Double-membrane balloon catheter

Abstract

The present invention provides a balloon catheter with improved functionality and safety in a balloon catheter having multiple expansion lumens. The double-membrane balloon catheter consists of a double-membrane balloon 8, an outer tube 4, an inner tube 5, and a gripping section. The double-membrane balloon 8 is composed of an inner balloon 3 and an outer balloon 2. The inner tube 5 has a guidewire lumen 5a and is inserted into the outer tube 4, sealing the respective ends of the inner balloon 3 and outer balloon 2. The outer tube 4 is shorter in length than the inner tube 5 and connects the respective proximal ends of the inner balloon 3 and outer balloon 2. Lumens 7a and 7b are formed between the outer tube 4 and the inner tube 5. The double-membrane balloon 8 is provided at the tip end of the outer tube 4 and the inner tube 5, and a gripping section is provided at the proximal end. A lumen 21 for liquid injection is provided between the outer balloon 2 and the inner balloon 3. A lumen 31 for gas injection is provided in the lumen of the inner balloon 3.

Description

Technical Field

[0001] The present invention relates to a balloon catheter, and particularly to a balloon catheter used for the treatment of aortic valve stenosis.

Background Art

[0002] When surgical treatment or transcatheter aortic valve implantation (TAVI / transcatheter aortic valve replacement: TAVR) is difficult in severe aortic valve stenosis, balloon aortic valvuloplasty (BAV) is performed. However, in current BAV, in order to prevent serious complications associated with the movement of the balloon during dilation, high-frequency pacing that reduces cardiac output is essential. In addition to the existence of patients who cannot tolerate high-frequency pacing, frequent high-frequency pacing has the problem of deteriorating the prognosis. There is a need for a technique that does not require high-frequency pacing and can be dilated frequently.

[0003] In general BAV, when performing balloon expansion and contraction, the balloon is expanded with a liquid in which a contrast agent is diluted with physiological saline. However, in the expansion and contraction of the balloon by the liquid, the expansion and contraction speed becomes slow, so the use of high-frequency pacing cannot be avoided. Therefore, by using a BAV (hereinafter, also referred to as "electrocardiogram-synchronized BAV" or "electrocardiogram-synchronized aortic valve dilation system") that performs balloon expansion and contraction with air and synchronizes the expansion and contraction timing with an electrocardiogram, the aortic valve can be expanded in accordance with the physiological rhythm. Therefore, since frequent dilation is possible without high-frequency pacing, in addition to being able to be performed on patients for whom conventional BAV treatment is impossible, there is an advantage that the effectiveness can be significantly improved compared with existing aortic valve balloons.

[0004] ECG-gated balloon aortic valve (BAV) expands the aortic valve with a balloon multiple times (at least 6 times), significantly increasing valve orifice area compared to conventional expansion methods that involve 1 to 3 expansions. This may allow for the saving of patients who could not be saved before (see Non-Patent Literature 1). The most serious complication in electrocardiogram-gated balloon aortic valve (BAV), which uses air to inflate and deflate a balloon, is air embolism (stroke) due to balloon rupture. To make electrocardiogram-gated BAV practical, this risk must be reduced to virtually zero.

[0005] As a technique to prevent balloon rupture, one of the inventors has already proposed a balloon catheter comprising a shaft, an inner balloon, and an outer balloon (see Patent Document 1). In this catheter, the outer balloon is attached to the shaft at both the tip and posterior ends so that it covers the inner balloon. Therefore, even if the outer balloon is damaged, as long as the inner balloon is not damaged, the fluid inside the balloon will not leak into the blood vessel, making it possible to perform treatment with a relatively higher safety than with a single-membrane balloon. The inner and outer balloons are then inflated gradually by injecting them with saline solution from a syringe. Even if the balloons were to rupture, saline solution poses no risk of air embolism, making it a highly safe procedure. However, because liquids are less compressible than air, there is a problem in that the expansion and contraction of balloons using liquids is slower than when using gases. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2011-152181 [Non-patent literature]

[0007] [Non-Patent Document 1] Konishi A, "The effect of multiple-inflation balloon aortic valvuloplasty", Heart and Vessels 2020, 35, 1557-1562 [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] In the balloon catheter described in Patent Document 1 mentioned above, water, saline solution, air, or an inert gas are listed as gases or liquids to be injected into the balloon, but it does not suggest which fluid is preferable to inject into which balloon, the outer or inner balloon. Furthermore, if the outer balloon is damaged, the inner balloon is made of a more flexible material than the outer balloon, so the inner balloon will expand and protrude from the tear in the outer balloon. If the operator continues the procedure without noticing the damage to the outer balloon, there is a risk of the inner balloon being damaged as well. However, the relationship between the type of fluid injected and the shape of the balloon has not been considered from the standpoint of functionality and safety. In view of the above circumstances, the present invention relates to a balloon catheter having a plurality of expansion lumens, The objective is to provide a balloon catheter with improved functionality and safety. [Means for solving the problem]

[0009] To solve the above problems, the double-membrane balloon catheter of the present invention comprises an inner balloon, an outer balloon covering the inner balloon, an inner tube having a guidewire lumen and sealing the tips of the inner and outer balloons, an outer tube shorter in length than the inner tube and connecting the base ends of the inner and outer balloons, a gas injection lumen formed between the inner circumferential surface of the inner balloon and the outer circumferential surface of the inner tube, through which gas is injected from the base end side of the outer tube via a first through-hole, and a liquid injection lumen formed between the inner circumferential surface of the outer balloon and the outer circumferential surface of the inner balloon, through which liquid is injected from the base end side of the outer tube via a second through-hole. By injecting gas into the inner balloon and liquid into the area inside and outside the outer balloon, which are two expansion / contraction sections formed by a double-membrane balloon, a highly safe balloon catheter can be created that eliminates the risk of air embolism even if the outer balloon ruptures. Furthermore, injecting gas into the inner balloon can improve the deflation response.

[0010] Furthermore, by continuously measuring the pressure of the liquid in the liquid injection lumen using a pressure sensor while the catheter is in use, damage or rupture of the outer balloon can be detected from the pressure changes. In addition, by measuring the pressure of the gas in the gas injection lumen using a pressure sensor, rupture or damage of the outer balloon can be detected with higher precision from the pressure changes in the two lumens. The liquid injected into the lumen for liquid injection is preferably water or saline solution, but a contrast agent may also be used, for example. The liquid injected into the lumen for gas injection is preferably carbon dioxide to account for the possibility of gas leakage into the bloodstream, but helium, air, or other inert gases may also be used from the viewpoint of the balloon's expansion and contraction speed. Furthermore, while the double-membrane balloon catheter of the present invention is suitably used in BAV (Body-Aortic Valve), it is not limited to the aortic valve and can be widely applied to any site where blood flow needs to be blocked.

[0011] In the double-membrane balloon catheter of the present invention, the cross-sectional shape of the outer balloon is preferably substantially polygonal. This makes it easier to create a gap between the inner and outer balloons, allowing the lumen for liquid injection to function as an anchor during balloon expansion and contraction. The substantially polygonal shape is not limited to triangles or quadrilaterals; it may also be a modified polygon such as a triangle, for example, like the Mitsubishi shape.

[0012] In the double-membrane balloon catheter of the present invention, the cross-sectional shape of the outer balloon is more preferably approximately equilateral triangle. By making the cross-sectional shape of the outer balloon approximately equilateral triangle, a physiologically expanded state can be achieved, and by positioning it along the shape of the aortic valve, effective treatment becomes possible. Furthermore, balloons with a circular cross-sectional shape tend to fold into a flat shape when the balloon deflates, which is a problem in terms of maneuverability when inserting and removing the catheter. However, by making the cross-sectional shape of the outer balloon approximately equilateral triangle, it becomes easier to fold into three parts, improving maneuverability. Note that the cross-sectional shape here is not limited to the final expanded shape, but may also be approximately equilateral triangle in shape during the expansion process, for example, the final expanded shape may be approximately circular.

[0013] In the double-membrane balloon catheter of the present invention, the outer balloon is composed of at least two layers, the outermost layer being made of a soft material, and one of the inner layers may contain a hard material. When the double-membrane balloon catheter is inserted to the location of the affected area and the balloon is expanded and contracted, the balloon may be rubbed and damaged by calcified tissue. Therefore, by making the outermost layer of the outer balloon a soft material, it can function as a buffer against external stimuli, resulting in a structure that is less burdensome on the patient's body. In addition, the hard material of the inner layer contributes to improving the fluid drainage force when the outer balloon is ruptured.

[0014] An aortic valve dilation system according to a first aspect of the present invention comprises a double-membrane balloon catheter as described above, and a drive unit that predicts the patient's pulsation based on the patient's arterial pressure waveform data, synchronizes the expansion and contraction timing of the gas injection lumen with the predicted pulsation, and discharges and draws gas into the gas injection lumen, thereby automatically expanding and contracting repeatedly in synchronization with the pulsation. Because the drive unit synchronizes with the patient's heartbeat, predicted based on arterial pressure waveform data, to expel and aspirate gas into the gas injection lumen of the double-membrane balloon catheter, frequent dilation is possible without the need for high-tachycardia pacing, enabling treatment for patients who could not be treated with conventional methods. Furthermore, by incorporating a double-membrane balloon catheter, the risk of balloon rupture is reduced while improving deflation response, resulting in a highly safe and effective system.

[0015] An aortic valve dilation system according to a first aspect of the present invention preferably includes a first pressure sensor for measuring the pressure of the fluid in the fluid injection lumen. By including the first pressure sensor, the pressure of the fluid in the fluid injection lumen can be continuously measured using the pressure sensor during use of the catheter, and the rupture or bursting of the outer balloon can be detected from the change in pressure.

[0016] An aortic valve expansion system according to a first aspect of the present invention may further include a second pressure sensor for measuring the pressure of the gas in the gas injection lumen. By further including the second pressure sensor, the rupture or damage of the outer balloon can be detected with higher accuracy from the pressure changes in the two lumens by measuring the pressure of the gas in the gas injection lumen.

[0017] In the aortic valve dilation system according to the first aspect of the present invention, the arterial pressure waveform data is preferably arterial pressure waveform data of left ventricular pressure. Having arterial pressure waveform data of left ventricular pressure allows for more accurate prediction of the patient's pulsation.

[0018] In the aortic valve dilation system according to the first aspect of the present invention, the drive unit may also correct the pulsation based on the patient's electrocardiogram data. By using electrocardiogram data in combination, the accuracy of pulsation prediction can be improved.

[0019] The aortic valve dilation system according to the second aspect of the present invention includes a double membrane balloon catheter having a lumen for gas injection, and predicts the patient's pulsation based on the patient's arterial pressure waveform data, and synchronizes the expansion and contraction timing of the lumen for gas injection with the predicted pulsation, and includes a drive unit that discharges and aspirates gas into the lumen for gas injection, and the lumen for gas injection is characterized in that it automatically repeats expansion and contraction in synchronization with the pulsation. Since the drive unit discharges and aspirates gas into the gas injection lumen of the double membrane balloon catheter in synchronization with the patient's pulsation predicted based on the arterial pressure waveform data, high-frequency pacing is not required, frequent dilation is possible, and treatment can be performed on patients who could not be treated by conventional methods. The double membrane balloon catheter expands and contracts the balloon by injecting and aspirating gas, and the gas injection lumen is formed at least between the inner peripheral surface of the inner balloon and the outer peripheral surface of the inner tube having a guide wire lumen.

Advantages of the Invention

[0020] According to the double membrane balloon catheter of the present invention, in a balloon catheter having a plurality of expansion lumens, there is an effect that functionality and safety are improved.

Brief Description of the Drawings

[0021] [Figure 1] Schematic cross-sectional view of the double membrane balloon catheter of Example 1 [Figure 2] Enlarged schematic view of the double membrane balloon of Example 1 [Figure 3] Functional explanatory diagram of the double membrane balloon catheter of Example 1 [Figure 4] Image diagram of the use of the double membrane balloon catheter [Figure 5] Schematic view of the outer tube of Example 2 [Figure 6] Enlarged schematic view of the double membrane balloon of Example 2 [Figure 7] Explanatory diagram of the outer balloon of Example 3 [Figure 8] Image diagram of the use of the double membrane balloon catheter of Example 3 [Figure 9] Comparative diagram of balloon deflation [Figure 10] Functional block diagram of the aortic valve dilation system in Example 4 [Figure 11] Functional diagram of the aortic valve dilation system in Example 4 [Figure 12] Functional block diagram of the aortic valve dilation system in Example 5 [Modes for carrying out the invention]

[0022] Hereinafter, an example of an embodiment of the present invention will be described in detail with reference to the drawings. It should be noted that the scope of the present invention is not limited to the following embodiments or illustrated examples, and numerous modifications and variations are possible. [Examples]

[0023] Figure 1 shows a schematic cross-sectional view of the double-membrane balloon catheter of Example 1. Figure 2 shows an enlarged schematic view of the double-membrane balloon of Example 1. As shown in Figure 1, the double-membrane balloon catheter 1 is a catheter used in balloon aortic valve repair (BAV) and consists of a double-membrane balloon 8, an outer tube 4, an inner tube 5, and a gripping section 6. The double-membrane balloon 8 consists of an inner balloon 3 and an outer balloon 2 that covers the inner balloon 3. The inner tube 5 has a guidewire lumen 5a and is inserted into the outer tube 4, sealing the ends of the inner balloon 3 and the outer balloon 2. The outer tube 4 is shorter than the inner tube 5 and connects the proximal ends of the inner balloon 3 and the outer balloon 2. As shown in Figure 2, a lumen (7a, 7b) is formed between the outer tube 4 and the inner tube 5. A guidewire 14 (see Figure 4) can be inserted through the guidewire lumen 5a. A double-membrane balloon 8 is provided at the tip end of the outer tube 4 and the inner tube 5, and a gripping portion 6 is provided at the base end of the outer tube 4 and the inner tube 5. The outer balloon 2 constituting the double-membrane balloon 8 is made of polyamide or polyether block amide, and the outer surface of the outer balloon 2 is provided with a soft polyurethane layer. The inner balloon 3 is also made of polyamide or polyether block amide. The polyamide or polyether block amide of the outer balloon 2 and the inner balloon 3 has a durometer hardness of 70-75D, and the polyurethane on the outer surface of the outer balloon 2 has a durometer hardness of 80-90A.

[0024] A lumen 21 for liquid injection is provided between the outer balloon 2 and the inner balloon 3. The lumen 21 for liquid injection is formed between the inner surface of the outer balloon 2 and the outer surface of the inner balloon 3, and liquid is injected from the proximal end of the outer tube 4 through the lumen 7a, which serves as a second through-hole. In this embodiment, physiological saline is used as the liquid for injection. Furthermore, a gas injection lumen 31 is provided in the lumen of the inner balloon 3. The gas injection lumen 31 is formed between the inner circumferential surface of the inner balloon 3 and the outer circumferential surface of the inner tube 5, and gas is injected from the base end side of the outer tube 4 through the lumen 7b, which serves as the first through-hole. Carbon dioxide is used as the gas to be injected.

[0025] The gripping section 6 is provided with a liquid inlet 61a, a gas inlet 61b, and a guidewire insertion port 61c. The liquid injection lumen 21 is connected to the lumen 7a and the liquid inlet 61a, and physiological saline is injected into the liquid injection lumen 21 through the liquid inlet 61a and the lumen 7a. Similarly, the gas injection lumen 31 is connected to the lumen 7b and the gas inlet 61b, and carbon dioxide gas is injected into the gas injection lumen 31 through the gas inlet 61b and the lumen 7b. Likewise, the guidewire lumen 5a and the guidewire insertion port 61c are also connected, and the guidewire 14 is inserted into the guidewire lumen 5a via the guidewire insertion port 61c.

[0026] Next, the method of adhering the double-membrane balloon 8 to the inner tube 5 or outer tube 4 will be described. As shown in the enlarged schematic diagram of Figure 2, at the adhesive portion 16a on the tip side of the double-membrane balloon catheter 1, the inner balloon 3 is adhered to the inner tube 5, and the outer balloon 2 is adhered to both the inner balloon 3 and the inner tube 5. Furthermore, at the proximal end adhesive portion 16b, the connecting tube 41 is inserted into the lumen 7b of the outer tube 4 and fixed in place. The inner balloon 3 is adhered to and fixed to the outer surface of the connecting tube 41. On the other hand, the outer balloon 2 is adhered to a part of the outer surface of the connecting tube 41 and the inner surface of the outer tube 4. As a result, the double-membrane balloon catheter 1 has two expansion lumens: a lumen 21 for liquid injection and a lumen 31 for gas injection.

[0027] Figure 4 shows an illustrative diagram of the use of a double-membrane balloon catheter. As shown in Figure 4, the double-membrane balloon catheter 1 involves inserting a guidewire 14 from the ascending aorta 51 of the heart 50 into the left ventricle 53, then guiding the double-membrane balloon 8 to the position of the aortic valve 52, where it expands and contracts.

[0028] The inflation and deflation method of the double-membrane balloon 8 will be explained with reference to Figure 3. Figure 3 is a functional diagram of the double-membrane balloon catheter of Example 1, where (1) shows the normal state and (2) shows the state when ruptured. For the sake of explanation, Figure 3 shows a simplified version of the double-membrane balloon catheter. When the double-membrane balloon 8 is expanded and contracted, as shown in Figure 3(1), first, saline solution 11 is injected into the liquid injection lumen 21 to expand the liquid injection lumen 21. Then, carbon dioxide gas 12 is injected into the gas injection lumen 31, and the gas injection lumen 31 is expanded and contracted to improve blood flow to the aortic valve 52. In aortic stenosis, calcium may be deposited and calcified in the aortic valve, and there is a problem that the outer balloon 2 may rupture each time the double-membrane balloon 8 expands and contracts as it comes into contact with the calcified affected area. However, in the double-membrane balloon catheter 1 of this embodiment, as shown in Figure 3(2), even if the outer balloon 2 ruptures, only the saline solution 11 injected into the liquid injection lumen 21 is released to the outside, eliminating the risk of air embolism and resulting in a highly safe structure. [Examples]

[0029] In Example 2, unlike the double-membrane balloon catheter 1 of Example 1, a configuration without an intermediate tube 41 will be described. Parts not specifically described are the same as in Example 1. Figure 5 is a schematic diagram of the outer tube of Example 2, where (1) is a cross-sectional image from a front view, (2) is a cross-sectional view AA of (1), and (3) is a cross-sectional view BB of (1). As shown in Figures 5(1) and (2), the outer tube 4a of Example 2 has a notched shape at its tip where only the lumen 70b is provided, and the lumen 70a is not provided. Also, as shown in Figures 5(1) and (3), the parts of the outer tube 4a other than the tip have lumens (70a, 70b).

[0030] Next, the method of adhering the double-membrane balloon 8 to the inner tube 5 or outer tube 4a will be described. Figure 6 shows an enlarged schematic diagram of the double-membrane balloon of Example 2. As shown in Figure 6, at the adhesive portion 16a on the tip side of the double-membrane balloon catheter 1a, the inner balloon 3 is adhered to the inner tube 5, and the outer balloon 2 is adhered to both the inner balloon 3 and the inner tube 5. Furthermore, at the adhesive portion 16b on the proximal end, the inner balloon 3 is fixed to the tip side of the outer tube 4a, and the outer balloon 2 is fixed to the proximal end side of the outer tube 4a. Specifically, the inner balloon 3 is adhered and fixed to the outer circumferential surface of the notched portion shown in Figure 5(2). On the other hand, the outer balloon 2 is adhered and fixed to the outer circumferential surface of the roughly cylindrical portion shown in Figure 5(3). As a result, the liquid injection lumen 21 and the lumen 70a, and the gas injection lumen 31 and the lumen 70b are connected, and the double-membrane balloon catheter 1a is a balloon catheter having two expansion lumens: the liquid injection lumen 21 and the gas injection lumen 31. In this way, by making the tip of the outer tube 4a notched, a balloon catheter having two expansion lumens can be realized without using an intermediate tube 41. [Examples]

[0031] Example 3 describes a configuration in which the outer balloon has a roughly equilateral triangular cross-sectional shape. Parts not specifically described are the same as in Example 1. Figure 7 is an explanatory diagram of the outer balloon of Example 3, where (1) is a left side view of the double-membrane balloon catheter of Example 3, and (2) is a schematic diagram of the aortic valve. As shown in Figure 7, in the double-membrane balloon catheter 1b of Example 3, the cross-sectional shape of the inner balloon 3 constituting the double-membrane balloon 8b is approximately circular, but the cross-sectional shape of the outer balloon 2b is approximately equilateral triangle. Therefore, rather than a gap being formed evenly between the outer balloon 2b and the inner balloon 3, the structure is such that a gap is more likely to be formed near the vertex of the approximately equilateral triangle of the outer balloon 2b. As shown in Figure 7(2), since the aortic valve 52 consists of three valves, when the double-membrane balloon 8b is inserted into the position of the aortic valve 52, the approximately equilateral triangular vertices of the outer balloon 2b fit into the base of each valve, following the shape of the aortic valve 52.

[0032] Next, the characteristics of using the double-membrane balloon catheter 1b will be described. First, a guidewire 14 is inserted from the ascending aorta 51 of the heart 50 into the left ventricle 53, and then the double-membrane balloon 8b is guided to the position of the aortic valve 52 (see Figure 4). Next, saline solution 11 is injected into the fluid injection lumen 21b to expand the fluid injection lumen 21b. After that, carbon dioxide gas 12 is injected into the gas injection lumen 31, and the blood flow to the aortic valve 52 is improved by expanding and contracting the gas injection lumen 31. This procedure is the same as in Example 1.

[0033] Figure 8 is an illustrative diagram of the use of the double-membrane balloon catheter of Example 3, where (1) shows the expanded state and (2) shows the deflated state. When the double-membrane balloon 8b is inserted at the position of the aortic valve 52 and saline solution 11 is injected into the liquid injection lumen 21b, carbon dioxide gas 12 is injected into the gas injection lumen 31 and the gas injection lumen 31 is expanded, the aortic valve 52 can be expanded with the approximately equilateral triangular vertices of the outer balloon 2b fitting into the positions of the bases of each valve of the aortic valve 52, as shown in Figure 8(1). The cross-sectional shape of the inner balloon 3 is approximately circular, while the cross-sectional shape of the outer balloon 2b is approximately equilateral triangular. Therefore, when the inner balloon 3 is expanded, the saline solution 11 injected into the liquid injection lumen 21b accumulates mostly near the approximately equilateral triangular vertices of the outer balloon 2b, as shown in Figure 8(1).

[0034] Next, when carbon dioxide gas 12 is drawn in from the gas injection lumen 31 and the gas injection lumen 31 is deflated, as shown in Figure 8(2), the saline solution 11 remains accumulated near the approximately equilateral triangular vertices of the outer balloon 2b as the inner balloon 3 deflates. As a result, the vertices (P1-P3) of the outer balloon 2b remain at the base of each valve as the inner balloon 3 and outer balloon 2b deflate. This provides an anchoring effect to the double-membrane balloon 8b, preventing displacement between the double-membrane balloon 8b and the aortic valve 52 during expansion and contraction, and enabling stable expansion and contraction.

[0035] Furthermore, the double-membrane balloon 8b has the advantage of not only providing the anchoring effect but also being highly convenient when inserting and removing the double-membrane balloon catheter. Figure 9 is a comparative explanatory diagram of balloon deflation, where (1) is a left side view of the double-membrane balloon catheter 1b of Example 3, (2) is a left side view of the double-membrane balloon catheter 100 of the comparative example, (3) is a left side view of the double-membrane balloon catheter 1b of Example 3 when deflated, and (4) is a left side view of the double-membrane balloon catheter 100 of the comparative example when deflated. Note that in all images of deflation, physiological saline 11 is not injected into the lumen for liquid injection. As shown in Figures 9(2) and (4), in the case of a double-membrane balloon catheter 100 in which the cross-sectional shape of the outer balloon 200 is approximately circular, when the outer balloon 200 and the inner balloon (not shown) are deflated, they become approximately flat. In contrast, as shown in Figures 9(1) and (3), in the case of a double-membrane balloon catheter 1b in which the cross-sectional shape of the outer balloon 2b is approximately equilateral triangle, when the outer balloon 2b and the inner balloon (not shown) are deflated, they deflate into three sections with the vertices of the triangle as folds. As a result, the maximum diameter φ1 when the balloon is deflated in Example 3 is smaller and more compact than the maximum diameter φ2 when the balloon is deflated in the Comparative Example, thus improving the operability when inserting and removing the double-membrane balloon catheter 1b. [Examples]

[0036] Figure 10 shows a functional block diagram of the aortic valve dilation system of Example 4. As shown in Figure 10, the aortic valve dilation system 10 consists of a double-membrane balloon catheter 1, a first pressure sensor 15a, a second pressure sensor 15b, and a drive unit 13, and the gas injection lumen (see Figures 2 and 3) automatically expands and contracts in sync with the pulsation. The drive unit 13 predicts the patient's pulsation based on the patient's arterial pressure waveform data, synchronizes the expansion and contraction timing of the gas injection lumen with the predicted pulsation, and discharges and draws gas into the gas injection lumen. Preferably, the patient's arterial pressure waveform data is left ventricular pressure. By using left ventricular pressure waveform data, the patient's pulsation can be predicted with higher accuracy.

[0037] The drive unit 13 is connected to an arterial pressure waveform data acquisition means and an arterial pressure synchronization calculation means (not shown). The arterial pressure waveform data acquisition means acquires the patient's arterial pressure waveform data, and the arterial pressure synchronization calculation means calculates data for synchronization with the pulse based on the arterial pressure acquired by the arterial pressure acquisition means. In this case, the drive unit 13 is driven in synchronization with the pulse based on the calculated data for synchronization with the pulse. Furthermore, the drive unit 13 may be connected to an electrocardiogram data acquisition means and an electrocardiogram synchronization calculation means (not shown) to correct the heartbeat based on the patient's electrocardiogram data. The electrocardiogram data acquisition means acquires the patient's electrocardiogram data, and the electrocardiogram synchronization calculation means calculates data for electrocardiogram synchronization based on the electrocardiogram data acquired by the electrocardiogram data acquisition means. In this case, the drive unit 13 corrects the heartbeat and drives based on the calculated electrocardiogram synchronization data. In this way, the accuracy of heartbeat prediction can be improved by using electrocardiogram data in combination.

[0038] The first pressure sensor 15a measures the pressure of the liquid in the liquid injection lumen 21. The second pressure sensor 15b measures the pressure of the gas in the gas injection lumen 31. Figure 11 is a functional diagram of the aortic valve expansion system of Example 4, where (1) shows the normal state and (2) shows the ruptured state for the outer balloon. As shown in Figure 11(1), if the outer balloon 2 is undamaged, under normal use, the gas pressure inside the inner balloon 3 measured by the first pressure sensor 15a and the liquid pressure inside the outer balloon 2 measured by the second pressure sensor 15b are approximately equal. However, as shown in Figure 11(2), when the outer balloon 2 is damaged, the internal pressure of the lumen connected to the outer balloon 2 will drop to approximately blood pressure due to liquid leakage. Therefore, by comparing the difference between the internal pressure of the inner balloon 3 measured by the first pressure sensor 15a and the internal pressure of the outer balloon 2 measured by the second pressure sensor 15b, damage can be detected and an emergency stop can be initiated. More specifically, using an emergency stop device connected to the first pressure sensor 15a and the second pressure sensor 15b, the aortic valve expansion system 10 can be emergency stopped when damage is detected. [Examples]

[0039] Figure 12 shows a functional block diagram of the aortic valve dilation system of Example 5. As shown in Figure 12, the aortic valve dilation system 10a consists of a double-membrane balloon catheter 1 and a drive unit 13, and the gas injection lumen (see Figures 2 and 3) automatically expands and contracts in sync with the pulsation. Note that, unlike the configuration shown in Figure 2, the liquid injection lumen 21 may also function as the gas injection lumen. The drive unit 13 predicts the patient's pulsation based on the patient's arterial pressure waveform data, synchronizes the expansion and contraction timing of the gas injection lumen with the predicted pulsation, and discharges and draws gas into the gas injection lumen. Preferably, the patient's arterial pressure waveform data is left ventricular pressure. By using left ventricular pressure waveform data, the patient's pulsation can be predicted with higher accuracy.

[0040] The drive unit 13 is connected to an arterial pressure waveform data acquisition means and an arterial pressure synchronization calculation means (not shown). The arterial pressure waveform data acquisition means acquires the patient's arterial pressure waveform data, and the arterial pressure synchronization calculation means calculates data for synchronization with the pulse based on the arterial pressure acquired by the arterial pressure acquisition means. In this case, the drive unit 13 is driven in synchronization with the pulse based on the calculated data for synchronization with the pulse. [Industrial applicability]

[0041] This invention is useful for balloon catheters that expand areas that block blood flow, such as the aortic valve. [Explanation of Symbols]

[0042] 1,1a,1b,100 Double-membrane balloon catheter 2,2b,200 Outer balloon 3. Inner balloon 4,4a Outer tube 5. Inner tube 5a Guidewire Lumen 6 Gripping part 7a~7c,70a,70b lumen 8,8b Double-membrane balloon 10,10a Aortic valve dilation system 11. Physiological saline 12. Carbon dioxide gas 13 Drive unit 14 Guidewire 15a, 15b Pressure Sensor 16a,16b Adhesive part 21,21b Lumen for liquid injection 31 Lumens for gas injection 41 Intermediate tube 50 Heart 51 Ascending aorta 52 Aortic valve 53 Left ventricle 61a Liquid inlet 61b Gas inlet 61c Guidewire insertion port P1~P3 site φ1, φ2 maximum diameter

Claims

1. The inner balloon, An outer balloon covering the inner balloon, An inner tube having a guidewire lumen and sealing the inner and outer balloon tips, An outer tube that is shorter in length than the inner tube and connects the inner and outer balloon base ends, A gas injection lumen is formed between the inner circumferential surface of the inner balloon and the outer circumferential surface of the inner tube, and gas is injected from the base end side of the outer tube through a first through hole, A liquid injection lumen is formed between the inner surface of the outer balloon and the outer surface of the inner balloon, through which liquid is injected from the base end side of the outer tube via a second through hole. Equipped with, The pressure of the liquid in the aforementioned liquid injection lumen is measured. The pressure of the gas in the aforementioned gas injection lumen is measured. The rupture or damage of the outer balloon is detected by the change in the pressure difference between the pressure in the liquid injection lumen and the pressure in the gas injection lumen. A double-membrane balloon catheter for an aortic valve dilation system, characterized in that it predicts the patient's pulsation based on the patient's arterial pressure waveform data, synchronizes the expansion and contraction timing of the gas injection lumen with the predicted pulsation, and discharges and draws gas into the gas injection lumen.

2. The double-membrane balloon catheter for an aortic valve dilation system according to claim 1, characterized in that the cross-sectional shape of the outer balloon is substantially polygonal.

3. The double-membrane balloon catheter for an aortic valve dilation system according to claim 2, characterized in that the cross-sectional shape of the outer balloon is substantially equilateral triangular.

4. The double-membrane balloon catheter for an aortic valve dilation system according to claim 1, characterized in that the outer balloon is composed of at least two layers, the outermost layer being made of a soft material and one of the inner layers containing a hard material.

5. An inner balloon, An outer balloon covering the inner balloon, An inner tube having a guidewire lumen and sealing the inner and outer balloon tips, An outer tube that is shorter in length than the inner tube and connects the inner and outer balloon base ends, A gas injection lumen is formed between the inner circumferential surface of the inner balloon and the outer circumferential surface of the inner tube, and gas is injected from the base end side of the outer tube through a first through hole, A liquid injection lumen is formed between the inner surface of the outer balloon and the outer surface of the inner balloon, through which liquid is injected from the base end side of the outer tube via a second through hole. A double-membrane balloon catheter equipped with, A drive unit that predicts the patient's pulsation based on the patient's arterial pressure waveform data, synchronizes the expansion and contraction timing of the gas injection lumen with the predicted pulsation, and discharges and draws gas into the gas injection lumen. A first pressure sensor for measuring the pressure of the liquid in the liquid injection lumen, A second pressure sensor for measuring the pressure of the gas in the gas injection lumen, The system includes a detection unit that detects the rupture or damage of the outer balloon based on the change in the pressure difference between the pressure in the liquid injection lumen and the pressure in the gas injection lumen. An aortic valve dilation system characterized in that the gas injection lumen automatically expands and contracts repeatedly in synchronization with the pulsation.

6. The aortic valve dilation system according to claim 5, characterized in that the cross-sectional shape of the outer balloon is substantially polygonal.

7. The aortic valve dilation system according to claim 6, characterized in that the cross-sectional shape of the outer balloon is substantially equilateral triangle.

8. The aortic valve dilation system according to claim 5, characterized in that the arterial pressure waveform data is arterial pressure waveform data of left ventricular pressure.

9. The aortic valve dilation system according to claim 5, characterized in that the drive unit corrects the pulsation based on the patient's electrocardiogram data.

10. The aortic valve dilation system according to claim 5, characterized in that the outer balloon is composed of at least two layers, the outermost layer being made of a soft material and one of the inner layers being made of a hard material.

Images