An image-guided zonal controllable laser ablation catheter system

Abstract

The application discloses an image-guided partition controllable laser ablation catheter system and a computing device, which comprises a catheter body, a plurality of ablation optical fibers, an ultrasonic detection unit, a multi-channel laser generating unit, an ultrasonic imaging processing unit and a control unit. The plurality of ablation optical fibers are divided into at least two independent optical fiber control areas in the cross section of the catheter body. The ultrasonic detection unit is arranged inside the distal end of the catheter body. The multi-channel laser generating unit is optically coupled with the plurality of ablation optical fibers through a proximal connector. The ultrasonic imaging processing unit is used for receiving echo signals and reconstructing real-time intravascular ultrasound images. The control unit is used for receiving and processing the real-time intravascular ultrasound images, segmenting the boundary profile of a target plaque, determining the distribution range, thickness distribution and position information of the target plaque relative to the distal end of the catheter body, and realizing directional, partition and plastic laser ablation of the target plaque. The application avoids injury to healthy tissues, improves the safety of the operation and ensures the optimization of the ablation effect.

Description

Technical Field

[0001] This invention relates to the field of interventional medical device technology, specifically to an image-guided, zone-controlled laser ablation catheter system and computing device. Background Technology

[0002] Atherosclerosis-induced vascular stenosis is the main pathological basis of cardiovascular disease. While traditional interventional treatments such as balloon angioplasty and stent implantation are widely used, risks of restenosis, thrombosis, and vascular injury remain when dealing with complex lesions (such as severe calcification and bifurcation). Laser ablation technology, due to its non-contact nature and controllable thermal effects, shows great potential in removing plaques and opening blocked blood vessels. However, most laser ablation devices often lack sufficient visual feedback and precise motion control, making the treatment process like "blind men feeling an elephant." Therefore, developing an ablation system capable of real-time imaging, intelligent identification, and precise control of energy output is of paramount clinical significance for improving the success rate of interventional procedures and reducing the incidence of complications.

[0003] Currently, most clinical endovascular ablation devices rely on external X-ray angiography for localization. X-rays can only show the outline of the blood vessel ("lumen"), but cannot clearly show the nature, thickness, and specific distribution of plaque within the vessel wall ("vessel wall"). This makes it difficult for doctors to accurately determine the timing and location of laser emission, easily leading to excessive damage to normal vessel walls or insufficient ablation of deep calcified plaques. Furthermore, because they typically employ a circumferential energy output mode, they cannot adapt to the uneven distribution of plaque within the vessel. For example, when plaques are only distributed on one side of the vessel, circumferential laser emission can unnecessarily damage the healthy intima on the opposite side, increasing the risk of postoperative vasospasm and dissection. Under cardiac and respiratory movements, the catheter's position within the vessel is dynamically changing. Some localization techniques cannot effectively compensate for errors caused by physiological displacement, leading to target point deviation in complex and tortuous vessels, affecting surgical precision.

[0004] To address the aforementioned issues, this invention proposes an image-guided, zone-controlled laser ablation catheter system to avoid accidental damage to healthy tissues, improve surgical safety, and ensure optimal ablation results. Summary of the Invention

[0005] In view of the above problems, the present invention provides an image-guided, zone-controlled laser ablation catheter system and computing device.

[0006] According to one aspect of the present invention, an image-guided, zone-controlled laser ablation catheter system is provided, comprising: The catheter body has an interventional end at its distal end that can reach the target lesion site via a vascular path. A guidewire lumen is provided axially through the catheter body to accommodate the guidewire for guidance. Multiple ablation fibers are distributed around the periphery of the guidewire cavity along the circumference of the catheter body and extend axially to the distal end of the catheter body; the multiple ablation fibers divide the cross-section of the catheter body into at least two independent fiber control regions, each fiber control region contains at least one ablation fiber and each fiber control region independently controls its laser emission state and emission parameters. An ultrasound detection unit, located inside the distal end of the catheter body, includes at least one ultrasound transducer for transmitting an ultrasound beam to the vascular wall tissue and receiving echo signals, so as to acquire intravascular ultrasound image data in real time, including the morphology, location, thickness and spatial relationship of the target plaque with respect to the catheter. The multi-channel laser generating unit is optically coupled to multiple ablation fibers via a near-end connector, and independently outputs modulated laser energy to each fiber control area. An ultrasound imaging processing unit, connected to an ultrasound detection unit, is used to receive echo signals and reconstruct real-time intravascular ultrasound images. The control unit, which is communicatively connected to the ultrasound imaging processing unit and the multi-channel laser generating unit, receives and processes real-time intravascular ultrasound images, segments the boundary contour of the target plaque, and determines the distribution range, thickness distribution, and position of the target plaque relative to the distal end of the catheter body in the circumferential direction of the blood vessel. Based on the spatial distribution characteristics of the target plaque, it spatially matches each fiber control zone on the cross-section of the catheter body with the sector occupied by the target plaque in the circumferential direction of the blood vessel. Based on the local characteristics of the target plaque corresponding to each fiber control zone, it generates laser control parameters for that fiber control zone, including the on / off state, output power, pulse width, and pulse interval of the fiber control zone. It controls the multi-channel laser generating unit to selectively activate one or more fiber control zones that match the spatial position of the target plaque to emit lasers according to the generated laser control parameters, and keeps the fiber control zones that do not correspond to the area of ​​the target plaque or the adjacent non-target tissue area closed or limits their output, so as to achieve directional, zoned, and malleable laser ablation of the target plaque.

[0007] In one alternative embodiment, the ultrasonic detection unit is disposed in the positioning cavity at the distal end of the catheter body and is circumferentially staggered with the ablation fiber, and includes at least one high-frequency array ultrasonic transducer and a signal preprocessing module. The signal preprocessing module is electrically connected to the ultrasonic imaging processing unit via a high-temperature shielded cable. It is used to perform pre-amplification and analog-to-digital conversion on the weak echo signal received by the ultrasonic transducer and output the ultrasonic echo digital signal. After receiving the ultrasound echo digital signal, the ultrasound imaging processing unit reconstructs the signal through a three-dimensional beamforming and sub-pixel interpolation algorithm to generate an intravascular ultrasound three-dimensional image containing the target plaque's three-dimensional spatial coordinate matrix, the vascular wall microstructure feature parameters, and the plaque-vascular wall interface gap data.

[0008] In one alternative approach, the control unit incorporates a multimodal target plaque feature learning database, which is generated by training based on clinical case data and includes laser ablation threshold curves, optimal ablation parameter combinations, and tissue damage risk coefficient matrices corresponding to calcified plaques, fibrous plaques, lipid plaques, and mixed plaques. The control unit communicates bidirectionally with the ultrasound imaging processing unit via a high-speed bus. After segmenting the target patch boundary contour, it extracts multidimensional feature parameters including the target patch ultrasound echo intensity value, gray-level co-occurrence matrix feature parameters, and patch density distribution index. Furthermore, based on the target patch local thickness gradient data and tissue damage risk coefficient corresponding to the fiber optic control area, it dynamically calls the optimal combination of ablation parameters to obtain personalized laser control parameters.

[0009] In one alternative embodiment, the distal end of the catheter body is fitted with a six-axis inertial measurement unit and an electromagnetic positioning and tracking probe; The six-axis inertial measurement unit is used to collect the spatial position coordinates, attitude angle data and displacement acceleration data of the distal end of the catheter body in real time; the electromagnetic positioning and tracking probe is used to calibrate the spatial positioning data of the catheter body to compensate for displacement errors caused by breathing and heartbeat. The control unit calculates the real-time pose deviation and displacement trend between the catheter and the target lesion site based on the precise spatial coordinate information of the target plaque transmitted by the ultrasound imaging processing unit and the calibrated spatial positioning data.

[0010] In one alternative embodiment, the distal end of the catheter body is provided with an electromagnetic positioning sensor and a distributed fiber Bragg grating shape sensor, which are electrically and optically connected to the navigation and positioning unit, respectively. The electromagnetic positioning sensor is used to acquire the position coordinates of the catheter in absolute space, and the fiber Bragg grating sensor is used to reconstruct the bending morphology information of the catheter in real time, so as to eliminate measurement drift and error based on the position coordinates and the bending morphology information. The navigation and positioning unit outputs the six-degree-of-freedom real-time pose of the distal end of the catheter within the blood vessel to the control unit. The control unit pre-aligns the spatial distribution map of the target plaque in the real-time intravascular ultrasound image with the three-dimensional anatomical model of the blood vessel through affine registration. The control unit performs real-time collision detection between the six-degree-of-freedom real-time pose and the three-dimensional anatomical model of the blood vessel, generating a sequence of fiber optic control zones to be activated in chronological order and corresponding laser parameters. During catheter advancement or rotation, the control unit dynamically adjusts the opening and closing timing and output power of each fiber optic control zone according to the sequence of fiber optic control zones and corresponding laser parameters, and automatically pauses ablation and issues a navigation correction prompt when the catheter deviates from its trajectory.

[0011] In an alternative embodiment, the system further includes a closed-loop power adjustment unit. During laser ablation, the control unit receives the dynamic intravascular ultrasound image sequence output by the ultrasound imaging processing unit at fixed time intervals through the closed-loop power adjustment unit and segments the target plaque boundary contour in each frame of the ultrasound image sequence to obtain the residual plaque thickness in the corresponding region of each activated fiber control area. Based on the residual patch thickness of continuous time frames, motion artifacts caused by breathing and heartbeat are filtered out to obtain a denoised attenuation sequence, and the instantaneous ablation rate of the attenuation sequence at the current moment is calculated. The control unit compares the instantaneous ablation rate with the preset desired ablation rate. If the instantaneous ablation rate is less than the desired ablation rate, the real-time output power of the corresponding fiber control area is increased proportionally. If the instantaneous ablation rate is greater than the desired ablation rate, the real-time output power is decreased proportionally, and the power adjustment is fed back to the multi-channel laser generating unit to counteract tissue inhomogeneity and the constant rate ablation effect of blood flow cooling.

[0012] In one optional embodiment, when performing spatial matching between the fiber control area and the target patch sector, the control unit calculates the matching degree between each fiber control area and the target patch sector using a spatial matching degree model; wherein, the expression for the spatial matching degree model is:

[0013] in, The spatial matching degree between the i-th fiber control region and the k-th target patch sector; This is the spatial intersection region between the i-th fiber control region and the k-th target patch sector; The overall spatial region of the k-th target patch sector; , , The influence weights of ultrasonic echo intensity, patch density, and patch thickness are respectively. The echo intensity value at spatial coordinates (x, y, z) in the three-dimensional intravascular ultrasound image; The density distribution index of the target patch at spatial coordinates (x, y, z); The value represents the local thickness of the target patch at spatial coordinates (x, y, z). Let be the spatial position vector of the center of the i-th fiber control zone; Let be the spatial position vector of the center of the k-th target patch sector; This is the spatial position deviation correction coefficient.

[0014] In one alternative approach, the formula for calculating the instantaneous ablation rate by the closed-loop power regulation unit is as follows:

[0015] in, Let be the instantaneous ablation rate at time t; The frame number of the time-series ultrasound images; This refers to the time interval for ultrasound image acquisition. for The thickness of the residual patch in the corresponding area of ​​the time-based fiber optic control zone; The thickness of the residual patch in the fiber-controlled region at time t; For time series weighting factors; This is the thickness attenuation correction factor; The initial thickness of the target plaque.

[0016] In one alternative approach, the formula for calculating the output power is:

[0017] The formula for calculating the pulse width is:

[0018] The formula for calculating the pulse interval is:

[0019] in, The personalized output power for the i-th fiber control zone; The laser ablation threshold power is the target patch type corresponding to the i-th fiber control region. The ultrasonic echo intensity value of the target patch in the region corresponding to the i-th fiber control zone; This represents the average ultrasonic echo intensity of the corresponding region across all fiber optic control zones. The standard deviation of the ultrasonic echo intensity; , , These are the feature weights for ultrasonic echo intensity, patch density, and patch thickness, respectively. The target patch density is the region corresponding to the i-th fiber control area. This represents the average patch density of the corresponding regions across all fiber control areas; The standard deviation of patch density; The target patch thickness corresponds to the region of the i-th fiber control zone; This represents the average patch thickness of the corresponding regions across all fiber control areas. The standard deviation of the patch thickness; The number of factors influencing the risk of tissue damage; Let be the weight coefficient of the j-th damage risk influencing factor; This represents the j-th damage risk coefficient for the region corresponding to the i-th fiber control zone. Let be the pulse width of the i-th fiber control region; The base pulse width; The maximum density of common clinical target plaques; This is the density influence coefficient; This represents the maximum thickness of commonly seen target plaques in clinical practice. This is the thickness influence coefficient; , These represent the maximum and minimum values ​​of the ultrasonic echo intensity, respectively. The pulse interval of the i-th fiber control zone; The basic pulse interval; Echo intensity influence coefficient; Density correction index; The baseline patch density is used.

[0020] According to another aspect of the present invention, a computing device is provided, comprising: a processor, a memory, a communication interface, and a communication bus, wherein the processor, the memory, and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the image-guided partitioned controllable laser ablation catheter system described above.

[0021] According to the solution provided by the present invention, the device includes a catheter body with an interventional end at its distal end that can reach the target lesion site via a vascular pathway. A guidewire lumen is axially disposed within the catheter body to accommodate and guide the guidewire. Multiple ablation fibers are distributed circumferentially around the guidewire lumen and extend axially to the distal end of the catheter body. The multiple ablation fibers are divided into at least two independent fiber control zones on the cross-section of the catheter body. Each fiber control zone contains at least one ablation fiber, and each fiber control zone independently controls its laser emission state and emission parameters. An ultrasound detection unit is disposed inside the distal end of the catheter body and includes at least one ultrasound transducer for emitting an ultrasound beam to the vascular wall tissue and receiving echo signals to acquire intravascular ultrasound image data in real time, including the morphology, location, thickness, and spatial relationship of the target plaque with respect to the catheter. A multi-channel laser generating unit is optically coupled to the multiple ablation fibers through a proximal connector to independently output modulated laser energy to each fiber control zone. An ultrasound imaging processing unit is connected to the ultrasound detection unit for receiving echo signals. The system receives and reconstructs real-time intravascular ultrasound images. A control unit, communicatively connected to both the ultrasound imaging processing unit and the multi-channel laser generator, receives and processes these images, segments the target plaque's boundary contour, and determines its circumferential distribution, thickness distribution, and position relative to the distal end of the catheter. Based on the spatial distribution characteristics of the target plaque, each fiber optic control zone on the catheter's cross-section is spatially matched with the sector occupied by the target plaque in the circumferential direction. Laser control parameters are generated for each fiber optic control zone based on its corresponding local characteristics, including its on / off state, output power, pulse width, and pulse interval. The multi-channel laser generator selectively activates one or more fiber optic control zones matching the spatial position of the target plaque according to the generated laser control parameters, while keeping or limiting the output of fiber optic control zones not corresponding to the target plaque or adjacent non-target tissue areas. This achieves directional, zoned, and malleable laser ablation of the target plaque. This invention avoids accidental damage to healthy tissue, improves surgical safety, and ensures optimal ablation results.

[0022] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0023] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings: Figure 1 A schematic diagram of the image-guided, zone-controlled laser ablation catheter system according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of the closed-loop power regulation and navigation correction assistance according to an embodiment of the present invention is shown; Figure 3 This illustration shows a schematic diagram of an image-guided, zone-controlled laser ablation catheter according to an embodiment of the present invention. Figure 1 ; Figure 4 This illustration shows a schematic diagram of an image-guided, zone-controlled laser ablation catheter according to an embodiment of the present invention. Figure 2 ; Figure 5 A schematic diagram of the frame of the image-guided, partition-controlled laser ablation catheter device according to an embodiment of the present invention is shown; Figure 6 A schematic diagram of the structure of a computing device according to an embodiment of the present invention is shown. Detailed Implementation

[0024] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this invention will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art.

[0025] Figure 1 A schematic flowchart of an image-guided, zone-controlled laser ablation catheter system according to an embodiment of the present invention is shown. Specifically, as... Figure 1 As shown, it includes: The catheter body has an interventional end at its distal end that can reach the target lesion site via a vascular path. A guidewire lumen is provided axially through the catheter body to accommodate the guidewire for guidance. Multiple ablation fibers are distributed around the periphery of the guidewire cavity along the circumference of the catheter body and extend axially to the distal end of the catheter body; the multiple ablation fibers divide the cross-section of the catheter body into at least two independent fiber control regions, each fiber control region contains at least one ablation fiber and each fiber control region independently controls its laser emission state and emission parameters. An ultrasound detection unit, located inside the distal end of the catheter body, includes at least one ultrasound transducer for transmitting an ultrasound beam to the vascular wall tissue and receiving echo signals, so as to acquire intravascular ultrasound image data in real time, including the morphology, location, thickness and spatial relationship of the target plaque with respect to the catheter. The multi-channel laser generating unit is optically coupled to multiple ablation fibers via a near-end connector, and independently outputs modulated laser energy to each fiber control area. An ultrasound imaging processing unit, connected to an ultrasound detection unit, is used to receive echo signals and reconstruct real-time intravascular ultrasound images. The control unit, which is communicatively connected to the ultrasound imaging processing unit and the multi-channel laser generating unit, receives and processes real-time intravascular ultrasound images, segments the boundary contour of the target plaque, and determines the distribution range, thickness distribution, and position of the target plaque relative to the distal end of the catheter body in the circumferential direction of the blood vessel. Based on the spatial distribution characteristics of the target plaque, it spatially matches each fiber control zone on the cross-section of the catheter body with the sector occupied by the target plaque in the circumferential direction of the blood vessel. Based on the local characteristics of the target plaque corresponding to each fiber control zone, it generates laser control parameters for that fiber control zone, including the on / off state, output power, pulse width, and pulse interval of the fiber control zone. It controls the multi-channel laser generating unit to selectively activate one or more fiber control zones that match the spatial position of the target plaque to emit lasers according to the generated laser control parameters, and keeps the fiber control zones that do not correspond to the area of ​​the target plaque or the adjacent non-target tissue area closed or limits their output, so as to achieve directional, zoned, and malleable laser ablation of the target plaque.

[0026] In this embodiment, traditional laser catheters use simultaneous emission from all circumferential fibers to form a ring-shaped ablation zone, which can cause unnecessary thermal damage to the contralateral healthy vessel wall when treating eccentric plaques. By dividing the ablation fibers into at least two independent control zones and combining this with plaque spatial distribution information provided by real-time intravascular ultrasound imaging, only the fiber control zone corresponding to the sector where the target plaque is located is selectively activated, while fibers in areas without plaques or adjacent non-target tissue areas are kept closed or have their output restricted. This achieves true directional ablation, significantly reducing the risks of vascular perforation, dissection, postoperative inflammation, and long-term restenosis. An ultrasound detection unit integrated at the distal end of the catheter acquires the morphology, location, thickness, and relative spatial relationship of the target plaque to the catheter in real time during the procedure. The control unit then segments the plaque boundary contour and spatially matches each fiber control zone with the sector occupied by the plaque in the circumferential direction of the vessel, ensuring that laser energy is precisely projected onto the target tissue and avoiding energy shifts caused by respiration, heartbeat, or catheter displacement. The control unit can independently generate laser control parameters for each fiber control zone based on the local plaque characteristics (such as plaque thickness, density, and composition within the sector). For different circumferential locations on the same catheter cross-section, lasers with different characteristics can be output simultaneously (e.g., high power for thick plaques, low power for thin plaques, and a specific pulse width for calcified areas), achieving sculpted ablation. For complex lesions such as eccentric plaques, irregular plaques, mixed plaques with unevenly distributed calcified nodules, and in-stent restenosis, the ablation range and intensity can be dynamically adjusted according to the actual spatial distribution of the plaque, avoiding damage to the stent structure or normal vessel wall. Simultaneously, because energy acts only on the target area, the total output energy is reduced, thus decreasing the risk of distal embolism.

[0027] Specifically, such as Figure 3 , Figure 4As shown, the catheter body is made of medical-grade thermoplastic polyurethane or polyetheretherketone (PEEK) material, with an outer diameter of approximately 2.0-2.5 mm (suitable for coronary arteries) and a length of approximately 150-180 cm. The distal 5-8 cm section is a flexible, bendable segment, while the proximal section is a push-in segment. A through-hole guidewire lumen 1, with an inner diameter of approximately 0.35-0.42 mm (compatible with 0.014-inch guidewires), is located along the axial center of the catheter body. The guidewire lumen extends the entire length of the catheter, opening distally at the catheter tip and proximally connecting to a standard Luer connector for guidewire insertion and flushing during the procedure. Multiple ablation fibers 2 (4, 6, 8, or 12 fibers can be selected as needed) are evenly or non-uniformly distributed circumferentially around the guidewire lumen. Each fiber is a low-hydroxyl, high numerical aperture silica fiber with a core diameter of approximately 200-300 μm, coated with polyimide or acrylate. The aforementioned ablation fibers are divided into four independent fiber control zones in cross-section, each containing two adjacent fibers. The ablation fibers corresponding to each control zone are converged into a single channel at the proximal end and optically coupled to the corresponding channel of the multi-channel laser generator unit via a connector. A high-frequency ultrasound transducer array is embedded within the circumferential gaps of the ablation fibers at the distal end of the catheter. This array employs a single-element mechanical rotating or ring array ultrasound transducer with an operating frequency of 20-60 MHz (selected according to vessel diameter; 40-45 MHz is commonly used for coronary arteries). The ultrasound transducer is mounted on a rotatable drive shaft at the distal end of the catheter and rotates at a speed of 30-60 revolutions per second via a micro-motor, achieving a 360° scan of the vessel wall. The echo signals received by the ultrasound transducers are pre-amplified and digitized by a signal preprocessing module integrated within the catheter (including a low-noise amplifier, bandpass filter, and analog-to-digital converter), and then transmitted to the external ultrasound imaging processing unit via a high-temperature shielded micro-coaxial cable. The external component is equipped with a multi-channel laser generating unit, typically using a xenon chloride excimer laser with an output wavelength of 308nm (ultraviolet band, shallow penetration depth, and minimal thermal damage). This laser is equipped with four independent optical channels, each with independently adjustable output power (0-80mJ / mm²). 2Adjustable pulse frequency (25-80Hz) and pulse width (50-200ns). The ultrasound imaging processing unit receives the digital echo signal from the distal end of the catheter, dynamically focuses and delays the raw radiofrequency data obtained from multi-channel or rotational scanning to form polar coordinate data of the B-mode image. Subpixel interpolation algorithms (such as bicubic interpolation or spline interpolation) are used to convert the polar coordinate data into a high-resolution cross-sectional image in Cartesian coordinates. By using a catheter retraction device (retracting at a uniform speed of 0.5-1mm / s), a sequence of ultrasound images of multiple consecutive cross-sections is acquired and spatially stacked using a known retraction distance to form a three-dimensional intravascular ultrasound image, including the spatial coordinate matrix of the target plaque, the ultrasound echo intensity value of each coordinate point, and the relative distance information between the plaque and the catheter. The control unit, an embedded industrial computer or medical workstation, is pre-trained on a labeled clinical ultrasound image dataset. The segmentation results include the inner edge (near the lumen) and outer edge (near the medial side) of the plaque, and calculate the circumferential distribution range of the plaque (starting and ending angles) and the plaque thickness at each angle. Based on the segmented circumferential distribution range of the plaque, four fiber optic control zones (each covering approximately 90° of a sector) on the catheter cross-section are matched with the sectors occupied by the plaque. For example, if the plaque is located within the circumferential range of 90°-240°, the matching results are: control zone 2 (90°-180°) and control zone 3 (180°-270°) are "active zones," and control zone 1 (0°-90°) and control zone 4 (270°-360°) are "closed zones." Simultaneously, for the active zones, local features such as the average plaque thickness and average ultrasound echo intensity (reflecting the degree of calcification) within the sector covered by each control zone are further calculated. Based on the local patch characteristics corresponding to each activated control region, the laser parameters for that control region are generated by looking up a table or applying an empirical formula. For example, if the patch thickness corresponding to a certain control region is relatively thick (>1.5mm), the output power is set to a higher level (e.g., 60mJ / mm). 2If the plaque has high echo intensity (indicating calcification), the pulse width is increased to improve ablation efficiency; if the plaque is thin (<0.5mm), the power is reduced and the pulse width is shortened to avoid damaging the vascular media. For the closed area, a "close" command is output, and the corresponding laser channel does not emit energy. The generated parameters such as the opening and closing status, power, pulse width, and interval of each control area are packaged and sent to the multi-channel laser generation unit through a serial communication interface or fiber optic communication link. After receiving the command, the laser generation unit executes the command in the next ablation cycle. The specific working process includes: preoperative ultrasound calibration in vitro (using a standard water bath and reflective target). Under the guidance of the guidewire, the catheter is pushed to the proximal end of the target lesion site via the radial or femoral artery. During this period, low-power ultrasound imaging mode can be activated to assist navigation. After reaching the target lesion, the ultrasound detection unit is activated to perform a 360° scan. The control unit reconstructs the intravascular ultrasound image in real time, automatically segments the plaque boundary contour, and displays the circumferential distribution, thickness, and degree of calcification of the plaque in a color-coded manner on the display screen. The doctor can manually review and fine-tune the segmentation results. The system automatically matches the fiber optic control zone with the plaque sector, generating laser parameters for each control zone. The physician can view the matching results on the interface (e.g., a circular sector diagram showing which control zones will be activated and their respective power settings), and can manually adjust them if necessary (e.g., forcibly shutting down a control zone that might be close to a branch vessel). The physician presses the foot pedal or clicks the "Ablation" button on the screen, and the control unit triggers the multi-channel laser generator according to preset parameters, activating the selected fiber optic control zone to emit laser light. During ablation, ultrasound imaging continues, and the control unit updates the plaque thickness changes in real time. Each ablation session typically lasts 1-5 seconds, followed by a pause of several seconds to observe the effect and allow blood flow to flush away debris. After the pause, the control unit re-segments the residual plaque and compares the ablation thickness with the pre-ablation image. If the residual plaque thickness is still greater than the target threshold (e.g., 0.2 mm), the parameters are automatically adjusted (or confirmed by the physician) for the next round of ablation until a satisfactory result is achieved. After ablation, the catheter is retracted into the guiding catheter and removed from the body along with the guidewire.

[0028] For example, a 68-year-old male was admitted to the hospital with unstable angina. Coronary angiography showed approximately 70% stenosis in the mid-segment of the right coronary artery, presenting as an eccentric lesion. Further intravascular ultrasound (pre- or intra-operative) confirmed that the target plaque was located within the circumferential range of 90° to 210° of the vessel cross-section (with the vessel center as the origin and 0° as the reference direction), with a maximum thickness of approximately 1.8 mm. Hyperechoic calcified nodules were visible within the plaque (indicating calcification), while the vessel wall on the opposite side (210° to 360° and 0° to 90°) was nearly normal fibrous tissue, with a thickness of only about 0.2-0.3 mm. If a traditional circumferential laser ablation catheter is used, all fibers emit simultaneously. While ablating the target plaque area in the 90°-210° range, it can also cause thermal damage to the healthy vessel wall in the 210°-360° and 0°-90° ranges, potentially leading to vascular dissection, delayed perforation, or excessive inflammatory response. In this embodiment, an 8-fiber, 4-control zone laser ablation catheter is advanced along the guidewire to the lesion site. The ultrasound detection unit is activated, acquiring cross-sectional ultrasound images in real time. The control unit segments the plaque boundary, determining the plaque's location within the 90°-210° range. Eight optical fibers are grouped into four control zones, each covering 90°: Control Zone 1 (315°-45°, spanning 0°), Control Zone 2 (45°-135°), Control Zone 3 (135°-225°), and Control Zone 4 (225°-315°). Control Zone 2 (45°-135°) overlaps with the plaque within the 90°-135° range, showing partial overlap and is marked as active. Control Zone 3 (135°-225°) overlaps with the plaque within the 135°-210° range, showing significant overlap and is marked as active. Control Zones 1 (315°-45°) and 4 (225°-315°) have no overlap or only minimal overlap with the plaque (healthy tissue areas) and are marked as deactivated. For control area 2, the plaque thickness was approximately 1.2 mm, with moderate calcification. The generation power was 50 mJ / mm². 2 The pulse width was 120 ns and the frequency was 40 Hz. For control region 3, the patch thickness was approximately 1.8 mm and contained hyperechoic calcified nodules. The generation power was 70 mJ / mm². 2 The pulse width was 180 ns (longer pulse widths aid in calcification ablation), and the frequency was 30 Hz (slightly lower frequency to reduce heat accumulation). Control zones 1 and 4: power 0 (off). The physician initiated ablation, with only the four fibers (out of eight) in control zones 2 and 3 emitting laser light. Ablation was paused after 3 seconds. Real-time ultrasound showed that the target plaque thickness decreased from 1.8 mm / 1.2 mm to 0.9 mm / 0.6 mm, while the thickness of the healthy vessel wall (corresponding to control zones 1 and 4) remained unchanged at 0.2-0.3 mm, with no signs of dissection or damage. The remaining plaque was re-segmented, parameters were updated, and the power in control zone 2 was reduced to 35 mJ / mm². 2 The power in control zone 3 drops to 45 mJ / mm 2After a second 2-second ablation, the residual plaque thickness decreased to below 0.3 mm, achieving the treatment goal. Final angiography showed the stenosis had decreased to below 20%, and intravascular ultrasound confirmed selective plaque ablation with the healthy vessel wall intact. The patient experienced no postoperative complications. Laser was fired only in the 90°-210° direction around the plaque, leaving the healthy side completely unaffected. On the same catheter cross-section, two different control zones (zones 2 and 3) employed different power and pulse width parameters based on the local characteristics of the plaques they covered. Through two rounds of ablation with different parameters, progressive, morphology-adaptive ablation of irregularly thick plaques was achieved.

[0029] In one alternative embodiment, the ultrasonic detection unit is disposed in the positioning cavity at the distal end of the catheter body and is circumferentially staggered with the ablation fiber, and includes at least one high-frequency array ultrasonic transducer and a signal preprocessing module. The signal preprocessing module is electrically connected to the ultrasonic imaging processing unit via a high-temperature shielded cable. It is used to perform pre-amplification and analog-to-digital conversion on the weak echo signal received by the ultrasonic transducer and output the ultrasonic echo digital signal. After receiving the ultrasound echo digital signal, the ultrasound imaging processing unit reconstructs the signal through a three-dimensional beamforming and sub-pixel interpolation algorithm to generate an intravascular ultrasound three-dimensional image containing the target plaque's three-dimensional spatial coordinate matrix, the vascular wall microstructure feature parameters, and the plaque-vascular wall interface gap data.

[0030] In this embodiment, due to the circumferential offset or axial spacing between the ultrasound probe and the laser emission window, a systematic deviation exists between the displayed plaque location and the actual laser-affected area, requiring physicians to make "psychological corrections" based on experience. By circumferentially staggered embedding of the ultrasound transducer and ablation fiber at the distal end of the catheter, the ultrasound detection field of view and the laser emission direction are highly coincident in space, fundamentally eliminating the aforementioned deviation and achieving true coaxial and same field of view for image ablation, significantly improving the spatial accuracy of directional ablation. Using a high-frequency (20-60MHz, or even up to 80MHz) array ultrasound transducer, compared to traditional intravascular ultrasound (typically 20-40MHz), provides higher spatial resolution (axial resolution up to 30-50μm, lateral resolution up to 100-200μm). This allows the system to clearly distinguish the interface between the plaque and the elastic membrane within the vessel wall. Signal preprocessing (low-noise amplification + analog-to-digital conversion) is performed directly at the distal end of the catheter (near the ultrasound transducer). Compared to transmitting weak analog signals over long distances outside the body for processing, this method minimizes interference from other electrical signals within the catheter (such as motor drive and electromagnetic positioning) and the external electromagnetic environment. It avoids attenuation, dispersion, and reflection artifacts caused by long cables, improving the signal-to-noise ratio of the ultrasound image by 10-20 dB and making weak signal structures such as hypoechoic lipid plaques and thin fibrous caps clearly visible. Through a three-dimensional beamforming algorithm (dynamically focusing the polar coordinate data obtained from the rotating scan in three-dimensional space) and sub-pixel interpolation (improving the image sampling accuracy to the sub-pixel level, typically 1 / 4-1 / 8 of the original pixel size), a high-precision three-dimensional image containing a three-dimensional spatial coordinate matrix can be directly output. Each plaque voxel has precise (x,y,z) coordinates, which can quantify and calculate three-dimensional morphological parameters such as plaque volume, surface area, eccentricity index, and thickness distribution gradient. It can clearly display the gap data of the plaque-vascular wall interface (such as whether there is plaque detachment, dissection, hematoma, etc.).

[0031] In one alternative approach, the control unit incorporates a multimodal target plaque feature learning database, which is generated by training based on clinical case data and includes laser ablation threshold curves, optimal ablation parameter combinations, and tissue damage risk coefficient matrices corresponding to calcified plaques, fibrous plaques, lipid plaques, and mixed plaques. The control unit communicates bidirectionally with the ultrasound imaging processing unit via a high-speed bus. After segmenting the target patch boundary contour, it extracts multidimensional feature parameters including the target patch ultrasound echo intensity value, gray-level co-occurrence matrix feature parameters, and patch density distribution index. Furthermore, based on the target patch local thickness gradient data and tissue damage risk coefficient corresponding to the fiber optic control area, it dynamically calls the optimal combination of ablation parameters to obtain personalized laser control parameters.

[0032] In this embodiment, the calcified plaques are high-density and low-water-content, requiring a high energy density (60-80 mJ / mm²). 2 Effective ablation requires a relatively long pulse width (150-200 ns); lipid plaques are low-density and rich in lipids, making them highly sensitive to lasers. Excessive energy can easily lead to lipid overheating and vaporization, microbubble rupture, and distal embolism, thus requiring lower power (20-30 mJ / mm²). 2 The ultrasound features include high echogenicity and short pulse width (50-80 ns); fibrous plaques have medium density and high water content, falling between the two. Through a multimodal feature learning database (generated from clinical case data), the system can automatically identify the plaque type in each fiber control zone based on real-time extracted plaque ultrasound features, and call the optimal ablation parameter combination corresponding to that type in the database to achieve true tissue-selective ablation. Ultrasound echo intensity values ​​accurately quantify the grayscale values ​​(0-255 levels or dB values) of the plaque region, distinguishing between calcification (high echo, >180), fibrosis (medium echo, 80-150), and lipids (low echo, <60). Grayscale co-occurrence matrix feature parameters include second-order statistical features such as contrast, correlation, energy, and homogeneity, used to quantify the texture regularity within the plaque (calcified plaques have coarse texture (high contrast), lipid plaques have uniform texture (low contrast), and fibrous plaques exhibit moderately regular striped texture). The plaque density distribution index is calculated by inverting the ultrasound backscatter integral or attenuation coefficient to determine the physical density (g / cm³) of the plaque. 3 Calcified plaques have the highest density (approximately 1.8-2.2 g / cm³). 3 The lipid plaque density is the lowest (approximately 1.0-1.2 g / cm³). 3It can identify plaque types with an accuracy far exceeding that of the human eye (sensitivity >90%, specificity >85%) and select optimal parameters accordingly. It allows for independent parameter generation for local plaque characteristics in different circumferential sectors within the same catheter cross-section. For example, a calcified nodule located in sector A (hyperechoic, high density) is set to high power and long pulse width; the adjacent sector B, a lipid core (hypoechoic, low density), is set to low power, short pulse width, and long interval; sector C, representing normal vessel wall, has its fiber optic cable shut off. This differentiated control at the sector level results in completely different laser characteristics output in different directions within the same laser emission cycle, achieving spatially selective ablation spectra. The tissue damage risk coefficient matrix records the probability and degree of thermal damage to surrounding healthy tissues (media, adventitia, elastic layer, peripheral nerves, etc.) caused by different types of plaques under different laser parameters. The control unit queries the risk coefficient while generating parameters to avoid parameter combinations exceeding safety boundaries. For example, in areas near the openings of branch vessels, even with thin plaques, the power will be automatically reduced or the ablation time for a single session will be shortened to prevent thermal diffusion damage to the branch vessel openings; in areas near nerve plexuses, pulse energy will be strictly controlled to avoid postoperative pain or vasospasm caused by nerve thermal damage.

[0033] In one alternative embodiment, the distal end of the catheter body is fitted with a six-axis inertial measurement unit and an electromagnetic positioning and tracking probe; The six-axis inertial measurement unit is used to collect the spatial position coordinates, attitude angle data and displacement acceleration data of the distal end of the catheter body in real time; the electromagnetic positioning and tracking probe is used to calibrate the spatial positioning data of the catheter body to compensate for displacement errors caused by breathing and heartbeat. The control unit calculates the real-time pose deviation and displacement trend between the catheter and the target lesion site based on the precise spatial coordinate information of the target plaque transmitted by the ultrasound imaging processing unit and the calibrated spatial positioning data.

[0034] In this embodiment, a six-axis inertial measurement unit (IMU, including a three-axis gyroscope and a three-axis accelerometer) can output the complete six-degree-of-freedom pose of the distal catheter in space in real time (three translational degrees of freedom x, y, z + three rotational degrees of freedom roll, pitch, yaw), with a sampling rate of up to several hundred hertz. This is equivalent to having a miniature "spatial locator" built into the catheter tip, allowing for precise determination of its absolute spatial attitude at every moment, regardless of how the catheter bends, rotates, or moves with the heartbeat. Relying solely on the IMU suffers from integration drift; the accelerometer obtains displacement through double integration, and small errors accumulate over time, leading to position divergence. By coupling an external electromagnetic field generator with a miniature receiving coil at the distal end of the catheter, the three-dimensional coordinates of the catheter in absolute space are directly measured (with sub-millimeter accuracy). The electromagnetic positioning data provides an absolute position reference at a lower frequency (e.g., 100Hz) to correct for IMU integration drift. Because electromagnetic positioning is an absolute measurement, it can detect catheter displacement (typically a periodic movement of 5-15 mm) caused by respiration and heartbeat in real time. This movement is separated from the IMU measurement values ​​to obtain the true position of the catheter relative to the heart (rather than absolute space), achieving sub-millimeter-level relative positioning accuracy within a beating heart. The control unit then calculates the positional deviation between the catheter and the target lesion in real time, as well as the displacement trend, displaying the numerical values ​​on the operating interface and even converting them into audio prompts (the greater the deviation, the higher the audio frequency), allowing physicians to adjust the catheter position intuitively and quantitatively. When the positional deviation exceeds a preset safety threshold (e.g., the catheter center offset from the target plaque center > 1 mm, or the angle between the catheter pointing angle and the plaque surface normal > 30°), the control unit automatically issues an audible and visual alarm and automatically pauses laser ablation if the deviation continues to worsen. This fundamentally avoids the risk of accidentally damaging healthy tissue or incomplete ablation due to catheter displacement, making it particularly suitable for complex lesions requiring long-term, multi-round ablation.

[0035] In one alternative embodiment, the distal end of the catheter body is provided with an electromagnetic positioning sensor and a distributed fiber Bragg grating shape sensor, which are electrically and optically connected to the navigation and positioning unit, respectively. The electromagnetic positioning sensor is used to acquire the position coordinates of the catheter in absolute space, and the fiber Bragg grating sensor is used to reconstruct the bending morphology information of the catheter in real time, so as to eliminate measurement drift and error based on the position coordinates and the bending morphology information. The navigation and positioning unit outputs the six-degree-of-freedom real-time pose of the distal end of the catheter within the blood vessel to the control unit. The control unit pre-aligns the spatial distribution map of the target plaque in the real-time intravascular ultrasound image with the three-dimensional anatomical model of the blood vessel through affine registration. The control unit performs real-time collision detection between the six-degree-of-freedom real-time pose and the three-dimensional anatomical model of the blood vessel, generating a sequence of fiber optic control zones to be activated in chronological order and corresponding laser parameters. During catheter advancement or rotation, the control unit dynamically adjusts the opening and closing timing and output power of each fiber optic control zone according to the sequence of fiber optic control zones and corresponding laser parameters, and automatically pauses ablation and issues a navigation correction prompt when the catheter deviates from its trajectory.

[0036] In this embodiment, the control unit aligns the spatial distribution of the target plaque in the intravascular ultrasound image with the three-dimensional anatomical model of the blood vessel through affine registration. Collision detection is then performed in conjunction with the real-time catheter pose to ensure precise spatial correspondence between the ablation fiber control area and the target plaque, avoiding accidental damage to adjacent non-target tissues. Based on real-time pose changes during catheter advancement or rotation, a sequence of fiber control areas to be activated and corresponding laser parameters are generated in chronological order. The activation and deactivation timing and output power of each control area are dynamically adjusted to achieve continuous and precise treatment with ablation occurring simultaneously.

[0037] For example, a patient has an eccentric lipid plaque in the mid-segment of their right coronary artery. The plaque is mainly distributed in the 90°–150° sector of the vessel circumference, with uneven thickness (1.2 mm at its thickest point and 0.3 mm at its thinnest). The physician plans to use a zoned (zone 1#, zone 2#, zone 3#) controllable laser ablation catheter for targeted ablation. The patient's coronary CTA data is reconstructed into a three-dimensional vascular anatomy model and imported into the system. After the catheter is inserted, three-dimensional ultrasound images of the target plaque area are acquired via pull-back intravascular ultrasound. The control unit performs affine registration between the plaque spatial distribution map and the CTA model to determine that the plaque is located in the 100°–140° sector of the vessel circumference. The distal end of the catheter is equipped with an electromagnetic sensor and a fiber Bragg grating sensor. When the physician pushes the catheter to the proximal end of the target lesion under X-ray fluoroscopy, the navigation and positioning unit outputs the six-DOF pose of the distal end of the catheter: coordinates (12.5, 23.1, 8.6) mm, pitch angle 2°, yaw angle -1°, and roll angle 0°. The control unit performs collision detection, determining that the distal end of the catheter is located at the proximal edge of the plaque. The current vascular sector 100°–140° corresponds to the 2nd and 3rd fiber optic control zones (a total of 6 control zones, one every 60°) in the circumferential direction of the catheter. Currently (0mm advance), the 2nd and 3rd control zones are activated, with powers of 0.8W (thick zone) and 0.4W (thin zone), respectively. After advancing 2mm, the power of the 2nd control zone decreases to 0.3W, while the 3rd control zone remains at 0.8W, and the 4th control zone begins pre-activation at 0.2W. After advancing 4mm, the 2nd control zone is deactivated, the power of the 3rd control zone decreases to 0.4W, and the power of the 4th control zone increases to 0.6W. When the physician inadvertently rotates the catheter towards a non-target sector (e.g., in the 200° direction), the electromagnetic positioning sensor and fiber optic grating sensor immediately detect the change in posture, and the roll angle changes from 0° to 18°. The control unit detected that the current vascular sector distal to the catheter had shifted to 200°–260°, which did not overlap with the plaque sector (100°–140°), indicating a deviation from the trajectory. The system automatically paused all laser output within 5ms and displayed a warning on the screen. After the physician adjusted the catheter to the correct position, the system automatically resumed ablation. Throughout the ablation process, the laser energy remained precisely applied to the target plaque sector, with no laser irradiation of adjacent normal vessel walls. Post-operative intravascular ultrasound confirmed that the plaque had been uniformly ablated to a residual thickness of <0.1mm, with no complications such as vascular perforation or dissection.

[0038] In an alternative embodiment, the system further includes a closed-loop power adjustment unit. During laser ablation, the control unit receives the dynamic intravascular ultrasound image sequence output by the ultrasound imaging processing unit at fixed time intervals through the closed-loop power adjustment unit and segments the target plaque boundary contour in each frame of the ultrasound image sequence to obtain the residual plaque thickness in the corresponding region of each activated fiber control area. Based on the residual patch thickness of continuous time frames, motion artifacts caused by breathing and heartbeat are filtered out to obtain a denoised attenuation sequence, and the instantaneous ablation rate of the attenuation sequence at the current moment is calculated. The control unit compares the instantaneous ablation rate with the preset desired ablation rate. If the instantaneous ablation rate is less than the desired ablation rate, the real-time output power of the corresponding fiber control area is increased proportionally. If the instantaneous ablation rate is greater than the desired ablation rate, the real-time output power is decreased proportionally, and the power adjustment is fed back to the multi-channel laser generating unit to counteract tissue inhomogeneity and the constant rate ablation effect of blood flow cooling.

[0039] In this embodiment, as Figure 2 As shown, by real-time monitoring of residual plaque thickness and calculation of the instantaneous ablation rate, the output power is dynamically adjusted after comparison with the expected rate in a closed loop, ensuring a constant ablation rate. This avoids excessively fast (potentially damaging normal tissue) or excessively slow (low treatment efficiency) local ablation caused by factors such as uneven tissue density and blood flow cooling effects. Using a sequence of residual plaque thickness in continuous time frames, an algorithm filters out periodic motion artifacts caused by respiration and heartbeat, obtaining a true thickness decay curve. This ensures the accuracy of the instantaneous ablation rate calculation and avoids misjudgments caused by catheter movement along the vessel wall. Each activated fiber control zone independently monitors the rate and adjusts the power, allowing for optimization based on the ablation response differences in different regions of the same plaque (such as the lipid core and fibrous cap regions), achieving truly personalized and adaptive ablation. Blood flow carries away the heat generated by the laser, leading to a decrease in ablation efficiency. The closed-loop power adjustment unit automatically increases the power when it detects a rate lower than the expected value to compensate for cooling losses and maintain a stable tissue thermal damage effect.

[0040] In one optional embodiment, when performing spatial matching between the fiber control area and the target patch sector, the control unit calculates the matching degree between each fiber control area and the target patch sector using a spatial matching degree model; wherein, the expression for the spatial matching degree model is:

[0041] in, The spatial matching degree between the i-th fiber control region and the k-th target patch sector; This is the spatial intersection region between the i-th fiber control region and the k-th target patch sector; The overall spatial region of the k-th target patch sector; , , The influence weights of ultrasonic echo intensity, patch density, and patch thickness are respectively. The echo intensity value at spatial coordinates (x, y, z) in the three-dimensional intravascular ultrasound image; The density distribution index of the target patch at spatial coordinates (x, y, z); The value represents the local thickness of the target patch at spatial coordinates (x, y, z). Let be the spatial position vector of the center of the i-th fiber control zone; Let be the spatial position vector of the center of the k-th target patch sector; This is the spatial position deviation correction coefficient.

[0042] In this embodiment, the matching degree decreases smoothly rather than abruptly to zero as the spatial distance between the center of the fiber control region and the center of the target patch sector increases through the exponential attenuation term. This is more consistent with actual physical scenarios; even with slight offsets, the laser can still produce partial ablation effects on the patch edges, allowing for rational power allocation rather than simple shutdown. Different target patch sectors have different echo intensities, densities, and thickness distributions, which can be addressed through the integration region. The weighted summation allows the matching degree to reflect which sub-regions within the patch most requiring ablation are covered by the fiber control region. For example, if the intersection region happens to contain the thickest, densest, and most echoing part of the patch, the matching degree may still be high even if the area is small.

[0043] In one alternative approach, the formula for calculating the instantaneous ablation rate by the closed-loop power regulation unit is as follows:

[0044] in, Let be the instantaneous ablation rate at time t; The frame number of the time-series ultrasound images; This refers to the time interval for ultrasound image acquisition. for The thickness of the residual patch in the corresponding area of ​​the time-based fiber optic control zone; The thickness of the residual patch in the fiber-controlled region at time t; For time series weighting factors; This is the thickness attenuation correction factor; The initial thickness of the target plaque.

[0045] In this embodiment, during intravascular ultrasound image acquisition, heartbeat and respiration cause periodic fluctuations in plaque thickness measurements. An exponential decay factor automatically downweights historical frames with excessively large thickness variations. Thickness jumps caused by physiological motion (e.g., spurious thickness changes due to catheter movement with the vessel wall) are often large, effectively suppressing their interference with rate calculation. This ensures that the instantaneous ablation rate reflects the true tissue ablation progress rather than motion artifacts. A time-series weighting factor increases the contribution of historical frames closer to the current time to rate calculation and decreases the contribution of more distant frames, thus ensuring that rate estimation can quickly respond to differences in effect caused by laser power adjustments or changes in tissue ablation characteristics, avoiding lag.

[0046] In one alternative approach, the formula for calculating the output power is:

[0047] The formula for calculating the pulse width is:

[0048] The formula for calculating the pulse interval is:

[0049] in, The personalized output power for the i-th fiber control zone; The laser ablation threshold power is the target patch type corresponding to the i-th fiber control region. The ultrasonic echo intensity value of the target patch in the region corresponding to the i-th fiber control zone; This represents the average ultrasonic echo intensity of the corresponding region across all fiber optic control zones. The standard deviation of the ultrasonic echo intensity; , , These are the feature weights for ultrasonic echo intensity, patch density, and patch thickness, respectively. The target patch density is the region corresponding to the i-th fiber control area. This represents the average patch density of the corresponding regions across all fiber control areas; The standard deviation of patch density; The target patch thickness corresponds to the region of the i-th fiber control zone; This represents the average patch thickness of the corresponding regions across all fiber control areas. The standard deviation of the patch thickness; The number of factors influencing the risk of tissue damage; Let be the weight coefficient of the j-th damage risk influencing factor; This represents the j-th damage risk coefficient for the region corresponding to the i-th fiber control zone. Let be the pulse width of the i-th fiber control region; The base pulse width; The maximum density of common clinical target plaques; This is the density influence coefficient; This represents the maximum thickness of commonly seen target plaques in clinical practice. This is the thickness influence coefficient; , These represent the maximum and minimum values ​​of the ultrasonic echo intensity, respectively. The pulse interval of the i-th fiber control zone; The basic pulse interval; Echo intensity influence coefficient; Density correction index; The baseline patch density is used.

[0050] In this embodiment, the output power formula is not only based on the ablation threshold power of the plaque type, but also adjusted by the ultrasonic echo intensity, plaque density, plaque thickness, and deviation from the overall mean and standard deviation. This allows the power to be finely adjusted according to the tissue characteristics of the corresponding region in each fiber control zone. The stronger the echo (usually indicating calcification), the higher the density, and the greater the thickness, the higher the output power, and vice versa, achieving true "on-demand power supply." Each fiber control zone is calculated independently, allowing different circumferential regions of the same duct and the same plaque to use drastically different combinations of laser parameters. For example, the lipid core region of the plaque can use low power, short pulses, and short intervals, while the calcified cap region can use high power, short pulses (due to high density), and long intervals (due to the need for heat dissipation), achieving differentiated ablation by region.

[0051] According to the solution provided by the present invention, the device includes a catheter body with an interventional end at its distal end that can reach the target lesion site via a vascular pathway. A guidewire lumen is axially disposed within the catheter body to accommodate and guide the guidewire. Multiple ablation fibers are distributed circumferentially around the guidewire lumen and extend axially to the distal end of the catheter body. The multiple ablation fibers are divided into at least two independent fiber control zones on the cross-section of the catheter body. Each fiber control zone contains at least one ablation fiber, and each fiber control zone independently controls its laser emission state and emission parameters. An ultrasound detection unit is disposed inside the distal end of the catheter body and includes at least one ultrasound transducer for emitting an ultrasound beam to the vascular wall tissue and receiving echo signals to acquire intravascular ultrasound image data in real time, including the morphology, location, thickness, and spatial relationship of the target plaque with respect to the catheter. A multi-channel laser generating unit is optically coupled to the multiple ablation fibers through a proximal connector to independently output modulated laser energy to each fiber control zone. An ultrasound imaging processing unit is connected to the ultrasound detection unit for receiving echo signals. The system receives and reconstructs real-time intravascular ultrasound images. A control unit, communicatively connected to both the ultrasound imaging processing unit and the multi-channel laser generator, receives and processes these images, segments the target plaque's boundary contour, and determines its circumferential distribution, thickness distribution, and position relative to the distal end of the catheter. Based on the spatial distribution characteristics of the target plaque, each fiber optic control zone on the catheter's cross-section is spatially matched with the sector occupied by the target plaque in the circumferential direction. Laser control parameters are generated for each fiber optic control zone based on its corresponding local characteristics, including its on / off state, output power, pulse width, and pulse interval. The multi-channel laser generator selectively activates one or more fiber optic control zones matching the spatial position of the target plaque according to the generated laser control parameters, while keeping or limiting the output of fiber optic control zones not corresponding to the target plaque or adjacent non-target tissue areas. This achieves directional, zoned, and malleable laser ablation of the target plaque. This invention avoids accidental damage to healthy tissue, improves surgical safety, and ensures optimal ablation results.

[0052] Figure 5 A schematic diagram of the frame of an image-guided, zone-controlled laser ablation catheter device according to an embodiment of the present invention is shown. The image-guided, zone-controlled laser ablation catheter device includes: The catheter body 510 has an interventional end at its distal end that can reach the target lesion site via a vascular path. A guidewire lumen is provided axially through the catheter body to accommodate the guidewire for guidance. Multiple ablation fibers 520 are distributed around the periphery of the guidewire cavity along the circumference of the catheter body and extend axially to the distal end of the catheter body; the multiple ablation fibers divide the cross-section of the catheter body into at least two independent fiber control regions, each fiber control region contains at least one ablation fiber and each fiber control region independently controls its laser emission state and emission parameters. The ultrasound detection unit 530 is located inside the distal end of the catheter body and includes at least one ultrasound transducer for transmitting an ultrasound beam to the blood vessel wall tissue and receiving echo signals to acquire intravascular ultrasound image data in real time, including the morphology, location, thickness and spatial relationship of the target plaque with respect to the catheter. The multi-channel laser generating unit 540 is optically coupled to multiple ablation fibers via a near-end connector, and independently outputs modulated laser energy to each fiber control area. The ultrasound imaging processing unit 550 is connected to the ultrasound detection unit and is used to receive echo signals and reconstruct real-time intravascular ultrasound images. The control unit 560 is communicatively connected to the ultrasound imaging processing unit and the multi-channel laser generating unit, respectively. It is used to receive and process real-time intravascular ultrasound images, segment the boundary contour of the target plaque, and determine the distribution range, thickness distribution, and position information of the target plaque in the circumferential direction of the blood vessel, as well as its position relative to the distal end of the catheter body. Based on the spatial distribution characteristics of the target plaque, it spatially matches each fiber control zone on the cross-section of the catheter body with the sector occupied by the target plaque in the circumferential direction of the blood vessel. Based on the local characteristics of the target plaque corresponding to each fiber control zone, it generates laser control parameters for that fiber control zone, including the on / off state, output power, pulse width, and pulse interval of the fiber control zone. It controls the multi-channel laser generating unit to selectively enable one or more fiber control zones that match the spatial position of the target plaque to emit lasers according to the generated laser control parameters, and keeps the fiber control zones that do not correspond to the area of ​​the target plaque or the adjacent non-target tissue area closed or limits their output, so as to achieve directional, zoned, and malleable laser ablation of the target plaque.

[0053] Figure 6 The diagram shows a structural schematic of an embodiment of the computing device of the present invention. The specific embodiments of the present invention do not limit the specific implementation of the computing device.

[0054] like Figure 6 As shown, the computing device may include: a processor 602, a communications interface 604, a memory 606, and a communications bus 608.

[0055] The processor 602, communication interface 604, and memory 606 communicate with each other via communication bus 608. Communication interface 604 is used to communicate with other network elements such as clients or other servers. The processor 602 executes program 610, specifically performing the relevant steps in the above-described embodiment of the image-guided, partitioned, controllable laser ablation catheter system.

[0056] Specifically, program 610 may include program code that includes computer operation instructions.

[0057] Processor 602 may be a central processing unit (CPU), an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement embodiments of the present invention. The computing device includes one or more processors, which may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0058] Memory 606 is used to store program 610. Memory 606 may include high-speed RAM memory, and may also include non-volatile memory, such as at least one disk storage device.

[0059] According to the solution provided by the present invention, the device includes a catheter body with an interventional end at its distal end that can reach the target lesion site via a vascular pathway. A guidewire lumen is axially disposed within the catheter body to accommodate and guide the guidewire. Multiple ablation fibers are distributed circumferentially around the guidewire lumen and extend axially to the distal end of the catheter body. The multiple ablation fibers are divided into at least two independent fiber control zones on the cross-section of the catheter body. Each fiber control zone contains at least one ablation fiber, and each fiber control zone independently controls its laser emission state and emission parameters. An ultrasound detection unit is disposed inside the distal end of the catheter body and includes at least one ultrasound transducer for emitting an ultrasound beam to the vascular wall tissue and receiving echo signals to acquire intravascular ultrasound image data in real time, including the morphology, location, thickness, and spatial relationship of the target plaque with respect to the catheter. A multi-channel laser generating unit is optically coupled to the multiple ablation fibers through a proximal connector to independently output modulated laser energy to each fiber control zone. An ultrasound imaging processing unit is connected to the ultrasound detection unit for receiving echo signals. The system receives and reconstructs real-time intravascular ultrasound images. A control unit, communicatively connected to both the ultrasound imaging processing unit and the multi-channel laser generator, receives and processes these images, segments the target plaque's boundary contour, and determines its circumferential distribution, thickness distribution, and position relative to the distal end of the catheter. Based on the spatial distribution characteristics of the target plaque, each fiber optic control zone on the catheter's cross-section is spatially matched with the sector occupied by the target plaque in the circumferential direction. Laser control parameters are generated for each fiber optic control zone based on its corresponding local characteristics, including its on / off state, output power, pulse width, and pulse interval. The multi-channel laser generator selectively activates one or more fiber optic control zones matching the spatial position of the target plaque according to the generated laser control parameters, while keeping or limiting the output of fiber optic control zones not corresponding to the target plaque or adjacent non-target tissue areas. This achieves directional, zoned, and malleable laser ablation of the target plaque. This invention avoids accidental damage to healthy tissue, improves surgical safety, and ensures optimal ablation results.

[0060] Those skilled in the art will understand that modules in the device of the embodiments can be adaptively changed and placed in one or more devices different from that embodiment. Modules, units, or components in the embodiments can be combined into a single module, unit, or component, and further, they can be divided into multiple sub-modules, sub-units, or sub-components. Except where at least some of such features and / or processes or units are mutually exclusive, any combination of all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or device so disclosed can be employed. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that serves the same, equivalent, or similar purpose. Furthermore, those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the following claims, any of the claimed embodiments can be used in any combination. The invention can be implemented by means of hardware comprising several different elements and by means of a suitably programmed computer. In the unit claims listing several devices, several of these devices may be embodied by the same hardware item. Unless otherwise specified, the steps in the above embodiments should not be construed as limiting the order of execution.

Claims

1. An image-guided, zone-controlled laser ablation catheter system, characterized in that, include: The catheter body has an interventional end at its distal end that can reach the target lesion site via a vascular path. A guidewire lumen is provided axially through the catheter body to accommodate the guidewire for guidance. Multiple ablation fibers are distributed around the periphery of the guidewire cavity along the circumference of the catheter body and extend axially to the distal end of the catheter body; the multiple ablation fibers divide the cross-section of the catheter body into at least two independent fiber control regions, each fiber control region contains at least one ablation fiber and each fiber control region independently controls its laser emission state and emission parameters. An ultrasound detection unit, located inside the distal end of the catheter body, includes at least one ultrasound transducer for transmitting an ultrasound beam to the vascular wall tissue and receiving echo signals, so as to acquire intravascular ultrasound image data in real time, including the morphology, location, thickness and spatial relationship of the target plaque with respect to the catheter. The multi-channel laser generating unit is optically coupled to multiple ablation fibers via a near-end connector, and independently outputs modulated laser energy to each fiber control area. An ultrasound imaging processing unit, connected to an ultrasound detection unit, is used to receive echo signals and reconstruct real-time intravascular ultrasound images. The control unit, which is communicatively connected to the ultrasound imaging processing unit and the multi-channel laser generating unit, receives and processes real-time intravascular ultrasound images, segments the boundary contour of the target plaque, and determines the distribution range, thickness distribution, and position of the target plaque relative to the distal end of the catheter body in the circumferential direction of the blood vessel. Based on the spatial distribution characteristics of the target plaque, it spatially matches each fiber control zone on the cross-section of the catheter body with the sector occupied by the target plaque in the circumferential direction of the blood vessel. Based on the local characteristics of the target plaque corresponding to each fiber control zone, it generates laser control parameters for that fiber control zone, including the on / off state, output power, pulse width, and pulse interval of the fiber control zone. It controls the multi-channel laser generating unit to selectively activate one or more fiber control zones that match the spatial position of the target plaque to emit lasers according to the generated laser control parameters, and keeps the fiber control zones that do not correspond to the area of ​​the target plaque or the adjacent non-target tissue area closed or limits their output, so as to achieve directional, zoned, and malleable laser ablation of the target plaque.

2. The image-guided, zone-controlled laser ablation catheter system according to claim 1, characterized in that, The ultrasonic detection unit is located in the positioning cavity at the distal end of the catheter body and is circumferentially interleaved with the ablation fiber. It includes at least one high-frequency array ultrasonic transducer and a signal preprocessing module. The signal preprocessing module is electrically connected to the ultrasonic imaging processing unit via a high-temperature shielded cable. It is used to perform pre-amplification and analog-to-digital conversion on the weak echo signal received by the ultrasonic transducer and output the ultrasonic echo digital signal. After receiving the ultrasound echo digital signal, the ultrasound imaging processing unit reconstructs the signal through a three-dimensional beamforming and sub-pixel interpolation algorithm to generate an intravascular ultrasound three-dimensional image containing the target plaque's three-dimensional spatial coordinate matrix, the vascular wall microstructure feature parameters, and the plaque-vascular wall interface gap data.

3. The image-guided, zone-controlled laser ablation catheter system according to claim 1, characterized in that, The control unit has a built-in multimodal target plaque feature learning database, which is generated by training based on clinical case data. It includes laser ablation threshold curves, optimal ablation parameter combinations, and tissue damage risk coefficient matrices corresponding to calcified plaques, fibrous plaques, lipid plaques, and mixed plaques. The control unit communicates bidirectionally with the ultrasound imaging processing unit via a high-speed bus. After segmenting the target patch boundary contour, it extracts multidimensional feature parameters including the target patch ultrasound echo intensity value, gray-level co-occurrence matrix feature parameters, and patch density distribution index. Furthermore, based on the local thickness gradient data of the target patch corresponding to the fiber control area and the tissue damage risk coefficient, the optimal combination of ablation parameters is dynamically called to obtain personalized laser control parameters.

4. The image-guided, zone-controlled laser ablation catheter system according to claim 1, characterized in that, The distal end of the catheter body is equipped with a six-axis inertial measurement unit and an electromagnetic positioning and tracking probe. The six-axis inertial measurement unit is used to collect the spatial position coordinates, attitude angle data and displacement acceleration data of the distal end of the catheter body in real time; the electromagnetic positioning and tracking probe is used to calibrate the spatial positioning data of the catheter body to compensate for displacement errors caused by breathing and heartbeat. The control unit calculates the real-time pose deviation and displacement trend between the catheter and the target lesion site based on the precise spatial coordinate information of the target plaque transmitted by the ultrasound imaging processing unit and the calibrated spatial positioning data.

5. The image-guided, zone-controlled laser ablation catheter system according to claim 1, characterized in that, The distal end of the duct body is equipped with an electromagnetic positioning sensor and a distributed fiber Bragg grating shape sensor, which are electrically and optically connected to the navigation and positioning unit, respectively. The electromagnetic positioning sensor is used to acquire the position coordinates of the catheter in absolute space, and the fiber Bragg grating sensor is used to reconstruct the bending morphology information of the catheter in real time, so as to eliminate measurement drift and error based on the position coordinates and the bending morphology information. The navigation and positioning unit outputs the six-degree-of-freedom real-time pose of the distal end of the catheter within the blood vessel to the control unit. The control unit pre-aligns the spatial distribution map of the target plaque in the real-time intravascular ultrasound image with the three-dimensional anatomical model of the blood vessel through affine registration. The control unit performs real-time collision detection between the six-degree-of-freedom real-time pose and the three-dimensional anatomical model of the blood vessel, generating a sequence of fiber optic control zones to be activated in chronological order and corresponding laser parameters. During catheter advancement or rotation, the control unit dynamically adjusts the opening and closing timing and output power of each fiber optic control zone according to the sequence of fiber optic control zones and corresponding laser parameters, and automatically pauses ablation and issues a navigation correction prompt when the catheter deviates from its trajectory.

6. The image-guided, zone-controlled laser ablation catheter system according to claim 1, characterized in that, The system also includes a closed-loop power adjustment unit. During the laser ablation process, the control unit receives the dynamic intravascular ultrasound image sequence output by the ultrasound imaging processing unit at fixed time intervals through the closed-loop power adjustment unit and segments the target plaque boundary contour in each frame of the ultrasound image sequence to obtain the residual plaque thickness in the corresponding area of ​​each activated fiber control region. Based on the residual patch thickness of continuous time frames, motion artifacts caused by breathing and heartbeat are filtered out to obtain a denoised attenuation sequence, and the instantaneous ablation rate of the attenuation sequence at the current moment is calculated. The control unit compares the instantaneous ablation rate with the preset desired ablation rate. If the instantaneous ablation rate is less than the desired ablation rate, the real-time output power of the corresponding fiber control area is increased proportionally. If the instantaneous ablation rate is greater than the desired ablation rate, the real-time output power is decreased proportionally, and the power adjustment is fed back to the multi-channel laser generating unit to counteract tissue inhomogeneity and the constant rate ablation effect of blood flow cooling.

7. The image-guided, zone-controlled laser ablation catheter system according to claim 1, characterized in that, When performing spatial matching between the fiber control area and the target patch sector, the control unit calculates the matching degree between each fiber control area and the target patch sector using a spatial matching degree model; wherein, the expression of the spatial matching degree model is: in, The spatial matching degree between the i-th fiber control region and the k-th target patch sector; This is the spatial intersection region between the i-th fiber control region and the k-th target patch sector; The overall spatial region of the k-th target patch sector; , , The influence weights of ultrasonic echo intensity, patch density, and patch thickness are respectively. The echo intensity value at spatial coordinates (x, y, z) in the three-dimensional intravascular ultrasound image; The density distribution index of the target patch at spatial coordinates (x, y, z); The value represents the local thickness of the target patch at spatial coordinates (x, y, z). Let be the spatial position vector of the center of the i-th fiber control zone; Let be the spatial position vector of the center of the k-th target patch sector; This is the spatial position deviation correction coefficient.

8. The image-guided, zone-controlled laser ablation catheter system according to claim 6, characterized in that, The formula for calculating the instantaneous ablation rate by the closed-loop power regulation unit is as follows: in, Let be the instantaneous ablation rate at time t; The frame number of the time-series ultrasound images; This refers to the time interval for ultrasound image acquisition. for The thickness of the residual patch in the corresponding area of ​​the time-based fiber optic control zone; The thickness of the residual patch in the fiber-controlled region at time t; For time series weighting factors; This is the thickness attenuation correction factor; The initial thickness of the target plaque.

9. The image-guided, zone-controlled laser ablation catheter system according to claim 3, characterized in that, The formula for calculating the output power is: The formula for calculating the pulse width is: The formula for calculating the pulse interval is: in, The personalized output power for the i-th fiber control zone; The laser ablation threshold power is the target patch type corresponding to the i-th fiber control region. The ultrasonic echo intensity value of the target patch in the region corresponding to the i-th fiber control zone; This represents the average ultrasonic echo intensity of the corresponding region across all fiber optic control zones. The standard deviation of the ultrasonic echo intensity; , , These are the feature weights for ultrasonic echo intensity, patch density, and patch thickness, respectively. The target patch density is the region corresponding to the i-th fiber control area. This represents the average patch density of the corresponding regions across all fiber control areas; The standard deviation of patch density; The target patch thickness corresponds to the region of the i-th fiber control zone; This represents the average patch thickness of the corresponding regions across all fiber control areas. The standard deviation of the patch thickness; The number of factors influencing the risk of tissue damage; Let be the weight coefficient of the j-th damage risk influencing factor; This represents the j-th damage risk coefficient for the region corresponding to the i-th fiber control zone. Let be the pulse width of the i-th fiber control region; The base pulse width; The maximum density of common clinical target plaques; This is the density influence coefficient; This represents the maximum thickness of commonly seen target plaques in clinical practice. This is the thickness influence coefficient; , These represent the maximum and minimum values ​​of the ultrasonic echo intensity, respectively. The pulse interval of the i-th fiber control zone; The basic pulse interval; Echo intensity influence coefficient; Density correction index; The baseline patch density is used.

10. A computing device, comprising: The processor, memory, communication interface, and communication bus are provided, wherein the processor, memory, and communication interface communicate with each other via the communication bus. The memory is used to store at least one executable instruction, which causes the processor to perform the operation corresponding to the image-guided partitioned controllable laser ablation catheter system described above.

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