JP2009213785A - Ultrasonic probe - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultrasonic probe that makes a stabilized oscillatory scanning. <P>SOLUTION: The ultrasonic probe includes an ultrasonic probe member 5 located at the distal end of the probe to radiate ultrasonic waves while making an oscillatory rotation on a fluctuating rotation shaft 7, a sheath 13 positioned to cover the ultrasonic probe member 5, and a first acoustic medium 14 filled up between the ultrasonic probe member 5 and the sheath 13. The external shape of the ultrasonic probe member 5 is symmetric about the oscillatory rotation shaft 7. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention is a guide for diagnosing stenosis in a blood vessel and placing an ICD left ventricular electrode in the coronary sinus in the heart by inserting it into a blood vessel or heart and scanning the ultrasound beam forward. The present invention relates to a forward-viewing thin-diameter ultrasonic probe.

  An electronic scanning method and a mechanical scanning method are known as a scanning method of an ultrasonic probe that scans an ultrasonic beam forward. In the electronic scanning method, a plurality of transducers are arranged in an array, a pulse transmission signal having a different phase is applied to each transducer to converge an ultrasonic beam, and scanning is performed by adjusting the applied phase. is there. The mechanical scanning method scans an ultrasonic beam by rotating or swinging a vibrator or an acoustic reflection mirror.

  Recently, there is a demand for a thin ultrasonic probe that can be inserted into a blood vessel or the like. However, in the electronic scanning method, it is difficult to dispose a transducer array that scans an ultrasonic beam forward at the tip due to dimensional restrictions. Also in the mechanical scanning system, there are large dimensional restrictions, and it is difficult to directly apply the configuration used in an ultrasonic endoscope used in the digestive tract field to a small-diameter ultrasonic probe.

As a configuration suitable for a small-diameter ultrasonic probe, Patent Document 1 discloses an ultrasonic probe that swings and scans a vibrator using at least one shape memory alloy actuator. The shape memory alloy actuator has a spring shape in which the shape is memorized in advance, and the temperature of the memory alloy actuator is adjusted by applying a voltage to both ends, and the shape memory alloy's shape restoring force is used to vibrate. The arm or plate holding the child is swung and scanned.
US Pat. No. 5,379,772

In the frequency band of ultrasonic waves used for medical purposes, ultrasonic waves cannot be transmitted into the body through the air. For this reason, in the small-diameter ultrasonic probe, the space between the transducer and the sheath needs to be filled with an acoustic medium that facilitates transmission of ultrasonic waves to the living body. As the acoustic medium, deaerated water, physiological saline, or the like can be used.
Here, in the technique described in Patent Document 1, when the arm or plate holding the vibrator is swung and scanned, the acoustic medium acts as a resistance by forming a turbulent flow and the like, and a stable rocking motion is generated. There is a problem of being disturbed. Along with this, the ultrasonic image is deteriorated.

  The present invention has been made in view of the above problems, and an object thereof is to provide an ultrasonic probe capable of stable swing scanning.

In order to solve the above problems, the present invention proposes the following means.
The present invention provides an ultrasonic probe that is disposed at the tip of a probe and that emits ultrasonic waves while oscillating and rotating about a oscillating rotation axis, and a sheath that is disposed so as to cover the ultrasonic probe. An ultrasonic probe comprising: a first acoustic medium filled between the ultrasonic probe member and the sheath, wherein an outer shape of the ultrasonic probe member is directed to the oscillation rotation axis. It is set as the axis | shaft object shape used as an axis | shaft.
That is, in a forward-viewing small-diameter ultrasonic probe that performs ultrasonic oscillation scanning on a plane parallel to the long axis direction of the probe, the oscillation member has a substantially axial target shape with respect to the oscillation rotation axis. Yes.
According to the present invention, when the ultrasonic probe member is swung and rotated, turbulence is less likely to occur in the acoustic medium filled around the ultrasonic probe member. As a result, the ultrasonic probe becomes less susceptible to the resistance of the acoustic medium, so that stable oscillation scanning is possible.

Further, the ultrasonic probe member includes a cylindrical housing cap, an ultrasonic probe that is disposed inside the housing cap and emits ultrasonic waves from an acoustic radiation surface, and the ultrasonic probe. A housing disposed between an outer surface other than the sound emitting surface and the inner surface of the housing cap, and a second acoustic medium filled between the sound emitting surface of the ultrasonic probe and the inner surface of the housing cap And preferably.
That is, the member that performs the swinging operation stores the ultrasonic probe with a substantially cylindrical housing and a substantially cylindrical cap, and an acoustic medium is filled between the acoustic radiation surface of the cap and the ultrasonic probe. To do.
According to the present invention, the ultrasonic probe is mounted on the housing, the housing is inserted into the housing cap, and the second acoustic medium is filled between the acoustic radiation surface and the housing cap. Can be easily manufactured.

Moreover, it is preferable that one end portion of the actuator that expands and contracts in response to the electric signal is connected to a portion other than the oscillating rotation shaft in the ultrasonic probe member.
According to the present invention, the swinging and rotating mechanism of the ultrasonic probe can be easily constructed.

  According to the ultrasonic probe of the present invention, when the ultrasonic probe member is swung and rotated, turbulence hardly occurs in the acoustic medium filled around the ultrasonic probe member. As a result, the ultrasonic probe becomes less susceptible to the resistance of the acoustic medium, so that stable oscillation scanning is possible.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
(Ultrasonic observation system)
FIG. 1 shows a schematic configuration diagram of an ultrasonic observation system using the ultrasonic probe according to the present embodiment. The ultrasonic probe 1 is provided with an ultrasonic probe member to be described later at the tip of a flexible probe 1a. In the ultrasonic observation system 100, the ultrasonic probe 1 is connected to the ultrasonic observation device 4 via the relay connector 2 and the relay cable 3. The ultrasonic observation apparatus 4 is provided with an ultrasonic signal transmission / reception circuit and an actuator driving circuit. The ultrasonic signal transmitting / receiving circuit drives the transducer of the ultrasonic probe 1 to transmit and receive an ultrasonic beam, and analyzes information on the radiation direction of the ultrasonic beam. The actuator driving circuit scans an ultrasonic beam in a one-dimensional direction by swinging a vibrator by an actuator. The relay cable 3 connecting the ultrasonic probe 1 and the ultrasonic observation device 4 includes an ultrasonic signal wire and an actuator driving wire.

(Ultrasonic probe)
FIG. 2 is a structural diagram of the distal end portion (P portion in FIG. 1) of the ultrasonic probe according to the present embodiment. 2A is a plan view, FIG. 2B is a side view, and only the outer sheath 13 is taken in a cross section to show the internal structure. As shown in FIG. 2, the ultrasonic probe 5 in which the transducer is accommodated is rotated by two rotating supports 6 provided on a probe tip member (catheter tip member) 11 of the ultrasonic probe 1. The shaft member 7 is rotatably supported.
The ultrasound probe member 5 has a substantially axial structure with respect to the rotation axis, and shows a cylindrical shape as an embodiment. As shown in FIG. 5A, the outer shape of the ultrasonic probe 5 may be a shape 51 in which the central portion in the axial direction bulges outward, and the central portion in the axial direction is inward as shown in FIG. 5B. The shape 52 may be recessed. Moreover, as shown in FIG.5 (c), the shape 53 whose outer diameter is changing in steps along an axial direction may be sufficient.

  Returning to FIG. 2, at least one end of at least two rotation transmission lines (for example, wires) 8 is fixed to the outer peripheral surface of the ultrasonic probe 5. The rotation transmission line 8 (8a, 8b) is disposed along a groove formed on the outer peripheral surface of the ultrasonic probe 5. This groove is formed in the vicinity of the end of a cylinder that does not hide the acoustic radiation surface 5 a of the ultrasonic probe 5. The multiple ends of the first rotation transmission line 8a are fixed to the probe tip member 11 via a spring member (elastic body) 9, and the multiple ends of the second rotation transmission line 8b are shape memory alloy actuators (hereinafter referred to as actuators) 10. It is being fixed to the probe tip member 11 via. The spring member 9 and the actuator 10 are arranged inside a spring arrangement hole 34 and an actuator arrangement hole 35 provided in the probe tip member 11.

  An actuator driving wire 12 is connected to both ends of the actuator 10 so that a voltage for expanding and contracting the actuator can be supplied. The actuator driving wire 12 is extended to a terminal (not shown) connected to the relay connector 2 of the ultrasonic probe 1 through a signal conducting hole (not shown) provided in the probe tip member 11. . The actuator 10 has a shape memory so that the spring contracts when a voltage is applied to both ends of the actuator 10 and the temperature rises. When a voltage is applied to both ends of the actuator 10, the actuator 10 contracts and pulls the second rotation transmission line 8 b connected to the actuator 10. Thereby, rotational power acts on the ultrasonic probe 5 connected to the second rotation transmission line 8b. At this time, the spring member 9 provided on the other side is stretched. On the other hand, when the voltage application to both ends of the actuator 10 is stopped, the reverse rotation power acts on the ultrasonic probe member 5 by the restoring force of the spring member 9. As a result, the ultrasonic probe 5 can be swung.

A sheath 13 is provided so as to cover and seal the ultrasonic probe member 5. The sheath 13 is attached in the distal direction in contact with at least a part of the probe distal end member 11. A space between the ultrasonic probe 5 and the sheath 13 is filled with a first acoustic medium 14 such as physiological saline.
The ultrasonic signal wire 21 led out from the ultrasonic probe 5 is connected to the relay connector 2 of the ultrasonic probe 1 through a signal lead hole (not shown) provided in the probe tip member 11. It extends to a terminal (not shown).

In FIG. 2, the spring member 9 and the actuator 10 are disposed closer to the center of the probe tip member 11, but the rotation transmission line 8 (8 a, 8 b) is disposed parallel to the long axis of the ultrasonic probe 1. Alternatively, it may be provided near the inner surface of the sheath 13.
In this embodiment, the ultrasonic probe 5 can be swung and rotated using the actuator 10 and the spring member 9. However, the ultrasonic probe 5 can be swung and rotated using another mechanism such as a link mechanism. It may be possible.
Further, the distal end portion of the ultrasonic probe 1 may be bent and deformed freely by an operation from the proximal end portion of the ultrasonic probe 1.

The probe tip member 11 may be provided with a guide wire channel 32 and a feeding / suction channel 33.
Although the distal end shape of the sheath 13 is hemispherical, of course, it is not limited to this shape and may be substantially cylindrical.
Further, for the purpose of shortening the hard portion (portion where the probe tip member 11 is disposed) at the tip of the ultrasonic probe 1, the probe tip member is bent and folded using the pulley 101 as shown in FIG. 11 may be stored.

(Ultrasonic probe)
FIG. 4 shows the structure of the ultrasonic probe according to this embodiment. FIG. 4 is a side cross-sectional view taken along line AA in FIG. As shown in FIG. 4, an ultrasonic probe 22 including a transducer 16 is disposed inside the ultrasonic probe member 5. A matching layer 17 (for example, made of epoxy resin with filler) and an acoustic lens 18 (for example, made of epoxy resin) are provided on the front surface of the vibrator 16 (piezoelectric element), and a backing layer 19 (for example, made of ferrite rubber) is provided on the back surface. Housed in the inner housing 20. The ultrasonic signal wires 21 are soldered to the electrode layers (not shown) on the front and rear surfaces of the transducer 16 and are routed from the back surface of the inner housing 20 (the above are collectively referred to as an ultrasonic probe 22). .)

  The ultrasonic probe 22 is housed in a substantially cylindrical housing 23 except for the acoustic radiation surface 5a. The housing 23 is covered with a cylindrical housing cap 24 (for example, made of polyether block amide). A sealed space between the acoustic lens 18 and the housing cap 24 is filled with a second acoustic medium 31 (for example, physiological saline). The second acoustic medium 31 may be the same material as the first acoustic medium described above.

Here, after assembling the ultrasonic probe 22 using the inner housing 20 and placing it in the housing 23, the objective of facilitating the manufacture of the ultrasonic probe 22 is provided. The ultrasonic probe 22 may be assembled directly in the housing 23. The housing cap 24 may have a shape obtained by cutting out a part of a cylinder. In this case, the housing cap 24 is bonded and fixed to the housing 23. The housing cap 24 may be opened at a portion corresponding to the acoustic radiation surface 5a of the ultrasonic probe 22.
When the diameter of the ultrasonic probe 1 is small and a sufficient diameter of the transducer 16 cannot be secured, the acoustic lens 18 may not be provided and only the matching layer 17 may be provided, or a plurality of matching layers 17 may be provided.

(Function)
Next, the operation of this embodiment will be described.
First, the ultrasonic probe 1 shown in FIG. 1 is inserted into the body from the tip. Next, by operating the ultrasonic observation apparatus 4, an AC voltage is applied to the vibrator 16 via the ultrasonic signal wire shown in FIG. Thereby, the vibrator 16 vibrates and ultrasonic waves are emitted from the acoustic radiation surface 5a. When the reflected wave from the body reaches the vibrator 16, a voltage proportional to the sound pressure of the reflected wave is generated in the vibrator 16. By inputting this voltage into the ultrasonic observation apparatus 4 shown in FIG. 1, information in the body can be analyzed.

  At the same time, a voltage is applied to the actuator 10 via the actuator wire shown in FIG. The actuator 10 is made of a shape memory alloy and stores a contracted shape. When a voltage is applied to the actuator 10, the temperature of the actuator 10 rises, a restoring force to the memory shape acts, and the actuator 10 contracts and deforms. Thereby, the second rotation transmission line 8b connected to the actuator 10 is pulled, and a positive direction torque acts on the ultrasonic probe 5 connected to the second rotation transmission line 8b. A first rotation transmission line 8 a is connected to the ultrasonic probe member 5, and the first rotation transmission line 8 a is drawn to the opposite side of the second rotation transmission line 8 b in the circumferential direction of the ultrasonic probe member 5. Therefore, the first rotation transmission line 8a is pulled by the positive direction torque acting on the ultrasonic probe member 5, and the spring member 9 connected to the first rotation transmission line 8a is extended and deformed. As a result, the ultrasonic probe 5 rotates in the positive direction.

Next, the voltage application to the actuator 10 is stopped. As a result, the restoring force of the actuator 10 to the memorized shape is eliminated and the actuator 10 expands and deforms, while the spring member 9 contracts and deforms. As a result, negative direction torque acts on the ultrasonic probe member 5 and the ultrasonic probe member 5 rotates in the negative direction.
Thus, by repeating the voltage application and stop to the actuator 10 in a pulse shape, the ultrasonic probe 5 can be swung and rotated in the circumferential direction. Thereby, an ultrasonic image can be generated by scanning an ultrasonic wave.

  Here, the ultrasound probe member 5 of the present embodiment has an axial target shape with the swing rotation axis as the target axis. Therefore, when the ultrasonic probe 5 is swung in the circumferential direction, turbulence is less likely to occur in the first acoustic medium 14 filled around the ultrasonic probe 5. As a result, the ultrasonic probe 5 is less susceptible to the resistance of the acoustic medium during the rocking rotation, so that stable rocking scanning is possible and the ultrasonic image can be stabilized.

  It should be noted that the technical scope of the present invention is not limited to the above-described embodiments, and includes those in which various modifications are made to the above-described embodiments without departing from the spirit of the present invention. In other words, the specific materials and layer configurations described in the embodiments are merely examples, and can be changed as appropriate.

It is a schematic block diagram of the ultrasonic observation system using the ultrasonic probe which concerns on this embodiment. (A) is a top view of the front-end | tip part (P part of FIG. 1) of the ultrasonic probe which concerns on this embodiment, (b) is a side view. It is a modification of an actuator. It is side surface sectional drawing of the ultrasonic probe member in the AA line of Fig.2 (a). It is a modification of an ultrasonic probe member.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Ultrasonic probe 1a ... Probe 5 ... Ultrasonic probe member 7 ... Rotary shaft member (oscillation rotary shaft) 10 ... Actuator 13 ... Sheath 14 ... First acoustic medium 22 ... Ultrasonic probe 23 ... Housing 24 ... Housing cap 31 ... second acoustic medium

Claims (3)

An ultrasonic probe that is arranged at the tip of the probe and emits ultrasonic waves while oscillating and rotating about an oscillation rotation axis; a sheath arranged to cover the ultrasonic probe; and the ultrasonic wave An ultrasonic probe comprising: a first acoustic medium filled between a probe member and the sheath;
2. The ultrasonic probe according to claim 1, wherein an outer shape of the ultrasonic probe is an axial object shape having the swing rotation axis as an object axis. The ultrasonic probe is
A cylindrical housing cap;
An ultrasonic probe disposed inside the housing cap and emitting ultrasonic waves from an acoustic emission surface;
A housing disposed between an outer surface of the ultrasonic probe other than the acoustic radiation surface and an inner surface of the housing cap;
A second acoustic medium filled between the acoustic radiation surface of the ultrasonic probe and the inner surface of the housing cap;
The ultrasonic probe according to claim 1, comprising:   The one end part of the actuator which expands and contracts according to an electric signal is connected to parts other than the said rocking | fluctuation rotating shaft in the said ultrasonic probe member, The Claim 1 or Claim 2 characterized by the above-mentioned. Ultrasonic probe.

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