Y.-Y.L. Wang, M.-Y. Jan, Y.-H. Chen, D.-J. Guo, J.-G. Bau, and W.-K. Wang (Taiwan)
p(z)= pmax sin( )/ Lznπ , n=1,2,3,…Indicator, stretching, blood pressure If the input force is at the one end and the other end is maintained at a static pressure, the pressure amplitude p(z) also has a standing wave behavior as
We conducted simulation experiments to study the arterial system by single tube models. We found that the 180 degree bending at the arch of the aorta, the large longitudinal stretching of the arterial wall and the high steady blood pressure increase the magnitude of the Transverse Kinetic Energy (TKE) of the artery under a constant energy input. It seems that these natural designs of the circulatory system favor a large transverse oscillation of the arterial wall. We then discussed that traditional concept that the pulsatile components of pressure and flow are a loss of energy needs to be scrutinized. This study also demonstrates how TKE can be taken as an indicator to study the efficiency of the arterial system. 2.1 Theory We have derived that for a harmonic blood pressure wave of frequency f, and amplitude p(z) at position z inside the artery, the time average transverse kinetic energy per unit length of the wall can be expressed as 222 /)(/ pwr EzpSfdzKd πλ= (1) Where wλ is the wall mass per unit axial length; S is the lumen cross-sectional area, and Ep is the pressure–strain elastic modulus. If a uniform elastic tube of length L is under a steady transverse harmonic vibration with the two ends maintained at static pressures, the pressure amplitude p(z) has a standing wave behavior as
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