser-induced graphene (LIG) is produced on both sides of the polyimide paper, resulting in paired compressible electrodes with 3D porous structures. When the elastic LIG electrodes are compressed, the effective electrode area, the relative distance between electrodes, and the dielectric property vary accordingly, thereby generating a sensitive pressure sensor in a relatively large working range (0-9.6 kPa). The sensitivity of the sensor is up to 7.71%/kPa -1 , and it can detect pressure as small as 10 Pa. The simple and robust structure allows the sensor to produce quick and repeatable responses. Our pressure sensor exhibits broad potential in practical applications in health monitoring, given its outstanding comprehensive performance combined with its simple and quick fabrication method.

Flexible electronics have gained great attention in recent years owing to their promising applications in biomedicine, sustainable energy, human-machine interaction, and toys for children. Paper mainly produced from cellulose fibers is attractive substrate for flexible electronics because it is biodegradable, foldable, tailorable, and light-weight. Inspired by daily handwriting, the rapid prototyping of sensing devices with arbitrary patterns can be achieved by directly drawing conductive inks on flat or curved paper surfaces; this provides huge freedom for children to design and integrate "do-it-yourself (DIY)" electronic toys. Herein, viscous and additive-free ink made from Ti 3 C 2 T X MXene sediment is employed to prepare disposable paper electronics through a simple ball pen drawing. The as-drawn paper sensors possess hierarchical microstructures with interweaving nanosheets, nanoflakes, and nanoparticles, therefore exhibiting superior mechanosensing performances to those based on single/fewer-layer MXene nanosheets. As proof-of-concept applications, several popular children's games are implemented by the MXene-based paper sensors, including "You say, I guess," "Emotional expression," "Rock-Paper-Scissors," "Arm wrestling," "Throwing game," "Carrot squat," and "Grab the cup," as well as a DIY smart whisker for a cartoon mouse. Moreover, MXene-based paper sensors are safe and disposable, free from producing any e-waste and hazard to the environment.
(© 2023 Wiley-VCH GmbH.)

The performance of two-dimensional (2D) materials is promising for electronic, photonic, and sensing devices since they possess large surface-to-volume ratios, high mechanical strength, and broadband light sensitivity. While significant advances have been made in synthesizing and transferring 2D materials onto different substrates, there is still the need for scalable patterning of 2D materials with nanoscale precision. Conventional lithography methods require protective layers such as resist or metals that can contaminate or degrade the 2D materials and deteriorate the final device performance. Current resist-free patterning methods are limited in throughput and typically require custom-made equipment. To address these limitations, we demonstrate the noncontact and resist-free patterning of platinum diselenide (PtSe 2 ), molybdenum disulfide (MoS 2 ), and graphene layers with nanoscale precision at high processing speed while preserving the integrity of the surrounding material. We use a commercial, off-the-shelf two-photon 3D printer to directly write patterns in the 2D materials with features down to 100 nm at a maximum writing speed of 50 mm/s. We successfully remove a continuous film of 2D material from a 200 μm × 200 μm substrate area in less than 3 s. Since two-photon 3D printers are becoming increasingly available in research laboratories and industrial facilities, we expect this method to enable fast prototyping of devices based on 2D materials across various research areas.

Microfluidics, Cell Culture Techniques, Hydrophobic and Hydrophilic Interactions, Endothelial Cells, and Endothelium, Vascular

On-chip vascular microfluidic models provide a great tool to study aspects of cardiovascular diseases in vitro. To produce such models, polydimethylsiloxane (PDMS) has been the most widely used material. For biological applications, its hydrophobic surface has to be modified. The major approach has been plasma-based surface oxidation, which has been very challenging in the case of channels enclosed within a microfluidic chip. The preparation of the chip combined a 3D-printed mold with soft lithography and commonly available materials. We have introduced the high-frequency low-pressure air-plasma surface modification of seamless channels enclosed within a PDMS microfluidic chip. The plasma treatment modified the luminal surface more uniformly than in previous works. Such a setup enabled a higher degree of design freedom and a possibility of rapid prototyping. Further, plasma treatment in combination with collagen IV coating created a biomimetic surface for efficient adhesion of vascular endothelial cells as well as promoted long-term cell culture stability under flow. The cells within the channels were highly viable and showed physiological behavior, confirming the benefit of the presented surface modification.

Objectives: We aimed to develop a video animation knowledge translation (KT) resource to explain the purpose, use and importance of evidence synthesis to the public regarding healthcare decision-making.
Methods: We drew on a user-centred design approach to develop a spoken animated video (SAV) by conducting two cycles of idea generation, prototyping, user testing, analysis, and refinement. Six researchers identified the initial key messages of the SAV and informed the first draft of the storyboard and script. Seven members of the public provided input on this draft and the key messages through think-aloud interviews, which we used to develop an SAV prototype. Seven additional members of the public participated in think-aloud interviews while watching the video prototype. All members of the public also completed a questionnaire on perceived usefulness, desirability, clarity and credibility. We subsequently synthesised all data to develop the final SAV.
Results: Researchers identified the initial key messages as 1) the importance of evidence synthesis, 2) what an evidence synthesis is and 3) how evidence synthesis can impact healthcare decision-making. Members of the public rated the initial video prototype as 9/10 for usefulness, 8/10 for desirability, 8/10 for clarity and 9/10 for credibility. Using their guidance and feedback, we produced a three-and-a-half-minute video animation. The video was uploaded on YouTube, has since been translated into two languages, and viewed over 12,000 times to date.
Conclusions: Drawing on user-centred design methods provided a structured and transparent approach to the development of our SAV. Involving members of the public enhanced the credibility and usefulness of the resource. Future work could explore involving the public from the outset to identify key messages in developing KT resources explaining methodological topics. This study describes the systematic development of a KT resource with limited resources and provides transferrable learnings for others wishing to do similar.
Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.
(© The Author(s) 2023.)

Humans, Knee Joint, Knee, Biomechanical Phenomena, Ligaments, Articular, Range of Motion, Articular, and Robotic Surgical Procedures

Medical device regulatory standards are increasingly incorporating computational modelling and simulation to accommodate advanced manufacturing and device personalization. We present a method for robust testing of engineered soft tissue products involving a digital twin paradigm in combination with robotic systems. We developed and validated a digital twin framework for calibrating and controlling robotic-biological systems. A forward dynamics model of the robotic manipulator was developed, calibrated, and validated. After calibration, the accuracy of the digital twin in reproducing the experimental data improved in the time domain for all fourteen tested configurations and improved in frequency domain for nine configurations. We then demonstrated displacement control of a spring in lieu of a soft tissue element in a biological specimen. The simulated experiment matched the physical experiment with 0.09 mm (0.001%) root-mean-square error for a 2.9 mm (5.1%) length change. Finally, we demonstrated kinematic control of a digital twin of the knee through 70-degree passive flexion kinematics. The root-mean-square error was 2.00°, 0.57°, and 1.75° degrees for flexion, adduction, and internal rotations, respectively. The system well controlled novel mechanical elements and generated accurate kinematics in silico for a complex knee model. This calibration method could be applied to other situations where the specimen is poorly represented in the model environment (e.g., human or animal tissues), and the control system could be extended to track internal parameters such as tissue strain (e.g., control knee ligament strain). Further development of this framework can facilitate medical device testing and innovative biomechanics research.
Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier Ltd.)

Humans, Child, Muscle, Skeletal physiology, Tendons, Ankle, Ankle Joint, and Cerebral Palsy

Neuromusculoskeletal models can be used to evaluate aberrant muscle function in cerebral palsy (CP), for example by estimating muscle and joint contact forces during gait. However, to be accurate, models should include representative musculotendon parameters. We aimed to estimate personalised parameters that capture the mechanical behaviour of the plantarflexors in children with CP and typically developing (TD) children. Ankle angle (using motion capture), torque (using a load-cell), and medial gastrocnemius fascicle lengths (using ultrasound) were measured during slow passive ankle dorsiflexion rotation for thirteen children with spastic CP and thirteen TD children. Per subject, the measured rotation was input to a scaled OpenSim model to simulate the torque and fascicle length output. Musculotendon model parameters were personalised by the best match between simulated and experimental torque-angle and fascicle length-angle curves according to a least-squares fit. Personalised tendon slack lengths were significantly longer and optimal fibre lengths significantly shorter in CP than model defaults and than in TD. Personalised tendon compliance was substantially higher in both groups compared to the model default. The presented method to personalise musculotendon parameters will likely yield more accurate simulations of subject-specific muscle mechanics, to help us understand the effects of altered musculotendon properties in CP.
(© 2022. The Author(s).)

Photonic integrated circuits (PICs) can drastically expand the capabilities of quantum and classical optical information science and engineering. PICs are commonly fabricated using selective material etching, a subtractive process. Thus, the chip's functionality cannot be substantially altered once fabricated. Here, we propose to exploit wide-bandgap non-volatile phase-change materials (PCMs) to create rewritable PICs. A PCM-based PIC can be written using a nanosecond pulsed laser without removing any material, akin to rewritable compact disks. The whole circuit can then be erased by heating, and a new circuit can be rewritten. We designed a dielectric-assisted PCM waveguide consisting of a thick dielectric layer on top of a thin layer of wide-bandgap PCMs Sb 2 S 3 and Sb 2 Se 3 . The low-loss PCMs and our designed waveguides lead to negligible optical loss. Furthermore, we analyzed the spatiotemporal laser pulse shape to write the PICs. Our proposed platform will enable low-cost manufacturing and have a far-reaching impact on the rapid prototyping of PICs, validation of new designs, and photonic education.

Humans, Printing, Three-Dimensional, Prostheses and Implants, Arthroplasty, Upper Extremity surgery, Fractures, Bone surgery, and Surgery, Computer-Assisted

The use of three-dimensional (3-D) technology in upper extremity surgery has the potential to revolutionize the way that hand and upper limb procedures are planned and performed. 3-D technology can assist in the diagnosis and treatment of conditions, allowing virtual preoperative planning and surgical templating. 3-D printing can allow the production of patient-specific jigs, instruments and implants, allowing surgeons to plan and perform complex procedures with greater precision and accuracy. Previously, cost has been a barrier to the use of 3-D technology, which is now falling rapidly. This review article will discuss the current status of 3-D technology and printing, including its applications, ethics and challenges in hand and upper limb surgery. We have provided case examples to outline how clinicians can incorporate 3-D technology in their clinical practice for congenital deformities, management of acute fracture and malunion and arthroplasty.