Method and apparatus for controlling scan line direction in a linear array ultrasonic doppler scanning system
First Claim
1. A Doppler scan line direction controller for a scanning system having a linear array of ultrasonic transducers adapted to scan a selected sample volume at which a fluid is flowing in a predetermined direction, the controller comprising:
- means for identifying the sample volume at which a Doppler determination is to be made;
means for designating the flow direction at said sample volume;
means responsive to said designated flow direction for designating an ideal scan line;
means for defining left and right limit angles for scanning of the sample volume by the array of transducers;
means operative if the ideal scan line is at an angle between said left and right limit angles for selecting the ideal scan line as the scan line direction; and
means operative if the ideal scan line is at an angle which is not between said left and right limit angles for designating a selected one of said limit angles as the scan line direction.
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Accused Products
Abstract
This invention relates to a method and apparatus for automatically controlling scan line direction in a linear array ultrasonic Doppler scanning system. More particularly, this system determines an ideal scan line angle and point of origin for a given sample volume having fluid flow in a given direction. The system then determines left and right limiting angles for the given sample volume taking into account the geometry of the viewing area relative to the sample volume and the maximum steering angle of the transducers of the transducer array being utilized. Where, because of pulse repetition rate considerations, a maximum depth from the sampling aperture of the linear array to the sample volume exists, this maximum depth is also taken into account in determining the limiting angles. The system then uses the ideal angle as a scan angle is such ideal angle is between the limiting angles and utilizes a selected one of the limiting angles determined in accordance with predetermined criteria, if the ideal angle is outside the limiting angles. Once the scan angle has been determined, this angle may be utilized to identify the aperture to be utilized for the given scan.
30 Citations
21 Claims
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1. A Doppler scan line direction controller for a scanning system having a linear array of ultrasonic transducers adapted to scan a selected sample volume at which a fluid is flowing in a predetermined direction, the controller comprising:
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means for identifying the sample volume at which a Doppler determination is to be made; means for designating the flow direction at said sample volume; means responsive to said designated flow direction for designating an ideal scan line; means for defining left and right limit angles for scanning of the sample volume by the array of transducers; means operative if the ideal scan line is at an angle between said left and right limit angles for selecting the ideal scan line as the scan line direction; and means operative if the ideal scan line is at an angle which is not between said left and right limit angles for designating a selected one of said limit angles as the scan line direction. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A method of controlling Doppler scan line direction in a linear array ultrasonic scanning system comprising the steps of:
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identifying a sample volume at which a Doppler determination is to be made; designated a flow direction at the sample volume; utilizing the flow direction to determine an ideal scan line; defining left and right limit angles for the scanning of the sample volume by the array; selecting the ideal scan line as the scan line direction if the ideal scan line is at an angle between the left and right limit angles; and designating a selected one of the limit angles as the scan line direction if the ideal scan line is at an angle which is not between the left and right limit angles. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification