Optical fiber probe imaging catheter module for intravascular frequency domain OCT (optical coherence tomography) imaging system

Abstract

The invention discloses an optical fiber probe imaging catheter module for an intravascular frequency domain OCT (optical coherence tomography) imaging system, which comprises a transparent protective sleeve and a lining tube arranged in the transparent protective sleeve, a transparent window is arranged at the front end of the transparent protective sleeve, and a single-mode optical fiber, a coreless optical fiber, a GRIN (gradient refractive index) lens and a reflector are sequentially arranged in the lining tube. And a torsion spring tube is arranged outside the single-mode optical fiber. The design of the optical fiber probe and the double-layer catheter is optimized, the imaging resolution is improved, the adaptability of the probe and tissue is enhanced, the optical signal transmission efficiency is improved, high-resolution and low-friction intravascular imaging is provided, and the OCT image quality and reliability are improved.

Description

Technical Field

[0001] The present invention belongs to the field of biomedical imaging technology, and relates to optical coherence tomography (OCT) technology, in particular to an optical fiber probe imaging catheter module for an intravascular frequency domain OCT imaging system. Background Art

[0002] Intravascular optical coherence tomography (OCT) has important application value in the diagnosis and interventional treatment of cardiovascular diseases due to its advantages of high resolution, non-destructiveness, and fast imaging speed. Compared with traditional imaging methods (such as MRI and CT), OCT has the advantage of no radiation damage and high resolution, which can clearly observe the tiny structural changes of the blood vessel wall.

[0003] OCT technology uses a fiber optic probe to transmit laser light in a tiny optical fiber to perform high-resolution tissue imaging. However, when implementing OCT in narrow blood vessels, the structural design of the fiber optic probe, the size and optical properties of the imaging catheter have a direct impact on the imaging quality, resolution and safety. In the existing technology, there are many challenges in the spot control of the fiber optic probe, the bending performance of the imaging catheter, and the scattering and resolution optimization of the optical system.

[0004] Therefore, it is necessary to design a fiber optic probe and imaging catheter suitable for intravascular OCT imaging to improve the imaging resolution of the system, enhance tissue differentiation, and improve the movement flexibility of the probe. Summary of the invention

[0005] The object of the present invention is to provide a high-precision, highly adaptable fiber optic probe imaging catheter module for an intravascular frequency domain OCT imaging system, which is suitable for high-precision imaging and real-time three-dimensional image reconstruction of the inner wall of the coronary artery.

[0006] The technical solution adopted by the present invention to solve its technical problems is: a fiber optic probe imaging catheter module for an intravascular frequency domain OCT imaging system, comprising a transparent protective sleeve and an inner lining tube arranged in the transparent protective sleeve, the inner lining tube adopts a low-friction polytetrafluoroethylene tube, the transparent protective sleeve adopts a polyether block amide tube, a transparent window is arranged at the front end of the transparent protective sleeve, a single-mode optical fiber, a coreless optical fiber, a GRIN gradient refractive index lens and a reflector are arranged in sequence in the inner lining tube, and a torsion spring tube is arranged outside the single-mode optical fiber.

[0007] The transparent window of the optical fiber probe imaging catheter module used in the intravascular frequency domain OCT imaging system is a cylindrical mirror, which ensures the consistent focusing of the laser beam and avoids image distortion.

[0008] The optical fiber probe imaging catheter module for the intravascular frequency domain OCT imaging system has a reflector angle set to 105°, which is used to deflect the light beam to a 90-degree side viewing angle to achieve cross-sectional imaging of the blood vessel wall.

[0009] The optical fiber probe imaging catheter module for the intravascular frequency domain OCT imaging system has a single-mode optical fiber diameter of 0.9 mm and a gradient refractive index lens focal length of 1 mm, so that the spot diameter can be controlled within 15 μm.

[0010] The optical fiber probe imaging catheter module for the intravascular frequency domain OCT imaging system has a transparent protective sleeve with an inner diameter of 0.8 mm, an outer diameter of 1 mm, and a length of 1 m.

[0011] Compared with the prior art, the present invention has significant advantages in the following aspects: 1. High-resolution imaging: Through the optimized fiber probe design and the precise structure of the imaging catheter, the light beam forms a clear and detailed focused spot on the target tissue, achieving high-resolution imaging better than 10μm.

[0012] 2. Stable intravascular imaging: The flexibility of the catheter and the low-friction inner layer design make the operation of the fiber optic probe in the blood vessel more stable, reducing interference and friction damage with the blood vessel wall.

[0013] 3. Reliable optical signal transmission: The torsion spring tube ensures stable optical signal transmission and the probe is flexible and durable, suitable for long-term continuous work.

[0014] 4. Compact structure and strong adaptability: The miniaturized design of the imaging catheter makes it easy to introduce into narrow parts of the human body, such as the coronary arteries, which enhances the flexibility of operation and is suitable for clinical needs. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is a cross-sectional view of the optical fiber probe of the present invention; Figure 2 is a cross-sectional view of the imaging catheter and the optical fiber probe of the present invention; Figure 3 Schematic diagram of the structure of the OCT imaging system.

[0016] The reference numerals of the figures are: 1—transparent protective sleeve, 2—inner liner tube, 3—single-mode optical fiber, 4—torsion spring tube, 5—coreless optical fiber, 6—gradient refractive index lens, 7—reflector, 8—target tissue. DETAILED DESCRIPTION

[0017] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

[0018] The present invention is used to achieve the following objectives: by optimizing the design of the fiber optic probe, the laser spot can be accurately focused on the target tissue 8, thereby improving the lateral and axial resolution; designing a flexible and sturdy imaging catheter to ensure stable movement of the probe in the blood vessel and reduce friction and damage to the tissue; optimizing the arrangement of the optical fiber and the lens in the catheter to ensure that the light signal is minimally lost during transmission and achieve high-quality imaging.

[0019] Reference Figure 1 , Figure 2 As shown, the present invention discloses a fiber optic probe imaging catheter module for an intravascular frequency domain OCT imaging system, which includes two parts: an imaging catheter and a fiber optic probe.

[0020] The fiber optic probe is the core part of the OCT fiber optic probe imaging catheter module of the present invention, and determines the optical performance of the imaging catheter. On the one hand, the fiber optic probe focuses the swept frequency light source beam into the sample to be tested, and on the other hand, collects the reflected or scattered light carrying the sample information and transmits it to the OCT system host, interferes with the reference arm in the coherent detection module and is collected by the signal acquisition module.

[0021] The optical fiber probe of the present invention adopts a side scanning solution based on a gradient refractive index lens 6. The single-mode optical fiber 1 is combined with a self-focusing lens GRIN design, and a reflector 7 is integrated at the front end of the gradient refractive index lens 6 to provide side imaging. It includes a single-mode optical fiber 1, a coreless optical fiber 5, a GRIN gradient refractive index lens 6 and a reflector 7 arranged in sequence in an inner liner tube 2. The single-mode optical fiber 1 is provided with a torsion spring tube 4. Figure 1 The gradient refractive index lens 6 can realize efficient focusing of the light beam to form a fine light spot. This structure is easy to miniaturize, flexible to bend, and improves the spatial resolution of the probe.

[0022] The reflector 7 is a microprism with an angle of 105°, which is used to deflect the light beam to a 90-degree side view angle to achieve cross-sectional imaging of the blood vessel wall. The microprism can reduce surface reflection and ensure that the laser beam enters the deep tissue. By controlling the focal length of the GRIN gradient refractive index lens 6 and the angle of the reflector 7, the spot diameter of the probe is controlled within 15μm, achieving spot optimization and meeting the requirements of high-resolution imaging in blood vessels.

[0023] The diameter of the single-mode optical fiber 1 is 0.9 mm, and the focal length of the gradient refractive index lens 6 is 1 mm, so that the spot diameter can be controlled within 15 μm.

[0024] The imaging catheter of the present invention adopts a distal drive solution, where a scanning mechanism provides a driving force at the distal end of the optical fiber probe to drive the optical fiber probe to perform high-speed circumferential scanning in the outer protective sleeve, while driving the imaging catheter as a whole to perform linear extension and retraction movements. The imaging catheter provides protection for the optical fiber probe and limits the optical fiber probe from performing high-speed rotational scanning inside it. The imaging catheter includes a transparent protective sleeve 1 and an inner lining tube 2 disposed in the transparent protective sleeve 1, and a transparent window is disposed at the front end of the transparent protective sleeve 1. Figure 2 shown.

[0025] A transparent window area is set at the front end of the imaging catheter to avoid scattering and attenuation during light transmission; a torsion spring tube 4 is added to the outside of the single-mode optical fiber 1 to ensure that the optical fiber does not twist or break during rotation, and provides a certain tensile strength to extend the service life of the probe.

[0026] The imaging catheter adopts a double-layer catheter. The inner liner 2 is made of low-friction PTFE (polytetrafluoroethylene), which has a smooth inner wall with low friction and good thermal stability; the outer transparent protective sleeve 1 is made of PEBA (polyether block amide), which has good deformation and elastic recovery and is the lightest heat-resistant and impact-resistant engineering thermoplastic elastomer. The inner PTFE provides a smooth moving channel for the fiber optic probe, and the outer PEBA material has good flexibility, adapts to the curvature of the blood vessel, and prevents direct contact between the probe and the blood vessel wall. The probe is installed in the imaging catheter with a double-layer structure of PTFE and PEBA, and the 90-degree deflection angle of the fiber optic probe is driven by a rotating motor for side-view imaging, ensuring high-quality imaging of the transparent window at the end of the catheter.

[0027] The outer layer of transparent PEBA material is integrally formed, and PTFE is added inside to enhance the lubrication performance. There is no PTFE lining tube 2 at the end near the imaging area of ​​the optical fiber probe, so that the attenuation of the optical signal is as small as possible. It is worth noting that since the protective sleeve is curved, it is equivalent to a cylindrical lens, which will cause the focused light spot to be widened to a certain extent, resulting in a decrease in the lateral resolution of the system. In order to avoid the jitter error caused by the unevenness of the protective sleeve, the imaging catheter is used for axial scanning as a whole, and the optical fiber probe and the imaging catheter do not have relative displacement along the axial direction, but are penetrated and withdrawn as a whole in the blood vessel. When the optical fiber probe is scanned circumferentially in the imaging catheter, the imaging area is fixed and does not bend or deflect with the scanning position.

[0028] The transparent window is a cylindrical mirror. The transparent window area at the end of the imaging catheter adopts a cylindrical mirror design to ensure consistent focus of the laser beam and avoid image distortion. The inner diameter of the protective sleeve is 0.8mm, the outer diameter is 1mm, and the length is 1m. The PTFE grease of the inner lining tube 2 is used to reduce the friction between the optical fiber probe and the protective sleeve, so that it can rotate more smoothly at high speed in the protective sleeve. The end of the protective sleeve is adhered to the fixed shell (white structural part) at the rotating interface end of the scanning mechanism, and axial scanning is achieved through a linear stepper motor, such as Figure 3 shown.

[0029] In practical applications, the COL (105°)-1310-AR-SC / APC fiber probe produced by Xi'an Femtosecond Technology Co., Ltd. is combined with the Kollmorgen KBM-17H01-C hollow direct drive motor. The present invention can also be supplemented by a fiber optic rotary connector to achieve circumferential scanning of the probe: the fiber optic rotary connector is used to achieve the transmission of optical signals between the fixed platform and the rotating probe to ensure that the signal remains stable during the rotation process; a fine-tuning structure can also be introduced between the coreless optical fiber 5 and the gradient refractive index lens 6 to achieve signal compensation and adjustment, and the focal length of the light beam can be finely adjusted as needed to further optimize the imaging quality.

[0030] The above embodiments are only illustrative of the principles and effects of the present invention, as well as some embodiments of its application. For those skilled in the art, several modifications and improvements may be made without departing from the creative concept of the present invention, and all of these belong to the protection scope of the present invention.

Claims

1. A fiber optic probe imaging catheter module for an intravascular frequency domain OCT imaging system, characterized in that: The invention comprises a transparent protective sleeve (1) and an inner lining tube (2) arranged in the transparent protective sleeve (1), wherein the inner lining tube (2) is made of a polytetrafluoroethylene tube, and the transparent protective sleeve (1) is made of a polyether block amide tube. A transparent window is arranged at the front end of the transparent protective sleeve (1). A single-mode optical fiber (1), a coreless optical fiber (5), a gradient refractive index lens (6) and a reflector (7) are arranged in sequence in the inner lining tube (2), and a torsion spring tube (4) is arranged outside the single-mode optical fiber (1).

2. The optical fiber probe imaging catheter module for an intravascular frequency domain OCT imaging system according to claim 1, characterized in that: The transparent window is a cylindrical mirror.

3. The optical fiber probe imaging catheter module for an intravascular frequency domain OCT imaging system according to claim 1 or 2, characterized in that: The angle of the reflector (7) is set to 105°.

4. The optical fiber probe imaging catheter module for an intravascular frequency domain OCT imaging system according to claim 3, characterized in that: The single-mode optical fiber (1) has a diameter of 0.9 mm, and the focal length of the gradient refractive index lens (6) is 1 mm.

5. The optical fiber probe imaging catheter module for an intravascular frequency domain OCT imaging system according to claim 4, characterized in that: The transparent protective sleeve (1) has an inner diameter of 0.8 mm, an outer diameter of 1 mm, and a length of 1 m.

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