Method for projecting perspective image of C-arm machine to examination part

Abstract

The invention discloses a method for projecting a perspective image of a C-arm machine to an inspection part, which comprises the following steps of: firstly, mounting a visible light laser emitting device on a C-arm rack, synchronizing projection axes of a laser beam and an X-ray beam in real time through a mechanical arm angle sensor to form a guide light spot which is overlapped with an image plane, and calibrating to obtain a perspective image of the C-arm machine; the laser mark can reflect the boundary center point of the display image; guide light coinciding with the image plane is formed through the projection axes of the laser beam and the X-ray beam, and a guide light spot coinciding with the image plane is formed. And the projection module can match the virtual image on the display in real time and project the virtual image to the body surface contour of the patient, so that the naked eye visible image of the skeleton can be directly displayed on the body surface of the patient in real time. The doctor does not need to walk back and forth between the display image and the body surface contour of the patient for comparison, meanwhile, the doctor can observe more visually, stereoscopically and accurately, the difference generated by subjective comparison of the doctor is reduced, and the judgment accuracy is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of C-arm machine image projection, and in particular to a method for projecting a C-arm machine fluoroscopic image onto an examination part. Background Art

[0002] A C-arm machine is a mobile medical imaging device with a C-shaped arc shape. It consists of an X-ray generator, an arc-shaped frame and a digital image receiving device. It generates real-time perspective images through the output of stable rays by a digital high-frequency host.

[0003] C-arms provide intraoperative navigation for operating rooms, emergency rooms, and orthopedics. During orthopedic surgery, they can accurately locate intervertebral spaces, guide implant placement, and verify reduction effects, significantly shortening surgical time and reducing radiation exposure risks. In interventional therapy, they support angiography, tumor ablation, and ERCP, assisting with precise positioning of catheter guidewires through dynamic imaging. Three-dimensional C-arms can also generate CT-like tomographic images through 190-degree rotational scanning, enabling three-dimensional visualization of bone structures and implants, replacing postoperative CT scans to reduce the likelihood of secondary surgery.

[0004] However, the digital images produced by current C-arm machines can generally only be displayed on a monitor and cannot be directly projected onto the body surface. Therefore, during surgery, the surgeon must move back and forth between the patient and the monitor, observing the image on the monitor and comparing it with the patient's actual body contours. This not only complicates the surgical process and adds unnecessary workload, but also creates a risk of discrepancies in the surgeon's subjective comparison between the image and the patient's contours, affecting the accuracy of the assessment.

[0005] Therefore, a method of projecting C-arm fluoroscopic images to the examination site is proposed to solve this problem. Summary of the Invention

[0006] The purpose of the present invention is to provide a method for projecting C-arm fluoroscopic images onto the examination site, which solves the problem that the digital image of the C-arm machine cannot be directly displayed on the body surface after fluoroscopic positioning, and the doctor still needs to compare the display image with the patient's body surface contour.

[0007] To achieve the above-mentioned object, the present invention provides the following technical solution: a method for projecting a C-arm fluoroscopic image onto an examination site, comprising the following steps:

[0008] Step 1: Laser installation: First, install the visible light laser emitting device on the C-arm frame. Use the robotic arm angle sensor to synchronize the projection axis of the laser beam and the X-ray beam in real time to form a guiding light spot that coincides with the image plane. After calibration, the laser mark can reflect the center point of the display image boundary.

[0009] Step 2: Equipment adjustment: Then push the C-arm machine smoothly to the side of the operating table, make sure the monitor is facing an angle that is convenient for the surgeon to observe, and adjust the height of the equipment so that the C-arm's tube and receiver are close to the patient's target area to be examined. Release the brake switch and manually adjust the C-arm so that the tube and the image receiving device form the best imaging plane.

[0010] Step 3: Image parameter setting: Then select the fluoroscopic mode or photography mode on the control panel, switch the automatic / manual exposure parameters according to the tissue thickness, and use the panel buttons to adjust the opening range of the rectangular beam limiter to accurately narrow the irradiation field to the target area and reduce scattered radiation.

[0011] Step 4: Image Adjustment: After pressing the foot switch to activate fluoroscopy, make real-time adjustments by observing the monitor. If the image appears whitish, lower the kV value. If the image is blurry, adjust the distance between the intensifier and the target area. Optimize the display by adjusting the contrast, rotation, and mirroring functions in the imaging workstation software.

[0012] Step 5: Real-time projection: Use AR glasses or a projector system to connect to the C-arm video output port, and use the projection axis of the laser beam and the X-ray beam to form a guide light that coincides with the image plane, so that the projection module can match the virtual image with the patient's body surface contour in real time.

[0013] Step 6: Dynamic Correction: When the C-arm angle changes, the compensation mechanism is automatically triggered, the projection brightness is adaptive, the image rotation correction is dynamically adapted to the perspective direction, and the magnification projection scaling is automatically calculated based on the SID.

[0014] Preferably, in step 1, a three-dimensional coordinate system is established using geometric parameters of the DICOM image, and mapping of image pixel coordinates to patient anatomical positions is achieved through markers or bony landmarks.

[0015] Preferably, in step 2, the tube and receiver of the C-arm need to be kept perpendicular to the central axis of the patient's examined part, and the rotation adjustment angle of the C-arm is 0°-120° and the tilt adjustment angle is ±30°.

[0016] Preferably, in step 3, the fluoroscopy mode includes (manual / IBS automatic brightness / pulse fluoroscopy), and the exposure parameters are 80-100 kV and 5-15 mAs.

[0017] Preferably, in step 3, during interventional procedures such as ERCP, the C-arm projection angle needs to be dynamically adjusted in accordance with the position of the endoscope to achieve visualization of the three-dimensional structure of the bile and pancreatic duct.

[0018] Preferably, in step 4, the kV value is adjusted by about ±10 kV each time, and the distance between the intensifier and the target site is maintained at 15-30 cm.

[0019] Preferably, in step 5, the projection module needs to cooperate with the infrared positioning camera to track the spatial position of the surgical area in real time.

[0020] Preferably, in step 5, a metal grid calibration plate is used to verify the projection error before first use, requiring the spatial registration error to be ≤ 2 mm, and the projection equipment needs to use a waterproof housing or a sterile protective cover to avoid contamination of the image field.

[0021] Preferably, in step 6, the angle of image rotation correction is within the range of ±180°, and the projection brightness optimizes the display contrast according to the ambient light intensity.

[0022] Preferably, in step 6, the projection system must not interfere with the beam limiter function, ensuring that the actual irradiation field completely overlaps with the projected marker.

[0023] Compared with the prior art, the present invention has the following beneficial effects:

[0024] This patented technology uses the projection axis of the laser beam and the X-ray beam to form a guiding light spot that coincides with the imaging plane. This allows the projection module to match the virtual image on the display and project it onto the patient's body contour in real time, thereby directly displaying the naked-eye image of the bones on the patient's torso in real time. This eliminates the need for doctors to walk back and forth between the display image and the patient's body contour to compare, and also makes the doctor's observation more intuitive, three-dimensional, and accurate, reducing the differences caused by the doctor's subjective comparison and improving the accuracy of judgment. DETAILED DESCRIPTION

[0025] The present invention will be described in more detail below by way of examples. These examples are merely illustrative and do not limit the scope of the present invention in any way.

[0026] The present invention provides a technical solution: a method for projecting a C-arm fluoroscopic image onto an examination site, comprising the following steps:

[0027] Step 1: Laser installation: First, install the visible light laser emitting device on the C-arm frame. Use the robotic arm angle sensor to synchronize the projection axis of the laser beam and the X-ray beam in real time to form a guiding light spot that coincides with the image plane. After calibration, the laser mark can reflect the center point of the display image boundary.

[0028] Step 2: Equipment adjustment: Then push the C-arm machine smoothly to the side of the operating table, make sure the monitor is facing an angle that is convenient for the surgeon to observe, and adjust the height of the equipment so that the C-arm's tube and receiver are close to the patient's target area to be examined. Release the brake switch and manually adjust the C-arm so that the tube and the image receiving device form the best imaging plane.

[0029] Step 3: Image parameter setting: Then select the fluoroscopic mode or photography mode on the control panel, switch the automatic / manual exposure parameters according to the tissue thickness, and use the panel buttons to adjust the opening range of the rectangular beam limiter to accurately narrow the irradiation field to the target area and reduce scattered radiation.

[0030] Step 4: Image Adjustment: After pressing the foot switch to activate fluoroscopy, make real-time adjustments by observing the monitor. If the image appears whitish, lower the kV value. If the image is blurry, adjust the distance between the intensifier and the target area. Optimize the display by adjusting the contrast, rotation, and mirroring functions in the imaging workstation software.

[0031] Step 5: Real-time projection: Use AR glasses or a projector system to connect to the C-arm video output port, and use the projection axis of the laser beam and the X-ray beam to form a guide light that coincides with the image plane, so that the projection module can match the virtual image with the patient's body surface contour in real time.

[0032] Step 6: Dynamic Correction: When the C-arm angle changes, the compensation mechanism is automatically triggered, the projection brightness is adaptive, the image rotation correction is dynamically adapted to the perspective direction, and the magnification projection scaling is automatically calculated based on the SID.

[0033] Example 1:

[0034] First, a visible light laser transmitter is installed on the C-arm gantry. The projection axis of the laser beam and the X-ray beam are synchronized in real time using the arm's angle sensor, forming a guide spot that coincides with the imaging plane. After calibration, the laser mark reflects the center of the monitor image boundary. The C-arm is then smoothly moved to the operating table, ensuring the monitor is oriented at an angle that is convenient for the surgeon. The height of the C-arm is adjusted so that the tube and receiver are close to the patient's target area. The brake is released, and the C-arm is manually adjusted to position the tube and receiver in the optimal imaging plane. Fluoroscopic or radiographic mode is then selected on the control panel. Automatic or manual exposure parameters are switched based on tissue thickness. The rectangular beam limiter opening is adjusted using the panel buttons to precisely narrow the irradiation field to the target area and minimize scattered radiation. After fluoroscopy is initiated by pressing the foot switch, adjustments can be made in real time by observing the monitor. If the image appears whitish, the kV value can be reduced. If the image is blurred, the distance between the intensifier and the target area can be adjusted. The contrast, rotation, and mirror functions can be adjusted to optimize the display using the imaging workstation software. AR glasses or a projector system are then connected to the C-arm's video output port. The laser beam and the X-ray beam's projection axis create a guide light that coincides with the image plane, allowing the projection module to align the virtual image with the patient's body contours in real time. Finally, when the C-arm angle changes, a compensation mechanism is automatically triggered, adaptively adjusting the projection brightness, dynamically adjusting the image rotation to match the perspective direction, and automatically calculating the magnification and projection scaling based on the SID.

[0035] Example 2:

[0036] In Example 1, the following steps are added:

[0037] In step 1, a three-dimensional coordinate system is established using the geometric parameters of the DICOM image, and the image pixel coordinates are mapped to the patient's anatomical position through markers or bony landmarks.

[0038] In step 2, the tube and receiver of the C-arm need to be kept perpendicular to the central axis of the patient's examined part. The rotation adjustment angle of the C-arm is 0°-120° and the tilt adjustment angle is ±30°;.

[0039] First, a visible light laser transmitter is installed on the C-arm gantry. The projection axis of the laser beam and the X-ray beam are synchronized in real time using the arm's angle sensor, forming a guide spot that coincides with the imaging plane. After calibration, the laser marker reflects the center point of the monitor image boundary. A three-dimensional coordinate system is established using the geometric parameters of the DICOM image. Image pixel coordinates are mapped to the patient's anatomical position using markers or bony landmarks. The C-arm is then smoothly moved to the operating table, ensuring the monitor is oriented for optimal viewing. The height of the C-arm is adjusted so that the tube and receiver are close to the patient's target area. The brakes are released, and the C-arm is manually adjusted to ensure the tube and receiver form an optimal imaging plane. The tube and receiver must remain perpendicular to the central axis of the patient's area. The C-arm has a rotation adjustment range of 0°-120° and a tilt adjustment range of ±30°. Fluoroscopic or radiographic mode is then selected on the control panel. Automatic / manual exposure parameters are switched based on tissue thickness. The rectangular beam limiter opening is adjusted using the panel buttons to precisely narrow the irradiation field to the target area and minimize scattered radiation. Then, after pressing the foot switch to start the fluoroscopy, adjust it in real time by observing the monitor. When the image is whitish, lower the kV value, when the image is blurred, adjust the distance between the intensifier and the target part, and optimize the display by adjusting the contrast / rotation / mirror function through the imaging workstation software. Then, use AR glasses or a projector system to connect to the video output port of the C-arm machine, and use the projection axis of the laser beam and the X-ray beam to form a guide light that coincides with the image plane, so that the projection module can match the virtual image with the patient's body surface contour in real time. Finally, when the angle of the C-arm changes, the compensation mechanism is automatically triggered, the projection brightness is adaptive, the image rotation correction is dynamically adapted to the fluoroscopy direction, and the magnification projection scaling is automatically calculated according to the SID.

[0040] Example 3:

[0041] In Example 2, the following steps are added:

[0042] In step 3, the fluoroscopy modes include (manual / IBS automatic brightness / pulse fluoroscopy), with exposure parameters of 80-100 kV and 5-15 mAs. During interventional procedures such as ERCP, the C-arm projection angle needs to be dynamically adjusted according to the endoscope position to achieve three-dimensional visualization of the bile and pancreatic duct structure.

[0043] In step 4, the kV value is adjusted by approximately ±10 kV each time, and the distance between the intensifier and the target site is maintained at 15-30 cm.

[0044] First, a visible light laser emitting device is installed on the C-arm frame. The projection axis of the laser beam and the X-ray beam are synchronized in real time through the robotic arm angle sensor to form a guiding light spot that coincides with the image plane. After calibration, the laser marker can reflect the center point of the display image boundary. The geometric parameters of the DICOM image are used to establish a three-dimensional coordinate system, and the image pixel coordinates are mapped to the patient's anatomical position through markers or bony landmarks. The C-arm is then smoothly pushed to the side of the operating table, ensuring that the display is facing an angle that is convenient for the surgeon to observe. At the same time, the height of the equipment is adjusted so that the C-arm's tube and receiver are close to the patient's target area to be examined. The brake switch is released and the C-arm is manually adjusted so that the tube and the image receiving device form the optimal imaging plane. The C-arm's tube and receiver need to remain perpendicular to the central axis of the patient's examined area. The C-arm's rotation adjustment angle is 0°-120° and the tilt adjustment angle is ±30°. Afterward, select fluoroscopy or photography mode on the control panel, switch between automatic and manual exposure parameters based on tissue thickness, and use the panel buttons to adjust the rectangular beam limiter opening to precisely narrow the irradiation field to the target area and reduce scattered radiation. Fluoroscopy modes include manual, IBS automatic brightness, and pulsed fluoroscopy, with exposure parameters ranging from 80-100 kV and 5-15 mAs. During interventional procedures such as ERCP, the C-arm projection angle must be dynamically adjusted in conjunction with the endoscope position to visualize the three-dimensional structure of the bile and pancreatic ducts. After depressing the foot switch to activate fluoroscopy, adjustments can be made in real time by observing the display. The kV value is lowered if the image appears whitish, and the distance between the intensifier and the target area is adjusted if the image is blurred. The contrast, rotation, and mirroring functions can be adjusted using the imaging workstation software to optimize the display. The kV value is adjusted approximately ±10 kV at a time, and the distance between the intensifier and the target area is maintained at 15-30 cm. Finally, AR glasses or a projector system are connected to the C-arm video output port. The projection axis of the laser beam and the X-ray beam forms a guide light that coincides with the image plane, enabling the projection module to match the virtual image to the patient's body contours in real time. Finally, when the C-arm angle changes, the compensation mechanism is automatically triggered, the projection brightness is adaptive, the image rotation correction is dynamically adapted to the perspective direction, and the magnification projection scaling is automatically calculated according to the SID.

[0045] Example 4:

[0046] In Example 3, the following steps are added:

[0047] In step 5, the projection module needs to cooperate with the infrared positioning camera to track the spatial position of the surgical area in real time; before the first use, the projection error must be verified with a metal grid calibration plate, and the spatial registration error must be ≤2mm. The projection equipment must use a waterproof casing or sterile protective cover to avoid contamination of the image field.

[0048] In step 6, the image rotation correction angle is within the range of ±180°, and the projection brightness optimizes the display contrast according to the ambient light intensity; the projection system must not interfere with the beam limiter function to ensure that the actual irradiation field completely overlaps with the projected mark.

[0049] First, a visible light laser emitting device is installed on the C-arm frame. The projection axis of the laser beam and the X-ray beam are synchronized in real time through the robotic arm angle sensor to form a guiding light spot that coincides with the image plane. After calibration, the laser marker can reflect the center point of the display image boundary. The geometric parameters of the DICOM image are used to establish a three-dimensional coordinate system, and the image pixel coordinates are mapped to the patient's anatomical position through markers or bony landmarks. The C-arm is then smoothly pushed to the side of the operating table, ensuring that the display is facing an angle that is convenient for the surgeon to observe. At the same time, the height of the equipment is adjusted so that the C-arm's tube and receiver are close to the patient's target area to be examined. The brake switch is released and the C-arm is manually adjusted so that the tube and the image receiving device form the optimal imaging plane. The C-arm's tube and receiver need to remain perpendicular to the central axis of the patient's examined area. The C-arm's rotation adjustment angle is 0°-120° and the tilt adjustment angle is ±30°. After that, select the fluoroscopy mode or photography mode on the control panel, switch the automatic / manual exposure parameters according to the tissue thickness, use the panel buttons to adjust the opening range of the rectangular beam limiter, accurately narrow the irradiation field to the target area, and reduce scattered radiation; the fluoroscopy mode includes (manual / IBS automatic brightness / pulse fluoroscopy), and the exposure parameters are 80-100kV, 5-15mAs; in interventional procedures such as ERCP, the C-arm projection angle needs to be dynamically adjusted in accordance with the position of the endoscope to achieve visualization of the three-dimensional structure of the bile and pancreatic duct. Then, after pressing the foot switch to start the fluoroscopy, adjust it in real time by observing the monitor. Reduce the kV value when the image is white, adjust the distance between the intensifier and the target area when the image is blurred, and adjust the contrast / rotation / mirror function through the imaging workstation software to optimize the display; the kV value is adjusted by about ±10kV each time, and the distance between the intensifier and the target area is kept at a distance of 15-30cm. Afterwards, AR glasses or a projector system are used to connect to the video output port of the C-arm machine. The projection axis of the laser beam and the X-ray beam forms a guide light that coincides with the image plane, allowing the projection module to match the virtual image with the patient's body contour in real time. The projection module needs to cooperate with the infrared positioning camera to track the spatial position of the surgical area in real time. Before the first use, the projection error must be verified with a metal grid calibration plate. The spatial registration error is required to be ≤2mm. The projection equipment must use a waterproof shell or sterile protective cover to avoid contaminating the image field. Finally, when the C-arm angle changes, the compensation mechanism is automatically triggered, the projection brightness is adaptive, the image rotation correction dynamically adapts to the perspective direction, and the magnification projection scaling is automatically calculated according to the SID. The image rotation correction angle is within the range of ±180°, and the projection brightness optimizes the display contrast according to the ambient light intensity. The projection system must not interfere with the beam limiter function to ensure that the actual irradiation field and the projection marker completely coincide.

[0050] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for projecting a C-arm fluoroscopic image onto an examination site, characterized by: The following steps are involved: Step 1: Laser installation: First, install the visible light laser emitting device on the C-arm frame. Use the robotic arm angle sensor to synchronize the projection axis of the laser beam and the X-ray beam in real time to form a guiding light spot that coincides with the image plane. After calibration, the laser mark can reflect the center point of the display image boundary. Step 2: Equipment adjustment: Then push the C-arm machine smoothly to the side of the operating table, make sure the monitor is facing an angle that is convenient for the surgeon to observe, and adjust the height of the equipment so that the C-arm's tube and receiver are close to the patient's target area to be examined. Release the brake switch and manually adjust the C-arm so that the tube and the image receiving device form the best imaging plane. Step 3: Image parameter setting: Then select the fluoroscopic mode or photography mode on the control panel, switch the automatic / manual exposure parameters according to the tissue thickness, and use the panel buttons to adjust the opening range of the rectangular beam limiter to accurately narrow the irradiation field to the target area and reduce scattered radiation. Step 4: Image Adjustment: After pressing the foot switch to activate fluoroscopy, make real-time adjustments by observing the monitor. If the image appears whitish, lower the kV value. If the image is blurry, adjust the distance between the intensifier and the target area. Optimize the display by adjusting the contrast, rotation, and mirroring functions in the imaging workstation software. Step 5: Real-time projection: Use AR glasses or a projector system to connect to the C-arm video output port, and use the projection axis of the laser beam and the X-ray beam to form a guide light that coincides with the image plane, so that the projection module can match the virtual image with the patient's body surface contour in real time. Step 6: Dynamic Correction: When the C-arm angle changes, the compensation mechanism is automatically triggered, the projection brightness is adaptive, the image rotation correction is dynamically adapted to the perspective direction, and the magnification projection scaling is automatically calculated based on the SID.

2. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 1, a three-dimensional coordinate system is established using the geometric parameters of the DICOM image, and mapping of the image pixel coordinates to the patient's anatomical position is achieved through markers or bony landmarks.

3. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 2, the tube and receiver of the C-arm need to be kept perpendicular to the central axis of the patient's examined part. The rotation adjustment angle of the C-arm is 0°-120° and the tilt adjustment angle is ±30°.

4. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 3, the fluoroscopy modes include (manual / IBS automatic brightness / pulse fluoroscopy), and the exposure parameters are 80-100 kV and 5-15 mAs.

5. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 3, during interventional procedures such as ERCP, the C-arm projection angle needs to be dynamically adjusted in accordance with the position of the endoscope to achieve visualization of the three-dimensional structure of the bile and pancreatic duct.

6. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 4, the kV value is adjusted by approximately ±10 kV each time, and the distance between the intensifier and the target site is maintained at 15-30 cm.

7. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 5, the projection module needs to cooperate with the infrared positioning camera to track the spatial position of the surgical area in real time.

8. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 5, the projection error needs to be verified with a metal grid calibration plate before the first use. The spatial registration error is required to be ≤ 2 mm. The projection equipment needs to use a waterproof shell or a sterile protective cover to avoid contamination of the image field.

9. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 6, the image rotation correction angle is within the range of ±180°, and the projection brightness optimizes the display contrast according to the ambient light intensity.

10. The method of projecting a C-arm fluoroscopic image onto an examination site according to claim 1, characterized in that: In step 6, the projection system must not interfere with the beam limiter function to ensure that the actual irradiation field completely coincides with the projection marker.