Study On The Correlation Between OBF、OBP And Age Based On Time-frequency Domain

Several studies indicate that the elderly prone to high blood pressure with the age growing. Elevated blood pressure can lead to the changes of hemodynamic parameters in the blood circulation system, and then cause abnormal changes in the physiological activities of the endothelium, heart and so on. So we could study on the correlation between ocular blood flow(OBF)、ocular blood pressure(OBP) and age by analyzing the changes of age on hemodynamic. The study appears to be a promising technique in the investigation of ocular vascular disease.The subjects are selected as healthy group(age:29-53) by physical examination. OBP is measured non-invasively by the thigh cuff method to produced sudden drops in arterial blood pressure and studies the evolution of the immediate OBF response with laser Doppler flowmetry(LSFG). This paper uses the interpolation cosine window, wavelet threshold filtering method to process the experimental data in order to deal with the noise caused by respiratory, instrument and artificial factors and reduce the error of the result.The paper sets out to fully examine the time domain relationship between OBF、OBP and age. The subject studies on the relationship between time-domain parameter Kr(L)、Kr(R)、 Tr(R) and age, respectively. The study shows Kr(R)、Kr(L)、Tr(R) significantly influenced by age. The study of time analysis for correlation between OBF、OBP and age is macro, which appear to be intuitive in the physiological characteristic. However, it is not an in-depth analysis for specific frequency on the physiological characteristic in all age groups.The paper examines the frequency domain relationship between OBF、OBP and age to solve the problem. The harmonic content of the envelope waveform of the blood flow velocity in the ophthalmic artery is analyzed in aging and OBF、OBP. The FI of the ophthalmic artery allows an assessment of the ocular circulation in consideration of age and OBF、OBP. FC has significance influence between OBF、OBP and age. The results show that the older the age, the smaller the FI and FC in OBF; the greater the FI and FC in OBP. The order age indicates that the physiological activities become weak and the results are consistent with the time domain analysis.This paper studies the correction between OBFP、OBP and age from time domain and frequency domain standpoint. The physiological characteristics of time domain analysis are intuitive and dynamic. It is described in different age groups, and expressed the human OBF and OBP automatic adjustment of physiological activities. Frequency domain analysis is more concise and profound. It analyzes the characteristics of each frequency band of human physiological activities. The results show that the first harmonic and the third peak is obviously, that is the heart activity, and the endothelial cell activity was the most significant. The analysis of the experimental data provides an important reference value for the early diagnosis of disease in clinical department of Ophthalmology.