Variable characteristic filters

Details Variable characteristic filters Variable characteristic filters

1983-12-22

1985-09-10

Howell, Kyle L.

Surgery

Truss

Pad

128663, 7386125, 307520, H03B 100

Patent

active

045409463

ABSTRACT:
A variable characteristic filter is described in which output signals are frequency analyzed by means of a frequency-to-voltage converter to derive a control signal. Variable impedance elements in the filter are controlled by the control signal to vary the filter characteristic automatically. The filter, including the frequency-to-voltage converter, may be such that the filter attenuation is reduced in the frequency region where the input or output signals mainly occur. The invention is particularly useful in Doppler blood-flow velocimeters to reduce noise.

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