JPS6318500B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a medium for ultrasonic diagnostic equipment. More specifically, the present invention relates to a gel agent for ultrasonic diagnostic equipment, which is obtained by gelling a water-wettable stock solution with a neutralized crosslinked acrylic acid polymer.

The method of capturing various images using ultrasound diagnostic equipment is an innovative method for discovering diseases and abnormalities and saving lives. It is well known that it is safe and tends to be widely used as a very useful diagnostic method. A transducer (also called a probe) connected to an ultrasound device is placed in close contact with the human epidermis, and as it is moved over the entire area to be examined, it is focused by a computer and the entire image is captured in perfect focus. be. Brain tumors, hematomas, stones, cardiac valve abnormalities, fetal placental conditions, etc. can be detected by collecting images of high-frequency sound waves that penetrate body tissues and bounce back as echoes. Therefore, it is read and diagnosed.

In that case, if a gap exists between the transducer and the human body epidermis, the ultrasonic waves are blocked and the transmission rate becomes zero, making it impossible to obtain the necessary image. Water, bioelectrode paste, mineral vegetable oil, etc. are used to fill this intervening space. As shown in FIG. 1, vegetable oil and water give preferable transmissibility values.
That is, in Figure 1, line 1 is air, line 2 is mineral oil,
Line 3 shows the transmissivity in the case of commercially available bioelectrode paste, line 4 shows the transmissibility in water, and line 5 shows the transmissivity in the case of vegetable oil.

However, even though they exhibit favorable transmissibility, vegetable oils are difficult to handle because their viscosity changes depending on temperature and there is a risk of rancidity, and when applied to the skin, it is very difficult to clean it after surgery. Water evaporates twice as much as it evaporates due to body temperature, dries in a short time, and immediately allows the formation of voids, and since both of them are free-flowing at temperatures around body temperature, they flow and are necessary. It is clear that it is extremely difficult to keep it in place. The paste for bioelectrodes is made by dissolving various substances such as electrolytes such as common salt in order to improve its conductivity. Therefore, if evaporation progresses even slightly, the turbidity will increase even more, and this will affect the transmittance. This will cause a sudden decline.

In other words, the medium for ultrasonic diagnostic equipment has the following properties: (1) The transmission efficiency of ultrasonic waves (including the case of echoes) is equal to or higher than that of water, (2) it does not run or drip on the skin surface, and (3) it does not dry easily.
(4) It has a viscosity suitable for the movement of the transducer and does not change in viscosity, (5) It is transparent and does not have turbidity due to crystal precipitation, (6) It is not toxic or irritates the skin, (7) It must have properties such as being easy to wipe off after use.

The present inventor has conducted extensive research to provide a medium for ultrasound diagnostic equipment that meets the above-mentioned essential requirements. Completed invention of gel for equipment.

A water-wetting stock solution is water, a mixture of water and a wetting agent,
or a wetting agent. The humectant is a drying agent that is commonly used in pharmaceuticals and cosmetics, such as alcohols and glycols, and is preferably of a variety quality that meets cosmetic raw material standards, is difficult to dry by itself, and can be mixed with water. There are substances that suppress drying when mixed with water, such as ethylene glycol monobutyl ether, butylene glycol, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl ether, propylene glycol, glycerin, and polyethylene glycol. Furthermore, water-soluble solids such as pyrrolidone carboxylate and lactic acid that have a drying suppressing effect, and surfactants such as sulfosuccinate ester and lauryl sulfate ester that have wetting properties can also be used.

Crosslinked acrylic acid polymers include acrylic acid or (and) methacrylic acid, divinylbenzene, pentaerythritol allyl ether, allyl cyanurate, phosphoric acid or phosphorous acid allyl esters, polyalkylene glycol diallyl ethers, A water-swellable crosslinked polymer obtained by copolymerizing with a so-called crosslinking agent, which has multiple copolymerizable fully functional groups such as alkylene bisacrylate and methacrylic alkylene dicarboxylate, and is an acrylic acid monomer. It also includes copolymerizable monomers such as maleic anhydride. These water-swellable polymers exhibit a thickening effect when neutralized with an inorganic or organic alkali. Alkali used as neutralizing agents include sodium carbonate, sodium bicarbonate, aqueous ammonia, sodium hydroxide, triethanolamine, and diethanolamine, which are listed in the Cosmetic Raw Materials Standards.

In addition, in the measurement room, etc., it is free to add coloring agents, flavoring agents, etc. to give a favorable impression to subjects and handlers, and to add preservatives, antifungal agents, etc. to improve preservability.

In water, a mixture of water and a wetting agent, or a wetting agent,
If desired, the mixture is subjected to treatments such as coloring, flavoring, and preservative treatment, and while stirring, a crosslinked acrylic acid polymer is slowly added and dissolved in an amount of usually 0.2 to 3.0% by weight.
When the polymer is dissolved transparently, stir slowly and neutralize by adding an amount of alkali corresponding to the amount of the polymer, or a weak alkali for better workability. In this way, a gel for an ultrasonic diagnostic apparatus of the present invention is obtained. This gel has a high ultrasound transmission rate, has a suitable viscosity, does not run or drip, is difficult to dry, is always transparent, is non-toxic and non-irritating, and is extremely easy to wipe off after surgery. It can be easily and completely removed by wiping it with a cloth or paper dampened with water, and because of its viscosity, it is difficult to enter the pores of the transducer, and even if it does enter, it is easily water-soluble. It is easy to clean and is extremely suitable in all respects, making it useful as an excellent medium for ultrasonic diagnostic equipment.

Examples are shown below. Parts expressing quantities are parts by weight.

Example 1 A very small amount of Embass Blue was added to a mixture of 20 parts of propylene glycol and 80 parts of water to give a pale blue color, and under stirring, a commercially available cross-linked acrylic acid polymer (Wako Pure Chemical Industries, Ltd. ) made by Hibis Wako 104)
Add and dissolve 0.5 part. Neutralize the clear solution with 0.4 part of monoethanolamine while stirring slowly.
B8H type rotational viscometer (20 rpm, 25℃ measurement) viscosity
Obtain 48000cps of gel. The ultrasonic transmittance of the gel of this example is shown by line 6 in FIG.

Example 2 Add 0.05 part of propyl oxybenzoate as a preservative to 100 parts of glycerin, dissolve 0.2 part of a commercially available cross-linked acrylic acid polymer while stirring, and gently stir the resulting transparent liquid to dissolve 0.3 part of triethanolamine. Neutralize in the section. Similarly, a gel with a viscosity of 56,000 cps is obtained. The drying curve obtained by comparing and measuring the same weight in the same type of shear dish at the same time at 37 ± 1℃ is the second
As shown in the figure, line 1 is water, line 2 is commercially available bioelectrode paste, line 3 is the gel of Example 1 without using propylene glycol, line 4 is the gel of Example 1, line 4 is the gel of Example 1, and line 4 is the gel of Example 1. 5 is the drying curve of the gel of Example 2, and it is known that 4 and 5 are superior to the others by a large difference, and 3 is the second best.

[Brief explanation of the drawing]

FIG. 1 is a graph showing the characteristics of ultrasonic transmissivity corresponding to the ultrasonic output, and FIG. 2 is a graph showing the characteristics of dryness over time.

Claims (1)

[Claims] 1. A gel for ultrasound diagnostic equipment, which is made by gelling a water-wettable stock solution selected from water, a mixture of water and a wetting agent, or a wetting agent with a crosslinked acrylic acid polymer and a neutralizing agent. agent.