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1.
J Pathol ; 261(1): 71-84, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37550801

RESUMO

Aberrant glycosylation is a universal feature of cancer cells, and cancer-associated glycans have been detected in virtually every cancer type. A common change in tumour cell glycosylation is an increase in α2,6 sialylation of N-glycans, a modification driven by the sialyltransferase ST6GAL1. ST6GAL1 is overexpressed in numerous cancer types, and sialylated glycans are fundamental for tumour growth, metastasis, immune evasion, and drug resistance, but the role of ST6GAL1 in prostate cancer is poorly understood. Here, we analyse matched cancer and normal tissue samples from 200 patients and verify that ST6GAL1 is upregulated in prostate cancer tissue. Using MALDI imaging mass spectrometry (MALDI-IMS), we identify larger branched α2,6 sialylated N-glycans that show specificity to prostate tumour tissue. We also monitored ST6GAL1 in plasma samples from >400 patients and reveal ST6GAL1 levels are significantly increased in the blood of men with prostate cancer. Using both in vitro and in vivo studies, we demonstrate that ST6GAL1 promotes prostate tumour growth and invasion. Our findings show ST6GAL1 introduces α2,6 sialylated N-glycans on prostate cancer cells and raise the possibility that prostate cancer cells can secrete active ST6GAL1 enzyme capable of remodelling glycans on the surface of other cells. Furthermore, we find α2,6 sialylated N-glycans expressed by prostate cancer cells can be targeted using the sialyltransferase inhibitor P-3FAX -Neu5Ac. Our study identifies an important role for ST6GAL1 and α2,6 sialylated N-glycans in prostate cancer progression and highlights the opportunity to inhibit abnormal sialylation for the development of new prostate cancer therapeutics. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.


Assuntos
Neoplasias da Próstata , Sialiltransferases , Masculino , Humanos , Glicosilação , Polissacarídeos/química , Polissacarídeos/metabolismo , Reino Unido , beta-D-Galactosídeo alfa 2-6-Sialiltransferase , Antígenos CD/metabolismo
2.
Sensors (Basel) ; 23(21)2023 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-37960361

RESUMO

Sensor Data Fusion (SDT) algorithms and models have been widely used in diverse applications. One of the main challenges of SDT includes how to deal with heterogeneous and complex datasets with different formats. The present work utilised both homogenous and heterogeneous datasets to propose a novel SDT framework. It compares data mining-based fusion software packages such as RapidMiner Studio, Anaconda, Weka, and Orange, and proposes a data fusion framework suitable for in-home applications. A total of 574 privacy-friendly (binary) images and 1722 datasets gleaned from thermal and Radar sensing solutions, respectively, were fused using the software packages on instances of homogeneous and heterogeneous data aggregation. Experimental results indicated that the proposed fusion framework achieved an average Classification Accuracy of 84.7% and 95.7% on homogeneous and heterogeneous datasets, respectively, with the help of data mining and machine learning models such as Naïve Bayes, Decision Tree, Neural Network, Random Forest, Stochastic Gradient Descent, Support Vector Machine, and CN2 Induction. Further evaluation of the Sensor Data Fusion framework based on cross-validation of features indicated average values of 94.4% for Classification Accuracy, 95.7% for Precision, and 96.4% for Recall. The novelty of the proposed framework includes cost and timesaving advantages for data labelling and preparation, and feature extraction.

3.
Sensors (Basel) ; 18(7)2018 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-29987218

RESUMO

Data annotation is a time-consuming process posing major limitations to the development of Human Activity Recognition (HAR) systems. The availability of a large amount of labeled data is required for supervised Machine Learning (ML) approaches, especially in the case of online and personalized approaches requiring user specific datasets to be labeled. The availability of such datasets has the potential to help address common problems of smartphone-based HAR, such as inter-person variability. In this work, we present (i) an automatic labeling method facilitating the collection of labeled datasets in free-living conditions using the smartphone, and (ii) we investigate the robustness of common supervised classification approaches under instances of noisy data. We evaluated the results with a dataset consisting of 38 days of manually labeled data collected in free living. The comparison between the manually and the automatically labeled ground truth demonstrated that it was possible to obtain labels automatically with an 80⁻85% average precision rate. Results obtained also show how a supervised approach trained using automatically generated labels achieved an 84% f-score (using Neural Networks and Random Forests); however, results also demonstrated how the presence of label noise could lower the f-score up to 64⁻74% depending on the classification approach (Nearest Centroid and Multi-Class Support Vector Machine).


Assuntos
Automação/métodos , Atividades Humanas , Redes Neurais de Computação , Smartphone , Aprendizado de Máquina Supervisionado , Aceleração , Humanos , Máquina de Vetores de Suporte
4.
Int J Gynecol Pathol ; 32(1): 141-5, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23202781

RESUMO

Serous carcinomas most commonly arise within the uterine corpus or ovary/fallopian tube, but there are 2 prior case reports of primary vaginal serous carcinoma. We report 2 examples of high-grade serous carcinoma arising within the urethra or a urethral diverticulum (1 case each). Both neoplasms exhibited the classic morphologic features of high-grade serous carcinoma, and a combination of clinical, radiologic, and pathologic examination excluded other possible sites of primary neoplasm.


Assuntos
Cistadenocarcinoma Seroso/patologia , Neoplasias Uretrais/patologia , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Gradação de Tumores
5.
Oncogene ; 42(12): 926-937, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36725887

RESUMO

Prostate cancer is the most common cancer in men and it is estimated that over 350,000 men worldwide die of prostate cancer every year. There remains an unmet clinical need to improve how clinically significant prostate cancer is diagnosed and develop new treatments for advanced disease. Aberrant glycosylation is a hallmark of cancer implicated in tumour growth, metastasis, and immune evasion. One of the key drivers of aberrant glycosylation is the dysregulated expression of glycosylation enzymes within the cancer cell. Here, we demonstrate using multiple independent clinical cohorts that the glycosyltransferase enzyme GALNT7 is upregulated in prostate cancer tissue. We show GALNT7 can identify men with prostate cancer, using urine and blood samples, with improved diagnostic accuracy than serum PSA alone. We also show that GALNT7 levels remain high in progression to castrate-resistant disease, and using in vitro and in vivo models, reveal that GALNT7 promotes prostate tumour growth. Mechanistically, GALNT7 can modify O-glycosylation in prostate cancer cells and correlates with cell cycle and immune signalling pathways. Our study provides a new biomarker to aid the diagnosis of clinically significant disease and cements GALNT7-mediated O-glycosylation as an important driver of prostate cancer progression.


Assuntos
Neoplasias da Próstata , Masculino , Humanos , Regulação para Cima , Glicosilação , Neoplasias da Próstata/metabolismo , Transdução de Sinais , Ativação Transcricional
6.
Front Oncol ; 12: 914078, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36033512

RESUMO

Prostate cancer (PCa) is the second most common male cancer worldwide, but effective biomarkers for the presence or progression risk of disease are currently elusive. In a series of nine matched histologically confirmed PCa and benign samples, we carried out an integrated transcriptome-wide gene expression analysis, including differential gene expression analysis and weighted gene co-expression network analysis (WGCNA), which identified a set of potential gene markers highly associated with tumour status (malignant vs. benign). We then used these genes to establish a minimal progression-free survival (PFS)-associated gene signature (GS) (PCBP1, PABPN1, PTPRF, DANCR, and MYC) using least absolute shrinkage and selection operator (LASSO) and stepwise multivariate Cox regression analyses from The Cancer Genome Atlas prostate adenocarcinoma (TCGA-PRAD) dataset. Our signature was able to predict PFS over 1, 3, and 5 years in TCGA-PRAD dataset, with area under the curve (AUC) of 0.64-0.78, and our signature remained as a prognostic factor independent of age, Gleason score, and pathological T and N stages. A nomogram combining the signature and Gleason score demonstrated improved predictive capability for PFS (AUC: 0.71-0.85) and was superior to the Cambridge Prognostic Group (CPG) model alone and some conventionally used clinicopathological factors in predicting PFS. In conclusion, we have identified and validated a novel five-gene signature and established a nomogram that effectively predicted PFS in patients with PCa. Findings may improve current prognosis tools for PFS and contribute to clinical decision-making in PCa treatment.

7.
Telemed J E Health ; 17(3): 211-6, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21375412

RESUMO

OBJECTIVE: Adapting therapeutic practice from traditional face-to-face exchange to remote technology-based delivery presents challenges for the therapist, patient, and technical writer. This article documents the process of therapy adaptation and the resultant specification for the SMART2 project-a technology-based self-management system for assisting long-term health conditions, including chronic pain. MATERIALS AND METHODS: Focus group discussions with healthcare professionals and patients were conducted to inform selection of therapeutic objectives and appropriate technology. RESULTS: Pertinent challenges are identified, relating to (1) reduction and definition of therapeutic objectives, and (2) how to approach adaptation of therapy to a form suited to technology delivery. The requirement of the system to provide dynamic and intelligent responses to patient experience and behavior is also emphasized. CONCLUSION: Solutions to these challenges are described in the context of the SMART2 technology-based intervention. More explicit discussion and documentation of therapy adaptation to technology-based delivery within the literature is encouraged.


Assuntos
Terapia Comportamental/métodos , Manejo da Dor , Telemedicina/métodos , Doença Crônica , Grupos Focais , Humanos , Dor/psicologia , Autocuidado
8.
Stud Health Technol Inform ; 169: 218-22, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21893745

RESUMO

This paper addresses the assessment and verification of health informatics professional competencies. Postgraduate provision in Health Informatics was targeted at informatics professionals working full-time in the National Health Service, in Northern Ireland, United Kingdom. Many informatics health service positions do not require a formal informatics background, and as we strive for professionalism, a recognized qualification provides important underpinning. The course, delivered from a computing perspective, builds upon work-based achievement and provides insight into emerging technologies associated with the 'connected health' paradigm. The curriculum was designed with collaboration from the Northern Ireland Health and Social Care ICT Training Group. Material was delivered by blended learning using a virtual learning environment and face-to-face sessions. Professional accreditation was of high importance. The aim was to provide concurrent qualifications: a postgraduate certificate, awarded by the University of Ulster and a professional certificate validated and accredited by a professional body comprising experienced health informatics professionals. Providing both qualifications puts significant demands upon part-time students, and a balance must be achieved for successful completion.


Assuntos
Informática Médica/métodos , Acreditação , Comportamento Cooperativo , Currículo , Educação Continuada , Educação Profissionalizante , Humanos , Informática Médica/educação , Programas Nacionais de Saúde , Irlanda do Norte , Competência Profissional , Ensino/métodos , Reino Unido
9.
BMC Cancer ; 10: 315, 2010 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-20569440

RESUMO

BACKGROUND: Genome wide association studies (GWAS) have identified several genetic variants that are associated with prostate cancer. Most of these variants, like other GWAS association signals, are located in non-coding regions of potential candidate genes, and thus could act at the level of the mRNA transcript. METHODS: We measured the expression and isoform usage of seven prostate cancer candidate genes in benign and malignant prostate by real-time PCR, and correlated these factors with cancer status and genotype at the GWAS risk variants. RESULTS: We determined that levels of LMTK2 transcripts in prostate adenocarcinomas were only 32% of those in benign tissues (p = 3.2 x 10(-7)), and that an independent effect of genotype at variant rs6465657 on LMTK2 expression in benign (n = 39) and malignant tissues (n = 21) was also evident (P = 0.002). We also identified that whilst HNF1B(C) and MSMB2 comprised the predominant isoforms in benign tissues (90% and 98% of total HNF1B or MSMB expression), HNF1B(B) and MSMB1 were predominant in malignant tissue (95% and 96% of total HNF1B or MSMB expression; P = 1.7 x 10(-7) and 4 x 10(-4) respectively), indicating major shifts in isoform usage. CONCLUSIONS: Our results indicate that the amount or nature of mRNA transcripts expressed from the LMTK2, HNF1B and MSMB candidate genes is altered in prostate cancer, and provides further evidence for a role for these genes in this disorder. The alterations in isoform usage we detect highlights the potential importance of alternative mRNA processing and moderation of mRNA stability as potentially important disease mechanisms.


Assuntos
Adenocarcinoma/genética , Fator 1-beta Nuclear de Hepatócito/genética , Proteínas de Membrana/genética , Polimorfismo de Nucleotídeo Único/genética , Hiperplasia Prostática/genética , Neoplasias da Próstata/genética , Proteínas Secretadas pela Próstata/genética , Proteínas Serina-Treonina Quinases/genética , Adenocarcinoma/patologia , Idoso , Idoso de 80 Anos ou mais , Predisposição Genética para Doença , Genótipo , Humanos , Masculino , Próstata/metabolismo , Próstata/patologia , Hiperplasia Prostática/patologia , Neoplasias da Próstata/patologia , Isoformas de Proteínas , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa
10.
Stud Health Technol Inform ; 160(Pt 1): 314-8, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20841700

RESUMO

A Brain Computer Interface (BCI) provides direct communication from the brain to a computer or electronic device. In order for BCIs to become practical assistive devices it is necessary to develop robust systems, which can be used outside of the laboratory. This paper appraises the technical challenges, and outlines the design of an intuitive user interface, which can be used for smart device control and entertainment applications, of specific interest to users. We adopted a user-centred approach, surveying two groups of participants: fifteen volunteers who could use BCI as an additional technology and six users with complex communication and assistive technology needs. Interaction is based on a four way choice, parsing a hierarchical menu structure which allows selection of room location and then device (e.g. light, television) within a smart home. The interface promotes ease of use which aim to improve the BCI communication rate.


Assuntos
Encéfalo/fisiologia , Gráficos por Computador , Eletroencefalografia/métodos , Avaliação das Necessidades , Tecnologia Assistiva , Interface Usuário-Computador , Reino Unido
11.
IEEE Trans Neural Syst Rehabil Eng ; 28(1): 113-122, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31751279

RESUMO

Rapid serial visual presentation (RSVP) based brain-computer interfaces (BCIs) can detect target images among a continuous stream of rapidly presented images, by classifying a viewer's event related potentials (ERPs) associated with the target and non-targets images. Whilst the majority of RSVP-BCI studies to date have concentrated on the identification of a single type of image, namely pictures, here we study the capability of RSVP-BCI to detect three different target image types: pictures, numbers and words. The impact of presentation duration (speed) i.e., 100-200ms (5-10Hz), 200-300ms (3.3-5Hz) or 300-400ms (2.5-3.3Hz), is also investigated. 2-way repeated measure ANOVA on accuracies of detecting targets from non-target stimuli (ratio 1:9) measured via area under the receiver operator characteristics curve (AUC) for N=15 subjects revealed a significant effect of factor Stimulus-Type (pictures, numbers, words) (F (2,28) = 7.243, p = 0.003 ) and for Stimulus-Duration (F (2,28) = 5.591, p = 0.011). Furthermore, there is an interaction between stimulus type and duration: F (4,56) = 4.419, p = 0.004 ). The results indicate that when designing RSVP-BCI paradigms, the content of the images and the rate at which images are presented impact on the accuracy of detection and hence these parameters are key experimental variables in protocol design and applications, which apply RSVP for multimodal image datasets.


Assuntos
Eletroencefalografia/métodos , Potenciais Evocados/fisiologia , Estimulação Luminosa/métodos , Adulto , Área Sob a Curva , Interfaces Cérebro-Computador , Calibragem , Feminino , Voluntários Saudáveis , Humanos , Masculino , Reprodutibilidade dos Testes , Percepção Visual/fisiologia , Adulto Jovem
12.
BMJ Health Care Inform ; 26(1)2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31857341

RESUMO

BACKGROUND: Home-based self-monitoring has failed to show intended savings to healthcare budgets yet it continues to emerge and gain popularity. OBJECTIVE: We set out to verify stakeholders' perspectives of remote vital sign telemonitoring. DESIGN: An observational design was adopted by devising a survey for distribution to service users and their informal carers. SAMPLE: Service users in South Eastern Health and Social Care Trust were included. A total of 274 questionnaires were issued. Data from 97 patients (35% response rate) and 49 carers were analysed. Of these, 81 patients and 48 of their carers experienced a monitoring service known as TF3 and 16 patients and 1 carer experienced a service known as U-Tell. The cohorts comprised people living with a number of long-term conditions: diabetes, hypertension after stroke, chronic heart failure, chronic obstructive pulmonary disorder, bronchiectasis and those requiring anticoagulation using warfarin. RESULTS: Analysis showed that respondents were supportive of the technology with 90.7% of patients agreeing or strongly agreeing with the statement: the remote monitoring system assisted me in managing my health on a day-to-day basis. The patients liked the technology largely because it provided empowerment and control for self-management and allowed them to continue with their lives without major disruption. These views were independent of the technology used and not associated with the patient's long-term conditions, gender or age. There were no reported adverse incidents. CONCLUSION: As self-monitoring becomes more relevant to healthcare delivery, the technology will be accepted by many in the population with long-term conditions.


Assuntos
Cuidadores , Doença Crônica , Monitorização Fisiológica/estatística & dados numéricos , Autogestão , Telemedicina , Sinais Vitais , Idoso , Feminino , Humanos , Masculino , Inquéritos e Questionários
13.
Int J Comput Assist Radiol Surg ; 14(4): 645-657, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30730031

RESUMO

INTRODUCTION: Unobtrusive metrics that can auto-assess performance during clinical procedures are of value. Three approaches to deriving wearable technology-based metrics are explored: (1) eye tracking, (2) psychophysiological measurements [e.g. electrodermal activity (EDA)] and (3) arm and hand movement via accelerometry. We also measure attentional capacity by tasking the operator with an additional task to track an unrelated object during the procedure. METHODS: Two aspects of performance are measured: (1) using eye gaze and psychophysiology metrics and (2) measuring attentional capacity via an additional unrelated task (to monitor a visual stimulus/playing cards). The aim was to identify metrics that can be used to automatically discriminate between levels of performance or at least between novices and experts. The study was conducted using two groups: (1) novice operators and (2) expert operators. Both groups made two attempts at a coronary angiography procedure using a full-physics virtual reality simulator. Participants wore eye tracking glasses and an E4 wearable wristband. Areas of interest were defined to track visual attention on display screens, including: (1) X-ray, (2) vital signs, (3) instruments and (4) the stimulus screen (for measuring attentional capacity). RESULTS: Experts provided greater dwell time (63% vs 42%, p = 0.03) and fixations (50% vs 34%, p = 0.04) on display screens. They also provided greater dwell time (11% vs 5%, p = 0.006) and fixations (9% vs 4%, p = 0.007) when selecting instruments. The experts' performance for tracking the unrelated object during the visual stimulus task negatively correlated with total errors (r = - 0.95, p = 0.0009). Experts also had a higher standard deviation of EDA (2.52 µS vs 0.89 µS, p = 0.04). CONCLUSIONS: Eye tracking metrics may help discriminate between a novice and expert operator, by showing that experts maintain greater visual attention on the display screens. In addition, the visual stimulus study shows that an unrelated task can measure attentional capacity. Trial registration This work is registered through clinicaltrials.gov, a service of the U.S. National Health Institute, and is identified by the trial reference: NCT02928796.


Assuntos
Atenção/fisiologia , Cateterismo Cardíaco/métodos , Competência Clínica , Simulação por Computador , Fixação Ocular/fisiologia , Dispositivos Eletrônicos Vestíveis , Feminino , Humanos , Masculino
14.
Elife ; 82019 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-31478829

RESUMO

Prostate is the most frequent cancer in men. Prostate cancer progression is driven by androgen steroid hormones, and delayed by androgen deprivation therapy (ADT). Androgens control transcription by stimulating androgen receptor (AR) activity, yet also control pre-mRNA splicing through less clear mechanisms. Here we find androgens regulate splicing through AR-mediated transcriptional control of the epithelial-specific splicing regulator ESRP2. Both ESRP2 and its close paralog ESRP1 are highly expressed in primary prostate cancer. Androgen stimulation induces splicing switches in many endogenous ESRP2-controlled mRNA isoforms, including splicing switches correlating with disease progression. ESRP2 expression in clinical prostate cancer is repressed by ADT, which may thus inadvertently dampen epithelial splice programmes. Supporting this, treatment with the AR antagonist bicalutamide (Casodex) induced mesenchymal splicing patterns of genes including FLNB and CTNND1. Our data reveals a new mechanism of splicing control in prostate cancer with important implications for disease progression.


Assuntos
Processamento Alternativo/efeitos dos fármacos , Androgênios/metabolismo , Neoplasias da Próstata/patologia , Proteínas de Ligação a RNA/biossíntese , Transcrição Gênica , Células Cultivadas , Humanos , Masculino , Proteínas de Ligação a RNA/genética , Receptores Androgênicos/metabolismo
15.
J Neural Eng ; 15(2): 021001, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29099388

RESUMO

Rapid serial visual presentation (RSVP) combined with the detection of event-related brain responses facilitates the selection of relevant information contained in a stream of images presented rapidly to a human. Event related potentials (ERPs) measured non-invasively with electroencephalography (EEG) can be associated with infrequent targets amongst a stream of images. Human-machine symbiosis may be augmented by enabling human interaction with a computer, without overt movement, and/or enable optimization of image/information sorting processes involving humans. Features of the human visual system impact on the success of the RSVP paradigm, but pre-attentive processing supports the identification of target information post presentation of the information by assessing the co-occurrence or time-locked EEG potentials. This paper presents a comprehensive review and evaluation of the limited, but significant, literature on research in RSVP-based brain-computer interfaces (BCIs). Applications that use RSVP-based BCIs are categorized based on display mode and protocol design, whilst a range of factors influencing ERP evocation and detection are analyzed. Guidelines for using the RSVP-based BCI paradigms are recommended, with a view to further standardizing methods and enhancing the inter-relatability of experimental design to support future research and the use of RSVP-based BCIs in practice.


Assuntos
Interfaces Cérebro-Computador , Encéfalo/fisiologia , Eletroencefalografia/métodos , Potenciais Evocados Visuais/fisiologia , Estimulação Luminosa/métodos , Interfaces Cérebro-Computador/tendências , Eletroencefalografia/tendências , Humanos , Fatores de Tempo
16.
J Pers Disord ; 21(3): 322-39, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17536943

RESUMO

This study aimed to confirm neuroaffective processing deficits in psychopaths by measuring late brain event-related potential (ERP) components and behavior in groups of psychopathic and nonpsychopathic inmates of a Singaporean prison while they performed two tasks. In a Categorization task, affective stimuli were task-relevant and required focused attention, while in a Vigilance task, affective pictures were presented in the background while participants discriminated vertical from oblique lines. Psychopaths showed differences in late positive ERPs that were sensitive to affective stimulus properties (valence and arousal) in the Categorization, but not in the Vigilance task, suggesting that only under conditions of focused attention did psychopaths show a neuroaffective processing deficit. In the Categorization task, psychopaths also showed a significantly larger prefrontal negative ERP (N350) whose amplitude correlated positively with the behavioral facet of psychopathy. In the Vigilance task, psychopaths both missed more targets and showed significantly smaller target-evoked parietal ERPs when viewing arousing pictures, suggesting their attentional focus was disrupted by the affective background.


Assuntos
Transtorno da Personalidade Antissocial/diagnóstico , Nível de Alerta , Potenciais Evocados , Transtornos do Humor/diagnóstico , Reconhecimento Visual de Modelos , Prisioneiros/psicologia , Adulto , Transtorno da Personalidade Antissocial/fisiopatologia , Eletroencefalografia , Humanos , Inibição Psicológica , Masculino , Pessoa de Meia-Idade , Transtornos do Humor/fisiopatologia , Tempo de Reação , Índice de Gravidade de Doença , Singapura
17.
Artif Intell Med ; 40(1): 1-14, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-16930965

RESUMO

OBJECTIVE: The auditory brainstem response (ABR) is an evoked response obtained from brain electrical activity when an auditory stimulus is applied to the ear. An audiologist can determine the threshold level of hearing by applying stimuli at reducing levels of intensity, and can also diagnose various otological, audiological, and neurological abnormalities by examining the morphology of the waveform and the latencies of the individual waves. This is a subjective process requiring considerable expertise. The aim of this research was to develop software classification models to assist the audiologist with an automated detection of the ABR waveform and also to provide objectivity and consistency in this detection. MATERIALS AND METHODS: The dataset used in this study consisted of 550 waveforms derived from tests using a range of stimulus levels applied to 85 subjects ranging in hearing ability. Each waveform had been classified by a human expert as 'response=Yes' or 'response=No'. Individual software classification models were generated using time, frequency and cross-correlation measures. Classification employed both artificial neural networks (NNs) and the C5.0 decision tree algorithm. Accuracies were validated using six-fold cross-validation, and by randomising training, validation and test datasets. RESULTS: The result was a two stage classification process whereby strong responses were classified to an accuracy of 95.6% in the first stage. This used a ratio of post-stimulus to pre-stimulus power in the time domain, with power measures at 200, 500 and 900Hz in the frequency domain. In the second stage, outputs from time, frequency and cross-correlation classifiers were combined using the Dempster-Shafer method to produce a hybrid model with an accuracy of 85% (126 repeat waveforms). CONCLUSION: By combining the different approaches a hybrid system has been created that emulates the approach used by an audiologist in analysing an ABR waveform. Interpretation did not rely on one particular feature but brought together power and frequency analysis as well as consistency of subaverages. This provided a system that enhanced robustness to artefacts while maintaining classification accuracy.


Assuntos
Estimulação Acústica , Audiometria de Resposta Evocada/métodos , Árvores de Decisões , Potenciais Evocados Auditivos do Tronco Encefálico , Redes Neurais de Computação , Processamento de Sinais Assistido por Computador , Software , Algoritmos , Limiar Auditivo , Sistemas de Apoio a Decisões Clínicas , Perda Auditiva/diagnóstico , Perda Auditiva/fisiopatologia , Humanos , Tempo de Reação , Reprodutibilidade dos Testes , Fatores de Tempo
18.
Artif Intell Med ; 41(3): 251-62, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17707617

RESUMO

OBJECTIVE: Diabetes affects between 2% and 4% of the global population (up to 10% in the over 65 age group), and its avoidance and effective treatment are undoubtedly crucial public health and health economics issues in the 21st century. The aim of this research was to identify significant factors influencing diabetes control, by applying feature selection to a working patient management system to assist with ranking, classification and knowledge discovery. The classification models can be used to determine individuals in the population with poor diabetes control status based on physiological and examination factors. METHODS: The diabetic patients' information was collected by Ulster Community and Hospitals Trust (UCHT) from year 2000 to 2004 as part of clinical management. In order to discover key predictors and latent knowledge, data mining techniques were applied. To improve computational efficiency, a feature selection technique, feature selection via supervised model construction (FSSMC), an optimisation of ReliefF, was used to rank the important attributes affecting diabetic control. After selecting suitable features, three complementary classification techniques (Naïve Bayes, IB1 and C4.5) were applied to the data to predict how well the patients' condition was controlled. RESULTS: FSSMC identified patients' 'age', 'diagnosis duration', the need for 'insulin treatment', 'random blood glucose' measurement and 'diet treatment' as the most important factors influencing blood glucose control. Using the reduced features, a best predictive accuracy of 95% and sensitivity of 98% was achieved. The influence of factors, such as 'type of care' delivered, the use of 'home monitoring', and the importance of 'smoking' on outcome can contribute to domain knowledge in diabetes control. CONCLUSION: In the care of patients with diabetes, the more important factors identified: patients' 'age', 'diagnosis duration' and 'family history', are beyond the control of physicians. Treatment methods such as 'insulin', 'diet' and 'tablets' (a variety of oral medicines) may be controlled. However lifestyle indicators such as 'body mass index' and 'smoking status' are also important and may be controlled by the patient. This further underlines the need for public health education to aid awareness and prevention. More subtle data interactions need to be better understood and data mining can contribute to the clinical evidence base. The research confirms and to a lesser extent challenges current thinking. Whilst fully appreciating the requirement for clinical verification and interpretation, this work supports the use of data mining as an exploratory tool, particularly as the domain is suffering from a data explosion due to enhanced monitoring and the (potential) storage of this data in the electronic health record. FSSMC has proved a useful feature estimator for large data sets, where processing efficiency is an important factor.


Assuntos
Glicemia/metabolismo , Sistemas de Apoio a Decisões Clínicas , Diabetes Mellitus Tipo 2/terapia , Hipoglicemiantes/uso terapêutico , Armazenamento e Recuperação da Informação , Sistemas Computadorizados de Registros Médicos , Modelos Biológicos , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Algoritmos , Glicemia/efeitos dos fármacos , Índice de Massa Corporal , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/tratamento farmacológico , Feminino , Conhecimentos, Atitudes e Prática em Saúde , Humanos , Hipoglicemiantes/administração & dosagem , Injeções , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/fisiopatologia , Educação de Pacientes como Assunto , Seleção de Pacientes , Reprodutibilidade dos Testes , Fatores de Risco , Fumar/efeitos adversos , Resultado do Tratamento
19.
J Electrocardiol ; 40(3): 292-9, 2007 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-17292383

RESUMO

BACKGROUND: Despite its widespread use, the limitations of the 12-lead electrocardiogram (ECG) are undisputed. The main deficiency is that just a small area of the precordium is interrogated and for some abnormalities information may be transmitted to a region of the body surface where information is not recorded. In this study, we attempted to optimize the 12-lead ECG by using a data-driven approach to suggest alternate recording sites. METHODS: A sequential lead selection algorithm was applied to a set of 744 body surface potential maps (BSPMs), consisting of recordings from subjects with myocardial infarction, left ventricular hypertrophy, and no apparent disease. A number of scenarios were investigated in which pairs of precordial leads were repositioned; these pairs were V3 and V5, V4 and V5, and V4 and V6. The algorithm was also used to find optimal positions for all 6 precordial leads. RESULT: Through estimation of entire surface potential distributions it was found that each of the scenarios, with 2 leads repositioned, captured more information than the standard 12-lead ECG. The scenario with V4 and V6 repositioned performed best with a root mean square error of 22.3 microvolts and a correlation coefficient of 0.967. This configuration also fared favorably when compared to the scenario where all 6 precordial leads were repositioned as optimizing all 6 leads offered no significant improvement. CONCLUSION: This study demonstrated the use of a lead selection algorithm in enhancing the 12-lead ECG. The results also indicated that repositioning just 2 precordial leads can provide the same level of information capture as that observed when all precordial leads are optimally placed.


Assuntos
Algoritmos , Mapeamento Potencial de Superfície Corporal/métodos , Bases de Dados Factuais , Diagnóstico por Computador/métodos , Hipertrofia Ventricular Esquerda/diagnóstico , Infarto do Miocárdio/diagnóstico , Garantia da Qualidade dos Cuidados de Saúde/métodos , Humanos , Armazenamento e Recuperação da Informação/métodos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
20.
Eur J Intern Med ; 18(8): 566-70, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18054705

RESUMO

An area of electrocardiography which has received much interest of late is that of synthesising the 12-lead ECG from a reduced number of leads. The main advantage of this approach is obvious, as fewer recording sites are required to capture the same information. This, in turn, streamlines the ECG acquisition process with little detriment to the integrity of information used for interpretation. In the current article, we provide an overview of ECG synthesis along with a description of various 'limited lead' systems that have been reported in the literature. Based on this, several suggestions as to what the ECG of the future may entail have been made.

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