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Few studies are interested in the noninvasive determination of propagation parameters. Reflected waves can be used as an intelligent tool for therapeutic measures. The amplitude and arrival time of reflected wave play an interesting role in investigating cardiovascular diseases. Therefore, this study aims to implement a method based on cepstral analysis for noninvasive decomposition of the incident and reflected waves and determination of local propagation parameters. The cepstral analysis is applied to the blood velocity, which is measured by using phase-contrast magnetic resonance imaging (PCMR) in 20 subjects. The determination of propagation parameters: arrival time, attenuation coefficient, reflection amplitude, and reflection coefficient is based on a mathematical model developed in the previous work. To evaluate the precision of the proposed approach, we focused on the effect of age. In addition, we intended to compare the obtained results to those obtained by the wave intensity analysis (WIA) method. A statistical test analysis was conducted to establish the relationship between the propagation parameters and the age. Our experimental results showed that there is no significant difference in terms of propagation parameters with age (p > 0. 0 5). Our experimental results correlated with reference values reported in previous studies conducted on the internal arterial carotid. The propagate parameters obtained by the proposed method varied slightly with age. Moreover, the reflection coefficient detected using our proposed method was close to that detected using WIA. We can conclude that the technique described in this paper offers a promising and efficient approach to separating measured velocity waveforms into their incident and reflected components noninvasively. [ABSTRACT FROM AUTHOR]

Background: Many cardiovascular diseases modified the arterial wall stiffness. Objectives: This work focuses on the quantification of the elastic biomechanical properties of the internal carotid (ICA) wall by applying the cepstral analysis on healthy volunteers aged from 22 to 86 years old. The purpose of this study is to compare two methods of measurement of arterial compliance (C) , arterial distensibility (D) , arterial elastance (Eh), and Young's modulus (E). Material and methods: First, arterial compliance and arterial distensibility were measured in function of wave speed (c) , which is measured in our previous works by using two methods. Second, elastance Eh was estimated through the ratio between diastolic radius (R) and C. Finally, E was estimated from a statistical study from the literature on h due to the difficulty of measuring wall thickness (h). Results: The Student test demonstrated that there is a very significant difference between young and old subjects in terms of elastance, compliance, and Young's modulus (p < 0. 0 0 1). These findings are in agreement with the reference values reported in the literature. They are very satisfying for distinguishing a pathological change in parietal elasticity. Conclusion: The in vivo application of these methods presents their potential for clinical measurement of arterial stiffness. [ABSTRACT FROM AUTHOR]

Characterization of the wave reflection and mainly its return time has significant clinical value in detecting cardiovascular and cerebrovascular diseases. Indeed, the return time is an indicator which is used to evaluate the performance of peripheral perfusion and the propagation speed for arterial stiffness measurement. The study is aimed at implementing a novel model based on cepstral analysis for estimation of the arrival time of reflected wave ( t 0). The proposed method is specially based on cepstral analysis of the simulated blood velocity wave by using the Matlab software. To achieve this aim, we used a theoretical bidimensional model to simulate blood flow velocity, and we combined this model with clinical data acquired in two healthy subjects using phase contrast magnetic resonance imaging (PCMRI). Values of the arrival time of reflected wave measured are similar to the theoretical values. The suggested model is validated in vivo. We can conclude that the novel approach described in this paper offers a promising efficient and convenient method to determinate noninvasively arrival time of reflected wave. [ABSTRACT FROM AUTHOR]

Local wave speed is a prognostic detector that allows the analysis of cardiovascular function. Objectives: This study compared wave speed (c) measurements at single-point and two-point techniques. Material and methods: c were determined from the cepstral analysis of the blood flow velocities, which identified the arrivals times of reflected waves. The blood velocities waveforms were measured by using phase-contrast magnetic resonance (PCMR) for 20 subjects on young and old healthy subjects.  Local wave speed was estimated through the arrivals time of reflections waves ( t r) and the distance separating the measurement site to reflection area (L) or the distance separating the two measurement sites. Results: Our obtained results were in total agreement with reference values reported in the literature. Moreover, the detected results show that there is a high correlation (r = 0. 8 7) between the two methods. Conclusion: The analysis of the wave speed variations with advancing age is also achieved out through different regression models. [ABSTRACT FROM AUTHOR]

Local wave speed plays an interesting role in investigating cardiovascular diseases and arterial wall stiffness. The aim of this study was to implement a novel method based on cepstral analysis for noninvasive determination of local wave speed in the carotid artery. To show the precision of the proposed method, we specially focused on the effect of age. In addition, we intended to compare the obtained results to those obtained by the foot-to-foot method. Our method consists in measuring the instantaneous blood velocity in the internal carotid by using phase-contrast magnetic resonance imaging in 20 healthy subjects distributed as follows: 10 young subjects aged between 22 and 41 years, and 10 old subjects aged between 50 and 86 years. The cepstral analysis was used to determine the arrival time of the reflection wave and the wave speed in the carotid artery. A statistical test analysis was conducted in order to establish the relation between the wave speed and the age in the sample under investigation. Our main finding was that there was a high significant difference between the two groups forming the studied sample (p < 0. 0 0 1). In terms of the internal carotid arterial branch, our experimental results were in total agreement with reference values by the invasive method reported in the literature. Moreover, the wave speed detected using our method correlated with that detected using foot-to-foot analysis (R = 0. 8 4 , p < 0. 0 0 1). We can conclude that the new technique described in this paper offers a promising, convenient and efficient method to measure wave speed noninvasively. [ABSTRACT FROM AUTHOR]