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14th Annual International Conference of the IEEE engineering in Medicine and Biology Society, EMBS 1992

作者： Rosa, E.R. Melo, M. F. Vidal Neto, A. Giannella Panerai, R.B. Biomedical Engineering Program COPPE Federal University of Rio de Janeiro P.O. Box 68510 Rio de Janeiro RJ21945 Brazil U N D Unidade de Nefrologia e Diálise Niteroi RJ Brazil

ISBN: (纸本)0780307852

Eight hemodialysis were monitored with the objective of detecting the onset of arterial hypotension. Electrical impedance measurements were obtained from the lower limbs together with body weight changes and arterial pressure at regular time intervals. Heart rate, stroke volume, mean blood flow, peripheral vascular resistance, the peak of the first derivative of the impedance signal and ' O ' wave amplitude were extracted from dZ/dt Clinical hypotension or drops in mean arterial blood pressure of more than 30 mmHg were observed in 6 HD. A multivariate regression model using body weight changes and peak dZ/dt suggests that it is possible to predict changes in arterial pressure with 6% error with an anticipation of up to 30 minutes in the phase of hemodialysis. The correlation obtained between basal impedance and body weight (r = 0.92, p © 1992 IEEE.

关键词： Blood pressure

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Mode conversion effect on the scattering of elastic spheres near resonance

Mode conversion effect on the scattering of elastic spheres ...

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IEEE Symposium (IUS) Ultrasonics

作者： J.C. Machado A. Ishimaru R.A. Sigelmann Biomedical Engineering Program COPPE UFRJ Rio de Janeiro Brazil Department of Electrical Engineering University of Washington Seattle WA USA

Presents experimental and theoretical investigations about the effect of mode conversion on the ultrasonic total cross section of polystyrene spheres near the resonance. An ultrasonic continuous-wave was transmitted through a random medium consisting of a suspension of polystyrene spheres (mean diameter 0.589 mm, standard deviation 0.066 mm) in a solution of water and sugar. The average total cross section of the particle distribution was obtained from measurements of the wave intensity attenuation, for frequency ranges of 0.85 to 3.0 MHz and 5.0 to 6.0 MHz, equivalent to ka ranges (k as the wave number and a as the average radius of the particles) of 1.05 to 3.71 and 6.18 to 7.41, respectively. Experimental results of the total cross section presents a resonant behavior, for ka between 1.07 to 1.38, that is demonstrated to be due to propagation of acoustic shear waves inside the particles

关键词： Acoustic scattering Spheres Plastic materials/devices

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

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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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The effect of the instantaneous RR interval on the dynamic properties of the heart rate and the ventricular repolarization duration variability

The effect of the instantaneous RR interval on the dynamic p...

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Computers in Cardiology (CinC)

作者： P.R.B. Barbosa J. Barbosa-Filho I. Cordovil J. Nadal Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Brazil Department of Cardiology Gama Filho University Brazil

instantaneous RR interval on HRV and VRD variability. High resolution ECG signals of 20 normal adults were analyzed, respectively, by the normal RR interval series and by detecting the distance between the peaks of R- and T-waves (RTm). HRV and VRD variability were assessed by the mean (M), the standard deviation (SD) and root-mean-squared difference (RMS) of consecutive normal RR and RTm intervals, stratified according to RR interval histogram. Results indicate that HRV reduces as mean RR interval shortens while the VRD variability paradoxically increases.

关键词： Heart rate Vents Heart rate variability Signal analysis Cardiology Cardiac disease Signal resolution Electrocardiography Aging Cardiovascular diseases

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Using ANOVA to analyse thalidomide’s molecular mechanisms in human PBMC microarrays

Using ANOVA to analyse thalidomide’s molecular mechanisms i...

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IEEE Symposium on Bioinformatics and Bioengineering (BIBE)

作者： Renata T. Paiva Barbara C. Dias Marcelo Ribeiro-Alves Ulisses G. Lopes Flavio F. Nobre MSc student Biomedical Engineering Program COPPE/UFRJ Rio de Janeiro Brazil Centre for Technological Development Health FIOCRUZ Rio de Janeiro Brazil Structural and Molecular Biology Program IBCCF/UFRJ Rio de Janeiro Brazil Biomedical Engineering Program COPPE/UFRJ Rio de Janeiro Brazil

Thalidomide is an anti-inflammatory and immunomodulatory drug that is the treatment of choice for erythema nodosum leprosum (ENL), an inflammatory cutaneous and systemic complication of multibacillary leprosy. Its use in leprosy and other conditions is controversial due to its teratogenic effects. Fifty years after the development of thalidomide, its action mechanism is still not well understood. In the present study we analyzed the in vitro effect of thalidomide on global gene expression in cultured human Peripheral Blood Mononuclear Cells (PBMC) of normal donors. We normalized the background subtracted spotted cDNA microarray data using a locally weighted linear regression and modeled its residual by a two-step analysis of variance to detect differentially expressed PBMC human genes in response to thalidomide. Using the full set of spotted genes, 13 genes were identified as differentially expressed genes. A reduced set was derived with a direct simple filtering approach and this set resulted in eight differentially expressed genes. Among these 21 genes, 15 are involved in the immune regulation processes.

关键词： Analysis of variance Humans Immune system Drugs In vitro Gene expression Blood Cells (biology) Linear regression Filtering

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A fractional electrical impedance model in detection of occlusal non-cavitated carious

A fractional electrical impedance model in detection of occl...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Andréa P. Morais Alexandre V. Pino Mãrcio N. Souza Biomedical Engineering Program COPPE Centro de Tecnologia Federal University of Rio de Janeiro Rio de Janeiro Brazil

Identification of occlusal caries remains a major concern for the diagnosis, which is still highly subjective and presents a considerable variability among clinicians. Dentists have been observed an increase of a specifically type of caries lesion, the hidden caries. Among the available techniques to assess the hidden caries, the measurement of electrical impedance has been shown to be one of the most promising. This paper presents a fractional electrical model for the tooth and uses such a model associated to a BioImpedance Spectroscopy (BIS) method based on the current response to a step voltage excitation. An analytical solution for the current response is presented based on a fractional calculus approach. Estimate parameters of the proposed model achieved using an in vitro data acquired in a protocol performed to collect bioimpedance data showed that it seems possible to detect occlusal non-cavitated caries, and that the principal confounding factor in the diagnosis of the incipient occlusal caries, the pigmented areas, can also be differentiated.

关键词： Teeth Dentistry Impedance Biological system modeling Bioimpedance Lesions Bioinformatics

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Wavelet analysis of phonocardiograms: differences between normal and abnormal heart sounds

Wavelet analysis of phonocardiograms: differences between no...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： F.C. Jandre M.N. Souza Biomedical Engineering Program-COPPE Centro de Tecnologia Federal University of Rio de Janeiro Rio de Janeiro Brazil

Phonocardiography-based diagnosis can be improved by modern techniques of signal processing. This work investigates the analysis of phonocardiograms using the time-frequency distribution generated by the cochlear wavelet transform. We show here a comparative study of normal and abnormal heart sounds, whose scalograms exhibit noticeable morphological differences in terms of duration and spectral composition of sounds. These differences suggest that the cochlear-wavelet-based scalogram can become an interesting approach to design automatic diagnosis systems.

关键词： Wavelet analysis Heart Frequency Pathology Cardiac disease Signal analysis Filters Signal resolution Statistics Wavelet transforms

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Design and evaluation of a linear servocontrolled pressure generator for studies in respiratory impedance

Design and evaluation of a linear servocontrolled pressure g...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： P.L. de Melo M.M. Werneck A. Giannella-Neto Biomedical Engineering Program COPPE Federal Universitoyf Rio de Janeiro Rio de Janeiro Rio de Janeiro Brazil

A very common problem in respiratory impedance measurement is the unreliability of the data in the low frequency range. The use of unbiased estimators is a good alternative to overcome this problem, provided that the generator is linear. This, however, is not the case in the great majority of the generators described so far, because the loudspeakers are non-linear systems. The generator described in this work is designed to overcome this problem by the use of a feedback loop which controls the loudspeaker cone position. The evaluation of the proposed generator has shown an effective decrease of non-linearities. In addition, an improvement in the frequency response was achieved (open loop=23 Hz: closed loop=44 Hz). The closed loop band includes the most common frequency range (2 to 32 Hz) used in the literature.

关键词： Loudspeakers Optical amplifiers Feedback loop Linearity Optical sensors Photodetectors Proportional control Frequency response Signal generators Signal analysis

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Noninvasive cardiac output estimates during quiet respiration through partial CO2 rebreathing

Noninvasive cardiac output estimates during quiet respiratio...

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Annual International Conference of the IEEE engineering in Medicine and Biology Society (EMBC)

作者： Marcos F. Vidal Melo Marcelo G. Abreu Antonio Giannella-Neto Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de Janeiro Rio de Janeiro Brazil

A noninvasive technique to measure cardiac output in spontaneously breathing subjects is evaluated. It is based on a differential form of the Fick equation and a partial rebreathing maneuver. Corrections for experimental error and a new ventilatory maneuver are introduced to reduce variability. Results suggest that the technique may attain error performance compatible with the invasive thermodilution method.

关键词： biomedical measurements Heating Cardiology

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IIWM (Integration ImageJ with MATLAB) program for Segmentation and Volume Estimation in Ultrasound Biomicroscopic Images of Mouse Colon Tumor

IIWM (Integration ImageJ with MATLAB) Program for Segmentati...

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Ultrasonics Symposium (LAUS), IEEE UFFC Latin America

作者： Igor Soares Colonna Yasmin Farias Romi de Sant'Anna Rodrigo Pereira de Oliveira João Carlos Machado Biomedical Engineering Program/COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil INFNET Institute Rio de Janeiro Brazil Department of Surgery Biomedical Engineering Program/COPPE and Post-Graduation Program in Surgical Sciences School of Medicine Federal University of Rio de Janeiro Rio de Janeiro Brazil

ISBN: (数字)9798350349085

ISBN: (纸本)9798350349092

This article proposes the creation, implementation and development of an integration plugin for ImageJ that makes calls in MATLAB functions for the segmentation UBM imagens, more specific endoluminal (eUBM) e transabdominal (tUBM), in the laboratory the images are generating with frequencies between 30-40 MHZ. These images allow view colon layer, identify tumors in colons, to calculate tumor volume and 3D visualization. This integration may to improve the time taken to perform the procedure and the user experience to reduce the number of tasks and change windows, making the experience more fluid and with less risk of errors.

关键词： Solid modeling Image segmentation Visualization Ultrasonic imaging Three-dimensional displays Biological system modeling Volume measurement

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