JP2736424B2 - Ultrasonic diagnostic probe coupler - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is a novel probe which is attached to the tip of a probe used for ultrasonic diagnosis and forms a contact medium between the skin of a human body and the ultrasonic probe. And a gel-like elastic coupler.

[Conventional technology]

Ultrasonic diagnostic methods are widely used among various diagnostic methods because they are inexpensive compared to other devices and can be easily implemented without burden on patients. There are a linear type, a convex type, a sector type, and a trapezoid type according to the scanning method, and the type is selected depending on a site to be diagnosed and its purpose. A dedicated probe is used for each scanning method. Among them, there is a method called the mechanical sector scanning method, which focuses strongly on the diagnosis part from a large aperture (part transmitting and receiving ultrasonic waves). In addition, subtle changes in the tissue can be reliably diagnosed. Although the diagnostic site varies depending on the measurement frequency, it has a great power in diagnosing superficial tissues such as the mammary gland, thyroid gland, and jugular vein. The probe has a cylindrical shape, and at the time of diagnosis, a so-called water in which a synthetic resin container having a shape corresponding to the part to be diagnosed is attached to the tip of the probe and deaerated water is sealed therein. Diagnosis is performed using bags.

[Problems to be solved by the invention]

However, the conventional method of mounting a container filled with degassed water at the tip of the probe has the following problems.
First, the preparation of degassed water and the operation of filling degassed water in a container are extremely complicated, and there is a slight amount of air at the interface between the tip of the probe and the degassed water. Therefore, there is a lot of noise and artifacts, and a clear image may not be obtained, and it is necessary to apply jelly so that there is no interface air layer between the skin contact surface of the container and the skin. There is a problem.

[Means for solving the problem]

In order to solve the above problem, the ultrasonic diagnostic probe coupler of the present invention is a gel-like elastic coupler detachably formed on the probe of the ultrasonic diagnostic probe, and is in a liquid state at room temperature. Polyurethane gel obtained by reacting a polyol having an alkylene oxide chain and / or a polyurethane polyol prepolymer having an alkylene oxide chain which is in a liquid state at normal temperature with a polyurethane polyisocyanate prepolymer having an alkylene oxide chain which is liquid at normal temperature. By performing a diagnosis using the coupler, a much clearer image can be obtained than before, and the operability is greatly improved without any other complicated operation. Things.

[Action]

Since the present invention is a gel-like elastic coupler, it can be easily attached to a probe of an ultrasonic diagnostic probe, and can be easily moved to a site where diagnosis is to be performed. And a clear image can be obtained.

Further, since the coupler of the present invention is a gel-like elastic body, it is easily adapted to the skin.

Further, the coupler of the present invention comprises a polyurethane gel, and more specifically, a polyol having an alkylene oxide chain in a liquid state at normal temperature or / and a polyurethane polyol prepolymer having an alkylene oxide chain in a liquid state at normal temperature. Since it is an elastic coupler of polyurethane gel obtained by reacting a polyurethane polyisocyanate prepolymer having an alkylene oxide chain which is liquid at normal temperature, it is very close to the ultrasonic wave propagation velocity of human tissues (excluding bones and lungs). It has a sound wave propagation speed, and has a low frequency requirement.

Also, the attenuation of the ultrasonic energy is relatively small, the acoustic impedance is almost equal to that of a human body tissue, and the noise and the artifact at the time of ultrasonic diagnosis are small. Further, since the gel of the present invention is a very flexible low modulus body, it can be easily adhered and adhered not only to a flat surface of a human body surface but also to a complicated uneven portion.

In addition, it has good shape retention, withstands deformation, and easily returns to its original shape, withstands pulling and scratch wear, can be used many times, and is economical. Furthermore, there is no substance that does not cause allergic reaction to the skin even after prolonged contact with the human body, does not irritate the skin, bleeds out from the inside of the gel-like elastic body, and adheres to the skin surface.

Further, the coupler of the polyurethane gel of the present invention is a one-component gel having segments of an alkylene oxide chain in a liquid state at ordinary temperature, and can maintain a constant gel state by the segments of the alkylene oxide chains in a liquid state. Since it does not contain any diluent for viscosity adjustment (for example, plasticizer or mineral oil, etc.),
It has characteristics such as no change in ultrasonic characteristics and physical and chemical properties over time due to bleed-out of a diluent or the like.

Next, the details of the one-component gel-like elastic body of the present invention will be described below.

The segmented polyurethane gel-like elastic body having an alkylene oxide (AO) such as polyethylene glycol (PEG) or polypropylene glycol (PPG) which is liquid at ordinary temperature used in the present invention is, for example, a polyether component (I) having the following structural formula. ) To (IV) and the polyisocyanate components (V) to (VIII) alone or in combination.

Each of these prepolymers has a functional group of —OH group or —NCO group, and the functional group reacts to form an interpenetrated network segment polyurethane having adhesiveness.

Here, the prepolymer as the polyol of the structural formulas (I) to (IV) will be described.

Structural formula (I) is a polyurethane polyol prepolymer that is a reaction product of a polyether polyol and a diisocyanate. Both terminal components consist of polyether polyol, and both terminals are -OH groups. The diisocyanate compound used here is the same as that in the polyurethane polyisocyanate prepolymer described later.
For example, φ-phenylene diisocyanate, 2,4-toluylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), naphthalene 1,5-diisocyanate, hexamethylene diisocyanate (HMDI),
Tetramethylene diisocyanate (TMDI), lysine diisocyanate, xylylene diisocyanate (XDI),
Water-added TDI, water-added MDI, dicyclohexyldimethylmethane p, p'-diisocyanate, diethyl fumarate diisocyanate, isophorone diisocyanate (IPDI) and the like can be optionally used.

The structural formula (II) is obtained by adding a polyether polyol to glycerol (l = 1) or sorbitol (l = 4) (ad
duct). (III) is obtained by adding polyether to trimethylolpropane. Similarly 1,2,
6-hexanetriol Trimethylolethane Pentaery slit C (CH ₂ OH) ₄ and polyglycerin n = a positive integer of 2 to 30] or an adduct of a polyhydric alcohol such as a partial ester thereof with a polyether polyol.

In this case, (AO) may be a homopolymer, a block copolymer or a random copolymer.
Structural formula (IV) is a polyether polyol having an alkylene oxide chain, and may have a -OH group at both ends or may have an alkyl group or an aromatic group blocked at one end, and is easily commercially available. Available at

(However, R ₁ and R ₂ are any of an alkyl compound, an alicyclic compound and an aromatic compound, and (AO) is an alkylene oxide chain.) (However, (AO) is an alkylene oxide chain, R is a hydrogen atom or any one of an alkyl compound, an alicyclic compound, and an aromatic compound, and l is an integer of 1 or 4.) (Where R is an alkyl group, an alicyclic compound, or an aromatic compound, (AO) is an alkylene oxide chain,
l is an integer of 1 or 4. The polyisocyanate prepolymer is (V)
It is represented by the formula of (VIII). (V) -1 and (V) -2 represent two molecules of triisocyanate (A) obtained by reacting trimethylolpropane and glycerol with diisocyanate.
O) is a tetrafunctional isocyanate obtained by dimerization with one molecule of the molecule. (V) -2 uses glycerol instead of trimethylolpropane. Since this kind of tetraisocyanate cannot be obtained by the reaction of two or three molecules of (AO) with two molecules of triisocyanate, it is necessary to make the amount of (AO) smaller than the stoichiometric amount to finely control the reaction. is there. For this reason, unreacted triisocyanate is mixed, but when this reacts with the polyol, the size of the segment polyurethane molecule varies, and it may act on a convenient side to control the softness of the gel-like elastic body. is there. (VI) is obtained by reacting a diisocyanate with a polyol (II), and is trifunctional or hexafunctional. (VII) is a reaction product of polyether polyol and diisocyanate and is bifunctional.

Next, the alkylene oxide chain represented by (AO) in the structural formula suitable for the present invention will be described. The alkylene oxide chain must be liquid at room temperature in order for the segmented polyurethane of the present invention to be a semi-solid, semi-liquid, low modulus structure exhibiting a gel-like elastic body at room temperature. That is, it is most desirable that all of the segments are liquid at room temperature, but it is rare that most of them are liquid. That is, if most of them are solid, the molecular motion of the segments is small and they do not work as a dispersion medium for structuring (gelling) the system. Also, even if a small portion of the solid is solid, it does not become a gel-like substance if it acts to restrict the free movement of molecules in other liquid segments.

However, even if only a small part is solid, the whole system may appear to be gel-like if this does not constrain the free movement of molecules in other liquid segments. Since the gel is most easily obtained when all the segments are composed of a liquid, the structure of the present invention is most suitable for always obtaining the gel.

Examples of the compound constituting the alkylene oxide chain include polymethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polypentamethylene glycol, polyhexamethylene glycol, polyheptamethylene glycol, and the like. Of these, polyethylene glycol, polypropylene glycol, and liquid substances that are easily available at room temperature
Low molecular weight polytetramethylene glycol. These copolymers, for example, Can be used. These copolymers may be either block polymers or random copolymers. Further, the segments in one prepolymer may be composed of different types of alkylene oxide chains.

Since the alkylene oxide chain must be a liquid at room temperature, the upper limit of the molecular weight is restricted. Conversely, if the molecular weight is low and the liquid state is too low, the distance between the cross-linking points is short, the molecular movement of the segments is suppressed, and the necessity of increasing the cross-linking density as a whole arises, so the structure is structured. The material is not a semi-liquid or semi-solid gel-like elastic body but tends to be a solid elastomer. For this reason, there is also a regulation on the lower limit of the molecular weight. The polyethylene glycol has a NW of 150-800, preferably 200-600. Polypropylene glycol is still liquid even if it has a molecular weight of tens of thousands, so its usable range is wide. However, if the chain is too long, the ratio of terminal functional groups is small and the probability of reaction is low. Therefore, it is necessary to mix a much larger amount of polyol than the theoretical amount for gelation. However, what results from this is a material which is rich in fluidity, poor in shape retention and extremely sticky, and is hard to say a gel-like elastic substance. Therefore, preferably a range of 200 to 30000 can be used. Since polytetramethylene glycol becomes a solid when the degree of polymerization is large, it can be used in the range of approximately MW 200 to 1000, preferably 400 to 800. Further, these copolymers can be used in a molecular weight range of several hundreds to several thousands.

Now, the reaction ratio between the polyol and the polyisocyanate will be described below. Empirically speaking, the gel-structured molecular assembly of the present invention has a segment length, or a linear chain, in which molecules having a relatively bulky structure have an appropriate molecular weight and can move freely. It is necessary that the end of the linear) has many molecules that can move freely. Therefore, if each of the polyol and the polyisocyanate is a single compound, it is necessary that one is a bifunctional compound and the other is a combination of trifunctional or more functional compounds. If either is monofunctional, it does not chain.

Bifunctional molecules form a linear molecule, which is not appropriate. That is, either one is bifunctional and the other is trifunctional or more polyfunctional, or a combination of three or more is good. However, the reactants of which all have too large a functional number have a high network chain concentration, so that a long liquid segment is required for gelation. However, the length of the segment is limited due to the necessity of the segment being liquid at room temperature and the problem of the probability of reaction. The number of functional groups from which a gel body is easily obtained is a combination of 2 to 4, and in particular, a combination of bifunctional and trifunctional is easy to adjust in combination.

In this case, one having a single functional group can be mixed and used as an internal dispersion medium for fine adjustment of physical properties such as softness and elasticity of the gel. If the polyol or polyisocyanate prepolymer has only a very long (AO) chain, a polyfunctional alcohol or a polyisocyanate (neither of which has an (AO) segment) may be used to form a network. The chain morphology may be adjusted to obtain a gel body.

The reaction ratio of each prepolymer of polyol and polyisocyanate can be regulated by the ratio of terminal functional groups, that is, the value of OH / NCO. If unreacted -NCO remains, post-reaction occurs, so OH / NCO must be 1 or more.

However, since the gist of the present invention is a gel system consisting of one component in which a gel-forming substance and a dispersion medium are covalently bonded in the same polymer molecule, OH / NCO is basically 1 or
It is a value close to it. However, since the reaction is a reaction between prepolymers, actually, in consideration of the probability of the reaction, if the basis of the gelation does not deviate from the essence of the present invention, those slightly larger than 1 are also included.

However, a two-component gel that acts as a dispersion medium and uses multiple extra polyol components to swell the network or does not gel without adding a plasticizer or the like is not intended in the present invention. Absent. Empirically OH / NCO
A gel essentially in accordance with the invention is obtained in the range from 1.0 to 1.5. However, in some cases, even in the range of 2 to 3 due to the probability of reaction due to the shape of the molecule and the morphological behavior of the molecular assembly, it is possible to obtain a gel that exhibits the same apparent behavior as the gel of the present invention in physical properties. Can be However, in this case, there is a concern that there is a bleed-out component over time, and the physical properties of the overall gel are inferior to those having an OH / NCO close to 1, so that the present invention It is not intended.

The molecular weight range of the polyol and polyisocyanate constituting the gel consisting essentially of a one-component system of the present invention is (A
O), isocyanate type, molecular shape and (AO) vary widely depending on whether it is a homopolymer or a copolymer, but it is approximately 1400 to 10000 for polyurethane polyol prepolymer, approximately 150 to 6000 for polyol, and polyurethane poly. Isocyanate prepolymer is roughly 500
~ 10000, but preferably about 1000 ~ 6000, 200 respectively
Can be selected in the range of ~ 3000, 800 ~ 5000.

The reaction rate may be adjusted by adding an appropriate amount (about 0.01 to 1.0%) of a tertiary amine such as dibutyltin dilaurate, trialkylamine or triethylenediamine as a catalyst for the reaction between the polyol and the polyisocyanate.

In addition, since the gel-like elastic body of the present invention is a so-called two-component polyurethane in which a polyol component and a polyisocyanate component are reacted, a casting mold having a predetermined shape is created, and the two components are mixed therein. By casting and curing, it can be formed into a fine and complicated shape as the object of the present invention.

As described in detail above, the gel-like elastic coupler of the present invention substantially satisfies the above-described condition as a probe for ultrasonic diagnostic probe and skin with almost no problem in practical use. It is a gel-like elastic coupler that can be suitably used for the purpose of (1).

(Example) Next, the present invention will be described in more detail with reference to examples.

<Example 1> 100 parts of a PPG-PEG block copolymer in which polyethylene glycol (PEG, MW: 335 each) is bonded to both ends of polypropylene glycol (PPG, MW: 100) (hereinafter, referred to as parts by weight), monomethoxy polyethylene Glycol (MW: 400)
33 parts of a polyether polyol which is liquid at room temperature, and a compound obtained by adding hexamethylene diisocyanate (HMDI) to a compound obtained by adding a PPG-PEG block copolymer to glycerin is used to obtain a polyether polyol which is obtained at room temperature. Triisocyanate in segment (MW: 3100) 140
Parts, 13 parts of a low molecular weight diisocyanate (trade name: Duranate D201, manufactured by Asahi Kasei Corporation) and 0.1 part of dibutyltin dilaurate as a catalyst were added, and the mixture was stirred well and mixed. Next, this was completely defoamed under reduced pressure, poured into a prescribed mold, and left at 60 ° C. for two days and nights to obtain the first
A gel-like elastic coupler having a shape as shown in the figure was obtained. FIG. 1 is a perspective view of the coupler of the present invention, and 1 is a coupler body. The size is about 8 cm in height, the width of the upper part is 5 cm × 6 cm
It is. 2 is a probe of an ultrasonic diagnostic probe (not shown)
The size of the recess is 32 mm. The shape of the concave portion is the same as the shape of the probe. In particular, the probe is formed so as to be in close contact with the deepest portion of the concave portion. Reference numeral 3 denotes a smooth portion without irregularities formed so as to be tightly contacted with a portion to be diagnosed without any gap, and has a substantially inverted trapezoidal shape. FIG. 2 is a plan view, and FIG.
-It is an X-ray cutting sectional view. This gel-like elastic body [OH] /
[NCO] is 1.04. This shape is designed to be optimal for thyroid diagnosis. This gel-like elastic coupler has the advantage that the surface is tacky and adheres well to irregularities on the skin of the human body. The probe equipped with the gel-like elastic coupler at the tip was used for thyroid diagnosis at a frequency of 7.5 MHz. As a result, a clear image with very few artifacts and noise was obtained. This is presumably because the gel-like elastic body as the contact medium was cast and cured in a state where the distortion was extremely small. Further, as can be seen from the composition, there is no low molecular compound such as a plasticizer that actually bleeds out, that is, there is no substance that adheres to the skin, so that it is sanitary. And it does not dry in the air. In addition, it has elasticity and flexibility, and has very excellent surface scratch resistance and abrasion resistance.

<Example 2> 36 parts of polyethylene glycol (PEG, MW: 600) and 34 parts of monomethoxypolyethylene glycol (MW: 400) were added to polypropylene glycol to trimethylolpropane for liquid polyether polyol at room temperature. Then, 76 parts of triisocyanate (MW: 1606) obtained by reacting xylylene diisocyanate (XDI) and 0.3 parts of dibutyltin dilaurate as a catalyst were added to the gel having the shape shown in FIG. An elastic body was obtained. FIG. 4 is a perspective view of the coupler of the present invention, which is substantially the same as the coupler of the first embodiment except that the coupler has a horizontally longer shape. FIG. 5 is a plan view of the coupler of FIG. 4, and FIG.
FIG. 5 is a sectional view taken along the line YY. This shape is designed to be optimal for the diagnosis of the mammary gland. This gel-like elastic body
The propagation speed of the 7.5 MHz ultrasonic wave was 1500 m / sec, which was very close to that of the human body. Attach this gel-like elastic coupler to the tip of the mechanical sector probe, 7.5MHz
When the diagnosis of the mammary gland was performed, a high-quality image with very few artifacts and noise was obtained.
The value of [OH] / [NCO] of the present gel-like elastic body was 1.44, and (AO) / (XDI) = 3.6 (weight ratio).

Example 3 110 parts of a block copolymer of PEG100-PPG2000-PEG100 (MW: 2200) and methoxypolyethylene glycol (MW: 40
0) Add 80 parts of propylene glycol to glycerin to liquid polyether polyol at room temperature and add 120 parts of triisocyanate (MW: 1564) reacted with xylylene diisocyanate and 0.2 parts of dibutyltin dilaurate as a catalyst. A gel elastic coupler having the shape shown in FIG. 7 was obtained in the same manner as in Example 1. FIG. 7 is a front view of the coupler of the present invention, which is different from the first embodiment in that the smooth portion has a curved surface. FIG. 8 is a plan view of the coupler of FIG. 7, and FIG. 9 is a side view of the coupler of FIG. This shape is designed to be optimal for diagnosis of jugular vein. [OH] / [NCO] of the present gel-like elastic body is 1.30, and (AO) / (XDI) = 6.5 (weight ratio). Although the present gel-like elastic body coupler is more hydrophobic than Examples 1 and 2, when this gel-like elastic body was attached to the tip of the probe and a diagnosis of jugular artery and vein was performed at 7.5 MHz, A high-quality image without artifacts and noise was obtained much more than when a water bag made of a conventional synthetic resin was used.

As described above, the gel-like elastic coupler of the present invention is a one-component gel having an alkylene oxide (AO) which is liquid at normal temperature in a segment, and the composition is attached to an ultrasonic diagnostic probe to perform diagnosis. By doing so, a clear image without noise and artifacts can be obtained, and as shown in each embodiment,
It can be easily molded into any shape.

〔The invention's effect〕

As described above, when the gel-like elastic coupler of the present invention is mounted on the ultrasonic diagnostic probe and the diagnosis is performed, noise and artifacts are reduced as compared with the conventional case where a container filled with degassed water is mounted. The operability is greatly improved, such that a clearer image with less water content can be obtained, and the labor for preparing degassed water and enclosing it in a container is not required.

Moreover, this gel-like elastic coupler has a polyol component having an alkylene oxide chain in a liquid state at normal temperature,
Similarly, it is made of a one-component polyurethane gel obtained by reacting an isocyanate component having an alkylene oxide chain in a liquid state at room temperature, and contains no water or oily organic substances. Since the organic substance has no possibility of bleeding out, it has extremely excellent storage stability, high repetitive useability, and no adverse effects such as skin irritation.

[Brief description of the drawings]

FIG. 1 is a perspective view of a coupler showing one embodiment of the present invention, FIG. 2 is a plan view of the coupler, FIG. 3 is a sectional view taken along the line XX of FIG. 2, and FIG. FIG. 5 is a plan view of the coupler of FIG. 4, FIG. 6 is a sectional view taken along the line Y--Y of FIG. 4, and FIG. 7 is still another embodiment of the present invention. 8 is a side view of the coupler of FIG. 7, and FIG. 9 is a plan view of the coupler of FIG. 1 ... coupler, 2 ... recess, 3 ... smooth part.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hidekazu Baroya 2--30 Azuchicho, Higashi-ku, Osaka City, Osaka Prefecture Inside Takiron Co., Ltd. (56) References JP-A-61-288840 (JP, A) JP-A-61 −288841 (JP, A) Actually open 1-300935 (JP, U)

Claims (1)

(57) [Claims] 1. A gel-like elastic coupler detachably formed on a probe of an ultrasonic diagnostic probe, wherein the polyol has an alkylene oxide chain which is in a liquid state at ordinary temperature and / or a liquid in a liquid state at ordinary temperature. A polyurethane polyol prepolymer having an alkylene oxide chain,
An ultrasonic diagnostic probe coupler comprising a polyurethane gel obtained by reacting a polyurethane polyisocyanate prepolymer having an alkylene oxide chain which is liquid at ordinary temperature.