EP0421286B1 - Piezoelectric transducer - Google Patents
Piezoelectric transducer Download PDFInfo
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- EP0421286B1 EP0421286B1 EP90118633A EP90118633A EP0421286B1 EP 0421286 B1 EP0421286 B1 EP 0421286B1 EP 90118633 A EP90118633 A EP 90118633A EP 90118633 A EP90118633 A EP 90118633A EP 0421286 B1 EP0421286 B1 EP 0421286B1
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- European Patent Office
- Prior art keywords
- layer
- transducer elements
- piezoelectric transducer
- transducer
- transducer according
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- Expired - Lifetime
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- 230000008878 coupling Effects 0.000 claims description 26
- 238000010168 coupling process Methods 0.000 claims description 26
- 238000005859 coupling reaction Methods 0.000 claims description 26
- 230000035939 shock Effects 0.000 claims description 19
- 239000000919 ceramic Substances 0.000 claims description 11
- 239000007787 solid Substances 0.000 claims description 8
- 238000002604 ultrasonography Methods 0.000 claims description 6
- 239000004593 Epoxy Substances 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 3
- 229920001296 polysiloxane Polymers 0.000 claims description 3
- 229920002635 polyurethane Polymers 0.000 claims description 3
- 239000004814 polyurethane Substances 0.000 claims description 3
- 238000007789 sealing Methods 0.000 claims 2
- 239000003566 sealing material Substances 0.000 claims 2
- 230000003247 decreasing effect Effects 0.000 claims 1
- 239000000463 material Substances 0.000 description 7
- 238000004382 potting Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 230000005855 radiation Effects 0.000 description 4
- 230000006978 adaptation Effects 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- 229910052782 aluminium Inorganic materials 0.000 description 2
- 150000001875 compounds Chemical class 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 238000004873 anchoring Methods 0.000 description 1
- 230000005540 biological transmission Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000009172 bursting Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 230000036039 immunity Effects 0.000 description 1
- 238000009413 insulation Methods 0.000 description 1
- 239000012212 insulator Substances 0.000 description 1
- 238000007788 roughening Methods 0.000 description 1
- 238000007493 shaping process Methods 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 238000002560 therapeutic procedure Methods 0.000 description 1
Images
Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B06—GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS IN GENERAL
- B06B—METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, e.g. FOR PERFORMING MECHANICAL WORK IN GENERAL
- B06B1/00—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
- B06B1/02—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy
- B06B1/06—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction
- B06B1/0607—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements
- B06B1/0622—Methods or apparatus for generating mechanical vibrations of infrasonic, sonic, or ultrasonic frequency making use of electrical energy operating with piezoelectric effect or with electrostriction using multiple elements on one surface
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- 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
- G10K11/02—Mechanical acoustic impedances; Impedance matching, e.g. by horns; Acoustic resonators
Definitions
- the invention relates to a piezoelectric transducer for generating focused ultrasonic shock waves for use in lithotripsy with the features of the preamble of claim 1.
- Piezoelectric transducers are generally known, for example from DE-PS 34 25 992.
- the use of a coupling medium for coupling the ultrasonic shock waves to the patient's body in such transducers is also well known.
- the energy densities that can be generated with piezoelectric materials are very high, but only a very small part of the available energy is introduced into the coupling medium (water or oil) in practice, since the sound-producing ceramic and the water / oil are acoustically very strong differentiate from each other.
- the known transducer is designed so that between the transducer elements and the coupling medium, an intermediate medium is provided at least from one layer, the acoustic impedance of which is between that of the ceramic of the transducer elements and that of the coupling medium and that the thickness of the layer is dimensioned such that the relationship d> ⁇ k .c LA applies, where ⁇ k is the propagation time of the sound in the piezoceramic of the transducer elements and c LA is the speed of sound in the respective intermediate medium.
- the thickness of the layer of the intermediate medium cannot be measured on the basis of the wavelength of the ultrasound, since the ultrasound shock waves generated by the transducer have a very wide frequency spectrum.
- an adaptation as known from US-PS 415 6863, does not provide anything for the present task solution. This is because there is only provision for the thickness of one Potting compound, which has the acoustic impedance of the coupling medium (water), to be dimensioned to a quarter of the wavelength of the sound waves emanating from the individual transducers.
- the requirements for impedance matching are completely different.
- a layer of the intermediate medium is introduced between the active surface of each piezoelectric transducer element and the coupling medium, it must have a certain thickness and a certain acoustic impedance in order to achieve optimal results.
- the acoustic impedance to be selected depends on the acoustic conditions at the interface between the active transducer elements and the layer of the intermediate medium or on the known sound transmission factors at the interface between two media of different acoustic impedance. In any case, it lies between that of the ceramic of the transducer elements and that of the coupling medium.
- the acoustic thickness of the layer of the intermediate medium must be greater than that of the ceramic of the transducer elements.
- the effect that more energy gets into the coupling medium can be increased in that several layers of intermediate media are provided between the transducer elements and the coupling medium, the acoustic impedances of which decrease from the first layer on the transducer elements in the direction of radiation of the ultrasonic shock waves.
- the layer or the layers of the intermediate media can each be assigned to one transducer element, uniformly all transducer elements together or mixed partially uniformly together and partially in each case to one transducer element.
- the described construction of the transducer according to the invention can be implemented in the case of self-focusing transducers, for example dome-shaped transducers, but also in the case of planar transducers.
- At least a layer of an intermediate medium is designed as an acoustic lens. This layer then takes over the task of focusing the ultrasonic shock waves on the focus of the transducer, so that no additional effort is required.
- the transducer in the direction of radiation of the ultrasonic shock waves, has a layer of an intermediate medium on the transducer elements, which has a surface that electrically connects the transducer elements and faces them. This surface is then connected to one pole of the pulse generator.
- the first layer is thus used as a common electrode for all transducer elements, which not only significantly reduces the amount of wiring previously required, but also makes the transducer overall more compact and less susceptible to faults.
- the first layer is solid and metallic.
- Aluminum for example, is suitable for this purpose, the acoustic impedance of which corresponds to the conditions mentioned.
- this embodiment can advantageously be developed further in that the layer is constructed as a solid, acoustic lens. This then again takes on the task of focusing the ultrasonic shock waves on the converter focus.
- Each transducer element has a so-called backing, the acoustic impedance is at least as large as that of the ceramic of the individual transducer elements. This measure ensures an almost reflection-free termination of the transducer elements, so that unwanted negative tensile impulses for lithotripsy are limited to a practically possible minimum.
- the backings can be designed in such a way that the sound coming from the ceramic is scattered so that it does not in the focus of the converter, which can be achieved, for example, by roughening the back of the backings or by shaping it into a cone, for example.
- transducer elements can also be provided with a common backing for their reflection-free termination.
- the energy density of the ultrasonic shock waves in the transducer focus compared to previous transducers has been increased by "passive” measures through the better coupling of the ultrasonic shock waves into the coupling medium, that is, through the better utilization of the energy generated by the transducer elements.
- some of the described embodiments also allow the energy density in the converter focus to be increased by “active” measures. This relates in particular to the control of the converter elements by means of higher voltages. Up to now, this was not easily possible primarily due to safety aspects, but also with regard to the converter's service life.
- the transducer elements with the electrically conductive carrier by means of electrically conductive fasteners are clamped, the carrier being connected to the other pole of the pulse generator. This makes it possible to control the converter elements with higher voltages without the converter elements bursting out of their anchoring, which would result in irreparable damage.
- a higher controllability with higher voltages, whereby the output power of the converter is actively increased, can be achieved in the embodiments of the converter described above, in which the first layer of an intermediate medium on the converter elements is solid and metallic and thus serves as an electrode that the space outlined by the first layer, the common backing, or the support is liquid-tight and gas-tight by means of electrically non-conductive side walls, and that this space is filled with a highly insulating medium.
- a gas, oil or also a solid insulator can be considered as a highly insulating medium.
- the transducer in such a way that an electrically conductive first layer forms the carrier, which is connected to one pole of the pulse generator, and that this carrier encloses a liquid-tight and gas-tight space with a housing, which is sealed with a highly insulating Medium is filled.
- This also results in a relative increase in the energy density of the ultrasonic shock waves generated by the transducer in focus due to a higher radiation power on the one hand and a better coupling of the energy into the coupling medium on the other hand.
- the first layer consists of a highly insulating potting material which also fills the spaces between the transducer elements.
- the first layer takes on both the task of impedance matching and the task of lateral electrical insulation of the converter elements from one another, as a result of which the converter can be controlled with higher voltages than before.
- Polyurethane epoxy mixtures or silicones are particularly suitable as potting material.
- FIG. 1 shows a dome-shaped and thus self-focusing transducer which bundles the generated ultrasonic shock wave from the piezoelectric transducer elements onto the focus 15 via a coupling medium 20.
- the transducer elements 2 are attached to a carrier 8 with their active surface.
- the carrier 8 is identical to the first layer 3, the thickness of which depends on the relationship d> ⁇ k .
- c LA is dimensioned, where ⁇ k is the transit time of the sound in the piezoceramic of the transducer elements 2 and c LA is the speed of sound in the layer 3.
- a further layer 4 of an intermediate medium serving for impedance matching is applied to layer 3, the acoustic impedance of which lies between that of layer 3 and that of coupling medium 20.
- the above relationship applies correspondingly to the thickness of layer 4, where c LA is the speed of sound in layer 4.
- the layer 3 or the carrier 8 is solid and metallic, that is to say electrically conductive. It serves as a common electrode for all converter elements 2 and is accordingly connected to one pole of a pulse generator 7.
- the other pole of the generator 7 is connected via a wiring 11 at the rear end of the converter elements 2 via electrically conductive individual backings 6.
- the conical shape of the backings 6 causes sound coming from the back to be scattered in such a way that it is not focused in the focus 15.
- Aluminum is considered as the material for the layer 3 or the carrier 8 if water is the coupling medium 20 is used.
- the formation of the first layer 3 as a solid support 8 enables it to enclose a liquid and gas-tight space with a housing 21, which is filled with a highly insulating medium 18.
- the medium 18 prevents a jump of sparks at the individual converter elements 2 at a high voltage applied to the elements 2. Accordingly, this converter can be controlled with a voltage which enables a significantly higher output compared to known converters.
- FIG. 2 shows an embodiment of a dome-shaped transducer in which the transducer elements 2 are braced on the back with electrically conductive individual backings 6 and with an electrically conductive carrier 8 by means of screws 9.
- Two layers 3 and 4 of intermediate media are applied to the converter elements 2 in order to adapt the impedance to the coupling medium (not shown).
- the first layer 3 is electrically conductive. It is used to supply the voltage from the pulse generator 7 to the converter elements 2.
- the other pole of the generator 7 is connected to the converter elements 2 via the carrier 8, screws 9 and backings 6.
- FIG. 3 shows a planar transducer in which the transducer elements with the individual backings 6 are clamped to the carrier 8 by screws 9.
- the adaptation of the acoustic impedance is achieved here by three layers 3, 4 and 5 of intermediate media on the transducer elements 2 of course, the conditions mentioned above for their acoustic impedances are met.
- Layer 5 is assigned to all transducer elements 2 together here. It is also designed as an acoustic lens which, together with the first matching layer (3), focuses the emitted ultrasonic shock waves.
- FIG. 4 also shows a planar transducer, in which three layers 3, 4 and 5 of intermediate media are applied to the transducer elements 2, as already explained in connection with the exemplary embodiment according to FIG. 3, in the radiation direction of the ultrasonic shock waves.
- the middle layer 4 is provided as a common layer and designed as a focusing acoustic lens.
- electrically non-conductive side walls 16, the common carrier 8 and the layer 4 outline a liquid and gas-tight space which is filled with a highly insulating medium 18.
- the converter elements have a common backing 14, which also closes the space outlined by the first layer 3 and the electrically non-conductive side walls 16, in which a highly insulating medium 18 is located.
- the back of the backing 14 is designed so that sound reflected from it is no longer focused in the focus of the transducer.
- All layers 3 to 6 are common for All transducer elements are provided, layers 4 and 5 being designed as lenses for focusing the ultrasonic shock waves.
- FIG. 7 shows, the use of a common backing 14 is also possible with a dome-shaped converter.
- the layers 3 and 4 of the intermediate media are each assigned to a converter element 2.
- FIG. 8 shows an extreme case in which the piezoceramic material 2 is in one piece. This is completed on the back by a backing 14. The impedance matching is done by two layers 3 and 4 of coupling media.
- FIG. 9 shows a particularly preferred embodiment of the converter. Only one layer 3 of an intermediate medium is shown here.
- Layer 3 consists of a highly insulating potting material, for which, for example, polyurethanes, epoxy mixtures or silicones can be used.
- the potting material has an acoustic impedance which again lies between that of the ceramic of the transducer elements 2 and that of the coupling medium 20.
- the spaces 22 between the individual transducer elements 2 are filled with it.
- this converter can be controlled with higher voltages than known converters.
- it has the advantage that the transducer elements 2 are embedded in the potting compound with absolute water protection, which results in an outstanding immunity to interference by the transducer.
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- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Acoustics & Sound (AREA)
- Multimedia (AREA)
- Mechanical Engineering (AREA)
- Transducers For Ultrasonic Waves (AREA)
- Ultra Sonic Daignosis Equipment (AREA)
- Investigating Or Analyzing Materials By The Use Of Ultrasonic Waves (AREA)
Description
Die Erfindung betrifft einen piezoelektrischen Wandler zur Erzeugung fokussierter Ultraschall-Stoßwellen für die Applikation in der Lithotripsie mit den Merkmalen des Oberbegriffs des Anspruchs 1.The invention relates to a piezoelectric transducer for generating focused ultrasonic shock waves for use in lithotripsy with the features of the preamble of claim 1.
Piezoelektrische Wandler sind grundsätzlich bekannt, beispielsweise aus der DE-PS 34 25 992. Auch die Verwendung eines Koppelmediums zur Ankopplung der Ultraschall-Stoßwellen an den Patientenkörper bei derartigen Wandlern ist hinlänglich bekannt.Piezoelectric transducers are generally known, for example from DE-PS 34 25 992. The use of a coupling medium for coupling the ultrasonic shock waves to the patient's body in such transducers is also well known.
Wenn die bekannten wandler zwar in der Praxis mit Erfolg in der Therapie eingesetzt werden, so stellt sich häufig das Problem, daß die Baumaße des Wandlers sehr groß sind, um die für die Desintegration des zu zerstörenden Konkrements erforderliche Energiedichte in seinem Fokus zu erhalten.If the known transducers are successfully used in practice in therapy, the problem often arises that the dimensions of the transducer are very large in order to obtain the focus on the energy density required for the disintegration of the calculus to be destroyed.
Die mit piezoelektrischen Materialien erzeugbaren Energiedichten sind sehr hoch, doch nur ein sehr geringer Teil der zur Verfügung stehenden Energie wird in der Praxis in das Koppelmedium(Wasser oder Öl) eingeleitet ,da sich die schallerzeugende Keramik und das Wasser/Öl akustisch sehr stark voneinander unterscheiden.The energy densities that can be generated with piezoelectric materials are very high, but only a very small part of the available energy is introduced into the coupling medium (water or oil) in practice, since the sound-producing ceramic and the water / oil are acoustically very strong differentiate from each other.
Vor dem Hintergrund der vorstehenden Ausführungen ist es nun die Aufgabe der vorliegenden Erfindung, einen Wandler der eingangs erwähnten Art so weiterzubilden, daß die Energiedichte der von ihm erzeugten Ultraschall-Stoßwellen in seinem Fokus so groß ist, daß eine Reduzierung seiner Baumaße möglich ist.Against the background of the foregoing, it is the object of the present invention to develop a transducer of the type mentioned at the outset in such a way that the energy density of the ultrasonic shock waves generated by it is so large in its focus that it is possible to reduce its dimensions.
Gelöst wird diese Aufgabe durch die Merkmale des Anspruches 1. Demgemäß wird der bekannte Wandler so ausgebildet, daß zwischen den Wandlerelementen und dem Koppelmedium ein Zwischenmedium zumindest aus einer Schicht vorgesehen ist, dessen akustische Impedanz zwischen jener der Keramik der Wandlerelemente und jener des Koppelmediums liegt und daß die Dicke der Schicht so bemessen ist, daß die Beziehung d>τk.cLA gilt, wobei τk die Laufzeit des Schalls in der Piezokeramik der Wandlerelemente und cLA die Schallgeschwindigkeit in dem jeweiligen Zwischenmedium ist.This object is achieved by the features of claim 1. Accordingly, the known transducer is designed so that between the transducer elements and the coupling medium, an intermediate medium is provided at least from one layer, the acoustic impedance of which is between that of the ceramic of the transducer elements and that of the coupling medium and that the thickness of the layer is dimensioned such that the relationship d> τ k .c LA applies, where τ k is the propagation time of the sound in the piezoceramic of the transducer elements and c LA is the speed of sound in the respective intermediate medium.
Die Bemessung der Dicke der Schicht des Zwischenmediums kann vorliegend nicht anhand der Wellenlänge des Ultraschalls vorgenommen werden, da die vom Wandler erzeugten Ultraschall-Stoßwellen ein sehr breites Frequenzspektrum aufweisen. Insofern gibt eine Anpassung, wie aus der US-PS 415 6863 bekannt, für die vorliegende Aufgabenlösung nichts her. Dort ist nämlich lediglich vorgesehen, die Dicke einer Vergußmasse, welche die akustische Impedanz des Ankopplungsmediums (Wasser) aufweist, zu einem Viertel der Wellenlänge der von den Einzelschwingern ausgehenden Schallwellen zu bemessen. Vorliegend sind die Voraussetzungen für die Impedanzanpassung ganz andere. Hier ist nicht die Einzelfrequenz bzw. - wellenlänge, sondern die Laufzeit des Schalls durch das einzelne Wandlerelement die Grundlage aller Überlegungen.In the present case, the thickness of the layer of the intermediate medium cannot be measured on the basis of the wavelength of the ultrasound, since the ultrasound shock waves generated by the transducer have a very wide frequency spectrum. In this respect, an adaptation, as known from US-PS 415 6863, does not provide anything for the present task solution. This is because there is only provision for the thickness of one Potting compound, which has the acoustic impedance of the coupling medium (water), to be dimensioned to a quarter of the wavelength of the sound waves emanating from the individual transducers. In the present case, the requirements for impedance matching are completely different. Here it is not the individual frequency or wavelength that is the basis of all considerations, but the transit time of the sound through the individual transducer element.
Wird zwischen die aktive Oberfläche jedes piezoelektrischen Wandlerelements und das Koppelmedium einer Schicht des Zwischenmediums eingebracht, so muß diese zur Erzielung optimaler Resultate eine bestimmte Dicke und eine bestimmte akustische Impedanz aufweisen.If a layer of the intermediate medium is introduced between the active surface of each piezoelectric transducer element and the coupling medium, it must have a certain thickness and a certain acoustic impedance in order to achieve optimal results.
Da es vorliegend nicht um eine Resonanzabstimmung geht, ist die Dämpfung in den Zwischenschichten nicht von großer Bedeutung, solange diese nicht extreme Werte annimmt und die notwendige Dicke, welche durch die oben genannte Bemessungsvorschrift gegeben ist, nicht um ein Vielfaches überschritten wird.Since it is not a question of resonance tuning in the present case, the damping in the intermediate layers is not of great importance, as long as it does not assume extreme values and the necessary thickness, which is given by the above-mentioned dimensioning regulation, is not exceeded many times over.
Die zu wählende akustische Impedanz richtet sich nach den akustischen Gegebenheiten an der Grenzfläche zwischen den aktiven Wandlerelementen und der Schicht des Zwischenmediums bzw. nach den bekannten Schalldurchgangsfaktoren an der Grenzfläche zwischen zwei Medien unterschiedlicher akustischer Impedanz. In jedem Falle liegt sie zwischen jener der Keramik der Wandlerelemente und jener des Koppelmediums.The acoustic impedance to be selected depends on the acoustic conditions at the interface between the active transducer elements and the layer of the intermediate medium or on the known sound transmission factors at the interface between two media of different acoustic impedance. In any case, it lies between that of the ceramic of the transducer elements and that of the coupling medium.
Die akustische Dicke der Schicht des Zwischenmediums muß größer sein als die der Keramik der Wandlerelemente.The acoustic thickness of the layer of the intermediate medium must be greater than that of the ceramic of the transducer elements.
Der Effekt, daß mehr Energie in das Koppelmedium gelangt, kann erhöht werden dadurch, daß mehrere Schichten von Zwischenmedien zwischen den Wandlerelementen und dem Koppelmedium vorgesehen sind, deren akustische Impedanzen von der ersten Schicht auf den Wandlerelementen her in Abstrahlungsrichtung der Ultraschall-Stoßwellen abnehmen.The effect that more energy gets into the coupling medium can be increased in that several layers of intermediate media are provided between the transducer elements and the coupling medium, the acoustic impedances of which decrease from the first layer on the transducer elements in the direction of radiation of the ultrasonic shock waves.
Stets wird der Schall jede Grenzschicht nur teilweise passieren, weil ein Anteil immer reflektiert wird. Diese Reflexion wird stets weich sein, das heißt eine Phasenumkehr wird eintreten, da die Impedanz jedes Zwischenmediums größer ist als jene des nächsten bzw. des Wassers. Trifft der reflektierte Anteil des Schalls dann an die vorangegangene Grenzschicht, wird er hart, das heißt ohne Phasenumkehr, reflektiert und läuft dann teilweise in die nächste Schicht eines Zwischenmediums bzw. am Ende in das Koppelmedium ein.The sound will always only partially pass each boundary layer because a part is always reflected. This reflection will always be soft, i.e. a phase reversal will occur because the impedance of each intermediate medium is greater than that of the next one or the water. If the reflected portion of the sound then hits the previous boundary layer, it becomes hard, that is to say without a phase reversal, and is reflected and then partially runs into the next layer of an intermediate medium or at the end into the coupling medium.
Gemäß vorteilhafter Ausgestaltungen kann die Schicht bzw.können die Schichten der Zwischenmedien jeweils einem Wandlerelement, einheitlich allen Wandlerelementen gemeinsam oder gemischt teilweise einheitlich gemeinsam und teilweise jeweils einem Wandlerelement zugeordnet sein.According to advantageous refinements, the layer or the layers of the intermediate media can each be assigned to one transducer element, uniformly all transducer elements together or mixed partially uniformly together and partially in each case to one transducer element.
Grundsätzlich läßt sich der geschilderte Aufbau des erfindungsgemäßen Wandlers realisieren bei selbstfokussierenden, also beispielsweise kalottenförmigen Wandlern, aber auch bei planaren Wandlern.Basically, the described construction of the transducer according to the invention can be implemented in the case of self-focusing transducers, for example dome-shaped transducers, but also in the case of planar transducers.
Bei letzteren kann vorteilhaft vorgesehen werden, daß zumindest eine Schicht eines Zwischenmediums als akustische Linse ausgebildet ist. Diese Schicht übernimmt dann die Aufgabe der Fokussierung der Ultraschall-Stoßwellen auf den Fokus des Wandlers, so daß ein zusätzlicher Mehraufwand nicht betrieben werden muß.In the latter case it can advantageously be provided that at least a layer of an intermediate medium is designed as an acoustic lens. This layer then takes over the task of focusing the ultrasonic shock waves on the focus of the transducer, so that no additional effort is required.
Gemäß einer weiteren vorteilhaften Ausführungsform weist der Wandler in Abstrahlungsrichtung der Ultraschall-Stoßwellen eine Schicht eines Zwischenmediums auf den Wandlerelementen auf, die eine die Wandlerelemente elektrisch miteinander verbindende, diesen zugekehrte Oberfläche aufweist. Diese Oberfläche ist dann mit dem einen Pol des Pulsgenerators verbunden. Die erste Schicht wird damit als gemeinsame Elektrode für alle Wandlerelemente genutzt, wodurch sich nicht nur der Aufwand bislang erforderlicher Verdrahtung erheblich reduziert, sondern der Wandler insgesamt kompakter und störungsunanfälliger wird.According to a further advantageous embodiment, in the direction of radiation of the ultrasonic shock waves, the transducer has a layer of an intermediate medium on the transducer elements, which has a surface that electrically connects the transducer elements and faces them. This surface is then connected to one pole of the pulse generator. The first layer is thus used as a common electrode for all transducer elements, which not only significantly reduces the amount of wiring previously required, but also makes the transducer overall more compact and less susceptible to faults.
Diese vorteilhafte Weiterbildung kann dadurch in einfacher Weise realisiert werden, daß die erste Schicht massiv und metallisch ist. Hierzu eignet sich beispielsweise Aluminium, dessen akustische Impedanz den erwähnten Bedingungen entspricht.This advantageous development can be implemented in a simple manner in that the first layer is solid and metallic. Aluminum, for example, is suitable for this purpose, the acoustic impedance of which corresponds to the conditions mentioned.
Im Falle eines planaren Wandlers kann diese Ausführungsform vorteilhaft dadurch weitergebildet werden, daß die Schicht als massive, akustische Linse aufgebaut ist. Diese übernimmt dann wieder die Aufgabe der Fokussierung der Ultraschall-Stoßwellen auf den Wandlerfokus.In the case of a planar transducer, this embodiment can advantageously be developed further in that the layer is constructed as a solid, acoustic lens. This then again takes on the task of focusing the ultrasonic shock waves on the converter focus.
Jedes Wandlerelement weist ein sogenanntes Backing auf, dessen akustische Impedanz mindestens so groß ist wie jene der Keramik der einzelnen wandlerelemente. Diese Maßnahme sichert einen nahezu reflexionsfreien Abschluß der Wandlerelemente, so daß für die Lithotripsie unerwünschte negative Zugimpulse auf ein praktisch mögliches Mindestmaß beschränkt werden.Die Backings können so ausgebildet sein, daß der von der Keramik herkommende Schall an ihrer Rückseite so gestreut wird,daß er nicht im Fokus des Wandlers gebündelt wird.Dies kann beispielsweise durch Aufrauhen der Rückseite der Backings oder durch entsprechende Formgebung zu beispielsweise einem Kegel erzielt werden.Each transducer element has a so-called backing, the acoustic impedance is at least as large as that of the ceramic of the individual transducer elements. This measure ensures an almost reflection-free termination of the transducer elements, so that unwanted negative tensile impulses for lithotripsy are limited to a practically possible minimum. The backings can be designed in such a way that the sound coming from the ceramic is scattered so that it does not in the focus of the converter, which can be achieved, for example, by roughening the back of the backings or by shaping it into a cone, for example.
Alle Wandlerelemente können aber auch mit einem gemeinsamen Backing für ihren reflexionsfreien Abschluß versehen sein.However, all transducer elements can also be provided with a common backing for their reflection-free termination.
Bei allen vorerwähnten Ausbildungen des Wandlers ist die Energiedichte der Ultraschall-Stoßwellen im Wandlerfokus gegenüber bisherigen Wandlern durch "passive" Maßnahmen erhöht worden durch die bessere Ankopplung der Ultraschall-Stoßwellen in das Koppelmedium, also durch die bessere Ausnutzung der von den wandlerelementen erzeugten Energie. Einige der beschriebenen Ausführungen gestatten aber auch zusätzlich zu dieser Maßnahme eine Erhöhung der Energiedichte im Wandlerfokus durch "aktive" Maßnahmen. Namentlich bezieht sich dies auf die Ansteuerung der Wandlerelemente durch höhere Spannungen. Dies war bislang in erster Linie aufgrund von Sicherheitsaspekten, aber auch mit Rücksicht auf die Standzeit des Wandlers nicht ohne weiteres möglich.In all of the above-mentioned designs of the transducer, the energy density of the ultrasonic shock waves in the transducer focus compared to previous transducers has been increased by "passive" measures through the better coupling of the ultrasonic shock waves into the coupling medium, that is, through the better utilization of the energy generated by the transducer elements. However, in addition to this measure, some of the described embodiments also allow the energy density in the converter focus to be increased by “active” measures. This relates in particular to the control of the converter elements by means of higher voltages. Up to now, this was not easily possible primarily due to safety aspects, but also with regard to the converter's service life.
Demgemäß ist es bei einer vorteilhaften Weiterbildung des Wandlers vorgesehen, daß die Wandlerelemente mit dem elektrisch leitenden Träger mittels elektrisch leitender Befestigungsmittel verspannt sind, wobei der Träger mit dem anderen Pol des Pulsgenerators verbunden ist. Hierdurch wird die Ansteuerung der Wandlerelemente mit höheren Spannungen möglich, ohne daß die Wandlerelemente aus ihrer Verankerung platzen, wodurch ein irreparabler Schaden entstünde.Accordingly, it is provided in an advantageous development of the transducer that the transducer elements with the electrically conductive carrier by means of electrically conductive fasteners are clamped, the carrier being connected to the other pole of the pulse generator. This makes it possible to control the converter elements with higher voltages without the converter elements bursting out of their anchoring, which would result in irreparable damage.
Eine höhere Ansteuerbarkeit mit höheren Spannungen, wodurch die Abgabeleistung des Wandlers aktiv erhöht wird, kann bei den weiter oben beschriebenen Ausführungsformen des Wandlers, bei denen die erste Schicht eines Zwischenmediums auf den Wandlerelementen massiv und metallisch ist und somit als eine Elektrode dient, dadurch erreicht werden, daß der durch die erste Schicht, dem gemeinsamen Backing, bzw. den Träger umrissene Raum mittels elektrisch nicht leitenden Seitenwänden flüssigkeits- und gasdicht abgeschlossen ist, und daß dieser Raum mit einem hochisolierenden Medium gefüllt ist. Als hochisolierendes Medium kann beispielsweise ein Gas, Öl oder auch ein fester Isolator in Betracht kommen.A higher controllability with higher voltages, whereby the output power of the converter is actively increased, can be achieved in the embodiments of the converter described above, in which the first layer of an intermediate medium on the converter elements is solid and metallic and thus serves as an electrode that the space outlined by the first layer, the common backing, or the support is liquid-tight and gas-tight by means of electrically non-conductive side walls, and that this space is filled with a highly insulating medium. A gas, oil or also a solid insulator can be considered as a highly insulating medium.
Es ist auch möglich, den Wandler so auszubilden, daß eine elektrisch leitende erste Schicht den Träger bildet, welche mit dem einen Pol des Pulsgenerators verbunden ist, und daß dieser Träger mit einem Gehäuse einen flüssigkeits- und gasdicht abgeschlossenen Raum umschließt, welcher mit einem hochisolierenden Medium gefüllt ist. Auch hierdurch ergibt sich eine relative Erhöhung der Energiedichte der von dem Wandler erzeugten Ultraschall-Stoßwellen im Fokus durch einerseits eine höhere Abstrahlleistung und andererseits durch eine bessere Einkoppelung der Energie in das Koppelmedium.It is also possible to design the transducer in such a way that an electrically conductive first layer forms the carrier, which is connected to one pole of the pulse generator, and that this carrier encloses a liquid-tight and gas-tight space with a housing, which is sealed with a highly insulating Medium is filled. This also results in a relative increase in the energy density of the ultrasonic shock waves generated by the transducer in focus due to a higher radiation power on the one hand and a better coupling of the energy into the coupling medium on the other hand.
Eine weitere Ausführungsform des Wandlers, bei dem aktiv und passiv für die Erhöhung der Energiedichte im Fokus gesorgt ist, ergibt sich, wenn die erste Schicht aus einem hoch isolierenden Vergußmaterial besteht, welches auch die Zwischenräume zwischen den Wandlerelementen ausfüllt. Hierbei übernimmt die erste Schicht sowohl die Aufgabe der Impedanzanpassung als auch die Aufgabe der seitlichen elektrischen Isolation der Wandlerelemente voneinander, wodurch der Wandler mit höheren Spannungen als bisher angesteuert werden kann.Another embodiment of the converter, in which active and If the focus is passively provided for increasing the energy density, the result is if the first layer consists of a highly insulating potting material which also fills the spaces between the transducer elements. Here, the first layer takes on both the task of impedance matching and the task of lateral electrical insulation of the converter elements from one another, as a result of which the converter can be controlled with higher voltages than before.
Als Vergußmaterial eignen sich besonders Polyurethane Epoxigemische oder Silikone.Polyurethane epoxy mixtures or silicones are particularly suitable as potting material.
Die Erfindung wird anhand einiger Ausführungsbeispiele näher erläutert. Hierbei zeigt:
- Figur 1
- ein erstes Ausführungsbeispiel des Wandlers,
Figur 2- ein zweites Ausführungsbeispiel,
Figur 3- ein drittes Ausführungsbeispiel,
- Figur 4
- ein viertes Ausführungsbeispiel,
Figur 5- ein fünftes Ausführungsbeispiel,
Figur 6- ein sechstes Ausführungsbeispiel,
- Figur 7
- ein siebentes Ausführungsbeispiel,
Figur 8- ein achtes Ausführungsbeispiel,
- Figur 9
- ein neuntes Ausführungsbeispiel,
- Figure 1
- a first embodiment of the converter,
- Figure 2
- a second embodiment,
- Figure 3
- a third embodiment,
- Figure 4
- a fourth embodiment,
- Figure 5
- a fifth embodiment,
- Figure 6
- a sixth embodiment,
- Figure 7
- a seventh embodiment,
- Figure 8
- an eighth embodiment,
- Figure 9
- a ninth embodiment,
In den Zeichnungen sind gleiche Teile mit denselben Bezugszeichen versehen.In the drawings, identical parts are provided with the same reference symbols.
Figur 1 zeigt einen kalottenförmigen und damit selbstfokussierenden Wandler, der von den piezoelektrischen Wandlerelementen die erzeugte Ultraschall-Stoßwelle über ein Koppelmedium 20 auf den Fokus 15 bündelt. Die Wandlerelemente 2 sind mit ihrer aktiven Oberfläche an einem Träger 8 verhaftet.FIG. 1 shows a dome-shaped and thus self-focusing transducer which bundles the generated ultrasonic shock wave from the piezoelectric transducer elements onto the
Der Träger 8 ist im gezeigten Ausführungsbeispiel identisch mit der ersten Schicht 3, deren Dicke nach der Beziehung d>τk . cLA bemessen ist, wobei τk die Laufzeit des Schalls in der Piezokeramik der Wandlerelemente 2 und cLA die Schallgeschwindigkeit in der Schicht 3 ist.In the exemplary embodiment shown, the
Auf die Schicht 3 ist eine weitere, der Impedanzanpassung dienenden Schicht 4 eines Zwischenmediums aufgebracht, dessen akustische Impedanz zwischen jener der Schicht 3 und jener des Koppelmediums 20 liegt. Für die Dicke der Schicht 4 gilt die obige Beziehung entsprechend, wobei hier cLA die Schallgeschwindigkeit in der Schicht 4 ist.A further layer 4 of an intermediate medium serving for impedance matching is applied to
Die Schicht 3 bzw. der Träger 8 ist hier massiv und metallisch, also elektrisch leitend. Er dient als eine gemeinsame Elektrode für alle Wandlerelemente 2 und ist entsprechend mit dem einen Pol eines Pulsgenerators 7 verbunden. Der andere Pol des Generators 7 ist über eine Verdrahtung 11 am rückseitigen Ende der Wandlerelemente 2 über elektrisch leitende Einzelbackings 6 angeschlossen. Die kegelförmige Gestalt der Backings 6 bewirkt, daß von ihrer Rückseite herkommender Schall so gestreut wird, daß er nicht im Fokus 15 gebündelt wird.The
Als Material für die Schicht 3 bzw. den Träger 8 kommt vorliegend Aluminium in Betracht, wenn Wasser als Koppelmedium 20 Verwendung findet.Aluminum is considered as the material for the
Die Ausbildung der ersten Schicht 3 als massiven Träger 8 ermöglicht es, daß dieser mit einem Gehäuse 21 einen flüssigkeits- und gasdichten Raum umschließt, der mit einem hochisolierenden Medium 18 gefüllt ist. Das Medium 18 verhindert einen Übersprung von Funken an den einzelnen Wandlerelementen 2 bei einer hohen, an die Elemente 2 gelegten Spannung. Dementsprechend kann dieser Wandler mit einer Spannung angesteuert werden, welche eine wesentlich höhere Abgabeleistung im Vergleich zu bekannten Wandlern ermöglicht.The formation of the
Figur 2 zeigt eine Ausführungsform eines kalottenförmigen Wandlers, bei dem die Wandlerelemente 2 rückseitig mit elektrisch leitenden Einzelbackings 6 und mit einem elektrisch leitenden Träger 8 durch Schrauben 9 verspannt sind.FIG. 2 shows an embodiment of a dome-shaped transducer in which the
Auf den Wandlerelementen 2 sind zwei Schichten 3 und 4 von Zwischenmedien aufgebracht zur Anpassung der Impedanz an das nicht dargestellte Ankoppelmedium.Two
Die erste Schicht 3 ist elektrisch leitend. Sie wird zur Zuführung der Spannung vom Pulsgenerator 7 an die Wandlerelemente 2 genutzt. Der andere Pol des Generators 7 ist mit den Wandlerelementen 2 über den Träger 8, Schrauben 9 und Backings 6 verbunden.The
Figur 3 zeigt einen planaren Wandler, bei dem die Wandlerelemente mit den Einzelbackings 6 durch Schrauben 9 mit dem Träger 8 verspannt sind. Die Anpassung der akustischen Impedanz wird hier durch drei Schichten 3,4 und 5 von Zwischenmedien auf den Wandlerelementen 2 erzielt, wobei selbstverständlich die eingangs genannten Bedingungen für deren akustische Impedanzen erfüllt sind.FIG. 3 shows a planar transducer in which the transducer elements with the
Die Schicht 5 ist hier allen Wandlerelementen 2 gemeinsam zugeordnet. Sie ist darüber hinaus als akustische Linse ausgebildet, die gemeinsam mit der ersten Anpaßschicht(3)die Fokussierung der abgestrahlten Ultraschall-Stoßwellen bewerkstelligt.
Figur 4 zeigt ebenfalls einen planaren Wandler, bei dem in Abstrahlungsrichtung der Ultraschall-Stoßwellen drei Schichten 3,4 und 5 von Zwischenmedien auf die wie schon in Verbindung mit dem Ausführungsbeispiel gemäß Figur 3 erläutert verspannten Wandlerelemente 2 aufgebracht sind. Hier ist die mittlere Schicht 4 als gemeinsame Schicht vorgesehen und als fokussierende Akustische Linse gestaltet.
FIG. 4 also shows a planar transducer, in which three
Vorliegend umreißen elektrisch nichtleitende Seitenwände 16, der gemeinsame Träger 8 und die Schicht 4 einen flüssigkeits- und gasdichten Raum, der mit einem hochisolierenden Medium 18 gefüllt ist.In the present case, electrically
Eine ähnliche Ausführungsform zeigt im übrigen Figur 5. Hier sind allerdings alle Schichten 3,4 und 5 einheitlich für alle Wandlerelemente 2 gemeinsam vorgesehen, von denen die Schichten 4 und 5 eine Linsenfunktion innehaben.A similar embodiment is shown in the rest of FIG. 5. Here, however, all
Bei dem in Figur 6 gezeigten Ausführungsbeispiel weisen die Wandlerelemente ein gemeinsames Backing 14 auf, welches zudem den von der ersten Schicht 3 und den elektrisch nichtleitenden Seitenwänden 16 umrissenen Raum abschließt, in welchem sich ein hochisolierendes Medium 18 befindet. Die Rückseite des Backings 14 ist so gestaltet, daß an ihr reflektierter Schall nicht mehr im Fokus des Wandlers gebündelt wird. Alle Schichten 3 bis 6 sind gemeinsam für alle Wandlerelemente vorgesehen, wobei die Schichten 4 und 5 der Fokussierung der Ultraschall-Stoßwellen dienend als Linsen ausgebildet sind.In the exemplary embodiment shown in FIG. 6, the converter elements have a common backing 14, which also closes the space outlined by the
Wie Figur 7 zeigt, ist die Verwendung eines gemeinsamen Backings 14 auch bei einem kalottenförmigen Wandler möglich. Hier sind die Schichten 3 und 4 der Zwischenmedien jeweils einem Wandlerelement 2 zugeordnet.As FIG. 7 shows, the use of a common backing 14 is also possible with a dome-shaped converter. Here, the
In Figur 8 ist ein extremer Fall dargestellt, indem das piezokeramische Material 2 einstückig ist. Dieses ist durch ein Backing 14 rückseitig abgeschlossen. Die Impedanzanpassung erfolgt durch zwei Schichten 3 und 4 von Koppelmedien.FIG. 8 shows an extreme case in which the
In Figur 9 ist schließlich eine besonders bevorzugte Ausführungsform des Wandlers dargestellt. Vorliegend ist nur eine Schicht 3 eines Zwischenmediums dargestellt. Die Schicht 3 besteht aus einem hochisolierenden Vergußmaterial, wofür beispielsweise Polyurethane, Epoxigemische oder Silikone verwendet werden können.Finally, FIG. 9 shows a particularly preferred embodiment of the converter. Only one
Das Vergußmaterial hat eine akustische Impedanz, die wieder zwischen jener der Keramik der Wandlerelemente 2 und jener des Koppelmediums 20 liegt. Mit ihm sind die Zwischenräume 22 zwischen den einzelnen Wandlerelementen 2 ausgefüllt.The potting material has an acoustic impedance which again lies between that of the ceramic of the
Dieser Wandler kann aufgrund der Isolation mit höheren Spannungen angesteuert werden als bekannte Wandler. Darüber hinaus hat er den Vorteil, daß die Wandlerelemente 2 absolut wassergeschützt in der Vergußmasse eingebettet sind, wodurch sich eine überragende Störunanfälligkeit des Wandlers ergibt.Due to the insulation, this converter can be controlled with higher voltages than known converters. In addition, it has the advantage that the
Claims (17)
- Piezoelectric transducer for producing focused ultrasound shock waves for application in lithotripsy, it being possible for the ultrasound shock waves thereof, which are emitted in pulses, to be transferred to the body of a patient via a coupling medium (20), comprising a plurality of individual ceramic piezoelectric transducer elements (2) connected to the poles of a pulse generator (7), which transducer elements (2) are fixed on a support (8) in mosaic fashion and electrically insulated from one another laterally, the acoustic sealing of the transducer elements being essentially free of reflection, characterised in that an intermediate medium of at least one layer (3, 4, 5) is provided between the transducer elements (2) and the coupling medium (20), acoustic impedance thereof being between that of the ceramic of the transducer elements (2) and that of the coupling medium (20), and in that the thickness of the layer (3, 4, 5) has dimensions such that the relationship d > τk · cLA applies, τk being the propagation time of the sound in the piezoelectric ceramic of the transducer elements (2) and cLA being the sound velocity in the particular intermediate medium.
- Piezoelectric transducer according to claim 1, characterised in that several layers (3, 4, 5) of intermediate media are provided between the transducer elements (2) and the coupling medium (20), the acoustic impedances thereof decreasing from the first layer (3) on the transducer elements (2), seen in the emission direction of the ultrasound shock waves, to the coupling medium (20).
- Piezoelectric transducer according to claim 1 or 2, characterised in that the layer or layers (3, 4, 5) of intermediate media is or are assigned in each case to one transducer element (2).
- Piezoelectric transducer according to claim 1 or 2, characterised in that the layer or layers (3, 4, 5) is or are assigned uniformly to all transducer elements (2) together.
- Piezoelectric transducer according to claim 1 or 2, characterised in that the layers (3, 4, 5) are assigned partly uniformly together and partly in each case to one transducer element (2).
- Piezoelectric transducer according to one of claims 1 to 5, characterised in that at least one intermediate medium (3, 4, 5) is designed as an acoustic lens.
- Piezoelectric transducer according to one of claims 1 to 6, characterised in that layer (3) on the transducer elements (2), first in the emission direction of the ultrasound shock waves, has a surface connecting the transducer elements (2) electrically with one another and facing the latter, which surface is connected to one pole of the pulse generator (7).
- Piezoelectric transducer according to one of claims 1 to 7, characterised in that the first layer (3) on the transducer elements (2) is solid and metallic.
- Piezoelectric transducer according to claim 8, characterised in that a layer (3) is designed as a solid acoustic lens.
- Piezoelectric transducer according to one of claims 1 to 9, characterised in that each transducer element has a backing (6), the acoustic impedance thereof being at least as large as that of the ceramic of the transducer elements (2).
- Piezoelectric transducer according to claim 10, characterised in that the backings (6, 14) are designed such that the sound originating from the rear side of the backing is scattered so that it is not bundled at the focal point.
- Piezoelectric transducer according to one of claims 1 to 9, characterised in that a common backing (14) for all transducer elements (2) is designed for them to have reflection-free sealing.
- Piezoelectric transducer according to one of claims 1 to 12, characterised in that the transducer elements (2) are braced by means of electrically conductive attachment means (9) to the electrically conductive support (8), and in that the support (8) is connected to the other pole of the pulse generator (7).
- Piezoelectric transducer according to claim 7, 8 or 9 in conjunction with claim 13, characterised in that the space defined by a layer (3, 4), the common backing (14), or the support (8), is sealed to be liquid-tight and gas-tight by means of electrically non-conductive side walls (16), and in that this space is filled with a highly insulating medium (18).
- Piezoelectric transducer according to one of claims 1 to 12, characterised in that an electrically conductive first layer (3) forms the support (8) which is connected to one pole of the pulse generator (7), and in that this support (8) with a housing (21) encloses a space sealed to be liquid-tight and gas-tight and which is filled with a highly insulating medium (18).
- Piezoelectric transducer according to one of claims 1 to 12, characterised in that the first layer (3) consists of a highly insulating sealing material which also fills the gaps (22) between the transducer elements (2).
- Piezoelectric transducer according to claim 16, characterised in that the sealing material consists of polyurethanes, epoxy mixtures or silicones.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE3932959A DE3932959C1 (en) | 1989-10-03 | 1989-10-03 | |
DE3932959 | 1989-10-03 |
Publications (3)
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---|---|
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EP0421286A3 EP0421286A3 (en) | 1992-06-03 |
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Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP90118633A Expired - Lifetime EP0421286B1 (en) | 1989-10-03 | 1990-09-28 | Piezoelectric transducer |
Country Status (3)
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---|---|
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EP (1) | EP0421286B1 (en) |
DE (2) | DE3932959C1 (en) |
Families Citing this family (32)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
SE465552B (en) * | 1989-03-21 | 1991-09-30 | Hans Wiksell | DEVICE FOR SUBDIVISION OF CONCRETE IN THE BODY OF A PATIENT |
DE3932967A1 (en) * | 1989-10-03 | 1991-04-11 | Wolf Gmbh Richard | ULTRASONIC SHOCK WAVE CONVERTER |
DE4000362C2 (en) * | 1990-01-09 | 1993-11-11 | Wolf Gmbh Richard | Ultrasonic transducer with piezoelectric transducer elements |
DE4117638A1 (en) * | 1990-05-30 | 1991-12-05 | Toshiba Kawasaki Kk | SHOCK WAVE GENERATOR WITH A PIEZOELECTRIC ELEMENT |
DE4307669C2 (en) * | 1993-03-11 | 1995-06-29 | Wolf Gmbh Richard | Device for generating sound pulses for medical applications |
US5438998A (en) * | 1993-09-07 | 1995-08-08 | Acuson Corporation | Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof |
US5415175A (en) * | 1993-09-07 | 1995-05-16 | Acuson Corporation | Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof |
US5743855A (en) * | 1995-03-03 | 1998-04-28 | Acuson Corporation | Broadband phased array transducer design with frequency controlled two dimension capability and methods for manufacture thereof |
DE4336149A1 (en) * | 1993-10-22 | 1995-04-27 | Siemens Ag | Ultrasonic transducer which is composed of a multiplicity of transducer elements |
US5371483A (en) * | 1993-12-20 | 1994-12-06 | Bhardwaj; Mahesh C. | High intensity guided ultrasound source |
FI95781C (en) * | 1994-04-19 | 1996-03-25 | Outokumpu Mintec Oy | Method and apparatus for cleaning the filter medium in a suction dryer |
DE19507478C1 (en) * | 1995-03-03 | 1996-05-15 | Siemens Ag | Therapy device for treatment with focused ultrasound |
US5713371A (en) * | 1995-07-07 | 1998-02-03 | Sherman; Dani | Method of monitoring cervical dilatation during labor, and ultrasound transducer particularly useful in such method |
DE19543741C1 (en) * | 1995-11-24 | 1997-05-22 | Wolf Gmbh Richard | Electroacoustic transducer generating focussed sound waves for lithotripsy |
DE19624443C2 (en) * | 1996-06-19 | 1998-05-14 | Wolf Gmbh Richard | Electroacoustic transducer |
US6669655B1 (en) * | 1999-10-20 | 2003-12-30 | Transurgical, Inc. | Sonic element and catheter incorporating same |
DE19954020C2 (en) * | 1999-11-10 | 2002-02-28 | Fraunhofer Ges Forschung | Method of manufacturing a piezoelectric transducer |
US6571444B2 (en) * | 2001-03-20 | 2003-06-03 | Vermon | Method of manufacturing an ultrasonic transducer |
US7867178B2 (en) * | 2003-02-26 | 2011-01-11 | Sanuwave, Inc. | Apparatus for generating shock waves with piezoelectric fibers integrated in a composite |
DE10340624B4 (en) * | 2003-09-03 | 2005-08-18 | Siemens Ag | Shock wave source for generating a focused shockwave |
US7302744B1 (en) | 2005-02-18 | 2007-12-04 | The United States Of America Represented By The Secretary Of The Navy | Method of fabricating an acoustic transducer array |
US20070239082A1 (en) * | 2006-01-27 | 2007-10-11 | General Patent, Llc | Shock Wave Treatment Device |
EP2092916A1 (en) * | 2008-02-19 | 2009-08-26 | Institut National De La Sante Et De La Recherche Medicale (Inserm) | A method of treating an ocular pathology by applying high intensity focused ultrasound and device thereof |
US7709997B2 (en) * | 2008-03-13 | 2010-05-04 | Ultrashape Ltd. | Multi-element piezoelectric transducers |
DE102009049487B4 (en) * | 2009-10-15 | 2015-05-13 | Richard Wolf Gmbh | Electroacoustic transducer |
WO2012025833A2 (en) | 2010-08-27 | 2012-03-01 | Socpra- Sciences Et Génie, S.E.C. | Mechanical wave generator and method thereof |
US9261442B2 (en) | 2011-12-01 | 2016-02-16 | Microbrightfield, Inc. | Acoustic pressure wave/shock wave mediated processing of biological tissue, and systems, apparatuses, and methods therefor |
US20130340530A1 (en) * | 2012-06-20 | 2013-12-26 | General Electric Company | Ultrasonic testing device with conical array |
US9555267B2 (en) | 2014-02-17 | 2017-01-31 | Moshe Ein-Gal | Direct contact shockwave transducer |
CN109939914A (en) * | 2017-12-20 | 2019-06-28 | 深圳先进技术研究院 | A kind of composite material physics focused transducer and its manufacturing method |
CN111940098B (en) * | 2020-04-08 | 2021-11-12 | 珠海艾博罗生物技术股份有限公司 | Side-excitation ultrasonic processor and processing method |
DE102021203544A1 (en) * | 2021-04-09 | 2022-10-13 | Richard Wolf Gmbh | Electroacoustic converter |
Family Cites Families (20)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4156863A (en) * | 1978-04-28 | 1979-05-29 | The United States Of America As Represented By The Secretary Of The Navy | Conical beam transducer array |
DE2926182A1 (en) * | 1979-06-28 | 1981-01-22 | Siemens Ag | Ultrasonic transducer elements arrangement - sandwiches each element between matching and damping sections for coping with irregular surfaces subjected to scanning for defects |
DE3002663A1 (en) * | 1980-01-25 | 1981-07-30 | Siemens AG, 1000 Berlin und 8000 München | ULTRASONIC transducer |
DE3165302D1 (en) * | 1980-03-20 | 1984-09-13 | Deritend Eng Co | Stripper |
DE3040563A1 (en) * | 1980-10-28 | 1982-05-27 | Siemens AG, 1000 Berlin und 8000 München | ELECTRICALLY ACTUATED ACTUATOR |
US4539554A (en) * | 1982-10-18 | 1985-09-03 | At&T Bell Laboratories | Analog integrated circuit pressure sensor |
DE3309236A1 (en) * | 1983-03-15 | 1984-09-20 | Siemens AG, 1000 Berlin und 8000 München | ULTRASONIC CONVERTER |
DE3319871A1 (en) * | 1983-06-01 | 1984-12-06 | Richard Wolf Gmbh, 7134 Knittlingen | PIEZOELECTRIC CONVERTER FOR DESTROYING CONCRETE IN THE BODY |
US4704556A (en) * | 1983-12-05 | 1987-11-03 | Leslie Kay | Transducers |
DE3425992C2 (en) * | 1984-07-14 | 1986-10-09 | Richard Wolf Gmbh, 7134 Knittlingen | Piezoelectric converter for the destruction of calculus inside the body |
DE3430161A1 (en) * | 1984-08-16 | 1986-02-27 | Siemens AG, 1000 Berlin und 8000 München | POROESE ADJUSTMENT LAYER IN AN ULTRASONIC APPLICATOR |
DE3437488A1 (en) * | 1984-10-12 | 1986-04-17 | Richard Wolf Gmbh, 7134 Knittlingen | SOUND TRANSMITTER |
DE3443295A1 (en) * | 1984-11-28 | 1986-06-05 | Wolfgang Prof. Dr. 7140 Ludwigsburg Eisenmenger | DEVICE FOR THE CONTACT-FREE CRUSHING OF CONCRETE IN THE BODY OF LIVING BEINGS |
JPS61144565A (en) * | 1984-12-18 | 1986-07-02 | Toshiba Corp | High-polymer piezo-electric type ultrasonic probe |
EP0209053A3 (en) * | 1985-07-18 | 1987-09-02 | Wolfgang Prof. Dr. Eisenmenger | Method and apparatus for the non-contacting disintegration of concretions in a living body |
US4879993A (en) * | 1986-10-29 | 1989-11-14 | Siemens Aktiengesellschaft | Shock wave source for generating a short initial pressure pulse |
DE8710118U1 (en) * | 1987-07-23 | 1988-11-17 | Siemens AG, 1000 Berlin und 8000 München | Shock wave generator for a device for the contactless destruction of concretions in the body of a living being |
EP0324948A3 (en) * | 1988-01-21 | 1989-10-25 | Dornier Medizintechnik Gmbh | Concretions destruction device |
US4869768A (en) * | 1988-07-15 | 1989-09-26 | North American Philips Corp. | Ultrasonic transducer arrays made from composite piezoelectric materials |
DE8815090U1 (en) * | 1988-12-03 | 1990-02-15 | Dornier Medizintechnik GmbH, 8000 München | Piezoceramic shock wave source |
-
1989
- 1989-10-03 DE DE3932959A patent/DE3932959C1/de not_active Expired - Lifetime
-
1990
- 1990-08-28 US US07/574,331 patent/US5111805A/en not_active Expired - Lifetime
- 1990-09-28 EP EP90118633A patent/EP0421286B1/en not_active Expired - Lifetime
- 1990-09-28 DE DE59007688T patent/DE59007688D1/en not_active Expired - Lifetime
Also Published As
Publication number | Publication date |
---|---|
DE3932959C1 (en) | 1991-04-11 |
DE59007688D1 (en) | 1994-12-15 |
EP0421286A2 (en) | 1991-04-10 |
US5111805A (en) | 1992-05-12 |
EP0421286A3 (en) | 1992-06-03 |
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