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1.
Comput Biol Med ; 80: 30-38, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-27888794

RESUMO

Monitoring the fetal cardiac activity during pregnancy is of crucial importance for evaluating fetus health. However, there is a lack of automatic and reliable methods for Fetal ECG (FECG) monitoring that can perform this elaboration in real-time. In this paper, we present a hardware architecture, implemented on the Altera Stratix V FPGA, capable of separating the FECG from the maternal ECG and to correctly identify it. We evaluated our system using both synthetic and real tracks acquired from patients beyond the 20th pregnancy week. This work is part of a project aiming at developing a portable system for FECG continuous real-time monitoring. Its characteristics of reduced power consumption, real-time processing capability and reduced size make it suitable to be embedded in the overall system, that is the first proposed exploiting Blind Source Separation with this technology, to the best of our knowledge.


Assuntos
Eletrocardiografia/métodos , Monitorização Fetal/métodos , Processamento de Sinais Assistido por Computador , Algoritmos , Análise por Conglomerados , Feminino , Feto/fisiologia , Humanos , Gravidez
2.
Ultrasonics ; 39(2): 143-50, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11270632

RESUMO

In this paper we present Flow Rate Profiler (FRP), an instrument for measuring the blood velocity by means of ultrasound-based techniques. The velocity is directly related to the shear rate, which is in turn proportional to the shear stress, a parameter expressing the pressure exerted by the blood on the vessel walls. The knowledge of this value is important in medicine to establish the state of the vessels, directly related to vascular diseases. FRP provides a non-invasive measure of the blood velocity by exploiting the red corpuscles property of diffusing ultrasound waves: in practice blood velocity is determined by a cross-correlation technique, which analyses the time shift between correlated subsequent echo waves, instead of frequency shift characteristic of the Doppler technique. The acquired data are then processed on a personal computer by means of mathematical techniques based on the evaluation of the correlation function, giving a reconstructed velocity profile and showing a good adherence with experimental data, since the average error is nearly the 10%. The reconstructed profile is displayed to the operator, who can follow the vessel status in real time. A few comparisons between the reconstructed and the experimental profiles are also presented, together with a study on a small set of patients suffering from artery hypertension.


Assuntos
Velocidade do Fluxo Sanguíneo , Hipertensão/diagnóstico por imagem , Ultrassonografia Doppler/instrumentação , Desenho de Equipamento , Humanos
4.
Biochem Mol Biol Int ; 38(2): 297-306, 1996 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8850525

RESUMO

In order to gain some insight into the mechanism by which nicotinamide nucleotides localize in mitochondria, NMN was added to rat liver mitochondria, with NAD synthesis tested both enzymatically and by means of HPLC. Evidence is given that the mitochondrial matrix contains a specific NMN adenylyltransferase (E.C. 2.7.7.1.), inhibited by PPi, AMP and ADP-ribose. Some features of this enzyme, including the substrate, pH and temperature dependence were also investigated.


Assuntos
Trifosfato de Adenosina/metabolismo , Mitocôndrias Hepáticas/metabolismo , NAD/biossíntese , Mononucleotídeo de Nicotinamida/metabolismo , Nicotinamida-Nucleotídeo Adenililtransferase/metabolismo , Adenosina Difosfato Ribose/farmacologia , Monofosfato de Adenosina/farmacologia , Animais , Difosfatos , Concentração de Íons de Hidrogênio , Masculino , Mitocôndrias Hepáticas/enzimologia , NADP/biossíntese , Ratos , Especificidade por Substrato
5.
G Ital Med Lav ; 12(1): 43-8, 1990 Jan.
Artigo em Italiano | MEDLINE | ID: mdl-2136340

RESUMO

Authors propose an original method for studying muscular hypotrophy considering mechanical output. Tests was performed on femoral quadriceps in order to have standardized parameters about work of normal, pathologic and retrained muscle.


Assuntos
Exercício Físico/fisiologia , Músculos/fisiologia , Adulto , Fatores Etários , Fenômenos Biomecânicos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Movimento , Doenças Musculares/fisiopatologia , Fatores Sexuais
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