Tyrimo hipotezė: atliekant laiptiškai sunkėjantį krūvį, pasiekus LKS, turėtų atsirasti pokyčiai žingsnio parametruose. Tyrimo tikslas: nustatyti širdies susitraukimų dažnio ir žingsnių parametrų sąsajas atliekant Conconi testą. Siekiant šio tikslo buvo užsibrėžti šie uždaviniai: 1. Nustatyti ir įvertinti ŠSD pokyčius Conconi testo metu ir nustatyti La kaupimosi slenksčius. 2. Nustatyti ir įvertinti žingsnio parametrų (žingsnio dažnio, žingsnio ilgio, atramos trukmės ir polėkio trukmės) pokyčius Conconi testo metu. 3. Nustatyti sąsajas tarp ŠSD ir žingsnio parametrų Conconi testo metu. Tiriamąją imtį sudarė 8 vyrai – ištvermės atstovai bėgikai, kurie atliko Conconi testą. Tiriant buvo naudojamas ActiGraph ActiTrain prietaisas, kuriuo registravome ŠSD ir žingsnių dažnį. Kinematiniams parametrams išmatuoti naudojome dvi, 100 Hz dažnio sinchronines kameras, kuriomis fiksavome žingsnio parametrus. Šiuos parametrus, specializuotą judesių analizės programą SIMI MOTION 2D, apskaičiavome atramos, polėkio ir žingsnio trukmes (s), žingsnio ilgį (m), žingsnio dažnį (k/s) ir bėgimo greitį (m/s). La slenksčio nustatymui naudojome Orgin 6.0 programą. Rodiklių sąsajos kaitai vertinti pasinaudojome Kauno mokslininkų (Vainoras ir kt. 2008) sukurta matricinės analizės metodika. Tyrimo rezultatai parodė, kad nuosekliai didėjant bėgimo greičiui ir pasiekus 14.57±1.47 km/h bėgimo greitį, pradeda kauptis laktatas, tuo pat metu ŠSD būna 171.91±7.66 t/min. Maksimalus ŠSD - 195.14±6.32 t/min... [toliau žr. visą tekstą] / The hypothesis of the work: there should be an appearance of changes in step parameters when reaching VMS while performing activities with gradual increase of workload. The aim of the work is to determine the links of heart rate and step parameters in the Conconi test. To achieve this aim we have been established the following objectives: 1. Identify and evaluate changes in heart rate and the La accumulation thresholds during the Conconi test. 2. Identify and evaluate the parameters of step (step frequency, stride length, head length and flight time) changes during the Conconi test. 3. Identify the relationship between heart rate and steps parameters. The sample consisted of 8 men - representatives of endurance runners who have completed the Conconi test. During the test was used an ActiGraph ActiTrain device, which registered the heart rate and steps rates. To measure the kinematic parameters, we used two synchronous cameras of 100 Hz, which recorded the steps parameters. These parameters with an specialized motion analysis program SIMI MOTION 2D we calculated the support, enthusiasm and step time (s), stride length (m), step frequency (t/s) and running speed (m/s). To determinate the La threshold we uses a 6.0 Orgin program. To evaluate the indicators of the interface changes we took advantage the analysis of a matrix methodology scientist of Kaunas (Vainoras et al. 2008). The results have shown that lactate begins to accumulate at a consistent increase in running speed... [to full text]

Made available in DSpace on 2016-01-26T12:51:53Z (GMT). No. of bitstreams: 1 paulorogeriocorrea_tese.pdf: 1233217 bytes, checksum: 4e4b574f24af12fb3446f5336ad9af00 (MD5) Previous issue date: 2006-12-01 / Heart Rate Variability (HRV) is the most frequently used non-invasive diagnostic method for evaluating the heart autonomic control. Taking into consideration that the autonomous nervous system modulates, in an important way, the cardiovascular function, any alteration in the autonomous cardiovascular function constitutes cause and/or coadjuvant condition for numerous diseases. Recent studies have shown that through the heart frequency variability, by evaluating it within time, frequency and chaos domain, the human organisms, generally speaking, show a behavior of nonlinear complex systems, thus following the laws of Chaos Theory. The HRV analysis, by other nonlinear dynamic methods in the myocardial revascularization surgery pre-operation period, could predict more morbidity in the post-operation period, for example, lung infections. Objective: Evaluate the heart rate variability (HRV) behavior in the chaos domain (nonlinear dynamic) in the preoperative period of surgical myocardial revascularization and its relationship to lung infections occurrences in postoperative stay. Casuistic and Method: 72 non-selected patients were studied (age range from 58.4±10.2 years old) with coronary artery disease and having elective surgery indication for myocardial revascularization. In order to quantify the HRV in the chaos domain, the Detrended Fluctuation Analysis (DFA total) variables, their short-term (α1) and long-term (α2) correlations, Approximate Entropy (-ApEn), Lyapunov Exponent (LE), self-correlation (Tau), Normalized Tau (nT) and Hurst Exponent (HE) were measured in temporal series of 1.000 RR intervals of electrocardiogram recorded on the day before the operation, with Polar S810i equipment. Results: The cut-off levels were determined with help from ROC curve being for DFA total, α1, α2, Approximate Entropy, Lyapunov Exponent, Tau, Normalized Tau and Hurst Exponent, respectively: 1.036917,  0.727273,  0.906397,  0.480176,  0.832,  28.23143, 11.312504,  and 0.210447. In the Chaos Domain, the DFA total, Normalized Tau , Approximate Entropy and Lyapunov Exponent in the pre-operation period, were associated with the lung infection occurrences in the postoperative period with P =0.0309, P=0.0232, P= 0.0307 and P= 0.0006, respectively. In conclusion, the nonlinear dynamic methods, in their respective cut-off levels, allowed differentiating the cases that evolved into lung infection in the postoperative period of surgical myocardial revascularization. / A Variabilidade da freqüência cardíaca (HRV Heart Rate Variability ) é o método diagnóstico não invasivo mais freqüentemente usado na avaliação do controle autonômico do coração. Considerando que o sistema nervoso autônomo modula, de maneira importante, a função cardiovascular, as alterações na função autonômica cardiovascular constituem causa e/ou condição coadjuvante de numerosas doenças. Estudos recentes têm mostrado que pela análise da variabilidade da freqüência cardíaca, avaliando-a nos domínios do tempo, da freqüência e do caos, os organismos humanos, de forma geral, comportam-se como sistemas complexos não-lineares, obedecendo-se, assim, às leis da Teoria do Caos. A análise da HRV por outros métodos de dinâmica não linear no período pré-operatório da cirurgia de revascularização do miocárdio poderia ser preditora de maior morbidade no pós-operatório, como por exemplo, infecções pulmonares. Objetivo: Avaliar o comportamento da variabilidade da freqüência cardíaca (HRV) no domínio do caos (dinâmica não-linear) no período pré-operatório da cirurgia de revascularização do miocárdio e sua relação com a ocorrência de infecções pulmonares no período pós-operatório hospitalar. Casuística e Método: Foram estudados 72 pacientes não-selecionados (média de idade de 58,4±10,2 anos) com doença arterial coronária e indicação eletiva de cirurgia de revascularização do miocárdio. Para quantificar a dinâmica da HRV no domínio do caos foram medidas as variáveis, Análise das Flutuações Depuradas de Tendências (DFA total), seus componentes de curto (α1) e longo (α2) prazos, Entropia Aproximada (-ApEn), Expoente de Lyapunov (LE), Autocorrelação (Tau), Tau normalizado e Expoente de Hurst (HE) em séries temporais de 1.000 intervalos RR do eletrocardiograma captados na véspera da operação, com equipamento Polar S810i. Resultados: Os respectivos valores de corte determinados com auxílio da curva ROC foram para: DFA total, α1, α2, Entropia aproximada, Expoente de Lyapunov, Tau, Tau normalizado e HE respectivamente: 1, 036917,  0, 727273,  0, 906397,  0, 480176,  0, 832,  28, 23143, 11, 312504,  0,210447. No domínio do caos, a DFA total, Tau normalizado, Entropia Aproximada e Expoente Lyapunov no período pré-operatório, se associaram com a ocorrência de infecções pulmonares no pós-operatório de revascularização do miocárdio com P =0, 0309, P=0, 0232, P= 0,0307 e P= 0,0006 respectivamente. Em conclusão, os métodos de dinâmica não-linear, nos seus respectivos níveis de corte, permitiram diferenciar os casos que evoluíram com infecção pulmonar no período pós-operatório de cirurgia de revascularização do miocárdio.

L'analyse de séries temporelles biomédicales chaotiques tirées de systèmes dynamiques non-linéaires est toujours un challenge difficile à relever puisque dans certains cas bien spécifiques les techniques existantes basées sur les multi-fractales, les entropies et les graphes de récurrence échouent. Pour contourner les limitations des invariants précédents, de nouveaux descripteurs peuvent être proposés. Dans ce travail de recherche nos contributions ont porté à la fois sur l’amélioration d’indicateurs multifractaux (basés sur une fonction de structure) et entropiques (approchées) mais aussi sur des indicateurs de récurrences (non biaisés). Ces différents indicateurs ont été développés avec pour objectif majeur d’améliorer la discrimination entre des signaux de complexité différente ou d’améliorer la détection de transitions ou de changements de régime du système étudié. Ces changements agissant directement sur l’irrégularité du signal, des mouvements browniens fractionnaires et des signaux tirés du système du Lorenz ont été testés. Ces nouveaux descripteurs ont aussi été validés pour discriminer des fœtus en souffrance de fœtus sains durant le troisième trimestre de grossesse. Des mesures statistiques telles que l’erreur relative, l’écart type, la spécificité, la sensibilité ou la précision ont été utilisées pour évaluer les performances de la détection ou de la classification. Le fort potentiel de ces nouveaux invariants nous laisse penser qu’ils pourraient constituer une forte valeur ajoutée dans l’aide au diagnostic s’ils étaient implémentés dans des logiciels de post-traitement ou dans des dispositifs biomédicaux. Enfin, bien que ces différentes méthodes aient été validées exclusivement sur des signaux fœtaux, une future étude incluant des signaux tirés d’autres systèmes dynamiques nonlinéaires sera réalisée pour confirmer leurs bonnes performances. / The analysis of biomedical time series derived from nonlinear dynamic systems is challenging due to the chaotic nature of these time series. Only few classical parameters can be detected by clinicians to opt the state of patients and fetuses. Though there exist valuable complexity invariants such as multi-fractal parameters, entropies and recurrence plot, they were unsatisfactory in certain cases. To overcome this limitation, we propose in this dissertation new entropy invariants, we contributed to multi-fractal analysis and we developed signal-based (unbiased) recurrence plots based on the dynamic transitions of time series. Principally, we aim to improve the discrimination between healthy and distressed biomedical systems, particularly fetuses by processing the time series using our techniques. These techniques were either validated on Lorenz system, logistic maps or fractional Brownian motions modeling chaotic and random time series. Then the techniques were applied to real fetus heart rate signals recorded in the third trimester of pregnancy. Statistical measures comprising the relative errors, standard deviation, sensitivity, specificity, precision or accuracy were employed to evaluate the performance of detection. Elevated discernment outcomes were realized by the high-order entropy invariants. Multi-fractal analysis using a structure function enhances the detection of medical fetal states. Unbiased cross-determinism invariant amended the discrimination process. The significance of our techniques lies behind their post-processing codes which could build up cutting-edge portable machines offering advanced discrimination and detection of Intrauterine Growth Restriction prior to fetal death. This work was devoted to Fetal Heart Rates but time series generated by alternative nonlinear dynamic systems should be further considered.