General Usability Research Articles

Usability Evaluation by Nurses of a Knowledge-Based System of Care Plans for People Hospitalized by COVID-19.

The aim of this study is to analyze the usability by nurses of the Knowledge-Based System "Diagnostics care for COVID-19." A convenience sample of 16 nurses was selected, among hospital workers and external experts. The group was divided into three subgroups intentionally to obtain different usability perspectives. Usability was evaluated by the System Usability Scale questionnaire. The participants completed the questionnaire on general usability, data inputs, and information output, after completing a minimum of 12 care plans. The first subgroup used real cases and the "think aloud" technique, the second simulated cases from the same hospital, and the third subgroup performed the external simulation. The highest scores were obtained in data inputs (94.38-97.50); and the lowest, in general usability (90.00-95.00). The subgroup of external experts scored the highest (93.13-95.63), and the first subgroup, which carried out real cases, gave the lowest score (90.00-94.38). The "think aloud" technique found an improvement in including more diagnoses and being able to carry out several plans for one person at the same time. The usability obtained was "excellent" in all subgroups and questionnaires, although the application showed limitations related to its characteristics imposed in the requirements specification.

A Single-Copter UWB-Ranging-Based Localization System Extendable to a Swarm of Drones

This paper presents a single-copter localization system as a first step towards a scalable multihop drone swarm localization system. The drone was equipped with ultrawideband (UWB) transceiver modules, which can be used for communication, as well as distance measurement. The location of the drone was detected based on fixed anchor points using a single type of UWB transceiver. Our aim is to create a swarm localization system that enables drones to switch their role between an active swarm member and an anchor node to enhance the localization of the whole swarm. To this end, this paper presents our current baseline localization system and its performance regarding single-drone localization with fixed anchors and its integration into our current modular quadcopters, which was designed to be easily extendable to a swarm localization system. The distance between each drone and the anchors was measured periodically, and a specially tailored gradient descent algorithm was used to solve the resulting nonlinear optimization problem. Additional copter and wireless-specific adaptations were performed to enhance the robustness. The system was tested with a Vicon system as a position reference and showed a high precision of 0.2 m with an update rate of <10 Hz. Additionally, the system was integrated into the FINken copters of the SwarmLab and evaluated in multiple outdoor scenarios. These scenarios showed the generic usability of the approach, even though no accurate precision measurement was possible.

Variational inference using approximate likelihood under the coalescent with recombination.

Coalescent methods are proven and powerful tools for population genetics, phylogenetics, epidemiology, and other fields. A promising avenue for the analysis of large genomic alignments, which are increasingly common, is coalescent hidden Markov model (coalHMM) methods, but these methods have lacked general usability and flexibility. We introduce a novel method for automatically learning a coalHMM and inferring the posterior distributions of evolutionary parameters using black-box variational inference, with the transition rates between local genealogies derived empirically by simulation. This derivation enables our method to work directly with three or four taxa and through a divide-and-conquer approach with more taxa. Using a simulated data set resembling a human–chimp–gorilla scenario, we show that our method has comparable or better accuracy to previous coalHMM methods. Both species divergence times and population sizes were accurately inferred. The method also infers local genealogies, and we report on their accuracy. Furthermore, we discuss a potential direction for scaling the method to larger data sets through a divide-and-conquer approach. This accuracy means our method is useful now, and by deriving transition rates by simulation, it is flexible enough to enable future implementations of various population models.

MIKADO: a smart city KPIs assessment modeling framework

Smart decision making plays a central role for smart city governance. It exploits data analytics approaches applied to collected data, for supporting smart cities stakeholders in understanding and effectively managing a smart city. Smart governance is performed through the management of key performance indicators (KPIs), reflecting the degree of smartness and sustainability of smart cities. Even though KPIs are gaining relevance, e.g., at European level, the existing tools for their calculation are still limited. They mainly consist in dashboards and online spreadsheets that are rigid, thus making the KPIs evolution and customization a tedious and error-prone process. In this paper, we exploit model-driven engineering (MDE) techniques, through metamodel-based domain-specific languages (DSLs), to build a framework called MIKADO for the automatic assessment of KPIs over smart cities. In particular, the approach provides support for both: (i) domain experts, by the definition of a textual DSL for an intuitive KPIs modeling process and (ii) smart cities stakeholders, by the definition of graphical editors for smart cities modeling. Moreover, dynamic dashboards are generated to support an intuitive visualization and interpretation of the KPIs assessed by our KPIs evaluation engine. We provide evaluation results by showing a demonstration case as well as studying the scalability of the KPIs evaluation engine and the general usability of the approach with encouraging results. Moreover, the approach is open and extensible to further manage comparison among smart cities, simulations, and KPIs interrelations.

A visual brain-computer interface as communication aid for patients with amyotrophic lateral sclerosis

ObjectiveBrain-Computer Interface (BCI) spellers that make use of code-modulated Visual Evoked Potentials (cVEP) may provide a fast and more accurate alternative to existing visual BCI spellers for patients with Amyotrophic Lateral Sclerosis (ALS). However, so far the cVEP speller has only been tested on healthy participants. MethodsWe assess the brain responses, BCI performance and user experience of the cVEP speller in 20 healthy participants and 10 ALS patients. All participants performed a cued and free spelling task, and a free selection of Yes/No answers. Results27 out of 30 participants could perform the cued spelling task with an average accuracy of 79% for ALS patients, 88% for healthy older participants and 94% for healthy young participants. All 30 participants could answer Yes/No questions freely, with an average accuracy of around 90%. ConclusionsWith ALS patients typing on average 10 characters per minute, the cVEP speller presented in this paper outperforms other visual BCI spellers. SignificanceThese results support a general usability of cVEP signals for ALS patients, which may extend far beyond the tested speller to control e.g. an alarm, automatic door, or TV within a smart home.

Conceptualizing Usability for the eHealth Context: Content Analysis of Usability Problems of eHealth Applications.

BackgroundUsability tests can be either formative (where the aim is to detect usability problems) or summative (where the aim is to benchmark usability). There are ample formative methods that consider user characteristics and contexts (ie, cognitive walkthroughs, interviews, and verbal protocols). This is especially valuable for eHealth applications, as health conditions can influence user-system interactions. However, most summative usability tests do not consider eHealth-specific factors that could potentially affect the usability of a system. One of the reasons for this is the lack of fine-grained frameworks or models of usability factors that are unique to the eHealth domain.ObjectiveIn this study, we aim to develop an ontology of usability problems, specifically for eHealth applications, with patients as primary end users.MethodsWe analyzed 8 data sets containing the results of 8 formative usability tests for eHealth applications. These data sets contained 400 usability problems that could be used for analysis. Both inductive and deductive coding were used to create an ontology from 6 data sets, and 2 data sets were used to validate the framework by assessing the intercoder agreement.ResultsWe identified 8 main categories of usability factors, including basic system performance, task-technology fit, accessibility, interface design, navigation and structure, information and terminology, guidance and support, and satisfaction. These 8 categories contained a total of 21 factors: 14 general usability factors and 7 eHealth-specific factors. Cohen κ was calculated for 2 data sets on both the category and factor levels, and all Cohen κ values were between 0.62 and 0.67, which is acceptable. Descriptive analysis revealed that approximately 69.5% (278/400) of the usability problems can be considered as general usability factors and 30.5% (122/400) as eHealth-specific usability factors.ConclusionsOur ontology provides a detailed overview of the usability factors for eHealth applications. Current usability benchmarking instruments include only a subset of the factors that emerged from our study and are therefore not fully suited for summative evaluations of eHealth applications. Our findings support the development of new usability benchmarking tools for the eHealth domain.

Feasibility of a Waistband-Type Wireless Wearable Electrocardiogram Monitoring System Based on a Textile Electrode: Development and Usability Study.

BackgroundElectrocardiogram (ECG) monitoring in daily life is essential for effective management of cardiovascular disease, a leading cause of death. Wearable ECG measurement systems in the form of clothing have been proposed to replace Holter monitors used for clinical ECG monitoring; however, they have limitations in daily use because they compress the upper body and, in doing so, cause discomfort during wear.ObjectiveThe purpose of this study was to develop a wireless wearable ECG monitoring system that includes a textile ECG electrode that can be applied to the lining of pants and can be used in the same way that existing lower clothing is worn, without compression to the upper body.MethodsA textile electrode with stretchable characteristics was fabricated by knitting a conductive yarn together with polyester-polyurethane fiber, which was then coated with silver compound; an ECG electrode was developed by placing it on an elastic band in a modified limb lead configuration. In addition, a system with analog-to-digital conversion, wireless communication, and a smartphone app was developed, allowing users to be able to check and store their own ECGs in real time. A signal processing algorithm was also developed to remove noise from the obtained signal and to calculate the heart rate. To evaluate the ECG and heart rate measurement performance of the developed module, a comparative evaluation with a commercial device was performed. ECGs were measured for 5 minutes each in standing, sitting, and lying positions; the mean absolute percentage errors of heart rates measured with both systems were then compared.ResultsThe system was developed in the form of a belt buckle with a size of 53 × 45 × 12 mm (width × height × depth) and a weight of 23 g. In a qualitative evaluation, it was confirmed that the P-QRS-T waveform was clearly observed in ECGs obtained with the wearable system. From the results of the heart rate estimation, the developed system could track changes in heart rate as calculated by a commercial ECG measuring device; in addition, the mean absolute percentage errors of heart rates were 1.80%, 2.84%, and 2.48% in the standing, sitting, and lying positions, respectively.ConclusionsThe developed system was able to effectively measure ECG and calculate heart rate simply through being worn as existing clothing without upper body pressure. It is anticipated that general usability can be secured through further evaluation under more diverse conditions.

Website usability analysis of United States emergency medicine residencies.

The Council of Residency Directors (CORD) in Emergency Medicine (EM) has recommended that all residency programs should conduct virtual interviews for the 2020 to 2021 application cycle due to the COVID-19 pandemic. While factors such as geographical region, city, program size, or hospital affiliation are not modifiable, EM residencies can bridge the information gap created by a lack of face-to-face interaction by representing themselves digitally. Measuring usability provides an objective method for EM residencies to improve their Web presence and effectively represent themselves to applicants. Our sample set included 55 U.S. EM residency program websites. Using methodology replicated from previous literature on health care website usability, we divided usability into four categories for quantifiable analysis: accessibility, marketing, content quality, and technology. Analysis was performed on each website and scored in all four categories. A "general usability" score was calculated for each website using a composite of the key factors within the four categories. Using a weighted percentage across all of the factors, an overall score was calculated. Content quality was the overall highest scoring category (mean± SD= 5.4, SE= 0.33). The overall lowest performing category was technology (mean± SD= 0.8± 0.09, SE= 0.01). Measuring usability can help EM residency programs identify ways to improve their Web presence. To effectively promote their programs, residencies need quality content that communicates their key features. Our recommendation is for all residency programs to periodically perform website audits and apply the usability measures outlined to improve their digital presence, especially during times when face-to-face interactions will be limited.

Book Review: Don't Make Me Think, Revisited.

Book Review: <i>Don't Make Me Think, Revisited</i>.

REVUB-Light: A parsimonious model to assess power system balancing and flexibility for optimal intermittent renewable energy integration – A study of Suriname

A new model, REVUB-Light, an extended modelling approach for the recently developed “Renewable Energy Variability Upscaling and Balancing” (REVUB) model, is highlighted in this study for its relatively simple and effective parameterization for power balance optimization simulations, considering high Intermittent Renewable Energy integration. We demonstrate the effective use of the REVUB-Light model, considering a study for Suriname. The results for different cases are compared to those of the REVUB model, previously used for similar assessments for Suriname. Following distinct optimization procedures, our results confirm the REVUB model findings, i.e., a highly complementary role for wind energy, with up to 20–30% feed-in potential, based on the assumed (currently most probable) hydrological and wind regimes. The REVUB-Light model is validated based on actual operational data, enabling assessments of the potential real world response, and the benefits of flexible (optimized) operational regimes, underlining its potential for renewable energy modelling. It is further shown that Suriname has potential for (near) 100% renewable energy supply, for the mid-term horizon (2030), if additional hydropower potential is developed in combination with hydro-supported wind energy. Overall, the parsimonious approach of REVUB-Light proves to be a reliable modelling tool, and facilitates general usability by “non-experts” such as policymakers.

Applying Website Rankings to Digital Health Centers in the United States to Assess Public Engagement: Website Usability Study.

BackgroundAs the public increasingly uses the internet to search for resources and information regarding health and medicine, it is important that health care organizations provide adequate web resources. Website usability refers to the ease of user experience on a website. In this study, we conducted usability analyses on digital health center websites.ObjectiveThe primary aims of this study were to (1) replicate a preexisting usability scoring methodology for digital health centers; (2) apply and test this replicated usability scoring methodology on a sample set of digital health center websites; and (3) derive recommendations from the results on potential areas of improvements for our sample of digital health center websites.MethodsWebsite usability testing was conducted from March 1, 2020, to March 15, 2020. We replicated a methodology and scoring system from previous literature and applied them to digital health center websites. Our sample included 67 digital health centers that were affiliated with US universities or hospital systems. Usability was split into the following four broad categories: accessibility, marketing, content quality, and technology. Usability tools were used to score websites in each of the four categories. The composite of the key factors of each category was used to generate a general usability and overall usability score for each website.ResultsThe category with the highest average score (6.3) was content quality. The content quality score also had the highest SD (2.18) and an SE of 0.27. The lowest performing category was technology, which had an average score of 0.9. The technology score also had the smallest SD (0.07) and an SE of 0.01.ConclusionsOur data suggest that content quality, on average, was the highest scoring variable among digital health center websites. As content is crucial to digital health knowledge, it is justified that digital health centers invest more resources into creating quality content. The overall lowest scoring variable was technology. Potential reasons for this finding include designated funding for servers, a lack of regulatory frameworks for social media presence and liability, and infrequent website audits. An easy approach for improving this variable is increasing website speed. Accessibility is another area that organizations can potentially improve. We recommend that these organizations perform periodic audits of their web presence with usability tools.

A methodology for domain and culture-oriented heuristics creation and validation

ABSTRACT Culture fit is an essential consideration while designing websites in this technologically evolving era, yet it is too often ignored in current usability evaluation methods. The heuristic evaluation is one such method, in which, generally, experts use a set of heuristics as a guide. These heuristics are well designed to pinpoint the general usability design faults; however, they limit identifying potential usability problems for specific domains and cultures. This article presents a formal methodology with a sequence of steps of how domain and culture-specific heuristics can be designed. This methodology is validated and applied in the context of websites for universities in Pakistan.

Prototype Development and Usability Evaluation of a Clinical Decision Support Tool for Pharmacogenomic Pharmacy in Practice.

Pharmacogenetics, a subset of precision medicine, provides a way to individualize drug dosages and provide tailored drug therapy to patients. This revolution in prescribing techniques has resulted in a knowledge deficit for many healthcare providers on the proper way to use pharmacogenetics in practice. This research study explored the potential adoption of clinical decision support system mobile apps by clinicians through investigating the initial usability of the PGx prototype application in an effort to address the lack of such tools used in practice. The study method included usage of a clinical decision support system programmed within our pharmacogenomics drug dosage application (called PGx) in a simulated environment. Study participants completed the System Usability Scale survey to report on the perceived usefulness and ease of use of the mobile app. The PGx app has a higher perceived usability than 85% of all products tested, considered very good usability for a product. This general usability rating indicates that the nurse practitioner students find the application to be a clinical decision support system that would be helpful to use in practice.

REStRAIN: Conceptualization of Agile Process Tools Integration with Reference to the Aerospace Industry

This paper describes the development of a framework that integrates engineering software and agile tools based on ontologies and business rules. The aim of this integration is to help project managers specify their own rules of integration between development software and agile tools. This integration circumvents the limitations of on-the-shelf plugins that perform a very basic integration that not only fails to satisfy the complex needs of project managers but also provides insufficient customization possibilities. A formalization of the domain knowledge ontology and its extension are presented. A generic integration algorithm is presented, and some of its performance properties are detailed. To examine the application and validation of the framework, it is deployed for the integration of spacecraft data definition software with issue management systems. This deployment shows how project managers can specify the integration rules that give them the appropriate feedback information at project level after spacecraft data updates. The evaluation of the framework is conducted at two stages. At the time of design, the usability of the framework is evaluated, and it is shown that the general usability criterion is 4.15 on a Likert-type five-point response scale. Additionally, a comparison with on-the-shelf integration plugins shows that less cognitive effort is required from project managers to customize the presented framework integration rules. At run time, the execution time of the presented framework integration algorithm is evaluated. This evaluation shows that even for updates of large data files on the development software, the agile tools are updated following project managers’ integration rules in a reasonable time.

Towards Standardized Acquisition with a Dual-probe Ultrasound Robot for Fetal Imaging.

Standardized acquisitions and diagnoses using robots and AI would potentially increase the general usability and reliability of medical ultrasound. Working towards this prospect, this paper presents the recent developments of a standardized acquisition workflow using a novel dual-probe ultrasound robot, for a project known as intelligent Fetal Imaging and Diagnosis (iFIND). The workflow includes an abdominal surface mapping step to obtain a non-parametric spline surface, a rule-based end-point calculation method to position each individual joint, and a motor synchronization method to achieve a smooth motion towards a target point. The design and implementation of the robot are first presented in this paper and the proposed workflow is then explained in detail with simulation and volunteer experiments performed and analyzed. The closed-form analytical solution to the specific motion planning problem has demonstrated a reliable performance controlling the robot to move towards the expected scanning areas and the calculated proximity of the robot to the surface shows that the robot maintains a safe distance while moving around the abdomen. The volunteer study has successfully demonstrated the reliable working and controllability of the robot in terms of acquiring desired ultrasound views. Our future work will focus on improving the motion planning, and on integrating the proposed standardized acquisition workflow with newly- developed ultrasound image processing methods to obtain diagnostic results in an accurate and consistent way.

Translation and cultural adaptation of IPOS (integrated palliative care outcome scale) in Estonia

BackgroundPatient Reported Outcome Measures (PROMs) are questionnaires that could be used in palliative care (PC) to evaluate patient well-being and monitor their care. PROMs enable a focus on what is important to patients by putting the patient at the center of care. Adapting an existing PROM requires considering cultural differences, general usability and understandability of translated terms.AimTo translate and culturally adapt both the patient and staff three and seven day versions of the Integrated Palliative care Outcome Scale (IPOS) into Estonian. The IPOS consist of 10 questions (staff versions 9 questions) and 17 close ended items. The sub aim is to describe the differences and discrepancies found during the adaptation process and compare the results with previous research.MethodsThe translation and adaptation process of IPOS was conducted using recommended guidelines consisting of six phases and included cognitive interviews with patients (n = 11) and palliative care multidisciplinary team members (n = 8). The study was conducted in two major Estonian hospitals.ResultsThe Estonian IPOS demonstrated face and content validity, acceptance by patients and staff. As a result of expert group review and cognitive interviews with patients and staff, 9 semantic changes were implemented.ConclusionsPatient and staff versions of the IPOS with a recall of 3 or 7 days were translated and culturally adapted for Estonia. The Estonian IPOS four versions are ready for use in Estonia.

MethCORR infers gene expression from DNA methylation and allows molecular analysis of ten common cancer types using fresh-frozen and formalin-fixed paraffin-embedded tumor samples

BackgroundTranscriptional analysis is widely used to study the molecular biology of cancer and hold great biomarker potential for clinical patient stratification. Yet, accurate transcriptional profiling requires RNA of a high quality, which often cannot be retrieved from formalin-fixed, paraffin-embedded (FFPE) tumor tissue that is routinely collected and archived in clinical departments. To overcome this roadblock to clinical testing, we previously developed MethCORR, a method that infers gene expression from DNA methylation data, which is robustly retrieved from FFPE tissue. MethCORR was originally developed for colorectal cancer and with this study, we aim to: (1) extend the MethCORR method to 10 additional cancer types and (2) to illustrate that the inferred gene expression is accurate and clinically informative.ResultsRegression models to infer gene expression information from DNA methylation were developed for ten common cancer types using matched RNA sequencing and DNA methylation profiles (HumanMethylation450 BeadChip) from The Cancer Genome Atlas Project. Robust and accurate gene expression profiles were inferred for all cancer types: on average, the expression of 11,000 genes was modeled with good accuracy and an intra-sample correlation of R2 = 0.90 between inferred and measured gene expression was observed. Molecular pathway analysis and transcriptional subtyping were performed for breast, prostate, and lung cancer samples to illustrate the general usability of the inferred gene expression profiles: overall, a high correlation of r = 0.96 (Pearson) in pathway enrichment scores and a 76% correspondence in molecular subtype calls were observed when using measured and inferred gene expression as input. Finally, inferred expression from FFPE tissue correlated better with RNA sequencing data from matched fresh-frozen tissue than did RNA sequencing data from FFPE tissue (P < 0.0001; Wilcoxon rank-sum test).ConclusionsIn all cancers investigated, MethCORR enabled DNA methylation-based transcriptional analysis, thus enabling future analysis of cancer in situations where high-quality DNA, but not RNA, is available. Here, we provide the framework and resources for MethCORR modeling of ten common cancer types, thereby widely expanding the possibilities for transcriptional studies of archival FFPE material.

Model-Based Approach to Investigate the Influences of Different Load States to the Vehicle Dynamics of Light Electric Vehicles

The need to find alternative urban mobility solutions for delivery and transport has led mobility companies to devote enormous resources for research-based solutions to increase vehicle safety. This paper documents a virtual approach to investigate the influences of different load states to the vehicle dynamic of light electric vehicle. A model basing on a three-dimensional multibody system was used, which consists of five bodies. By applying methods of multibody modelling the generalized equations of motion were generated. To include the behavior within the contact point between road and vehicle a simplified tire models was added. The implementation of the equations allowed a first validation of the model via simulations. In a final modeling step the simulation results were interpreted in respect of plausibility. Afterwards, the model was simulated numerically to investigate different load states of the vehicle, by applying constant steering stimuli and variable velocities. In sum, the investigated model approach is useful to identify safety relevant parameters and shows the effects of load states to the vehicle dynamics. Furthermore, it behaves plausibly regarding general vehicle dynamics. These results prove the general usability of the model for the development controllers and estimators in driver assistances systems.

Suitability Pre-Assessment of in-Sewer Heat Recovery Sites Combining Energy and Wastewater Perspectives

In many countries around the world heating (and cooling) has been and will remain the biggest energy sector, but it is still widely dominated by fossil energy sources today. Wastewater as a source of renewable energy contains large amounts of heat and due to its place-bound localization in urban sewer systems it is usually also situated in very close distance to potential heat consumers. However, one has to keep in mind that heat extraction from wastewater might have undesired impacts on temperature-sensitive treatment processes in the related wastewater treatment plant (WWTP). To assess the potential impact of in-sewer heat recovery on inflow temperature, two different approaches are available today: a simple (but less significant) alligation alternate, or very accurate (but less practical) mathematical models. To close the gap between practicability and significance this article introduces a novel approach to pre-assess the suitability of in-sewer heat recovery sites based on little and easily available data considering energy- and wastewater-related perspectives. A case study application demonstrates the informative value and general usability of the approach. Consequently, the proposed procedure can provide guidance and a template for related investigations at any place in a conventional (combined or separated) sewer system.

Improving existing analysis pipeline to identify and analyze cancer driver genes using multi-omics data

The cumulative of genes carrying mutations is vital for the establishment and development of cancer. However, this driver gene exploring research line has selected and used types of tools and models of analysis unsystematically and discretely. Also, the previous studies may have neglected low-frequency drivers and seldom predicted subgroup specificities of identified driver genes. In this study, we presented an improved driver gene identification and analysis pipeline that comprises the four most widely focused analyses for driver genes: enrichment analysis, clinical feature association with expression profiles of identified driver genes as well as with their functional modules, and patient stratification by existing advanced computational tools integrating multi-omics data. The improved pipeline's general usability was demonstrated straightforwardly for breast cancer, validated by some independent databases. Accordingly, 31 validated driver genes, including four novel ones, were discovered. Subsequently, we detected cancer-related significantly enriched gene ontology terms and pathways, probable drug targets, two co-expressed modules associated significantly with several clinical features, such as number of positive lymph nodes, Nottingham prognostic index, and tumor stage, and two biologically distinct groups of BRCA patients. Data and source code of the case study can be downloaded at https://github.com/hauldhut/drivergene.