Piezoelectric driving miniature optical probe for cerebrovascular interventional imaging

Abstract

The invention relates to the technical field of medical instruments, in particular to a piezoelectric driving miniature optical probe for cerebrovascular interventional imaging, which comprises a glass tube base body, a single piezoelectric ceramic piece and the like, and is characterized in that the glass tube base body is of a hollow cylindrical structure, and an inclined groove is formed in the axial center of the glass tube base body; the single piezoelectric ceramic piece is fixed on the outer side of the glass tube base body. Through a hollow rod type stator structure composed of a single piezoelectric ceramic piece and a glass tube base body with a 10-degree inclined groove, mode conversion from longitudinal vibration to longitudinal-torsional coupling vibration is achieved, an elliptical motion track is formed at the position of a miniature magnetic ring at the front end of the stator, 360-degree optical scanning is achieved through friction driving of a rotor, and the mechanical property of the motor is improved. Compared with a traditional far-end miniature probe with the diameter usually larger than 1.5 mm, the whole outer diameter of the probe is reduced to 0.4 mm, and smooth navigation and passing in tortuous and narrow brain middle artery (the diameter is usually smaller than 0.5 mm) are easier.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels. Background Technology

[0002] In modern medicine, cerebrovascular diseases such as aneurysms, vascular stenosis, and thrombosis are the main causes of serious complications such as stroke. Intravascular interventional imaging technology has become a key means of diagnosis and treatment. Intravascular optical coherence tomography (OCT) imaging technology is widely used in the coronary and carotid artery fields due to its high resolution, but it faces severe challenges when applied to the complex network of cerebral blood vessels, especially the middle cerebral arteries. Cerebral blood vessels are densely branched, highly tortuous, and have small diameters (the diameter of middle cerebral artery branches is often less than 0.5 mm), which places extremely high demands on the diameter, flexibility, and navigation capabilities of interventional catheters.

[0003] Existing endovascular imaging catheters are mainly divided into two types: proximal-driven and distal micro-probe. Proximal-driven catheters rely on mechanical transmission. For example, patent CN213155792U discloses a rotation retraction device and an intravascular OCT-IVUS dual-catheter imaging system. This rotation retraction drive device uses only one rotation retraction unit to control the OCT or IVUS catheter, which simplifies the structural components and provides clear imaging, simplifying operation. However, in highly tortuous cerebral blood vessels, this device is prone to non-uniform rotational distortion (NURD) artifacts due to uneven torque transmission in the catheter, leading to image distortion.

[0004] Telescopic miniature probes, such as the one in patent CN107411708A, provide a dual-modal endoscope for optical coherence tomography and photoacoustic imaging, driven by a built-in miniature electromagnetic motor. While this effectively avoids Nurd artifacts, traditional piezoelectric or electromagnetic drive schemes typically require multiple piezoelectric ceramics, complex wiring layouts, or metal stators, making it difficult to further miniaturize the probe diameter (usually greater than 0.5 mm). This also introduces wire artifacts, and the alignment of optical components relies on additional fixing components, increasing signal attenuation and probe rigidity, affecting flexibility and navigation performance in narrow cerebral blood vessels. Furthermore, existing telescopic miniature probes present engineering challenges in applying preload: for piezoelectric actuators with a diameter less than 1 mm, traditional spring or mechanical preload methods struggle to achieve stable and controllable preload, resulting in low or unstable drive efficiency.

[0005] Existing magnetic navigation technologies (such as magnetically controlled capsule endoscopes), such as patent CN120130901A, propose a rotation strategy-based magnetically controlled capsule endoscope steering control device and method. Although it can achieve guidewire-free navigation through an external magnetic field and reduce mechanical damage to the inner wall of the cavity, it is mostly used for larger capsule devices (usually with a diameter greater than 8 mm). It is difficult to directly apply to cerebral vascular microprobes that require 360° high-speed optical scanning, and it is not effectively integrated with the distal piezoelectric drive scanning mechanism, so it cannot simultaneously meet the requirements of miniaturization, high-precision imaging and precise magnetically controlled navigation.

[0006] To overcome the above-mentioned defects, this invention introduces a micro magnetic ring structure on the basis of a traditional single-piece piezoelectric driven micro optical probe, so as to realize the controllable application of pre-pressure magnetically. At the same time, it combines with an external magnetic field to realize the flexible magnetic navigation of the probe, thereby significantly improving the navigation capability and safety of the probe in tortuous and narrow cerebral blood vessels, while maintaining the miniaturization advantage of a diameter of less than 0.4 mm, and realizing high-precision 360° full-field imaging with the elimination of artifacts. Summary of the Invention

[0007] To overcome the shortcomings of the prior art, the present invention provides a piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels, thereby solving the problems in the prior art.

[0008] The piezoelectrically driven miniature optical probe for interventional cerebrovascular imaging provided in this application adopts the following technical solution: A piezoelectrically driven miniature optical probe for interventional cerebrovascular imaging includes a miniature probe stator, a miniature probe rotor, and a single-mode optical fiber. The miniature probe stator comprises a glass tube substrate, a monolithic piezoelectric ceramic sheet, and a miniature magnetic ring I. The glass tube substrate is a hollow cylindrical structure with an inclined groove at its axial center. The monolithic piezoelectric ceramic sheet is fixed to the outside of the glass tube substrate, and the miniature magnetic ring I is fixed to the front end of the glass tube substrate. The miniature probe rotor includes a rotating lens and a miniature magnetic ring II. The miniature magnetic ring II is fixed to the rear end of the rotating lens, and the miniature probe rotor is disposed inside the front end of the glass tube substrate and coaxially aligned with the single-mode optical fiber. The monolithic piezoelectric ceramic sheet... The piezoelectric ceramic sheet generates longitudinal vibration under AC voltage excitation, and achieves longitudinal-torsional mode conversion through the inclined groove of the glass tube substrate, forming an elliptical motion trajectory at the micro magnetic ring I. The micro magnetic ring II is driven by friction to drive the rotating lens to achieve 360° optical scanning. The micro magnetic ring I and micro magnetic ring II provide pre-pressure between the stator and rotor through magnetic attraction, and interact with the external magnetic field to achieve probe navigation. The inclined groove structure of the glass tube substrate converts the longitudinal vibration generated by the single piezoelectric ceramic sheet into longitudinal and circumferential waves through reflection and propagation, synthesizing an elliptical motion trajectory at the end of the glass tube substrate. Friction drives the micro probe rotor to rotate, achieving full-field optical scanning.

[0009] Furthermore, the outer diameter of the glass tube substrate is 0.3 to 0.5 mm and the inner diameter is 0.181 to 0.190 mm, and the inclined groove is a single 10° to 15° inclined groove.

[0010] Furthermore, the single piezoelectric ceramic sheet has a thickness of 0.11 mm to 0.15 mm, vibrates along the d31 mode, and is fixed to the outside of the glass tube substrate by epoxy resin bonding.

[0011] Furthermore, the rotating lens is a 35° to 45° chamfered optical microlens with an outer diameter of 0.181 to 0.190 mm and a length of 0.5 to 1 mm. It is tightly fitted to the end face of the single-mode optical fiber, and coaxial alignment is achieved by utilizing the hollow structure of the glass tube substrate.

[0012] Furthermore, the micro magnetic ring I and micro magnetic ring II are made of neodymium iron boron permanent magnet material and are fixed to the front end of the glass tube substrate and the rear end of the rotating lens respectively by epoxy resin. The magnetization direction is set along the axial or radial direction to achieve mutual magnetic attraction and provide adjustable pre-pressure.

[0013] Furthermore, the pre-pressure can be linearly adjusted by adjusting the thickness or magnetic strength of the micro magnetic ring II.

[0014] Furthermore, it also includes a probe drive wire; the probe drive wire is connected to the monolithic piezoelectric ceramic sheet and is used to transmit a single-phase AC drive signal.

[0015] Furthermore, it also includes a transparent protective tube; the transparent protective tube covers the outside of the probe and provides biocompatibility protection.

[0016] Furthermore, the single-mode optical fiber is used to transmit optical signals with wavelengths from 1200nm to 1400nm, and the 35° to 45° chamfered surface of the rotating lens is used to laterally reflect light signals to achieve 360° scanning of the inner wall of blood vessels.

[0017] The advantages and positive effects of this invention are: (1) The mode conversion from longitudinal vibration to longitudinal torsional coupling vibration is achieved by a hollow rod stator structure composed of a single piezoelectric ceramic sheet and a glass tube substrate with a 10° inclined groove. An elliptical motion trajectory is formed at the micro magnetic ring at the front end of the stator. The rotor is driven by friction to achieve 360° optical scanning. This longitudinal torsional vibration mode conversion mechanism only requires a single piezoelectric ceramic sheet and a single-phase drive circuit. It does not require multiple ceramic sheets, complex wires or metal stators. Unlike traditional remote micro probes with a diameter usually greater than 0.5 mm, the overall outer diameter of the probe of this invention is reduced to 0.4 mm, which makes it easier to navigate and pass through the tortuous and narrow middle cerebral artery (which usually has a diameter less than 0.5 mm).

[0018] (2) By setting micro magnetic ring I and micro magnetic ring II at the stator end and the lens rotor end respectively, the two provide pre-pressure between the stator and rotor through magnetic attraction (axial or radial magnetization). This magnetic pre-pressure structure does not require additional mechanical pre-tightening components (such as springs or complex fixing parts), which solves the engineering problem of unstable and difficult precise adjustment of traditional pre-pressure application of micro piezoelectric actuators with diameters less than mm. At the same time, by adjusting the thickness of micro magnetic ring II to change the magnetic intensity, the pre-pressure can be linearly and reliably adjusted, ensuring high and stable friction drive efficiency, and improving the reliability and life of the probe in high-speed rotating scanning.

[0019] (3) By using the same set of micro magnetic rings I and II, the probe can interact with the external magnetic field (gradient magnetic field or rotating magnetic field) while providing pre-pressure, thus achieving precise turning, bending and assisted propulsion of the probe in tortuous cerebral blood vessels, significantly reducing the dependence on guidewires and the risk of mechanical friction damage to the blood vessel walls; unlike existing magnetic navigation technologies (such as magnetically controlled drives mainly used for larger capsule endoscopes), this invention integrates micro magnetic rings into a distal piezoelectric driven optical probe with a diameter of only .mm, realizing the coordinated work of magnetic navigation and high-speed optical scanning without interfering with the independent imaging function of piezoelectric drive, thereby providing higher navigation controllability and safety in complex cerebral vascular environments. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural schematic diagram of the piezoelectrically driven micro-optical probe for interventional imaging of cerebrovascular diseases according to the present invention. Figure 2 This is a schematic diagram of the three-dimensional structure of the microprobe stator of the piezoelectrically driven microoptical probe for interventional imaging of cerebrovascular diseases according to the present invention. Figure 3 This is a schematic diagram of the three-dimensional structure of the microprobe rotor of the piezoelectrically driven microoptical probe for interventional imaging of cerebrovascular diseases according to the present invention. Figure 4 This is a schematic diagram of the vibration principle of the stator of the piezoelectrically driven micro-optical probe for interventional imaging of cerebrovascular diseases according to the present invention. Figure 5 This is a simulated elliptical motion trajectory diagram of the mass point at the stator end of the piezoelectrically driven micro-optical probe for interventional imaging of cerebrovascular diseases according to the present invention. Figure 6 This is a schematic diagram illustrating the optical transmission and scanning principle of the piezoelectrically driven miniature optical probe for interventional cerebrovascular imaging of the present invention. Figure 7 This is an optical simulation result diagram of the piezoelectrically driven micro-optical probe for interventional imaging of cerebral blood vessels according to the present invention; Figure 8 This is a schematic diagram of the piezoelectrically driven micro-optical probe for interventional imaging of brain blood vessels navigating within a blood vessel, according to the present invention.

[0021] Explanation of reference numerals in the attached figures: 1-Miniature probe stator, 2-Miniature probe rotor, 3-Single-mode optical fiber, 4-Transparent protective tube, 11-Monolithic piezoelectric ceramic sheet, 12-Glass tube substrate, 13-Miniature magnetic ring I, 14-Probe drive wire, 21-Rotating lens, 22-Miniature magnetic ring II. Detailed Implementation

[0022] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Example: A piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels, based on Figures 1-8 As shown, it includes a miniature probe stator 1, a miniature probe rotor 2, and a single-mode optical fiber 3; The micro probe stator 1 includes a glass tube substrate 12, a single piezoelectric ceramic sheet 11, and a micro magnetic ring I 13. The glass tube substrate 12 is a hollow cylindrical structure with an inclined groove at the axial center. The single piezoelectric ceramic sheet 11 is fixed to the outside of the glass tube substrate 12, and the micro magnetic ring I 13 is fixed to the front end of the glass tube substrate 12. The miniature probe rotor 2 includes a rotating lens 21 and a miniature magnetic ring II 22. The miniature magnetic ring II 22 is fixed to the rear end of the rotating lens 21. The miniature probe rotor 2 is disposed inside the front end of the glass tube substrate 12 and is coaxially aligned with the single-mode optical fiber 3. The single piezoelectric ceramic sheet 11 generates longitudinal vibration under AC voltage excitation, and achieves longitudinal-torsional mode conversion through the inclined groove of the glass tube substrate 12, forming an elliptical motion trajectory at the micro magnetic ring I 13. The micro magnetic ring II 22 is driven by friction to drive the rotating lens 21 to achieve 360° optical scanning. Miniature magnetic ring I13 and miniature magnetic ring II22 provide pre-pressure between the stator and rotor through magnetic attraction and interact with the external magnetic field to achieve probe navigation; The inclined groove structure of the glass tube substrate 12 causes the longitudinal vibration generated by the single piezoelectric ceramic sheet 11 to be reflected and propagated into longitudinal and circumferential waves, which are synthesized into elliptical motion trajectories at the end of the glass tube substrate 12. The friction drives the micro probe rotor 2 to rotate, realizing full-field optical scanning.

[0024] The glass tube substrate 12 has an outer diameter of 0.4 mm and an inner diameter of 0.185 mm, and the inclined groove is a single 10° inclined groove.

[0025] The single piezoelectric ceramic sheet 11 has a thickness of 0.12 mm, vibrates along the d31 mode, and is fixed to the outside of the glass tube substrate 12 by epoxy resin bonding.

[0026] The rotating lens 21 is a 37° chamfered optical microlens with an outer diameter of 0.185 mm and a length of 1 mm. It is tightly fitted to the end face of the single-mode fiber 3 and coaxial alignment is achieved by utilizing the hollow structure of the glass tube substrate 12.

[0027] The miniature magnetic rings I13 and II22 are made of neodymium iron boron permanent magnet material and are fixed to the front end of the glass tube substrate 12 and the rear end of the rotating lens 21 respectively by epoxy resin. The magnetization direction is set along the axial or radial direction to achieve mutual magnetic attraction and provide adjustable pre-pressure.

[0028] The preload can be linearly adjusted by changing the thickness or magnetic strength of the micro magnetic ring II22.

[0029] It also includes a probe drive wire 14; the probe drive wire 14 is connected to a single piezoelectric ceramic plate 11 and is used to transmit single-phase AC drive signals.

[0030] It also includes a transparent protective tube 4; the transparent protective tube 4 covers the outside of the probe and provides biocompatibility protection.

[0031] The single-mode fiber 3 is used to transmit 1310nm wavelength optical signals, and the 37° chamfered bevel of the rotating lens 21 is used to reflect light signals laterally to achieve 360° scanning of the inner wall of blood vessels.

[0032] In modern medicine, the diagnosis and treatment of cerebrovascular diseases rely heavily on endovascular interventional imaging technology, especially optical coherence tomography (OCT) imaging, which is highly valued for its micron-level resolution. However, cerebral blood vessels are highly tortuous and have small diameters (the branches of the middle artery are often less than 0.5 mm). Traditional distal micro-optical probes still face significant challenges in terms of diameter miniaturization, elimination of non-uniform rotational distortion (NURD) artifacts, stable application of stator and rotor pre-pressure, and safe navigation within tortuous blood vessels.

[0033] Based on this, such as Figure 1 As shown, this embodiment provides a magnetically controlled piezoelectrically driven miniature optical probe for cerebrovascular interventional imaging. The miniature optical probe is located at the distal end of the catheter body and is used to achieve magnetically controlled navigation and 360° full-field optical coherence tomography imaging in tortuous cerebral blood vessels. Its overall outer diameter is 0.4 mm, including a miniature probe stator 1, a miniature probe rotor 2, a single-mode optical fiber 3, and a transparent protective tube 4. The distal end of the probe is the miniature probe rotor 2, the middle section is the miniature probe stator 1, the single-mode optical fiber 3 is fixed inside the rear half of the stator, and the transparent protective tube 4 is a biocompatible polymer tube (such as polyimide or PTFE) that covers the entire probe exterior, providing flexibility and biocompatibility protection to ensure smooth probe advancement within the blood vessel.

[0034] like Figure 2 As shown, the micro probe stator 1 includes a single piezoelectric ceramic sheet 11, a glass tube substrate 12 with a 10° inclined groove, a micro magnetic ring I 13, and a probe drive wire 14. The glass tube substrate 12 is precision-manufactured using glass drawing technology, with a hollow cylindrical structure, an outer diameter of 0.4 mm, an inner diameter of 0.185 mm, and a length of approximately 510 mm. A single 10° inclined groove (groove width approximately 0.05 mm, groove surface is a free surface) is machined at the axial center. The single piezoelectric ceramic sheet 11 is made of PZT5H or a similar piezoelectric material, with a thickness of 0.12 mm, and is fixed to the outer surface of the glass tube substrate 12 along its length (31 modes) by epoxy resin bonding. The micro magnetic ring I 13 is a neodymium iron boron (NFB) permanent magnet ring. Or other biocompatible magnetic materials (such as SmCo), with an outer diameter of 0.185 mm, an inner diameter of approximately 0.15 mm, and a thickness of 0.1-0.3 mm, axially or radially magnetized, are fixed to the front end of the glass tube substrate 12 by epoxy resin. The probe drive wire 14 consists of two thin copper wires (0.0 mm in diameter), one end of which is connected to the positive and negative poles of the single piezoelectric ceramic sheet 11, and the other end extends along the conduit to the external control system for transmitting single-phase AC drive signals (frequency 3050 kHz, voltage amplitude 50200 Vpp).

[0035] like Figure 3 As shown, the miniature probe rotor 2 includes a rotating lens 21 and a miniature magnetic ring II 22. The rotating lens 21 is a 37° chamfered optical microlens (made of fused silica or optical glass), with an outer diameter of 0.185 mm and a length of 1 mm. The chamfered surface is coated with an anti-reflection film (for a wavelength of 1310 nm). The miniature magnetic ring II 22 is a neodymium iron boron permanent magnet ring matched with the miniature magnetic ring I 13, with a thickness of 0.1-0.5 mm (adjustable). It is axially or radially magnetized and fixed to the rear end of the rotating lens 21 with epoxy resin. The magnetic poles of the miniature magnetic ring I 13 and the miniature magnetic ring II 22 are arranged opposite each other (opposite poles attract or like poles repel), providing axial magnetic attraction preload (range 110 mN, which can be precisely linearly adjusted by the thickness of the miniature magnetic ring).

[0036] like Figure 4 and Figure 5 As shown, the piezoelectric drive and rotation principle is as follows: An external signal generator generates a single-phase sinusoidal AC voltage, which, after power amplification, is applied to a single piezoelectric ceramic sheet 11 through a probe drive wire 14, exciting its first-order longitudinal vibration (inverse piezoelectric effect, 31-mode) along its length. This longitudinal vibration propagates as a stress wave to the 10° inclined groove of the glass tube substrate 12. Free reflection from the groove surface causes part of the longitudinal wave to be converted into a circumferential transverse wave, realizing the longitudinal-torsional mode conversion. At the micro-magnetic ring I13 at the front end of the glass tube substrate 12, the longitudinal vibration couples with the second-order torsional vibration, and the particle forms a micrometer-level elliptical motion trajectory (amplitude 15μm, such as...). Figure 5As shown in the simulation, the elliptical trajectory drives the micro magnetic ring II22 and the entire micro probe rotor 2 to rotate at high speed (the speed can reach 1000-3000 rpm) through friction, realizing 360° continuous optical scanning.

[0037] Preload Application and Adjustment: The magnetic attraction between miniature magnetic ring I13 and miniature magnetic ring II22 provides a stable preload between the stator and rotor, ensuring friction drive efficiency. This magnetic preload eliminates the need for additional mechanical components (such as springs), solving the problem of difficult preload application in traditional miniature piezoelectric actuators with a diameter less than 1 mm. By replacing the miniature magnetic ring II22 with one of different thicknesses or adjusting the magnetization intensity, the preload can be linearly adjusted to achieve optimal drive stability.

[0038] like Figure 6 and Figure 7 As shown, the optical transmission and scanning principle is as follows: A single-mode fiber 3 (core diameter approximately 9 μm, cladding 125 μm) is fixed to the rear half of the glass tube substrate 12 inside by epoxy resin. Its end face is tightly fitted to the rear end of the rotating lens 21 (gap < 1 μm, naturally coaxially aligned using the hollow structure of the glass tube, requiring no additional alignment components). A 1310 nm near-infrared light signal is transmitted from an external laser source through the single-mode fiber 3 to the rotating lens 21. After total internal reflection by a 37° chamfered inclined surface, it is laterally emitted and focused on the blood vessel wall (focal plane distance 1.49 mm, focal spot diameter 9.05 μm, as shown). Figure 7 As shown in the optical simulation, the rotor rotates at high speed to achieve 360° circumferential scanning, and the echo signal returns along the original path to form a high-resolution OCT image.

[0039] like Figure 8 As shown, the magnetic navigation principle is as follows: The micro magnetic rings I13 and II22 at the distal end of the probe form an integrated magnetic component, which interacts with the external magnetic field (permanent magnet or electromagnetic coil system). The external magnetic field generates a gradient magnetic field (for auxiliary propulsion and traction) and a rotating magnetic field (for steering control). By referencing the three-dimensional magnetic drive method (determining the positional relationship between the external magnet and the probe magnetic rings, the range of magnetic force and driving angle, and ensuring that the horizontal force is ≥0 to achieve stable drive), in tortuous cerebral blood vessels, the operator can achieve precise steering, bending adaptation and low-resistance propulsion of the probe by adjusting the direction and intensity of the external magnetic field, which significantly reduces the dependence on the guidewire and the risk of mechanical damage to the blood vessel wall, while not interfering with the independent optical scanning function of piezoelectric drive.

[0040] The cerebrovascular interventional imaging process in this embodiment is as follows: (1) Probe preparation: Integrate the miniature optical probe into the distal end of the intravascular imaging catheter and connect it to the extracorporeal OCT system and signal generator.

[0041] (2) Vascular insertion: The catheter is advanced to the entrance of the target vessel through a standard interventional route (such as the femoral artery), and the probe is initially steered using an external magnetic field.

[0042] (3) Magnetic navigation: When entering the tortuous cerebral blood vessel segment, the external magnetic field gradient and rotation are adjusted under real-time X-ray or ultrasound guidance to achieve precise navigation of the probe to the lesion area without guide wire or with low damage.

[0043] (4) Optical scanning: After reaching the target position, a single-phase AC drive signal is applied to start the piezoelectric rotation (2000 rpm) and simultaneously acquire the 1310 nm OCT signal to achieve 360° full field of view high-resolution imaging.

[0044] (5) Image reconstruction: The extracorporeal system processes the echo signal to form a cross-section and three-dimensional image of the blood vessel.

[0045] (6) Probe withdrawal: After scanning is completed, turn off the drive signal and use an external magnetic field to smoothly withdraw the probe.

[0046] In one variant embodiment, the micro magnetic ring can be an electromagnetic ring (which generates a controllable magnetic field when energized) to further achieve dynamic adjustment of pre-pressure; the external magnetic field system can be integrated with real-time feedback closed-loop control to improve navigation accuracy; and the transparent protective tube 4 can be coated with a hydrophilic coating to further reduce propulsion resistance.

[0047] This embodiment achieves synergistic optimization of a 0.4mm diameter micro-optical probe in eliminating NURD artifacts, stabilizing pre-pressure application, and providing high-safety magnetic navigation through the above-described structure and process. The imaging resolution reaches the micrometer level, and the risk of navigation damage is significantly reduced, making it suitable for complex cerebrovascular interventional diagnosis and treatment.

[0048] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels, characterized in that, It includes a micro probe stator (1), a micro probe rotor (2), and a single-mode optical fiber (3); the micro probe stator (1) includes a glass tube substrate (12), a single piezoelectric ceramic sheet (11), and a micro magnetic ring I (13). The glass tube substrate (12) is a hollow cylindrical structure with an inclined groove at the axial center. The single piezoelectric ceramic sheet (11) is fixed to the outside of the glass tube substrate (12), and the micro magnetic ring I (13) is fixed to the front end of the glass tube substrate (12). The micro probe rotor (2) includes a rotating lens (21) and a micro magnetic ring II (22). The micro magnetic ring II (22) is fixed to the rear end of the rotating lens (21). The micro probe rotor (2) is disposed inside the front end of the glass tube substrate (12) and is coaxially aligned with the single-mode optical fiber (3). The single piezoelectric ceramic sheet (11) generates longitudinal vibration under AC voltage excitation, and achieves longitudinal torsional mode conversion through the inclined groove of the glass tube substrate (12), forming an elliptical motion trajectory at the micro magnetic ring I (13), and drives the micro magnetic ring II (22) to drive the rotating lens (21) to achieve 360° optical scanning through friction. The micro magnetic ring I (13) and micro magnetic ring II (22) provide pre-pressure between the stator and rotor through magnetic attraction and interact with the external magnetic field to realize probe navigation; The inclined groove structure of the glass tube substrate (12) causes the longitudinal vibration generated by the single piezoelectric ceramic sheet (11) to be converted into longitudinal and circumferential waves through reflection and propagation. These waves synthesize an elliptical motion trajectory at the end of the glass tube substrate (12), and the friction drives the micro probe rotor (2) to rotate, thereby realizing full-field optical scanning.

2. The piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels according to claim 1, characterized in that, The outer diameter of the glass tube substrate (12) is 0.3 to 0.5 mm and the inner diameter is 0.181 to 0.190 mm. The inclined groove is a single 10° to 15° inclined groove.

3. The piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels according to claim 1, characterized in that, The single piezoelectric ceramic sheet (11) has a thickness of 0.11 mm to 0.15 mm, vibrates along the d31 mode, and is fixed to the outside of the glass tube substrate (12) by epoxy resin bonding.

4. The piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels according to claim 1, characterized in that, The rotating lens (21) is a 35° to 45° chamfered optical microlens with an outer diameter of 0.181 to 0.190 mm and a length of 0.5 to 1 mm. It is closely attached to the end face of the single-mode optical fiber (3) and coaxial alignment is achieved by utilizing the hollow structure of the glass tube substrate (12).

5. A piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels according to any one of claims 1-4, characterized in that, The micro magnetic ring I (13) and micro magnetic ring II (22) are made of neodymium iron boron permanent magnet material and are fixed to the front end of the glass tube substrate (12) and the rear end of the rotating lens (21) respectively by epoxy resin. The magnetization direction is set along the axial or radial direction to achieve mutual magnetic attraction and provide adjustable pre-pressure.

6. A piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels according to claim 5, characterized in that, The pre-pressure can be linearly adjusted by adjusting the thickness or magnetic strength of the micro magnetic ring II (22).

7. A piezoelectrically driven miniature optical probe for interventional cerebrovascular imaging according to claim 6, characterized in that, It also includes a probe drive wire (14); the probe drive wire (14) is connected to the single piezoelectric ceramic plate (11) and is used to transmit a single-phase AC drive signal.

8. A piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels according to claim 7, characterized in that, It also includes a transparent protective tube (4); the transparent protective tube (4) covers the outside of the probe and provides biocompatibility protection.

9. A piezoelectrically driven miniature optical probe for interventional imaging of cerebral blood vessels according to claim 1, characterized in that, The single-mode optical fiber (3) is used to transmit optical signals with wavelengths from 1200nm to 1400nm, and the 35° to 45° chamfered bevel of the rotating lens (21) is used to reflect light signals laterally to achieve 360° scanning of the inner wall of blood vessels.

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