Extraction of Arterial Wall Characteristics Using the Step-Stimulation Approach

The study aimed to non-invasively acquire certain essential parameters related to the wall properties of an in situ artery using the step-stimulation approach. 57 healthy subjects (26 males and 31 females) were included in the study. After the radial artery was stimulated by a step displacement, the arterial wall immediately generated a transient oscillatory waveform in response to the step stimulation. The transient step response was detected using a force sensor and was further analyzed in time domain. The natural frequency of the radial artery were found to be greater in the male group than in the female group (7.77±0.79 versus 7.20±0.88 Hz, p=0.019), with no significant difference in the logarithmic decrement and the damping ratio. The male group had a significantly higher pulse wave velocity than that in the female group (3.51±0.33 versus 3.14±0.32 m/sec, p=0.001). Moreover, the logarithmic decrement and the damping ratio both correlated negatively with the pulse wave velocity (r=-0.37 and r=-0.37). But, the natural frequency correlated positively with the pulse wave velocity (r=0.14). The present results suggest that arterial wall variables obtained from transient responses may serve as useful indicators of arterial stiffness.