Iterative time delay values for ultrasound beamforming

A digital signal processor (DSP) IC for ultrasound signal processing, comprising:

• a substrate having a semiconductor surface;
• a multiply-accumulate (MAC) unit on said semiconductor surface that is operable to compute respective time delays for receive beamforming for an ultrasound beamforming system having a plurality of transducer elements, wherein respective time delays at a later time sample (n+1) for a second focal point on a scan line are iteratively computed from respective time delays at an earlier time sample (n) for a first focal point along said scan line using an iterative equation
• τ
• i
• 
• [
• n
• +
• 1
• ]
• =
• (
• x
• c
• -
• x
• i
• )
• 
• (
• f
• s
• c
• )
• 
• sin
• 
• (
• θ
• )
• +
• 2
• 
• n
• +
• 1
• 4
• +
• τ
• i
• 2
• 
• [
• n
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• where xc is a position corresponding to a spatial center of active ones of said plurality of transducer elements at said time sample (n) and said time sample (n+1), xi is a position of an ith element of said plurality of transducer elements, θ is a steering angle that defines an angle between said scanline and a reference axis, fs is a sampling frequency, and c is the speed of sound in said target tissue region.

An ultrasound system, comprising:

• a plurality of transducer elements for transmitting ultrasound transmit sound waves toward a target tissue region and receiving reflected sound signals from said target tissue region in response to said transmit pulses;
• a transmit section for generating drive signals that drive said plurality of transducer elements for said transmitting said transmit sound waves, and
• a receive section for processing a plurality of sensing signals generated by said plurality of transducers responsive to receiving said reflected sound signals,
• a beamformer control unit comprising a computing device coupled said transmit section and said receive section for calculating respective time delays for said sensing signals associated with each of said plurality of transducer elements at a time sample (n) for focusing to a first focal point along a scan line and at a later time sample (n+1) for a second focal point on said scan line, wherein said calculating comprises:
• for said time sample (n), calculating respective time delays for said sensing signals received from each of said plurality of transducer elements for focusing said reflected sound waves from said first focal point, and
• for said time sample (n+1), calculating respective time delays said sensing signals received from each of said plurality of transducer elements for focusing said reflected sound waves from said second focal point,
• wherein said respective time delays for said receive section at said time sample (n+1) are computed iteratively from said respective time delays at said time sample (n);
• a summer for summing said sensing signals to form a beamformed signal,
• a backend imaging display processor coupled to receive and process said beamformed signal to generate a display signal, said display signal being suitable for causing display devices to produce an image, and
• a display device for receiving said display signal and producing said image.