Abstract:
Because of the stabilization of arterial pressure against external pressure disturbances, arterial baroreceptor reflex is an important negative feedback system. The assessment of the baroreflex function would require quantifying not only the dynamic but also static properties because the baroreflex sensitivity might be quickly changed during cardiovascular diseases. The time-domain analysis has evaluated the stable gains around the operating point, but might not accurately characterize the dynamic baroreflex properties with unstable hemodynamics and background noise. The FFT analysis in the frequency domain has identified dynamic properties under noisy conditions, requiring longer data segments to remove the noise and to evaluate the properties with low-frequency band. To evaluate the time-varying gain around the operating point, the spontaneous baroreflex method has adjusted the time window in the short-time FFT; however it might not be suitable for the evaluation of short-term changes in baroreflex properties, at multiple pressure points with noise. In contrast, a modified wavelet-based time-frequency analysis could identify the dynamic baroreflex property from the transient step pressure inputs, because of high temporal resolution.

Brief Biography of the Speaker:
Koji Kashihara received PhD (Eng.) degree in 2001 from Tokyo Institute of Technology. He belonged to National Cardiovascular Center Research Institute, RIKEN, University of Sydney, etc. He is currently a researcher at Nagoya University. His research interests are human brain activities and autonomic nervous system.