US3818426A - Ultrasonic image recording system - Google Patents

Ultrasonic image recording system Download PDF

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US3818426A
US3818426A US00222578A US22257872A US3818426A US 3818426 A US3818426 A US 3818426A US 00222578 A US00222578 A US 00222578A US 22257872 A US22257872 A US 22257872A US 3818426 A US3818426 A US 3818426A
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image recording
field
array
ultrasonic
charge
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US00222578A
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D Bonnet
H Rabenhorst
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F Hoffmann La Roche AG
Kontron Inc
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F Hoffmann La Roche AG
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N29/00—Investigating or analysing materials by the use of ultrasonic, sonic or infrasonic waves; Visualisation of the interior of objects by transmitting ultrasonic or sonic waves through the object
    • G01N29/22—Details, e.g. general constructional or apparatus details
    • G01N29/24—Probes
    • G01N29/2437—Piezoelectric probes
    • A—HUMAN NECESSITIES
    • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
    • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
    • A61B8/00—Diagnosis using ultrasonic, sonic or infrasonic waves
    • A61B8/42—Details of probe positioning or probe attachment to the patient
    • A61B8/4272—Details of probe positioning or probe attachment to the patient involving the acoustic interface between the transducer and the tissue
    • A61B8/4281—Details of probe positioning or probe attachment to the patient involving the acoustic interface between the transducer and the tissue characterised by sound-transmitting media or devices for coupling the transducer to the tissue
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01H—MEASUREMENT OF MECHANICAL VIBRATIONS OR ULTRASONIC, SONIC OR INFRASONIC WAVES
    • G01H3/00—Measuring characteristics of vibrations by using a detector in a fluid
    • G01H3/10—Amplitude; Power
    • G01H3/12—Amplitude; Power by electric means
    • G01H3/125—Amplitude; Power by electric means for representing acoustic field distribution
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J31/00—Cathode ray tubes; Electron beam tubes
    • H01J31/08—Cathode ray tubes; Electron beam tubes having a screen on or from which an image or pattern is formed, picked up, converted, or stored
    • H01J31/495—Pick-up tubes adapted for an input of sonic, ultrasonic, or mechanical vibrations and having an electric output

Definitions

  • This invention relates to an ultrasonic image recording system.
  • X-rays are still used practically exclusively at the present time to detect internal structures in human and animal tissue. Apart from the fact that the tissue is exposed to health risks due to high-energy radiation, the contrast of the optical images produced could be greatly improved upon.
  • X-rays An alternative to the use of X-rays is irradiation with ultrasonics, to which the different types of tissue are permeable to very different degrees and thus offer good contrast. This irradiation is also completely harmless provided the total radiation power is below the cavitation limit. Since the sound radiated by conventional ultrasonic sources is coherent, holographic recordings are possible, which enable the irradiated tissue to be viewed stereoscopically, and this is very important, for example, for detection of the position of carcinomas and tumors.
  • a device presently available for sonic image recording is the Sokoloff tube.
  • the front plate of this tube is a thin quartz disc.
  • ultrasonic waves impinging thereon produce a dipole pattern due to the piezoelectric effect, the pattern being distributed over the area of the plate in the form of an image and being capable of scanning by an electron beam.
  • a sound pattern distributed over an area can be converted into a sequence of electrical signals which can then be displayed as an image, for example, by means of a cathode ray tube.
  • the diameter of the quartz disc used is limited to about -6 cm, but it would be desirable to have available an image recording surface of linear dimensions of at least cm or above, for example, when it is required to observe a wider area of the human body.
  • the purpose of the present invention is to enable the image recording surface of an ultrasonic image recording system to be increased.
  • an ultrasonic image recording system including piezoelectric sound-sensitive means for exposure to a field of ultrasonic radiation to be imaged, in which system the piezoelectric means is in the form of a thin layer of piezoelectric material having charge-sensitive components distributed in an array on the layer of piezoelectric material and pick-up means provided for deriving from the charge-sensitive components electrical signals significant of the level of sound at corresponding points of the ultrasonic field.
  • the piezoelectric layer might comprise a coating deposited on a substrate and the charge-sensitive components could be field-effect transistors.
  • the pick-up means may include a crossbar arrangement including one group of parallel conductors connected to the sources of the transistors in respective columns of the array and another group of parallel conductors at right angles to the first group connected to the gates of the transistors in respective rows of the array.
  • FIG. I is a cross section showing a single image point of an image recording surface of a system embodying the invention.
  • FIG. 2 is a schematic diagram of an ultrasonic image recording system according to the present invention.
  • an ultrasonic image recording surface including a piezoelectric layer in the form of a coating 2 of a suitable material such as cadmium sulphide (CdS) disposed on a substrate 1 which might comprise a plastic foil.
  • a coating 2 of a suitable material such as cadmium sulphide (CdS) disposed on a substrate 1 which might comprise a plastic foil.
  • the thickness of coating 2 should be between l0 and 50 am.
  • the coating is polycrystalline, the individual crystallites being oriented with the c-axis (in whose direction there is the maximum piezo effect) perpendicular to the substrate 1.
  • An array or raster of thin film field-effect transistors are formed on the coating 2 by known vapor-coating processes.
  • One such transistor shown in FIG. 1 comprises a drain 3, a source 4, a further coating 5 of CdS and a gate 6.
  • the CdS coating 5 is about 1 pm thick, and the electrodes 3, 4 and 6 are some hundreds of Angstroms thick.
  • Ultrasonic radiation incident on the image recording surface produces periodically alternating dipole moments at the ultrasonic frequency in the CdS coating 2, and these modulate the current flow between the source and drain of each field-effect transistor.
  • An electrical signal significant of the sound pressure at an image point can be derived by applying suitable voltages simultaneously to the gate and source of the fieldeffect transistor at the image point while the drain is at a fixed potential.
  • the array of field-effect transistors is used to derive signals in succession from the image points of the image recording surface. As is illustrated in FIG.
  • the transistors 5' in the array can be scanned sequentially by a known crossbar arrangement, one group of parallel conductors 7 being connected to the source of the transistors in each column of the array and another group of parallel conductors 8 at right angles to the first group being conneced to the gates of each row of the array.
  • the transmission of scanning voltages from a potential source 12 from one source conductor to another and from one gate conductor to another is effected at the point or line frequency required for the particular application in which the system is used and could be implemented by, for example, a suitable timer 9 and commutators I0 and I].
  • the electrical output signal from the transistors is obtained as. a voltage signal at a resistor R situated in a line connecting the drains of all the transistors 5 to earth, is amplified (not shown) and converted to a visual image in a cathode ray tube (television display tube).
  • the thickness of the substrate 1 and of the CdS coating 2 should be such that a sound wave impinging from above produces an antinode in the CdS coating 2 and a node at the underside of the substrate ll.
  • An image recording system embodying the invention may be used both for the direct production of images of structures or, more advantageously, for producing ultrasonic holograms. This second alternative comes to mind because, as mentioned hereinbefore, ultrasonic waves are coherent due to their method of generation.
  • the coating had a resistance of more than 10 cm and was vapor-coated in the form of a piezoelectrically active coating.
  • An array of "X10 CdS field-effect transistors were formed on the coating in the form of a raster by a known process using a masking technique.
  • the image represented by the output electrical signal obtained from the system is reproduced in visual form in a conventional television unit.
  • the image sequency is at the maximum time acceptable in medicine, i.e., 1 second.
  • the system is suitable for ultrasonic image recording at an ultrasonic frequency of 10 MHz.
  • An ultrasonic image recording system comprising:
  • piezoelectric sound-sensitive means having a thin layer of piezoelectric material for exposure to a field of ultrasonic radiation to be imaged;
  • charge-sensitive component means distributed in an array on said layer of piezoelectric material
  • said piezoelectric layer comprises a coating deposited on a substrate.
  • a system according to claim 1 wherein said charge-sensitive component means are field-effect transistors.
  • said piezoelectric layer comprises cadmium sulphide and said charge-sensitive component means are cadmium sulphide thin-film field-effect transistors.
  • the pickup means includes crossbar arrangement means c0mprising a first group of parallel conductors connected to the transistor sources in respective columns of the array and a second group of parallel conductors at right angles to the first group connected to the transistor gates in respective rows of the array.

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • General Physics & Mathematics (AREA)
  • General Health & Medical Sciences (AREA)
  • Pathology (AREA)
  • Radiology & Medical Imaging (AREA)
  • Veterinary Medicine (AREA)
  • Heart & Thoracic Surgery (AREA)
  • Medical Informatics (AREA)
  • Molecular Biology (AREA)
  • Surgery (AREA)
  • Animal Behavior & Ethology (AREA)
  • Nuclear Medicine, Radiotherapy & Molecular Imaging (AREA)
  • Public Health (AREA)
  • Biomedical Technology (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • Biophysics (AREA)
  • Immunology (AREA)
  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Measurement Of Velocity Or Position Using Acoustic Or Ultrasonic Waves (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)

Abstract

An ultrasonic image recording system comprising a thin layer piezoelectric material for exposure to a field of ultrasonic radiation to be imaged and defining an image recording surface. A plurality of thin film field-effect transistors are distributed in an array on the piezoelectric material and are electrically connected in a crossbar arrangement to derive signals in succession from image points of the image recording surface.

Description

United States Patent [1 1 Bonnet et a1.
ULTRASONIC IMAGE RECORDING SYSTEM Inventors: Dieter Bonnet, Eschborn; Helmut Rabenhorst, Frankfurt-Niederrad, both of Germany Assignee: Hoffmann-LaRoche Inc., Nutley,
Filed: Feb. 1, 1972 Appl. No.: 222,578
Foreign Application Priority Data Feb. 17, 1971 Germany 2107555 US. Cl. 340/5 MP, 310/8.l, 317/235 M Int. Cl. H04b 11/00 Field of Search 340/5 MP, 5 H, 10;
References Cited UNITED STATES PATENTS 6/1967 Fyler 340/5 MP June 18, 1974 3,460,005 8/1969 Kanda et al. 317/235 M 3,475,551 10/1969 Green et a1. 340/5 MP 3,675,472 7/1972 Kay et al 340/5 MP FOREIGN PATENTS OR APPLICATIONS 1,244,551 9/1971 Great Britain 340/5 H Primary Examiner-Richard A. Farley Attorney, Agent, or FirmSamuel L. Welt; Bernard S. Leon [5 7] ABSTRACT 5 Claims, 2 Drawing Figures PAIENIED JUN] 81974 FIG. 1
I FROM ALL DRA NS MF II, IIJTII +4- m m 1 L FIG. 2
POTENTIAL SOURCE TIMER BACKGROUND OF THE INVENTION This invention relates to an ultrasonic image recording system.
X-rays are still used practically exclusively at the present time to detect internal structures in human and animal tissue. Apart from the fact that the tissue is exposed to health risks due to high-energy radiation, the contrast of the optical images produced could be greatly improved upon.
An alternative to the use of X-rays is irradiation with ultrasonics, to which the different types of tissue are permeable to very different degrees and thus offer good contrast. This irradiation is also completely harmless provided the total radiation power is below the cavitation limit. Since the sound radiated by conventional ultrasonic sources is coherent, holographic recordings are possible, which enable the irradiated tissue to be viewed stereoscopically, and this is very important, for example, for detection of the position of carcinomas and tumors.
A device presently available for sonic image recording is the Sokoloff tube. The front plate of this tube is a thin quartz disc. When the disc is placed in a field of ultrasonic radiation, ultrasonic waves impinging thereon produce a dipole pattern due to the piezoelectric effect, the pattern being distributed over the area of the plate in the form of an image and being capable of scanning by an electron beam. In this way a sound pattern distributed over an area can be converted into a sequence of electrical signals which can then be displayed as an image, for example, by means of a cathode ray tube. For practical reasons, the diameter of the quartz disc used is limited to about -6 cm, but it would be desirable to have available an image recording surface of linear dimensions of at least cm or above, for example, when it is required to observe a wider area of the human body.
SUMMARY OF THE INVENTION The purpose of the present invention is to enable the image recording surface of an ultrasonic image recording system to be increased. This is achieved by providing an ultrasonic image recording system including piezoelectric sound-sensitive means for exposure to a field of ultrasonic radiation to be imaged, in which system the piezoelectric means is in the form of a thin layer of piezoelectric material having charge-sensitive components distributed in an array on the layer of piezoelectric material and pick-up means provided for deriving from the charge-sensitive components electrical signals significant of the level of sound at corresponding points of the ultrasonic field. For example, the piezoelectric layer might comprise a coating deposited on a substrate and the charge-sensitive components could be field-effect transistors.
Supplemental to the above, the pick-up means may include a crossbar arrangement including one group of parallel conductors connected to the sources of the transistors in respective columns of the array and another group of parallel conductors at right angles to the first group connected to the gates of the transistors in respective rows of the array.
BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a cross section showing a single image point of an image recording surface of a system embodying the invention.
FIG. 2 is a schematic diagram of an ultrasonic image recording system according to the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. I there is shown an ultrasonic image recording surface including a piezoelectric layer in the form of a coating 2 of a suitable material such as cadmium sulphide (CdS) disposed on a substrate 1 which might comprise a plastic foil. The thickness of coating 2 should be between l0 and 50 am. The coating is polycrystalline, the individual crystallites being oriented with the c-axis (in whose direction there is the maximum piezo effect) perpendicular to the substrate 1.
An array or raster of thin film field-effect transistors are formed on the coating 2 by known vapor-coating processes. One such transistor shown in FIG. 1 comprises a drain 3, a source 4, a further coating 5 of CdS and a gate 6. The CdS coating 5 is about 1 pm thick, and the electrodes 3, 4 and 6 are some hundreds of Angstroms thick.
Ultrasonic radiation incident on the image recording surface produces periodically alternating dipole moments at the ultrasonic frequency in the CdS coating 2, and these modulate the current flow between the source and drain of each field-effect transistor. An electrical signal significant of the sound pressure at an image point can be derived by applying suitable voltages simultaneously to the gate and source of the fieldeffect transistor at the image point while the drain is at a fixed potential. The array of field-effect transistors is used to derive signals in succession from the image points of the image recording surface. As is illustrated in FIG. 2, the transistors 5' in the array can be scanned sequentially by a known crossbar arrangement, one group of parallel conductors 7 being connected to the source of the transistors in each column of the array and another group of parallel conductors 8 at right angles to the first group being conneced to the gates of each row of the array.
The transmission of scanning voltages from a potential source 12 from one source conductor to another and from one gate conductor to another is effected at the point or line frequency required for the particular application in which the system is used and could be implemented by, for example, a suitable timer 9 and commutators I0 and I]. The electrical output signal from the transistors is obtained as. a voltage signal at a resistor R situated in a line connecting the drains of all the transistors 5 to earth, is amplified (not shown) and converted to a visual image in a cathode ray tube (television display tube).
For optimum operation, the thickness of the substrate 1 and of the CdS coating 2 should be such that a sound wave impinging from above produces an antinode in the CdS coating 2 and a node at the underside of the substrate ll.
An image recording system embodying the invention may be used both for the direct production of images of structures or, more advantageously, for producing ultrasonic holograms. This second alternative comes to mind because, as mentioned hereinbefore, ultrasonic waves are coherent due to their method of generation.
EXAMPLE A 20 pm thick 10 10cm CdS coating consisting of high-orientation crystallites was vapor-coated on a 1 mm thick glass plate in a high vacuum at 300C. The coating had a resistance of more than 10 cm and was vapor-coated in the form of a piezoelectrically active coating. An array of "X10 CdS field-effect transistors were formed on the coating in the form of a raster by a known process using a masking technique. The piezoelectric modules of the coating of 2.10 Coulombs/dyne and the transconductivity of the transistors of 2.10 A/V together give a minimum detectable sonic radiation intensity of 310 W/cm Scanning of the array of transistors is effected by means of known shift registers controlling the application of scanning pulses to vapor-coated conductors which connect the gates of the transistors in each row and the sources of the transistors in each column. The image represented by the output electrical signal obtained from the system is reproduced in visual form in a conventional television unit. The image sequency is at the maximum time acceptable in medicine, i.e., 1 second. The system is suitable for ultrasonic image recording at an ultrasonic frequency of 10 MHz.
We claim:
1. An ultrasonic image recording system comprising:
piezoelectric sound-sensitive means having a thin layer of piezoelectric material for exposure to a field of ultrasonic radiation to be imaged;
charge-sensitive component means distributed in an array on said layer of piezoelectric material; and,
pick-up means for deriving from the charge-sensitive component means electrical signals significant of the level of sound at corresponding points of the ultrasonic field.
2. A system according to claim 1, wherein said piezoelectric layer comprises a coating deposited on a substrate.
3. A system according to claim 1 wherein said charge-sensitive component means are field-effect transistors.
4. A system according to claim 3, wherein said piezoelectric layer comprises cadmium sulphide and said charge-sensitive component means are cadmium sulphide thin-film field-effect transistors.
5. A system according to claim 4, wherein the pickup means includes crossbar arrangement means c0mprising a first group of parallel conductors connected to the transistor sources in respective columns of the array and a second group of parallel conductors at right angles to the first group connected to the transistor gates in respective rows of the array.

Claims (5)

1. An ultrasonic image recording system comprising: piezoelectric sound-sensitive means having a thin layer of piezoelectric material for exposure to a field of ultrasonic radiation to be imaged; charge-sensitive component means distributed in an array on said layer of piezoelectric material; and, pick-up means for deriving from the charge-sensitive component means electrical signals significant of the level of sound at corresponding points of the ultrasonic field.
2. A system according to claim 1, wherein said piezoelectric layer comprises a coating deposited on a substrate.
3. A system according to claim 1 wherein said charge-sensitive component means are field-effect transistors.
4. A system according to claim 3, wherein said piezoelectric layer comprises cadmium sulphide and said charge-sensitive component means are cadmium sulphide thin-film field-effect transistors.
5. A system according to claim 4, wherein the pick-up means includes crossbar arrangement means comprising a first group of parallel conductors connected to the transistor sources in respective columns of the array and a second group of parallel conductors at right angles to the first group connected to the transistor gates in respective rows of the array.
US00222578A 1971-02-17 1972-02-01 Ultrasonic image recording system Expired - Lifetime US3818426A (en)

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DE19712107555 DE2107555B2 (en) 1971-02-17 1971-02-17 ULTRASONIC IMAGE ARRANGEMENT

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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4089927A (en) * 1975-09-26 1978-05-16 Minnesota Mining And Manufacturing Company Strain sensor employing bi layer piezoelectric polymer
US4141021A (en) * 1977-02-14 1979-02-20 Varian Associates, Inc. Field effect transistor having source and gate electrodes on opposite faces of active layer
US4359767A (en) * 1980-03-17 1982-11-16 Siemens Aktiengesellschaft Ultrasonic array
US4378510A (en) * 1980-07-17 1983-03-29 Motorola Inc. Miniaturized accelerometer with piezoelectric FET
US4740829A (en) * 1982-09-02 1988-04-26 Canon Kabushiki Kaisha Semiconductor device having a thin layer comprising germanium atoms as a matrix with a restricted range of hydrogen atom concentration
US4767973A (en) * 1987-07-06 1988-08-30 Sarcos Incorporated Systems and methods for sensing position and movement
US4814842A (en) * 1982-05-13 1989-03-21 Canon Kabushiki Kaisha Thin film transistor utilizing hydrogenated polycrystalline silicon
US20050174014A1 (en) * 2002-06-06 2005-08-11 Christian Korden Adjustable filter and method for adjusting the frequency

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3325777A (en) * 1964-08-26 1967-06-13 Litton Prec Products Inc Image forming apparatus
US3460005A (en) * 1964-09-30 1969-08-05 Hitachi Ltd Insulated gate field effect transistors with piezoelectric substrates
US3475551A (en) * 1966-11-29 1969-10-28 Lockheed Aircraft Corp Solid state acoustic image converter
GB1244551A (en) * 1969-02-28 1971-09-02 British Aircraft Corp Ltd Improvements relating to acoustic detector arrays
US3675472A (en) * 1968-12-12 1972-07-11 Nat Res Dev Apparatus and method for images of the interior structure of solid objects

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3325777A (en) * 1964-08-26 1967-06-13 Litton Prec Products Inc Image forming apparatus
US3460005A (en) * 1964-09-30 1969-08-05 Hitachi Ltd Insulated gate field effect transistors with piezoelectric substrates
US3475551A (en) * 1966-11-29 1969-10-28 Lockheed Aircraft Corp Solid state acoustic image converter
US3675472A (en) * 1968-12-12 1972-07-11 Nat Res Dev Apparatus and method for images of the interior structure of solid objects
GB1244551A (en) * 1969-02-28 1971-09-02 British Aircraft Corp Ltd Improvements relating to acoustic detector arrays

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4089927A (en) * 1975-09-26 1978-05-16 Minnesota Mining And Manufacturing Company Strain sensor employing bi layer piezoelectric polymer
US4141021A (en) * 1977-02-14 1979-02-20 Varian Associates, Inc. Field effect transistor having source and gate electrodes on opposite faces of active layer
US4359767A (en) * 1980-03-17 1982-11-16 Siemens Aktiengesellschaft Ultrasonic array
US4378510A (en) * 1980-07-17 1983-03-29 Motorola Inc. Miniaturized accelerometer with piezoelectric FET
US4814842A (en) * 1982-05-13 1989-03-21 Canon Kabushiki Kaisha Thin film transistor utilizing hydrogenated polycrystalline silicon
US4740829A (en) * 1982-09-02 1988-04-26 Canon Kabushiki Kaisha Semiconductor device having a thin layer comprising germanium atoms as a matrix with a restricted range of hydrogen atom concentration
US4767973A (en) * 1987-07-06 1988-08-30 Sarcos Incorporated Systems and methods for sensing position and movement
US20050174014A1 (en) * 2002-06-06 2005-08-11 Christian Korden Adjustable filter and method for adjusting the frequency

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SE367115B (en) 1974-05-13
GB1323618A (en) 1973-07-18
IL38529A0 (en) 1972-03-28
DE2107555A1 (en) 1972-08-31
DD99695A5 (en) 1973-08-12
NL7200651A (en) 1972-08-21
DE2107555B2 (en) 1972-08-31
CH545984A (en) 1974-02-15
IL38529A (en) 1975-03-13
CA955323A (en) 1974-09-24

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