JP2001327500A - Ultrasonic probe - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ultrasonic probe subjected to revolution control smoothly and accurately, capable of being easily enhanced in user's convenience, capable of being miniaturized, capable of certainly preventing the leak of a liquid acoustic matching material and having a simple structure. SOLUTION: A vibrator array part 14 directly fixed to a motor 22 is arranged in a hermetically closed vibrator case 32 and the periphery thereof is filled with oil 36 being the acoustic matching material. An expansion and contraction absorbing part for absorbing the volumetric change of the acoustic matching material is arranged along the axial direction of an insertion part 108 having the vibrator case 32 provided to the leading end thereof.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic probe, and more particularly to an improvement of a small ultrasonic probe for insertion into a body cavity.

[0002]

2. Description of the Related Art Conventionally, by emitting ultrasonic waves into a living body and receiving ultrasonic waves reflected from the living body,
2. Description of the Related Art An ultrasonic diagnostic apparatus that acquires image information to form and observe an ultrasonic image of a living body has been widely used. An ultrasonic probe including an ultrasonic transducer for actually transmitting and receiving ultrasonic waves is connected to the ultrasonic diagnostic apparatus, and the ultrasonic probe has various shapes and shapes depending on a part to be diagnosed. , And the size is appropriately used. For example, the ultrasonic probe 100 shown in FIG. 2 is a transesophageal probe, and is a probe for orally obtaining an ultrasonic image of a heart or the like from an esophageal wall. FIG. 2 shows a transducer array section 1 in which a plurality of ultrasonic transducers are arranged at a distal end section 102 inserted into a body cavity.
04 is viewed from the ultrasonic transmitting / receiving surface side. The distal end portion 102 is connected to the operation section 106 via an insertion portion 108 which is an insertion shaft for inserting the distal end portion 102 into a body cavity, and the position and the direction of the distal end portion 102 are operated from outside the body cavity. A signal line for transmitting / receiving ultrasonic waves to / from the ultrasonic vibrator, a wire for mechanically driving the vibrator array unit 104, and the like are inserted into the insertion unit. Further, the insertion portion 108 is flexible and can be bent along a body cavity such as an esophagus to be inserted, while reducing the physical and mental discomfort of the subject when inserting the distal end portion 102,
The distal end portion 102 can easily reach a target diagnostic position. For example, the insertion section 108 is operated by the dials 106 a and 106 b of the operation section 106 so that the distal end 10 can be inserted.
2 can be bent up and down and left and right.
4 can be directed at an appropriate position and in an appropriate direction.

As described above, a wire for mechanically scanning the vibrator array portion 104 of the distal end portion 102 is inserted into the insertion portion 108. One end of this wire is wound around a rotatable holder (for example, a pulley-shaped holder) that supports the vibrator array unit 104 on the tip end 102 side, and the other end is a drive wheel (for example, a pulley) provided on the operation unit 106. Shape). Then, by rotating the drive wheels manually or by a motor or the like, the transducer array unit 104 is rotated at a desired angle to rotate the ultrasonic scanning surface. As a result, it is possible to obtain a three-dimensional ultrasonic image. Note that the tip portion 102 has a substantially dome shape having an ultrasonic transmission portion, and the transducer array portion 104
Is disposed inside the sealed distal end portion 102, and transmits and receives ultrasonic waves to and from the living body through the ultrasonic transmission portion.
By arranging the transducer array section 104 inside the sealed distal end section 102, it is possible to prevent the transducer array section 104 from being damaged and to facilitate cleaning of the ultrasonic probe 100 after use. As described above, when the vibrator array unit 104 is disposed inside the distal end portion 102, the vibrator array unit 104
If there is an air layer between the ultrasonic transmission / reception surface and the inner wall surface of the distal end portion 102, the ultrasonic waves will be significantly attenuated. Therefore, the inside of the distal end portion 102 is filled with a liquid acoustic matching material (for example, oil) so that an air layer is not formed.

[0004]

However, in the conventional vibrator array unit 104, when rotating as described above, the rotating force generated at a position distant from the vibrator array unit 104 is transmitted through a wire or the like. This is performed by transmitting to the transducer array unit 104. When the vibrator array unit 104 is rotated by a wire, the wire needs to be pushed and pulled while a predetermined tension is applied to the wire. At this time, the wire elongates. If the wire is stretched, an error occurs between the amount of rotation recognized on the driving wheel side and the actual amount of rotation of the vibrator array unit 104, and accurate rotation control of the vibrator array unit 104 cannot be performed. Occurs. As a result, the quality of the formed three-dimensional ultrasonic image is reduced. In addition, the insertion portion 10
There is a limit in improving the flexibility and reducing the thickness of the ultrasonic probe 8, and there is a problem in that the usability of the ultrasonic probe 100 and the miniaturization are hindered.

Also, as described above, the vibrator array section 10
When a drive mechanism using a wire or the like is used for rotation of 4, it is necessary to sufficiently seal the sliding portion of the wire or the like so that the liquid acoustic matching material filled inside the distal end portion 102 does not leak. . However, it is known that the ultrasonic vibrator generates heat when driven, and the acoustic matching material expands so that the tip 10
2, there is a problem that the liquid acoustic matching material may leak even if the internal pressure is increased and the seal is applied.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described conventional problems, and has as its object to smoothly and accurately control the rotation of an ultrasonic probe and to easily improve usability and miniaturization. It is another object of the present invention to provide an ultrasonic probe having a simple structure capable of reliably preventing leakage of a liquid acoustic matching material.

[0007]

In order to achieve the above object, a vibrator case which can be inserted into a body cavity, and an ultrasonic wave which is rotatably arranged inside a distal end of the vibrator case and is provided within the body cavity. And a motor that is disposed inside the tip of the vibrator case and rotationally drives the ultrasonic vibrator.

According to this configuration, the motor for directly rotating the ultrasonic vibrator is accommodated in the vibrator case in which the ultrasonic vibrator is disposed, so that the ultrasonic vibrator can be accurately rotated. . Also, at this time, only the signal lines that can be fixedly arranged are drawn out from the vibrator case without sliding, etc., so that the inside of the vibrator case and the outside thereof can be easily and reliably sealed. In addition, the sealing property of the vibrator case can be improved.

[0009] In order to achieve the above object, a vibrator case insertable into a body cavity, an ultrasonic vibrator disposed inside the distal end of the vibrator case and transmitting and receiving ultrasonic waves in the body cavity, A liquid acoustic matching material filled at least around the ultrasonic vibrator in the vibrator case, and a swelling / absorbing portion that is formed in communication with an injection space of the acoustic matching material and absorbs a volume change of the acoustic matching material, It is characterized by including.

According to this structure, even if the liquid acoustic matching material expands due to the heat generated by driving the ultrasonic vibrator, it is possible to avoid an increase in the pressure inside the vibrator case. Leakage can be reliably prevented.

In order to achieve the above object, a vibrator case insertable into a body cavity, and an ultrasonic wave rotatably disposed inside the distal end of the vibrator case for transmitting and receiving ultrasonic waves within the body cavity A vibrator, a motor disposed inside the tip of the vibrator case and rotationally driving the ultrasonic vibrator, and a liquid acoustic matching material filled at least around the ultrasonic vibrator in the vibrator case. And a swelling / absorbing portion which is formed in communication with the injection space of the acoustic matching material and absorbs a volume change of the acoustic matching material.

According to this configuration, the accurate rotation of the ultrasonic vibrator becomes possible as described above. In addition, by disposing the motor in the vibrator case, heat is generated by driving the motor.However, the expansion / contraction absorbing portion can sufficiently absorb the expansion of the liquid acoustic matching material due to the generated heat. Sufficient and reliable sealing of the vibrator case can be ensured.

[0013] In order to achieve the above object, in the above structure, the expansion / contraction absorbing portion is housed along the axial direction of an insertion shaft provided with the vibrator case at the tip. I do.

The insertion shaft has an elongated shape for inserting the vibrator case into a desired position in the body cavity. By arranging the expansion / contraction absorbing portion in the internal space, even if the expansion amount of the acoustic matching material is large, the expansion can be easily absorbed without preparing a special space.

[0015] In order to achieve the above object, in the above structure, the expansion / contraction absorbing portion is formed of a telescopic body whose volume can be changed.

Here, the elastic body is a flexible tube or the like having a movable portion that can expand and contract while maintaining a seal while being able to expand in any direction. According to this configuration,
Expansion and contraction can be easily absorbed while maintaining the internal pressure of the vibrator case at a predetermined value.

In order to achieve the above object, the above structure is characterized in that the expansion / contraction absorbing portion changes in volume in the axial direction of the insertion shaft.

According to this configuration, even when the expansion amount of the acoustic matching material is large, it can be sufficiently expanded in the insertion axis direction, so that the expansion of the acoustic matching material can be easily absorbed.

In order to achieve the above object, the above structure is characterized in that the expansion / contraction absorbing portion has a bellows shape.

According to this configuration, the volume of the insertion shaft in the axial direction can be changed with a simple configuration.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings. Since the outer shape of the ultrasonic probe of the present embodiment is substantially the same as the conventional ultrasonic probe 100 shown in FIG. 2, the description of the outer shape and the like will be made with reference to FIG. Detailed description is omitted.

FIG. 1A is a schematic sectional view of the internal structure of a distal end portion 12 (corresponding to the distal end portion 102 in FIG. 2) of the ultrasonic probe 10 of the present embodiment, and shows a plurality of ultrasonic vibrations. FIG. 4 is a longitudinal sectional view illustrating a structure along a plane perpendicular to an ultrasonic transmitting / receiving surface 14a of a transducer array unit 14 in which transducers (piezoelectric transducers) are arranged. FIG. 1B is a cross-sectional view. In the ultrasonic probe 10 shown in FIG. 1, the vibrator array unit 14 rotates around a rotation axis (not shown) extending in the vertical direction on the paper surface, and the three-dimensional ultrasonic probe is rotated. It forms a sound wave image.

The ultrasonic transmitting / receiving surface 1 of the transducer array section 14
A silicon lens 16 that functions as an acoustic lens or the like serving as an acoustic matching layer is bonded to the front surface of 4a. The silicon lens 16 is fixed to one surface of a cylindrical vibrator holder 18 having a hollow portion 18a therein. Specifically, a concave portion 18b formed on one surface side of the vibrator holder 18
Silicon lens 16 is fixed so as to cover. As a result, the vibrator array section 14 is fixedly arranged in the space formed by the concave portion 18b and the silicon lens 16.
As shown in FIG. 1B, a signal line 20a connected to each of the ultrasonic vibrators constituting the vibrator array unit 14 is connected to the other side of the vibrator holder 18 through a cavity 18a. That is, it is pulled out and bundled on the opposite side of the ultrasonic transmission / reception surface 14a, and is guided as a signal cable 20 to the ultrasonic diagnostic apparatus via the insertion unit 108 and the operation unit 106 in FIG.

The characteristic feature of the present embodiment is that the transducer array 14, specifically, a motor 22 for rotating the transducer holder 18 supporting the transducer array 14 is disposed inside the tip 12. Is being done. In the case of the present embodiment, the motor 22 has a ring-shaped rotor, and the rotor is fixed to the outer peripheral surface of the hollow portion 18 a of the vibrator holder 18. The motor 22 is fixed at a predetermined position in the vibrator holder 18 by a fixed stand 24 fixed inside the vibrator holder 18. A signal line 22 a for controlling the driving of the motor 22 is provided from the distal end portion 12 to the insertion section 108 and the operation section 1 similarly to the signal cable 20.
The motor 22 is guided to the ultrasonic diagnostic apparatus side through 06 to perform desired rotational drive control. further,
A bearing 26 is disposed on the fixed stand 24, and supports the vibrator holder 18 rotatably.
Therefore, the vibrator holder 18 is driven based on the driving of the motor 22.
Can be smoothly and accurately rotated, and a high-quality three-dimensional ultrasonic image can be obtained by rotation of the ultrasonic transmitting / receiving surface 14a of the vibrator array unit 14.

Further, at predetermined positions on the outer peripheral portion of the vibrator holder 18, detection chips for detecting the rotation angle of the vibrator holder 18, specifically, permanent magnets 28 are arranged at a plurality of positions. (In FIG. 1, the permanent magnets 28 whose pole phases are shifted are arranged in two stages, for example, every 30 °). On the other hand, a magnetic resistance sensor 30 for detecting the position of the permanent magnet 28 is fixed to a fixed stand 24 fixing the motor 22 and the like via a stand 30a.
The magnetoresistive sensor 30 recognizes the rotation angle of the vibrator holder 18 based on a magnetic change by the permanent magnet 28 and, like the signal cable 20, inserts the operation unit 106 and the operation unit 106.
The information of the rotation angle is sent to the ultrasonic diagnostic apparatus side via. The ultrasonic diagnostic apparatus synthesizes an ultrasonic image based on an ultrasonic echo signal provided by the signal cable 20 and an angle signal provided from the magnetoresistive sensor 30 to form a three-dimensional ultrasonic image. I do. Although FIG. 1 shows an example in which the rotation of the vibrator holder 18 is detected, the rotation angle of the rotor portion of the motor 22 may be detected.

The above-described rotary drive mechanism including the transducer array unit 14 and the motor 22 of the ultrasonic probe 10 configured as described above facilitates failure prevention and cleaning after use of the ultrasonic probe 10. In view of the above, the dome-shaped vibrator case 32 is covered in a hermetically sealed state. Transducer case 32
Is a vibrator array unit 1 arranged downward in FIG.
4 has an ultrasonic transmission section 34 that can transmit ultrasonic waves emitted from the transducer array section 14 on a surface facing the ultrasonic transmission / reception surface 14a (silicon lens 16). In the case of FIG. 1A, the whole of the vibrator case 32 is made of an ultrasonic-permeable material, for example, a resin, and the members are integrated, the number of parts is reduced,
Improves sealing performance. The ultrasonic transmission unit 3
Numeral 4 is made of, for example, a film having a thickness of about 0.5 mm, and enables excellent transmission and reception of ultrasonic waves while completely shielding the movable part including the transducer array unit 14 from the outside. In FIG. 1A, the vibrator case 32 is a single dome-shaped component. However, if the hermetically sealed state of the vibrator case 32 can be maintained, the vibrator case 32 may be composed of a plurality of divided components.

As described above, the ultrasonic vibrator provided in the vibrator array unit 14 is excited by a drive pulse transmitted from the operation unit 106 via the signal cable 20 to generate an ultrasonic wave. The light is radiated to the site to be examined in the living body via the sound wave transmitting unit 34. The echo from the test site reaches the ultrasonic vibrator via the ultrasonic transmitting unit 34 and is received and converted into an electric signal. The electric signal is transmitted to the operation unit 106 via the signal cable 20. You. In this way, the ultrasound probe 10 generates a signal for obtaining an ultrasound image of the test site. Here, the silicon lens 16 rotates together with the transducer array unit 14. That is, since the silicon lens 16 rotates relative to the ultrasonic transmission portion 34, they cannot be fixed to each other. On the other hand, as described above, transmission and reception of ultrasonic waves between the silicon lens 16 and the ultrasonic transmission unit 34 are required in order to transmit and receive ultrasonic waves between the ultrasonic transducer and the test site satisfactorily. Needs to be reduced. Therefore, the minute gap between the silicon lens 16 and the ultrasonic transmission part 34 is filled with oil 36 as an acoustic matching material. The oil 36 may be selected to have a low viscosity that can reduce the above-described acoustic loss at this boundary and does not cause resistance to the rotation of the vibrator array unit 14 including the silicon lens 16. preferable. In the case of the present embodiment, the entire interior of the distal end portion 12 including the motor 22 is filled with the oil 36.

As shown in this embodiment, the tip 1
By disposing the motor 22 inside the second vibrator case 32, the vibrator array unit 14 can be rotated without forming a sliding portion or the like with respect to the sealed vibrator case 32 outside. Therefore, the sealing property of the vibrator case 32 can be easily improved. In other words, only the signal lines of the transducer array section 14, the motor 22, the magnetic resistance sensor and the like are drawn out of the transducer case 32, and these signal lines can be easily tightly sealed with resin or the like. is there. Therefore, leakage to the liquid acoustic matching material can be reliably prevented. Further, since it is not necessary to insert a driving wire or the like for rotating the ultrasonic vibrator into the inside of the insertion portion 108 as in the related art, it is possible to improve the flexibility of the insertion portion 108 and easily reduce the diameter. It is possible to improve the usability and downsize easily.

Incidentally, it is known that the ultrasonic vibrator constituting the vibrator array section 14 generates heat when driven.
When the ultrasonic vibrator generates heat, the oil 36 as the acoustic matching material filled in the vibrator case 32 expands. As described above, by arranging the motor 22 inside the vibrator case 32, mechanical sealing can be improved. However, the internal pressure of the vibrator case 32 increases due to the expansion of the oil 36, and the liquid Leakage of the acoustic matching material may be caused.

In the present embodiment, in order to absorb the expansion of the oil 36, which is an acoustic matching material, a bellows-shaped expansion / contraction absorbing portion 38 which is formed in communication with the oil injection space and absorbs the volume change of the oil 36 is provided. Have. The expansion / contraction absorbing portion 38 has a vibrator case 32 at the tip, and is arranged along the axial direction of an insertion portion 108 which is an insertion shaft for inserting the vibrator case 32 to a desired position in a body cavity. Specifically, as shown in FIG. 1A, the insertion portion 10 is inserted from the rear end of the vibrator case 32.
8 extends towards the inside of the hollow shaft. Here, as described above, by disposing the motor 22 inside the vibrator case 32, there is no need to dispose the rotating wire of the vibrator array unit 14 inside the insertion portion 108 as in the related art.
A space corresponding to the space can be formed, and the expansion / contraction absorbing portion 38 can be easily arranged. In the case of the present embodiment, the expansion / contraction absorbing section 38
Has a bellows shape that can be extended and contracted in the axial direction.
Even if the expansion of 6 is large, the expansion can be released to the space in the axial direction, so that a good expansion / contraction absorption effect can be obtained without preparing a special space inside the vibrator case 32. Since the signal cable 20 is also inserted into the insertion section 108, the expansion / contraction absorption section 38 is
It is preferable to be arranged at a position eccentric from the center of 8.

Further, as shown in FIG. 1, when the motor 22 is disposed inside the vibrator case 32,
Generates heat from the motor 22 as well. As a result, the expansion amount of the oil 36 increases as compared with the case where the motor 22 is not arranged.
Even when the amount of expansion of the oil 36 increases, the expansion can be satisfactorily absorbed by the expansion / contraction absorbing portion 38.

In the present embodiment, the case where the expansion / contraction absorbing portion 38 is formed in a bellows shape is shown. However, any structure capable of absorbing the expansion / contraction of the liquid acoustic matching material can be used. The same effects as those of the present embodiment can also be obtained by a variable body having a movable portion that can be extended and contracted while maintaining a tube having a property and a seal, for example, a piston-shaped one configured by a slidable double tube. .

[0033]

According to the present invention, since the motor for directly rotating the ultrasonic vibrator is housed in the vibrator case in which the ultrasonic vibrator is arranged, the ultrasonic vibrator can be accurately rotated. can do. Also, at this time, only the signal lines that can be fixedly arranged without being slid are drawn out of the vibrator case, so that the inside of the vibrator case and the outside thereof can be easily and reliably sealed. Thus, the sealing property of the vibrator case can be improved.

When the inside of the vibrator case is filled with a liquid acoustic matching material, the expansion / contraction absorbing portion is formed so as to communicate with the injection space of the acoustic matching material and absorbs a change in volume of the acoustic matching material. Even if the liquid acoustic material expands due to the heat generated by the driving of the ultrasonic vibrator, the expanded portion is absorbed by the expansion / contraction absorber, so that a pressure increase in the vibrator case can be avoided. As a result, liquid leakage of the liquid acoustic matching material can be reliably prevented.

Further, when a motor for rotating the ultrasonic vibrator together with the liquid acoustic matching material is provided in the vibrator case,
Even if the expansion amount of the acoustic matching material due to the heat generated by the motor increases, the expansion and contraction absorbing portion can sufficiently absorb the expansion, and the liquid acoustic matching material can be reliably prevented from leaking.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating a structure of a distal end portion of an ultrasonic probe according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram illustrating an overall configuration of an ultrasonic probe according to an embodiment of the present invention.

[Explanation of symbols]

10 ultrasonic probe, 12 tip part, 14 transducer array part, 14a ultrasonic transmitting / receiving surface, 16 silicon lens,
18 vibrator holder, 18a cavity, 18b recess, 2
0 signal cable, 20a signal line, 22 motor, 2
4 fixed stand, 26 bearing, 28 permanent magnet, 30 magnetoresistive sensor, 32 vibrator case, 34
Ultrasonic transmission part, 36 oil (acoustic matching material), 38 expansion and contraction absorption part.

Claims (7)

[Claims] A vibrator case that can be inserted into a body cavity; an ultrasonic vibrator that is rotatably disposed inside a distal end of the vibrator case and that transmits and receives ultrasonic waves within the body cavity; A motor disposed inside the distal end for driving the ultrasonic vibrator to rotate, the ultrasonic probe comprising: 2. A vibrator case insertable into a body cavity, an ultrasonic vibrator disposed inside a tip of the vibrator case for transmitting and receiving ultrasonic waves in the body cavity, and at least the ultrasonic wave in the vibrator case An ultrasonic wave, comprising: a liquid acoustic matching material filled around a vibrator; and a swelling / absorbing portion formed in communication with an injection space of the acoustic matching material and absorbing a volume change of the acoustic matching material. Probe. A vibrator case that can be inserted into a body cavity; an ultrasonic vibrator that is rotatably disposed inside a distal end of the vibrator case and transmits and receives ultrasonic waves within the body cavity; A motor disposed inside the tip to rotationally drive the ultrasonic vibrator; a liquid acoustic matching material filled at least around the ultrasonic vibrator in the vibrator case; and a filling space for the acoustic matching material. And an expansion / contraction absorber formed in communication with the acoustic matching material to absorb a change in volume of the acoustic matching material. 4. The ultrasonic probe according to claim 2, wherein the expansion / contraction absorbing section is accommodated along an axial direction of an insertion shaft provided with the vibrator case at a distal end. An ultrasonic probe characterized by the following. 5. The ultrasonic probe according to claim 2, wherein the expansion / contraction absorber is formed of a telescopic body having a variable volume. Probe. 6. The ultrasonic probe according to claim 5, wherein the expansion / contraction absorbing portion changes in volume in an axial direction of the insertion axis. 7. The ultrasonic probe according to claim 6, wherein the expansion / contraction absorber has a bellows shape.