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Simultaneous follow-up of mouse colon lesions by colonoscopy and endoluminal ultrasound biomicroscopy

World Journal of Gastroenterology 2013年第44期19卷 8056-8064页

作者： Rossana C Soletti Kelly Z Alves Marcelo AP de Britto Dyanna G de Matos Mnica Soldan Helena L Borges Joo C Machado Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de Janeiro RJ 21941-972 Brazil Post-Graduation Program in Surgical Sciences Department of Surgery School of Medicine Federal University of Rio de Janeiro Rio de Janeiro RJ 21941-972 Brazil Biomedical Science Institute Federal University of Rio de Janeiro Rio de JaneiroRJ 21941-972 Brazil Division of Gastroenterology Endoscopy UnitClementino Fraga Filho University Hospital Federal University of Rio de Janeiro RJ 21941-972 Brazil

AIM:To evaluate the potential use of colonoscopy and endoluminal ultrasonic biomicroscopy(eUBM)to track the progression of mouse colonic ***:Ten mice were treated with a single azoxy-methane intraperitoneal injection(week 1)followed by seven days of a dextran sulfate sodium treatment in their drinking water(week 2)to induce inflammationassociated colon *** was performed simultaneously with colonoscopy at weeks 13,17-20 and21.A 3.6-F diameter 40 MHz mini-probe catheter was used for eUBM *** ultrasound mini-probe catheter was inserted into the accessory channel of a pediatric flexible bronchofiberscope,allowing simultaneous acquisition of colonoscopic and eUBM *** image acquisition,the mice were anesthetized with isoflurane and kept in a supine position over a stainless steel heated surgical waterbed at 37℃.Both eUBM and colonoscopic images were captured and stored when a lesion was detected by colonoscopy or when the eUBM image revealed a modified colon wall *** the procedure,the colon was irrigated with water that was injected through a flush port on the mini-probe catheter and that acted as the ultrasound coupling medium between the transducer and the colon *** the acquisition of the last eUBM/colonoscopy section for each animal was completed,the colons were fixed,paraffin-embedded,and stained with hematoxylin and *** images acquired at the first time-point for each mouse were compared with subsequent eUBM/colonoscopic images of the same sites obtained in the following acquisitions to evaluate lesion ***:All 10 mice had eUBM and colonoscopic images acquired at week 13(the first time-point).Two animals died immediately after the first imaging acquisition and,consequently,only 8 mice were subjected to the second eUBM/colonoscopy imaging acquisition(at the second time-point).Due to the advanced stage of colonic tumorigenesis,5 animals died after the second time-point image acquisition,and t

关键词： Ultrasound biomicroscopy Animal model Diagnostic imaging Colonic neoplasm Longitudinal study

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Coherence and causal coherence applied to HRV analysis: A novel approach showing differences between inspiration and expiration

Coherence and causal coherence applied to HRV analysis: A no...

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World Congress on Medical Physics and biomedical engineering

作者： Fonseca, D.S. Beda, A. Simpson, D.M. Miranda De Sá, A.M.F.L. Biomedical Engineering Program COPPE Federal University of Rio de Janeiro P. O. Box 68.510 Rio de Janeiro Brazil Institute of Technology Federal University of Pará Belém Brazil Institute of Sound and Vibration Research University of Southampton Southampton United Kingdom

ISBN: (纸本)9783642293047

Heart rate variability (HRV) analysis has been extensively used in the study of the autonomic control of the cardiovascular system. However, the interpretation of respiratory sinus arrhythmia (RSA) has not been unanimous among researches. This study proposes a new approach for HRV analysis using coherence, causal coherence, and autoregressive modeling with missing samples (gapped data) in order to assess differences between inspiration and expiration in coupling of air flow and heart-rate. Simulation was used to test this approach and the technique was applied to a data recorded from patients. Significant differences were found between inspiration and expiration, with higher values for the former. The methodology proposed showed promise in providing new insights into cardio-respiratory interactions. © 2013 Springer-Verlag.

关键词： Diseases

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An ERD/ERS analysis of the relation between human arm and robot manipulator movements

An ERD/ERS analysis of the relation between human arm and ro...

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Biosignals and Biorobotics Conference (BRC), ISSNIP

作者： Ernesto Pablo Lana Bruno Vilhena Adorno Carlos Julio Tierra-Criollo Graduate Program in Electrical Engineering Federal University of Minas Gerais Belo Horizonte Minas Gerais Brazil Graduate Program in Electrical Engineering Federal University of Minas Gerais and with Biomedical Engineering Program-COPPE Federal University of Rio de Janeiro Brazil

This work aims to analyze the relation between the movement of an anthropomorphic robotic manipulator with the brain cortex response elicited in healthy subjects for three experimental conditions. The experiment was divided in three parts: in the first one, the subject only observes the movement of the robotic manipulator; in the second part, the subject follows the robot movement with his right arm; finally, in the third part, the subject imagines the execution of the corresponding movement synchronized with the movement of the robot. Event related (de)synchronization in each of the recorded electroencephalogram (EEG) channels was analyzed. Event related desyn-chronization was present in alpha and beta bands in various areas of the cortex, including occipital, parietal, central and prefrontal areas. The results provided some physiological insights into human-robot interaction for future developments in brain-machine interfaces.

关键词： Manipulators Electroencephalography Visualization Correlation Synchronization Elbow

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Feature selection and classifier performance in computer-aided diagnosis for breast ultrasound

Feature selection and classifier performance in computer-aid...

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International Conference & Expo on Emerging Technologies for a Smarter World (CEWIT)

作者： W. Gómez A. Rodríguez W. C. A. Pereira A. F. C. Infantosi Technology Information Laboratory CINVESTAV-IPN Ciudad Victoria Mexico Biomedical Engineering Program/COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil

We propose a feature selection method for classifying breast ultrasound (BUS) images based on mutual information technique and statistical tests. The BUS dataset consisted of 641 BUS images (228 carcinomas and 413 benign lesions) and every image was segmented by a technique based on Watershed transform. Thereafter, 22 morphological features were computed from segmented lesions and the resultant feature space was ranked by mutual information approach, where the first feature presents the largest discrimination power between benign and malignant classes. Next, feature subsets were built by adding iteratively the first m ranked attributes until all of the 22 features were considered. The .632+ bootstrap method estimated the discrimination performance of each feature subset in terms of the area under the ROC curve (AUC), by using the Fisher discriminant analysis (FLDA) as classifier. The results pointed out that the AUC values were 0.952 and 0.953 for the reduced (with seven features) and complete sets (with 22 features), respectively. Hence, dimensionality reduction was reached while maintaining the classification performance.

关键词： Lesions Breast Image segmentation Ultrasonic imaging Cancer Mutual information Computer aided diagnosis

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Computational simulations of time of flight and attenuation of first arriving signal from healing process of diaphyseal femur fractures.

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Proceedings of Meetings on Acoustics 2013年第1期19卷

作者： Paulo Tadeu C. Rosa Aldo J. Fontes-Pereira Wagner C. Pereira COPPE - Biomedical Engineering Program Federal University of Rio de Janeiro Rio de Janeiro Rio de Janeiro 21941-914 Brazil COPPE - Biomedical Engineering Program Federal University of Rio de Janeiro Brazil

Quantitative Ultrasound (QUS) has been proposed to evaluate structural conditions from bone tissue in a non-invasive way. These techniques are based on the fact that the ultrasound propagation depends directly of tissues structures, so, they carry information about them. Based on these arguments, the aim of this work was to estimate the time?of-flight (TOF) and attenuation of The first arriving signal (FAS) using computational simulations (Wave2000® CyberLogic, inc., NY, EUA) in an axial transmission model in different kinds of fracture, during the healing process. In this work we used QUS techniques to analyze the fracture healing process. The FAS has been chosen because it does not suffer interference of other waves since it is the first signal to arrive at the receiver. TOF increases immediately after bone fracture. When bone tissue starts to consolidate, TOF decreases and stabilizes with the same value of the intact bone. Attenuation is bigger in oblique and spiculate fracture than transversal ones for the same stage which suggests that attenuation is sensitive to the kind of fracture. Other studies are being conducted to clarify this point.

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Iterative optimization algorithm - An alternative clustering tool for biological analysis using flow cytometry data

Iterative optimization algorithm - An alternative clustering...

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2012 Pan American Health Care Exchanges, PAHCE 2012 - Conference, Workshops, and Exhibits. Cooperation / Linkages: An Independent Forum for Patient Aare and Technology Support

作者： Alves, E.T.A. Frucht, L.C. Souza, M.N. Nóbrega, A.F.A. Biomedical Engineering Program COPPE/UFRJ Rio de Janeiro RJ Brazil Microbiology Institute CCS/UFRJ Rio de Janeiro RJ Brazil Inovecare Company Brazil

ISBN: (纸本)9781467311328

This work concerns a program (EFlow) that has been developed to assist experts in clustering flow cytometry multivariate data. EFlow aims to reduce subjectivity but keeping the expert's control over the analysis. In the present paper we will focus on the use of the iterative optimization algorithm. This algorithm is a hill-climbing unsupervised procedure that in general guarantees good local but not global optimization. A comparison between clustering processes achieved by an expert in flow cytometry and by EFlow was performed in a data related to bone marrow cells stained for the surface expression of molecules (B220, IgM and CD23) that characterize the B cell lineage. This data set is considered to present a medium difficult and had 63780 cells with 7 channels or dimensions. Two types of clustering processes were compared, one with four clusters and another with five clusters. The results obtained by EFlow were considered satisfactory by the expert as they were significantly in agreement with his classification. In some clusters, EFlow classified correctly up to 100% of the cells. At the present time few commercial cytometry software offer equivalent clustering analysis. © 2012 IEEE.

关键词： Cytology

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Exploring Possibilities for Real-Time Muscle Dynamics State Estimation from EMG signals

Exploring Possibilities for Real-Time Muscle Dynamics State ...

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IEEE RAS & EMBS International Conference on biomedical Robotics and Biomechatronics

作者： Luciano L. Menegaldo The Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering Biomedical Engineering Program (PEB/COPPE) Universidade Federal do Rio de Janeiro

ISBN: (纸本)9781457711992

Real-time estimation of muscle state (activation, force and length) can be used for visualization of muscle function in neuromuscular rehabilitation and control of wearable assistive and augmenting devices. This paper proposes two formulations for developing linear state estimations of muscle dynamics in isometric contractions: the Luemberger observer and the Kalman filter. One of the main requirements of an estimator for such application is small lag, and a Finite Impulse Response (FIR) pre-filter was used to eliminate part of the high-frequency content of the EMG signal. A run test with human soleus EMG sample was performed. Both Luemberger observer and Kalman filter provided reasonably accurate estimations of the muscle state, compared to usual off-line EMG-driven analysis. In addition, the role of some Kalman filter parameters is analyzed.

关键词： Electromyogram State estimation Kalman filters muscles filter parameters Frequency spectra Time Estimation muscle function signals

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Ultrasound propagation through bone fractures with reamed intramedullary nailing: results from numerical simulations

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Proceedings of Meetings on Acoustics 2013年第1期19卷

作者： Fernanda Catelani Ana Paula M. Ribeiro Carlos Alberto V. Melo Wagner C. Pereira Christiano B. Machado COPPE - Biomedical Engineering Program Federal University of Rio de Janeiro Brazil Biomedical Ultrasound Laboratory Estácio de Sá University Brazil Physical Therapy Department Estácio de Sá University Brazil Biomedical Ultrasound Laboratory Estácio de Sá University Sans Souci s/n Nova Friburgo Rio de Janeiro 28600000 Brazil

Low-intensity pulsed ultrasound stimulation (LIPUS) accelerates fracture healing, enhancing the release of inflammatory mediators and subsequent bone formation. The reamed intramedullary nailing (with the same diameter of the medullary cavity) is a surgical procedure widely used in Medicine. The aim of this work was to study ultrasound propagation inside fractures with and without reamed intramedullary nailing using 2D simulations. It was used a custom-made simulation code applied to numerical models (a 4-mm thick cortical plate, a medullary cavity with radius 4 mm with and without reamed nailing, and fracture gaps varying from 1 to 3 mm). A 1-MHz emitter was positioned above fracture center and fourteen receptor transducers were uniformly placed inside fracture gap. The acquired signals were used to estimate the time-of-flight of the first arriving signal (TOF) and the energy amplitude by means of the root mean square (RMS). TOF was slightly influenced by fracture gap variations. It was observed an increase in RMS values with the presence of metal nailing, due to the reflection in the interface water-metal. The receptors placed near cortical plates received more energy (constructive interference between the direct and lateral waves). For the case of reamed nailing, ultrasound stimulation may be intensified.

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Temperature-induced changes in soft tissues analyzed by spectral methods and transient elastography: A comparative study

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AIP Conference Proceedings 2012年第1期1433卷 228-232页

作者： G. A. Cortela N. Benech W. C. A. Pereira C. Negreira Laboratorio de Acústica Ultrasonora Instituto de Física Facultad de Ciencias Montevideo Uruguay Biomedical Engineering Program COPPE/UFRJ Rio de Janeiro RJ Brazil

Some biological tissues, such as skeletal muscle, have regular or quasi-periodic structures. Periodicity of these structures can be investigated by spectral methods based on ultrasonic backscattered signals. These methods estimate the Mean Scatterer Spacing (MSS). In this work we analyzed the MSS dependence with temperature in bovine skeletal muscle tissue samples. Through spectral analysis we found that the relative variation of the MSS, in the temperature range 20 - 48°C was of ~ 2% /°C. For the same sample and under the same experimental conditions, we analyzed the propagation velocity of shear waves by transient elastography. It was determined that the relative variation of shear elastic modulus was ~ 3% /°C in the same temperature range. The repeatability of the results was tested in three tissue samples, with a set of 6 measurements on each. The relative variation is therefore similar for both parameters. Thus, this study shows that both techniques can be used as a method of noninvasive thermometry for small temperature range. In addition we emphasize the conceptual differences between both methods. As temperature changes, MSS estimation varies due to two physical phenomena. An apparent variation in mean spacing is produced because the sound speed is temperature-dependent, while tissue expansion produces a real change. In practice it is difficult to discriminate the weight of each component in the MSS variation. On the other side, transient elastography is less sensitive to thermal expansion. Thus it measures the actual shear wave speed change with temperature. This differentiation between both methods could be used to construct useful thermoelastic models for soft tissues in the future.

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Analysis of tumor morphology and vasculature in an animal model of colorectal cancer using in vivo contrast-enhanced endoluminal ultrasound biomicroscopy

Analysis of tumor morphology and vasculature in an animal mo...

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IEEE International Ultrasonics Symposium

作者： Rossana Soletti Marcelo A. P. de Britto Helena L. Borges Joao C. Machado Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil Post-Graduation Program in Surgical Sciences Biomedical Science Institute Federal University of Rio de Janeiro Rio de Janeiro Brazil Biomedical Engineering Program and Post-Graduation Program in Surgical Sciences School of Medicine Federal University of Rio de Janeiro Rio de Janeiro Brazil

ISBN: (纸本)9781467345613

Colorectal cancer (CRC) has a high incidence in the world, being the third leading cause of cancer-related mortality in the United States. Ninety percent of the malignant tumors can be cured if diagnosed in the early stages of localized disease and this motivates a great interest in the development and design of experimental models for CRC detection, staging and monitoring. The aim of this work was to use VEGFR2 (vascular endothelial growth factor receptor 2)-targeted ultrasound contrast agent (UCA) coupled to an endoluminal ultrasound biomicroscopy (eUBM) system to diagnose colon tumors and to analyze tumor vasculature. Colon tumors were induced in mice by using azoxymethane/dextran sulfate sodium and according to histopathology, 55% of colon tumors were adenomas and 45% were adenocarcinomas. Images of the lesion were obtained before and 2-15 minutes after VEGFR2-targeted UCA injection into the mice tail. Compared to post-mortem histopathology, all colonic lesions (lymphoid hyperplasias, ulcerations, thickened mucosa and tumors) were correctly diagnosed by eUBM. In addition, when coupled to a VEGFR2-targeted UCA, the eUBM system provided hyperechoic image areas compatible with intense VEGFR2 staining by immunohistochemical diagnosis. The results suggest that eUBM associated to UCA is a promising tool for histopathologycal and molecular imaging, and could be used to diagnose, stage and monitor colon tumor morphology and vasculature.

关键词： Ultrasound biomicroscopy Ultrasound contrast Agent Mice Colon Cancer VEGFR2

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