A method for optimizing the bending angle of a puncture needle

Abstract

The present invention discloses a method for optimizing the bending angle of a puncture needle, S1: segmenting the liver blood vessels by a threshold segmentation method in a CT image; S2: constructing a puncture plane; S3: marking the position of the puncture needle tip; S4: drawing the initial shape of the puncture needle; S5: judging whether the puncture path coincides with the initial shape trajectory of the puncture needle, and if not, proceeding to the next step; S6: adjusting the position of the puncture needle after bending so that it coincides with the entry point and the exit point; S7: marking the position of the puncture needle in the puncture plane, drawing a puncture path diagram, judging whether it conforms to the vascular structure, and determining the optimal bending angle. Combined with the patient's three-dimensional anatomical model of the liver blood vessels, the bending angle of the puncture needle is adjusted based on the entry point, exit point and bending point, which effectively solves the uncertainty of the bending angle of the puncture needle required for different patients, realizes the quantitative calculation of the bending angle of the puncture needle, and helps to reduce the difficulty of surgery, shorten the operation time, and improve the success rate of clinical operations.

Description

Technical Field

[0001] The invention relates to the technical field of image processing, and in particular to a method for optimizing the bending angle of a puncture needle. Background Art

[0002] In minimally invasive surgery, especially percutaneous transhepatic puncture drainage (TIPS), planning a precise puncture path is crucial. Traditional puncture techniques often face problems such as the puncture needle trajectory is not straight enough and the bending angle is too large, which increases the risk of damage to surrounding tissues and the incidence of postoperative complications in actual operations. With the advancement of medical imaging technology, doctors have obtained more detailed information about the patient's anatomical structure, but how to effectively use this information to optimize the puncture path remains a challenge.

[0003] Existing puncture path planning methods usually rely on the doctor's experience to analyze the patient's CT anatomical images to determine the puncture path. However, in the actual puncture process, there may be many variables, including improper bending angle of the puncture needle, wrong selection of puncture direction, and the relative position relationship between the needle and the target tissue. These factors may lead to unsatisfactory puncture results, increase surgical risks, and prolong operation time. The main reason for the above variables is that the complex spatial anatomical relationship between the hepatic vein and the portal vein is not fully considered. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for optimizing the bending angle of a puncture needle.

[0005] The purpose of the present invention is achieved through the following technical solution: A method for optimizing the bending angle of a puncture needle comprises the following steps:

[0006] S1: Segment the liver vessels of the patient's portal venous phase CT image using the threshold segmentation method and perform three-dimensional visualization;

[0007] S2: Select the entry point, exit point and bending point to construct the puncture plane, and establish a coordinate system to draw the position of each point;

[0008] S3: Mark the position of the puncture needle tip, measure the angle and length of the puncture needle in its initial state, and calculate the position of each point;

[0009] S4: The curved part of the puncture needle is simulated by a Bezier curve, and the end of the guide tube is simulated by a straight line. Point to the tip of a needle Points and draw the initial shape of the puncture needle;

[0010] S5: Determine whether the puncture path coincides with the initial shape trajectory of the puncture needle. If so, the puncture path is determined to be correct and the optimal bending angle is 0. If not, proceed to the next step.

[0011] S6: Click to Nine bending points are evenly selected at the point, the optimal bending angle between the puncture needle and the insertion path after the corresponding bending is calculated, and the position of the puncture needle after the bending is adjusted to make it coincide with the entry point and the exit point;

[0012] S7: Mark the position of the puncture needle on the puncture plane, draw a puncture path diagram corresponding to the optimal bending angle, and determine whether the puncture path conforms to the vascular structure. If not, change the bending point. When all bending points do not conform, return to step S2 to recreate the puncture plane until the correct puncture path is found and the optimal bending angle is determined.

[0013] Preferably, in step S2, several access points are selected on the right branch of the hepatic vein, denoted as Point; select several exit points at the bifurcation of portal vein and the left and right branches of portal vein, and record them as Point; define four distal bending starting points of the puncture needle at the left and right front and back end positions of the inferior vena cava, respectively, and record them as point.

[0014] Preferably, in step S4, the curved portion of the puncture needle is simulated by a second-order Bezier curve, and the formula is:

[0015] ;

[0016] in, As parameters, is a point on the curve.

[0017] Preferably, step S6 further includes the following steps:

[0018] S61: Click to Select nine bending points evenly at the point ,according to The point on the curve is around one of Point rotation, the rotation formula is:

[0019] ;

[0020] in, For any point, is the rotation center coordinate, is the rotation angle, is the coordinate after rotation;

[0021] S62: Calculate the rotated straight lines separately - With straight line - The slope of

[0022] S63: Calculation Click to The difference between the horizontal and vertical coordinates of the point is used to translate the bent puncture needle to a corresponding distance. Point and Points overlap.

[0023] Preferably, in step S7, on the curve - Select 10 points uniformly on the surface and calculate their positions, mark these 10 points on the puncture plane, and Point and The points are connected into lines to obtain the puncture path.

[0024] The present invention has the following advantages: by combining the patient's three-dimensional anatomical model of liver blood vessels, the present invention adjusts the bending angle of the puncture needle based on the entry point, exit point and bending point, effectively solving the uncertainty of the puncture needle bending angle required for different patients, and realizing quantitative calculation of the puncture needle bending angle, which helps to reduce the difficulty of surgery, shorten the operation time, and improve the success rate of clinical operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A schematic diagram of the process of optimizing the bending angle of the puncture needle;

[0026] Figure 2 This is a schematic diagram of the initial shape of the distal end of the puncture needle;

[0027] Figure 3 For puncture needle Schematic diagram of the trajectory after the point is bent and translated. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features of the embodiments may be combined with each other.

[0031] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0032] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use, or the positions or positional relationships commonly understood by those skilled in the art, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0033] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In this embodiment, if Figure 1 As shown, a method for optimizing the bending angle of a puncture needle comprises the following steps:

[0035] S1: Segment the liver vessels of the patient's portal phase CT image by the threshold segmentation method, and perform three-dimensional visualization processing; specifically, import the patient's portal phase CT image into Mimics software and segment the liver vessels according to the threshold segmentation method, and use the software to perform three-dimensional visualization. The threshold segmentation method here is an existing image segmentation method, which has not been improved here and will not be described in detail. The selected threshold range is adjusted according to the patient's liver vascular CT value.

[0036] S2: Select the entry point, exit point and bending point to construct the puncture plane, and establish a coordinate system to draw the position of each point; further, in step S2, select several entry points on the right branch of the hepatic vein, recorded as Point; select several exit points at the bifurcation of portal vein and the left and right branches of portal vein, and record them as Point; define four distal bending starting points of the puncture needle at the left and right front and back end positions of the inferior vena cava, respectively, and record them as Specifically, three points were taken at intervals of 0.5 cm from the right branch of the hepatic vein to the opening of the inferior vena cava. In the same way, three points were selected at the bifurcation of the portal vein and the left and right branches of the portal vein. Then, based on the experience of the interventional physician, four distal bend start points of the puncture needle are defined at the left and right anterior and posterior endpoints of the inferior vena cava. Point. , and Select three points and determine the puncture plane according to the three-point plane equation. Establish a rectangular coordinate system according to the geometric figure and draw the position of each point. The three-point plane equation is:

[0037] ;

[0038] by The point is the origin, the direction of the puncture needle is the Y axis, and the direction perpendicular to the puncture needle is the X axis. , and The relative position of the points is displayed in the coordinate system and marked , Point coordinates.

[0039] S3: Mark the tip of the puncture needle, measure the angle and length of the initial state of the puncture needle, and calculate the position of each point; specifically, the bending start end point is Point, the end of the gray guide tube is the bending end point Point, the needle tip is The angle between the tangent line at the bend and the tangent line at the needle tip is defined as the bend angle. , the intersection point is , the length of the gray guide tube in the bent part is L, and the definitions of each point are as follows Figure 2 As shown, the data obtained by measurement is L=5.5cm, =20°, - =2.4cm, - =3.0cm, - =3.0cm, assuming The point is the origin of the rectangular coordinate system (0, 0). According to the above, the coordinate system is established and the calculation is The point coordinates are (0, -2.4), The point coordinates are (-1.03, -5.22), The point coordinates are (-2.06, -8.04).

[0040] S4: The curved part of the puncture needle is simulated by a Bezier curve, and the end of the guide tube is simulated by a straight line. Point to the tip of a needle Points and draw the initial shape of the puncture needle;

[0041] S5: Determine whether the puncture path coincides with the initial shape trajectory of the puncture needle. If so, the puncture path is determined to be correct and the optimal bending angle is 0. If not, proceed to the next step. In other words, determine whether the straight line - Is it consistent with the straight line - Overlap, if overlap, then the puncture needle does not need to be bent, the best bending angle is 0, otherwise go to the next step.

[0042] S6: Click to Nine bending points are evenly selected at the point, the optimal bending angle between the puncture needle and the insertion path after the corresponding bending is calculated, and the position of the puncture needle after the bending is adjusted to make it coincide with the entry point and the exit point;

[0043] S7: Mark the position of the puncture needle on the puncture plane, draw a puncture path diagram corresponding to the optimal bending angle, and determine whether the puncture path conforms to the vascular structure. If not, change the bending point. When all bending points do not conform, return to step S2 to recreate the puncture plane until the correct puncture path is found and the optimal bending angle is determined.

[0044] In this embodiment, in step S4, the curved portion of the puncture needle is simulated by a second-order Bezier curve, and the formula is:

[0045] ;

[0046] in, As parameters, is a point on the curve.

[0047] Further, such as Figure 3 As shown, step S6 also includes the following steps:

[0048] S61: Click to Select nine bending points evenly at the point ,according to The point on the curve is around one of Point rotation, the rotation formula is:

[0049] ;

[0050] in, For any point, is the rotation center coordinate, is the rotation angle, is the coordinate after rotation;

[0051] S62: Calculate the rotated straight lines separately - With straight line - When the slope error between the two is the smallest, the corresponding angle is the optimal bending angle ;

[0052] S63: Calculation Click to The difference between the horizontal and vertical coordinates of the point is used to translate the bent puncture needle to a corresponding distance. Point and Points overlap, exist - In a straight line or close to it.

[0053] Furthermore, in step S7, in the curve - Select 10 points uniformly on the surface and calculate their positions, mark these 10 points on the puncture plane, and Point and Specifically, whether the puncture path is suitable is determined by checking whether the puncture path is in the blood vessel. If the puncture path is not suitable, the puncture path is replaced in step S61. Point, when all If the point is still not suitable after replacement, return to step S2, recreate the puncture plane, and repeat steps S3 to S7 until the correct puncture path is found. is the optimal bending angle.

[0054] Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments, or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for optimizing the bending angle of a puncture needle, characterized in that: The following steps are involved: S1: Segment the liver vessels of the patient's portal venous phase CT image using the threshold segmentation method and perform three-dimensional visualization; S2: Select the entry point, exit point and bending point to construct the puncture plane, and establish a coordinate system to draw the position of each point; S3: Mark the position of the puncture needle tip, measure the angle and length of the puncture needle in its initial state, and calculate the position of each point; S4: The curved part of the puncture needle is simulated by a Bezier curve, and the end of the guide tube is simulated by a straight line. Point to the tip of a needle Points and draw the initial shape of the puncture needle; S5: Determine whether the puncture path coincides with the initial shape trajectory of the puncture needle. If so, the puncture path is determined to be correct and the optimal bending angle is 0. If not, proceed to the next step. S6: Click to Nine bending points are evenly selected at the point, the optimal bending angle between the puncture needle and the insertion path after the corresponding bending is calculated, and the position of the puncture needle after the bending is adjusted to make it coincide with the entry point and the exit point; S7: Mark the position of the puncture needle on the puncture plane, draw a puncture path diagram corresponding to the optimal bending angle, and determine whether the puncture path conforms to the vascular structure. If not, change the bending point. When all bending points do not conform, return to step S2 to recreate the puncture plane until the correct puncture path is found and the optimal bending angle is determined; In step S2, several access points are selected on the right branch of the hepatic vein, denoted as Point; select several exit points at the bifurcation of portal vein and the left and right branches of portal vein, and record them as Point; define four distal bending starting points of the puncture needle at the left and right front and back end positions of the inferior vena cava, respectively, and record them as point; In step S4, the curved part of the puncture needle is simulated by a second-order Bezier curve, and the formula is: ； in, As parameters, is a point on the curve; The step S6 further includes the following steps: S61: Click to Select nine bending points evenly at the point ,according to The point on the curve is around one of Point rotation, the rotation formula is: ； in, For any point, is the rotation center coordinate, is the rotation angle, is the coordinate after rotation; S62: Calculate the rotated straight lines separately - With straight line - When the slope error between the two is the smallest, the corresponding angle is the optimal bending angle ; S63: Calculation Click to The difference between the horizontal and vertical coordinates of the point is used to translate the bent puncture needle to a corresponding distance. Point and Points overlap.

2. The method for optimizing the bending angle of a puncture needle according to claim 1, characterized in that: In step S7, the curve - Select 10 points uniformly on the surface and calculate their positions, mark these 10 points on the puncture plane, and Point and The points are connected into lines to obtain the puncture path.

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