Apparatus, system and method for detecting the external elastic lamina (EEL) from intravascular OCT images

Abstract

Provided herein are one or more devices, systems, methods, and storage media for medical optical imaging devices, such as optical coherence tomography (OCT), single mode OCT, and / or multimodal OCT devices and systems, and methods and storage media used therewith, for detecting the external elastic lamina (EEL) and / or luminal edge. One or more embodiments provide at least one method, device, apparatus, system, or storage medium for obtaining information, such as the molecular structure of a blood vessel, and providing the ability to manipulate the blood vessel information. In addition to controlling one or more imaging modalities, the EEL detection technology can function for one or more applications, such as manual or automated EEL detection, stent positioning and selection, co-registration, imaging, and the like.

Description

Technical Field

[0001] Cross - Reference to Related Applications This application is related to and claims priority to U.S. Non - Provisional Patent Application No. 17 / 492,376, filed on October 1, 2021, the disclosure of which is incorporated herein by reference in its entirety.

[0002] The present disclosure generally relates to the field of computer imaging and / or optical imaging, and in particular, to devices, systems, methods, and storage media for using multiple imaging modalities (optical coherence tomography (OCT), multimode OCT (MMO - OCT), near - infrared fluorescence (NIRF), near - infrared autofluorescence (NIRAF), etc.) to detect the external elastic lamina (EEL) from OCT images. Examples of OCT applications include imaging, evaluating, and diagnosing biological objects such as those in gastrointestinal, cardiac, and / or ophthalmic applications, and acquisition by one or more optical instruments (one or more optical probes, one or more catheters, one or more endoscopes, one or more capsules, one or more needles (e.g., biopsy needles), etc.). In this specification, in applications using an apparatus or system that uses and / or controls multiple imaging modalities, one or more devices, systems, methods, and storage media for characterizing, inspecting, and / or diagnosing a sample or object and / or measuring the viscosity of a sample or object are discussed.

Background Art

[0003] Optical Coherence Tomography (OCT) is a technique for acquiring high-resolution cross-sectional images of tissues and materials, enabling real-time visualization. The purpose of OCT technology is to measure the optical time delay using an interference optical system or interference method such as Fourier transform or Michelson interferometer. The light from the light source is split by a splitter (e.g., a beam splitter) and sent to the reference arm and the sample (or measurement) arm. The reference beam is reflected from the reference mirror (partial reflection element or other reflection element) of the reference arm, and the sample beam is reflected or scattered from the sample of the sample arm. Both beams are combined (or recombined) by the splitter to generate interference fringes. The output of the interferometer is detected by one or more detectors such as a photodiode or a multi-array camera in one or more devices such as a spectrometer (e.g., Fourier transform infrared spectrometer). Interference fringes are generated when the path length of the sample arm matches the path length of the reference arm within the coherence length of the light source. By evaluating the output beam, the spectrum of the input radiation can be derived as a function of frequency. The frequency of the interference fringes corresponds to the distance between the sample arm and the reference arm. The higher the frequency, the greater the difference in path length.

[0004] During vascular diagnosis and intervention procedures such as percutaneous coronary intervention (PCI), users of Optical Coherence Tomography (OCT) may struggle to understand the tomographic images in the correlation with other modalities due to information overload, which may lead to confusion in image interpretation.

[0005] In one or more procedures such as PCI, there is no algorithm or procedure that can automatically detect the EEL and assist the physician in selecting the stent size during PCI procedures. Therefore, there is a need to provide an automatic detection method for detecting the EEL and assisting the user in selecting or setting the stent size.

[0006] Accordingly, it would be desirable to provide at least one imaging optical device, system, method, and storage medium for detecting an EEL automatically in order to use, control, and / or enhance one or more imaging modalities and to assist a user in selecting a stent size. SUMMARY OF THE INVENTION

[0007] Accordingly, a broad object of the present disclosure is to provide an apparatus, system, method, and storage medium for imaging (e.g., OCT, NIRF, NIRAF, etc.) for using and / or controlling one or more imaging modalities and for automatically detecting an EEL to assist a user in selecting a stent size (e.g., diameter, length, diameter and length, wall area (e.g., area between the EEL and the lumen, wall area selected by the user, predetermined wall area, automatically selected wall area, etc.), etc.). It is also a broad object of the present disclosure to provide an OCT device, system, method, and storage medium using an interference optical system (e.g., SD-OCT, SS-OCT, etc.) such as an interferometer.

[0008] One or more embodiments provide at least one method, device, apparatus, system, or storage medium for automatically detecting an EEL to assist a user in selecting a stent size (e.g., diameter, length, diameter and length, wall area (e.g., area between the EEL and the lumen, wall area selected by the user, predetermined wall area, automatically selected wall area, etc.), etc.).

[0009] In one or more procedures, one or more algorithms or methods described herein can be used to automatically detect an EEL and provide assistance and / or warnings to a user (e.g., a physician, technician, etc.) when the selected reference frame is appropriate or inappropriate.

[0010] The present disclosure describes means for enabling an OCT user to focus on a region of interest in all imaging modalities (e.g., tomographic images, near-infrared autofluorescence (NIRAF) information in a carpet view, near-infrared fluorescence (NIRF) information in a carpet view, three-dimensional (3D) rendering of coronary vessels in a half-tube display, lumen diameter display, longitudinal view, angiographic view, etc.). As will be described later, all of the displayed imaging modalities can be controlled by any one of several control bars that enable the user to simultaneously change and update each display and appropriately emphasize NIRF and / or NIRAF data. Thereby, the user can obtain a panoramic view of the structural information of blood vessels using multimodality, and is also provided with the possibility of setting functions for a more focused focus.

[0011] One or more embodiments of the present disclosure can be used in clinical applications such as inter-vascular imaging, intravascular imaging, evaluation of atherosclerotic plaques, evaluation of heart stents, coronary intravascular imaging using blood clearing, balloon sinuplasty, nasal stent placement, arthroscopic examination, ophthalmology, ear research, veterinary use and research, etc.

[0012] According to at least another aspect of the present disclosure, one or more of the techniques described herein may be employed as a feature, or in combination with such a feature, to reduce at least one of the manufacturing and maintenance costs of such devices, instruments, systems, and storage media, by reducing or minimizing the number of optical components and / or processing components, and thanks to efficient techniques for reducing the cost of using / manufacturing one or more devices, instruments, systems, and storage media.

[0013] The following paragraphs describe specific illustrative embodiments. Other embodiments may include alternatives, equivalents, and modifications. Additionally, the illustrative embodiments may include several novel features, and certain features may not be essential to some embodiments of the devices, systems, and methods described herein.

[0014] According to other aspects of the present disclosure, one or more additional devices, one or more systems, one or more methods, and one or more storage media using OCT and / or other imaging modality technologies are discussed herein. Further features of the present disclosure will be partly understandable and partly apparent from the following description and with reference to the accompanying drawings.

Brief Description of the Drawings

[0015] For the purpose of illustrating various aspects of the present disclosure (like numbers indicate like elements), the drawings show simplified forms that may be adopted. However, of course, the present disclosure is not limited to, or by, the precise arrangements and means shown. The accompanying drawings and figures are referred to in order to assist those skilled in the art in making and using the subject matter of this specification.

[0016]

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[0017] Embodiments will be described below with reference to the accompanying drawings. The same numbers refer to the same elements throughout. Note that the following description is illustrative and exemplary in nature and is not intended to limit the present disclosure or its use or application. The relative arrangement, numerical expressions, and numerical values of the components and steps described in the embodiments do not limit the scope of the present disclosure unless specifically stated otherwise. Techniques, methods, and devices well known to those skilled in the art may not be described in detail as those skilled in the art do not need to know their details to enable the use of the embodiments described below. Also, an endoscope used for examining the inside of the human body, as disclosed below, can also be used for examining other objects. Examples of special endoscopes, which are examples of endoscopes in which the embodiments can be implemented, include intravascular endoscopes, anoscopes, arthroscopes, arterioscopes, arthroscopes, bronchoscopes, capsule endoscopes, choledochoscopes, colonoscopes, vaginoscopes, cystoscopes, encephaloscopes, esophagogastroduodenoscopes, esophagoscopes, gastroscopes, hysteroscopes, laparoscopes, laryngoscopes, mediastinoscopes, nephroscopes, neuroendoscopes, proctoscopes, resectoscopes, nasal endoscopes, sigmoidoscopes, sinuscopes, thoracoscopes, ureteroscopes, hysteroscopes, borescopes, fiberscopes, inspection cameras, and any special endoscope that can be adapted to include the embodiments. The endoscope may be flexible or rigid. The embodiments may be a probe or an imaging device.

[0018] This specification discloses one or more devices, optical systems, methods, and storage media for obtaining direct images (e.g., black and white, color, etc.) of a subject such as tissue using the following: imaging functions, features, techniques, or methods; registration functions, features, techniques, or methods; and / or selection of an appropriate registration method. And / or, this specification discloses one or more devices, optical systems, methods, and storage media for performing diagnosis, perfusion, aspiration, dilation (e.g., balloon), culture, tissue sampling, biopsy execution, drug implant, and / or other types of diagnosis and / or treatment using imaging features, functions, or techniques. According to at least one aspect of the present disclosure, the one or more devices, optical systems, methods, and storage media described in this specification use imaging functions, features, techniques, or methods, registration functions, features, techniques, or methods, selection of an appropriate registration method, and / or use an EEL detection method.

[0019] In one or more embodiments, multiple imaging modalities may be used to plan a procedure and confirm the success of a percutaneous coronary intervention (PCI) procedure in a hospital catheterization laboratory.

[0020] This specification discloses one or more devices, systems, methods, and storage media for characterizing tissue (or an object or sample) using multiple imaging techniques or modalities (e.g., OCT, NIRF, NIRAF, etc.). Figures 1A - 18 schematically and visually depict some embodiments of the present disclosure (which may be implemented by one or more embodiments of the apparatus, system, method, and / or computer-readable storage medium of the present disclosure).

[0021] Turning now to the details of the drawings, FIG. 1A shows an OCT system 100 (also referred to herein as "system 100") that functions to utilize OCT technology (e.g., one or more embodiments of the EEL detection technology described herein) along with an optical probe application according to one or more aspects of the present disclosure. System 100 includes a light source 101, a reference arm 102, a sample arm 103, a splitter 104 (also referred to herein as a "beam splitter"), reference mirrors (also referred to herein as "reference reflections") 105 and one or more detectors 107. System 100 may include a phase shifting device or unit 130, and in one or more embodiments, the phase shifting device or unit may be omitted. In one or more embodiments, system 100 may include a patient interface device or unit ("PIU") 110 and a catheter 120 (shown schematically in FIGS. 1A - 1B), and system 100 can interact with a sample or target 106 (e.g., via catheter 120 and / or PIU 110). In one or more embodiments, system 100 includes an interferometer, or the interferometer is defined by one or more components of system 100, such as at least light source 101, reference arm 102, sample arm 103, splitter 104, reference mirror 105, etc.

[0022] The light source 101 functions to emit light towards the splitter 104, and the splitter 104 separates the light from the light source 101 into a reference beam entering the reference arm 102 and a sample beam entering the sample arm 103. The beam splitter 104 is positioned or arranged at an angle with respect to the reference mirrors 105, one or more detectors 107, and the sample or target 106. The reference beam passes through a phase-shifting unit 130 (when included in the system as shown in the system 100), and the reference beam is reflected by the reference mirror 105 of the reference arm 102. On the other hand, the sample beam is reflected or scattered from the sample 106 through the PIU (Patient Interface Unit) 110 and the catheter 120 of the sample arm 103. Both the reference beam and the sample beam are combined (or recombined) at the splitter 104 to generate interference fringes. The output of the system 100 and / or its interferometer is continuously acquired by one or more detectors 107 (such as photodiodes, multi-array cameras, etc.). The one or more detectors 107 measure the interference or interference fringes between the two combined or recombined radiation or light beams. In one or more embodiments, a fringe effect is created, and the reference beam and the sample beam travel different optical path lengths so that they can be measured by the one or more detectors 107. The electrical analog signal obtained from the output of the system 100 and / or its interferometer is converted into a digital signal and analyzed by a computer such as computers 1200, 1200' (shown in FIGS. 17 or 18 described later respectively). In one or more embodiments, the light source 101 may be a radiation source or a broadband light source that emits at a broadband wavelength. In one or more embodiments, a Fourier analyzer including software and electronic devices can be used to convert the electrical analog signal into an optical spectrum.

[0023] The light source 101 may include a plurality of light sources or may be a single light source. The light source 101 generates broadband laser light in one or more embodiments. The light source 101 may include one or more of a laser, an organic light-emitting diode (OLED), a light-emitting diode (LED), a halogen lamp, an incandescent lamp, a supercontinuum light source excited by a laser, and / or a fluorescent lamp. The light source 101 may be any light source that can provide light separable into at least three bands, and each band is further dispersed to provide light used for spectral encoding of spatial information. The light source 101 may be fiber-coupled or free-space coupled to other components of one or more of the systems (system 100, system 100', system 100", system 100''', etc.) described herein.

[0024] According to at least one aspect of the present disclosure, the OCT system is characterized by being implemented using an optical fiber. As described above, one application of the OCT technology of the present disclosure is to use the catheter 120 in combination with OCT, as schematically shown in FIGS. 1A-1B.

[0025] Referring now to FIG. 1B, a schematic diagram of at least one embodiment of an imaging system 20 that can be used in combination with one or more pullback embodiments and / or one or more EEL detection techniques described herein is shown. The imaging system 20 may include an angiography system 30, an intravascular imaging system 40, an image processor 50, a display or monitor 1209, and an electrocardiogram (ECG) device 60. The angiography system 30 includes an X-ray imaging device such as a C-arm 22 connected to an angiography system control unit 24 and an angiography image processor 26 for acquiring an angiography image frame of an object or patient 106.

[0026] The intravascular imaging system 40 of the imaging system 20 may include a console 32, a catheter 120, and a patient interface unit or PIU 110 that connects between the catheter 120 and the console 32 to obtain intravascular image frames. The catheter 120 can be inserted into the blood vessels of the patient 106. The catheter 120 can function as a light irradiator and a data collection probe disposed in the lumen of a specific blood vessel such as, for example, the coronary artery. The catheter 120 may include a probe tip, one or more radiopaque markers, an optical fiber, and a torque wire. The probe tip may include one or more data collection systems. The catheter 120 can be passed through the artery of the patient 106 to obtain an image of the coronary artery. The patient interface unit 110 may include a motor M therein to enable a pullback of the imaging optical system during the acquisition of intravascular image frames. By the imaging pullback technique, an image of the blood vessel can be obtained. The imaging pullback path can represent a co-registration path, which may be a region of interest or a target region of the tube.

[0027] The console 32 may include a light source 101 and a computer 1200. The computer 1200 may include features as described herein (see, for example, FIGS. 1A, 14-17, etc.), or may be the computer 1200' (see, for example, FIG. 18, etc.) or other computers or processors described herein. In one or more embodiments, the computer 1200 may have an intravascular system controller 35 and an intravascular image processor 36. The intravascular system controller 35 and / or the intravascular image processor 36 can function to control the motor M within the patient interface unit 110. Also, the intravascular image processor 36 can perform various steps for image processing and control the information to be displayed.

[0028] Within the imaging system 20, various types of intravascular imaging systems can be used. The intravascular imaging system 40 is merely an example of an intravascular imaging system that can be used within the imaging system 20. By way of example, various types of intravascular imaging systems can be used, including, for example, an OCT system, a multimodality OCT system, or an IVUS system.

[0029] Also, the imaging system 20 may be connected to an electrocardiogram (ECG) device 60 to record the electrical activity of the heart over a period of time using electrodes placed on the skin of the patient 106. The imaging system 20 may also include an image processor 50 to receive angiography data, intravascular imaging data, and data from the ECG device 60, perform various image processing steps, and transmit to a display 1209 for displaying angiography image frames together with a co-registration path. In FIG. 1B, the image processor 50 associated with the imaging system 20 appears to be external to both the angiography system 30 and the intravascular imaging system 40, but the image processor 50 may be included within the angiography system 30, the intravascular imaging system 40, the display 1209, or a stand-alone device. Alternatively, if various image processing steps are performed using one or more of the angiography image processor 26, the intravascular image processor 36 of the imaging system 20, or other processors described herein (e.g., computer 1200, computer 1200', etc.), the image processor 50 may not be necessary.

[0030] In one or more embodiments, one or more imaging modalities can be used to plan a procedure in a hospital catheterization laboratory and confirm the success of a percutaneous coronary intervention (PCI) procedure, or one or more imaging modalities can be used to plan and perform one or more other procedures (such as imaging, EEL detection, etc.). FIG. 2A shows at least one example of the overall workflow of EEL detection. In one or more embodiments, the method may include the following steps: (i) calibrating the OCT signal intensity or the signal intensity of other modalities to remove the effect of depth (see, for example, step S200 in FIG. 2A); (ii) detecting the lumen (see, for example, step S201 in FIG. 2A); (iii) determining whether the lumen is located within a predetermined distance (such as within 3.0 mm, within 2.0 mm, within 1.0 mm to 3.0 mm, etc.) from the catheter center (see, for example, step S202 in FIG. 2A); (iv) if it is "Yes" in S202, taking the moving average of the signal intensity for a predetermined number or set number XX of A-lines (such as 10 A-lines, 5 A-lines, 3 A-lines, 1 to 10 A-lines, 10 or more A-lines, 15 A-lines, the number of A-lines set by the user, etc.) (for example, range = 20, ~0.1 mm) (see, for example, step S203 in FIG. 2A), and then proceeding to steps S204 - S206 described below, or if it is "No" in S202, determining and / or marking that EEL detection did not occur (see, for example, step S202b in FIG. 2A); (v) in step S204, finding the position where the average intensity has changed or changed abruptly by a predetermined amount (such as 5 percent or more, 10 percent or more, 5 - 10% or more, the amount set or defined by the user, etc.) (see, for example, step S204 in FIG. 2A); (vi) detecting the EEL position based on the position of the detected change or abrupt change (such as from low intensity to high intensity) and the intensity of the EEL or the detected change or abrupt change (see, for example, step S205 in FIG. 2A);(vii) Determine whether the detected EEL position is within a predetermined distance from the lumen (for example, within 1 mm, within 2 mm, within 1 - 2 mm, within a distance set by the user, within the maximum penetration depth of one or more imaging modalities, within 1 - 2 mm in the case of the OCT imaging modality, etc.) (see, for example, step S206 in FIG. 2A); (viii) If it is “Yes” in S206, proceed to steps S210 and S211 described below, or if it is “No” in S206, proceed to step S207; (ix) In step S207, determine whether plaque is present (see, for example, step S207 in FIG. 2A), and if it is “Yes” in S207, (x) After performing EEL vicinity curvature processing (for example, evaluating the curvature in the vicinity of the pre - EEL and performing processing on it (as shown in, for example, FIG. 2B) to obtain or find the EEL vicinity curvature (as shown in, for example, FIG. 2C)) (see, for example, step S208 in FIG. 2A), proceed to steps S209 - S211 described below, or if it is “No” in S207, (xi) Proceed to steps S209 - S211 by interpolating from the detection results in the vicinity (see, for example, step S209 in FIG. 2A); (xii) Interpolate between the detected points and perform smoothing (see, for example, step S210 in FIG. 2A);and, (xiii) a step of checking whether the smoothed EEL is continuous in Cartesian coordinates except at the positions of the side branches or plaques (see, for example, step S211 in FIG. 2A). As shown in FIGS. 2B-2C, in one or more embodiments where it is determined that a plaque is present or located, the method may include a step of finding the EEL within the pre-neighborhood and / or neighborhood curvature frame and / or plaque frame, and a line can be created from the apex of the detected EEL (for example, the neighborhood EEL curvature line 301 as shown in FIG. 2B). The intermediate connection points correspond to non-invisible plaque EEL points. For example, the upper circles 304 in FIGS. 2B and 2C may correspond to the plaque positions. In FIG. 2B, when the plaque 304 is present, the wall becomes thick, and the EEL may not be visible. In contrast, in FIG. 2B, in regions where the wall is not so thick or thin, the EEL may be visible. Similarly, the non-invisible plaque EEL points of the remaining frames can be detected. In one or more embodiments, the interpolation points 300 (such as those shown in FIG. 2B) can be used to create the neighborhood curvature line 301. By this step, the method or algorithm can appropriately expand or find the EEL line 303 in one or more images (for example, from FIG. 2B where the EEL 303 is not fully displayed or described to FIG. 2C where the EEL 303 is fully displayed). In this way, an accurate image or frame can be obtained, and the lumen 302 and the EEL 303 can be distinguished. In one or more embodiments, the method can use the obtained EEL neighborhood curvature line frame (for example, any combination of the EEL pre-neighborhood curvature frame, the EEL post neighborhood curvature frame, the EEL neighborhood curvature frame, any combination of the EEL pre-neighborhood curvature frame and the EEL post neighborhood curvature frame, any combination of the EEL pre-neighborhood curvature frame and other types of EEL neighborhood curvature frames, etc.) to determine the EEL neighborhood curvature line.;

[0031] Angiography shows an overall image of a patient's coronary artery tree. Intravascular imaging modalities such as intravascular ultrasound (IVUS), optical coherence tomography (OCT), multimodality OCT (MM-OCT), etc. can provide information on the vessel wall by capturing a cross-sectional view of the target coronary artery. In one or more embodiments, a method for selecting an appropriate method for registering one or more intravascular images with one or more angiography images is described based on how at least one angiography image was obtained. Registration of intravascular images and angiography images can help physicians / personnel connect information from different imaging modalities and understand one or more conditions of the patient.

[0032] In one or more embodiments of step S203, the number of A-lines to be analyzed may be set by the user, or may be a predetermined number (or may be selected from a set of predetermined numbers). In at least one embodiment, the number of A-lines to be analyzed can be 10 A-lines, but the number of A-lines to be analyzed can depend on the total number of A-lines and the available computing power. In one or more embodiments, the number of A-lines to be analyzed may be set as a default value by software or by a device or system that utilizes an algorithm or process, and / or, preferably, the user may determine or set the number.

[0033] Additionally or alternatively, for step S203, in one or more embodiments, the number of pixels to be grouped when taking the moving average can be determined or an instruction can be received. In one or more embodiments, 20 pixels can be set to a value corresponding to 0.1 mm or ~0.1 mm. In one or more embodiments, since the OCT penetration depth is about 2 - 3 mm and one or more features of the detection target may be located within 1 - 2 mm, a resolution of 0.1 mm or ~0.1 mm can be used or may be appropriate. In one or more embodiments, the resolution may be set by the user according to the needs of the user and / or the procedure. If the user desires, the user can determine the number of pixels to be grouped when taking the moving average. Additionally or alternatively, in one or more embodiments, as the amount of data acquired by the device or system increases, the device or system may be able to independently learn or determine what the optimal number is.

[0034] In one or more embodiments, such as one or more embodiments of step S205, other features (e.g., other than a sudden intensity change from low to high intensity) can be used to detect the EEL. For example, in one or more embodiments, the texture information of the media or the plaque type can be used. Calcified plaques are relatively easy to identify, and their features can be emphasized by applying signal intensity calibration.

[0035] In one or more embodiments, since the EEL may be located outside the tunica media and plaque, (even if the EEL cannot be detected at 360 degrees in Cartesian coordinates) the EEL can be detected relatively accurately when the user, device, or system can identify the characteristics of the tunica media and plaque. One or more embodiments can detect the EEL at 360 degrees in Cartesian coordinates. Preferably, the EEL is located outside the tunica media and plaque. In one or more embodiments, EEL detection can be used in combination with the evaluation of tissue type characteristics, including the evaluation of plaque type characteristics. If different plaque types and tunica media can be identified by other algorithms or processes (such as deep learning, etc.), EEL detection can be performed more easily.

[0036] In one or more embodiments, the visibility of the structure can be improved by using signal correction of OCT (or other modalities). In one or more embodiments, by using smoothing (moving average) of the A-line signal, rapid changes in signal intensity caused by false features can be avoided. In one or more embodiments, by using polar coordinates and / or Cartesian coordinates, the detection curve can be smoothed and / or meaningless detections can be avoided. In one or more embodiments, by utilizing the lumen detection result, regions where the EEL may not be detected can be identified.

[0037] In one or more embodiments, it is preferable to set an angle threshold. In one or more embodiments, 360 degrees is set as the angle. In one or more embodiments where the EEL may not be detected at 360 degrees, as one of the thresholds, an angle of 180 degrees or more at which the EEL can be visualized can be used. In one or more embodiments where an angle of 180 degrees or more at which the EEL can be visualized is used as one of the thresholds for a specific clinical trial, the angle threshold can preferably be set to about 180 degrees or can be set to 180 degrees. In one or more embodiments, preferably, the angle is 180 degrees or less (for example, in a test or procedure where one of the thresholds used is an angle of 180 degrees or more at which the EEL can be visualized).

[0038] Preferably, in one or more embodiments, the EEL position may not change dramatically from one frame to the next, or may not change dramatically. In one or more embodiments where the EEL position does not change dramatically from one frame to the next, if the EEL is not detected (or cannot be detected) within the currently processed frame, the software, or the device or system using the algorithm or process, can check neighboring frames to determine whether the EEL or a part of the EEL can be detected within that frame. If the EEL can be detected within that frame, the original frame and the frame in which the EEL can be detected can be registered, for example, via the lumen edge, to determine the EEL position of the original frame. In one or more embodiments where the angle at which the EEL is not detected is small enough (e.g., the angle is less than 15 degrees, the angle is less than 10 degrees, the angle is less than 5 degrees, etc.), the software or the process or algorithm may be interpolated in polar coordinates or Cartesian coordinates.

[0039] In one or more embodiments, the use of Cartesian coordinates may be helpful for EEL detection. Preferably, the EEL may be a continuous path within the blood vessel in Cartesian coordinates. In one or more embodiments where the detected EEL contour is not continuous, the EEL contour may be modified to be continuous. In one or more embodiments where the detected EEL contour is not continuous, the EEL contour may be modified to be continuous except for the presence of branches or plaques. If branches or plaques are present, the EEL can be estimated by the EEL or a part of the EEL within the frame before the plaque appears.

[0040] In one or more embodiments, since stents cannot usually be placed where side branches or plaques are present, the use of Cartesian coordinates serves to (1) ensure the continuity of the EEL and (2) identify cases inappropriate for EEL detection. For the second scenario of identifying cases inappropriate for EEL detection, software, or a device or system using an algorithm or process, can still present the results to the user and ask the user whether the user wants to use the frame as a reference frame. In one or more embodiments, the lumen and / or side branches may be detected within the range detectable by OCT or other imaging modalities.

[0041] In one or more embodiments, the algorithm or process can determine how deep the EEL can be located and / or how deep the EEL can be located. Since a reference frame (e.g., a reference frame for PCI procedures) can be selected as a frame in which the blood vessel looks normal, the three layers of the blood vessel (e.g., the intima, media, and adventitia) can be clearly visualized. In situations where the intima, media, and adventitia layers are used, the EEL (the boundary between the media and the adventitia) can be located within 1 to 2 mm from the lumen surface.

[0042] In one or more embodiments, EEL detection can assist in PCI procedures, particularly in navigating stent sizing and stent placement positions. Therefore, if the EEL cannot be detected in a relatively shallow region from the lumen edge, the current frame may not need to be used as the reference frame, except when the user selects or sets that the current frame can be used as the reference frame by using the lumen edge to determine the stent size (diameter).

[0043] FIG. 3 shows an embodiment of a catheter 120 including a sheath 121, a coil 122, a protector 123, and an optical probe 124. As schematically shown in FIGS. 1A-1B, catheter 120 is preferably connected to PIU 110 to spin coil 122 by pullback (e.g., at least one embodiment of PIU 110 functions to spin coil 122 by pullback). Coil 122 delivers torque from its proximal end to its distal end (e.g., via or by the rotation motor of PIU 110). In one or more embodiments, coil 122 is fixed to / with optical probe 124 such that the distal end of optical probe 124 also spins to view a full 360-degree view of the living organ, sample, or substance being evaluated (such as a hollow organ like a blood vessel or heart). For example, to provide access to internal organs that are difficult to access (such as intravascular imaging, the digestive tract, other narrow areas, etc.), within the sample arm of the OCT interferometer (such as sample arm 103 shown in FIG. 1A), there may be a fiber optic catheter and an endoscope. When a beam of light passing through optical probe 124 inside catheter 120 or the endoscope rotates across the surface of interest, cross-sectional images of one or more samples are obtained. To acquire three-dimensional data, optical probe 124 is simultaneously translated longitudinally during rotational spin to result in a helical scan pattern. This translation can be done by pulling back the tip of probe 124 towards the proximal end, and is thus called pullback.

[0044] In one or more embodiments, one or more components (one or more components of the probe (e.g., catheter 120 (see, e.g., FIGS. 1A-1B), needle, capsule, patient interface unit (e.g., patient interface unit 110), etc.)) are connected to one or more other components (optical components, light source (e.g., light source 101), deflection unit (e.g., a deflection or deflected unit that functions to deflect light from the light source to the optical interference system and then send the light received from the optical interference system to at least one detector; a deflection or deflected unit including at least one of one or more interferometers, circulators, beam splitters, isolators, couplers, fused fiber couplers, partially cut mirrors with holes, partially cut mirrors with taps, etc.), sample arm 102, connection component and / or a motor that functions to supply power to patient user interface 110, etc.). To this end, patient user interface 110 may include (or may comprise) a connection component (or interface module) (such as a rotary joint). For example, when the connection member or interface module is a rotary joint, the rotary joint preferably functions as described below. In one or more other embodiments, the rotary joint may be at least one of a contact type rotary joint, a lensless rotary joint, a lens-based rotary joint, or other rotary joints known to those skilled in the art.

[0045] In at least one embodiment, PIU 110 may include an optical fiber rotary joint (FORJ), a rotary motor, and a translational electric stage (e.g., part of PIU 110), and a catheter connector (e.g., part of PIU 110). With the FORJ, an optical signal can be transmitted without interruption while rotating the fiber along the fiber axis. The FORJ may have a free space optical beam combiner including a rotor and a stator.

[0046] The description of elements with the same numbers that exist in system 100’ and have been previously described (such as for system 100) will not be repeated, and the entirety of which is hereby incorporated by reference.

[0047] In at least one embodiment, the consoles 1200, 1200' control the movement of a motor and a translational electric stage (hereinafter referred to as "motor" or "motor and stage"), acquire intensity data from at least one detector 107, and display a scanned image (e.g., on a monitor or screen such as a display, or on the screen or monitor 1209 shown in console 1200 of FIG. 17 and / or console 1200' of FIG. 18 described below). In one or more embodiments, the consoles 1200, 1200' function to change the speed of the motor and / or stop the motor. The motor may be a stepper or DC servo motor to control the speed to improve the positional accuracy.

[0048] In one or more embodiments, the console or computer 1200, 1200' functions to control the system 100 (and other systems such as the system 100', system 100", system 100''', etc. described hereinafter), the catheter 120, and / or one or more other aforementioned components of the system 100. In at least one embodiment, the console or computer 1200, 1200' functions to acquire intensity data from at least one detector 107 of the OCT system / device / apparatus and display an image (e.g., on a monitor or screen such as a display, or on the screen or monitor 1209 shown in console 1200 of FIG. 17 and / or console 1200' of FIG. 18 described hereinafter). The output of one or more components of the system 100 (and other systems such as the system 100', system 100", system 100''', etc. described hereinafter) is acquired by at least one detector 107 of the OCT system / device / apparatus (e.g., a photodiode, a photomultiplier tube (PMT), a line scan camera, or a multi-array camera, etc.). The electrical analog signal obtained from the output of the system 100 (and / or other systems such as the system 100', system 100", system 100''', etc. described hereinafter) or one or more of its components is converted into a digital signal and analyzed by a computer such as computers 1200, 1200' (e.g., shown in FIGS. 1A - 1B and FIGS. 14 - 17). In one or more embodiments, the light source 101 may be a radiation source or a broadband light source that emits radiation at a broadband wavelength. In one or more embodiments, an electrical analog signal can be converted into an optical spectrum using a Fourier analyzer including software and electronic equipment. In some embodiments, at least one detector 107 includes three detectors configured to detect light in three different bands.

[0049] This specification discloses one or more devices, optical systems, methods, and storage media for obtaining a direct image (e.g., black and white, color, etc.) of a subject such as tissue using the following: imaging functions, features, techniques, or methods; registration functions, features, techniques, or methods; and / or selection of an appropriate registration method. And / or, this specification discloses one or more devices, optical systems, methods, and storage media for performing diagnosis, perfusion, aspiration, dilation (e.g., balloon), culture, tissue sampling, biopsy execution, drug implant, and / or other types of diagnosis and / or treatment using imaging features, functions, or techniques. According to at least one aspect of the present disclosure, the one or more devices, optical systems, methods, and storage media described herein use imaging functions, features, techniques, or methods, registration functions, features, techniques, or methods, and / or selection of an appropriate registration method.

[0050] In one or more embodiments, when planning a procedure and confirming the success of a percutaneous coronary intervention (PCI) procedure in a hospital's catheterization laboratory, multiple imaging modalities may be used. FIG. 4 shows at least one example of the overall workflow in a catheterization laboratory. In one or more embodiments, the method may include the following steps: (i) preparing the patient (e.g., the aforementioned patient 106) (see, e.g., step S1000 in FIG. 4); (ii) obtaining at least one angiographic image (see, e.g., step S1001 in FIG. 4); (iii) analyzing the angiographic image (see, e.g., step S1002 in FIG. 4); (iv) determining whether an intravascular image is needed (see, e.g., step S1003 in FIG. 4), and if "No", proceeding to step S1008 described below, or if "Yes", proceeding to steps S1004 - S1008; (v) if an intravascular image is needed in step S1003, obtaining the intravascular image (see, e.g., step S1004 in FIG. 4); (vi) obtaining an angiographic image (see, e.g., step S1005 in FIG. 4); (vii) performing co-registration (see, e.g., step S1006 in FIG. 4; see also FIG. 6 described below); (viii) analyzing the intravascular shadow image (see, e.g., step S1007 in FIG. 4); (ix) determining whether PCI is needed (see, e.g., step S1008 in FIG. 4), and if "Yes", then (x) performing PCI (see, e.g., step S1009 in FIG. 4), then returning to step S1001, or if "No", then (xii) saving all the images (see, e.g., step S1010 in FIG. 4), and then closing the case (see, e.g., step S1011 in FIG. 4). Angiography shows an overall view of the patient's coronary artery tree. Intravascular imaging modalities such as intravascular ultrasound (IVUS), optical coherence tomography (OCT), multi-modal OCT (MM-OCT), etc. can provide information on the vessel wall by capturing a cross-sectional view of the target coronary artery.In one or more embodiments, a method for selecting an appropriate method for registering one or more intravascular images with one or more angiographic images based on how at least one angiographic image was obtained is described. Registration of intravascular images with angiographic images can assist a physician / practitioner in piecing together information from different imaging modalities and understanding one or more conditions of a patient.

[0051] As shown in the flowchart of FIG. 2A, lumen edge detection may be performed after calibration of the OCT signal intensity, before calibration, or both (before and after calibration). One or more embodiments may include, as described above, calibrating the signal intensity of OCT (or other imaging modality) to remove depth effects. One or more embodiments may include determining whether plaque is present and / or confirming whether the smoothed EEL is continuous in Cartesian coordinates (excluding the positions of branches or plaque). In one or more embodiments, the positions of branches or plaque may be considered to determine whether the EEL is continuous. In one or more embodiments, a determination is made to detect whether the lumen is located within a part of the catheter or within a predetermined distance from the catheter center, and if the answer is "No", EEL detection is not performed. In one or more embodiments, as described above, a determination is made as to whether the EEL is located within a predetermined distance from the lumen, and if the answer is "No", a determination is made to check whether plaque is present (if the answer to the latter determination is "No", interpolation is performed from nearby detection results).

[0052] One or more embodiments of the devices, systems, methods, or algorithms described herein can analyze intravascular images. For example, in at least one embodiment shown in FIG. 5, intravascular images can be analyzed using one or more methods, which may include the following steps: (i) detecting the lumen edge (see, e.g., step S500 in FIG. 5); (ii) determining a reference frame (see, e.g., step S501 in FIG. 5); (iii) determining whether an EEL is recognized in the reference frame (see, e.g., step S502 in FIG. 5), and if it is “Yes” in step S502, proceeding to steps S503, S504, and S508 shown in FIG. 5, or if it is “No” in step S502, proceeding to step S505 shown in FIG. 5; (iv) when an EEL is recognized within the reference frame (i.e., “Yes” in step S502 of FIG. 5), detecting the EEL (see, e.g., step S503 in FIG. 5), measuring the diameter of the EEL (see, e.g., step S504 in FIG. 5), and determining the diameter and length of the stent (see, e.g., step S508 in FIG. 5); (v) when an EEL is not recognized within the reference frame (i.e., “No” in step S502 of FIG. 5), determining whether an EEL is recognized in nearby frames (e.g., frames before and after the reference frame, several frames away from the reference frame, frames near the reference frame, etc.) (see, e.g., step S505 in FIG. 5), and if it is “No” in step S505, proceeding to step S507 in FIG. 5, or if it is “Yes” in step S505, proceeding to step S506 in FIG. 5; (vi) in step S506, determining whether to change the reference frame to a nearby frame (e.g., frames before and after the reference frame, several frames away from the reference frame, frames near the reference frame, etc.) (see, e.g., step S506 in FIG. 5), and if it is “Yes” in step S506 of FIG. 5, proceeding to steps S503, S504, and S508, or if it is “No” in step S506 of FIG. 5, proceeding to step S507 in FIG. 5; (vii) in step S507, measuring the diameter of the lumen (see, e.g., step S507 in FIG. 5); and (viii) determining the diameter and length of the stent (see, e.g., step S508 in FIG. 5).In one or more embodiments, a good predictor of subsequent cardiac events or acute cardiac events, or a good predictor for other analysis (manual or automatic), can be the wall area (e.g., the area between the EEL and the lumen, the wall area selected by the user, a predetermined wall area, an automatically selected wall area, etc.).

[0053] In one or more embodiments, user markup can be used to assist or enhance the learning process. For example, the user can change the EEL position automatically detected by the software, device, system, method, or algorithm described herein. In at least one embodiment therefor, the graphical user interface (GUI) may be provided with buttons and / or guidance for navigating the user. This may be similar to the lumen detection and its modification process or may be added to the lumen detection and its modification process. When the user changes the EEL position, the system, device, method, and / or algorithm can identify the pattern of failed cases and learn the pattern for subsequent detections.

[0054] In one or more embodiments, the EEL can be automatically detected to assist the user in selecting the size and / or shape of the stent (e.g., stent diameter, stent length, stent circumference, stent volume, stent shape, etc.). Along with the automatic detection of the EEL, the devices, systems, methods, and / or algorithms of the present disclosure can be used to warn the user whether the selected reference frame is appropriate.

[0055] One or more embodiments of the present disclosure can correct for signal strength degradation due to depth and analyze the corrected strength, so that one or more features located at positions relatively deeper than the lumen surface can be emphasized for detection. As described above, one or more embodiments can utilize one or both of polar coordinate information and Cartesian coordinate information to create a more realistic contour. In one or more embodiments, the contour of the EEL is preferably continuous. When there are plaques and the position of the EEL is too far from the lumen edge to be detected by OCT or other imaging modalities, it may be observed that the EEL contour is disrupted. In use in PCI procedures, EEL detection can be used to determine whether the selected reference frame is appropriate. If the EEL cannot be detected, or can be detected at an angle smaller than the angle at which it should be detected, or can be detected at an angle smaller than the angle at which it is preferably detected, the device, system, method, and / or algorithm can warn the user about the possibility that the selection of one or more reference frames is inappropriate. In one or more embodiments, software can be used to warn the user about the possibility that the selection of one or more reference frames is inappropriate. One or more embodiments can utilize the lumen detection result to determine whether to detect the EEL. For example, in at least one embodiment, if the lumen is not detected within a distance of 3 mm or other predetermined or set distance (such as 1 mm, 2 mm, 1 - 3 mm, any distance set by the user, a distance set by the imaged anatomical structure, a distance set or limited by the anatomical structure, etc.) from the catheter center or from other predetermined or set positions within or around the catheter, the EEL may not be detected by the device, system, method, or algorithm, or a warning or message indicating that the EEL is not detected or that the EEL has not been detected may be issued to the user. In one or more embodiments, the EEL is preferably located further from the catheter compared to the lumen position.

[0056] FIG. 6 depicts an embodiment of the overall workflow of coregistration (e.g., an example of one or more steps of step S1006 of the "coregister" sub-process box shown in FIG. 4). In one or more embodiments, the method may include the step of acquiring an intravascular image (see, e.g., step S9001 in FIG. 6), and may also include the step of acquiring an angiographic image simultaneously with, before, or after the intravascular image (see, e.g., step S9002 in FIG. 6). Hereinafter, the detailed workflow of the first three steps of coregistration (import of the angiographic image (see, e.g., step S9003 in FIG. 6), detection of the marker position (see, e.g., step S9004 in FIG. 6), and creation of the coregistration path (see, e.g., step S9005 in FIG. 6)) will be described. Since the imaging catheter path can be used as the coregistration path, the accuracy of coregistration can depend on the generation accuracy of the imaging catheter path. After the angiographic image is imported into the system (see, e.g., step S9003 in FIG. 6), the system checks whether cardiac phase information is associated with the imported angiographic image. If so, the system checks whether the imported angiographic image contains a sufficient number of frames (e.g., a predetermined number or a number exceeding a threshold, a number available over a predetermined period, etc.) in which no contrast agent is present within a predetermined region (e.g., the target vessel (i.e., the defective region where the intravascular image is acquired)). One or more criteria for the number of frames may be determined in relation to the cardiac cycle. The present system or device determines that the number of frames is sufficient when angiographic frames without contrast agent are available over at least one cardiac cycle (or in such a case). This confirmation process may be assisted by the user as needed. Based on such two pieces of information (i.e., the availability of cardiac phase information and the availability of the number of angiographic frames without contrast agent), the present system can automatically select any of the following coregistration path generation processes.

[0057] In one or more embodiments, there may be cases where the angiographic image has cardiac phase information (e.g., the angiographic data is synchronized with the ECG signal), and the number of angiographic frames in which no contrast agent is present within a predetermined region (e.g., the target vessel) is sufficient. In this case, the system can directly detect the co-registration path (e.g., the imaging catheter path). The detection accuracy can be improved by the effect of cardiac motion involving the use of cardiac phase information and by confirming the position of the detected imaging catheter path using the detected marker position. In one or more embodiments, there may be cases where the angiographic image does not have cardiac phase information and / or the number of angiographic frames in which no contrast agent is present within the target vessel is not sufficient. In this case, it is difficult to directly detect the co-registration path (e.g., the imaging catheter path) from each angiographic frame. Therefore, the system accurately generates the co-registration path or the imaging catheter path by using the detected marker position. In one or more embodiments, the co-registration method may include the step of finding on the angiographic image the position where each intravascular image was acquired (e.g., see step S9006 in FIG. 6), and may also include the step of displaying information (such as the position) on the GUI (e.g., see step S9007 in FIG. 6).

[0058] In one or more embodiments, the acquired and / or imported angiographic frames are preferably divided into two groups as follows by selecting each frame for evaluation: (1) frames in which there is no contrast agent in the target vessel (frames captured before the contrast agent reaches the intravascular imaging region), and (2) frames in which there is contrast agent in the target vessel. Next, the imaging catheter path can be detected from each angiographic frame in group (1), and from each angiographic frame in group (2), the vessel contour and the radiopaque marker on the imaging catheter can be detected. As an example, a guide wire through which the imaging catheter passes when delivering it to the target vessel, or the drive cable of the imaging catheter, can be used as the imaging catheter path. The imaging catheter path and the vessel contour can be detected by applying edge detection filters such as Sobel, Canny, Prewitt, Roberts, Kernel, Laplacian of Gaussian, or others, and / or any combination thereof. The radiopaque marker can be detected, for example, by a Viterbi-based method and / or a machine learning or deep learning-based method. The detected information is stored in each angiographic frame together with the cardiac phase information. The cardiac phase information can be obtained based on the ECG signal. One way to evaluate the cardiac phase information is to calculate the percentage of the cardiac cycle length.After the process of detecting and storing the entire angiographic frame has been performed (for example, the step of selecting the first frame, the step of determining whether a contrast agent is present within the target (e.g., the target blood vessel), the step of detecting the intravascular imaging catheter path when the contrast agent is not present, the step of storing the detected catheter path and its cardiac phase information together with the frame when the contrast agent is not present, the step of detecting the blood vessel contour and markers of the target region when the contrast agent is present, the step of storing the detected blood vessel contour, markers and their cardiac phase information together with the frame when the contrast agent is present, the step of checking whether the evaluated frame is the last frame, the step of transitioning to the next frame when the evaluated frame is not the last frame, etc.), the system or device can select one angiographic frame from group (2) and find an angiographic frame with the same cardiac phase from group (1). Next, the imaging catheter path detected within the angiographic frame selected from group (1) can be overlaid on the angiographic frame selected from group (2).Using this overlaid image, the system or device can determine or evaluate whether the detected marker is located or disposed on the detected imaging catheter path or within a specific distance from the imaging catheter path (e.g., refer to one or more of the following: the step of determining whether the detected catheter path is located within the detected vascular contour; the step of determining whether the detected marker position is on the catheter path when the detected catheter path is located within the detected vascular contour; the step of determining whether the detected marker position is close enough to the catheter path when the detected marker position is not on the catheter path; the step of determining whether there is another frame without contrast agent at the same cardiac phase, and if so, returning to the step of overlaying the selected frames, and if not, proceeding to the step of determining whether the frame with contrast agent is the last frame; or, if the detected marker position is close enough to the catheter path, proceeding to the step of finding the closest point on the catheter path and updating the marker position, and then proceeding to the step of saving the information on the catheter path position together with the selected angiographic frame with contrast agent and the detected / updated marker position; or, in the step of determining whether the detected marker is on the catheter path, if the detected marker position is on the catheter path, proceeding directly to the saving step). The distance threshold may be predetermined by the system or determined by the user. If the overlaid image meets both criteria, the information on the detected catheter path position is saved together with the angiographic frame selected from group (2). If the detected marker is not located or disposed on the detected imaging catheter path but is located or disposed within a specific distance, the position closest to the marker position detected on the imaging catheter path is searched for, and that position, by updating the detected marker position, is saved together with the angiographic frame selected from group (2).In addition, the system can also confirm whether the detected imaging catheter path is located between or within the detected vascular contours and confirm that the detected imaging catheter path can be a representative line in the longitudinal direction of the blood vessel. If the overlaid images do not meet any of the criteria, the system searches for another angiographic frame in group (1) and follows the same process. If there is no other angiographic frame of the same cardiac phase in group (1), the system stops the process for the angiographic frame selected from group (2). Next, the system selects another frame from group (2) and repeats the entire series of processes until the last frame of group (2) is processed. In fact, at least this embodiment and other embodiments regarding the execution of co-registration can be used as described in PCT / US2020 / 015403 filed on January 28, 2020 (the entire disclosure of which is incorporated herein by reference) and U.S. Patent Application No. 62 / 798,885 filed on January 30, 2019 (the entire disclosure of which is incorporated herein by reference).

[0059] According to at least one aspect of the present disclosure, as described above, one or more additional methods for detecting lumens, stents, and / or artifacts in OCT images or images of other imaging modalities are provided herein or can be used in combination with one or more of the features or aspects of the present disclosure, and are also discussed in U.S. Patent Application No. 16 / 414,222 (filed on May 16, 2019, published as U.S. Patent Application Publication No. 2019 / 0374109 on December 12, 2019, the entire disclosure of which is incorporated herein by reference).

[0060] Computers such as consoles or computers 1200, 1200', etc. can perform any of the aforementioned steps (e.g., those in FIGS. 2A - 2C, FIGS. 4, 5, 6, etc.) for the systems (system 100, system 100', system 100", system 100''', etc.) being manufactured or used.

[0061] Figures 7A to 7B show at least one example of the abrupt change in signal intensity and the detection of the EEL position. A device, system, method, or algorithm can also detect layers such as the intima, media, adventitia, etc. based on various changes in signal intensity as shown in FIGS. 7A and 7B (see FIG. 7A for the detection of the adventitia and media, and FIG. 7B for the detection of the intima, media, and adventitia, for example).

[0062] Figures 8A and 8B show at least one example of an original frame and a corrected frame, respectively. FIGS. 8A and 8B show frame 334 of the experiment performed.

[0063] FIG. 9 shows at least one embodiment using ground truth data (201 in FIG. 9), data from the original image in FIG. 8A (203 in FIG. 9), data from the corrected image in FIG. 8B (202 in FIG. 9), and the corresponding RMSE values, maximum values, and minimum values. As shown in FIG. 9, for the corrected data, the RMSE value is 0.0197, the maximum value is 0.0446 mm, and the minimum value is 5.64×10 -5 mm. For the original data, the RMSE value is 0.104 mm, the maximum value is 0.191 mm, and the minimum value is 8.73×10 -4 mm.

[0064] Figures 10A and 10B show at least another embodiment of an original image frame and a corrected image frame, respectively. FIGS. 10A and 10B show frame 560 of the experiment performed.

[0065] FIG. 11 shows at least one embodiment using ground truth data (204 in FIG. 11), data from the original image in FIG. 10A (206 in FIG. 11), data from the corrected image in FIG. 10B (205 in FIG. 11), and the corresponding RMSE values, maximum values, and minimum values. As shown in FIG. 11, for the corrected data, the RMSE value is 0.120 mm, the maximum value is 0.246 mm, and the minimum value is 1.37×10 -7 mm. For the original data, the RMSE value is 0.235 mm, the maximum value is 0.609 mm, and the minimum value is 5.48×10-4 It was in mm. The detection results of the outer membrane 91, the middle membrane 92, and the inner membrane 93 are shown on the right side of FIG. 11.

[0066] FIGS. 12A and 12B respectively show at least further embodiments of the original image frame and the corrected image frame. FIGS. 12A and 12B show frame 613 of the experiment performed.

[0067] FIG. 13 shows at least one embodiment using the ground truth data (207 in FIG. 13), the data from the original image in FIG. 12A (209 in FIG. 13), the data from the corrected image in FIG. 12B (208 in FIG. 13), and the corresponding RMSE values, maximum values, and minimum values. As shown in FIG. 13, for the corrected data, the RMSE value is 0.104 mm, the maximum value is 0.201 mm, and the minimum value is 1.14×10 -3 mm. For the original data, the RMSE value is 0.272 mm, the maximum value is 0.612 mm, and the minimum value is 1.39×10 -4 mm.

[0068] According to one or more further aspects of the present disclosure, a benchtop system can be utilized together with the EEL detection techniques disclosed herein. FIG. 14 shows an example of a system that can utilize EEL detection techniques for benchtop use, such as for ophthalmic applications. Light from the light source 101 is delivered and split by the deflector 108 to the reference arm 102 and the sample arm 103. In the reference arm 102, the reference beam passes through the length adjuster 904 (optional in one or more embodiments), is reflected from a reference mirror (such as the reference mirror or reference reflection 105 shown in FIG. 1A), and in the sample arm 103, the sample beam is reflected or scattered from the sample, target, or object 106 (e.g., via the PIU 110 and the catheter 120). In one embodiment, both beams are combined at the deflector 108 to generate interference fringes. In one or more embodiments, the beams proceed to the combiner 903, and the combiner 903 combines the beams via the circulator 901 and the deflector 108. The combined beam is preferably sent to one or more detectors, such as one or more detectors 107. The output of the beam splitter (see, e.g., the beam splitter 104 in FIG. 1A), the deflector 108, and / or the interferometer is continuously acquired by one or more detectors, such as one or more detectors 107. The electrical analog signal is converted to a digital signal and analyzed by a computer, such as the computer 1200 (see FIGS. 1A - 1B; also shown in FIGS. 14 - 17 described below) or the computer 1200' (see, e.g., FIG. 18 described below).

[0069] In one or more embodiments, the sample arm 103 may include a phase shifter unit 103 in a benchtop system as shown in the system 100” of FIG. 15. The sample 106 can be placed at the location of the mirror 105 used in combination with the phase shifter unit 130 (e.g., as shown in FIG. 1A). The light from the light source 101 is delivered and split by the splitter 104 to the reference arm 102 and the sample arm 103. In the reference arm 102, the reference beam passes through the length adjuster 904, is reflected from a reference mirror (such as the reference mirror 105 shown in FIGS. 14 - 16), and in the sample arm 103, the sample beam passes through a phase shifter unit (such as the phase shifter unit 130, etc.) and is reflected or scattered from the sample, target, and / or object 106. In one embodiment, both beams are combined at the splitter 104 to generate interference fringes. In one or more embodiments, the beams proceed to the combiner 903, and the combiner 903 combines both beams via the circulator 901 and the splitter 104, and the combined beam is sent to one or more detectors (such as one or more detectors 107, etc.). The output of the beam splitter 104 and / or the interferometer is continuously acquired by one or more detectors such as one or more detectors 107. The electrical analog signal is converted into a digital signal and analyzed by a computer.

[0070] There are numerous digital and analog methods for calculating EEL detection, rotation, intensity, or other measured values described herein, and / or for controlling and / or manufacturing MMOCT devices / apparatus, systems, and / or storage media. In at least one embodiment, a computer such as a console or computer 1200, 1200’, etc. may be dedicated for controlling and / or using the OCT devices, systems, methods, and / or storage media described herein and used in combination therewith.

[0071] According to one or more further aspects of the present disclosure, one or more other systems can be utilized together with the OCT techniques for detecting lumen edges and artifacts disclosed herein. FIG. 16 shows an example of a system 100''' that can utilize EEL detection techniques for ophthalmic applications and the like. Light from a light source 101 is separated by a deflector 108 (e.g., a beam splitter or other deflector or deflected part described herein) located inside an OCT imaging engine 150 and sent to a reference arm 102 and a sample arm 103. The OCT imaging engine 150 may include, in one or more embodiments, an OCT interferometer 151 (which may house or include the deflector 108) and a wavelength-sweeping engine 152. The reference beam passes through a length adjuster 904 (which can function to vary the distance of a reference mirror (such as a reference mirror or reference reflection 105; also shown in FIG. 1A)), is reflected from the reference reflection 105 of the reference arm 102, while the sample beam is reflected or scattered from a sample, target, or object 106 in the sample arm 103. In one embodiment, both beams are combined at the deflector 108 to generate interference fringes. In one or more embodiments, the combined beam is sent to one or more detectors. The output of the interferometer 151 is continuously acquired by one or more detectors such as one or more detectors 107. The electrical analog signal is converted to a digital signal and analyzed by a computer (such as a computer 1200 (see, e.g., FIGS. 1A - 1B; also shown in FIGS. 14 - 17 described below), a computer 1200' (see, e.g., FIG. 18 described below), etc.). In one or more embodiments, the sample arm 103 includes a PIU 110 and a catheter 120 in such a form that the sample beam is reflected or scattered from the sample, target, or object 106 described herein. In one or more embodiments, the PIU 110 may include one or more motors to control the pullback operation of the catheter 120 (or one or more of its components) and / or to control the rotation or spin of the catheter 120 (or one or more of its components).For example, the PIU 110 may include a pullback motor (PM) and a spin motor (SM), and / or may include a motion control unit 112 that functions to perform a pullback function and / or a rotation function using the pullback motor PM and / or the spin motor SM. As described herein, the PIU 110 may include a rotary joint (e.g., a rotary joint RJ as shown in FIG. 16). The rotary joint RJ may be connected to the spin motor SM such that the catheter 120 can acquire one or more views or images of the sample 106. Using a computer 1200 (or computer 1200'), one or more of the pullback motor PM, the spin motor SM, and / or the motion control unit 112 can be controlled. The OCT system may include one or more of an OCT engine 150, a computer (e.g., computer 1200, computer 1200', etc.), the PIU 110, the catheter 120, a monitor, etc. One or more embodiments of the OCT system can interact with one or more external systems, such as an angio system, an external display, one or more hospital networks, an external storage medium, a power source, a bedside controller (e.g., connected to the OCT system using Bluetooth® technology or other methods known in wireless communication).

[0072] Unless otherwise specified in this specification, like numbers indicate like elements. For example, there are variations or differences between systems such as system 100, system 100', system 100", system 100''', etc. (e.g., differences in the position of the reference reflection 105 (and / or reference arm 102) according to the OCT system or method used), but one or more of their features such as the light source 101, the deflector 108, and other components (e.g., console 1200, console 1200', etc.) may be the same as or similar to each other. It will be apparent to those skilled in the art that the light source 101, at least one detector 107, and / or one or more other elements of system 100 may function in the same or similar manner as the similarly numbered elements of one or more other systems (such as system 100, system 100', system 100", system 100''', etc.) described in this specification. It will be apparent to those skilled in the art that alternative embodiments of system 100, system 100', system 100", system 100''', and / or one or more of the similarly numbered elements of such a system include other variations as described in this specification, but may function in the same or similar manner as the similarly numbered elements of any of the other systems (or their components) described in this specification. In fact, there are specific differences between system 100, system 100', system 100" and system 100''' described in this specification, but there are similarities between the systems described in this specification. Similarly, a console or computer 1200, such as console or computer 1200, 1200', etc., can be used in one or more systems (such as system 100, system 100', system 100", system 100''', etc.), but one or more other consoles or computers (such as console or computer 1200', etc.) can be added or used as an alternative.

[0073] Methods for calculating power and / or detecting EELs abound, both digital and analog. In at least one embodiment, a computer such as console or computer 1200, 1200', etc. may be dedicated to controlling and monitoring OCT equipment, systems, methods, and / or storage media described herein.

[0074] The electrical signals used for imaging may be sent via a cable or wire (such as cable or wire 113 (see FIG. 17)), to one or more processors (computer 1200 (see, for example, FIGS. 1A-1B and FIGS. 14-17), computer 1200' (see, for example, FIG. 18) described below, etc.).

[0075] FIG. 17 provides various components of a computer system 1200 (see, e.g., the console or computer 1200 shown in FIGS. 1A-1B and FIGS. 14-17). The computer system 1200 may include a central processing unit (“CPU”) 1201, a ROM 1202, a RAM 1203, a communication interface 1205, a hard disk (and / or other storage device) 1204, a screen (or monitor interface) 1209, a keyboard (or input interface; may include a mouse and other input devices in addition to the keyboard) 1210, and a BUS or other connection lines (e.g., connection line 1213) between one or more of the foregoing components (e.g., as shown in FIG. 17). Further, the computer system 1200 may include one or more of the foregoing components. For example, the computer system 1200 may include a CPU 1201, a RAM 1203, an input / output (I / O) interface (such as communication interface 1205), and a bus (which may include one or more wires 1213 as a communication system between the components of the computer system 1200; in one or more embodiments, the computer system 1200 and at least its CPU 1201 can communicate with one or more of the foregoing components of the FORJ or devices or systems using it described hereinbefore (such as system 100, system 100', system 100'' and / or system 100''', etc.) via one or more wires 1213), and one or more other computer systems 1200 may include one or more combinations of other foregoing components. The CPU 1201 is configured to read and execute computer-executable instructions stored in a storage medium. The computer-executable instructions may include instructions for performing the methods and / or calculations described herein. The computer system 1200 may include one or more additional processors in addition to the CPU 1201, and the processors including the CPU 1201 may be used for the control and / or manufacture of devices, systems, or storage media that are used in combination with it or in combination with any of the lumen detection, stent detection, and / or artifact detection techniques described herein.System 1200 may further include one or more processors connected via a network connection (e.g., via network 1206). The CPU 1201 and additional processors used by system 1200 may be located within the same telecommunications network or in different telecommunications networks (e.g., the execution, manufacture, control, and / or use of the technology can be remotely controlled).

[0076] The I / O interface or communication interface 1205 provides a communication interface to input / output devices (which may include light source 101, RJ, PM, SM, unit 150, unit 112, microphone, communication cable and network (wired or wireless), keyboard 1210, mouse (see, for example, mouse 1211 shown in FIG. 18), touch screen or screen 1209, light pen, etc.). The monitor interface or screen 1209 provides a communication interface thereto.

[0077] Any method and / or data of the present disclosure (such as equipment, systems, storage media used in combination therewith, and / or methods for detecting EEL, lumen edges, stents, and / or artifacts included in OCT images as described herein, methods for using and / or manufacturing the same, etc.) can be stored in a computer-readable storage medium. In order to cause a processor (such as the processor or CPU 1201 of the aforementioned computer system 1200) to execute the steps of the methods disclosed herein, commonly used computer-readable and / or writable storage media can be used (for example, hard disks (such as hard disk 1204, magnetic disks, etc.), flash memories, CDs, optical disks (such as compact disks ("CDs"), digital versatile disks ("DVDs"), Blu-ray (trademark) disks, etc.), magneto-optical disks, random access memories ("RAM") (such as RAM 1203, etc.), DRAMs, read-only memories ("ROM"), storage of distributed computer systems, memory cards or the like (such as other semiconductor memories such as non-volatile memory cards, solid-state drives (SSDs) (see SSD 1207 in FIG. 18), SRAMs, etc.), any combination thereof, one or more of servers / databases, etc.). The computer-readable storage medium may be a non-transitory computer-readable medium, and / or the computer-readable medium may include all computer-readable media with the sole exception that it is transitory and propagating a signal. The computer-readable storage medium may include media that store information for a predetermined period, a limited period, or a short period, and / or only in the presence of power, such as random access memory (RAM), register memory, processor cache, etc.Embodiments of the present disclosure can also be realized by a computer of a system or apparatus including computer-executable instructions (e.g., one or more programs) recorded on a storage medium (more precisely, which can also be referred to as a "non-transitory computer-readable storage medium") being read and executed to perform one or more functions of the above-described embodiments and / or one or more circuits (e.g., an application-specific integrated circuit (ASIC)) for performing one or more functions of the above-described embodiments, and further, can be realized by a method executed by a computer of a system or apparatus reading and executing computer-executable instructions from the storage medium to perform one or more functions of the above-described embodiments and / or controlling one or more circuits to perform one or more functions of the above-described embodiments.

[0078] According to at least one aspect of the present disclosure, the foregoing methods, apparatuses, systems, and computer-readable storage media associated with a processor (such as the processor of the aforementioned computer 1200, the processor of computer 1200', etc.) may be implemented using suitable hardware as illustrated. The functions of one or more aspects of the present disclosure may be implemented using suitable hardware as illustrated in FIG. 17. Such hardware may be any of a known processor operable to execute standard digital circuits, software, and / or firmware programs, or one or more programmable digital devices or systems (such as programmable read-only memory (PROM), programmable array logic device (PAL), etc.), and may be implemented using known techniques. The CPU 1201 (shown in FIG. 17 or FIG. 18) may include and / or consist of one or more microprocessors, nanoprocessors, one or more graphics processing units (also referred to as "GPUs", visual processing units (also referred to as "VPUs")), one or more field programmable gate arrays (referred to as "FPGAs"), or other types of processing components (such as application specific integrated circuits (ASICs)). Further, various aspects of the present disclosure may be implemented by software and / or programs that can be stored in a suitable storage medium (such as a computer-readable storage medium, hard drive, etc.) or a medium for transportability and / or distribution (such as a floppy disk, memory chip, etc.). The computer may include a separate computer or a network of separate processors for reading and executing computer-executable instructions. The computer-executable instructions may be provided to the computer, for example, from a network or a storage medium.

[0079] As described above, FIG. 18 shows the hardware structure of an alternative embodiment of the computer or console 1200'. The computer 1200' includes a central processing unit (CPU) 1201, a graphics processing unit (GPU) 1215, a random access memory (RAM) 1203, a network interface device 1212, an operation interface 1214 such as a universal serial bus (USB), and a memory such as a hard disk drive or a solid state drive (SSD) 1207. Preferably, the computer or console 1200' includes a display 1209. The computer 1200' may be connected to a rotary joint (e.g., RJ in FIG. 16), a motor PM, a motor SM, and / or one or more other components of a system (e.g., system 100, system 100', system 100", system 100''', etc.) via the operation interface 1214 or the network interface 1212. Computers such as the computers 1200, 1200', etc. may include an RJ, a PM, and / or an SM in one or more embodiments. The operation interface 1214 is connected to an operation unit such as a mouse device 1211, a keyboard 1210, a touch panel device, etc. The computer 1200' may include two or more of each component. Alternatively, the CPU 1201 or the GPU 1215 may be replaced with a field programmable gate array (FPGA), an application specific integrated circuit (ASIC), or another processing unit according to the design of the computer (e.g., the computer 1200, the computer 1200', etc.).

[0080] The computer program is stored in the SSD 1207, and the CPU 1201 loads the program into the RAM 1203 and executes the program instructions to perform not only the basic input, output, calculation, memory writing, and memory reading processes but also one or more processes described in this specification.

[0081] Computers such as computers 1200, 1200' communicate with the PIU 110 of the system (systems 100, 100', 100", 100''', etc.), the rotary joint (e.g., RJ, etc.), the motors PM, SM, the catheter 120 and / or one or more other components to perform imaging and reconstruct an image from the acquired intensity data. The monitor or display 1209 can display the reconstructed image and also display imaging conditions or other information regarding the object to be imaged. Also, the monitor 1209 provides a graphical user interface for the user to operate the system (e.g., system 100, system 100', system 100", system 100''', etc.) during the execution of, for example, OCT or other imaging techniques (such as EEL and / or detection of the lumen edge, etc.). The operation signal is input from the operation unit (e.g., the mouse device 1211, the keyboard 1210, the touch panel device, etc.) to the operation interface 1214 of the computer 1200'. In response to the operation signal, the computer 1200' commands the system (e.g., system 100, system 100', system 100", system 100''', etc.) to set or change imaging conditions, start or end imaging, and / or start or end lumen detection, stent detection, and / or artifact detection. The laser source 101 of the OCT system may have an interface for communicating with the computers 1200, 1200' to transmit and receive status information and control signals.

[0082] Similarly, the present disclosure and / or one or more components of its devices, systems, storage media, and / or methods can also be used in conjunction with an optical coherence tomography probe. Such probes include U.S. Patent Nos. 7,872,759, 8,289,522, and 8,928,889 to Tearney, configurations and methods for facilitating photoluminescence imaging (such as those disclosed in U.S. Patent No. 7,889,348 to Tearney), and disclosures directed to multimodality imaging disclosed in U.S. Patent No. 9,332,942, U.S. Patent Publication Nos. 2010 / 0092389, 2012 / 0101374, 2016 / 0228097, 2010 / 0092389, and 2018 / 0003481 (each of the patents and patent publications is incorporated herein by reference in its entirety), etc. As described above, any feature or aspect of the present disclosure can be used in combination with an OCT imaging system, apparatus, method, storage medium, or other aspect or feature described in U.S. Patent Application No. 16 / 414,222 (filed on May 16, 2019, published as U.S. Patent Publication No. 2019 / 0374109 on December 12, 2019, the entire disclosure of which is incorporated herein by reference in its entirety).

[0083] The present disclosure and / or one or more components of the devices, systems, storage media, and / or methods of the present disclosure can also be used in combination with the evaluation of arterial wall characteristics (such as in OCT imaging) of an OCT imaging system, etc., disclosed in U.S. Patent Application Publication No. 2020 / 0359911 (the entire disclosure of which is incorporated herein by reference in its entirety).

[0084] The disclosure of this specification has been described with reference to specific embodiments, but of course, these embodiments are merely (and not limited to) examples of the principles and uses of the present disclosure. Therefore, of course, many changes can be made to the exemplary embodiments, and other configurations can be devised without departing from the gist and scope of the present disclosure. The following claims should be given the broadest interpretation so as to encompass all such changes as well as equivalent structures and functions.

Claims

1. 1. An imaging instrument for detecting the external elastic lamina (EEL), comprising: one or more processors; The one or more processors: calibrating signal intensities of one or more imaging modalities to remove depth effects; detecting a lumen; determining whether the lumen is located within a predetermined distance of the catheter or a portion of the catheter; if the lumen is located within the predetermined distance from the catheter or the portion of the catheter, (i) taking a running average of the signal strength for a predetermined number of A-lines, (ii) finding a location where the average signal strength suddenly changes by a predetermined amount, and (iii) detecting a location of the EEL based on the detected change by the predetermined amount. Operates to perform Imaging equipment.

2. (i) the predetermined distance from the catheter or the portion of the catheter is one or more of: within 3.0 mm, within 2.0 mm, within 1.0 mm to 3.0 mm, between about 1.0 mm to about 3.0 mm, or less; and / or a distance set by a user of the imaging device; (ii) the portion of the catheter is a center of the catheter, a side of the catheter, and / or a portion of the catheter set by a user of the imaging device; (iii) the predetermined number of A-lines is one or more of 10 A-lines, 5 A-lines, 3 A-lines, 1-10 A-lines, 10 or more A-lines, 15 A-lines, and / or a number of A-lines set by a user of the imaging device; and / or (iv) the predetermined amount of the detected change includes one or more of: 5 percent or more; 10 percent or more; 5-10% or more; a change from low intensity to high intensity; and / or an amount set or defined by a user of the imaging device; 10. The imaging device of claim 1, wherein the imaging device is one or more of:

3. the one or more processors are further operable to determine whether the EEL is continuous in Cartesian and / or polar coordinates, except for a location of a side branch in or near the lumen, or a location of a plaque in or near the lumen.

10. The imaging instrument of claim 1.

4. The one or more processors are further operable to automatically detect an EEL; and indicating that an EEL was not detected if the lumen is not located within the predetermined distance of the catheter or the portion of the catheter; or if the lumen is located within the predetermined distance from the catheter or the portion of the catheter, determining whether the EEL is located within a predetermined distance from the lumen, and if the EEL is located within the predetermined distance from the lumen, interpolating between the detected points, performing smoothing on the EEL, and determining whether the smoothed EEL is continuous in Cartesian and / or polar coordinates; or if the EEL is not located within the predetermined distance from the lumen, determining whether plaque is present, and if plaque is present, performing processing on an EEL pre-proximal curvature image or frame to obtain an EEL proximal curvature image or frame that includes a complete EEL, interpolating from nearby detections, interpolating between the detected points, performing smoothing on the EEL, and determining whether the smoothed EEL is continuous in Cartesian and / or polar coordinates; or if plaque is not present, interpolating from nearby detections, interpolating between the detected points, performing smoothing on the EEL, and determining whether the smoothed EEL is continuous in Cartesian and / or polar coordinates. The imaging apparatus of claim 1 , further operable to perform the following:

5. (i) the predetermined distance from the catheter or the portion of the catheter is one or more of: within 3.0 mm, within 2.0 mm, within 1.0 mm to 3.0 mm, and / or a distance equal to or less than a value between about 1.0 mm and about 3.0 mm; (ii) the portion of the catheter is a center of the catheter, a side of the catheter, and / or a portion of the catheter set by a user of the imaging device; (iii) the predetermined number of A-lines is one or more of 10 A-lines, 5 A-lines, 3 A-lines, 1-10 A-lines, 10 or more A-lines, 15 A-lines, and / or a number of A-lines set by a user of the imaging device; (iv) the detected change of the predetermined amount includes one or more of: 5 percent or more; 10 percent or more; 5-10% or more; a change from low intensity to high intensity; and / or an amount set or defined by a user of the imaging device; and / or (v) the predetermined distance between the detected EEL location and the lumen is one or more of within 1 mm, within 2 mm, within 1-2 mm, a distance equal to or less than a value between about 1.0 mm and about 3.0 mm, and / or within a distance set by a user of the imaging device; 5. The imaging device of claim 4, wherein the imaging device is one or more of:

6. The one or more processors are further operable to determine whether the smoothed EEL is continuous in the Cartesian coordinates and / or the polar coordinates, except for a location of a side branch or a location of a plaque.

6. The imaging apparatus of claim 5.

7. The one or more processors: detecting lumen edges in one or more intravascular images; determining one or more reference frames; determining whether the EEL is found in the one or more reference frames; detecting the EEL; measuring the diameter of the EEL; determining a size and shape of a stent to be used in said lumen; The imaging apparatus of claim 1 , further operable to perform the following:

8. 1. A method for detecting the external elastic lamina (EEL), comprising: calibrating signal intensities of one or more imaging modalities to remove depth effects; detecting a lumen; determining whether the lumen is located within a predetermined distance of the catheter or a portion of the catheter; if the lumen is located within the predetermined distance from the catheter or the portion of the catheter, (i) taking a running average of the signal strength for a predetermined number of A-lines, (ii) finding a location where the average signal strength suddenly changes by a predetermined amount, and (iii) detecting a location of the EEL based on the detected change by the predetermined amount. The method includes:

9. determining whether the EEL is located within a predetermined distance from the lumen; if the EEL is located within the predetermined distance from the lumen, interpolating between the detected points and performing smoothing on the EEL and checking whether the smoothed EEL is continuous in Cartesian and / or polar coordinates; The method of claim 8 further comprising:

10. the predetermined distance between the detected EEL location and the lumen is one or more of: within 1 mm, within 2 mm, within 1-2 mm, within a distance of about 1.0 mm to about 3.0 mm, and / or within a distance set by a user of an imaging device; and / or the verifying step includes verifying whether the smoothed EEL is continuous in the Cartesian and / or polar coordinates, except for the location of side branches in or near the lumen, or the location of plaque in or near the lumen; The method of claim 9 , wherein the one or more of

11. if the EEL is not located within the predetermined distance from the lumen, determining whether plaque is present; if plaque is present, performing processing on the EEL pre-neighborhood curvature image or frame to obtain an EEL near-neighborhood curvature image or frame including the complete EEL, and interpolating from nearby detection results, interpolating between detected points, performing smoothing on the EEL, and checking whether the smoothed EEL is continuous in Cartesian and / or polar coordinates; or if plaque is not present, interpolating from nearby detection results, interpolating between detected points, performing smoothing on the EEL, and checking whether the smoothed EEL is continuous in Cartesian and / or polar coordinates; The method of claim 9 further comprising:

12. the verifying step verifies whether the smoothed EEL is continuous in the Cartesian and / or polar coordinates, except for the location of side branches in or near the lumen, or the location of plaque in or near the lumen. The method of claim 11.

13. (i) the predetermined distance from the catheter or the portion of the catheter is one or more of: within 3.0 mm, within 2.0 mm, within 1.0 mm to 3.0 mm, and / or a distance equal to or less than a value between about 1.0 mm and about 3.0 mm; (ii) the portion of the catheter is a center of the catheter, a side of the catheter, and / or a portion of the catheter set by a user of an imaging device; (iii) the predetermined number of A-lines is one or more of 10 A-lines, 5 A-lines, 3 A-lines, 1-10 A-lines, 10 or more A-lines, 15 A-lines, and / or a number of A-lines set by a user of the imaging device; and / or (iv) the detected change of the predetermined amount includes one or more of: 5 percent or more; 10 percent or more; 5-10% or more; a change from low intensity to high intensity; and / or an amount set or defined by a user; The method of claim 8, wherein the one or more of

14. detecting lumen edges in one or more intravascular images; determining one or more reference frames; determining whether the EEL is found in the one or more reference frames; detecting the EEL; measuring the diameter of the EEL; determining a size and shape of a stent to be used in said lumen; The method of claim 8 further comprising:

15. if the EEL is not found in the reference frame, determining whether the EEL is found in one or more of nearby frames, frames before and after the reference frame, a few frames away from the reference frame, and / or frames near the reference frame; if the EEL is not observed in one or more of nearby frames, frames before and after the reference frame, frames several frames away from the reference frame, and / or frames near the reference frame, measuring the diameter of the lumen and determining the size and shape of the stent; if the EEL is found in one or more of a nearby frame, a frame before or after the reference frame, a few frames away from the reference frame, and / or a frame near the reference frame, determining whether to change the reference frame to one or more of the nearby frames, the frames before or after the reference frame, the few frames away from the reference frame, and / or the frames near the reference frame; Detecting the EEL, measuring the diameter of the EEL, and determining the size and shape of the stent if it is decided to change the reference frame to one or more of the nearby frame, the frame before or after the reference frame, the few frames away from the reference frame, and / or the frame near the reference frame; and / or if it is not determined to change the reference frame to one or more of the nearby frame, the frame before or after the reference frame, the few frames away from the reference frame, and / or the frame near the reference frame, measuring the diameter of the lumen and determining the size and shape of the stent; The method of claim 14 , further comprising one or more of:

16. - issuing a warning on the display if the reference frame is not appropriate or if the reference frame should be changed; and / or based on said detection of EEL, issuing a warning on a display if the reference frame is not appropriate or if the reference frame should be changed; The method of claim 15 , further comprising one or more of:

17. the size and shape of the stent include one or more of a diameter and length of the stent, a circumference of the stent, and / or a volume of the stent; an imaging device that assists a user of the imaging device in selecting the size and / or shape of the stent; The method of claim 14.

18. displaying a graphical user interface (GUI) on the display; a user of the display and / or one or more of the GUI changes the position of the EEL and / or the GUI includes buttons and / or guidance for navigating the user; The method of claim 14.

19. correcting for signal intensity falloff due to depth such that one or more features of the imaged object are located relatively deeper than a surface or edge of the lumen, and analyzing the corrected intensities; The method of claim 14 further comprising:

20. A non-transitory computer-readable storage medium having stored thereon at least one program for causing a computer to execute a method for detecting an external elastic lamina (EEL), comprising: The method comprises: calibrating signal intensities of one or more imaging modalities to remove depth effects; detecting a lumen; determining whether the lumen is located within a predetermined distance of the catheter or a portion of the catheter; if the lumen is located within the predetermined distance from the catheter or the portion of the catheter, (i) taking a running average of the signal strength for a predetermined number of A-lines, (ii) finding a location where the average signal strength suddenly changes by a predetermined amount, and (iii) detecting a location of the EEL based on the detected change by the predetermined amount. A non-transitory computer readable storage medium comprising:

Images