An intraoperative real-time optical coherence imaging guided laser ablation treatment system

Abstract

The application provides an intraoperative real-time optical coherence imaging guided laser ablation treatment system, which comprises an optical guiding module, a laser treatment module and a real-time monitoring and feedback module; high-resolution three-dimensional information and blood vessel function information obtained by the optical coherence imaging guiding module are used to accurately segment the region of a tumor site, and the power and irradiation time of a radiation laser light source are accurately controlled according to the information; meanwhile, a temperature sensor monitors the tissue temperature at any time, and the system pauses laser diagnosis and treatment when the temperature exceeds the set threshold range, so that precise laser ablation treatment is realized; the application aims to overcome the problems that the current laser ablation treatment lacks real-time and accurate segmentation of tumor regions and lacks real-time monitoring and feedback of the tissues around the tumor during the operation, so that real-time and accurate laser ablation treatment of the tumor site during the operation is realized.

Description

Technical Field

[0001] This invention relates to the fields of optical imaging and biomedical technology, and in particular to a laser ablation treatment system guided by real-time optical coherence imaging during surgery. Background Technology

[0002] Reports indicate a gradual increase in the incidence of tumor-related lesions and diseases, which can currently be treated and eliminated through methods such as laser therapy. However, current surgical laser treatments lack monitoring or feedback systems throughout the entire process, with treatment effectiveness largely dependent on the therapist's experience. This can easily lead to overtreatment, and the irreversible tissue damage caused by overtreatment may be irreparable. In recent years, laser ablation therapy, utilizing optical imaging guidance technology, has provided a new means to achieve integrated diagnosis and treatment of diseases.

[0003] Optical coherence tomography (OCT) is characterized by its high resolution, non-contact nature, and non-invasiveness. Optical coherence tomography angiography (OCTA), an important branch of OCT technology, is a novel imaging modality built upon optical coherence tomography. It displays the three-dimensional structure of tissues and blood vessels at micrometer-level resolution, overcoming the limitation of OCT in providing blood flow information. This allows for the acquisition of high-resolution blood flow information at different depths within organs, enabling early disease treatment.

[0004] Laser ablation can treat tumorous lesions in the body. It can accurately target and completely kill tumorous lesions, and the ablation procedure is relatively short, avoiding the huge trauma caused by surgery. However, because the local temperature is too high during laser ablation, it can damage surrounding normal tissues, nerves, and blood vessels while eliminating tumorous lesions, leading to corresponding complications for patients. Summary of the Invention

[0005] The main objective of this invention is to overcome the aforementioned deficiencies in the prior art and propose an intraoperative real-time optical coherence imaging-guided laser ablation treatment system, which aims to overcome the current problems of lack of real-time and precise segmentation of the tumor area and lack of real-time monitoring and feedback of the surrounding tissues in laser ablation treatment during surgery.

[0006] The present invention adopts the following technical solution:

[0007] A laser ablation treatment system guided by real-time optical coherence imaging during surgery includes: an optical guidance module, a laser treatment module, and a real-time monitoring and feedback module; wherein:

[0008] The optical guidance module includes a tunable laser (1) for the light output device of the optical guidance module, the scanning rate of the tunable laser determines the imaging rate of the system; a first fiber coupler (2) for the proportional distribution of light energy after the laser is coupled to multiple optical fibers; a fiber circulator (3) for a split three-port device; a first fiber collimator (4) for controlling the divergence angle of the laser beam and collimating the beam after it comes out of the fiber; a reflector (6) for reflecting the laser, and the laser returning along the original path interferes in the second fiber coupler (5); a balance detector (7) for eliminating common-mode noise, the balance detector consists of two balanced photodiodes and an ultra-low noise, high-speed transimpedance amplifier, and uses the subtraction of two optical input signals as a balance receiver; and a first signal transmission cable (16) for transmitting the original tissue optical signal obtained by the optical guidance module to the workstation (15), the workstation processes the signal to determine the light energy required for laser treatment of the tissue.

[0009] The laser treatment module includes a radiation laser (8) for emitting pulsed excitation light to irradiate the irradiated object; a photodetector (9) for monitoring the emitted light frequency; a wavelength division multiplexer (10) for coupling beams of different wavelengths into the same optical fiber for transmission; a second fiber collimator (11) for controlling the divergence angle of the laser beam and collimating the beam after it comes out of the optical fiber; a two-dimensional scanning galvanometer (12) for optical path deflection, irradiating the laser beam onto the tissue sample (13) and realizing high-frequency movement of the light spot at equal intervals; the workstation (15) feeds back a first signal to the laser treatment module through the second signal transmission cable (17), and the radiation laser starts to irradiate the tissue with a laser of set power, while the treatment effect is evaluated in real time;

[0010] The real-time monitoring and feedback module includes a temperature sensor (14) for real-time monitoring of the radiation temperature of the tissue surrounding the tumor during the operation. The workstation (15) monitors the transmitted tissue temperature signal in real time. When the tissue temperature reaches the set threshold, the workstation feeds back a second signal through the second signal transmission cable (17) to stop the laser radiation.

[0011] Specifically, it also includes the preprocessing of raw optical signals from the tissue in real time during the operation:

[0012] The preprocessing includes, but is not limited to, background noise removal, wavenumber calibration, spectral shaping, and dispersion compensation.

[0013] Specifically, it also includes the segmentation of the tumor boundary region, as follows:

[0014] The image of the preprocessed raw optical signal of the tissue during real-time surgery defines the output of each pixel as the probability of the boundary of the corresponding tissue lesion. The result is normalized by the Softmax function. Using the labeled clinical image as the ground truth, a loss function based on a combination of edge loss and mutual exclusion loss is constructed for further training, and finally the task of segmenting the tissue image during real-time surgery is achieved.

[0015] Specifically, the workstation processes the signal to determine the light energy required for laser treatment of the tissue, specifically:

[0016] Laser treatment assessment is performed based on the three-dimensional structural information and blood flow function information acquired by the signal acquisition equipment of the optical guidance system. The acquired segmented intraoperative real-time tissue images are used to quantify the lesion area, and a three-dimensional structural reconstruction is performed on the lesion area to obtain lesion information in the lateral and depth directions. Simultaneously, the acquired optical coherence angiography images are used to quantitatively analyze blood flow velocity and vascular density information. The changing trends of the three-dimensional structural information and blood flow function information are matched with safety thresholds set by professional medical personnel. The optical guidance module is used to determine the laser energy range required for specific diseases or specific areas, and the real-time monitoring and feedback module enables real-time intraoperative laser energy setting for different diseases and severities.

[0017] Specifically, the real-time monitoring and feedback module includes:

[0018] Temperature sensors are used to monitor the radiation temperature of the tissue surrounding the tumor in real time during surgery. The workstation monitors the transmitted tissue temperature signal in real time. When the tissue temperature reaches the set threshold or the treatment time and effect reach the expected effect, the workstation feeds back a second signal through the second signal transmission cable to stop laser radiation.

[0019] As can be seen from the above description of the present invention, compared with the prior art, the present invention has the following beneficial effects: The present invention proposes an intraoperative real-time optical coherence imaging-guided laser ablation treatment system, comprising: an optical guidance module, a laser treatment module, and a real-time monitoring and feedback module. Through the high-resolution three-dimensional information and vascular function information obtained by the optical coherence imaging guidance module, the tumor site is accurately segmented, thereby accurately controlling the power and radiation time of the radiating laser source. Simultaneously, a temperature sensor continuously monitors the tissue temperature; when the temperature exceeds a set threshold range, the system pauses laser treatment, achieving precise laser ablation treatment. This aims to overcome the current problems of lacking real-time precise segmentation of the tumor area and lacking real-time monitoring and feedback of the surrounding tissues in laser ablation treatment during surgery, thereby achieving intraoperative real-time precise laser ablation treatment of the tumor site. Attached Figure Description

[0020] Figure 1This is a schematic diagram illustrating the principle of a laser ablation treatment system guided by real-time optical coherence imaging during surgery, as described in an embodiment of the present invention.

[0021] Figure 2 This is a logic flowchart of a laser ablation treatment system guided by real-time optical coherence imaging during surgery, as described in an embodiment of the present invention.

[0022] Figure 3 This is a preliminary experiment used in this invention to verify the feasibility of a laser ablation treatment system guided by real-time optical coherence imaging during surgery.

[0023] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Detailed Implementation

[0024] This invention proposes an intraoperative real-time optical coherence imaging-guided laser ablation treatment system, which aims to overcome the current problems of lack of real-time and precise segmentation of the tumor area and lack of real-time monitoring and feedback of the surrounding tissues in laser ablation treatment during surgery, thereby realizing real-time and precise laser ablation treatment of the tumor site during surgery.

[0025] like Figure 1 This is a schematic diagram illustrating the principle of a laser ablation treatment system guided by real-time optical coherence imaging in an embodiment of the present invention, comprising: an optical guidance module, a laser treatment module, and a real-time monitoring and feedback module; wherein:

[0026] The optical guidance module includes a tunable laser (1) for the light output device of the optical guidance module, the scanning rate of the tunable laser determines the imaging rate of the system; a first fiber coupler (2) for the proportional distribution of light energy after the laser is coupled to multiple optical fibers; a fiber circulator (3) for a split three-port device; a first fiber collimator (4) for controlling the divergence angle of the laser beam and collimating the beam after it comes out of the fiber; a reflector (6) for reflecting the laser, and the laser returning along the original path interferes in the second fiber coupler (5); a balance detector (7) for eliminating common-mode noise, the balance detector consists of two balanced photodiodes and an ultra-low noise, high-speed transimpedance amplifier, and uses the subtraction of two optical input signals as a balance receiver; and a first signal transmission cable (16) for transmitting the original tissue optical signal obtained by the optical guidance module to the workstation (15), the workstation processes the signal to determine the light energy required for laser treatment of the tissue.

[0027] The optical guidance module needs to accurately determine the location of tissue lesions, laser energy, and radiation time, and accordingly control the laser intensity and irradiation range to achieve precise treatment guided by real-time optical coherence imaging during surgery. The optical coherence imaging guidance module includes a swept-frequency laser that transmits laser light to the tumor site. After interacting with the biological tissue, the swept-frequency laser light is scattered back into the optical fiber and interferes at the fiber coupler, amplifying the optical signal from the tumor site. A photodetector converts the amplified interference signal into a photoelectric signal, forming a current signal that is transmitted to the workstation via a first signal transmission cable for image information reconstruction.

[0028] The laser treatment module includes a radiation laser (8) for emitting pulsed excitation light to irradiate the irradiated object; a photodetector (9) for monitoring the emitted light frequency; a wavelength division multiplexer (10) for coupling beams of different wavelengths into the same optical fiber for transmission; a second fiber collimator (11) for controlling the divergence angle of the laser beam and collimating the beam after it comes out of the optical fiber; a two-dimensional scanning galvanometer (12) for optical path deflection, irradiating the laser beam onto the tissue sample (13) and realizing high-frequency movement of the light spot at equal intervals; and a workstation (15) for feeding back a first signal to the laser treatment module through a second signal transmission cable (17), at which point the radiation laser begins to irradiate the tissue with a laser of set power, while simultaneously evaluating the treatment effect in real time.

[0029] The laser therapy module can focus the laser on the tumor site in a spatial optical path, and achieve safe laser ablation treatment based on the photoacoustic effect and selective photothermal theory. The laser therapy module includes a radiation laser, which uses a 532nm wavelength laser with adjustable power, and the diameter of the laser spot focused on the tissue is about 300um; the radiation laser emitted by the laser of the laser therapy module is transmitted to the same optical fiber through a wavelength division multiplexer and the laser of the optical guidance module and is expanded and collimated by the second fiber collimator (11). The optical path is deflected and focused on the tumor site by the two-dimensional galvanometer system, realizing common-path focusing and real-time imaging guidance;

[0030] The real-time monitoring and feedback module includes a temperature sensor (14) for real-time monitoring of the radiation temperature of the tissue surrounding the tumor during the operation. The workstation (15) monitors the transmitted tissue temperature signal in real time. When the tissue temperature reaches the set threshold, the workstation feeds back a second signal through the second signal transmission cable (17) to stop the laser radiation.

[0031] The real-time monitoring and feedback module utilizes a temperature sensor to monitor and provide feedback on tissue temperature changes during laser treatment of the tumor site. This module includes a temperature sensor to monitor the radiation temperature of the tissue surrounding the tumor in real time, and the workstation monitors the transmitted tissue temperature signal. It further performs quantitative analysis of blood flow velocity, vessel density, and other information using acquired optical coherence angiography images. The module also matches the trends of changes in three-dimensional structural information and blood flow function information with safety thresholds set by medical professionals to determine the required laser energy range for specific diseases or regions. When the temperature of the tissue surrounding the tumor reaches the set threshold, the workstation stops laser radiation via a second signal transmission cable.

[0032] Specifically, the workstation processes the signal to determine the light energy required for laser treatment of the tissue, specifically:

[0033] Laser treatment assessment is performed based on the three-dimensional structural information and blood flow function information acquired by the signal acquisition equipment of the optical guidance system. The acquired segmented intraoperative real-time tissue images are used to quantify the lesion area, and a three-dimensional structural reconstruction is performed on the lesion area to obtain lesion information in the lateral and depth directions. Simultaneously, the acquired optical coherence angiography images are used to quantitatively analyze blood flow velocity and vascular density information. The changing trends of the three-dimensional structural information and blood flow function information are matched with safety thresholds set by professional medical personnel. The optical guidance module is used to determine the laser energy range required for specific diseases or specific areas, and the real-time monitoring and feedback module enables real-time intraoperative laser energy setting for different diseases and severities.

[0034] To achieve intraoperative real-time optical coherence imaging-guided laser ablation, obtaining accurate images of the tumor region is crucial. Real-time acquisition of optical signals from the original tissue site is essential to recover as much detailed structural information as possible and enhance image contrast. Necessary preprocessing of the interference signals is required before performing a Fast Fourier Transform (FFT). This preprocessing mainly includes background noise removal, wavenumber calibration, spectral shaping, and dispersion compensation. The preprocessed image outputs the probability of each pixel representing the corresponding lesion boundary, and the results are normalized using a Softmax function. Using a small number of labeled clinical images as ground truth, a loss function based on a combination of edge loss and mutual exclusion loss is constructed for further training, ultimately achieving real-time image segmentation during surgery. The optical coherence imaging system obtains accurate images of the tumor site. By analyzing the three-dimensional structural and blood flow information of the image and matching it with safety thresholds set by medical professionals, the power and time of laser ablation treatment are determined. This information is used to determine whether further radiation therapy is needed and to control the intensity of the laser source during laser ablation treatment.

[0035] like Figure 2This is a logic flowchart of a laser ablation treatment system guided by real-time optical coherence imaging during surgery, as described in an embodiment of the present invention.

[0036] For the original tissue OCT signal, signal calibration preprocessing is first performed, including background noise removal, beam calibration, spectral shaping, and dispersion compensation. After preprocessing, feature extraction is performed, including phase extraction, phase correction, phase variance, intensity extraction, clutter filtering, and intensity variance. Based on the extracted features, the lesion area is segmented using a deep learning-based segmentation algorithm. Then, the signal is imported into the laser ablation screen control unit to set specific laser parameters for laser treatment and real-time monitoring and evaluation.

[0037] The feasibility of this invention is further verified using laser irradiation of a fresh liver excised from an organ as an example. The laser ablation treatment system designed in this experiment mimics the radiation component of an actual laser treatment system, which is widely used in hospitals. This invention employs a 700-1100 nm wavelength pulsed laser. To observe the laser radiation process guided by real-time optical coherence imaging, a relatively low-power laser was selected to observe the image changes of a fresh liver excised from an organ. For example... Figure 3 As shown, interference signals are acquired at the selected region, and the acquired optical coherence signals are analyzed (e.g., amplitude, frequency). A segmentation algorithm is used to determine the laser radiation range at the selected region. Furthermore, the structural and functional information of the selected region is used to determine the effect and stage of laser treatment, thereby guiding the setting of laser output power. Then, based on nodes calibrated by medical professionals, the changing trends of these extracted quantities are determined and matched to obtain the threshold range for temperature control of specific diseases or regions. This allows for systematic monitoring and feedback of the laser treatment process at each moment. When the temperature exceeds the set threshold range, the system pauses the laser treatment, achieving the control objective. In summary, the preliminary experiments of this invention demonstrate the feasibility of the proposed optical coherence imaging-guided laser radiation process.

[0038] The present invention discloses an intraoperative real-time optical coherence imaging-guided laser ablation treatment system. Through the high-resolution three-dimensional information and vascular function information obtained by the optical coherence imaging guidance module, the system accurately segments the tumor area and accurately controls the power and radiation time of the radiation laser source. At the same time, the temperature sensor constantly monitors the tissue temperature. When the temperature exceeds the set threshold range, the system pauses the laser treatment, thereby achieving precise laser ablation treatment.

[0039] The above are merely specific embodiments of the present invention, but the design concept of the present invention is not limited thereto. Any non-substantial modifications made to the present invention using this concept shall be considered as infringing upon the protection scope of the present invention.

Claims

1. A laser ablation treatment system guided by real-time optical coherence imaging during surgery, characterized in that, include: Optical guidance module, laser treatment module, real-time monitoring and feedback module; among which: The optical guidance module includes a tunable laser (1) as the light output device of the optical guidance module; a first fiber coupler (2) for the proportional distribution of light energy after the laser is coupled to multiple optical fibers; a fiber circulator (3) which is a three-port optical device; a first fiber collimator (4) for controlling the divergence angle of the laser beam and collimating the beam after it comes out of the fiber; a reflector (6) for reflecting the laser, and the laser returning along the original path interferes in the second fiber coupler (5); a balance detector (7) for eliminating common-mode noise, which consists of two balanced photodiodes and an ultra-low noise, high-speed transimpedance amplifier, and achieves balanced reception by subtracting the two optical input signals from each other; and a first signal transmission cable (16) for transmitting the original tissue optical signal obtained by the optical guidance module to the workstation (15), where the workstation processes the signal to determine the light energy required for laser treatment of the tissue. The laser treatment module includes a radiation laser (8) for emitting pulsed excitation light to irradiate the irradiated object; a photodetector (9) for monitoring the emitted light frequency; a wavelength division multiplexer (10) for coupling beams of different wavelengths into the same optical fiber for transmission; a second fiber collimator (11) for controlling the divergence angle of the laser beam and collimating the beam after it comes out of the optical fiber; a two-dimensional scanning galvanometer (12) for optical path deflection, irradiating the laser beam onto the tissue sample (13) and realizing high-frequency movement of the light spot at equal intervals; the workstation (15) feeds back a first signal to the laser treatment module through a second signal transmission cable (17), and the radiation laser starts to irradiate the tissue sample (13) with a laser of set power, while the treatment effect is evaluated in real time; The real-time monitoring and feedback module includes a temperature sensor (14) for real-time monitoring of the radiation temperature of the tissue surrounding the tumor during surgery. The workstation (15) monitors the transmitted tissue temperature signal in real time. When the tissue temperature reaches the set threshold, the workstation feeds back a second signal through the second signal transmission cable (17) to stop laser radiation. It also includes preprocessing of the raw tissue optical signals: The preprocessing includes background noise removal, wavenumber calibration, spectral shaping, and dispersion compensation. This also includes tumor boundary region segmentation, specifically: The image of the original tissue optical signal preprocessing defines the pixel output as the probability of the corresponding tissue lesion boundary, and the result is normalized by the Softmax function. Using the labeled clinical image as the ground truth, a loss function based on the combination of edge loss and mutual exclusion loss is constructed for further training, and finally the task of intraoperative real-time tissue image segmentation is achieved. The workstation processes the signal to determine the light energy required for laser treatment of the tissue, specifically: Laser treatment is evaluated using three-dimensional structural information and blood flow function information acquired by the signal acquisition device of the optical guidance module. The intraoperative real-time tissue image after image segmentation is used to quantify the lesion area, and a three-dimensional structural reconstruction is performed on the lesion area to obtain lesion information in the lateral and depth directions. Simultaneously, quantitative analysis of blood flow velocity and vascular density information is conducted using the acquired optical coherence angiography images. The changing trends of the three-dimensional structural information and blood flow function information are matched with safety thresholds calibrated by professional medical personnel. The optical guidance module is used to determine the laser energy range required for specific diseases or specific areas, and the real-time monitoring and feedback module enables real-time intraoperative laser energy setting for different diseases and severities.

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