Ultrasonic transducer for fetal monitoring

Claim 2

An arrangement adapted to transmit and receive sonic energy comprising a housing member of insulating material having a facing surface, said housing member having a layer of conductive material adjacent and extending over said facing surface; first and second openings defined in said housing member, first and second non-conductive windows closing said openings and having front and rear surfaces, said front surfaces being essentially flush with said facing surface, first and second transducers mounted to the rear surface of said windows and spaced from and out of contact with said housing, means for connecting one of said transducers so that it may to be excited to transmit sonic energy, means for connecting the other of said transducers so that it may receive reflected sonic energy and means for connecting said conductive layer to ground.

Claim 3

The arrangement of claim 1 wherein said housing member is cast of an electrical insulating material and said conductive layer comprises a filling of conductive material adjacent said facing surface.

Claim 4

An arrangement adapted to transmit and receive ultrasonic energy comprising a housing member having a center line, first and second transducers disposed equidistant on either said of said center and angled with respect to said center line so as to define a focal point a first predetermined distance therefrom substantially on said center line, third and fourth transducers disposed equidistant on either side of said center line between said first and second transducers and angled with respect to said center line so as to define a focal point a second predetermined distance therefrom substantially on said center line, means for connecting one of said first and second and one of said third and fourth transducers to a source of alternating electrical energy whereby said transducers may be excited to transmit sonic energy, means for connecting the other of said transducers so that they may receive reflected sonic energy and convert such received energy to alternating electrical energy, said housing member defining four planar surfaces, first and second of said surfaces defining the angle of said first and second transducers, third and fourth of said surfaces defining the angle of said third and fourth transducers, an opening defined in each of said planar surfaces, windows of electrical insulating material closing said openings and having front and rear surfaces, said front surfaces being substantially flush with said planar surfaces, said transducers bonded to the rear surfaces of said windows and spaced from said housing member to acoustically and electrically isolate said transducers from said housing member.

Claim 5

An arrangement adapted to transmit and receive ultrasonic energy comprising a housing member having a center line, first and second transducers disposed equidistant on either said of said center and angled with respect to said center line so as to define a focal point a first predetermined distance therefrom substantially on said center line, third and fourth transducers disposed equidistant on either side of said center line between said first and second transducers and angled with respect to said center line so as to define a focal point a second predetermined distance therefrom substantially on said center line, means for connecting one of said first and second and one of said third and fourth transducers to a source of alternating electrical energy whereby said transducers may be excited to transmit sonic energy, means for connecting the other of said transducers so that they may receive reflected sonic energy and convert such received energy to alternating electrical energy, said housing member defining four planar surfaces, first and second of said surfaces defining the angle of said first and second transducers, third and fourth of said surfaces defining the angle of said third and fourth transducers, an opening defined in each of said planar surfaces, windows of electrical insulating material closing said openings and having front and rear surfaces, said front surfaces being substantially flush with said planar surfaces, said transducers bonded to the rear surfaces of said windows and spaced from said housing member to acoustically and electrically isolate said transducers from said housing member.

Claim 6

Apparatus for detecting the heart activity of a fetus and adapted to transmit and receive sonic energy comprising a housing member of insulating material having a facing surface adapted to be placed on the abdomen of the fetuS carrier, a conductive layer at said facing surface, first and second openings in said housing, first and second window members of non-conductive material having front and rear surfaces, said windows supported on said housing in said openings with the front surfaces thereof substantially flush with said facing surface, first and second transducers mounted to said first and second windows behind said rear surface and physically space from said housing to acoustically and electrically isolate said transducers from said housing, means for connecting one of said transducers so that it may to be electrically excited to transmit sonic energy and means for connecting the other of said transducers so that it may receive reflected sonic energy and convert the received sonic energy to electrical signals and means for connecting said conductive layer to ground.

Claim 7

Apparatus for detecting the heart activity of a fetus and adapted to transmit and receive sonic energy comprising a housing member of insulating material having a facing surface adapted to be placed on the abdomen of the fetuS carrier, a conductive layer at said facing surface, first and second openings in said housing, first and second window members of non-conductive material having front and rear surfaces, said windows supported on said housing in said openings with the front surfaces thereof substantially flush with said facing surface, first and second transducers mounted to said first and second windows behind said rear surface and physically space from said housing to acoustically and electrically isolate said transducers from said housing, means for connecting one of said transducers so that it may to be electrically excited to transmit sonic energy and means for connecting the other of said transducers so that it may receive reflected sonic energy and convert the received sonic energy to electrical signals and means for connecting said conductive layer to ground.

Claim 8

The arrangement of claim 4 where said housing member is cast of an electrical insulating material and filled with a conductor adjacent said facing surface.

Claim 9

The arrangement of claim 4 wherein the thickness of said windows is essentially one-quarter of a wave length of the sonic energy transmitted by the transducers.