JPH03178647A - Spacer for mounting probe for ultrasonic diagnosis - Google Patents

Abstract

PURPOSE:To allow the sure mounting of a probe for ultrasonic diagnosis to a body surface by making the spacer out of a specific polyurethane gel-like elastic body and forming a through-hole to be fitted with the probe of the probe in the central part thereof. CONSTITUTION:The spacer 1 consists of the polyurethane gel-like elastic body obtd. by bringing a polyol having an alkylene oxide chain or/and a polyurethane polyol prepolymer having the alkylene oxide chain and a polyurethane polyisocyanate prepolymer having the alkylene oxide chain into reaction. This elastic body is the one-component type gel of the segment polyurethane of an internal penetration type constructed by the segments of the alkylene oxide. This gel has good tackiness and water resistance and is entirely harmless to the human body. The polyurethane gel-like elastic body is adjusted in the hardness by an ASKER F type hardness meter to the range within 20 to 80 deg.. The spacer, therefore, has the shape holdablity to enable the spacer to sufficiently hold the probe 2, the flexibility to enable the spacer to come into tight contact with the body surface and the mechanical strength to enable the spacer to withstand many times of use.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a spacer for mounting an ultrasonic diagnostic probe made of a polyurethane gel-like elastic body.

[Conventional technology]

As is well known, ultrasonic diagnostic methods are widely used because they are easy to perform and do not place any burden on patients. For example, the continuous wave Doppler method is suitable for measuring comparative differences and intracardiac pressure from the maximum blood flow velocity, and the pulsed Doppler method is also suitable for measuring hemodynamic changes and cardiac output during exercise stress. More useful.

However, when applying a jelly-like substance to the anterior chest wall and attaching a continuous wave Doppler probe over it to continuously monitor blood flow waveforms at the mitral valve orifice in the supine, sitting or standing position, the following steps should be taken: There was a problem like this.

[Problem to be solved by the invention]

In other words, if the probe is attached over the jelly-like material as described above, it is difficult to securely fix the probe, which may cause the probe to move during continuous monitoring, or the jelly-like material may flow and cause the probe to be damaged. A minute gap may be created between the child's probe and the body surface.

Therefore, there is a problem that noise and artifacts increase, making it difficult to obtain a clear monitor image.

The present invention has been made in view of such problems, and its purpose is to allow the probe to be attached to the body surface in a securely fixed state so as not to move, and to allow the probe of the probe to An object of the present invention is to provide a novel spacer for attaching a probe, which can prevent a jelly-like substance filled between the body surface and the body surface from flowing out, and obtain clear continuous monitor images.

[Means to solve the problem]

As a result of extensive research by the present inventors, the above objective was achieved by reacting a polyol having an alkylene oxide chain or/and a polyurethane polyol prepolymer having an alkylene oxide chain with a polyurethane polyisocyanate prepolymer having an alkylene oxide chain. The hardness measured by the Asker-F hardness tester is 20-8.
It is said to be distantly related to the spacer for mounting an ultrasound diagnostic probe, which is made of a polyurethane gel-like elastic material with a temperature of 0 degrees, and has a through hole formed in the center to fit the probe of the ultrasound diagnostic probe. After discovering this fact, we have completed the present invention.

Hereinafter, the present invention will be specifically explained with reference to the drawings.

FIG. 1 is a plan view showing an example of the shape of the spacer of the present invention, FIG. 2 is a sectional view taken along the line 1--1 in FIG. 1, and FIG. 3 is a sectional view showing the spacer in use.

As shown in FIGS. 1 and 2, the spacer l of the present invention has a through hole La in the center into which a continuous wave Doppler probe is inserted, and preferably the lower surface 1b is connected to the upper surface 1.
The bottom is shaped like a donut plate inclined at an angle of about 10° to 40° with respect to c.

When attaching the probe to the body surface using this spacer 1, the probe 2a of the probe 2 is fitted into the through hole 1a of the spacer l as shown in FIG. The surface 1 may be filled with a substance 4 and brought into close contact with the body surface 3, and the probe 2 may be pressed down with a rubber band (not shown) or the like. If the lower surface 1b is inclined like this spacer 1, by rotating the probe 2 together with the spacer 1 during installation, the direction of the ultrasound beam B can be changed within a range twice the inclination angle. Therefore, there is an advantage that the target site can be searched easily.

In such a spacer I of the present invention, ■ probe 2;
■Have the adhesiveness to prevent the spacer l from sliding ■Have the flexibility to be able to come into close contact with the body surface 3■Mechanical strength to withstand multiple uses (Tensile, tearing, abrasion); ■Water resistance; ■Safety for humans.

If the conditions (■■) are not satisfied, the mounting angle and mounting position of the probe 2 will shift during continuous monitoring, resulting in Doppler signal artifacts and the monitor image becoming unclear. In addition, if the conditions of Since there is a gap between the two, it is still difficult to obtain a clear image.
5 things become difficult. Furthermore, if the condition (■) is not met, it will be uneconomical because it will be damaged immediately and cannot be reused, and if the condition (■) is not met, the jelly-like material 4 cannot be washed with water after use, making it difficult to handle. becomes inconvenient. Also, ■ is the most basic condition, and if this is not met, it cannot be used with confidence.

The spacer 1 of the present invention is made of a polyurethane gel-like elastic body obtained by reacting a polyol having an alkylene oxide chain or/and a polyurethane polyol prepolymer having an alkylene oxide chain, and a polyurethane polyisocyanate prepolymer having an alkylene oxide chain. This elastic body is an interpenetrated network structured by alkylene oxide segments.
It is a one-part gel of segmented polyurethane, has good adhesiveness and water resistance, and is completely harmless to the human body.

Moreover, this polyurethane gel-like elastic body is
The hardness measured by the mold hardness tester is adjusted to be within the range of 20 to 80 degrees, so it has shape retention that can sufficiently support the probe 2 and flexibility that allows it to come into close contact with the body surface 3. It also has mechanical strength that can withstand repeated use. Therefore, all of the conditions (1) to (4) mentioned above are satisfied.

A polyurethane gel-like elastic body whose hardness is less than 20 degrees as measured by the Asker F-type hardness tester is too flexible and cannot exhibit shape retention sufficient to support the probe 2, and its mechanical strength also decreases. Therefore, it is unsuitable as a material for the spacer of the present invention. On the other hand, a polyurethane gel-like elastic body with a hardness greater than 80 degrees has too little flexibility, so the adhesion with the body surface 3 may decrease and the jelly-like material 4 may flow out, so it is still unsuitable. be. A more preferable hardness of the polyurethane gel-like elastic body is 25 to 65 degrees.

The spacer 1 made of such a polyurethane gel-like elastic body is made of polyether components (1) to (IV) having the following structural formula.
one or more of the following, and a polyisocyanate component (V
) to (■) can be easily formed into a bottom shape by mixing one or more of them, injecting the mixture into a mold, and allowing them to react.

(2) 1" L standing L) (However, R+, Rz are alkyl compounds, alicyclic compounds,
It is any aromatic compound, and (AO) is an alkylene oxide chain. ) (However, (AO) is an alkylene oxide tomb, and R
is a hydrogen atom, an alkyl compound, an alicyclic compound, or an aromatic compound, and l is l or an integer of 4. ) (The following is a blank space) A': 00-Nigami (The following is a blank space) 1st position ±■) 1st position ±■) QCNRNCQ-(AO)-CNRNCO (However, RH
It is either an alkyl group, an alicyclic compound, or an aromatic compound, (AO) is an alkylene oxide chain, and l is an integer of l or 4. ) To explain the prepolymers as polyols of the above structural formulas (1) to (rV), structural formula (1) is a polyether polyol and diisocyanate-1.
It is a polyurethane polyol prepolymer which is a reaction product of ., both terminal components are polyether polyol, and both terminals are 10H groups. The diisocyanate compounds used here are the same as those in the polyurethane polyisocyanate prepolymers described below, such as 1-diisocyanate, 2-24-toluylene diisocyanate (TDI), 4-diphenylmethane diisocyanate (Ml). ), naphthalene 1,5-diisocyanate, hexamethylene diisocyanate (H?IDI)
, tetramethy1/diisocyanate) (TMDI),
lysine diisocyanate, pheasantyl diisocyanate)
(XDI), water-added TD11 water-added MDI, dicyclohexyldimethylmethane p,p'-diisocyanate, stylfumarate diisocyanate, isophorone diisocyanate (IPDI), etc. can be used arbitrarily.

Moreover, structural formula (II) is obtained by adding a polyether polyol to glycerol (ff=1) or sorbitol (ff=4).

Structural formula (1) is the addition of polyether to trimethylolpropane, and the formula (1) is trimethylolpropane with polyether added. 011 ) 4 and polyglycerin 1i0 (Cllz-Cll-CHz-0),
Adducts of polyhydric alcohols and polyether polyols such as H (n = positive integer of 2 to 30) H and its partial esters can also be used. 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 -OH groups at both ends, or may have one end blocked with an alkyl group, aromatic group, etc., and is easily available as a commercial product. available at.

Next, to explain the polyisocyanate prepolymers of structural formulas (V) to (■), structural formula (V)-1 consists of two molecules of triisocyanate obtained by reacting trimethylolpropane with diisocyanate (80). A polyisocyanate prepolymer of structural formula (V)-2 is a tetrafunctional tetraisocyanate dimerized with one molecule of the formula (V)-2, and glycerol is used instead of trimethylolpropane. This single tetraisocyanate cannot be obtained by the reaction of two or three molecules of (80) with two molecules of triisocyanate, so the reaction is subtly controlled by reducing the amount of (AO) below the chemical equivalent. need to be adjusted. Therefore, unreacted triisocyanate is mixed in, but when this reacts with the polyol, the size of the segmented polyurethane molecules will vary, which may work in a direction that is more convenient for controlling the hardness of the gel-like elastic body.

Structural formula (Ml) is a polyol of structural formula (II) reacted with diisocyanate-1, and is trifunctional or hexafunctional, and structural formula (■) is a polyol of structural formula (In). It is made by reacting with diisocyanate and is trifunctional.

Structural formula (■) is a reaction product of polyether polyol and diisocyanate-1, and is difunctional.

The alkylene oxide chain represented by (AO) in the above structural formulas (1) to (■) is such that the polyurethane gel-like elastic body has sufficient adhesiveness at room temperature and has an Asker-F hardness of 20 to 80 degrees. '3, it is necessary to have both flexibility to allow close contact with the body surface and shape retention to sufficiently support the probe.
I: Considering this, it is desirable that most or all of the alkylene oxide chains be in a liquid state at room temperature. If most of the segment is solid, the molecular motion of the segments will be small and it will not work as a dispersion medium for structuring (gelling) the system.

Examples of compounds constituting the alkylene oxide chain include polymethylene glycol, polyethylene glycol, polypropylene glycol, polymethylene glycol, and polytetramethylene glycol: l! Among these, those that are easily available as liquid substances at room temperature are polyethylene glycol, polyethylene glycol, (ll
It is polytetramethylene glycol with half the amount of K.

In addition, these copolymers, such as I3HO-(CHIC)120) or-(C)l-CHzO)
-%-(CHzCHtO)Rho 11,flO-(C)I
zCHgO)1- (C)lx(JltCHtCHgO
) knee(CHzCHzO)n -H (1.m, n is an integer of 1 or more) A polymer represented by the following formula can also be used. These copolymers may be either block copolymers or random copolymers. Further, segments in one prepolymer may be composed of different types of alkylene oxide chains.

In order to obtain a polyurethane gel-like elastic body having a hardness of 20 to 80 degrees as measured by the Asker-F hardness tester, it is necessary to control the molecular weight of the above-mentioned compound constituting the alkylene oxide chain. Even if the compound is in liquid form, if the molecular weight is too low, the crosslinking density will be high, and the hardness of the polyurethane gel-like elastic body will exceed the above range, making it difficult to obtain the flexibility to adhere closely to the body surface. In addition, even if the compound is liquid, if the molecular weight is too large and the chain is too long, the reaction probability will be low, so even if the compound is blended at more than 6ffi, the hardness of the polyurethane gel-like elastic body will fall below the above range, and the probe will be damaged. It becomes difficult to obtain sufficient shape retention and mechanical strength to support it. A suitable molecular weight of l1lIIIl is about 150 to 1000 in the case of polyethylene glycol, more preferably 300
It is about 800. In addition, liquid polypropylene glycol and polybutylene glycol can be used in a wide range of applications even if the molecular weight is 200 to 3000 for the above reasons.
Those having a molecular weight of about 100% are preferably used. In addition, in the case of polytetramethylene glycol, if the degree of polymerization is high, it becomes solid, so it is about 200 to 1000, preferably 40
Those having a molecular weight of about 0 to 800 are used. Furthermore, in the case of these copolymers, those having a molecular weight of several hundred to several thousand are used.

Next, the reaction ratio between the polyol component and the polyisocyanate-1 component will be explained. Empirically speaking, the polyurethane gel-like elastic body constituting the spacer of the present invention has a relatively bulky structure and has an appropriate molecular weight and can move freely. ) is required to have an appropriate amount of freely movable molecules at the ends.

Therefore, if polyol and polyisocyanate are each a single compound, it is necessary that one is a difunctional compound and the other is a combination of trifunctional or higher functional compounds. If either of them is monofunctional, there will be no chain, and if either is bifunctional, it will be a linear molecule, which is not appropriate. In other words, one of them is difunctional and the other is trifunctional or more polyfunctional, or a combination of trifunctional or more functional is preferable. However, reactants with too large functional numbers have a high network chain concentration (because
Long liquid segments are required for gelation. However, there is a limit to the length of the segment due to the probability of reaction. A combination of 2 to 4 functional groups makes it easy to obtain a gel-like elastic body, and a combination of bifunctional and trifunctional groups is particularly easy to adjust in terms of formulation. In this case, in order to finely adjust the hardness and other physical properties of the gel-like elastic body, one having one functional group can be mixed and used as an internal dispersion medium. In addition, if the (AO) chains of polyols and polyisocyanate brepolymers are quite long, polyfunctional polyhydric alcohols or polyhydric incyanates (both of which do not have (AO) segments) may be mixed. By adjusting the network chain morphology,
Efforts may be made to obtain a gel-like elastic body.

The reaction ratio of each prepolymer of polyol and polyisocyanate is the ratio of terminal functional groups, 011/N
It can be regulated by the value of GO. If unreacted -NGO remains, a post-reaction will occur, so OH/NGO must be 1 or more. However, since the gel-like elastic material in the present invention is a one-component system that is covalently bonded within the molecules of the same polymer, basically 0)1/NGO is 1 or close to it. belongs to. However, since this is a reaction between prepolymers, if the probability of reaction is actually taken into consideration, some cases that are slightly larger than 1 are included. From my experience, OH/
A polyurethane gel-like elastic body suitable for the spacer of the present invention can be obtained when the NGO is in the range of 1°0 to 1.5. Furthermore, due to the probability of reaction depending on the shape of the molecule and the morphological behavior of the molecular assembly, a gel-like elastic body may be obtained that exhibits similar apparent behavior even when O)I/NCO is in the range of 2 to 3. However, such materials are unsuitable for use as a polyurethane gel-like elastic material constituting the spacer of the present invention because they may contain components that bleed out over time and have poor overall physical properties.

The molecular weight range of polyols and polyisocyanates is (
AO), type of isocyanate, molecular shape, and (AO
) varies widely depending on whether it is a homopolymer or a copolymer, but it is approximately 1,400 to 10,000 for polyurethane polyol prepolymers, and approximately 1 for polyols.
50 to 6,000, and approximately 500 to 10,000 for polyurethane polyisocyanate prepolymer, preferably approximately 1,000 to 6,000.200 to 3,000.80 respectively.
It can be selected from 0 to 5000.

The reaction rate can be increased by adding an appropriate amount (approximately 0.01 to 1.0%) of a tertiary amine such as dibutyltin dilaurate, trialkylamine, or triethylene cyanochloride as a reaction catalyst between polyol and polyisocyanate. May be adjusted.

[For production]

As described above, the spacer of the present invention includes a polyol having an alkylene oxide group and/or a polyurethane polyol prepolymer having an alkylene oxide chain;
It consists of a polyurethane gel-like elastic body obtained by reacting a polyurethane polyisocyanate prepolymer having an alkylene oxide chain, and this elastic body is a component of an internal segmented polyurethane structured by alkylene oxide segments. It is a type gel. Therefore, the spacer of the present invention does not contain any bleed-out components such as residual monomers or residual solvents, so it does not irritate the skin, and since it does not breed bacteria, it does not cause skin irritation, and it can be used for a long time. However, it is completely harmless to the human body. Furthermore, by adjusting the type and molecular weight of the alkylene oxide chain, this polyurethane gel-like elastic material has a hardness of 2.
Because it is adjusted to be within the range of 0 to 80 degrees,
It has shape retention that can sufficiently support the probe and flexibility that allows it to come into close contact with the body surface, and also has good mechanical strength (tensile, tear, abrasion, etc.), adhesiveness, water resistance, etc. Therefore, the probe of the probe is inserted into the through hole of the spacer of the present invention, the inside of the through hole is filled with a jelly-like substance, the spacer is attached to the body surface, and a rubber band (not shown) is placed over the probe. If the spacer is held in place by pressing the probe with a tool such as the I don't feel sad. Therefore, it is possible to obtain clear images because there are almost no artifacts or noises caused by displacement of the probe or generation of gaps during continuous monitoring. In addition, since the spacer of the present invention has good mechanical strength and water resistance as described above, the jelly-like substance attached can be easily removed by removing the spacer from the probe and washing it with water after use. Can be used over and over again.

〔Example〕

Example 1 100 parts by weight of a PEG-PPG-PEG block copolymer (molar ratio 1:2:1, MW: 2000) in which polyethylene glycol is bonded to both ends of polypropylene glycol, and monomethoxy polyethylene glycol (MW: 5)
A triisocyanate (MW:
3100) and 0.1 ffiffi parts of dibutyltin dilaurate as a catalyst were added and mixed by stirring well.

This mixture is completely degassed under reduced pressure, injected into a mold, and left at 60°C overnight to form a donut plate-shaped spacer (outer diameter: 60 mm) made of polyurethane gel-like elastic material as shown in Figure 1. , through-hole diameter: 14 mm, maximum thickness: 10 mm, minimum thickness: 2.5 mm). The value of O11/NG O of this product is 1.5.

This spacer was transparent and had good adhesiveness, and its hardness was measured with an Asker F type hardness meter (polymer meter (horizontal crack)) and found to be 26 degrees.

Next, the probe of a continuous wave Doppler probe is inserted into the through hole of this spacer, filled with jelly, and pasted on the anterior chest wall of the human body, and then pressed down with a rubber band from above to measure the double-phase valve orifice blood flow waveform. Continuous monitoring showed that there was no deviation in the position of the probe or any leakage of the blemishes, and clear images with extremely low noise and artifacts were obtained. After the monitoring was completed, the spacer was placed 711 cm away from the anterior chest wall and the condition of the skin was examined, but no rash was observed.

After that, remove the spacer from the probe and wash it with water.
The attached jelly could be removed using simple IQ.

Example 2 Polyethylene glycol (MW: 600) Wo100
Weight parts and monomethoxypolyethylene glycol (MW:
400) and triisocyanate (MW': 1) obtained by adding polypropylene glycol to glycerin and reacting it with xylylene diisocyanate.
564) and 0.1 part by weight of dibutyltin dilaurate as a catalyst were added and mixed with thorough stirring.

This mixture was completely defoamed under reduced pressure, poured into a mold, and left at 60° C. overnight to obtain a spacer made of a polyurethane gel-like elastic body having the same shape and dimensions as in Example 1. The value of 011/NCO for this product is 1.2.

Like the one in Example 1, this spacer was transparent and had good adhesiveness, and its hardness was measured with an Asker F-type hardness meter (polymer meter (m!!!) and it was 64 degrees. Ta.

Next, when the double-phase valve orifice blood flow waveform was continuously monitored using this spacer in the same manner as in Example 1, no displacement of the probe or outflow of the jelly was observed, and noise and artifacts were extremely low. A clear image was obtained. Furthermore, the condition of the skin after the monitoring was completed did not show any signs of irritation, and the jelly was easily removed by washing with water.

〔Effect of the invention〕

As is clear from the above description, the spacer of the present invention can securely attach and fix the probe to the body surface without shifting its position, and can also prevent jelly-like substances from flowing out, so it can eliminate noise and artifacts even in continuous monitoring. It is possible to obtain an extremely small number of images, and since it is completely non-toxic to the human body, it can be applied to the body surface for a long time with peace of mind.It also has good mechanical strength and water resistance, so it becomes jelly-like after use. It has the remarkable effect that objects can be removed by washing with water and used repeatedly.

[Brief explanation of drawings]

FIG. 1 is a plan view showing one embodiment of the spacer of the present invention, and FIG.
The figure is a sectional view taken along the line 1-1 in FIG. 1, and FIG. 3 is a sectional view showing the state in which the spacer of the present invention is used. ■...Spacer, 1a...Through hole, 2...Ultrasonic diagnostic probe, 2a...Probe.

Claims (1)

[Claims] (1) A polyol having an alkylene oxide chain or/and a polyurethane polyol prepolymer having an alkylene oxide chain and a polyurethane polyisocyanate prepolymer having an alkylene oxide chain are reacted, and the hardness according to the Asker F hardness tester is 20. A spacer for attaching an ultrasonic diagnostic probe, which is made of a polyurethane gel-like elastic material with an angle of about 80 degrees, and has a through hole formed in the center thereof into which the probe of the ultrasonic diagnostic probe is inserted.