Method and apparatus for digital delay of ultrasound signals upon reception thereof

An apparatus for use in an ultrasound system for delaying by a desired amount ultrasound signals received in a channel, said received ultrasound signals being chronologically spaced in a series, which chronological spacing is substantially the same as a sample period according to a clock signal, said apparatus comprising:

• means for digitally delaying a first received ultrasound signal by a selected delay which is an integer multiple of said sample period;
• means for digitally forming a plurality of interpolation signals from said delayed first received ultrasound signal and said next successively delayed received ultrasound signal in said series;
• and
• means for selecting for further processing one among said delayed ultrasound signals and said plurality of interpolated signals which has a delay closest to said desired amount.

An apparatus for use in an ultrasound system for delaying by a desired amount digital ultrasound signals received in a channel, said received ultrasound signals being chronologically spaced in a series, which chronological spacing is substantially the same as a sample period according to a clock signal, said apparatus comprising:

• a shift register to which said ultrasound signals are supplied, said shift register having a plurality of outputs at which a first received ultrasound signal is present delayed by respective successively incremental delays, each of which is an integer multiple of said sample period;
• a first multiplexer having a plurality of inputs respectively connected to the outputs of said shift register, a control input, and an output, first multiplexer, in response to a signal at said control input, through-connecting an output of said shift register having a delay closest to said desired amount to the output of said first multiplexer;
• a further register having an input to which the delayed first received ultrasound signal from the output of said first multiplexer is supplied, said further register holding said delayed first received ultrasound signal therein for a period of time corresponding to said chronological spacing of said signals in said series, and thereafter releasing said delayed first received said ultrasound signal;
• an interpolator having a first input to which said next successively delayed received ultrasound signal in said series is supplied, and a second input to which said delay first received ultrasound signal from said further register is simultaneously supplied, said interpolator digitally forming a plurality of interpolated signals from the signals at said first and second inputs thereof at a plurality of interpolator outputs;
• and
• a second multiplexer having a plurality of inputs respectively connected to said plurality of interpolator outputs, and having a control input, said second multiplexer, in response to a signal at said control input, selecting one of the signals at said interpolator outputs having a delay which is closest to said desired amount.