18 research outputs found

    Equine body weight estimation using three-dimensional images

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    Includes bibliographical references.2015 Summer.Accurately estimating the body weight (BW) of a horse is important in order to make appropriate management and treatment decisions. Most field equine veterinarians and experienced equine people, however, visually estimate BW because large animal scales are impractical for field use due to the weight (>80 kg), size (length >200 cm), and cost (>$1,000). There are some alternative BW estimation methods such as a weight tape or BW estimation using a combination of heart girth and body length measurements. These methods, however, have 5 - 15% or even higher margin of error. According to human studies, there is a high correlation between BW and body volume (BV). Correlation coefficient (R) between these two variables is 0.996-0.998. Our study was designed to develop methods to estimate the BW of horses by using 3D image based BV measurement. 3D imaging technology allows easy and accurate measurement of diverse indices of an object, including the volume. Recent development of Structure-light 3D scanning technology allows 3D scanning of an object as large as 3 by 3 square meter in a short time. In this study, 3D images of 22 and 11 horses were obtained by using 3D scanning (3DScan) and photogrammetry (2Dto3D), respectively. BV and trunk volume (TV) of the horses were measured from the obtained 3D images. Measurements of BW using five conventional methods (visual estimation, 2 weight tapes (Purina, Shell), estimated BW by using heart girth and body length (Carroll’s formula), and a large animal scale) were also conducted, and the data of body condition score (BCS), sex, coat color, and coat type of the horses were collected. Linear regression models to estimate the BW of the horse based on the volume and other independent variables were developed using regression model stepwise selection procedures (P<0.05). Variables selected in 3DScan method were BV, sex, and coat type, and, in 2Dto3D method, BV (TV) was selected. The coefficient of determination of the developed regression models were 0.95 and 0.78-0.82, respectively, and the average percent errors of the predicted BW compared to the true BW of horses were 2.07 % and 2.67 %, respectively. The accuracy of the 3DScan method was significantly more accurate than WT, Carroll’s formual, and VE (P<0.05). 3D image based BW measurement method had higher accuracy and convenience compared to conventional alternative BW measuring methods. Accurate and easy determination of BW using 3D images will allow for regular BW measurement in the field and allow optimal equine health management by equine stakeholders and practitioners. The 3D images obtained in this study were highly detailed. Further graphical analysis of the obtained 3D images will make it possible to use this technology on automatic evaluation of body condition score, equine conformation evaluation, breed registration, and the study of pharmacokinetics and dynamics of newly developed drugs. This research findings may also have utility for application to wild or zoo animals such as the elephant, rhinoceros, or even the tiger where hands on collection of body weight would be challenging

    Can 3D Camera Imaging Provide Improved Information to Assess and Manage Lymphoedema in Clinical Practice?

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    Background Accurate diagnosis and measurement of limb volume in people with lymphoedema is important in order to provide best information for treatment, management and self-management. Current assessment methods lack detail and accuracy. Three-dimensional camera imaging (3DCI) holds the potential to be cheap, accurate, and provide additional material about limb shape not provided by current methods. However, there is a need to ensure that this assessment method is valid and reliable. Methodology This prospective, observational, longitudinal study utilised a diagnostic test study framework to determine the validity, reliability and accuracy of 3DCI compared to circumferential tape measurement (CTM) and perometry and to explore whether shape is a feasible alternative to measure upper limb lymphoedema. Twenty women with breast cancer-related lymphoedema were recruited. Phase one assessed criterion validity, intra-rater reliability, and accuracy of 3DCI by measuring limb volume of each participant with CTM, perometry and 3DCI four times over six months. Phase two investigated the use of limb shape as a method of lymphoedema assessment using oedema maps and calculations of shape redundancy derived from the 3DCI images in phase one. These data sets were matched against limb volume to determine criterion validity, intra-rater reliability and accuracy. Results 3DCI had high intra-rater correlation (ICC=0.87; p<0.00). Concurrent validity ranged from 0.82 to 0.86 against perometry and CTM, with good sensitivity (91.7% to 100%) and moderate specificity (50% to 66.7%). Limb shape calculation (shape redundancy) had moderate intra-rater correlation (ICC=0.71; p=0.01); but correlated poorly with limb volume (r=0.19 to 0.39). Coloured oedema maps were sensitive to change over time with colours clearly identifying problem areas and fluctuations within the affected limb. Conclusion Our study shows that 3DCI is a reliable, valid and accurate method of limb volume measurement, and that it could provide supportive information in clinical assessment. In addition, limb shape provides insight into localised areas of swelling, which other methods of lymphoedema measurement do not. However, shape redundancy requires further refinement

    Contextual game design: from interface development to human activity recognition

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    A dissertação focasse nos seguintes pontos: Criação de diferentes interfaces usando o sensor Kinect, para reablitação de pacientes com cancro de mama. E, reconhecimento de atividade humana (problema derivado aquando a criação das interfaces)

    Use of neoadjuvant chemotherapy in locally advanced breast cancer in the Netherlands

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    Use of neoadjuvant chemotherapy in locally advanced breast cancer in the Netherlands P.E.R. Spronk1, A.C.M. Van Bommel1, S. Siesling2,3, M.J.T. Baas- Vrancken Peeters4, C.H. Smorenburg5. 1Leiden University Medical Centre, Surgery, Leiden, Netherlands; 2Comprehensive Cancer Centre the Netherlands IKNL, Epidemiology, Utrecht, Netherlands; 3University of Twente, MIRA Biomedical science and Technical Medicine, Twente, Netherlands; 4Netherlands Cancer Institute/Antoni van Leeuwenhoek, Surgery, Amsterdam, Netherlands; 5Netherlands Cancer Institute/Antoni van Leeuwenhoek, Medical Oncology, Amsterdam, Netherlands Background: Neoadjuvant chemotherapy (NAC) is the treatment of choice for patients with locally advanced breast cancer (LABC). The aim of this study is to examine the use of NAC for LABC in all Dutch hospitals participating in breast cancer care and to assess what patient, tumour and hospital characteristics influence its use. Material and Methods: Data were derived from the national multidisciplinary NABON Breast Cancer Audit (NBCA), regarding all women aged >18 years and newly diagnosed with LABC from January 2011 to September 2013. Multivariable logistic regression was used to assess the association between the use of NAC and patient, tumour and hospital related factors. Results: Of 1419 woman diagnosed with LABC, 70% were treated with NAC. This percentage varied from 12.5% to 90% between hospitals and did not increase over time. Factors associated with the use of NAC included young age, large tumour size, more advanced nodal disease and triple negative or hormone-receptor negative tumours. Also patients treated in hospitals with a multidisciplinary preoperative work-up and participation in neoadjuvant studies were more likely to receive NAC. However, considerable variation between hospitals remained after casemix correction. Table 1. Multivariable odds ratios (ORs) for receipt of NAC among 1419 stage III patients 2011 through 2013 OR 95% CI P-value Age 0.000 5 cm 5.68 2.34−13.79 Clinical nodal status 0.000 cNx/N0 ref. cN1 1.32 0.86−2.04 cN2 2.93 1.18−7.29 cN3 10.28 4.18−25.25 Receptor status 0.000 Triple negative 2.35 1.40−3.93 HR−, Her2+ 3.37 1.67−6.78 HR+, Her2+ 0.91 0.51−1.60 HR+, Her2− ref. Type of surgery 0.026 Breast conservation therapy 2.05 1.09−3.84 Mastectomy ref. Multidisciplinary team 0.021 Yes 1.98 1.11−3.53 No ref. Type of hospital 0.569 General 1.20 0.73−1.98 Top clinical ref. Academic 1.50 0.64−3.47 Hospital surgical volume 0.729 200 1.27 0.70−2.31 Study participation 0.005 Yes 1.80 1.20−2.70 No ref. Conclusions: There is considerable variation in the use of NAC for LABC in the Netherlands. Although various patient, tumor and institutional factors are associated with the use of NAC in LABC, these can only explain part of the observed variation in treatment patterns between hospitals

    The use of consumer depth cameras for calculating body segment parameters.

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    Body segment parameters (BSPs) are pivotal to a number of key analyses within sports and healthcare. Accuracy is paramount, as investigations have shown small errors in BSPs to have significant impact upon subsequent analyses, particularly when analysing the dynamics of high acceleration movements. There are many techniques with which to estimate BSPs, however, the majority are complex, time consuming, and make large assumptions about the underlying structure of the human body, leading to considerable errors. Interest is increasingly turning towards obtaining person-specific BSPs from 3D scans, however, the majority of current scanning systems are expensive, complex, require skilled operators, and require lengthy post processing of the captured data. The purpose of this study was to develop a low cost 3D scanning system capable of estimating accurate and reliable person-specific segmental volume, forming a fundamental first step towards calculation of the full range of BSPs.A low cost 3D scanning system was developed, comprising four Microsoft Kinect RGB-D sensors, and capable of estimating person-specific segmental volume in a scanning operation taking less than one second. Individual sensors were calibrated prior to first use, overcoming inherent distortion of the 3D data. Scans from each of the sensors were aligned with one another via an initial extrinsic calibration process, producing 360&deg; colour rendered 3D scans. A scanning protocol was developed, designed to limit movement due to postural sway and breathing throughout the scanning operation. Scans were post processed to remove discontinuities at edges, and parameters of interest calculated using a combination of manual digitisation and automated algorithms.The scanning system was validated using a series of geometric objects representative of human body segments, showing high reliability and systematic over estimation of scan-derived measurements. Scan-derived volumes of living human participants were also compared to those calculated using a typical geometric BSP model. Results showed close agreement, however, absolute differences could not be quantified owing to the lack of gold standard data. The study suggests the scanning system would be well received by practitioners, offering many advantages over current techniques. However, future work is required to further characterise the scanning system's absolute accuracy
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