Fuzzy logic tissue flow determination system
AssigneeSiemens Medical Systems, Inc.
InventorsQinglin Ma, John C. Lazenby
Life of this patent
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Abstract
A fuzzy logic tissue/flow determination system receives echo amplitude, color amplitude, and velocity signals from an ultrasound imaging system. These values are applied to a set of fuzzy rules which quantify the amount by which the signal values vary from preset thresholds. The outputs of the fuzzy rules provide an indication of the plausibility that the echo signals represent a tissue or flow condition. The outputs from all the fuzzy rules are combined and de-fuzzified to produce a combined plausibility of the signals representing either a tissue or flow condition. The tissue/flow decision is made based on which plausibility is larger.
Claims6
A method of determining tissue/flow conditions from echo amplitude, color amplitude, and velocity ultrasound signals, comprising:
- precomputing according to a set of fuzzy logic rules a number of color amplitude thresholds against which the color amplitude signal is compared to determine if the echo amplitude, color amplitude and velocity signals are to be displayed as flow or as tissue:
- selecting from a memory one of the number of color amplitude thresholds based on a value of the echo amplitude and velocity signals,
- comparing the color amplitude signal with the selected color amplitude threshold;
- and
- displaying the echo amplitude, color amplitude, and velocity signals as flow if the color amplitude signal exceeds the selected color amplitude threshold or displaying the echo amplitude, color amplitude, and velocity signals as tissue if the color amplitude signal is less than the selected color amplitude threshold.
An ultrasound imaging system for creating color images of a patient, comprising:
- a transducer for directing ultrasonic signals into the patient and receiving echo signals from the patient;
- a beamformer that receives the echo signals and combines them;
- a B-mode processor that receives the combined echo signals and produces a signal indicative of the amplitude of the combined echo signals;
- a color mode processor that receives the combined echo signals and produces a color amplitude signal and a velocity signal that are indicative of the amplitude and velocity of a non-stationary part of the combined echo signals;
- a tissue/flow processor that analyzes the signal indicative of the amplitude of the combined echo signals, and the color amplitude and velocity signals that are indicative of the non-stationary part of the combined echo signals to determine whether a source of the echo signals is tissue or moving blood flow, the tissue/flow processor including a memory that stores a number of color threshold values that indicates that the source of the echo signals is moving blood flow if the color amplitude signal exceeds a selected color threshold value that is determined by a value of amplitude and velocity signals;
- a monitor that is directed by the tissue/flow processor to display the combined echo signals as greyscale pixels if the source of the echo signals is tissue or displays the combined echo signals as color pixels if the source of the echo signals is moving blood flow.
Dependencies are inferred from the claim text.