Intestinal tract wall holding device

Abstract

To provide an intestinal tract wall holding device capable of moving, at constant speed, a target portion of an intestinal tract to be subjected to inspection or treatment, or capable of holding the target portion for a certain time without applying an excessive load to a subject.SOLUTION: An intestinal tract wall holding device is a device to be orally input and includes a holding base material formed of a cable of a shape memory material. The holding base material is in a first state of being contracted at the time of oral input, and, after receiving stimulation input, is deployed into a second state of generating a hollow part for pressing an internal surface of an intestinal tract wall by an outer peripheral surface of the cable and securing circulation in the intestinal tract.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an intestinal wall-retaining device that can be orally administered and retained at the intestinal wall. [Background technology]

[0002] 2. Description of the Related Art There is known a capsule-type medical device that is swallowed by a subject such as a patient and passes through a body cavity passage to enable examination, treatment, and the like (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2003-325438 A Summary of the Invention [Problem to be solved by the invention]

[0004] Conventional capsule-type medical devices are used to examine or treat subjects during the process from oral administration to excretion. However, conventional capsule-type medical devices move passively through the body cavity duct, and their positions change irregularly due to, for example, the effects of gravity, making it difficult to continuously examine target sites set at regular intervals or to stay at a specific target site for treatment. In addition, when the target site is the intestinal tract, such as the duodenum, small intestine, or large intestine, the medical device may interfere with the flow of digestive matter or gas in the body cavity, which may affect the physical condition of the subject.

[0005] The present invention has been made to solve such problems, and provides an intestinal wall retention device that can move the target part of the intestine to be examined or treated at a constant speed and retain it for a constant period of time without placing an excessive burden on the subject. [Means for solving the problem]

[0006] An intestinal wall retention device in one embodiment of the present invention is an intestinal wall retention device that is orally ingested and comprises a retention base material formed of cords of a shape-memory material, which is in a contracted first state when orally ingested and expands to a second state after receiving a stimulus input in which the outer peripheral surfaces of the cords press against the inner wall surface of the intestinal wall and create a hollow portion that ensures flow within the intestinal tract. Effect of the Invention

[0007] The present invention provides an intestinal wall retention device that can move the target area of ​​the intestine to be examined or treated at a constant speed and retain it for a constant period of time without placing an excessive burden on the subject. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a conceptual diagram showing how the intestinal wall retention device according to the present embodiment is taken into the body of a subject and remains at a target site. [Diagram 2] FIG. 1 is a schematic diagram showing the appearance of the intestinal wall retention device deployed in the large intestine. [Diagram 3] FIG. 2 is a schematic diagram illustrating the outer shapes of the intestinal wall retention device in the first state and the second state in this embodiment. [Figure 4] FIG. 2 is a schematic diagram illustrating the outer shapes of an intestinal wall retention device in a first modified example in a first state and a second state. [Diagram 5] FIG. 13 is a schematic diagram illustrating device arrangements of the intestinal wall retention device in the second and third modified examples. [Figure 6] FIG. 13 is a schematic diagram illustrating the displacement action of the intestinal wall retention device in the large intestine in the fourth modified example. [Figure 7] FIG. 13 is a schematic diagram illustrating an outer circumferential groove provided in an intestinal wall retention device in a fourth modified example. [Figure 8] FIG. 13 is a schematic diagram illustrating the rupture promoting structure of the intestinal wall retention device in the fifth and sixth modified examples. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] With reference to the accompanying drawings, an embodiment of the present invention will be described. In each drawing, the same reference numerals are used to denote the same or similar configurations. In addition, when there are a plurality of structures having the same or similar configurations in each drawing, in order to avoid complication, some of the structures may be given reference numerals and the same reference numerals may not be used to denote the other structures. In addition, not all of the configurations described in the embodiment are necessarily essential as means for solving the problem.

[0010] FIG. 1 is a conceptual diagram showing how the intestinal wall retention device 100 according to this embodiment is taken into the body of a subject and measures at a target site. The intestinal wall retention device 100 according to this embodiment is an orally administered device that is taken into the body by being swallowed through the mouth of the subject. As will be described in detail later, the intestinal wall retention device 100 changes to a second state, which is an expanded state, when it receives a stimulus input in a first state, which is a contracted state. When orally administered, the intestinal wall retention device 100 is prepared in the first state, which is a contracted state, so that the subject can easily swallow the intestinal wall retention device 100. Note that the intestinal wall retention device 100 in the first state may be housed in an enteric capsule that houses it so that the intestinal wall retention device 100 is easier for the subject to swallow. In this case, it is preferable that the intestinal wall retention device 100 receives a stimulus input after the enteric capsule has dissolved and changes to the second state, but it may also receive a stimulus input at a stage when the enteric capsule has dissolved to a certain extent, and change to the second state so as to break through the remaining enteric capsule.

[0011] The intestinal wall retention device 100 is deployed from the first state to the second state when it detects a stimulus input at a predetermined position in the intraluminal passage. The deployed intestinal wall retention device 100 performs an operation such as measurement or treatment at a target site according to the function given to the device. The target site is determined for each use of the intestinal wall retention device, and for example, the target site may be an intestinal tract such as the duodenum, small intestine, or large intestine. The intestinal wall retention device 100 in this embodiment is, as an example, capable of measuring and treating the target site of the large intestine. The elements and configurations of other types of intestinal wall retention devices may be appropriately changed according to the properties of the target site, etc.

[0012] The intestinal wall retaining device 100 is mainly composed of a device storage section 110 and a retaining substrate 170. The device storage section 110 is provided on at least one of the ends of the retaining substrate. The device storage section 110 is a module that stores a device, such as a temperature measuring unit, determined according to the application of the intestinal wall retaining device 100. The device storage section 110 may store a battery that supplies power to the device and the heating wire described below. The retaining substrate 170 is formed of a cord of a shape memory material. Specifically, for example, the retaining substrate 170 is formed by preparing a wire shape from a temperature responsive shape memory polymer (SMP) as a material and winding it in a spiral shape.

[0013] The temperature-responsive shape-memory polymer is hard like plastic at temperatures lower than the adjusted glass transition temperature (e.g., 35°C), and when heated to above the glass transition temperature, it softens to a rubber-like shape and changes to a memorized shape. Then, when it returns to a temperature lower than the glass transition temperature, it becomes hard like plastic while maintaining the memorized shape. That is, when the holding substrate 170 in this embodiment receives a temperature rise stimulus as an input stimulus that temporarily raises the temperature higher than the glass transition temperature, it develops from the first state to the second state.

[0014] The retaining substrate 170 is memorized so that the outer shape of the spiral expands when it is heated to a temperature equal to or higher than the glass transition temperature, and in the second state in which it expands and unfolds within the large intestine 910 as shown in the figure, it becomes large enough to press against the inner wall surface 911 of the large intestine 910. Specifically, the retaining substrate 170 expands to such an extent that the outer peripheral surface of the cord presses against the inner wall surface 911, and the thus expanded spiral shape creates a hollow portion that sufficiently ensures circulation within the intestinal tract, as indicated by the dotted arrow.

[0015] That is, the outer circumferential surface of the cord expands to the extent that it presses against the inner wall surface 911, and the intestinal wall retention device 100 is semi-fixed or indwelling fixed at that site. Semi-fixation refers to a fixation in which the degree to which the outer circumferential surface of the cord presses against the inner wall surface 911 is set to be suppressed to a light extent, and the intestinal wall retention device 100 is subjected to peristaltic movement in the second state in which it is deployed in a spiral shape, and moves slowly downstream (toward the anus). That is, it can be expected to move at a relatively slow and constant speed, without moving at high speed or staying at a bent part due to the influence of gravity, as in the case of an endoscopic capsule, for example. If the intestinal wall retention device 100 moves slowly while being semi-fixed with respect to the inner wall surface 911 in this way, it can continuously inspect target sites set at regular intervals within the intestine.

[0016] On the other hand, indwelling fixation is fixation when the degree to which the outer circumferential surfaces of the cords press against the inner wall surface 911 is set relatively strong, and the intestinal wall retention device 100 remains at the specific target site in the second state in which it is deployed in a spiral shape. When the intestinal wall retention device 100 is indwelling and fixed to the inner wall surface 911 in this way, it is possible to observe changes over time at the specific target site and to perform treatment such as tissue resection.

[0017] Moreover, whether semi-fixed or indwelling and fixed, the retaining substrate 170 does not divide the intestinal tract into upstream and downstream as, for example, an inflated balloon does, and has a hollow portion that sufficiently ensures circulation within the intestinal tract, so that it is expected that the circulation of digestive matter and body cavity gas is not hindered and the burden on the subject is reduced. In other words, the intestinal wall retaining device 100 imposes little burden on the subject, and can be moved slowly through the intestinal tract or retained at a specific target site for a certain period of time.

[0018] 2 is a schematic diagram showing the state of the intestinal wall retaining device 100 deployed in the large intestine. The retaining substrate 170 incorporates the heating wire 120 as a core material, and when power is supplied to the heating wire 120 from a battery (not shown), the SMP rises in temperature to or above the glass transition temperature, and is deployed in the large intestine 910. The intestinal wall retaining device 100 also includes an activation switch (not shown) that starts the supply of power from the battery to the heating wire 120. When the activation switch is switched from off to on, the heating wire 120 generates heat, and the retaining substrate 170 reaches or exceeds the glass transition temperature, and is deployed from the first state to the second state. Then, when a set time has elapsed, the activation switch is switched from on to off, the heating wire 120 stops generating heat, and the retaining substrate 170 returns to a temperature below the glass transition temperature, maintaining the shape of the second state.

[0019] The activation switch switches from off to on when a pH sensor 112 for detecting the hydrogen ion concentration (pH) of the external environment, which is provided near the end of the retaining substrate 170, detects that the pH is within a preset pH range. It is known that the pH in the body cavity passage increases from the stomach to the intestines, and when it is desired to turn on the activation switch in the large intestine, the pH range to be set should be set to match the pH range detected in the large intestine. In particular, since the pH increases rapidly when moving from the stomach to the small intestine, in the case of an intestinal wall retaining device intended for the small intestine, the activation condition may be set with attention paid to the amount of change in pH.

[0020] The activation switch is not limited to being activated based on the detection result of the pH sensor 112, and various configurations are possible. For example, the activation switch may be configured to be activated when a timer started at the time of oral administration reaches a predetermined time. In this case, the predetermined time of the timer may be set in consideration of the target site where the intestinal wall retention device 100 is to be developed from the first state to the second state and the characteristics of the subject's intestinal condition, etc. With this configuration, the intestinal wall retention device 100 can be developed from the first state to the second state at a desired target site without a complex configuration.

[0021] Alternatively, the activation switch may be configured to detect an excitation signal transmitted by an operator operating the intestinal wall retention device 100 operating a terminal at hand, and switch from off to on. In this case, the activation switch includes a wireless communication unit that detects the excitation signal transmitted from the terminal. With this configuration, the operator can deploy the intestinal wall retention device 100 from the first state to the second state at any target site. Of course, the activation switch may be configured to have a plurality of these configurations.

[0022] As shown in the figure, the large intestine 910 has crescent folds 912 at predetermined intervals. When the intestinal wall retention device 100 fits between two crescent folds 912, the intestinal wall retention device 100 is more stably deployed to the second state on the inner wall 911. In the example shown in the figure, the spiral structure of the retention base material 170 deployed to the second state is about two revolutions (two turns), but the number of turns in the second state can be appropriately changed depending on the purpose, use, etc. of the intestinal wall retention device 100. If the number of turns in the second state is reduced, the size in the first state can also be reduced, making it easier for the subject to swallow when orally ingested.

[0023] As described above, the device storage section 110 is provided at the end of the intestinal wall retention device 100, and the device storage section 110 stores, for example, a temperature measurement unit 111 for measuring the temperature of a target site. The temperature measurement unit 111 includes, for example, a temperature sensor, a sensor circuit, a memory, etc. When the device storage section 110 stores the temperature measurement unit 111, it is preferable to cover it with a material having high thermal conductivity and protect the surface with a hydrophilic coating so that the temperature measurement unit 111 can accurately measure the temperature of the target site.

[0024] The device stored in the storage section 110 is not limited to the temperature measurement unit 111, and may be any device that measures or treats a target site. The measuring device may be a camera unit, a pH sensor, a gas sensor, a biosensor that detects a specific chemical substance, or the like, and the treating device may be a mechanism for administering medicine, an electric scalpel that excises a lesion site, a clip that holds the lesion site, or an actuator that moves these devices closer to the lesion site. For example, the camera unit includes an image sensor, a lens group, an image processing circuit, a memory, an LED for illumination, or the like. When the device storage section 110 stores a camera unit, it is preferable to cover the camera unit with a hemisphere of transparent resin and protect the surface with a hydrophilic coating so that the camera unit can clearly capture the target site. When the intestinal wall retaining device 100 is used as a device for measuring the pH in the intestinal tract of a subject, the above-mentioned pH sensor 112 may be used as an activation switch and a measurement sensor that measures the pH of the target site. In this case, the pH sensor 112 may be provided near the end of the holding substrate 170 as described above, or may be housed in the storage unit 110. The device may also include a control chip for controlling the sensor and actuator, a memory unit for storing the observation results, a wireless unit for transmitting the results to the outside, etc. The above-mentioned battery, activation switch, and timer may also be stored in the storage unit 110.

[0025] Next, the external shapes of the intestinal wall retention device 100 in the first and second states will be described. Fig. 3 is a schematic diagram illustrating the external shapes of the intestinal wall retention device in this embodiment in the first and second states. Specifically, the first state is shown in a schematic diagram observed from the front, and the second state is shown in a schematic diagram observed from the front and from the side.

[0026] As shown in the figure, the intestinal wall retention device 100 is spiral in the first state. If the length in the central axis direction along the central axis of the spiral is L1 and the maximum value of the width perpendicular to the central axis (i.e., the maximum diameter when the spiral is projected onto a plane perpendicular to the central axis of the spiral) is D1, the intestinal wall retention device 100 in this embodiment satisfies the relationship L1>D1. It has been verified that when such a relationship is satisfied, the subject can relatively easily swallow the intestinal wall retention device 100 in the first state while ensuring a length that can press the inner wall surface of the intestinal wall when deployed in the second state. In one example, D1=11.0 mm and L1=22.5 mm.

[0027] As shown in the figure, the intestinal wall retention device 100 is also spiral when deployed in the second state. If the length in the central axis direction along the central axis of the spiral is L2 and the maximum value of the width perpendicular to the central axis (i.e., the maximum diameter when the spiral is projected onto a plane perpendicular to the central axis of the spiral) is D2, the intestinal wall retention device 100 in this embodiment satisfies the relationships L2>L1 and D2>D1. D2 is determined according to the standard diameter of the large intestine 910, which is the target site, and specifically, is determined to be a diameter that presses the inner wall 911 at a location other than the semicircular folds 912. As described above, it is preferable that L2 is determined to be a length that fits between two semicircular folds 912. As an example, D2=40.0 mm and L2=40.0 mm. Note that φ1, which is the diameter of the cord, does not change in either the first state or the second state, and as an example, φ1=3.0 mm.

[0028] In the second state of the intestinal wall retention device 100 in this embodiment, L2>D2, but it may be configured so that L2=D2 or D2>L2. If it is configured so that D2>L2, the possibility of the device being deployed in a state where it hangs over the crescent folds 912 can be reduced.

[0029] Next, several modified examples will be described that provide new advantages while maintaining the advantages of the intestinal wall retention device 100, such as ease of swallowing when orally ingested in the first state and ensuring circulation within the intestinal tract in the second state. In the following modified examples, the same components as those in the above-mentioned intestinal wall retention device 100 are given the same reference numerals and their explanations will be omitted, and differences from the intestinal wall retention device 100 will be mainly described.

[0030] Fig. 4 is a schematic diagram for explaining the external shapes of the intestinal wall retention device 101 in the first modified example in the first state and the second state. Specifically, it is a diagram similar to Fig. 3, and shows a schematic diagram observed from the front for the first state, and a schematic diagram observed from the front and from the side for the second state.

[0031] As shown in the figure, the intestinal wall retention device 101 is spiral in the first state. If the length in the central axis direction along the central axis of the spiral is L3 and the maximum value of the width perpendicular to the central axis (i.e., the maximum diameter when the spiral is projected onto a plane perpendicular to the central axis of the spiral) is D3, the intestinal wall retention device 101 in the first modified example satisfies the relationship L3>D3. This relationship is similar to the first state of the intestinal wall retention device 100, and the subject can swallow the intestinal wall retention device 101 in the first state relatively easily. As an example, D3=11.0 mm and L3=14.7 mm.

[0032] As shown in the figure, the intestinal wall retaining device 101 becomes annular when deployed in the second state. The annular shape in this case includes a C-shape. In the second state deployed in an annular shape, the length in the central axis direction along the central axis of the ring is equal to φ2, which is the diameter of the cord. Note that some twisting may occur when deployed in the second state. In that case, the length in the central axis direction is larger than φ2 by the amount of twisting. The maximum value of the width perpendicular to the central axis (i.e., the maximum diameter when the ring is projected onto a plane perpendicular to the central axis of the ring) is D4, which is equal to the diameter of the ring. D4 is determined according to the standard diameter of the large intestine 910, which is the target site, and specifically, is determined to be a diameter that presses the inner wall 911 at a location other than the crescent fold 912. In one embodiment, D4=40.0 mm. Note that φ2, which is the diameter of the cord, does not change in either the first state or the second state, and in one embodiment, φ2=3.0 mm.

[0033] Thus, according to the intestinal wall retaining device 101 in the first modified example, the second state is annular, so that, for example, in the process of changing from the first state to the second state, the retaining base material 170 is guided by the boundary between the crescent folds 912 and the inner surface wall 911, and can be easily deployed so as to stand upright against the intestinal tract.

[0034] 5 is a schematic diagram for explaining the device arrangement of the intestinal wall retention device 102 in the second modified example and the intestinal wall retention device 103 in the third modified example. Specifically, both drawings show the cross-sectional appearance of the retention substrate 172 (second modified example) and the retention substrate 173 (third modified example) which are expanded into the second state and press the inner surface wall 911.

[0035] In the intestinal wall retaining device 100 described above, the device storage section 110 was provided at the end of the retaining substrate 170. However, there are cases where it is preferable to place a device for observing or treating a target site at a location other than the end. Thus, if the surface of the outer circumferential surface of the retaining substrate 172 that contacts the inner wall surface 911, which is the intestinal wall, when deployed in the second state is defined as the first surface, and the surface that does not contact the surface is defined as the second surface, the intestinal wall retaining device 102 in the second modified example has the device storage section 130 provided on the side of the second surface.

[0036] As indicated by the dotted arrow, device storage section 130 provided on the second surface side stores device 131 for observing or treating the inner space side of the intestinal tract or the opposing inner wall surface 911. Device 131 includes, for example, a force sensor, and detects the amount of digestive matter passing through the intestine.

[0037] When the retaining substrate 173 is deployed in the second state, the surface of the outer circumferential surface that contacts the inner wall surface 911, which is the intestinal wall, is defined as the first surface, and the surface that does not contact is defined as the second surface. In the intestinal wall retaining device 103 in the third modified example, a device storage section 130 is provided on the side of the first surface.

[0038] As indicated by the dotted arrow, device storage section 130 provided on the first surface side stores device 132 for observing and treating inner wall surface 911 of the intestinal tract. Device 132 includes, for example, a temperature sensor, and detects changes in the surface temperature of inner wall surface 911 at predetermined intervals. Alternatively, device 132 may be a drug administration device that directly administers a drug to a target site to be treated.

[0039] Note that, in addition to their respective device storage sections 130, the intestinal wall retaining devices 102 and 103 may also have device storage sections 110 at their ends, similar to the intestinal wall retaining device 100. Also, depending on the devices to be mounted, a plurality of device storage sections may be provided along the extension direction of the retaining substrate, and in this case, a configuration may be provided in which device storage sections are provided on both the first surface side and the second surface side.

[0040] 6 is a schematic diagram illustrating the movement of the intestinal wall retention device 104 in the fourth modified example as it is displaced within the large intestine 910. As shown in the figure, the retention base material 174 of the intestinal wall retention device 104 is provided with a plurality of magnet pieces 140, e.g., neodymium magnets, spaced apart along its extension direction.

[0041] As shown in the figure, the intestinal wall holding device 104 deployed in the second state in the large intestine 910 is displaced so as to advance and retreat in the large intestine 910 along its extension direction by the action of the magnetism generated by the drive device 200. Specifically, the operator who operates the intestinal wall holding device 104 brings the drive device 200 close to the body surface near the large intestine 910 of the subject, and operates the magnetic generating unit 210 built into the drive device 200 to be driven. When the magnetic generating unit 210 receives the operation of the operator, it drives in one direction while generating a magnetic field. The magnet piece 140 displaces the holding base material 174, and thus the intestinal wall holding device 104, in the intestine by the action of the magnetism generated by the magnetic generating unit 210. Such a magnet piece 140 acts as a drive mechanism for displacing the holding base material 174 deployed in the second state in the large intestine 910.

[0042] The configuration of the drive mechanism is not limited to the magnet pieces 140 arranged discretely on the holding substrate 174, and various configurations may be adopted. For example, the holding substrate 174 may be formed by including magnetic nanoparticles, or if an external magnetic generating unit 210 is not used, the holding substrate 174 itself may be provided with a propulsion device.

[0043] When deployed in the second state, a first surface of the outer circumferential surface of the holding base material 174 that contacts the inner wall surface 911 is provided with an outer circumferential groove 150 as a recess. Specifically, two outer circumferential grooves 150 are provided parallel to the extension direction of the holding base material 174.

[0044] 7 is a schematic diagram illustrating the outer circumferential groove 150 provided in the intestinal wall retention device 104 in the fourth modified example. Specifically, the cross section of the retention base material 174 that is deployed in the second state and presses against the inner wall 911 is shown.

[0045] The edge portions of the openings of the two outer peripheral grooves 150 engage with the inner surface wall 911, and when the retaining substrate 174 advances or retreats in the directions indicated by the dotted arrows, the edge portions scrape off bacteria and cell tissue 913 from the inner surface wall 911 and store them inside the grooves. That is, the intestinal wall retaining device 104 functions as a sampling device that samples substances such as bacteria and cell tissue 913 present on the surface of the large intestine 910. The substances sampled in this manner are subjected to testing or the like after the intestinal wall retaining device 104 is expelled from the body.

[0046] The shape of the recesses provided on the first surface is not limited to the outer circumferential groove 150 described above. For example, a plurality of hemispherical recesses may be provided. Also, for example, the edge portion may be processed into a wavy shape so that the cell tissue 913 can be efficiently scraped off. Also, the drive mechanism provided in the retention substrate 174 may be used not only for sampling the substance but also for moving the intestinal wall retention device 104 to a desired position. The drive mechanism for moving to a desired position may be applied to each of the intestinal wall retention devices already described.

[0047] 8 is a schematic diagram illustrating the breakage promoting structure of the intestinal wall retaining device 105 in the fifth modified example and the intestinal wall retaining device 106 in the sixth modified example. In each of the intestinal wall retaining devices described so far, it is assumed that after being deployed to the second state, the retaining base material breaks due to repeated peristaltic action, for example, and small pieces generated by the breakage peel off from the inner wall surface 911. These small pieces are connected to each other by the heating wire 120, and are eventually discharged together from the body. The intestinal wall retaining device 105 in the fifth modified example and the intestinal wall retaining device 106 in the sixth modified example have a breakage promoting structure that causes such breakage in a short period of time.

[0048] 8(a) shows the intestinal wall retention device 105 in the fifth modified example deployed in the second state. The retention base material 175 of the intestinal wall retention device 105 has a plurality of reduced diameter sections 161 provided along the extension direction. The reduced diameter sections 161 are sections formed to have a smaller diameter than other sections. The reduced diameter sections 161 can be formed in a U-shape or V-shape across their width.

[0049] 8(b) shows the intestinal wall retaining device 106 in the sixth modified example deployed in the second state. The retaining base material 176 of the intestinal wall retaining device 106 is divided into a plurality of small pieces along the extension direction, and adjacent small pieces are connected by joints 162 made of a slow-soluble material. Nifedipine (NFD) can be used as the slow-soluble material, for example. The size of the slow-soluble material and the joints 162 are determined according to the desired target decomposition time after oral administration.

[0050] When the intestinal wall retaining device has a rupture-promoting structure like the intestinal wall retaining device 105 in the fifth variant and the intestinal wall retaining device 106 in the sixth variant, it is expected that the device will be deployed to the second state, and the retaining base material will rupture relatively soon after the measurement or treatment is completed, and will be quickly expelled from the body.

[0051] In each of the intestinal wall retaining devices described above, it is assumed that the retaining base breaks after deployment to the second state and the device is then naturally excreted from the body, but the device may be forcibly excreted from the body using an instrument. For example, a catheter may be inserted through the anus, and a hook member protruding from the tip of the catheter may be hooked onto the intestinal wall retaining device, which may then be pulled out of the body.

[0052] Although all of the intestinal wall retention devices described above use SMP as the shape memory material, the shape memory material is not limited to SMP, and for example, a temperature responsive shape memory alloy may be used. Also, all of the intestinal wall retention devices described above use the heating wire 120 as the element for increasing the temperature of the shape memory material, but the element for increasing the temperature of the shape memory material is not limited to the heating wire 120, and for example, a material that generates heat by chemically reacting with acid in the intestinal tract may be included.

[0053] In addition, although it is assumed that the intestinal wall retention device described above is swallowed by the subject in the first state and taken into the body, it may be pushed into the intestinal tract from the anus using an instrument, and after it reaches a target position, an input stimulus is applied to cause it to expand from the first state to the second state. In many cases, the first state of each intestinal wall retention device can be inserted through the anus without any problems. If it can be made to reach the intestinal tract from the anal side, even subjects with problems in swallowing function can use the intestinal wall retention device. [Explanation of symbols]

[0054] 100, 101, 102, 103, 104, 105, 106... intestinal wall holding device, 110, 130... device storage section, 111... temperature measurement unit, 112... pH sensor, 120... heating wire, 131, 132... device, 140... magnet piece, 150... outer peripheral groove, 161... narrowed diameter section, 162... slow-dissolving joint, 170, 172, 173, 174, 175, 176... holding substrate, 200... driving device, 210... magnetic generation unit, 910... large intestine, 911... inner wall surface, 912... crescent fold, 913... cell tissue

Claims

1. An intestinal wall retention device for oral administration, comprising: A support substrate formed of a shape memory material stripe is provided, The supporting substrate is When orally administered, the catheter is in a contracted first state, After receiving a stimulus input, the intestinal wall retention device expands to a second state in which the outer peripheral surfaces of the cords press against the inner wall surface of the intestinal wall and create a hollow portion that ensures flow within the intestinal tract.

2. The intestinal wall retention device according to claim 1 , wherein the cord is spiral in the first state and spiral or annular in the second state.

3. The intestinal wall retention device according to claim 2 , wherein in the second state, a length along the central axis of the spiral or ring is shorter than a maximum diameter when projected onto a plane perpendicular to the central axis of the spiral or ring.

4. The intestinal wall retention device according to claim 3 , wherein in the first state, a length along the central axis of the spiral is longer than a maximum diameter when projected onto a plane perpendicular to the central axis of the spiral.

5. The intestinal wall retention device according to claim 1 , further comprising at least one of a battery and a device provided on at least one of the ends of the retention substrate.

6. The intestinal wall retention device according to claim 1 , wherein the retention substrate is provided with a device on one of a first surface that contacts the intestinal wall and a second surface that does not contact the outer circumferential surface when the retention substrate is deployed in the second state.

7. The intestinal wall retention device according to claim 1 , further comprising a drive mechanism for displacing the retention substrate deployed in the second state within the intestinal tract.

8. The intestinal wall retention device according to claim 7 , wherein the retention substrate is formed by containing magnetic nanoparticles.

9. The intestinal wall retention device according to claim 7 , wherein the retention base has a plurality of magnet pieces discretely arranged along the extension direction.

10. The intestinal wall retention device according to claim 7 , wherein the retention base has a recess on at least a first surface of the outer circumferential surface that contacts the intestinal wall when deployed in the second state.

11. The intestinal wall retaining device according to claim 1 , wherein the retaining base material has a plurality of reduced diameter portions provided along the extension direction.

12. 2. The intestinal wall retaining device according to claim 1, wherein the retaining base material is divided into a plurality of small pieces along the stretching direction, and adjacent small pieces are connected by joints made of a slowly soluble material.

13. 2. The intestinal wall retention device of claim 1, comprising an enteric capsule housing the retention substrate in the first state.

14. The intestinal wall retention device according to claim 1 , further comprising a switch for initiating the stimulation input.

15. A pH sensor is provided to detect the pH of the external environment. The intestinal wall retention device according to claim 14, wherein the switch activates the stimulus input based on an output from the pH sensor.

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