Ablation device and system

Abstract

The invention provides an ablation device and system. According to the ablation system, the ablation device with the two stages of focusing assemblies is arranged, light pulses can be effectively focused, distortion is reduced, and meanwhile the driving device drives vibration displacement to expand the ablation area; the device has the advantages that the nonlinear effect in ultrafast laser pulse transmission is effectively inhibited, catheter miniaturization is achieved, the ablation view field is expanded, and the ablation efficiency and depth are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to an ablation device and system, belonging to the field of interventional therapy medical instruments. BACKGROUND

[0002] Atherosclerotic plaques can be divided into fibrous, lipid and calcified types according to their composition. Among them, the calcified plaque, especially the moderate to severe calcification, leads to vascular stenosis. Due to the difficulty in device delivery and the complexity of plaque modification, the clinical prognosis is generally poor, which has become a key challenge in the treatment of atherosclerotic lesions.

[0003] The existing clinical interventional treatment methods mainly include mechanical resection, shock wave lithotripsy and excimer laser ablation. Mechanical resection removes calcified tissue through directional rotary cutting or plaque rotary grinding mechanism, but the operation process has a high risk of complications and is highly dependent on the experience of the operator. Shock wave lithotripsy is derived from kidney stone treatment technology, which uses a balloon to transmit shock waves to crack calcification to improve the compliance of the lumen. Although the procedure is simple and safe, when it comes to severe intraluminal calcification, small lumen area or even complete occlusion of the lesion (such as chronic total occlusion), the guide wire or balloon cannot pass through, resulting in the inapplicability of this technology. Excimer laser ablation uses 308 nm high-energy photons to break molecular bonds through photochemical action to achieve tissue vaporization. Although it can forward ablate obstructive lesions, the ablation effect on severe calcified plaques is limited.

[0004] In contrast, ultrafast laser has an extremely narrow pulse width below picoseconds, which generates extremely high peak power density at the focal point. Through the plasma-mediated photoionization mechanism, the tissue is removed instantaneously, and because the pulse width is less than the thermal relaxation time of biological tissue, the thermal damage to the surrounding tissue is significantly reduced. Ultrafast laser has been successfully applied in corneal surgery and has verified the effectiveness and safety of calcified tissue on dentin and bone tissue.

[0005] However, the application of ultrafast laser to the ablation of intravascular calcified plaques faces multiple technical obstacles. First, the transmission of ultrafast laser pulses is easily affected by the nonlinear effects of optical fibers, resulting in pulse distortion and loss of original tissue effects. The existing ablation system lacks an effective mechanism to suppress nonlinear effects. Second, in order to achieve effective ablation, the beam needs to be focused to a very small range to obtain high power density. However, the traditional design sets optical elements for focusing at a position far from the front end of the optical fiber, resulting in an increase in the overall size of the catheter, making it difficult to pass through narrow cavities. At the same time, the field of view is limited, and the ablation area cannot cover the outer diameter of the catheter, making the catheter unable to advance and ablate, which severely restricts the ablation depth and efficiency.

[0006] Therefore, it is necessary to provide an ablation device and an ablation system using the ablation device to solve the above problems. SUMMARY

[0007] The present application aims to provide an ablation system, which can effectively inhibit nonlinear effects in superfast laser pulse transmission, realize catheter miniaturization, expand the ablation field of view, and improve the ablation efficiency and depth by setting the structure of the ablation device.

[0008] To achieve the above-mentioned purposes of the present application, the present application provides an ablation system, comprising: A laser emitting device for generating optical pulses with a pulse width less than 100 ps; An ablation device for transmitting the optical pulses generated by the laser reflecting device and acting on the region of interest; wherein the ablation device comprises a two-stage focusing assembly configured to perform two-stage focusing on the transmitted optical pulses; a first focusing member provided at the end of the ablation optical fiber and a second focusing member provided at the end of the body; and A driving device drivingly connected with the ablation device to drive the ablation device to perform vibrational displacement.

[0009] As a further improvement of the present application, the ablation device further comprises: A body; An ablation optical fiber configured to transmit the optical pulses, and the ablation optical fiber is a hollow-core optical fiber; An actuator configured to drive the ablation optical fiber to perform high-frequency vibrational scanning, and the actuator is drivingly connected with the driving device; The ablation optical fiber, the two-stage focusing assembly, and the actuator are arranged along the extension center line of the body.

[0010] As a further improvement of the present application, the ablation optical fiber extends through the actuator to form an optical fiber cantilever on one side of the actuator; one end of the optical fiber cantilever is fixed on the actuator, and the other end extends away from the actuator.

[0011] As a further improvement of the present application, the first focusing member is an optical fiber cantilever end cap formed at the extension end of the optical fiber cantilever; and the optical fiber cantilever end cap has a first beam numerical aperture.

[0012] As a further improvement of the present application, the second focusing member is a focusing lens provided at the end of the body, and the spacing between the focusing lens and the first focusing member is adjusted so that the first beam numerical aperture of the first focusing member is greater than the second beam numerical aperture of the second focusing member.

[0013] As a further improvement of the present application, the second focusing member further comprises a reflecting member provided on the side of the focusing lens away from the ablation optical fiber to change the transmission direction of the optical pulses.

[0014] As a further improvement of the present application, the ablation system further comprises an imaging device for acquiring real-time images of the region of interest, guiding the ablation device to move to the region of interest.

[0015] As a further improvement of the present application, the ablation system further comprises a coupling device for coupling the imaging beam of the imaging device and the light pulse of the ablation device, and coupling into the ablation fiber in the ablation device.

[0016] As a further improvement of the present application, the driving device comprises a signal generator, a voltage amplifier, or other devices capable of signal generation and amplification.

[0017] To achieve the above-mentioned purposes, the present application further provides an ablation device, comprising: a body; an ablation fiber configured to transmit laser, and the ablation fiber is a hollow core fiber; a two-stage focusing assembly configured to focus the laser transmitted through the ablation fiber in two stages; comprising a first focusing member arranged at the end of the ablation fiber and a second focusing member arranged at the end of the body; an actuator configured to drive the ablation fiber to perform high-frequency vibration scanning; The ablation fiber, the two-stage focusing assembly and the actuator are arranged along the extension center line of the body.

[0018] The present application has the following advantages: By setting the ablation device with a two-stage focusing assembly, the light pulse can be effectively focused; and by selecting a hollow core fiber as the ablation fiber, the distortion can be effectively reduced; in combination with the driving device driving the vibration displacement to expand the ablation area, and having the advantages of effectively suppressing the nonlinear effect in the transmission of ultrafast laser pulse, realizing the miniaturization of the catheter, expanding the ablation field of view, improving the ablation efficiency and depth. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 is a structural schematic diagram of the ablation system of the present application.

[0020] Figure 2 is Figure 1 a structural schematic diagram of the ablation device.

[0021] Figure 3 is Figure 1 a structural schematic diagram of another embodiment of the ablation device. DETAILED DESCRIPTION

[0022] Embodiments of the present application are described in detail below with reference to the attached drawing figures, wherein the same or like component have the same or similar designations. The embodiments described below are exemplary in nature, and are intended to be illustrative of the present application rather than to limit the same.

[0023] In the description of the present application, it is to be understood that the terms "first", "second", "third" and the like, merely mean different instances and do not imply a relative importance or a specific order of precedence. Thus, a feature specified as "first", "second", "third" can include one or more of the features implicitly or explicitly. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly specified otherwise.

[0024] In the conventional existing intravascular ultrafast laser ablation technology, due to the pulse width of the ultrafast laser being in the femtosecond to picosecond order, the pulse is easily affected by nonlinear effects in the process of fiber transmission, resulting in pulse distortion, so that the high peak power density characteristics cannot be maintained; at the same time, the existing focusing structure needs to set additional optical elements in the front end of the light beam, which increases the outer diameter size of the catheter, making it difficult to pass through the narrow blood vessel lumen, and the ablation field is limited, which cannot cover the circumferential area of the outer diameter of the catheter, resulting in insufficient ablation depth, and the catheter cannot be advanced for ablation. Among them, pulse distortion will weaken the ability of ultrafast laser to ablate calcified tissue through plasma-mediated photoionization mechanism, and the excessive size of the catheter and the small field of view directly limit its applicability in severe calcified lesions, especially when facing blood vessels with significantly reduced lumen area, it cannot meet the clinical demand for miniaturization and high-efficiency ablation.

[0025] For example, when dealing with chronic total occlusion lesions of coronary artery, the lumen is narrow due to moderate to severe calcification, and the guide wire is difficult to pass through the occluded segment, so it needs to rely on the forward ablation of the catheter to establish a channel. However, the existing ultrafast laser ablation catheter cannot enter the narrow area due to its large size, and its ablation field can only cover part of the plaque, and cannot form a continuous channel for the catheter to advance; further, the pulse distortion caused by nonlinear effects makes the peak power density at the focal point lower than the tissue ablation threshold, so it cannot effectively ablate the severely calcified tissue. Therefore, the surgical process is forced to be interrupted, and the lesion treatment cannot be completed.

[0026] If the above problems are not solved, it will lead to the fact that the ultrafast laser cannot be effectively applied to the intravascular ablation of severe calcified lesions, which limits its popularization and use in clinical practice, increases the risk of surgical failure and the incidence of patient complications; specifically, the limitations of catheter size and field of view will hinder its delivery and operation in narrow lumens, and pulse distortion will directly reduce the ablation effectiveness of calcified plaques, making it difficult for the technology to replace existing mechanical resection or shock wave lithotripsy methods.

[0027] Referring to Figure 1 As shown in the accompanying drawings, the present application provides an ablation system 100, comprising: A laser emitting device 1 for generating optical pulses with a pulse width less than 100 ps; An ablation device 2 for delivering the optical pulses generated by the laser emitting device 1 and acting on the region of interest; wherein the ablation device 2 comprises a two-stage focusing assembly 21 configured to perform two-stage focusing on the delivered optical pulses; a first focusing member 211 disposed at the end of an ablation optical fiber 22 and a second focusing member 212 disposed at the end of a body 23; and A driving device 3 drivingly connected with the ablation device 2 to drive the ablation device 2 to perform vibrational displacement.

[0028] In the present application, the laser emitting device 1 is a device capable of generating laser pulses, the core of which is to output a light beam with a specific pulse width and energy to meet the subsequent ablation requirements.

[0029] Further, the laser emitting device 1 is capable of outputting optical pulses with a pulse width less than 100 ps; wherein the optical pulses with a pulse width less than 100 ps specifically refer to ultrafast laser pulses, which have an extremely short pulse duration, usually in the order of picoseconds (ps) or femtoseconds (fs). Such an extremely short pulse width enables the laser to achieve extremely high peak power density at the focal point, thereby realizing precise ablation of the tissue through nonlinear effects while minimizing thermal damage.

[0030] Referring to Figure 2 and Figure 3 As shown, the ablation device 2 is used to deliver the optical pulses generated by the laser emitting device 1 to the target region and interact with the region of interest to achieve tissue removal. In the present application, the ablation device 2 comprises a two-stage focusing assembly 21, an ablation optical fiber 22, a body 23, and an actuator 24, wherein the ablation optical fiber 22 is configured to transmit optical pulses, in a preferred embodiment of the present application, the ablation optical fiber 22 is a hollow-core optical fiber; the actuator 24 is configured to drive the ablation optical fiber 22 to perform high-frequency vibrational scanning, and the actuator 24 is drivingly connected with the driving device 3; the ablation optical fiber 22, the two-stage focusing assembly 21, and the actuator 24 are arranged along the extension centerline of the body 23.

[0031] Further, the body 23 is an external support structure or housing of the ablation device 2, which provides mechanical protection and positioning for the internal components; the body 23 can be made of biocompatible materials, such as medical-grade polymers (e.g., polyurethane, polyimide) or metal alloys (e.g., nickel-titanium alloy), to ensure its safety and stability for in vivo use. Of course, the body 23 can also be designed as a flexible or semi-rigid tubular structure to facilitate delivery and operation in narrow cavities such as blood vessels, while maintaining sufficient support strength.

[0032] The ablation fiber 22 is a core component for transmitting the light pulses generated by the laser emitting device 1. Preferably, the ablation fiber 22 is a hollow core fiber; wherein the hollow core fiber can adopt a photonic crystal fiber (PCF) structure, which restricts the transmission of light in the core through a periodic air hole array, effectively suppressing nonlinear effects and dispersion. The hollow core fiber can also be a hollow waveguide with a specific inner wall coating that can guide the transmission of light pulses therein while reducing energy loss and pulse distortion.

[0033] The ablation fiber 22 extends through the actuator 24 to form a fiber cantilever 221 on one side of the actuator 24; one end of the fiber cantilever 221 is fixed on the actuator 24, and the other end extends away from the actuator.

[0034] Wherein, the ablation fiber 22 extending through the actuator 24 means that the ablation fiber 22 passes through the inside of the actuator 24 or through the central hole of the actuator 24. Its role is to ensure that the actuator 24 can directly and effectively exert driving force on the ablation fiber 22, thereby achieving high-frequency vibration scanning. This direct driving method avoids energy loss and vibration attenuation that may be caused by indirect connection, ensuring driving efficiency. At the same time, the ablation fiber 22 extends away from the actuator 24 on the other side of the actuator 24 to form a free fiber cantilever 221; so that the end of the ablation fiber 22 has greater activity space and vibration freedom.

[0035] The two-stage focusing assembly 21 is configured to perform two-stage focusing on the transmitted light pulses; including a first focusing member 211 arranged at the end of the ablation fiber 22 and a second focusing member 212 arranged at the end of the body 23. In this application, the first focusing member 211 is a fiber cantilever end cap formed at the extended end of the fiber cantilever 221; and the fiber cantilever end cap has a first beam numerical aperture.

[0036] In this application, the fiber cantilever end cap is an optical element integrated at the end of the ablation fiber 22 for realizing beam focusing or shaping, which helps to maintain the miniaturized design of the catheter; it can be formed, for example, by fusing a certain length of coreless fiber at the end face of the hollow core fiber, and then firing a ball lens at the head end of the coreless fiber; or, one or several of a ball lens, a GRIN lens, a 3D printed lens, a superlens, etc. can also be used as a fiber type focusing element. In addition, a diffractive optical element or a microlens array can also be formed directly on the fiber end face through micro-nano processing technology, or a thin film structure with focusing function can be grown on the fiber end by chemical vapor deposition (CVD) or atomic layer deposition (ALD) technology.

[0037] The fiber cantilever end cap has a first beam numerical aperture, which describes the size of the light fiber or optical element collecting or emitting light ray angle, directly affects the focusing characteristics and divergence angle of the light beam. By accurately setting the first beam numerical aperture, the focusing characteristics of the light beam can be optimized to ensure high-precision focusing of the light pulse, thereby expanding the ablation field. The first beam numerical aperture can be achieved by selecting optical elements such as ball lenses, GRIN lenses, etc. with different parameters; or, it can also be obtained by lengthening the length of the coreless fiber in the hollow core fiber end cap and / or reducing the diameter of the ball mirror; it can also be controlled by adjusting the geometric shape, material refractive index or optical design parameters of the end cap.

[0038] The second focusing member 212 is arranged at the end of the body 23. By adjusting the distance between the second focusing member 212 and the first focusing member 211, the first beam numerical aperture of the first focusing member 211 is greater than the second beam numerical aperture of the second focusing member 212, so as to expand the ablation field.

[0039] In the present application, the second focusing member 212 is a focusing lens arranged at the end of the body 23. The focusing lens is an optical element, whose main function is to converge or diverge light, thereby changing the propagation characteristics of the light beam and realizing the focusing of the light beam.

[0040] Further, the focusing lens serves as the second stage of the two-stage focusing assembly 21, and is used for further fine focusing of the light pulse transmitted by the first focusing member 211. The focusing lens can be implemented in various forms, for example, it can be a convex lens, such as a double-convex lens or a plano-convex lens, which realizes the convergence of light through its curved surface; it can also be a gradient refractive index (GRIN) lens, whose refractive index is distributed in a gradient along the radial direction, thereby realizing the continuous bending and focusing of light inside the lens; it can also be a compound lens, which is composed of multiple lenses of different types to optimize the focusing performance and correct aberrations; or it can be an ultralens, which realizes precise regulation of the light wave front through nanostructures; the focusing lens is arranged at the end of the body 23, and this position selection is helpful to realize effective two-stage focusing in the limited space of the ablation catheter 2.

[0041] In the present application, the first beam numerical aperture of the first focusing member 211 is greater than the second beam numerical aperture of the second focusing member 212, which is achieved by adjusting the distance between the second focusing member 212 and the first focusing member 211. Further, the distance adjustment refers to changing the axial distance of the second focusing member (focusing lens) 212 relative to the first focusing member 211. By design or adjustment, the light beam emitted from the second focusing member 212 has a relatively small numerical aperture. This relationship allows the second focusing member 212 to more effectively reshape and expand the field of view of the light beam from the first focusing member 211.

[0042] In a preferred embodiment of the present application, the end of the body 23 can be embedded with a gradient refractive index (GRIN) lens as the second focusing member 212. The GRIN lens can be selected in a size of 1.0 mm or 1.8 mm to meet the miniaturization requirement of the catheter; the first focusing member 211 can be a ball lens fused on the end of the hollow core optical fiber cantilever 221, or directly formed by the end face of the hollow core optical fiber. During assembly, the axial distance between the GRIN lens and the first focusing member 211 (e.g. ball lens) can be adjusted by a micro screw adjustment mechanism or a set of precision shims to adjust the numerical aperture of the second light beam output by the second focusing member 212. In this way, when the actuator 24 drives the optical fiber cantilever 221 to perform high-frequency vibration scanning, the scanning light beam output by the first focusing member 211 is subjected to secondary focusing by the GRIN lens, and the final scanning amplitude will be effectively amplified, thereby expanding the ablation field.

[0043] In a preferred embodiment of the present application, the second focusing member 212 of the present application further includes a reflecting member 2121 arranged on the side of the focusing lens away from the ablation optical fiber 22 to change the transmission direction of the light pulse.

[0044] The reflecting member 2121 is an optical element for changing the transmission direction of the light pulse. It can be implemented in various forms, for example, it can be a micro mirror with a high-reflectivity film layer on its surface to ensure effective reflection of the light pulse energy; or it can also be a micro prism that changes the light path direction by using the principle of total internal reflection. The reflecting member 2121 plays a key role in the ablation system, as it enables the light pulse to be diverted from the original axial emission direction to the lateral direction, thereby expanding the ablation range. The reflecting member 2121 is designed in such a way as to ensure that the light pulse has completed the expected focusing process through the focusing lens before being reflected. Specifically, the reflecting member 2121 can be fixed with the focusing lens by optical adhesive bonding, or precisely installed by micro mechanical structure to ensure its position and angle accuracy. In addition, the reflecting surface can also be directly integrated on the base of the focusing lens through an integrated manufacturing process to form a composite optical element. This design of positional relationship ensures that the light pulse can be effectively guided to the lateral direction after focusing without interfering with the focusing effect. Changing the transmission direction of the light pulse means that the light pulse originally propagating along the axis of the ablation device is deviated from the axis by the reflecting member 2121, for example, to the lateral direction perpendicular to the axis or at a certain angle. This function enables the ablation system to effectively act on the lesion area located on the side of the blood vessel wall. The main implementation is to utilize the optical reflection characteristics of the reflecting member 2121, for example, by tilting the reflecting surface of the reflecting member 2121 to make the incident light pulse exit at a preset angle after reflection.

[0045] Further, by adding the reflecting member 2121 in the second focusing member 212, the ablation device 2 can further change the transmission direction of the light pulse after focusing. Specifically, the light pulse generated by the laser emitting device 1 is first transmitted through the ablation optical fiber 22, and then preliminarily focused by the first focusing member 211 arranged at the end of the ablation optical fiber 22. Then, the light pulse enters the second focusing member 212 arranged at the end of the body 23, where the focusing lens further finely focuses the light pulse to achieve the required peak power density. After that, the light pulse is incident on the reflecting member 2121 arranged on the side of the focusing lens away from the ablation optical fiber 22. The reflecting member 2121 reflects the focused light pulse from the original axial emission direction to the lateral direction according to its design angle and optical characteristics. This combination of structures enables the light pulse to change direction flexibly while maintaining high focusing, thereby expanding the ablation area from the front to the side. In this way, the ablation device 2 can not only ablate the lesion in the front direction, but also effectively treat the calcified plaque on the side of the blood vessel wall, greatly widening the application range and treatment capacity of the ablation system.

[0046] Specifically, the laser emitting device 1 generates light pulses with a pulse width less than 100 ps, which are transmitted via the hollow-core ablation fiber 22 in the ablation device 2, effectively suppressing nonlinear effects. When the actuator 24 drives the ablation fiber 22 to perform high-frequency vibration scanning, the formed fiber cantilever 221 also vibrates. At this time, the fiber cantilever end cap directly integrated at the extended end of the fiber cantilever 221 acts as the first focusing member 211, which preliminarily focuses the transmitted light pulses and outputs them with a specific first beam numerical aperture. This direct integration avoids the need for an additional bulky optical element at the fiber end, significantly reducing the overall size of the ablation device 2, making it more suitable for narrow cavities. At the same time, the first beam numerical aperture provided by the fiber cantilever end cap cooperates with the second focusing member 212 arranged at the end of the body to form a two-stage focusing assembly, ensuring that the light pulses can form a high-energy density focal point in the region of interest after two-stage focusing, achieving precise ablation. The vibration of the fiber cantilever 221 drives the end cap to vibrate, allowing the preliminarily focused light beam to scan, providing a scanning range for the subsequent second-stage focusing, and further expanding the ablation field of view.

[0047] When the actuator 24 vibrates under high-frequency driving, the root of the fiber cantilever 221 fixed on the actuator 24 also vibrates, and the free end extending away from the actuator 24 can produce a significantly increased amplitude. When the actuator 24 drives the fiber cantilever 221 to perform high-frequency vibration scanning, the first focusing member 211 at the end of the fiber cantilever 221 also performs a large amplitude scanning. Subsequently, the light pulses passing through the first focusing member 211 are further focused and shaped by the second focusing member 212. In this way, the large amplitude vibration of the fiber cantilever 221 is effectively converted into an expanded light beam scanning range, significantly improving the scanning efficiency and ablation field of view of the ablation device 2.

[0048] In this application, the actuator 24 can adopt a piezoelectric ceramic actuator, which generates deformation by applying voltage, thereby driving the ablation fiber 22 to perform high-frequency vibration; and such an actuator 24 has the characteristics of fast response speed and high displacement precision. Further, the actuator 24 can also adopt an electrostatic actuator or an electromagnetic actuator, which drives the ablation fiber 22 to perform scanning motion through electrostatic force or electromagnetic force, achieving precise control of the light beam.

[0049] In the present application, the ablation fiber 22, the two-stage focusing assembly 21 and the actuator 24 are arranged along the extension center line of the body 23, realizing the compactness and high efficiency of the ablation device 2. Specifically, the light pulses generated by the laser emitting device 1 are first transmitted by the ablation fiber 22; and by being arranged at the extension end of the ablation fiber 22 and the actuator 24 is drivingly connected with the driving device 3, receives the control signal emitted by the driving device 3 and converts it into mechanical vibration, thereby driving the ablation fiber 22 to perform high-frequency vibration scanning. This scanning motion makes the light pulses form a scanning pattern in the action area, effectively expanding the action range of the laser and solving the problem of limited field of view of a single fixed focus. Subsequently, the scanned light pulses enter the two-stage focusing assembly 21, which further focuses the light pulses to ensure that the laser energy reaches the required ablation threshold in the target area. The ablation fiber 22, the two-stage focusing assembly 21 and the actuator 24 are arranged along the extension center line of the body 23. This central alignment structure design not only minimizes the cross-sectional area of the ablation device 2, making it able to smoothly pass through the narrow blood vessel lumen, but also ensures the accurate alignment of the optical path and the mechanical scanning axis, avoiding the problems of beam deviation or uneven scanning, thereby ensuring the precision and efficiency of ablation. Overall, this scheme optimizes the structure and arrangement of internal components, enabling the ablation device 2 to maintain the advantages of ultrafast laser ablation while having the capabilities of miniaturization and wide-field scanning, greatly improving its applicability and effectiveness in interventional therapy.

[0050] The driving device 3 is drivingly connected with the ablation device 2 to drive the ablation device 2 to perform vibration displacement. For example, a micro piezoelectric actuator is connected with the distal structure of the ablation device 2. When the piezoelectric actuator receives a driving signal, it will produce high-frequency vibration, thereby driving the distal end of the ablation device 2, including the ablation fiber 22 and the focusing member 21, to perform two-dimensional scanning motion. This vibration displacement enables the laser focus to move quickly within the region of interest, forming a scanning pattern and thereby expanding the coverage range of a single ablation, realizing uniform ablation of larger area calcified plaques. Preferably, the driving device 3 includes a signal generator, a voltage amplifier, or other devices that can realize signal generation and amplification functions.

[0051] The driving device 3 of the present application forms a complete signal chain by integrating a signal generator, a voltage amplifier or other devices with similar functions, to accurately control the vibration displacement of the ablation device 2. Specifically, the signal generator is responsible for generating the original electrical signals used to drive the ablation device 2 to perform high-frequency vibration scanning. These signals can be of a specific frequency and waveform, such as a modulated signal used to achieve a spiral or point cloud scanning pattern. Since the actuator 24 in the ablation device 2 usually requires a relatively high driving voltage to generate sufficient vibration amplitude, the low-voltage signals generated by the signal generator are input to the voltage amplifier. The voltage amplifier boosts the voltage amplitude of these signals to the operating range required by the actuator 24, ensuring that the actuator 24 can respond efficiently and produce the expected mechanical vibration. In this way, the driving device 3 can provide stable and controllable electrical signals, enabling the ablation device 2 connected to the driving device 3 to achieve precise and high-frequency vibration displacement. This precise signal generation and amplification mechanism enables the ablation device 2 to perform effective scanning, thereby expanding the ablation field and ensuring uniformity of ablation, solving the problem of limited scanning accuracy and efficiency caused by insufficient control of driving signals in traditional solutions.

[0052] As a specific implementation, the driving device 3 can include a digital signal generator and a high-voltage linear amplifier. The digital signal generator can be based on a microcontroller or a dedicated digital signal processor, generating two or more phase-adjustable and frequency-controllable sine wave signals through internal programming. The frequency of these signals can be set near the resonant frequency of the actuator 24 in the ablation device 2 to achieve efficient driving. These digital signals are converted to analog voltage signals by internal or external digital-to-analog converters. Subsequently, these analog voltage signals are input to one or more high-voltage linear amplifiers. The high-voltage linear amplifier amplifies the input low-voltage analog signals to a voltage range of tens of volts or even hundreds of volts to meet the driving voltage requirements of the piezoelectric actuator in the ablation device 2. The amplified high-voltage signals are connected to the electrodes of the actuator 24 through wires, driving the actuator 24 to produce precise mechanical vibrations, which in turn drive the ablation device 2 to perform the preset vibration displacement.

[0053] Further, the ablation system further comprises an imaging device 4 for acquiring real-time images of the region of interest, guiding the ablation device 2 to move to the region of interest.

[0054] In particular, the imaging device 4 is a device capable of capturing and processing information of a target region, which functions to provide visual or physical state data about the region of interest. Possible implementations include but are not limited to: imaging devices based on optical principles, such as endoscopic systems, which acquire images through optical fibers or miniature cameras; or imaging devices based on acoustic principles, such as ultrasound probes, which form images through sound wave reflections. In addition, it can also be other imaging methods based on electromagnetic waves, such as X-ray imaging devices. The acquisition of real-time images of the region of interest means that the imaging device 4 can continuously or at high frequency capture image data of the target region and update in time.

[0055] The present application introduces an imaging device 4 into the ablation system, which enables real-time visualization of the entire ablation process. Specifically, the laser emitting device 1 generates optical pulses with a pulse width less than 100 ps, which are delivered and act on the region of interest by the ablation device 2, which includes a two-stage focusing assembly 21 that focuses the optical pulses in two stages and vibrates the ablation device 2 to expand the ablation range through the driving device. On this basis, the imaging device 4 continuously acquires real-time images of the region of interest, which are transmitted to a display device or a processing unit. The operator or the system can clearly identify the position, boundary and state of the target region by analyzing these real-time images. Based on this visual information, the system or the operator can accurately control the driving device to guide the movement of the ablation device 2 so that the focused spot accurately targets or covers the region of interest. This real-time feedback and guidance mechanism makes the ablation process no longer blind, but targeted and controlled, thereby significantly improving the precision and safety of ablation. Given that the ablation system itself has efficient and precise ultrafast laser ablation capabilities, the introduction of the imaging device 4 further enables real-time positioning and guidance, which enables the ultrafast laser ablation technology to overcome the deficiencies of traditional methods in positioning accuracy and operation efficiency, especially when dealing with complex and narrow intravascular lesions, it can ensure that the ablation spot accurately acts on the calcified plaque and avoid unnecessary damage to the surrounding healthy tissue.

[0056] As a specific embodiment, the imaging device 4 can be an optical coherence tomography (OCT) system. The OCT system can emit a low-coherence light beam and transmit it to the region of interest through an optical fiber. The reflected light beam is collected and processed to generate cross-sectional images of the region of interest in real time. These real-time OCT images are displayed on a monitor for the operator, who can clearly see the location and shape of the calcified plaque in the blood vessel. According to the real-time images on the monitor, the operator can adjust the position and direction of the ablation device 2 by manipulating the control handle or joystick connected to the driving device. For example, when the OCT images show that the focal point of the ablation device 2 is offset from the calcified plaque, the operator can immediately adjust the driving device to move the ablation device 2 until its focal point is precisely aligned with the calcified plaque. This real-time guidance of human-computer interaction ensures the accuracy and controllability of the ablation process.

[0057] Further, the ablation system also includes a coupling device 5, which in this application is an optical element or system that mainly functions to combine light beams from different light sources or with different characteristics into the same optical path. Its implementation can include but is not limited to: using a dichroic mirror that can selectively reflect or transmit light beams according to the wavelength of light, for example, designing the imaging light beam and the ablation light pulse in different wavelength ranges, and using the dichroic mirror to achieve beam combination; or using a fiber coupler to combine the optical signals in multiple optical fibers into one output optical fiber.

[0058] This application introduces a coupling device 5 to combine the imaging light beam generated by the imaging device 4 with the ablation light pulse generated by the laser emission device 1. Specifically, the imaging device is used to obtain real-time images of the region of interest, and the imaging light beam emitted carries information for diagnosis and guidance. At the same time, the laser emission device 1 generates ultrafast light pulses with a pulse width less than 100 ps for precise ablation of the region of interest. The coupling device 5, as a key link, precisely aligns and combines the two light beams with different functions in space into a single optical path. Subsequently, the combined light is efficiently coupled into the ablation optical fiber 22 in the ablation device 2, so that the ablation operation under imaging guidance can be realized in a highly integrated and miniaturized system. The imaging light beam provides real-time images of the lesion area before or during ablation, guiding the ablation device 2 to move precisely to the target position; while the ablation light pulse, under the precise guidance of imaging, efficiently and low-heat-damage ablates the lesion tissue. This design of sharing the optical path avoids the problems of system complexity, increased volume, and reduced coupling efficiency caused by the separation of imaging and ablation light paths in traditional schemes, ensuring accurate transmission and efficient use of light beams in narrow cavities, greatly improving the precision and convenience of interventional therapy.

[0059] As a specific embodiment, a dichroic mirror can be used as the coupling device 5. For example, the imaging device 4 can be an optical coherence tomography (OCT) system, which emits an imaging beam with a wavelength of 1300 nm. The laser emitting device 1 generates ultrafast laser pulses with a wavelength of 1030 nm. A dichroic mirror is placed in the transmission path of the imaging beam and the ablation light pulses, which is designed to efficiently reflect the 1030 nm laser pulses while efficiently transmitting the 1300 nm imaging beam. By precisely adjusting the position and angle of the dichroic mirror, the two beams of light can be combined into a coaxial beam. Subsequently, this combined beam of light is focused and introduced into the core of the hollow-core ablation fiber 22 in the ablation device 2 through a coupling lens system, such as an aspherical lens or a GRIN lens. At the distal end of the ablation fiber 22, the light beam is focused by two stages of focusing components 211 and 212 and acts on the region of interest. At the same time, the imaging beam reflected from the region of interest returns along the same optical path, passes through the dichroic mirror again, and is reflected into the detector of the OCT system, thereby achieving real-time imaging.

[0060] Through the above technical solution, the imaging beam of the imaging device 4 and the light pulses of the ablation device 2 are combined and coupled into the ablation fiber 22 in the ablation device through the coupling device 5, effectively solving the problems of complex system structure, increased volume, and reduced coupling efficiency caused by independent transmission of the imaging beam and the ablation light pulses.

[0061] The above technical solution will be further described through a more specific example as follows: Suppose in an interventional therapy, it is necessary to accurately ablate the calcified plaque in the blood vessels of a patient. The traditional and existing ablation method may face problems such as difficulty in passing through narrow blood vessels due to the large size of the catheter, low efficiency due to limited ablation field of view, and distortion of ultrafast laser pulses during transmission. To this end, the present application proposes an ablation system to solve these technical challenges. Subsequently, these ultrafast light pulses are introduced into the ablation device 2.

[0062] The ablation device 2 is designed as a microcatheter that can reach the region of interest, i.e., the location of the calcified plaque, through the blood vessel system. During the transmission of the light pulses, the two-stage focusing assembly 21 inside the ablation device 2 plays a key role. The first focusing component 211, such as a micro-ball lens, is precisely set at the output end of the ablation fiber 22. When the light pulses exit from the ablation fiber 22, the ball lens performs preliminary convergence on them, causing the numerical aperture of the light beam to be preliminarily expanded.

[0063] Subsequently, the light pulse preliminarily converged by the first focusing member 211 continues to transmit forward and encounters the second focusing member 212 arranged at the end of the body 23. The second focusing member 212, for example a micro convex lens, further finely focuses the light pulse. By adjusting the distance between the first focusing member 211 and the second focusing member 212, the size and position of the final focal spot can be accurately controlled, ensuring that the light pulse forms a high enough peak power density on the calcified plaque to achieve effective ablation. This two-stage focusing cascade design not only enables effective focusing of the light beam, but also expands the final ablation field by optimizing the optical path design, thereby improving the ablation efficiency and solving the problem of small ablation field in traditional schemes.

[0064] Meanwhile, the driving device 3 is drivingly connected with the ablation device 2 to drive the ablation device 2 to perform vibrational displacement. For example, a micro piezoelectric actuator is connected with the distal structure of the ablation device 2. When the piezoelectric actuator receives a driving signal, it generates high-frequency vibration, thereby driving the distal end of the ablation device 2, including the ablation optical fiber 22 and the first focusing member 211, to perform two-dimensional scanning motion. This vibrational displacement enables the laser focal point to move quickly within the region of interest, forming a scanning pattern, thereby expanding the coverage of a single ablation and achieving uniform ablation of larger area calcified plaques. This dynamic scanning mechanism effectively solves the problem of limited ablation range in traditional schemes.

[0065] Thus, the ablation system generates ultrafast light pulses by the laser emitting device 1, realizes accurate focusing of the light pulse and expansion of the ablation field by the two-stage focusing assembly 2 in the ablation device 2, and drives the ablation device 2 to perform vibrational displacement by the driving device 3 to achieve large-scale scanning. These technical features cooperate with each other to solve the problems of large catheter size, small ablation field and pulse distortion when using ultrafast laser to ablate calcified plaques in blood vessels, and provide an efficient, accurate and minimally invasive interventional ablation scheme.

[0066] In summary, the laser emitting device 1 used in the present application can generate light pulses with a pulse width of less than 100 ps, which is in sharp contrast to the nanosecond or longer pulse width lasers used in the prior art. The use of such ultrafast laser enables extremely high peak power density to be obtained at the focal point, and precise "cold" ablation of calcified plaques is achieved through the plasma-mediated photoionization mechanism, thereby significantly improving the ablation effectiveness of severe calcified plaques and minimizing the incidental thermal damage to the blood vessel wall.

[0067] In addition, the ablation catheter in the prior art often faces the problem of oversize catheter and limited ablation field when achieving ultrafast laser transmission and focusing. For example, some solutions focus by placing a large volume optical element at the front end of the optical fiber, which makes the catheter difficult to pass through the narrow cavity, and the field of view is small, which limits the ablation efficiency. The ablation device 2 of the present application realizes a compact optical design by introducing a two-stage focusing assembly 21, and setting the first focusing member 211 in the two-stage focusing assembly 21 at the end of the ablation optical fiber 22, and the second focusing member 212 at the end of the body 23. This two-stage focusing structure 21, for example, through the combination of a micro ball lens and a convex lens, effectively reduces the overall size of the catheter while ensuring the focusing effect, and expands the ablation range, thereby improving the applicability and efficiency of interventional therapy.

[0068] Furthermore, in order to expand the ablation range, the prior art usually needs a complex mechanical scanning mechanism. The present application drives the ablation device 2 to perform vibrational displacement through the driving connection of the driving device 3 and the ablation device 2, which realizes the dynamic scanning of the light pulse in the region of interest. For example, by driving the ablation device 2 to perform high-frequency two-dimensional scanning through the piezoelectric actuator 24, the laser focal point can cover a larger area to form a uniform ablation pattern. Compared with the fixed focal point or simple linear scanning that may exist in the prior art, this driving method provides more flexible and efficient ablation coverage capability, further improving the treatment effect on large area calcified plaques.

[0069] In summary, the ablation system of the present application systematically solves the core technical problems of pulse distortion, large catheter size and small ablation field in the prior art of ultrafast laser intravascular ablation by integrating an ultrafast laser source, an innovative two-stage focusing structure 21 and an efficient vibration driving mechanism. This technical solution not only improves the ablation effectiveness and safety of severe calcified plaques, but also makes significant progress in catheter miniaturization and ablation efficiency, providing a highly innovative and practical solution for the field of intravascular interventional therapy.

[0070] The above embodiments are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the present application.

Claims

1. An ablation system, characterized in that, include: A laser emitting device used to generate light pulses with a pulse width of less than 100 ps; An ablation device is used to transmit an optical pulse generated by the laser reflecting device and act on a region of interest; wherein the ablation device includes a two-stage focusing assembly configured to focus the transmitted optical pulse in two stages; including a first focusing member disposed at the end of the ablation fiber and a second focusing member disposed at the end of the body; and The driving device is connected to the ablation device and drives the ablation device to vibrate and move.

2. The ablation system according to claim 1, characterized in that, The ablation device further includes: ontology; The ablation fiber is configured to transmit the optical pulse, and the ablation fiber is a hollow fiber. An actuator is configured to drive the ablation fiber to perform high-frequency vibration scanning, and the actuator is drivenly connected to the driving device. The ablation fiber, the two-stage focusing assembly, and the actuator are all arranged along the extended centerline of the body.

3. The ablation system according to claim 2, characterized in that, The ablation fiber passes through the actuator to extend on one side of the actuator to form a fiber cantilever; one end of the fiber cantilever is fixed to the actuator, and the other end extends away from the actuator.

4. The ablation system according to claim 3, characterized in that, The first focusing member is an optical fiber cantilever end cap formed at the extended end of the optical fiber cantilever; and the optical fiber cantilever end cap has a first beam numerical aperture.

5. The ablation system according to claim 3, characterized in that, The second focusing component is a focusing lens disposed at the end of the main body. The distance between the focusing lens and the first focusing component is adjusted so that the first beam numerical aperture of the first focusing component is greater than the second beam numerical aperture of the second focusing component.

6. The ablation system according to claim 5, characterized in that, The second focusing component further includes a reflective component disposed on the side of the focusing lens away from the ablation fiber, so as to change the transmission direction of the light pulse.

7. The ablation system according to claim 1, characterized in that, The ablation system also includes an imaging device, which is used to acquire real-time images of the region of interest and guide the ablation device to move to the region of interest.

8. The ablation system according to claim 7, characterized in that, The ablation system further includes a coupling device for combining the imaging beam of the imaging device and the optical pulse of the ablation device and coupling them into the ablation fiber in the ablation device.

9. The ablation system according to claim 1, characterized in that, The driving device includes a signal generator, a voltage amplifier, or other devices that can generate and amplify signals.

10. An ablation device, characterized in that, include: ontology; The ablation fiber is configured to transmit laser light, and the ablation fiber is a hollow fiber. A two-stage focusing assembly is configured to focus the laser transmitted via the ablation fiber in two stages. It includes a first focusing component disposed at the end of the ablation fiber and a second focusing component disposed at the end of the body; An actuator is configured to drive the ablation fiber to perform high-frequency vibration scanning; The ablation fiber, the two-stage focusing assembly, and the actuator are all arranged along the extended centerline of the body.

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