JPH1085221A - Ultrasonic probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic probe having a slender distal end suited for insertion into a coelom, without transmitting rotary energy mechanically. SOLUTION: This ultrasonic probe 100A is for imaging a tissue from within a patient's coelom. The ultrasonic probe 100A includes a slender main body part 104 and an end pojtion, the end portion including a housing 122 in proximity to the distal end 108 of the ultrasonic probe, an ultrasonic beam emission assembly 124A having a turnable member, and a drive for causing turning movement by means of a turnable part. The housing 122 includes an acoustically transmissive part, and the turnable part is appropriately connected to the housing 122. The turnable part is capable of being attached to either a transducer that emits ultrasonic waves or a reflector reflecting the ultrasonic waves, and sweeps the ultrasonic waves while turning. The drive 120A is placed in proximity to the transducer, and all driving motions for causing the turning movement are produced in proximity to the distal end of the ultrasonic probe.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an intracavity ultrasonic probe, and more particularly, to scanning a tissue surrounding an ultrasonic probe by mechanically moving a transducer within the ultrasonic probe. The present invention relates to an intracavity ultrasonic probe.

[0002]

2. Description of the Related Art For many diseases, it is possible to make a more accurate diagnosis if an image of a body tissue affected by the disease can be observed. However, many body tissues cannot be easily observed. Recently, ultrasound imaging has been widely used to diagnose diseases in body cavities such as the vascular system, gastrointestinal tract, and the like. This requires the insertion of an ultrasound probe into the targeted body region via a catheter. Ultrasound probes send acoustic pulses into the body and detect reflections of the pulses from tissue boundaries caused by differences in acoustic impedance. The difference in the time required for the transducer to receive the reflected pulse corresponds to a change in the distance from the ultrasound source to the tissue boundary. By stepping or sweeping the ultrasound probe by a selected angle, it is possible to obtain a two-dimensional ultrasound image corresponding to a map of the acoustic impedance boundaries. The intensity and location of the reflections from these boundaries will provide information about the condition of the body tissue being imaged.

Generally, for diagnostic ultrasound imaging,
There are two types of ultrasound probes. In the first type, a synthetic aperture technique is used. For example, U.S. Pat. No. 4,917,097 (Proudian et al.) And U.S. Pat. No. 5,186,177 (O'Donnell et al.)
Teach a method of electronically steering an ultrasonic beam from a transducer using a synthetic aperture. Generally, this requires sequential excitation of selected elements in an array of transducer elements. In the second type, scanning is performed by mechanically rotating the means for directing the acoustic pulse. The mechanical rotation type includes several subclasses. In the first subclass, either the distal (distant from the operator) transducer or the mirror is rotated from the proximal end of the catheter by an extended drive shaft with a proximal motor. (U.S. Pat. No. 4,793,931 (Yock) and U.S. Pat.
ock)). For the second subclass, rotation is restricted to the distal end and a small motor (US Pat. No. 5,240,00)
No. 3 (Lancee et al.) And US Pat. No. 5,176,1.
No. 41 (Bom et al.) And a fluid-driven turbine using either a transducer or a mirror (U.S. Pat.
No. 402 (Yeung and Dias) is rotated. In a third subclass, a fixed proximal transducer is acoustically coupled to a rotating acoustic waveguide that transmits sound to a distal end (see, for example, US Pat. No. 5,284,148 (Dias).
And Melton)). For example, US Pat.
In another subclass, such as 9,418 (Lum et al.), The external drive causes the tube to rotate, which in turn causes the reflective element at the tip of the tube to rotate and reflect the ultrasound. .

[0004]

At present, the most widely used type of intracavity ultrasound probe is a mechanical rotary system with a transducer having a single planar element located at the distal end of the catheter. It is. This is preferred because of its superior image quality compared to current synthetic aperture systems. However, mechanically rotating ultrasound probes have several disadvantages. In the case of an ultrasound probe with a drive motor proximal to the operator, i.e., distal from the transducer, generally, the mechanical energy transmitted to the tip of the catheter containing the transducer is surrounded by a sheath. A required drive cable is required. Long cables cannot transfer energy evenly to the tip of the catheter and cause the transducer or reflector to rotate evenly. In addition, ultrasonic probes are prone to failure over time because the cable rotates rapidly and repeatedly within the sheath. On the other hand, if the drive motor is located near the tip of the catheter, the motor must be small. Such fragile motors are electrically and mechanically complex and very expensive. For example,
In the case of mechanical parts that endure severe movement, such as ball bearings, the motor is likely to fail. What is needed is an ultrasound probe with a structurally simple actuator at the tip of the catheter to move the transducer and scan the tissue.

[0005]

According to the present invention, there is provided an ultrasonic probe for imaging tissue from within a body cavity of a patient. The ultrasound probe is elongate and has a distal end suitable for insertion into a body cavity. The proximal end of the ultrasound probe remains outside the body.

[0006] The ultrasonic probe includes a housing proximate the distal end of the ultrasonic probe, an ultrasonic beam emitting assembly with a pivotable portion, and a drive for causing the pivoting motion by the pivoting portion. ing. The housing has an acoustically transparent portion. The pivotable part is movable and suitably connected to the housing, ie the pivotable part can be connected indirectly to the housing, for example via an electromagnet. The pivotable portion can be attached to either a transducer that emits ultrasound or a reflector for reflecting ultrasound from an ultrasound source. In any event, the pivotable portion sweeps the ultrasonic energy over a selected angle when pivoting. The drive is located in close proximity to the transducer and the entire drive movement to produce the pivoting movement will occur close to the distal end of the ultrasound probe.

With the ultrasonic probe of the present invention, the cable no longer needs to transfer rotational energy from the proximal end to the distal end of the ultrasonic probe as in prior art devices. In fact, there is no need to mechanically transfer energy from the proximal end of the ultrasound probe to the tip. The ultrasonic probe of the present invention can be used effectively for imaging of a tissue in a body cavity such as a blood vessel. This imaging can be performed by swiveling the platform on which the transducer is mounted and scanning the tissue with an acoustic beam of ultrasonic pulses. As the platform pivots, the transducer mounted on the platform swings back and forth, resulting in a sweep of the acoustic beam over a selected angle. Preferably, the platform pivots in the form of rocking (ie, seesaw motion) around a midpoint of the platform. In the case of the preferred device, this fulcrum is a torsion arm, which can allow the platform to pivot by torsion. Therefore, no mechanical sliding, rolling or frictional movement occurs. As a result, the possibility that the ultrasonic probe breaks down is reduced.

Furthermore, unlike an ultrasonic probe with a motor, the electromechanical system used to drive the pivoting motion in the present invention is relatively simple. No advanced locking and rotating mechanism is required at the distal end of the ultrasound probe where the transducer is located. Thus, for an ultrasonic probe, the manufacture of a compact drive used for the actuation of the swivel movement is made possible with high reliability. This allows the manufacture of an ultrasound probe that can be used even in small blood vessels or small body cavities. Both forward and side monitoring transducers can be implemented in the same ultrasound probe. This reduces the time required for the imaging process and eliminates the need for manipulating the catheter inside the body, since multiple instrument changes are not required when both forward and side monitoring capabilities are required. The trauma caused by this is reduced.

[0009]

According to the present invention, there is provided an ultrasonic probe which can be inserted into the body of a patient and has an operating mechanism close to the tip of the probe. If the actuation means is at the tip,
Eliminates the need for a long mechanical energy transmission system to transmit energy from a motor or similar mechanical actuator outside the body. Thus, cumbersome mechanisms such as cables for mechanically rotating the transducer in a 360 ° cycle within the protective shell or sheath are eliminated.

FIG. 1 shows an outline of a typical ultrasonic probe of the present invention. The ultrasound probe 100 includes an end 102 for insertion into a patient's body cavity, for example, an artery, and a proximal end 103 for medical personnel to control the operation of the ultrasound probe. End 102 and proximal end 103
Between them is an elongated body portion 104. This elongated body portion 104 is connected to an “imaging head” 106 at the distal end 108 of the ultrasound probe. As used herein, the term "distal" end of an ultrasound probe refers to an end that can be inserted into a body cavity of a patient, for example, a lumen of a blood vessel. "Body cavity" used in this book
The term generally refers to a hollow area surrounded by a wall, but the hollow area is not necessarily completely sealed. Further, it is not limited to easily accessible body cavities, such as the oral cavity, rectum, and the like. In the following description, a blood vessel is used as an example of a body cavity in which an ultrasonic probe can be used. However, it should be understood that the present invention can be adapted for use in various body cavities, such as the heart, esophagus, stomach, intestine, peritoneal cavity, bladder, uterus.

FIG. 2 shows a method of using the ultrasonic probe 100 in the blood vessel 112. The imaging head 106 includes a transducer and an actuating mechanism for moving the transducer to scan the blood vessel 112 with the ultrasound beam. Ultrasonic beams are composed of pulses. The proximal end 103 remote from the distal end 108
It is electrically connected to a controller 114 (FIG. 1) that controls the transmission and reception of ultrasound and the steering of the ultrasound radiating assembly. The controller 114 may also be capable of performing an analysis of an electronic signal emitted from the ultrasound probe as a result of the imaging head 106 receiving the ultrasound signal. Preferably, the controller 114 is further capable of storing and displaying data. In this case, the controller 114 may include a computer, a CRT monitor, and the like.

The proximal end 103 is desirably removable from the controller to facilitate insertion of the ultrasound probe into a desired location within a body cavity. An elongated sheath 116 is shown surrounding a substantial portion of the elongated body portion 104 of the ultrasound probe 100. Such a sheath can be inserted into a body cavity, for example, after the ultrasound probe (eg, where the ultrasound probe is a guidewire) is positioned at a desired location. Such sheaths include, for example, angiographic catheters, pacing catheters, athetectome
It can be used to introduce various objects such as a cutting tool for my) into a body cavity. Instead of a sheath, the structure 116 can be, for example, the catheter itself. It is contemplated that those skilled in the art will be able to manufacture imaging ultrasound probes that are not guidewires based on the present disclosure. Such a non-guidewire ultrasound probe can be introduced into a body cavity using a sheath or guidewire.

FIG. 3A shows in greater detail a portion of an embodiment of an ultrasound probe in the form of an imaging guidewire at the distal end 108 (shown as 100A in FIG. 3A). ing. In this embodiment, the elongated body portion 104 of the imaging guidewire 100A includes
Tubular wall 121 connected to imaging head 106
It has. The imaging head 106 includes a microactuator 12 with a pivotable transducer assembly 124A for emitting and receiving ultrasonic signals.
A housing 122 for accommodating and protecting 0A is provided. The housing 122 includes the transducer assembly 1
It is acoustically substantially transparent (or anechoic) to the ultrasound emitted by 24A. Alternatively, the housing 12
2 can also have a window for sending and receiving ultrasonic waves, depending on the application. Support 126
Is located close to the microactuator 120A and firmly supports it against the housing 122 and the tubular wall 121, except where flexibility of the wall is considered.

An imaging guidewire (ie,
The ultrasound probe has an imaginary centerline extending longitudinally along the elongated body portion 104. Imaging ・
The centerline of the imaging guidewire near the head 106 is substantially straight and coincides with the longitudinal axis 123 of the distal portion of the imaging guidewire 100A. The converter 144 (see FIG. 6) is connected to the microactuator 1
It is located laterally from 20A. As used herein, "lateral" refers to the longitudinal axis 123 of the imaging guidewire.
Represents the positional relationship in the radial direction with respect to. The housing 122 contains a liquid 127. Liquid 127
Is matched with the ultrasonic impedance of the housing 122 to reduce reverberation that attenuates the turning motion of the microactuator 120A. The support 126 may form a liquid tight seal with the housing containing the liquid, but may be made non-liquid tight to allow for the injection of fluid from the proximal end into the chamber formed by the housing 122. It is also possible. The transducer assembly 124A is generally planar, and its reference point is
It is almost perpendicular to the vertical axis 123 of 0A. When the transducer assembly 124A emits an ultrasonic beam, the microactuator 120A causes the transducer assembly 124A to swing and, as shown in FIG. 3B, to be perpendicular to the longitudinal axis 123 of the imaging guidewire. The ultrasonic beam is swept on a flat surface. The sweeping operation of the ultrasonic beam is indicated by a double-headed arrow E.

In an alternative embodiment, the transducer and microactuator are positioned so that the ultrasound beam sweeps a plane parallel to the longitudinal axis 123 of the imaging guidewire. The sweep path of the ultrasonic beam is shown in FIG.
In (C), the symbol displayed with F that enters the page +
Indicated by Wires for exciting the transducers and microactuators of the transducer assembly 124A can be placed along the cable 129 within the tubular wall 121 (see FIG. 3A). A relatively stiff but flexible wire core 128 contacts the support 126 to insert and push the guidewire into the body cavity. Preferably, the wire core 128 is attached to the support 126 to facilitate insertion. As an alternative, it is possible to combine the wire core 128 with the cable. For example, the wire core 128 can be the core of a coaxial cable, with the outer conductor of the coaxial cable connected to ground. The guidewire of the present invention has a conventional structure that allows the guidewire to perform fully. For example, the tubular wall 121 of the guidewire includes a coil so that the guidewire can be made flexible. For the method of manufacturing, using, and the structure of the guide wire, see, for example, S. P. N. 5,517,989 (Frisb
ie et al.), U.S.A. S. P. N. 5,497,782 (Fu
goso), U.S.A. S. P. N. 5,520,189 (M
alinowski et al.) and U.S.A. S. P. N. 5,
546,948 (Hamm et al.).

In another embodiment of the ultrasonic probe of the present invention, the distal end of the ultrasonic probe is shown in FIG. 4, but the transducer of transducer assembly 124B is distal of microactuator 120B. Is fixed to
A means of axial scanning is obtained, ie the scanning angle can comprise a midline along the longitudinal axis 123 of the ultrasound probe.

In yet another embodiment of the ultrasound probe, shown in FIG. 5, the transducer assembly 124C includes an ultrasound probe 10 along the longitudinal axis 123 of the ultrasound probe.
It is supported proximate the distal end 108 of the OC. The transducer assembly 124C emits an ultrasonic beam axially toward the proximal end. Micro actuator 120C
And since the pivotable reflector 130 is mounted at an oblique angle with respect to the longitudinal axis 123 of the ultrasound probe, the reflector radially reflects the axially directed ultrasound beam. The pivotable reflector 130 is
Since the side position of the ultrasonic probe 100C is swept by the ultrasonic beam while turning, the wall surface of the blood vessel 112 located on the side of the ultrasonic probe is scanned.

FIG. 6 shows the stage 132 of the ultrasonic probe according to the present invention in more detail. FIG. 7 shows a cross-sectional view of the stage 132 along the lines 7 to 7 in FIG. As used herein, the term "stage" refers to a structure including a substrate, a plate, a torsion arm, a magnetic material, and a transducer, as will be described below. The depression 133 in the stage 132 is surrounded by wall surfaces 134A, 134B, 134C, 134D, and edges 136A, 136B, 136 are formed on the wall surface.
C and 136D are formed. Almost rectangular plate 1
38 are two torsion arms 14 located near the midpoint of each opposing edge of stage 132
0A, 140C support the midpoint of two opposing edges. Plate 138, whose thickness is much less than the other two dimensions, is balanced on the torsion arm by the center of gravity of the plate resting on an imaginary line connecting torsion arms 140A, 140C. Torsion arm 140A, 140C
Is approximately perpendicular to the thickness dimension. Thus, the effort required to pivot or rotate the plate with the torsion arm is minimized. If desired, gravity at the center of the plate can be applied to the torsion arms 140A, 140C without significantly affecting the performance of the ultrasound probe.
Can be offset slightly from As used herein, the term "transducer assembly"
Represents the structure, if any, including plates, transducers, and magnetic materials. The term "pivot" when referring to movement of a plate or transducer assembly refers to a rotational movement about a support arm that pivots or rotates as if at a pivot. Thus, the torsional movement of the torsion arm is considered to be "slewing" as long as the rotation or swinging of the plate or transducer assembly is observed as if by a hinge or pivot. Since the torsion arms 140A and 140C are fixed to the wall surface of the stage 132, when the plate 138 generates a reciprocating swinging movement, a sweeping scan can be performed by a transducer fixed to the plate.

By forming a layer of a magnetic material 142 such as, for example, nickel ferrite (represented herein as "NiFe") material on the surface of plate 138,
Almost the entire surface is covered. Thus, when a fluctuating magnetic field is applied to the plate, the plate pivots on the torsion arm without trying to move up and down as a whole. Preferably, a layer of magnetic material 142 is provided on the upper surface of plate 138 for ease of manufacture. As used herein, “upper surface” refers to a surface that faces away from the depression 133. If selected, it is also possible to form a layer of magnetic material on the upper surface of plate 138 and cover half of the surface only on one side of torsion arms 140A, 140C.

The transducer assembly 124 includes a plate 1
Included is a magnetic material 142 and a transducer 144 attached to the upper surface of the. Electric wires 146A, 146C
Are connected to the connection pads 148A from the electrodes (not shown) of the transducer.
148C. Connection pad 148A, 148
C can also be connected to wires 150A, 150C to supply electrical energy to converter 144. Alternatively, wires 146A, 146C, 150
A, instead of one or more of 150C, a stage,
That is, properly doped channels in the torsion arm and frame of stage 132 can be used. Electrodes are connected to the surface of the transducer 144 to electrically generate and receive ultrasonic waves by the piezoelectric effect. When the transducer 144 is energized and the plate 138 is swirled by the fluctuating magnetic field, the transducer generates ultrasonic waves,
Scan tissue of blood vessels perpendicular to the flat surface of the transducer.

FIG. 8 is an exploded view showing a method of arranging the microactuator with respect to the converter. The microactuator 120X can be viewed as including a plate 138 (see FIG. 7) and torsion arms 140A, 140C, and a stage 132 with a magnetic material 142 that forms a layer on the plate. The transducer assembly 124 includes a torsion arm 140 caused by a variation in the magnetic field in which the magnetic material is located.
A, due to the pivoting movement of plate 138 around 140C. An electromagnet 154 is in proximity to the stage to apply a fluctuating magnetic field. The electromagnet 154 includes a coil 156 wound around the magnetic core 152. By passing a current through the coil 156, a fluctuating magnetic field can be generated. Magnetic core 152 of electromagnet 154
Extends parallel to (and preferably along) the longitudinal axis 123 of the ultrasound probe. In this sense, the length of the electromagnet can be extended along the longitudinal axis 123 of the ultrasonic probe, and is not limited by the diameter of the ultrasonic probe in this embodiment, so using a long magnetic core, This means that the number of turns can be increased. Such an actuator is suitable for use in an ultrasound probe similar to that shown in FIG. The coil 156 is wound such that the axis of the coil is perpendicular to the plane of the stage 132 and the plate 138 is approximately positioned about the axis of the coil, parallel to the longitudinal axis 123 of the ultrasound probe.
Thus, the magnetic field lines pass through the plate in a direction substantially perpendicular to the plane of the stage 132. Stage 132
Can be secured to the electromagnet 154 by commonly known securing means such as adhesives, clips, clamps and the like. Optionally, the stage 132 and the electromagnet 154 can be fixed and protected using a tube 160 with end plates. If a short core is used so that the electromagnet and stage 132 can be laterally snapped into the interior of the imaging head 106, this configuration of the plate 138 with electromagnet 154 is similar to that of FIG.
The present invention is also applicable to the ultrasonic probe (A).

FIG. 9A shows an exploded view of another embodiment of a transducer assembly and microactuator particularly suitable for the ultrasonic probe of FIG. 3A. In the case of this embodiment, the stage 132 is almost the same as the stage 132 of FIG. The electromagnet 154Y is U
The magnetic core 152Y is provided. U-shaped magnetic core 152Y
Has an elongated core body 155A with a first leg 155B and a second leg 155C extending substantially perpendicularly from its end. The first leg 155B is located more distally than the second leg 155C in the ultrasonic probe. The coil 156Y is wound around the magnetic core 158Y. Since the axis of the coil is substantially parallel to the longitudinal axis 123 of the ultrasonic probe, a long electromagnet can be used.
Stage 132 is adjacent to, but preferably supported by, first leg 155B at the distal end of the ultrasound probe. Thus, the magnetic field lines of the electromagnet 154Y
The first leg 155B is led from the elongated core body 155A.
And passes through the stage 132. Therefore,
When the current flowing through the coil 156Y fluctuates, the electromagnetic field of the electromagnet fluctuates, and the torsion arms 140AY and 140A
The plate rotates due to the CY. As also shown in FIG. 8, the electromagnet 154Y can be located close to the stage 132 or can be fixed thereto. An alternative to the U-shaped core is an L-shaped core, again allowing the stage 132 to be placed on the leg at the distal end of the core. An electromagnet provided with a U-shaped core or an L-shaped core can also be used for the ultrasonic probe of FIG.

The strength of the electromagnet can be increased by increasing the number of coil loops, increasing the cross-sectional area of the core (and thus the loop size),
And can be increased by increasing the current in the coil. The plate 138 (see FIGS. 7 and 14) is small, and as shown in part in FIG. 9B, only the magnetic field lines through the magnetic material of the plate affect the pivoting motion and increase the effective magnetic field strength. , The electromagnet 154Z
Can include a core 152Z that includes fingers 158A extending from a core body 158B. Since the core body 158B is large, the loop of the coil 156 can be enlarged. Magnetic field lines concentrate on fingers 158A and pass through the magnetic material on plate 138. The finger 15 is provided between the main body 158B of the magnetic core and the stage 132.
It is also possible to arrange a spacer 159 with a gap 159A for receiving 8A to help secure the stage to the electromagnet 154Z. The spacer 159 is mounted on the stage 13
It is possible to have a plane dimension almost similar to 2.

In the above configuration, the stage 132 and the electromagnet can be accommodated in the imaging head 106 without increasing the radial size of the imaging head. Methods for making coils and electromagnets for microactuators are known in the art. Depending on the method, for example, it is necessary to use a metal coil by vapor deposition, or else it is necessary to dope a silicon material to form a conductive coil for the electromagnet. For example, Wabner et al.
reactors with Moving M
Agnetsfor Linear, Torsion
al or MultiaxialMotion "S
sensors and Actuators, A. 3
2, pp. 598-603, 1992, Kami
ns et al. "Diffusion of Impuri
ties in Polysilicon. " Ap
pl. Phys. 43 (1), January 1972
Pages 83-91, Mandurah et al., "A Mo
del for Conduction in Poly
crystalline Silicon, Part
1: Theory. "IEEE Trans. of
Electron. Devices, Vol.
ED-28, no. 10, October 1981, 11
See pages 63-1170.

In another embodiment, the imaging system
It is possible for the head 106 to have more than one transducer. In fact, each was arranged such that the ultrasound waves were directed in different directions by the transducers provided on it,
It is possible to have more than one stage. This can be done, for example, by combining the transducer assemblies of FIGS. 3A and 4.

The method of manufacturing the device will be described below.
Microactuators and transducer assemblies are described, for example, in Magneti by Judy and Muller.
c Microactuation of Torsio
nal Polysilicon structure
e "Dig. Int. Conf. Solid-
State Sensors and Actuator
s, Stockholm Sweden 25-29 June 1995 pages 332-339, Ahn and
Allen, "A Fully Integrated
d Micromagnetic Actuatorw
it a multilevel meander
MagneticCore "Tech. Dig.
IEEE Solid-State Sensor a
nd Actuator Workshop (Hilt
on Head '92), Hilton Head
Island, SC, June 22-25, 1992
Day 14-18, Liu et al., "Out-of-
Plane Permalloy Magnetic
Actuators forDelta-Wing C
ontrol "Proc. IEEE Micro
Electro Mechanical System
s (MEMS '95), Amsterdam The Netherlands February 29, 1995, pages 7-12, Judy
and Muller "Magnetic Mic
activation of Polysilicon
Flexure Structures " M
microelectromechanical S
systems 4 (4) December 1995 162-
169 pages, "Microfabr" by Pister et al.
icated Hinges "Sensors an
d Actuators, A.D. 33 1992
It can be manufactured by employing micromachining methods for semiconductors known in the art, such as pages 249-256.

FIGS. 10 to 14 show a silicon substrate, for example, an anticorrosion layer made of silicon dioxide (SiO ₂ ) or glass;
A plate and torsion arm made of, for example, polysilicon or silicon nitride (Si ₃ N ₄ ) and, for example, 80
A possible method for performing such micromachining using a layer of magnetic material formed on a plate, such as permalloy, a nickel ferrite (referred to herein as NiFe) composed of 20% nickel and 20% iron, is shown. Have been. In the scientific literature, a material based on 80% nickel and 20% iron may be represented by Ni80Fe20. It should be noted that other magnetic materials can be used as long as the plate can be swiveled by electromagnetism. In short, a substrate having approximately the desired thickness of the stage 132 is obtained. For example, an anticorrosion layer 170 such as SiO ₂ (silicon dioxide) is deposited on a silicon substrate 168, and then a thin film 172 of polysilicon or silicon nitride is formed. For example, a magnetic material layer of NiFe is deposited on a layer of polysilicon or silicon nitride. In addition, using suitable masking and etching techniques, the plate 138 and the selected portions of the conductive seed film layer 174, plate material, and anticorrosion layer 170 are removed by removing the plate 138 and the selected portions of the magnetic material layer 178 (eg, NiFe). The torsion arms 140A and 140C are formed. The silicon substrate 168, the anticorrosion layer 170, the silicon nitride layer 172, and the magnetic material layer 178 (for example, Ni
Methods for forming such a conformable layer of Fe) are known in the art. Furthermore, the depression 133 can be formed by selectively etching the silicon substrate 168.

An alternative to polysilicon or silicon nitride is
For example, polyimide such as PI-2611 manufactured by DuPont (Wilmngton, DE). The layer of polyimide is generally formed by spin coating. These layers can be removed by dry plasma etching. Polyimide materials suitable for such applications are available from DuPont and Ciba Geigy Corp.
It is commercially available from chemical supply companies such as (Greensboro, NC). Methods for spin coating and etching of a polyimide layer are known in the art. For example, Ahn et al., "A Planar
Variable Reluctance Magn
etic Micromotor with Full
y Integrated Stator And W
wrapped Coils "Proc. IEEE
Micro Electro Mechanical
Systems (MEMS '93), Fort L
Auddale, F1, February 7-1, 1993
See day 0. For example, layers of such materials available for forming support arms, such as silicon nitride, polysilicon, and polyimide, may be used herein as the support arm and bottom layer of the transducer assembly are formed from such layers.
Called "transducer support layer".

In order to clarify the method of forming the stage 132 of the present invention, the following describes a silicon substrate layer, a SiO ₂ anticorrosion layer, a silicon nitride plate having a torsion arm,
An embodiment including a magnetic material layer of NiFe will be described. As is generally known, glass and SiO ₂ can be etched with compatible chemicals such as, for example, buffered hydrofluoric acid (HF) mixtures, and silicon can be made of potassium hydroxide (KO).
H) or tetramethyl ammonium hydroxide (TMA)
H) etching, glass, SiO ₂
Polysilicon and silicon nitride can be dry etched by plasma chemistry known to those skilled in the art, and silicon nitride can also be wet etched with phosphoric acid (H ₃ PO ₄ ). . As is also known, these etching methods depend on the respective material (eg, silicon, silicon nitride, polysilicon, SiO ₂ , NiF
It has a different effect on e). This difference is due to the physical and chemical properties inherent in the material. The different etch rates of these materials using a variety of etchants allow for differentially quick or very slow etches depending on the material.

As an example, the silicon nitride layer 172 and the anticorrosion layer 1
It is possible to consider the layers of material shown in FIG. 10 including 70 (SiO ₂ ) and a silicon substrate 168 and only a small amount of a conductive seed film 174. The silicon nitride layer 172 can be lithographically masked and patterned using high temperature H ₃ PO ₄ at about 50 ° C. The acid is relatively fast and completes the etching of the exposed silicon nitride regions, but for the exposed anticorrosion layer 170 (SiO ₂ ), the etching rate is significantly, ie, orders of magnitude, slower.
The lithographic masking material on the silicon nitride layer can be removed by an oxygen plasma, which has minimal effect on the exposed corrosion protection layer 170 (SiO ₂ ). The oxygen plasma does not act on the exposed silicon nitride layer. At this stage of the process, the lithographic masking material on the silicon nitride layer has been removed and the openings in the silicon nitride layer expose a thin layer of SiO ₂ . The exposed anticorrosion layer 170 (SiO ₂ ) is removed, for example, by subjecting it to a characteristic timed immersion of about 10 seconds in 10: 1 hydrofluoric acid.
Next, the silicon substrate 168 is exposed. Finally,
It is possible to perform etching on a silicon substrate by using etching with KOH or TMAH. The effect of the appropriate dilute solution at the appropriate temperature on the anticorrosion layer 170 (SiO ₂ ) and the silicon nitride layer 172 is minimal. Exposure of the material to TMAH or high temperature KOH for a reasonable amount of time will result in etching pits in the silicon substrate being substantially formed by the openings in silicon nitride layer 172 and anticorrosion layer 170 (SiO ₂ ). Applying this general process method produces the structure in question.

In the art, solid state
How to etch various materials used in semiconductor technology
The law is known. For example, etch silicon dioxide
For more information on how to apply
Other authors, "Mechanisof dry etchin"
go of silicon dioxide -Ac
case study of direct react
eve ionetching " Electr
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Written by Etch Rates of Doped Oxid
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Di, August 1973. Polysilicon edge
For more information on ching, see Bergeron et al., Contr.
old Anisotropic Etching
 of Polysilicon "Solid St
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Month, pages 98-103, B.I. L. Sopori "A
 New Defect Etch for Poly
crystalline Silicon " E
electrochem. Soc. Solid St
ate and Technology, 131
(3), pp. 667-672, described in March 1984
There is. For the etching of silicon nitride, see van G
Elder et al., "The etching of Si.
silicone Nitride in Phosphor
ic Acid with Silicon Diox
"ide as a mask" Electro
chem. Soc. Solid State an
d Technology, 114 (8), 196.
August, 1995, pages 869 to 872. Siri
Regarding the etching of the con J. Declerc
q “Anew CMOS Technology U
sing Anisotropic Etching
of Silicon "IEEE J. of So
lid State Circuits, Vol. S
C-10, no. 4, August 1975, 191-1
96 pages; E. FIG. Bean "Anisotrop
ic Etching of Silicon, "I
EEE Trans. Electron. Devi
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October 978, pp. 1185-1193, Osa
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MAH etches forsilicon m
micromatching, "Sensors an
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35-339, Robbins et al., Chemi
cal Etching of Silicon. T
he system of HF, HNO_Three, H
_TwoO, and HC _TwoH_ThreeOO_TwoJ. Of The
 Electrochemical Society,
 107 (2), February 1960, 108-111
There is description on the page. The converter is a silicon substrate 168.
It is also possible to place it on the magnetic material layer before etching.
You.

As an example to illustrate the formation of a plate with a transducer as shown in FIG. 10, a SiO ₂ anticorrosion layer 170 of desired shape, size, thickness, and pattern is formed on a silicon substrate 168. Is done. Anticorrosion layer 170
Is covered by a transducer support (silicon nitride) layer 172.
The silicon nitride layer 172 is further covered, masked, and etched with photoresist to support the magnetic material and the transducer and to withstand the harshness of the torsional rotation of the torsion arm that is repeated during operation. A suitable, desired size, shape, and pattern will be formed. Further, the silicon nitride layer 172
By depositing a conductive seed film 174 comprising, for example, a chromium film and a copper film on selected surfaces of the substrate, the deposition of magnetic material is facilitated.

In the case of FIG. 11, a layer 176 of photoresist is used.
Is used to cover areas of the silicon nitride layer 172 where deposition of magnetic material is undesirable. Next, the silicon nitride layer 172
Is electroplated with a layer of magnetic material 178 (NiFe) of a desired thickness on a portion of the conductive seed film 174 that is not covered by the layer 176 of photoresist. In the case of FIG. 12, after removal of the photoresist and conductive seed film 174 in selected areas,
On the silicon nitride layer 172, a desired size, thickness, and
The NiFe layer having the shape remains.

In the case of FIG. 13, the plate 138 and the silicon nitride layer 172 designated to be torsion arms are shaped to shape the silicon substrate 168 forming the depression 133 (see also FIGS. 6 and 14). The anticorrosion layer 170 below the portion is etched with HF. When the selected material of the anticorrosion layer 170 is removed by etching, a desired silicon substrate region is exposed. This exposed silicon substrate region of silicon substrate 168 is
To increase the depth of 3A, use KOH etching solution or T
It is possible to perform etching with a MAH solution. When this etching is completed, a depression 133 shown in FIG. 14 is formed. Next, the transducer 144 can be secured to the plate 138. Connection pads 148A, 148C,
Also, by using the electric wires 146A and 146C, the converter and the controller 1 can be connected via the electric wires 150A and 150C.
Fourteen interfaces are possible. These steps can be performed by well-known procedures.

Depending on the application of the ultrasonic probe, the size, shape, thickness, and other dimensional characteristics of the microactuator and transducer can be modified to suit the application. For example, the dimensions of an intravascular ultrasound probe are much smaller than an endoscopic ultrasound probe. In the case of an intravascular ultrasonic probe, the silicon substrate 16
8 is generally about 100-700 μm, preferably about 4
It is possible to have a thickness between 00 and 500 μm. The plate 138 is rectangular and about 2,000 to 10,000
Preferably, it has a thickness of about 4,000 to 9,000 mm. Plate 138 may have a surface area of between about 0.2 and 0.2 to provide sufficient surface to support the transducer.
It can have a width of 0.7 mm, preferably about 0.3-0.4 mm, and a length of about 0.2-2 mm, preferably about 0.5-1 mm. Torsion arm 140A,
Preferably, 140C is relatively short compared to the width of the plate to reduce stress due to the weight of the plate. However, the torsion arm 140
A, 140C is desirably long enough to allow the swiveling of plate 138 to sweep over a desired angle, which corresponds to the angle swept by the perpendicular of the plate. This angle is less than 180 °,
Generally, it is about 10-90 °. The angle is desirably about ± 45 ° with respect to the perpendicular of the plate.

Further, it is desirable that the width of the plate 138 is not excessive so that the plate does not hit the base of the depression 133. As the plate becomes wider, the force for rotating the plate 138 by the torsion arms 140A and 140C also needs to be increased, and the sweep cycle becomes slower. In general, the plate 138 is about 1: 3 to 1:
1, possibly from square to rectangular, depending on the 1: 2 width (ie, side perpendicular to the torsion arm) to length ratio. The length is reduced by the torsion to reduce the force required to pivot the plate.
It is desirable to be parallel to the arms 140A and 140C.

As described above, the magnetic material is a torsion
Plate 1 on both sides of arms 140A, 140C
Preferably, it is applied to the upper surface of the. For example, on the surface of the plate 138, the magnetic material layer 17 such as NiFe may be disposed such that the north pole is located on one side of the torsion arms 140A and 140C and the south pole is located on the other side.
8 is formed, an electromagnet below the plate (eg,
When a magnetic field is applied to plate 138 by electromagnet 154 of FIG. 8, one pole of the electromagnet exerts an attractive force on the magnetic material in one half of the plate and a repulsive force on the magnetic material in the other half. Thus, plate 138 rotates around the torsion arm. When the polarity of the electromagnet is reversed, the plate 138 pivots in the opposite direction.

In order to effectively use the surface area of the plate,
Magnetic material occupies almost all of the upper surface of the plate. Its thickness is plate, i.e., less than 25% of the thickness of the Si ₃ N ₄ is desirable. Various modifications to the electromagnetic operation described above are possible. For example, the poles of the electromagnet can be located below one side of the plate 138. Another method of operation is to form a magnetic material on the plate 138 with one pole (eg, north pole) at the top and the other pole at the bottom, and two poles of the electromagnet, The plate is to be placed under each of the halves.

The transducer 144 covers substantially all of the upper surface of the magnetic material layer 178 and the upper surface of the plate 138 (not covered by the magnetic material) in order to utilize the surface of the plate effectively. The converter 144
It has the usual electrodes, wires and transducer elements known in the art for transducers of ultrasonic probes. Methods for making small transducers for use in a body lumen, such as intravascularly, are known in the art. For example, an intravascular ultrasound probe can include a silicon substrate layer having a thickness of about 500 μm. The Si ₃ N ₄ plate can be about 9,000 mm thick, 400 μm wide, and about 1,000 μm long. The magnetic material layer 178 (NiFe) has a thickness of about 10 μm and can cover almost all of the upper surface of the plate. The transducer comprises a layer of about 80 μm thick piezoelectric material (eg, PZT lead zirconate titanate), a quarter-wave matching layer of graphite about 40 μm thick, and an epoxy about 300 μm thick and It is possible to construct from a thick tungsten backing material. The transducer covers almost all of the upper surface of the plate and thus the NiF
e can also be covered. The transducer can also be made of quarter-wave material, with the addition of a compatible matching layer material such as graphite. Both acoustic matching and backing techniques for making transducers, as well as applicable materials, are well known in the art.

The combined thickness of the transducer, magnetic material, anticorrosion layer, and plate is thin compared to its length and width. Therefore, the combination structure also has a substantially plate shape. The torsion arms 140A and 140C are
Each can have a length of about 5-20 μm. The silicon substrate 168 can have a thickness of about 400-500 μm. This will accommodate recesses 133 with a depth of about 300-400 μm. The anticorrosion layer 170 has a total of about 150 to 500 mm,
Extremely thin. Therefore, the stage 132 has substantially the same thickness as the silicon substrate 168.

As mentioned above, the actuation mechanism and stage 132 with the transducer assembly are located within a housing 122 that is substantially transparent to ultrasound. Preferably, the housing is mechanically rugged and has an appropriate thickness to withstand operation in the insertion process. The ultrasonic probe of the present invention is, for example, a guide wire, a core for facilitating feeding of the guide wire into a body cavity, a low friction surface of a body suitable for sliding a sheath and guiding to a desired position, and the like. Such as the conventional structure that allows the proper functioning of a typical probe. Generally known techniques can be used for manufacturing such a structure.

The operation of the ultrasonic probe will be described below. The ultrasonic probe of the present invention can be inserted into a selected body cavity by standard methods known in the art. When the ultrasonic probe of FIG. 6 or FIG. 14 operates, the controller 114 (see FIG. 1) controls the current flowing through the coil of the electromagnet. As a result, the electromagnet (FIG. 6)
14 (not shown in FIG. 14) changes its magnetic field so as to attract or repel the magnetic material layer 178 which is a ferromagnetic material. FIG. 15 is a cross-sectional view of stage 132, in an orientation perpendicular to stage 132 of FIG. 14, showing plate 138 pivoted such that the plane of the plate forms an angle with the plane of the stage. ing. This position can be achieved, for example, by passing a current through the coil of the electromagnet and energizing the electromagnet, thereby repelling one half of the magnetic material layer 178 and attracting the other. It is. Converter 14
When the transducer element 4 is electrically excited, for example, a piezoelectric element, an ultrasonic pulse is delivered perpendicular to the plane of the transducer, ie, substantially perpendicular to the plane of the plate 138. As shown in FIG. 16, when a current is passed through the coil of the electromagnet in the opposite direction, each half of the magnetic material layer 178 turns the plate 138 by suction and repulsion by the electromagnet, and the stage 132 Make different angles to the plane. Plate 1
As 38 pivots, the transducer assembly 124 is swung by the torsion arm and the ends of the transducer assembly are swung causing reciprocation. As the pivoting motion of the plate 138 is repeated periodically, the transducer assembly 124 sweeps over a range of angles to scan the tissue surrounding the ultrasound probe.

When current does not flow through the coils of the electromagnet, the plate 138 is biased and the transducer assembly 12 is biased.
For example, a method of enabling the user to attach the permanent magnet 4 to a desired position includes providing a permanent magnet (not shown) near the magnetic material layer 178. The size and strength of the permanent magnet is selected so that the constant magnetic field of the permanent magnet exerts a continuous force, biasing the plate 138 to the desired position. By moving the ultrasound probe periodically to scan a large area, it may be necessary to move the imaging head (shown as 106 in FIG. 1) to assume various positions or orientations. There is. This can include, for example, moving the imaging head along the longitudinal axis of the ultrasound probe,
This can be done by withdrawing and by rotating the ultrasound probe on the longitudinal axis of the ultrasound probe.

In an alternative embodiment of the ultrasonic probe of the present invention shown in FIG. 17, one end is connected by a support arm 140Z to a wall 134Z surrounding the recess 133,
A supported flap 138Z is included. This flap 138Z functions similarly to the plate 138 of FIG. 16 and supports the magnetic material layer 178Z and the transducer 144Z. Such devices are described, for example, in Liu et al. (1995)
), By Judi and Muller (1995), a method of making a microactuator with a support beam or cantilever. Again, if the electromagnet does not operate, a permanent magnet can be used to bias the transducer assembly into the desired position.

For example, a converter, such as converter 144,
It can be used for both transmission and reception of ultrasonic signals. As described above, the controller 114 is used to control the emission of the ultrasound signal and to analyze the received ultrasound signal. Systems for controlling the emission, reception, and analysis of ultrasound signals are known in the art.

FIG. 18 shows an embodiment in which the stage 132 is provided with a gimbal converter in which a first plate 138D and a second plate 138E are respectively turned about 90 ° about an axis. . First plate 1
38D are torsion arms 140D and 140D '
And the transducer assembly 124D as a whole swings. At the center of the transducer assembly 124D, a transducer subassembly 124E including a second plate 138E is attached to the torsion arm 140E,
Turn by 140E '. Transducer subassembly 1
24E is also a transducer 1 covering its upper surface.
44. Torsion arm 140D, 14
0D 'are aligned with each other, but are orthogonal to the torsion arms 140E, 140E', which are aligned with each other. In the case of the transducer subassembly 124E, a layer 14 of magnetic material is deposited on the second plate 138E.
2E, torsion arms 140E, 140
It is possible to have different poles on each side of E '. Similarly, for the transducer assembly 124D, a layer 142D of magnetic material can be applied to the first plate 138D outside the transducer subassembly 124E. Transducer assembly 1 by electromagnet
By applying a magnetic field separately to 24D and transducer subassembly 124E, the transducer can be pivoted to cause oscillation by torsion arms 140D, 140D 'and torsion arms 140E, 140E'. .

One method of applying a magnetic field separately comprises two coils, the inner coil being the transducer subassembly 1
24E and the outer coil controls the magnetic field for the transducer assembly 124D.
Or, in part, by an electromagnet adapted to cancel the magnetic field to the transducer subassembly. Therefore, the ultrasonic probe can be manufactured so that three-dimensional scanning, that is, imaging can be performed without moving the imaging head 106 (see FIGS. 1 and 2). However, when imaging a wide area in a body cavity, it is considered that the ultrasonic probe must be moved to various positions in the body cavity.

The torsion arms 140D, 140D '
And 140E, 140E ', one of the alternative ways of initiating the pivoting movement of the transducer is to use the electrostatic mechanism shown in FIG.
By electrostatically (instead of magnetically) attracting different parts of the As used herein, the term "electrostatic force" refers to the attraction or repulsion generated by the electric field of two charged but not in contact. This may be done, for example, by placing mesas under each half of the first plate 138D and 138E and adjusting the charge of each mesa to aspirate different portions of the plate. It is possible. In this embodiment, the configuration of the silicon substrate 168, anticorrosion layer 170, plate 138, and transducer assembly 124 is similar to the configuration of FIG. 16 except that no magnetic material is deposited on the plate. It is. For example, Pd / A
A conductive metal mesa 190A made of a g-alloy is fixed to the silicon substrate 168 below the plate 138 on one side of the torsion arm 140. A second conductive metal mesa 190B is disposed on the substrate on the other side of torsion arm 140. Electrostatic driver 19
When 2A applies an electrostatic force acting on conductive metal mesa 190A, plate 138 pivots.

FIG. 19 is for illustrative purposes only. However, it will be apparent to those skilled in the art that other circuit elements may be configured to perform the operating function. The control voltage VC drives the transistor 194 with a control pulse. If the control voltage is high, the transistor saturates and the current in inductor 196 reaches a steady state value determined by power supply voltage V ₊ and resistor R1. When the control voltage is low, transistor 194 turns off and the inductor causes charge to be pumped through the diode into conductive metal mesa 190. Plate 138 and conductive metal mesa 190A act as plates of the capacitor, and are attracted to each other by electrostatic force therebetween. As charge drains through the leakage path, plate 138 returns to its neutral position, such that the opposite second conductive metal mesa 190B attracts the plate to the opposite side. The second conductive metal mesa 190B is controlled by a driver circuit 192B similar to the electrostatic driver 192A, and these drivers cooperate to form a plate 138.
The corresponding side divided in half is alternately sucked. Thus, for example, by controlling the the applied control voltage, such as V _C, it is possible to reciprocally pivot the plate 138. Microfabrication methods for small electrostatic microactuators are known in the art. For example, Garabedian et al., "Microfabricated surface."
plasmon sensing system "S
sensor and Actuators, A, 4
3 (1994), pp. 202-207, Rich
Ards et al., "Surface-plasmon ex"
Cituation using a Polariza
Tion-preserving optical f
iber and an index-matchin
g fluid optical cell "App
lied Optics, 32 (16) (199
3), pages 2901 to 2906.

The following summarizes the present invention. 1. A distal end (108) suitable for insertion into a body cavity
An ultrasound probe (100) for imaging tissue from within a patient's body cavity comprising a proximal end opposite a distal end (108), comprising: (a) an elongated body portion (104); b) connected distally to the elongated body portion (104), (i) comprising a portion that is substantially transparent to ultrasound and proximate the distal end (108) of the ultrasound probe (100). (122) a transducer (eg, 144) for emitting an ultrasonic beam and a pivotable member (13) for directing the ultrasonic beam in a selected direction.
8), wherein the pivotable member (138) is supported by one or more support arms (eg, 140A, 140C) suitably connected in the housing, and the support arms (eg, 140A, 140C). ) Scans the wall of the body cavity with an ultrasonic beam and performs the torsion or bending of the pivotable member (1) to perform imaging.
38) to allow a reciprocating swiveling movement.
An ultrasonic beam transmitting means (for example, 124A) in the housing (122) for transmitting ultrasonic waves;
(Iii) all drive movements are ultrasound probes (100)
The transducer (e.g., 1
44), said housing (1)
22) An ultrasonic probe, including an end (102), including a drive (eg, 120A) for driving the pivoting movement of the pivotable member (138) therein.

2. The sheath (116) is slid over the elongated body portion (104) and the elongated body portion (10
4. The ultrasonic probe according to claim 1, comprising a surface capable of guiding along 4) to a desired position.

3. The pivotable member (138) is plate-shaped and comprises a supporting torsion arm (140A, 140C) connected to a fixed support (eg, 136A, 136C) fixed to the housing (122). And the supporting torsion arm (140
A, 140C) is an ultrasonic probe according to any one of the above items 1-2, wherein the probe is flexible or capable of twisting in order to enable a pivoting movement of the pivoting member (138).

4. The above-mentioned 1-3, wherein the supporting torsion arms (140A, 140C) of the pivotable member (138) are made of a material substantially selected from the group consisting of polysilicon, silicon nitride, and polyimide.
The ultrasonic probe according to any one of the above.

5. The pivotable member (138) comprises a reflector (130) for reflecting the ultrasound beam or comprises the transducer emitting an ultrasound beam to direct the beam in a selected direction. The ultrasonic probe according to any one of the above items 1 to 4.

6. An ultrasonic probe according to any one of the preceding claims, wherein the pivotable member (138) comprises a transducer (144) for emitting an ultrasonic beam and directs the beam in a selected direction.

7. A driving device is provided with an electrostatic means (192A, 1D) for driving a turning motion for scanning by an ultrasonic beam.
92B) and one of the electromagnets (154).
7. The ultrasonic probe according to any one of items 6 to 6,

8. The driving device is an ultrasonic beam 3
The above-mentioned 1 which is not provided with a rotating mechanism for rotational movement in the ultrasonic beam sending means for scanning at 60 ° cycle.
8. The ultrasonic probe according to any one of items 7 to 7,

9. A pivotable member (138) includes a transducer (144) and includes a midpoint, the pivotable member pivoting about the midpoint for scanning by the ultrasonic beam, and a drive ( For example, 120A) includes a layer of magnetic material on a pivotable member, wherein the pivotable member is adapted to pivot in response to a change in a magnetic field. An ultrasonic probe as described.

10. One or more support arms (eg,
140A, 140C), a plate-shaped ultrasonic transmitter (138) is provided, and the ultrasonic transmitter (13
8) includes a transducer (eg, 144) and a distal end (10).
8) The method using an ultrasonic probe, which is disposed in the housing (122), wherein (a) an ultrasonic wave provided with a plate-shaped ultrasonic transmitter (138) including a transducer (for example, 144). Inserting an acoustic probe (100) into the body cavity; and (b) a transducer (e.g., 14
Generating an ultrasonic beam at 4) and (c) bending or twisting one or more support arms (eg, 1).
40A, 140C) reciprocating a plate-shaped ultrasonic transmitter (138) on a pivot axis.

[0060]

As described in detail above, according to the ultrasonic probe of the present invention, the cable no longer has rotational energy from the proximal end to the distal end of the ultrasonic probe as in the prior art device. There is no need to communicate. In fact, there is no need to mechanically transfer energy from the proximal end of the ultrasound probe to the tip. The ultrasonic probe of the present invention can be used effectively for imaging of a tissue in a body cavity such as a blood vessel. Also, the electromechanical system used to drive the pivoting motion in the present invention is relatively simple. Therefore, for the ultrasonic probe in which the transducer is arranged, it is possible to manufacture with high reliability a miniature drive used for differential swiveling movement. This allows the manufacture of an ultrasound probe that can be used even in small blood vessels or small body cavities. Both forward and side monitoring transducers can be implemented in the same ultrasound probe. This reduces the time required for the imaging process and eliminates the need for manipulating the catheter inside the body, since multiple instrument changes are not required when both forward and side monitoring capabilities are required. The trauma caused by this is reduced.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of an ultrasonic probe according to the present invention.

FIG. 2 is a schematic view of an imaging guidewire according to the present invention, shown positioned within a blood vessel.

FIG. 1 is a schematic view of an imaging guidewire according to the present invention as viewed in an axial direction. B. FIG. 4 is a schematic view of the embodiment according to FIG. C. FIG. 4 is a schematic view in axial direction of another embodiment according to FIG. 3 (A), showing the turning direction.

FIG. 4 is a schematic view of another embodiment of the ultrasonic probe according to the present invention.

FIG. 5 is a schematic view of yet another embodiment of an ultrasonic probe according to the present invention.

FIG. 6 is an isometric view of an embodiment of an ultrasonic probe according to the present invention, showing the transducer on a slab-shaped stage.

FIG. 7 is a sectional view taken along lines 7-7 of FIG. 6;

FIG. 8 is a partial exploded view of a microactuator of an ultrasonic probe according to the present invention, showing an electromagnet.

FIG. FIG. 7 is a partial exploded view of another ultrasonic probe microactuator according to the present invention, showing an electromagnet. B. FIG. 6 is a partial exploded view of another ultrasonic probe microactuator according to the present invention, showing an electromagnet having fingers on a magnetic core.

FIG. 10 is a cross-sectional view of a layer of material during formation of an embodiment of a stage when manufacturing a microactuator for an ultrasonic probe according to the present invention.

FIG. 11 is a cross-sectional view of a layer of material during formation of an embodiment of a stage when manufacturing a microactuator for an ultrasonic probe according to the present invention, showing the preparation for forming a pattern on the layer of magnetic material.

FIG. 12 is a cross-sectional view of a layer of material during formation of an embodiment of a stage when manufacturing a microactuator of an ultrasonic probe according to the present invention, showing the layer of magnetic material formed.

FIG. 13 is a cross-sectional view of a layer of material during formation of an embodiment of a stage in manufacturing a microactuator of an ultrasonic probe according to the present invention, illustrating the formation of a dimple capable of pivoting the transducer assembly. It is.

FIG. 14 is a cross-sectional view of a layer of material during formation of an embodiment of a stage in manufacturing a microactuator of an ultrasonic probe according to the present invention, showing a transducer disposed on a plate.

FIG. 15 is a cross-sectional view of an embodiment of a stage in an ultrasonic probe according to the present invention, showing a plate swiveled in a first direction.

FIG. 16 is a cross-sectional view of an embodiment of a stage in an ultrasonic probe according to the present invention, showing a plate turned in a second direction.

FIG. 17 is a cross-sectional view of another embodiment of a stage in an ultrasonic probe according to the present invention, showing the flap supported at the end of the flap.

FIG. 18 is a schematic plan view of a stage according to the present invention showing a gimbal transducer assembly.

FIG. 19 is a schematic diagram of a stage and an electrostatic actuation system according to the present invention.

[Explanation of symbols]

 Reference Signs List 100 ultrasonic probe 100A imaging guidewire 102 end 103 proximal end 104 elongated body portion 106 imaging head 108 distal end 120 microactuator 122 housing 123 imaging guidewire longitudinal axis 124 transducer assembly 130 pivotable reflector 132 Stage 133 Indentation 134 Wall 136 Edge 138 Plate 140 Torsion arm 142 Magnetic material 144 Transducer 148 Connection pad 152 Magnetic core 154 Electromagnet 155 Leg 156 Coil 158A Finger 158B Core body 159 Spacer 159A Silicon erosion 17 Silicon air gap 16 Layer 174 conductive seed film 176 layer of photoresist 178 layer of magnetic material 190 conductive gold Mesa 192 electrostatic driver 194 transistor 196 inductor

Claims (1)

[Claims] A distal end (10) suitable for insertion into a body cavity.
8) and a proximal end opposite the distal end (108);
An ultrasound probe (100) for imaging tissue from within a body cavity of a patient, comprising: (a) an elongated body portion (104); (b) distally connected to the elongated body portion (104); i) a housing (122) having a portion that is substantially transparent to ultrasound and proximate a distal end (108) of the ultrasound probe (100); and (ii) emitting an ultrasound beam. And a pivotable member (138) for directing the ultrasound beam in a selected direction, said pivotable member (138) being connected to one or more suitably connected housings. Support arm (140
A, 140C) and the support arm (1
40A, 140C) adapted to scan a wall of a body cavity with an ultrasonic beam and to allow reciprocating pivotal movement of said pivotable member (138) by torsion or bending for imaging. (122) an ultrasound beam delivery means (124A) for delivering ultrasound, and (iii) such that all drive movements occur close to the distal end of the ultrasound probe (100). A drive (120A) located in the housing (122) and proximate to the transducer (144) for driving a pivoting movement of the pivotable member (138); A), an ultrasound probe.