Patent ID: 6010456
Filing Date: 2000-01-04
Classification: G01S

Abstract:
A system for imaging ultrasound scatterers, comprising:an ultrasound transducer array comprising a multiplicity of transducer elements;a transmitter coupled to said transducer array and programmed to pulse selected transducer elements which form a transmit aperture with a base waveform having a first peak power level during a first transmit firing and a coded waveform having a second peak power level during a second transmit firing, said first and second transmit firings being focused at a transmit focal position, said first peak power level being greater than said second peak power level, and said coded waveform being a function of a transmit code convolved with said base waveform;a receiver coupled to said transducer array and programmed to receive first and second sets of signals from selected transducer elements which form a receive aperture subsequent to said first and second transmit firings respectively and output first and second beamsummed signals respectively derived from said first and second sets of signals;a switching arrangement having an input for receiving said first and second beamsummed signals and having first and second outputs, said switching arrangement passing said first beamsummed signal to said first output in a first state and passing said second beamsummed signal to said second output in a second state;a decoding filter having an input coupled to said second output of said switching arrangement and having an output, said decoding filter being programmed to output a pulse-compressed signal in response to input of said second beamsummed signal;a subtractor for subtracting a first signal derived from said pulse-compressed signal from a second signal derived from said first beamsummed signal to form a difference signal;a processor for forming an image signal derived from said difference signal; anda display device for displaying an image which is a function of said image signal.