JP7404622B2 - Measuring catheter - Google Patents

Description

The present invention relates to a catheter that is inserted into a living body and is equipped with a sensor that detects substances within the living body.

There are cases where it is desired to directly measure a specific substance present in a living body without taking it out of the body. This is particularly useful, for example, when there is a concern that substances may change in quality or increase or decrease when taken out of the body, or when it is desired to directly understand substances within the body without any time loss.

Therefore, a catheter equipped with a sensor that is inserted into a biological lumen and directly detects substances in the biological lumen has been proposed. For example, Japanese Patent No. 3691036 (Patent Document 1) discloses a chemical testing device that measures the concentration of nitric oxide in blood. Furthermore, Japanese Patent Application Laid-Open No. 63-40532 (Patent Document 2) states that it is possible to measure oxygen, carbon dioxide, hydrogen, sodium, potassium, calcium, chlorine, glucose, urea, uric acid, creatinine, etc. in blood. It has been suggested that it is important for monitoring pathological conditions.

Patent No. 3691036 Japanese Unexamined Patent Publication No. 63-40532

However, upon confirmation by the present inventor, a new fact was discovered that the measurement results obtained with the conventional measurement catheter are unstable and lack reliability.

An object of the present invention is to provide a measurement catheter with a novel structure that can improve the reliability of measurement results of substances in a living body lumen.

Hereinafter, aspects of the present invention made to solve such problems will be described. Note that the constituent elements employed in each aspect described below can be employed in any possible combination.

A first aspect of the present invention is a measurement catheter that is inserted into a living body and includes a sensor that detects a substance in the living body cavity, and is provided with an approach mechanism that allows the sensor to approach a wall surface of the living body cavity. and the approach mechanism holds the sensor in contact with the wall surface of the biological lumen , the sensor has a housing that covers the detection site, and the housing has a is provided with a partially open window, and the detection region is exposed through the window , and the approach mechanism moves the opening periphery of the window into the body cavity. It is held in contact with the wall surface .

According to the measurement catheter structured according to this aspect, by bringing the sensor closer to the wall surface of the living body cavity using the approach mechanism, the detection position of the sensor in the body cavity can be stabilized. As a result, for example, in addition to substances that constantly flow through the body lumen, substances that exit from the wall of the body lumen, and even substances whose concentration etc. This enables more accurate detection.

In addition, in the measurement catheter of this embodiment, the sensor and the wall surface of the living body lumen are in direct contact with each other, so that the measurement position of the sensor in the living body lumen can be further stabilized.

Furthermore, in the measurement catheter of this embodiment, it is also possible to adjust the detection direction, detection position, detection level, etc. of the substance by the sensor, for example, by appropriately setting the position and size of the window of the housing. become. Specifically, for example, it is also possible to open the window portion of the housing at a position facing the wall surface of the living body lumen, and further bring the window portion closer to the wall surface of the living body lumen using an access mechanism as necessary. Thereby, it is also possible to accurately detect substances present near the wall of the living body cavity by reducing the influence of substances located far from the wall of the body cavity.
In a second aspect of the present invention, in the measurement catheter according to the first aspect, the opening peripheral portion of the window portion is arranged on the outer circumferential surface toward the wall surface of the body lumen rather than the outer circumferential surface of the catheter main body. This is something that stands out.

In a third aspect of the present invention, in the measurement catheter according to the first or second aspect, the approaching mechanism changes the diameter from a contracted state to an expanded state, thereby moving the sensor to the wall surface of the living body lumen. It is said to be an extension body that brings the body closer to the body.

According to the measurement catheter structured according to the present aspect, for example, the sensor attached to the expandable body can be moved into the biological cavity by utilizing the fact that the outer peripheral surface of the expandable body is positioned close to the wall surface of the biological cavity during expansion. It may also be supported close to the wall surface. Alternatively, the sensor may be supported close to the wall of the living body lumen by, for example, pushing the catheter main body including the sensor with the expansion body to bring it closer to the wall of the living body lumen. More specific aspects of the expansion body are exemplified in the eighth and ninth aspects below.

A fourth aspect of the present invention is the measurement catheter according to the third aspect, wherein the expandable body is a balloon.

A fifth aspect of the present invention is a measurement catheter that is inserted into a living body and includes a sensor that detects a substance in the living body cavity , and is provided with an approach mechanism that brings the sensor close to the wall surface of the living body cavity. a guide member for bending the catheter body when the approach mechanism is inserted into the catheter body ; It is composed of

Examples of the guide member in the measurement catheter of this embodiment include an operating wire that is inserted into the catheter main body and exerts a bending force near the sensor attachment part on the distal end side by pushing and pulling operations from the proximal end side, and a Examples include a guide wire that guides the catheter body, and a stylet that is provided with a distal end portion that is bent in advance and inserted into the catheter body. By using such a guide member, the approach mechanism can be realized with simpler equipment than, for example, when using a balloon or the like.
A sixth aspect of the present invention is the measuring catheter according to the fifth aspect, wherein the guide member includes an operating wire that is inserted into the catheter body and has a distal end fixed to the catheter body. be.
A seventh aspect of the present invention is the measuring catheter according to the sixth aspect, in which the catheter main body has a deformation allowing portion on the proximal end side of the fixed portion of the operation wire.
An eighth aspect of the present invention is the measurement catheter according to any one of the fifth to seventh aspects, including a first lumen through which the sensor body having the sensor is inserted, and a second lumen through which the guide member is inserted. It is equipped with lumens.
A ninth aspect of the present invention is the measuring catheter according to the eighth aspect, in which the distal end of the second lumen is closed, and the guide is directed to the blocked distal end portion of the second lumen. The tip of the operating wire as a member is fixed.
A tenth aspect of the present invention is the measurement catheter according to the eighth aspect, wherein the guide member includes a stylet provided with a bent portion.
An eleventh aspect of the present invention is the measurement catheter according to any one of the first to tenth aspects, further comprising a contact pressure sensor that measures the contact pressure between the sensor and the wall surface of the body lumen. It is something that exists.
In the measurement catheter of this embodiment, by using the measurement value of the contact pressure sensor, it is possible to detect, for example, whether or not the sensor is in contact with the wall surface of the living body cavity, or to detect whether or not the sensor is in contact with the wall surface of the body cavity. It also becomes possible to avoid excessive pressure.
A twelfth aspect of the present invention is the measurement catheter according to any one of the first to eleventh aspects, wherein the sensor targets a wall-producing substance produced on the wall surface of the body lumen. It is something.
The measurement catheter of this embodiment has a high accuracy, for example, for substances that exist close to the wall of the body lumen, or substances that are produced from the wall of the body lumen and disappear in a relatively short time. This makes it possible to perform measurements with good stability.
A thirteenth aspect of the present invention is the measurement catheter according to any one of the first to twelfth aspects, wherein the sensor is an NO sensor that detects nitric oxide, and the sensor is an NO sensor that detects nitrogen monoxide. The wall surface is the inner surface of the blood vessel wall, and the approach mechanism allows the sensor to approach the inner surface of the blood vessel wall.
The measurement catheter of this embodiment can detect nitric oxide with higher accuracy than, for example, the chemical test device having a conventional structure described in Patent Document 1. In other words, nitric oxide is produced by vascular endothelial cells and exists in blood vessels, but in the blood it is quickly oxidized to nitrite ions, dissolved in the blood and transported, or combined with hemoglobin and transported. detected, making it undetectable. With the measuring catheter of this embodiment, it becomes possible to efficiently detect nitric oxide in the blood vessel born from the inner surface of the blood vessel wall.
A fourteenth aspect of the present invention is a measurement catheter that is inserted into a living body and includes a sensor that detects a substance in the living body cavity, and is provided with an approach mechanism that brings the sensor close to the wall surface of the living body cavity. and the approach mechanism holds the sensor in contact with the wall surface of the body lumen, and the approach mechanism maintains a length from the distal end side of the core wire inserted into the catheter body. The skeletal structure is configured such that the distal ends of the plurality of filamentary parts extending in the direction are free ends separated from each other in the circumferential direction and can be expanded so as to expand , and the sensor is provided on the outer peripheral surface of the filamentous part. This is what is being done.

According to the present invention, it is possible to provide a measurement catheter with a novel structure that can improve the reliability of measurement results of substances in a living body lumen.

FIG. 1 is a side view of a measurement catheter as a first embodiment of the present invention. FIG. 3 is a perspective view of a measurement catheter as a second embodiment of the present invention. FIG. 3 is a perspective view of a measurement catheter as another embodiment of the present invention. FIG. 7 is a perspective view of a measurement catheter as yet another embodiment of the present invention. FIG. 7 is a cross-sectional view of a measurement catheter according to a third embodiment of the present invention, in which (a) shows a deflated state of the balloon, and (b) shows an inflated state of the balloon. FIG. 3 is a sectional view of a measurement catheter as another embodiment of the present invention. FIG. 4 is a cross-sectional view of a measurement catheter according to a fourth embodiment of the present invention, in which (a) shows a state before the skeletal structure is expanded, and (b) shows a state after the skeletal structure is expanded. show. FIG. 3 is a sectional view of a measurement catheter as another embodiment of the present invention. FIG. 7 is a side view of a deployment structure used in a measurement catheter according to a fifth embodiment of the present invention. FIG. 12 is a sectional view of a measurement catheter according to a sixth embodiment of the present invention, and corresponds to the XX section in FIG. 11. FIG. 11 is an enlarged view showing the XI-XI cross section of FIG. 10; FIG. 7 is a sectional view of a measurement catheter according to a seventh embodiment of the present invention. FIG. 7 is a sectional view of a measuring catheter as an eighth embodiment of the present invention, in which (a) shows a state before a stylet is inserted, and (b) shows a state with a stylet inserted.

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1, a part of a measurement catheter 10 according to a first embodiment of the present invention is shown inserted into a blood vessel 12. The measuring catheter 10 includes a hollow catheter main body 14 and a sensor 16 provided on the distal end side of the catheter main body 14.

The catheter body 14 is shaped like a tube and has a lumen (not shown), and is percutaneously inserted into the lumen 17 of the blood vessel 12, which is a living body lumen. The catheter body 14 is made of a material having appropriate flexibility, such as various synthetic resins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyurethane, and polyether polyamide, and metals such as stainless steel. It can be curved and deformed in accordance with the curvature of the blood vessel 12. The catheter body 14 may also have a structure in which a synthetic resin tube is reinforced with a metal mesh or the like.

The sensor 16 has a structure in which a housing 18 is provided so as to cover a detection section 20 as a detection part. The housing 18 has a hollow cylindrical shape as a whole, and its internal space communicates with the lumen of the catheter body 14 . The housing 18 includes a window 22 that penetrates a portion of the peripheral wall and opens to the side. Furthermore, a tapered tip 24 is provided on the distal end side of the housing 18 . Note that the window portion 22 is not limited to the form provided in the peripheral wall portion of the housing 18, and may be provided so as to open at the distal end surface of the housing 18, for example.

The detection unit 20 detects nitrogen monoxide (hereinafter referred to as NO) that comes into contact with it using various known detection principles such as an electrode method (electrochemical method), and is housed in the housing 18 . Note that when a specific surface of the detection unit 20 is used as a detection surface that can detect NO that comes into contact, it is desirable that the detection surface is positioned toward the window 22 of the housing 18 . Note that, as the detection unit 20 of the sensor 16, various known NO sensors may be employed, such as the NO sensor manufactured by Innovative Instruments, which is also described in Japanese Patent No. 3,691,036. The detection unit 20 detects NO within the lumen 17 of the blood vessel 12, and in particular, NO as a wall-producing substance produced within the wall (endothelial cells) of the blood vessel 12 is the main detection target. Therefore, in the sensor 16 , a side surface of the detection section 20 close to the blood vessel wall 28 is exposed through the window section 22 of the housing 18 . Further, the sensor 16 has a side surface of the detection section 20 far from the blood vessel wall 28 covered by the housing 18 . Due to these, NO at a position close to the wall inner surface 29 of the blood vessel wall 28 is easier to detect than NO at a position farther from the wall inner surface 29 of the blood vessel wall 28. In this embodiment, the lumen 17 of the blood vessel 12 is the internal cavity of the living body, and the inner wall surface 29 of the blood vessel wall 28 is the wall surface of the internal cavity of the living body.

A sensor wire (not shown) connected to the detection section 20 extends from the detection section 20 toward the proximal end side, and is inserted into the catheter body 14 . The sensor wiring is, for example, a lead wire in which a core wire of a conductor is covered with an insulator. The sensor wiring taken out to the proximal end side of the catheter body 14 is connected to a measuring device (not shown), thereby making it possible to measure NO based on the detection signal of the sensor 16.

A balloon 26 as an approach mechanism is provided on the side of the peripheral wall of the housing 18 opposite to the window 22 (lower side in FIG. 1). The balloon 26 is provided on the outer peripheral side of the housing 18, and is an expandable body that can be inflated by external operation. It is desirable that the balloon 26 be able to be deflated again from the inflated state.

After the distal end of the measuring catheter 10 is percutaneously inserted into the blood vessel 12 with the balloon 26 constricted and folded, liquid or gas is fed into the balloon 26, as shown in FIG. Inflate the balloon 26. As a result, the balloon 26 is inflated to the side of the housing 18, and the balloon 26 is pressed against the wall inner surface 29 of the blood vessel wall 28. Then, a reaction force against the contact of the balloon 26 with the blood vessel wall 28 is applied to the housing 18, and the housing 18 is urged toward the side where the window portion 22 opens. As a result, the sensor 16 including the housing 18 approaches the inner wall surface 29 of the blood vessel wall 28 in the direction in which the window section 22 opens, and the detection section 20 housed in the housing 18 approaches the wall surface 29 of the upper blood vessel wall 28 in FIG. The inner surface 29 is approached.

In this way, by bringing the sensor 16 close to the wall inner surface 29 of the blood vessel wall 28 by the balloon 26, the detection position of the sensor 16 within the blood vessel 12 can be stabilized. Therefore, it becomes possible to detect NO flowing together with blood, NO calculated in the endothelial cells of the blood vessel wall 28, etc. at a stable position with higher accuracy.

In particular, NO, which is the measurement target of the sensor 16, is produced in the endothelial cells of the blood vessel wall 28 and exists in the blood vessel 12, but has a short half-life and is quickly oxidized to nitrite ions in the blood. It becomes undetectable because it is transported by being dissolved in or combined with hemoglobin. In the measurement catheter 10, since the sensor 16 is brought close to the blood vessel wall 28, it becomes possible to efficiently detect NO as a wall-producing substance produced on the wall inner surface 29 of the blood vessel 12. Furthermore, in the measurement catheter 10, since the sensor 16 is brought close to the blood vessel wall 28, it is possible to detect NO in real time, and for example, it is also possible to measure changes in NO concentration.

Further, by bringing the detection unit 20 of the sensor 16 closer to the blood vessel wall 28, NO produced in the endothelial cells of the blood vessel wall 28 is more likely to be detected by the detection unit 20 before it combines with hemoglobin. Therefore, the amount of NO produced in the endothelial cells of the blood vessel wall 28 can be accurately measured by the sensor 16.

For example, NO produced in endothelial cells composing the inner wall surface 29 of the blood vessel 12 plays a role in relaxing the blood vessel 12. In this way, if we directly measure and directly understand substances in the body's lumen that have some kind of effect on the human body or whose amount changes due to some change in the human body, we can detect problems such as arteriosclerosis. In addition to making it possible to detect diseases before they occur and to treat them at an early stage, the present invention provides new effects such as being able to provide indicators for responding to sudden changes during surgery.

In the sensor 16 of this embodiment, a detection section 20 for detecting NO is housed in a housing 18, and NO that comes into contact with the detection section 20 through a window 22 of the housing 18 is detected. Therefore, for example, by appropriately setting the position, size, etc. of the window portion 22 of the housing 18, it is possible to adjust the detection direction, detection position, detection level, etc. of the substance by the sensor 16. In this embodiment, the window 22 of the housing 18 is formed to open at a position facing the blood vessel wall 28, and the window 22 is brought close to the blood vessel wall 28 by the balloon 26. Therefore, it is possible to accurately detect NO present on the side close to the blood vessel wall 28 by reducing the influence of NO present on the side far from the blood vessel wall 28, and to detect the NO production ability of the blood vessel wall 28. can be grasped.

In the measurement catheter 10 of this embodiment, the detection target of the sensor 16 is NO, which is a wall-producing substance produced in the blood vessel wall 28. Then, as described above, the sensor 16 is brought close to the blood vessel wall 28, the detection part 20 of the sensor 16 is housed in the housing 18, and the window part 22 of the housing 18 is brought close to the blood vessel wall 28. . Therefore, NO produced in the blood vessel wall 28 can be accurately and stably measured before oxidation or binding with hemoglobin occurs.

Furthermore, since the detection unit 20 is housed in the housing 18 and the housing 18 is pressed by the reaction force of the balloon 26 against the blood vessel wall 28, the reaction force of the balloon 26 does not directly affect the detection unit 20. You can prevent this from happening.

Note that the peripheral edge of the opening of the window 22 in the housing 18 can also be held in contact with the inner wall surface 29 of the blood vessel wall 28 by the balloon 26. According to this, direct contact between the sensor 16 and the blood vessel wall 28 makes it possible to further stabilize the measurement position of the sensor 16 within the blood vessel 12. Furthermore, since NO produced in the endothelial cells of the blood vessel wall 28 is collected into the housing 18 in a state where it is difficult to come into contact with the blood flow, the NO production ability of the endothelial cells of the blood vessel wall 28 can be measured with higher precision. becomes possible.

Furthermore, when the opening peripheral portion of the window portion 22 in the housing 18 is brought into contact with the blood vessel wall 28, the contact pressure of the housing 18 against the blood vessel wall 28 is reduced while reducing or avoiding blood intrusion into the housing 18. It is desirable to make it small. The contact pressure of the housing 18 against the blood vessel wall 28 can also be confirmed by, for example, providing the housing 18 with a contact pressure sensor that measures the contact pressure.

Further, a selective membrane that transmits the substance to be detected may be provided to cover the window 22 of the housing 18. That is, in this embodiment, a gas permeable membrane that restricts or prevents the passage of red blood cells in the blood and allows the passage of NO is provided so as to cover the window 22 of the housing 18, so that no gas can enter the housing 18. The infiltration of red blood cells (hemoglobin) can be reduced or avoided. The gas permeable membrane that allows NO to pass through is made of, for example, a polymer material, and in particular, excellent gas permeability can be achieved by being made of an amorphous polymer. In other words, by forming the polymer with a relatively large molecular gap of about 2 to 10 nm, it can sufficiently allow the passage of NO, and the red blood cells, which are about 7 to 8 μm in diameter and 2 μm in thickness, can absorb gas. Passage through the molecular gaps of the permeable membrane can be restricted.

Furthermore, when the window portion 22 of the housing 18 is covered with a selective membrane (for example, a gas permeable membrane), the inside of the housing 18 may be filled with the detection liquid. In this embodiment, a liquid such as physiological saline that is soluble in NO and does not affect the human body is used as the detection liquid. However, the detection liquid may be a solvent that does not easily dissolve the substance to be detected, and regardless of which solvent is used, the pressure, potential, concentration, etc. of NO can be allowed to permeate the selective membrane. The NO that has passed through the selective membrane is dissolved in the detection liquid in the housing 18, and the NO in the detection liquid is detected by the detection unit 20 disposed in the detection liquid.

FIG. 2 partially shows a measurement catheter 30 as a second embodiment of the invention. The measurement catheter 30 has a structure in which a balloon 34 as an expander is attached to a catheter main body 32. The balloon 34 is provided so as to surround the outer periphery of the catheter main body 32, and its distal end and proximal end are fixed to the outer circumferential surface of the catheter main body 32. The balloon 34 can be inflated by feeding liquid or gas into the balloon 34 through the lumen of the catheter body 32.

A sensor 36 is fixed to the balloon 34. The sensor 36 of this embodiment is a sheet-shaped NO sensor, and is fixed to the outer peripheral surface of the balloon 34. Note that as means for transmitting the detection signal of the sensor 36 to a measuring device (not shown), a sensor wiring extending from the sensor 36 to the proximal end side of the catheter body 32 and connected to the measuring device may be provided, or A wireless transmitter may be provided that transmits the 36 detection signals as wireless signals to the measurement equipment.

The measurement catheter 30 having such a structure is percutaneously inserted into a blood vessel (not shown) with the balloon 34 inflated, and then the balloon 34 is inflated. Although not shown in the figure, the catheter main body 32 and the balloon 34 are inserted into a blood vessel while being inserted into a delivery catheter (not shown). 34 may be inflated.

Then, as the sensor 36 fixed to the outer peripheral surface of the balloon 34 approaches the blood vessel wall as the balloon 34 expands, the sensor 36 accurately detects and measures NO produced in the endothelial cells of the blood vessel wall. can do. Note that when the balloon 34 is in an inflated state, the sensor 36 may be in contact with the inner surface of the blood vessel wall or may be apart from the inner surface of the blood vessel wall. If the sensor 36 is in contact with the blood vessel wall due to the internal pressure of the balloon 34, the influence of blood flow can be reduced in the detection of NO, and since the flexible balloon 34 and the thin film sensor 36 are in contact, it is possible to reduce the influence of blood flow on the vascular endothelium. Damage is also less likely to occur. If the sensor 36 is located away from the blood vessel wall, damage to the endothelial cells of the blood vessel wall due to contact between the sensor 36 and the balloon 34 can be more reliably prevented, and the influence of the balloon 34 on blood flow is also reduced.

Although FIG. 2 shows an example in which a pair of sensors 36, 36 are fixed to the outer peripheral surface of the balloon 34 on both sides in the radial direction, the number and arrangement of the sensors 36 fixed to the balloon 34 are not particularly limited. Specifically, a pair of sensors 36, 36 may be fixed at multiple locations in the longitudinal direction, as in the measurement catheter 40 shown in FIG. 3. Further, in the measuring catheter 40 of FIG. 3, a contact pressure sensor 42 is provided on the surface of the balloon 34 to measure the contact pressure between the balloon 34 and the blood vessel wall 28. The contact pressure sensor 42 is, for example, a piezoelectric sensor, and is sandwiched between the blood vessel wall 28 and the balloon 34 to generate a voltage corresponding to the applied pressure. Then, the voltage generated by the contact pressure sensor 42 is processed by a measuring device (not shown), so that the pressure acting on the contact pressure sensor 42 is measured. In this way, by providing the contact pressure sensor 42, it is possible to determine whether or not the sensor 36 provided on the balloon 34 is in contact with the blood vessel wall 28, as well as how much force the sensor 36 has on the blood vessel wall 28. Based on the detection result of the contact pressure sensor 42, it is possible to determine whether the contact pressure sensor 42 is in contact with the contact pressure sensor 42. Therefore, by adjusting the internal pressure of the balloon 34 based on the detection result of the contact pressure sensor 42, excessive pressing of the sensor 36 against the blood vessel wall 28 can be prevented.

In addition, like the measuring catheter 50 shown in FIG. 4, two balloons 34, 34 can also be provided side by side in the longitudinal direction of the catheter main body 32. In FIG. 4, two balloons 34, 34 are provided, but for example, three or more balloons may also be provided. In addition, the balloon 34 located on the upstream side of the blood flow in the blood vessel is used as an occlusion balloon to temporarily block or reduce the blood flow, so that the influence of the blood flow is reduced by the balloon 34 on the downstream side. It is also possible to measure NO. In this case, the sensor 36 does not need to be fixed to each balloon 34 as shown in FIG. 4, and the sensor 36 may be provided only to the downstream balloon 34.

FIG. 5 partially shows a measurement catheter 60 as a third embodiment of the invention. The measurement catheter 60 has a structure in which a balloon catheter 64 and a sensor body 66 are inserted into a delivery catheter 62.

The delivery catheter 62 has a flexible tube shape with a single lumen structure. As shown in FIG. 5(a), both the balloon catheter 64 and the sensor 74 are inserted into one lumen 68 of the delivery catheter 62.

The balloon catheter 64 has a structure in which a balloon 72 as an expander is attached to a hollow shaft 70 in an externally inserted state, and each of the distal and proximal ends of the balloon 72 is fixed to the shaft 70. are doing. By feeding liquid or gas into the balloon 72 through the inner cavity of the shaft 70, it is possible to inflate the balloon 72 and change its diameter.

The sensor body 66 includes a sensor 74 that measures NO, and a sensor wiring 76 that is connected to the sensor 74 and extends toward the base end. The sensor wiring 76 is, for example, a lead wire having an insulating film around a conductor, and its base end is connected to a measuring device (not shown). The detection signal of the sensor 74 is transmitted to the measurement equipment via the sensor wiring 76.

Then, with the measuring catheter 60 percutaneously inserted into the lumen 17 of the blood vessel 12, the balloon catheter 64 and the sensor body 66 are made to protrude further toward the distal end than the delivery catheter 62. As shown in FIG. 5(b), by inflating the balloon 72 of the balloon catheter 64 protruding from the delivery catheter 62 between the sensor body 66 and the lower portion of the blood vessel wall 28 in FIG. 5(b), The sensor 74 is brought close to the upper portion of the blood vessel wall 28 in FIG. 5(b). Thus, the access mechanism of this embodiment is comprised of the balloon 72 of the balloon catheter 64. It is desirable that the sensor wiring 76 of the sensor body 66 has enough flexibility to be bent by contact with the inflated balloon 72. Note that the sensor body 66 does not necessarily have to be located above the balloon 72, and its position relative to the balloon 72 is not limited.

In the measurement catheter 60 of FIG. 5, the delivery catheter 62 has a single lumen structure, and the balloon catheter 64 and the sensor body 66 are inserted into the same lumen 68. However, for example, a delivery catheter 82 having a double lumen structure, such as a measurement catheter 80 shown in FIG. 6, may also be employed. The delivery catheter 82 has a first lumen 84 into which the balloon catheter 64 is inserted and a second lumen 86 into which the sensor body 66 is inserted, which are provided independently of each other. According to this, it is possible to prevent the balloon catheter 64 and the sensor body 66 from interfering with each other within the delivery catheter 82. Further, it becomes easier to set the relative positional relationship between the balloon catheter 64 and the sensor body 66, and it becomes possible to accurately set the amount of approach of the sensor 74 to the blood vessel wall 28.

FIG. 7 partially shows a measuring catheter 90 as a fourth embodiment of the present invention. The measurement catheter 90 has a structure in which a sensor body 94 is inserted into a delivery catheter 62 having a single lumen structure.

The sensor body 94 has a structure in which a skeletal structure 98 as an extension body is attached to a core wire 96. The skeleton structure 98 includes a plurality of linear portions 100 made of NiTi alloy, stainless steel, or the like. The skeletal structure 98 is capable of expanding in diameter when in the deployed state, for example, due to the elasticity or shape memory effect of the skeletal structure 98 itself. In the skeletal structure 98 of this embodiment, the filament portion 100 is formed of a NiTi alloy, and the diameter expands in the expanded state due to the shape memory effect. When the skeleton structure 98 is inserted into the delivery catheter 62, it is held in a contracted state with a small diameter by the delivery catheter 62, as shown in FIG. 7(a). Further, when the skeleton structure 98 is taken out from the delivery catheter 62 toward the distal end side, the diameter of the skeleton structure 98 is automatically expanded due to superelasticity, as shown in FIG. 7(b). However, the mechanism for expanding and changing the diameter of the skeletal structure 98 is not particularly limited. For example, a balloon is provided on the outer peripheral surface of the core wire 96 located on the inner peripheral side of the skeletal structure 98, and the balloon is inflated. By doing so, it is also possible to expand the skeleton structure 98 with a balloon and change its diameter. Further, for example, by heating the skeletal structure 98 with a heater, the shape memory effect of the skeletal structure 98 can be exerted, and the diameter of the skeletal structure 98 can be expanded.

A sensor 36 for measuring NO is attached to each linear portion 100 of the skeleton structure 98. The sensor 36 may be attached to all the linear parts 100 or only to selected linear parts 100. Note that the sensor 36 is preferably disposed on the outer peripheral surface of the skeleton structure 98 in the expanded state.

Then, by percutaneously inserting the delivery catheter 62 into a blood vessel (not shown) and displacing the delivery catheter 62 relative to the sensor body 94 toward the proximal end, the skeletal structure 98 of the sensor body 94 is inserted into the blood vessel (not shown). 62 protrudes toward the distal side. As a result, the restraint of the skeletal structure 98 by the delivery catheter 62 is released, and the skeletal structure 98 automatically expands in diameter to the expanded state. As a result, as shown in FIG. 7(b), the sensor 36 fixed to the linear portion 100 of the skeletal structure 98 approaches the blood vessel wall (not shown).

Note that the skeletal structure 98 shown in FIG. 7 is merely an example, and the specific structure of the skeletal structure is not particularly limited. Specifically, for example, as in the skeletal structure 112 of the measurement catheter 110 shown in FIG. It is also possible to adopt a structure in which the tips are separated from each other on the distal end side. When the skeletal structure 112 is taken out from the delivery catheter 62 to the distal end side, the distal end side is expanded so that the sensor 36 provided on the striated portion 114 approaches a blood vessel wall (not shown).

FIG. 9 shows a measurement catheter 120 as a fifth embodiment of the present invention. The measurement catheter 120 includes a delivery catheter 62 with a single lumen structure and a stent 122 as a skeletal structure housed in the delivery catheter 62. Note that FIG. 9 shows a state in which the stent 122 has been taken out from the delivery catheter 62 to the distal end side and expanded within the blood vessel 12.

The stent 122 has a structure in which a plurality of filamentous portions 124 are fixed with ring members 126 at both ends on the distal side and the proximal side. Although the striated portion 124 of this embodiment has a bifurcated structure at the middle portion, the structure of the strut is not particularly limited. Furthermore, the filamentous portions 124 and the ring members 126, 126 may be integrated. For example, the plurality of filamentous portions 124 and the ring members 126, 126 may be integrally formed by cutting a metal cylindrical material. A structure cut out from the outside may also be adopted.

A sensor 36 for measuring NO is attached to the striated portion 124 of the stent 122. Furthermore, a contact pressure sensor 42 is attached to the striated portion 124 to measure the contact pressure against the blood vessel wall 28. In this embodiment, the sensor 36 is arranged at the center portion of the linear portion 124 in the length direction, and the contact pressure sensors 42 are arranged on both sides of the sensor 36 in the linear portion 124.

The measurement catheter of this embodiment is constructed by inserting this stent 122 into the delivery catheter 62 in a contracted state. Then, the delivery catheter 62 is percutaneously inserted into the blood vessel 12, and the stent 122 is pushed out toward the distal end of the delivery catheter 62, thereby expanding the diameter of the stent 122 to the expanded state. Then, the stent 122 is placed in the blood vessel 12 by pressing the striated portion 124 of the expanded stent 122 against the blood vessel wall 28 . As a result, the sensor 36 attached to the filament 124 is brought closer to the blood vessel wall 28 by the expansion of the stent 122, and is held in contact with the inner wall surface 29 of the blood vessel wall 28. Therefore, the access mechanism of this embodiment is constituted by self-expansion of the stent 122.

With the stent 122 indwelled in the lumen 17 of the blood vessel 12, the contact pressure of each striated portion 124 against the blood vessel wall 28 is measured by the contact pressure sensor 42. Therefore, it is possible to determine whether or not each filament 124 is in contact with the blood vessel wall 28, and furthermore, to what extent it is in contact with the blood vessel wall 28, based on the measurement results of the contact pressure sensor 42. It is said that

Further, the amount of NO produced in the endothelial cells of the blood vessel wall 28 is measured by the sensor 36 provided on the striated portion 124 in contact with the blood vessel wall 28 . In this embodiment, since the sensor 36 is in contact with the blood vessel wall 28, NO measurement is less affected by blood, and the amount of NO production in the endothelial cells of the blood vessel wall 28 can be measured with higher reliability. .

The contact pressure sensor 42 and the sensor 36 in this embodiment are configured to transmit, for example, a detection signal from inside the blood vessel 12 to a measuring device outside the body by wireless communication when the stent 122 is placed in the lumen 17 of the blood vessel 12. It can also be done. According to this, sensor wiring for extracting the detection signal is not required, so for example, when continuously detecting over a long period of time, it is possible to insert the sensor wiring percutaneously into the blood vessel 12. No need to maintain.

Furthermore, since the approach mechanism for bringing the sensor 36 close to the blood vessel wall 28 is constituted by the stent 122, even if the sensor 36 is held in contact with the inner wall surface 29 of the blood vessel wall 28, the blood flow can be greatly reduced. There is no obstruction.

FIG. 10 partially shows a measuring catheter 130 as a sixth embodiment of the present invention. The measurement catheter 130 includes a hollow catheter body 132. The catheter main body 132 has a substantially tubular shape, and a portion of the peripheral wall thereof is a coil-shaped deformation allowing portion 134 formed by tightly winding a metal wire in a spiral shape. The opening on the distal side of the deformation allowing portion 134 in the catheter body 132 is closed by a distal tip 136 whose distal end surface is rounded into a hemispherical shape.

A core wire 138 is inserted into the catheter body 132. The core wire 138 is elongated and has a tapered shape that gradually becomes smaller in diameter toward the tip. The core wire 138 has a distal end portion fixed to the distal tip 136. This core wire 138 adjusts the shape stability of the measurement catheter 130, and prevents unnecessary bending in the deformation allowing portion 134 of the catheter body 132, for example.

A manipulation wire 140 serving as a guide member is inserted into the catheter body 132. The tip of the operating wire 140 is fixed to the deformation allowing portion 134 or the tip 136 . Then, by pushing the operating wire 140 toward the distal end of the catheter body 132 or pulling it toward the proximal end, the catheter body 132 can be bent at the deformation allowing portion 134 .

A sensor wiring 142 is inserted into the catheter body 132. The sensor wiring 142 is a lead wire provided with an insulating film, and has a distal end fixed to the distal tip 136 and a distal end connected to the sensor 144 . The sensor 144 is an NO sensor, and is embedded and fixed in the distal tip 136 and exposed on the outer peripheral surface of the distal tip 136. For example, the sensor wiring 142 transmits the detection signal of the sensor 144 to the proximal end side of the measurement catheter 130. Note that the sensor wiring 142 of this embodiment has three core wires, as shown in FIG. 11, and is connected to a working electrode, a counter electrode, and a reference electrode (not shown) of the sensor 144.

The measurement catheter 130 is percutaneously inserted into a blood vessel (not shown). The measurement catheter 130 inserted into the blood vessel is bent at the deformation allowing portion 134 by pushing the operation wire 140 toward the distal end of the catheter body 132. As a result, the sensor 144 provided at the distal end portion of the measurement catheter 130 moves upward in FIG. 10 and approaches the blood vessel wall (not shown). As a result, the position of the sensor 144 within the blood vessel is stabilized, and the influence of blood on the detection results is reduced. Note that in this embodiment, the sensor 144 approaches the blood vessel wall by pushing the operating wire 140 toward the distal end, but the sensor 144 can also approach the blood vessel wall by pulling the operating wire 140 toward the proximal end. .

According to the structure of this embodiment, since the approach mechanism is composed of the operation wire 140 inserted into the catheter body 132, a device for inflating the balloon is not required compared to the case where a balloon is used as the approach mechanism. Therefore, the approach mechanism can be more easily realized.

FIG. 12 partially shows a measuring catheter 150 as a seventh embodiment of the present invention. The measurement catheter 150 has a structure in which a sensor body 66 is inserted into a catheter body 152.

The catheter body 152 is tubular in shape and has a lumen 154 extending therethrough in the length direction. A portion of the peripheral wall of the catheter body 152 has a double structure to form a wire insertion region 156. A manipulation wire 158 as a guide member is inserted into the wire insertion region 156 of the catheter body 152, and the tip portion of the manipulation wire 158 is adhered to the wall of the wire insertion region 156 with an adhesive 159, and the catheter body 152.

A sensor body 66 is inserted into the lumen 154 of the catheter body 152. The sensor body 66 includes a sensor 74 and a sensor wiring 76 that extends from the sensor 74 toward the base end and is connected to a measuring device (not shown).

The measuring catheter 150 can bend the distal end portion of the catheter main body 152 by pushing the operating wire 158 toward the distal end of the catheter main body 152 or pulling it toward the proximal end within a blood vessel (not shown). ing. That is, in FIG. 12, when the operating wire 158 is pushed in, the distal end portion of the catheter body 152 is bent so as to be inclined downward toward the distal end. In FIG. 12, when the operating wire 158 is pulled, the distal end portion of the catheter body 152 bends upward toward the distal end. As a result, the sensor body 66 inserted into the catheter body 152 is bent, and the sensor 74 approaches the blood vessel wall. As a result, the position of the sensor 74 within the blood vessel is stabilized, and the influence of blood on the NO detection result by the sensor 74 is reduced, thereby improving measurement accuracy and reliability.

According to the structure of this embodiment, since the approach mechanism is constituted by the operation wire 158 inserted into the catheter main body 152, the approach mechanism can be more easily realized.

FIG. 13 shows a measurement catheter 160 as an eighth embodiment of the present invention. The measurement catheter 160 includes a catheter body 162. The catheter main body 162 has a double lumen structure having a first lumen 164 and a second lumen 166, and a sensor body 66 is inserted into the first lumen 164.

Then, in a state where the catheter body 162 is percutaneously inserted into a blood vessel (not shown), a stylet 168 as a guide member is inserted into the second lumen 166 of the catheter body 162. The stylet 168 is a member that is harder than the catheter body 162 and has a rod shape. The stylet 168 is provided with a bent portion 170, and the stylet 168 has a distal end thereof that is inclined relative to the proximal end side of the bent portion 170.

As a result, when the stylet 168 is inserted into the second lumen 166 of the catheter body 162, the catheter body 162 is pressed by the distal side of the bent portion 170 of the stylet 168, and the catheter body 162 is moved along the stylet 168. partially bent. As a result, the distal end portion of the catheter body 162 approaches the blood vessel wall 28, and the sensor 74 approaches the blood vessel wall 28. As a result, the position of the sensor 74 within the blood vessel is stabilized, and the influence of blood on the NO detection result by the sensor 74 is reduced, thereby improving measurement accuracy and reliability. In this embodiment, the access mechanism that brings the sensor 74 close to the blood vessel wall 28 is provided by a stylet 168 that is inserted into the catheter body 162.

According to the structure of this embodiment, since the approach mechanism is configured by inserting the stylet 168 into the second lumen 166 of the catheter main body 162, the approach mechanism can be realized more easily.

Although the embodiments of the present invention have been described in detail above, the present invention is not limited by the specific description. For example, a guide wire as a guide member is inserted in advance into a blood vessel at a position close to the blood vessel wall, and a catheter body equipped with a sensor is inserted into the blood vessel while being extended along the guide wire. can also be guided close to the blood vessel wall.

In the embodiment described above, a measuring catheter for measuring NO produced in the blood vessel wall was exemplified, but the substance measured by the measuring catheter according to the present invention is not limited to NO. For example, gaseous substances such as oxygen and carbon dioxide, exudable proteins, physiologically active substances such as autacoids and hormones, cytokines, oxidative stress markers, vascular endothelial growth factor (VEGF), neurotransmitters, and others, hydrogen, sodium, and potassium. Various substances can be measured, such as , calcium, chlorine, glucose, urea, uric acid, and creatinine. Furthermore, the measuring catheter can also be used to measure substances in living body lumens other than blood vessels. Note that the internal cavity of a living body can be any region that exists within the body, and includes the inside of body cavities such as the thoracic cavity, heart cavity, and abdominal cavity, the interior of hollow organs such as the digestive and respiratory organs, and the interior of sensory organs such as the ears and nose. including. Further, the substances measured by the measuring catheter are not necessarily limited to substances produced within the walls of the living body lumen.

The specific shape and detection principle of the sensor shown in the embodiments are merely examples and are not particularly limited. That is, the specific shape of the sensor is changed as appropriate depending on the shape and size of the member that supports the sensor, the size of the sensor insertion site in the body cavity, and the like. The detection principle of the sensor is changed as appropriate depending on the required detection accuracy, the type of substance to be detected, and the like.

Furthermore, it is also possible to employ a combination of a sensor that detects substances in a living body cavity and another sensor such as a sensor that measures basic biological functions (vital signs). According to this, it becomes possible to correlate the production amount of a substance in a living body lumen and the state of basic biological functions. Note that, as sensors for measuring basic biological functions, there are, for example, a temperature sensor, a blood pressure sensor, a blood flow rate sensor, a pH sensor, and the like.

The measuring catheter according to the present invention can serve as a therapeutic catheter. For example, a measurement catheter in which a sensor is provided on the surface of the balloon can also be used as a treatment catheter in balloon expansion angioplasty. Can measure substances.
Furthermore, the present invention originally includes each of the inventions described in (i) to (x) below, and additional notes will be made regarding their configurations and effects.
The present invention
(i) A measurement catheter that is inserted into a living body and equipped with a sensor that detects a substance in the living body lumen, the measuring catheter being provided with an approach mechanism that brings the sensor closer to the wall surface of the living body lumen. ,
(ii) The measurement catheter according to (i), wherein the approach mechanism holds the sensor in contact with the wall surface of the living body lumen;
(iii) the measuring catheter according to (i) or (ii), which is provided with a contact pressure sensor that measures the contact pressure between the sensor and the wall surface of the living body lumen;
(iv) The measurement according to any one of (i) to (iii), wherein the sensor has a housing that covers the detection site, and the housing is provided with a partially open window. catheter,
(v) The measuring catheter according to any one of (i) to (iv), wherein the sensor detects a wall-producing substance produced on the wall surface of the living body lumen;
(vi) The sensor is an NO sensor that detects nitric oxide, and the wall surface of the body lumen is an inner surface of a blood vessel wall, and the approach mechanism approaches the sensor to the inner surface of the blood vessel wall. The measurement catheter according to any one of (i) to (v),
(vii) Any one of (i) to (vi), wherein the approach mechanism is an expander that causes the sensor to approach the wall surface of the biological lumen by changing its diameter from a contracted state to an expanded state. The measuring catheter described in section
(viii) the measurement catheter according to (vii), wherein the expandable body is a balloon;
(ix) The measurement catheter according to (vii), wherein the expansion body is an expandable skeletal structure including a plurality of striations;
(x) The measurement catheter according to any one of (i) to (vi), wherein the approach mechanism is constituted by a guide member that is inserted into the catheter body and bends the catheter body.
Including inventions related to.
In the invention described in (i) above, the detection position of the sensor in the living body cavity can be stabilized by bringing the sensor close to the wall surface of the living body cavity using the approach mechanism. As a result, for example, in addition to substances that constantly flow through the body lumen, substances that exit from the wall of the body lumen, and even substances whose concentration etc. This enables more accurate detection.
In the invention described in (ii) above, the sensor and the wall surface of the living body lumen are in direct contact with each other, so that the measurement position of the sensor in the living body lumen can be further stabilized.
In the invention described in (iii) above, by using the measured value of the contact pressure sensor, for example, it is possible to detect whether or not the sensor is in contact with the wall surface of the biological lumen, or to detect whether or not the sensor is in contact with the wall surface of the biological lumen. It also becomes possible to avoid excessive pressing of the sensor.
In the invention described in (iv) above, for example, by appropriately setting the position and size of the window portion of the housing, it is also possible to adjust the detection direction, detection position, detection level, etc. of the substance by the sensor. Become. Specifically, for example, it is also possible to open the window portion of the housing at a position facing the wall surface of the living body lumen, and further bring the window portion closer to the wall surface of the living body lumen using an access mechanism as necessary. Thereby, it is also possible to accurately detect substances present near the wall of the living body cavity by reducing the influence of substances located far from the wall of the body cavity.
The invention described in (v) above targets, for example, substances that exist close to the wall of a living body cavity, or substances that are produced from the wall of a body cavity and disappear in a relatively short time. , it becomes possible to measure accurately and stably.
In the invention described in (vi) above, nitrogen monoxide can be detected with higher accuracy than, for example, the chemical test device having a conventional structure described in Patent Document 1. In other words, nitric oxide is produced by vascular endothelial cells and exists in blood vessels, but in the blood it is quickly oxidized to nitrite ions, dissolved in the blood and transported, or combined with hemoglobin and transported. detected, making it undetectable. With the measurement catheter of this embodiment, it becomes possible to efficiently detect nitric oxide in the blood vessel that is generated from the inner surface of the blood vessel wall.
In the invention described in (vii) above, for example, by utilizing the fact that the outer circumferential surface of the expandable body is positioned close to the wall surface of the biological cavity during expansion, the sensor attached to the expandable body is brought close to the wall surface of the biological cavity. It may be supported. Alternatively, the sensor may be supported close to the wall of the living body lumen by, for example, pushing the catheter main body including the sensor with the expansion body to bring it closer to the wall of the living body lumen. More specific aspects of the extension body are exemplified by the aspects (viii) and (ix) above.
The guide member in the invention described in (x) above may be, for example, an operating wire that is inserted into the catheter main body and exerts a bending force near the sensor attachment part on the distal end side by push/pull operation from the proximal end side, or an operating wire that is inserted into the catheter main body Examples include a guide wire that guides the catheter body, a stylet that is provided with a distal end portion that is bent in advance, and is inserted into the catheter body. By using such a guide member, the approach mechanism can be realized with simpler equipment than, for example, when using a balloon or the like.

10, 30, 40, 50, 60, 80, 90, 110, 120, 130, 150, 160: measurement catheter, 12: blood vessel, 16, 36, 74, 144: sensor, 17: lumen (body lumen) ), 18: Housing, 20: Detection part (detection part), 22: Window part, 26, 34, 72: Balloon (approach mechanism, expansion body), 28: Blood vessel wall, 29: Wall inner surface (wall surface of biological lumen) ), 42: Contact pressure sensor, 98, 112: Skeletal structure (approach mechanism, expansion body), 100, 114, 124: String portion, 122: Stent (approach mechanism, expansion body), 132, 152, 162: Catheter body, 140, 158: Operation wire (approach mechanism, guide member), 168: Stylet (approach mechanism, guide member)

Claims (14)

A measurement catheter equipped with a sensor that is inserted into a living body and detects a substance in the living body cavity,
an approach mechanism is provided for bringing the sensor close to a wall of the body lumen, and the approach mechanism holds the sensor in contact with the wall of the body lumen ;
The sensor has a housing that covers the detection site, the housing is provided with a partially open window, and
The detection site is exposed through the window, and
The measurement catheter , wherein the approach mechanism holds the opening peripheral portion of the window portion in contact with the wall surface of the living body lumen. The opening periphery of the window portion is closer to the wall surface of the body lumen than the outer peripheral surface of the catheter body. The measuring catheter according to claim 1, wherein the measuring catheter projects toward the outer circumferential surface. The measurement catheter according to claim 1 or 2, wherein the approach mechanism is an expander that causes the sensor to approach the wall surface of the living body lumen by changing its diameter from a contracted state to an expanded state. The measurement catheter according to claim 3 , wherein the expansion body is a balloon. A measurement catheter equipped with a sensor that is inserted into a living body and detects a substance in the living body cavity,
an approach mechanism is provided for bringing the sensor close to a wall of the body lumen, and the approach mechanism holds the sensor in contact with the wall of the body lumen ;
A measurement catheter , wherein the access mechanism is constituted by a guide member that is inserted into the catheter body and bends the catheter body . The guide member is inserted into the catheter main body and has a distal end fixed to the catheter main body. 6. The measuring catheter according to claim 5, further comprising a manipulation wire attached thereto. The catheter main body has a deformation allowing portion on the proximal end side of the fixing portion of the operating wire. The measurement catheter according to claim 6, comprising: a first lumen through which the sensor body having the sensor is inserted; and a first lumen through which the guide member is inserted. The measurement catheter according to any one of claims 5 to 7, further comprising a second lumen. The tip of the second lumen is blocked, and the blocked tip of the second lumen is The measurement according to claim 8, wherein the tip of the operating wire serving as the guide member is fixed to the guide member. catheter. According to claim 8, the guide member includes a stylet provided with a bent portion. catheter for measurement. The measurement catheter according to any one of claims 1 to 10, further comprising a contact pressure sensor that measures the contact pressure between the sensor and the wall surface of the living body lumen. The measurement catheter according to any one of claims 1 to 11 , wherein the sensor detects a wall-producing substance produced on the wall surface of the body lumen. 2. The sensor is an NO sensor that detects nitric oxide, and the wall surface of the body lumen is an inner surface of a blood vessel wall, and the approach mechanism causes the sensor to approach the inner surface of the blood vessel wall. The measuring catheter according to any one of items 1 to 12 . A measurement catheter equipped with a sensor that is inserted into a living body and detects a substance in the living body cavity,
an approach mechanism is provided for bringing the sensor close to a wall of the body lumen, and the approach mechanism holds the sensor in contact with the wall of the body lumen;
The approach mechanism has a skeletal structure that can be expanded so that the distal ends of a plurality of filamentous parts extending in the length direction from the distal end side of the core wire inserted into the catheter body are set as free ends separated from each other in the circumferential direction. A measurement catheter having a body, and the sensor is provided on the outer circumferential surface of the striated portion.

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