检索结果-内蒙古大学图书馆

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

作者： Antonio Giannella Neto Marcio J. O. do Vale Marcos F. Vidal Melo Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil

This work presents a simple, reliable and accurate calibration technique for pneumotacographs. It is based on a polynomial curve fitting which minimizes the calculated volume error for a set of injections of a calibrated syringe. In conditions similar to human spirometry the results meet the standards of the American Thoracic Society.

关键词： Converters Fitting

来源：评论

学校读者我要写书评

暂无评论

An investigation of the statistics of coherence estimates in EEG signals

An investigation of the statistics of coherence estimates in...

引用

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

作者： A. M. F. L. Miranda de Sá D. M. Simpson A. F. C. Infantosi Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil

Coherence has been used to study the dependence between EEG derivations as a function of frequency. In order bto arrive at meaningful conclusions the statistics of the estimates must be known and are investigated in this paper — since the literature is rather confusing in this respect. The work is based on simulations with random signals and comparison with the values given in the literature.

关键词： Coherence

来源：评论

学校读者我要写书评

暂无评论

Preliminary study of Pseudoarthrosis ultrasonic characterization

Preliminary study of Pseudoarthrosis ultrasonic characteriza...

引用

IEEE Symposium (IUS) Ultrasonics

作者： Daniel Patterson Matusin Wagner Coelho de A. Pereira Christiano Bittencourt Machado Manoel L. Ferreira Alberto Schanaider Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil

Pseudoarthosis is a consequence of a failure in bone fracture healing process, resulting in a non-union and relative motion between fragments. The evolution of fracture consolidation and the diagnosis of pseudoarthrosis have often a follow-up with conventional X-rays exams. Quantitative ultrasound (US) characterization has the advantage of being a non-ionizing energy and of low cost. A pulse-echo substitution method to characterize biological tissues by backscattered US was implemented. Pseudoarthrosis characterization was made by parameters Apparent Integrated Backscatter - AIB, Frequency Slope Apparent Backscatter - FSAB and Time Slope Apparent Backscatter - TSAB. Initials results have shown that parameters AIB and FSAB were able to differentiate normal from pseudoarthrotic tissues with statistical significance. Additional experiments with a greater number of samples are to be made, as well as some methodological adjustments aiming in vivo applications.

关键词： Bones Backscatter X-rays Costs Surgery Transducers Evolution (biology) Ultrasonic imaging Biological tissues Frequency

来源：评论

学校读者我要写书评

暂无评论

Characterization of Thermal Properties of Polymethylmethacrylate Bone Cement for Therapeutic Ultrasound Application

Characterization of Thermal Properties of Polymethylmethacry...

引用

Pan American Health Care Exchanges, PAHCE

作者： A. M. C. Lopes K. A. Coelho L. F. Pereira W. C. A. Pereira Biomedical Engineering Program - COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil

Biomaterials interact with biological systems and are intended to replace tissues and body organ functions. They can be classified as natural or synthetic. Polymethylmethacrylate (PMMA) is a synthetic biomaterial used, from the 1940’s to the present day, in orthopedic surgeries to replace joint surfaces and/or repair fractures. The basis of its components remains the same, small changes create variations in its properties; therefore, it is necessary to measure them. This work aims to characterize the thermal properties of PMMA, comparing them with those of soft tissues, bone and metallic prosthesis. The PMMA sample was stimulated 11 times for 3 seconds each by the modified transient plane source (MTPS), presenting the following averages: thermal conductivity =0.229± 0.006K(W/mK); effusivity =581.20± 6.22W$\mathrm{s}^{1/2}$/$\mathrm{m}^{2}$K and specific heat =1204.23± 6.88 ***. oC-1. The thermal properties obtained suggest that the cement would not cause local overheating, thus enabling the use of TUS on the region containing PMMA. The metallic prosthesis seems to play an important role in the dissipation of the heat generated, contributing to the non-heating of the multilayer system. However, more studies are needed to clarify this issue.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Morphological Operators on the Segmentation of Breast Ultrasound Images

Morphological Operators on the Segmentation of Breast Ultras...

引用

Pan American Health Care Exchanges Conference, Workshops and Exhibits (PAHCE 2009)

作者： W. Gomez L. Leija W. C. A. Pereira A. F. C. Infantosi Department of Electrical Engineering Bioelectronics CINVESTAV-IPN Biomedical Engineering Program - COPPE Federal University of Rio de Janeiro

ISBN: (纸本)9781424436682

This work presents a computerized lesion segmentation technique on breast ultrasound images. There were applied known techniques such as morphological filtering, Watershed transform and average radial derivative function. To evaluate the performance of the proposed method the resulting segmentation contours were compared with 36 breast US images manually delineated by two senior radiologists. Further, two evaluation parameters were used: the percentage of coincidence (CP) and the proportional distance (PD). The former indicates the similarity between contours, while the latter express the dissimilarity. The accuracy of the proposed method was evaluated by considering images with CP ≥ 80% and PD ≤ 10% as adequately delineated.

关键词： Breast ultrasound Segmentation Morphological operators

来源：评论

学校读者我要写书评

暂无评论

Source Derivation assuming a spherical geometry for the head: Applications in topographic brain mapping

Source Derivation assuming a spherical geometry for the head...

引用

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

作者： C. J. Tierra Criollo J. R. Bokehi D. M. Simpson A. F. C. Infantosi Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil

Source Derivation (SD) is a technique that emphasizes brain electrical activity below the electrodes. Topographic maps have been made to compare the effects of different assumptions regarding head geometry, II the spatial selectivity of SD. First, we used a local orthogonal tangential coordinate system assuming a planar surface, then a spherical head was considered and a local curvilinear coordinate system was employed. The algorithm is based on the finite difference method for non-uniform grids. With simulated and EEG data, improved source derivation in spherical geometry was found.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Evaluation of materials for confection of phantoms to mimetize acoustic properties of tendons

引用

Research on biomedical engineering 2021年第1期37卷 47-52页

作者： Gomes, Gabriela Beatriz De Matheo, Lucas Lobianco da Silva, Flavia Fernandes Ferreira Maggi, Luis Eduardo von Krüger, Marco Antônio de Albuquerque Pereira, Wagner Coelho Programa de Engenharia Biomédica COPPE Universidade Federal do Rio de Janeiro Rio de JaneiroRJ Brazil Biomedical Engineering Program COPPE Federal University of Rio de Janeiro Rio de JaneiroRJ Brazil Programa de Pós-Graduação em Ciências da Saúde na Amazônia Ocidental Universidade Federal do Acre Rio BrancoAC Brazil Graduate Program in Health Sciences in the Western Amazon Federal University of Acre Rio BrancoAC Brazil

Background: The tendon is a structure found in different parts of the human body. Damages within tendons cause movement deficit and discomfort, which requires medical and therapeutic treatment. One useful tool is the therapeutic ultrasound;however, fine adjustment is required to avoid further lesions to the patient. Aiming at enhancing the resources for the research in the study of therapeutic ultrasound and the knowledge regarding its application to tendons, the objective of this work is to evaluate materials to prepare ultrasonic phantoms that mimic the acoustic properties of the tendons. Materials and methods: The acoustic characterization of a pig tendon and three PVCP-based phantoms were made. The transmission-reception method was used, and the propagation speed and attenuation of each phantom were calculated. Results: The tendon showed an attenuation of 4.8 ± 1.7 dB cm−1 and propagation speed of 1497.5 ± 21.6 m s−1. The attenuation of the phantoms varied from 1.3 ± 1.2 to 4.0 ± 1.0 dB cm−1 and velocity from 1509.9 ± 31.8 to 1519.8 ± 26.7 m s−1. Conclusions: We concluded that among the materials used, it was possible to find values statistically similar to this animal tendon in the PVCP phantom with 15% glycerin and 10% PVC powder. Complementary studies with other materials and protocols are needed to mimic other values found in the literature. © 2020, Sociedade Brasileira de Engenharia Biomedica.

关键词： Ultrasonics

来源：评论

学校读者我要写书评

暂无评论

Use of Endoluminal and Transabdominal Ultrasound Biomicroscopy to Measure Colon Wall Thickness in Healthy and Tumor-Bearing Mice

Use of Endoluminal and Transabdominal Ultrasound Biomicrosco...

引用

Ultrasonics Symposium (LAUS), IEEE UFFC Latin America

作者： Juliana Oliveira da Silva Fernandes Rodrigo Pereira de Oliveira João Carlos Machado Biomedical Engineering Program/COPPE Federal University of Rio de Janeiro Rio de Janeiro Brazil Biomedical Engineering Program/COPPE and Post-Graduation Program in Surgical Sciences/Department of Surgery/School of Medicine Federal University of Rio de Janeiro Rio de Janeiro Brazil

ISBN: (数字)9798350349085

ISBN: (纸本)9798350349092

Colorectal cancer (CRC) ranks among the most prevalent tumors, particularly affecting men and women, with mouse models and imaging technologies like colonoscopy, endoluminal (eUBM), and transabdominal (tUBM) ultrasound biomicroscopy playing pivotal roles in exploring new treatment avenues. The evaluation of colon wall thickness (Wt), a significant marker of tumor presence, is feasible through eUBM or tUBM, contrasting with colonoscopy's limitations. This study scrutinizes the consistency of Wt measurements obtained via eUBM and tUBM in mice, with or without colon tumors induced by azoxymethane (AOM) and dextran sulfate sodium salt (DSS). UBM images were captured using both eUBM and tUBM instruments, with subsequent Wt measurements performed using ImageJ software. Comparison between Wt obtained from eUBM and tUBM images used the One-Way ANOVA, for normal distributed data, or the Kruskal-Wallis test otherwise. Local Ethics Committee for Animal Use in Research approved the work (protocol 014/20). In general, the results indicate a substantial median Wt disparity between control and tumor groups measured by both techniques (p<0.05). Notably, discrepancies in Wt findings between the two methods were observed in the control group (p<0.05), despite the excellent resolution of the images in delineating colon layers.

关键词： Ultrasonic imaging Ultrasonic variables measurement Colonoscopy Mice Colon Software measurement Spatial resolution

来源：评论

学校读者我要写书评

暂无评论

Evaluation of heating patterns generated by therapeutic ultrasound insonation in muscle phantoms

Evaluation of heating patterns generated by therapeutic ultr...

引用

Pan American Health Care Exchanges, PAHCE

作者： R. L. Q. Basto N. S. Amorim E. R. Monteiro J. N. N. Quaresma R. M. Cotta M. A. von Krüger W. C. A. Pereira POLI & COPPE LTTC-Laboratory of Transmission and Technology of Heat Mechanical Engineering Program UFRJ Rio de Janeiro Brazil COPPE Laboratory of Ultrasound Biomedical Engineering Program UFRJ Rio de Janeiro Brazil

The present work aims at studying the effect of heating patterns generated by therapeutic ultrasound (US) insonation on tissue mimicking device called Phantom. With this purpose, it was constructed a cylindrical calorimeter (80 mm height and 42 mm diameter) which was filled with muscle mimic phantom, for acquisition of temperature an array of thermocouples was placed at 2 and 6 cm depth. Ultrasound physiotherapy equipment was used at two therapeutic frequency (1 and 3 MHz), three intensities, and continuous irradiation mode and applied for 300s static mode. The experimental temperatures elevation profiles in Phantom were compared to a 2D bio-heat equation model, permitting a critical evaluation of such experimental data. The acoustic heating model was based on the US absorption equation, assuming linear propagation and neglecting stationary wave and multiplies reverberation effects. The comparison between experimental and mathematical simulation for the central thermocouple showed that, for far field the correlation between the experimental and simulated values are higher than for the near field.

关键词： Ultrasonic imaging Phantoms Biological system modeling Mathematical model Temperature distribution Temperature measurement Heating

来源：评论

学校读者我要写书评

暂无评论

Study of acoustic features of newborn cries that correlate with the context

Study of acoustic features of newborn cries that correlate w...

引用

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

作者： H.E. Baeck M.N. Souza Program of Biomedical Engineering Federal University of Rio de Janeiro (COPPE-EE) Rio de Janeiro Brazil

Many researches related to the infant cry analysis intent to estimate the context and/or obtain objective information concerning the physical and emotional condition of newborns. Using several techniques in signal processing, peculiar acoustics features, such as the fundamental frequency and formants, are classically analyzed. However, the findings reveal the existence of some contests with respect to the conclusions. In this article a specific phonologic program was used to analyze the cry signal, aiming to investigate the real significance of some classical frequency domain parameters. The results point out that just two among four studied parameters seem to contribute in the analysis of the cry signal context. Beside the significance of the two parameters in such analysis, the problem complexity indicate that the more researches are necessary to find out new parameters, maybe correlated with psychoacoustic principles.

关键词： Pediatrics Signal analysis Information analysis Frequency domain analysis biomedical acoustics biomedical engineering Acoustic signal processing biomedical signal processing Psychology Humans

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：