JPH042335A - Ultrasonic probe - Google Patents

Abstract

PURPOSE:To improve endurance in disinfection or the like with a higher durability of an acoustic lens exposed outside by forming a ceramic coated layer covering a surface portion of the acoustic lens exposed outside with a thickness less than a specified ratio of a wavelength of an ultrasonic wave. CONSTITUTION:An external surface of an ultrasonic probe 14 is covered with a ceramic coated layer 50. The thickness of the ceramic coated layer 14 is made less, preferably to check attenuation of ultrasonic waves. When the wavelength of the ultrasonic wave is represented by lambda, the thickness is preferably below (1/4)lambda-(1/8)lambda. If possible, it should be (1/8)lambda or less. For example, when 7.5MHz is given, lambda is 533mum and when 10MHz, lambda is 400mum. The ceramic coated layer 50 can secure anti-corrosiveness sufficiently even with the thickness thereof being several mum, about 5mum, for instance.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to an ultrasonic probe for performing observation diagnosis using ultrasonic waves.

[Prior Art] In recent years, endoscopes have been known in which an ultrasonic probe for observing and diagnosing parts of a living body using ultrasonic waves is incorporated into an endoscope (for example, Japanese Patent Laid-Open No. 60-227740). (see official bulletin). Generally, this type of ultrasonic probe has a structure in which electrodes are attached to both sides of a piezoelectric element. Then, by applying an electric signal between the electrodes, the piezoelectric element generates ultrasonic waves, and the ultrasonic waves are radiated into the test medium. Furthermore, the piezoelectric element is capable of receiving ultrasonic waves reflected from a medium, generating electric signals between electrodes, and extracting the electric signals.

Incidentally, an acoustic lens having ultrasonic matching characteristics is disposed on the front surface electrode of the piezoelectric element, and the acoustic lens focuses ultrasonic waves.

Further, an ultrasonic damper layer made of a synthetic resin mixed with a conductive substance is disposed on the electrode on the back side of the piezoelectric element to absorb ultrasonic waves generated on the back side of the piezoelectric element. The piezoelectric element, acoustic lens, and ultrasonic damper layer are housed in a housing with an insulating member interposed therebetween.

[Problems to be Solved by the Invention] Incidentally, the piezoelectric element, the acoustic lens, and the ultrasonic damper layer are attached to the housing via an insulating member.

At least the outer surface of the acoustic lens must be exposed to the outside.

However, when this type of ultrasonic probe is sterilized with ethylene oxide gas, the ethylene oxide gas or chlorofluorocarbon gas may come into contact with the exposed acoustic lens or the outer exposed surface of the ultrasonic damper layer. Deteriorates the resin material, adhesive, etc. of the sound wave damper layer. For this reason, the outer exposed surface portions of the acoustic lens, the ultrasonic damper layer, etc. gradually become so-called tattered and cannot be used normally.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide an ultrasonic probe with improved durability during disinfection, etc. by increasing the durability of at least the acoustic lens exposed to the outside. It is in.

[Means and effects for solving the problems] In order to solve the above problems, the present invention provides an ultrasonic probe in which an acoustic lens is disposed on the surface side of an ultrasonic transducer.
A ceramic coat layer is installed to cover at least the surface portion of the acoustic lens exposed to the outside.The thickness of the ceramic coat layer is (1/4) when the wavelength of the ultrasonic wave is λ.
) It is formed to a thickness of λ or less. Therefore, during disinfection and the like, the ceramic coating layer prevents the acoustic lens from deteriorating and improves its durability.

[Embodiment] FIGS. 1 to 7 show a first embodiment of the present invention. The first embodiment relates to an ultrasonic endoscope A in which an ultrasonic probe is incorporated into the endoscope.

As shown in FIG. 2, this ultrasonic endoscope A includes an operating section 1, and an auxiliary operating section 2 is attached to this operating section 1. A long insertion section 3 is connected to the sub-operation section 2 . The insertion section 3 is inserted into the distal end of the flexible tube section 4 through the bending section 5 and the distal end forming section 6.
will be established. The bending portion 5 is configured to be freely curved as described later, and the bending portion 5 is forcibly bent by remote operation using an operation knob 7 provided on the operation portion 1.

A motor 9 serving as a drive source is housed in a case 8 of the sub-operation section 2 . The rotation of this motor 9 is transmitted to an output shaft 11 via a speed reduction mechanism 10 consisting of a pair of gears. This output shaft 11 is arranged coaxially with the insertion section 3. A rotation detection section 12 is provided at one end of the output shaft 11. The other end of the output shaft 11 is the insertion part 3
The flexible shaft 13 is connected to the flexible shaft 13, which is inserted through the flexible shaft 13.

The flexible shaft 13 is made of a tightly wound coil or the like and is bendable. An ultrasonic probe 14, which will be described later, is connected to the tip of the flexible shaft 13. This ultrasonic probe 14 is installed in a scanning chamber 15 of the tip component 6 containing a liquid that acts as an ultrasonic transmission medium. Further, the flexible shaft 13 is inserted into a guide tube 16.

This guide tube 16 is connected to the first tube 17 on the proximal side.
and a second tube 18 on the distal side are connected by a connecting tube 19, and the base end of the first tube 170 is connected to the base end of the flexible shaft 13 inside the case 8 of the sub-operation section 2. It is installed in a liquid-tight manner. Also, the second tube 1
The tip of the tip 8 communicates with a passage 20 inside the tip component 6, which will be described later. Then, the liquid ultrasonic medium 2 extends from the scanning chamber] 5 through the passage 20 to the kite tube 16.
Or filled. The tip of the flexible shaft 13 is the ultrasonic probe 1
4, and the rotational force from the drive source is transmitted to the ultrasonic probe 14 via the flexible shaft 13 to rotate the ultrasonic probe 4.

The first tube 17 is made of a relatively hard synthetic resin such as Teflon, and the second tube 18 is made of a highly elastic and flexible synthetic resin such as polyurethane that is resistant to oil, water, and abrasion. Molded. That is, the second tube 18 of the guide tube 16 is located within the curved portion 5. Furthermore, since the guide tube 16 is filled with the ultrasonic medium 21, this acts as a lubricant. Further, a helical tube 22 formed by spirally bending a band-shaped metal plate is fitted onto the outer periphery of the portion of the second tube 18 located within the curved portion 5.

As shown in FIGS. 5 and 6, the curved portion 5 is constructed by arranging a large number of tubular bodies 23 in the axial direction and rotatably connecting adjacent tubular bodies 23 to each other. A pair of tubular wire receivers 24 are provided on the inner peripheral surface of each tube body 23 in correspondence with each other in the circumferential direction, and an operating wire 25 is inserted through these wire receivers 24. These operating wires 2
The tip of 5 is fixed to the tube body 23 at the most distal end. Also,
The base ends of these operating wires 25 are guided to the operating section 1 and connected to the bending operating mechanism. Here, by operating the bending operation mechanism using the operation knob 7, each bending operation wire 25 is pushed or pulled, and the bending portion 5 is bent in the direction of the pull, as shown in FIG. 7, for example. .

Note that a signal cable 26 is inserted into the flexible shaft 13 as shown in FIG.

The ultrasonic probe 14 is constructed as shown in FIG. That is, a first ultrasonic transducer section 31 and a second ultrasonic transducer section 32 are incorporated into both ends of a cylindrical housing 30 made of a conductive material. Each ultrasonic transducer section 31, 32 is a piezoelectric element 3 made of a piezoelectric material such as PZT.
3, a front electrode 35 is provided on the surface of the piezoelectric element 33, and a back electrode 36 is provided on the back surface of the piezoelectric element 33. That is, the piezoelectric element 33 of each ultrasonic transducer section 31, 32 is sandwiched between the front electrode 35 and the back electrode 36. Then, by applying an electric signal between the piezoelectric elements 33 through the electrodes 35 and 36, the piezoelectric elements 33 are excited to cause ultrasonic vibrations.

Further, on the surface of the surface electrode 35 of each piezoelectric element 33, a lens layer 37 as an acoustic lens having an acoustic matching function is provided. This lens layer 37 is designed to focus the ultrasonic waves emitted from the ultrasonic transducer section 3132. As the material of the lens layer 37, for example, epoxy resin is used.

A damper layer 38 is filled in a portion between each of the ultrasonic transducer portions 31 and 32. This damper layer 38 is formed by mixing a conductive substance such as tungsten powder into an epoxy-based synthetic resin, for example.

The piezoelectric element 33, lens layer 37, and damper layer 38
is accommodated in the housing 30 via a cylindrical insulating member 39. Further, the nousing 30, the damper layer 38, and the insulating member 39 are each divided into two at the middle portion, and are integrated into one piece through another insulating layer 40 having approximately the same acoustic impedance as the damper layer 38. is joined to.

In addition, the surface electrode 3 in each ultrasonic transducer part 31, 32
5, the outer conductors 44.4 of separate signal cables 4243 are connected through separate lead wires 41 and housing 30.
5. Further, each back electrode 36 is connected to an internal conductor 48.49 of a signal cable 42.43 via a lead wire 4647, respectively.

Furthermore, as shown in FIG. 1, the outer surface of the ultrasonic probe 14 is coated with a ceramic coating layer 50. The thickness of this ceramic coat layer 50 is preferably thin in order to suppress attenuation of ultrasonic waves.

When the wavelength of ultrasound is λ, (1/4)λ~(1/8
) It is desirable to form it with a thickness of λ or less. If possible,(
1/4) λ or less. For example, when 7.5H2, λ is 533 μm, and when 1OH2, λ is 40 μm.
It is 0 μm. Note that even if the ceramic coat layer 50 has a thickness of several μm, for example, about 5 μm, sufficient corrosion resistance can be ensured.

The ceramic material of this ceramic coat layer 50 is AI 03 BN and SiC.

5isN4 etc. can be used. As this coating method, vapor phase coating techniques such as CVD, plasma CDV, sputtering, and ion implantation can be used. Therefore, at present, the processing is relatively simple and it is possible to easily form it thin.

As shown in FIG. 1, the entire outer surface of the ultrasonic probe 14, including the housing 30, may be coated, but in particular only the outer surface of the lens layer 37 from which ultrasonic waves are emitted may be coated. You may also do so. Furthermore, only the thickness of the ceramic coat layer 50 covering the outer surface of the lens layer 37 may be limited to the above-mentioned thickness, and the other portions may be coated to a greater thickness.

Further, as shown in FIG. 3, the ultrasonic probe 14 has its shaft portion 51 supported by a sliding bearing 52, so that it can rotate within the scanning chamber 15.

An injection port 53 is provided in the front wall of the scanning chamber 15, and the injection port 53 is normally sealed with a plug 54 screwed into the injection port 53.

Further, a balloon (not shown) is attached to the outer periphery of the tip component 6. The front and rear edges of this balloon form a circumferential groove 56 formed on the outer periphery of the distal end portion 6.
57 and is attached in a liquid-tight manner. An ultrasonic medium can be supplied to and discharged from the inside of the balloon through a liquid supply path 58.

According to the ultrasonic transducer sections 31 and 32 having such a configuration,
When the piezoelectric element 33 is driven by applying a driving voltage between the front surface electrode 35 and the back surface electrode 36, the ultrasonic waves emitted to the surface side of each piezoelectric element 33 are transmitted through the resin layer having an acoustic matching function. 37, it is converged and emitted as an ultrasonic beam.

On the other hand, the ultrasonic waves emitted to the back side of the piezoelectric element 33 are attenuated by half of the damper layer 38 in front of the insulating layer 4 [), and further pass through the insulating layer 40 and are distributed to the back side of the other piezoelectric element 33. The remaining half of the damper layer 38 provided is damped. Therefore, according to this, two ultrasonic transducer parts 3], 32
damper layer 38 without impairing the damping effect in
Since the piezoelectric elements 33 can be shared, two piezoelectric elements 33 can be provided without changing the size of the ultrasound probe 14. Furthermore, since the damper layer 38 is separated into two parts and insulated via the insulating layer 40, short circuits between the back electrodes 36 and 36 of each piezoelectric element 33 can be prevented.

On the other hand, after using this ultrasonic endoscope A, it is cleaned and disinfected. When this disinfection is performed by exposing to ethylene oxide gas, the plug 54 on the front wall of the scanning chamber 15 is removed 1 and the injection port 53 is opened. Furthermore, a sealing portion (not shown) located on the side of the glj operation section 2 of the guide tube 16 is opened. While the ultrasonic endoscope A is upright, two units of the ultrasonic medium filled in the guide tube 16 are discharged and removed from the scanning chamber 15 through the passage 20. Then, it is placed in a sterilization tank with the scanning chamber 15 etc. open to the outside, and exposed to ethylene oxide gas. Sterilize. At this time, the ethylene oxide gas enters the scanning chamber 15 and infects its interior and the outer surface of the ultrasonic probe 4 with IM bacteria.

However, since the outer surface of the ultrasonic probe 4, including its acoustic lens portion, is covered with the ceramic coating layer 50, it will not be deteriorated by the components of the ethylene oxide gas. Also, protect the parts that are glued with 1-boxy adhesive.

In other words, the ceramic coat layer 50 has excellent chemical resistance and corrosion resistance, and prevents deterioration of what it covers.

On the other hand, after sterilization, the ultrasonic medium 21 is injected from the injection port 53 side, and the guide tube 16 is filled from the scanning chamber 15 through the passage 20 and sealed, thereby allowing normal use.

FIG. 8 shows a modification of the ultrasonic probe 14.

This incorporates only one ultrasonic transducer section 3]. An insulating layer 60 is provided on the back side of the damper layer 38. The rest of the structure is the same as that of the above embodiment, but a ceramic coat layer 50 similar to the above is formed on the outer surface of the ultrasonic probe 14.

Note that in the above-mentioned embodiment No.]- and its modifications, an insulating member 39 was provided to support other members, but this insulating member 39 is omitted, and instead, a ceramic coat layer is provided on the inner surface of the 71 housing 30. may be provided to ensure insulation. In this way, the conductive housing 30 can be directly used to incorporate other members without providing the thick insulating member 39.

FIG. 9 shows a modification of the distal end portion 6 of the insertion portion 3. As shown in FIG. This tip component 6 communicates a balloon 61 attached to its outer periphery with the scanning chamber 5 through a communication path 62. This communication path 62 is formed so as to communicate from the vicinity of the tip of the scanning chamber 5 to the tip of the tube 61. Furthermore, the guide tube 16 is passed through the passage 20 at the rear end portion of the scanning chamber 15 . The rear end of the balloon 61 communicates with another passage 63 formed within the insertion section 3 . Ultrasonic probe installed in the scanning chamber 15 ] 4 is the scanning chamber 1
5 to form a scanning range in the front-back direction. Note that the formation of the ceramic coat layer on the ultrasonic probe 14 and the like are the same as those in the above embodiment.

Therefore, when this type of device is sterilized with ethylene oxide gas, the ultrasonic medium 21 is suctioned and removed from the passage 63. This interior is sterilized while communicating with the exterior. Therefore, although the ultrasonic probe 14 is exposed to ethylene oxide gas, it is protected by the ceramic coat layer.

Further, if the ultrasonic medium 2 is injected through the passage 20 (7) and filled into the scanning chamber 15 or the balloon 61 and sealed, it can be used normally.

10 and 11 show a second embodiment of the present invention. The general configuration of the entire ultrasound endoscope B according to this embodiment is as shown in FIGS.

The insertion portion 71 includes a tip portion 72, a curved portion 73, and a flexible portion 7.
4, and an ultrasonic probe 75 similar to that described above is provided at the distal end of the insertion portion 71. Furthermore, an endoscope operating section 76 is connected to the rear end of the insertion section 7, and the bending section 73 is connected to the endoscope operating section 76.
A bending operation knob 77 for bending the air and water supply button 78
etc. are provided. Further, a universal cord 79 is connected to the endoscope operation section 76. A connector 80 is provided at the tip of the universal cord 79 to be connected to a light source device (not shown).

An ultrasonic probe 75 is provided at the rear end of the endoscope operation section 76.
A sub-operation unit 8 is provided for driving and operating the. An electrical cable cord 82 is connected to this sub-operation section 81,
A connector 83 is provided at the tip of the electric cable cord 82 to be connected to an ultrasonic observation device (not shown). Note that 84 is an eyepiece provided at the rear end of the sub-operation section 81, and this eyepiece 84 is located above the center of gravity of the endoscope operation section 76.

Details of the sub-operation section 81 are shown in FIG. 11. This 11th
In the figure, reference numeral 91 denotes a sub-operation section main body, and a driving section unit 93 for rotating the ultrasound probe 75 in a direction perpendicular to the axial direction of the endoscope insertion section 71 is housed in the sub-operation section main body 91. ing. This drive unit 93 includes a base 94, a shaft holder 95 provided on this base 94, and a bearing 96° 96° on this shaft holder 95.
a hollow drive shaft 98 rotatably supported via 7;
This drive shaft 98 is connected to a pulley 99. Belt 100 Pulley 1
The probe shaft 103 has a rear end portion fixed to the hollow portion of the drive shaft 98 by a screw 104. The ultrasonic probe 75 is attached to the tip of the probe shaft 103, and the rotational force of the motor 102 is transmitted to the ultrasonic probe 75 via the probe shaft 103. Further, the probe shaft 103 has a hollow structure, and a signal cable 110 connected to the ultrasound probe 75 is inserted through the hollow portion.

A through hole 111 is provided at the rear end of the drive shaft 98 at its axial center.
A rotary signal transmission unit 12 having a rotary type signal transmission unit 12 is fitted and fixed with a screw 113. This rotary signal transmission section 112 is composed of a slip ring 114 that rotates together with the drive shaft 98 and a brush 115 that contacts this slip ring 114.
One end of the signal cable 117 connected to the amplification amplifier 116 is connected to the brush 115. A signal from the ultrasonic probe 75 is amplified by an amplification amplifier via a rotary signal transmission section 112.

Furthermore, a ceramic coat layer is formed on the slip ring 114 on the opposing surface thereof. This ceramic coat layer prevents adjacent slip rings 114 from being electrically connected to each other. The ceramic coat layer is formed in the same manner as the ceramic coat layer in the embodiment described above, but may be formed thicker.

In this way, the slip ring 1 is made of ceramic coated layer.
14, the storage space is smaller compared to the conventional one in which an insulating ring is inserted, and the sub-operation part 81 can be made more compact. In other words, the height H shown in FIG. 10 can be reduced.

12 to 13 show a third embodiment of the present invention. This embodiment relates to an ultrasound probe 131 introduced into a body cavity through a channel of an endoscope 130.

As shown in FIG. 13, this ultrasonic probe 131 has a scanning chamber 133 formed at the distal end of a sheath 132, and an ultrasonic probe 134 is rotatably housed within this scanning chamber 133. This ultrasonic probe 134 is constructed in the same manner as in the above embodiment, and at least the outer surface of the acoustic lens is similarly coated with a ceramic coating layer to a predetermined thickness.

As shown in FIG. 13, the rotation axis 13 of the ultrasonic probe 134
5 is pivotally supported in a hole 137 bored in a housing 136 at the tip. A flexible shaft 1 inserted into the sheath 132 is attached to the rotating shaft 135 of the ultrasonic probe 134.
It is connected to 38. The flexible shaft 138 is connected to a rotational drive source (not shown) installed in an operating section 139 attached to the proximal end of the ultrasound probe 131. Note that the ultrasonic probe [31] is connected to the ultrasonic observation device [42] via an electric cable cord 141. The ultrasonic observation device 142 is the light source device 14 for an endoscope.
It is attached to 3.

Note that a ceramic coat layer is formed on the outer circumferential surface of the rotating shaft 135 of the ultrasonic probe 134 and on the inner surface of the hole 137 that pivotally supports this. By forming the ceramic coat layer in this way, the lubricity of the shaft support is ensured. In other words, there is no need to use a separate bearing such as a ball bearing or a sliding bearing. Therefore, this shaft support becomes compact, and its diameter can be reduced even though it is of a mechanical scan type.

FIG. 12 shows this ultrasonic probe 131 introduced into the bile duct 144 through the channel of the endoscope 130.

It should be noted that the present invention is not limited to the above-mentioned embodiments, and various modifications can be made without changing the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, the acoustic lens disposed on the surface side of the ultrasonic transducer can be prevented from deteriorating during disinfection, etc., and its durability can be improved. Moreover, since the thickness of the ceramic coat layer is formed to be less than (1/4) λ, where λ is the wavelength of the ultrasonic wave, the acoustic characteristics are not impaired thereby.

[Brief explanation of drawings]

1 to 7 show a first embodiment of the present invention, FIG. 1 is a longitudinal sectional view of an ultrasound probe, and FIG. 2 is a perspective view showing the schematic configuration of an ultrasound endoscope. 3 is a longitudinal sectional view of the distal end of the ultrasonic endoscope insertion section, FIG. 4 is a sectional view taken along line A-A in FIG. 3, and FIG. longitudinal section,
6 and 7 are longitudinal sectional views of the curved portion. FIG. 8 is a longitudinal sectional view showing a modification of the ultrasonic probe in the first embodiment of the present invention. FIG. 9 is a longitudinal sectional view showing a modification of the distal end portion of the ultrasonic endoscope insertion section in the first embodiment of the present invention. 10 and 11 show a second embodiment of the present invention, in which FIG. 10 is a side view of the ultrasonic endoscope, and FIG. 11 is a longitudinal section of the operating section thereof. Figures 12 and 13 show a third embodiment of the present invention, with Figure 12 being an explanatory diagram of how the ultrasound endoscope is used, and Figure 13 being a sectional view of the tip of the ultrasound probe. be. A...Ultrasonic endoscope, 3...Insertion section, 6...Tip component, 14...Ultrasonic probe, 31.32...Ultrasonic transducer part, 37...Lens layer , 50...ceramic coat layer. Applicant's agent Patent attorney Takehiko Suzue (Figure, Figure, Figure) 4 Figure, Figure, Figure

Claims (1)

[Claims] In an ultrasonic probe in which an acoustic lens is arranged on the surface side of an ultrasonic transducer, a ceramic coat layer is provided to cover at least the surface portion of the acoustic lens exposed to the outside, and the thickness of the ceramic coat layer is determined by the thickness of the ultrasonic probe. An ultrasonic probe characterized in that the ultrasonic probe is formed to have a thickness of (1/4) λ or less, where λ is the wavelength.