EP0102179A1 - Ultraschallwandler mit einstellbarem Fokus für Tomographie - Google Patents

Ultraschallwandler mit einstellbarem Fokus für Tomographie Download PDF

Info

Publication number
EP0102179A1
EP0102179A1 EP83304222A EP83304222A EP0102179A1 EP 0102179 A1 EP0102179 A1 EP 0102179A1 EP 83304222 A EP83304222 A EP 83304222A EP 83304222 A EP83304222 A EP 83304222A EP 0102179 A1 EP0102179 A1 EP 0102179A1
Authority
EP
European Patent Office
Prior art keywords
ultrasonic transducer
transducer
region
piezoelectric material
central
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Granted
Application number
EP83304222A
Other languages
English (en)
French (fr)
Other versions
EP0102179B1 (de
Inventor
Perry Kaminski
Eugene A. Larson
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Technicare Corp
Original Assignee
Technicare Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Family has litigation
First worldwide family litigation filed litigation Critical https://patents.darts-ip.com/?family=27017086&utm_source=google_patent&utm_medium=platform_link&utm_campaign=public_patent_search&patent=EP0102179(A1) "Global patent litigation dataset” by Darts-ip is licensed under a Creative Commons Attribution 4.0 International License.
Priority claimed from US06/400,551 external-priority patent/US4445380A/en
Application filed by Technicare Corp filed Critical Technicare Corp
Publication of EP0102179A1 publication Critical patent/EP0102179A1/de
Application granted granted Critical
Publication of EP0102179B1 publication Critical patent/EP0102179B1/de
Expired legal-status Critical Current

Links

Images

Classifications

    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18—Methods or devices for transmitting, conducting or directing sound
    • G10K11/26—Sound-focusing or directing, e.g. scanning
    • G10K11/32—Sound-focusing or directing, e.g. scanning characterised by the shape of the source
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18—Methods or devices for transmitting, conducting or directing sound
    • G10K11/26—Sound-focusing or directing, e.g. scanning
    • G—PHYSICS
    • G10—MUSICAL INSTRUMENTS; ACOUSTICS
    • G10K—SOUND-PRODUCING DEVICES; METHODS OR DEVICES FOR PROTECTING AGAINST, OR FOR DAMPING, NOISE OR OTHER ACOUSTIC WAVES IN GENERAL; ACOUSTICS NOT OTHERWISE PROVIDED FOR
    • G10K11/00—Methods or devices for transmitting, conducting or directing sound in general; Methods or devices for protecting against, or for damping, noise or other acoustic waves in general
    • G10K11/18—Methods or devices for transmitting, conducting or directing sound
    • G10K11/26—Sound-focusing or directing, e.g. scanning
    • G10K11/30—Sound-focusing or directing, e.g. scanning using refraction, e.g. acoustic lenses

Definitions

  • This invention relates to ultrasonic transducers for diagnostic imaging and, in particular, to transducers of a novel geometric design with variable focal ranges and reduced sidelobe patterns.
  • Ultrasonic transducers are used in ultrasonic diagnostic systems to transmit waves of ultrasonic energy into a patient's body. Tissue interfaces in the body reflect some of this energy back toward the transducer in the form of echoes. The echoes are received by the transducer and converted into electrical signals. These signals may be processed by associating them with their times of arrival to reconstruct an image of the tissue or make fluid flow measurements.
  • Focusing may be done in the signal processing, as in the case of phased arrays, or may be provided by the geometric shape of the transducer. Geometric focusing advantageously eliminates much electrical complexity usually required to achieve the same result in the signal processing section of the system. However, geometric focal characteristics are idealized normally for only a single focal point or line of focal points, which restricts the range of good image resolution.
  • a selectable focus transducer is shown in U.S. Patent 4,138,895.
  • the transducer there shown comprises a disc divided into a center electroded region and an annular electroded region. A user can select just the center electrode for a large depth of focus, or the central and annular regions together for a smaller depth of focus.
  • An acoustic lens provides the transducer arrangement with the desired aperture with point focal characteristics.
  • Transducers like antennas, have transmissive characteristics that can be analyzed in terms of main and sidelobes. It is desirable in general to have small sidelobes for an ultrasonic transducer, since large sidelobes can result in the reception and introduction of noise in a reproduced ultrasound image.
  • an ultrasonic transducer prefferably has good geometric focal characteristics which are adjustable so as to provide good resolution over a range of tissue depths. It is further desirable to reduce the transducer sidelobe patterns so as to minimize noise in the reproduced image.
  • an ultrasonic transducer assembly having a novel geometric focal characteristic.
  • the transducer or transducer and lens arrangement resembles a concave spherical surface with opposite sides relative to the center of the surface canted toward each other in a semi-conical aspheric configuration.
  • the geometric focal characteristic thus provides a concentration of ultrasonic energy over a particular range of interest.
  • the transducer material is divided into a center disc and an annular ring.
  • the center disc When the center disc is activated, the range of optimal focus is located a relatively short distance from the transducer.
  • the range of optimal focus is located at a relatively greater distance from the transducer.
  • sidelobes of a transducer of the present invention are reduced by apodization, wherein damping material is located at the outer periphery on the back of the transducer.
  • a proximity switch is provided in the transducer assembly to switch between the long and short focal ranges.
  • the transducer electronics including the switch contacts are surrounded by a continuous shield.
  • the proximity switch comprises a reed switch which is controlled by a magnet located external to the shield. The use of a proximity switch such as a reed switch thus permits the focal ranges to be switched without physically interrupting the shield and hence impairing the noise characteristic of the transducer assembly.
  • a conical transducer is shown in cross-section.
  • the transducer includes a conical surface 12 of piezoelectric ceramic material on a backer 10.
  • the conical transducer exhibits an idealized aperture outlined at 16, which comprises a line of geometric focal points 14 emanating from the center of the transducer.
  • Conical transducers are advantageous in that they exhibit a narrow region-of sharply defined focal points. Their disadvantage is that the energy emitted by the conical surface is relatively evenly distributed over the line of focal points. It would be desirable to be able to concentrate the emitted energy in a particular region of the aperture, so as to improve the sensitivity of the transducer at a particular tissue depth of interest.
  • FIGURE 2a illustrates a spherical transducer in cross-section.
  • This transducer includes a spherical surface 22 of piezoelectric material mounted on a backer 20.
  • the spherical transducer exhibits an idealized aperture outlined at 26, which contains a single geometric focal point 24.
  • the ultrasonic energy emitted from the spherical surface of the transducer 22 converges at this point, and diverges beyond it.
  • the spherical transducer is capable of producing sharply focused images of tissue in the vicinity of the geometric focal point 24 by reason of the concentrated ultrasonic energy at the point.
  • the aperture is only sharply focused at one point, with resolution degrading at regions removed from this point.
  • FIGURE 3a A transducer constructed in accordance with the principles of the present invention is shown in cross-section in FIGURE 3a.
  • the transducer there shown is neither conical nor spherical, but exhibits many of the advantages of these two transducer types while overcoming several of their shortcomings.
  • the novel transducer of FIGURE 3a includes an aspheric surface 32 of piezoelectric material mounted on a backer 30.
  • the shape of the surface 32 is difficult to visualize in three dimensions, but in two dimensional cross-section it resembles a spherical surface transducer which has been bent at the center point 38.
  • the halves of the spherical surface on either side of the center point appear to be folded toward each other.
  • the transducer exhibits the idealized aperture outlined at 36, in which most of the emitted ultrasonic energy is focused at points 34 in an elongated focal region.
  • the ultrasonic energy emitted by the novel transducer is neither focused along the entire center line of the transducer, nor is it focused at a single point. Rather, it is concentrated in an elongated region of optimal focus in which tissue of a significant depth can be imaged with good lateral resolution.
  • the elongated region in a constructed embodiment of the present invention can extend over a six to seven centimeter depth for a 19 mm, 3.5 MHz transducer.
  • an aspheric surface piezolectric element 300 includes a central area 312 which is electrically separate from an outer annulus 314.
  • the piezoelectric material is mounted in a cylindrical mount 306.
  • the inner area 312 may be activated alone, or a switch 316 may be closed to activate both areas 312 and 314 simultaneously to focus the transducer over different depths of focus.
  • the concave front of the transducer 300 is filled in with an epoxy material to provide a flat face 302 on the transducer.
  • FIGURE 5 A preferred embodiment of the present invention is shown in FIGURE 5.
  • the piezoelectric material exhibits a conical shape, and contains an annular groove which divides the material into an inner conical region 212 and an annular outer region 214.
  • the center region 212 may be activated alone or together with the annular region 214 by closing a switch 216. When the switch 216 is open, the center region 212 will focus in the near field out to a point 218 at approximately 9 centimeters, and when the two regions are activated together, far field focusing is effected out to a point 201 at approximately 14 centimeters.
  • the acoustic lens 210 On the face of the piezoelectric material is an acoustic lens having a spherical face 210.
  • the combination of the conical piezoelectric material 212, 214 and the spherical faced lens provide the aspheric aperture characteristic of the embodiments of FIGURES 3a and 4.
  • the concave lens is again filled in with epoxy to provide a flat face 208 on the transducer.
  • the acoustic lens 210 was composed of a high acoustic impedance and velocity epoxy material, and the filler material at 208 was a lower acoustic impedance and velocity epoxy material.
  • the conical piezoelectric transducer 212, 214 and the spherical acoustic lens provide the desired elongated focal region aperture, and the filler 208 forms a simple plano-convex lens which extends the focal zone to point 201. It follows from the principles of this embodiment that an aspheric transducer could also be made utilizing a spherical piezoelectric disc and a conical faced lens.
  • FIGURE 5 is more easily manufactured than the other illustrated embodiments of the present invention. This is because a conical ceramic transducer can be readily manufactured and the spherical acoustic lens can be formed by a simple lapping technique.
  • the embodiment of FIGURE 4, with its aspheric ceramic surface, should be formed by grinding the ceramic material with a precise, numerically controlled lathe, for example.
  • FIGURE 6 is composed of a flat disc 400 of piezoelectric material, including a central disc 404 and an annular ring 406, the activation of which is controlled by a switch 416.
  • the disc 400 is fronted with an acoustic lens 402 having an aspheric surface. This combination of piezoelectric material and aspheric lens will produce the same aperture as the embodiments of FIGURES 4 and 5.
  • a conical transducer such as that shown in FIGURE la will exhibit a lobe pattern as shown in FIGURE lb, with a large main lobe 40 and sizeable sidelobes 42 and 42'.
  • the large sidelobes 42 and 42' are undesirable in an ultrasonic diagnostic system.
  • the spherical transducer of FIGURE 2a will exhibit a more acceptable lobe pattern as shown in FIGURE 2b.
  • the pattern there shown includes a large main lobe 50 and small sidelobes 52, 52'.
  • the aspheric transducer of the present invention will exhibit a lobe pattern intermediate those of FIGURES lb and 2b.
  • the lobe pattern of a transducer of the present invention is improved in accordance with a further aspect of the present invention by providing backing material around the outer perimeter of the transducer as shown at 304 in FIGURES 4 and 5. This ring of backing material damps vibrations at the outer perimeter of the piezoelectric material thereby reducing the energy radiated from the perimeter of the piezoelectric material.
  • the ring of backing material may be extended to back the central region 212 or 312 to damp vibrations at the perimeter of the central region when it is operated alone.
  • This damping technique causes the transducer to be a non-uniform radiator, which "smears" the small side lobes of the transducer as shown in FIGURE 3b, which illustrates a large main lobe 60 and side lobes 62, 62', which are approximately the same size as the side lobes 52, 52' of the spherical transducer.
  • FIGURE 7a illustrates the focal pattern of a simple dual aperture spherical transducer, including a central spherical region 120 and an outer annular region 122.
  • the transducer When both regions 120 and 122 of the transducer are activated simultaneously, the transducer exhibits an aperture outlined at 124, which narrows sharply at a focal region 125. Focusing is ineffective beyond the near field limit'129 of the transducer, which is approximately equal to the radius of the transducer squared, divided by the wavelength of operation.
  • the near field limit 129 is thus a linear function of the area of the transducer, which in this case is the total of both regions 120 and 122.
  • the aperture is as outlined by dotted lines 126.
  • This aperture produces a focal region 127 closer to the transducer, with a near field limit at 128 by reason of the reduced area of the transducer.
  • the aperture outlined at 126 does not narrow as sharply as the aperture outlined at 124, however, and the focal region 127 has a greater lateral dimension 1 than focal region 125. This is because the focus is changed by changing the near field limit from 129 to 128; the geometric focus remains the same, generally located slightly beyond the far focal region 125.
  • FIGURE 7b illustrates the focal pattern of a simple dual aperture conical transducer having an inner conical surface 130 and an outer annular surface 132.
  • the energy from surface 130 focuses along the broken line shown at 137 and bounded by dotted lines 136.
  • the line of focal points is extended to include the points indicated at 135 as well as those at 137, bounded by dashed lines 134. Switching from operation using both regions to operation using only the center region 130 reduces the near field limit, since the transducer area changes, and also reduces the geometric focal length to only the focal points included in aperture outline 136. A line of distributed energy focal points is produced in both cases.
  • FIGURE 7c illusrates the focal pattern of-a dual focus aspheric transducer of the present invention.
  • a narrow focal region 145 is produced at the narrow portion of the aperture outlined by dashed lines 144.
  • the area of the full transducer provides a near field limit indicated at 129.
  • the area of the transducer is reduced, which moves the near field limit to the line indicated at 128.
  • the geometric focus of the transducer also changes, since its effective radiating surface is aspheric.
  • the aperture of the central region appears as outlined by dotted lines 146, containing a relatively narrow focal region 147.
  • the focal region 147 is laterally narrower than region 127 of the spherical transducer by reason of the relocation of the geometric focus of the transducer to an area closer to the transducer. Good lateral resolution is therefore provided in both region 145 and region 147.
  • the diameter d' of the central region 140 can be made larger than the diameter d of the equivalent central region 120 of the spherical transducer of FIGURE 7a.
  • the larger region will transmit and receive more energy than a smaller region, thereby increasing the sensitivity of the transducer.
  • the larger central region 140 contributes to the narrowing effect on the aperture 146.
  • the ultrasonic transducer of the present invention is conveniently mounted in a probe assembly such as that shown in FIGURE 8.
  • the probe assembly there shown advantageously provides an electrically shielded environment which reduces the tendency to pick up stray electronic interference.
  • the probe assembly also provides a means for switching the focus of the transducer in a manner which does not interrupt the shielded environment. As the focus of the transducer is switched, the tuning of the transducer is also changed and a signal is provided which indicates the selected focal characteristics.
  • the probe assembly of FIGURE 8 includes a forward plastic cylindrical section 150 with a closed acoustic window face 151.
  • the aspheric transducer 152 is located behind the window 151.
  • Leads 156 extend from the separate regions of the transducer.
  • the interior of the cylindrical section 150 is lined with a nonmagnetic shield 154 such as copper.
  • the rear portion of the cylindrical section 150 narrows to a smaller diameter as indicated by dividing ridge 157.
  • Two dimples shown at 158 are provided on the outside .of the narrow portion which form a portion of the detent mechanism of the switch.
  • the end 159 of the cylindrical section 150 is open.
  • a plastic ring 160 slides over the narrow portion of the cylindrical section 150 up to the ridge 157.
  • On the inner surface of the ring 160 is a small b d ll 162 which rides between the dimples 158 and snaps into them to provide a detent mechanism for the ring.
  • a groove 168 is formed around the inner surface of the ring to hold a magnet 164 in a predetermined position relative to the ball bearing 162.
  • a small pin 166 extends from the inner surface of the ring at the bottom of the ring.
  • a rear cylindrical section 170 slides over the remainder of the narrow portion of section 150.
  • a recessed collar 176 is then located under the ring 160.
  • the collar 176 has a slot 174 in it so that pin 166 can move from one end of the slot to the other as the ring 160 is turned. The pin and slot thereby provide a stop for the ring to permit the ring to be turned only through the arc of the slot.
  • the wires 156 from the transducer are soldered to a small printed circuit board 190, mounted on an r.f. connector 180.
  • the r.f. connector 180 is inserted into the open end 159 of the section 150 up to the lip 181 of the connector.
  • Mounted on the connector at a plastic ring 182 are three reed switches 184, 186 and 188.
  • the reed switches are wired to the printed circuit board 190.
  • the r.f. connector 180 and copper shield 154 provide a completely shielded cavity for the wiring, printed circuit board, switches, and board components in the inside of the section 150.
  • the ring performs three switching functions in the probe assembly.
  • the focal characteristics of the transducer are switched between short focus using only the central disc of the transducer, and long focus by connecting the central disc and annular ring of the transducer together to be activated simultaneously.
  • the tuning of the circuitry on circuit board 190 is switched to match the respective electrical characteristics of the transducer in the two operating modes.
  • a resistance value on the circuit board is changed to produce a signal indicative of the operating mode, which signal is coupled out through the connector along with signals to and from the transducer.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Acoustics & Sound (AREA)
  • Multimedia (AREA)
  • Ultra Sonic Daignosis Equipment (AREA)
  • Transducers For Ultrasonic Waves (AREA)
EP83304222A 1982-07-21 1983-07-20 Ultraschallwandler mit einstellbarem Fokus für Tomographie Expired EP0102179B1 (de)

Applications Claiming Priority (4)

Application Number Priority Date Filing Date Title
US40054782A 1982-07-21 1982-07-21
US400551 1982-07-21
US06/400,551 US4445380A (en) 1982-07-21 1982-07-21 Selectable focus sphericone transducer and imaging apparatus
US400547 1982-07-21

Related Child Applications (1)

Application Number Title Priority Date Filing Date
EP86200472.8 Division-Into 1986-03-21

Publications (2)

Publication Number Publication Date
EP0102179A1 true EP0102179A1 (de) 1984-03-07
EP0102179B1 EP0102179B1 (de) 1987-09-16

Family

ID=27017086

Family Applications (2)

Application Number Title Priority Date Filing Date
EP83304222A Expired EP0102179B1 (de) 1982-07-21 1983-07-20 Ultraschallwandler mit einstellbarem Fokus für Tomographie
EP86200472A Expired - Lifetime EP0196139B1 (de) 1982-07-21 1983-07-20 Ultraschallwandler-Sondengerät mit Doppelöffnung

Family Applications After (1)

Application Number Title Priority Date Filing Date
EP86200472A Expired - Lifetime EP0196139B1 (de) 1982-07-21 1983-07-20 Ultraschallwandler-Sondengerät mit Doppelöffnung

Country Status (4)

Country Link
EP (2) EP0102179B1 (de)
AU (1) AU572464B2 (de)
DE (2) DE3382654T2 (de)
IL (1) IL69293A0 (de)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0150843A2 (de) * 1984-02-02 1985-08-07 COMPAGNIE GENERALE D'ELECTRICITE Société anonyme dite: Gerät mit lokalisierten Schallwellen zur Objektstrukturuntersuchung
AU572464B2 (en) * 1982-07-21 1988-05-12 Technicare Corp. Selectable focus ultrasonic transducer
EP0373603A2 (de) * 1988-12-14 1990-06-20 Matsushita Electric Industrial Co., Ltd. Ultraschallsonde
EP0383629A1 (de) * 1989-02-17 1990-08-22 Kabushiki Kaisha Toshiba Vorrichtung zum Zerstören von Konkrementen
EP0421279A1 (de) * 1989-09-29 1991-04-10 Terumo Kabushiki Kaisha Ultraschall-Diagnoseapparat mit selektiven Fokusmustern
WO1999010875A2 (de) * 1997-08-23 1999-03-04 Valeo Schalter Und Sensoren Gmbh Ultraschallwandler mit in wandlerlängsrichtung angeordneter platine für eine elektrische schaltung
DE10114819A1 (de) * 2001-03-26 2002-10-10 Siemens Ag Verfahren zur Verbesserung des Signalempfangs eines Ultraschall-Näherungsschalters und Ultraschall-Näherungsschalter mit verbessertem Signalempfang

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20220373372A1 (en) * 2021-05-19 2022-11-24 Honeywell International Inc. Fluid sensor for bubble and occlusion detection

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3903990A (en) * 1972-10-18 1975-09-09 Hitachi Ltd Acoustic lens
US3958559A (en) * 1974-10-16 1976-05-25 New York Institute Of Technology Ultrasonic transducer
US4138895A (en) * 1977-10-20 1979-02-13 Rca Corporation Switchable depth of focus pulse-echo ultrasonic-imaging display system
US4276779A (en) * 1979-03-29 1981-07-07 Raytheon Company Dynamically focussed array
GB2075797A (en) * 1980-05-09 1981-11-18 Tokyo Shibaura Electric Co An ultrasonic probe and its driving method

Family Cites Families (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3193198A (en) * 1963-11-12 1965-07-06 Honeywell Inc Control apparatus
US4016751A (en) * 1973-09-13 1977-04-12 The Commonwealth Of Australia Care Of The Department Of Health Ultrasonic beam forming technique
US4398539A (en) * 1980-06-30 1983-08-16 Second Foundation Extended focus transducer system
US4557146A (en) * 1982-07-21 1985-12-10 Technicare Corporation Selectable focus ultrasonic transducers for diagnostic imaging
US4445380A (en) * 1982-07-21 1984-05-01 Technicare Corporation Selectable focus sphericone transducer and imaging apparatus
DE3382654T2 (de) * 1982-07-21 1993-05-13 Technicare Corp Ultraschallwandler-sondengeraet mit doppeloeffnung.

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3903990A (en) * 1972-10-18 1975-09-09 Hitachi Ltd Acoustic lens
US3958559A (en) * 1974-10-16 1976-05-25 New York Institute Of Technology Ultrasonic transducer
US4138895A (en) * 1977-10-20 1979-02-13 Rca Corporation Switchable depth of focus pulse-echo ultrasonic-imaging display system
US4276779A (en) * 1979-03-29 1981-07-07 Raytheon Company Dynamically focussed array
GB2075797A (en) * 1980-05-09 1981-11-18 Tokyo Shibaura Electric Co An ultrasonic probe and its driving method

Cited By (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AU572464B2 (en) * 1982-07-21 1988-05-12 Technicare Corp. Selectable focus ultrasonic transducer
EP0150843A2 (de) * 1984-02-02 1985-08-07 COMPAGNIE GENERALE D'ELECTRICITE Société anonyme dite: Gerät mit lokalisierten Schallwellen zur Objektstrukturuntersuchung
FR2559266A1 (fr) * 1984-02-02 1985-08-09 Comp Generale Electricite Dispositif a ondes acoustiques focalisees pour etudier la structure d'un objet
EP0150843A3 (de) * 1984-02-02 1985-12-18 COMPAGNIE GENERALE D'ELECTRICITE Société anonyme dite: Gerät mit lokalisierten Schallwellen zur Objektstrukturuntersuchung
EP0373603A2 (de) * 1988-12-14 1990-06-20 Matsushita Electric Industrial Co., Ltd. Ultraschallsonde
EP0373603A3 (de) * 1988-12-14 1991-11-13 Matsushita Electric Industrial Co., Ltd. Ultraschallsonde
EP0383629A1 (de) * 1989-02-17 1990-08-22 Kabushiki Kaisha Toshiba Vorrichtung zum Zerstören von Konkrementen
US5076277A (en) * 1989-02-17 1991-12-31 Kabushiki Kaisha Toshiba Calculus destroying apparatus using feedback from a low pressure echo for positioning
EP0421279A1 (de) * 1989-09-29 1991-04-10 Terumo Kabushiki Kaisha Ultraschall-Diagnoseapparat mit selektiven Fokusmustern
WO1999010875A2 (de) * 1997-08-23 1999-03-04 Valeo Schalter Und Sensoren Gmbh Ultraschallwandler mit in wandlerlängsrichtung angeordneter platine für eine elektrische schaltung
WO1999010875A3 (de) * 1997-08-23 1999-05-06 Itt Mfg Enterprises Inc Ultraschallwandler mit in wandlerlängsrichtung angeordneter platine für eine elektrische schaltung
DE10114819A1 (de) * 2001-03-26 2002-10-10 Siemens Ag Verfahren zur Verbesserung des Signalempfangs eines Ultraschall-Näherungsschalters und Ultraschall-Näherungsschalter mit verbessertem Signalempfang

Also Published As

Publication number Publication date
EP0196139A2 (de) 1986-10-01
EP0196139A3 (en) 1990-12-05
DE3373739D1 (en) 1987-10-22
AU572464B2 (en) 1988-05-12
DE3382654D1 (de) 1993-03-04
AU1712483A (en) 1984-01-26
DE3382654T2 (de) 1993-05-13
IL69293A0 (en) 1983-11-30
EP0196139B1 (de) 1993-01-20
EP0102179B1 (de) 1987-09-16

Similar Documents

Publication Publication Date Title
US4557146A (en) Selectable focus ultrasonic transducers for diagnostic imaging
JPH0414014B2 (de)
US4276779A (en) Dynamically focussed array
US4398539A (en) Extended focus transducer system
US5922962A (en) Sparse two-dimensional transducer array with compound lens
EP0031614B2 (de) Bogenförmige Anordnung mehrerer Ultraschallwandler
JPH0856949A (ja) 超音波プローブ
EP0102179B1 (de) Ultraschallwandler mit einstellbarem Fokus für Tomographie
WO2001058601A1 (en) Forward and side looking ultrasonic imaging
US4607186A (en) Ultrasonic transducer with a piezoelectric element
EP3371624B1 (de) Ultraschallsystem zur bereitstellung von ultraschallbildern mit variablen frequenzen eines volumetrischen bereichs mit einem störer- analysator
JPS58161492A (ja) リニア・フェーズド・アレイ超音波変換器
KR101356615B1 (ko) 신호경로가 일체로 된 하우징을 사용하는 초음파 트랜스듀서
US5418759A (en) Ultrasound transducer arrangement having an acoustic matching layer
US5025789A (en) Shock wave source having a central ultrasound locating system
CA1212448A (en) Selectable focus sphericone transducer, imaging apparatus and switching means
US4794929A (en) Echography probe and echograph fitted, with a probe of this type
KR102456228B1 (ko) 투명 초음파 센서 기반 초음파 광학 복합 이미징 시스템
US7300403B2 (en) Wide aperture array design with constrained outer probe dimension
US4443733A (en) Tapered wave transducer
US4915114A (en) Shock wave source having central locating system & disposed in a cavity free of shock waves
GB2059716A (en) Device and transducer for ultrasound echographic examination
JP4519330B2 (ja) 超音波探触子
US4612809A (en) Curved-array ultrasonic probe using low-velocity fluid
JP3358907B2 (ja) 配列型の超音波探触子

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

AK Designated contracting states

Designated state(s): DE FR GB NL

17P Request for examination filed

Effective date: 19840813

GRAA (expected) grant

Free format text: ORIGINAL CODE: 0009210

AK Designated contracting states

Kind code of ref document: B1

Designated state(s): DE FR GB NL

PG25 Lapsed in a contracting state [announced via postgrant information from national office to epo]

Ref country code: FR

Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES

Effective date: 19870916

REF Corresponds to:

Ref document number: 3373739

Country of ref document: DE

Date of ref document: 19871022

EN Fr: translation not filed
PLBI Opposition filed

Free format text: ORIGINAL CODE: 0009260

26 Opposition filed

Opponent name: SIEMENS AKTIENGESELLSCHAFT, BERLIN UND MUENCHEN

Effective date: 19880614

NLR1 Nl: opposition has been filed with the epo

Opponent name: SIEMENS AKTIENGESELLSCHAFT

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: DE

Payment date: 19900831

Year of fee payment: 8

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: GB

Payment date: 19910709

Year of fee payment: 9

RDAG Patent revoked

Free format text: ORIGINAL CODE: 0009271

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: PATENT REVOKED

PGFP Annual fee paid to national office [announced via postgrant information from national office to epo]

Ref country code: NL

Payment date: 19910731

Year of fee payment: 9

27W Patent revoked

Effective date: 19910612

GBPR Gb: patent revoked under art. 102 of the ep convention designating the uk as contracting state
NLR2 Nl: decision of opposition
APAH Appeal reference modified

Free format text: ORIGINAL CODE: EPIDOSCREFNO