80 research outputs found

    Simplified Building Models Extraction From Ultra-Light UAV Imagery

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    Generating detailed simplified building models such as the ones present on Google Earth is often a difficult and lengthy manual task, requiring advanced CAD software and a combination of ground imagery, LIDAR data and blueprints. Nowadays, UAVs such as the Falcon 8 have reached the maturity to offer an affordable, fast and easy way to capture large amounts of oblique images covering all part of a building. In this paper we present a state-of-the-art photogrammetry and visual reconstruction pipeline provided by Pix4D applied to medium resolution imagery acquired by such UAVs. The key element of simplified building models extraction is the seamless integration of the outputs of such a pipeline for a final manual refinement step in order to minimize the amount of manual wor

    Identification of neuropathic pain in patients with neck/upper limb pain: Application of a grading system and screening tools.

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    The Neuropathic Pain Special Interest Group (NeuPSIG) of the International Association for the Study of Pain has proposed a grading system for the presence of neuropathic pain (NeP) using the following categories: no NeP, possible, probable, or definite NeP. To further evaluate this system, we investigated patients with neck/upper limb pain with a suspected nerve lesion, to explore: (i) the clinical application of this grading system; (ii) the suitability of 2 NeP questionnaires (Leeds Assessment of Neuropathic Symptoms and Signs pain scale [LANSS] and the painDETECT questionnaire [PD-Q]) in identifying NeP in this patient cohort; and (iii) the level of agreement in identifying NeP between the NeuPSIG classification system and 2 NeP questionnaires. Patients (n = 152; age 52 ± 12 years; 53% male) completed the PD-Q and LANSS questionnaire and underwent a comprehensive clinical examination. The NeuPSIG grading system proved feasible for application in this patient cohort, although it required considerable time and expertise. Both questionnaires failed to identify a large number of patients with clinically classified definite NeP (LANSS sensitivity 22%, specificity 88%; PD-Q sensitivity 64%, specificity 62%). These lowered sensitivity scores contrast with those from the original PD-Q and LANSS validation studies and may reflect differences in the clinical characteristics of the study populations. The diagnostic accuracy of LANSS and PD-Q for the identification of NeP in patients with neck/upper limb pain appears limited

    Cancer treatment-related neuropathic pain:proof of concept study with menthol—a TRPM8 agonist

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    PURPOSE: Effective treatment of neuropathic pain without unacceptable side effects is challenging. Cancer sufferers increasingly live with long-term treatment-related neuropathic pain, resulting from chemotherapy-induced peripheral neuropathy (CIPN) or surgical scars. This proof-of-concept study aimed to determine whether preclinical evidence for TRPM8 ion channels in sensory neurons as a novel analgesic target could be translated to clinical benefit in patients with neuropathic pain, using the TRPM8 activator menthol. PATIENTS AND METHODS: Patients with problematic treatment-related neuropathic pain underwent a baseline assessment using validated questionnaires, psychophysical testing, and objective functional measures. The painful area was treated with topical 1 % menthol cream twice daily. Assessments were repeated at 4–6 weeks. The primary outcome was the change in Brief Pain Inventory total scores at 4–6 weeks. Secondary outcomes included changes in function, mood and skin sensation. RESULTS: Fifty-one patients (female/male, 32/19) were recruited with a median age of 61 (ranging from 20 to 89). The commonest aetiology was CIPN (35/51), followed by scar pain (10/51). Thirty-eight were evaluable on the primary outcome. Eighty-two per cent (31/38) had an improvement in total Brief Pain Inventory scores (median, 47 (interquartile range, 30 to 64) to 34 (6 to 59), P < 0.001). Improvements in mood (P = 0.0004), catastrophising (P = 0.001), walking ability (P = 0.008) and sensation (P < 0.01) were also observed. CONCLUSION: This proof-of-concept study indicates that topical menthol has potential as a novel analgesic therapy for cancer treatment-related neuropathic pain. Improvements in patient-rated measures are supported by changes in objective measures of physical function and sensation. Further systematic evaluation of efficacy is required

    Is Meta-Analysis for Utility Values Appropriate Given the Potential Impact Different Elicitation Methods Have on Values?

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    A growing number of published articles report estimates from meta-analysis or meta-regression on health state utility values (HSUVs), with a view to providing input into decision-analytic models. Pooling HSUVs is problematic because of the fact that different valuation methods and different preference-based measures (PBMs) can generate different values on exactly the same clinical health state. Existing meta-analyses of HSUVs are characterised by high levels of heterogeneity, and meta-regressions have identified significant (and substantial) impacts arising from the elicitation method used. The use of meta-regression with few utility values and inclusion criteria that extend beyond the required utility value has not helped. There is the potential to explore greater use of mapping between different PBMs and valuation methods prior to data synthesis, which could support greater use of pooling values. Researchers wishing to populate decision-analytic models have a responsibility to incorporate all high-quality evidence available. In relation to HSUVs, greater understanding of the differences between different methods and greater consistency of methodology is required before this can be achieved

    M?todo de avalia??o de algoritmos de detec??o e remo??o de sombra em imagens a?reas

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    Submitted by PPG Engenharia El?trica ([email protected]) on 2018-06-08T13:54:41Z No. of bitstreams: 1 RICARDO_VINICIUS_DOTH_DIS.pdf: 9281309 bytes, checksum: d26fbf7274d4c8eb7158a2d987437b1b (MD5)Approved for entry into archive by Sheila Dias ([email protected]) on 2018-06-18T12:49:23Z (GMT) No. of bitstreams: 1 RICARDO_VINICIUS_DOTH_DIS.pdf: 9281309 bytes, checksum: d26fbf7274d4c8eb7158a2d987437b1b (MD5)Made available in DSpace on 2018-06-18T12:58:59Z (GMT). No. of bitstreams: 1 RICARDO_VINICIUS_DOTH_DIS.pdf: 9281309 bytes, checksum: d26fbf7274d4c8eb7158a2d987437b1b (MD5) Previous issue date: 2018-03-27Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPESWide Area Motion Imagery (WAMI) systems acquire large area aerial images in real time to provide accurate situational awareness information from a region (BLASCH et al., 2014). This system is applied for urban aerial monitoring. Unfavorable environmental conditions, such as shadow regions, are factors that increase system complexity by compromising the effectiveness of tracking algorithms and human visual interpretation (PORTER; FRASER; HUSH, 2010). Several techniques of shadow removal in aerial images have been developed, however due to the characteristics of the shadow and aerial image, a specific method to evaluate and compare the removal is unknown. The main objective of this study is to develop a method to evaluate shadow removal algorithms in aerial images acquired by the WAMI system. This work proposes a radiometric approach modifying the illumination in a controlled environment, simulating an aerial scene, acquiring images with and without the presence of shadows. The image with shadows is processed by the evaluated shadow removal algorithm, with the ideal output being the shadow free image. Shadow detection is evaluated using the confusion matrix concept. Shadow removal is evaluated using the structural similarity index (SSIM). As a result the reduced scale aerial scene model is presented to generate shadow and freeshadow images and the evaluation of 3 shadow removal methods using the data sets of images obtained from the scale model applying the methodology developed.Sistemas WAMI (Wide Area Motion Imagery) adquirem imagens a?reas de grandes ?reas em tempo real para prover informa??es precisas de uma determinada regi?o (BLASCH et al., 2014). Este sistema ? aplicado para monitoramento a?reo urbano. Condi??es ambientais desfavor?veis, como ?reas sombreadas, s?o fatores que aumentam a complexidade do sistema comprometendo a efic?cia de algoritmos de rastreamento e a interpreta??o visual humana (PORTER; FRASER; HUSH, 2010). Diversas t?cnicas de remo??o de sombra em imagens a?reas foram desenvolvidas, no entanto devido ?s caracter?sticas da sombra e da imagem a?rea ? desconhecido um m?todo espec?fico para avaliar e comparar a remo??o de sombras em imagens a?reas. O objetivo principal deste estudo ? desenvolver um m?todo para avaliar algoritmos de remo??o de sombra em imagens a?reas adquiridas pelo sistema WAMI. Este trabalho prop?e uma abordagem radiom?trica modificando a ilumina??o em um ambiente controlado, simulando uma cena a?rea, adquirindo imagens com e sem sombras. A imagem com sombra ? processada pelo algoritmo de remo??o de sombra avaliado, sendo a imagem sem sombra o resultado ideal a ser alcan?ado. A detec??o de sombra ? avaliada utilizando o conceito de matriz de confus?o (error matrix). A remo??o de sombra ? avaliada utilizando o ?ndice de similaridade estrutural entre duas imagens (SSIM). Foram desenvolvidos o modelo de cena a?rea em escala reduzida para gerar imagens com e sem sombra e a avalia??o de 3 m?todos de remo??o de sombras utilizando os data sets de imagens obtidas do modelo em escala aplicando a metodologia descrita
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