Ultrasonic interrogating system and exciter-detector circuit therefor

Claim 2

An ultrasonic interrogating system comprising: a plurality of ultrasonic transducers; means for selectively exciting the transducers electrically in a predetermined sequence to produce ultrasonic emission; raster scanned display means; a single preamplifier having an output connected to the display means and an input; means for coupling the respective excited transducers to the input of the preamplifier in the predetermined sequence to transmit to the display means echoes of the ultrasonic emission of the respective excited transducers returned to said respective excited transducers; a single tuning inductor effectively connected in parallel with the excited transducers as to echoes of the ultrasonic emission; and means for synchronizing the display means of the coupling means to present the echoes of the ultrasonic emission on the display means.

Claim 3

The system of claim 1, in which the plurality of ultrasonic transducers comprises a fixed segmented transducer array having a plurality of discrete adjacent transducer elements and the preamplifier is packaged with the transducer array.

Claim 4

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.

Claim 5

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.

Claim 6

The system of claim 3, in which the first coupling means includes a single preamplifier packaged with the transducer array.

Claim 7

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.

Claim 8

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.

Claim 9

The system of claim 5, in which the plurality of transducers comprises a fixed segmented transducer array having a plurality of discrete adjacent transducer elements and the single inductive reactance comprises a tuning inductor packaged with the transducer array.

Claim 10

The system of claim 6, in which the transducer array comprises a single piece of piezoelectric material having a first and second opposite surfaces, a common conductive electrode covering the first surface of the piezoelectric material, and a plurality of adjacent insulated conductive strips equal in number to the transducer elements covering the second surface of the piezoelectric material, the strips are connected to the respective switching devices, and the common electrode is grounded.

Claim 11

The system of claim 5, in which the means for selectively exciting the transducers comprises means upon closure of each switching device for exciting the corresponding transducer electrically to produce ultrasonic emission.

Claim 12

The system of claim 8, in which the transducers each have an internal capacitance and the means upon closure of each switching device for exciting the corresponding transducer electrically comprises: means prior to closure of each switching device for slowly charging the internal capacitance of the corresponding transducer to be excited; and means upon closure of each switching device for rapidly discharging the internal capacitance of said corresponding transducer to excite it electrically to produce ultrasonic emission.

Claim 13

The system of claim 9, in which the means for charging the internal capacitance of the corresponding transducer comprises a shared direct current voltage source having first and second output terminals, a charging resistor connected in series between the first output terminal of the source and the junction between the switching device and the respective transducer, and means for connecting the second output terminal of the source to the single inductive reactance and the plurality of series sets to complete a charging circuit for the transducer between the first and second output terminals of the source without short circuiting the internal capacitance of the transducers by the inductive reactance.

Claim 14

The system of claim 10, in which the means for discharging the internal capacitance of the respective transducers comprises a common node at a potential different from the potential across the first and second output terminals, and means for connecting the common node to the single inductive reactance and the plurality of series sets to complete a discharging circuit for the transducers to the potential at the common node when the respective switching devices are closed.

Claim 15

The system of claim 5, in which the receiver includes a raster scan display producing scan lines corresponding to said respective transducers, means for modulating the intensity of the scan lines responsive to the echoes returned to the corresponding transducers, and means for synchronizing the scan lines to the closing means.

Claim 16

The system of claim 5, in which the plurality of transducers comprises N discrete adjacent transducer elements, and the closing means comprises means for simultaneously closing the switching devices connected in series with a selected group of A adjacent transducer elements and means for sequentially displacing the selected group of A transducer elements B transducer elements from the preceeding group in the sequence.

Claim 17

The system of claim 13, in which B is one.

Claim 18

The system of claim 13, in which A is four and N is sixty-four.

Claim 19

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.

Claim 20

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.

Claim 21

The system of claim 16, additionally comprising a first source of direct current voltage having first and second output terminals across which a potential difference appears, the first output terminal of the first source being connected to the first circuit node and the second output terminal of the first source being connected to ground; and a second source of direct current voltage having first and second output terminals across which a potential difference appears, the first output terminal of the second source being connected to the second circuit node and the second output terminal of the second source being connected to ground.

Claim 22

The system of claim 17, in which the first and second potentials have different polarities.

Claim 23

The system of claim 16, in which the switching means operates cyclically, the switching means being open during a first interval of each operating cycle, and the receiver includes a display having a scan line with an intensity modulated by the single applied to the input of the receiver and means responsive to the switching means for synchronizing the scan line of the display to the closures of the switch.

Claim 24

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.

Claim 25

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.

Claim 26

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.

Claim 27

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.

Claim 28

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.

Claim 29

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.

Claim 30

The combination according to claim 22 wherein the first terminal of said inductive reactance is coupled with said second common electrical point and the second terminal thereof is coupled with ground.

Claim 31

The combination according to claim 22 wherein said first terminal of said inductive reactance is coupled with said first common electrical point and the second terminal thereof is coupled with said first voltage supply terminal.

Claim 32

The combination according to claim 24 wherein said second common electrical point is coupled with ground.

Claim 33

The combination according to claim 22 further including a preamplifier having an input coupled with said output terminal and an output for coupling with the raster scan display means.

Claim 34

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.

Claim 35

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.

Claim 36

The combination according to claim 27, further including a preamplifier having an input coupled with said output terminal and an output for coupling with the raster scan display means.

Claim 37

The combination according to claim 28 wherein said first voltage supply terminal is adapted for coupling with a source of positive direct-current voltage; said second voltage supply terminal is adapted for connection with a source of negative direct-current voltage; and said switching transistors are PNP transistors with said first, second and control electrodes corresponding respectively to emitter, collector and base electrodes thereof.

Claim 38

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.

Claim 39

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.

Claim 40

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.

Claim 41

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.

Claim 42

The circuit of claim 31, additionally comprising a third voltage supply terminal, a plurality of charging resistors equal in number to the transducers, connected between the third voltage supply terminal and the junctions between the respective transducers and switching devices such that the voltage at said junctions changes rapidly when the respective switching devices are closed.

Claim 43

The circuit of claim 32, additionally comprising means for selectively closing the switching devices in a predetermined sequence.