RESUMO
This work proposes the clino-ortho maneuver to analyze the metabolic energy expenditure variability by Indirect Calorimetry (IC). This analysis uses a hybrid calorimeter which includes simultaneously the mixing-chamber (MC) and the breath by breath (BbB) IC techniques. VO2 and VCO2 short-term variability was characterized as metabolic variability in the MC technique by intra-group standard deviation averages. When the BbB technique was used the metabolic variability characterization was done by VO2 and VCO2 discrete time series power spectrum analysis in the 0-0.5 Hz band. Thus a statistical population of 17 young healthy volunteers was studied using a clino-ortho maneuver with 30-30 minutes in each position after 8 hours of fasting. The results showed an energy expenditure change of 40% in Kcal/day (p<0.01). The metabolic variability was partially significant using the MC technique while BbB total power spectrum changed from 35 to 60 for the VO2 and from 24 to 37 for the VCO2 (ml/bth)(2), (p<0.05) in the region from 0 to 0.04 Hz. It was concluded that using this new measurement technique and the clino-ortho maneuver metabolic variability information not yet studied was revealed.
Assuntos
Testes Respiratórios/instrumentação , Testes Respiratórios/métodos , Adolescente , Adulto , Índice de Massa Corporal , Calorimetria Indireta , Dióxido de Carbono/análise , Desenho de Equipamento , Frequência Cardíaca , Humanos , Modelos Biológicos , Oxigênio/análise , Consumo de Oxigênio , Valores de ReferênciaRESUMO
This paper proposes a discrete random time series modeling for the VO2 and VCO2 measurement in the indirect calorimetry technique (ICT). Mathematical equations are developed in order to establish clear differences between the breath-by-breath and mixing chamber measurement based calorimeters. This simple model offers not only a physiological ICT definition approach but also defines the idea of VO2 and VCO2 short-term variability information for research. The preliminary results show a new physiological information when a computer oriented algorithm model implementation was applied to a data acquisition system in order to obtain the power spectrum analysis from a typical observation subject submitted to the clino-ortho maneuver.
Assuntos
Testes Respiratórios/instrumentação , Calorimetria Indireta/métodos , Dióxido de Carbono/metabolismo , Consumo de Oxigênio , Oxigênio/metabolismo , Algoritmos , Testes Respiratórios/métodos , Desenho de Equipamento , Humanos , Modelos Estatísticos , Reprodutibilidade dos Testes , Respiração , Sistema Respiratório , Processamento de Sinais Assistido por Computador , SoftwareRESUMO
Methods to predict fragmentation efficiency are still needed for extracorporeal shock wave lithotripsy (ESWL). Imaging studies of kidney stones could be a useful tool to guide ESWL. Artificial and real kidney stones were analyzed using standard clinical CT imaging procedures. The objective was to compare CT image properties of phantom and real kidney stones. Image properties of both groups were compared and show a good agreement between them. These preliminary images will be used to measure CT attenuation coefficients of real and artificial stones and find a relationship between attenuation values and the fragmentation coefficient of renal calculi exposed to shock waves.
Assuntos
Interpretação de Imagem Assistida por Computador/métodos , Imageamento Tridimensional/métodos , Cálculos Renais/diagnóstico por imagem , Cálculos Renais/terapia , Litotripsia/métodos , Radiografia Intervencionista/métodos , Tomografia Computadorizada por Raios X/métodos , Algoritmos , Humanos , Aumento da Imagem/métodos , Técnicas In Vitro , Imagens de Fantasmas , Radiografia Intervencionista/instrumentação , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Four temporal and four spectral parameters of heart rate variability were compared after they were computed with two different time series generation methods: the RR intervals and the numerical values of heart rate provided by the Finapres. Recordings were obtained from 10 healthy subjects throughout five experimental conditions: supine, standing, controlled breathing, exercise and recovery. The mean and the RMS value of successive differences showed significant differences between the two methods. The spectral parameters were statistically different only during standing and exercise. The larger high frequency component and the lower HF/LF ratio by the Finapres method, observed during exercise, can be explained by the higher breathing influence on the peak-to-peak pressure intervals, in relation to RR intervals. Therefore, the high frequency component within mechanic intervals could possibly reflect the non-neural respiratory influence. In conclusion, values of heart rate provided by the Finapres are not completely interchangeable with those obtained from the ECG during the studied conditions.