A method and system for stabilizing and adjusting a three-dimensional view based on a catheter perspective

Abstract

A kind of three-dimensional view anti-shake and adjustment method and system based on catheter perspective, it contains the following steps: receiving catheter and electrode position;According to current perspective and received catheter and electrode position, calculate new perspective;Anti-shake calculation is carried out based on new perspective and current perspective;Based on the position and angle of three-dimensional view camera are adjusted after anti-shake new perspective.Adjustment system contains: signal processing module, for receiving and processing the signal of catheter and electrode position, and provide to display device;Computer processing module, for continuously receiving the position information of electrode on catheter obtained by signal processing module, calculate and real-time display three-dimensional imaging graph and catheter position, and provide to display device for observation adjustment.The present application displays the certain tracking perspective of three-dimensional structure graph on visual device, displays the real-time position of catheter with calculated perspective, facilitates the observation of specific area, greatly reduces the time and delay of manual adjustment perspective.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electrosurgery, in particular to a catheter perspective-based three-dimensional view anti-shake and adjustment method and system. BACKGROUND

[0002] In the existing catheter intervention surgery of cardiology, by obtaining the real-time position signal of the catheter on the endocardium, a three-dimensional heart chamber model can be constructed, and the real-time position of the catheter is displayed at the same time. Different perspectives are changed to observe different heart regions. The operation of adjusting the perspective is similar to the operation of ordinary three-dimensional software. In order to observe the heart chamber region of interest, a lot of time is often spent on adjusting the perspective.

[0003] According to the patent document retrieval, CN108720921A invention patent application discloses an automatic adjustment and tracking method of perspective during catheter ablation. The perspective of the three-dimensional view is controlled by detecting the ablation target and through the pre-setting. In essence, the perspective is controlled by the ablation target position.

[0004] CN109715103A invention patent application relates to a device for remote operation of robotic catheterization. A MR-safe robot body and actuator are used to allow a remote controller to control the operation of the actuator to remotely manipulate the catheter in or outside the patient's body, thereby obtaining MR intraoperative images. However, the above-mentioned application focuses on real-time MR control and positioning, rather than three-dimensional imaging. Although the application mentions endoscopic view, it does not further explain the three-dimensional form and source of the view, and does not further operate on the basis of the view.

[0005] CN104127243A invention application discloses a catheter anti-shake control method of a cardiac interventional magnetic navigation system. The control method finds a trajectory suitable for the catheter to change the posture according to the angle difference between the current posture of the catheter and the next target posture, so that the catheter is always in a posture controllable state during the posture transformation. The anti-shake method is used to control and is not used for the display of three-dimensional view. SUMMARY

[0006] The present application is to overcome the deficiencies of the prior art, and provides a catheter perspective-based three-dimensional view anti-shake and adjustment method.

[0007] A catheter perspective-based three-dimensional view anti-shake and adjustment method comprises the following steps:

[0008] S1, receiving the position of the catheter and the electrode;

[0009] S2, calculating a new perspective according to the current perspective and the received position of the catheter and the electrode;

[0010] S3, performing anti-shake calculation based on the new view angle and the current view angle;

[0011] S4, adjusting the position and angle of the three-dimensional view camera based on the anti-shake new view angle.

[0012] A three-dimensional view anti-shake and adjustment system based on a catheter view angle comprises:

[0013] A signal processing module for receiving and processing signals of the catheter and electrode positions and providing to a display device;

[0014] A computer processing module for continuously receiving position information of the electrodes on the catheter obtained by the signal processing module, calculating and displaying a three-dimensional imaging graph and the catheter position in real time, and providing to a display device for observation and adjustment.

[0015] The present application has the following beneficial effects compared with the prior art:

[0016] In the prior art, different view angles are changed to observe different heart regions, and the operation of adjusting the view angle is similar to the operation of ordinary three-dimensional software, and often a lot of time is spent on adjusting the view angle in order to observe the interested heart cavity region. The present application displays a certain tracking view angle of a three-dimensional structure graph on a visual device, calculates the view angle parameters through the catheter orientation, performs superposition of anti-shake and adjustment calculation, displays the real-time position of the catheter with the calculated view angle, facilitates observation of a specific region, and greatly reduces the time and delay of manual adjustment of the view angle.

[0017] The technical solutions of the present application will be further described below in combination with the drawings and embodiments: BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A flowchart of the three-dimensional view anti-shake and adjustment method based on a catheter view angle of the present application;

[0019] Figure 2 A three-dimensional view anti-shake and adjustment system based on a catheter view angle in an embodiment of the present application

[0020] Figure 3 A three-dimensional view angle and parameter graph in an embodiment of the present application;

[0021] Figure 4 A three-dimensional view angle calculation flowchart in an embodiment of the present application;

[0022] Figure 5 A three-dimensional heart model graph constructed by the system in an embodiment of the present application. DETAILED DESCRIPTION

[0023] The embodiments of the technical solutions of the present application will be described in detail below with reference to the drawings. It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should be understood as their usual meanings understood by those skilled in the art to which the present application belongs.

[0024] In combination Figure 1 It is explained that a three-dimensional view anti-shake and adjustment method based on a catheter perspective includes the following steps:

[0025] S1: receiving a catheter and electrode position;

[0026] S2: calculating a new perspective according to the current perspective and the received catheter and electrode position;

[0027] S3: performing anti-shake calculation based on the new perspective and the current perspective;

[0028] S4: adjusting the position and angle of the three-dimensional view camera based on the anti-shake new perspective.

[0029] In the anti-shake and perspective adjustment process of the present application, enabling the tracking mode directly switches the three-dimensional display perspective to the catheter perspective, and disabling the tracking mode keeps the last catheter tracking perspective, thereby allowing a one-time switch to the catheter perspective by enabling and then disabling the tracking mode. After enabling the catheter perspective tracking mode, the perspective is continuously adjusted according to the received catheter and electrode position information. The receiving and adjusting cycle is repeated, and a complete adjustment and anti-shake perspective process is as shown in Figure 1

[0030] Further, the position received in step S1 is the real-time position of each electrode on each catheter, and the position coordinates have been converted to the same coordinate system as the 3D model obtained by modeling. These information is the basis for subsequent new perspective calculation.

[0031] Based on the above implementation, the calculation of the new perspective of the catheter in step S2 is that before each adjustment of the perspective, the three-dimensional model currently being displayed has a perspective, which is referred to as the current perspective. In order to maintain the stability of the picture, the upward vector of the current perspective remains unchanged. The calculation method of the new perspective according to the real-time catheter and electrode position can be various, for example, according to the positions of the catheter head electrode 1 and the electrode 2, a direction vector is calculated, and the direction vector is used as the new perspective direction. In one embodiment of the present embodiment, the three-dimensional view perspective calculation is performed as shown in the flowchart of Figure 3

[0032] The calculation process of the new perspective in step S2 is as follows:

[0033] S2-1, obtaining the current upward vector of the camera;

[0034] ​​S2-2, get the position of catheter electrode 1 and electrode 2, calculate the target point position of camera according to the position of electrode 1;

[0035] S2-3, calculate the projection direction according to the position of electrode 1 and electrode 2, and make normalization processing;

[0036] S2-4, calculate the cross product of the projection direction and the upward vector, and judge whether the upward vector is parallel to the new projection direction;

[0037] S2-5, if parallel, adjust the upward vector to the standard vector;

[0038] S2-6, calculate the origin position according to the user-specified scaling factor;

[0039] S2-7, calculate the translation vector, and calculate the new origin position according to the user-specified angle;

[0040] S2-8, complete the calculation of the new view angle, and enter the anti-shake calculation.

[0041] The calculation process of step S2 needs to use the current view angle of the three-dimensional view, because the position of the catheter and the electrode cannot completely determine all parameters of the view angle, using the current view angle as an auxiliary input parameter can ensure that the view angle will not change greatly, thereby avoiding causing large shaking of the view picture.

[0042] In another embodiment of the present embodiment, different electrodes of the catheter can be specified, such as electrode 1 and electrode 4 (end electrode), or the direction vector can be calculated according to the comprehensive value of multiple electrodes.

[0043] In another embodiment of the present embodiment, a predefined angle can adjust the view angle direction to a direction with a specified angle with the electrode pointing direction, which is convenient for observing the region of interest. The size of the angle can also be adjusted at any time through control, which is convenient for displaying from different angles.

[0044] Due to the continuous change of the catheter position, the operator enables the catheter tracking, in order to prevent the view angle from changing too fast due to the change of the catheter position, an anti-shake design can be added, and there are various methods for anti-shake, for example: the angle change between the new direction and the original direction can be calculated, and only when the angle change exceeds a certain threshold, the new direction is enabled, or a moving average algorithm or an exponential average algorithm can also be used.

[0045] In an embodiment of the present embodiment, in step S3, an exponential average algorithm is used to calculate the anti-shake view angle, and the method is as follows:

[0046] Record the view angle parameters P of the last N times, N can be specified by the user, and S is the view angle parameter after anti-shake processing;

[0047]

[0048] Wherein, S0 represents the initial value of the view angle after the anti-shake calculation, P0 represents the initial value of the view angle before the anti-shake calculation, S t represents the value of the view angle after the anti-shake calculation at time t, S t-1 represents the value of the view angle after the anti-shake calculation at time t-1, P t represents the value of the view angle before the anti-shake calculation at time t, and a is the exponential average coefficient.

[0049] The smoothed view angle parameter S is used for the control of the camera parameters.

[0050] Further, the step S4 is to adjust the up vector, the origin and the target point parameters of the camera, calculate new camera parameters, and apply the anti-shake processed parameters to the three-dimensional view, i.e., complete the picture view angle tracking adjustment.

[0051] Based on the existing view angle, further operation control can still be performed. In one embodiment of the present embodiment, after the catheter tracking view angle is started, the scaling of the three-dimensional graph can still be adjusted, and the detailed steps of the setting are as follows:

[0052] Step S5, operation control of the three-dimensional graph under the new view angle; specifically:

[0053] S5-1, obtaining the current projection direction of the camera;

[0054] S5-2, obtaining the current origin of the camera;

[0055] S5-3, obtaining the current target point of the camera;

[0056] S5-4, calculating the scaling adjustment amount;

[0057] S5-5, calculating the new origin;

[0058] S5-6, calculating the new target point;

[0059] S5-7, setting the new origin and target point and the projection direction;

[0060] S5-8, resetting the clipping area, i.e., the front and rear clipping planes.

[0061] Displaying a certain tracking view angle of the three-dimensional structure graph on the visual device, calculating the view angle parameters by specifying a specific catheter, and superimposing the anti-shake and manual adjustment calculation to display the real-time position of the catheter and the 3D graph of the heart near the catheter with the calculated view angle, which is convenient for observing a specific area.

[0062] Also provided is a catheter perspective based 3D view tracking and stabilization system, characterized in that it comprises

[0063] a signal processing module for receiving and processing signals of the catheter and electrode positions and providing to a display device;

[0064] a computer processing module for continuously receiving the position information of the electrodes on the catheter obtained by the signal processing module, calculating and displaying in real time a 3D imaging map and the catheter position, and providing to a display device for observation and adjustment.

[0065] An embodiment, as shown in Figures 1-5 ,

[0066] A catheter perspective based 3D view tracking and stabilization method comprises the following steps:

[0067] S1, receiving the catheter and electrode positions;

[0068] S2, calculating a new perspective according to the current perspective and the received catheter and electrode positions;

[0069] S3, performing stabilization calculation based on the new perspective and the current perspective;

[0070] S4, adjusting the position and angle of the 3D view camera based on the stabilized new perspective.

[0071] The calculation process of step S2 requires the use of the current perspective of the 3D view, because the positions of the catheter and electrodes cannot completely determine all the parameters of the perspective. Using the current perspective as an auxiliary input parameter can ensure that the perspective does not change greatly, thereby avoiding causing large shaking of the view picture. The steps are as shown in Figure 3 ,

[0072] Obtain the current viewUp vector of the camera, denoted as up;

[0073] Obtain the positions of the catheter electrode 1 and electrode 2, calculate the target point position of the camera according to the position of electrode 1, denoted as target;

[0074] Calculate the projection direction according to the positions of electrode 1 and electrode 2, denoted as dir, and perform normalization processing;

[0075] Calculate the cross product of dir and up to determine whether the up vector is parallel to the new projection direction;

[0076] If parallel, adjust up to a standard vector, for example (0, 1, 0) or (1, 1, 0);

[0077] Calculate the origin position pos according to the specified zoom coefficient zoom;

[0078] A translation vector left is calculated, and a new origin position is calculated according to a user-specified angle.

[0079] The anti-shake calculation is entered, and the algorithm of step S3 is used to further reduce the picture shaking caused by the movement of the catheter. An exponential average algorithm is used to calculate the view angle after anti-shaking, and the method is as follows:

[0080] The view angle parameters P of the last N times are recorded, and N can be specified by the user. S is the view angle parameter after anti-shaking processing.

[0081]

[0082] wherein S0 represents the initial value of the view angle after anti-shaking calculation, P0 represents the initial value of the view angle before anti-shaking calculation, S t represents the value of the view angle after anti-shaking calculation at time t, S t-1 represents the value of the view angle after anti-shaking calculation at time t-1, P t represents the value of the view angle before anti-shaking calculation at time t.

[0083] wherein a is an exponential average coefficient, and the smaller the coefficient, the more obvious the smoothing effect.

[0084] The smoothed view angle parameter S can be used for the control of the camera parameters. The anti-shaking algorithm of the embodiment is only an example method, and different anti-shaking algorithms can be changed to achieve different anti-shaking effects.

[0085] In the adjustment of step S4, several control parameters of the camera in the three-dimensional view are involved, including Position origin 402, FocalPoint target point 403, and View Up upward vector 401, FrontClipping near clipping plane 404, and BackClipping far clipping plane 405. The origin is the position of the camera, the target point is the focus point to which the camera is aligned, Position and Focal Point together determine the projection direction of the camera, the ViewUp vector is the upward orientation vector of the camera, that is, it determines the rotation orientation of imaging, Front Clipping and Back Clipping are the clipping of the imaging depth, Front Clipping ensures that all used three-dimensional pixels have valid 2D coordinates. Together with Back Clipping, it also helps to prevent overflow of the depth buffer value into imaging. These parameters determine the unique display result of the three-dimensional view on a two-dimensional display device (usually a display).

[0086] After the new camera parameters are calculated in step S4, the parameters after the anti-shake processing are applied to the three-dimensional view, that is, the parameters such as View Up 401, Position 402 and Focal Point 403 of the camera are adjusted, so that the effect of picture view angle tracking adjustment is achieved.

[0087] In step S5, the user can still perform further operation control based on the existing view angle. In one embodiment of the present embodiment, after the catheter tracking view is started, the scaling ratio of the three-dimensional view can be adjusted, and the setting steps are as follows:

[0088] The current projection direction of the camera is obtained, denoted as dir;

[0089] The current origin of the camera is obtained, denoted as pos;

[0090] The current target point of the camera is obtained, denoted as foc;

[0091] The zoom adjustment amount is calculated, which can be determined according to the preset zoom adjustment step and user input; the new origin is calculated, denoted as pos2, which is the result of translating the original pos along the dir vector by the above zoom adjustment amount;

[0092] The new target point is calculated, denoted as foc2, which is also the result of translating the original pos along the dir vector by the above zoom adjustment amount;

[0093] The new origin and target point and projection direction are set;

[0094] The clipping region, that is, the front and rear clipping planes, is reset.

[0095] The operation of step 5 is based on the existing view angle to perform further operation control. Through the user operation under the catheter view angle, the uncertainty caused by the automatic view angle can be corrected, and the operation can be scaling, rotation, etc. These operation controls complement each other with the previous steps, and can greatly facilitate the need for observation of a specific position.

[0096] The steps S1 to S5 are repeatedly performed, so that the catheter real-time tracking observation effect is achieved, and a switch is also provided to switch the real-time tracking. The operator can close the real-time tracking, and after the tracking is closed, the camera view angle remains unchanged, that is, the view angle obtained when the last tracking is retained, so that after entering the catheter view angle, the real-time tracking can be closed to avoid the picture view angle switching caused by subsequent catheter tracking. At this time, step S5 can still be executed, which facilitates the operator to continue to adjust to observe the region of interest.

[0097] A three-dimensional view tracking and anti-shake system based on a catheter view angle comprises:

[0098] a signal processing module for receiving and processing the signals of the catheter and electrode positions and providing to the display device;

[0099] a computer processing module for continuously receiving the position information of the electrodes on the catheter from the signal processing module, calculating and displaying the three-dimensional imaging and the catheter position in real time, and providing to the display device for observation and adjustment.

[0100] Figure 2 A three-dimensional view tracking and anti-shake system diagram based on the catheter perspective is shown. The real-time signals of the catheter on the endocardium can be used for mapping modeling. The signals are processed by the signal processing module 102 to generate a three-dimensional graph of the heart and a combined illustration of the activation signals, and are displayed on the display device 103 (usually a display). Mapping modeling is a basic function of each three-dimensional mapping system. The result of mapping modeling by the mapping system is to construct a three-dimensional model of the heart chamber.

[0101] Figure 5 An example of a three-dimensional heart model generated by the system of the present embodiment is shown. The computer processing module continuously receives real-time position information of the electrodes on the catheter, and can display the catheter position in real time while displaying the three-dimensional imaging, and adjust the perspective of the three-dimensional image to observe the region of interest. The usual adjustment method is to continuously adjust the camera parameters through the keyboard or mouse, such as (as shown): the origin 402, the target point 403 and the upward vector 401, so that the continuously adjusted three-dimensional image can be seen on the display device. Figure 3 A typical example of a three-dimensional imaging image of a specific chamber of the heart in the catheter perspective is shown on the display device, in which 201 is an example of a real-time positioned catheter. Figure 5

[0102] The present application has been disclosed above with a preferred embodiment, however, it is not intended to limit the present application. Any person skilled in the art can make some changes or modifications to the above disclosed structure and technical content without departing from the scope of the present application, and the equivalent embodiments with equivalent changes are still within the scope of the present application.​

Claims

1. A method for stabilizing and adjusting a three-dimensional view based on a catheter perspective, the method comprising: Comprising the following steps: ​ S1, receiving catheter and electrode position; S2, calculating new view angle according to current view angle and received catheter and electrode position; Step S2 calculates the new view angle of the catheter, which is the view angle of the three-dimensional model currently being displayed before each adjustment, denoted as the current view angle, and the upward vector of the current view angle remains unchanged; The calculation process of the new view angle in step S2 is as follows: S2-1, obtaining the current upward vector of the camera; S2-2, obtaining the positions of electrode 1 and electrode 2, and calculating the target point position of the camera according to the position of electrode 1; S2-3, calculating the projection direction according to the positions of electrode 1 and electrode 2, and performing normalization processing; S2-4, calculating the cross product of the projection direction and the upward vector to determine whether the upward vector is parallel to the new projection direction; S2-5, if parallel, adjusting the upward vector to the standard vector; S2-6, calculating the origin position according to the user-specified scaling factor; S2-7, calculating the translation vector and the new origin position according to the user-specified angle; S2-8, completing the calculation of the new view angle; S3, performing anti-shake calculation based on the new view angle and the current view angle; S4, adjusting the position and angle of the three-dimensional view camera based on the anti-shake new view angle.

2. The method of claim 1, wherein: The positions received in step S1 are the real-time positions of each electrode on each catheter, and the position coordinates have been converted to the same coordinate system as the 3D model obtained by modeling.

3. The method of claims 1-2, wherein: The anti-shake calculation of step S3 uses the moving plane algorithm or the exponential average algorithm.

4. The method of claim 3, wherein: The anti-shake calculation process of step S3 is as follows: Record the view angle parameters P of the last N times, and S is the view angle parameter after anti-shake processing; Wherein, S0 represents the initial value of the angle of view after the anti-shake calculation, P0 represents the initial value of the angle of view before the anti-shake calculation, and a is the exponential average coefficient, S t represents the value of the angle of view after the anti-shake calculation at time t, S t-1 represents the value of the angle of view after the anti-shake calculation at time t-1, P t represents the value of the angle of view before the anti-shake calculation at time t. The smoothed view angle parameter S is used for camera parameter control.

5. The method of claim 3, wherein: Step S4 adjusts the upward vector, origin and target point parameters of the camera, and applies the anti-shake processed parameters to the three-dimensional view, which completes the picture view adjustment.

6. The method of claim 3, wherein: It also includes step S5, operation control of three-dimensional graphics under new view angle; specifically: S5-1, obtaining the current projection direction of the camera; S5-2, obtaining the current origin of the camera; S5-3, obtaining the current target point of the camera; S5-4, calculating the scaling adjustment amount; S5-5, calculating the new origin; S5-6, calculating the new target point; S5-7, setting the new origin and target point and projection direction; S5-8, resetting the clipping area, i.e. the front and rear clipping planes.

7. A catheter perspective based three-dimensional view stabilization and adjustment system, comprising: For implementing the three-dimensional view anti-shake and adjustment method of any one of claims 1-6, the method comprises: A signal processing module for receiving and processing the signals of the catheter and electrode positions, and providing to the display device; A computer processing module for continuously receiving the position information of the electrodes on the catheter obtained by the signal processing module, calculating and displaying the three-dimensional imaging graph and the catheter position in real time, and providing to the display device for observation and adjustment.

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