Intravascular ultrasonic catheter capable of eliminating bubbles and improving image quality

Abstract

The invention provides an intravascular ultrasonic catheter capable of eliminating bubbles and improving image quality, which comprises an imaging assembly, an outer sheath tube, a catheter seat and an air filtering device, and is characterized in that the imaging assembly comprises an ultrasonic transducer and is arranged in the outer sheath tube; the near end of the outer sheath tube is connected with the catheter seat, and a water injection opening is formed in the catheter seat and communicated with a water injection cavity of the outer sheath tube. The air filtering device is communicated with the water inlet end of the water injection opening, and a hydrophilic porous membrane is arranged in a water passing channel of the air filtering device. The hydrophilic porous membrane is used for filtering air in normal saline needing to be injected into the water injection cavity, the air in the normal saline is prevented from entering the outer sheath tube, and the situation that due to the fact that many bubbles exist in the normal saline between the outer sheath tube and the ultrasonic transducer, multiple reflection or signal loss of ultrasonic waves is generated when the imaging assembly works is avoided; an image is distorted.

Description

Technical Field

[0001] The invention relates to the technical field of medical devices, and in particular to an intravascular ultrasonic catheter capable of eliminating bubbles and improving image quality. Background Art

[0002] Intravascular ultrasound (IVUS) refers to ultrasound imaging in blood vessels using ultrasound technology and interventional catheter technology. A miniaturized ultrasound transducer is pushed to the target position in the blood vessel through an interventional catheter, and then the ultrasound transducer is withdrawn. While withdrawing, the ultrasound transducer generates an ultrasound signal, which propagates and is reflected in human tissue. The ultrasound transducer receives the reflected ultrasound signal and converts it into an electrical signal, which is transmitted back to the IVUS host system through a wire. The image processing unit of the IVUS host system processes and displays the electrical signal, thereby obtaining image information of the vascular lumen and wall to characterize the lesion morphology, quantify plaque load, guide the selection of device size, evaluate device implantation, and identify complications, assisting the surgeon in preoperative evaluation and postoperative optimization, and playing an important role in assisting decision-making.

[0003] The current IVUS catheters include electronic phased array type and mechanical rotation type. The mechanical rotation IVUS catheter only needs a single transducer assembly, which obtains images by rotating at a minimum speed of 1800 rpm. Therefore, the catheter diameter can be very small, and it is easier to pass through narrow parts to obtain blood vessel images. It has a simple structure and low manufacturing cost. However, the mechanical rotation IVUS catheter needs to be flushed and exhausted with saline before entering the human blood vessels. The gas dissolved in the saline used to flush the IVUS catheter will accumulate and overflow to a certain extent. During use, there are many bubbles in the saline between the outer sheath and the ultrasonic transducer, and even the bubbles adhere to the surface of the ultrasonic transducer, which will cause multiple reflections of the ultrasonic wave or signal loss, causing image distortion, which may lead to image loss of key positions of the blood vessels.

[0004] In view of this, this application is filed. Summary of the invention

[0005] The present invention provides an intravascular ultrasound catheter for eliminating bubbles and improving image quality, so as to solve at least one of the above technical problems.

[0006] An intravascular ultrasonic catheter for eliminating bubbles and improving image quality comprises an imaging component, an outer sheath tube, a catheter seat and an air filter, wherein the imaging component comprises an ultrasonic transducer and is arranged in the outer sheath tube; the proximal end of the outer sheath tube is connected to the catheter seat, and the catheter seat is provided with a water injection port, which is communicated with a water injection cavity of the outer sheath tube; the air filter is communicated with a water inlet end of the water injection port, and a hydrophilic porous membrane is provided in a water passage of the air filter.

[0007] Preferably, the radius of the pores of the hydrophilic porous membrane is defined as r 亲水 , the surface tension of water is γ, and the contact angle of water at the entrance of the capillary pore of the hydrophilic porous membrane is θ when the capillary and the air and water interface are critically leakable gas. 亲水 , the critical pressure threshold of gas leakage is ΔP 亲水 The air pressure applied to the hydrophilic porous membrane in the water passage is P 亲水 ; then: P 亲水 <ΔP 亲水 , and ΔP 亲水 =2γcos(θ 亲水 ) / r 亲水 .

[0008] Preferably, an air outlet is provided on the water passage, the air outlet is located at the water inlet side of the hydrophilic porous membrane, and a hydrophobic porous membrane is provided inside the air outlet.

[0009] Preferably, the radius of the pores of the hydrophobic porous membrane is defined as r 疏水 The contact angle of water at the entrance of the capillary pore of the hydrophobic porous membrane is θ when the capillary pore and the air and water interface are critically leakable liquids. 疏水 , the critical pressure threshold of liquid leakage is ΔP 疏水 The air pressure applied to the hydrophobic porous membrane in the water passage is P 疏水 ; then: P 疏水 <ΔP 疏水 , and ΔP 疏水 =2γcos(180°-θ 疏水 ) / r 疏水 .

[0010] Preferably, the radius of the pores of the hydrophilic porous membrane is defined as r 亲水 , the surface tension of water is γ, and the contact angle of water at the entrance of the capillary pore of the hydrophilic porous membrane is θ when the capillary and the air and water interface are critically leakable gas. 亲水 , the critical pressure threshold of gas leakage is ΔP 亲水 The air pressure applied to the hydrophilic porous membrane in the water passage is P 亲水; then: P 亲水 <ΔP 亲水 , and ΔP 亲水 =2γcos(θ 亲水 ) / r 亲水 ; and said r 亲水 Greater than r 疏水 , P 亲水 <ΔP 疏水 , P 疏水 <ΔP 亲水 .

[0011] Preferably, a pressure regulating valve is provided on one side of the water inlet of the water passage, and the pressure regulating valve is used to control the pressure on the water inlet side of the hydrophilic porous membrane in the water passage.

[0012] Preferably, it further comprises a vacuum pump, and the vacuum pump is arranged on a side of the hydrophobic porous membrane away from the water passage.

[0013] Preferably, the surface of the ultrasonic transducer is coated with a hydrophilic coating.

[0014] Preferably, the hydrophilic coating is semi-aliphatic methyl vinyl ether-maleic anhydride copolymer or polyvinyl pyrrolidone.

[0015] Preferably, a one-way valve is provided at the inlet end of the air filter device.

[0016] The intravascular ultrasonic catheter of the present invention is provided with an air filter at the water inlet end of the water injection port, and uses a hydrophilic porous membrane to filter the air in the saline solution to be injected into the water injection cavity, thereby blocking the air in the saline solution from entering the outer sheath tube, and preventing the presence of a large number of bubbles in the saline solution between the outer sheath tube and the ultrasonic transducer, which causes the imaging component to generate multiple reflections of ultrasonic waves or signal loss during operation, thereby distorting the image. Therefore, there is no need to repeatedly flush and exhaust air during the operation of the intravascular ultrasonic catheter due to bubbles, which prolongs the operation time and brings a bad experience to the operator and the patient.

[0017] Furthermore, by coating the surface of the ultrasonic transducer with a hydrophilic coating, the adhesion of the transducer surface to the bubbles is reduced. The magnitude of the adhesion is related to the contact angle between the saline and the transducer surface. The better the hydrophilicity of the transducer surface, the smaller the contact angle, the smaller the adhesion, and the easier it is for the bubbles to detach from the transducer surface. This reduces the adhesion of bubbles on the transducer surface, thereby reducing the loss of ultrasonic signals and distortion of ultrasonic images caused by bubbles adhering to the transducer surface, thereby better assisting the surgeon in making decisions during surgery, reducing the possibility of repeated withdrawal imaging operations, and shortening the operation time. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a schematic structural diagram of an intravascular ultrasound catheter for eliminating bubbles and improving image quality according to an embodiment of the present invention;

[0019] Figure 2 yes Figure 1 A schematic diagram of the structure of an air filter device;

[0020] Figure 3 It is a schematic structural diagram of an air filter device according to a preferred embodiment of the present invention;

[0021] Figure 4 It is a schematic structural diagram of an air filter device according to a preferred embodiment of the present invention;

[0022] Figure 5 It is a schematic diagram of the force exerted on air at the pores of a wetted hydrophilic porous membrane in the implementation of the present invention;

[0023] Figure 6 yes Figure 5 Schematic diagram of force analysis;

[0024] Figure 7 Schematic diagram of the force of physiological saline on the hydrophobic porous membrane in the implementation of the present invention;

[0025] Figure 8 yes Figure 7 Schematic diagram of force analysis;

[0026] Fig. 9 It is a schematic diagram of bubble adhesion between the surface of an object made of a hydrophobic material and the surface of an object made of a hydrophilic material according to an embodiment of the present invention.

[0027] Reference numerals:

[0028] 1. Imaging component; 11. Ultrasonic transducer; 12. Driving shaft; 2. Outer sheath; 21. Water injection chamber; 22. Drain hole; 23. Tip tube; 24. Support tube; 25. Telescopic component; 26. Stress relief tube; 3. Catheter seat; 31. Water injection port; 4. Air filter; 41. Water passage; 411. Air outlet; 42. Hydrophilic porous membrane; 43. Hydrophobic porous membrane; 44. Vacuum pump; 5. One-way valve. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. Therefore, the following detailed description of the embodiments of the present invention provided in the drawings is not intended to limit the scope of the invention claimed for protection, but merely represents the selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0030] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicating orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0031] The specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0032] Please refer to Figures 1 to 2 An intravascular ultrasound catheter for eliminating bubbles and improving image quality includes an imaging component 1, an outer sheath tube 2, a catheter seat 3 and an air filter device 4.

[0033] The imaging component 1 includes an ultrasonic transducer 11, and the imaging component 1 is arranged in the outer sheath tube 2; the proximal end of the outer sheath tube 2 is connected to the catheter seat 3, and the catheter seat 3 is provided with a water injection port 31, and the water injection port 31 is connected to the water injection cavity 21 of the outer sheath tube 2; the distal end of the outer sheath tube 2 is provided with a drainage hole 22, and the drainage hole 22 is connected to the water injection cavity 21.

[0034] Before the intravascular ultrasound catheter is used, physiological saline is injected into the water injection cavity 21 of the outer sheath tube 2 through the water injection port 31, so that the air in the gap between the outer sheath tube 2 and the imaging assembly 1 is expelled from the proximal end of the catheter to the distal end, and discharged from the drainage hole 22 at the distal end of the outer sheath tube 2. However, due to the dissolved gas in the physiological saline, the gas will gather and overflow from the physiological saline during the use of the intravascular ultrasound catheter, forming bubbles between the outer sheath tube 2 and the ultrasonic transducer 11, and even the bubbles will adhere to the surface of the ultrasonic transducer 11, interfering with the operation of the ultrasonic transducer 11, easily leading to multiple reflections of ultrasound or signal loss, causing image distortion, and possibly leading to image loss of key positions of the blood vessel.

[0035] Please refer to Figure 1 and Figure 2 , the air filter device 4 is connected to the water inlet end of the water injection port 31, and a hydrophilic porous membrane 42 is provided in the water passage 41 of the air filter device 4. The hydrophilicity of the hydrophilic porous membrane 42 enables the membrane material to better contact and separate with water during the water treatment process, and has excellent water and gas separation performance. The hydrophilic porous membrane 42 arranged in the water passage 41 can filter the gas in the physiological saline, block the air in the physiological saline from entering the outer sheath tube 2, and only pass the physiological saline from which the gas has been removed. Thereby preventing the presence of more bubbles in the physiological saline between the outer sheath tube 2 and the ultrasonic transducer 11, causing the imaging component 1 to generate multiple reflections of ultrasonic waves or signal loss during operation, causing image distortion. Therefore, there is no need to repeatedly flush and exhaust air due to bubbles during the operation of the intravascular ultrasonic catheter, which leads to prolonged operation time and brings a bad experience to the operator and the patient.

[0036] For further information, please refer to Figure 3 In a preferred embodiment, an air outlet 411 is provided on the water passage 41, and the air outlet 411 is located at the water inlet side of the hydrophilic porous membrane 42, and a hydrophobic porous membrane 43 is provided inside the air outlet 411. The hydrophobic porous membrane 43 has good waterproof performance, and can block the saline solution and discharge the gas in the saline solution.

[0037] By setting an air outlet 411 with a hydrophobic porous membrane 43 on the water inlet side of the hydrophilic porous membrane 42, the gas in the physiological saline can be discharged from the hydrophobic porous membrane 43 more quickly, preventing accumulation on the inlet side of the hydrophilic porous membrane 42, increasing the gas pressure and affecting the use effect of the hydrophilic porous membrane 42.

[0038] For further information, please refer to Figure 4In a preferred embodiment, a vacuum pump 44 is provided on the air outlet side of the hydrophobic porous membrane 43, i.e., the side away from the inside of the water passage 41. The vacuum pump 44 can draw air toward the hydrophobic porous membrane 43, thereby increasing the pressure applied by the saline solution inside the water passage 41 to the hydrophobic porous membrane 43, and improving the efficiency and ability of the hydrophobic porous membrane 43 to filter air in the saline solution.

[0039] Please refer to Figures 5 to 9 When the air filter device 4 is in use, the hydrophilic porous membrane 42 is moistened by saline solution, and the pores in the membrane are filled with water. When external saline solution is applied to one side of the hydrophilic porous membrane 42 at a certain pressure, the saline solution easily overcomes the resistance of the hydrophilic porous membrane 42 and flows out from the other side of the hydrophilic porous membrane 42. When air is introduced from one side of the moistened hydrophilic porous membrane 42 at a certain pressure, a balance is reached between the applied pressure and the surface tension of the water, and the water at the entrance of the pores in the hydrophilic porous membrane 42 forms a meniscus.

[0040] The radius of the pores of the hydrophilic porous membrane 42 is defined as r. 亲水 , the surface tension of water is γ, and the contact angle of water at the entrance of the capillary pores of the hydrophilic porous membrane 42 is θ when the capillary pores and the air and water interfaces are critically leakable gas. 亲水 , the critical pressure threshold of gas leakage is ΔP 亲水 The water meniscus has a radius of R 亲水 According to the Young-Lap l ace equation, the force balance relationship at the meniscus water is as follows: ΔP 亲水 =2γ / R 亲水 The water bend takes into account that the arc radius is a trigonometric function of the contact angle θ, that is, R 亲水 =r 亲水 / cos(θ 亲水 ), therefore, the Young-Lap l ace equation can be rewritten as: ΔP 亲水 =2γcos(θ) / r 亲水 .

[0041] In the air filter device 4, the air pressure applied to the hydrophilic porous membrane 42 in the water passage 41 is P 亲水 ; then: P 亲水 <ΔP 亲水 In this pressure range, the hydrophilic porous membrane 42 can only pass the saline solution but cannot pass the gas in the saline solution.

[0042] For the hydrophobic porous membrane 43, the pores in the membrane are filled with air, and the air can easily pass through the hydrophobic membrane through the capillaries in the membrane. However, when water under the action of external force wants to pass through the hydrophobic porous membrane 43, due to the surface tension of the water, the water is blocked at the opening of the capillaries in the membrane. A similar force analysis can be performed, and the radius of the capillaries of the hydrophobic porous membrane 43 is defined as r. 疏水 The contact angle of water at the entrance of the capillary pores of the hydrophobic porous membrane 43 is θ when the capillary pores and the air and water interfaces are critically leakable. 疏水 , the critical pressure threshold of liquid leakage is ΔP 疏水 The air pressure applied to the hydrophobic porous membrane in the water passage is P 疏水 ; then: P 疏水 <ΔP 疏水 , and ΔP 疏水 =2γcos(180°-θ 疏水 ) / r 疏水 .

[0043] In the air filter device 4, when the force applied by the saline on one side of the hydrophobic porous membrane 43 is less than the ΔP hydrophobic leakage threshold, the saline cannot pass through the hydrophobic porous membrane 43, but the bubbles in the saline can pass through the hydrophobic porous membrane 43 and be discharged.

[0044] In a preferred embodiment, a pressure regulating valve is provided at one side of the water inlet of the water passage 41, and the pressure regulating valve is used to control the pressure at the water inlet side of the hydrophilic porous membrane 42 in the water passage 41. Since the water pressure at similar water levels is also similar, the hydrophilic porous membrane 42 and the hydrophobic porous membrane 43 are arranged adjacent to each other, and the pressure regulating valve controls the pressure in the water passage 41 to simultaneously meet the requirements of being less than ΔP hydrophobic and less than ΔP hydrophilic.

[0045] In a preferred embodiment, r 亲水 Greater than r 疏水 , while P 亲水 <ΔP 疏水 , P 疏水 <ΔP 亲水 This is because r 亲水 The larger the diameter, the more efficient the water injection and exhaust in the outer sheath will be, which is more conducive to shortening the operation time.

[0046] Please refer to Figure 1 A one-way valve 5 is provided at the inlet end of the air filter device 4, so when the saline is injected, there is no need to worry about the saline overflowing in the reverse direction.

[0047] Furthermore, the surface of the ultrasonic transducer 11 is coated with a hydrophilic coating. The bubbles adhered to the surface of the ultrasonic transducer 11 are affected by the buoyancy of the saline and the adhesion force of the transducer surface. When the buoyancy is greater than the adhesion force, the bubbles detach from the transducer surface. The magnitude of the adhesion force is related to the contact angle between the saline and the transducer surface. The better the hydrophilicity of the transducer surface, the smaller the contact angle, the smaller the adhesion force, and the easier it is for the bubbles to detach from the transducer surface. The current transducer surface is often made of hydrophobic materials such as epoxy glue and silver powder mixture, parylene, etc., which have a large contact angle with water and are easy to adhere to bubbles.

[0048] Preferably, the hydrophilic coating is a semi-fatty methyl vinyl ether-maleic anhydride copolymer. In other embodiments, it may also be polyvinyl pyrrolidone or other hydrophilic polymers.

[0049] The specific structures of the imaging assembly 1 and the outer sheath tube 2 are not limited, and they can be used to perform ultrasound imaging in the blood vessel using ultrasound technology and interventional catheter technology. In this embodiment, the outer sheath tube 2 includes a tip tube 23, a support tube 24, a telescopic assembly 25, and a stress relief tube 26; the imaging assembly 1 includes a drive shaft 12 and an ultrasound transducer 11; a drive shaft seat is provided in the catheter seat 3, and the imaging assembly 1 can perform axial and circumferential movement in the outer sheath tube 2.

[0050] The above are only preferred implementations of the present invention. The protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

Claims

1. An intravascular ultrasound catheter for eliminating bubbles and improving image quality, characterized in that: include, an imaging assembly, including an ultrasound transducer; An outer sheath tube, wherein the imaging assembly is disposed inside the outer sheath tube; A catheter seat, the proximal end of the outer sheath is connected to the catheter seat, and the catheter seat is provided with a water injection port, the water injection port is communicated with the water injection cavity of the outer sheath; An air filter device is connected to the water inlet end of the water injection port, and a hydrophilic porous membrane is arranged in the water passage of the air filter device.

2. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 1, characterized in that: The radius of the pores of the hydrophilic porous membrane is defined as r. 亲水 , the surface tension of water is γ, and the contact angle of water at the entrance of the capillary pore of the hydrophilic porous membrane is θ when the capillary and the air and water interface are critically leakable gas. 亲水 , the critical pressure threshold of gas leakage is ΔP 亲水 The air pressure applied to the hydrophilic porous membrane in the water passage is P 亲水 ; then: P 亲水 <ΔP 亲水 , and ΔP 亲水 =2γcos(θ 亲水 ) / r 亲水 .

3. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 1 or 2, characterized in that: An air outlet is provided on the water passage, and the air outlet is located at the water inlet side of the hydrophilic porous membrane. A hydrophobic porous membrane is provided inside the air outlet.

4. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 3, characterized in that: The radius of the pores of the hydrophobic porous membrane is defined as r. 疏水 The contact angle of water at the entrance of the capillary pore of the hydrophobic porous membrane is θ when the capillary and air and water interfaces are critically leakable liquids. 疏水 , the critical pressure threshold of liquid leakage is ΔP 疏水 The air pressure applied to the hydrophobic porous membrane in the water passage is P 疏水 ; then: P 疏水 <ΔP 疏水 , and ΔP 疏水 =2γcos(180°-θ 疏水 ) / r 疏水 .

5. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 4, characterized in that: The radius of the pores of the hydrophilic porous membrane is defined as r. 亲水 , the surface tension of water is γ, and the contact angle of water at the entrance of the capillary pore of the hydrophilic porous membrane is θ when the capillary and the air and water interface are critically leakable gas. 亲水 , the critical pressure threshold of gas leakage is ΔP 亲水 The air pressure applied to the hydrophilic porous membrane in the water passage is P 亲水 ; then: P 亲水 <ΔP 亲水 , and ΔP 亲水 =2γcos(θ 亲水 ) / r 亲水 ; and said r 亲水 Greater than r 疏水 , P 亲水 <ΔP 疏水 , P 疏水 <ΔP 亲水 .

6. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 5, characterized in that: A pressure regulating valve is provided on one side of the water inlet of the water passage, and the pressure regulating valve is used to control the pressure on the water inlet side of the hydrophilic porous membrane in the water passage.

7. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 3, characterized in that: It also includes a vacuum pump, which is arranged on a side of the hydrophobic porous membrane away from the water passage.

8. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 3, characterized in that: The surface of the ultrasonic transducer is coated with a hydrophilic coating.

9. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 8, characterized in that: The hydrophilic coating is a semi-fatty methyl vinyl ether-maleic anhydride copolymer or polyvinyl pyrrolidone.

10. The intravascular ultrasound catheter for eliminating bubbles and improving image quality according to claim 1, characterized in that: A one-way valve is provided at the inlet end of the air filter device.

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