Electromagnetic transducer

Claim 2

An electromagnetic transducer for generating transient acoustic pulses of high amplitude comprising: first conductor means mounted on a carrier of high sonic impedance and held against movement thereby, an acoustic emitter incorporating second conductor means, said second conductor means being located parallel to said first conductor means and movable relative thereto to cause pressure pulses to be generated by said emitter; and electrical supply means for supplying electric current pulses to said first and second conductor means, said supply means being operable as required to supply said pulses contradirectionally to said first and second conductor means to generate a repulsive force between them whereby said acoustic emitter generates a positive pressure pulse, and co-directionally to generate an attractive force between them whereby said acoustic emitter generates a negative pressure pulse, said carrier and said acoustic emitter being so mounted, and said first and second conductor means being so coupled electromagnetically, that said carrier and said acoustic emitter comprise means for generating said positive and negative pulses of magnitudes effective to disintegrate a concretion within living tissue and to destroy living tissue through cavitation, respectively.

Claim 3

A transducer as claimed in claim 1, wherein said first and second conductor means each comprise an array of elongate parallel conductors, and the spacing between mutually adjacent conductors of the co-operating first and second conductor means is less than about 10 mm.

Claim 4

A transducer as claimed in claim 2, wherein said spacing is less than about 5 mm.

Claim 5

A transducer as claimed in claim 2 wherein said elongate conductors are in the form of wires.

Claim 6

A transducer as claimed in claim 2 wherein said elongate conductors are in the form of strips.

Claim 7

A transducer as claimed in claim 2 wherein the two parallel arrays of said first and second conductor means generate repulsive forces when connected in series and generate attractive forces between them when connected in parallel.

Claim 8

A transducer as claimed in claim 1, wherein said first and second conductor means form a bifilar system.

Claim 9

A transducer as claimed in claim 1, wherein said first and second conductor means each comprise a single conductor wound in a spiral configuration.

Claim 10

A transducer as claimed in claim 1, wherein said acoustic emitter has an emitting surface shaped so as to have a focus, pulsation of said emitting surface being effective to focus sonic pulses at said focus.

Claim 11

A transducer as claimed in claim 9 wherein said first and second conductor means are supported by carriers which have the form of concentric spheroidal caps.

Claim 12

A transducer as claimed in claim 1 which is also operable as a sound receiver and wherein at least one conductor of each of a plurality of aligned pairs of conductors making up said first and second conductor means is connectable to a d.c. source, in such a way that the displacement of the second conductor means in each case, which is reinforced by an acoustic reception signal impinging on the acoustic emitter induces a voltage in at least one of said conductors which is proportional to the speed of displacement of said second conductor means and is picked up by an evaluator circuit.

Claim 13

A transducer as claimed in claim 1 further comprising means for feeding a high-frequency current to at least one conductor of each of a plurality of aligned pairs of conductors making up said first and second conductor means and an evaluator circuit arranged to detect electrical coupling between the first and second conductor means as a function of their mutual spacing.

Claim 14

A transducer as claimed in claim 12, wherein said evaluator circuit detects capacitative coupling between said first and second conductor means.

Claim 15

A transducer as claimed in claim 12 wherein said evaluator circuit detects inductive coupling between said first and second conductor means.

Claim 16

Apparatus for locating and disintegrating concretions and tissue in a patient's body, comprising means for holding a fluid transmission medium for sonic waves, and an electromagnetic transducer as claimed in claim 1 located within said fluid holding means and arranged to emit pressure pulses focussed at a point outside the fluid medium.

Claim 17

Apparatus as claimed in claim 15 wherein the first and second conductor means are in a planar configuration and a lens is provided in said fluid medium holding means for focussing said pressure pulses.

Claim 18

Apparatus as claimed in claim 15 wherein said first and second conductor means are mounted in carriers of concentric spheroidal shape.

Claim 19

An electromagnetic transducer for generating transient acoustic pulses of high amplitude and also being operable as a sound receiver, comprising: first conductor means mounted on a carrier of high sonic impedance and held against movement thereby, an acoustic emitter incorporating second conductor means, said second conductor means being located parallel to said first conductor means and movable relative thereto to cause pressure pulses to be generated by said emitter; and electrical supply means for supplying electric current pulses to said first and second conductor means, said supply means being operable as required to supply said pulses contradirectionally to said first and second conductor means to generate a repulsive force between them whereby said acoustic emitter generates a positive pressure pulse, and co-directionally to generate an attractive force between them whereby said acoustic emitter generates a negative pressure pulse, wherein at least one conductor of each of a plurality of aligned pairs of conductors making up said first and second conductor means is connectable to a d.c. source, in such a way that the displacement of the second conductor means in each case, which is reinforced by an acoustic reception signal impinging on the acoustic emitter induces a voltage in at least one of said conductors which is proportional to the speed of displacement of said second conductor means and is picked up by an evaluator circuit.

Claim 20

An electromagnetic transducer for generating transient acoustic pulses of high amplitude and also being operable as a sound receiver, comprising: first conductor means mounted on a carrier of high sonic impedance and held against movement thereby, an acoustic emitter incorporating second conductor means, said second conductor means being located parallel to said first conductor means and movable relative thereto to cause pressure pulses to be generated by said emitter; and electrical supply means for supplying electric current pulses to said first and second conductor means, said supply means being operable as required to supply said pulses contradirectionally to said first and second conductor means to generate a repulsive force between them whereby said acoustic emitter generates a positive pressure pulse, and co-directionally to generate an attractive force between them whereby said acoustic emitter generates a negative pressure pulse, wherein at least one conductor of each of a plurality of aligned pairs of conductors making up said first and second conductor means is connectable to a d.c. source, in such a way that the displacement of the second conductor means in each case, which is reinforced by an acoustic reception signal impinging on the acoustic emitter induces a voltage in at least one of said conductors which is proportional to the speed of displacement of said second conductor means and is picked up by an evaluator circuit.

Claim 21

An electromagnetic transducer for generating transient acoustic pulses of high amplitude comprising: first conductor means mounted on a carrier of high sonic impedance and held against movement thereby, an acoustic emitter incorporating second conductor means, said second conductor means being located parallel to said first conductor means and movable relative thereto to cause pressure pulses to be generated by said emitter; electrical supply means for supplying electric current pulses to said first and second conductor means, said supply means being operable as required to supply said pulses contradirectionally to said first and second conductor means to generate a repulsive force between them whereby said acoustic emitter generates a positive pressure pulse, and co-directionally to generate an attractive force between them whereby said acoustic emitter generates a negative pressure pulse; means for feeding a high-frequency current to at least one conductor of each of a plurality of aligned pairs of conductors making up said first and second conductor means; and an evaluator circuit arranged to detect electrical coupling between the first and second conductor means as a function of their mutual spacing.

Claim 22

An electromagnetic transducer for generating transient acoustic pulses of high amplitude comprising: first conductor means mounted on a carrier of high sonic impedance and held against movement thereby, an acoustic emitter incorporating second conductor means, said second conductor means being located parallel to said first conductor means and movable relative thereto to cause pressure pulses to be generated by said emitter; electrical supply means for supplying electric current pulses to said first and second conductor means, said supply means being operable as required to supply said pulses contradirectionally to said first and second conductor means to generate a repulsive force between them whereby said acoustic emitter generates a positive pressure pulse, and co-directionally to generate an attractive force between them whereby said acoustic emitter generates a negative pressure pulse; means for feeding a high-frequency current to at least one conductor of each of a plurality of aligned pairs of conductors making up said first and second conductor means; and an evaluator circuit arranged to detect electrical coupling between the first and second conductor means as a function of their mutual spacing.

Claim 23

A transducer as claimed in claim 19, wherein said evaluator circuit detects capacitative coupling between said first and second conductor means.

Claim 24

A transducer as claimed in claim 19 wherein said evaluator circuit detects inductive coupling between said first and second conductor means.