Method and apparatus for ultrasonic beamforming using golay-coded excitation

An imaging system comprising:

• a transducer array including a multiplicity of transducer elements for transmitting wave energy in response to electrical activation and transducing returned wave energy into electrical signals;
• a display monitor for displaying an image having an image portion which is a function of an image signal;
• and
• a data processor programmed to:
• (a) activate a plurality of said transducer elements to transmit focused wave energy encoded with a first Golay code of a Golay code pair during a first transmit event and to transmit focused wave energy encoded with a second Golay code of said Golay code pair during a second transmit event;
• (b) form first and second receive signals from electrical signals supplied from said plurality of transducer elements subsequent to said first and second transmit events respectively;
• (c) filter said first and second receive signals as a function of said first and second Golay codes respectively to form first and second filtered signals respectively;
• (d) add said first and second filtered signals to form a decoded signal;
• (e) form an image signal from said decoded signal;
• and
• (f) send said image signal to said display monitor.

A system for transmitting ultrasound energy into an acoustic medium and receiving ultrasound energy returned from the acoustic medium subsequent to transmission comprising:

• an ultrasound transducer array including a multiplicity of transducer elements for transducing ultrasound energy into electrical energy and for transducing electrical energy into ultrasound energy;
• a transmitter coupled to said transducer array when in a transmit mode and programmed to activate a plurality of said transducer elements to transmit focused ultrasound energy encoded with a first Golay code of a Golay code pair during a first transmit event and to transmit focused ultrasound energy encoded with a second Golay code of said Golay code pair during a second transmit event subsequent to said first transmit event;
• a receiver coupled to said transducer array when in a receive mode and programmed to form first and second beamsummed receive signals from electrical signals supplied from said plurality of transducer elements subsequent to said first and second transmit events respectively;
• a filter programmed to filter said first and second beamsummed receive signals as a function of said first and second Golay codes respectively to form first and second filtered signals respectively;
• and
• a summer for adding said first and second filtered signals to form a decoded signal.

A transmission and reception system comprising:

• a transducer array including a multiplicity of transducer elements for transducing wave energy into electrical energy and for transducing electrical energy into wave energy;
• a transmitter coupled to said transducer array when in a transmit mode and programmed to activate a plurality of transducer elements to transmit focused wave energy encoded with a first Golay code of a Golay code pair during a first transmit event and to transmit focused wave energy encoded with a second Golay code of said Golay code pair during a second transmit event subsequent to said first transmit event;
• a receiver coupled to said transducer array when in a receive mode and programmed to form first and second beamsummed receive signals from electrical signals supplied from said plurality of transducer elements subsequent to said first and second transmit events respectively;
• a filter programmed to filter said first and second beamsummed receive signals as a function of said first and second Golay codes respectively to form first and second filtered signals respectively;
• and
• a summer for adding said first and second filtered signals to form a decoded signal.

A method of operating an imaging system comprising a multiplicity of transducer elements for transmitting wave energy in response to electrical activation and transducing returned wave energy into electrical signals, and a display monitor for displaying an image having an image portion which is a function of an image signal, said method comprising the steps of:

• (a) activating a plurality of said transducer elements to transmit focused wave energy encoded with a first Golay code of a Golay code pair during a first transmit event and to transmit focused wave energy encoded with a second Golay code of said Golay code pair during a second transmit event;
• (b) forming first and second receive signals from electrical signals supplied from said plurality of transducer elements subsequent to said first and second transmit events respectively;
• (c) filtering said first and second receive signals as a function of said first and second Golay codes respectively to form first and second filtered signals respectively;
• (d) adding said first and second filtered signals to form a decoded signal;
• (e) forming an image signal from said decoded signal;
• and
• (f) sending said image signal to said display monitor.

A method of imaging a medium, comprising the steps of:

• transmitting focused wave energy encoded with a first Golay code of a Golay code pair into a medium during a first transmit event;
• transducing wave energy returned from the medium after the first transmit event into a first set of electrical receive signals following said first transmit event;
• beamforming said first set of electrical receive signals to form a first beamsummed signal;
• filtering said first beamsummed signals as a function of said first Golay code to form a first filtered signal;
• transmitting focused wave energy encoded with a second Golay code of said Golay code pair during a second transmit event;
• transducing wave energy returned from the medium after the second transmit event into a second set of electrical receive signals following said second transmit event;
• beamforming said second set of electrical receive signals to form a second beamsummed signal;
• filtering said second beamsummed signal as a function of said second Golay code to form a second filtered signal;
• adding said first and second filtered signals to form a decoded signal;
• forming an image signal from said decoded signal;
• and
• displaying an image having an image portion which is a function of said image signal.