Blood pressure measurement catheter

Abstract

The present disclosure provides a blood pressure measurement catheter, comprising: a distal sleeve, a proximal portion and a pressure sensor; the distal sleeve has a guide wire lumen; the proximal portion is coupled with the distal sleeve; the pressure sensor is arranged in the lumen of the proximal portion and separates the lumen of the proximal portion into a measurement cavity, the measurement cavity is in communication with the guide wire lumen of the distal sleeve, and the pressure sensor is used to measure the blood pressure of the blood flow flowing into the measurement cavity through the distal sleeve and generate a blood pressure signal. The blood pressure measurement catheter provided by the present disclosure can reduce the thickness of the distal sleeve, avoid forming a protrusion, so that the distal sleeve can pass through a narrower lesion, widen the application range, and also increase the pushability of the pressure catheter in the blood vessel.

Description

[0001] This application is a divisional application of the patent application filed on August 2, 2019, with application number 2019107101097 and invention title "Intravascular Pressure Measurement Catheter". Technical Field

[0002] This invention relates to a blood pressure measuring catheter. Background Technology

[0003] The fractional flow reserve (FFR) of the coronary arteries refers to the ratio of the maximum blood flow available to the myocardium supplied by the vessel in the presence of coronary artery stenosis to the theoretically maximum blood flow available to the same area under normal conditions. It has become a crucial functional evaluation indicator, providing significant guidance for treatment strategies in coronary artery disease. Medically, FFR is widely used for the accurate diagnosis of functional myocardial ischemia in coronary artery disease, helping physicians determine the presence of stenosis and the necessity of percutaneous coronary intervention (PCI). Furthermore, it can be used to evaluate the efficacy of stent implantation. FFR accurately reflects the functional severity of stenosis, helping physicians more objectively select indications for interventional treatment, guide optimized stent implantation, and assess treatment effectiveness and long-term efficacy. For example, when the FFR is less than 0.7–0.8, borderline coronary artery lesions should be considered for stent implantation or coronary artery bypass grafting. Therefore, assessing FFR can greatly assist physicians in making accurate judgments, avoiding overtreatment due to misdiagnosis.

[0004] Currently, most pressure-sensing catheters use a Rapid Exchange (RX) port. The distal portion of the catheter has a lumen for the guidewire. By fitting this distal portion onto the guidewire, the pressure-sensing catheter can be moved along the guidewire to the predetermined position. Before coronary intervention, the pressure-sensing catheter is passed through the distal and proximal (right) sides of the stenosis, and distal and proximal blood pressure are recorded, respectively. This allows for the calculation of the FFR value of the stenosis.

[0005] However, the placement of pressure sensors often results in bulges in the pressure sensing catheter (where the pressure sensor is located). As the catheter moves along the guidewire within the blood vessel, it may struggle to pass through some severe narrowings, making it impossible to measure the pressure at the narrowing point. Furthermore, during the passage of the pressure sensing catheter through the narrowing lesion, the pressure sensor may come into contact with the lesion, thus affecting the pressure sensor's measurement and preventing the acquisition of accurate FFR values, which in turn cannot provide doctors with precise diagnostic information. Summary of the Invention

[0006] This disclosure addresses the aforementioned technical problems in the prior art by providing an intravascular pressure measuring catheter, an intravascular pressure measuring method, and an intravascular pressure detection device capable of measuring pressure in narrowed blood vessels.

[0007] This disclosure relates to an intravascular pressure measurement catheter, comprising: a distal cannula having a guidewire lumen slidably receiving a separate medical guidewire; a proximal portion connected to the distal cannula; a pressure sensor disposed within the lumen of the proximal portion and separating the lumen of the proximal portion into a measurement chamber, the measurement chamber being in communication with the guidewire lumen of the distal cannula, the pressure sensor being used to measure blood pressure of blood flowing into the measurement chamber and generate a blood pressure signal, and the proximal portion further comprising a signal path for transmitting the blood pressure signal from the pressure sensor.

[0008] The intravascular pressure measurement catheter disclosed herein reduces the thickness of the distal cannula, preventing the formation of bulges. This allows the distal cannula to pass through narrower lesions, broadening its application range and increasing the catheter's maneuverability within the blood vessel. Furthermore, the pressure sensor is protected by the proximal portion of the catheter wall, reducing the impact on the sensor during impacts or bending of the catheter, thus improving the accuracy of blood pressure measurement.

[0009] Additionally, in the intravascular pressure measurement catheter disclosed herein, optionally, the pressure sensor includes a sensing portion and a lead portion. The sensing portion has a sensing area for sensing pressure, and the lead portion outputs the blood pressure signal generated by the sensing area. Thus, medical personnel can connect the lead portion to an external device via a signal path and read the measured blood pressure information through the external device.

[0010] Additionally, in the intravascular pressure measurement catheter disclosed herein, optionally, a quick-change port for receiving the medical guidewire is provided on the side wall of the distal cannula. In this case, the guidewire can guide the pressure measurement catheter through the quick-change port, thereby allowing the intravascular pressure measurement catheter to slide along the guidewire, thus positioning the catheter at a specific location within the patient's body and improving the efficiency of interventional procedures.

[0011] Furthermore, in the intravascular pressure measuring catheter disclosed herein, optionally, the Young's modulus of at least the proximal portion where the pressure sensor is located is greater than that of the distal cannula. In this case, the proximal portion can better protect the pressure sensor and reduce the impact of deformation of the intravascular pressure measuring catheter on the pressure sensor, thereby ensuring the measurement accuracy of the pressure sensing device.

[0012] Additionally, in the intravascular pressure measurement catheter disclosed herein, the pressure sensor may optionally be a thin-film pressure sensor, and may form an angle with the length direction of the proximal portion. This allows the thin-film pressure sensor to measure blood pressure at a suitable angle.

[0013] Additionally, the intravascular pressure measuring catheter disclosed herein may optionally include an intermediate portion connecting the distal cannula and the proximal portion, wherein the Young's modulus of the intermediate portion is between that of the distal cannula and the proximal portion. This increases the robustness of the intravascular pressure measuring catheter in blood vessels, facilitating operation by physicians.

[0014] Additionally, the intravascular pressure measuring catheter disclosed herein may optionally include an outer tube covering the distal cannula and the proximal portion. This reduces the impact of collisions between the intravascular pressure measuring catheter and the vessel wall on the stability of the measuring catheter before it enters the coronary artery.

[0015] Additionally, in the intravascular pressure measurement catheter disclosed herein, the included angle may optionally be 45° to 135°. This allows for better contact with blood flow, resulting in more accurate blood pressure measurement.

[0016] Additionally, in the intravascular pressure measurement catheter disclosed herein, optionally, the guidewire lumen can slidably receive a medical guidewire having an outer diameter of approximately 0.2 mm to 1 mm. This increases the types of guidewires that can be received.

[0017] Furthermore, in the intravascular pressure measurement catheter disclosed herein, optionally, the distal cannula and the proximal portion are coaxial. This improves the stability of the intravascular pressure measurement catheter.

[0018] According to the intravascular pressure measuring catheter of the present invention, an intravascular pressure measuring catheter, an intravascular pressure measuring method, and an intravascular pressure detection device capable of measuring pressure in narrowed blood vessels can be provided. Attached Figure Description

[0019] Figure 1 This is a schematic cross-sectional view of the intravascular pressure measuring catheter according to an embodiment of the present invention.

[0020] Figure 2 This is a partial cross-sectional schematic diagram of the intravascular pressure measuring catheter involved in an embodiment of the present invention.

[0021] Figure 3 This is a partial cross-sectional schematic diagram of an intravascular pressure measuring catheter according to another embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram showing the combination of the pressure sensor and the base of the intravascular pressure measuring catheter according to an embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram showing the lead portion of the pressure sensor of the intravascular pressure measuring catheter according to an embodiment of the present invention.

[0024] Explanation of symbols in the attached drawings:

[0025] 1…Intravascular pressure measurement catheter, 2…Medical guidewire, 10…Distal cannula, 20…Proximal portion, 30…Pressure sensor, 40…Base, 11…Annular cannula, 12…Outer tube, F…Blood flow direction, θ…Angle between pressure sensor and horizontal plane, 31…Sensing part, 32…Leading part, 32a, 32b, 32c…Pin. Detailed Implementation

[0026] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the following description, the same reference numerals are used for the same parts, and repeated descriptions are omitted. Furthermore, the drawings are merely schematic diagrams, and the proportions of the parts or the shapes of the parts may differ from the actual figures.

[0027] Figure 1 This is a schematic cross-sectional view of the intravascular pressure measuring catheter 1 according to an embodiment of the present invention.

[0028] like Figure 1 As shown, the intravascular pressure measuring catheter 1 (hereinafter, sometimes simply referred to as "pressure measuring catheter 1", "blood pressure measuring catheter 1", or "measuring catheter 1") includes a distal cannula 10 having a guidewire lumen that slidably receives a separate medical guidewire 2 (hereinafter, sometimes also referred to as "guidewire 2" or "guidewire 2"); a proximal portion 20 connected to the distal cannula 10; and a pressure sensor 30 disposed within the lumen of the proximal portion 20, separating the lumen of the proximal portion 20 into a measuring chamber, which communicates with the guidewire lumen of the distal cannula 10. The pressure sensor 30 is used to measure the blood pressure of the blood flow flowing into the measuring chamber and generate a blood pressure signal. The proximal portion 20 also includes a signal path for transmitting the blood pressure signal from the pressure sensor 30.

[0029] The intravascular pressure measuring catheter 1 disclosed herein reduces the thickness of the distal cannula 10, preventing bulging. This allows the distal cannula 10 to pass through narrower lesions, broadening its application range. It also increases the mobility of the pressure measuring catheter 1 within the blood vessel, facilitating physician operation and saving surgical time. Furthermore, the pressure sensor 30 is protected by the proximal portion of the catheter wall, reducing the impact on the pressure sensor during impacts or bending of the pressure measuring catheter 1, thus improving the accuracy of blood pressure measurement.

[0030] In the blood pressure measurement catheter 1 according to this embodiment, the distal cannula 10 has a guidewire lumen. The guidewire lumen slidably receives a separate medical guidewire 2. Therefore, by receiving the distal cannula 10 and sliding it along the medical guidewire 2, the distal cannula 10 and the pressure sensor 30 disposed on the proximal portion 20 can be delivered to a predetermined location in the patient's body (e.g., a vein or artery). Thus, blood pressure can be measured at this predetermined location (e.g., a lesion location) to obtain a reading of the fractional flow reserve (FFR) at that location, providing a reference for subsequent interventional treatment.

[0031] As mentioned above, the fractional flow reserve (FFR) value (or simply "FFR value") is used to assess the degree to which a stenotic lesion obstructs blood flow through a blood vessel, providing physicians with information for deciding whether to perform interventional treatment. Generally, to calculate the FFR value for a given stenosis, blood pressure readings are measured and collected separately on both the distal side (e.g., downstream of the stenosis) and the proximal side (e.g., upstream of the stenosis, near the aorta). The blood pressure gradient of the stenotic lesion reflects the severity of the stenosis. The more severe the stenosis, the greater the pressure drop, and the lower the FFR value.

[0032] In some examples, the guidewire lumen can slidably receive a medical guidewire 2 with an outer diameter of approximately 0.2 mm to 1 mm. This allows for an increase in the types of guidewires 2 that can be received.

[0033] In some examples, a quick-change port for receiving the medical guidewire 2 is provided on the side wall of the distal cannula 10. In this case, the guidewire 2 can guide the pressure measuring catheter 1 through the quick-change port, thereby allowing the intravascular pressure measuring catheter 1 to slide along the guidewire 2, thus positioning the catheter at a specific location within the patient's body and improving the efficiency of interventional procedures.

[0034] In some examples, the Young's modulus of the proximal portion 20 of the pressure sensor 30 is at least greater than that of the distal cannula 10. In this case, the proximal portion 20 can better protect the pressure sensor 30 and reduce the pressure on the pressure sensor 30 caused by deformation of the intravascular pressure measuring catheter 1, thereby ensuring the measurement accuracy of the pressure sensing device.

[0035] In some examples, an intermediate portion is also included connecting the distal cannula 10 and the proximal portion 20, the Young's modulus of which is between that of the distal cannula 10 and the proximal portion 20. This increases the robustness of the intravascular pressure measuring catheter 1 in the blood vessel, facilitating its operation by the physician.

[0036] In some examples, the material of the proximal portion 20 is not particularly limited, but a material with high hardness is preferred to ensure that the physician can advance the distal cannula 10 along the medical guide wire 2 into the patient's blood vessel through the proximal portion 20 during interventional treatment, thereby locating the stenotic lesion.

[0037] In some examples, the proximal portion 20 may be more rigid and stiffer than the distal cannula 10 to allow for better movement and advancement of the distal cannula 10. In some examples, the proximal portion 20 may be made of medical-grade stainless steel. In other examples, the proximal portion 20 may also be made of other materials such as nickel-titanium alloy, nylon, plastic, polyimide (PI), etc.

[0038] In some examples, the pressure sensor 30 includes a sensing portion 31 and a lead portion 32. The sensing portion 31 has a sensing area for sensing pressure, and the lead portion 32 outputs the blood pressure signal generated by the sensing area through pins (32a, 32b, 32c). Thus, medical personnel can connect the lead portion to an external device via a signal path and read the measured blood pressure information through the external device.

[0039] In some examples, the signal path can be connected to devices located outside the patient, such as medical devices like processors, displays, computers, and monitors.

[0040] In some examples, an outer tube 12 covering the distal cannula 10 and the proximal portion 20 is also included. This reduces the impact of collisions between the intravascular pressure measuring catheter 1 and the vessel wall on the stability of the measuring catheter 1 before it enters the coronary artery.

[0041] Additionally, in some examples, an annular cannula 11 serving as a positioning marker may be provided at the distal end of the distal cannula 10. The annular cannula 11 is flexible and contains a material opaque to X-rays. In other examples, the annular cannula 11 may be flexible. Thus, damage to the blood pressure measuring catheter 1 can be reduced as it moves within the patient's blood vessels.

[0042] In this embodiment, as described above, during interventional treatment, the distal cannula 10 needs to be moved by manipulating the proximal portion 20 (specifically, the blood pressure measuring catheter 1). When moving or adjusting the distal cannula 10 within the blood vessel along the medical guidewire 2, the distal cannula 10 may touch blood vessels near the distal cannula 10 or areas with significant vascular curvature. In such cases, even if the distal cannula 10 slides along the medical guidewire 2 and touches a nearby blood vessel, the flexibility of the annular cannula 11 at the foremost end of the distal cannula 10 minimizes damage to the blood vessel.

[0043] Furthermore, in this embodiment, since the annular sleeve 11 contains a material that is opaque to X-rays, when a human body is irradiated with X-rays, the annular sleeve 11 can form an opaque pattern. Through this opaque pattern, doctors and others can quickly locate the corresponding positioning markers.

[0044] In some examples, the outer peripheral surface of the outer tube 12 is preferably tangent to the annular sleeve 11, thereby improving the operability of the distal sleeve 10 and the annular sleeve 11. The material of the outer tube 12 may be polyester, polyamide, nylon, nylon elastomer, polyurethane, polyimide (PI), etc.

[0045] In other examples, the outer tube 12 can be part of the forming process of the distal sleeve 10. For example, the outer tube 12 can be tightly connected to the distal sleeve 10 by welding. Alternatively, the guidewire lumen of the distal sleeve 10 can be formed by thermoforming.

[0046] Figure 2 This is a partial cross-sectional schematic diagram of the intravascular pressure measuring catheter 1 according to an embodiment of the present invention. Figure 3 This is a partial cross-sectional schematic diagram of the intravascular pressure measuring catheter 1 according to another embodiment of the present invention. Figure 4 This is a schematic diagram showing the combination of the pressure sensor 30 and the base 40 of the intravascular pressure measuring catheter 1 according to an embodiment of the present invention.

[0047] Figure 5 This is a schematic diagram showing the lead portion 32 of the pressure sensor 30 of the intravascular pressure measuring catheter 1 according to an embodiment of the present invention.

[0048] In some examples, pressure sensor 30 is disposed in the proximal portion 20. Blood flows into the proximal portion 20 through the distal cannula 10 and comes into contact with pressure sensor 30, which (more specifically, the measuring portion of pressure sensor 30) is capable of sensing and / or measuring the patient's intravascular blood pressure and generating a blood pressure signal. Pressure sensor 30 is connected to a signal path, through which the blood pressure signal generated by pressure sensor 30 is transmitted to, for example, an external processing device (not shown).

[0049] In some examples, the pressure sensor 30 may be a thin-film pressure sensor and form an angle θ with the length direction of the proximal portion 20. This allows the thin-film pressure sensor 30 to measure blood pressure at an appropriate angle.

[0050] In some examples, the included angle θ ranges from 45° to 135°. This allows for better contact with blood flow, resulting in more accurate blood pressure measurements.

[0051] like Figure 2 As shown, blood flows in the direction indicated by the arrow, and pressure sensor 30 is able to measure the pressure of the blood flow flowing in the F direction. In other examples, pressure sensor 30 can form an angle θ with the horizontal plane L1 in the L2 direction, and the angle θ can be between 45° and 135°.

[0052] like Figure 3 As shown, in some other examples, the pressure sensor 30 can be positioned tangentially to the quick-exchange port. In this case, blood can flow out of the quick-exchange port along the pressure sensor 30, reducing the impact of blood backflow on blood pressure measurement and thus improving the accuracy of blood pressure measurement.

[0053] In some examples, the pressure sensor 30 may be a capacitive pressure sensor, a resistive pressure sensor, or the like. Alternatively, the pressure sensor 30 may be a MEMS pressure sensor. For example, the pressure sensor 30 may have a measurement range of approximately -50 mm Hg to approximately +300 mm Hg. Depending on the type of pressure sensor 30, the signal path may be a conductive medium, such as an electrical wire. Furthermore, in some embodiments, the signal path may also be a wireless communication line, an infrared communication line, or an ultrasonic communication line.

[0054] like Figure 4 , Figure 5 As shown, in some examples, the proximal portion 20 may also be provided with a pedestal 40 for supporting the pressure sensor 30. The lead portion 32 of the pressure sensor 30 is combined with the pedestal 40, and the sensing portion 31 is used to measure blood flow pressure. In some examples, the pedestal 40 may be an alloy made of one or more of the following materials: cobalt-chromium alloy, titanium alloy, aluminum alloy, or stainless steel, or a composite material of any of the above alloys. Alternatively, it may be made of rigid engineering plastics such as ABS, PMMA, or PET, which have sufficient flexural strength to effectively suppress stent stress deformation.

[0055] In other examples, the base 40 can be fixed to the lumen of the proximal portion 20 by means of welding, fitting, bonding, etc.

[0056] In addition, in some examples, the base 40 can be configured according to the shape of the proximal portion 20 so that the pressure sensor 30 can measure the pressure of blood in the blood vessels without any impact, and measure the blood pressure value more accurately, providing doctors with accurate data results.

[0057] In some examples, the pressure sensor 30 may not need to be fixed with the base 40; instead, it can be directly positioned within the lumen of the proximal portion 20. Thus, the pressure sensor 30 can directly receive the pressure of the blood within the vessel, unaffected by the base 40.

[0058] In other examples, a gel may be filled between the pressure sensor 30 and the proximal portion 20. Specifically, a medical-grade silicone gel may be used, thereby preventing liquids such as blood from seeping into the lead portion 32, thus improving the reliability of the pressure sensor 30 and the signal pathway transmitting the blood pressure signal. Furthermore, the silicone gel can also provide cushioning for the pressure sensor 30.

[0059] Generally, during interventional treatment, the doctor or other operators first advance a medical guidewire 2 along a blood vessel from a location on the patient's body (e.g., the femoral artery) to, for example, the coronary artery of the heart. Then, using contrast agents, they locate the blood vessel where a lesion may occur, and then advance a blood pressure measuring catheter 1 along the medical guidewire 2 to a predetermined position. In this case, the blood pressure measuring catheter 1 moves the distal cannula 10 through the medical guidewire 2 (see figure), allowing the guidewire lumen to slide past the medical guidewire 2, and moves the distal cannula 10 (and the pressure sensor 30 disposed on the distal cannula 10) by manipulating (e.g., pushing and / or pulling) the external blood pressure measuring catheter 1 (or an operating device connected to the blood pressure measuring catheter 1 (not shown)) until the pressure sensor 30 is in the predetermined position.

[0060] In some examples, the distal cannula 10 and the proximal portion 20 are coaxial. This improves the stability of the intravascular pressure measurement catheter 1.

[0061] In some examples, since the distal cannula 10 is moved along the medical guidewire 2 to a predetermined position within the patient's blood vessel, it is not necessary to reposition the medical guidewire 2 when operating the blood pressure measuring catheter 1 according to the embodiments of the present invention.

[0062] Specifically, for example, when the pressure sensor 30 on the blood pressure measuring catheter 1 is positioned distal to the stenosis (e.g., downstream of the stenosis), blood pressure is first measured on the distal side of the stenosis. Then, without adjusting the position of the medical guidewire 2, the pressure sensor 30 can be moved (e.g., advanced and / or retracted) by the distal cannula 10 to the proximal side of the stenosis. Thus, blood pressure readings at both the distal and proximal ends of the stenosis can be read without moving the medical guidewire 2. This reduces the complexity of the interventional procedure and saves surgical time.

[0063] While the present invention has been specifically described above in conjunction with the accompanying drawings and embodiments, it is to be understood that the above description does not limit the invention in any way. Those skilled in the art can make modifications and variations to the present invention as needed without departing from its essential spirit and scope, and all such modifications and variations fall within the scope of the present invention.

Claims

1. A blood pressure measurement catheter, characterized by, include: Distal cannula, proximal portion, and pressure sensor; The distal cannula has a guidewire lumen; The proximal portion is connected to the distal sleeve; The pressure sensor is disposed within the lumen of the proximal portion of the cannula, separating the lumen of the proximal portion into a measuring chamber. The measuring chamber communicates with the guidewire lumen of the distal cannula. The pressure sensor measures the blood pressure of the blood flowing into the measuring chamber via the distal cannula and generates a blood pressure signal. The guidewire lumen slidably receives individual medical guidewires. A quick exchange port for receiving the medical guidewire is provided on the side wall of the distal cannula. The pressure sensor is positioned tangentially to the quick exchange port so that blood flows out from the quick exchange port along the pressure sensor.

2. The blood pressure measuring catheter as described in claim 1, characterized in that, An annular sleeve serving as a positioning marker is also provided at the front end of the distal sleeve.

3. The blood pressure measuring catheter as described in claim 2, characterized in that, The annular sleeve is flexible and contains a material that is opaque to X-rays.

4. The blood pressure measuring catheter as described in claim 1, characterized in that, It also has an outer tube that covers the distal end sleeve and the proximal end portion.

5. The blood pressure measuring catheter as described in claim 4, characterized in that, The outer circumferential surface of the outer tube is tangent to the annular sleeve.

6. The blood pressure measuring catheter as described in claim 1, characterized in that, The pressure sensor is filled with gel between itself and the proximal portion.

7. The blood pressure measuring catheter as described in claim 1, characterized in that, The distal end sleeve and the proximal end portion are coaxial.

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