| 摘要 |
A device for measuring one of the transverse components Vx of the speed of moving organs and blood flows by means of ultrasonic echography, the axial component Vz, oriented parallel to the axis Oz of the ultrasonic beam, being measured by a first intercorrelation circuit (51z) which operates with a sampling step DELTA T and which supplies, on the basis of two successive echographic lines shifted through k DELTA T, (k=-I, -I+1, . . . , I), 2I+1 correlation function values according to z, a first maximum-value searching circuit (53z) which supplies the value Io of k which corresponds to the largest value of said correlation functions according to z. The device includes: a bidimensional mosaic (10) of piezoelectric transducers which are centered around the origin O of a system of axes Ox, Oy which forms a trihedron with said axis Oz, a circuit (20) for forming 2Nx+1 receiving channels which correspond to the beams centered around (kxpx,O,O), where kx=-Nx, -Nx+1, . . . , Nx and px is the pitch of the channels according to x, a buffer memory (50) in which there are stored the echographic signals received by each of the 2Nx+1 receiving channels, taken for the values Io-1, Io, Io+1 of k, a second circuit (51x) for intercorrelation between a signal received by the central receiving channel (O,O,O) and the next signal received by the receiving channel (kxpx, O,O) supplying the three intercorrelation functions Cx(kxpx,O,(Io-1) DELTA T), cx(kxpx,O,Io DELTA T), Cx(kxpx,O,(Io+1) DELTA T), a circuit (53x) for linear interpolation in x which supplies, on the basis of said 3 intercorrelation functions, the correlation peak Cx(kxpx) according to x, a second maximum-value searching circuit (54x), which supplies, on the basis of the 2Nx+1 values of kx, the value kxo for which Cx(kxpx) is maximum, the tranverse component Vx satisfying the equation: Vx=kxopx/T where T is the recurrent period of the echographic signals. Application: the formation of echographic images of moving organs and blood flows.
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