JPH07163560A - Auxiliary sheet for ultrasonic, diagnosis, couplant and ultrasonic probe - Google Patents

Abstract

PURPOSE:To provide an auxiliary sheet for ultrasonic diagnosis which does not stick to the body surface and is easy to handle, a couplant and an ultrasonic probe having such couplant. CONSTITUTION:A water absorptive resin sheet (more particularly, a water absorptive sheet formed by crosslinking a resin consisting essentially of an ethylene oxide) 3 is used as the auxiliary sheet or couplant disposed between the ultrasonic probe 1 and the body surface.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic diagnostic auxiliary sheet or couplant, and an ultrasonic diagnostic probe.

[0002]

2. Description of the Related Art In recent years, ultrasonic diagnosis has become widespread as a method for diagnosing the state of lesions in a living body. In the ultrasonic diagnosis, when an air layer exists between the ultrasonic probe and the body surface, a reflected wave is generated between the air layer and the interface, the acoustic characteristics deteriorate, and accurate diagnosis cannot be performed. Therefore, it is necessary to interpose between the ultrasonic probe and the body surface a medium whose acoustic characteristics are close to those of the living body. Such a medium is commonly referred to as couplant.

Conventionally, the followings have been put into practical use as couplants or their equivalents. (1) Jelly applied to the acoustic radiation surface or body surface of an ultrasonic probe (2) Film body (coupler) such as silicone rubber containing water (3) For example, disclosed in Japanese Utility Model Publication No. 61-82606. As described above, a frame is provided on the acoustic emission surface of the ultrasonic probe, and water and water-absorbent resin powder are filled inside the frame.

However, the couplant of the above construction has the following problems. (1) Before using, jelly must be extruded from the tube and applied to the ultrasonic probe or body surface, which is troublesome. Although this jelly uses ingredients that are not medically problematic, when it is applied to the body surface, it causes discomfort to the patient, it takes a lot of time to wipe it after diagnosis, and inadequate wiping There are problems such as dirty clothes.

(2) A mechanism for attaching the coupler to the ultrasonic probe is required, which complicates the structure. In addition, when left in the air for a long period of time, moisture evaporates and the characteristics change. Therefore, it is necessary to store in a sealed state, which is inconvenient to handle. (3) Since the water-absorbent resin that has absorbed water has a weak self-shape retention property, a frame is required to assist shape retention.
The structure becomes complicated.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object thereof is a diagnostic aid that is easy to use and does not stick to the body surface without causing any trouble in diagnosis. To provide a sheet or a couplant or an ultrasonic probe having such a couplant.

[0007]

The invention according to claim 1 for solving the above-mentioned problems is an ultrasonic diagnostic auxiliary sheet comprising a water absorbent resin sheet obtained by crosslinking a resin containing ethylene oxide as a main component. The invention according to claim 2 uses a water-absorbent resin sheet attached to an acoustic radiation surface of the ultrasonic probe as the couplant provided between the ultrasonic probe and the body surface. Is.

The invention according to claim 3 is characterized in that a non-water-absorbing layer is formed on the surface of the water-absorbent resin sheet on the acoustic emission surface side of the ultrasonic probe. The invention according to claim 4 is the couplant according to claim 2, wherein a water-absorbent resin sheet is molded and an attachment portion of the ultrasonic probe to the acoustic radiation surface is integrally formed. Further, the invention of claim 5 is an ultrasonic probe having a piezoelectric vibrator and an acoustic radiation portion, and a couplant made of a water absorbent resin sheet is attached to the surface of the acoustic radiation portion.

The ultrasonic diagnostic auxiliary sheet according to the first aspect of the invention is a sheet having a continuous structure with a uniform shape retention in a dry state, and gels only by absorbing water before use.
Then, by bringing the gelled sheet into close contact with the body surface, ultrasonic coupling with the interface is performed. The couplant of the invention according to claim 2 uses a water-absorbent resin sheet including the water-absorbent resin sheet as couplant.
Before use, it is a non-water-absorbing sheet, and the sheet shape is maintained even if it absorbs water. Therefore, it is easy to install and the structure is simple in both non-water-absorbing state and water-absorbing state.

In the couplant of the third aspect of the present invention, the non-water-absorbing layer is formed on the surface of the water-absorbent resin sheet on the acoustic radiation side of the ultrasonic probe, so that the ultrasonic probe of the water-absorbent resin sheet is used. The attachment to the probe is facilitated, and also in the couplant of the invention according to claim 4, the water absorbing resin sheet is integrally formed with the attaching portion to the acoustic radiation surface of the ultrasonic probe, so that the water absorbing resin sheet is also absorbed. It becomes easy to attach the flexible resin sheet to the ultrasonic probe.

An ultrasonic probe according to a fifth aspect of the present invention has an ultrasonic probe having a piezoelectric vibrator and an acoustic radiation portion, and a couplant made of a water absorbent resin sheet is attached to the surface of the acoustic radiation portion. As a child, the ultrasonic diagnosis can be performed by freely moving it to an arbitrary position on the body surface simply by allowing the couplant to absorb water before use.

A detailed description will be given below with reference to the drawings. 1 to 3 show an embodiment of the present invention, FIG. 1 is a side view of an ultrasonic probe provided with a couplant, and FIG. 2 is an exploded perspective view for explaining a mounting method of the couplant in FIG. 3 and 4 are partial sectional views of the couplant in FIG. FIG. 4 is a side view of an ultrasonic probe provided with a couplant showing another embodiment of the present invention, and FIGS. 5 to 6 show still another embodiment of the present invention. 5 is a perspective view of the couplant, and FIG. 6 is a cross-sectional view for explaining a method of mounting the couplant of FIG. FIG. 7 is a sectional view of an ultrasonic probe showing still another embodiment of the present invention.

First, the invention according to claim 1 provides an auxiliary sheet for ultrasonic diagnosis comprising a water absorbent resin sheet obtained by crosslinking a resin containing ethylene oxide as a main component.
The resin containing ethylene oxide as a main component is water-soluble, but when it is molded into a sheet and cross-linked, it becomes insoluble in water and exhibits water absorption. This sheet is the same as a normal plastic sheet when it is not allowed to absorb water, and when it absorbs water, it swells and gels. This water-impregnated state is used by allowing it to stand still so as to be in close contact with the patient's body surface. Moreover, you may attach and use it for the acoustic radiation surface of an ultrasonic probe.

The resin containing ethylene oxide as a main component can be molded into a sheet by itself, and does not require any other component (binder). Therefore, the crosslinked sheet becomes a homogeneous sheet containing no foreign matter in a water absorbing state, There is no risk of damaging the ultrasonic transmission characteristics. The water absorbent sheet of the present invention can have a water content of more than 90% by adjusting the degree of cross-linking, and the acoustic impedance of the living body (1.5 to 1.
It is possible to obtain almost the same acoustic impedance as 6 × 10 ⁶ kg / m ² · s). Moreover, even in that state, it has sufficient strength and shape-retaining property for use, and is therefore most suitable as an auxiliary sheet for ultrasonic diagnosis. In addition, this water-absorbent sheet is easily dried for post-treatment such as incineration if left unattended, but the evaporation of water is slight even if it is used for a long time within the range of the time required for diagnosis, and it is excellent. The acoustic conduction properties are maintained.

The resin containing ethylene oxide as the main component used in the present invention is not particularly limited, but ethylene oxide is the main component (preferably 90% or more, more preferably 95%) in the organic compound having two active hydrogen groups. % Or more) and a high molecular weight compound obtained by reacting a polymer obtained by addition-polymerizing alkylene oxide with polyvalent carboxylic acid, polyvalent carboxylic anhydride, lower alkyl ester of polyvalent carboxylic acid or diisocyanate It is a suitable resin because it has good moldability.

Examples of the organic compound having two active hydrogen groups include ethylene glycol, propylene glycol, bisphenol A, aniline propylene glycol, polytetramethylene glycol, and the like. Examples of the oxide include ethylene oxide alone or a mixture thereof with propylene oxide, butylene oxide, styrene oxide, α-olefin epoxide and the like.

Further, as the polycarboxylic acid, phthalic acid,
Examples thereof include isophthalic acid, terephthalic acid, sebacic acid, dimer acid, pyromellitic acid, and their anhydrides or lower alkyl esters. Examples of the lower alkyl esters include methyl ester, dimethyl ester and diethyl ester.

Examples of diisocyanates include tolylene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and xylidene diisocyanate.

As a method for producing a sheet from a resin containing ethylene oxide as a main component, there are a solution casting method, a melt extrusion method, a calender method and the like. If it is a homopolymer of ethylene oxide, a sheet can be obtained by forming an aqueous solution into a sheet by a casting method or an extrusion method and drying the sheet. Further, the above resins can be easily formed into a sheet by melt extrusion molding by utilizing good thermoplasticity. The sheet may contain a heat stabilizer, an antioxidant, a colorant and the like as required, and may also contain a deodorant, a fragrance and the like.

Crosslinking of the sheet can be carried out by irradiation with ionizing radiation or ultraviolet rays. As the ionizing radiation, an electron beam, γ ray, X ray or the like can be used. Irradiation is preferably carried out in a substantially oxygen-free state such as substitution with an inert gas such as nitrogen. When the dose of ionizing radiation is less than 0.5 Mrad, the degree of crosslinking is too small to obtain the required water absorption, and when it exceeds 20 Mrad, the water absorption is extremely reduced. 20
The range of Mrad is preferred. As a crosslinking method, it is also possible to mix a resin containing ethylene oxide as a main component with a crosslinking agent and perform heat crosslinking.

Generally, the thickness of the auxiliary sheet of the present invention is preferably in the range of 0.1 to 2 mm in the non-water absorbing state. Thickness is 0.1
If it is less than mm, the sheet may be broken during the diagnosis due to lack of strength in a water absorbing state. If the thickness exceeds 2 mm, the probability that foreign matter existing in the sheet during the sheet production will increase. Further, when it is used by being placed on the body surface of a patient, the water absorption rate exceeds 90%, so that it may feel heavy to the patient depending on the size, and handling becomes difficult, which is not preferable.

The above-mentioned crosslinked sheet exhibits a water absorption capacity of 10 to 30 times its own weight depending on the degree of crosslinking, but as an ultrasonic diagnostic auxiliary sheet, the water absorption rate (absorption of ion-exchanged water at 20 ° C. to absorb excess water). The total weight of water when cut is 90)
The range of about 95% to 95% is preferable from the viewpoint of both the sheet strength when absorbing water and the ultrasonic transmission characteristics. This water absorption rate can be adjusted by the degree of crosslinking, that is, the absorbed dose of the ionizing radiation.

Next, an embodiment in which the water absorbent sheet is attached to the ultrasonic probe for use will be described. Figure 1
3 shows one embodiment, and in these drawings, a disk-shaped water absorbent resin sheet 3 is arranged on the acoustic radiation surface 2 of the ultrasonic probe 1. The non-water-absorbent layer 3 which is thinner than the water-absorbent resin sheet 3 is formed on one surface of the water-absorbent resin sheet 3 by a method such as heat fusion, dry lamination, or coextrusion.
a is formed, and the non-water absorbing layer 3a is arranged so as to be on the acoustic radiation surface 2 side of the ultrasonic probe 1. As the material of the non-water absorbing layer 3a, polyethylene, polypropylene, ABS, polystyrene, polyvinyl chloride, polyvinylidene chloride, polyethylene terephthalate and the like are suitable.

Then, the non-water absorbing layer 3a is attached to the acoustic radiation surface 2 of the ultrasonic probe 1 by a method such as adhesion, heat fusion, and ultrasonic welding. An annular holding plate 4 having a hole 4a in the center is attached to the surface of the water absorbent resin sheet 3 opposite to the surface facing the acoustic radiation surface 2 by a method such as bonding or welding.

The couplant thus constructed supplies water to the water absorbent resin sheet 3 before use. Then,
The water-absorbent resin sheet 3 swells, and in particular, the hole 4a portion of the holding plate projects outward through the hole 4a as shown in FIG. 3 to form a living body contacting spherical surface 3b. Then, by pressing the biological contact spherical surface 3b containing water against the body surface,
Ultrasonic coupling with the interface is made.

Since the water-absorbent resin sheet 3 has low tackiness, it does not stick to the body surface. Further, stable diagnosis can be performed without any change in characteristics (viscosity) due to body temperature, which is a problem with conventional jelly. Further, by providing the non-water absorbing layer 3a on the water absorbent resin sheet 3, the water absorbent resin sheet 3
Is easy to attach to the ultrasonic probe 1, and
It has the effects of reinforcing the water-absorbent resin sheet 3 that has swollen with water and suppressing the swelling of the water-absorbent resin sheet 3 in the planar direction. In the above-mentioned embodiment, in order to form the living body contacting spherical surface 3b, the annular holding plate 4 is provided on the water-absorbent resin sheet 3, but as shown in FIG. 4, the function of couplant is secured without the holding plate. it can.

Next, a second embodiment will be described with reference to FIGS. In the figure, the couplant is in the shape of a cup having a flat surface portion 3b and a mounting portion 3c standing upright from the periphery thereof. Such a couplant can be formed by three-dimensionally forming a water-absorbent resin sheet by vacuum forming, pressure forming, press forming, or by forming a water-soluble sheet that is the predecessor of the water-absorbent resin sheet in the same manner and then crosslinking it. Easily obtained.

In this couplant, for example, as shown in FIG. 6, a sound emitting surface can be fitted, and a simple holding ring 41 can be attached to the ultrasonic probe 1 by screwing or magnetizing. Positioning and mounting are extremely easy. In this case, the attachment of the couplant to the ultrasonic probe 1 returns to the original shape when the couplant absorbs and swells water. It will be apparent that if a pressing ring as shown in FIG. 5 is used, even a planar couplant having no mounting portion 3c can be used.

Next, a third embodiment will be described with reference to FIG. In the figure, a transducer array 11 of the ultrasonic probe 10 is shown.
The backing material 12 is provided on the back side, and the acoustic lens 14 is provided on the front side via the matching layer 13. In this case, the acoustic emitting portion is the acoustic lens 14, but in the case of an ultrasonic probe without the acoustic lens 14, the acoustic emitting portion may be an acoustic matching body (matching layer). The acoustic lens 14 of the present embodiment is preferably polystyrene, polypropylene, fluorine resin, polystyrene foam, or one obtained by compression-adhering micro beads of silicone rubber surface-treated with polystyrene.

A water-absorbent resin sheet 15 as a couplant is adhered to the surface of the acoustic lens 14, that is, the acoustic radiation surface,
It is attached by a technique such as welding. Next, the operation of the above configuration will be described. Before use, water is supplied to the water absorbent resin sheet 15. Then, the water absorbent resin sheet 15
Swells. And the water absorbent resin sheet 15 containing water
By pressing against the body surface, ultrasonic coupling with the interface is made. According to such a configuration, the ultrasonic probe 10
Since it is only necessary to attach the water absorbent resin sheet 15 to the acoustic lens 14 of No. 3, the structure is simple. Further, since the water-absorbent resin sheet 15 has low adhesiveness, it does not stick to the body surface.

As described above, according to the present invention, since it can be handled in the form of a sheet instead of the couplant which is conventionally handled in the form of jelly or powder, it is cut into a proper size in a non-water-absorbing (dry) state. It can be distributed and stored by storing it in a sterile bag. In addition, it is easy to attach a water-absorbent resin sheet to the ultrasonic probe regardless of whether it is water-absorptive or water-absorptive, and it is easy if the user simply absorbs water without using any special means. It can be used after swelling and gelling.

A water-absorbent sheet obtained by crosslinking a resin containing ethylene oxide as a main component can be dried and incinerated if left for 1 to several days after use, and since the components are hydrogen, carbon and oxygen, it can be incinerated. Is also advantageous in that it does not produce harmful components. In addition, since the water-absorbent sheet obtained by crosslinking a resin containing ethylene oxide as a main component has a characteristic of having good absorption of ionic water, for example, even water containing a disinfectant component should absorb water rapidly. You can

Although the above description relates to an auxiliary sheet or couplant for ultrasonic diagnosis, the present invention can also be applied to a material for ultrasonic treatment. A water-absorbent sheet obtained by cross-linking a resin containing ethylene oxide as a main component is also useful as an electrode used for current diagnosis such as electrocardiogram measurement by utilizing the electric conductivity at the time of water absorption.

[0034]

[Example] Polyethylene glycol obtained by adding ethylene oxide to ethylene glycol (weight average molecular weight 1
20,000) 100 parts of dimethyl terephthalate 2.2
1 part by weight and subjected to polyesterification reaction to give a weight average molecular weight of 1
After obtaining 30,000 compounds, a single-screw extruder was used to extrude at a T-die temperature of 120 ° C., and a cast sheet having a thickness of 500 μm was collected. The sheet was irradiated with γ rays at an absorbed dose of 10 Mrad to obtain a water absorbent sheet. Then, it was cut into a size of 20 cm × 30 cm. The above sheet was sufficiently absorbed with ion-exchanged water (water absorption rate: 93%), excess water was cut off and placed on the abdomen, and ultrasonic diagnosis was performed using a convex probe made by GE Yokogawa Medical System.

The water-absorbed sheet swelled and gelled to a thickness of 1 mm in a flexible state and was well fit to the body surface and adhered to it, but it did not stick to the skin at all and did not break at the time of diagnosis. Further, the sheet had a good water retention property, and even when the ultrasonic probe was pressed against it, the water did not flow out unintentionally and there was no discomfort. The image obtained using the sheet of the present invention is
It had the same sharpness as the case of using a conventional jelly containing a tube (Aquasonic 100, manufactured by Parker Laboratories). Further, the used sheet was almost dried when left for one day and could be easily incinerated.

[0036]

According to the present invention, by using a water-absorbent resin in the form of a sheet, an image sharpness comparable to that of a conventional couplant can be obtained, and it is not sticky on the body surface and is easy to handle. An auxiliary sheet for acoustic diagnosis or couplant or an ultrasonic probe having such couplant can be obtained.

[Brief description of drawings]

FIG. 1 is a side view of an ultrasonic probe provided with a couplant according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view illustrating a method for mounting the couplant in FIG.

FIG. 3 is a partial sectional view of the couplant in FIG.

FIG. 4 is a configuration diagram of another embodiment of the present invention.

FIG. 5 is a perspective view of a couplant according to still another embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a method of mounting the couplant in FIG.

FIG. 7 is a configuration diagram of yet another embodiment of the present invention.

[Explanation of symbols]

 1 Ultrasonic probe 2 Acoustic emission surface 3 Water absorbing resin sheet 3a Non-water absorbing layer 11 Transducer array (piezoelectric oscillator)

Claims (5)

[Claims] 1. An ultrasonic diagnostic auxiliary sheet comprising a water absorbent resin sheet obtained by crosslinking a resin containing ethylene oxide as a main component. 2. A couplant using a water-absorbent resin sheet attached to an acoustic radiation surface of an ultrasonic probe as the couplant provided between the ultrasonic probe and the body surface. 3. The couplant according to claim 2, wherein a non-water-absorptive layer is formed on the surface of the water-absorbent resin sheet on the acoustic emission surface side of the ultrasonic probe. 4. The couplant according to claim 2, wherein a water-absorbent resin sheet is molded and an attachment portion of the ultrasonic probe to the acoustic radiation surface is integrally formed. 5. An ultrasonic probe having a piezoelectric vibrator and an acoustic radiation portion, and a couplant made of a water-absorbent resin sheet attached to the surface of the acoustic radiation portion.