ANALYSIS OF THORACIC DUCT FLOW WAVES USING FAST FOURIER TRANSFORM IN SHEEP

S Iizuka, M Onizuka, M Inagaki, S Ishikawa, K Mitsui, T Mitsui

Abstract


We measured the lymph flow of the thoracic duct using an ultrasound transit-timeflowmeter and then analyzed the obtained flow signals by fast Fourier transform. We found thatthe wave form included a low frequency component (-0.1 Hz) as well as high frequencycomponents which represented cardiac pulsation and respiratory movement. The low frequencycomponent signified an intrinsic thoracic duct pulsation. When venous outflow pressure wasincreased, the frequency of the thoracic duct pulsation increased, whereas the frequencies ofcardiac pulsation and respiratory movement were unchanged. These findings suggest thatthoracic duct pulsation is independent of cardiac pulsation and respiratory movement.

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