The dissipation of suction waves in flexible tubes

Abstract

It is noted that waves with “suction effect” are observed in pulmonary veins and in coronary arteries. In spite of this, the dissipation of “suction waves” has not been studied before. This paper aims to investigate the dissipation of “suction wave” (a single negative sinusoidal wave) in the time domain using wave intensity analysis (WIA) in vitro. The pump generates a single half sinusoidal wave by pushing the piston forward or a negative half sinusoidal wave by pulling the piston backward. The simultaneous measurements of pressure and flow were taken at steps of 5cm along the 2m length tube. The separated forward pressure, forward wave intensity and forward energy can be obtained using WIA. The results show that pressure and velocity pulse of suction wave is greater than those of pushing wave. The degree of dissipation of the “suction” wave is greater than that of “pushing” wave. Therefore, it is concluded in this paper that under the same conditions such as initial pressure and displaced volume, the “suction” pressure and flow pulse are greater than “pushing” pulse and the degree of “suction” wave dissipated faster than “pushing” wave.