Analise dos fenomenos sonoros articulares do joelho atraves de processamento digital / Analysis of the knees articular sonorous phenomena using digital processes

AUTOR(ES)
DATA DE PUBLICAÇÃO

1999

RESUMO

The purpose of this study is to investigate the knees articular sonorous phenomena, through arthrosonography, using digital processes. Two hundred and fifteen (215) volunteers, of both sexes, with ages varying between 10 and 75, participated in this study. From this total, 145 volunteers didn t have a historic of articular diseases and 70 had rheumatic diseases. The recording of the knees articular sounds was obtained in an a,coustic chamber, using a Sennheiser ultradirectional condenser microphone and a Kudelski . analogic tape recorder. The recordings were subsequently transferred to a Taskam digital tape recorder and then to a microcomputer, in order to be handled and analyzed. The results obtained indicated that both the knees of the volunteers without articular diseases (assymptomatic knee) and the ones of those with rheumatic diseases (symptomatic knees) could be included in a common classification. This is due to the fact that the purpose of this study was only to identify, recognize and analyze the articular sonorous phenomena observed. Concerning the time scale, during the knee movement, articular sonorous phenomena of short duration, such as claps, cracks and thuds, could be observed. In these cases, the duration of the sound remained between 0.02 and 0.04 seconds. Sonorous long time knee phenomena, with duration of about 1.0 second, such as articular crepitation, were present. Knees were classified as "sonorous silence type", when the total absence of articular sonorous phenomena was registered by the microphone in the recordings. Knees were classified as "weak, medium and strong sonorous type" depending on the minar or major presence of articular noises in the recordings. Three parameters were used in the analysis of those articular sounds: waveforms, frequency noise spectrum and potential spectra density. The potential spectra density was used only to analyze short time phenomena. The results of this study showed that the arthrosonography technique is, a good toei for recording and analyzing articular sounds produced during the knees movements, allowing a good characterization of articular sonorous phenomena. For the purpose of this study, the microphone proved to be a good transducer in terms of frequency and dynamic sensitivities, for utilization in human joint emissions, since it captures ali the characteristics of the articular sounds, allowing the identification of each acoustic phenomenon through its spectral composition

ASSUNTO(S)

knee joints som sound articulações joelhos

ACESSO AO ARTIGO

Documentos Relacionados