Tissue surface ablation temperature identification system and monitoring method based on real-time image feedback

Abstract

The invention relates to a tissue surface ablation temperature identification system based on real-time image feedback and a temperature monitoring method. The system comprises an ablation device, an image acquisition device and a temperature identification device, wherein the ablation device is provided with a model of a color and temperature corresponding relation of a tumor target tissue surface image; the image acquisition device is used for acquiring the tumor target tissue surface image in real time; the temperature identification device is used for matching the color and the temperature of the image; the real-time temperature value of the surface of the tumor target tissue is monitored through the system. According to the method, a corresponding relation model of tumor target tissue surface images and temperature data is established, the images of the tumor tissue surface are continuously shot in the ablation process, and the temperature change of the tumor surface in the ablation process is displayed in real time through processing of a computer; accurate reference can be provided for a doctor to select ablation parameters in the microwave ablation operation process.

Description

Technical Field

[0001] The invention relates to a tissue surface ablation temperature recognition system and a monitoring method based on real-time image feedback, belonging to the technical field of ablation. Background Art

[0002] In recent years, ablation technology has begun to be widely used in the treatment of various solid tumors, especially in the treatment of liver cancer and lung cancer. During microwave ablation, doctors are usually unable to intuitively monitor the temperature changes of the ablated tissue and its surrounding organs at risk. Generally, CT images are taken in stages during the ablation process, and then the doctor judges the current ablation results based on his own experience. In order to ensure that the ablation results meet expectations, the accuracy of judgment is generally improved by increasing the number of CT scans, which increases the risk of patients being exposed to radiation, increases the economic burden on patients, and increases the complexity of the doctor's surgical process. Moreover, there is a lag between CT images and the actual ablation results, and the ablation results cannot be monitored in real time.

[0003] The existing technology is to estimate the intraoperative ablation effect through preoperative simulated ablation images. Since the simulated effect is usually calculated through ex vivo data and empirical data, and lacks the correction of real-time data during the operation, the simulated ablation images are usually quite different from the actual ablation effect, and the clinical value is difficult to reflect.

[0004] Due to the above reasons, there is no effective means to continuously monitor the entire ablation process during surgery. Summary of the invention

[0005] The technical problem to be solved by the present invention is: by constructing a corresponding relationship between the surface image of the ablated tissue and the temperature, it can assist doctors in more accurately identifying and monitoring the temperature changes on the surface of the ablated tissue during the operation, and then adjust the ablation parameters to prevent the ablation operation from damaging other normal tissues.

[0006] In order to solve the above technical problems, on the one hand, the present invention proposes a tissue surface ablation temperature recognition system based on real-time image feedback, comprising: The ablation device is configured with a model of the corresponding relationship between the color and temperature of the tumor target tissue surface image, referred to as the first relationship model; An image acquisition device, used for acquiring a surface image of a tumor target tissue in real time, referred to as a first image; The temperature recognition device is used to match the color of each pixel of the first image with the first relationship model to obtain the real-time temperature value of the surface of the tumor target tissue.

[0007] On the other hand, the present invention also proposes a tissue surface ablation temperature monitoring method based on real-time image feedback, using the above-mentioned tissue surface ablation temperature recognition system, comprising the following steps: The image acquisition device acquires the first image in real time; The temperature recognition device searches for the temperature value corresponding to the color of each pixel of the first image from the first relationship model, that is, obtains the real-time temperature value of the surface of the tumor target tissue.

[0008] The present invention establishes a model database of the correspondence between the surface image of the target tumor tissue and the temperature data, continuously captures images of the surface of the tumor tissue as the first image during the ablation process, and then searches the first relationship model for the temperature value corresponding to the color of each pixel of the first image. This can display and monitor the temperature changes of the tumor surface during the ablation process in real time, and can provide accurate reference for doctors to select ablation parameters during microwave ablation surgery, thereby preventing excessive ablation. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 Schematic diagram of the structure of the ablation needle in an embodiment of the present invention.

[0010] Figure 2 yes Figure 1 Schematic diagram of the cross section at the inner rod.

[0011] Figure numerals: 1. ablation needle; 2. needle rod body; 3. sleeve; 4. channel. DETAILED DESCRIPTION

[0012] In clinical treatment, ablation surgery lacks appropriate real-time monitoring means, resulting in an uncontrollable ablation process. Intermittent ablation is required, and the ablation range is observed intermittently through images to ensure the safety and reliability of the ablation process and to ensure that there is no excessive ablation. During tumor ablation surgery, in order to monitor the temperature changes of the tumor target tissue during the ablation process, doctors generally use side temperature measurement, or some design temperature measurement points on the ablation needle, but neither of the above two temperature measurement methods can reflect the local temperature changes of the tumor target tissue in real time. The temperature measurement points designed on some ablation needles can only measure the temperature of the cooling water, and cannot measure the temperature changes of the tumor at all. In addition, in the prior art, it is not possible to display the temperature changes of the tumor on the ablation system in a timely and accurate manner, and observe the degeneration trend of the entire tumor. The technical solution of the present invention can intuitively observe the changes in the local temperature of the tumor during the ablation process.

[0013] The technical solution proposed by the present invention is further described in detail below in conjunction with embodiments and drawings, but the implementation mode of the present invention is not limited thereto.

[0014] Embodiment 1: This embodiment provides a tissue surface ablation temperature recognition system based on real-time image feedback, including: The ablation device is configured with a model of the corresponding relationship between the color and temperature of the tumor target tissue surface image, referred to as the first relationship model; An image acquisition device, used for acquiring a surface image of a tumor target tissue in real time, referred to as a first image; The temperature recognition device is used to match the color of each pixel of the first image with the first relationship model to obtain the real-time temperature value of the surface of the tumor target tissue.

[0015] The surface image of the tumor target tissue as the first image can be acquired through a natural cavity or an artificial cavity. Taking the acquisition through an artificial cavity as an example, the ablation device includes an ablation needle, such as Figure 1 As shown, the ablation needle includes a needle rod body and a sleeve arranged on the needle rod body, and the sleeve is provided with a channel for the shooting element of the image acquisition device to pass freely. The image acquisition device in this embodiment is preferably an endoscope. When the ablation needle 1 is inserted into the tumor target tissue for ablation, the endoscope is inserted from the channel 4 to collect the color change of the surface image of the tumor target tissue, which corresponds to the first relationship model pre-stored in the ablation system, so as to display the temperature change of the surface of the tumor target tissue in real time. In some cases, the endoscope can also be used to shoot the surface of the tumor target tissue through the natural cavity to obtain the first image.

[0016] In order to accurately know the specific position of the first image collected in the entire tumor target tissue, the present invention also uses image acquisition equipment such as CT and MRI to collect image data of the tumor, and simulates a three-dimensional model of the tumor target tissue in the ablation system. The first image and the three-dimensional model of the tumor target tissue are registered, and the real-time temperature value of the surface of the tumor target tissue is reflected on the three-dimensional model, which can intuitively display the temperature change at the first image on the surface of the tumor target tissue.

[0017] Since the ablation shape of the ablation needle is an ellipsoid or a sphere, and before the operation planning, some pre-stored data of the ablation needle needs to be input, including the ablation needle model, needle rod diameter, effective length, location of the ablation center, and ablation power, time, ablation range, etc. The first image and ablation center information on the three-dimensional model of the tumor target tissue can be used to simulate a temperature change model that matches the ablation shape.

[0018] In this embodiment, an experimental method is used to obtain the first relationship model. For the rigor of the experiment and to reduce errors, the equipment of this experiment will be as consistent as possible with the equipment of the surgical process. In addition, in order to keep the image information collected by the endoscope consistent with the image information of the tumor target tissue collected during the operation and reduce color difference, the experiment will simulate the surgical environment of human tissue.

[0019] The steps of the experimental method are as follows: The first step is to place the ex vivo tissue in a light-proof box to simulate the ablation environment of human liver tissue, so that the subsequent endoscopic shooting results are consistent with the actual ablation process. Multiple temperature measurement points are set on the surface of the ex vivo tissue, and thermocouples are set on the temperature measurement points to measure the temperature of the temperature measurement points through the thermocouples.

[0020] In this embodiment, the ex vivo tissue is a pig liver that was isolated within 4 hours. Before ablation, the pig liver was stored in an electric constant temperature water tank to maintain the liver tissue temperature at 36.5±2°C.

[0021] The second step is to insert the ablation needle through the box into the ex vivo tissue to simulate the ablation process of the ex vivo tissue. It should be noted that in order to collect image information of temperature changes on the surface of the ex vivo tissue, the ablation needle should not be inserted too deep; the existing ablation needle does not have a shooting function, such as Figure 1 and 2 As described above, this embodiment improves the existing ablation needle 1, installs a sleeve 3 on the needle shaft body 2, and opens a channel 4 for the endoscope to freely enter and exit on the sleeve 3. The endoscope channel 4 can move with the ablation needle, so that the endoscope can display the ablation process in real time during the actual operation. This embodiment is also used to simulate this shooting process through the above settings. By adjusting the endoscope lens angle and the distance from the endoscope lens to the needle tip, the endoscope is fixed in place, and the image of the tissue surface can be captured at this time.

[0022] The endoscope in this embodiment adopts the Guantai series submillimeter ultra-fine fiber endoscope, which has the functions of fiber optic image transmission and light guide. The probe has good flexibility and a smaller diameter, and can be used to detect through curved and narrow channels. It can be directly observed through the eyepiece, and can also be connected to the display screen through the USB OTG interface to capture and process images, which is easy to operate. The endoscope has a field of view of 70°-120°, a one-way bending angle of the probe of ≥150°, a depth of field of 5-50mm, and a fiber optic light guide function, which is convenient for lighting.

[0023] It should be noted that due to the limitations of the endoscope's field of view, bending angle and depth of field, if the endoscope and ablation needle are fixed as one, the image collected by the endoscope will be unclear during the movement of the ablation needle, or the tumor target area will partially or completely move out of the endoscope lens during the movement, making it impossible to accurately puncture.

[0024] The third step is to extend the endoscope from the channel 4, and adjust the lens angle of the endoscope and the distance from the endoscope lens to the needle tip so that an image of the ex vivo tissue surface within the visible range can be captured.

[0025] Step 4: Set the ablation parameters of the ablation needle and ablate the ex vivo tissue. During the ablation process, take photos of the ex vivo tissue to obtain multiple sets of first images. According to the RGB value of each pixel in the first image, the corresponding relationship between the ex vivo tissue surface temperature value and the RGB value is obtained, which is referred to as the first relationship model.

[0026] The process of obtaining the first relationship model can be summarized as follows: the ablation device ablates the ex vivo tissue, sets multiple temperature measuring points in the ex vivo tissue, continuously collects the first image of the ex vivo tissue ablation process, and the temperature values ​​of the temperature measuring points, obtains the relationship between each temperature measuring point and the RGB color value of the pixel corresponding to the temperature measuring point in the first image, and thus establishes the first relationship model.

[0027] During the actual ablation operation, the doctor obtains the real-time temperature value of the tissue surface through the real-time image of the tissue surface based on the first relationship model. That is, the real-time image of the tissue surface is obtained through the endoscope matched with the ablation needle, and the real-time temperature value of the tissue surface is obtained by reverse deduction through the RGB value of the image according to the first relationship model database, so that the doctor can adjust the ablation parameters in real time, and prevent the ablation operation from damaging other normal tissues while ensuring the ablation effect.

[0028] Since the RGB value of each pixel in the first image contains data from three channels, the first relationship model is very complex. In order to simplify the first relationship model, preferably, the first image is grayed to obtain a second image, and a corresponding relationship model between each temperature measurement point of the ex vivo tissue and the grayscale value of the corresponding pixel of the second image is further obtained, which is referred to as the second relationship model for short, so as to obtain the real-time temperature value corresponding to the tissue surface through the grayscale image of the real-time image of the tissue surface based on the second relationship model.

[0029] There are many methods for converting the RGB value of the first image into the gray value, all of which are prior art. For example, the following method can be used: The corresponding relationship between the RGB value of the first image and the gray value of the second image is: Gray=(R*19595+G*38469+B*7472)>>16, Where Gray is the gray value of a pixel in the second image, R is the red channel value of the corresponding pixel in the first image, G is the green channel value of the corresponding pixel in the first image, and B is the blue channel value of the corresponding pixel in the first image.

[0030] It should be noted that the first relationship model in the present invention can be continuously optimized and modified according to the temperature values ​​measured and the image information collected during the actual ablation surgery, in order to obtain a more accurate database.

[0031] Embodiment 2: This embodiment proposes a tissue surface ablation temperature monitoring method based on real-time image feedback, which is applied to the tissue surface ablation temperature identification system based on real-time image feedback in Embodiment 1. The method includes the following steps: Use CT, MRI and other imaging equipment to collect imaging information of tumor target tissues, determine the specific location of target tissues, and do related work such as surgical planning; Inserting the ablation needle into the tumor target tissue; The image acquisition device adopts an endoscope, such as Figure 1 and Figure 2 As shown, the endoscope is inserted into the body through the channel 4 reserved on the ablation needle, so that the endoscope can clearly collect image information of the surface of the tumor target tissue; Set the ablation parameters of the ablation needle and start ablation; Acquire a first image in real time through an endoscope; The temperature recognition device searches for the temperature value corresponding to the color of each pixel of the first image from the first relationship model, that is, obtains the real-time temperature value of the surface of the tumor target tissue, and displays it in real time on the display interface of the ablation device.

[0032] The temperature recognition device searches for the temperature value corresponding to the color of each pixel of the first image from the first relationship model, that is, obtains the real-time temperature value of the surface of the tumor target tissue.

[0033] This embodiment can also be improved as follows: the ablation device generates a three-dimensional model of the tumor target tissue, aligns the first image with the three-dimensional model, and reflects the real-time temperature value of the surface of the tumor target tissue on the three-dimensional model, thereby obtaining the real-time temperature field of the surface of the tumor target tissue.

[0034] Real-time information of the first image is continuously collected, and real-time temperature change information on the three-dimensional model is obtained through a first relationship model database pre-stored in the ablation system.

[0035] In this embodiment, the first relationship model is obtained by using the experimental method in the first embodiment, and the first relationship model is obtained according to the RGB value of each pixel in the first image and the measured temperature value.

[0036] In this embodiment, the second relationship model library is obtained using the method in the first embodiment, the first image is grayed to obtain the second image, and the correspondence between each temperature measurement point of the ex vivo tissue and the gray value of the corresponding pixel of the second image is further obtained.

[0037] The technical solutions proposed in Embodiment 1 and Embodiment 2 of the present invention can be used in ablation surgeries such as microwave, radio frequency, and ultrasound.

[0038] It should be noted that the above schematically describes the present invention and its implementation methods, which are not restrictive, and the drawings show only one of the implementation methods of the present invention. Therefore, if a person skilled in the art is inspired by it and does not deviate from the purpose of the invention, and does not creatively design methods and embodiments similar to the technical solution, they should all fall within the scope of protection of the present invention.

Claims

1. A tissue surface ablation temperature recognition system based on real-time image feedback, characterized in that: include: The ablation device is configured with a model of the corresponding relationship between the color and temperature of the tumor target tissue surface image, referred to as the first relationship model; An image acquisition device, used for acquiring a surface image of a tumor target tissue in real time, referred to as a first image; The temperature recognition device is used to match the color of each pixel of the first image with the first relationship model to obtain the real-time temperature value of the surface of the tumor target tissue.

2. The tissue surface ablation temperature recognition system based on real-time image feedback according to claim 1, characterized in that: The ablation device comprises an ablation needle, and the ablation needle comprises a needle rod body and a sleeve arranged on the needle rod body, and the sleeve is provided with a channel for the shooting element of the image acquisition device to pass freely.

3. The tissue surface ablation temperature recognition system based on real-time image feedback according to claim 1, characterized in that: The shooting element of the image acquisition device is a shooting element that can pass through a natural cavity.

4. The tissue surface ablation temperature recognition system based on real-time image feedback according to claim 2, characterized in that: The ablation device is used to generate a three-dimensional model of the tumor target tissue, and to align the first image with the three-dimensional model, and the obtained real-time temperature value of the surface of the tumor target tissue is reflected on the three-dimensional model.

5. A method for monitoring ablation temperature using the tissue surface ablation temperature recognition system according to claim 1, comprising the following steps: The image acquisition device acquires the first image in real time; The temperature recognition device searches for the temperature value corresponding to the color of each pixel of the first image from the first relationship model, that is, obtains the real-time temperature value of the surface of the tumor target tissue.

6. The ablation temperature monitoring method according to claim 5, characterized in that: The ablation device generates a three-dimensional model of the tumor target tissue, aligns the first image with the three-dimensional model, and reflects the real-time temperature value of the surface of the tumor target tissue on the three-dimensional model, thereby obtaining the real-time temperature field of the surface of the tumor target tissue.

7. The ablation temperature monitoring method according to claim 5 or 6, characterized in that: The first relationship model is obtained by the following method: The ablation device ablates the ex vivo tissue, sets multiple temperature measuring points in the ex vivo tissue, continuously collects the first image during the ex vivo tissue ablation process, and the temperature values ​​of the temperature measuring points, obtains the relationship between each temperature measuring point and the RGB color value of the pixel in the first image corresponding to the temperature measuring point, and thus establishes a first relationship model.

8. The ablation temperature monitoring method according to claim 7, characterized in that: The first image is grayed to obtain a second image, and the corresponding relationship between each temperature measurement point of the ex vivo tissue and the grayscale value of the corresponding pixel of the second image is further obtained, which is referred to as the second relationship model, so as to obtain the real-time temperature value of the tumor target tissue surface through the grayscale image of the real-time image of the tumor target tissue surface based on the second relationship model.

9. The ablation temperature monitoring method according to claim 8, characterized in that: The corresponding relationship between the RGB value of each pixel of the first image and the grayscale value of the corresponding pixel of the second image is: Gray=(R*19595+G*38469+B*7472)>>16; Where Gray is the gray value of a pixel in the second image, R is the red channel value of the corresponding pixel in the first image, G is the green channel value of the corresponding pixel in the first image, and B is the blue channel value of the corresponding pixel in the first image.

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