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1.
J Telemed Telecare ; : 1357633X241233788, 2024 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-38484299

RESUMO

OBJECTIVE: To evaluate the clinical outcomes of a remote mental health program for managing anxiety and depression, primarily using asynchronous digital communication. METHODS: This retrospective cohort study examined U.S. adults seeking remote care for anxiety and depression from January 2021 to May 2022. The program involves clinician-led assessment, patient education, medication management, and ongoing monitoring, primarily via text. Anxiety and depression were measured using Patient Health Questionnaire (PHQ-9) and Generalized Anxiety Disorder (GAD-7) scores. Outcomes examined were changes in scores, 50% score improvement rate, and remission rate (score <5) at 1, 3, and 6 months. RESULTS: During the period evaluated, 11,844 program participants met the inclusion criteria. Most were female (n = 8328, 70.3%); their age ranged from 18-82 years (median 31 years). At baseline, median PHQ-9 and GAD-7 scores were 13 (IQR 9-17); 67% and 69% met score criteria for depression and anxiety, respectively. Most participants (80%) were prescribed a selective serotonin reuptake inhibitor (SSRI). By one month, average PHQ-9 and GAD-7 scores decreased significantly by 9.2 and 9.1 points (both p < .01). At 1-month follow-up, the 50% score improvement rate was 66% for PHQ-9 and 69% GAD-7 (p < .01). Scores continued to decrease with follow-up. At 3 months, over half achieved remission (percent [95% CI]: 52% [51-54] for anxiety, 53% [52-55] for depression). Similar improvement was observed at 6 months and in sensitivity analyses accounting for loss to follow-up. CONCLUSIONS: Use of a remote mental health program with digital tools was associated with significant clinical improvement in anxiety and depression. Challenges remain in maintaining patient engagement and ensuring appropriate care quality monitoring in digital mental health programs. Additional research comparing remote digital care to traditional in-person models is warranted. Studies should examine long-term outcomes, optimal care protocols, and the challenges to integrating these programs into existing healthcare systems and ensuring equitable access.

2.
J Med Internet Res ; 22(10): e23197, 2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-32961527

RESUMO

BACKGROUND: Patient-facing digital health tools have been promoted to help patients manage concerns related to COVID-19 and to enable remote care and self-care during the COVID-19 pandemic. It has also been suggested that these tools can help further our understanding of the clinical characteristics of this new disease. However, there is limited information on the characteristics and use patterns of these tools in practice. OBJECTIVE: The aims of this study are to describe the characteristics of people who use digital health tools to address COVID-19-related concerns; explore their self-reported symptoms and characterize the association of these symptoms with COVID-19; and characterize the recommendations provided by digital health tools. METHODS: This study used data from three digital health tools on the K Health app: a protocol-based COVID-19 self-assessment, an artificial intelligence (AI)-driven symptom checker, and communication with remote physicians. Deidentified data were extracted on the demographic and clinical characteristics of adults seeking COVID-19-related health information between April 8 and June 20, 2020. Analyses included exploring features associated with COVID-19 positivity and features associated with the choice to communicate with a remote physician. RESULTS: During the period assessed, 71,619 individuals completed the COVID-19 self-assessment, 41,425 also used the AI-driven symptom checker, and 2523 consulted with remote physicians. Individuals who used the COVID-19 self-assessment were predominantly female (51,845/71,619, 72.4%), with a mean age of 34.5 years (SD 13.9). Testing for COVID-19 was reported by 2901 users, of whom 433 (14.9%) reported testing positive. Users who tested positive for COVID-19 were more likely to have reported loss of smell or taste (relative rate [RR] 6.66, 95% CI 5.53-7.94) and other established COVID-19 symptoms as well as ocular symptoms. Users communicating with a remote physician were more likely to have been recommended by the self-assessment to undergo immediate medical evaluation due to the presence of severe symptoms (RR 1.19, 95% CI 1.02-1.32). Most consultations with remote physicians (1940/2523, 76.9%) were resolved without need for referral to an in-person visit or to the emergency department. CONCLUSIONS: Our results suggest that digital health tools can help support remote care and self-management of COVID-19 and that self-reported symptoms from digital interactions can extend our understanding of the symptoms associated with COVID-19.


Assuntos
Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Pneumonia Viral/diagnóstico , Adulto , Inteligência Artificial , Betacoronavirus , COVID-19 , Teste para COVID-19 , Feminino , Humanos , Masculino , Pandemias , Encaminhamento e Consulta , Estudos Retrospectivos , SARS-CoV-2 , Autorrelato
3.
World J Surg ; 44(3): 764-772, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-31712843

RESUMO

INTRODUCTION: Early physiological assessment of multiple injured patients is crucial for decision making and has relied on personal experience of trauma experts. We have developed a new visual analytics tool (Sankey diagram, Watson Trauma Health care tool) that includes known prognostic parameters for polytrauma patients to help guide assessment and treatment decisions for physicians involved in trauma care. METHODS: A prospectively collected trauma database of a single level I trauma center (3655 patients) was used. INCLUSION CRITERIA: age >16 years, an injury severity score (ISS) >16 and presence of a complete data set in the database. Data collected included admission values of patient age, injury scoring, shock classification, temperature, acid-base and hemostasis parameters. All of these parameters were collected daily as longitudinal parameters. Endpoints of the clinical course we considered were sepsis, SIRS and early in hospital mortality (<72 h). A proof of concept of the visualization was developed over a 2-year period in a cooperation between physicians and engineers. Statistically, the most predictive parameters were selected by binary logistic regression and ROC analysis. RESULTS: A dynamic interactive multilayer Sankey diagram, based on cohort similarities, was developed in a collaboration between the University Hospital of Zurich, Department of Trauma and IBM, from August 2017 until January 2018. It is a modular tool and allows any user to add a new patient, or work with an existing case. The visualization used the data-driven documents (D3) interactive visualization library to create a responsive graphic. CONCLUSIONS: This application summarizes the experience of 3655 polytrauma patients and might serve as a guide for clinical decisions and educative purposes, as well as new scientific questions for the polytrauma patient. LEVEL OF EVIDENCE: IV.


Assuntos
Bases de Dados Factuais , Traumatismo Múltiplo/fisiopatologia , Adolescente , Adulto , Idoso , Tomada de Decisão Clínica , Feminino , Humanos , Escala de Gravidade do Ferimento , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Adulto Jovem
4.
Ugeskr Laeger ; 180(41)2018 Oct 08.
Artigo em Dinamarquês | MEDLINE | ID: mdl-30327082

RESUMO

Persistent left-sided superior vena cava (PLSVC) is a central venous anomaly in up to 0.5% of the population. It is usually asymptomatic due to drainage into the right atrium via the coronary sinus. This case report describes placement of a dialysis catheter in a 55-year-old patient with PLSVC and subsequent complications following the uncertainty of the placement. In 10%, PLSVC drains to the left atrium inducing risk of left-to-right shunt and fatal paradoxical emboli in case of catheterisation. Hence, clarification of the central venous haemodynamics by relevant imaging modalities is advised, if suspicion arises.


Assuntos
Cateterismo Venoso Central/métodos , Diálise Renal/métodos , Malformações Vasculares/cirurgia , Veia Cava Superior/anormalidades , Cateterismo Venoso Central/efeitos adversos , Humanos , Pessoa de Meia-Idade , Malformações Vasculares/diagnóstico por imagem , Veia Cava Superior/diagnóstico por imagem
5.
J Forensic Sci ; 63(1): 299-304, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28464277

RESUMO

Immersion Pulmonary Edema (IPE) reduces the transport of gases over the respiratory membrane due to edema in the interstitium and respiratory zones. IPE has previously been described in both swimmers and divers, with a few known fatal cases. We have reviewed 42 SCUBA and snorkeling-related drowning deaths, and through a thorough analysis of each case, including both diving physiology and forensic pathology, we present IPE as a differential diagnosis to drowning in four cases. Our findings propose that; absence of watery content in the stomach and conducting airways, and liquid filled lungs without hyperexpansion, may be compatible with IPE. We suggest that IPE should be considered in cases where witness testimony reveals; no obvious signs of aspiration and rapid respiratory deterioration despite continuous breathing through an appropriate air source. The diagnosis should be based on the overall impression, including both the autopsy findings and the circumstances regarding the accident.


Assuntos
Mergulho , Edema Pulmonar/diagnóstico , Adulto , Diagnóstico Diferencial , Afogamento/diagnóstico , Feminino , Patologia Legal , Humanos , Pulmão/patologia , Masculino , Pessoa de Meia-Idade , Sistema Respiratório/patologia , Estômago/patologia
6.
Congenit Heart Dis ; 13(2): 263-270, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29280293

RESUMO

OBJECTIVE: Cyanotic congenital heart disease is a systemic disease, with effects on multiple organ systems. A high prevalence of subclinical hypothyroidism (SCH) has been reported in a small cohort of cyanotic congenital heart disease patients. Subclinical hypothyroidism has been associated with various adverse cardiovascular effects, as well as an increased risk of progression to overt hypothyroidism. The aim of this study was to examine the prevalence of SCH in cyanotic congenital heart disease patients, consider possible etiologies, and evaluate thyroid function over time. METHODS: First, 90 clinically stable cyanotic congenital heart disease patients were examined with blood samples (thyroid-stimulating hormone, C-reactive protein, hemoglobin, hematocrit, and N-terminal pro-brain-natriuretic peptide) in a cross-sectional descriptive study. Second, a longitudinal follow-up study of 43 patients originating from the first study part, was carried out. These patients had thyroid function parameters (thyroid-stimulating hormone, thyroid hormones, and thyroid peroxidase antibodies) evaluated biannually. RESULTS: Elevated thyroid-stimulating hormone was present in 24% of the 90 screened patients. During follow-up (6.5 ± 1.0 years), SCH (defined as ≥2 consecutive elevated thyroid-stimulating hormone values) was present in 26%. Three patients progressed to overt hypothyroidism. Patients with SCH were younger (34 ± 12 vs 42 ± 16 years; P = .01) and had a lower oxygen saturation (80 ± 5 vs 84 ± 6%; P = .03). CONCLUSION: Subclinical hypothyroidism is a very common finding in cyanotic congenital heart disease. This is not associated with increased levels of C-reactive protein, heart failure, or autoimmunity but appears to be associated with cyanosis and age. Since the clinical impact of SCH is uncertain, further studies are needed to determine this. Regular thyroid evaluation is recommended in cyanotic congenital heart disease patients since SCH can develop to overt hypothyroidism.


Assuntos
Cardiopatias Congênitas/complicações , Hipotireoidismo/epidemiologia , Hipóxia/complicações , Hormônios Tireóideos/sangue , Adulto , Biomarcadores/sangue , Estudos Transversais , Dinamarca/epidemiologia , Progressão da Doença , Feminino , Seguimentos , Cardiopatias Congênitas/sangue , Humanos , Hipotireoidismo/sangue , Hipotireoidismo/etiologia , Hipóxia/sangue , Estudos Longitudinais , Masculino , Prevalência , Prognóstico , Estudos Retrospectivos
7.
Stud Health Technol Inform ; 245: 332-336, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-29295110

RESUMO

Epidemiological models are key tools in assessing intervention policies for population health management. Statistical models, fitted with survey or health system data, can be combined with lab and field studies to provide reliable predictions of future population-level disease dynamics distributions and the effects of interventions. All too often, however, the end result of epidemiological modeling and cost-effectiveness studies is in the form of a report or journal paper. These are inherently limited in their coverage of locations, policy options, and derived outcome measures. Here, we describe a tool to support population health policy planning. The tool allows users to explore simulations of various policies, to view and compare interventions spanning multiple variables, time points, and locations. The design's modular architecture, and data representation separate the modeling methods, the outcome measures calculations, and the visualizations, making each component easily replaceable. These advantages make it extremely versatile and suitable for multiple uses.


Assuntos
Política de Saúde , Modelos Estatísticos , Política Pública , Análise Custo-Benefício , Humanos , Saúde da População
8.
Diving Hyperb Med ; 46(3): 142-149, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-27723014

RESUMO

AIM: The purpose was to explore causative tendencies among diving fatalities to prevent similar injuries in the future. METHODS: We report 33 fatal diving injuries that occurred among Danish divers during the period 1999-2012 in Scandinavian waters. The study was performed as a retrospective overview. The empiric data consists of police reports, forensic autopsy reports and examination of the diving equipment. Data were assembled and analyzed using Pivot and Excel. Frequencies and means (± SD) were used to describe categorical and continuous variables respectively. RESULTS: The mean age was 38.9 years and drowning was considered the cause of death in 24 of 28 divers for whom a diagnosis was possible. Elevated body mass index (18 of 22 divers had a BMI 〉 25) was overrepresented in our group compared to the background population. A drysuit was worn by 17 divers. Diving independently of a dive centre and mishandling of buoyancy aids were common risk factors. Only two divers released their weights. Three-quarters of those who did not would have increased their chance of survival by doing so; nevertheless, in a quarter of cases the weights were not readily releasable or not releasable at all. CONCLUSION: Unfamiliarity with drysuit diving, lack of a diving buddy and mismanagement of weights were important contributors to diving injuries.


Assuntos
Causas de Morte , Mergulho/estatística & dados numéricos , Adulto , Índice de Massa Corporal , Certificação , Dinamarca/epidemiologia , Mergulho/lesões , Mergulho/psicologia , Afogamento/etiologia , Afogamento/mortalidade , Análise de Falha de Equipamento/estatística & dados numéricos , Feminino , Primeiros Socorros , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Pânico , Aptidão Física , Estudos Retrospectivos , Fatores de Risco , Estações do Ano , Distribuição por Sexo , Adulto Jovem
9.
J Med Imaging (Bellingham) ; 3(2): 026501, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27340682

RESUMO

The evolution of cloud computing is driving the next generation of medical imaging systems. However, privacy and security concerns have been consistently regarded as the major obstacles for adoption of cloud computing by healthcare domains. OpenID Connect, combining OpenID and OAuth together, is an emerging representational state transfer-based federated identity solution. It is one of the most adopted open standards to potentially become the de facto standard for securing cloud computing and mobile applications, which is also regarded as "Kerberos of cloud." We introduce OpenID Connect as an authentication and authorization service in cloud-based diagnostic imaging (DI) systems, and propose enhancements that allow for incorporating this technology within distributed enterprise environments. The objective of this study is to offer solutions for secure sharing of medical images among diagnostic imaging repository (DI-r) and heterogeneous picture archiving and communication systems (PACS) as well as Web-based and mobile clients in the cloud ecosystem. The main objective is to use OpenID Connect open-source single sign-on and authorization service and in a user-centric manner, while deploying DI-r and PACS to private or community clouds should provide equivalent security levels to traditional computing model.

10.
IEEE Trans Vis Comput Graph ; 22(1): 569-78, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26529525

RESUMO

A composite indicator (CI) is a measuring and benchmark tool used to capture multi-dimensional concepts, such as Information and Communication Technology (ICT) usage. Individual indicators are selected and combined to reflect a phenomena being measured. Visualization of a composite indicator is recommended as a tool to enable interested stakeholders, as well as the public audience, to better understand the indicator components and evolution over time. However, existing CI visualizations introduce a variety of solutions and there is a lack in CI's visualization guidelines. Radial visualizations are popular among these solutions because of CI's inherent multi-dimensionality. Although in dispute, Radar-charts are often used for CI presentation. However, no empirical evidence on Radar's effectiveness and efficiency for common CI tasks is available. In this paper, we aim to fill this gap by reporting on a controlled experiment that compares the Radar chart technique with two other radial visualization methods: Flower-charts as used in the well-known OECD Betterlife index, and Circle-charts which could be adopted for this purpose. Examples of these charts in the current context are shown in Figure 1. We evaluated these charts, showing the same data with each of the mentioned techniques applying small multiple views for different dimensions of the data. We compared users' performance and preference empirically under a formal task-taxonomy. Results indicate that the Radar chart was the least effective and least liked, while performance of the two other options were mixed and dependent on the task. Results also showed strong preference of participants toward the Flower chart. Summarizing our results, we provide specific design guidelines for composite indicator visualization. Fig. 1: Three radial solutions for composite indicator visualizations compared empirically for users' performance and preferences.

11.
J Med Imaging (Bellingham) ; 2(4): 046501, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26835497

RESUMO

IHE XDS-I profile proposes an architecture model for cross-enterprise medical image sharing, but there are only a few clinical implementations reported. Here, we investigate three pilot studies based on the IHE XDS-I profile to see whether we can use this architecture as a foundation for image sharing solutions in a variety of health-care settings. The first pilot study was image sharing for cross-enterprise health care with federated integration, which was implemented in Huadong Hospital and Shanghai Sixth People's Hospital within the Shanghai Shen-Kang Hospital Management Center; the second pilot study was XDS-I-based patient-controlled image sharing solution, which was implemented by the Radiological Society of North America (RSNA) team in the USA; and the third pilot study was collaborative imaging diagnosis with electronic health-care record integration in regional health care, which was implemented in two districts in Shanghai. In order to support these pilot studies, we designed and developed new image access methods, components, and data models such as RAD-69/WADO hybrid image retrieval, RSNA clearinghouse, and extension of metadata definitions in both the submission set and the cross-enterprise document sharing (XDS) registry. We identified several key issues that impact the implementation of XDS-I in practical applications, and conclude that the IHE XDS-I profile is a theoretically good architecture and a useful foundation for medical image sharing solutions across multiple regional health-care providers.

12.
IEEE Trans Vis Comput Graph ; 19(12): 2179-88, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24051784

RESUMO

We propose a novel approach of distance-based spatial clustering and contribute a heuristic computation of input parameters for guiding users in the search of interesting cluster constellations. We thereby combine computational geometry with interactive visualization into one coherent framework. Our approach entails displaying the results of the heuristics to users, as shown in Figure 1, providing a setting from which to start the exploration and data analysis. Addition interaction capabilities are available containing visual feedback for exploring further clustering options and is able to cope with noise in the data. We evaluate, and show the benefits of our approach on a sophisticated artificial dataset and demonstrate its usefulness on real-world data.


Assuntos
Algoritmos , Gráficos por Computador , Interpretação de Imagem Assistida por Computador/métodos , Reconhecimento Automatizado de Padrão/métodos , Interface Usuário-Computador , Simulação por Computador , Modelos Teóricos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
13.
J Digit Imaging ; 26(3): 440-6, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23179406

RESUMO

In June 2008, the Canadian Association of Radiologists published its Standards for Irreversible Compression in Digital Diagnostic Imaging within Radiology (Canadian Association of Radiologists 2012). The study suggested that at low levels of compression there was no difference in diagnostic accuracy between uncompressed JPEG and JPEG 2000. There were two exceptions; CT neurological and CT body images resulted in lower rating of image quality (Koff et al., J Digit Imaging 22(6):569-78, 2009). The slice thicknesses used in the previous study were greater than 5 mm. However, other studies (Ringl et al., Radiology 240:869-87, 2006) suggest that thin CT slices might modify image tolerance to irreversible compression. Therefore, a new clinical evaluation using CT slices less than 3 mm was initiated. We examined CT images in four body regions (chest, body, musculoskeletal, and neurological). Twenty-five radiologists from across Canada participated. Each read a total of 70 CTs in his specialty; 10 at each of seven levels of compression (uncompressed, JPEG and JPEG 2000 at low, medium, and high compression (varying by region)). Each reader diagnosed the case, rated his confidence, and compared the compressed to the uncompressed image and rated the degree of degradation. Data were analyzed for sensitivity, specificity, accuracy, confidence, and degradation at three levels and two types of compression as well as the original image. There were no overall differences in sensitivity, specificity, accuracy, or confidence. JPEG images, at all levels of compression, were rated lower in terms of perceived difference (4.16/5 vs. 4.53/5 for JPEG 2000 and 4.68/5 for uncompressed). However, the rating of perceived difference was not significantly correlated with accuracy. Analysis of individual body regions did not reveal any systematic effects of compression in any region.


Assuntos
Compressão de Dados/métodos , Guias de Prática Clínica como Assunto , Interpretação de Imagem Radiográfica Assistida por Computador/métodos , Tomografia Computadorizada por Raios X/métodos , Canadá , Humanos , Sensibilidade e Especificidade
14.
Biomaterials ; 33(23): 5776-87, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22594972

RESUMO

Regulating molecular interactions in the T-cell synapse to prevent autoimmunity or, conversely, to boost anti-tumor immunity has long been a goal in immunotherapy. However, delivering therapeutically meaningful doses of immune-modulating compounds into the synapse represents a major challenge. Here, we report that covalent coupling of maleimide-functionlized nanoparticles (NPs) to free thiol groups on T-cell membrane proteins enables efficient delivery of compounds into the T-cell synapse. We demonstrate that surface-linked NPs are rapidly polarized toward the nascent immunological synapse (IS) at the T-cell/APC contact zone during antigen recognition. To translate these findings into a therapeutic application we tested the NP delivery of NSC-87877, a dual inhibitor of Shp1 and Shp2, key phosphatases that downregulate T-cell receptor activation in the synapse, in the context of adoptive T cell therapy of cancer. Conjugating NSC-87877-loaded NPs to the surface of tumor-specific T cells just prior to adoptive transfer into mice with advanced prostate cancer promoted a much greater T-cell expansion at the tumor site, relative to co-infusing the same drug dose systemically, leading to enhanced survival of treated animals. In summary, our studies support the application of T-cell-linked synthetic NPs as efficient drug delivery vehicles into the IS, as well as the broad applicability of this new paradigm for therapeutically modulating signaling events at the T-cell/APC interface.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Fatores Imunológicos/administração & dosagem , Sinapses Imunológicas/metabolismo , Nanopartículas/química , Linfócitos T/citologia , Animais , Células Cultivadas , Fatores Imunológicos/uso terapêutico , Imunoterapia , Masculino , Maleimidas/química , Espectrometria de Massas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Próstata/patologia , Neoplasias da Próstata/terapia , Compostos de Sulfidrila/química
15.
IEEE Trans Vis Comput Graph ; 17(5): 584-97, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21041874

RESUMO

Visual exploration of multivariate data typically requires projection onto lower dimensional representations. The number of possible representations grows rapidly with the number of dimensions, and manual exploration quickly becomes ineffective or even unfeasible. This paper proposes automatic analysis methods to extract potentially relevant visual structures from a set of candidate visualizations. Based on features, the visualizations are ranked in accordance with a specified user task. The user is provided with a manageable number of potentially useful candidate visualizations, which can be used as a starting point for interactive data analysis. This can effectively ease the task of finding truly useful visualizations and potentially speed up the data exploration task. In this paper, we present ranking measures for class-based as well as non-class-based scatterplots and parallel coordinates visualizations. The proposed analysis methods are evaluated on different data sets.

17.
J Exp Psychol Appl ; 16(1): 1-15, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20350040

RESUMO

The output of binary cuing systems, such as alerts or alarms, depends on the threshold setting-a parameter that is often user-adjustable. However, it is unknown if users are able to adequately adjust thresholds and what information may help them to do so. Two experiments tested threshold settings for a binary classification task based on binary cues. During the task, participants decided whether a product was intact or faulty. Experimental conditions differed in the information participants received: all participants were informed about a product's fault probability and the payoffs associated with decision outcomes; one third also received information regarding conditional probabilities for a fault when the system indicated or did not indicate the existence of one (predictive values); and another third received information about conditional probabilities for the system indicating a fault, in the instance of the existence or lack thereof, of an actual fault (diagnostic values). Threshold settings in all experimental groups were nonoptimal, with settings closest to the optimum with predictive-values information. Results corresponded with a model describing threshold settings as a function of the conditional probabilities for the different outcomes. From a practical perspective, results indicate that predictive-values information best supports decisions about threshold settings. Consequently, for users to adjust thresholds, they should receive information about predictive-values, provided that such values can be computed.


Assuntos
Tomada de Decisões , Psicologia Experimental/métodos , Psicologia Experimental/estatística & dados numéricos , Sinais (Psicologia) , Humanos , Teoria Psicológica , Detecção de Sinal Psicológico
18.
IEEE Trans Vis Comput Graph ; 15(6): 913-20, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19834154

RESUMO

Spatiotemporal analysis of sensor logs is a challenging research field due to three facts: a) traditional two-dimensional maps do not support multiple events to occur at the same spatial location, b) three-dimensional solutions introduce ambiguity and are hard to navigate, and c) map distortions to solve the overlap problem are unfamiliar to most users. This paper introduces a novel approach to represent spatial data changing over time by plotting a number of non-overlapping pixels, close to the sensor positions in a map. Thereby, we encode the amount of time that a subject spent at a particular sensor to the number of plotted pixels. Color is used in a twofold manner; while distinct colors distinguish between sensor nodes in different regions, the colors' intensity is used as an indicator to the temporal property of the subjects' activity. The resulting visualization technique, called Growth Ring Maps, enables users to find similarities and extract patterns of interest in spatiotemporal data by using humans' perceptual abilities. We demonstrate the newly introduced technique on a dataset that shows the behavior of healthy and Alzheimer transgenic, male and female mice. We motivate the new technique by showing that the temporal analysis based on hierarchical clustering and the spatial analysis based on transition matrices only reveal limited results. Results and findings are cross-validated using multidimensional scaling. While the focus of this paper is to apply our visualization for monitoring animal behavior, the technique is also applicable for analyzing data, such as packet tracing, geographic monitoring of sales development, or mobile phone capacity planning.


Assuntos
Comportamento Animal/fisiologia , Análise por Conglomerados , Biologia Computacional/métodos , Gráficos por Computador , Comportamento Espacial/fisiologia , Doença de Alzheimer , Animais , Animais Geneticamente Modificados , Modelos Animais de Doenças , Feminino , Masculino , Camundongos , Fatores de Tempo
19.
J Digit Imaging ; 22(6): 569-78, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18931879

RESUMO

New technological advancements including multislice CT scanners and functional MRI, have dramatically increased the size and number of digital images generated by medical imaging departments. Despite the fact that the cost of storage is dropping, the savings are largely surpassed by the increasing volume of data being generated. While local area network bandwidth within a hospital is adequate for timely access to imaging data, efficiently moving the data between institutions requires wide area network bandwidth, which has a limited availability at a national level. A solution to address those issues is the use of lossy compression as long as there is no loss of relevant information. The goal of this study was to determine levels at which lossy compression can be confidently used in diagnostic imaging applications. In order to provide a fair assessment of existing compression tools, we tested and compared the two most commonly adopted DISCOM compression algorithms: JPEG and JPEG-2000. We conducted an extensive pan-Canadian evaluation of lossy compression applied to seven anatomical areas and five modalities using two recognized techniques: objective methods or diagnostic accuracy and subjective assessment based on Just Noticeable Difference. By incorporating both diagnostic accuracy and subjective evaluation techniques, enabled us to define a range of compression for each modality and body part tested. The results of our study suggest that at low levels of compression, there was no significant difference between the performance of lossy JPEG and lossy JPEG 2000, and that they are both appropriate to use for reporting on medical images. At higher levels, lossy JPEG proved to be more effective than JPEG 2000 in some cases, mainly neuro CT. More evaluation is required to assess the effect of compression on thin slice CT. We provide a table of recommended compression ratios for each modality and anatomical area investigated, to be integrated in the Canadian Association of Radiologists standard for the use of lossy compression in medical imaging.


Assuntos
Diagnóstico por Imagem/instrumentação , Diagnóstico por Imagem/normas , Processamento de Imagem Assistida por Computador/normas , Guias de Prática Clínica como Assunto , Processamento de Sinais Assistido por Computador/instrumentação , Algoritmos , Análise de Variância , Artefatos , Canadá , Feminino , Humanos , Angiografia por Ressonância Magnética/normas , Imageamento por Ressonância Magnética/normas , Masculino , Probabilidade , Controle de Qualidade , Curva ROC , Tomografia Computadorizada por Raios X/normas , Ultrassonografia Doppler/normas
20.
Radiographics ; 28(7): 1817-33, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18772272

RESUMO

The sharing of radiologic images has become a fundamental part of radiology services and is essential for delivering high-quality care. Film is quickly becoming obsolete as a means of transporting and sharing large volumes of imaging data. Image sharing has evolved from film to transportable media (eg, compact disks) to direct electronic exchange over the Internet. The latter two means of image sharing have associated work flow-related and technical challenges for which solutions are being developed. Integrating the Healthcare Enterprise (IHE) provides a standards-based approach to the development of robust, universally accepted solutions. Several IHE profiles have been developed to provide a framework for current image sharing efforts. The Philadelphia and New Jersey Health Information Exchanges and the Canada Health Infoway represent efforts to apply IHE technical profiles to facilitate the secure and confidential exchange of electronic images over the Internet. The research community is concomitantly developing solutions that solve image exchange issues that are specific to research (eg, the sharing of deidentified data) but that might also be encountered in the general population. The personal health record is a more recent development that may provide consumers with direct control over the process of sharing images electronically with their healthcare providers.


Assuntos
Disseminação de Informação/métodos , Informática Médica/métodos , Informática Médica/organização & administração , Sistemas de Informação em Radiologia/tendências , Radiologia/organização & administração , Canadá , Estados Unidos
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