In vivo temperature control system

Abstract

The present invention addresses the problem of providing an in vivo temperature control system that enables the internal temperature of a biological organ such as the esophagus to be monitored, and enables spatial changes inside a biological lumen to be detected on the basis of the temperature distribution inside the biological lumen in the longitudinal direction being measured on a time-series basis by injecting a liquid therein. Provided is an in vivo temperature control system comprising: a catheter that can be inserted inside a biological lumen; two or more temperature sensors arranged to be able to measure the temperature distribution in the longitudinal direction of the biological lumen; a liquid reservoir that stores a liquid; and a control unit that estimates spatial changes inside the biological lumen on the basis of the change in temperature before and after discharging the liquid of the liquid reservoir to the outside via the catheter. The change in temperature is measured by each of the two or more temperature sensors.

Description

[Technical Field]

[0001] The present invention relates to an in vivo temperature control system capable of estimating spatial changes within a living lumen. [Background technology]

[0002] Atrial fibrillation is a type of arrhythmia in which repeated irregular contractions of the atria cause poor blood circulation, leading to discomfort and fatigue. Therefore, a widely used treatment for atrial fibrillation is catheter ablation (pulmonary vein isolation), which cauterizes the pulmonary veins, the main source of atrial fibrillation, and the surrounding myocardial tissue, such as the posterior wall of the left atrium.

[0003] On the other hand, during catheter ablation treatment, the proximity of the ablation site (left atrium) to the esophagus raises the risk of damage to the esophagus, leading to serious esophageal complications such as left atrium-esophageal fistula and esophago-vagal nerve paralysis, making it necessary to properly manage the temperature inside the esophagus.

[0004] As a means of controlling the temperature inside the esophagus, a temperature measuring device has been reported in which a catheter equipped with a temperature sensor is inserted into the esophagus via an approach through the patient's nose (transnasal) or mouth (oral), and the temperature sensor measures the internal temperature of the esophagus, and if it is determined that the internal temperature has reached a threshold value, an alarm is output externally (Patent Document 1).

[0005] Also, a device has been reported that calculates the remaining time until the temperature inside the esophagus reaches a temperature limit value based on the rate of temperature change in the internal temperature of the esophagus, and outputs the calculated time to the outside (Patent Document 2).

[0006] In addition, a system has been reported that uses an esophageal catheter equipped with first and second expansion members that contact the esophageal wall, and controls the temperature inside the esophagus by injecting a liquid between the expansion members (Patent Document 3). [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent No. 6618254 [Patent Document 2] Patent No. 6804910 [Patent Document 3] Patent Publication No. 2019-80783 Summary of the Invention [Problem to be solved by the invention]

[0008] To properly control the temperature inside the esophagus during catheter ablation treatment, it is necessary to continuously monitor the temperature inside the esophagus and take preventive measures before the tissue inside the esophagus is damaged.

[0009] The temperature measuring device described in Patent Document 1 monitors the internal temperature of the esophagus during ablation treatment and outputs an alarm externally when it is determined that the internal temperature has reached a threshold, making it possible to take preventative measures such as temporarily halting the ablation before the esophagus is heated or cooled and damaged. However, during ablation treatment, the esophageal temperature can fluctuate rapidly, and if the alarm is not acknowledged in time, necessary treatment may be delayed.

[0010] The device described in Patent Document 2 can calculate the time it takes for the temperature inside the esophagus to reach a dangerous temperature at which the esophagus may be damaged, based on the rate of temperature change inside the esophagus, and output the calculated value to an external device, thereby predicting rapid changes in esophageal temperature and providing time for necessary treatment. However, because it does not have a mechanism for controlling the temperature inside the esophagus to a safe temperature, if treatment is delayed, the risk of esophageal damage cannot be reduced.

[0011] The esophageal temperature control system described in Patent Document 3 can appropriately control the temperature inside the esophagus by creating a space between two expansion members and injecting a liquid into that space in the esophagus while stopping the flow of water. However, because the pressure of the ablation catheter on the myocardial tissue easily narrows or blocks the adjacent esophageal lumen, the injected liquid may not reach the entire lumen, making it difficult to control the temperature inside the esophagus.

[0012] Therefore, the present invention aims to provide an in vivo temperature control system that can monitor the internal temperature of a biological organ such as the esophagus and detect spatial changes within a biological lumen based on time-series measurement of the temperature distribution in the longitudinal direction within the biological lumen due to the injection of a liquid. [Means for solving the problem]

[0013] The present inventors have conducted extensive research to solve the above problems and have discovered the following inventions (1) to (6). (1) a catheter that can be inserted into a biological lumen; two or more temperature sensors arranged so as to be able to measure the temperature distribution in the longitudinal direction of the biological lumen; a liquid storage section that stores a liquid; a control unit that estimates a spatial change within the biological lumen based on a temperature change before and after the liquid in the liquid storage unit is released to the outside via the catheter; and Equipped with the spatial change is a narrowing or occlusion of the biological lumen; The temperature change is measured by each of the two or more temperature sensors. R, When estimating the spatial change in the biological lumen, if a temperature change greater than a preset threshold is detected by all of the two or more temperature sensors, the control unit determines that the biological lumen is not in a narrowed or blocked state. In vivo temperature control system. (2) a catheter that can be inserted into a biological lumen; two or more temperature sensors arranged so as to be able to measure the temperature distribution in the longitudinal direction of the biological lumen; a liquid storage section that stores a liquid; a control unit that estimates a spatial change in the biological lumen based on a temperature change before and after the liquid in the liquid storage unit is released to the outside via the catheter; and Equipped with the spatial change is a narrowing or occlusion of the biological lumen; The temperature change is measured by each of the two or more temperature sensors. R, When estimating the spatial change in the biological lumen, the control unit determines that the biological lumen is in a narrowed or blocked state based on an index as to whether or not, among the temperature changes in the longitudinal axis direction of the biological lumen detected by the two or more temperature sensors, any one of the temperature sensors detects a temperature change smaller than a preset threshold, and all of the temperature sensors located downstream in the liquid flow direction from the temperature sensor that detected the temperature change smaller than the threshold detect a temperature change larger than a preset threshold. In vivo temperature control system. (3) A monitor is provided to display the signal detected by the temperature sensor as visual information, The monitor has a means for informing an operator of spatial changes within the biological lumen. 1) or (2) 1. An in vivo temperature control system as described. (4) An alarm output unit is provided that outputs an alarm to the outside when it is determined that the biological lumen is in a stenotic state or an occluded state. Either 1) to (3) 1. An in vivo temperature control system as described. [Effects of the Invention]

[0014] According to the present invention, a temperature sensor measures the internal temperature of a biological lumen and can adjust it to a predetermined temperature using a liquid, and by measuring the temperature change in the longitudinal direction of the biological lumen due to the injection of liquid, spatial changes within the biological lumen can be detected. [Brief explanation of the drawings]

[0015] [Figure 1] 1 is an external view of an in vivo temperature control system according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a schematic diagram showing the internal structure of the in vivo temperature control system shown in FIG. [Figure 3] 10 is a schematic diagram showing the temperature change over time in the living body temperature before and after injecting a liquid into a living body lumen in a first control operation of the living body temperature control system. FIG. [Figure 4]10 is a schematic diagram showing the change in temperature over time in the temperature inside the living body before and after injecting a liquid into a narrowed living body lumen in a first control operation of the living body temperature control system. FIG. [Figure 5] 10 is a schematic diagram showing the temporal change in the temperature inside the living body before and after injecting a liquid into a closed living body lumen in a first control operation of the living body temperature control system. FIG. [Figure 6] 10 is a flowchart showing the operation procedure of the control unit in the first control operation of the in vivo temperature control system. DETAILED DESCRIPTION OF THE INVENTION

[0016] Specific embodiments of the present invention will be described below with reference to the accompanying drawings, but the present invention is not limited to these embodiments. Furthermore, appropriate modifications are possible within the scope of the effects of the present invention. The same reference numerals will be used for the same elements.

[0017] First Embodiment FIG. 1 is an external view of an in vivo temperature control system 1 according to a first embodiment. The in vivo temperature control system 1 can be used, for example, to monitor the internal temperature of the esophagus, which is close to the heart of the ablation target, and to cool the internal temperature of the esophagus with a liquid when performing an ablation procedure using a balloon ablation catheter that heats the inside of the balloon with a high-frequency current. The biological organs to which the in vivo temperature control system 1 can be applied are not particularly limited, and the system may be applied to the pharynx, larynx, lungs, esophagus, stomach, etc., but is particularly preferably used to cool the inside of the esophagus.

[0018] Here, the in vivo temperature control system 1 comprises an in vivo temperature control device 2 that delivers or aspirates temperature-controlled liquid to a catheter 3, a catheter 3 that can be inserted into a living body and has a hole that can deliver or aspirate liquid into the living body, a temperature probe 4 that can be inserted into the catheter 3 and has two or more temperature sensors 42 arranged so that the temperature distribution in the longitudinal direction of the living body lumen can be measured, a monitor 5 that can display signals from the temperature probe 4, a dual-purpose liquid delivery and aspirating tube 6 that is connected to a pump 21 and a pressure center 22 and connects the in vivo temperature control device 2 and the catheter 3, and a liquid waste section 7.

[0019] FIG. 2 is a schematic diagram showing the internal structure of the in vivo temperature control device 2 shown in FIG.

[0020] The in vivo temperature control device 2 includes a pump 21 that pumps or sucks liquid into the catheter 3, a pressure sensor 22 that detects the internal pressure of the catheter 3, a liquid storage section 23 that stores the temperature-controlled liquid, and a control section 24 that controls the operation of the pump based on a signal detected from the temperature probe 4 or a signal detected from the pressure sensor 22.

[0021] The pump 21 provided in the in vivo temperature control device 2 is a roller-type tube pump, and by rotating the roller of the pump 21 in the forward direction, liquid can be sent from the liquid storage section 23 to the catheter 3, and by rotating the roller of the pump 21 in the reverse direction, liquid can be sucked from the tip or hole of the catheter 3.

[0022] The liquid reservoir 23 of the in vivo temperature control system 1 of the first embodiment is a commercially available infusion bag containing physiological saline, glucose solution, or the like, and is configured to be able to be housed within the in vivo temperature control device 2. The in vivo temperature control device 2 also has a Peltier element 231 and an in-device temperature sensor (not shown) that are arranged in contact with the liquid reservoir 23 and measure the temperature inside the liquid reservoir 23, and can control the temperature of the liquid stored in the liquid reservoir 23 by controlling the temperature of the Peltier element 231 based on a signal detected from the in-device temperature sensor. When performing catheter ablation using a hot balloon, the temperature of the liquid inside the liquid reservoir 23 is preferably controlled to between 0°C and 15°C, and more preferably between 0°C and 10°C.

[0023] The liquid reservoir 23 may have any form as long as it can store a liquid such as saline, and may be built into the in vivo temperature control device 2 or may be external to the in vivo temperature control device 2. When the liquid reservoir 23 is built into the in vivo temperature control device 2, it is preferable that the temperature of the liquid in the liquid reservoir 23 can be controlled as described above. As an alternative to the first embodiment, the infusion bag may be cooled with a cooling agent such as ice instead of the Peltier element 231, or a pre-frozen infusion bag may be thawed before use. Furthermore, purified water or tap water may be used as the liquid in addition to saline or glucose solution.

[0024] Furthermore, when used for cryoablation, it is necessary to warm the inside of the body more than usual, and the in vivo temperature control system of the present invention may be used for this purpose. In this case, a heating resistor may be used to heat the temperature of the liquid stored in the liquid storage section 23 to 30 to 45°C.

[0025] The control unit 24 included in the in vivo temperature control device 2 detects a signal (for example, thermoelectromotive force) from the temperature sensor 42 in the temperature probe 4 connected to the in vivo temperature control device 2 and converts it into temperature information (in vivo temperature).

[0026] The control unit 24 also controls the pump 21, and drives the pump 21 to discharge the liquid in the liquid storage unit 23 to the outside via the catheter 3 based on a signal detected from the temperature probe 4 or a liquid delivery command issued by operating the monitor 5. In addition, the control unit 24 provided in the in vivo temperature control device 2 preferably includes a circuit for controlling the driving of the pump 21 based on a signal detected by the pressure sensor 22. For example, the control unit 24 of the in vivo temperature control system 1 according to the first embodiment includes a mechanism for converting information related to the amount of displacement from the dual-purpose liquid delivery and suction tube 6 into numerical pressure information.

[0027] The controller 24 also includes a circuit for estimating spatial changes within the biological lumen (e.g., a constricted or blocked state within the lumen) based on temperature changes of two or more temperature sensors 42 arranged in the longitudinal direction of the biological lumen before and after the release of the liquid into the biological lumen. Specifically, whether the liquid can flow smoothly from upstream to downstream, i.e., whether the biological lumen is in a constricted or blocked state, is estimated from the temperature changes measured by each of the two or more temperature sensors arranged in the longitudinal direction of the biological lumen. In this case, it is preferable that the controller 24 be able to preset whether the multiple temperature sensors 42 arranged in the longitudinal direction are located upstream or downstream in the direction of the liquid flow. Alternatively, the controller 24 may determine whether the temperature sensors 42 are located upstream or downstream in the direction of the liquid flow based on the temperature transition of each temperature sensor 42 that detects a temperature change when the liquid flows from upstream to downstream. Furthermore, in the first embodiment of the in vivo temperature control system, the control means for controlling the operation of the pump 21 and the circuit for estimating spatial changes within the biological lumen are performed by the same control unit 24, but this is not limited to this, and a configuration in which separate control units are provided for each and control them, or a configuration in which a separate control means is provided via the Internet, may also be used.

[0028] In addition, it is preferable that control unit 24 includes a circuit for controlling the internal temperature of liquid storage unit 23 based on a signal detected by an internal temperature sensor that measures the temperature inside liquid storage unit 23.

[0029] The in vivo temperature control device 2 also includes an alarm output unit (not shown), and the control unit 24 also has a control function of outputting a predetermined alarm (audio, etc.) from the alarm output unit when it is determined that a predetermined condition is met. Specifically, when it is determined that the biological lumen is in a narrowed or blocked state, the control unit 24 outputs an alarm command to the alarm output unit, which then issues an audio warning. In the in vivo temperature control system of the first embodiment, the control means for controlling the operation of the pump 21 and the circuit for outputting an alarm command to the alarm output unit are both implemented by the same control unit 24, but this is not limited thereto, and a configuration in which separate control units are provided for each and control these, or a configuration in which separate control means is provided via the Internet, may also be used.

[0030] The catheter 3 is a tubular member that can be inserted into a living body via a transnasal or transoral approach, and can deliver or aspirate liquid through a lumen at the tip of the catheter or through holes in the surface. Specifically, the catheter 3 has a tube portion 31 that can be inserted into a living body, and a valved connector 32 fixed to the base end of the tube portion 31 in the longitudinal direction.

[0031] The material of the tube portion 31 may be any flexible material that can be inserted into a living body via the nose or mouth, such as thermoplastic resins such as polyvinyl chloride, polyurethane, silicone, etc. It is also preferable that the tube portion 31 contains a material that is radiopaque so that the placement site in the living body can be confirmed.

[0032] For example, when the tube portion 31 is inserted transnasally into the living body through the nose, the length of the tube portion 31 is preferably about 200 mm to 1000 mm, the outer diameter is preferably about φ1.7 mm to 6.0 mm, and the inner diameter is preferably about φ1.0 mm to 5.0 mm.

[0033] The valved connector 32 is fixed to the base end of the tube section 31 and can be connected to the dual-purpose liquid supply and suction tube 6. It is equipped with a port 321 for supplying or suctioning liquid from the tip end of the tube section 31, and a valve 322 for fixing the temperature probe 4 when inserting the temperature probe 4 into the catheter 3. It is preferable that the valve 322 can be opened and closed by rotational movement or the like. With the above configuration, the temperature probe 4 can be operated when the valve 322 is open, and can be fixed when the valve 322 is closed.

[0034] The temperature probe 4 is a component that is inserted into a living body via the nose or mouth and used to measure the internal temperature of a biological lumen. It consists of a shaft portion 41 that is inserted into the living body, two or more temperature sensors 42 arranged on the temperature probe so that the temperature distribution in the longitudinal direction of the biological lumen can be measured, and a handle portion 43.

[0035] The material of the shaft portion 41 may be any flexible material that can be inserted into the body via the nose or mouth, and thermoplastic resins such as polyether block amide, polyurethane, nylon, polyolefin, polyamide, and polyether polyamide can be used.

[0036] The outer diameter of the shaft portion 41 is preferably about 1.0 mm to 4.0 mm, and even better if it is a diameter that can be inserted into the lumen of the catheter 3. The length is preferably about 300 mm to 1100 mm, and when used by inserting it into the lumen of the catheter 3, the temperature sensor 42 is preferably disposed at a position that protrudes from the tip side of the catheter 3.

[0037] The shaft 41 may have a function that allows the tip side to be deflected by operating the handle 43. This reduces the risk of the temperature probe 4 getting lost in the airway when inserted into the esophagus, particularly via the nose or mouth, when applied to the esophagus. Furthermore, because the esophagus is not linear but meanders from the pharynx to the cardia of the stomach, deflection allows the temperature sensor 42 to be positioned at the desired esophageal location.

[0038] The temperature sensor 42 may be positioned in any way so long as it is capable of measuring the temperature distribution in the longitudinal direction of the biological lumen, but when positioned on the temperature probe 4, it is preferably positioned at the tip. The number of temperature sensors 42 may be two or more, but it is preferable to have three or more in order to measure the temperature distribution in the longitudinal direction inside the biological lumen over time and detect spatial changes more accurately.

[0039] Any material with good thermal conductivity may be used for the temperature sensor 42, and it is even better if it has X-ray contrast properties in order to measure the temperature in the vicinity of the ablation site.

[0040] The handle portion 43 has a connector 431 for connecting to the in vivo temperature control device 2, and in the in vivo temperature control system 1 of the first embodiment, the in vivo temperature control device 2 and the temperature probe 4 are connected via a connection cable 44.

[0041] In the first embodiment, the catheter 3 for discharging the liquid to the outside and the temperature probe 4 having the temperature sensor 42 disposed therein are separate, and the temperature probe 4 is configured to be inserted into the catheter 3, but in another embodiment, the temperature sensor may be disposed on the tube portion of the catheter 3. In this case, it is preferable that a hole capable of delivering the liquid into the living body is disposed on the base end side in the longitudinal direction of the temperature sensor disposed in the catheter 3.

[0042] The monitor 5 can display the internal temperature information of the living body detected by the temperature probe 4 as visual information such as digital numbers, bar graphs, and trend graphs. In addition, when the temperature inside the living organ exceeds a preset threshold, the display color changes, providing the operator with visual information of the temperature change.

[0043] The monitor 5 also has a means for informing the operator of spatial changes within the biological lumen, and can visually communicate to the operator, when a spatial change occurs within the biological lumen, whether the biological lumen is narrowed or blocked. This allows the operator to quickly recognize a narrowed or blocked esophagus during, for example, arrhythmia treatment using catheter ablation, thereby reducing the risk of esophageal damage by releasing pressure and moving the ablation source away from the esophagus. Furthermore, if the operator recognizes a narrowed or blocked esophagus and manipulates the ablation catheter to prevent the narrowed or blocked esophagus, the liquid can flow smoothly from upstream to downstream, allowing for effective temperature control within the esophagus using the liquid.

[0044] Furthermore, the monitor 5 preferably has means for transmitting to the operator operational information such as liquid delivery and suction operation information, warning information such as errors and alarms that have occurred in the system, operating time, the number of liquid delivery and suction operations, and the amount of liquid delivered, etc. This allows the operator to be informed of the operating status, malfunctions, and dangers not only visually but also audibly.

[0045] Furthermore, the monitor 5 preferably has a touch panel display 51, allowing various parameters related to the operation of the system to be input, and transmitting the input parameters to the control unit 24 of the in vivo temperature control device 2. This allows the operator to start and stop the operation of the in vivo temperature control device 2 and set and change various parameters from a remote location.

[0046] Furthermore, the monitor 5 can transmit signals to the control unit 24 of the in vivo temperature control device 2 so that liquid can be injected and suctioned regardless of the internal temperature of the living lumen. This allows the operator to issue drive commands for liquid injection and suction at any timing.

[0047] The liquid delivery and suction tube 6 is a tube for delivering liquid from the liquid storage section 23 to the catheter 3 via the pump 21 when delivering the liquid, and for delivering the liquid from the catheter 3 to the liquid waste section 7 when suctioning the liquid. Here, the liquid waste section 7 is a section for storing unnecessary liquid after suctioning the liquid from the body.

[0048] The liquid supply / suction tube 6 includes an enlarged portion 61 , a flow path switching portion 62 , a liquid supply port 63 for connection to the liquid storage portion 23 , and a connection port 64 for connection to the catheter 3 .

[0049] As described above, the swelling portion 61 is a tube formed in a bag shape, and is designed to expand and contract due to the pressure inside the tube. As a result, by detecting the amount of displacement of the swelling portion 61 with the contact-type position displacement meter 221, it is possible to measure the internal pressure of the catheter 3 connected to the dual-purpose fluid supply and suction tube 6 via the dual-purpose fluid supply and suction tube 6.

[0050] In the first embodiment, the flow path switching unit 62 is a three-way check valve 621, and is connected to the primary side of the pump 21. As a result, when liquid is to be delivered, the pump 21 rotates forward, which switches the flow path of the three-way check valve 621 to a direction that connects the liquid storage unit 23 and the pump 21, and the liquid flows into the catheter 3. When liquid is to be aspirated from the catheter 3, the pump 21 rotates backward, which switches the flow path of the three-way check valve 621 to a direction that connects the pump 21 and the waste liquid unit 7, and the aspirated liquid is discharged into the waste liquid unit 7.

[0051] The liquid supply port 63 may have any form as long as it can supply liquid from the liquid storage section 23 into the liquid supply and suction tube 6. Since the liquid storage section 23 is an infusion bag, the liquid supply port 63 in the first embodiment is preferably a needle 631 that can be pierced into the infusion bag.

[0052] The connection port 64 may be in any form as long as it can be connected to the catheter 3, but is preferably a three-way stopcock. This allows for manual delivery and suction of liquid by connecting a syringe or the like when the in vivo temperature control system malfunctions.

[0053] Hereinafter, a first control operation procedure will be described for detecting spatial changes within the esophagus by measuring temperature changes in the longitudinal direction within the esophagus due to the injection of a liquid during arrhythmia treatment by catheter ablation.

[0054] (Step 1: Pumping liquid (cooling water) into the body lumen) In order to ascertain in advance the state of stenosis or obstruction in the esophagus 71, before starting catheter ablation, the operator operates the monitor 5 to send a liquid. Specifically, by operating the touch panel display 51 of the monitor 5, a drive command for the liquid sending speed and liquid sending time is output from the control unit 24 to the pump 21 according to preset conditions, and the liquid 73 (cooling water) is sent from the liquid storage unit 23 through the liquid sending and suction tube 6 and the catheter 3 into the esophagus.

[0055] In addition to starting the liquid delivery operation by directly operating the touch panel display 51, the control unit 24 may also start the liquid delivery operation when a specific condition is met, such as when the internal temperature of the esophagus 71 exceeds a threshold. In this case, when catheter ablation to cauterize cardiac tissue near the left atrium is initiated, the internal temperature of the nearby esophagus 71 gradually rises, and the internal temperature of the esophagus measured by the temperature sensor 42 of the temperature probe 4 also gradually rises. The control unit 24 can preset an internal esophageal temperature threshold at which delivery of the cooled liquid 73 (cooling water) begins, and constantly compares the temperature information from the temperature sensors 42 with the threshold. When the temperature information detected by at least one of the temperature sensors 42 reaches the threshold, the control unit 24 outputs a drive command for the liquid delivery speed and liquid delivery time to the pump 21, and the liquid 73 (cooling water) is delivered from the liquid storage unit 23 to the esophagus via the liquid delivery / suction tube 6 and the catheter 3.

[0056] (Step 2: Evaluating temperature changes in biological lumen) The control unit 24 measures whether there is a change in temperature detected by all of the temperature sensors 42 arranged from the upstream side to the downstream side in the flow direction of the liquid 73 before and after sending the liquid 73 into the esophagus 71. In the first control operation procedure, information on whether the temperature sensor 42 is located on the upstream side or the downstream side in the flow direction of the liquid 73 is set in advance in the control unit 24. This allows the control unit 24 to determine the temperature change in the flow direction of the liquid 73 without determining the position information of the temperature sensor 42.

[0057] If a temperature change is observed in the temperature inside the esophagus 71 detected by all of the temperature sensors 42 before and after the liquid 73 is delivered into the esophagus 71, i.e., if the liquid 73 flows smoothly from the upstream side to the downstream side and the temperature inside the esophagus 71 drops, the control unit 24 determines that the esophagus 71 is not in a stenotic or obstructed state. For example, as shown in FIG. 3 , if the temperature inside the esophagus 71 detected by all of the temperature sensors 42 (Ch. 1 to Ch. 6) of the temperature probe 41 inserted into the esophagus 71 due to the injection of the liquid 73 detects a temperature change greater than a preset threshold, the control unit 24 determines that the esophagus 71 is not in a stenotic or obstructed state. Specifically, for example, when the temperature inside the esophagus 71 is about 37°C, if the temperature change inside the esophagus 71 detected by all of the temperature sensors 42 is 3°C / second or more, the control unit 24 preferably determines that the esophagus 71 is not in a stenotic or obstructed state.

[0058] On the other hand, if there is a temperature change in any one of the temperature sensors 42 located upstream in the flow direction of the liquid 73, there is a temperature change in the temperature sensor 42 located downstream in the flow direction of the liquid 73, and the temperature change detected by the temperature sensor 42 located between the upstream and downstream temperature sensors 42 is smaller than a preset threshold, the control unit 24 determines that the esophagus 71 is in a constricted state. Specifically, for example, when the temperature in the esophagus 71 is about 37°C, as shown in Fig. 4, if the temperature change in the esophagus 71 detected by the temperature sensors 42 (Ch. 5, Ch. 6) located upstream in the flow direction of the liquid 73 and the temperature sensors 42 (Ch. 1 to Ch. 3) located downstream is 3°C / second or more and the temperature change in the esophagus detected by the temperature sensor 42 (Ch. 4) located between the upstream and downstream temperature sensors 42 is 0 to 3°C / second, the control unit 24 preferably determines that the esophagus 71 is in a constricted state due to compression by the myocardial tissue 72.

[0059] Furthermore, when the temperature change detected by any one of the temperature sensors 42 located upstream in the flow direction of the liquid 73 is smaller than a preset threshold, and the temperature changes in the esophagus detected by all of the temperature sensors 42 located downstream in the flow direction of the liquid 73 relative to the temperature sensor 42 that detected the temperature change smaller than the threshold are smaller than a preset threshold, the controller 24 determines that the esophagus 71 is in an obstructed state. Specifically, for example, when the temperature in the esophagus 71 is about 37°C, as shown in Fig. 5, if the temperature change in the esophagus 71 detected by the temperature sensors (Ch. 5, Ch. 6) located upstream is 3°C / second or more and the temperature change in the esophagus detected by the temperature sensors 42 (Ch. 1 to Ch. 4) located downstream is 0 to 3°C / second, the controller 24 preferably determines that the esophagus 71 is compressed by the myocardial tissue 72 and is in an obstructed state.

[0060] (Step 3: Alert the operator) When a spatial change occurs in the biological lumen, that is, when the control unit 24 determines that the esophagus 71 is in a narrowed or blocked state, the control unit 24 notifies the operator of the result of the determination by visual means or auditory means. Specifically, the control unit 24 can notify the operator by displaying visual information on the monitor 5 that the esophagus 71 is in a narrowed or blocked state, or by issuing a warning such as an alarm from the warning output unit.

[0061] A flowchart showing an example of the operation procedure of the control unit 24 in the first control method will be described with reference to FIG.

[0062] In this example of operation procedure, first, the control unit 24 detects a signal (e.g., thermoelectromotive force) from the temperature sensor 42 in the temperature probe 4 connected to the in vivo temperature control device 2 and converts it into temperature information (in vivo temperature). Then, based on the temperature measurement data, the average temperature per unit time is calculated.

[0063] Next, the control unit 24 determines whether or not liquid has been delivered into the biological lumen. If it determines that liquid has been delivered, it measures how much the internal body temperature detected by the plurality of temperature sensors 42 has changed after the delivery from the instantaneous or average internal body temperature before the delivery, and determines whether the temperature change in the biological lumen obtained by each temperature sensor 42 is greater than a preset threshold (first threshold). If all temperature sensors 42 detect a temperature change greater than the preset threshold, the control unit 24 determines that the biological lumen is not in a constricted or occluded state.

[0064] On the other hand, if a temperature sensor 42 detects a temperature change smaller than a preset threshold (first threshold), the control unit 24 then determines whether all temperature sensors 42 located downstream in the liquid flow direction from the temperature sensor 42 that detected the temperature change smaller than the threshold have detected a temperature change larger than the preset threshold (first threshold), using this as an index. Here, if all temperature sensors 42 located downstream in the liquid flow direction detect a temperature change larger than the preset threshold, the control unit 24 determines that the biological lumen is in a stenotic state. On the other hand, if all temperature sensors 42 located downstream in the liquid flow direction do not detect a temperature change larger than the preset threshold, the control unit 24 determines that the biological lumen is in an occluded state.

[0065] Furthermore, if a plurality of temperature sensors 42 detect a temperature change smaller than a preset threshold (first threshold), the controller 24 may then determine whether all temperature sensors 42 located downstream in the liquid flow direction from the starting temperature sensor 42, starting from the temperature sensor 42 located furthest downstream in the liquid flow direction, detect a temperature change larger than the preset threshold. Here, if all temperature sensors 42 located downstream in the liquid flow direction from the starting temperature sensor 42 detect a temperature change larger than the preset threshold, the controller 24 determines that the biological lumen is in a stenotic state. On the other hand, if all temperature sensors 42 located downstream in the liquid flow direction from the starting temperature sensor 42 do not detect a temperature change larger than the preset threshold, the controller 24 determines that the biological lumen is in an occluded state.

[0066] Furthermore, if none of the temperature sensors 42 detects a temperature change greater than a preset threshold value (first threshold value), the controller 24 determines that the inside of the body lumen is in an occluded state.

[0067] When it is determined that the inside of the biological lumen is in a constricted or blocked state, the control unit displays visual information indicating the constricted or blocked state on the monitor 5, or issues a warning such as an alarm from the warning output unit. [Industrial Applicability]

[0068] The present invention is applicable to medical fields where it is necessary to detect temperature rise or cooling within a living lumen, and is particularly applicable to cooling after temperature rise during catheter ablation. [Explanation of symbols]

[0069] 1. In vivo temperature control system, 2. In vivo temperature control device, 3. Catheter, 4. Temperature probe, 5. Monitor, 6. Dual-purpose tube for fluid supply and suction, 7. Drainage section, 21. Pump, 22. Pressure sensor, 23. Fluid storage section, 24. Control section, 31. Tube section, 32. Valved connector, 41. Shaft section, 42. Temperature sensor, 43. Handle section, 44 Connection cable, 51, touch panel display, 61, ampulla, 62, flow path switching section, 63, liquid supply port, 64, connection port, 71, esophagus, 72, myocardial tissue, 73, liquid, 221, contact type position displacement sensor, 231, Peltier element, 321, port, 322, valve, 431, connector, 621, three-way check valve, 631, needle

Claims

1. a catheter that can be inserted into a biological lumen; two or more temperature sensors arranged to be able to measure the temperature distribution in the longitudinal direction of the biological lumen; a liquid storage section that stores a liquid; a control unit that estimates a spatial change in the biological lumen based on a temperature change before and after the liquid in the liquid storage unit is released to the outside via the catheter; and Equipped with the spatial change is a narrowing or occlusion of the biological lumen; the temperature change is measured by each of the two or more temperature sensors; When estimating the spatial change in the biological lumen, if a temperature change greater than a preset threshold is detected by all of the two or more temperature sensors, the control unit determines that the biological lumen is not in a narrowed or blocked state. In vivo temperature control system.

2. a catheter that can be inserted into a biological lumen; two or more temperature sensors arranged to be able to measure the temperature distribution in the longitudinal direction of the biological lumen; a liquid storage section that stores a liquid; a control unit that estimates a spatial change in the biological lumen based on a temperature change before and after the liquid in the liquid storage unit is released to the outside via the catheter; and Equipped with the spatial change is a narrowing or occlusion of the biological lumen; the temperature change is measured by each of the two or more temperature sensors; When estimating the spatial change in the biological lumen, the control unit determines that the biological lumen is in a narrowed or blocked state based on an index as to whether or not, among the temperature changes in the longitudinal axis direction of the biological lumen detected by the two or more temperature sensors, any one of the temperature sensors detects a temperature change smaller than a preset threshold value, and all of the temperature sensors located downstream in the flow direction of the liquid from the temperature sensor that detected the temperature change smaller than the threshold value detect a temperature change larger than a preset threshold value. In vivo temperature control system.

3. a monitor that displays the signal detected by the temperature sensor as visual information; 3. The in vivo temperature control system according to claim 1, wherein said monitor has means for notifying an operator of spatial changes within said living lumen.

4. The in vivo temperature control system according to any one of claims 1 to 3, further comprising an alarm output unit that outputs an alarm to the outside when it is determined that the biological lumen is in a narrowed or blocked state.

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