Ultrasonic interrogating system and exciter-detector circuit therefor

An ultrasonic interrogating system comprising:

• a fixed segmented transducer array having a plurality of discrete adjacent transducer elements;
• means for selectively exciting the transducer elements to ultrasonic emission in a predetermined sequence;
• a raster scanned display;
• a plurality of switches equal in number to the transducer elements packaged with the transducer array;
• a common transmission line having a first end and a second end;
• first means for coupling each transducer element responsive to a respective switch when closed to the first end of the transmission line;
• second means for coupling the second end of the transmission line to the display;
• means for selectively closing the switches in the predetermined sequence to transmit to the display via the transmission line echoes of the ultrasonic emission of the respective excited transducers returned to said respective excited transducers;
• a single tuning inductor packaged with the transducer array;
• means for connecting the single tuning inductor effectively in parallel with the respective excited transducer elements as to echoes of the ultrasonic emission;
• and
• means for synchronizing the display to the switch closing means to present the echoes on the display.

An ultrasonic imaging system comprising:

• a single inductive reactance;
• a plurality of transducers;
• a plurality of switching devices each connected in series with a unique one of the transducers to form a plurality of series sets;
• means for electrically connecting the plurality of series sets in parallel with one another;
• means for selectively exciting the transducers electrically in a predetermined sequence to produce ultrasonic emission;
• means for connecting the single inductive reactance effectively in parallel with the plurality of series sets as to echoes of the ultrasonic emission;
• a receiver having an input across which the single inductive reactance in parallel with the series sets is coupled;
• and
• means for selectively closing the switching devices in the predetermined sequence to transmit to the receiver echoes of the ultrasonic emission of the respective transducers returned to said respective transducers.

An ultrasonic interrogating system comprising:

• an ultrasonic transducer having internal capacitance;
• a charging resistor connected in series with the transducer to form therebetween a junction;
• a first circuit node at a first direct current potential coupled to the charging resistor and transducer in series to slowly change the potential at the junction through the charging resistor toward the first direct current potential;
• a second circuit node at a second direct current potential different from the first potential;
• normally open switching means coupling the junction of the charging resistor and the transducer to the second circuit node;
• means for closing the switching means to change the potential at the junction rapidly toward the second potential to excite the transducer electrically to produce ultrasonic emission;
• a tuning inductor;
• means for connecting the tuning inductor effectively in parallel with the transducer as to echoes of the ultrasonic emission returned to the transducer, without short-circuiting the internal capacitance of the transducer by the inductor as to direct current;
• a receiver having an input;
• and
• means for coupling the transducer and the tuning inductor effectively in parallel as to echoes of the ultrasonic emission across the input of the receiver.

An ultrasonic interrogating system comprising:

• an ultrasonic transducer having an internal capacitance;
• means for cyclically displaying ultrasonic echoes received by the transducer during a first period of each cycle without displaying such signals during a second period of each cycle;
• means for slowly charging the internal capacitance of the transducer to a first potential during the second period of each cycle;
• means for rapidly discharging the internal capacitance of the transducer to a second potential different from the first potential during the first period of each cycle to excite the transducer to ultrasonic emission;
• a tuning inductor;
• and
• means for connecting the transducer and the tuning inductor effectively in series as to direct current during the second period of each cycle and for connecting the transducer and the tuning inductor effectively in parallel as to alternating current during the first period of each cycle.

An exciter-detector circuit for use in an ultrasonic imaging system including in combination:

• at least first and second voltage supply terminals;
• an inductive reactance;
• a plurality of transducers;
• a plurality of switching devices, each connected in series with a unique one of said transducers to form a plurality of series sets;
• means for electrically connecting said series sets in parallel with one another and in series with said inductive reactance across said first and second voltage supply terminals;
• and
• an output terminal coupled with said inductive reactance at a junction thereof with said series sets.

An exciter-detector circuit particularly adapted for use in a real-time ultrasonic imaging system which includes sequential activating means and raster scanned display means, said circuit including in combination:

• a plurality of sequentially activated transducers, each of said transducers having first and second terminals;
• at least first and second voltage supply terminals;
• a plurality of switching means each having first, second, and control electrodes, the first electrodes of said switching means being coupled in circuit with a first common electrical point, and the second electrode of each of said switching means being coupled with the first terminal of a unique one of said transducers;
• means for coupling said first voltage supply terminal with the first common electrical point;
• a plurality of resistors, each resistor being coupled between said second voltage supply terminal and the first terminal of a unique one of said transducers;
• means for coupling the second terminals of all said transducers to a second common electrical point;
• an inductive reactance having first and second terminals and connected in series circuit common with said plurality of said transducers and said plurality of said switching means, with the first terminal thereof coupled to one of said first and second common electrical points;
• means coupled with the control electrodes of said switching means for controlling the conductivity thereof according to a predetermined pattern;
• and
• an output terminal coupled with the one of said first and second common points to which the first terminal of said inductive reactance is coupled.

An exciter-detector circuit particularly adapted for use in a real-time ultrasonic imaging system which includes sequential activating means and raster scan display means, said circuit including in combination:

• a plurality of sequentially activated transducers, each of said transducers having first an second terminals;
• at least first and second voltage supply terminals;
• a plurality of switching transistors each having first, second and control electrodes, the first electrodes of said switching transistors being coupled in circuit with a first common electrical point, and the second electrode of each of said transistors being coupled with the first terminal of a unique one of said transducers;
• an inductive reactance having first and second terminals, the first terminal being coupled with said first common electrical point and the second terminal being coupled with said first voltage supply terminal;
• a plurality of resistors, each said resistor being connected between said second voltage supply terminal and the first terminal of a unique one of said transducers;
• means coupling the second terminals of all of said transducers with ground;
• means coupled with the control electrodes of said switching transistors for controlling the conductivity thereof according to a predetermined pattern;
• and
• an output terminal coupled with said first common electrical point.

An exciter-detector circuit specially adapted for use in a real-time ultrasonic imaging system which includes sequential activating means and raster scan display means, said circuit comprising:

• a plurality of sequentially activated transducers, each of said transducers having first and second terminals;
• a first voltage source of a first polarity;
• a second voltage source of a second polarity;
• a plurality of switching transistors, each said switching transistor being connected between said first voltage source and said first terminal of a unique one of said transducers;
• a plurality of resistors, each said resistor being connected between said second voltage source and said first terminal of a unique one of said transducers;
• means connecting said second terminals of all said transducers to a common electrical point;
• an inductor connected between said common electrical point and ground;
• and
• a preamplifier having an input connected to said common electrical point and an output for coupling to said display means.

An exciter-detector circuit for use in an ultrasonic imaging system including in combination:

• at least first and second voltage supply terminals;
• an inductive reactance;
• a plurality of transducers;
• a plurality of switching devices, each connected in series with a unique one of said transducers to form a plurality of series sets;
• means for electrically connecting said series sets in parallel with one another across said first and second voltage supply terminals;
• means for coupling said inductive reactance between one of said voltage supply terminals and a common junction of said series sets;
• and
• an output terminal coupled with said inductive reactance at said common junction.