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6 Applications and Methods in Biosignal Processing

Fig. 6.41: Explanted mechanical prosthetic heart valve with white thrombus between the housing

ring and valve leaflet.

0.0

0.1

0.2

0.3

0.4

-20000

-10000

0

10000

20000

hinge noise

Time t / s

Signal amplitude

leaflet 1

leaflet 2

closing

open

Fig. 6.42: Sounds of a mechanical heart valve prosthesis (two-leaflet prosthesis) over one cardiac

cycle after high-pass filtering with 8 kHz.