Ultrasonic multi-sector scanner

An improved multi-sector scanner ultrasonic imaging system comprising:

• a single linear transducer array for making overlapping sector scans including a plurality of electroacoustic transducer elements divisible into multiple sub-arrays of contiguous active elements which have origin points spaced longitudinally along the array and which are each operative to generate angulated acoustic beams and to detect received echoes and perform a wide angle sector scan,
• switch means for connecting said sub-arrays of active elements in sequence to a plurality of transmitting and receiving channels for sequentially generating transducer excitation pulses after predetermined time delays and for delaying received echo electrical signals for varying predetermined time delays,
• means for controlling the time delays in said transmitting and receiving channels to steer the transmitted acoustic beams at many angles relative to the normal to each sub-array and to focus the received echoes, and
• means for summing the delayed echo signals for the plural channels connected to each sub-array and for processing and displaying the summed echo signals in real time on a cathode ray tube as a visual image of the insonified object region.

An improved multi-sector scanner ultrasonic imaging system comprising:

• a linear transducer array for making overlapping sector scans including a plurality of equally spaced electroacoustic transducer elements divisible into multiple sub-arrays of contiguous active elements which have origin points spaced longitudinally along the array and which are each operative to generate angulated acoustic beams and to detect received echoes and perform a sector scan,
• switch means for connecting said sub-arrays of active elements in sequence to a plurality of transmitting and receiving channels for sequentially generating transducer excitation pulses after predetermined time delays and for delaying received echo electrical signals for varying predetermined time delays,
• means for controlling the time delays in said transmitting and receiving channels to steer the transmitted acoustic beams at multiple angles relative to the normal to each sub-array and to focus the received echoes, and
• means for summing the delayed echo signals for the plural channels connected to each sub-array and for processing and displaying the summed echo signals in real time on a cathode ray tube as a visual image of the insonified object region,
• wherein said transmitting channels are comprised by a reversible digital shift register having a stage for each channel with an output from each stage coupled to a transmit pulser for generating the transducer element excitation pulses, a source of scan pulses coupled by switches to either end of said shift register, and a variable frequency clock connected to couple clock pulses to the shift register stages at a frequency determined by a control circuit to thereby control the time delays in the transmitting channels.

An improved multi-sector scanner ultrasonic imaging system comprising:

• a linear transducer array for making overlapping sector scans including a plurality of equally spaced electroacoustic transducer elements divisible into multiple sub-arrays of contiguous active elements which have origin points spaced longitudinally along the array and which are each operative to generate angulated acoustic beams and to detect received echoes and perform a sector scan,
• switch means for connecting said sub-arrays of active elements in sequence to a plurality of transmitting and receiving channels for sequentially generating transducer excitation pulses after predetermined time delays and for delaying received echo electrical signals for varying predetermined time delays,
• means for controlling the time delays in said transmitting and receiving channels to steer the transmitting acoustic beams at multiple angles relative to the normal to each sub-array and to focus the received echoes, and
• means for summing the delayed echo signals for the plural channels connected to each sub-array and for processing and displaying the summed echo signals in real time on a cathode ray tube as a visual image of the insonified object region,
• wherein said receiving channels and means for controlling the time delays in the receiving channels comprise a plurality of sets of analog charge coupled device delay lines of different lengths which are combined to achieved graduated time delays in the various channels, and a variable frequency clock connected to each set of analog delay lines and supplying clock pulses thereto, said clocks operating at different frequencies.

An improved multi-sector scanner ultrasonic imaging system comprising:

• a linear transducer array for making overlapping sector scans including a plurality of equally spaced electroacoustic transducer elements divisible into multiple sub-arrays of contiguous active elements which have origin points spaced longitudinally along the array and which are each operative to generate angulated acoustic beams and to detect received echoes and perform a sector scan,
• switch means for connecting said sub-arrays of active elements in sequence to a plurality of transmitting and receiving channels for sequentially generating transducer excitation pulses after predetermined time delays and for delaying received echo electrical signals for varying predetermined time delays,
• means for controlling the time delays in said transmitting and receiving channels to steer the transmitted acoustic beams at multiple angles relative to the normal to each sub-array and to focus the received echoes, and
• means for summing the delayed echo signals for the plural channels connected to each sub-array and for processing and displaying the summed echo signals in real time on a cathode ray tube as a visual image of the insonified object region,
• wherein said means for processing and displaying the summed echo signals includes a peak detecting scan converter for displaying on the cathode ray tube the echo signals with the largest amplitude in overlapping areas of the sector scans.

An improved multi-sector scanner ultrasonic imaging system comprising:

• a single linear transducer array for making overlapping sector scans including a plurality of equally spaced electroacoustic transducer elements divisible into multiple sub-arrays of contiguous active elements with the origin points of the sub-arrays spaced longitudinally along the array, each sub-array being operable to transmit angulated acoustic beams, detect the received echoes, and perform a sector scan,
• a plurality of transmitting channels and receiving channels for generating transducer element excitation pulses after predetermined time delays and for amplifying and delaying received echo electrical signals for predetermined time delays,
• sector select switch means for coupling the multiple sub-arrays of active elements in sequence to prescribed transmitting and receiving channels,
• means for controlling the time delays in the transmitting channels and receiving channels to at least steer the transmitting beam at many angles relative to the normal at the center of each sub-array and also to at least focus the received echoes at a constant range,
• means for summing the delayed echo signals at the plural receiving channels for an active sub-array, and
• means for processing and displaying in real time only the largest amplitude summed echo signal at every image point as a visual image of the insonified object region.