Structural oct integrated with octa imaging system and imaging method

Abstract

The embodiment of the application provides a kind of structure OCT and OCTA integration imaging system and control method, belong to photoelectric technology field.The system includes: first frequency-swept light source, second frequency-swept light source, coupling unit, optical fiber rotary driver, imaging catheter, control module;Optical fiber rotary driver includes high-speed scanning motor, retraction motor and low-speed scanning motor;When being in OCT imaging state, retraction motor and high-speed scanning motor operate;First frequency-swept light source emits first initial signal, and converts first initial signal into first detection signal;OCT scanning is carried out to target object based on first detection signal;When the system is in OCTA imaging state, retraction motor and low-speed scanning motor operate;Second frequency-swept light source emits second initial signal, and converts second initial signal into second detection signal;OCTA scanning is carried out to plaque based on second detection signal.The application can realize the automatic detection and scanning imaging of plaque.

Description

Technical Field

[0001] This invention relates to the field of optoelectronic technology, and more specifically, to an integrated structural OCT and OCT imaging system and method. Background Technology

[0002] Detecting neovascularization within vulnerable plaques using imaging techniques is of great significance. Optical coherence tomography (OCT) is currently recognized as the highest-resolution imaging method in the field of intravascular imaging, providing excellent visualization of lesions such as intimal plaques, thin fibrous caps, and dissections, but it is not easy to detect neovascularization.

[0003] In addition, OCT has insufficient penetration depth in vascular tissue, usually only about 1.2mm to 1.5mm, and plaque components further inhibit the penetration depth of OCT, which makes it impossible to image new blood vessels deep in the plaque. Summary of the Invention

[0004] To address the aforementioned technical problems, embodiments of this application provide an integrated structural OCT and OCT imaging system and method.

[0005] In a first aspect, embodiments of this application provide an integrated structural OCT and OCT imaging system. The system includes a first frequency-scanning light source, a second frequency-scanning light source, a coupling unit, a fiber optic rotation driver, an imaging conduit, a control module, and a data processing module. The fiber optic rotation driver includes a high-speed scanning motor, a retraction motor, and a low-speed scanning motor. The first frequency-scanning light source and the second frequency-scanning light source are respectively communicatively connected to the coupling unit. The coupling unit is communicatively connected to the fiber optic rotation driver. The fiber optic rotation driver is communicatively connected to the imaging conduit. The first frequency-scanning light source, the second frequency-scanning light source, the fiber optic rotation driver, and the data processing module are respectively electrically connected to the control module.

[0006] When the system is in OCT imaging mode, the control module controls the high-speed scanning motor to engage and enter the drive train, and the retraction motor and the high-speed scanning motor operate; wherein, the retraction motor and the high-speed scanning motor are used to provide power to the imaging catheter;

[0007] The control module is also used to control the first frequency sweep light source to emit a first initial signal, and the coupling unit is used to convert the first initial signal into a first detection signal;

[0008] The control module is also used to control the imaging catheter to perform OCT scanning on the target object based on the first detection signal to obtain OCT data;

[0009] When the system is in OCTA imaging mode, the control module is used to control the data processing module to calculate the OCT data to obtain the patch and patch location of the target object; calculate the OCTA retraction start position based on the patch location, and the control module controls the probe inside the imaging catheter to move to the OCTA retraction start position;

[0010] The control module controls the high-speed scanning motor to disconnect, and the low-speed scanning motor to engage with the transmission chain. At this time, the retraction motor and the low-speed scanning motor are running; wherein, the retraction motor and the low-speed scanning motor are used to provide power to the imaging catheter.

[0011] The control module is further configured to control the second frequency sweep light source to emit a second initial signal, and the coupling unit is configured to convert the second initial signal into a second detection signal; wherein the first initial signal and the second initial signal are optical signals, and the wavelength of the first initial signal is less than the wavelength of the second initial signal;

[0012] The control module is also used to control the imaging catheter to perform OCTA scanning on the plaque based on the second detection signal to obtain OCTA data.

[0013] In one embodiment, the coupling unit includes a first coupler, a second coupler, a first circulator, a second circulator, a reflective unit, and a balance detector; the first circulator and the second circulator are respectively communicatively connected to the first coupler, and the first circulator and the second circulator are also respectively communicatively connected to the second coupler; the first circulator is communicatively connected to the reflective unit, and the second coupler is communicatively connected to the balance detector.

[0014] The first coupler is used to split the first initial signal into a first reference signal and a first sample signal, the first reference signal entering the reference arm via the first circulator;

[0015] The reflection unit is used to focus and reflect the first reference signal to obtain the first reflected signal;

[0016] The first sample signal is emitted from the imaging conduit via the second circulator and the optical fiber rotation driver. After being reflected by the target object, it interferes with the first reflected signal to obtain an interference signal.

[0017] The balanced detector is used to convert the interference signal into an electrical signal.

[0018] In one embodiment, the reflecting unit includes a collimator, a lens, and a reflector.

[0019] In one embodiment, the data processing module is further configured to acquire multiple electrical signals and reconstruct the multiple electrical signals into the OCT data.

[0020] In one embodiment, the fiber optic rotary actuator further includes a clutch, a timing belt, a slip ring, and a lead screw; the retraction motor is mechanically connected to the lead screw, and the lead screw is tactilely connected to the slip ring;

[0021] The OCT scan includes rotational scanning and retraction scanning. When the system is in OCT imaging mode, the high-speed scanning motor is used to provide continuous rotational power to the imaging core of the imaging catheter, so that the imaging core can achieve the rotational scanning, wherein the rotation angle is 360 degrees.

[0022] The retraction motor is used to drive the lead screw to rotate, so that the slip ring retracts and drives the imaging catheter to achieve the retraction scan;

[0023] The slip ring is also used to advance when the system needs to be reset.

[0024] In one embodiment, when the system is in OCTA imaging mode, the low-speed scanning motor is mechanically connected to the toothed pulley of the synchronous belt, and the low-speed scanning motor is used to drive the imaging guide tube to perform pause-step scanning by driving the slip ring.

[0025] Secondly, embodiments of this application provide an imaging method applied to the integrated structural OCT and OCT imaging system described in the first aspect. The system includes a first frequency sweeping light source, a second frequency sweeping light source, a coupling unit, a fiber optic rotary driver, an imaging guide tube, a control module, and a data processing module. The fiber optic rotary driver includes a high-speed scanning motor, a retraction motor, and a low-speed scanning motor.

[0026] When the system is in OCT imaging mode, the high-speed scanning motor is controlled to engage and enter the drive chain, and the retraction motor and the high-speed scanning motor operate; wherein, the retraction motor and the high-speed scanning motor are used to provide power to the imaging catheter;

[0027] Transmit a first initial signal and convert the first initial signal into a first detection signal;

[0028] Based on the first detection signal, an OCT scan is performed on the target object to obtain OCT data;

[0029] When the system is in OCTA imaging mode, the OCT data is calculated to obtain the patch location of the target object; the OCTA retraction start position is calculated based on the patch location, and the control module controls the probe inside the imaging catheter to move to the OCTA retraction start position;

[0030] The high-speed scanning motor is disconnected, while the retraction motor and the low-speed scanning motor are operated; wherein, the retraction motor and the low-speed scanning motor are used to provide power to the imaging catheter;

[0031] A second initial signal is emitted, and the second initial signal is converted into a second detection signal; wherein the first initial signal and the second initial signal are optical signals, and the wavelength of the first initial signal is shorter than the wavelength of the second initial signal;

[0032] The patch is scanned using the second detection signal to obtain OCTA data.

[0033] In one embodiment, controlling the high-speed scanning motor to engage into the drive train, and the retraction motor and the high-speed scanning motor operating, includes:

[0034] The high-speed scanning motor provides continuous rotation power to the imaging core of the imaging catheter, enabling the imaging core to perform rotational scanning, wherein the rotation angle is 360 degrees.

[0035] The retraction motor drives the lead screw to rotate, causing the slip ring to retract and drive the imaging catheter to perform a retraction scan.

[0036] In one embodiment, the control of the high-speed scanning motor to disconnect and the low-speed scanning motor to engage with the drive train, at which point the operation of the retraction motor and the low-speed scanning motor includes:

[0037] When the system is in OCTA imaging mode, the low-speed scanning motor is mechanically connected to the toothed pulley of the synchronous belt. The low-speed scanning motor is used to drive the imaging guide to perform pause-step scanning by driving the slip ring.

[0038] In one embodiment, the method further includes:

[0039] The actual physical dimensions of the retraction during OCTA scanning are determined using the following formula.

[0040]

[0041] Among them, L i The actual physical dimensions from the start of the rollback to the i-th frame are represented by L, where L represents the total OCT rollback length, F represents the total number of OCT rollback frames, and f represents the total number of OCT rollback frames. i This represents the i-th frame.

[0042] This application has the following beneficial effects:

[0043] This application achieves deeper penetration by using a longer wavelength light source in combination with rotating motor switching and light source switching, and uses a stepper motor to perform step-pause dense A-line scanning to realize OCTA imaging of neovascularization within plaques, providing more information support for the diagnosis, prevention and treatment of vulnerable plaques. Attached Figure Description

[0044] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0045] Figure 1 A schematic diagram of an integrated structural OCT and OCTA imaging system provided in an embodiment of this application;

[0046] Figure 2 This is a schematic diagram of the internal structure of the fiber optic rotary driver provided in an embodiment of this application;

[0047] Figure 3 This is a schematic diagram of lumen area identification provided in an embodiment of this application;

[0048] Figure 4 This is a schematic diagram illustrating the penetration depth of light of different wavelengths in water, as provided in the embodiments of this application. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0050] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0051] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0052] In the description of this invention, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of this invention is usually placed, they are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0053] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0054] It should be noted that, where there is no conflict, the features in the embodiments of the present invention can be combined with each other.

[0055] Example 1

[0056] In unstable angina pectoris (UAP), the culprits of intraplaque neovascularization (NV) exhibit higher plaque vulnerability. Therefore, detecting intraplaque neovascularization through imaging techniques is crucial for the diagnosis, prevention, and treatment of vulnerable plaques. Optical coherence tomography (OCT) is currently recognized as the highest-resolution imaging method in the field of intravascular imaging, providing excellent visualization of lesions such as intimal plaques, thin fibrous caps, and dissections. However, it is not adept at detecting neovascularization (NV). Reconstruction of images of newly formed microvessels requires optical coherence tomography angiography (OCTA).

[0057] OCTA imaging based on dense A-line scanning uses the method of comparing component changes between adjacent A-lines. Since the time interval between A-lines is much smaller than the time interval between B-scans, it can be used for microvascular imaging of tissues with some shaking, in addition to vascular imaging of stable tissues.

[0058] Furthermore, OCT's penetration depth within vascular tissue is insufficient, typically only around 1.2mm to 1.5mm, and plaque components further inhibit this penetration, making it impossible to image neovascularization deep within the plaque. Therefore, it is necessary to take measures to improve the penetration depth of the OCT system. Theoretically, different wavelengths of light have varying abilities to bypass obstacles, with longer wavelengths having stronger penetrating power. Therefore, using longer wavelength light sources could be considered to enhance penetration depth.

[0059] Based on this, this embodiment provides an integrated imaging method that can realize OCT and OCTA imaging by changing the scanning mode by switching the rotary motor, and can improve the penetration depth by switching the sweep frequency light source.

[0060] For details, see Figure 1 The integrated OCT and OCT imaging system includes a first frequency sweep light source, a second frequency sweep light source, a coupling unit, a fiber optic rotary driver, an imaging conduit, a control module, and a data processing module. The fiber optic rotary driver includes a high-speed scanning motor, a retraction motor, and a low-speed scanning motor. The first and second frequency sweep light sources are respectively communicatively connected to the coupling unit, the coupling unit is communicatively connected to the fiber optic rotary driver, the fiber optic rotary driver is communicatively connected to the imaging conduit, and the first, second, and third frequency sweep light sources, the fiber optic rotary driver, and the data processing module are respectively electrically connected to the control module.

[0061] When performing OCT imaging:

[0062] When OCT imaging is required, the control module controls the high-speed scanning motor to enter the drive train, while the low-speed scanning motor is disconnected, and the retraction motor and the high-speed scanning motor operate; wherein, the retraction motor and the high-speed scanning motor are used to provide power to the imaging catheter;

[0063] Preferably, the retraction motor is a stepper motor; the high-speed scanning motor is a brushless motor, and the motor parameters meet the requirements of OCT imaging; the low-speed scanning motor is a stepper motor, and the motor parameters meet the requirements of OCTA imaging.

[0064] The control module is also used to control the first frequency sweep light source to emit a first initial signal, and the coupling unit is used to convert the first initial signal into a first detection signal;

[0065] The control module is also used to control the imaging catheter to perform OCT scanning on the target object based on the first detection signal to obtain OCT data;

[0066] When performing OCTA imaging:

[0067] When OCTA imaging is required, the control module controls the data processing module to calculate the OCT data to obtain the patch location of the target object; based on the patch location, the OCTA retraction start position is calculated, and the control module controls the probe to move to the OCTA retraction start position;

[0068] The control module controls the high-speed scanning motor to disconnect, and the retraction motor and the low-speed scanning motor to operate; wherein, the retraction motor and the low-speed scanning motor are used to provide power to the imaging catheter;

[0069] The control module is further configured to control the second frequency sweep light source to emit a second initial signal, and the coupling unit is configured to convert the second initial signal into a second detection signal; wherein the first initial signal and the second initial signal are optical signals, and the wavelength of the first initial signal is less than the wavelength of the second initial signal;

[0070] The control module is also used to control the imaging catheter to perform OCTA scanning on the plaque based on the second detection signal to obtain OCTA data.

[0071] The wavelengths of the first and second frequency sweep light sources can be determined as follows:

[0072] Maximum penetration depth Z in tissue max The calculation formula is as follows:

[0073] Formula 1:

[0074]

[0075] In the formula, λ0 is the center wavelength of the light source, n is the refractive index of the tissue, and Δ λ Let be the spectral resolution. As can be seen from the above formula, under the condition of consistent spectral resolution, the penetration depth of the system is positively correlated with the center wavelength of the light source. Therefore, theoretically, the longer the center wavelength, the greater the penetration depth.

[0076] In fact, the infrared spectrum has absorption peaks related to water. At certain wavelengths, water absorbs light significantly more strongly. Human tissue is over 70% water, and water's two near-infrared absorption peaks are located at 1460 nm and 1920 nm, respectively. According to relevant research, the relationship between infrared wavelength and penetration depth in tissue is shown in the following figure. Figure 4 .

[0077] The center wavelengths of swept frequency light sources include 1060nm, 1310nm, 1550nm, and 1700nm, among others. Figure 4 It can be seen that light with wavelengths of 1310nm and 1700nm is at the peak position, with a higher penetration depth, while light with a wavelength of 1500nm is at the trough position, with a lower penetration depth. It can also be seen that as the center wavelength increases, the required scanning bandwidth of the light source must also gradually increase (as shown by the dotted line in the figure). Therefore, in order to improve the system's penetration depth, light sources with sufficiently wide bandwidths should be selected in the 1310nm and 1700nm bands, with bandwidths of no less than 60nm and 100nm respectively.

[0078] While improving the system's penetration depth, it is also necessary to consider the system's axial resolution. The formula for calculating the system's axial resolution is as follows:

[0079] Formula 2:

[0080]

[0081] Δ z λ0 represents the axial resolution; a smaller resolution value indicates higher resolution. λ0 is the center wavelength. λ Let be the full width at half maximum (FWHM) of the light source spectrum. As can be seen from the above equation, increasing the center wavelength will reduce the axial resolution of the system. Therefore, simply replacing the 1310nm light source with a 1700nm light source will sacrifice the axial system resolution.

[0082] In summary, in order to balance axial resolution and penetration depth, a dual-source complementary approach using 1310nm and 1700nm light sources is adopted to improve the penetration depth of the original system, namely the first and second frequency sweep light sources.

[0083] Please see Figure 2 In one embodiment, the coupling unit includes a first coupler, a second coupler, a first circulator, a second circulator, a reflective unit, and a balance detector; the first circulator and the second circulator are respectively communicatively connected to the first coupler, and the first circulator and the second circulator are also respectively communicatively connected to the second coupler; the first circulator is communicatively connected to the reflective unit, and the second coupler is communicatively connected to the balance detector.

[0084] The first coupler is used to split the initial signal into a reference signal and a sample signal, the reference signal entering the reference arm via the first circulator;

[0085] The reflection unit is used to focus and reflect the reference signal to obtain a reflected signal;

[0086] The sample signal is emitted from the imaging conduit via the second circulator and the fiber optic rotation driver. After being reflected by the target object, it interferes with the reflected signal to obtain an interference signal.

[0087] The balanced detector is used to convert the interference signal into an electrical signal.

[0088] In one embodiment, the data processing module is further configured to acquire multiple electrical signals and reconstruct the multiple electrical signals into the OCT data.

[0089] In one embodiment, the fiber optic rotary driver further includes a clutch, a timing belt, a slip ring, and a lead screw; the stepper motor is mechanically connected to the lead screw, and the lead screw is tactilely connected to the slip ring;

[0090] The OCT scan includes rotational scanning and retraction scanning. When the system is in OCT imaging mode, the high-speed scanning motor is used to provide continuous rotational power to the imaging core of the imaging catheter, so that the imaging core can achieve the rotational scanning, wherein the rotation angle is 360 degrees.

[0091] The retraction motor is used to drive the lead screw to rotate, causing the slip ring to retract and drive the imaging catheter to achieve the retraction scan.

[0092] In one embodiment, when the system is in OCTA imaging mode, the low-speed scanning motor is mechanically connected to the toothed pulley of the synchronous belt, and the low-speed scanning motor is used to drive the imaging guide tube to perform pause-step scanning.

[0093] The integrated structural OCT and OCTA imaging system provided in this embodiment can automatically detect plaque location and automatically complete OCTA scanning imaging of neovascularization within the plaque, based on conventional OCT imaging. By coordinating the switching of rotary motors and light sources, a longer wavelength light source is used to achieve a deeper penetration depth. A stepper motor is used to perform step-stop dense A-line scanning to realize OCTA imaging of neovascularization within the plaque, providing more information support for the diagnosis, prevention, and treatment of vulnerable plaques.

[0094] Example 2

[0095] In addition, this embodiment provides an imaging method.

[0096] The method includes:

[0097] The high-speed scanning motor is controlled to engage and enter the drive train, putting the system into OCT imaging mode, during which the retraction motor and the high-speed scanning motor operate; wherein, the retraction motor and the high-speed scanning motor are used to provide power to the imaging catheter;

[0098] Transmit a first initial signal and convert the first initial signal into a first detection signal;

[0099] Based on the first detection signal, an OCT scan is performed on the target object to obtain OCT data;

[0100] When OCTA data needs to be acquired, the OCT data is calculated to obtain the patch location of the target object; the OCTA retraction start position is calculated based on the patch location, and the control module controls the probe inside the imaging catheter to move to the OCTA retraction start position;

[0101] The high-speed scanning motor is disconnected, and the low-speed scanning motor engages with the transmission chain. At this time, the retraction motor and the low-speed scanning motor are running; wherein, the retraction motor and the retraction motor are used to provide power to the imaging catheter.

[0102] A second initial signal is emitted, and the second initial signal is converted into a second detection signal; wherein the first initial signal and the second initial signal are optical signals, and the wavelength of the first initial signal is shorter than the wavelength of the second initial signal;

[0103] The patch is scanned using the second detection signal to obtain OCTA data.

[0104] In one embodiment, controlling the low-speed scanning motor to disconnect and the retraction motor and the high-speed scanning motor to operate includes: the high-speed scanning motor providing continuous rotational power to the imaging core of the imaging catheter, enabling the imaging core to perform rotational scanning, wherein the rotation angle is 360 degrees; the retraction motor driving the lead screw to rotate, causing the slip ring to retract and drive the imaging catheter to perform retraction scanning.

[0105] Specifically, the system uses a 1310nm light source by default for OCT imaging, providing higher axial resolution. The light emitted from the 1310nm swept-frequency light source is split into two beams with a 50:50 ratio by coupler one, which then enter the reference arm and sample arm via circulator one and circulator two, respectively. The light entering the reference arm first exits from the optical fiber through a collimator, becoming a parallel beam. The distance between the collimator and the lens is adjusted to match the optical path of the sample arm. It then passes through the lens for focusing, and a mirror placed at the focal point reflects the light back. The light then enters coupler two through port 3 of circulator one, interfering with the light from the sample arm. Coupler two has a 50:50 splitting ratio. Light entering the sample arm passes through a fiber optic rotary driver into the imaging catheter. During OCT imaging, the fiber optic rotary driver controls a clutch to engage a high-speed scanning motor with a toothed pulley. This motor, via a synchronous belt and a slip ring, provides continuous rotation power to the imaging core of the imaging catheter, completing a 360° scan. A retraction motor, by rotating a lead screw, provides forward or backward power to the slip ring. During the retraction of the slip ring, the imaging catheter performs a retraction scan. At the end of the imaging catheter is a deflecting lens, which directs light out of the catheter in a predetermined direction. The emitted light enters the tissue under test, is reflected back to the catheter, and then returns along the sample arm's optical path. The returned light enters coupler two through port 3 of circulator two, interfering with the light returning from the reference arm. The interference signal exits from the two ports of coupler two and enters the positive and negative channels of the balanced detector, converting into electrical signals. These electrical signals are acquired by a data acquisition card built into the computer. The trigger and clock signals of the acquisition card are provided by a swept-frequency light source. Finally, the acquired signals undergo data processing and image reconstruction in the computer.

[0106] In one embodiment, controlling the high-speed scanning motor to disconnect and the operation of the retraction motor and the low-speed scanning motor includes: when the system is in OCTA imaging mode, the low-speed scanning motor is mechanically connected to the toothed pulley of the synchronous belt, and the low-speed scanning motor is used to drive the imaging guide to perform pause-step scanning by driving the slip ring.

[0107] This system enables automated OCTA scanning of neovascularization within plaques. The first step is to determine the location of the plaque, which is achieved through an algorithm that identifies the lumen area. The software automatically calculates the lumen area for each frame of the OCT image and identifies the frame with the smallest lumen area, such as... Figure 3 As shown. The OCTA retraction field of view is set to 10mm, taking 5mm before and after the minimum lumen area, for a total of 10mm. If the calculation result shows that the retraction before and after the minimum lumen area is less than 5mm, for example, the front end of the minimum lumen area is only 2mm, then the front end is scanned and retracted by 2mm according to the actual size, and the rear end is scanned by 8mm, for a total retraction length of 10mm. Frame number f i Compared with the actual physical size L iThe corresponding methods are as follows:

[0108] Formula 3:

[0109]

[0110] Among them, L i The actual physical dimensions from the start of the rollback to the i-th frame are represented by L, where L represents the total OCT rollback length, F represents the total number of OCT rollback frames, and f represents the total number of OCT rollback frames. i This represents the i-th frame.

[0111] After confirming the length and position of the OCTA retraction scan, the control module automatically moves the probe to the retraction start position and automatically begins OCTA scanning imaging. First, the control circuit switches the light source switch, turning on the 1700nm light source and turning off the 1310nm light source to provide deeper penetration. In the fiber optic rotary driver section, the clutch disengages the high-speed scanning motor, connecting the low-speed scanning motor to the toothed pulley. This drives the imaging catheter via a synchronous belt for pause-stepping scanning. Pause-stepping scanning means that the catheter does not rotate continuously for one full revolution; instead, the motor controls the catheter to rotate a certain angle each time, pausing at that position. Data is acquired during the pause, collecting several A-line data points at the same position. Timing control prevents data acquisition during the stepping rotation, maintaining relative stability of the A-line scan. Because OCTA imaging focuses only on plaque location, a slower retraction speed and shorter retraction distance provide higher radial resolution. The scanned data is then processed using a dense A-line OCTA algorithm to reconstruct images of neovascularization within the plaque.

[0112] It should be noted that this system can perform separate OCT imaging and OCTA imaging according to actual needs, and it is not necessary to perform OCT imaging first and then OCTA imaging. Specifically, this can be set by manually switching the light source or using a clutch.

[0113] The imaging method provided in this embodiment, based on conventional OCT imaging, can also automatically detect plaque location and automatically complete OCTA scanning imaging of neovascularization within the plaque. By coordinating the switching of the rotary motor and the switching of the light source, a longer wavelength light source is used to achieve a deeper penetration depth. A stepper motor is used to perform step-pause dense A-line scanning to realize OCTA imaging of neovascularization within the plaque, providing more information support for the diagnosis, prevention, and treatment of vulnerable plaques.

[0114] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An integrated structural OCT and OCTA imaging system, characterized in that, The system includes a first frequency sweep light source, a second frequency sweep light source, a coupling unit, a fiber optic rotary driver, an imaging catheter, a control module, and a data processing module. The fiber optic rotary driver includes a high-speed scanning motor, a retraction motor, and a low-speed scanning motor. The first and second frequency sweep light sources are communicatively connected to the coupling unit, the coupling unit is communicatively connected to the fiber optic rotary driver, the fiber optic rotary driver is communicatively connected to the imaging catheter, and the first, second, and third frequency sweep light sources, the fiber optic rotary driver, and the data processing module are electrically connected to the control module. When the system is in OCT imaging mode, the control module controls the high-speed scanning motor to engage and enter the drive train, and the retraction motor and the high-speed scanning motor operate; wherein, the retraction motor and the high-speed scanning motor are used to provide power to the imaging catheter; The control module is also used to control the first frequency sweep light source to emit a first initial signal, and the coupling unit is used to convert the first initial signal into a first detection signal; The control module is also used to control the imaging catheter to perform OCT scanning on the target object based on the first detection signal to obtain OCT data; When the system is in OCTA imaging mode, the control module controls the data processing module to calculate the OCT data to obtain the patch and patch location of the target object; the OCTA retraction start position is calculated based on the patch location, and the control module controls the probe inside the imaging catheter to move to the OCTA retraction start position; The control module controls the high-speed scanning motor to disconnect, and the low-speed scanning motor to engage with the transmission chain. At this time, the retraction motor and the low-speed scanning motor are running; wherein, the retraction motor and the low-speed scanning motor are used to provide power to the imaging catheter. The control module is further configured to control the second frequency sweep light source to emit a second initial signal, and the coupling unit is configured to convert the second initial signal into a second detection signal; wherein the first initial signal and the second initial signal are optical signals, and the wavelength of the first initial signal is less than the wavelength of the second initial signal; The control module is also used to control the imaging catheter to perform OCTA scanning on the plaque based on the second detection signal to obtain OCTA data.

2. The integrated structural OCT and OCT imaging system according to claim 1, characterized in that, The coupling unit includes a first coupler, a second coupler, a first circulator, a second circulator, a reflective unit, and a balanced detector; the first circulator and the second circulator are respectively communicatively connected to the first coupler, and the first circulator and the second circulator are also respectively communicatively connected to the second coupler; the first circulator is communicatively connected to the reflective unit, and the second coupler is communicatively connected to the balanced detector. The first coupler is used to split the first initial signal into a first reference signal and a first sample signal, the first reference signal entering the reference arm via the first circulator; The reflection unit is used to focus and reflect the first reference signal to obtain the first reflected signal; The first sample signal is emitted from the imaging conduit via the second circulator and the optical fiber rotation driver. After being reflected by the target object, it interferes with the first reflected signal to obtain an interference signal. The balanced detector is used to convert the interference signal into an electrical signal.

3. The integrated structural OCT and OCT imaging system according to claim 2, characterized in that, The reflection unit includes a collimator, a lens, and a reflector.

4. The integrated structural OCT and OCT imaging system according to claim 2, characterized in that, The data processing module is also used to acquire multiple electrical signals and reconstruct the multiple electrical signals into the OCT data.

5. The integrated structural OCT and OCT imaging system according to claim 1, characterized in that, The fiber optic rotary driver further includes a clutch, a timing belt, a slip ring, and a lead screw; the retraction motor is mechanically connected to the lead screw, and the lead screw is tactilely connected to the slip ring; The OCT scan includes rotational scanning and retraction scanning. When the system is in OCT imaging mode, the high-speed scanning motor provides continuous rotational power to the imaging core of the imaging catheter, enabling the imaging core to perform the rotational scanning, wherein the rotation angle is 360 degrees. The retraction motor is used to drive the lead screw to rotate, so that the slip ring retracts and drives the imaging catheter to achieve the retraction scan; The slip ring is also used to advance when the system needs to be reset.

6. The integrated structural OCT and OCT imaging system according to claim 5, characterized in that, When the system is in OCTA imaging mode, the low-speed scanning motor is mechanically connected to the toothed pulley of the synchronous belt, and the low-speed scanning motor is used to perform pause-step scanning by driving the imaging guide tube.

7. The integrated structural OCT and OCT imaging system according to any one of claims 1 to 6, characterized in that, The actual physical dimensions of the retraction during OCTA scanning are determined using the following formula. ； in, Indicates the distance from the starting position of the pullback to the... i The actual physical size at the frame. Indicates the total length of OCT pullback. This indicates the total number of frames rolled back by OCT. Indicates the first i frame.

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