Vector velocity estimation using directional beam forming and cross correlation
AssigneeB-K Medical A/S
InventorJørgen Arendt Jensen
Life of this patent
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Abstract
The two-dimensional velocity vector using a pulsed ultrasound field can be determined with the invention. The method uses a focused ultrasound field along the velocity direction for probing the moving medium under investigation. Several pulses are emitted and the focused received fields along the velocity direction are cross-correlated. The time shift between received signals is found from the peak in the cross-correlation function and the velocity is thereby determined.
Claims20
An apparatus for measuring the velocity of a moving object or a collection of moving objects moving in a predetermined direction and at a predetermined distance, the apparatus comprising:
- a generator for generating excitation signals,
- an emitting transducer for transforming the excitation signals into wave energy and for emitting said wave energy in a predetermined direction of propagation towards the object or objects,
- a receiving transducer for receiving from said moving object or objects, signals generated by interaction with said wave energy emitted from said emitting transducer,
- said emitting transducer and said receiving transducer having respective sensitivities for selectively creating a plurality of focal points, which in combination define a focus line at the predetermined distance and extending in the predetermined direction of movement, and
- means for calculating a correction of signals received from the moving object or objects on the focus line, and for calculating, based on the correlation, the velocity of the moving object or objects in the direction of the focus line.
A method for measuring the velocity of a moving object or a collection of moving objects moving in a predetermined direction and at a predetermined distance, the method comprising:
- emitting excitation signals of pulses of wave energy in a predetermined direction of propagation towards the object or objects,
- receiving from said moving object or objects, reflected signals resulting from interaction of emitted wave energy with the moving object or objects,
- the emission of excitation signals and the reception of reflected signals having respective sensitivities for selectively creating a plurality of focal points, which in combination define a focus line at the predetermined distance and extending in the predetermined direction,
- calculating a correlation of signals received from the moving object or objects on the focus line, and
- calculating, based on the correlation, the velocity of the moving object or objects in the direction of the focus line.
Dependencies are inferred from the claim text.