Aortic visceral artery zone endoluminal stent release angle calibration method

Abstract

The present application relates to the technical field of medical devices, in particular to a method for calibrating the release angle of an endoluminal stent in the visceral artery area of the aorta, comprising S1: obtaining the spatial direction change information of the branch opening of the visceral artery area in the aorta before and during the release of the endoluminal stent, and determining the real-time angle drift state of the visceral artery opening relative to the axial direction of the aorta; S2: matching the actual direction of the visceral artery opening with the designed direction of the corresponding connection area of the endoluminal stent, determining the compensation amount of the release angle of the stent caused by the structural change of the aorta, and generating the release angle calibration result; S3: adjusting the rotation posture of the stent during the release of the endoluminal stent, so that the corresponding connection area of the stent is corrected synchronously with the direction change of the visceral artery opening, and the release angle calibration of the endoluminal stent in the visceral artery area of the aorta is completed. The present application improves the matching reliability of the fenestrated or branched endoluminal stent and the visceral artery vessel opening.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a method for calibrating the release angle of an endovascular stent in the aortic visceral artery region. Background Technology

[0002] Endovascular aortic repair is an important minimally invasive treatment for aortic diseases such as aortic aneurysm and aortic dissection. For complex aortic lesions involving visceral arteries such as the celiac trunk, superior mesenteric artery, and renal artery, endovascular stents with fenestration or branching structures are usually required to isolate the lesion area while maintaining blood flow to important branches. Due to the dense branching and complex spatial relationships of visceral arteries, the stent deployment process must ensure accurate alignment between the stent's corresponding connection area and the opening direction of the target visceral artery. Currently, in clinical practice, aortic anatomical references are usually established based on preoperative computed tomography angiography images, and the stent deployment angle is determined by combining intraoperative fluoroscopic images. However, there are differences between the preoperative image acquisition status and the actual intraoperative status. Moreover, the aorta is a dynamic vascular structure with elasticity and pulsation characteristics. Under the influence of heart pulsation, respiratory movements, blood pressure changes, and the action of delivery devices, the position of the aortic centerline, the direction of the vascular cross section, and the orientation of the visceral artery opening space may all change. This causes the stent release angle planned preoperatively to deviate from the actual vascular space direction during the operation, thereby affecting the accurate correspondence between the stent fenestration area or branch connection area and the target vessel.

[0003] Existing methods for calibrating the deployment angle of endovascular stents primarily focus on preoperative 3D image planning, intraoperative 2D fluoroscopic positioning, and postoperative image verification. These methods typically treat the aortic structure as a relatively fixed spatial object, lacking a continuous sensing and compensation mechanism for the dynamic drift of the visceral artery orifice direction during deployment. Furthermore, during stent deployment, changes in stent deployment status, local aortic morphology, and differences in vascular compliance can lead to dynamic spatial mismatch between the stent connection area and the target visceral artery orifice. Traditional methods struggle to identify these changes in a timely manner and perform active calibration during deployment, easily causing stent fenestration or branch structure positioning deviations, increasing the risks of subsequent guidewire insertion difficulties, insufficient connection, and reduced blood flow reconstruction effectiveness. Summary of the Invention

[0004] This invention provides a method for calibrating the release angle of endovascular stents in the aortic visceral artery region. It can dynamically calibrate the release angle of endovascular stents based on the real-time spatial changes in the aortic visceral artery region, thereby improving the accuracy and reliability of endovascular stent release in complex aortic regions.

[0005] A method for calibrating the release angle of an endovascular stent in the aortic visceral artery region includes the following steps: S1: Before and during the release of the endovascular stent, acquire information on the spatial orientation change of the branch openings in the aortic visceral artery region, and determine the real-time angular drift state of the visceral artery openings relative to the aortic axis based on the information on the spatial orientation change of the branch openings. S2: Based on the real-time angle drift state, match the actual direction of the visceral artery opening with the design direction of the corresponding connection area of ​​the endovascular stent, determine the stent release angle compensation amount caused by the change in aortic structure, and generate release angle calibration results. S3: Based on the release angle calibration result, adjust the stent rotation posture during the release of the endovascular stent so that the corresponding connection area of ​​the stent is synchronously corrected as the opening direction of the visceral artery changes, thus completing the release angle calibration of the endovascular stent in the aortic visceral artery region.

[0006] Optionally, S1 specifically includes: S11: Before and during endovascular stent deployment, acquire real-time time-series three-dimensional angiographic images of the aortic visceral artery region, and simultaneously record cardiac cycle phase signals and respiratory phase signals. S12: Based on the cardiac cycle phase signal and respiratory phase signal, the time-series three-dimensional angiography image is gated and three-dimensionally reconstructed to extract the coordinate set of feature points at the aortic centerline and the openings of each visceral artery. S13: Using the tangent direction of the aortic centerline at the horizontal section where the visceral artery opening is located at the current moment as the real-time axial reference, and the perpendicular line connecting the feature point of the visceral artery opening and the aortic centerline as the radial reference, a local spatial coordinate system is constructed that is dynamically updated with the periodic pulsation morphology of the aorta.

[0007] Optionally, S1 further includes tracking the spatial direction vector of the feature point coordinate set in the local spatial coordinate system in a continuous time series, calculating the real-time deflection angle of the spatial direction vector relative to the real-time axial reference, and determining the real-time deflection angle as the real-time angular drift state of the visceral artery opening relative to the aortic axis.

[0008] Optionally, the process of constructing the local spatial coordinate system includes: For each visceral artery opening feature point, determine the centerline position point in the aortic centerline that is spatially closest to the visceral artery opening feature point, and use the centerline position point as the centerline reference point corresponding to the visceral artery opening feature point. The direction of the aortic centerline at the location of the centerline reference point is taken as the real-time axial reference direction at the current moment, and the direction from the centerline reference point to the corresponding visceral artery opening feature point is taken as the radial reference direction at the current moment. A circumferential reference direction perpendicular to the aortic axis is determined based on the real-time axial reference direction and the radial reference direction, and the real-time axial reference direction, the radial reference direction, and the circumferential reference direction are jointly constructed into a dynamic local spatial coordinate system for the corresponding visceral artery opening; the dynamic local spatial coordinate system is updated synchronously with the changes in aortic pulsation morphology and the changes in the position of the visceral artery opening in the time-series three-dimensional angiography images.

[0009] Optionally, S2 specifically includes: S21: Obtain the theoretical spatial orientation of each connection area of ​​the intracavitary stent pre-stored in the preoperative planning or stent design parameters; S22: The determined real-time angle drift state is converted into the actual spatial direction vector of the visceral artery opening, and the actual spatial direction vector is compared with the theoretical spatial direction vector of the corresponding connection region to calculate the spatial direction deviation matrix between the actual spatial direction vector and the theoretical spatial direction vector. S23: Based on the spatial direction deviation matrix, decompose the circumferential rotation deviation component around the aortic axis and the axial deflection deviation component perpendicular to the aortic axis, and perform a reverse superposition operation based on the circumferential rotation deviation component and the axial deflection deviation component to obtain the stent release angle compensation amount. S24: Combine the stent release angle compensation amount with the timestamp of the current release stage and the real-time deformation phase information of the aorta to generate a release angle calibration result, and output it as an angle calibration command for the stent release system to recognize.

[0010] Optionally, the theoretical spatial direction is referenced to the preset reference direction of the support body axis, including the design deflection angle and design circumferential azimuth angle of the center point of each connection area opening relative to the support body axis.

[0011] Optionally, the bracket release angle compensation amount includes the bracket body rotation compensation angle and the connecting branch orientation compensation angle, and the release angle calibration result includes the compensation execution time, compensation direction and compensation amplitude.

[0012] Optionally, S3 specifically includes: S31: Analyze the release angle calibration result, extract the compensation execution time, compensation direction and compensation amplitude, and convert them into rotation drive parameters for controlling the rotation actuator of the support delivery system; S32: During the endovascular stent release process, continuously acquire the real-time angle drift status updated at the current time point, and decompose the release angle calibration result into a static compensation benchmark and a dynamic tracking margin; based on the dynamic tracking margin, perform real-time incremental correction on the rotation drive parameters to compensate for transient fluctuations in the ostial direction caused by the periodic pulsation of the aorta.

[0013] Optionally, the rotation drive parameters include rotation direction, rotation angle increment, and rotation angular velocity limit value. Based on the corrected rotation drive parameters, the rotation actuator of the delivery system is controlled to drive the stent body to rotate around its axis according to a preset rotation action sequence, so that the actual spatial orientation of the stent's corresponding connection area dynamically follows the real-time actual direction of the visceral artery opening.

[0014] Optionally, S3 further includes comparing the real-time angular deviation between the actual spatial orientation of the corresponding connection area of ​​the stent and the real-time actual direction of the visceral artery opening during the operation of the rotating actuator. When the real-time angular deviation converges to within a preset tolerance threshold range, the current rotation posture is locked and the anchoring structure of the endovascular stent is released to complete the endovascular stent release angle calibration in the aortic visceral artery region.

[0015] The beneficial effects of this invention are: This invention addresses the problem that existing methods for endovascular stent deployment in the aortic visceral artery region primarily rely on preoperative CTA planning and intraoperative static imaging, which struggle to adapt to dynamic changes in the spatial orientation of the visceral artery orifices caused by aortic pulsation, respiratory movements, and interventional procedures. It proposes a deployment angle calibration method based on the real-time angle drift of the visceral artery orifice. By continuously acquiring three-dimensional vascular state changes in the aortic visceral artery region, a local spatial reference relationship is constructed and updated synchronously with the periodic morphological changes of the aorta. The method identifies the directional drift of the visceral artery orifice relative to the aortic axis in real time and matches this drift state with the theoretical spatial orientation of the stent connection area to obtain the spatial orientation deviation and deployment angle compensation. This invention solves the problem of stent fenestration or branch connection area misalignment caused by the inconsistency between the preoperative planned coordinate system and the actual intraoperative vascular coordinate system in traditional methods, improving the accuracy and adaptability of stent deployment angle calibration in complex aortic visceral artery regions.

[0016] This invention addresses the problem of difficulty in maintaining angle calibration results due to continuous changes in aortic morphology during endovascular stent deployment. It proposes a deployment posture control method based on a combination of static compensation benchmark and dynamic tracking margin. By converting the deployment angle calibration results into rotational drive parameters executable by the stent delivery system, and incrementally correcting these parameters based on real-time angle drift, the rotational posture of the stent body and the orientation of the connection area can dynamically follow the actual direction of the visceral artery opening. By comparing the angular deviation between the actual spatial orientation of the stent connection area and the actual direction of the visceral artery opening in real time, the rotational posture is locked and stent deployment is completed once the deviation converges to a preset tolerance range. This invention achieves active angle calibration and dynamic posture maintenance during stent deployment, reducing the final deployment deviation caused by aortic dynamic deformation, improving the matching reliability of fenestrated or branched endovascular stents with visceral artery openings, and reducing the risk of subsequent branch connection difficulties and abnormal blood flow reconstruction. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the method flow according to an embodiment of the present invention; Figure 2 This is a schematic diagram illustrating the execution steps of S2 in an embodiment of the present invention; Figure 3 This is a schematic diagram of the execution steps of S3 in an embodiment of the present invention. Detailed Implementation

[0019] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Those skilled in the art may employ other alternative methods to implement some well-known technologies; moreover, the accompanying drawings are only for more specific description of the embodiments and are not intended to specifically limit the present invention.

[0020] like Figures 1-3 As shown, a method for calibrating the release angle of an endovascular stent in the aortic visceral artery region includes the following steps: S1: Before and during the release of the endovascular stent, acquire information on the spatial orientation changes of the branch openings in the aortic visceral artery region, and determine the real-time angular drift state of the visceral artery openings relative to the aortic axis based on the information on the spatial orientation changes of the branch openings.

[0021] S1 specifically includes: S11: Before and during the release of the endovascular stent, the three-dimensional angiography image sequence of the aortic artery region is continuously acquired at preset time intervals using an intraoperative three-dimensional angiography device. At the same time, the patient's electrocardiogram (ECG) signal and respiratory monitoring signal are acquired. The ECG signal is converted into the corresponding cardiac cycle phase signal, and the respiratory monitoring signal is converted into the corresponding respiratory phase signal.

[0022] The acquired continuous three-dimensional angiography images are represented as follows: ; in, Represents time-series three-dimensional angiography images. Indicates the first Three-dimensional angiography images corresponding to each acquisition time. , Indicates the number of images acquired consecutively. The current acquisition time is indicated. The preset time interval is used to determine the sampling density of the intraoperative three-dimensional angiography image sequence. The value is 0.5, which ensures that at least multiple time points of three-dimensional vascular state change information can be acquired within each cardiac cycle, and can cover the aortic spatial attitude change process within the respiratory cycle, thereby ensuring that the time-series three-dimensional angiography images can continuously represent the dynamic drift state of the visceral artery opening direction.

[0023] The synchronously acquired cardiac cycle phase signal and respiratory phase signal are represented as follows: ; ; in, This represents a sequence of phase signals during the cardiac cycle. Indicates the first The cardiac cycle phase corresponding to each time point Represents the respiratory phase signal sequence. Indicates the first The respiratory phase corresponding to each time point.

[0024] S12: Based on cardiac cycle phase signals and respiratory phase signals, gating and three-dimensional reconstruction of time-series three-dimensional angiography images are performed to reduce the influence of periodic displacement of vascular position caused by cardiac pulsation and respiratory movement, and the coordinate set of feature points at the aortic centerline and the openings of each visceral artery is extracted from the reconstructed three-dimensional aortic structure.

[0025] Based on the cardiac cycle phase signal and the respiratory phase signal, a three-dimensional angiographic image with the same phase is selected as the reconstruction input, represented as: ; in, This represents the set of three-dimensional angiography images after gating. Indicates the selected target cardiac cycle phase. Indicates the selected target respiratory phase.

[0026] Based on the selected 3D angiography images, vascular structure reconstruction was performed to obtain the coordinate set of feature points at the aortic centerline and the openings of visceral arteries, represented as follows: ; ; in, Indicates the central line of the aorta. Indicates the first on the central axis of the aorta One spatial sampling point, This represents the set of coordinates of feature points at the opening of visceral arteries. Indicates the first The coordinates of the feature points corresponding to the openings of the visceral arteries.

[0027] S13: Using the tangent direction of the aortic centerline at the horizontal section where the visceral artery opening is located at the current moment as the real axial reference, and the direction of the perpendicular line connecting the characteristic point of the visceral artery opening and the aortic centerline as the radial reference, a local spatial coordinate system is constructed that is dynamically updated with the periodic pulsation morphology of the aorta.

[0028] For any visceral artery opening feature point At the aortic centerline The corresponding projection point is determined in the middle, and is represented as: ; in, Representing feature points The corresponding projection point on the central line of the aorta. This indicates spatial distance calculation.

[0029] Using the tangential direction of the aortic centerline at the projection point as the real axial reference, it is expressed as: ; in, This represents the real axis reference direction vector at the current moment. This indicates the direction of tangential change of the aortic centerline at the projection point at the current moment.

[0030] Using the direction from the projection point of the aortic centerline to the characteristic point of the visceral artery opening as the radial reference, it is expressed as: ; in, This represents the radial reference direction vector at the current moment. This indicates the coordinates of the feature point of the visceral artery opening at the current moment. This indicates the coordinates of the projection point of the aortic centerline at the current moment.

[0031] A dynamic local space coordinate system is constructed based on the real-time axial and radial reference directions, and is represented as follows: ; in, Indicates the first The dynamic local spatial coordinate system corresponding to the opening of each visceral artery It indicates the circumferential direction determined by the axial reference direction and the radial reference direction.

[0032] S14: In the continuous time series, the coordinate set of feature points at the opening of each visceral artery is mapped to the local spatial coordinate system of the artery. The trajectory of the change of the feature point direction is tracked to obtain the visceral artery opening direction vector. The deflection angle of the direction vector relative to the real-time axial reference is calculated. The real-time deflection angle is determined as the real-time angular drift state of the visceral artery opening relative to the aortic axis.

[0033] For any point in a continuous time series, the vector of the visceral artery opening direction is calculated as follows: ; in, Indicates the first The spatial direction vector of the opening of each visceral artery at the current moment.

[0034] The angle between this direction vector and the real-time axial reference direction is calculated and expressed as: ; in, Indicates the current time. The real-time deflection angle of each visceral artery opening relative to the aortic axis. This indicates the inner product operation of direction vectors.

[0035] The real-time deflection angle change in a continuous time series is represented as: ; in, This indicates the real-time angular drift of the visceral artery orifice relative to the aortic axis. This indicates the reference deflection angle in the initial state before stent release. This indicates the initial time point before stent release.

[0036] In the above manner, the real-time angular drift state of the visceral artery opening relative to the aortic axis, which changes with aortic pulsation, respiratory movement, and interventional procedures, is obtained. This real-time angular drift state serves as the basis for calculating the stent release angle compensation and generating the release angle calibration results in subsequent steps.

[0037] S2: Based on the real-time angle drift state, the actual direction of the visceral artery opening is matched with the design direction of the corresponding connection area of ​​the endovascular stent to determine the stent release angle compensation amount caused by changes in the aortic structure and generate release angle calibration results.

[0038] S2 specifically includes: S21: Before the intracavitary stent is released, read the pre-stored intracavitary stent structure information in the preoperative planning data or stent design parameters to obtain the theoretical spatial orientation of each connection area of ​​the selected intracavitary stent.

[0039] The connecting regions include fenestrated areas or branch connecting regions corresponding to visceral arteries such as the celiac trunk, superior mesenteric artery, and renal artery.

[0040] Using the main axis of the intracavitary stent as a spatial direction reference, a coordinate reference system for the stent body is established. Based on the spatial position of the center point of the opening of each connection area in this reference coordinate system, the design deflection relationship of each connection area relative to the main axis of the stent body is determined.

[0041] For any connected region, its theoretical spatial orientation is represented as: ; in, Indicates the first The theoretical spatial orientation of each connected region Indicates the first The design deflection angle of each connection area relative to the axis of the main support body Indicates the first The design circumferential azimuth angle of each connection area relative to the reference direction of the main support body. Indicates the connection area number.

[0042] By using the above method, the theoretical spatial orientation of each connection area of ​​the intracavitary stent is obtained, which serves as the benchmark for subsequent spatial orientation comparison.

[0043] S22: Based on the real-time angular drift state of the visceral artery openings relative to the aortic axis obtained in S1, convert the positional changes of each visceral artery opening into the actual spatial direction vector under the current dynamic state of the aorta.

[0044] For any visceral artery opening, its actual spatial direction vector is represented as: ; in, Indicates the first The actual spatial direction vector of each visceral artery opening at the current moment. This indicates the current time of stent release.

[0045] The actual spatial direction vector is spatially matched with the theoretical spatial direction vector of the corresponding intracavitary stent connection area, and the directional difference between the two is calculated.

[0046] Spatial orientation deviation is expressed as: ; in, Indicates the first The first connection region and the first Spatial directional deviation between the openings of the visceral arteries Indicates the theoretical spatial direction of the connected region. This indicates the actual spatial direction of the corresponding visceral artery opening.

[0047] Arrange the spatial orientation deviations corresponding to all connected regions to form a spatial orientation deviation matrix, represented as follows: ; in, This represents the spatial orientation deviation matrix at the current moment. Indicates the number of intracavitary stent connection areas. This indicates the number of openings of the corresponding visceral arteries.

[0048] The dynamic spatial mismatch between the endovascular stent connection area and the visceral artery opening is obtained by using the spatial orientation deviation matrix.

[0049] This step, based on the real-time angular drift of the visceral artery openings relative to the aortic axis obtained in S1, spatially transforms the positional changes of each visceral artery opening under the current dynamic morphology of the aorta, obtaining the actual spatial orientation of the visceral artery openings corresponding to the current release moment. Subsequently, the actual spatial orientation of the visceral artery openings is matched one-to-one with the theoretical spatial orientation of the corresponding connection region of the endovascular stent obtained in advance. By comparing the directional differences between the two in the aortic spatial coordinate system, the spatial orientation deviation between each connection region and the corresponding visceral artery opening is determined. The spatial orientation deviations corresponding to all connection regions are summarized and arranged to form a spatial orientation deviation matrix, which characterizes the dynamic spatial mismatch between each connection region of the endovascular stent and the target visceral artery opening. The spatial orientation deviation matrix reflects the real-time changes between the actual orientation of the visceral artery opening and the stent design orientation caused by aortic pulsation deformation, respiratory displacement, and interventional operations, and serves as the input basis for subsequent calculation of stent release angle compensation.

[0050] S23: Since the angular deviation of the aortic visceral artery region usually includes both rotational deviation around the aortic axis and directional offset perpendicular to the aortic axis, it is necessary to decompose the spatial directional deviation matrix into directions.

[0051] Based on the aortic axial direction, the directional deviation in the spatial directional deviation matrix is ​​decomposed to obtain the circumferential rotational deviation component around the aortic axis. and the axial deflection component perpendicular to the aortic axis ; in, This represents the circumferential rotational deviation component, used to characterize the rotational mismatch of the endovascular stent connection region around the aortic axis. This represents the axial deflection deviation component, used to characterize the tilt mismatch of the connecting region along the spatial direction of the aorta.

[0052] The process of decomposing the directional deviation in the spatial directional deviation matrix is ​​as follows: 1. Determine the aortic axial reference direction based on the current aortic centerline direction, and map the spatial direction deviations corresponding to each connected region in the spatial direction deviation matrix to the spatial direction where the aortic axial reference direction is located; 2. Calculate the projection changes of each spatial directional deviation in the rotation direction around the aortic axis, and extract the part reflecting the degree of circumferential misalignment between the stent connection area and the visceral artery opening as the circumferential rotation deviation component; 3. Extract the directional changes perpendicular to the aortic axial reference direction from each spatial deviation to obtain the axial deflection deviation component that reflects the degree of inclination of the connecting region along the radial or axial direction of the aorta.

[0053] The reverse compensation calculation for the support release attitude is performed based on the circumferential rotational deviation component and the axial deflection deviation component, and is expressed as follows: ; in, This indicates the amount of compensation for the stent release angle. This function represents the reverse compensation calculation based on spatial orientation deviation. It is used to determine the stent release angle compensation amount that can offset the drift of the visceral artery opening direction based on the circumferential rotation deviation component and axial deflection deviation component obtained by decomposing the spatial orientation deviation matrix.

[0054] The execution steps of the function for reverse compensation calculation based on spatial orientation deviation are as follows: 1. Analyze the deviation corresponding to each connected region in the spatial direction deviation matrix, determine the degree of influence of the deviation in the circumferential and axial directions of the aorta, and decompose the deviation into circumferential rotational deviation component and axial deflection deviation component. 2. Based on the importance of the visceral artery corresponding to each connection region, the spatial distance between the connection region and the target vessel opening, and the current release stage, the deviation components of different connection regions are weighted and fused to obtain the comprehensive deviation that needs to be corrected for the overall release posture of the stent. 3. Generate a compensation direction opposite to the actual deviation direction based on the comprehensive deviation direction, and convert the detected visceral artery opening drift direction into the reverse adjustment direction of the stent release system to offset the angle mismatch caused by the dynamic changes of the aorta; 4. Based on the transmission relationship between the main structure of the support and the structure of the connecting area, the circumferential rotational deviation is converted into the rotational compensation angle of the main support, and the axial deflection deviation is converted into the directional compensation angle of the connecting branch. 5. Based on the current real-time aortic deformation phase and stent release stage, the rotation compensation angle of the stent body and the orientation compensation angle of the connecting branch are corrected in a timely manner to avoid overcompensation during the transient positional changes caused by aortic periodic pulsation or respiratory motion. 6. Output the final stent release angle compensation amount and convert this compensation amount into a release angle calibration result, which is used to control the rotation direction and adjustment range during the stent release process.

[0055] The stent release angle compensation amount is further broken down as follows: ; in, Indicates the rotation compensation angle of the main support body. Indicates the directional compensation angle of the connecting branch.

[0056] Through the above processing, the rotation direction of the main support body and the direction of each connection area can be compensated accordingly.

[0057] S24: After obtaining the stent release angle compensation amount, the timing of compensation execution is determined by combining the timestamp corresponding to the current stent release stage and the real-time deformation phase information of the aorta, so as to avoid performing incorrect compensation during the transient position change stage caused by the periodic movement of the aorta.

[0058] The release angle calibration result is generated based on the current release phase status and is expressed as follows: ; in, This indicates the release angle calibration result. This indicates the amount of compensation for the stent release angle. Indicates the timestamp of compensation execution. This indicates the current real-time deformation phase information of the aorta.

[0059] Release angle calibration results include: The compensation execution time is used to determine the time point for the stent release system to adjust the execution angle; The compensation direction is used to determine the rotation direction of the main support body and the adjustment direction of the connection area; The compensation amplitude is used to determine the corresponding rotation adjustment amount.

[0060] Finally, the release angle calibration result is converted into an angle calibration command that the stent release system can recognize and output to the stent release control terminal, so that the subsequent release process can adjust the angle according to the real-time spatial changes in the aortic visceral artery region.

[0061] Through the above steps, the release angle calibration is achieved based on the spatial mismatch between the dynamic drift state of the aortic visceral artery orifice and the theoretical direction of the stent connection area. This avoids the stent release direction deviation caused by planning the angle solely based on preoperative static images, and improves the matching accuracy between the fenestration area or branch connection area and the target vessel during endovascular stent release in complex aortic visceral artery regions.

[0062] S3: Based on the release angle calibration results, adjust the stent rotation posture during the endovascular stent release process so that the corresponding connection area of ​​the stent is synchronously corrected as the opening direction of the visceral artery changes, thus completing the endovascular stent release angle calibration in the aortic visceral artery region.

[0063] S3 specifically includes: S31: Analyze the release angle calibration results obtained in S24, extract the corresponding compensation execution time, compensation direction and compensation amplitude, and convert the release angle calibration results into executable rotational variation parameters according to the control mode of the rotating actuator of the support delivery system.

[0064] The rotational variation parameters include rotational direction change, rotational angle increment, and rotational angular velocity limit, which are used to control the rotational actuator of the support delivery system to complete the corresponding angle adjustment.

[0065] The rotational variation parameter is expressed as: ; in, This indicates the rotational parameters at the current moment. Indicates rotational change of direction. Indicates the increment of rotation angle. Indicates the current stent release time. This represents the rotational angular velocity limit, used to restrict the maximum rotational speed of the stent delivery system's rotating actuator during angle calibration. This prevents excessively rapid rotational adjustments from causing significant transient friction, torsional loads, and positional disturbances between the endovascular stent and the aortic wall, while ensuring timely response to changes in the orientation of the visceral artery openings during the calibration process. The value is typically 0.5-3° / s. During endovascular stent deployment in the aortic-visceral artery region, angle calibration does not involve large-amplitude, rapid rotation. Instead, it primarily compensates for small-scale angle mismatches caused by aortic cross-sectional rotational drift, changes in vascular compliance, and changes in stent deployment posture. In clinical practice, the angle adjustment of fenestrated or branched endovascular stents is usually within a certain range. Within a certain range, slow posture correction needs to be completed before the stent is fully anchored. When the rotational angular velocity is higher than 3° / s, since the stent is still in the released state, the rotational action of the distal end of the delivery system may produce lag and torsional release phenomena through the flexible structure of the catheter, causing a new deviation between the proximal operation angle and the actual rotation angle of the distal stent. At the same time, it may increase local mechanical stimulation of the vessel wall, which is not conducive to precise control. When the rotational angular velocity is lower than 0.5° / s, although rotational stability can be improved, due to the continuous pulsation and respiratory-induced displacement in the aortic visceral artery region, the adjustment speed is too low and may not be able to complete the angle compensation within the effective release window, causing the stent connection area to miss the best alignment opportunity.

[0066] In the specific execution process, the rotation direction and rotation angle increment are determined according to the rotation compensation angle of the stent body, and the rotation angle velocity limit value is determined according to the current release stage and the real-time motion state of the aorta, so that the rotation actuator can complete the angle adjustment while ensuring the stable release of the stent.

[0067] Through the above processing, the release angle calibration result obtained based on the spatial drift of the aortic visceral artery opening is converted into a rotation control command that the stent delivery system can directly execute.

[0068] S32: During the endovascular stent deployment process, the real-time angular drift status of the visceral artery opening relative to the aortic axis at the current time point is continuously acquired. Based on the compensation trend in the deployment angle calibration results, the deployment angle calibration results are divided into a static compensation benchmark to offset the overall spatial mismatch and a dynamic tracking margin to respond to the periodic changes of the aorta.

[0069] Among them, the static compensation benchmark is used to correct the fixed deviation between the preoperative planned direction and the current actual vascular direction, while the dynamic tracking margin is used to compensate for the transient angle changes caused by aortic pulsation and respiratory movements during the release process.

[0070] The release angle calibration results are decomposed into: ; in, This indicates the current release angle calibration result. This represents the static compensation baseline, used to characterize the amount of angle compensation required to offset the fixed directional deviation between the preoperative planned state and the actual intraoperative spatial state of the aorta and visceral arteries during endovascular stent deployment. The value ranges from 3-5° to cover the common fixed angular mismatch range in the aorta and visceral artery region, while avoiding excessive initial rotational compensation that could affect stent deployment stability. This indicates the dynamic tracking margin.

[0071] Based on the current real-time angle drift changes, the rotation drive parameters are incrementally corrected, as follows: ; in, This indicates the corrected rotational drive parameters. This represents the real-time incremental correction amount generated based on the dynamic tracking margin.

[0072] During the specific execution process, the direction of the visceral artery opening is continuously shifted based on the changing trend of the real-time angle drift state between consecutive time points. When transient directional fluctuations caused by the periodic pulsation of the aorta are detected, the rotation angle increment is finely adjusted by dynamically tracking the margin to keep the stent rotation posture near the target direction.

[0073] S33: Based on the corrected rotational drive parameters obtained in S32, send them to the rotational actuator of the stent delivery system, so that the rotational actuator drives the stent body inside the cavity to rotate and adjust around its axis according to the preset rotational action sequence.

[0074] The preset rotation sequence is divided according to the release phase of the support, including the initial rotation adjustment phase, the release and holding phase, and the angle fine-tuning phase.

[0075] During the initial rotation adjustment phase, the overall orientation of the stent body is corrected based on the rotation angle increment, so that the stent connection area quickly approaches the direction of the corresponding visceral artery opening. During the release and hold phase, the rotational attitude is slightly adjusted based on the dynamic tracking margin to counteract the directional changes caused by aortic pulsation; During the angle fine-tuning phase, precise rotational adjustments are performed based on the real-time trend of angle deviation changes, so that the stent connection area gradually approaches the direction of the target visceral artery opening.

[0076] Through the above control process, the actual spatial orientation of the stent's corresponding connection area can dynamically follow the actual direction of the visceral artery opening in real time.

[0077] S34: During the operation of the rotating actuator, continuously acquire the actual spatial orientation of the corresponding connection area of ​​the stent and compare it with the actual direction of the visceral artery opening at the current moment to obtain the real-time angle deviation.

[0078] Real-time angle deviation is expressed as: ; in, This indicates the real-time angle deviation at the current moment. This indicates the actual spatial orientation of the connection area corresponding to the bracket. This indicates the actual direction of the opening of the visceral artery in real time.

[0079] The completion of angle calibration is determined by the real-time angle deviation changes over a continuous period of time.

[0080] When the real-time angle deviation gradually decreases and converges to the preset tolerance threshold range, it is determined that the current stent connection area and the visceral artery opening have reached the target space matching state, and the rotation actuator is controlled to lock the current rotation posture.

[0081] After rotational attitude locking, the anchoring structure of the intracavitary stent is released, allowing the stent to maintain its current calibrated spatial orientation to complete the final implantation.

[0082] Through the above steps, dynamic calibration of the endovascular stent release angle based on the real-time spatial orientation change of the aortic visceral artery opening is achieved, enabling the stent connection area to continuously match the orientation of the target visceral artery opening during release, reducing stent release angle deviation caused by dynamic anatomical changes in complex aortic regions.

[0083] The preset tolerance threshold is used to determine whether the actual spatial orientation of the corresponding connection area of ​​the endovascular stent and the real-time actual direction of the visceral artery opening have reached an acceptable matching state. That is, when the real-time angle deviation converges to this range, it is considered that the stent connection area has met the release angle accuracy requirements, and the rotation posture can be locked and subsequent anchoring release can be performed. It is set to 1-3°. When the preset tolerance threshold is less than 1°, due to the proximity to the range of intraoperative three-dimensional image reconstruction error, vascular periodic motion error and actuator control error, the rotation actuator may continuously make small adjustments, resulting in a prolonged stent release time. At the same time, it is easily affected by transient aortic pulsation and will produce overcorrection. When the preset tolerance threshold is greater than 3°, although it can improve the posture locking speed, for visceral artery region fenestration or branch connection structures, a large residual angle deviation may cause circumferential misalignment between the stent connection area and the target vessel opening, increasing the risk of difficulty in subsequent branch catheter entry and insufficient connection.

[0084] This invention encompasses any substitutions, modifications, equivalent methods, and solutions made within the spirit and scope of this invention. To provide the public with a thorough understanding of this invention, specific details are described in detail in the following preferred embodiments; however, those skilled in the art will fully understand the invention even without these details. Furthermore, to avoid unnecessary misunderstanding of the essence of this invention, well-known methods, processes, procedures, components, and circuits are not described in detail.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta, characterized in that, Includes the following steps: S1: Before and during the release of the endovascular stent, acquire information on the spatial orientation change of the branch openings in the aortic visceral artery region, and determine the real-time angular drift state of the visceral artery openings relative to the aortic axis based on the information on the spatial orientation change of the branch openings. S2: Based on the real-time angle drift state, match the actual direction of the visceral artery opening with the design direction of the corresponding connection area of ​​the endovascular stent, determine the stent release angle compensation amount caused by the change in aortic structure, and generate release angle calibration results. S3: Based on the release angle calibration result, adjust the stent rotation posture during the release of the endovascular stent so that the corresponding connection area of ​​the stent is synchronously corrected as the opening direction of the visceral artery changes, thus completing the release angle calibration of the endovascular stent in the aortic visceral artery region.

2. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 1, characterized in that, S1 specifically includes: S11: Before and during endovascular stent deployment, acquire real-time time-series three-dimensional angiographic images of the aortic visceral artery region, and simultaneously record cardiac cycle phase signals and respiratory phase signals. S12: Based on the cardiac cycle phase signal and respiratory phase signal, the time-series three-dimensional angiography image is gated and three-dimensionally reconstructed to extract the coordinate set of feature points at the aortic centerline and the openings of each visceral artery. S13: Using the tangent direction of the aortic centerline at the horizontal section where the visceral artery opening is located at the current moment as the real-time axial reference, and the perpendicular line connecting the feature point of the visceral artery opening and the aortic centerline as the radial reference, a local spatial coordinate system is constructed that is dynamically updated with the periodic pulsation morphology of the aorta.

3. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 2, characterized in that, The S1 further includes tracking the spatial direction vector of the feature point coordinate set in the local spatial coordinate system in a continuous time series, calculating the real-time deflection angle of the spatial direction vector relative to the real-time axial reference, and determining the real-time deflection angle as the real-time angular drift state of the visceral artery opening relative to the aortic axis.

4. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 2, characterized in that, The process of constructing the local spatial coordinate system includes: For each visceral artery opening feature point, determine the centerline position point in the aortic centerline that is spatially closest to the visceral artery opening feature point, and use the centerline position point as the centerline reference point corresponding to the visceral artery opening feature point. The direction of the aortic centerline at the location of the centerline reference point is taken as the real-time axial reference direction at the current moment, and the direction from the centerline reference point to the corresponding visceral artery opening feature point is taken as the radial reference direction at the current moment. A circumferential reference direction perpendicular to the aortic axis is determined based on the real-time axial reference direction and the radial reference direction, and the real-time axial reference direction, the radial reference direction, and the circumferential reference direction are jointly constructed into a dynamic local spatial coordinate system for the corresponding visceral artery opening; the dynamic local spatial coordinate system is updated synchronously with the changes in aortic pulsation morphology and the changes in the position of the visceral artery opening in the time-series three-dimensional angiography images.

5. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 1, characterized in that, S2 specifically includes: S21: Obtain the theoretical spatial orientation of each connection area of ​​the intracavitary stent pre-stored in the preoperative planning or stent design parameters; S22: The determined real-time angle drift state is converted into the actual spatial direction vector of the visceral artery opening, and the actual spatial direction vector is compared with the theoretical spatial direction vector of the corresponding connection region to calculate the spatial direction deviation matrix between the actual spatial direction vector and the theoretical spatial direction vector. S23: Based on the spatial direction deviation matrix, decompose the circumferential rotation deviation component around the aortic axis and the axial deflection deviation component perpendicular to the aortic axis, and perform a reverse superposition operation based on the circumferential rotation deviation component and the axial deflection deviation component to obtain the stent release angle compensation amount. S24: Combine the stent release angle compensation amount with the timestamp of the current release stage and the real-time deformation phase information of the aorta to generate a release angle calibration result, and output it as an angle calibration command for the stent release system to recognize.

6. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 5, characterized in that, The theoretical spatial direction is referenced to the preset reference direction of the support body axis, including the design deflection angle and design circumferential azimuth angle of the center point of each connection area opening relative to the support body axis.

7. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 5, characterized in that, The release angle compensation amount of the support includes the rotation compensation angle of the support body and the orientation compensation angle of the connecting branch. The release angle calibration result includes the compensation execution time, compensation direction and compensation amplitude.

8. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 1, characterized in that, S3 specifically includes: S31: Analyze the release angle calibration result, extract the compensation execution time, compensation direction and compensation amplitude, and convert them into rotation drive parameters for controlling the rotation actuator of the support delivery system; S32: During the endovascular stent release process, continuously acquire the real-time angle drift status updated at the current time point, and decompose the release angle calibration result into a static compensation benchmark and a dynamic tracking margin; based on the dynamic tracking margin, perform real-time incremental correction on the rotation drive parameters to compensate for transient fluctuations in the ostial direction caused by the periodic pulsation of the aorta.

9. A method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 8, characterized in that, The rotation drive parameters include rotation direction, rotation angle increment, and rotation angular velocity limit. Based on the corrected rotation drive parameters, the rotation actuator of the delivery system is controlled to drive the stent body to rotate around its axis according to a preset rotation action sequence, so that the actual spatial orientation of the stent's corresponding connection area dynamically follows the real-time actual direction of the visceral artery opening.

10. The method for calibrating the release angle of an endovascular stent in the visceral artery region of the aorta according to claim 9, characterized in that, S3 further includes, during the operation of the rotating actuator, comparing the real-time angular deviation between the actual spatial orientation of the corresponding connection area of ​​the stent and the real-time actual direction of the visceral artery opening. When the real-time angular deviation converges to within a preset tolerance threshold range, locking the current rotation posture and releasing the anchoring structure of the endovascular stent, thereby completing the calibration of the endovascular stent release angle in the aortic visceral artery region.

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