公开(公告)号：US11885877B2

公开(公告)日：2024-01-30

申请号：US17053928

申请日：2019-04-24

申请人： DALHOUSIE UNIVERSITY

发明人： Christopher Samson ,  Jeremy Brown ,  Katherine Latham ,  Robert Adamson

IPC分类号： G01S15/89 ,  G01S7/52

CPC分类号： G01S15/8904 ,  G01S7/52085 ,  G01S15/8915 ,  G01S15/8959

摘要： Encoded transmit signals are provided to an ultrasound array such diverging ultrasound waves are sequentially transmitted. Each diverging ultrasound wave is generated by a respective set of encoded transmit signals, where each set of encoded transmit signals is encoded by a respective row of an N×N invertible orthogonal matrix. Only a selected subset of M rows, with N

公开(公告)号：US11255965B2

公开(公告)日：2022-02-22

申请号：US16469903

申请日：2017-12-15

申请人： DALHOUSIE UNIVERSITY

发明人： Jeremy Brown ,  Christopher Samson ,  Katherine Latham

IPC分类号： G01S15/89 ,  G01S7/52 ,  A61B8/08

摘要： Fresnel elevation focusing at a selected elevation angle is performed by transmitting a sequential set of Fresnel-focused ultrasound pulses, where a different Fresnel phase pattern is used for each pulse, and where the receive signals are coherently compounded. The different Fresnel patterns cause the secondary lobe energy to be reduced via averaging of variations of the pressure fields in the secondary lobe regions. In some embodiments, the method of coherently compounded Fresnel focusing is combined with coherently compounded defocused wave (e.g. plane wave or diverging wave) imaging in the azimuth direction. Each of the elevation slices are collected by changing the Fresnel patterns respectively employed when the sequence of plane waves or diverging waves are transmitted, such that the coherent compounding can benefit both planes simultaneously. Hadamard receive encoding and subsequent dynamic receive beamforming may be employed to further improve performance in the elevation direction.

公开(公告)号：US10996332B2

公开(公告)日：2021-05-04

申请号：US15756833

申请日：2016-02-25

申请人： DALHOUSIE UNIVERSITY

发明人： Jeremy Brown ,  Katherine Latham

IPC分类号： H04B1/02 ,  G01S15/89 ,  G10K11/34 ,  A61B8/00 ,  A61B8/12 ,  A61B8/08 ,  B06B1/02 ,  G01N29/26 ,  G01N29/24 ,  G01S7/52

摘要： Systems and methods are disclosed for performing imaging with a crossed-electrode ultrasound transducer array, where ultrasound transducer array is configured for focusing in one direction via conventional time-delay phased array beamforming, and for focusing in a second direction via a Fresnel aperture formed via the application of bias voltages. The ultrasound transducer array connections are switched between transmit and receive operations, such that the Fresnel aperture is generated in the first direction upon transmit, and in the second direction upon receive. One or both of the transmit Fresnel aperture and the receive Fresnel aperture are configured as a set of delay-corrected Fresnel sub-apertures, where the delay associated with each Fresnel sub-aperture is selected to compensate for variations in path lengths between the Fresnel sub-apertures and the focal point. The use of multiple Fresnel sub-apertures and time delay corrections overcomes problems associated with steering-induced bandwidth degradation.