JP2015224880A - Liquid leakage sensor and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a liquid leakage sensor which is easy to handle and inexpensive and has extremely high versatility, and a manufacturing method thereof.SOLUTION: The liquid leakage sensor for detecting the leakage of a liquid includes an upper sheet having conductivity acting as an electrode and liquid permeability, a lower sheet having conductivity acting as an electrode and liquid permeability, and a porous paper pulp sheet held by the upper and lower sheets and having water absorbency and diffusivity. The upper sheet and the paper pulp sheet as well as the lower sheet and the paper pulp sheet are bonded together by a water-soluble adhesive whose insulation resistance increases by drying. As a liquid on the upper sheet penetrates the paper pulp sheet passing therethrough and reaches the lower sheet, electrical continuity is established between the upper sheet and the lower sheet.

Description

  The present invention relates to a leakage sensor that detects leakage of liquid, and particularly in artificial dialysis, blood that is purified by an artificial kidney and returns from the dialysis machine to the human body is removed from the human body or the dialysis needle is connected to a tube. The present invention relates to a blood leak detection sensor that detects a blood leak in which blood leaks in the vicinity of a dialysis needle by dropping a contact to perform a warning.

  FIG. 1 shows a schematic structure and operating principle of a conventional blood leak detection sensor. The circuit portion of the blood leak detection sensor 10 is composed of a pair of comb circuits 12 and 12 'created by etching a copper clad laminate, and terminals 13 and 13' are connected to one ends of the pair of comb circuits 12 and 12 ', respectively. Is formed. The terminals 13 and 13 'are formed by etching a plastic sheet such as polyimide and performing gold plating or the like. The electrical wiring is performed by soldering the lead wire to the terminals 13 and 13 '.

  The pair of comb circuits 12, 12 'is attached to the base material 14 having good water absorption. The pair of comb circuits 12 and 12 'are normally separated and open, and when the base material 14 is wetted by gauze or the like with the lost blood, the pair of comb circuits 12 and 12' is closed. It becomes energized.

  Such a blood leakage detection sensor 10 is fixed to a human body with an adhesive tape or the like in the vicinity of a dialysis needle or an injection needle, and a detector such as a terminal 13 and an LED warning lamp 15 is connected to a lead wire 15 via a power supply 16. Connect and use. When the pair of comb circuits 12, 12 'gets wet with the lost blood, the copper clad laminate of the pair of comb circuits 12, 12' conducts and informs the doctor or nurse with a detector buzzer or warning light.

  The blood leakage detection sensor 10 shown in FIG. 1 can be energized when the pair of comb circuits 12 and 12 ′ are closed only after the blood permeated by the blood leakage sufficiently permeates the water-absorbing base material 14. Therefore, in order to detect blood leakage, a large amount of blood is required, and there is a drawback that detection sensitivity is poor. Moreover, in order to form a pair of comb circuits, an expensive copper foil film is necessary as a raw material, and it is necessary to design various sizes of large and small sizes each time according to the use form of the blood leakage detection sensor. is there.

  FIG. 2 shows a schematic structure and operating principle of a conventional blood leak detection sensor 20 different from the blood leak detection sensor of FIG. The blood leak detection sensor 20 has first and second metal mesh sheets 21 and 22 that are electrically conductive and flexible and act as electrodes, the first metal mesh sheet 21, the first metal mesh sheet 21, and the second metal mesh sheet 21. A water-permeable cloth sheet 23 sandwiched between two metal mesh sheets 22, a water-impermeable resin sheet 24 is provided on the upper side of the first metal mesh sheet 21 to suppress metal allergy, A water permeable mesh resin sheet 25 is provided under the second metal mesh sheet 22. The first metal mesh sheet 21 and the second metal mesh sheet 22 each have a terminal at one end, and lead wires 26 and 27 are soldered to the terminals.

  The water-permeable reticulated resin sheet 25 is wetted by the lost blood, and this blood leakage permeates the second metal reticulated sheet 22, further wets the water-permeable cloth sheet 23, and finally the first metal reticulated sheet. When reaching 21, the first metal mesh sheet 21 and the second metal mesh sheet 22 become conductive.

  Such a blood leak detection sensor 20 is fixed to a human body with an adhesive tape or the like in the vicinity of a dialysis needle or an injection needle, and a detector is provided between the first metal mesh sheet 21 and the second metal mesh sheet 22. The lead wires 26 and 27 are used for connection through the terminal 28. When the first metal mesh sheet 21 and the second metal mesh sheet 22 become conductive due to blood leakage, a buzzer or warning light of the detector 28 is used to notify the doctor or nurse.

  The blood leak detection sensor 20 shown in FIG. 2 must use an expensive metal mesh sheet, and since the metal mesh sheet is used, sufficient consideration must be given to the disposal of such material. It is. Furthermore, in order to suppress metal allergy, it is necessary to use a resin sheet. Therefore, there is a drawback that the manufacturing cost is high.

  In addition, since the blood leak detection sensor 20 is usually manufactured with a standard size, there is no degree of freedom such that the dimensions can be freely cut according to the usage pattern.

  FIG. 3a shows a schematic structure and operating principle of a conventional blood leak detection sensor 30, which is different from the blood leak detection sensor shown in FIGS. The blood leakage detection sensor 30 is a sensor that utilizes light transmission and reflection, and a base material 31 that is fixed to a human body in the vicinity of a dialysis needle and an injection needle, and the base material 31 is irradiated with light facing the skin. The light transmitting unit 32 that is connected to the light transmitting unit 32, the light receiving unit 33 that faces the skin of the base material 31 and receives reflected light from the skin side, and the light transmitting unit 32 and the light receiving unit 33. When the light emitted from the light is reflected on the skin side, the light receiving intensity detecting means 36 for detecting the intensity of the reflected light is provided. The light transmitting unit 32 and the light receiving unit 33 have storage spaces 34 and 34 ′ opened on the opposite side of the skin on one side, respectively. A translucent fiber assembly 35 having different light transmittances depending on the amount of impregnation is filled. The blood leak detection sensor 30 detects blood leak by measuring the change in the light transmittance.

  FIG. 3 b shows a usage pattern of the blood leak detection sensor 30. When the blood leak detection sensor 30 is fixed to the wrist, the light emitted from the light transmitting portion 32 such as a small LED of the blood leak detection sensor 30 near the tip of the dialysis needle 37 is a transparent fiber assembly. When the body is impregnated due to blood leakage, the light transmittance decreases according to the amount of impregnation, thereby reducing the light receiving sensitivity of the light receiving unit 33, and this change is detected by the light receiving intensity detecting means 36. The When a decrease in light transmission is measured, a blood leak is sensed and a buzzer or warning light is activated to inform the doctor or nurse.

  Since the blood leakage detection sensor using such light characteristics can only detect local blood leakage in a patient whose detection area is extremely limited, there is a problem in terms of reliability in detecting blood leakage related to human life. In addition, since an electronic circuit for light emission and light reception is necessary, there is a problem that the manufacturing cost is increased.

  An object of the present invention is to provide a highly versatile leak detection sensor, such as a leak detection sensor that is easy to handle and inexpensive, preventing a serious accident caused by blood leak, particularly in a medical field, and a manufacturing method thereof. There is to do.

  The liquid leakage detection sensor for detecting liquid leakage according to the present invention includes a conductive and liquid permeable upper sheet that functions as an electrode, a conductive and liquid permeable lower sheet that functions as an electrode, and an upper sheet. And a porous paper pulp sheet sandwiched by the lower sheet and having water absorption and diffusibility. The upper sheet and the paper pulp sheet and the lower sheet and the paper pulp sheet are bonded together by a water-soluble adhesive whose insulation resistance is increased by drying. The liquid on the upper sheet passes through the paper pulp sheet and reaches the lower sheet, whereby the upper sheet and the lower sheet are electrically connected.

  According to the present invention, in artificial dialysis, blood that has been purified by an artificial kidney and returned to the human body from the dialyzer is removed from the human body or the contact between the dialysis needle and the tube is dropped. It is possible to provide a low-cost blood leak detection sensor with a simple configuration that prevents a serious accident that leaks in the vicinity of a needle, detects the blood leak, and issues an alarm.

  In addition, according to the present invention, an inexpensive and easy-to-manufacture disposable blood leak detection sensor that uses an adhesive made of paper pulp and natural materials and solves the physiological and disposal environment problems such as hygiene and allergies. It is possible to provide.

  In addition, according to the present invention, it is possible to easily attach and detach to / from a patient in a medical field, and a part of an indwelling needle such as a chemical solution used after the operation during or after the operation can be removed or a blood leak can be quickly detected and seriously detected. It is possible to provide a blood leak detection sensor capable of preventing an accident.

  In addition, according to the present invention, when used or wound around the affected area of the patient, in addition to the patient's blood leakage, the liquid leakage and urinary incontinence can be easily detected, and an alarm is issued to inform the surroundings. It is possible to provide a versatile liquid leakage sensor capable of performing

  In addition, according to the present invention, it can be formed into a single sheet and can be easily cut into a free shape with a scissors or the like, and can be easily manufactured or cut according to the body and part of the patient. In addition, it is possible to provide an economical blood leak / leak sensor that can also be used for cutting off.

  In addition, according to the present invention, it is possible to provide an environment-friendly blood leakage / leakage detection sensor that is inexpensive, can be disposable, and can be discarded and incinerated as it is once used.

FIG. 1 shows a schematic structure and operating principle of a conventional blood leak detection sensor. FIG. 2 shows a schematic structure and operating principle of a conventional blood leak detection sensor different from the blood leak detection sensor of FIG. FIG. 3a shows a schematic structure and a principle of operation of a conventional blood leak detection sensor different from the blood leak detection sensor of FIG. 1 and FIG. FIG. 3a shows a usage pattern of the blood leak detection sensor in FIG. 3a. FIG. 4a shows a cross-sectional view of a leak detection sensor of the present invention. FIG. 4b shows an assembled perspective view of the leak detection sensor of the present invention. FIG. 5a shows a usage pattern of the leak detection sensor of the present invention, and particularly shows a schematic electric circuit for detecting leak using the leak detection sensor. FIG. 5b shows a usage pattern of the leak detection sensor of the present invention, and particularly shows a configuration of a power feeding terminal used with the electric circuit of FIG. 5a. FIG. 6 specifically shows that the liquid leakage detection sensor of the present invention is formed as a sheet material and can be used by freely cutting it with a squeeze or the like.

  FIG. 4 shows the structure of the leak detection sensor of the present invention. In particular, FIG. 4a shows a sectional view of the leak detection sensor, and FIG. 4b shows an assembled perspective view.

  The leak sensor 40 is a conductive sheet that acts as an electrode, and is a liquid permeable upper sheet 41 and lower sheet 42 formed of carbon nanotube (CNT) paper or carbon mixed paper mixed with Japanese paper. In between, it is comprised so that the porous paper pulp sheet 43 excellent in the water absorption and the diffusibility which is generally called the paper towel may be pinched.

  The upper sheet 41 and the paper pulp sheet 43 and the lower sheet 42 and the paper pulp sheet 43 are bonded to each other by a water-soluble adhesive 44 such as starch powder that increases the insulation resistance when dried. When the leak sensor 40 is used in a medical field, the material must be guaranteed to be safe. Therefore, it is preferable to use an adhesive using starch gelation made from natural ingredients such as potato or tapioca, avoiding chemically synthesized adhesives and resin adhesives. The water-soluble starch starch adhesive has a crystal structure when heated, increases its adhesive strength, and at the same time increases its insulation resistance. Keep insulation high.

  The actual manufacturing of the leak sensor 40 is performed by thinly applying a water-soluble adhesive 44 such as starch powder on both sides of the paper pulp sheet 43, and superposing the upper sheet 41 and the lower sheet 42 on the upper and lower sides thereof, and It is pressed and dried at once with a hot press, and finished into a single sheet. At that time, by using a long roll and a rotary heat press to roll the sheet material, it is possible to produce a leak detection sensor that can be mass-produced and is much cheaper than conventional products. The sheet material of the completed long roll can be cut into a free shape according to the usage pattern at the medical site according to the usage form, such as a bent part or stenosis part of the patient's body. It is possible to freely form a shape according to a complicated affected part.

  In the leak sensor 40, for example, when blood leakage or chemical liquid is dropped on the upper sheet 41, these liquids are diffused inside the upper sheet 41, and the upper sheet 41 and the paper pulp sheet 43 are bonded together. These liquid water molecules enter the gaps between the crystal molecules of the water-soluble adhesive 44, and the crystal structure relaxes and simultaneously penetrates the crystal branches and diffuses into the paper pulp sheet 43. This permeation of water molecules lowers the insulation resistance value at the same time as dissolving the crystal having a high insulation degree. The liquid such as blood leakage and chemical liquid diffused in the paper pulp sheet 43 penetrates the liquid further deeply due to the capillary phenomenon caused by the fibers of the paper pulp sheet 43 and is guided to the lower sheet 42, and between the upper sheet 41 and the lower sheet 42. Is made electrically conductive.

  FIG. 5 shows a usage pattern of the leak detection sensor of the present invention. In particular, FIG. 5a shows a schematic electric (detection) circuit for detecting leak using the leak detection sensor, and FIG. FIG. 6 shows the configuration of a clip, which is a power supply terminal used with the electrical circuit of FIG.

  The surfaces of the upper sheet 41 and the lower sheet 42 have conductivity. In order to provide power supply terminals on the upper sheet 41 and the lower sheet 42, for example, a copper foil terminal must be adhered to the surface of the sheet with a conductive adhesive. However, since the material of the upper sheet 41 and the lower sheet 42 is formed of carbon nanotube (CNT) paper mixed with Japanese paper or carbon mixed paper, a power supply position is set in advance, and power supply is appropriately performed in a medical field. It is not realistic to provide a terminal. The liquid leakage detection sensor of the present invention is formed as a sheet material, and has one feature in that it can be freely cut off by squeezing or the like and applied to an affected area.

  In order to make the best use of this feature, a power supply clip is provided, and FIG. 5 b shows a configuration of a power supply clip 50 for the upper sheet 41 and a power supply 50 ′ for the lower sheet 42. Each of the power feeding clips 50 and 50 ′ is formed of an insulating resin such as plastic, and the sandwiched portion can be strongly meshed with a spring. The power supply clip 50 for the upper sheet 41 has a metal electrode plate 51 mounted above the narrow end, and the power supply 50 'for the lower sheet 42 is mounted below the narrow end. A metal electrode plate 51 ′. Lead wires 52 and 52 'are attached to the metal electrode plates 51 and 51', respectively. Each of the metal electrode plates 51 and 51 ′ has a saw-toothed surface on the side in contact with the sheet, and ensures secure attachment so that it does not come off when the sheet is squeezed.

  As shown in FIG. 5a, power feeding clips 50 and 50 ′ are attached to the leak detection sensor 40, respectively, and power is fed to the power feeding clip 50 and power supply clips 50 and LED warning lights 54 by lead wires 52 and 52 ′. The clip 50 'is connected to form a detection circuit. The detection circuit is normally open.

  In a medical field, a leak detection sensor 40 that forms a detection circuit is fixed to a human body with an adhesive tape or the like in the vicinity of a dialysis needle or an injection needle. As shown in FIG. When the liquid drops and the lump 45 such as blood leakage and chemical liquid exist, the feeding clip 50 and the feeding clip 50 ′ are electrically connected as described above, and the detection circuit is closed. As a result, the LED warning lamp 54 is turned on to notify the doctor or nurse.

  FIG. 6 specifically shows that the liquid leakage detection sensor of the present invention is formed as a sheet material and can be used by freely cutting it with a squeeze or the like.

  The sheet material is not only usable as a leak detection sensor as it is, but also the sheet materials 61 and 62 cut out in accordance with the affected part of the patient and after the sheet materials 61 and 62 are cut out. Even the sheet material 60 can be used as a leakage sensor. As described above, the present invention provides a simple leak detection sensor that is inexpensive, is disposable, and is environmentally friendly and can be disposed of by incineration.

40: Liquid leakage detection sensor 41: Upper sheet 42: Lower sheet 43: Paper pulp sheet 44: Water-soluble adhesive 45: Blood leakage, lump of chemical liquid 50, 50 ': Feeding clip 51, 51': Metal electrode plate 52, 52 ': Lead wire 53: Power supply 54: LED warning light

In order to make the best use of this feature, a power supply clip is provided, and FIG. 5 b shows a configuration of a power supply clip 50 for the upper sheet 41 and a power supply 50 ′ for the lower sheet 42. Each of the power feeding clips 50 and 50 'is formed of an insulating resin such as plastic, and the sandwiched portion can be strongly meshed with the spring. The power supply clip 50 for the upper sheet 41 has a metal electrode plate 51 mounted above the tip of the narrow portion, and the power supply clip 50 ′ for the lower sheet 42 is below the tip of the narrow portion. It has a metal electrode plate 51 'mounted. Lead wires 52 and 52 'are attached to the metal electrode plates 51 and 51', respectively. Each of the metal electrode plates 51 and 51 ′ has a sawtooth surface on the side that comes into contact with the sheet, and ensures secure attachment so that it does not come off when the sheet is squeezed.

Claims (6)

In the leak detection sensor that detects the leak of liquid,
A conductive and liquid permeable top sheet that acts as an electrode;
A conductive and liquid permeable lower sheet acting as an electrode;
A porous paper pulp sheet having water absorbency and diffusibility, sandwiched between the upper sheet and the lower sheet;
A water-soluble adhesive that increases the insulation resistance by drying, which bonds between the upper sheet and the paper pulp sheet and between the lower sheet and the paper pulp sheet;
Consists of
The liquid on the upper sheet passes through the paper pulp sheet and reaches the lower sheet, whereby the upper sheet and the lower sheet are electrically connected to each other. Sensing sensor.   The liquid leakage sensor according to claim 1, wherein the upper sheet and the lower sheet are formed of carbon nanotube (CNT) paper or carbon mixed paper mixed with Japanese paper.   The leak sensor according to claim 1 or 2, wherein the water-soluble adhesive is a gelatinized natural food starch powder. A power supply clip for the upper sheet formed of an insulating resin, wherein the power supply clip has a metal electrode plate mounted above the tip of the narrow part;
A power supply clip for the lower sheet formed of an insulating resin, wherein the power supply clip has a metal electrode plate attached below the tip of the narrow part;
The leak sensor according to any one of claims 1 to 3, further comprising:   The leak sensor according to claim 4, wherein a surface of the metal electrode plate on a side in contact with the upper or lower sheet is processed into a sawtooth shape. In a manufacturing method of a leak detection sensor for detecting leakage of a liquid,
Providing a conductive and liquid permeable upper sheet that acts as an electrode;
Preparing a lower sheet having electrical conductivity and liquid permeability that acts as an electrode;
Preparing a paper pulp sheet, and applying a water-soluble adhesive that increases insulation resistance by drying on both sides of the paper pulp sheet;
A step of heating and pressing the upper sheet and the lower sheet 42 on top and bottom of the paper pulp sheet coated with the water-soluble adhesive on both sides, and then drying to finish into a roll-shaped sheet material;
A method for producing a leak detection sensor, comprising: