JP7611466B2 - Intragastric detector - Google Patents

Description

The present invention relates to an intragastric placement detector that is used to detect whether the distal portion of a tube inserted from outside the body is placed in the stomach.

For example, for patients who have difficulty eating normally, one established method of administering nutrition is to insert a feeding tube through the nose or mouth into the esophagus and place it in the stomach, then supply a liquid nutritional supplement from outside the body into the feeding tube, which then sends the nutritional supplement to the stomach.

In this method, it is important that the procedure for inserting the distal part of the feeding tube into the stomach is performed properly. In other words, once the distal part of the feeding tube is inserted into the body, it cannot be seen, so if during the procedure the surgeon accidentally inserts it into the airway instead of the esophagus, it is impossible for him or her to visually confirm this. If nutritional supplements were to be supplied while the tube is inserted into the airway, the nutritional supplements would flow into the lungs, creating a dangerous situation, so it is necessary to check from outside the body whether the distal part is indwelling in the stomach before starting to supply the nutritional supplements.

One known method of confirmation is, for example, to send air into the proximal part of the feeding tube after the surgeon intuitively judges that the feeding tube has been inserted from outside the body. The air sent into the feeding tube circulates through the feeding tube and makes a bubbling sound when released into the stomach, and since this sound can be heard from outside the body, it can be confirmed by hearing. Here, if it is assumed that the distal part of the feeding tube has been mistakenly inserted into the trachea or lungs, this is not a particular problem since air is simply sent into the trachea or lungs, but since a sound similar to that produced when air is released into the stomach is generated, there is room for improvement in terms of the means of confirming that the tube is securely placed in the stomach.

Another method of confirmation is to aspirate gastric juice. In this method, the surgeon intuitively determines that the feeding tube has been inserted from outside the body, and then aspirates gastric juice from the proximal part of the feeding tube using a syringe or similar. If gastric juice can be seen from the proximal part of the feeding tube, it can be determined that the distal part of the feeding tube is indwelling in the stomach. However, if the distal part of the feeding tube has been inserted into the trachea or lungs, phlegm may be aspirated, and because phlegm and gastric juice can be visually similar, there is a risk of misjudging that the tube is indwelling in the stomach, even though it has been inserted into the trachea or lungs.

In addition, for example, there is a method in which an X-ray-opaque material is placed in the distal part of the nutrition tube, and the position of the distal part of the nutrition tube is identified by X-ray photography. This method makes it possible to accurately determine whether or not the distal part of the nutrition tube is placed in the stomach.

Patent Document 1 also discloses a catheter position confirmation member having an indicator that changes color upon contact with gastric juice. The indicator is provided in the proximal portion of the catheter, and liquid aspirated from the distal portion of the catheter is allowed to flow to the proximal portion, allowing it to come into contact with the indicator, making it possible to determine whether the aspirated liquid is gastric juice or not.

Patent document 2 discloses a stomach arrival confirmation device that includes a gastric juice reactor that uses gastric juice as an electrolyte to generate electromotive force, and an alarm that is activated by the electromotive force generated from the gastric juice reactor. The gastric juice reactor includes a pair of electrodes that form a voltaic cell using gastric juice as an electrolyte.

Patent No. 4605159 JP 2015-196040 A

However, the above-mentioned methods of pumping air and suctioning gastric juice as methods for determining whether the distal portion of the feeding tube is in the stomach cannot completely prevent the distal portion of the feeding tube from being erroneously inserted into the trachea or lungs, so it is conceivable to use an X-ray device to make an accurate determination. However, an X-ray device is a large device, and the facilities to which it can be applied are limited. In addition, the patient must be moved to the X-ray room, which places a heavy burden on the patient and causes problems such as exposure to X-rays.

Therefore, if an indicator is provided on the proximal part of the catheter as in Patent Document 1, for example, various problems caused by X-ray photography can be solved. However, if the catheter is mistakenly inserted into the trachea or lungs and phlegm is aspirated, the catheter position confirmation member cannot be used and it must be removed from the nose or mouth and a new catheter position confirmation member must be inserted through the nose or mouth, which is a burden for the patient and extends the treatment time, and furthermore the catheter position confirmation member is wasted.

Although the use of the device in Patent Document 2 also solves various problems caused by X-ray photography, there is a risk that accurate judgment may be difficult due to changes in electromotive force depending on the amount of gastric juice and the state of contact of the electrodes with the gastric juice. Also, if the electromotive force obtained in the gastric juice reactor is less than the operating power of the alarm, the alarm will not operate, but there is a problem in that it is not possible to determine whether the alarm does not operate because the electromotive force is insufficient even though the gastric juice reactor is installed in the stomach, or because the gastric juice reactor is not installed in the stomach and no electromotive force is being generated in the first place, resulting in a lack of accuracy.

The present invention was made in consideration of these points, and its purpose is to make it possible to accurately and quickly determine whether the distal part of the tube is placed in the stomach while minimizing the burden on the patient.

In order to achieve the above object, a first aspect of the present disclosure can be based on an intragastric placement detector that detects whether a distal portion of a tube inserted from outside the body is placed in the stomach. The intragastric placement detector includes a tubular body housed inside the tube that is inserted from outside the body into the stomach via the nose or mouth, and a suction unit that is connected to the proximal portion of the tubular body and applies negative pressure to the inside of the tubular body. The distal portion of the tubular body is provided with a distal opening that is closed with a dissolving member that dissolves when contacted with gastric juice.

With this configuration, when the tubular body is inserted into the stomach through the nose or mouth, it is possible that the distal portion may be mistakenly inserted into the trachea or lungs. In this case, since there is no gastric juice in the trachea or lungs, the dissolving material in the distal portion of the tubular body does not dissolve, and the distal opening remains closed. Therefore, even if negative pressure is applied to the inside of the tubular body by the suction unit, phlegm and the like will not flow into the inside of the tubular body through the distal opening, and the procedure of inserting the distal portion into the stomach can be continued using the same intragastric placement detector. This reduces the burden on the patient and shortens the procedure time.

When the distal part of the tubular body is inserted into the stomach, gastric juice, which is present in the stomach, comes into contact with the dissolving member. The dissolving member that comes into contact with the gastric juice dissolves, and the distal opening is opened. At this time, if negative pressure is applied to the inside of the tubular body by the suction part, gastric juice may flow into the inside of the tubular body from the distal opening. When gastric juice flows into the inside of the tubular body, the negative pressure causes the flowing gastric juice to flow to the proximal part of the tubular body, making it possible for the surgeon to visually confirm the flow.

In addition, as described below, when the fluid is contained inside the tubular body, the fluid flows to the proximal part of the tubular body due to the negative pressure, so the fluid can be visually confirmed by the surgeon. In this case, gastric juice may not flow to the proximal part of the tubular body.

In other words, if the distal portion of the tubular body is not retained in the stomach, gastric juice or fluid will not flow to the proximal portion, so if the surgeon visually observes any liquid at the proximal portion of the tubular body, it means that the distal portion of the tubular body is retained in the stomach and gastric juice or fluid has flowed to the proximal portion of the tubular body. Therefore, it is possible to accurately determine whether or not the distal portion of the tube is retained in the stomach.

In a second aspect of the present disclosure, a fluid is contained inside the tubular body. In this case, the fluid may be, for example, ink or water.

In a third aspect of the present disclosure, the fluid undergoes a color change upon contact with gastric juices.

With this configuration, for example, when gastric juice flows into the inside of the tubular body from the distal opening, it comes into contact with the fluid, causing the fluid to change color. The fluid that has undergone this color change flows to the proximal part due to the negative pressure inside the tubular body, allowing the surgeon to visually confirm that gastric juice has flowed into the inside of the tubular body, making it easy to tell.

In a fourth aspect of the present disclosure, the suction unit is configured as a manual suction device and is equipped with a retention mechanism that maintains a state in which negative pressure is applied inside the tubular body.

With this configuration, the surgeon can operate the manual suction device to apply negative pressure to the inside of the tubular body. The state in which negative pressure is applied can be maintained by the retention mechanism, so that the inside of the tubular body can be constantly kept in a state of negative pressure. Therefore, as soon as the dissolving member is dissolved, gastric juice can be made to flow to the proximal part, and it can be quickly notified that the distal part of the tube has been placed in the stomach.

In a fifth aspect of the present disclosure, the proximal portion of the tubular body is provided with a storage portion capable of storing the color-changing fluid, and the storage portion is made of a translucent material.

With this configuration, when the fluid flows to the proximal portion due to the negative pressure inside the tubular body, it is contained in the containing section. Because the containing section is translucent, it is easy to visually tell that the fluid has been contained in the containing section and that the fluid has undergone a color change.

In a sixth aspect of the present disclosure, the distal portion of the tubular body is provided with an inlet opening for allowing the color-changing fluid to flow into the interior of the tubular body, and a lid for opening and closing the inlet opening.

With this configuration, the fluid can be allowed to flow into the inside of the tubular body when the inflow opening is opened. After the fluid has flowed into the inside of the tubular body, the inflow opening can be closed with the lid, thereby keeping the fluid contained inside the tubular body.

In a seventh aspect of the present disclosure, a membrane is provided inside the tubular body to separate the space located on the distal opening side from the space on the proximal side, and is arranged to detach or tear from the inner surface of the tubular body due to the negative pressure, and the fluid is contained distal to the membrane.

According to this configuration, by storing the fluid in a portion distal to the membrane, it is possible to prevent the fluid from flowing to the proximal portion before the inflow of gastric juice. This allows the fluid to be kept in the distal portion from the manufacturing stage until immediately before use. Furthermore, when negative pressure is applied by the suction portion, the membrane separates or tears from the inner surface of the tubular body, so the flow of the fluid or gastric juice to the proximal portion is not impeded.

In an eighth aspect of the present disclosure, a membrane is provided inside the tubular body to separate the space located on the distal opening side from the space on the proximal side, and is configured to be torn by an external operation, and the fluid is contained distal to the membrane.

This configuration allows the fluid to be retained in the distal portion from the manufacturing stage until immediately before use, and by rupturing the membrane immediately before use begins, the flow of fluid and gastric juices to the proximal portion is not impeded.

In a ninth aspect of the present disclosure, the distal portion of the tubular body is provided with a permeable membrane that allows hydrogen ions to pass through. The fluid undergoes a color change upon contact with hydrogen ions.

With this configuration, hydrogen ions in the gastric juice permeate the permeable membrane and enter the inside of the tubular body. The fluid inside the tubular body undergoes a color change upon contact with the hydrogen ions.

In a tenth aspect of the present disclosure, the dissolving member can be configured to dissolve after hydrogen ions have permeated the permeable membrane.

In an eleventh aspect of the present disclosure, an intragastric placement detector that detects that a distal portion of a tube inserted from outside the body is placed in the stomach can be assumed. The intragastric placement detector includes a detection circuit unit that is inserted from outside the body through the nose or mouth into the stomach, a current supply unit that supplies current to a conductor portion of the detection circuit unit, and a notification unit that is connected in a conductive state to the conductor portion of the detection circuit unit and placed outside the body, and that goes into a first state when a current flows in the detection circuit unit and goes into a second state when a current does not flow in the detection circuit unit. The conductor portion of the detection circuit unit is configured to be disconnected when it comes into contact with a liquid in the body. The conductor portion may also be covered with a coating material that dissolves when it comes into contact with a liquid in the body.

According to this configuration, when the distal part of the tube is inserted into the stomach, the detection circuit part comes into contact with internal fluids such as gastric juice. If the conductor part of the detection circuit part is covered with a coating material, this coating material dissolves when it comes into contact with internal fluids, exposing the conductor part. In addition, if the conductor part itself is wetted with water, even if it is not gastric juice, or is inactive due to a chemical reaction and breaks, a coating material is required to prevent the conductor part from coming into contact with internal fluids before it is inserted into the stomach. If the exposed conductor part comes into contact with internal fluids, it will break, and no current will flow in the detection circuit part. On the other hand, when the distal part of the tube is inserted into the trachea or lungs, the coating part will remain covering the conductor part, and current will flow in the detection circuit part. Therefore, the procedure of inserting the distal part into the stomach can be continued using the same intragastric indwelling detector, which reduces the burden on the patient and shortens the procedure time.

That is, when the detection circuit unit is inserted into the stomach from outside the stomach, the detection circuit unit switches from a state in which current flows through it to a state in which current does not flow through it. This switch in current flow causes the notification unit to switch from a first state to a second state. If the notification unit is, for example, a light bulb, the light bulb is lit (first state) when current flows through the detection circuit unit, and the light bulb is turned off (second state) when current no longer flows through the detection circuit unit, so that it can be accurately determined from outside the body that the distal portion of the tube has been placed in the stomach.

In a twelfth aspect of the present disclosure, the detection circuit unit includes a flexible substrate. The conductor wire is provided on a surface of the substrate. The substrate may be, for example, sheet-like or spherical.

According to this configuration, since the substrate on which the conductor portion is provided is flexible, even a wide substrate can be accommodated in a curved state in a tube and inserted into the stomach. After insertion into the stomach, the substrate can be removed from the tube and spread out, allowing the substrate to be positioned over a wide area within the stomach. As a result, even if bodily fluids are present only in a part of the stomach, the bodily fluids can cause the conductor portion to break.

In a thirteenth aspect of the present disclosure, the conductive wire portion is provided continuously from one surface of the substrate to the other surface.

With this configuration, even if bodily fluids are present only on one side or the other side of the substrate, the conductor portion can be disconnected by the bodily fluids.

In a fourteenth aspect of the present disclosure, the conductor section includes a first conductor section and a second conductor section spaced apart from each other, and the notification section includes a first notification section and a second notification section. The first notification section is connected to the first conductor section, and the second notification section is connected to the second conductor section.

For example, if bodily fluids are present only in a portion of the stomach, it is possible that only one of the first and second conductor parts will break and the other will not. However, with this configuration, even if only one of the conductors breaks, the alarm can still be activated, making it possible to accurately determine from outside the body that the distal part of the tube has been placed in the stomach.

In a fifteenth aspect of the present disclosure, the conductor portion is formed by adhering a large number of conductive particles to the base material. Adhesion may also be achieved using an adhesive, in which case the adhesive dissolves upon contact with fluids in the body.

With this configuration, when the adhesive comes into contact with fluids in the body, the adhesive dissolves, causing the conductive particles to detach from the base material, thereby ensuring that the conductor section is disconnected.

In a sixteenth aspect of the present disclosure, the conductive wire portion is formed by adhering a large number of conductive particles to the substrate, the conductive particles reacting with fluids in the body to become inactive.

With this configuration, when the fluid inside the body comes into contact with the conductive particles, the conductive particles undergo a chemical reaction with the fluid inside the body and become inactive. This causes the conductive wire to break.

As explained above, it is possible to accurately and quickly determine whether the distal part of the tube is placed in the stomach while minimizing the burden on the patient.

FIG. 2 is an exploded view of the intragastric indwelling detector according to the first embodiment of the present invention. FIG. 1 is a diagram showing an example of a nutritional administration method in which a nutritional agent is delivered directly from outside the body to the stomach using a feeding tube. FIG. 1 shows an example of a feeding tube. FIG. 13 is a diagram showing the state in which an intragastric indwelling detector is set in a feeding tube. FIG. 2 is an enlarged view of the distal portion of the tubular body and its vicinity. FIG. 2 is an exploded perspective view of a distal portion of the tubular body and its vicinity. FIG. 5B is a view according to another example. FIG. 2 is an enlarged view showing the proximal portion, the storage portion, and the suction portion of the tubular body. 1 is an exploded perspective view of a proximal portion of a tubular body, a storage portion, and a suction portion. FIG. FIG. 11 is a perspective view showing an intragastric indwelling detector according to a second embodiment of the present invention. 9 is a cross-sectional view taken along line IX-IX of FIG. FIG. 2 is a perspective view showing a base material, a conductive wire portion, and a connecting wire. 1 is a perspective view showing the state in which the detection circuit unit is attached to the outer peripheral surface of the distal portion of the feeding tube. 1 is a perspective view showing the state in which the detection circuit unit is housed inside the distal portion of the feeding tube. FIG. FIG. 10 is a view corresponding to FIG. 8 according to a modified example of the second embodiment of the present invention.

The following describes in detail an embodiment of the present invention with reference to the drawings. Note that the following description of the preferred embodiment is essentially merely an example and is not intended to limit the present invention, its applications, or its uses.

Figure 1 shows an intragastric placement detector 1 according to an embodiment of the present invention. The intragastric placement detector 1 is an instrument for detecting that the distal portion 101 of a nutrition tube 100 inserted from outside the body of a patient (shown in Figure 2) 200 is placed in the stomach 201. The nutrition tube 100 is placed so that it passes from a hole in the nose 202 of the patient 200 through the nasal cavity 203, then through the throat 204 and esophagus 205 in order to reach the stomach 201. The nutrition tube 100 can also be placed so that it passes from the mouth of the patient 200 through the throat 204 and esophagus 205 in order to reach the stomach 201.

With the distal portion 101 (shown in FIG. 3) of the nutrition tube 100 placed in the stomach 201, the proximal portion 102 (shown in FIG. 3) of the nutrition tube 100 protrudes from the nose 202 (or mouth) of the patient 200 to the outside of the body. This patient 200 has difficulty eating normally, and for such a patient 200, nutrition is administered by supplying a liquid nutritional agent from outside the body into the nutrition tube 100 and sending the nutritional agent directly to the stomach 201. The process of inserting the nutrition tube 100 is performed by a medical professional, who will be referred to as the surgeon.

As shown in FIG. 3, the nutrition tube 100 used for this nutrition administration is a conventionally known component, and is sometimes called a catheter. The material constituting the nutrition tube 100 is, for example, a flexible resin material having translucency. The length of the nutrition tube 100 is set so that the proximal portion 102 protrudes from the nose 202 (or mouth) to the outside of the body when the distal portion 101 of the nutrition tube 100 reaches the stomach 201. The proximal portion 102 of the nutrition tube 100 is provided with a connector 102a that is connected to a supply tube (not shown) that supplies nutrients. The connector 102a is, for example, cylindrical, and is made of a resin material that is harder than the material constituting the main body of the nutrition tube 100. The inner hole of the connector 102a is connected to the inner hole of the main body of the nutrition tube 100.

In this specification, the term "distal portion" refers to the portion or side that is far from the surgeon's perspective, and conversely, the term "proximal portion" refers to the portion or side that is close to the surgeon's perspective. The distal portion can also be called the tip portion, and the proximal portion can also be called the base end portion.

(Configuration of intragastric indwelling detector 1)
As shown in FIG. 1, the intragastric placement detector 1 includes a tubular body 10 that is inserted into the stomach from outside the body through a nose 202 (or mouth), a storage section 20 for storing a fluid 15 described later, and a suction section 30 for applying a negative pressure to the inside of the tubular body 10. The tubular body 10 is made of the same material as that of the nutrition tube 100, and is flexible and can be easily bent. The material of the tubular body 10 may be colorless and transparent, or colored and transparent, or may be milky white, but has a predetermined translucency. The predetermined translucency is a translucency that allows the color and approximate shape of an object present inside the tubular body 10 to be visually recognized from the outside. In addition, the tubular body 10 may be colored in a different color from the nutrition tube 100 to allow the operator to recognize that the nutrition tube 100 and the intragastric placement detector 1 are separate. After confirmation of the placement of the nutrition tube 100 is completed, the intragastric placement detector 1 is removed.

As shown in FIG. 4, the tubular body 10 is a member that is housed inside the nutrition tube 100 before the nutrition tube 100 is inserted into the body, and has a distal portion 11 and a proximal portion 12, similar to the nutrition tube 100. The outer diameter of the tubular body 10 is set smaller than the inner diameter of the nutrition tube 100, making it possible to easily house the tubular body 10 inside the nutrition tube 100. When the tubular body 10 is housed in the nutrition tube 100, the distal portion 11 of the tubular body 10 may be inserted into the nutrition tube 100 from the proximal portion 102 of the nutrition tube 100. When the tubular body 10 is housed in the nutrition tube 100, a gap may be formed in a portion of the circumferential direction between the outer peripheral surface of the tubular body 10 and the inner peripheral surface of the nutrition tube 100. This makes it possible to prevent the outer circumferential surface of the tubular body 10 from coming into close contact with the inner circumferential surface of the nutrition tube 100, and allows the tubular body 10 to be easily removed from the nutrition tube 100 later.

The length of the tubular body 10 is set to be longer than the length of the nutrition tube 100. Specifically, the relative lengths of the tubular body 10 and the nutrition tube 100 are set so that, when the tubular body 10 is housed in the nutrition tube 100, at least a part of the distal part 11 of the tubular body 10 does not protrude from the distal part 101 of the nutrition tube 100, and at least a part of the proximal part 12 of the tubular body 10 protrudes from the proximal part 102 of the nutrition tube 100. Since the distal part 11 of the tubular body 10 does not protrude from the distal part 101 of the nutrition tube 100, even in the case of a disease or symptom in which gastric acid refluxes from the stomach to the esophagus, the distal part 11 of the tubular body 10 does not come into contact with the refluxed gastric acid, and erroneous judgment can be prevented. The length of the tubular body 10 may be the same as the length of the nutrition tube 100.

As shown by the dashed line in FIG. 1, the inside of the tubular body 10 contains a fluid 15 that undergoes a color change upon contact with gastric juice, which is an example of a liquid in the body, that is, upon contact with hydrogen ions. The fluid 15 is a liquid that changes color depending on the hydrogen ion concentration (pH) of the liquid it comes into contact with. The color change can be, for example, a change in color tone, a change in color, or a change in both color tone and color. In order to clearly cause this color change, the fluid 15 is adjusted to be alkaline before coming into contact with the gastric juice. The fluid 15 can be composed of a liquid that undergoes a significant color change when the pH of the liquid it comes into contact with is 5.0 or less, or 4.0 or less. If the fluid 15 is alkaline, it is preferable in that it then reacts with gastric acid of pH 1, and changes in order from neutral to acidic, and the color change becomes more noticeable. The fluid 15 may also be neutral. Furthermore, even if the difference in pH is small, it is sufficient that the color change can be visually recognized. Fluid 15 may be one whose color changes due to a change in its chemical structure that is dependent on the pH, or one whose color changes due to alteration or decomposition of its chemical structure that is dependent on the pH.

Such fluid 15 may contain, for example, anthocyanin. Fluid 15 can also be obtained by adding food coloring to water, etc., so that even if fluid 15 leaks from tubular body 10, it will not be a problem for patient 200.

The fluid 15 may be, for example, India ink or water. In this case, there is no change in color before and after contact with gastric juice, but it is possible to identify that the fluid has flowed to the proximal portion 12 of the tubular body 10, as described below.

As shown in Figures 5A and 5B, the distal portion 11 of the tubular body 10 is provided with an inflow opening 11a for allowing the fluid 15 to flow into the inside of the tubular body 10, and a lid 13 for opening and closing the inflow opening 11a. The inflow opening 11a opens at the tip surface of the distal portion 11 of the tubular body 10 and communicates with the inside of the tubular body 10. A screw groove 11c is formed on the inner peripheral surface of the inflow opening 11a.

The lid 13 has a blocking plate portion 13a and a male screw portion 13b, and is made of, for example, a hard resin material. The blocking plate portion 13a is a portion for blocking the inflow opening 11a, and is a disk-shaped portion larger than the inflow opening 11a. The male screw portion 13b is a cylinder-shaped portion protruding from the back surface of the blocking plate portion 13a, and a screw thread that screws into the screw groove 11c is formed on its outer circumferential surface. Therefore, the inflow opening 11a can be blocked by the lid 13 by inserting the male screw portion 13b from its tip into the inflow opening 11a and screwing it into the screw groove 11c and tightening it. On the other hand, the lid 13 can be removed to open the inflow opening 11a by rotating the male screw portion 13b in the loosening direction. In this example, the fluid 15 is introduced into the tubular body 10 through the inflow opening 11a while the inflow opening 11a is open, and then the inflow opening 11a is closed by the lid 13. Note that the lid 13 does not have to be a screw-in type, and may be, for example, pressed into the inflow opening 11a.

Also, as shown in the example in FIG. 6, a structure for preventing the lid 13 from falling off may be provided. In this example, a locking portion 11d extending radially inward is provided on the inner surface of the distal portion 11 of the tubular body 10. On the other hand, the lid 13 is provided with an insertion portion 13c that is inserted into the distal portion 11 of the tubular body 10. The insertion portion 13c has a length that allows it to be inserted proximally beyond the locking portion 11d even when the lid 13 is removed. The tip portion 13d of the insertion portion 13c is formed so that it comes into contact with and locks onto the locking portion 11d from its proximal side when inserted proximally beyond the locking portion 11d. The shape of the tip portion 13d of the insertion portion 13c can be, for example, a shape with a larger diameter than the base end portion of the insertion portion 13c. This prevents the lid 13 from falling off the tubular body 10.

The distal portion 11 of the tubular body 10 is provided with a distal opening 11b. The distal opening 11b opens on the outer circumferential surface of the tubular body 10. In this embodiment, two distal openings 11b, 11b are provided at intervals from each other in the circumferential direction of the tubular body 10. The number of distal openings 11b can be, for example, three or more. Also, only one distal opening 11b may be provided, and the number is not particularly limited. A plurality of distal openings 11b may be provided at intervals from each other in the axial direction of the tubular body 10. The distal opening 11b may be circular, elliptical, or rectangular, and its shape is not particularly limited. The distal opening 11b may be an elliptical shape or a slit shape that is long in the axial direction of the tubular body 10.

Of the two distal openings 11b, 11b, one of the distal openings 11b is closed by a dissolving member 14 that dissolves upon contact with gastric juice. The dissolving member 14 is made of a material that dissolves upon contact with a strong acidic liquid such as gastric juice. The time required for the dissolving member 14 to dissolve after coming into contact with gastric juice can be set by selecting the thickness of the dissolving member 14 and the material of the dissolving member 14. In this embodiment, the time required for the dissolving member 14 to dissolve after coming into contact with gastric juice is set to, for example, several seconds to several tens of seconds.

Such a dissolving member 14 can be composed of, for example, a membrane-like member synthesized from hypromellose, macrogol, and titanium oxide, a membrane-like member synthesized from hypromellose, macrogol, and talc, an oblate, etc. The dissolving member 14 does not have a negative effect on the human body, so even if it dissolves in the stomach 201, it does not cause any problems for the patient 200.

In this embodiment, the distal portion 11 of the tubular body 10 is provided with a permeable membrane 17 that allows hydrogen ions to pass through. That is, of the two distal openings 11b, 11b, the other distal opening 11b is covered with the permeable membrane 17. An example of such a permeable membrane 17 is a cationic ion exchange membrane. By using a cationic ion exchange membrane, hydrogen ions can be moved from the gastric acid side to the inside of the tubular body 10. It is sufficient to use the concentration gradient of hydrogen ions to move hydrogen ions from the gastric acid side to the inside of the tubular body 10, and the type of fluid 15 can be selected to satisfy such conditions. The permeable membrane 17 may be omitted, and in this case, the other distal opening 11b can be closed with a dissolving member 14. The fluid 15 is also designed not to pass through the permeable membrane 17.

When both the dissolving member 14 and the permeable membrane 17 are provided, the dissolving member 14 is configured to dissolve after the hydrogen ions have permeated the permeable membrane 17. In other words, the thickness and material of the dissolving member 14 are selected so that it does not dissolve immediately upon contact with gastric juice, but dissolves after a predetermined time has passed. This ensures that the fluid 15 reacts with the hydrogen ions, and a clear color change occurs in the fluid 15.

As shown in FIG. 1, a membrane 16 is provided inside the tubular body 10 to separate the space located on the distal opening 11b side from the space on the proximal part 12 side. The membrane 16 is located closer to the distal part 11 than the middle part of the tubular body 10, and the membrane 16 divides the internal space of the tubular body 10 into at least two parts. The thickness of the membrane 16 is set to be thinner than the thickness of the peripheral wall of the tubular body 10, and is provided so that it can be detached or torn from the inner surface of the tubular body 10 by the negative pressure generated in the suction part 30 described later. Specifically, by providing a thin-walled fragile part on the peripheral part of the membrane 16, when the negative pressure generated in the suction part 30 acts on the inside of the tubular body 10, the fragile part can be broken and the membrane 16 can be detached from the inner surface of the tubular body 10. In addition, by providing a thin-walled fragile part in the membrane 16 itself, the membrane 16 can be torn when the negative pressure generated in the suction part 30 acts on the inside of the tubular body 10.

The membrane 16 can also be configured to tear when operated from the outside. For example, a weak part can be provided in the membrane 16 so that the membrane 16 tears when the tubular body 10 is twisted. Also, a button-like object can be provided on the outside of the tubular body 10, and the membrane 16 can be torn by the pressure acting on the button.

The fluid 15 is contained on the distal portion 11 side of the membrane 16. The provision of the membrane 16 makes it possible to prevent the fluid 15 from flowing toward the proximal portion 12 side before the intragastric indwelling detector 1 is used.

As shown in FIG. 7, the proximal portion 12 of the tubular body 10 is provided with a storage portion 20 capable of storing the fluid 15. The storage portion 20 is made of a light-transmitting material. The storage portion 20 is adapted to have a suction portion 30, which is made of a manual suction device, attached thereto. As shown in FIG. 8, the storage portion 20 is made of a container, and its internal space R serves as a storage space for the fluid 15. The internal space R is connected to the inside of the tubular body 10.

Examples of the material constituting the storage section 20 include a resin material having a predetermined translucency. Since the storage section 20 has a predetermined translucency, it is possible to visually determine from the outside whether or not the fluid 15 is contained in the internal space R, and, if the fluid 15 is contained in the internal space R, the color of the fluid 15. The volume of the storage section 20 may be the same as the volume of the fluid 15, or it may be larger or smaller than the volume of the fluid 15, but it is preferable that the volume be large enough to confirm the color of the fluid 15 contained in the storage section 20.

The housing 20 is provided with a connecting tube 21 that is connected to the proximal portion 12 of the tubular body 10. The connecting tube 21 is formed in a cylindrical shape with an outer diameter that decreases toward the tip. Meanwhile, the proximal portion 12 of the tubular body 10 is provided with a tubular connector 12a to which the housing 20 is connected. The inner peripheral surface 12b of the connector 12a is tapered so that the outer peripheral surface of the connecting tube 21 of the housing 20 fits into it. When the connecting tube 21 of the housing 20 is inserted into the connector 12a, the outer peripheral surface of the connecting tube 21 is in close contact with the inner peripheral surface 12b of the connector 12a over the entire circumference, ensuring liquid-tightness and air-tightness. A seal material (not shown) may be provided between the housing 20 and the connector 12a.

The suction section 30 is, for example, a syringe, and includes a cylinder 31, a piston 32, and an operating rod 33. The tip of the cylinder 31 is provided with a connecting tube 31a that is connected to the storage section 20. The connecting tube 31a is formed in a cylindrical shape with an outer diameter that decreases toward the tip. On the other hand, on the opposite side of the connecting tube 21 in the storage section 20, a connecting hole 22 to which the cylinder 31 is connected is formed. The inner peripheral surface of the connecting hole 22 is tapered so that the outer peripheral surface of the connecting tube 31a of the cylinder 31 fits into it. When the connecting tube 31a of the cylinder 31 is inserted into the connecting hole 22, the outer peripheral surface of the connecting tube 31a is in close contact with the inner peripheral surface of the connecting hole 22 over the entire circumference, ensuring liquid-tightness and air-tightness. A seal material (not shown) may be provided between the cylinder 31 and the connecting hole 22.

The piston 32 is disposed in the cylinder 31. The space S in the cylinder 31 on the tip side of the piston 32 is connected to the internal space R of the storage section 20. The operating rod 33 is connected to the piston 32 and is a member for operating the piston 32. When the piston 32 is pulled toward the base end by the operating rod 33 with the cylinder 31 connected to the storage section 20 and the storage section 20 connected to the tubular body 10, negative pressure is generated in the space S, and the negative pressure generated in the space S also acts on the internal space R of the storage section 20 and the internal space of the tubular body 10.

The suction unit 30 is equipped with a holding mechanism 34 that maintains a state in which negative pressure is applied inside the tubular body 10. The holding mechanism 34 is a mechanism that enables the operating rod 33 to be fixed to the cylinder 31 at a predetermined position, and can be configured, for example, as a clamping mechanism. In this case, the operating rod 33, which has been retracted until the negative pressure is generated, is clamped to prevent movement relative to the cylinder 31, thereby maintaining negative pressure applied inside the tubular body 10. The holding mechanism 34 may be another mechanism.

(Detection Method)
Next, a method for detecting whether the distal portion 101 of the nutrition tube 100 is placed in the stomach 201 using the intragastric placement detector 1 according to the first embodiment configured as described above will be described. First, the intragastric placement detector 1 is prepared in which the fluid 15 is contained in the tubular body 10. The inflow opening 11a is closed with the lid 13.

Then, as shown in FIG. 4, the tubular body 10 of the intragastric placement detector 1 is housed in the nutrition tube 100. At this time, by making the length of the tubular body 10 longer than the nutrition tube 100, the dissolving member 14 and the permeable membrane 17 provided in the tubular body 10 can be arranged so as to protrude to the outside from the distal part 101 of the nutrition tube 100. In addition, the storage part 20 is connected to the tubular body 10, and the suction part 30 is connected to the storage part 20. The storage part 20 and the suction part 30 are in a state of protruding to the outside from the proximal part 102 of the nutrition tube 100. This improves the visibility of the storage part 20 and improves the operability of the suction part 30.

After connecting the storage section 20 and the suction section 30, the operating rod 33 of the suction section 30 is pulled to generate negative pressure in the space S inside the cylinder 31, and the operating rod 33 is fixed by the holding mechanism 34. At this time, negative pressure acts inside the tubular body 10, but since the distal openings 11b, 11b are closed by the dissolving member 14 and the permeable membrane 17, respectively, and the inflow opening 11a is also blocked, the negative pressure inside the tubular body 10 is maintained. In other words, the negative pressure is set so that the dissolving member 14 and the permeable membrane 17 are not torn, and the membrane 16 is not torn or detached.

Then, the distal portion 101 of the nutrition tube 100, together with the tubular body 10 of the intragastric placement detector 1, is inserted from the nose 202 of the patient 200 through the nasal cavity 203 and into the throat 204. When the fluid reaches the stomach 201 through the throat 204 and the esophagus 205, the gastric juice in the stomach 201 comes into contact with the dissolving member 14 and the permeable membrane 17 provided in the tubular body 10. At this time, the distal portion 101 of the nutrition tube 100, together with the tubular body 10 of the intragastric placement detector 1, may be inserted from the patient's mouth into the stomach 201. Hydrogen ions in the gastric juice permeate the permeable membrane 17 and come into contact with the fluid 15. The fluid 15 changes color upon contact with the hydrogen ions.

Gastric fluid also comes into contact with the dissolving member 14. After the hydrogen ions permeate the permeable membrane 17, the dissolving member 14 dissolves. When the dissolving member 14 dissolves, the distal opening 11b opens, and the negative pressure causes gastric fluid to flow from the distal opening 11b into the inside of the tubular body 10 and come into contact with the fluid 15. This also causes the fluid 15 to change color. When the distal opening 11b opens, not only gastric fluid but also air in the stomach 201 may flow into the inside of the tubular body 10 from the distal opening 11b.

The membrane 16 can be configured so that it detaches or tears when negative pressure is applied. This allows the fluid 15 contained on the distal portion 11 side to flow toward the proximal portion 12 side. The fluid 15 that has flowed toward the proximal portion 12 side is contained in the internal space R of the containing portion 20. The fluid 15 contained in the containing portion 20 undergoes a color change, and this color can be visually recognized by the surgeon from the outside.

On the other hand, if the distal portion 101 of the nutrition tube 100 is mistakenly inserted from the throat 204 into the airway 206 when being inserted together with the tubular body 10 of the intragastric placement detector 1, there is no acidic liquid such as gastric juice in the airway 206 or in the lungs, so there are no hydrogen ions that can permeate the permeable membrane 17, and the dissolving member 14 does not dissolve. As a result, the color of the fluid 15 does not change. Furthermore, because the dissolving member 14 does not dissolve, the fluid 15 does not flow toward the proximal portion 12, but remains on the distal portion 11 side.

In other words, if the distal portion 11 of the tubular body 10 is not placed in the stomach 201, the fluid 15 will not flow to the proximal portion 12. Therefore, when the surgeon visually observes the fluid 15 at the proximal portion 12 of the tubular body 10, it means that the distal portion 11 of the tubular body 15 is placed in the stomach 201 and the fluid 15 has flowed to the proximal portion 12 of the tubular body 10. Therefore, it is possible to accurately determine whether the distal portion 101 of the nutrition tube 100 is placed in the stomach 201.

The fluid 15 may not be contained in the tubular body 10. In this case, when the dissolving member 14 comes into contact with gastric juice and dissolves, the gastric juice flows to the proximal portion 12 of the tubular body 10 and is contained in the container 20, so that the surgeon can visually observe the gastric juice at the proximal portion 12 of the tubular body 10. Visual observation of the gastric juice at the proximal portion 12 of the tubular body 10 means that the distal portion 11 of the tubular body 15 is placed in the stomach 201 and the dissolving member 14 has been dissolved by the gastric juice. Therefore, even in this form, it is possible to accurately determine whether the distal portion 101 of the nutrition tube 100 is placed in the stomach 201.

(Embodiment 2)
9 and 10 show an intragastric placement detector 40 according to a second embodiment of the present invention. This embodiment 2 differs from the first embodiment in that an electrical circuit is used to detect whether the distal portion 101 of the nutrition tube 100 inserted from outside the body is placed in the stomach 201. The intragastric placement detector 40 according to the second embodiment will be described in detail below.

The intragastric placement detector 40 comprises a detection circuit section 41, a current supply section 42, and an alarm section 43. The detection circuit section 41 is inserted from outside the body into the stomach 201 via the nose 202 (or mouth), and comprises a base material 44, a conductor section 45, and a covering material 46 that covers them, as shown in FIG. 10. The covering material 46 is not essential and may be omitted. For example, the conductor section 45 itself may be wetted by water instead of gastric juice, or may be inactive and break due to a chemical reaction. In this case, the covering material 46 is required to prevent the conductor section 45 from coming into contact with liquids in the body before being inserted into the stomach.

The substrate 44 is in the form of a flexible sheet, and is made of, for example, a soft resin material. The shape of the substrate 44 is not limited to a sheet shape, and may be, for example, a spherical shape. The resin material that makes up the substrate 44 has insulating properties. The shape of the substrate 44 is not particularly limited, and may be, for example, a rectangular shape, a circular shape, an oval shape, or the like. The size of the substrate 44 is not particularly limited as long as it is large enough to be placed in the stomach 201, and may be set, for example, to have vertical and horizontal dimensions of 20 mm or more, or 30 mm or more.

The conductor portion 45 is made of a material that conducts electricity (conductive material), and is provided on one surface of the substrate 44 in the examples shown in Figs. 9 to 11. The conductor portion 45 has flexibility and pliability so that it does not break even when bent. The pattern (shape) of the conductor portion 45 is not particularly limited, but for example, as shown in Fig. 11, it can be a shape that combines a bent portion 45a and a linearly extending portion 45b. By providing the bent portion 45a, the formation range of the conductor portion 45 on the substrate 44 can be widened. In addition, since multiple bent portions 45a exist on one substrate 44, there are no areas on the substrate 44 where the conductor portion 45 is sparse, and the conductor portion 45 can be formed relatively densely on the substrate 44. The reasons why it is preferable to form the conductor portion 45 in a wide formation range and why it is preferable to form the conductor portion 45 densely will be described later.

The conductor portion 45 is configured to be disconnected by contact with gastric juice. Disconnection includes a state in which the conductor portion 45 is physically disconnected and electricity no longer flows, as well as a state in which the conductor portion 45 exists but the conductive material constituting the conductor portion 45 is inactivated and electricity no longer flows. As one form of the conductor portion 45, it can be configured by adhering a large number of conductive particles to the substrate 44 with an adhesive. For example, the conductor portion 45 can be obtained by applying a conductive ink to the substrate 44 and drying it. Alternatively, a large number of conductive particles may be pressed against the substrate 44 without using an adhesive.

In the case of conductive ink, ink containing conductive substances such as copper or silver fine particles (nanoparticles) can be used. The area coated with this conductive ink functions as a circuit after drying. When the circuit formed by coating the conductive ink is wetted, it becomes inactive as an electrical circuit. In addition, if the metal contained in the conductive ink has a high ionization tendency so that it is oxidized to HCl, the circuit can be destroyed by being oxidized and the particles no longer conducting electricity. Examples of metals that make up the fine particles contained in the conductive ink include calcium, magnesium, cobalt, zinc, nickel, lithium, iron, rubidium, chromium, strontium, manganese, etc., and any one or any combination of these metals can be used. Since the amount of these metals used is small, their impact on the human body is almost negligible.

A large number of conductive particles are arranged to form the above pattern and are attached to one side of the substrate 44 with an adhesive, thereby obtaining a conductive wire portion 45 having a pattern as shown in FIG. 11. In this case, an agent that dissolves when gastric fluid comes into contact with the conductive wire portion 45 can be used as the adhesive. By using such an adhesive, when gastric fluid comes into contact with the conductive wire portion 45, the adhesive dissolves, and at least a portion of the conductive particles are detached from the substrate 44, and the conductive wire portion 45 is physically disconnected and electricity no longer flows. The composition of the adhesive can be adjusted, and the width and diameter of the conductive wire portion 45 can be set so that the conductive wire portion 45 is physically disconnected within, for example, 2 to 3 seconds or 10 seconds upon contact with gastric fluid. As the adhesive, for example, various adhesives that are harmless to the human body can be used.

The conductor section 45 can also be formed by, for example, adhering a linear conductor to one side of the substrate 44 using the above-mentioned adhesive. The conductor section 45 can also be formed by combining a linear conductor with conductive particles.

The conductor portion 45 may also be formed by adhering a large number of conductive particles that react with gastric fluid and become inactive to the substrate 44. Such conductive particles may be formed, for example, of copper. Copper becomes inactive when it reacts with gastric acid, so that although it exists as the conductor portion 45, electricity does not flow through the conductor portion 45. The width and diameter of the conductor portion 45 may be set so that at least a portion of the conductor portion 45 becomes inactivated and no longer conducts electricity within, for example, 2 to 3 seconds or 10 seconds after coming into contact with gastric fluid.

The covering portion 46 may be any portion that covers at least the surface of the substrate 44 on which the conductor portion 45 is provided and the conductor portion 45, but in this embodiment, it is formed to cover the entire conductor portion 45 and the entire substrate 44. The material of the covering portion 46 can be the same as the material of the dissolving member 14 in embodiment 1, and has softness and flexibility. The covering portion 46 is also insulating. The time required for the covering portion 46 to dissolve after coming into contact with gastric juice, i.e., the time required for at least a portion of the conductor portion 45 to be exposed, is set to, for example, several seconds to several tens of seconds.

The current supply unit 42 shown in FIG. 9 is a part for supplying current to the conductor 45 of the detection circuit 41. In this figure, it is configured to be able to supply current from a commercial power source to the conductor 45, and includes a plug 42a that is connected to an outlet, and conductors 47, 47 that are covered with an insulating material that is acid-resistant. The conductors 47, 47 are designed not to break even when they come into contact with gastric juice, and the insulating material is designed not to dissolve or decompose even when they come into contact with gastric juice. The current supply unit 42 may be provided with a voltage adjustment unit for setting the supply voltage to a predetermined voltage, an ON/OFF switch, etc. Also, the current supply unit 42 may be configured to use a battery (including a primary battery and a secondary battery) as a power source. The conductors 47, 47 may be embedded in the peripheral wall of the nutrition tube 100.

The alarm unit 43 can be configured, for example, as a light bulb. The alarm unit 43 and the detection circuit unit 41 are connected in series using conductors 47, 47, so that current from the power source is supplied to the alarm unit 43 and the detection circuit unit 41. In other words, the alarm unit 43 is connected in a conductive state to the conductor 45 of the detection circuit unit 41.

The distance between the alarm unit 43 and the detection circuit unit 41 can be set as desired by adjusting the length of the conductors 47 and the connection position of the alarm unit 43 to the conductor 47. In this embodiment, the length of the conductors 47 and the connection position of the alarm unit 43 to the conductor 47 are set so that the alarm unit 43 can be placed outside the body while the detection circuit unit 41 is placed in the stomach 201.

For example, as shown in FIG. 12, the detection circuit unit 41 can be attached to the outer circumferential surface of the distal portion 101 of the nutrition tube 100. Since the detection circuit unit 41 is flexible, it can be curved to fit the outer circumferential surface of the nutrition tube 100. In this case, the conductors 47, 47 are fixed to the outer circumferential surface of the nutrition tube 100 and extended to the proximal portion 102, and the notification unit 43 is provided near the tip of the conductor 47, so that the notification unit 43 can be placed outside the body through the nose 202 (or mouth). This allows the surgeon to see the notification unit 43.

Also, as shown in FIG. 13, the detection circuit unit 41 may be housed inside the distal portion 101 of the nutrition tube 100. In this case, by housing the detection circuit unit 41 inside the nutrition tube 100 in a curved state, it becomes possible to house a detection circuit unit 41 that is larger than the inner diameter of the nutrition tube 100. The conductors 47, 47 may be extended through the nutrition tube 100 to the proximal portion 102, and the notification unit 43 may be provided near the tip of the conductor 47. The method of use will be described later.

If the conductor 45 is not broken, a current flows in the detection circuit 41, whereas if the conductor 45 is broken, no current flows in the detection circuit 41. If a current flows in the detection circuit 41, the notification unit 43 is turned on (first state), whereas if no current flows in the detection circuit 41, the notification unit 43 is turned off (second state).

(Detection Method)
Next, a detection method for detecting that the distal portion 101 of the nutrition tube 100 is placed in the stomach 201 using the intragastric placement detector 1 according to the first embodiment configured as described above will be described. As shown in FIG. 12, after the detection circuit unit 41 is attached to the outer peripheral surface of the distal portion 101 of the nutrition tube 100, the distal portion 101 of the nutrition tube 100 is inserted from the nose 202 of the patient 200 through the nasal cavity 203 into the throat 204. Alternatively, the distal portion 101 of the nutrition tube 100 is inserted from the mouth into the stomach 201. Since the conductor portion 45 is protected by the covering portion 46 until it reaches the stomach 201, the conductor portion 45 is not broken on the way and the notification portion 43 remains lit. When the conductor portion 45 reaches the stomach 201 through the throat 204 and the esophagus 205, gastric juice in the stomach 201 comes into contact with the covering portion 46, and the covering portion 46 dissolves.

When the covering portion 46 dissolves, the conductor portion 45 becomes exposed, and gastric juice comes into contact with the conductor portion 45. This breaks the conductor portion 45, and the notification portion 43 switches to an off state. This switching of the notification portion 43 to an off state can be visually confirmed outside the body, so that it is possible to accurately determine from outside the body that the distal portion 101 of the nutrition tube 100 has been placed in the stomach 201.

In addition, gastric juice in the stomach 201 is not necessarily distributed evenly, so there may be areas where there is sufficient gastric juice and areas where there is not. Assuming such a case, the wider the area in which the conductor portion 45 is formed, the higher the probability that the conductor portion 45 will reach an area where there is sufficient gastric juice. Similarly, the more densely the conductor portion 45 is formed, the higher the probability that the conductor portion 45 will reach an area where there is sufficient gastric juice.

In the example shown in FIG. 13, the detection circuit unit 41 is housed in the distal portion 101 of the nutrition tube 100, making it easier to perform the insertion procedure. In addition, when it is predicted that the distal portion 101 of the nutrition tube 100 has reached the stomach 201, the detection circuit unit 41 can be brought out from the nutrition tube 100 to the outside by feeding the conductor 47 from the outside. This spreads the detection circuit unit 41, allowing it to be present over a wide area within the stomach 201, and increasing the probability that the conductor unit 45 will reach an area with sufficient gastric juice.

Figure 14 shows a modified example of the second embodiment. In this modified example, the conductor portion includes a first conductor portion 45A, a second conductor portion 45B, a third conductor portion 45C, a fourth conductor portion 45D, and a fifth conductor portion 45E that are spaced apart from one another. Correspondingly, the notification portion includes a first notification portion 43A, a second notification portion 43B, a third notification portion 43C, a fourth notification portion 43D, and a fifth notification portion 43E.

The first conductor portion 45A is provided continuously from one surface to the other surface of the substrate 44. Specifically, it extends along one surface of the substrate 44, then passes through an end of the substrate 44 to the other surface of the substrate 44, and continues to extend along the other surface. Similarly, the second conductor portion 45B to the fifth conductor portion 45E are provided continuously from one surface to the other surface of the substrate 44. In this way, by providing a plurality of conductor portions 45A to 45E on one substrate 44, the formation range of the conductor portions 45A to 45E is widened, and the conductor portions 45A to 45E can be formed densely. The number of conductor portions is not limited to five, and may be four or less, six or more, or one. The conductor portion may be provided only on one surface of the substrate 44.

The current supply unit 42 is a part for supplying current individually to the first to fifth conductor parts 45A to 45E. This current supply unit 42 includes a first conductor 47A, 47A connected to the first conductor part 45A and the first notification part 43A, a second conductor 47B, 47B connected to the second conductor part 45B and the second notification part 43B, a third conductor 47C, 47C connected to the third conductor part 45C and the third notification part 43C, a fourth conductor 47D, 47D connected to the fourth conductor part 45D and the fourth notification part 43D, and a fifth conductor 47E, 47E connected to the fifth conductor part 45E and the fifth notification part 43E. Note that while FIG. 14 shows a schematic diagram of the connection between the plug 42a and each of the conductors 47A-47E, as shown in FIG. 9, they are connected to each of the conductors 45A-45E and the notification units 43A-43E so that they can supply current.

In the case of the modified example, if the first conductor portion 45A is disconnected in the stomach 201, for example, only the first notification portion 43A is turned off, and the other notification portions 43B to 43E remain on. This allows the distal portion 101 of the nutrition tube 100 to be determined from outside the body as being in the stomach 201, but in order to further increase the accuracy of the determination, a determination criterion can be set such that, for example, unless two or more notification portions are turned off, it is not determined that the distal portion 101 of the nutrition tube 100 is in the stomach 201.

In the above embodiment 2, the notification unit is described as being a light bulb, but it is not limited thereto, and may be, for example, a light-emitting body that emits light when a current is supplied, such as a light-emitting diode, or a component that emits sound when a current is supplied, such as a speaker. Also, a component such as a liquid crystal display panel or an organic EL panel may be used as the notification unit, and in this case, by using different screen display forms depending on whether a current is being supplied or not, the surgeon can determine whether the distal portion 101 of the nutrition tube 100 has been placed in the stomach 201.

The above-described embodiments are merely illustrative in all respects and should not be interpreted as limiting. Furthermore, all modifications and variations within the scope of the claims are within the scope of the present invention.

As described above, the intragastric placement detector of the present invention can be used, for example, to detect whether the distal portion of a nutrition tube inserted from outside the body is placed in the stomach.

REFERENCE SIGNS LIST 1 Gastric placement detector 10 Tubular body 11a Inflow opening 11b Distal opening 13 Lid 14 Dissolving member 15 Fluid 16 Membrane 17 Permeable membrane 20 Storage section 30 Suction section 34 Retention mechanism 40 Gastric placement detector 41 Detection circuit section 42 Current supply section 43 Notification section 43A First notification section 43B Second notification section 44 Base material 45 Conductor section 45A First conductive section 45B Second conductive section 46 Covering section 100 Nutrition tube

Claims (10)

An intragastric placement detector for detecting whether a distal portion of a tube inserted from outside the body is placed in the stomach,
A tubular body that is housed inside the tube that is inserted into the stomach from outside the body via the nose or mouth;
a suction unit connected to a proximal portion of the tubular body and applying a negative pressure to the inside of the tubular body;
The gastric indwelling detector has a distal opening at a distal portion of the tubular body, the distal opening being closed with a dissolving member that dissolves upon contact with gastric fluid. 2. The stomach indwelling detector according to claim 1,
An intragastric indwelling detector, wherein a fluid is contained inside the tubular body. 3. The intragastric indwelling detector according to claim 2,
The fluid in the gastric indwelling detector changes color upon contact with gastric juice. The intragastric indwelling detector according to claim 2 or 3,
The suction unit is composed of a manual suction instrument, and is an intragastric placement detector having a holding mechanism that maintains a state in which negative pressure is applied inside the tubular body. The intragastric indwelling detector according to any one of claims 2 to 4,
A storage portion capable of storing the fluid is provided at a proximal portion of the tubular body,
The storage section is an intragastric detector made of a light-transmitting material. The intragastric indwelling detector according to any one of claims 2 to 5,
An intragastric detector in which an inflow opening for allowing the fluid to flow into the inside of the tubular body and a lid for opening and closing the inflow opening are provided at the distal portion of the tubular body. 7. The intragastric detector according to claim 2,
An intragastric detector in which a membrane for separating a space located on the distal opening side from a space on the proximal side is provided inside the tubular body so as to detach or tear from the inner surface of the tubular body due to the negative pressure, and the fluid is contained distal to the membrane. 7. The intragastric detector according to claim 2,
An intragastric detector in which a membrane is provided inside the tubular body to separate the space located on the distal opening side from the space on the proximal side so as to be torn by external operation, and the fluid is contained distal to the membrane. 4. The intragastric indwelling detector according to claim 3,
A permeable membrane that allows hydrogen ions to pass through is provided at the distal portion of the tubular body,
The fluid in the gastric indwelling detector changes color upon contact with hydrogen ions. 10. The stomach indwelling detector according to claim 9,
The dissolving member is configured to dissolve after hydrogen ions have permeated through the permeable membrane.

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