A spring coil simulation method, device and equipment for surgical planning

Abstract

The embodiments of this specification disclose a coil simulation method, device, and apparatus for surgical planning. The method includes: obtaining morphological parameters of intracranial aneurysm imaging data to be processed; determining the diameter and length of the coil based on the morphological parameters of the intracranial aneurysm imaging data to be processed, so as to determine the model of the coil; based on the model of the coil and a preset packing rate, determining the various models of the packing coils by using a method of gradually decreasing coil models or decreasing coil packing rates, determining the various models of the packing coils that meet the preset packing rate, and using the last coil that meets the preset packing rate as the final coil to complete coil simulation. The method can automatically perform surgical planning, realize automatic coil simulation, reduce or eliminate the influence of human factors, and improve the prognosis of aneurysm embolization treatment.

Description

Technical Field

[0001] This specification relates to the fields of computer technology and artificial intelligence, and in particular to a coil simulation method, device, and apparatus for surgical planning. Background Art

[0002] Intracranial aneurysms are often abnormal bulges in the walls of intracranial arteries and are the leading cause of subarachnoid hemorrhage. Rupture and bleeding can leave patients with disability or even death. The widespread use of 3D angiography, the maturing of neurointerventional techniques, and the development of novel embolization technologies and materials have boosted the application and promotion of endovascular interventional therapy, helping to enhance its effectiveness and safety. Endovascular interventional therapy for intracranial aneurysms offers advantages such as rapid recovery and minimal invasiveness, and has become the primary treatment approach. Currently, aneurysm embolization is the primary treatment method, primarily using a microcatheter to deliver coils into the aneurysm cavity to occlude the aneurysm. This coiling procedure artificially enlarges and slows blood flow, significantly slowing blood flow to near-stagnation within a short period of time. This thrombus forms, significantly reducing pressure within the aneurysm and minimizing the risk of rupture, ultimately achieving the desired aneurysm treatment outcome. Therefore, the choice of coil is crucial for aneurysm treatment. In the prior art, for surgical planning of aneurysm embolization, the selection of coils often relies on the physician's experience, which is prone to human factors and is not conducive to predicting the treatment effect.

[0003] Therefore, a new method is needed to reduce or eliminate the influence of human factors and improve the prognosis of aneurysm embolization treatment. Summary of the Invention

[0004] The embodiments of this specification provide a coil simulation method, device and equipment for surgical planning, which are used to solve the following technical problems: In the prior art, in aneurysm embolization treatment, the selection of coils often depends on the doctor's experience, which has a high human factor and is not conducive to predicting the treatment effect.

[0005] To solve the above technical problems, the embodiments of this specification are implemented as follows:

[0006] The embodiments of this specification provide a coil simulation method for surgical planning, comprising:

[0007] Acquiring morphological parameters of intracranial aneurysm image data to be processed;

[0008] Determining the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed, so as to determine the model of the basket ring;

[0009] Based on the model of the basketed coil and the preset filling rate, the method of gradually decreasing the spring coil model or decreasing the spring coil filling rate is adopted to determine the various models of the filling coils, and the various models of the filling coils that meet the preset filling rate are determined. The last spring coil that meets the preset filling rate is used as the finishing coil to complete the spring coil simulation.

[0010] The embodiments of this specification provide a coil simulation device for surgical planning, comprising:

[0011] An acquisition module, for acquiring morphological parameters of intracranial aneurysm image data to be processed;

[0012] a basket ring determination module, which determines the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed, so as to determine the model of the basket ring;

[0013] The module for determining the stuffing ring and the ending ring determines the models of the stuffing rings based on the models of the basket rings and the preset stuffing rate, adopts a method of gradually decreasing the models of the spring rings or decreasing the stuffing rate of the spring rings, determines the models of the stuffing rings that meet the preset stuffing rate, and uses the last spring ring that meets the preset stuffing rate as the ending ring to complete the simulation of the spring rings.

[0014] An embodiment of this specification further provides an electronic device, including:

[0015] at least one processor; and,

[0016] a memory communicatively connected to the at least one processor; wherein,

[0017] The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

[0018] Acquiring morphological parameters of intracranial aneurysm image data to be processed;

[0019] Determining the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed, so as to determine the model of the basket ring;

[0020] Based on the model of the basketed coil and the preset filling rate, the method of gradually decreasing the spring coil model or decreasing the spring coil filling rate is adopted to determine the various models of the filling coils, and the various models of the filling coils that meet the preset filling rate are determined. The last spring coil that meets the preset filling rate is used as the finishing coil to complete the spring coil simulation.

[0021] At least one of the above technical solutions adopted in the embodiments of this specification can achieve the following beneficial effects: automatic surgical planning, automatic simulation of spring coils, reduction or elimination of the influence of human factors, and improvement of the prognosis of aneurysm embolization treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of this specification or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0023] Figure 1 A schematic diagram of a coil simulation method for surgical planning provided in an embodiment of this specification;

[0024] Figure 2 A framework diagram of a coil simulation method for surgical planning provided in an embodiment of this specification;

[0025] Figure 3 This is a schematic diagram of a spring coil simulation device for surgical planning provided in an embodiment of this specification. DETAILED DESCRIPTION

[0026] In order to help those skilled in the art better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments of this specification, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of this application.

[0027] In the interventional treatment of aneurysms, dense embolization of the aneurysm using coils through vascular intervention is an important approach. This method involves introducing coils into the aneurysm via a catheter, reducing its volume and leading to a decrease in blood flow, ideally resulting in complete occlusion of the aneurysm. In practice, multiple coils are placed into the aneurysm for embolization. The first coil, also known as the initial coil, forms the entire framework and basket of coils for the aneurysm. Furthermore, the basket is packed, allowing the coils to entangle more tightly, forming a dense embolic mass. The closing coil reduces the risk of coils protruding into the parent vessel and causing thrombosis. The dense embolization of the aneurysm neck by the closing coil significantly reduces the risk of aneurysm recurrence. Therefore, during surgical planning, the selection of the basket, packing, and closing coils is crucial for successful surgical planning.

[0028] Based on this, an embodiment of this specification provides a coil simulation method for surgical planning. Figure 1 A schematic diagram of a coil simulation method for surgical planning provided in an embodiment of this specification is shown as follows: Figure 1 As shown, the spring coil simulation method includes the following steps:

[0029] Step S101: Acquire morphological parameters of intracranial aneurysm image data to be processed.

[0030] In the embodiments of this specification, the morphological parameters of the intracranial aneurysm image data to be processed include at least the major diameter, minor diameter, and volume of the intracranial aneurysm. Acquisition of the morphological parameters of the intracranial aneurysm image data to be processed is a prior art and will not be further described here.

[0031] In the embodiments of this specification, the intracranial aneurysm to be treated can be a micro aneurysm, a small aneurysm or a medium aneurysm. Specifically, the diameter of a micro aneurysm is 0-3 mm, the diameter of a small aneurysm is 3-5 mm, and the diameter of a medium aneurysm is 5-10 mm.

[0032] Step S103: Based on the morphological parameters of the intracranial aneurysm image data to be processed, the diameter and length of the basket ring are determined to determine the model of the basket ring.

[0033] In the first solution of this specification, the model of the basket ring is determined using a conventional strategy. In the embodiment of this specification, when the intracranial aneurysm to be treated is a small aneurysm or a micro aneurysm, the short diameter of the small aneurysm or the micro aneurysm is used as the diameter of the basket ring;

[0034] Specifically in the embodiment, in the embodiment of this specification, when the intracranial aneurysm to be treated is a medium-sized aneurysm, the diameter of the basket ring = (the long diameter of the aneurysm in the morphological parameters of the intracranial aneurysm imaging data to be processed + the long diameter of the aneurysm in the morphological parameters of the intracranial aneurysm imaging data to be processed) / 2.

[0035] In the embodiment of the present specification, 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as the first candidate length of the basket ring;

[0036] Three times the long diameter of the intracranial aneurysm image data to be processed is used as the second candidate length of the basket ring;

[0037] The smaller length between the first candidate length of the basket ring and the second candidate length of the basket ring is used as the length of the basket ring.

[0038] In the embodiment of this specification, the method of using 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed as the first candidate length of the basket ring specifically includes:

[0039] Using a first preset multiple of the intracranial aneurysm volume in the morphological parameters of the intracranial aneurysm image data to be processed as the preset total length, wherein the first preset multiple is 0.3 / 0.8;

[0040] 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as the first candidate length of the basket ring.

[0041] In the embodiment of this specification, when the first candidate length of the basket ring is used as the length of the basket ring, if the first candidate length of the basket ring is less than 3 mm, the shortest spring coil length among the spring coil models corresponding to the diameter of the basket ring is used as the length of the basket ring;

[0042] When the first candidate length of the basket ring is between 3 mm and 5 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, then the second longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, then the second shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring;

[0043] If the first candidate length of the basket ring is between 5 mm and 10 mm, the longest spring coil length among the spring coil models corresponding to the basket ring diameter is used as the length of the basket ring;

[0044] When the first candidate length of the basket ring is greater than or equal to 10 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, the longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, the shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring.

[0045] It should be noted that the length of the spring coil can be divided into four levels: shortest, second shortest, second longest, and longest.

[0046] In the second embodiment of this specification, the large circle strategy is used to determine the size of the basket ring. It should be noted that the large circle strategy is mainly used for medium-sized aneurysms. In another embodiment of this specification, the diameter and length of the basket ring are determined based on the morphological parameters of the intracranial aneurysm image data to be processed to determine the size of the basket ring, specifically including:

[0047] Obtaining an average value of aneurysm diameters in the intracranial aneurysm image data to be processed based on the long diameter of the aneurysm in the intracranial aneurysm image data to be processed and the short diameter of the aneurysm in the intracranial aneurysm image data to be processed;

[0048] taking the average value of the aneurysm diameters at a second preset multiple as the diameter of the basket ring;

[0049] The longest diameter of the spring coil model corresponding to the diameter of the basket ring is used as the length of the basket ring;

[0050] The model of the basket ring is determined based on the diameter of the basket ring and the length of the basket ring.

[0051] In one embodiment of the present specification, the second preset multiple is 1.5, that is, the diameter of the basket ring = (aneurysm long diameter + aneurysm short diameter) / 2*second preset multiple = (aneurysm long diameter + aneurysm short diameter) / 2*1.5.

[0052] It should be noted that, regardless of whether the conventional strategy or the large circle strategy is adopted, the diameter and length of the basket ring are preferably integers. If the calculated diameter of the basket ring is not an integer, the rounding method is used to make the diameter of the basket ring an integer.

[0053] Step S105: Based on the model of the basketed coil and the preset filling rate, the model of the spring coil is gradually reduced or the filling rate of the spring coil is gradually reduced to determine the models of the filling coils, and the models of the filling coils that meet the preset filling rate are determined. The last spring coil that meets the preset filling rate is used as the finishing coil to complete the simulation of the spring coil.

[0054] In the embodiments of this specification, the preset filling rates are 25%, 30%, and 35%. Generally speaking, the preset filling rate does not exceed 30%, and is preferably 30%.

[0055] Continuing with the previous example of postponement, in a conventional strategy, in one embodiment of this specification, based on the model of the basket ring and the preset filling rate, a method of gradually decreasing the spring coil model is adopted to determine the various models of the packing ring that meet the preset filling rate, specifically including:

[0056] A method of gradually decreasing the spring coil models is adopted. On the premise that the filling rate of the already filled spring coils is less than or equal to the preset filling rate, the length of the subsequent filling coil is ensured to be less than the length of the previous filling coil, so as to determine the various models of filling coils that meet the preset filling rate.

[0057] In the embodiment of this specification, if the intracranial aneurysm to be treated is a micro-aneurysm or a medium-sized aneurysm, a method of gradually decreasing the coil size is adopted. On the premise of meeting the preset packing rate, the coil size with the longest length is selected as the packing coil size.

[0058] If the intracranial aneurysm to be treated is a small aneurysm, the method of gradually decreasing the spring coil model is adopted. On the premise of meeting the preset filling rate, the model of the packing coil is determined by gradually decreasing the spring coil length.

[0059] Continuing with the previous example, in the large coil strategy, since the method of decreasing the filling rate of the spring coil is adopted, it is necessary to determine the filling rate corresponding to each spring coil. In one embodiment of this specification, the method of decreasing the filling rate of the spring coil specifically includes:

[0060] Based on the model of the basket coil, a first packing rate of a first spring coil is obtained;

[0061] Obtaining a second packing ratio of a second spring coil serving as a packing coil based on the first packing ratio of the spring coil and a preset packing coefficient;

[0062] Obtaining a third packing ratio of a third spring coil based on the second packing ratio and the preset packing coefficient;

[0063] The operation is cyclically performed until the sum of the first filling rate, the second filling rate, the third filling rate, and the nth filling rate meets the preset filling rate.

[0064] In the embodiment of this specification, based on the model of the basket ring and the preset packing rate, the method of decreasing the packing rate of the spring coil is adopted to determine the various models of the packing ring, and the various models of the packing ring that meet the preset packing rate are determined, specifically including:

[0065] Determining the model of the second spring coil serving as the stuffing ring based on the second stuffing rate, the diameter of the second spring coil serving as the stuffing ring, and the length of the second spring coil, wherein the length of the second spring coil is not greater than the diameter of the basket ring;

[0066] Based on the third packing ratio, obtaining the diameter and length of the third spring coil, and determining the model of the third spring coil of the packing ring, wherein the length of the third spring coil is not greater than the diameter of the second spring coil;

[0067] The operation is repeated to obtain the diameter of the n-th spring coil and the length of the n-th spring coil, and to determine the model of the n-th spring coil, until all models of packing coils that meet the preset packing rate are determined.

[0068] To further understand the large coil strategy, the following will be explained with reference to a specific embodiment. After the large coil strategy is used to determine the size of the basket coil, based on the size of the basket coil and the volume of the aneurysm, the packing rate of the spring coil corresponding to the basket coil is obtained and set as A1, where A1 = spring coil volume / aneurysm volume, where Correspondingly, the filling rate of the second spring coil is set to A2, then A2 = preset filling coefficient * A1, and so on, the filling rate of the nth spring coil is A n =Preset filling coefficient*A n-1 = preset filling coefficient (n-2)*A1. Based on the preset filling rate of 100% full capacity standard, then A1+A2+......+A n ≈100%. Generally speaking, in this large coil strategy, the number of spring coils is 5. After obtaining the filling rate of each spring coil, the model of each spring coil can be determined.

[0069] It should be noted that in the large coil strategy, after the basket coil is determined, the diameter of the spring coil may be repeated when filling the filling coil. Specifically, in this embodiment, when the diameter of the basket coil is ≥4mm, the diameter of the spring coil used for the filling coil is less than 50% of the diameter of the basket coil. When the spring coil diameter is ≥3mm, the same diameter can be repeated up to 2 times. When the spring coil diameter is ≤2mm, there is no limit on the number of times the spring coil diameter is repeated.

[0070] Regarding the closing ring, in one embodiment of the present specification, if the diameter of the last spring ring of the filling ring is greater than 2 mm, the method further includes: adding a spring ring with a diameter of 2 mm and a length of 1 mm as the closing ring.

[0071] In order to further understand the method provided in the embodiments of this specification, Figure 2 This is a framework diagram of a coil simulation method for surgical planning provided in an embodiment of this specification. Figure 2 As shown, after obtaining the morphological parameters of the aneurysm, the surgical plan is planned. For the surgical plan of coil interventional treatment, coil simulation is further performed, including: conventional strategy and large coil strategy. At the same time, the filling rate and embolization length will be displayed in real time.

[0072] By using the method provided in the embodiments of this specification, surgical planning can be automatically performed, automatic simulation of coils can be achieved, the influence of human factors can be reduced or eliminated, and the prognosis of aneurysm embolization treatment can be improved.

[0073] The embodiment of this specification provides a spring coil simulation method for surgical planning. Correspondingly, the embodiment of this specification also provides a spring coil simulation device for surgical planning. Figure 3 This is a schematic diagram of a coil simulation device for surgical planning provided in an embodiment of this specification, as shown in FIG. Figure 3 As shown, the spring coil simulation device includes:

[0074] An acquisition module 301 acquires morphological parameters of intracranial aneurysm image data to be processed;

[0075] A basket ring determination module 303 determines the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed, so as to determine the model of the basket ring;

[0076] The packing ring and finishing ring determination module 305 determines the various models of the packing rings based on the models of the basket rings and the preset packing rate, adopts a method of gradually decreasing the models of the spring rings or decreasing the packing rate of the spring rings, determines the various models of the packing rings that meet the preset packing rate, and uses the last spring ring that meets the preset packing rate as the finishing ring to complete the simulation of the spring rings.

[0077] In the embodiment of this specification, when the intracranial aneurysm to be treated is a small aneurysm or a micro aneurysm, the short diameter of the small aneurysm or the micro aneurysm is used as the diameter of the basket ring;

[0078] When the intracranial aneurysm to be processed is a medium-sized aneurysm, the diameter of the basket ring = (the long diameter of the aneurysm in the morphological parameters of the intracranial aneurysm image data to be processed + the long diameter of the aneurysm in the morphological parameters of the intracranial aneurysm image data to be processed) / 2.

[0079] In the embodiment of the present specification, 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as the first candidate length of the basket ring;

[0080] Three times the long diameter of the intracranial aneurysm image data to be processed is used as the second candidate length of the basket ring;

[0081] The smaller length between the first candidate length of the basket ring and the second candidate length of the basket ring is used as the length of the basket ring.

[0082] In the embodiment of this specification, the method of using 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed as the first candidate length of the basket ring specifically includes:

[0083] Using a first preset multiple of the intracranial aneurysm volume in the morphological parameters of the intracranial aneurysm image data to be processed as the preset total length, wherein the first preset multiple is 0.3 / 0.8;

[0084] 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as the first candidate length of the basket ring.

[0085] In the embodiment of this specification, when the first candidate length of the basket ring is used as the length of the basket ring, if the first candidate length of the basket ring is less than 3 mm, the shortest spring coil length among the spring coil models corresponding to the diameter of the basket ring is used as the length of the basket ring;

[0086] When the first candidate length of the basket ring is between 3 mm and 5 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, then the second longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, then the second shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring;

[0087] If the first candidate length of the basket ring is between 5 mm and 10 mm, the longest spring coil length among the spring coil models corresponding to the basket ring diameter is used as the length of the basket ring;

[0088] When the first candidate length of the basket ring is greater than or equal to 10 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, the longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, the shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring.

[0089] In the embodiment of this specification, based on the model of the basket ring and the preset filling rate, the method of gradually decreasing the spring coil model is adopted to determine the various models of the packing ring that meet the preset filling rate, specifically including:

[0090] A method of gradually decreasing the spring coil models is adopted. On the premise that the filling rate of the already filled spring coils is less than or equal to the preset filling rate, the length of the subsequent filling coil is ensured to be less than the length of the previous filling coil, so as to determine the various models of filling coils that meet the preset filling rate.

[0091] In the embodiment of this specification, if the intracranial aneurysm to be treated is a micro-aneurysm or a medium-sized aneurysm, a method of gradually decreasing the coil size is adopted. On the premise of meeting the preset packing rate, the coil size with the longest length is selected as the packing coil size.

[0092] If the intracranial aneurysm to be treated is a small aneurysm, the method of gradually decreasing the spring coil model is adopted. On the premise of meeting the preset filling rate, the model of the packing coil is determined by gradually decreasing the spring coil length.

[0093] In the embodiment of this specification, determining the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed to determine the model of the basket ring specifically includes:

[0094] Obtaining an average value of aneurysm diameters in the intracranial aneurysm image data to be processed based on the long diameter of the aneurysm in the intracranial aneurysm image data to be processed and the short diameter of the aneurysm in the intracranial aneurysm image data to be processed;

[0095] taking the average value of the aneurysm diameters at a second preset multiple as the diameter of the basket ring;

[0096] The longest diameter of the spring coil model corresponding to the diameter of the basket ring is used as the length of the basket ring;

[0097] The model of the basket ring is determined based on the diameter of the basket ring and the length of the basket ring.

[0098] In the embodiment of this specification, the method of decreasing the packing rate of the spring coil specifically includes:

[0099] Based on the model of the basket coil, a first packing rate of a first spring coil is obtained;

[0100] Obtaining a second packing ratio of a second spring coil serving as a packing coil based on the first packing ratio of the spring coil and a preset packing coefficient;

[0101] Obtaining a third packing ratio of a third spring coil based on the second packing ratio and the preset packing coefficient;

[0102] The operation is cyclically performed until the sum of the first filling rate, the second filling rate, the third filling rate, and the nth filling rate meets the preset filling rate.

[0103] In the embodiment of this specification, based on the model of the basket ring and the preset packing rate, the method of decreasing the packing rate of the spring coil is adopted to determine the various models of the packing ring, and the various models of the packing ring that meet the preset packing rate are determined, specifically including:

[0104] Determining the model of the second spring coil serving as the stuffing ring based on the second stuffing rate, the diameter of the second spring coil serving as the stuffing ring, and the length of the second spring coil, wherein the length of the second spring coil is not greater than the diameter of the basket ring;

[0105] Based on the third packing ratio, obtaining the diameter and length of the third spring coil, and determining the model of the third spring coil of the packing ring, wherein the length of the third spring coil is not greater than the diameter of the second spring coil;

[0106] The operation is repeated to obtain the diameter of the n-th spring coil and the length of the n-th spring coil, and to determine the model of the n-th spring coil, until all models of packing coils that meet the preset packing rate are determined.

[0107] An embodiment of this specification further provides an electronic device, including:

[0108] at least one processor; and,

[0109] a memory communicatively connected to the at least one processor; wherein,

[0110] The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

[0111] Acquiring morphological parameters of intracranial aneurysm image data to be processed;

[0112] Determining the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed, so as to determine the model of the basket ring;

[0113] Based on the model of the basketed coil and the preset filling rate, the method of gradually decreasing the spring coil model or decreasing the spring coil filling rate is adopted to determine the various models of the filling coils, and the various models of the filling coils that meet the preset filling rate are determined. The last spring coil that meets the preset filling rate is used as the finishing coil to complete the spring coil simulation.

[0114] In the embodiment of this specification, when the intracranial aneurysm to be treated is a small aneurysm or a micro aneurysm, the short diameter of the small aneurysm or the micro aneurysm is used as the diameter of the basket ring;

[0115] When the intracranial aneurysm to be processed is a medium-sized aneurysm, the diameter of the basket ring = (the long diameter of the aneurysm in the morphological parameters of the intracranial aneurysm image data to be processed + the long diameter of the aneurysm in the morphological parameters of the intracranial aneurysm image data to be processed) / 2.

[0116] In the embodiment of the present specification, 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as the first candidate length of the basket ring;

[0117] Three times the long diameter of the intracranial aneurysm image data to be processed is used as the second candidate length of the basket ring;

[0118] The smaller length between the first candidate length of the basket ring and the second candidate length of the basket ring is used as the length of the basket ring.

[0119] In the embodiment of this specification, the method of using 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed as the first candidate length of the basket ring specifically includes:

[0120] Using a first preset multiple of the intracranial aneurysm volume in the morphological parameters of the intracranial aneurysm image data to be processed as the preset total length, wherein the first preset multiple is 0.3 / 0.8;

[0121] 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as the first candidate length of the basket ring.

[0122] In the embodiment of this specification, when the first candidate length of the basket ring is used as the length of the basket ring, if the first candidate length of the basket ring is less than 3 mm, the shortest spring coil length among the spring coil models corresponding to the diameter of the basket ring is used as the length of the basket ring;

[0123] When the first candidate length of the basket ring is between 3 mm and 5 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, then the second longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, then the second shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring;

[0124] If the first candidate length of the basket ring is between 5 mm and 10 mm, the longest spring coil length among the spring coil models corresponding to the basket ring diameter is used as the length of the basket ring;

[0125] When the first candidate length of the basket ring is greater than or equal to 10 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, the longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, the shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring.

[0126] In the embodiment of this specification, based on the model of the basket ring and the preset filling rate, the method of gradually decreasing the spring coil model is adopted to determine the various models of the packing ring that meet the preset filling rate, specifically including:

[0127] A method of gradually decreasing the spring coil models is adopted. On the premise that the filling rate of the already filled spring coils is less than or equal to the preset filling rate, the length of the subsequent filling coil is ensured to be less than the length of the previous filling coil, so as to determine the various models of filling coils that meet the preset filling rate.

[0128] In the embodiment of this specification, if the intracranial aneurysm to be treated is a micro-aneurysm or a medium-sized aneurysm, a method of gradually decreasing the coil size is adopted. On the premise of meeting the preset packing rate, the coil size with the longest length is selected as the packing coil size.

[0129] If the intracranial aneurysm to be treated is a small aneurysm, the method of gradually decreasing the spring coil model is adopted. On the premise of meeting the preset filling rate, the model of the packing coil is determined by gradually decreasing the spring coil length.

[0130] In the embodiment of this specification, determining the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed to determine the model of the basket ring specifically includes:

[0131] Obtaining an average value of aneurysm diameters in the intracranial aneurysm image data to be processed based on the long diameter of the aneurysm in the intracranial aneurysm image data to be processed and the short diameter of the aneurysm in the intracranial aneurysm image data to be processed;

[0132] taking the average value of the aneurysm diameters at a second preset multiple as the diameter of the basket ring;

[0133] The longest diameter of the spring coil model corresponding to the diameter of the basket ring is used as the length of the basket ring;

[0134] The model of the basket ring is determined based on the diameter of the basket ring and the length of the basket ring.

[0135] In the embodiment of this specification, the method of decreasing the packing rate of the spring coil specifically includes:

[0136] Based on the model of the basket coil, a first packing rate of a first spring coil is obtained;

[0137] Obtaining a second packing ratio of a second spring coil serving as a packing coil based on the first packing ratio of the spring coil and a preset packing coefficient;

[0138] Obtaining a third packing ratio of a third spring coil based on the second packing ratio and the preset packing coefficient;

[0139] The operation is cyclically performed until the sum of the first filling rate, the second filling rate, the third filling rate, and the nth filling rate meets the preset filling rate.

[0140] In the embodiment of this specification, based on the model of the basket ring and the preset packing rate, the method of decreasing the packing rate of the spring coil is adopted to determine the various models of the packing ring, and the various models of the packing ring that meet the preset packing rate are determined, specifically including:

[0141] Determining the model of the second spring coil serving as the stuffing ring based on the second stuffing rate, the diameter of the second spring coil serving as the stuffing ring, and the length of the second spring coil, wherein the length of the second spring coil is not greater than the diameter of the basket ring;

[0142] Based on the third packing ratio, obtaining the diameter and length of the third spring coil, and determining the model of the third spring coil of the packing ring, wherein the length of the third spring coil is not greater than the diameter of the second spring coil;

[0143] The operation is repeated to obtain the diameter of the n-th spring coil and the length of the n-th spring coil, and to determine the model of the n-th spring coil, until all models of packing coils that meet the preset packing rate are determined.

[0144] The foregoing description of this specification describes specific embodiments. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims can be performed in an order different from that described in the embodiments and still achieve the desired results. Furthermore, the processes depicted in the accompanying drawings do not necessarily require the specific order shown or the sequential order to achieve the desired results. In certain embodiments, multitasking and parallel processing are also possible or may be advantageous.

[0145] The various embodiments in this specification are described in a progressive manner. Similar portions between the various embodiments can be referenced to each other, and each embodiment focuses on the differences between the other embodiments. In particular, the device, electronic device, and non-volatile computer storage medium embodiments are generally similar to the method embodiments, so their descriptions are relatively simplified. For relevant details, refer to the descriptions of the method embodiments.

[0146] The apparatus, electronic device, and non-volatile computer storage medium provided in the embodiments of this specification correspond to the method. Therefore, the apparatus, electronic device, and non-volatile computer storage medium also have similar beneficial technical effects as the corresponding method. Since the beneficial technical effects of the method have been described in detail above, the beneficial technical effects of the corresponding apparatus, electronic device, and non-volatile computer storage medium will not be repeated here.

[0147] In the 1990s, technological improvements could be clearly distinguished as either hardware improvements (for example, improvements to circuit structures such as diodes, transistors, and switches) or software improvements (improvements to process flows). However, with the advancement of technology, many process flow improvements today can now be considered direct improvements to hardware circuit structures. Designers almost always create the corresponding hardware circuit structure by programming the improved process flow into the hardware circuit. Therefore, it cannot be said that a process flow improvement cannot be implemented using hardware modules. For example, a programmable logic device (PLD), such as a field programmable gate array (FPGA), is an integrated circuit whose logical function is determined by user programming. Designers can "integrate" a digital system on a PLD by programming it themselves, without having to hire a chip manufacturer to design and produce a dedicated integrated circuit chip. Moreover, nowadays, instead of manually fabricating integrated circuit chips, this programming is mostly done using "logic compiler" software. This is similar to the software compiler used when developing programs. Before compilation, the original code must also be written in a specific programming language, called a hardware description language (HDL). There is not just one HDL, but many, such as ABEL (Advanced Boolean Expression Language), AHDL (Altera Hardware Description Language), Confluence, CUPL (Cornell University Programming Language), HDCal, JHDL (Java Hardware Description Language), Lava, Lola, MyHDL, PALASM, RHDL (Ruby Hardware Description Language), etc. The most commonly used ones are VHDL (Very-High-Speed ​​Integrated Circuit Hardware Description Language) and Verilog. Those skilled in the art will also understand that by simply programming the method flow in one of these hardware description languages ​​and then programming it into an integrated circuit, a hardware circuit that implements the logic method flow can be easily obtained.

[0148] The controller can be implemented in any suitable manner. For example, the controller can take the form of a microprocessor or processor and a computer-readable medium storing computer-readable program code (e.g., software or firmware) executable by the (micro)processor, logic gates, switches, application-specific integrated circuits (ASICs), programmable logic controllers, and embedded microcontrollers. Examples of controllers include, but are not limited to, the following microcontrollers: ARC 625D, Atmel AT91SAM, Microchip PIC18F26K20, and Silicone Labs C8051F320. The memory controller can also be implemented as part of the control logic of the memory. Those skilled in the art will also know that in addition to implementing the controller in a purely computer-readable program code format, the controller can be implemented in the form of logic gates, switches, application-specific integrated circuits, programmable logic controllers, and embedded microcontrollers by logically programming the method steps. Therefore, such a controller can be considered a hardware component, and the devices included therein for implementing various functions can also be considered as structures within the hardware component. Or even, the devices for implementing various functions can be considered as both software modules that implement the method and structures within the hardware component.

[0149] The systems, devices, modules, or units described in the above embodiments may be implemented by computer chips or entities, or by products having certain functions. A typical implementation device is a computer. Specifically, the computer may be, for example, a personal computer, a laptop computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.

[0150] For the convenience of description, the above devices are described as being divided into various units according to their functions. Of course, when implementing one or more embodiments of this specification, the functions of each unit can be implemented in the same or multiple software and / or hardware.

[0151] Those skilled in the art will appreciate that the embodiments of this specification may be provided as methods, systems, or computer program products. Therefore, the embodiments of this specification may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Furthermore, the embodiments of this specification may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0152] This specification is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of this specification. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data optimization device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data optimization device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0153] These computer program instructions may also be stored in a computer readable memory capable of directing a computer or other programmable data optimization device to operate in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0154] These computer program instructions may also be loaded onto a computer or other programmable data optimization device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, whereby the instructions executed on the computer or other programmable device provide for implementing the process described in the flow. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0155] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0156] Memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

[0157] Computer-readable media includes permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. The information can be computer-readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer-readable media does not include transitory computer-readable media (transitory media), such as modulated data signals and carrier waves.

[0158] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a..." does not preclude the presence of additional identical elements in the process, method, commodity, or apparatus that includes the element.

[0159] This specification may be described in the general context of computer-executable instructions, such as program modules, executed by a computer. Generally, program modules include routines, programs, objects, components, data structures, and the like that perform specific tasks or implement specific abstract data types. The specification may also be practiced in distributed computing environments where tasks are performed by remote processing devices connected through a communications network. In a distributed computing environment, program modules may be located in both local and remote computer storage media, including storage devices.

[0160] The various embodiments in this specification are described in a progressive manner. Similar parts between the various embodiments can be referred to in conjunction with each other. Each embodiment focuses on the differences between the other embodiments. In particular, the system embodiments are generally similar to the method embodiments, so the description is relatively simple. For relevant parts, refer to the description of the method embodiments.

[0161] The foregoing is merely an embodiment of the present invention and is not intended to limit the present application. For those skilled in the art, various modifications and variations may be made to the present application. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included within the scope of the claims of the present application.

Claims

1. A coil simulation method for surgical planning, characterized in that: The method comprises: Acquiring morphological parameters of intracranial aneurysm image data to be processed; Based on the morphological parameters of the intracranial aneurysm image data to be processed, the diameter and length of the basket ring are determined to determine the model of the basket ring, wherein 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as a first candidate length of the basket ring; three times the long diameter of the aneurysm in the intracranial aneurysm image data to be processed is used as a second candidate length of the basket ring; and the smaller length between the first candidate length of the basket ring and the second candidate length of the basket ring is used as the length of the basket ring; Based on the model of the basketed coil and the preset filling rate, the method of gradually decreasing the spring coil model or decreasing the spring coil filling rate is adopted to determine the various models of the filling coils, and the various models of the filling coils that meet the preset filling rate are determined. The last spring coil that meets the preset filling rate is used as the finishing coil to complete the spring coil simulation.

2. The method according to claim 1, wherein When the intracranial aneurysm to be treated is a small aneurysm or a micro aneurysm, the short diameter of the small aneurysm or the micro aneurysm is used as the diameter of the basket ring.

3. The method according to claim 1, wherein The method of using 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed as the first candidate length of the basket ring specifically includes: Using a first preset multiple of the intracranial aneurysm volume in the morphological parameters of the intracranial aneurysm image data to be processed as the preset total length, wherein the first preset multiple is 0.3 / 0.8; 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as the first candidate length of the basket ring.

4. The method according to claim 1, wherein When the first candidate length of the basket ring is used as the length of the basket ring, if the first candidate length of the basket ring is less than 3 mm, the shortest spring coil length among the spring coil models corresponding to the diameter of the basket ring is used as the length of the basket ring; When the first candidate length of the basket ring is between 3 mm and 5 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, then the second longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, then the second shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; If the first candidate length of the basket ring is between 5 mm and 10 mm, the longest spring coil length among the spring coil models corresponding to the basket ring diameter is used as the length of the basket ring; When the first candidate length of the basket ring is greater than or equal to 10 mm, if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is greater than or equal to 1.5, the longest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring; if the ratio of the long diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed to the short diameter of the aneurysm in the morphological parameters of the intracranial image data to be processed is less than 1.5, the shortest spring coil length in the spring coil model corresponding to the basket ring diameter is used as the length of the basket ring.

5. The method according to claim 2, wherein The method of gradually decreasing the spring coil models based on the model of the basket ring and the preset filling rate is used to determine the models of the packing rings that meet the preset filling rate, specifically including: A method of gradually decreasing the spring coil models is adopted. On the premise that the filling rate of the already filled spring coils is less than or equal to the preset filling rate, the length of the subsequent filling coil is ensured to be less than the length of the previous filling coil, so as to determine the various models of filling coils that meet the preset filling rate.

6. The method according to claim 5, wherein If the intracranial aneurysm to be treated is a micro-aneurysm or a medium-sized aneurysm, a method of gradually decreasing the coil size is adopted, and on the premise of meeting the preset packing rate, the coil size with the longest length is selected as the packing coil size; If the intracranial aneurysm to be treated is a small aneurysm, the method of gradually decreasing the spring coil model is adopted. On the premise of meeting the preset filling rate, the model of the packing coil is determined by gradually decreasing the spring coil length.

7. The method according to claim 1, wherein The method of determining the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed, so as to determine the model of the basket ring, specifically includes: Obtaining an average value of aneurysm diameters in the intracranial aneurysm image data to be processed based on the long diameter of the aneurysm in the intracranial aneurysm image data to be processed and the short diameter of the aneurysm in the intracranial aneurysm image data to be processed; taking the average value of the aneurysm diameters at a second preset multiple as the diameter of the basket ring; The longest diameter of the spring coil model corresponding to the diameter of the basket ring is used as the length of the basket ring; The model of the basket ring is determined based on the diameter of the basket ring and the length of the basket ring.

8. The method according to claim 7, wherein The method for decreasing the packing rate of the spring coil specifically includes: Based on the model of the basket coil, a first packing rate of a first spring coil is obtained; Obtaining a second packing ratio of a second spring coil serving as a packing coil based on the first packing ratio of the spring coil and a preset packing coefficient; Obtaining a third packing ratio of a third spring coil based on the second packing ratio and the preset packing coefficient; The operation is cyclically performed until the sum of the first filling rate, the second filling rate, the third filling rate, and the nth filling rate meets the preset filling rate.

9. The method according to claim 8, wherein The method of determining the various models of the packing rings based on the model of the basket ring and the preset packing rate by decreasing the packing rate of the spring coils, and determining the various models of the packing rings that meet the preset packing rate, specifically includes: Determining the model of the second spring coil serving as the stuffing ring based on the second stuffing rate, the diameter of the second spring coil serving as the stuffing ring, and the length of the second spring coil, wherein the length of the second spring coil is not greater than the diameter of the basket ring; Based on the third packing ratio, obtaining the diameter and length of the third spring coil, and determining the model of the third spring coil of the packing ring, wherein the length of the third spring coil is not greater than the diameter of the second spring coil; The operation is repeated to obtain the diameter and length of the n-th spring coil and determine the model of the n-th spring coil, until all models of packing coils that meet the preset packing rate are determined.

10. A coil simulation device for surgical planning, characterized in that: The device comprises: An acquisition module, for acquiring morphological parameters of intracranial aneurysm image data to be processed; a basket ring determination module, which determines the diameter and length of the basket ring based on the morphological parameters of the intracranial aneurysm image data to be processed, so as to determine the model of the basket ring, wherein 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as a first candidate length of the basket ring; three times the long diameter of the aneurysm in the intracranial aneurysm image data to be processed is used as a second candidate length of the basket ring; and the smaller length between the first candidate length of the basket ring and the second candidate length of the basket ring is used as the length of the basket ring; The module for determining the stuffing ring and the ending ring determines the models of the stuffing rings based on the models of the basket rings and the preset stuffing rate, adopts a method of gradually decreasing the models of the spring rings or decreasing the stuffing rate of the spring rings, determines the models of the stuffing rings that meet the preset stuffing rate, and uses the last spring ring that meets the preset stuffing rate as the ending ring to complete the simulation of the spring rings.

11. An electronic device comprising: at least one processor; as well as, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to: Acquiring morphological parameters of intracranial aneurysm image data to be processed; Based on the morphological parameters of the intracranial aneurysm image data to be processed, the diameter and length of the basket ring are determined to determine the model of the basket ring, wherein 1 / 3 to 1 / 2 of the preset total length corresponding to the intracranial aneurysm image data to be processed is used as a first candidate length of the basket ring; three times the long diameter of the aneurysm in the intracranial aneurysm image data to be processed is used as a second candidate length of the basket ring; and the smaller length between the first candidate length of the basket ring and the second candidate length of the basket ring is used as the length of the basket ring; Based on the model of the basketed coil and the preset filling rate, the method of gradually decreasing the spring coil model or decreasing the spring coil filling rate is adopted to determine the various models of the filling coils, and the various models of the filling coils that meet the preset filling rate are determined. The last spring coil that meets the preset filling rate is used as the finishing coil to complete the spring coil simulation.

Images