Technical Design Considerations Research Articles

Extending Droplet-Based Microfluidic Tools to Single-Atom Heterogeneous Catalysis.

From energy-related transformations to organic syntheses, single-atom heterogeneous catalysts (SACs) are offering new prospects to tackle sustainability challenges. However, scarce design guidelines and poor mechanistic understanding due to a lack of discovery and operando characterization tools impede theirbroader development. This perspective offers a glimpse into how droplet-based microfluidic technologies mayhelp solve both of these issues, and provides technical considerations for platform design to systematically fabricate SACs and study them under operational conditions during liquid-phase organic syntheses.

Technical and functional design considerations for a real-world interpretable AI solution for NIR perfusion analysis (including cancer)

Near infrared (NIR) analysis of tissue perfusion via indocyanine green fluorescence assessment is performed clinically during surgery for a range of indications. Its usefulness can potentially be further enhanced through the application of interpretable artificial intelligence (AI) methods to improve dynamic interpretation accuracy in these and also open new applications. While its main use currently is for perfusion assessment as a tissue health check prior to performing an anastomosis, there is increasing interest in using fluorophores for cancer detection during surgical interventions with most research being based on the paradigm of static imaging for fluorophore uptake hours after preoperative dosing. Although some image boosting and relative estimation of fluorescence signals is already inbuilt into commercial NIR systems, fuller implementation of AI methods can enable actionable predictions especially when applied during the dynamic, early inflow-outflow phase that occurs seconds to minutes after ICG (or indeed other fluorophore) administration. Already research has shown that such methods can accurately differentiate cancer from benign tissue in the operating theatre in real time in principle based on their differential signalling and could be useful for tissue perfusion classification more generally. This can be achieved through the generation of fluorescence intensity curves from an intra-operative NIR video stream. These curves are processed to adjust for image disturbances and curve features known to be influential in tissue characterisation are extracted. Existing machine learning based classifiers can then use these features to classify the tissue in question according to prior training sets. The use of this interpretable methodology enables accurate classification algorithms to be built with modest training sets in comparison to those required for deep learning modelling in addition to achieving compliance with medical device regulations. Integration of the multiple algorithms required to achieve this classification into a desktop application or medical device could make the use of this method accessible and useful to (as well as useable by) surgeons without prior training in computer technology. This document details some technical and functional design considerations underlying such a novel recommender system to advance the foundational concept and methodology as software as medical device for in situ cancer characterisation with relevance more broadly also to other tissue perfusion applications.

A Review on the Technical Design Considerations of Indoor Suspended Ceilings

A Review on the Technical Design Considerations of Indoor Suspended Ceilings

Technical Design Considerations of a Human-Scale Talbot-Lau Interferometer for Dark-Field CT.

Computed tomography (CT) as an important clinical diagnostics method can profit from extension with dark-field imaging, as it is currently restricted to X-rays' attenuation contrast only. Dark-field imaging allows access to more tissue properties, such as micro-structural texture or porosity. The up-scaling process to clinical scale is complex because several design constraints must be considered. The two most important ones are that the finest grating is limited by current manufacturing technology to a [Formula: see text] period and that the interferometer should fit into the CT gantry with minimal modifications only. In this work we discuss why an inverse interferometer and a triangular G1 profile are advantageous and make a compact and sensitive interferometer implementation feasible. Our evaluation of the triangular grating profile reveals a deviation in the interference pattern compared to standard grating profiles, which must be considered in the subsequent data processing. An analysis of the grating orientation demonstrates that currently only a vertical layout can be combined with cylindrical bending of the gratings. We also provide an in-depth discussion, including a new simulation approach, of the impact of the extended X-ray source spot which can lead to large performance loss and present supporting experimental results. This analysis reveals a vastly increased sensitivity to geometry and grating period deviations, which must be considered early in the system design process.

Technical considerations in PCR-based assay design for diagnostic DNA methylation cancer biomarkers

BackgroundDNA methylation biomarkers for early detection, risk stratification and treatment response in cancer have been of great interest over the past decades. Nevertheless, clinical implementation of these biomarkers is limited, as only < 1% of the identified biomarkers is translated into a clinical or commercial setting. Technical factors such as a suboptimal genomic location of the assay and inefficient primer or probe design have been emphasized as important pitfalls in biomarker research. Here, we use eleven diagnostic DNA methylation biomarkers for colorectal cancer (ALX4, APC, CDKN2A, MGMT, MLH1, NDRG4, SDC2, SFRP1, SFRP2, TFPI1 and VIM), previously described in a systematic literature search, to evaluate these pitfalls.ResultsTo assess the genomic assay location, the optimal genomic locations according to TCGA data were extracted and compared to the genomic locations used in the published assays for all eleven biomarkers. In addition, all primers and probes were technically evaluated according to several criteria, based on literature and expert opinion. Both assay location and assay design quality varied widely among studies.ConclusionsLarge variation in both assay location and design hinders the development of future DNA methylation biomarkers as well as inter-study comparability.

How Will Cell-Free Systems Be Deployed?

The cell-free system has recently been investigated as a way to achieve uniform communication performance over the 5G cellular system. However, deploying cell-free systems in commercial mobile networks is a challenging task. One major bottleneck is the need to install access points (APs) on a large scale. APs will be gradually introduced into the mobile system and will need to be compatible with the existing cellular system. As a solution, we propose a transitional system architecture for beyond 5G, where the cell-free system and the legacy cellular system coexist. We call the proposed system a cell-free and legacy coexistence network (CLCN). In this article, the discussion focuses on technical challenges, design considerations, and practical CLCN system layouts. Simulations confirm that the gradual installation of APs in legacy cellular systems can reduce the performance gap between users and improve the average spectral efficiency of the system. The results show that CLCN can provide users uniformly high performance, which has long been a challenge for cellular systems.

AI Certification: Advancing Ethical Practice by Reducing Information Asymmetries

As artificial intelligence (AI) systems are increasingly deployed, principles for ethical AI are also proliferating. Certification offers a method to both incentivize adoption of these principles and substantiate that they have been implemented in practice. This paper draws from management literature on certification and reviews current AI certification programs and proposals. Successful programs rely on both emerging technical methods and specific design considerations. In order to avoid two common failures of certification, program designs should ensure that the symbol of the certification is substantially implemented in practice and that the program achieves its stated goals. The review indicates that the field currently focuses on self-certification and third-party certification of systems, individuals, and organizations - to the exclusion of process management certifications. Additionally, the paper considers prospects for future AI certification programs. Ongoing changes in AI technology suggest that AI certification regimes should be designed to emphasize governance criteria of enduring value, such as ethics training for AI developers, and to adjust technical criteria as the technology changes. Overall, certification can play a valuable mix in the portfolio of AI governance tools.

Important Technical Considerations in Design of Battery Chargers of Electric Vehicles

There are many important trade-offs and constraints on cost, volume, weight, conduction losses, switching losses, microcontrollers, isolation, voltage and current levels, voltage and current ripples, battery specifications, charging–discharging algorithms, control system, switch gate drivers, and efficiency of battery chargers in electric vehicles. In this paper, a well-known power electronic topology commonly used in recent relevant studies is considered, and some important technical considerations with regard to the mentioned trade-offs and constraints are discussed in detail for the first time. The discussion concerns the practical and theoretical experiences in implementation of battery chargers and charging stations of electric vehicles exclusively, and it can be extended to various other power electronic topologies.

A Smart Network of Service Robots: Technical Challenges and Design Considerations

Recent advancement in communication technology to support cloud robotics is expected to bring a remarkable evolution in industry automation. As another big opportunity for research, this article is intended to provide implications of what service robots, as opposed to industrial robots used in a structured setting, can bring into our daily lives in the near future. With a brief review of recent research and standardization activities, several technical challenges and design consideration points on service robot operation are discussed with the focus on some of the key aspects such as autonomic networking for service disruption minimization, robot utilization improvement, and cybersecurity.

Review of Technical Design and Safety Requirements for Vehicle Chargers and Their Infrastructure According to National Swedish and Harmonized European Standards

Battery electric vehicles demand a wide variety of charging networks, such as charging stations and wallboxes, to be set up in the future. The high charging power (typically in the range of a couple of kW up to a couple of hundred kW) and the possibly long duration of the charging process (up to more than 24 h) put some special requirements on the electrical infrastructure of charging stations, sockets, and plugs. This paper gives an overview of the technical design requirements and considerations for vehicle charging stations, sockets, and plugs, including their infrastructure, according to the Swedish Standard 4364000, “Low-voltage electrical installations—Rules for design and erection of electrical installations”, and the corresponding harmonized European standards. In detail, the four internationally categorized charging modes are explained and the preferable charging plugs, including their two-bus communication, according to European Directives are shown. The dimensioning of the supply lines and the proper selection of the overcurrent protection device, the insulation monitor, and the residual current device are described. Furthermore, a comprehensive overview of the required safety measures, such as the application of an isolation transformer or the implementation of an overvoltage protection mechanism, and the limits for conducted electromagnetic emissions, such as low-frequency harmonics or high-frequency (150 kHz to 108 MHz) emissions, are given.

Abstract 2861: Targeting cancer with antibody-drug conjugates: Promises and challenges

Abstract Chemotherapy is inherently associated with side effects due to its poor selectivity towards tumor cells/tissues. Antibody-drug conjugate (ADC) technology promises to overcome barriers of classical chemotherapy by utilizing monoclonal antibodies to deliver potent payloads to selected target cancer cells. The antibody and cytotoxic payload are joined by a chemical linker resulting in an agent with the prospect of increased selectivity, anti-cancer activity, and improved systemic circulation. As of 2019, the US Food and Drug Administration (FDA) has approved five ADCs with cancer indications, including brentuximab vedotin for treatment of CD30-expressing lymphomas, trastuzumab emtansine for Her2-positive breast cancer, inotuzumab ozogamicin for CD22-positive acute lymphoblastic leukemia (ALL), gemtuzumab ozogamicin for CD33-positive acute myeloid leukemia (AML), and polatuzumab vedotin for diffuse large B-cell lymphoma (DLBCL). Currently, there are about 80 ADCs under clinical development in nearly 130 clinical trials. Despite initial success, there are still many challenges in the development of ADCs with respect to their safety and efficacy profiles. In this study, we aim to survey the recent efforts in the design and development of ADCs. We have focused on site-specific conjugation methods for producing homogenous ADCs with consistent drug-antibody ratio (DAR) - a challenge often observed in conventional conjugation methods. This information is further discussed with respect to the ADC interaction with target cells to elicit cytotoxicity. The survey results will be presented, giving perspective on technical considerations for ADC design towards better correlation between preclinical and clinical results and overall safer and more efficacious products. Citation Format: Alexis Dean, Julianne Twomey, Baolin Zhang. Targeting cancer with antibody-drug conjugates: Promises and challenges [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 2861.

Critical science agency and power hierarchies: Restructuring power within groups to address injustice beyond them

AbstractPromoting critical science agency (CSA) may be one way to promote educational justice. CSA is using science with other powerful forms of knowledge to address issues of injustice. However, the process of enacting CSA is always embedded within a sociopolitical context, which positions some students with more power than others. Drawing upon a social practice theory analytical lens with a focus on power and using critical participatory ethnography methods, this study investigated the ways middle school students restructured power hierarchies as they worked to complete the design challenge of making their classroom community more sustainable, and how power hierarchy restructuring impacted students' opportunities to enact CSA. Findings show as the students enacted collective CSA, they were responding to unmet students' needs grounded in systems of power operating within their classroom. Throughout the engineering design process, students' understandings of their defined issue of injustice was both refined and critical to their technical and social design considerations. Finally, as the groups enacted CSA, power hierarchy disruptions, though incomplete, through the recognition of students' expertize and distributing roles, supported their efforts to address their class‐wide concerns. These findings highlight how restructuring power hierarchies supported youth enacting collective CSA, which then further supported them in reshaping their classroom community to be more justice‐oriented.

Developing Infographics to Facilitate HIV-Related Patient-Provider Communication in a Limited-Resource Setting.

Productive patient-provider communication is a recognized component of high-quality health care that leads to better health outcomes. Well-designed infographics can facilitate effective communication, especially when culture, language, or literacy differences are present. This study aimed to rigorously develop infographics to improve human immunodeficiency virus (HIV)-related patient-provider communication in a limited-resource setting. A secondary purpose was to establish through participant feedback that infographics convey intended meaning in this clinical and cultural context. We adapted a participatory design methodology, developed in a high-resource setting, for use in the Dominican Republic. Initially, content to include was established using a data-triangulation method. Then, infographics were iteratively generated and refined during five phases of design sessions with three stakeholder groups: (1) 25 persons living with HIV, (2) 8 health care providers, and (3) 5 domain experts. Suggestions for improvement were incorporated between design sessions and questions to confirm interpretability of infographics were included at the end of each session. Each participant group focused on different aspects of infographic designs. Providers drew on past experiences with patients and offered clinically and contextually relevant recommendations of symbols and images to include. Domain experts focused on technical design considerations and interpretations of infographics. While it was difficult for patient participants to provide concrete suggestions, they provided feedback on the meaning of infographics and responded clearly to direct questions regarding possible changes. Fifteen final infographics were developed and all participant groups qualitatively confirmed that they displayed the intended content in a culturally appropriate and clinically meaningful way. Incorporating perspectives from various stakeholders led to the evolution of designs over time and generated design recommendations that will be useful to others creating infographics for use in similar populations. Next steps are to assess the feasibility of using infographics to improve clinical communication and patient outcomes.

A survey of mmWave user association mechanisms and spectrum sharing approaches: an overview, open issues and challenges, future research trends

Fifth generation (5G) cellular networks promise to support multi-radio access technologies (multi-RATs) with low and high frequencies aiming at delivering good coverage, several gigabits data rate, and ultra-reliable services. In this context, user-association and resource allocation appear to be a huge challenge due to the variety of specifications and varied propagation environments. In this treatise, the focus is on the technical and administrative difficulties of the adoption of user association (UA) mechanism and spectrum sharing approach (SSA) in millimeter wave (mmWave) systems, for example, the technical design considerations and their underlying options, as well as their impact on users and network performance. In addition, details on the importance of the rules and regulations of SSA are presented. This study also identified a few possible design solutions and potential promising technologies in both UA and SSA. In the context of UA, several mechanisms are identified, such as backhaul-, caching-, and hybrid multi-criteria-aware UA to achieve seamless connectivity and to enhance the network utility. In the context of SSA, this study pinpoints varied subjects that need to be explored, such as joint efficient rules and regulations enactment, assessment of fairness and independence in multi-independent mobile network operators (multi-IMNOs) that support SSA, as well as the implementation of hybrid-SSA via Virtualized Cloud Radio Access Network. Finally, attention is drawn to several key conclusions to enable readers and interested researchers to learn about the most controversial points of mmWave 5G cellular networks.

Incorporating Multiple Perspectives Into the Development of an Electronic Survivorship Platform for Head and Neck Cancer.

To improve the care of survivors of head and neck cancer, we developed the Head and Neck Survivorship Tool: Assessment and Recommendations (HN-STAR). HN-STAR is an electronic platform that incorporates patient-reported outcomes into a clinical decision support tool for use at a survivorship visit. Selections in the clinical decision support tool automatically populate a survivorship care plan (SCP). We aimed to refine HN-STAR by eliciting and incorporating feedback on its ease of use and usefulness. Human-computer interaction (HCI) experts reviewed HN-STAR using think-aloud testing and the Nielsen Heuristic Checklist. Nurse practitioners (NPs) thought aloud while reviewing the clinical decision support tool and SCP and responded to an interview. Survivors used HN-STAR as part of a routine visit and were interviewed afterward. We analyzed themes from the feedback. We described how we addressed each theme to improve the usability of HN-STAR. Five HCI experts, 10 NPs, and 10 cancer survivors provided complementary usability insight that we categorized into themes of improvements. For ease of use, themes included technical design considerations to enhance user interface, ease of completion of a self-assessment, streamlining text, disruption of the clinic visit, and threshold for symptoms to appear on the SCP. The theme addressing usefulness was efficiency and comprehensiveness of the clinic visit. For each theme, we report revisions to HN-STAR in response to the feedback. HCI experts provided key technical design insights into HN-STAR, whereas NPs and survivors provided usability feedback and clinical perspectives. We incorporated the feedback into the preparation for additional testing of HN-STAR. This method can inform and improve the ease of use and usefulness of the survivorship applications.

Technology for detecting spectral radiance by a snapshot multi-imaging spectroradiometer

Technologies to determine spectral sky radiance distributions have evolved in recent years and have enabled new applications in remote sensing, for sky radiance measurements, in biological/diagnostic applications and luminance measurements. Most classical spectral imaging radiance technologies are based on mechanical and/or spectral scans. However, these methods require scanning time in which the spectral radiance distribution might change. To overcome this limitation, different so-called snapshot spectral imaging technologies have been developed that enable spectral and spatial non-scanning measurements. We present a new setup based on a facet mirror that is already used in imaging slicing spectrometers. By duplicating the input image instead of slicing it and using a specially designed entrance slit, we are able to select nearly 200 (14 × 14) channels within the field of view (FOV) for detecting spectral radiance in different directions. In addition, a megapixel image of the FOV is captured by an additional RGB camera. This image can be mapped onto the snapshot spectral image. In this paper, the mechanical setup, technical design considerations and first measurement results of a prototype are presented. For a proof of concept, the device is radiometrically calibrated and a 10 mm × 10 mm test pattern measured within a spectral range of 380 nm–800 nm with an optical bandwidth of 10 nm (full width at half maximum or FWHM). To show its potential in the UV spectral region, zenith sky radiance measurements in the UV of a clear sky were performed. Hence, the prototype was equipped with an entrance optic with a FOV of 0.5° and modified to obtain a radiometrically calibrated spectral range of 280 nm–470 nm with a FWHM of 3 nm. The measurement results have been compared to modeled data processed by UVSPEC, which showed deviations of less than 30%. This is far from being ideal, but an acceptable result with respect to available state-of-the-art intercomparisons.

Quality Assessments of Long-Term Quantitative Proteomic Analysis of Breast Cancer Xenograft Tissues.

Clinical proteomics requires large-scale analysis of human specimens to achieve statistical significance. We evaluated the long-term reproducibility of an iTRAQ (isobaric tags for relative and absolute quantification)-based quantitative proteomics strategy using one channel for reference across all samples in different iTRAQ sets. A total of 148 liquid chromatography tandem mass spectrometric (LC-MS/MS) analyses were completed, generating six 2D LC-MS/MS data sets for human-in-mouse breast cancer xenograft tissues representative of basal and luminal subtypes. Such large-scale studies require the implementation of robust metrics to assess the contributions of technical and biological variability in the qualitative and quantitative data. Accordingly, we derived a quantification confidence score based on the quality of each peptide-spectrum match to remove quantification outliers from each analysis. After combining confidence score filtering and statistical analysis, reproducible protein identification and quantitative results were achieved from LC-MS/MS data sets collected over a 7-month period. This study provides the first quality assessment on long-term stability and technical considerations for study design of a large-scale clinical proteomics project.

Real-time monitoring of protein precipitation in a tubular reactor for continuous bioprocessing

Real time monitoring is critical to apply continuous bioprocesses successfully. This requires the integration of flow cells into continuous reactors. Potential continuous steps include protein precipitation, used in plasma purification, antibody enrichment and virus inactivation. Consequently we developed real-time monitoring of protein precipitation in a tubular reactor by pH, conductivity, turbidity and image processing. Feasibility studies were then performed for each monitoring method. Since integrated flow cells can affect time to reach steady state due to its inherent residence time distribution (RTD) property, we first determined flow behavior in flow cell is best described by laminar flow in pipes model, in order to find acceptable levels of volumetric flowrates that is not impractically high. Separately, we found pH highly important for protein precipitation while conductivity has high sensitivity to changes in buffer content. Turbidity signals are lumped values of floc properties while image processing can separately measure flocs by area, size and count. Also, the time and behavior to reach steady state amid changing precipitating conditions was investigated, to select for correct collection times to ensure high product quality. Lastly, we report the technical considerations in reactor design, construction and operation.

The Creation and Evolution of the Transcription Center, Smithsonian Institution's Digital Volunteer Platform

This article discusses the technical design considerations in creating and evolving a digital volunteer platform for transcribing historic documents and collection records. We outline the thought process of our technical team in attempting to architect and build a system that could achieve a mission of collecting knowledge to promote discovery as well as a platform that was extensible, versatile, able to be integrated, and adaptable to future needs. A unique and unexpected aspect of our project is that the digital volunteers not only contributed data but also shaped (and continue to shape) the technical product, user interface, and user experience.

Robotic-assisted real-time MRI-guided TAVR: from system deployment to in vivo experiment in swine model.

Real-time magnetic resonance imaging (rtMRI) guidance provides significant advantages during transcatheter aortic valve replacement (TAVR) as it provides superior real-time visualization and accurate device delivery tracking. However, performing a TAVR within an MRI scanner remains difficult due to a constrained procedural environment. To address these concerns, a magnetic resonance (MR)-compatible robotic system to assist in TAVR deployments was developed. This study evaluates the technical design and interface considerations of an MR-compatible robotic-assisted TAVR system with the purpose of demonstrating that such a system can be developed and executed safely and precisely in a preclinical model. An MR-compatible robotic surgical assistant system was built for TAVR deployment. This system integrates a 5-degrees of freedom (DoF) robotic arm with a 3-DoF robotic valve delivery module. A user interface system was designed for procedural planning and real-time intraoperative manipulation of the robot. The robotic device was constructed of plastic materials, pneumatic actuators, and fiber-optical encoders. The mechanical profile and MR compatibility of the robotic system were evaluated. The system-level error based on a phantom model was 1.14 ± 0.33 mm. A self-expanding prosthesis was successfully deployed in eight Yorkshire swine under rtMRI guidance. Post-deployment imaging and necropsy confirmed placement of the stent within 3 mm of the aortic valve annulus. These phantom and in vivo studies demonstrate the feasibility and advantages of robotic-assisted TAVR under rtMRI guidance. This robotic system increases the precision of valve deployments, diminishes environmental constraints, and improves the overall success of TAVR.