JPS6269135A - Liquid leak detector - Google Patents

Abstract

PURPOSE:To improve safety of the titled detector by fitting flexible electric conductors in two rows to flexible base material having absorbency and incorporating a circuit main body with the base material. CONSTITUTION:The base material 1 having an opening is wound in an arm-belt shape round a part where a liquid transfusion needle 7 of the tip of a liquid transfusion circuit 6 connected with a liquid transfusion bottle 5 is stuck and fixed thereon. The base material 1 is formed of nonwoven cloth or the like and the material absorbing water and forming a continuous phase of the water and moreover, having flexibility is used. Further, the electric conductors 10 and 10' in two rows having flexibility are provided to the base material 1 and connected with the circuit main body 4 by connectors 11 and 11' connected with the electric conductors 10 and 10'. Then, when the base material is fitted to a necessary part and the circuit main body 4 is connecterd with the connectors 11 and 11' connected with the electric conductors 10 and 10', in case there is a leak of the transfusion liquid, electric resistance between the electric conductors 10 and 10' fitted in two rows is lowered by moisture infiltrating into the base material 1 and an electric current is applied and an alarm is sounded by an action of an electric circuit.

Description

[Detailed Description of the Invention] (Industrial Application Field) The present invention relates to a liquid leakage detection device, and particularly to a liquid leakage detection device for detecting liquid leakage from a shunt in extracorporeal blood circulation treatment, a junction between a blood collection needle and a blood circuit, a punctured part of a blood collection needle, etc. The present invention relates to a device useful for detecting blood leakage or infusion leakage from a puncture site of an infusion needle during infusion.

(Conventional technology and problems) Blood leakage from multiple sources during extracorporeal blood circulation can be life-threatening, and can even lead to transfusion! Early detection of blood and transfusion leaks is extremely important, as leaks impede effective treatment.

In conventional blood dialysis, plasma separation, and other relatively short-time extracorporeal blood circulation treatments, blood leaks can be detected early because the patient or the doctor monitors for blood leaks. However, in the case of long-term extracorporeal blood circulation treatments such as recently developed wearable artificial kidneys and extracorporeal circulation lung support, conventional human monitoring of blood leakage is impossible.

However, at present, no device has been proposed that automatically detects the overflow of blood or transfusion fluid.

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a device for automatically detecting leaks of liquids, in particular blood and transfusions. g of the present invention! The leak detection device consists of two rows of visible conductors, each with a connector connected to it, attached to a water-absorbing, combustible base material, and the flexible conductors and the detection circuit body can be attached and detached using connectors. The present invention is characterized in that it is configured such that liquid leakage is detected by a decrease in electrical resistance between the conductors.

(Function) The device of the present invention is a conventionally known method for detecting wetness of a diaper, in which two conductors are placed apart, and when the electrical resistance decreases due to permeated urine, the device closes the gap between the two conductors. In reality, the method of detecting flowing current and issuing an alarm is that the conductor placed on the base material is a point electrode, so it can only detect local leaks, and it is also mechanically strong. Therefore, it lacks flexibility and cannot be used in areas that come into direct contact with the human body.Moreover, the detection circuit and base material are connected by lead wires, making the device complex and causing problems such as poor insulation. Therefore, this problem can be solved by attaching two rows of flexible conductors to a combustible base material that has water absorption properties, and by integrating the circuit body and the base material.
We have been able to provide a compact liquid leakage detection device that is free from malfunctions and can be safely used even in parts that come into direct contact with the human body.

(Example) Next, an example of the liquid leakage detection device of the present invention will be described with reference to the drawings. Fig. 1 shows an example in which the device of the present invention is used for extracorporeal blood circulation treatment, in which a base material l having two rows of conductors is attached to the upper part of the arteriovenous shank 1 to 2.2' of the membrane. It is wrapped around the base material in the shape of a wristband, and the circuit body is detachably connected to the end of the base material.

FIG. 2 shows an example in which the device of the present invention is used to detect infusion overflow in an infusion, and shows a substrate l having an opening at the part where an infusion needle 7 at the tip of an infusion circuit 6 connected to an infusion bottle 5 is punctured. is wound and fixed in the form of a wrist band, as in Fig. 1.

The water-absorbing base material 1 to which the conductor is attached is formed of a cloth-like body knitted or woven with natural fibers or synthetic fibers, or non-woven fabric, paper, film, etc., and absorbs water to form a continuous phase of water,
Moreover, it is flammable. Normally, nonwoven fabric or gauze is preferably used. Further, any shape can be used depending on the mounting location. When wrapping around the arm, a rectangular shape is preferable.

The conductors attached to the base material 1 in two rows may be of any kind as long as they are flammable and conductive. For example, direct wires such as tungsten, stainless steel, nickel, and copper with a length of approximately 0, os to 2 m, and plated fibers made of acrylic, vinylon, and other fibers plated with silver, copper, nickel, etc., are used.

Also, paints with conductive properties, such as powders in which silver, aluminum, or copper particles are plated with silver, using epoxy resin as a binder, etc.
Alternatively, it may be attached to the surface of the υ substrate by printing, coating, or dipping the substrate using conductive ink.

A film made of aluminum, copper, stainless steel, nickel, etc. may be attached to the surface of the base material.

In particular, plated fibers can be easily sewn into fibrous base materials such as non-woven fabrics, and have approximately the same visibility as the base material.
Therefore, it can be used conveniently without causing any discomfort when attached to the human body.

As shown in FIG. 3, these plated fibers i10, 10' are sewn into a comb-like shape in two rows from the end of a base material I made of a rectangular non-woven fabric so as to keep the spacing constant. A connector 11, 11' is connected to the end of the connector 11, 11' to detachably connect a channel main body [8] to be described later. The connector connects the conductor and the circuit body both electrically and mechanically, and can use the known attachment/detachment mechanism. An inexpensive commercially available hook is used.

The detection sensitivity of liquid leakage can be adjusted by changing the spacing between the two rows of conductors. If this interval is narrow, the sensitivity will be high, and if this interval is wide, the sensitivity will be low. When plated fibers are attached to a non-woven fabric base material as shown in Figure 3, a liquid leakage of +cc can be detected within about 15 seconds if the interval is normally 8 to 20 hours, preferably Fi+o to 15 degrees. can.

In order to protect the base material and the conductor from damage caused by external forces, it is preferable to cover both sides of the base material 1 with a water-absorbing sheet 12, as shown in the cross-sectional view in FIG. It is important that such a water-absorbing sheet has water-absorbing properties similar to the base material, and that it is also flammable and non-stick. Usually non-woven fabric or paper-like material is used. The sheet can be integrated with the base material by sandwiching the base material between two sheets and sewing the peripheral edges of the two sheets.

When attaching the base material to the human body, if the base material does not come into close contact with the human body, malfunctions or detection delays may occur. It is preferable to attach double-sided adhesive tape 13 to at least both ends of the back surface (the surface in contact with the human body) of the protective sheet covering the material. By attaching the adhesive tape to both ends of a rectangular protective sheet in multiple directions, it is easy to attach it to the arm, etc., and since both ends of the base material are completely adhesive-sealed to the human body. Blood leakage can be detected reliably.

When using the ring-shaped base material 1 to detect leaks such as infusions, adhesive tape is pasted on the entire back surface of the base material, and when it is attached to a human body, the infusion needle is sometimes inserted into the center opening of the base material. It is used by attaching it to the skin surface so that it is placed in place.

The circuit main body 4 can be composed of a known alarm circuit.
For example, as shown in Fig. 5, it is composed of a sensitivity setting circuit 21, a comparison circuit 22, and an alarm buzzer 23, and a reference resistor and a conductor are connected in series to the power supply voltage, and changes in the voltage across the reference resistor are compared. The sensitivity voltage is compared with a preset sensitivity voltage in the circuit, and the buzzer is activated when the voltage falls below the set voltage.

The buzzer stops when the circuit body is removed from the base material.

Instead of operating at a constant voltage as shown in FIG. 5, it may also be operated at a constant current. Alternatively, the reference resistor may be made variable and the setting signal of the comparison circuit may be fixed. The circuit main body can also be composed of a commercially available melody IC 24, a piezoelectric buzzer 25, and a battery 26 as shown in FIG. In this case, melody IC
When operated as a one-shot type, when blood leakage is detected, a predetermined melody can be played for a certain period of time.

It is also possible to perform remote wireless monitoring using the alarm buzzer as a transmitter. In this case, if each detection device emits a signal of a different wavelength and a corresponding lamp is installed in the monitoring room, blood leakage can be centrally monitored.

The circuit body 4 has a connector 14.14 which is coupled to a connector 11.11' connected to the conductor 10.10'.
' is connected. When a hook as shown in FIG. 3 is used as a connector, a corresponding hook is also attached to the circuit body. With such a connector, the circuit body and the conductor are connected and integrated, making it convenient to handle the device and completely preventing problems such as poor insulation.

To use the apparatus of the present invention, the base material 4 is applied to the required area as shown in FIG. 1 or 2, and the circuit body 4 is connected to the connector connected to the conductor.

If there is a leak of blood or transfusion, the moisture that permeates into the base material lowers the electrical resistance between the conductors attached in two rows, energizes them, and causes an alarm to be issued by the action of the electric circuit. The voltage for detecting the presence or absence of this current is 3.
Since a low voltage of V or less is sufficient, there is no danger at all even if the conductor comes into direct contact with the human body.

The device of the present invention can be used to detect leaks from diapers in addition to detecting leaks from blood and transfusions as described above.

(Effects) As described above, since the liquid leakage detection device of the present invention has a conductor attached to a combustible base material, it can be bent and folded freely and can be optimally attached to the human body. Since the base material is integrated, it is a compact device that does not break down.

[Brief explanation of drawings]

Figures 1 and 2 are perspective views showing how the device of the present invention is used, Figure 3 is a plan view of a base material to which a conductor is attached, and Figure 4 is a protective sheet on the base material. Covered state a! 5 and 6 are circuit configuration diagrams. 1... Base material 4... Circuit body 10.10'... Conductor 11.11' and 14.14'... Connector patent applicant stock Company Tafu Resos Pack Co., Ltd.

Claims (1)

[Claims] 1. Two rows of combustible conductors, each connected with a connector, are attached to a combustible base material having water absorbing properties, and the combustible conductors and the main body of the detection circuit are connected to each other. A liquid leakage detection device characterized in that the liquid leakage detection device is configured such that liquid leakage is detected by a decrease in electrical resistance between the conductors, which are detachably intertwined with each other by a connector. 2. The liquid leakage detection device according to claim 1, wherein both sides of the combustible base material are covered with flexible and water-absorbing protective sheets. 3. The liquid leak detection device according to claim 2, wherein double-sided adhesive tape is bonded to at least both ends of the back surface of the protective sheet.