RESUMO
This paper presents results of a study on M-mode echocardiogram analysis and classification using the recently developed data-dependent system (DDS) methodology along with clustering techniques. Results of thirty clinically obtained waveforms yielded a correct classification rate of between 83% and 90%, depending on the features used for clustering. The choice of features was facilitated, in part, by a study of six hypothetical waveforms representing an echocardiogram in transition from normal to stenosed. The DDS approach offers potential in the identification and recognition of various cardiac abnormalities, based on echocardiographic data. A comparison with Fourier analysis confirmed the results and points to the advantages of DDS in (a) minimizing false negatives and (b) providing additional features for improved discrimination.
Assuntos
Ecocardiografia/métodos , Coração/anatomia & histologia , Estenose da Valva Mitral/diagnóstico , Valva Mitral/anatomia & histologia , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Análise de Fourier , Humanos , Masculino , Pessoa de Meia-IdadeAssuntos
Computadores , Ecocardiografia/métodos , Estenose da Valva Mitral/diagnóstico , Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
This paper briefly examines the experimentally observed effects in, and symmetry arguments for, the constituents of bone which lead to a transversely isotropic configuration for the elastic behavior of bone. Based on this, a regime for computing the anisotropic elastic constants is considered in terms of ultrasonic transit time measurements. To extend the usefulness of ultrasonic techniques to an in vivo situation, a mathematical model for bone is developed in outline form and numerical results for the characteristic frequency equation discussed.