Method and apparatus for compensation during ultrasound examination
AssigneeNorth American Philips Corporation
InventorKenneth R. Torrence
Life of this patent
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Abstract
The time-gain function of an ultrasound receiver for medical examinations is modified to compensate for different attenuation characteristics in body structures. The slope of the time-gain function is increased at times associated with pulse transmission through the highly attenuating body wall and may be decreased at times associated with pulse transmission through fluid filled body structures. The time-gain compensation, in combination with probe focus compensation and a highly linear receiver transfer function provides sharply increased diagnostic quality. The location and attenuating characteristics of body structures may be determined from a prior knowledge of their depth within the body or from distinctive signatures in ultrasound echos.
Claims11
A method for processing received signals in an echo ultrasound examination system comprising the steps of:
- amplifying the signals with a gain controlled amplifier;
- increasing the gain of the amplifier as a function of time to compensate for the attenuation of ultrasound energy at varying depths within a body;
- identifying characteristic signatures of varying tissue types by measuring the level of scattered echos returned from said tissue types;
- and
- adjusting the rate of the gain variation of the amplifier, in response to said signatures, to compensate for the varying degrees of attenuation attributable to different tissue types.
Apparatus for compensation of an echo ultrasound examination system comprising:
- a gain controlled amplifier connected to amplify echo signals received from a body;
- a time-gain compensation ramp generator connected to control the gain of the amplifier receiver;
- and
- means for identifying signal signatures characteristic of body tissue types having varying attenuation levels in scattered echo signals returned from said tissue types and for controlling the slope of a time-gain compensation ramp produced by said generator in response to the identification.
Dependencies are inferred from the claim text.