A method and apparatus for monitoring contrast extravasation

Abstract

This invention discloses a method and device for monitoring contrast agent extravasation, belonging to the field of medical device technology. The method involves dividing the contrast agent injection area into a proximal and distal needle region by identifying the center coordinates of the injection area; projecting a plurality of laser lines onto the proximal and distal needle regions based on the center coordinates; monitoring the deformation difference of the laser lines in the proximal needle region and the intensity ratio of the laser lines in the proximal and distal needle regions based on the laser lines during injection; determining the presence of contrast agent extravasation risk and issuing an alarm command when the deformation difference is not less than a preset deformation threshold and the intensity ratio is not greater than a preset intensity threshold. Therefore, this invention effectively solves the problems of high misdiagnosis rate and low real-time performance in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to a method and apparatus for monitoring contrast agent extravasation. Background Technology

[0002] Contrast agent extravasation, also known as contrast agent leakage, is a known complication in contrast-enhanced medical imaging. Specifically, it refers to the situation where, during intravenous injection of iodine-containing contrast agents (commonly known as contrast agents) for enhanced CT scans, angiography, or other imaging examinations, due to various reasons such as puncture, vascular issues, or the patient's own condition, a portion of the high-concentration contrast agent fails to successfully enter the target blood vessel lumen and instead leaks or infiltrates into the subcutaneous tissue and soft tissue spaces surrounding the blood vessel.

[0003] This process is closely related to the injection method used in the examination. To ensure image quality, modern imaging examinations often use high-pressure injectors to rapidly inject contrast agents into the vein at extremely high flow rates, typically 3–6 mL / s. While this high-pressure, high-speed injection mode provides clear images, it also brings significant risks: if the needle tip punctures the blood vessel wall or is not fully placed within the blood vessel lumen, the chemically irritating contrast agent will surge into the interstitial space in a very short time. Studies have shown that under high pressure, more than 5 ml of subcutaneous fluid can form within just 30 seconds. Due to the high osmotic pressure of the contrast agent, it causes surrounding tissue fluid to accumulate in the leakage area, exacerbating local swelling and pressure. This rapid, tension-induced swelling can lead to serious consequences. The most direct harm is the compression of local nerves and blood vessels. When pressure continues to increase, it may impede blood circulation and nerve function in the distal extremities, potentially leading to septal syndrome or skin necrosis in severe cases. In addition, high concentrations of contrast agents have direct chemical toxicity to subcutaneous tissues, which may cause skin erythema, blisters, and even full-thickness skin necrosis and ulceration. The risk is even higher for patients with poor vascular conditions, dulled senses, or the elderly.

[0004] Currently, clinical detection of contrast agent extravasation mainly relies on manual observation by healthcare professionals. This includes closely monitoring the patient's injection site for swelling, pain, and changes in skin color and temperature during and after injection. However, this method has inherent limitations. First, initial signs of extravasation may not be obvious, making it easy to miss them through visual observation alone. Second, detection is delayed; there is often a time lag between the occurrence of extravasation and its perception by the patient or healthcare professional, during which time a considerable amount of contrast agent may have already extravasated. Therefore, current methods for detecting contrast agent extravasation suffer from high misdiagnosis rates and low real-time accuracy. Summary of the Invention

[0005] This invention provides a method and apparatus for monitoring contrast agent extravasation, which can solve the problems of high misdiagnosis rate and low real-time performance in the prior art.

[0006] An embodiment of the present invention provides a method for monitoring contrast agent extravasation, comprising: Obtain the contrast agent injection area, identify the center coordinates of the contrast agent injection area, and divide the contrast agent injection area into a proximal needle area and a distal needle area; Based on the center coordinates, several laser lines are projected onto the near needle area and the far needle area; During the injection process, the deformation difference of the laser lines in the near-needle area and the light intensity ratio of the laser lines in the near-needle area and the far-needle area are monitored according to the laser lines. When the deformation difference is not less than a preset deformation threshold and the light intensity ratio is not greater than a preset light intensity threshold, it is determined that there is a risk of contrast agent extravasation, and an alarm command is issued.

[0007] Furthermore, obtaining the contrast agent injection area includes: The patient's limbs placed on the injection table are photographed to generate several photos to be identified, and the shooting coordinates of each photo are recorded. The photo to be identified is input into a preset injection area recognition model so that the injection area recognition model can identify and mark the puncture point area, indwelling needle area and adhesive tape area in each photo to be identified. The photograph to be identified, which simultaneously marks the puncture point area, the indwelling needle area, and the adhesive tape area, is used as the target photograph. The contrast agent injection area is determined based on the shooting coordinates of the target photograph.

[0008] Furthermore, determining the contrast agent injection area based on the shooting coordinates of the target photograph includes: Identify the pixel coordinates of the puncture point area, indwelling needle area, and adhesive tape area in the target photograph, as well as the center pixel coordinates of the target photograph; Based on the coordinate difference between the marked coordinates and the center pixel coordinates, the direction and distance of movement of the shooting coordinates are determined. Based on the shooting coordinates, the direction of movement, and the distance of movement, the contrast agent injection area is determined to be centered on the puncture point area, the indwelling needle area, and the adhesive tape area.

[0009] Furthermore, the step of projecting a plurality of laser lines onto the near-needle area and the far-needle area according to the center coordinates includes: Obtain the initial offset angle of the projected laser line; Based on the center coordinates and the initial offset angle, the target offset angle is calculated, and the laser line projection angle is adjusted to the target offset angle so that the laser line of the laser device is projected onto the near needle area and the far needle area at a preset tilt angle.

[0010] Furthermore, during the injection process, monitoring the deformation difference of the laser lines in the near-needle area and the intensity ratio of the laser lines in the near-needle area and the far-needle area, based on the laser lines, includes: An imaging lens is used to project the refracted light from the laser lines on the near-needle area onto the area array image sensor to form a light spot; During the injection process, the movement distance of the light spot on the area array image sensor is monitored, and the deformation difference of the laser line on the near-needle area is calculated; The intensity of the first reflected light from the laser line in the distal needle area and the intensity of the second reflected light from the laser line in the proximal needle area are monitored, and the intensity ratio is determined based on the intensity of the first reflected light and the intensity of the second reflected light.

[0011] An embodiment of the present invention also provides a contrast agent extravasation monitoring device, comprising: an aiming module, a laser module, a monitoring module, and an alarm module; The aiming module is used to acquire the contrast agent injection area, identify the center coordinates of the contrast agent injection area, and divide the contrast agent injection area into a near-needle area and a far-needle area. The laser module is used to project several laser lines onto the near needle area and the far needle area according to the center coordinates. The monitoring module is used to monitor the deformation difference of the laser line in the near needle area and the light intensity ratio of the laser line in the near needle area and the far needle area during the injection process. The alarm module is used to determine the risk of contrast agent extravasation when the deformation difference is not less than a preset deformation threshold and the light intensity ratio is not greater than a preset light intensity threshold, and to issue an alarm command.

[0012] Furthermore, the aiming module includes: a camera, a region recognition submodule equipped with an injection region recognition model, and a region positioning submodule; The camera is used to take pictures of the patient's limbs placed on the injection table, generate several photos to be identified, and record the shooting coordinates of each photo to be identified. The region recognition submodule is used to input the photo to be recognized into a preset injection region recognition model so that the injection region recognition model can recognize and identify the puncture point region, indwelling needle region and adhesive tape region in each photo to be recognized. The regional positioning submodule is used to take the photograph to be identified, which is simultaneously marked with the puncture point area, the indwelling needle area and the adhesive tape area, as the target photograph, and determine the contrast agent injection area based on the shooting coordinates of the target photograph.

[0013] Furthermore, the region positioning submodule determines the contrast agent injection area based on the shooting coordinates of the target photograph, including: Identify the pixel coordinates of the puncture point area, indwelling needle area, and adhesive tape area in the target photograph, as well as the center pixel coordinates of the target photograph; Based on the coordinate difference between the marked coordinates and the center pixel coordinates, the direction and distance of movement of the shooting coordinates are determined. Based on the shooting coordinates, the direction of movement, and the distance of movement, the contrast agent injection area is determined to be centered on the puncture point area, the indwelling needle area, and the adhesive tape area.

[0014] Furthermore, the laser module includes: a laser device and a control submodule; The control submodule is used to obtain the initial projection angle of the laser line; calculate the target offset angle that the laser line needs to be adjusted according to the center coordinates and the initial projection angle; and adjust the laser device according to the target offset angle. The laser device is used to emit laser lines so that the laser lines are projected onto the near needle area and the far needle area at a preset tilt angle.

[0015] Furthermore, the monitoring module includes: an imaging lens, an area array image sensor, and a computing submodule; The imaging lens is used to project the refracted light from the laser lines on the near needle area onto the area array image sensor to form a light spot; The calculation submodule is used to monitor the movement distance of the light spot on the area array image sensor during the injection process and calculate the deformation difference of the laser line on the near-needle area. Monitor the first reflected light intensity of the distal needle area and the second reflected light intensity of the proximal needle area, and determine the light intensity ratio based on the first reflected light intensity and the second reflected light intensity.

[0016] The following benefits can be obtained by implementing the present invention: This invention provides a method and apparatus for monitoring contrast agent extravasation. The method involves dividing the contrast agent injection area into a proximal and distal needle region by identifying the center coordinates of the injection site. Based on the center coordinates, several laser lines are projected onto the proximal and distal needle regions. During injection, the deformation difference of the laser lines in the proximal needle region and the intensity ratio of the laser lines in the proximal and distal needle regions are monitored. When the deformation difference is not less than a preset deformation threshold and the intensity ratio is not greater than a preset intensity threshold, a risk of contrast agent extravasation is determined, and an alarm command is issued. This invention, by monitoring the deformation difference of the laser lines in the proximal needle region during injection, can determine the height of the injection area bulge, judge whether contrast agent extravasation has occurred, and, because the contrast agent liquid itself has a certain absorption property for light of specific wavelengths, when the contrast agent extravasates and enters the subcutaneous tissue, it changes the tissue's scattering coefficient, causing more light to be absorbed or scattered in other directions after entering the subcutaneous tissue, thereby reducing the light intensity returning to the camera. Therefore, the intensity ratio of the laser lines on the near-needle area and the far-needle area is also monitored to determine whether the contrast agent has extravasated. By using these two monitoring data, the extravasation of the contrast agent can be monitored in a timely and accurate manner, effectively solving the problems of high misdiagnosis rate and low real-time performance in the existing technology. Attached Figure Description

[0017] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a flowchart illustrating a method for monitoring contrast agent extravasation according to a certain embodiment of this application.

[0019] Figure 2 This is a schematic diagram of a contrast agent extravasation monitoring device provided in one embodiment of this application.

[0020] Figure 3 This is a schematic diagram of the structure of a terminal device provided in a certain embodiment of this application. Detailed Implementation

[0021] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0023] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0024] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0025] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0026] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0027] In the description of the embodiments of this application, unless otherwise expressly specified and limited, technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0028] See Figure 1To address the problems in the prior art, an embodiment of the present invention provides a method for monitoring contrast agent extravasation, comprising: S1. Obtain the contrast agent injection area, identify the center coordinates of the contrast agent injection area, and divide the contrast agent injection area into a proximal needle area and a distal needle area. Preferably, obtaining the contrast agent injection area includes: S11. Take pictures of the patient's limbs placed on the injection table, generate several photos to be identified, and record the shooting coordinates of each photo to be identified. In a preferred embodiment of the present invention, a camera positioned at a fixed distance from the laser line outlet is used to capture in real time a photograph of the area to be identified with a field of view of ≥120 cm × 80 cm.

[0029] S12. Input the photo to be identified into a preset injection area recognition model so that the injection area recognition model can identify and mark the puncture point area, indwelling needle area and adhesive tape area in each photo to be identified. In a preferred embodiment of the present invention, a model for identifying the injection area, including the puncture point area, the indwelling needle area, and the adhesive tape area, is trained in advance using the YOLOv5-nano lightweight model.

[0030] Specifically, several photos containing the puncture point, indwelling needle, and adhesive tape were taken, and the puncture point area, indwelling needle area, and adhesive tape area were labeled to construct a training dataset. The YOLOv5-nano lightweight model was trained using this training dataset. During training, a loss function was used to evaluate the model's prediction results. If the loss function value showed a convergence trend, training was considered complete; otherwise, the model parameters were adjusted according to the loss function, and a new round of training was conducted.

[0031] Furthermore, to improve recognition efficiency, RANSAC filtering is applied before the photo to be recognized is input into the injection area recognition model to remove noise such as hair and sweat, thereby improving detection accuracy.

[0032] S13. The photograph to be identified, which simultaneously marks the puncture point area, the indwelling needle area, and the adhesive tape area, is used as the target photograph, and the contrast agent injection area is determined based on the shooting coordinates of the target photograph.

[0033] Preferably, determining the contrast agent injection area based on the shooting coordinates of the target photograph includes: Identify the marked pixel coordinates of the puncture point area, indwelling needle area, and adhesive tape area in the target image, as well as the center pixel coordinates of the target image; determine the direction and distance of movement of the shooting coordinates based on the coordinate difference between the marked coordinates and the center pixel coordinates; and determine the contrast agent injection area centered on the puncture point area, indwelling needle area, and adhesive tape area based on the shooting coordinates, the direction of movement, and the distance of movement.

[0034] In a preferred embodiment of the present invention, the annotation frames of the puncture point area, the indwelling needle area and the adhesive tape area are integrated to form a single annotation frame encompassing the puncture point area, the indwelling needle area and the adhesive tape area, and the annotation pixel coordinates of the annotation frame are determined. Based on the annotation pixel coordinates and the center pixel coordinates of the target image, the relative position of the annotation pixel coordinates and the center pixel coordinates and the coordinate difference are determined. Based on the camera's shooting coordinates, relative position, and coordinate difference, the relative position between the contrast agent injection area and the camera is determined. This allows for camera movement control, ensuring that the puncture point area, indwelling needle area, and adhesive tape area are centered within the contrast agent injection area captured by the camera. The camera has a frame rate ≥15 fps and a trigger port that synchronizes with the syringe's high-pressure start signal hardware. Furthermore, based on the direction of the indwelling needle in the indwelling needle area, the area where the indwelling needle is located in the contrast agent injection area is defined as the near-needle area, and the area far from the needle is defined as the far-needle area.

[0035] S2. Based on the center coordinates, project several laser lines onto the near needle area and the far needle area; Preferably, the step of projecting a plurality of laser lines onto the near-needle area and the far-needle area according to the center coordinates includes: Obtain the initial offset angle of the laser device; calculate the target offset angle based on the center coordinates and the initial offset angle, and control the laser device to adjust to the target offset angle so that the laser line emitted by the laser device is projected onto the near needle area and the far needle area at a preset tilt angle.

[0036] In a preferred embodiment of the present invention, since lasers can cause damage to the human eye, in order to prevent accidental injury to patients and medical personnel, the laser device is always kept in the off state when no contrast agent injection area is detected.

[0037] Furthermore, in this embodiment, the laser device emits a laser wavelength of 635–660 nm and a power of 30–150 mW. The position of the camera and the offset angle of the laser device are calibrated in advance. After the camera is aligned with the contrast agent injection area, the laser projection angle of the laser device is adjusted according to its center coordinates and calibration formula, so that all laser lines are projected onto the contrast agent injection area at a preset tilt angle.

[0038] In another preferred embodiment, a laser galvanometer is disposed at the light outlet of the laser device, and the laser emission angle of the laser device is fixed on the laser galvanometer. The laser galvanometer is used to change the projection angle of the laser on the contrast agent injection area. Specifically, the laser galvanometer is a one-dimensional MEMS galvanometer with a maximum optical angle of ±20° and a response time of 0.7 ms. The position of the camera and the offset angle of the laser galvanometer are pre-calibrated. After the camera is aligned with the contrast agent injection area, the projection angle of the laser galvanometer is adjusted according to its center coordinates and calibration formula, so that all laser lines are projected onto the contrast agent injection area at a preset tilt angle.

[0039] Furthermore, by monitoring images from the camera, the distance the center coordinates have moved is determined, and if the patient's position has moved more than 5 mm based on the moving distance, the camera is re-aimed to avoid false alarms.

[0040] S3. During the injection process, monitor the deformation difference of the laser lines in the near-needle area and the light intensity ratio of the laser lines in the near-needle area and the far-needle area according to the laser lines. Preferably, during the injection process, monitoring the deformation difference of the laser line in the near-needle area and the intensity ratio of the laser lines in the near-needle area and the far-needle area, based on the laser lines, includes: An imaging lens is used to project the refracted light rays of the laser lines in the near-needle area onto an array image sensor to form a light spot. During the injection process, the movement distance of the light spot on the array image sensor is monitored, and the deformation difference of the laser lines in the near-needle area is calculated. The first reflected light intensity of the laser lines in the far-needle area and the second reflected light intensity of the laser lines in the near-needle area are monitored, and the light intensity ratio is determined based on the first reflected light intensity and the second reflected light intensity.

[0041] In a preferred embodiment of the present invention, the laser device, imaging lens, and area array image sensor (CMOS image sensor) are arranged as follows: Figure 3 As shown, the oblique (near-direct) laser triangulation method is used to calculate the deformation difference of the laser line in the near-needle area, that is, the height difference of the skin elevation in the near-needle area. The oblique laser triangulation method is a non-contact, high-precision optical measurement technique. It uses a laser beam at a certain tilt angle (close to a right angle) to calculate the deformation difference of the laser line in the near-needle area. Figure 3The laser beam (θ1 is close to 0°) is projected onto the surface of the object being measured. The reflected light from the laser spot is received at another angle by an area array image sensor. By measuring the change in the position of the spot on the imaging surface of the area array image sensor, the height or contour change of the object's surface is accurately calculated based on the geometric principle of triangles.

[0042] Furthermore, the laser device has 10 lines, which can cover an area of ​​≥60 mm × 40 mm, improving the accuracy of volume reconstruction. When Δh is detected to be close to the threshold, the number of lines is automatically increased (N=20) and the interval between laser lines is reduced to achieve sub-millimeter level local re-inspection.

[0043] Furthermore, the formula for calculating the deformation difference is: ; Where Δh is the deformation difference, Δu is the displacement of the light spot on the detector, a is the distance from the laser incident point to the front principal surface of the lens, b is the distance from the laser incident point to the front principal surface of the lens, θ1 is the angle between the laser beam and the normal to the object surface, i.e., the incident angle, θ2 is the angle between the optical axis of the imaging lens and the normal to the object surface, i.e., the receiving angle, and θ3 is the angle between the imaging surface of the image sensor and the optical axis of the imaging lens.

[0044] Furthermore, the reflected light intensity is an attribute of the image captured by the camera. The average brightness value of the corresponding area is calculated to obtain the reflected light intensity of the corresponding area.

[0045] S4. When the deformation difference is not less than a preset deformation threshold and the light intensity ratio is not greater than a preset light intensity threshold, it is determined that there is a risk of contrast agent extravasation, and an alarm command is issued.

[0046] In a preferred embodiment of the present invention, the deformation difference directly reflects the volume expansion and surface displacement caused by subcutaneous fluid accumulation, which is the most direct consequence of extravasation. When contrast agent extravasates into the subcutaneous tissue, it alters the scattering characteristics and surface texture of the skin tissue, resulting in a characteristic change in the spatial distribution of reflected light intensity—specifically, a relative darkening near the needle. Therefore, by simultaneously detecting both the deformation difference and the light intensity ratio, misjudgments caused by patient movement or differences in skin color can be avoided, effectively improving the accuracy of the detection.

[0047] See Figure 2 This is a contrast agent extravasation monitoring device provided in an embodiment of the present invention, comprising: an aiming module 101, a laser module 102, a monitoring module 103, and an alarm module 104; The aiming module 101 is used to acquire the contrast agent injection area, identify the center coordinates of the contrast agent injection area, and divide the contrast agent injection area into a near-needle area and a far-needle area. The laser module 102 is used to project a plurality of laser lines onto the near needle area and the far needle area according to the center coordinates. The monitoring module 103 is used to monitor the deformation difference of the laser line in the near needle area and the light intensity ratio of the laser line in the near needle area and the far needle area during the injection process. The alarm module 104 is used to determine the risk of contrast agent extravasation when the deformation difference is not less than a preset deformation threshold and the light intensity ratio is not greater than a preset light intensity threshold, and to issue an alarm command.

[0048] Preferably, the aiming module 101 includes: a camera, a region recognition submodule equipped with an injection region recognition model, and a region positioning submodule; The camera is used to take pictures of the patient's limbs placed on the injection table, generate several photos to be identified, and record the shooting coordinates of each photo to be identified. The region recognition submodule is used to input the photo to be recognized into a preset injection region recognition model so that the injection region recognition model can recognize and identify the puncture point region, indwelling needle region and adhesive tape region in each photo to be recognized. The regional positioning submodule is used to take the photograph to be identified, which is simultaneously marked with the puncture point area, the indwelling needle area and the adhesive tape area, as the target photograph, and determine the contrast agent injection area based on the shooting coordinates of the target photograph.

[0049] Preferably, the region positioning submodule determines the contrast agent injection area based on the shooting coordinates of the target photograph, including: Identify the pixel coordinates of the puncture point area, indwelling needle area, and adhesive tape area in the target photograph, as well as the center pixel coordinates of the target photograph; Based on the coordinate difference between the marked coordinates and the center pixel coordinates, the direction and distance of movement of the shooting coordinates are determined. Based on the shooting coordinates, the direction of movement, and the distance of movement, the contrast agent injection area is determined to be centered on the puncture point area, the indwelling needle area, and the adhesive tape area.

[0050] Preferably, the laser module 102 includes: a laser device and a control submodule; The control submodule is used to obtain the initial projection angle of the laser line; calculate the target offset angle that the laser line needs to be adjusted according to the center coordinates and the initial projection angle; and adjust the laser device according to the target offset angle. The laser device is used to emit laser lines so that the laser lines are projected onto the near needle area and the far needle area at a preset tilt angle.

[0051] Preferably, the monitoring module 103 includes: an imaging lens, an area array image sensor, and a computing submodule; The imaging lens is used to project the refracted light from the laser lines on the near needle area onto the area array image sensor to form a light spot; The calculation submodule is used to monitor the movement distance of the light spot on the area array image sensor during the injection process and calculate the deformation difference of the laser line on the near-needle area. Monitor the first reflected light intensity of the distal needle area and the second reflected light intensity of the proximal needle area, and determine the light intensity ratio based on the first reflected light intensity and the second reflected light intensity.

[0052] It is understood that the above-described device embodiments correspond to the method embodiments of the present invention, and can realize the method for monitoring contrast agent extravasation provided by any of the above-described method embodiments of the present invention.

[0053] It should be noted that the device embodiments described above are merely illustrative, and some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Furthermore, in the accompanying drawings of the device embodiments provided by this invention, the connection relationships between modules indicate that they have communication connections, which can specifically be implemented as one or more communication buses or signal lines. Those skilled in the art can understand and implement this without any creative effort.

Claims

1. A method for monitoring contrast agent extravasation, characterized in that, include: Obtain the contrast agent injection area, identify the center coordinates of the contrast agent injection area, and divide the contrast agent injection area into a proximal needle area and a distal needle area; Based on the center coordinates, several laser lines are projected onto the near needle area and the far needle area; During the injection process, the deformation difference of the laser lines in the near-needle area and the light intensity ratio of the laser lines in the near-needle area and the far-needle area are monitored according to the laser lines. When the deformation difference is not less than a preset deformation threshold and the light intensity ratio is not greater than a preset light intensity threshold, it is determined that there is a risk of contrast agent extravasation, and an alarm command is issued.

2. The method for monitoring contrast agent extravasation as described in claim 1, characterized in that, The acquisition of the contrast agent injection area includes: The patient's limbs placed on the injection table are photographed to generate several photos to be identified, and the shooting coordinates of each photo are recorded. The photo to be identified is input into a preset injection area recognition model so that the injection area recognition model can identify and mark the puncture point area, indwelling needle area and adhesive tape area in each photo to be identified. The photograph to be identified, which simultaneously marks the puncture point area, the indwelling needle area, and the adhesive tape area, is used as the target photograph. The contrast agent injection area is determined based on the shooting coordinates of the target photograph.

3. The method for monitoring contrast agent extravasation as described in claim 2, characterized in that, Determining the contrast agent injection area based on the shooting coordinates of the target photograph includes: Identify the pixel coordinates of the puncture point area, indwelling needle area, and adhesive tape area in the target photograph, as well as the center pixel coordinates of the target photograph; Based on the coordinate difference between the marked coordinates and the center pixel coordinates, the direction and distance of movement of the shooting coordinates are determined. Based on the shooting coordinates, the direction of movement, and the distance of movement, the contrast agent injection area is determined to be centered on the puncture point area, the indwelling needle area, and the adhesive tape area.

4. The method for monitoring contrast agent extravasation as described in claim 3, characterized in that, The step of projecting a plurality of laser lines onto the near-needle area and the far-needle area according to the center coordinates includes: Obtain the initial projection angle of the laser line; Based on the center coordinates and the initial projection angle, the target offset angle that the laser line needs to be adjusted is calculated. Based on the target offset angle, the laser device is adjusted so that the laser line emitted by the laser device is projected onto the near needle area and the far needle area at a preset tilt angle.

5. The method for monitoring contrast agent extravasation as described in claim 4, characterized in that, During the injection process, monitoring the deformation difference of the laser line in the near-needle area and the intensity ratio of the laser lines in the near-needle area and the far-needle area, based on the laser lines, includes: An imaging lens is used to project the refracted light from the laser lines on the near-needle area onto the area array image sensor to form a light spot; During the injection process, the movement distance of the light spot on the area array image sensor is monitored, and the deformation difference of the laser line on the near-needle area is calculated; The intensity of the first reflected light from the laser line in the distal needle area and the intensity of the second reflected light from the laser line in the proximal needle area are monitored, and the intensity ratio is determined based on the intensity of the first reflected light and the intensity of the second reflected light.

6. A monitoring device for contrast agent extravasation, characterized in that, include: Aiming module, laser module, monitoring module, and alarm module; The aiming module is used to acquire the contrast agent injection area, identify the center coordinates of the contrast agent injection area, and divide the contrast agent injection area into a near-needle area and a far-needle area. The laser module is used to project several laser lines onto the near needle area and the far needle area according to the center coordinates. The monitoring module is used to monitor the deformation difference of the laser line in the near needle area and the light intensity ratio of the laser line in the near needle area and the far needle area during the injection process. The alarm module is used to determine the risk of contrast agent extravasation when the deformation difference is not less than a preset deformation threshold and the light intensity ratio is not greater than a preset light intensity threshold, and to issue an alarm command.

7. The contrast agent extravasation monitoring device as described in claim 6, characterized in that, The aiming module includes: a camera, a region recognition submodule equipped with an injection region recognition model, and a region positioning submodule; The camera is used to take pictures of the patient's limbs placed on the injection table, generate several photos to be identified, and record the shooting coordinates of each photo to be identified. The region recognition submodule is used to input the photo to be recognized into a preset injection region recognition model so that the injection region recognition model can recognize and identify the puncture point region, indwelling needle region and adhesive tape region in each photo to be recognized. The regional positioning submodule is used to take the photograph to be identified, which is simultaneously marked with the puncture point area, the indwelling needle area and the adhesive tape area, as the target photograph, and determine the contrast agent injection area based on the shooting coordinates of the target photograph.

8. The monitoring device for contrast agent extravasation as described in claim 7, characterized in that, The region localization submodule determines the contrast agent injection area based on the shooting coordinates of the target photograph, including: Identify the pixel coordinates of the puncture point area, indwelling needle area, and adhesive tape area in the target photograph, as well as the center pixel coordinates of the target photograph; Based on the coordinate difference between the marked coordinates and the center pixel coordinates, the direction and distance of movement of the shooting coordinates are determined. Based on the shooting coordinates, the direction of movement, and the distance of movement, the contrast agent injection area is determined to be centered on the puncture point area, the indwelling needle area, and the adhesive tape area.

9. The monitoring device for contrast agent extravasation as described in claim 8, characterized in that, The laser module includes: a laser device and a control submodule; The control submodule is used to obtain the initial projection angle of the laser line; calculate the target offset angle that the laser line needs to be adjusted according to the center coordinates and the initial projection angle; and adjust the laser device according to the target offset angle. The laser device is used to emit laser lines so that the laser lines are projected onto the near needle area and the far needle area at a preset tilt angle.

10. The monitoring device for contrast agent extravasation as described in claim 9, characterized in that, The monitoring module includes: an imaging lens, an area array image sensor, and a computing submodule; The imaging lens is used to project the refracted light from the laser lines on the near needle area onto the area array image sensor to form a light spot; The calculation submodule is used to monitor the movement distance of the light spot on the area array image sensor during the injection process and calculate the deformation difference of the laser line on the near-needle area. Monitor the first reflected light intensity of the distal needle area and the second reflected light intensity of the proximal needle area, and determine the light intensity ratio based on the first reflected light intensity and the second reflected light intensity.

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