CN113100935A

CN113100935A - A preoperative puncture path planning method and training system for lung puncture surgery

Info

Publication number: CN113100935A
Application number: CN202110393964.7A
Authority: CN
Inventors: 李育文; 陈成; 李明
Original assignee: University of Shanghai for Science and Technology
Current assignee: University of Shanghai for Science and Technology
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2021-07-13

Abstract

The invention discloses a preoperative puncture path planning method and a preoperative puncture path planning system for a pulmonary puncture operation. The method comprises the following steps: acquiring a 4D lung CT image by using a CT scanner; constructing a respiratory motion linear model based on the CT image and the acquired in-vitro respiratory signal; constructing a four-dimensional lung breathing visualization model by adopting a digital reconstruction rendering method based on the breathing motion linear model; displaying a focus area according to the lung breathing four-dimensional visualization model; determining a puncture needle inserting point and a target point based on the focus area; and determining a puncture path by adopting a path planning algorithm based on the puncture needle inserting point and the target point. The invention can accurately and effectively assist doctors in planning puncture paths and training before operations.

Description

Preoperative puncture path planning method and training system for lung puncture operation

Technical Field

The invention relates to the field of clinical medical operations, in particular to a preoperative puncture path planning method and a training system for a lung puncture operation.

Background

Lung cancer poses a great threat to the life health of people as one of the most rapidly growing malignant tumors. At present, the percutaneous puncture operation has become an important means for diagnosing and treating the lung cancer due to the advantages of small wound removing area, low operation price, good operation effect, quick postoperative recovery and the like. The puncture operation is mainly used for puncturing a puncture needle into the focus position of a patient so as to extract tissues or secretions at the focus position for testing or inject medicines into a body cavity. The applications of the lung cancer diagnosis and treatment mainly include needle biopsy and near-distance particle therapy. Needle biopsy aspirates into the lesion by puncturing to obtain a small amount of tissue for pathological examination and diagnosis. The close range particle therapy is that radioactive particles are placed in a body cavity, so that the radioactive particles are close to a tumor part to kill tumor cells, the tumor tissue can be continuously damaged, meanwhile, the radioactive damage to surrounding normal tissues is reduced, the number of the implanted particles can be changed according to patients, illness states, target area shapes and unknown specific conditions, the flexibility is high, and the treatment effect is very good.

For the current common preoperative method of the puncture surgery, before the surgery, a surgeon firstly carries out tomography scanning on a focus area of a patient through CT (computed tomography) or MR (magnetic resonance) equipment, a focus scanning image is guided into a computer, the area of a lesion tissue is determined, a puncture target point is selected at a proper position of the area, a proper needle insertion point is selected through a computer graphic tool, and finally the puncture surgery is carried out according to a planned path in the surgery process. However, there are many disadvantages in the preparation processes before the operation, the first is that the respiratory motion of the lung is a dynamic process, generally, images of several respiratory nodes are obtained after scanning, and no dynamic respiratory model is constructed by rendering the images; the second doctor needs to plan the puncture path before the operation, but no effective measures are available for simulating the planned puncture path to evaluate the risk degree of the puncture path; the third aspect is to the complex surgical environment, and there is no effective means for the physician to systematically train before surgery.

Disclosure of Invention

The invention aims to provide a preoperative puncture path planning method and a training system for a lung puncture operation, wherein the respiratory motion behavior of a lung anatomical structure is reconstructed by a four-dimensional visualization technology, and an optimal puncture path is generated by adopting a path planning algorithm, so that the damage of the operation to other tissues and organs can be reduced to the greatest extent.

In order to achieve the purpose, the invention provides the following scheme:

a preoperative puncture path planning method for a pulmonary puncture operation comprises the following steps:

acquiring a 4D lung CT image by using a CT scanner;

constructing a respiratory motion linear model based on the CT image and the acquired in-vitro respiratory signal;

constructing a four-dimensional lung breathing visualization model by adopting a digital reconstruction rendering method based on the breathing motion linear model;

displaying a focus area according to the lung breathing four-dimensional visualization model;

determining a puncture needle inserting point and a target point based on the focus area;

and determining a puncture path by adopting a path planning algorithm based on the puncture needle inserting point and the target point.

Further, the constructing a respiratory motion linear model based on the CT image and the acquired external respiratory signal specifically includes:

the 4D lung CT images correspond to the in-vitro signals one by one, and matching points are determined;

acquiring three-dimensional deformation displacement of each registration point in time by using 4D lung CT elastic registration;

performing time fitting on the three-dimensional deformation displacement to obtain an in-vitro respiration signal fitting curve and a registration point fitting curve;

and performing linear fitting on the in-vitro respiration signal fitting curve and the registration point fitting curve to obtain a respiration motion linear model.

Further, constructing a four-dimensional lung respiration visualization model by a digital reconstruction rendering method based on the respiratory motion linear model specifically includes:

determining CT images at various moments in each respiratory cycle based on the respiratory motion linear model;

and rendering the CT image at each moment by adopting a digital reconstruction rendering method to complete the construction of the lung breathing four-dimensional visualization model.

Further, the target point is the centroid of the focal region.

The invention also provides a training system before the lung puncture operation, which is applied to the method and comprises the following steps:

the human lung dynamic model importing unit is used for importing the lung breathing four-dimensional visualization model into Unity to generate a ward scene;

the head-mounted device is worn on the head of a doctor, and when the head-mounted device is worn, the ward scene appears in the visual field of a wearer;

the operating handle is used for training operation;

and the VR execution unit is used for performing puncture surgery simulation training.

Further, the VR execution unit includes:

the preparation module is used for selecting the needed surgical instrument through the operating handle;

the puncture module is used for simulating a lung puncture operation along the planned puncture path through the operating handle;

the display module is used for displaying the puncture depth, angle and speed in the puncture process;

and the interaction module is used for reminding the user of the current puncture condition and giving an alarm when the puncture depth and/or the deviation degree are/is greater than the preset deviation value.

Furthermore, the display module is also used for displaying the virtual biological tissue information within the preset range around the focus position of the patient according to the 3D image data and the spatial position of the patient and the focus position.

Further, the display module is further configured to display size information of the puncture path, and the size information of the puncture path is represented by different colors.

Further, the display module is also used for displaying the deviation degree of the puncture path from the preset puncture path in the puncture process of the doctor.

Furthermore, the interaction module reminds the user of the current puncture condition in any one or more modes of characters, voice, images and images.

According to the specific embodiment provided by the invention, the invention discloses the following technical effects:

the respiratory motion behavior of the lung anatomical structure is reconstructed through a four-dimensional visualization technology, and an optimal puncture path is generated by adopting a path planning algorithm, so that the damage of the operation to other tissues and organs can be reduced to the maximum extent.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings without inventive exercise.

Fig. 1 is a flowchart of a preoperative puncture path planning method for a pulmonary puncture operation according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a lung breathing four-dimensional visualization model;

fig. 3 is a detailed operation flow of the training system before the lung puncture operation.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in further detail below.

As shown in fig. 1, the method for planning a puncture path before a pulmonary puncture operation includes:

step 101: a CT scanner was used to acquire 4D lung CT images.

The focus part is scanned through scanning equipment, three-dimensional image data of the focus of the puncture object are obtained, and meanwhile, a respiratory signal of the puncture object is collected.

During data acquisition, a patient lies on the back in a CT bed and keeps the posture fixed. The marker is attached to the body surface of the chest xiphoid process position of the patient, and the patient is guided to do free breathing. Firstly, starting a binocular stereoscopic vision system, and collecting displacement data of a marker; and after the patient breathes stably, starting the CT scanner to perform dynamic lung scanning.

Step 102: and constructing a respiratory motion linear model based on the CT image and the acquired external respiratory signal.

The 4D lung CT images correspond to the in-vitro signals one by one, and the three-dimensional deformation displacement of each registration point to time is obtained by utilizing the 4D lung CT elastic registration; and then obtaining an in vitro respiration signal fitting curve and a registration control point fitting curve by applying time fitting, and finally linearly fitting the deformation displacement of each control point and the corresponding respiration signal value to complete the construction of a respiration motion linear model.

Step 103: based on the respiratory motion linear model, a digital reconstruction rendering method is adopted to construct a lung respiratory four-dimensional visualization model, as shown in fig. 2.

Through a linear model of respiratory motion, the CT picture can be known to be at a specific time point of a respiratory cycle, the image at each time is loaded into a texture memory of a processor for initialization rendering, and a three-dimensional dynamic rendering image synchronous with actual respiration is finally formed through high-speed rendering based on a GPU accelerated volume rendering algorithm by cyclic execution, so that the construction of a four-dimensional lung visualization model is completed.

Step 104: and displaying a focus area according to the lung breathing four-dimensional visualization model.

Step 105: and determining a puncture needle inserting point and a target point based on the lesion area.

Step 106: and determining a puncture path by adopting a path planning algorithm based on the puncture needle inserting point and the target point.

Firstly, displaying the size, position, shape and form of a focus on a constructed lung four-dimensional visualization model, extracting the centroid of the focus and outlining a motion track in a respiratory cycle.

The method comprises the steps that a doctor selects a certain moment in a respiratory cycle, the moment is the optimal needle insertion moment judged by the doctor clinically, the centroid position of a focus at the moment is used as a target point of a puncture needle, and blood vessels, organs and the like on a path are avoided to the greatest extent through a path planning algorithm, so that the optimal needle insertion point is selected.

The path planning algorithm is to fill the non-tissue area in the four-dimensional model, add the limitation condition of the needle insertion point area, search the optimal solution, namely the optimal puncture path, which occupies the largest proportion of the non-tissue area in the needle insertion area, so as to avoid the tissue and organ as much as possible, thereby reducing the injury of the operation to the lowest.

and the human lung dynamic model importing unit is used for importing the lung breathing four-dimensional visualization model into Unity to generate a ward scene.

The head-mounted device is worn on the head of a doctor, and after the head-mounted device is worn, the ward scene can appear in the visual field of a wearer.

And the operating handle is used for training operation.

The human lung dynamic model importing unit is used for importing the constructed four-dimensional visual model of the human lung into the Unity, synthesizing a scene of a ward in the Unity through size adjustment, position adjustment and rotation selection, and setting a related script control, so that the scene can completely appear in the visual field of an operator wearing the head-mounted display equipment; and the VR executing unit completes the operation process in the constructed scene for the doctor by operating the virtual reality handle.

Wherein, VR execution unit includes:

and the preparation module is used for selecting the required surgical instrument through the operating handle.

And the puncture module is used for simulating a lung puncture operation along the planned puncture path through the operating handle.

And the display module is used for displaying the puncture depth, angle and speed in the puncture process. The display module is also used for displaying the virtual biological tissue information within the preset range around the focus position of the patient according to the 3D image data and the space position of the patient and the focus position. And displaying the dimension information of the puncture path, and representing the dimension information of the puncture path by different colors. And displaying the deviation degree of the doctor from the preset puncture path in the puncture process.

And the interaction module is used for reminding the user of the current puncture condition and giving an alarm when the puncture depth and/or the deviation degree are/is greater than the preset deviation value. The current puncture condition of the user is reminded in any one or more modes of characters, voice, images and images, or when the puncture path deviates from the preset path, a warning mark is displayed on an interface, and the doctor is reminded by vibrating an operating handle. The specific operation flow of the training system is shown in fig. 3.

The main operation steps are as follows:

step 1, a doctor wears VR equipment, and presents corresponding operation environments (wards, patients, surgical instruments and the like) through the head-worn display equipment by the human lung model importing unit.

And 2, operating the VR operating handle by the doctor to select surgical instruments and selecting postures of the patient during puncture through the preparation module.

And 3, operating the VR operating handle by the doctor through the puncture module to simulate a puncture operation, wherein in the puncture process, the doctor can acquire the information of the virtual biological tissues and the puncture depth and angle in the preset range around the focus part of the patient, the puncture advancing speed and the deviation degree from the preset puncture path in the puncture process through the display module. The internal part and the external part of the puncture needle are respectively expressed by different colors; through the interaction module, when the puncture path deviates from the preset path, the interface displays the warning mark and reminds a doctor through vibration of the operating handle.

And 4, through the interaction module, after the simulated puncture operation is finished, a doctor operates the VR operating handle to perform the operation process playback function, and notes are given to the puncture process.

The principles and embodiments of the present invention have been described herein using specific examples, which are provided only to help understand the method and the core concept of the present invention; meanwhile, for a person skilled in the art, according to the idea of the present invention, the specific embodiments and the application range may be changed. In view of the above, the present disclosure should not be construed as limiting the invention.

Claims

1. a preoperative puncture path planning method for lung puncture operation, is characterized in that, comprises:

Use a CT scanner to acquire 4D lung CT images;

Constructing a linear model of respiratory motion based on the CT image and the acquired extracorporeal respiratory signal;

Based on the linear model of breathing motion, a digital reconstruction rendering method is used to construct a four-dimensional visualization model of lung breathing;

Display the lesion area according to the four-dimensional visualization model of lung respiration;

determining a puncture needle entry point and a target point based on the lesion area;

Based on the puncture needle entry point and the target point, a path planning algorithm is used to determine the puncture path.

2. The preoperative puncture path planning method for lung puncture surgery according to claim 1, wherein the construction of a linear model of breathing motion based on the CT image and the acquired extracorporeal breathing signal specifically includes:

One-to-one correspondence between 4D lung CT images and in vitro signals to determine matching points;

Using 4D lung CT elastic registration to obtain the three-dimensional deformation and displacement of each registration point with respect to time;

Performing time fitting on the three-dimensional deformation displacement to obtain a fitting curve of an in vitro breathing signal and a fitting curve of a registration point;

Linear fitting is performed on the in vitro breathing signal fitting curve and the registration point fitting curve to obtain a breathing motion linear model.

3. The preoperative puncture path planning method for lung puncture surgery according to claim 1, characterized in that, based on the linear model of breathing motion, a digital reconstruction rendering method is used to construct a four-dimensional visualization model of pulmonary respiration, which specifically comprises the following steps: :

Based on the breathing motion linear model, determine the CT image at each moment in each breathing cycle;

The CT image at each moment is rendered by the digital reconstruction rendering method to complete the construction of the four-dimensional visualization model of lung breathing.

4 . The preoperative puncture path planning method according to claim 1 , wherein the target point is the centroid of the lesion area. 5 .

5. A preoperative training system for lung puncture surgery, wherein the training system is applied to the method according to any one of claims 1-4, and the training system comprises:

The human lung dynamic model import unit is used to import the 4D visualization model of lung breathing into Unity to generate ward scenes;

A head-mounted device, which is used to be worn on the doctor's head. When the head-mounted device is worn, the ward scene will appear in the wearer's field of vision;

Operating handle for training operations;

VR execution unit for puncture surgery simulation training.

6. The preoperative training system for lung puncture surgery according to claim 5, wherein the VR execution unit comprises:

a preparation module for selecting the required surgical instrument through the operating handle;

a puncture module, used for simulating a lung puncture operation along the planned puncture path through the operating handle;

The display module is used to display the depth, angle and speed of the puncture in the puncture process;

The interaction module is used to remind the user of the current puncture situation, and issue an alarm when the puncture depth and/or deviation is greater than a preset deviation value.

7 . The preoperative training system for lung puncture surgery according to claim 6 , wherein the display module is also used to display presets around the patient’s lesion according to the 3D image data and spatial position of the patient and the lesion. 8 . Scope of virtual biological tissue information.

8 . The preoperative training system for lung puncture surgery according to claim 5 , wherein the display module is further configured to display the size information of the puncture path, and the size information of the puncture path is displayed in different colors. 9 . express.

9 . The preoperative training system for lung puncture surgery according to claim 5 , wherein the display module is further configured to display the degree of deviation from the preset puncture path during the doctor's puncture. 10 .

10 . The preoperative training system for lung puncture surgery according to claim 1 , wherein the interaction module reminds the user of the current puncture situation through any one or more of text, voice, video, and image. 11 .