Imaging System

Abstract

An imaging system for a patient is provided, comprising an imaging probe and an imaging assembly. The imaging probe comprises an elongate shaft, a rotatable optical core, and an optical assembly disposed proximate to a distal end of the optical core. The shaft comprises a proximal end, a distal section, and a lumen extending between the proximal end and the distal section. The optical core has a proximal end and a distal end, and at least a portion of the optical core is disposed within the lumen of the shaft. The optical assembly is configured to direct light toward tissue to be imaged and collect reflected light from the tissue to be imaged. The imaging assembly is constructed and arranged to be optically coupled to the imaging probe. The imaging assembly is configured to emit light into the imaging probe and receive reflected light collected by the optical assembly.

Description

[Technical Field]

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 017258, entitled "Imaging System," filed April 29, 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] This application claims the benefit of U.S. Provisional Application No. 63 / 154934, entitled "Optical Imaging Systems," filed March 1, 2021, the contents of which are incorporated herein by reference in their entirety.

[0003] This application is related to U.S. Provisional Application No. 62 / 148,355, entitled "Micro-Optic Probes for Neurology," filed April 16, 2015, the contents of which are incorporated herein by reference in their entirety.

[0004] This application is related to U.S. Provisional Application No. 62 / 322,182, entitled "Micro-Optic Probes for Neurology," filed April 13, 2016, the contents of which are incorporated herein by reference in their entirety.

[0005] This application is related to International Patent Application No. PCT / US2016 / 027764, entitled "Micro-Optic Probes for Neurology," filed April 15, 2016, and International Publication No. WO 2016 / 168605, published October 20, 2016, the contents of which are incorporated herein by reference in their entirety.

[0006] This application is related to U.S. Patent Application No. 15 / 566,041, entitled "Micro-Optic Probes for Neurology," filed October 12, 2017, U.S. Patent Application Publication No. 2018 / 0125372, published May 10, 2018, the contents of which are incorporated herein by reference in their entirety.

[0007] This application is related to U.S. Provisional Application No. 62 / 212,173, entitled "Micro-Optic Probes for Neurology," filed August 31, 2015, the contents of which are incorporated herein by reference in their entirety.

[0008] This application is related to U.S. Provisional Application No. 62 / 368,387, filed July 29, 2016, entitled "Micro-Optic Probes for Neurology," the contents of which are incorporated herein by reference in their entirety.

[0009] This application is related to International Patent Application No. PCT / US2016 / 049415, entitled "Micro-Optic Probes for Neurology," filed August 30, 2016, and International Publication No. WO 2017 / 040484, published March 9, 2017, the contents of which are incorporated herein by reference in their entirety.

[0010] This application is related to U.S. Patent Application No. 15 / 751,570, entitled "Micro-Optic Probes for Neurology," filed February 9, 2018, and U.S. Patent No. 10,631,718, issued April 28, 2020, the contents of which are incorporated herein by reference in their entirety.

[0011] This application is related to U.S. Patent Application No. 16 / 820991, entitled "Micro-Optic Probes for Neurology," filed March 17, 2020, U.S. Patent Application Publication No. 2021 / 0045622, published February 18, 2021, the contents of which are incorporated herein by reference in their entirety.

[0012] This application is related to U.S. Provisional Application No. 62 / 591,403, entitled "Imaging System," filed November 28, 2017, the contents of which are incorporated herein by reference in their entirety.

[0013] This application is related to U.S. Provisional Application No. 62 / 671,142, entitled "Imaging System," filed May 14, 2018, the contents of which are incorporated herein by reference in their entirety.

[0014] This application is related to International Patent Application No. PCT / US2018 / 062766, entitled "Imaging System," filed November 28, 2018, and International Publication No. WO 2019 / 108598, published June 6, 2019, the contents of which are incorporated herein by reference in their entirety.

[0015] This application is related to U.S. Patent Application No. 16 / 764,087, entitled "Imaging System," filed May 14, 2020, U.S. Patent Application Publication No. 2020 / 0288950, published September 17, 2020, the contents of which are incorporated herein by reference in their entirety.

[0016] This application is related to U.S. Provisional Application No. 62 / 732,114, entitled "Imaging System with Optical Pathway," filed September 17, 2018, the contents of which are incorporated herein by reference in their entirety.

[0017] This application is related to International Patent Application No. PCT / US2019 / 051447, entitled "Imaging System," filed September 17, 2019, and International Publication No. WO 2020 / 061001, published March 26, 2020, the contents of which are incorporated herein by reference in their entirety.

[0018] This application is related to U.S. Patent Application No. 17 / 276,500, entitled "Imaging System with Optical Pathway," filed March 16, 2021, the contents of which are incorporated herein by reference in their entirety.

[0019] This application is related to U.S. Provisional Application No. 62 / 840,450, entitled "Imaging Probe with Fluid Pressurization Element," filed April 30, 2019, the contents of which are incorporated herein by reference in their entirety.

[0020] This application is related to International Patent Application No. PCT / US2020 / 030616, entitled "Imaging Probe with Fluid Pressurization Element," filed April 30, 2020, and International Publication No. WO 2020 / 223433, published November 5, 2020, the contents of which are incorporated herein by reference in their entirety.

[0021] This application is related to U.S. Provisional Application No. 62 / 850945, filed May 21, 2019, entitled "OCT-Guided Treatment of a Patient," the contents of which are incorporated herein by reference in their entirety.

[0022] This application is related to U.S. Provisional Application No. 62 / 906,353, entitled "OCT-Guided Treatment of a Patient," filed September 26, 2019, the contents of which are incorporated herein by reference in their entirety.

[0023] This application is related to International Patent Application No. PCT / US2020 / 033953, entitled "Systems and Methods for OCT-Guided Treatment of a Patient," filed May 21, 2020, and International Publication No. WO 2020 / 237024, published November 26, 2020, the contents of which are incorporated herein by reference in their entirety.

[0024] [Field of the Invention] The present invention relates generally to imaging systems, and more particularly to intravascular imaging systems that include imaging probes and delivery devices. [Background technology]

[0025] Imaging probes for imaging various internal body parts of a patient, such as intravascular probes for imaging the patient's heart, are commercially available. Current imaging probes are limited in their ability to reach certain anatomical locations due to their size and rigidity. Current imaging probes are inserted over guidewires, which can compromise their placement and limit the use of one or more delivery catheters into which the imaging probe is inserted. There is a need for imaging systems having probes with reduced diameters and increased flexibility, as well as systems with one or more delivery devices that are compatible with these improved imaging probes. Summary of the Invention

[0026] In accordance with one aspect of the inventive concept, an imaging system for a patient includes an imaging probe, an optical assembly, and the imaging assembly. The imaging probe includes an elongate shaft having a proximal end, a distal section, and a lumen extending between the proximal and distal sections, and a rotatable optical core having proximal and distal ends, at least a portion of the rotatable optical core disposed within the lumen of the elongate shaft. The optical assembly is disposed proximate the distal end of the rotatable optical core and configured to direct light toward and collect reflected light from a tissue to be imaged. The imaging assembly is constructed and arranged to be optically coupled to the imaging probe and configured to emit light into the imaging probe and receive reflected light collected by the optical assembly.

[0027] In some embodiments, the imaging system further includes a retraction assembly having a carrier, the imaging probe including a pullback connector, and the carrier configured to removably attach to the pullback connector. The imaging system may further include a delivery catheter operably attached to the retraction assembly and into which the imaging probe can be inserted, the carrier comprising a two-piece assembly configured to allow an operator to adjust the position of the pullback connector relative to the delivery catheter. The two-piece assembly may be configured to adjust the position of the pullback connector relative to the delivery catheter by a distance of at least 5 mm, at least 7 mm, and / or at least 15 mm. The two-piece assembly may be configured to adjust the position of the pullback connector relative to the delivery catheter in small increments of 1.0 mm, 0.7 mm, 0.5 mm, and / or 0.3 mm.

[0028] In some embodiments, the imaging system may further comprise an algorithm configured to determine the duration. The algorithm may be further configured to calculate a dynamic parameter of the vascular flow based on the determined duration.

[0029] In some embodiments, the imaging system is configured to perform a pullback procedure, and the imaging system is further configured to initiate the pullback procedure based on detection of a T wave.

[0030] In some embodiments, the imaging system is configured to perform a pullback process, and the imaging system is further configured to initiate the pullback process based on analysis of the angiographic image.

[0031] In some embodiments, the imaging system is configured to perform the pullback process, and the imaging system is further configured to initiate the pullback process based on an analysis of an EKG signal (e.g., an EKG signal generated via analysis of the OCT data by an algorithm of the imaging system).

[0032] In some embodiments, the imaging system is configured to perform a pullback procedure, and the imaging system is further configured to initiate the pullback procedure based on detection of removal of blood from the imaged location.

[0033] In some embodiments, the imaging system is configured to perform a pullback process, and the imaging system is further configured to initiate the pullback process based on the simultaneous existence of two trigger conditions: a first trigger condition may include detection of removal of blood from the imaged location, and a second trigger condition may be based on analysis of the EKG signal.

[0034] In some embodiments, the optical assembly is configured to be positioned within a first blood vessel, and the imaging system is configured to generate an image of a target location outside the first blood vessel. The first blood vessel may include a blood vessel of the brain, and the target location may include a location within the brain outside the blood vessel of the brain. Light directed at and / or collected from the tissue passes through cerebrospinal fluid. The target location may include a location having one or more physiological markers of disease, such as tumor tissue, neuritic plaques, amyloid plaques, cerebral infarction, atherosclerosis, and / or other tissue associated with a patient's disease or disorder. The target location may include an intravascular location, an extravascular location, a perivascular structure, the subarachnoid space, and / or arachnoid trabeculae.

[0035] In some embodiments, the imaging system is configured to display the image data in a first mode including an oblique representation of the imaged tissue and a second mode including a fly-through representation of the imaged tissue, and the imaging system can be configured to allow an operator to transition between the first mode and the second mode.

[0036] In some embodiments, the optical assembly is configured to be placed intraluminally in the intracranial vasculature to generate images of one or more physiological markers of vascular dementia and / or Alzheimer's disease (e.g., where these physiological markers are in the intraluminal and / or extraluminal anatomical locations where the optical assembly is placed). The physiological markers may include one, two, or more markers selected from the group consisting of amyloid plaques, neuritic plaques, cerebral infarction, atherosclerosis, and combinations thereof.

[0037] The technology described herein, its attributes and attendant advantages, will be best appreciated and understood in consideration of the following detailed description taken in conjunction with the accompanying drawings illustrating exemplary embodiments.

[0038] [Incorporated by reference] All publications, patents, and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference. The contents of all publications, patents, and patent applications mentioned in this specification are incorporated herein by reference in their entirety for all purposes. [Brief explanation of the drawings]

[0039] [Figure 1] 1 shows a schematic diagram of an imaging system consistent with the concepts of the present invention, the imaging system including an imaging probe and independent retraction and rotation assemblies. [Figure 1A]FIG. 1 shows a schematic diagram of an imaging system consistent with the concepts of the present invention, the imaging system including an imaging probe operably attachable to a patient interface module and a separate pullback module operably attachable to the patient interface module and the imaging probe. [Figure 1B] 1 shows a schematic diagram of an imaging system consistent with the concepts of the present invention, the imaging system including an imaging probe operably attachable to a module having a first connector for attachment to a rotational power element and a second connector for attachment to a retraction power element. [Figure 2A] 1 illustrates a perspective view of a connector attached to a patient interface module consistent with the concepts of the present invention. [Figure 2B] 1 illustrates a perspective view of a pullback housing consistent with the concepts of the present invention; [Figure 3] 1 illustrates a perspective view of a connector attached to a patient interface module consistent with the concepts of the present invention. [Figure 4] 1 shows a perspective view of an adapter for use with an imaging system consistent with the concepts of the present invention; [Figure 5A] 1 shows a perspective view of a pullback module operably attached to a portion of an imaging probe and delivery catheter consistent with the concepts of the present invention. [Figure 5B] 1 illustrates an exploded view of a portion of a pullback module consistent with the concepts of the present invention. [Figure 6] 1 shows a flowchart of a method for calculating fractional flow reserve (FFR) using OCT consistent with the concepts of the present invention. [Figure 7] 1 shows a flowchart of a method for initiating pull-back imaging consistent with the concepts of the present invention. [Figure 8] 1 shows a flowchart of a method for initiating pullback imaging based on multiple triggers consistent with the concepts of the present invention. [Figure 9]1 shows an OCT image showing blood vessels floating in cerebral fluid, consistent with the concepts of the present invention. [Figure 10A] 1 shows a portion of an imaging probe consistent with the concepts of the present invention. [Figure 10B] 1 shows a portion of an imaging probe consistent with the concepts of the present invention. [Figure 10C] 1 shows a portion of an imaging probe consistent with the concepts of the present invention. [Figure 11A] 1 shows a display of luminal image data consistent with the concepts of the present invention. [Figure 11B] 1 shows a display of luminal image data consistent with the concepts of the present invention. [Figure 11C] 1 shows a display of luminal image data consistent with the concepts of the present invention. [Figure 11D] 1 shows a display of luminal image data consistent with the concepts of the present invention. [Figure 11E] 1 shows a display of luminal image data consistent with the concepts of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0040] The technology of the present embodiment will be described in detail below, examples of which are illustrated in the accompanying drawings. Similar reference numerals may be used to refer to similar components. However, the following description is not intended to limit the present disclosure to a specific embodiment, and should be interpreted as including various modifications, equivalents, and / or alternatives to the embodiments described herein.

[0041] With respect to the terms used herein, it will be understood that the terms "comprise" (and any form of related term), "have" (and any form of related term), "include" (and any form of related term), or "comprise" (and any form of related term) specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or combinations thereof.

[0042] Additionally, while terms such as first, second, and third may be used herein to describe various limiting elements, parts, components, regions, layers, and / or sections, it will be understood that these limiting elements, parts, components, regions, layers, and / or sections should not be limited by these terms. These terms are used only to distinguish one limiting element, part, component, region, layer, or section from another limiting element, part, component, region, layer, or section. Thus, without departing from the teachings of the present application, a first limiting element, part, component, region, layer, or section described below may also be referred to as a second limiting element, part, component, region, layer, or section.

[0043] Furthermore, when an element is referred to as being "on," "mounted," "connected," or "coupled" to another element, it will be understood that it may be directly on, mounted, connected, or coupled to the other element, or that one or more intervening elements may be present. In contrast, when an element is referred to as being "directly on," "directly mounted," "directly connected," or "directly coupled" to another element, there are no intervening elements present. Other terms used to describe relationships between elements (e.g., "between" and "directly between," "adjacent" and "directly adjacent," etc.) should be interpreted similarly.

[0044] Furthermore, when a first element is referred to as being "in," "on," and / or "within" a second element, it will be understood that the first element may be disposed within an interior space of the second element, within a portion of the second element (e.g., within a wall of the second element), on an exterior and / or interior surface of the second element, and any combination or combinations thereof.

[0045] As used herein, the term "proximate," when used to describe the proximity of a first component or first location to a second component or second location, should be interpreted to include one or more locations near the second component or second location, as well as locations in, on, and / or within the second component or second location. For example, a component positioned proximate to an anatomical location (e.g., the location of a target tissue) includes a component positioned near the anatomical location, as well as a component positioned in, on, and / or within the anatomical location.

[0046] Spatially relative terms such as "bottom," "lower," "belower," "top," and "upper" may be used to describe the relationship of one element and / or feature to another, for example, as depicted in the figures. Furthermore, it should be understood that spatially relative terms are intended to encompass various orientations of the device during use and / or operation in addition to the orientation depicted. For example, if the device in the figures were flipped over, elements described as "below" and / or "below" other elements or features would then be oriented "above" such other elements or features. The device may be oriented otherwise (e.g., rotated 90 degrees or oriented in another direction), and the spatially relative descriptions used herein would be interpreted accordingly.

[0047] As used herein, the terms "reduce," "reducing," "reduction," and the like include reducing the amount, including reducing to zero. Reducing the likelihood of occurrence includes preventing (suppressing) occurrence. Accordingly, the terms "prevent," "preventing," and "prevention" include the act of "reducing."

[0048] The term "and / or" as used herein should be construed as a specific disclosure of each of the two specified features or components, whether or not accompanied by the other. For example, "A and / or B" should be considered a specific disclosure of (i) A, (ii) B, and (iii) A and B, as if each were individually set forth herein.

[0049] As used herein, the term "one or more" can mean one, two, three, four, five, six, seven, eight, nine, ten, or up to any number more.

[0050] As used herein, the terms "and combinations thereof" and "and combinations thereof" may be used after a list of items that are included singly or collectively, respectively. For example, components, processes, and / or other items selected from the group consisting of A, B, C, and combinations thereof, are intended to include a set of one or more elements consisting of one, two, three, or more items A, one, two, three, or more items B, and / or one, two, three, or more items C.

[0051] In this specification, unless otherwise stated, "and" means "or," and "or" can mean "and." For example, if a feature is described as having A, B, or C, the feature can have A, B, C, or any combination thereof. Similarly, if a feature is described as having A, B, and C, the feature can have only one or two of A, B, or C.

[0052] As used herein, when a quantifiable parameter is described as having a value "between" a first value X and a second value Y, the parameter is intended to include parameters having a value of at least X, a value less than or equal to Y, and / or a value of at least X and less than or equal to Y. For example, a value between 1 and 10 is intended to include a value of at least 1 (including values ​​greater than 10), a value less than 10 (including values ​​less than 1), and / or values ​​greater than 1 and less than 10.

[0053] As used in this disclosure, the phrase "configured to" may be used interchangeably with, for example, "suitable for," "capable of," "designed to," "adapted to," "made to," and "capable of," depending on the context. The phrase "configured to" does not necessarily mean "specially designed" in hardware. In some contexts, the phrase "device configured to" may mean that the device is "capable of" operating with another device or component.

[0054] As used herein, the term "about" or "approximately" shall refer to plus or minus 30%.

[0055] The term "threshold" as used herein refers to a maximum level, minimum level, and / or range of values ​​that correlate to a desired or undesirable state. In some embodiments, a system parameter is maintained above a minimum threshold, below a maximum threshold, within a threshold range, and / or outside a threshold range of values ​​that will cause a desired effect (e.g., effective treatment) and / or prevent or mitigate (hereinafter, inclusively referred to as "prevent") an undesirable event (e.g., device and / or clinical adverse event). In some embodiments, a system parameter is maintained above a first threshold (e.g., above a first temperature threshold to produce a desired therapeutic effect on tissue) and below a second threshold (e.g., below a second temperature threshold to prevent undesirable tissue damage). In some embodiments, thresholds are determined to include a safety margin, such as to account for patient variability, system variability, tolerances, etc. As used herein, "above a threshold" refers to a parameter being above a maximum threshold, below a minimum threshold, within a threshold range, and / or outside a threshold range.

[0056] As described herein, "room pressure" is intended to mean the pressure of the environment surrounding the systems and devices of the present invention. Positive pressure includes pressures greater than room pressure or simply greater than another pressure, such as a positive pressure differential across a fluid path component such as a valve. Negative pressure includes pressures less than room pressure or less than another pressure, such as a negative pressure differential across a fluid path component such as a valve. Negative pressure may include a vacuum, but does not mean a pressure below room pressure. As used herein, the term "vacuum" may be used to refer to a full or partial vacuum or any of the negative pressures described herein.

[0057] The term "diameter" as used herein to describe a non-circular shape should be interpreted as the diameter of an imaginary circle that approximates the shape being described. When describing a cross-section, such as a cross-section of a component, the term "diameter" should be interpreted as representing the diameter of an imaginary circle having the same cross-sectional area as the cross-section of the component being described.

[0058] As used herein, the terms "major axis" and "minor axis" of a component are the length and diameter of an imaginary cylinder of smallest volume that can completely enclose the component.

[0059] As used herein, the term "functional element" should be interpreted to include one or more elements configured and arranged to perform a function. A functional element may include a sensor and / or a transducer. In some embodiments, a functional element (e.g., a functional element configured as a therapeutic element) is configured to deliver energy and / or treat tissue. Alternatively or additionally, a functional element (e.g., a functional element including a sensor) may be configured to record one or more parameters, such as patient physiological parameters, patient anatomical parameters (e.g., tissue shape parameters), patient environment parameters, and / or system parameters. In some embodiments, a sensor or other functional element is configured to perform a diagnostic function (e.g., collect data used to perform a diagnosis). In some embodiments, a functional element is configured to perform a therapeutic function (e.g., deliver therapeutic energy and / or a therapeutic agent). In some embodiments, the functional element includes one or more elements constructed and arranged to perform a function selected from the group consisting of: delivering energy, extracting energy (e.g., to cool a component), delivering a drug or other agent, manipulating a system component or a patient's tissue, recording or sensing a parameter, such as a patient physiological parameter or a system parameter, and a combination of one or more of these. The functional element may include a fluid and / or a fluid delivery system. The functional element may include a reservoir, such as an inflatable balloon or other fluid-holding reservoir. A "functional assembly" may include an assembly constructed and arranged to perform a function, such as a diagnostic function and / or a therapeutic function. The functional assembly may include an expandable assembly. The functional assembly may include one or more functional elements.

[0060] As used herein, the term "transducer" should be interpreted to include any component or combination of components that receives energy or any input and generates an output. For example, a transducer may include an electrode that receives electrical energy and distributes the electrical energy to tissue (e.g., based on the size of the electrode). In some forms, a transducer converts an electrical signal into any output, such as light (e.g., a transducer including a light-emitting diode or a light bulb), sound (e.g., a transducer including a piezoelectric crystal configured to transmit ultrasonic energy), pressure (e.g., applied pressure or force), thermal energy, cryogenic energy, chemical energy, mechanical energy (e.g., a transducer including a motor or solenoid), magnetic energy, and / or a different electrical signal (e.g., one that is different from the input signal to the transducer). Alternatively or additionally, a transducer can convert a physical quantity (e.g., a change in a physical quantity) into an electrical signal. Transducers may include any component that delivers energy and / or agents to tissue, such as transducers configured to deliver electrical energy (e.g., transducers comprising one or more electrodes), optical energy (e.g., transducers comprising lasers, light emitting diodes, and / or optical components such as lenses or prisms), mechanical energy (e.g., transducers comprising tissue manipulation elements), acoustic energy (e.g., transducers comprising piezoelectric crystals), chemical energy, electromagnetic energy, magnetic energy, and combinations of one or more of these to tissue.

[0061] As used herein, the term "fluid" refers to a liquid, gas, gel, or any flowable material, such as a material that can pass through a lumen and / or opening.

[0062] As used herein, the term "material" may refer to a single material or a combination of two, three, four, or more materials.

[0063] As used herein, the term "lesion" includes a portion of a blood vessel (e.g., an artery) that is in an undesirable condition. As used herein, lesion is intended to include a narrowing of the blood vessel (e.g., stenosis) and / or a portion of the blood vessel that has calcium, lipid, cholesterol, and / or other plaque buildup, with or without stenosis.

[0064] It is understood that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination. For example, it is understood that all features recited in any claim (independent or dependent) may be combined in any manner.

[0065] It should be understood that at least some of the figures and descriptions of the invention have been simplified to focus on elements relevant to a clear understanding of the invention, while other elements that would be understood by one of ordinary skill in the art to form part of the invention have been omitted for clarity, although such elements are well known in the art and will not be described herein because they do not necessarily facilitate a better understanding of the invention.

[0066] The terms defined in this disclosure are used only to describe specific embodiments of the present disclosure and are not intended to limit the scope of the present disclosure. Terms described in the singular are intended to include the plural unless the context clearly dictates otherwise. All terms used herein, including technical or scientific terms, have the same meaning as commonly understood by those skilled in the art unless otherwise defined herein. Terms defined in commonly used dictionaries should be interpreted as having the same or similar meaning as the contextual meaning of the relevant technology, and should not be interpreted as having an ideal or exaggerated meaning unless explicitly defined herein. In some cases, the terms defined in this disclosure should not be interpreted to exclude embodiments of the present disclosure.

[0067] Provided herein is an imaging system for a patient including an imaging probe and an imaging assembly. The imaging probe includes an elongate shaft, a rotatable optical core, and an optical assembly. The shaft includes a proximal end, a distal section, and a lumen extending between the proximal end and the distal section. The rotatable optical core includes a proximal end and a distal end, and at least a portion of the rotatable optical core is disposed within the lumen of the elongate shaft. The optical assembly is disposed proximate the distal end of the rotatable optical core and is configured to direct light toward tissue and collect reflected light from the tissue. The imaging system may include one or more algorithms configured to improve performance of the system.

[0068] Imaging systems of the present inventive concept provide image data representative of arteries, veins, and / or other body conduits and may be used to image one or more devices inserted into those conduits. The imaging system may also be used to image tissue and / or other structures outside of blood vessels and / or other lumens into which an imaging probe is inserted. The imaging system may provide image data related to healthy tissue as well as diseased tissue, such as blood vessels containing stenoses, myocardial bridges, and / or other vascular narrowings ("lesions" or "stenoses" herein) and / or blood vessels containing aneurysms. The system may also be configured to provide treatment information, such as when the treatment information is used by an operator (e.g., a patient's clinician) to plan treatment and / or predict treatment outcomes.

[0069] Referring now to FIG. 1 , a schematic diagram of an imaging system including an imaging probe and separate retraction and rotation assemblies consistent with the concepts of the present invention is shown. The imaging system 10 (system 10) is constructed and arranged to collect image data (herein “image data” or “OCT data”) of an imaging location (e.g., a portion of a patient's blood vessel or other vessel, such as during a pullback procedure) and generate one or more images based on the recorded data, such as when the imaging system 10 (system 10) comprises an optical coherence tomography (OCT) imaging system constructed and arranged to collect image data and generate one or more images based on the recorded data. The imaging system 10 includes a catheter-based probe, an imaging probe 100 (probe 100), and a rotation assembly 500 and a retraction assembly 800 operably attachable to and detachable from the imaging probe 100. The imaging probe 100 may further include a console 50 configured to operably connect to the imaging probe 100, such as via the rotation assembly 500 and / or the retraction assembly 800. Imaging probe 100 may be introduced into a patient's vessel, such as a patient's blood vessel or other vessel, using one or more delivery catheters, such as the illustrated delivery catheter 80. Additionally or alternatively, imaging probe 100 may be introduced through an introducer device, such as an endoscope, arthroscope, balloon dilator, or the like. In some embodiments, imaging probe 100 is configured to be introduced into a patient's body vessel selected from the group consisting of an artery, a vein, an artery in or near the heart, a vein in or near the heart, an artery in or near the brain, a vein in or near the brain, a peripheral artery, a peripheral vein, a patient's chamber, a patient's channel, a patient's canal (e.g., the epidural space and / or intrathecal space of a patient's spine), a patient's duct, a conduit or other internal location, such as the esophagus, accessed through a natural body orifice, a body cavity or other internal location, such as the abdomen, accessed through a surgically created opening, and a combination of one or more of these.Imaging system 10 may further include multiple imaging devices, including the illustrated second imaging device 15. Imaging system 10 may further include a therapy device 16 configured to treat the patient. Imaging system 10 may further include one or more devices configured to monitor one, two, or more physiological and / or other parameters of the patient, such as the illustrated patient monitoring device 17. Imaging system 10 may further include an injector 20 configured to inject one or more fluids, such as the illustrated injectate 21, such as a flushing fluid, an imaging contrast agent (e.g., a radiopaque contrast agent), and / or other fluids. Imaging system 10 may further include an implant, such as implant 31, that may be implanted into the patient via a delivery device, such as implant delivery device 30 and / or implant delivery catheter 80.

[0070] In some embodiments, the imaging probe 100 and / or other components of the imaging system 10 are configured and arranged similarly to similar components described in applicant's co-pending U.S. patent application Ser. No. 15 / 566,041, filed Oct. 12, 2017, entitled "Micro-Optical Probe for Neurology," the contents of which are incorporated herein by reference in their entirety for all purposes. The imaging probe 100 may be configured and arranged to collect image data from a patient site, such as an intravascular cardiac site, an intracranial site, or other site accessible via the patient's vascular system. In some embodiments, the imaging system 10 is configured and arranged similarly to similar systems and methods of use described in applicant's co-pending U.S. patent application Ser. No. 16 / 820,991, filed Mar. 27, 2020, entitled "Imaging System with Imaging Probe and Delivery Device," the contents of which are incorporated herein by reference in their entirety for all purposes.

[0071] Delivery catheter 80 includes shaft 81 as an elongate shaft having a lumen 84 extending therethrough and a connector 82 disposed at the proximal end of shaft 81. Connector 82 may include a Touhy connector or a valved connector, such as a valved connector configured to prevent fluid from exiting the associated delivery catheter 80 (with or without a separate shaft disposed within connector 82). Connector 82 may include ports 83, such as ports constructed and arranged to allow the introduction of fluid into delivery catheter 80 and / or the removal of fluid from delivery catheter 80. In some embodiments, a flushing fluid as described herein is introduced through one or more ports 83, for example, to remove blood or other undesirable material from a location proximal to optical assembly 115 (e.g., from a location proximal to optical assembly 115 to a location distal to optical assembly 115). Port 83 may be disposed on a side of connector 82 and may include a luer fitting, cap, and / or valve. The shaft 81, connector 82, and port 83 may each comprise standard materials and be similar in construction to commercially available introducers, guide catheters, diagnostic catheters, mid-catheters, and microcatheters used in interventional procedures. The delivery catheter 80 may comprise a catheter configured to deliver the imaging probe 100 to an intracerebral location, an intracardiac location, and / or another location within a patient.

[0072] The imaging system 10 may include two or more delivery catheters 80, e.g., three or more delivery catheters 80. The multiple delivery catheters 80 may include at least one vascular introducer and other delivery catheters 80 that can be inserted into a patient's body after the vascular introducer is placed through the patient's skin. The two or more delivery catheters 80 may collectively have a set of inner diameters (ID) and outer diameters (OD), such that, for example, a first delivery catheter 80 slidably receives a second delivery catheter 80 (e.g., the outer diameter of the second delivery catheter is equal to or smaller than the inner diameter of the first delivery catheter), and a second delivery catheter 80 slidably receives a third delivery catheter 80 (e.g., the outer diameter of the third delivery catheter is equal to or smaller than the inner diameter of the second delivery catheter). In these configurations, for example, a first delivery catheter 80 can be advanced to a first anatomical location, and a second delivery catheter 80 can be advanced through the first delivery catheter to a second anatomical location distal or remote (hereinafter "distal") relative to the first anatomical location, using successive delivery catheters 80 as needed. In some embodiments, the delivery catheter 80 can be similar in structure and arrangement to like components described in applicant's co-pending U.S. patent application Ser. No. 16 / 820,991, filed March 27, 2020, entitled "Imaging System with Imaging Probe and Delivery Apparatus," the contents of which are incorporated herein by reference in their entirety for all purposes.

[0073] The imaging probe 100 comprises an elongate body having an elongate shaft 120 as one or more elongate shafts and / or tubes. The shaft 120 comprises a proximal end 1201, a distal end 1209, and a lumen 1205 extending between the proximal end 1201 and the distal end 1209. In some embodiments, the lumen 1205 may comprise multiple coaxial lumens within one or more of the elongate shafts 120, such as one or more lumens that abut each other to define a single lumen 1205. In some embodiments, at least a portion of the shaft 120 comprises a torque shaft. In some embodiments, a portion of the shaft 120 has a braided structure. In some embodiments, a portion of the shaft 120 comprises a helically cut tube (e.g., a helically cut metal tube). In some embodiments, the pitch of the helical cut may vary along the length of the cut, for example, to vary the stiffness of the shaft 120 along the length of the cut. The portion of the shaft 120 may comprise a tube made of a nickel-titanium alloy. The shaft 120 operably surrounds the optical core 110 as a rotatable optical fiber. The optical core 110 is disposed, for example, within a lumen 1205 and has a proximal end 1101 and a distal end 1109. The optical core 110 may comprise a dispersion-shifted optical fiber, such as a depressed-clad dispersion-shifted fiber (e.g., a non-zero dispersion-shifted (NZDS) fiber). The shaft 120 further comprises a distal portion 1208 having a window 130 that is a transparent window (e.g., a window that is relatively transparent to one or more frequencies of light transmitted through the optical core 110). The optical assembly 115 is operably attached to the distal end 1109 of the optical core 110. The optical assembly 115 is disposed within the window 130 of the shaft 120. The optical assembly 115 may comprise a GRIN lens optically coupled to the distal end 1109 of the optical core 110.The optical assembly 115 may have a structure and arrangement similar to the optical assembly 115 described in the applicant's co-pending U.S. patent application Ser. No. 16 / 764,087, filed May 14, 2020, entitled "Imaging System," and the applicant's co-pending U.S. patent application Ser. No. 17 / 276,500, filed March 16, 2021, entitled "Imaging System with Optical Path," the contents of each of which are incorporated herein by reference in their entirety for all purposes. A connector assembly 150 is disposed at the proximal end of the shaft 120. The connector assembly 150 operably attaches the imaging probe 100 to the rotation assembly 500, as described herein. The connector assembly 150 surrounds and is operably attached to an optical connector 161, which is fixedly attached to the proximal end of the optical core 110. A second connector, pullback connector 180 (connector 180), is disposed on shaft 120. Connector 180 is detachable and may be adjustably positioned along the length of shaft 120. Connector 180 may be positioned along shaft 120 adjacent to the proximal end of delivery catheter 80, such as by a clinician, operator, or other user of system 10 (herein "user" or "operator"), after imaging probe 100 has been inserted into a patient's body via delivery catheter 80. Shaft 120 may include a portion between connector assembly 150 and the location where connector 180 is positioned, a proximal portion of shaft 120 (e.g., proximal portion of imaging probe 100), and a service loop 185, which adjusts slack in shaft 120. In some embodiments, optical core 110 comprises a single length of optical fiber without any splices along its length. In some embodiments, the imaging probe 100 includes a single optical splice, such as a splice between the optical assembly 115 and the distal end 1109 of the optical core 110 (e.g., in the absence of a splice along the length of the optical core 110).

[0074] In some embodiments, shaft 120 comprises a multi-piece structure, such as an assembly of two or more tubes that can be connected in various ways. In some embodiments, one or more tubes of shaft 120 may comprise tubing made of polyethylene terephthalate (PET), such as when a PET tube surrounds and forms a joint between two axially aligned tubes (e.g., two portions of shaft 120). In some embodiments, one or more PET tubes are tensioned after assembly (e.g., by longitudinally stretching the tubes when shaft 120 is assembled), for example, to prevent or at least reduce the tendency of the PET tube to wrinkle while shaft 120 is advanced through a tortuous path. In some embodiments, one or more portions of shaft 120 comprise a coating made of one, two, or more materials and / or surface modification processes, for example, to provide a hydrophilic or lubricious coating. In some embodiments, one or more metal portions (e.g., nickel titanium portions) of shaft 120 are surrounded by a tube (e.g., a polymer tube), such as to improve adhesion of a coating to that portion of shaft 120.

[0075] The imaging probe 100 may include one or more visualized markers along its length (e.g., along the shaft 120), as shown in the figures, markers 131a-131b (hereinafter also referred to as "markers 131"). The markers 131 may include markers selected from the group consisting of radiopaque markers, ultrasound-reflective markers, magnetic markers, ferrous materials, and combinations of one or more thereof. In some embodiments, the markers 131 include markers positioned at certain locations (e.g., within and / or at least proximate to the distal portion 1208) to assist a user of the imaging system 10 in performing a pullback operation (hereinafter "pullback" or "pullback"). This ensures that the tip 119 is positioned distal to the proximal end of the implant after the pullback is completed (e.g., so that the imaging probe 100 can be safely advanced through the implant after the pullback).

[0076] In some embodiments, the system 10 is configured to perform the pullback process, and the system 10 is further configured to initiate the pullback process based on analysis of an electrocardiogram (EKG) signal, such as an EKG signal generated via analysis of the OCT data by algorithm 51 as described with reference to FIG. 7 and the description herein.

[0077] In some embodiments, the imaging probe 100 includes a viscous damping material, gel 118 (e.g., injected or otherwise provided during manufacturing), disposed within the shaft 120 and surrounding the optical assembly 115 and a distal portion of the optical core 110. The gel 118 may include a non-Newtonian fluid, such as a shear-thinning fluid. In some embodiments, the gel 118 has a static viscosity greater than 500 centipoise and a shear viscosity less than the static viscosity. In these embodiments, the ratio of the static viscosity to the shear viscosity of the gel 118 may be between 1.2:1 and 100:1. In some embodiments, the gel 118 is injected (e.g., during the manufacturing process) through the distal end of the window 130. In some embodiments, the gel 118 includes a gel that is visible under UV light (e.g., if the gel 118 includes one or more materials that fluoresce under UV light). In some embodiments, during the manufacturing process in which gel 118 is injected into shaft 120 through window 130, shaft 120 is illuminated with UV light while the injection process is controllably monitored (e.g., so that injection is stopped when gel 118 has sufficiently advanced into shaft 120). Gel 118 may include a gel as described with reference to applicant's co-pending U.S. patent application Ser. No. 15 / 566,041, filed Oct. 12, 2017, entitled "Micro-Optical Probe for Neurology," and applicant's co-pending U.S. patent application Ser. No. 16 / 764,087, filed May 14, 2020, entitled "Imaging System," the contents of each of which are incorporated herein by reference in their entirety for all purposes.

[0078] The imaging probe 100 may include a distal tip 119. In some embodiments, the distal tip 119 may include a spring tip configured to improve the “navigability” (trackability and / or steerability) of the imaging probe 100, for example, within tortuous paths (e.g., within the blood vessels or other ducts of the brain or heart having tortuous paths). In some embodiments, the spring tip 119 has a length of 5 mm to 100 mm (e.g., a spring having a length of 5 mm to 100 mm). In some embodiments, the spring tip 119 may include a user-shapeable spring tip (e.g., at least a portion of the spring tip 119 is malleable). The imaging probe 100 may be rotated (e.g., via a connector 180) to adjust the orientation of the non-linear portion of the spring tip 119 (e.g., to adjust the trajectory of the spring tip 119 within the patient's vasculature). Alternatively or additionally, the distal tip 119 may comprise a cap, plug, or other element configured to seal the distal opening of the window 130. In some embodiments, the distal tip 119 may comprise a radiopaque marker configured to enhance visibility of the imaging probe 100 under x-ray or fluoroscopy. In some embodiments, the distal tip 119 may comprise a relatively short lumen guidewire pathway that allows for "quick exchange" movement of the imaging probe 100 over a guidewire (not shown) of the system 10.

[0079] In some embodiments, at least the distal portion of the imaging probe 100 (e.g., the distal portion 1208 of the shaft 120 surrounding the optical assembly 115) has an outer diameter of 0.030 inches or less, and may have an outer diameter of, for example, 0.025 inches or less, 0.020 inches or less, or 0.016 inches or less.

[0080] In some embodiments, the imaging probe 100 may be constructed and configured for use in intravascular neurological procedures (e.g., procedures in which blood, vasculature, and other tissues adjacent to the brain are visualized, and / or procedures in which devices placed temporarily or permanently adjacent to the brain are visualized). An imaging probe 100 configured for use in neurological procedures may have an overall length of at least 150 cm, such as a length of approximately 300 cm. Alternatively or additionally, the imaging probe 100 may be constructed and configured for use in intravascular cardiac procedures (e.g., procedures in which blood, vasculature, and other tissues adjacent to the heart are visualized, and / or procedures in which devices placed temporarily or permanently adjacent to the heart are visualized). An imaging probe 100 configured for use in cardiovascular procedures may have an overall length of at least 120 cm, such as a overall length of approximately 280 cm (e.g., to allow placement of the proximal end of the probe 100 outside of a sterile field). In some embodiments, such as when deployed outside a sterile field, the imaging probe 100 may have a length greater than 220 cm and / or less than 320 cm.

[0081] The rotational assembly 500 includes a connector assembly 510 operably attached to a rotational joint 550. The rotational assembly 500 further includes a power element 530 as a motor or other source of rotational energy. The power element 530 is operably attached to the rotational joint 550 via a link assembly 540. In some embodiments, the link assembly 540 includes one or more gears, belts, pulleys, or other power transmission mechanisms. The power element 530 is capable of driving (e.g., rotating via the link assembly 540) the rotational joint 550 (and the optical core 110) at a speed of at least 100 revolutions per second, e.g., 200 revolutions per second or more, 250 revolutions per second or more, 400 revolutions per second or more, or between 20 and 1000 revolutions per second. The power element 530 may include a mechanism selected from the group consisting of a motor, a servo, a stepper motor (e.g., a stepper motor including a gearbox), a linear actuator, a hollow core motor, and combinations thereof. In some embodiments, the rotation assembly 500 is configured to rotate the optical assembly 115 and the rotatable optical core 110 in unison.

[0082] The connector assembly 510 is operably attached to the connector assembly 150 of the imaging probe 100, allowing the optical connector 161 to operably engage the rotary joint 550. In some embodiments, the connector assembly 510 operably engages the connector assembly 150. In some embodiments, the connector assembly 510 operably engages the connector assembly 150, thereby allowing the rotary joint 550 and the optical connector 161 to rotate freely within the engaged assembly.

[0083] The retraction assembly 800 includes a connector assembly 820 operably attached to a reference point, such as the connector 82 of the delivery catheter 80, for example, to establish a reference point for the retraction assembly 800 relative to the patient. The connector assembly 820 can be attached to a reference point, such as a patient introduction device, a surgical table, and / or another fixed or semi-fixed reference point. A retraction element, a puller 850, is attachable to and detachable from the connector 180 of the imaging probe 100, such as via a carrier 855. The retraction assembly 800 retracts at least a portion of the imaging probe 100 (e.g., a portion of the imaging probe 100 distal to the attached connector 180) relative to the established reference point. In some embodiments, the retraction assembly 800 is configured to retract at least a portion of the imaging probe 100 (e.g., at least the optical assembly 115 and a portion of the shaft 120) at a rate of 5 mm / sec to 100 mm / sec, for example, 60 mm / sec. In some embodiments, the retraction assembly 800 is configured to retract at least a portion of the imaging probe 100 at a rate of at least 60 mm / sec, at least 80 mm / sec, at least 100 mm / sec, and / or at least 150 mm / sec. Additionally or alternatively, the pullback process may be performed for 0.5 to 25 seconds, e.g., about 20 seconds (e.g., at 5 mm / sec over a distance of 100 mm). The service loop 185 of the imaging probe 100 may be disposed between the retraction assembly 800 and / or at least the connector assembly 820 and the rotating assembly 500, thereby allowing the imaging probe 100 to be retracted relative to the patient while the rotating assembly 500 remains stationary (e.g., attached to a portion of the operating table and / or console 50).

[0084] Retraction assembly 800 further comprises a linear drive power element 830. In some embodiments, power element 830 may comprise a linear actuator, a worm drive operably attached to a motor, a pulley system, and / or other linear force transmission mechanism. Puller 850 may be operably attached to power element 830 via a link assembly 890. In some embodiments, link assembly 890 may comprise one or more components of a "pullback assembly," as described with reference to FIGS. 1A and 2A. Alternatively or additionally, link assembly 890 may comprise one or more components of a closed-type pullback connector, as described with reference to FIG. 1B. One or more components of link assembly 890 may establish a reference frame (e.g., an internal pullback reference) between puller 850 and power element 830 such that a pullback force is applied from power element 830 through link assembly 890 to puller 850, causing puller 850 to retract relative to a distal portion of link assembly 890 (e.g., relative to the distal end of sheath 895 as described with reference to FIG. 1A ). In some embodiments, the distal end of link assembly 890 and connector assembly 820 are fixed relative to one another, and puller 850 translates linearly between the distal end of link assembly 890 and connector assembly 820 in response to a force applied by power element 830.

[0085] The console 50 includes an imaging assembly 300, a user interface 55, a processor 52, and one or more algorithms 51. The processor 52 may include one or more memory storage elements, such as one or more memory circuits, that store software routines, algorithms (e.g., algorithm 51), other operational instructions for the system 10, and data acquired by the imaging probe 100, the second imaging device 15, and / or other components of the system 10. The imaging assembly 300 may be configured to provide light to and collect light from the optical assembly 115 (e.g., via the optical core 110). The imaging assembly 300 may include a light source 310. The light source 310 may include one or more light sources configured to provide light of one or more wavelengths to the optical assembly 115 via the optical core 110. The light source 310 is configured to provide light to the optical assembly 115 (via the optical core 110) so that image data may be collected, including cross-sectional, longitudinal, and / or volumetric information related to the patient region or implanted device being imaged. The light source 310 may be configured to provide light such that the collected image data includes tissue characteristics within the patient region being imaged, such as to quantify, identify, or otherwise provide information related to a patient disease or disorder present within the patient region being imaged. The light source 310 may deliver broadband light and be configured to have a center wavelength in the range of 350 nm to 2500 nm, 800 nm to 1700 nm, 1280 nm to 1310 nm, or approximately 1300 nm (e.g., light delivered in a sweep range of 1250 nm to 1350 nm). The light source 310 may have a sweep rate of at least 50 KHz. In some embodiments, the light source 310 has a sweep rate of at least 100 KHz, and may have a sweep rate of, for example, at least 200 Khz, at least 300 KHz, at least 400 KHz, and / or at least 500 KHz.These faster sweep speeds offer many advantages, such as providing higher frame rates and being compatible with rapid pullback and rotation speeds. For example, a higher sweep speed allows the required sampling density (e.g., the amount of luminal surface area swept by the rotating beam) to be achieved in a shorter time. This is advantageous in most situations, especially when there is relative motion between the probe and the surface / tissue being imaged, such as the arteries of a beating heart. The bandwidth of the light source 310 may be selected to achieve the desired resolution and can be varied according to the needs of the intended use of the imaging system 10. In some embodiments, the bandwidth is approximately 5% to 15% of the central wavelength, allowing for a resolution of 20 μm to 5 μm. The light source 310 can be configured to deliver light at a power level that meets ANSI Class 1 ("eye safety") limits, although higher power levels may be employed. In some embodiments, the light source 310 delivers light in the 1.3 μm band at a power level of approximately 20 mW. As the central wavelength of the delivered light increases, tissue light scattering decreases, but water absorption increases. The light source 310 may transmit light at a wavelength of approximately 1300 nm to balance these two effects. The light source 310 may be configured to deliver shorter wavelength light (e.g., approximately 800 nm light) for traversing a patient region being imaged that contains a large amount of fluid. Alternatively or additionally, the light source 310 may be configured to deliver longer wavelength light (e.g., approximately 1700 nm light), such as to reduce high levels of scattering within the patient region being imaged. In some embodiments, the light source 310 comprises a tunable light source (e.g., the light source 310 emits a single wavelength that is repeatedly changed over time) and / or comprises a broadband light source. The light source 310 may comprise a single spatial mode light source or a multimode light source (e.g., a multimode light source with spatial filtering).

[0086] The light source 310 may have a relatively long effective coherence length, e.g., greater than 10 mm, at least 50 mm, at all frequencies within the source bandwidth. This coherence length capability enables a longer effective scan range achievable by the system 10. This is because light returning from a distant object (e.g., tissue) being imaged must maintain phase coherence with the returning reference light to produce detectable interference fringes. For swept-source lasers, the instantaneous linewidth is very narrow (i.e., as the laser sweeps, it outputs a very narrow frequency band that varies with the sweep rate). Similarly, for broad-bandwidth light sources, the detector geometry must be able to select a very narrow linewidth from the source spectrum. The coherence length is inversely proportional to the linewidth. A longer scan range allows for imaging larger or more distant objects (e.g., imaging more distal tissue). Current systems have a short coherence length, which is associated with a reduced image capture range and artifacts (ghosting) arising from objects outside the effective scanning range.

[0087] The console 50 may include one or more algorithms, such as the illustrated algorithm 51, that may be configured to adjust (e.g., automatically and / or semi-automatically adjust) one or more operational parameters of the imaging system 10, such as the operational parameters of the console 50, the imaging probe 100, and / or the delivery catheter. The console 50 may further include a processor 52 as a processing assembly configured to execute the algorithm 51 and / or perform any type of data processing, such as digital signal processing as described with reference to FIG. 4. Additionally or alternatively, the algorithm 51 may be configured to adjust operational parameters of a separate device, such as the injector 20 or implant delivery apparatus 30 as described herein. In some embodiments, the algorithm 51 is configured to adjust the operational parameters based on one or more sensor signals, such as sensor signals provided by sensor-based functional elements of the inventive concepts described herein. The algorithm 51 can be configured to adjust operational parameters selected from the group consisting of rotational parameters such as the rotational speed of the optical core 110 and / or the optical assembly 115, retraction parameters of the shaft 120 and / or the optical assembly 115 such as retraction speed, distance, start position, end position, and / or retraction start timing (e.g., when retraction is initiated), positional parameters such as the position of the optical assembly 115, image display parameters such as a line spacing parameter such as the number of lines per frame, scaling of display size relative to vessel diameter, configuration parameters of the imaging probe 100, injectate 21 parameters such as a saline-to-contrast ratio configured to determine an appropriate refractive index, light source 310 parameters such as the delivered power and / or frequency of the delivered light, and combinations of one or more of these. In some embodiments, the algorithm 51 is configured to adjust retraction parameters, such as a parameter that causes the initiation of (trigger) pullback.The pullback is initiated based on a parameter selected from the group consisting of, for example, lumen flushing (the lumen proximate the optical assembly 115 is sufficiently cleared of blood and other material that would interfere with the creation of an image), an indicator signal received from the injector 20 (e.g., a signal indicating that sufficient flushing fluid has been delivered), a change in collected image data (e.g., a change in the image that correlates to adequate evacuation of blood from around the optical assembly 115 is detected based on the collected image data), and a combination of one or more of these. In some embodiments, the algorithm 51 is configured to adjust configuration parameters of the imaging system 10 associated with the imaging probe 100, such as when the algorithm 51 identifies the attached imaging probe 100 (e.g., automatically via an RF identifier and / or other embedded identifier) ​​and adjusts parameters of the imaging system 10, such as the optical path length parameter, the dispersion parameter, and / or other parameters listed above.

[0088] In some embodiments, the algorithm 51 is configured to cause (trigger) the initiation of pullback based on a time gate parameter. In some embodiments, a T-wave trigger (e.g., provided by a separate device) may be provided to the console 50 to initiate pullback when a low-motion portion of the cardiac cycle is detected. As an alternative to or in addition to a T-wave trigger, a motion pattern (e.g., a relative motion pattern) may be tracked (e.g., using angiography) between one or more portions (e.g., components or other features) of the probe 100 and relatively stable (e.g., non-moving) portions of the patient's anatomy (e.g., ribs, sternum, and / or spine).

[0089] When the console 50 of the system 10 is first installed in a clinical setting (e.g., a catheterization lab), a simple calibration routine can be used to set the latency between the angiography system and the system 10. Essentially, the probe 100 is provided, the clinical angiography system is activated, and an angiography image feed is provided to the console 50 (e.g., using any standard analog or digital video connection). The video frame provided by the angiography system is registered according to the clock of the console 50 and used as a reference time frame. A pullback of the probe 100 (e.g., pullback in patient or non-patient simulation mode) is initiated (also coordinated by the clock of the console 50), and an angiogram is captured. A trained user or technician reviews the angiography image frames and designates the first frame in which motion is detected. This process sets the associated latency according to the clock of the console 50. The motion detection described above may be automated, for example, using a neural network trained to recognize movement of the probe 100 (e.g., movement of the marker band on the probe 100) during angiography.

[0090] In some embodiments, the calibration process for setting a latency between the angiography system and system 10 and the imaging process performed during the relatively low motion of the cardiac cycle include the following steps: First, once the probe 100 is inserted into the patient and positioned within the target anatomical structure (tissue), an angiogram begins. Second, system 10 analyzes the relative motion between one or more parts of the probe 100 (e.g., the motion of a marker band or other part of the probe 100 that tracks the patient's beating heart) and more stable features in the image, such as an image of the sternum or spine. Once the cardiac rhythm is established and the low motion segments are identified (this analysis, which may be velocity vector analysis, neural network analysis, etc., typically takes 5-10 cardiac cycles), an indicator is provided and the "metronome" of system 10 is started. System 10 can reference the output of the metronome because one or more portions of probe 100 (e.g., one or more marker bands) can be radio-invisible during the flushing period, such as when a radiopaque flushing material is injected to remove blood from the target area being imaged. In another embodiment, a non-radiopaque flushing material (e.g., dextran) may be used. In a third step, flushing is initiated, for example, by an operator or by an automated method controlled by system 10. Flushing should continue for multiple cardiac cycles, e.g., 3-5 cardiac cycles. In a fourth step, system 10 detects clearing of the vessel being imaged while analyzing one or more images generated by system 10. In a fifth step, during a low-motion portion of the metronome (e.g., a predicted low-motion portion of the cardiac cycle), pullback is initiated to account for latency between system 10 and the previously installed angiography system. In some embodiments, the pullback ends about halfway through the cardiac cycle or less, e.g., to remain within the low motion portion of the cardiac cycle. System 10 may be configured to provide a pullback speed of at least 50 mm / sec, such as at least 100 mm / sec or 200 mm / sec.In a sixth step, a pullback sequence of images with minimal motion artifacts may be provided to the operator and / or used for CFD calculations, implant (e.g., stent) length measurements, etc. As described herein, using image captures when there is little motion avoids errors associated with motion artifacts, particularly longitudinal motion artifacts.

[0091] In some embodiments, algorithm 51 is configured to perform one, two, or more analyses (e.g., filtering or other image processing analyses) of the OCT data that provide image stabilization (e.g., of the displayed OCT data).

[0092] The imaging system 10 may include one or more interconnecting cables, such as a bus 58. The bus 58 may operably connect the rotation assembly 500 to the console 50, the retraction assembly 800 to the console 50, and / or the rotation assembly 500 to the retraction assembly 800. The bus 58 may include one or more optical transmission fibers, electrical transmission cables, fluid conduits, and combinations of one or more of these. In some embodiments, the bus 58 includes at least one optical transmission fiber that optically couples the rotation joint 550 to the imaging assembly 300 of the console 50. Additionally or alternatively, the bus 58 includes power and / or data transmission cables that transmit power and / or power information to one or more of the powering elements 530, 830.

[0093] The second imaging device 15 may comprise one or more imaging devices selected from the group consisting of an X-ray device, a single or dual plane fluoroscopy device, a CT scanner, an MRI device, a PET scanner, an ultrasound imager, and one or more combinations thereof. In some embodiments, the second imaging device 15 includes a device configured to perform rotational angiography.

[0094] The treatment device 16 may include an occlusion treatment device or other treatment device selected from the group consisting of a balloon catheter, a drug-eluting balloon, an aspiration catheter, a sonolysis device, an atherectomy device, a thrombus removal device such as a stent retriever, a Trevo™ stentriever, a Solitaire™ stentriever, a Revive™ stentriever, an Eric™ stentriever, a Lazarus™ stentriever, a stent delivery catheter, a microblade implant, an embolization system, a WEB™ Embolization System, a Luna™ Embolization System, a Medina™ Embolization System, or one or more combinations thereof, configured and arranged to dilate a stenosis or other narrowing in a patient's blood vessel or other vessel. In some embodiments, the imaging probe 100 is configured to collect data related to the treatment device 16 (e.g., position, orientation, and / or other configuration data of the treatment device 16) after the treatment device 16 is inserted into the patient.

[0095] The patient monitoring device 17 may include one or more monitoring devices (monitoring devices) selected from the group consisting of an electrocardiogram monitor, an electroencephalogram monitor, a blood pressure monitor, a blood flow monitor, a respiratory monitor, a patient movement monitor (patient monitor), a T-wave trigger monitor, and combinations thereof.

[0096] The injector 20 may comprise a power injector, syringe pump, peristaltic pump, or other fluid delivery device configured to inject contrast agents, such as radiopaque contrast agents, and / or other fluids. In some embodiments, the injector 20 is configured to deliver contrast agents and / or other fluids (e.g., contrast agents, saline, and / or dextran). In some embodiments, the injector 20 delivers fluids using the flushing process described herein. In some embodiments, the injector 20 delivers contrast agents or other fluids through a delivery catheter 80 having an inner diameter of 5 French to 9 French, a delivery catheter 80 having an inner diameter of 0.53 inches to 0.70 inches, or a delivery catheter 80 having an inner diameter of 0.0165 inches to 0.027 inches. In some embodiments, the contrast agents or other fluids are delivered through a smaller diameter delivery catheter, such as a 4 French (e.g., for distal injection). In some embodiments, the injector 20 delivers contrast and / or other fluids through the lumen of one or more delivery catheters 80, within which one or more smaller delivery catheters 80 are also present. In some embodiments, the injector 20 is configured to deliver two different fluids simultaneously and / or sequentially, such as, for example, a first fluid from a first reservoir containing a first concentration of contrast, and a second fluid from a second reservoir containing less or no contrast.

[0097] The injectate 21 may include a fluid selected from the group consisting of an optically transparent material, saline, a visualizeable material, a contrast agent, dextran, an ultrasound-reflective material, a magnetic material, and combinations thereof. The injectate 21 may include a contrast agent and saline. The injectate 21 may include at least 20% contrast agent. During acquisition of image data, a flushing process may be performed by, for example, delivering one or more fluids, the injectate 21 (e.g., pushed by the injector 20 or other fluid delivery device), to remove blood or other somewhat opaque material (hereinafter referred to as "opaque material") proximate the optical assembly 115 (e.g., to remove opaque material between the optical assembly 115 and a delivery catheter and / or between the optical assembly 115 and a blood vessel wall), thereby, for example, allowing light dispensed from the optical assembly 115 to reach and reflect back from all tissues and other objects being imaged. In such flushing embodiments, the injectate 21 may include an optically transparent material, such as saline. Injectate 21 may include one or more visualizeable materials as described herein.

[0098] Alternatively or in addition to its use in the flushing process, the injectate 21 may include a material configured to be viewed by a second imaging device 15. For example, the injectate 21 may include a contrast agent configured to be viewed by a second imaging device 15 including a fluoroscope or other x-ray device, an ultrasound reflective material configured to be viewed by a second imaging device 15 including an ultrasound imager, and / or a magnetic material configured to be viewed by a second imaging device 15 including an MRI device.

[0099] The implant 31 may include an implant (e.g., a temporary or long-term implant) for treating one or more of a vascular occlusion or an aneurysm. In some embodiments, the implant 31 includes one or more implants selected from the group consisting of a flow diverter, a Pipeline™ flow diverter, a Surpass™ flow diverter, an embolic coil, a stent, a Wingspan™ stent, a covered stent, an implant for treating an aneurysm, and a combination of one or more of the foregoing.

[0100] The implant delivery device 30 may include a catheter or other tool used to deliver the implant 31, such as when the implant 31 includes a self-expanding portion or a balloon-expandable portion. In some embodiments, the imaging system 10 includes an imaging probe 100, one or more implants 31, and / or one or more implant delivery devices 30. In some embodiments, the imaging probe 100 is configured to collect data related to the implant 31 and / or implant delivery device 30 (e.g., the anatomical position, orientation, and / or other configuration data of the implant 31 and / or implant delivery device 30) after the implant 31 and / or implant delivery device 30 are inserted into a patient.

[0101] In some embodiments, one or more system components, such as the console 50, delivery catheter 80, imaging probe 100, rotation assembly 500, retraction assembly 800, treatment device 16, injector 20, and / or implant delivery device 30, further include one or more functional elements (hereinafter referred to as "functional elements"), such as illustrated functional elements 59, 89, 199, 599, 899, 99a, 99b, and / or 99c. Each functional element may include at least two functional elements. Each functional element may include one or more elements selected from the group consisting of sensors, transducers, and combinations thereof. The functional element may include a sensor configured to generate a signal. The functional element may include a sensor selected from the group consisting of a physiological sensor, a pressure sensor, a strain gauge, a position sensor, a GPS sensor, an accelerometer, a temperature sensor, a magnetic sensor, a chemical sensor, a biochemical sensor, a protein sensor, a flow sensor such as an ultrasonic flow sensor, a gas detection sensor such as an ultrasonic bubble detector, a sound sensor such as an ultrasonic sensor, and combinations thereof. The sensor may include a physiological sensor selected from the group consisting of a pressure sensor such as a blood pressure sensor, a blood gas sensor, a flow sensor such as a blood flow sensor, a temperature sensor such as a blood temperature sensor or other tissue temperature sensor, and combinations thereof. The sensor may include a position sensor configured to generate a signal related to a vascular pathway shape (e.g., a two-dimensional or three-dimensional vascular pathway shape). The sensor may include a magnetic sensor. The sensor may include a flow sensor. The system may further include an algorithm configured to process the signal generated by the sensor-based functional element. Each functional element may include one or more transducers. Each functional element may include one or more transducers selected from the group consisting of a heating element, such as a heating element configured to deliver heat sufficient to ablate tissue, a cooling element, such as a cooling element configured to deliver cryogenic energy to ablate tissue, an acoustic transducer, such as an ultrasound transducer, a vibration transducer, and combinations thereof.

[0102] In some embodiments, the imaging probe 100 includes a fluid propulsion element and / or fluid pressurizing element (hereinafter "fluid pressurizing element"), FPE 1500. The FPE 1500 may be configured to prevent and / or reduce the presence of air bubbles in the gel 118 proximate the optical assembly 115. The FPE 1500 may be fixedly attached to the optical core 110 such that rotation of the optical core 110 rotates the fluid propulsion element, creating a pressure increase in the gel 118 configured to reduce the presence of air bubbles from locations proximate the optical assembly 115. Such one or more fluid pressurizing elements, FPE 1500, may reduce the likelihood of air bubbles forming in the gel 118, reduce the size of air bubbles in the gel 118, and / or redirect any air bubbles formed in the gel 118 away from locations that could adversely affect the collection of image data by the optical assembly 115 (e.g., redirect air bubbles away from the optical assembly 115). In some embodiments, the fluid propulsion element, FPE1500, of the imaging probe 100 has a structure and arrangement similar to the fluid propulsion element described in applicant's co-pending International Patent Application No. PCT / US2020 / 030616, filed April 30, 2020, entitled "Imaging Probe with Fluid Pressurizing Element," the contents of which are incorporated herein by reference for all purposes.

[0103] In some embodiments, the imaging probe 100 has an overall length of at least 120 cm, e.g., at least 160 cm, and may be, for example, about 280 cm. In some embodiments, the imaging probe 100 has an overall length of 350 cm or less. In some embodiments, the imaging probe 100 has an insertable length configured for insertion into a patient (hereinafter, "insertable length") of at least 90 cm, e.g., at least 100 cm, and may be, for example, about 145 cm. In some embodiments, the imaging probe 100 has an insertable length of 250 cm or less, e.g., 200 cm or less. In some embodiments, the tip 119 comprises a spring tip having a length of at least 5 mm, e.g., at least 25 mm, e.g., about 15 mm. In some embodiments, the tip 119 comprises a spring tip having a length of 75 mm or less, e.g., 30 mm or less. In some embodiments, the distal portion of shaft 120 (e.g., window 130) has an outer diameter of less than 2 Fr, e.g., less than 1.4 Fr, e.g., about 1.1 Fr. In some embodiments, the distal portion of shaft 120 (e.g., window 130) has an outer diameter of at least 0.5 Fr, e.g., at least 0.9 Fr. In some embodiments, shaft 120 is made of one or more materials selected from the group consisting of polyetheretherketone (PEEK), nylon, polyether block amide, nickel titanium alloy, and combinations thereof.

[0104] In some embodiments, the minimum radius of curvature of at least a portion (e.g., the most flexible portion) of imaging probe 100 is less than 5 mm, such as less than 4 mm, such as less than 3 mm, such as less than 2 mm, such as about 1 mm. In some embodiments, optical core 110 comprises an optical fiber having a diameter less than 120 μm, such as less than 100 μm, less than 80 μm, less than 60 μm, such as about 40 μm. In some embodiments, the numerical aperture of optical core 110 is one or more of 0.11, 0.14, 0.16, 0.17, 0.18, 0.20, and / or 0.25. In some embodiments, optical assembly 115 comprises a lens selected from the group consisting of a molded lens, a GRIN lens, a molded lens, a fused and polished lens, a lens having an axicon structure (e.g., an axicon nanostructure), and combinations thereof. In some embodiments, the outer diameter of the lenses of the optical assembly 115 may be less than 200 μm, such as less than 170 μm, such as less than 150 μm, such as less than 100 μm, or such as about 80 μm. In some embodiments, the length of the lenses of the optical assembly 115 may be less than 3 mm, such as less than 1.5 mm. In some embodiments, the length of the lenses of the optical assembly 115 may be at least 0.5 mm, such as at least 1 mm. In some embodiments, the focal length of the lenses of the optical assembly 115 may be at least 0.5 mm and / or 5.0 mm or less, such as at least 1.0 mm and / or 3.0 mm or less, such as about 0.5 mm. In some embodiments, the optical assembly 115 may have a longer focal length, such as to view structures outside of a blood vessel or other vessel into which the optical assembly 115 is inserted, as described below with reference to FIG. 9. The working distance (also called depth of field, confocal length, or Rayleigh range) of the optical assembly 115 may be up to 1 mm, for example up to 5 mm, for example up to 10 mm, for example greater than 1 mm and / or less than 5 mm.In some embodiments, the outer diameter of the optical assembly 115 is at least 80 μm and / or not more than 200 μm, e.g., at least 150 μm and / or not more than 170 μm, e.g., about 150 μm. In some embodiments, the system 10 (e.g., the retraction assembly 800) is configured to perform pullback of the probe 100 at a speed of at least 10 mm / sec and / or not more than 300 mm / sec, e.g., at least 50 mm / sec and / or not more than 200 mm / sec, e.g., about 100 mm / sec. In some embodiments, the system 10 (e.g., the retraction assembly 800) is configured to perform pullback by a distance of at least 25 mm and / or not more than 200 mm, e.g., at least 25 mm and / or not more than 150 mm, e.g., about 50 mm. In some embodiments, system 10 (e.g., retraction assembly 800) is configured to perform pullback over a period of at least 0.2 seconds and / or not more than 5.0 seconds, and the pullback period may be, for example, at least 0.5 seconds and / or not more than 2.0 seconds, or may be, for example, about 1.0 second. In some embodiments, system 10 (e.g., rotation assembly 500) is configured to rotate optical core 110 at an angular velocity of at least 20 revolutions per second and / or not more than 1000 revolutions per second, and the angular velocity may be, for example, at least 100 revolutions per second and / or not more than 500 revolutions per second, or may be, for example, about 250 revolutions per second. In some embodiments, the inner diameter of delivery catheter 80 is at least 0.016 inches and / or not more than 0.050 inches, and may be, for example, at least 0.016 inches and / or not more than 0.027 inches, or may be, for example, about 0.021 inches. In some embodiments, the sweep rate of the light source 310 is at least 20 kHz and / or not more than 2000 kHz, such as at least 50 kHz and / or not more than 500 kHz, for example, about 200 kHz.In some embodiments, the sweep bandwidth of the light source 310 is at least 30 nm and / or 250 nm or less, e.g., at least 50 nm and / or 150 nm or less, e.g., about 100 nm. In some embodiments, the center wavelength of the light source 310 is at least 800 nm and / or 1800 nm or less, e.g., at least 1200 nm and / or 1350 nm or less, e.g., about 1300 nm. In some embodiments, the light intensity of the light source 310 is at least 5 mW and / or 500 mW or less, e.g., at least 10 mW and / or 50 mW or less, e.g., about 20 mW.

[0105] 1A, a schematic diagram of an imaging system consistent with the concepts of the present invention is shown, the system including an imaging probe operably attachable to a patient interface module and a separate pullback module operably attachable to the patient interface module and the imaging probe. The imaging system 10 may include a patient interface module 200. The patient interface module 200 includes a housing 201 that encloses at least a portion of the rotation assembly 500 and at least a portion of the retraction assembly 800. The imaging system 10 may further include a second separate component, a pullback module 880 (module 880). The pullback module 880 includes a housing 881 that encloses at least a portion of the retraction assembly 800. The pullback module 880 and the patient interface module 200 may be operably attached to one another via a link assembly 890, which is a connector assembly. The pullback module 880 and the patient interface module 200 are constructed and arranged (by having separate housings) to be positionable in different locations (e.g., the link assembly 890 connecting the modules 880 and 200 may have a length of at least 15 cm so that the modules can be positioned at least 15 cm apart). For example, the patient interface module 200 may be positioned on or near a rail of a surgical table, and the pullback module 880 may be positioned near the patient's vascular access site (e.g., within 30 cm of the vascular access site where the imaging probe 100 enters the patient). The link assembly 890 may include a link 891 slidably received within a sheath 895. The link 891 is operably attached to the puller, and a proximal end 893 of the link 891 may include a connection point 842. The power element 830 may include a detachable connector 835 at the connection point 842. The components shown in FIG. 1A may be similar in structure and arrangement to similar components described elsewhere herein with reference to FIG. 1.

[0106] Pullback module 880 may include a connector assembly 820b operably attached to connector 82 of delivery catheter 80, as described with reference to FIGURE 2B. Connector assembly 845 may include a connector 840 operably attached to connector assembly 820a of patient interface module 200, as described with reference to FIGURE 2A.

[0107] Referring now to FIG. 1B, a schematic diagram of an imaging system consistent with the concepts of the present invention is shown, including an imaging probe operably attachable to a module having a first connector for attachment to a rotational power element and a second connector for attachment to a retraction power element. The imaging system 10 may include a patient interface module 200 as described herein. The imaging system 10 may further include a connector module 410. The module 410 includes a housing 411 that encloses at least a portion of the retraction assembly 800, the service loop 185 of the imaging probe 100, the connector assembly 150′, and the connector 840′. The module 410 may be configured to operably attach both the imaging probe 100 and a link puller 850′ to the patient interface module 200. The components shown in FIG. 1B may be similar in structure and arrangement to like components described elsewhere herein with reference to FIG. 1. The module 410 may be operably attached to a delivery catheter 480. The delivery catheter 480 may be of a similar structure and arrangement to the delivery catheter 80 described with reference to FIG. 1 . The delivery catheter 480 may include a window 485 as at least an optically transparent portion thereof. The window 485 may be located at or near a distal portion of the delivery catheter 480. The window 485 may comprise a material that is transparent to the imaging modality utilized by the imaging probe 100, for example, so that the imaging probe 100 can image through the window 485 when the optical assembly 115 is retracted within the window 485. In some embodiments, the module 410, the delivery catheter 480, and the imaging probe 100 collectively form a catheter assembly 490.

[0108] Referring now to FIG. 2A, a perspective view of a connector attached to a patient interface consistent with the concepts of the present invention is shown. The patient interface module 200 is configured to provide rotation to a rotatable optical core of the imaging probe and to provide power to translate at least a portion of the imaging probe, as described herein. The patient interface module 200 includes a rotation assembly 500 and at least a portion of a retraction assembly 800. A housing 201 surrounds the patient interface module 200. The patient interface module 200 may include one or more user interface elements, such as buttons 205a, 205b, as one or more inputs, and one or more outputs, such as an indicator 206, as shown. The patient interface module 200 includes a first physical connector assembly, connector assembly 510, for operably connecting to a connector assembly 150 as described herein. The patient interface module 200 may further include a second physical connector assembly, connector assembly 820a, for operably connecting to a connector 840, also as described herein. Connector assembly 150 and connector 840 may each comprise a bayonet-style connector configured and arranged to be at least partially inserted into connector assemblies 510, 820a, respectively. Connector assemblies 150 and connector 840 may then be rotated (e.g., rotated approximately 45 degrees) to lock their connection with connector assemblies 510, 820a, respectively, as described herein. Connector assembly 150 and / or connector 840 may comprise various forms of connectors, such as bayonet-style or other locking connectors.

[0109] Referring now to FIG. 2B, a perspective view of a pullback assembly consistent with the present concepts is shown. The pullback module 880 is operably attachable to a portion of the imaging probe 100 of the present concepts and provides a retraction force to the probe, thereby pulling at least a portion of the probe proximally relative to a patient (e.g., relative to a patient introducer), as described herein. The pullback module 880 may have a structure and arrangement similar to that of a pullback module as described in applicant's co-pending U.S. patent application Ser. No. 16 / 764,087, filed May 14, 2020, entitled "Imaging System," the contents of which are incorporated herein by reference in their entirety. The pullback module 880 is operably attachable to the distal end of a link 891 (not shown). The link assembly 890 may be slidably received through the pullback module 880. A sheath 895 may be fixedly attached to the proximal end of the module 880. Link 891 is slidably received along the length of module 880 and is operably attached at its distal end to puller 850 .

[0110] The pullback module 880 may include a two-part housing 881 including a top housing 881a and a bottom housing 881b. The module 880 may include a translating cart, the puller 850 (not shown, but positioned below the carrier 855 as described herein). The puller 850 may be configured to translate (move in parallel) within the module 880. The module 880 may include a biasing element, the spring 852 (not shown). The spring 852 may provide a biasing force to the puller 850, for example, to bias the puller 850 distally.

[0111] Upper housing 881a may include a first cavity, a retention port 884, and a second cavity, a trench 889. Retention port 884 and trench 889 may be separated by a protruding retention wall 888 (wall 888). Connector assembly 820b (physical connector assembly 820b) may include housing 881a's retention port 884, including wall 888, and a retention mechanism, a clip 885. Clip 885 may be configured to releasably engage the proximal end of a delivery catheter, such as connector (sheath connector) 82 of delivery catheter 80, for example, when connector 82 is a Tuohy-Borst connector. Physical connector assembly 820b may further include a biasing element, a spring 886 (not shown). Spring 886 may provide a biasing force to maintain clip 885 in an engaged position around connector 82.

[0112] The pullback module 880 may further comprise a carrier 855. The carrier 855 is operably attachable to the puller 850, for example, through a slot in the housing 881a. The carrier 855 is translatable within the trench 889 corresponding to the puller 850, which translates correspondingly with the link 891. The carrier 855 is operably attachable to a portion of the imaging probe 100, such as the pullback connector 180. The pullback connector 180 may comprise a "torquer" or other device attached to the shaft 120 of the imaging probe 100. The sheath 895 of the link assembly 890 can provide a frame of reference between the connector 840 and the pullback module 880, such that when the proximal end of the link 891 retracts relative to the connector 840, the distal end of the link 891 retracts toward the sheath 895 (i.e., toward the proximal end of the pullback module 880). This relative motion transfers power applied at connector 840 (e.g., via power element 830, as described herein) to puller 850. Puller 850 then transfers power to imaging probe 100, causing imaging probe 100 to retract relative to the patient.

[0113] In operation, imaging probe 100 may be manually advanced (e.g., by the patient's clinician) through the patient's vasculature. Pullback module 880 may be attachable to the patient (e.g., to delivery catheter 80 via connector 82), and connector 180 may be operably connected to imaging probe 100 and positionable proximate delivery catheter 80 (e.g., torquer connector 180 may be fastened to imaging probe 100 near delivery catheter 80). Connector 180 (not shown) may be operably disposed within carrier 855, and a driving force may be applied to the distal end of link 891. Carrier 855 retracts into trench 889, retracting imaging probe 100 relative to the patient. After retraction, connector 180 may be detached (e.g., lifted) from carrier 855, and carrier 855 and imaging probe 100 may be independently advanced again. For example, once the proximal end of link 891 is allowed to advance, carrier 855 can be advanced again by the bias of spring 852, and imaging probe 100 can be manually advanced again by an operator of system 10. After both are advanced again, subsequent retraction can be performed by repositioning connector 180 within carrier 855. Carrier 855 can include a catch, such as a "cup" shape, hook, or other catchable portion, so that carrier 855 can only apply a retraction force to connector 180. In this configuration, if carrier 855 were to translate distally, connector 180 would automatically disengage from carrier 855 (e.g., connector 180 would fall out of the cup portion of carrier 855).

[0114] In some embodiments, the carrier 855 has a structure and arrangement similar to the carrier 855 described with reference to FIGS. 5A and 5B. Here, as shown in FIGS. 5A and 5B, the carrier 855 can comprise a two-piece assembly that allows for fine adjustment of the carrier 855 to accommodate changes in the relative position of the pullback connector 180 with respect to the delivery catheter 80. The adjustment feature of the two-piece assembly is constrained laterally and allows for axial adjustment. The carrier 855 can also include one or more user-graspable protrusions and one or more teeth on a first portion of the two-piece assembly that engage with notches on a second portion of the two-piece assembly, thereby locking the components together during use. By depressing the protrusions, the carrier 855 can be adjusted and locked into a new position.

[0115] Referring now to FIG. 3, a perspective view of a connector attached to a patient interface module is shown, consistent with the concepts of the present invention. Patient interface module 200 may be similar in construction and arrangement to patient interface module 200 described with reference to FIG. 2A. Patient interface module 200 includes connector assembly 510, a first physical connector assembly, for operably connecting to connector assembly 150′. Patient interface module 200 may further include connector assembly 820a, a second physical connector assembly, for operably connecting to connector 840′. Connector assembly 150′ and connector 840′ may each include a bayonet-style connector constructed and arranged to be at least partially inserted into connector assemblies 510, 820a, respectively.

[0116] As described herein, system 10 may be constructed and arranged to provide improved imaging of a patient's anatomical structures (e.g., one or more blood vessels or other vessels of the patient) and implants, catheters, and / or other devices disposed within the patient's body (e.g., disposed within the patient's blood vessels or other vessels). In some embodiments, system 10 is configured to provide information used (e.g., by a clinician) to perform a treatment (e.g., a therapeutic intervention), which information is based at least on optical coherence tomography data. For example, OCT and other data collected by system 10 may be used to plan a treatment and / or predict a treatment outcome (e.g., for planning and / or prediction performed by system 10, an operator of system 10, or a combination of both), which may affect, for example, a treatment delivered to a patient (herein "OCT-guided procedure" and / or "OCT-guided therapy").

[0117] As described herein, the imaging probe 100 may have at least one of a size (e.g., diameter and / or length), scanning range, flexibility, and / or imaging capabilities configured to provide improved imaging. The imaging probe 100 may have a size and / or flexibility configured to enable imaging of tight (rigid) lesions within a blood vessel. As used herein, a tight lesion may include a lesion in which the resulting lumen (i.e., the lumen within the lesion) has a diameter (e.g., the smallest diameter along the length of the lesion) of less than 2 mm (0.080 inches). A commercially available OCT catheter positioned to image a lesion with a lumen of this small diameter effectively blocks proximally applied flush media from propagating to a location distal to the lesion, which would preclude use of the commercially available device. However, the imaging probe 100 may be configured and arranged to image these tight lesions, e.g., lesions having a resulting lumen diameter as small as, for example, 1.5 mm (0.060 inch), for example, 1.3 mm (0.053 inch), for example, 1.1 mm (0.043 inch), and / or as small as, for example, 0.9 mm (0.036 inch). For example, the distal portion of the imaging probe 100 may have an outer diameter of 2.6 Fr (0.034 inch) or less, for example, 1.7 Fr (0.022 inch) or less. This allows the system 10 to be used to image a potential vessel (e.g., an artery) having a tight lesion, such as when the distal portion of the imaging probe 100 is inserted into and through the stenosis, for example, in a "pre-treatment" imaging procedure (e.g., a procedure performed before the present invention or other treatment of a stenosis). As described herein, currently available OCT imaging systems may be too large to provide useful data (e.g., unable to penetrate and / or provide sufficient blood clearance in tight lesions), and other types of imaging systems, such as angiography, may not provide sufficiently accurate results when imaging tight lesions (e.g., may falsely indicate no need for treatment, such as when providing fractional flow reserve (FFR) information).In some embodiments, system 10 is used to perform pre-treatment imaging (e.g., of tight lesions) to collect data that enables OCT-guided treatment, and the data provided by system 10 (e.g., using at least images from probe 100) is used by an operator (e.g., a clinician) to make decisions about future treatments. In these embodiments, system 10 may also be used to image similar anatomical locations after treatment has been administered (in a "post-treatment" imaging process).

[0118] In some embodiments, system 10 is configured to perform pre-treatment imaging (e.g., tight lesion or otherwise) and provide OCT-guided treatment, with the following features of system 10: the distal portion of probe 100 (including, e.g., optical assembly 115) has a diameter of less than 2.6 Fr (0.034 inch), which may be, for example, 2.0 Fr (0.026 inch) or less, or, for example, 1.7 Fr (0.022 inch) or less.

[0119] In some embodiments, system 10 is configured to perform pre-treatment imaging (e.g., tight lesion or otherwise) and provide OCT-guided treatment by the following features of system 10: optical assembly 115 is rotated (e.g., via rotating assembly 500) at a rate greater than 180 revolutions per second, and the rotation rate may be, for example, at least 200, 250, 400, and / or 500 revolutions per second.

[0120] In some embodiments, system 10 is configured to perform pre-treatment imaging (e.g., tight lesion or otherwise) and provide OCT-guided treatment, with the following features of system 10: the radius of the scanning range of system 10 is at least 7 mm, and may be, for example, at least 11 mm. The long scanning range of system 10 provides many advantages, such as the ability to image from the vessel being imaged to any side branches of that vessel, the ability to image large vessels when optical assembly 115 is positioned eccentrically within the vessel lumen (e.g., adjacent to a portion of the vessel wall), and / or the ability to generally image larger vessels, such as the left main artery, carotid artery, or large peripheral arteries.

[0121] In some embodiments, the system 10 is configured to perform pre-treatment imaging (e.g., of tight lesions or otherwise) and provide OCT-guided therapy, characterized by a pullback distance greater than 7.5 cm, such as 10 cm or more or 15 cm or more. The pullback may be performed at a speed of at least 25 mm / sec and / or within a period of 4 seconds or less (e.g., a complete pullback of at least 7.5 cm, at least 10 cm, and / or at least 15 cm in 4 seconds or less). The operable pullback speed of the imaging probe 100 may be determined by the relationship between the rotational speed of the optical assembly 115 and the desired frame density (e.g., frames / mm) of the OCT image data, by dividing the rotational speed by the frame density to obtain the pullback speed. The imaging probe 100 may have a rotational speed greater than 180 Hz, such as at least 200 Hz or at least 250 Hz. The imaging probe 100 may have a frame spacing of 0.2 mm or less (i.e., a frame density of at least 5 frames / mm). The imaging probe 100 may have a laser scanning frequency of at least 200 KHz.

[0122] In some embodiments, system 10 is configured to perform pre-treatment imaging (e.g., of tight lesions or otherwise) and provide OCT-guided therapy, characterized by a pullback speed (translation speed of optical assembly 115 during pullback) of at least 50 mm / sec. In these embodiments, the rotational speed of optical assembly 115 may be at least 180 Hz, at least 200 Hz, and / or at least 250 Hz. In these embodiments, the frame interval may be a minimum of 0.2 mm.

[0123] In some embodiments, system 10 is configured to perform pre-treatment imaging (e.g., tight lesion or otherwise) and provide OCT-guided treatment by the following features of system 10: the number of lines per frame is at least 400 lines / frame, e.g., at least 800 lines / frame, where a frame contains approximately 360 degrees of continuous image data (i.e., one complete rotation of optical assembly 115 provides one frame of image data); in some embodiments, system 10 is configured to capture frames at a rate sufficient to allow for downsampling of the frames (e.g., downsampling performed before analog-to-digital conversion of the data and / or other bandwidth-limited data processing).

[0124] In some embodiments, system 10 is configured to perform pre-treatment imaging (e.g., of solid lesions or otherwise) and provide OCT-guided treatment, characterized by a scanning frequency of at least 50 kHz, such as 200 kHz or more, 350 kHz or more, and / or 500 kHz or more. In these embodiments, the number of lines per frame may be at least 400 lines / frame or at least 800 lines / frame (e.g., the number of lines per frame is equal to the scanning frequency divided by the rotational speed of optical assembly 115).

[0125] In some embodiments, system 10 has a laser scanning frequency of 200 kHz or greater, a pullback speed of 60 mm / sec or greater or 100 mm / sec or greater, and / or a rotational speed of 250 Hz or greater. System 10 may be configured to enable imaging of at least 50 mm of a blood vessel, e.g., at least 50 mm imaged in 0.5 seconds or less, with 800 or more scan lines per rotation, a pitch of approximately 400 μm, and / or a frame density of at least 2.5 frames / mm and / or at least 5.0 frames / mm. In some embodiments, system 10 is configured to perform pullback during the resting portion of the cardiac cycle to minimize motion artifacts. In some embodiments, system 10 has a rotational speed of up to 400 kHz, e.g., 250 kHz or greater, 300 kHz or greater, or 350 kHz or greater.

[0126] In some embodiments, system 10 is configured to perform pre-treatment imaging (e.g., for tight lesions or otherwise) and provide OCT-guided treatments due to a feature of system 10 in which processor 52 is configured to identify (e.g., via algorithm 51) reflections generated at the bonded interface between optical assembly 115 and optical core 110. The optical interface between optical assembly 115 (e.g., optical assembly 115 with a GRIN lens) and optical core 110 (e.g., optical core 110 with an NZDS fiber) may have a relatively large refractive index mismatch and provide a distinct reflection. This reflection may provide a reference point for OCT image data collected by system 10. In some embodiments, the interface may be identified by algorithm 51 with or without rotation of optical core 110.

[0127] Referring now to FIG. 4 , a perspective view of an adapter for use with an imaging assembly consistent with the concepts of the present invention is shown. Retraction assembly 800 may include an interface adapter 860. Adapter 860 may be configured and arranged to simplify insertion and / or connection of imaging probe 100 to connector 82. Adapter 860 includes a hub 861 and a protrusion 862 extending distally from hub 861. Adapter 860 includes a conduit 863 extending axially through adapter 860. In some embodiments, conduit 863 comprises a tapered conduit that tapers distally as shown. The proximal end of conduit 863 may have a diameter at least two times larger than the distal end of conduit 863. In some embodiments, protrusion 862 is configured and arranged to be slidably and lockably received by a portion of connector 82 (e.g., when connector 82 is a Tuohy Borst-style connector configured to lockably engage protrusion 862). In some embodiments, the hub 861 is configured and arranged to be disposed within a retention port 884 of a pullback module 880, similar to that described with reference to Figures 2B, 5A, and 5B. In some embodiments, the imaging probe 100 is slidably disposed within the conduit 863 prior to clinical processing (e.g., during the manufacturing and / or packaging process), such as to simplify one or more steps of the clinical processing.

[0128] 5A and 5B, which respectively show a perspective view of a pullback module operably attached to a portion of an imaging probe and a delivery catheter, and an exploded view of a portion of the pullback module, consistent with the concepts of the present invention. In FIG. 5A, a pullback connector 180 is operably attached and disposed in a carrier 855 of a pullback module 880. A hub 861 is disposed within a retention port 884. A connector 82 is disposed distal to a protrusion 862, on which the connector 82 can be slidably received to form a fluid-tight connection between the delivery catheter 80 and the adapter 860.

[0129] 5B shows a two-piece embodiment of carrier 855 in an exploded view. Carrier 855 may include an inner portion 8551, which is slidably disposed within outer portion 8555. Inner portion 8551 may include one or more alignment features, such as tracks 8552a and 8552b (shown). Outer portion 8555 may include one or more alignment features, such as rails 8556a and 8556b (rail 8556b is shown), which fit into tracks 8552a and 8552b of inner portion 8551. Inner portion 8551 may include one or more operator-operable protrusions, such as protrusions 8553a and 8553b (shown). Each protrusion 8553 may include a tooth 8554, such as tooth 8554a (shown), as an engagement feature. Teeth 8554 may be located on an outwardly facing surface of protrusion 8553 and may align with one or more mating engagement portions of outer portion 8555, shown as teeth 8557a, 8557b. Inner portion 8551 may be constructed and arranged to be slidably positioned within outer portion 8555 in a releasably locking manner, such that teeth 8554 engage teeth 8557 to maintain the longitudinal position between portions 8551, 8555. In some embodiments, protrusion 8553 is constructed and arranged to resiliently deform inward when grasped and clamped (e.g., clamped together) by an operator of system 10. When grasped in this manner, teeth 8554 and teeth 8557 disengage, thereby allowing the operator to adjust the longitudinal position of inner portion 8551 relative to outer portion 8555. In some embodiments, with carrier 855 in a fully advanced position and connector 180 positioned within carrier 855 while imaging probe 100 is advanced to a desired position, the operator can retract inner portion 8551 to fully engage connector 180. For example, with this adjustment, when carrier 855 is retracted during a pull-back process, there is no initial gap between the distal wall of inner portion 8551 and the distal edge of connector 180.The position of the inner portion 8551 can be configured to allow for position adjustment up to a maximum level, for example, up to at least 5 mm, at least 7 mm, 15 mm, etc. Adjustment of the inner portion 8551 can be made in increments as small as 1.0 mm, 0.7 mm, 0.5 mm, and / or 0.3 mm, for example.

[0130] Referring now to Figure 6, there is shown a flowchart of a method for calculating blood flow parameters in a blood vessel consistent with the concepts of the present invention. Method 1000 of Figure 6 is described using system 10 described with reference to Figures 1-3. The method of Figure 6 is described when system 10 is used to generate image data from one or more arteries of a patient's heart. It should be considered within the spirit and scope of this application that similar methods are applicable to other blood vessels and / or other internal locations of a patient's anatomy (e.g., arteries and / or veins of a patient's brain or peripheral vasculature).

[0131] In step 1100, the imaging probe 100 is inserted into a selected blood vessel of the patient, a pullback is performed within the selected blood vessel, and OCT data is recorded. In some embodiments, the selected blood vessel includes one or more arteries, veins, and / or other conduits (hereinafter "arteries"). The selected blood vessel may have been pre-selected for diagnosis by an operator of the system 10 (e.g., the patient's clinician), such as an artery that may require interventional treatment. Alternatively, or additionally, the operator of the system 10 may select the blood vessel for diagnosis during step 1100. In some embodiments, the selected blood vessel is manually entered into the system 10, such as by the operator of the system 10. In some embodiments, the selected blood vessel includes an artery selected from the group consisting of the left circumflex artery (LCx), the right coronary artery (RCA), the left anterior descending artery (LAD), and combinations thereof. In some embodiments, the data is entered into the system 10 by an operator during a processing step, such as step 1130 described herein. For example, while system 10 (e.g., algorithm 51) is performing one or more background calculations, system 10 may be further configured to accept operator input (e.g., an operator performs required and / or other data input while system 10 is processing data) so that overall processing time is reduced.

[0132] The imaging probe 100 is inserted into a selected blood vessel (referred to herein as the “selected blood vessel,” “imaged blood vessel,” “selected artery,” “imaged artery,” “selected vein,” or “imaged vein,” as appropriate). If more than one artery is selected for diagnosis, step 1100 and subsequent steps may be repeated for each selected artery. The placement of the probe 100 (e.g., positioning of the optical assembly 115) is performed to effectively acquire the images required for one or more of the various calculations (e.g., flow calculations) performed by the system 10. The anatomical location where pullback begins (e.g., the position of the optical assembly 115 at the start of pullback) is selected as a location beyond (i.e., distal to) the distal end of the most distally lesioned portion of the artery (e.g., the most distal portion of the lesion). The location where pullback ends (e.g., the position of the optical assembly 115 at the end of pullback) is selected as a location within the most distally positioned guide catheter (e.g., the distal portion of the delivery catheter 80) into which the imaging probe 100 will be inserted.

[0133] In some embodiments, an operator may input one, two, or more patient parameters into system 10, such as via user interface 55 of console 50. The input one, two, or more patient parameters may be selected from the group consisting of patient weight, the presence of one or more patient diseases (e.g., in addition to cardiovascular disease such as diabetes, if applicable), gender, age, height, TIMI score, previous coronary intervention such as stent implant, bypass graft, and combinations thereof.

[0134] In step 1120, system 10 may be used to capture non-OCT image data of the selected patient, for example, via a second imaging device 15 described herein. As used herein, "non-OCT data" includes, but is not limited to, angiography image data, ultrasound image data, MRI image data, PET scan image data, and / or other non-OCT image data. In some embodiments, the non-OCT data includes two or more of angiography image data, ultrasound image data, MRI image data, PET scan image data, and / or other non-OCT image data. In some embodiments, the non-OCT data includes angiography image data and one or more of ultrasound image data, MRI image data, PET scan image data, and / or other non-OCT image data.

[0135] This non-OCT data may be stored in a memory of the system 10, such as the memory of the processor 52 of the console 50. For example, an angiographic image of one or more blood vessels is obtained using a contrast injection, and the angiographic data is saved in the memory of the system 10 (e.g., data capture and / or saving performed automatically by the system 10). Alternatively or additionally, an operator may manually enter relevant patient data (e.g., data similar to and / or extracted from the angiographic data or other non-OCT data) into the console 50 (e.g., via a keyboard or other user input element 57 of the user interface 55). Step 1120 may be performed (e.g., repeated in whole or in part) during any step of the method of FIG. 6 described herein. For example, step 1120 may be performed before, during, and / or after the pullback performed in step 1100 described herein.

[0136] In step 1130, the OCT-recorded data is analyzed. In some embodiments, both OCT and non-OCT data (e.g., angiography data) are analyzed (e.g., OCT data is analyzed in combination with non-OCT data). Steps 1131, 1132, and / or 1133 (or portions thereof) may be performed sequentially, simultaneously, or alternately as recorded data is analyzed by system 10.

[0137] In step 1131, the recorded OCT data is analyzed by the system 10. In some embodiments, the OCT data may be analyzed to identify one or more of: a lumen boundary, side branches, healthy (e.g., non-diseased) portions of the lumen, diseased portions of the lumen, the type of disease being imaged, the location of a guidewire within the image, and one or more combinations thereof. In some embodiments, the guidewire is removed from the OCT data. In some embodiments, the system 10 identifies healthy portions of the imaged artery based on the OCT data. The healthy portions may be determined by identifying visible intima, media, and / or adventitia layers within the OCT data. In some embodiments, the myocardial volume may be estimated based on the diameter of one or more identified healthy portions of the imaged artery. In some embodiments, the myocardial volume estimation may be based on both OCT data and non-OCT data (e.g., angiography data).

[0138] System 10 may include a weighting function (e.g., algorithm 51 may include a weighting function) configured to prioritize data (e.g., prioritize data types) in one or more calculations, e.g., to bias calculations based on OCT data over calculations based on non-OCT data, or vice versa. In some embodiments, system 10 (e.g., via algorithm 51) identifies the presence of disease proximate one or more side branches of the imaged artery. For example, if disease is detected near a side branch (e.g., if disease is detected medial to a side branch), the weighting function may be configured to prioritize angiography data associated with the diseased side branch (e.g., to bias calculations in favor of weighting angiography over OCT data).

[0139] System 10 may be configured to calculate (e.g., via algorithm 51) the branching angle of a side branch from the imaged artery. In some embodiments, the branching angle is used by algorithm 51 to calculate the vessel diameter of the side branch. System 10 may be configured to reconstruct at least a portion of the side branch from OCT data (e.g., from image slices of OCT data) and / or from non-OCT data (e.g., from angiography data). In some embodiments, system 10 is configured to calculate the relationship between the branching angle of the side branch and the diameter of the side branch (e.g., the size of the side branch relative to the size of the imaged artery). In these embodiments, if the relationship between the branching angle and diameter of the side branch is outside of an expected range, system 10 may be configured to “flag” this anomaly (e.g., identify the anomaly and store associated information) and / or alert an operator of system 10 to this anomaly.

[0140] In some embodiments, the system 10 is configured to identify a portion of the OCT data representing the smallest lumen diameter (e.g., a portion of healthy tissue having the smallest lumen diameter). Additionally, the system 10 may be configured to identify two to five sections of the OCT data along the length of the imaged lumen during pullback (e.g., equally spaced sections along the length of the imaged lumen). The identified sections may be used to estimate the non-diseased vessel size (e.g., lumen diameter) of the selected artery. In some embodiments, at least one of the identified sections includes a proximal section, and at least one of the identified sections includes a distal section (e.g., the proximal and distal sections are proximal to the proximal and distal ends, respectively, of the imaged lumen). In some embodiments, the proximal and / or distal sections are within the proximal and distal 10% of the length of the imaged lumen. In some embodiments, the weighting function is configured to apply a weight (i.e., a weighting factor) to each section based on a confidence level of the OCT data for that section. Confidence can be determined in several ways, such as the percentage of clear lumen detected in a single frame (e.g., more than 75% of the circumference needs to be clear to have high confidence), and / or the amount of change in lumen area from frame to frame (e.g., discontinuous frames need to be weighted less). Confidence can also be derived from the deviation in circularity of the cross-section of the imaged vessel.

[0141] In some embodiments, system 10 identifies diseased areas based on OCT and / or non-OCT data (e.g., via algorithm 51). In some embodiments, the type of disease may be identified by system 10, such as when system 10 identifies the plaque composition of a diseased portion of an artery.

[0142] In some embodiments, system 10 (e.g., via algorithm 51) determines the time (alternatively known as "duration" and used herein) required for contrast or other flushing medium (e.g., injectate 21) to be removed from a selected vessel segment (e.g., a segment being imaged) after injector 20 stops injecting into the selected vessel. In other words, duration is the length of time between the cessation of flushing medium delivery and the point at which enough blood returns to the vessel segment being imaged to prevent acceptable images of that vessel segment (e.g., the returning blood obscures imaging of the lumen wall). Duration indicates the relative blood flow within the selected vessel segment being imaged. Duration may be measured with the optical core 110 rotating but longitudinally stable (e.g., the optical core 110 is neither retracted nor advanced). Duration may be calculated based on OCT data and / or non-OCT data (e.g., angiography data). Algorithm 51 may receive a signal (e.g., a signal from injector 20) indicative of the injection status of injector 20 (e.g., indicating when injection has started and / or stopped). Additionally or alternatively, a functional element of system 10 (e.g., functional element 89 of delivery catheter 80) may include a pressure transducer configured to monitor fluid pressure within delivery catheter 80. The pressure within delivery catheter 80, as provided via a signal from pressure sensor-based functional element 89, may be analyzed by algorithm 51 to determine the status of the flushing process (e.g., a status related to the start and / or stop of injection of flushing medium).

[0143] In step 1132, non-OCT data (e.g., angiography data) may be analyzed. In some embodiments, the non-OCT data may be analyzed to identify one or more of: blood vessel shape (e.g., curvature, taper, and / or trajectory), side branch location (e.g., size and location of side branches of one or more major arteries being diagnosed), blood vessel length, blood vessel diameter, and one or more combinations thereof. In some embodiments, the non-OCT data may be analyzed to estimate one or more of myocardial mass, collateral blood flow, size of the cardiac region (myocardium) supplied by an artery (e.g., a selected artery), and one or more combinations thereof. In some embodiments, the non-OCT data analyzed in step 1132 includes angiography image data and one or more of ultrasound image data, MRI image data, PET scan image data, and / or other non-OCT image data. In some embodiments, the non-OCT data includes angiography data that is converted into QCA data by system 10. In some embodiments, the non-OCT data includes PET scan data that system 10 converts into myocardial damage data (e.g., when system 10 adjusts blood vessel size in the damaged region).

[0144] In step 1133, the OCT data and non-OCT data (e.g., angiography data) may be registered (e.g., correlated). In some embodiments, the data may be registered using the position, size, and shape of one or more side branches of a selected artery. In some embodiments, system 10 may include a digital model of expected side branches of one or more major blood vessels of the heart, e.g., the LCx, RCA, and / or LAD arteries. In some embodiments, the digital model is used by system 10 to register the data.

[0145] In step 1140, values ​​of cardiovascular dynamic parameters (e.g., flow velocity, fluid pressure, pressure loss over a distance, fractional flow reserve, etc.) may be calculated based on the analyzed data (e.g., collected and / or analyzed OCT and / or non-OCT data). In some embodiments, system 10 is configured to estimate distal microvascular resistance of a selected artery.

[0146] In some embodiments, the measured size of the imaged artery is adjusted by system 10 (e.g., the size of the imaged artery determined in step 1130 is adjusted by algorithm 51). System 10 can adjust the measured size of the imaged artery based on Murray's Law. For example, system 10 may assume a constant shear stress in all non-diseased regions of the imaged artery. This adjustment can minimize an error function of the flow calculated by system 10 using Murray's Law. In some embodiments, the flow calculation is adjusted using a weighting function based on the confidence level of the analyzed data. For example, if Murray's Law suggests an adjustment to the measured size and the confidence level of the imaged cross-section is relatively low, system 10 can be configured to adjust the flow calculation based on the adjustment suggested by Murray's Law. Alternatively, if the confidence level is high, one or more adjustments based on Murray's Law can be ignored by system 10.

[0147] The size of the myocardium supplied may be estimated by system 10 (e.g., using algorithm 51) based on the selected arterial vessel type and / or the calculated size. In some embodiments, the estimated myocardium size may be compared to an estimated size calculated based on non-OCT data (e.g., angiography data), as described in step 1132. In some embodiments, if the non-OCT-based estimate and the OCT-based estimate differ, the operator is alerted by system 10 (e.g., via display 56 or other user output element of user interface 55). In some embodiments, system 10 accepts user input (e.g., via user input element 57 of user interface 55) to adjust the estimate. In some embodiments, the OCT-based estimate is given a higher weight (e.g., by a weighting function of system 10) than the angiography-based estimate (e.g., the OCT-based estimate is favored by system 10). In some embodiments, the data is displayed to the operator as a color map (e.g., a color map shown on display 56). In some embodiments, the color map may show the estimated myocardium size supplied by the selected artery (e.g., the amount of myocardial tissue supplied by the selected artery). In some embodiments, hyperemic microvascular resistance is estimated by system 10 (eg, via algorithm 51) for all or at least a portion of the heart outside the imaged region.

[0148] In some embodiments, pressure throughout the cardiac vasculature (the "coronary artery tree") is calculated. In some embodiments, a fractional flow reserve (FFR) is calculated (e.g., calculated from the lowest pressure). The FFR may be calculated for selected arteries, such as each selected artery (e.g., each artery selected and imaged using OCT). In some embodiments, the system 10 may be configured to alert the operator (via the user interface 55) if significant collateral blood flow is detected (e.g., blood flow exceeding a threshold value of the system 10), if myocardial estimates differ significantly between OCT-based and non-OCT-based estimates (e.g., angiography-based estimates) (e.g., the difference exceeds a threshold value of the system 10), if a TIMI score indicates myocardial tissue damage, if an area of ​​no flow is detected angiographically (e.g., indicating an obstruction), and one or more combinations thereof.

[0149] In some embodiments, system 10 (e.g., via algorithm 51) may calculate one or more cardiovascular blood flow dynamic parameters based on the duration of contrast and / or other injectants 21 within the selected vascular segment.

[0150] In some embodiments, the duration may be used as an estimate of regional blood flow (e.g., similar to the TIMI blood flow score used in angiography). The estimate of regional blood flow (e.g., as determined by system 10) may be used by system 10 to improve the accuracy of calculations of cardiovascular blood flow dynamics.

[0151] In some embodiments, the OCT data and non-OCT data (e.g., angiography data) are displayed (e.g., on display 56), e.g., in an overlay configuration (e.g., OCT data overlaid on angiography data and / or other non-OCT data), e.g., after multiple sets of data are registered.

[0152] In some embodiments, a graph of lumen diameter (also referred to herein as a "lumenogram") is displayed, such as a graph of lumen diameter along the length of the pullback. In some embodiments, the lumenogram may be based on an average diameter (the average of multiple chords drawn through the center of gravity of the lumen) or on an "effective" diameter, such as, for example, the diameter of a circle having the same area as the area of ​​the irregular lumen itself. The effective diameter may be determined (e.g., by an algorithm in system 10) using Green's theorem.

number

[0153] For image data captured by imaging probe 100, once the lumen boundary has been identified (e.g., by an algorithm of system 10), the area of ​​irregular objects (e.g., lumens with non-circular circumferences) can be easily calculated with constraints through the use of Green's Theorem. However, in some applications of system 10, a lumenogram based on effective diameter is not the most appropriate method for providing physiological information about a vessel segment (e.g., pressure loss along a vessel segment). In some embodiments, system 10 calculates a "hydraulic diameter" for various locations along a lumen segment, such as the hydraulic diameter determined by an algorithm of system 10 based on the Darcy-Weisbach equation, which is modified as follows:

number

[0154] It can be seen that the pressure loss of a vessel segment depends more directly on its hydraulic diameter, rather than on its area or effective diameter. The hydraulic diameter is defined as:

number

[0155] To calculate the hydraulic diameter, an algorithm (e.g., algorithm 51) of system 10 may calculate the circumference at multiple axial locations along a vessel segment. Note that for a perfect circle, the hydraulic diameter and effective diameter are the same. The more the cross-section is from circular, the greater the difference between the hydraulic diameter and the effective diameter, reducing the accuracy of an effective diameter-based lumenogram for providing pressure loss information. [Table 1]

[0156] As shown in Table 1, the effective diameter and effective area remain constant even when the ellipse changes shape by a factor of 10 or more. However, using the hydraulic diameter in a lumenogram can more accurately show that the expected pressure loss changes significantly in the right sense (i.e., a "squished" ellipse will have a higher pressure loss as expected).

[0157] The system 10 may determine the circumference at various (eg, relatively consecutive) locations along the vessel segment using the following calculation.

number

[0158] In some embodiments, system 10 displays a hydraulic diameter-based lumenogram to visually communicate pressure loss along a vessel, and also displays an effective diameter-based lumenogram to visually communicate information related to sizing and / or selection of a stent for placement in the vessel being imaged. Alternatively or additionally, specific hydraulic diameter and / or effective diameter information may be displayed by system 10 (e.g., in a pop-up window containing numerical information) at one or more locations along the displayed lumenogram.

[0159] In some embodiments, the system 10 displays a lumenogram based on hydraulic diameter along one axis, with the longitudinal position of the pullback image displayed on the other axis. In some embodiments, displaying the numerical hydraulic diameter may be avoided (e.g., the hydraulic diameter is displayed only as a visual indicator) because it may be misinterpreted by the operator. Regions of rapidly changing hydraulic diameter may be highlighted and / or color-coded by the system 10. In some embodiments, the hydraulic axis is displayed as a simple line plot. Alternatively or additionally, the hydraulic axis may be displayed to resemble an angiogram (e.g., a shadow chart). This type of display is more effective at conveying pressure loss in a vessel segment, which is a key factor in determining whether and how to treat the vessel.

[0160] The system 10 may provide a lumenogram based on hydraulic diameter to provide pressure loss information, while providing numerical information (typically effective diameter and / or effective area) on a display that is not linearly scaled (e.g., does not include a diameter and / or area display axis that is linearly proportional to the numerical display value).

[0161] In some embodiments, one or more side branches (or portions thereof) of a selected artery are displayed. In some embodiments, the operator may (e.g., manually) add data to system 10 adjacent to the displayed OCT data indicating the presence of disease, e.g., at the proximal or distal end of the lumen or within the side branch (e.g., the operator visually determines the presence of disease via information provided by second imaging device 15 and manually enters relevant disease type and / or disease location data into system 10). In some embodiments, calculated vessel size is displayed with OCT and / or non-OCT images (e.g., angiographic images). In some embodiments, system 10 allows the operator to edit the displayed calculations (e.g., to allow the operator to manually adjust the system 10 calculations).

[0162] In some embodiments, the operator of system 10 plans a treatment procedure based on the displayed data. In some embodiments, the operator indicates the length and location of a “treatment region” to be evaluated by system 10 (e.g., the operator indicates the treatment region by clicking on a displayed image). In some embodiments, system 10 displays estimated vessel diameters at the proximal and distal ends of the selected treatment region. In some embodiments, the vessel diameter is estimated by system 10 (e.g., via algorithm 51) using Green's theorem. In some embodiments, system 10 displays one or more pieces of information related to the selected treatment region, such as any warnings related to the treatment region and / or plaque composition within the treatment region. In some embodiments, post-treatment flow dynamics (e.g., FFR) can be estimated assuming that the planned treatment (e.g., stenting) opens the treated vessel to estimated diameters at the proximal and distal ends of the selected treatment region (e.g., two diameters can be used to indicate vessel tapering). In some embodiments, post-treatment flow dynamics can be estimated based on the calculated pre-treatment flow dynamics and the proposed treatment. In some embodiments, the operator can change the proposed treatment region and the system 10 can update the flow dynamics based on the new treatment region. In some embodiments, the operator can indicate two or more treatment regions (e.g., two or more non-contiguous treatment regions) and post-treatment flow dynamics can be estimated for each treatment region.

[0163] As described herein, system 10 can be configured to calculate flow characteristics through one or more blood vessels imaged using probe 100 (e.g., via one or more pullbacks). System 10 can be configured to calculate flow dynamics (e.g., flow field and / or pressure loss) through an imaged blood vessel (e.g., an artery where a procedure has been or will be performed). In some embodiments, system 10 calculates coronary blood flow and pressure loss using a full 3D Navier-Stokes simulation of the blood vessel imaged using imaging probe 100. In some embodiments, system 10 is configured to include numerous geometric and other features of the imaged region in its analysis (e.g., via algorithm 51), such as when all important morphological features are represented. System 10 can directly measure pressure within the blood vessel, and FFR at locations along the length of the blood vessel can be calculated as described herein. Regions where abrupt changes in FFR occur (e.g., identified by system 10) can be used to justify therapeutic intervention (e.g., stenting). In some embodiments, system 10 calculates flow dynamics (e.g., flow dynamics of the imaged cardiac and / or other vessels) based on hydraulic diameter data (e.g., hydraulic diameter data calculated by system 10 based on image data collected by system 10). Alternatively or additionally, system 10 calculates flow dynamics based on mean diameter data calculated by system 10 based on image data collected by system 10. In some embodiments, system 10 calculates flow dynamics based on both mean diameter and hydraulic diameter information (e.g., as collected by system 10).

[0164] Referring now to FIG. 7, a flowchart of a method for performing a pullback process based on a pullback trigger condition consistent with the concepts of the present invention is shown. Method 4000 of FIG. 7 is described using system 10, as described with reference to FIGS. 1-3. In step 4010, optical assembly 115 is positioned (e.g., by a clinician) distal to a location to be imaged by system 10. The imaging location may include a segment of a lumen, such as a blood vessel. Once optical assembly 115 is positioned distal to the imaging location, system 10 is ready to perform a pullback process relative to that location, and method 4000 continues to step 4020.

[0165] In step 4020, system 10 enters a "ready" state for pullback and begins monitoring for a "pullback trigger condition" that allows pullback to be initiated immediately. In some embodiments, algorithm 51 analyzes information collected from one or more components of system 10, such as information recorded by imaging assembly 300, second imaging device 15, patient monitor 17, functional element 199, and / or functional element 89. Based on the analysis of the information, algorithm 51 may determine whether a pullback trigger condition has occurred to initiate a pullback process. In some embodiments, the pullback trigger condition is based on a point in the patient's cardiac cycle, for example, if patient monitor 17 includes an electrocardiogram (EKG) monitor. Algorithm 51 may be configured to initiate pullback during a particular portion of the cardiac cycle, for example, a portion of the cardiac cycle in which myocardial movement adjacent to the imaging location (e.g., a quiescent portion of the cardiac cycle) is relatively low. In some embodiments, algorithm 51 is configured to initiate pullback when an EKG T-wave is detected. In some embodiments, the pullback trigger condition is based on angiography data, for example, if the second imaging device 15 includes a device configured to perform angiography, such as rotational angiography. In some embodiments, the algorithm 51 analyzes cardiac motion (e.g., myocardial motion) based on the angiography data. Additionally or alternatively, the algorithm 51 may analyze the angiography data to determine a point in the cardiac cycle. The system 10 may be configured to initiate pullback when cardiac motion is determined to be minimal based on this analysis by the algorithm 51. In some embodiments, the position of the marker 131 of the imaging probe 100 is analyzed by the algorithm 51 (e.g., through analysis of angiography data including the reflection of the radiopaque-based marker 131), and pullback is initiated when the marker 131 is determined to be stationary or at least when its motion is determined to be minimal (e.g., pullback is initiated when the motion of the marker 131 is determined to be relatively minimal compared to its motion at other points in the cardiac cycle).Alternatively or additionally, the position of the distal tip 119 may be analyzed by the algorithm 51 to determine the time of minimum motion of the vessel segment being imaged.

[0166] In some embodiments, the algorithm 51 is configured to analyze data (e.g., OCT data) to detect EKG (electrocardiogram) patterns. For example, the algorithm 51 may analyze OCT data including image motion data and / or speckle analysis data to detect EKG patterns. In some embodiments, continuous EKG patterns may be detected by the algorithm 51 after a period of time (e.g., multiple seconds, multiple minutes). The generated EKG patterns may be used to predict the timing of one, two, or more future heartbeats, for example, the timing of one or more future heartbeats may be used to trigger a pullback process (e.g., a pullback process performed after the flushing process is initiated). These embodiments enable detection of EKG patterns (e.g., additional EKG-triggered pullback) based solely on the OCT data, thereby eliminating the need for a separate device to provide an EKG signal (e.g., avoiding the need to connect to an external trigger and / or precise synchronization with an angiogram).

[0167] In step 4030, if a pullback trigger condition is detected, method 4000 proceeds to step 4040. If a pullback trigger condition is not detected, an operator of system 10 may cancel automatic pullback detection in step 4035. If automatic pullback detection is not canceled in step 4035, method 4000 returns to step 4030. If automatic pullback detection is canceled in step 4035, method 4000 proceeds to step 4050. In step 4050, pullback may be disabled and algorithm 51 stops monitoring for a pullback trigger condition. In some embodiments, after step 4050, an operator may re-enable pullback and resume monitoring (e.g., return to step 4020). If a pullback trigger condition is detected in step 4030, method 4000 proceeds to step 4040, where pullback is initiated.

[0168] Referring now to FIG. 8, a flowchart is shown for performing pullback processing based on multiple pullback trigger conditions consistent with the concepts of the present invention. Method 4100 of FIG. 8 is described using system 10, as described with reference to FIGS. 1-3. Method 4100 herein describes an embodiment in which a first condition of the multiple pullback trigger conditions includes detecting a cleared vessel segment. For example, algorithm 51 may analyze data to determine that the vessel segment selected for imagement has been sufficiently cleared of blood for "appropriate" OCT imaging. In some embodiments, algorithm 51 may detect the vessel lumen based on one or more known lumen characteristics (e.g., predetermined lumen characteristics). In some embodiments, the vessel lumen is detected using numerical property techniques (e.g., edge detection techniques) and / or a trained neural network. Once a reliable lumen is detected (e.g., continuously detected over several consecutive frames, such as 2-10 consecutive frames), proper vessel clearance is established and pullback may be initiated. A second of the multiple pullback trigger conditions includes detection of a point in the patient's cardiac cycle (e.g., pullback is initiated during an optimal point in the cardiac cycle for OCT imaging, such as when algorithm 51 analyzes an EKG signal to detect a cardiac cycle point with minimal movement). Illustrated steps 4120, 4122, and 4124 describe embodiments in which a flash is initiated based on a "flash trigger condition," such as when a certain point in the patient's cardiac cycle is reached. In some embodiments, the flash is initiated at the discretion of the operator (e.g., a clinician action not triggered by system 10).

[0169] In step 4110, optical assembly 115 is positioned distal to a location to be imaged by system 10. The imaging location may include a segment of a luminal vessel, such as a blood vessel. After optical assembly 115 is positioned distal to the imaging location, system 10 is ready to perform a pullback process for that location, and method 4100 continues to step 4120. In some embodiments, a first of multiple pullback trigger conditions detected by algorithm 51 in method 4100 includes detection of vessel segment clearing (removal) (e.g., algorithm 51 detects that sufficient blood has been removed from the vessel segment selected to be imaged for proper OCT imaging).

[0170] In step 4120, algorithm 51 monitors the patient's EKG signal and estimates a delay between the time when the injection of the flush is initiated and the time when the selected vessel segment is sufficiently cleared of blood for proper OCT imaging. In some embodiments, algorithm 51 predicts (e.g., based on the EKG signal and the estimated delay) the optimal point in the cardiac cycle to trigger (e.g., begin) the injection of the flush so that the selected vessel segment is sufficiently cleared (cleared) during the optimal portion of the cardiac cycle for proper OCT imaging (e.g., the optimal point in the cardiac cycle to initiate pullback). In some embodiments, the estimated delay is based on the anatomical location of the selected vessel and / or the length of delivery catheter 80 (e.g., the catheter through which the flush is injected into the selected vessel).

[0171] In step 4122, algorithm 51 may initiate flash detection (e.g., upon detecting sufficient clearing of a vessel segment selected for suitable OCT imaging). In some embodiments, algorithm 51 is configured to detect sufficient clearing as described herein with reference to FIG. 8. After flash detection is initiated, in step 4124, algorithm 51 monitors the patient's EKG signal and initiates flash processing based on the prediction generated in step 4120.

[0172] If sufficient vessel segment clearance (removal) is not detected in step 4130, an operator of system 10 can cancel the pullback in step 4135, and flush detection is stopped in step 4138. In some embodiments, if sufficient vessel segment clearance is not detected within a period of time (e.g., a period of time from the start of the flushing process), algorithm 51 may enter a warning mode and pullback may be automatically canceled by system 10. In some embodiments, the period of time may be within 5 seconds from the start of the flushing process, for example, within 2 seconds. If sufficient vessel segment clearance is detected, method 4100 proceeds to step 4140.

[0173] In step 4140, after sufficient vessel segment clearance (removal) is detected, algorithm 51 enables automatic pullback of imaging probe 100 and begins monitoring the patient's EKG signal for pullback trigger conditions based on the patient's cardiac cycle. In some embodiments, algorithm 51 is configured to initiate pullback when a T wave is detected in the EKG signal. In steps 4145 and 4155, algorithm 51 monitors the cardiac cycle-based pullback trigger conditions, monitoring whether sufficient vessel segment clearance is still present (e.g., still detected). If sufficient vessel segment clearance is not detected (e.g., no longer detected) in step 4155, step 4170 is performed, in which algorithm 51 enters a warning mode and disables pullback. If an EKG pullback trigger condition is detected in step 4145, method 4100 proceeds to step 4160, in which pullback is initiated.

[0174] Although the embodiment of FIG. 8 is described as including a first pullback trigger associated with the clearing (removal) of a vessel segment and a second pullback trigger associated with the patient's cardiac cycle, alternative and / or additional patient, system, and / or method parameters may be monitored by system 10 (e.g., analyzed by algorithm 51) and used to initiate the pullbacks.

[0175] Referring now to FIG. 9 , an OCT image showing blood vessels floating in cerebrospinal fluid is shown, consistent with the concepts of the present invention. The image shown in FIG. 9 can be displayed to an operator (e.g., on a display 56 of a system 10 described herein). In some embodiments, the system 10 is configured such that the optical assembly 115 of the imaging probe 100 is positioned within a first location (e.g., a blood vessel) to capture images of a location outside the first location (e.g., outside a patient's blood vessel or other vessel, as described herein). For example, the optical assembly 115 may be positioned within a first blood vessel (e.g., an artery or vein) of the patient's heart, thereby providing images of, for example, an outside location proximate to the wall of the first blood vessel (e.g., a location where a flushing medium is also delivered) of a second blood vessel, a chamber, heart wall tissue, and / or any cardiac tissue of the heart. The optical assembly 115 may be positioned within a first blood vessel (e.g., an artery or vein) of the patient's brain, to provide, for example, images of locations proximate to the wall of the first blood vessel in the brain (e.g., via delivered and / or reflected light from the probe 100 passing through the brain's cerebrospinal fluid), images of a second blood vessel in the brain, the ventricles, the cortical tissue of the brain, the white matter of the brain, the gray matter of the brain, the fornix, the hippocampus, and / or any brain tissue (e.g., healthy and / or diseased tissue as described herein). The optical assembly 115 may be positioned within a first blood vessel (e.g., an artery, vein, or a channel of the spinal cord such as the epidural space, subdural space, or subarachnoid space) proximate to the patient's spine, to provide, for example, images of locations proximate to the wall of the first blood vessel in the spine, images of a second blood vessel in the spine, different channels of the spinal cord, nerve bundles of the spinal cord, and / or spinal tissue. The optical assembly 115 may be positioned within a first blood vessel (e.g., an artery, vein, channel, chamber, or any duct of a patient) proximate an anatomical location selected from the group consisting of a perivascular structure or other perivascular location of a patient, a subarachnoid space of a patient, arachnoid trabeculae of a patient, and combinations thereof, thereby, for example, providing images within and / or outside the blood vessel in which the optical assembly 115 is positioned.The optical assembly 115 may be positioned within a first blood vessel (e.g., a patient's artery, vein, channel, canal, duct, chamber, or any canal) at a location proximate to a target tissue or other target location of a patient to be diagnosed and / or treated (e.g., a target location including tumor tissue, neuritic plaques, amyloid plaques, cerebral infarction, atherosclerosis, and / or other diseased and / or non-diseased tissue outside the first blood vessel), thereby providing, for example, images of the target tissue, which can be used to provide diagnostic information for the target tissue and / or to perform and / or evaluate treatment of the target tissue. The optical assembly 115 may be positioned within a lumen of the intracranial vasculature to generate images of one or more physiological markers of vascular dementia and / or Alzheimer's disease. The physiological markers may include markers within the blood vessel in which the optical assembly 115 is positioned and / or markers outside (e.g., proximal to) the blood vessel in which the optical assembly 115 is positioned. The physiological markers of vascular dementia and / or Alzheimer's disease may include one, two, or more markers selected from the group consisting of amyloid plaques, neuritic plaques, cerebral infarction, atherosclerosis, and combinations thereof. In some embodiments, algorithm 51 is configured to analyze the OCT data to identify one, two, or more physiological markers of a disease (e.g., vascular disease). In some embodiments, the one or more physiological markers (e.g., disease markers) identified by algorithm 51 include tumor tissue, amyloid plaques, neuritic plaques, cerebral infarction, and / or atherosclerosis. System 10 may be configured to provide image data that includes (e.g., identifies in a provided image) one or more physiological markers (e.g., disease markers), such as tumor tissue, amyloid plaques, neuritic plaques, cerebral infarction, and / or atherosclerosis. The delivery catheter 80 may be positioned within an internal body space (e.g., a non-luminal space) adjacent to the target tissue to be imaged, and the optical assembly 115 may be positioned within a portion of the delivery catheter 80 (e.g., may be retracted within the delivery catheter 80 during a pullback process).In some embodiments, system 10 is configured to provide an extended scanning range for generating images, e.g., at least 7 mm or at least 11 mm (e.g., to provide an image of a 14 mm diameter). In some embodiments, system 10 is configured to provide image data at a location at least 5 mm, at least 7 mm, or at least 9 mm outside a blood vessel (e.g., a blood vessel or other vessel of a patient having a diameter of at least 0.9 mm, at least 1.4 mm, or at least 2 mm). In some embodiments, optical assembly 115 has a focal length of at least 5 mm, e.g., a focal length of at least 7 mm, at least 10 mm, at least 12 mm, and / or at least 15 mm. In these embodiments, the working distance may be at least 10 mm, at least 15 mm, or at least 20 mm.

[0176] 10A-10C, various views of a portion of an imaging probe consistent with the concepts of the present invention are shown. In FIG. 10A, the distal portion of the imaging probe 100 is shown. A shaft 120 surrounds the optical core 110 and the optical assembly 115. A distal tip 119 includes a spring tip extending from the distal end of the shaft 120. In some embodiments, the distal tip 119 includes a palladium spring. In some embodiments, the distal tip 119 includes one or more anchoring elements, a retainer 1191. The illustrated retainer 1191 extends proximally from the spring tip 119 and is anchored within the distal end of the shaft 120. The retainer 1191 may be fixedly attached to the coil of the spring tip 119. In some embodiments, the proximal end of the retainer 1191 has a limited surface area perpendicular to the distal end of the optical assembly 115 (e.g., as shown, the proximal end of the retainer 1191 is pointed). The shape of the proximal end of the retainer 1191 can be selected to minimize the amount of light reflected from the retainer 1191 back into the optical assembly 115. In some embodiments, the distal portion 1208 of the shaft 120 includes a tip portion 1207 that is distal to the window 130. The tip portion 1207 can be configured to surround the core wire 1192. The tip portion 1207 can include a heat shrink material configured to reduce its diameter (e.g., shrink) around the core wire 1192 after the retainer 1191 is attached within the distal end of the window 130. In some embodiments, tip portion 1207 has an outer diameter (e.g., outer diameter after heat shrinking) that is approximately equal to the outer diameter of window 130 and / or equal to the outer diameter of the spring portion of spring tip 119 (e.g., providing a smooth outer diameter of imaging probe 100 from spring tip 119 to window 130). In some embodiments, tip portion 1207 has an inner diameter (e.g., inner diameter after heat shrinking) that is approximately equal to the outer diameter of core wire 1192. In some embodiments, tip portion 1207 is sized to help ensure that core wire 1192 is concentrically positioned about the longitudinal axis of imaging probe 100.

[0177] The optical assembly 115 may be disposed at the distal end of the optical core 110. The optical assembly 115 may include a lens assembly 1151 optically and physically coupled to the distal end of the optical core 110. The lens assembly 1151 may include a GRIN lens having a beveled distal end. The beveled distal end of the lens assembly 1151 may include a fully internally reflective surface. The optical assembly 115 may include a lens marker 1156 (marker 1156), which is an element that can be imaged by a separate imaging device (e.g., the second imaging device 15 of FIG. 1). The marker 1156 may include a radiopaque marker configured to be imaged using fluoroscopy or other X-ray-based imaging devices. In some embodiments, the marker 1156 includes a wire coil helically wrapped around the distal portion of the optical core 110. In some embodiments, the marker 1156 is adjacent to the proximal end of the lens assembly 1151 (e.g., the marker 1156 is proximate the junction of the lens assembly 1151 and the optical core 110). In some embodiments, the marker 1156 has an outer diameter approximately equal to the outer diameter of the lens assembly 1151. In some embodiments, the marker 1156 is positioned in direct contact with the optical core 110 (e.g., in direct contact with the glass surface of the optical core 110). In some embodiments, the marker 1156 has a pitch at least 1.5 times greater than the diameter of the wire of the marker 1156, such that there is spacing between coils of at least half the width of the wire of the marker 1156. This spacing may increase the flexibility of the marker 1156, for example, to prevent stress concentrations in the optical core 110 (e.g., stress concentrations at the proximal and / or distal ends of the marker 1156, which may reach undesirably high levels if the marker 1156 is too stiff). In some embodiments, the marker 1156 is adhered to the optical core 110 using an adhesive. In some embodiments, the spacing between the coils of the marker 1156 is sufficient to allow adhesive to penetrate the coils of the marker 1156 and distribute the adhesive evenly around the marker 1156. In some embodiments, the marker 1156 is adhered using an adhesive that is visible under UV light.In some embodiments, during manufacturing, a UV light may be used to inspect the marker 1156 to ensure that the adhesive is properly applied and distributed around the periphery of the marker 1156 (e.g., around the coil of the marker 1156). In some embodiments, the adhesive used to adhere the marker 1156 is also configured to support the joint between the optical core 110 and the lens assembly 1151.

[0178] An elongated tube 1154 can surround at least the distal portion of the optical core 110, the lens assembly 1151, and the sealing element, the plug 1153. In some embodiments, the tube 1154 surrounds at least a portion of the marker 1156. The tube 1154 can include a heat shrink material. The tube 1154 can include PET. At least a portion of the tube 1154 can be adhesively or otherwise attached to at least a portion of the lens assembly 1151, the optical core 110, and / or the plug 1153. The plug 1153 can be configured to prevent and / or at least limit the escape of the gel 118 into the illustrated space 1152, which is a cavity formed between the lens assembly 1151 and the plug 1153. The space 1152 can be filled with air and / or one or more other fluids. The fluid within the space 1152 can be configured to provide desired optical properties between the lens assembly 1151 and the fluid (eg, to provide a glass-to-air interface).

[0179] The imaging probe 100 may include a fluid propulsion element, FPE 1500, located on the optical core 110 proximal to the lens assembly 1151. The FPE 1500 may be similar to the FPE 1500 described herein with reference to FIG.

[0180] 10B shows a perspective view of the optical assembly 115 and the distal portion of the optical core 110. In some embodiments, the plug 1153 has a smaller outer diameter than the lens assembly 1151. In some embodiments, the tube 1154 is heat shrunk onto both the lens assembly 1151 and the plug 1153, such that the tube 1154 is arranged in a profile similar to that shown in FIG. 10B, the space 1152 has a varying outer diameter, and at least a portion of the diameter of the tube 1154 is smaller than the outer diameter of the lens assembly 1151. In some embodiments, the tube 1154 does not contact the beveled distal end of the lens assembly 1151, such that, for example, only the fluid in the space 1152 contacts the distal end of the lens assembly 1151 and ensures total internal reflection at the distal end of the lens assembly 1151 (e.g., due to a glass-to-air interface at the distal end of the lens assembly 1151). In some embodiments, the reduced diameter of the plug 1153 allows the imaging probe 100 to achieve a tighter (i.e., smaller) radius of curvature than could be achieved if the plug 1153 had the same or larger outer diameter compared to the lens assembly 1151.

[0181] FIG. 10C shows a perspective view of a portion of shaft 120 with optical core 110 removed for clarity of illustration. Shaft 120 may include at least a first (proximal) portion, tube 121, fixedly attached to a second (distal) portion, window 130, via joint 125. Tube 121 may include an elongated, hollow member such as a hypotube (e.g., a metal tube that may have one or more engineered features along its length). In some embodiments, tube 121 includes a hypotube having a spiral cut along at least a portion of its length. In some embodiments, the spiral cut in tube 121 has a strain relief at the proximal end of the spiral cut configured to reduce the possibility of plastic deformation at the end of the spiral cut. The strain relief may include an end having a radius greater than the width of the remainder of the spiral cut. This strain relief reduces stress concentrations on tube 121 (e.g., when that region of tube 121 is bent). In some embodiments, tube 121 comprises a nickel-titanium alloy (e.g., a superelastic nickel-titanium alloy). In some embodiments, tube 121 comprises a plastic material such as polyimide and / or PEEK. In some embodiments, window 130 comprises a transparent, elongated, hollow member as described above with reference to FIG. 1. Joint 125 may include at least a distal portion of tube 121 and at least a proximal portion of window 130. The distal portion of tube 121 may include a tapered portion, taper 1211. Taper 1211 may be configured such that the outer diameter of tube 121 decreases from the proximal end of taper 1211 to the distal end of taper 1211. Tube 121 may include a lumen 1215 (not shown) therethrough.

[0182] Tube 123, an elongated segment, is partially inserted into lumen 1215 of tube 121. Tube 123 may have an outer diameter approximately equal to the diameter of lumen 1215. In some embodiments, tube 123 has an outer diameter slightly larger than the diameter of lumen 1215 (so that, for example, tube 123 can be press-fit into lumen 1215). Alternatively, tube 123 may have a diameter equal to or slightly smaller than the diameter of lumen 1215 (so that, for example, tube 123 can be press-fit into lumen 1215). Tube 123 may include a lumen 1235 therethrough. In some embodiments, lumen 1235 has a diameter larger than the outer diameter of optical core 110 (so that, for example, optical core 110 can be slidably disposed through lumen 1235). Additionally or alternatively, lumen 1235 may have a diameter smaller than the outer diameter of FPE 1500 (e.g., the inner diameter of tube 123), thereby preventing FPE 1500 (not shown in FIG. 10C ) from translating proximally beyond tube 123 (e.g., as FPE 1500 translates proximally, FPE 1500 contacts the end of tube 123, preventing FPE 1500 from entering lumen 1235). In some embodiments, the proximal portion of window 130 slidably receives the distal portion of tube 123. The proximal portion of window 130 may further slidably receive at least a distal portion of taper 1211 of tube 121. Window 130 may be fixedly attached to tube 121 and / or tube 123 via compression and / or adhesive. In some embodiments, the proximal end of window 130 is reduced (e.g., contracted) on tube 121 and / or tube 123 to provide a compression joint. In some embodiments, window 130 comprises a material configured to contract when tension is applied (e.g., when window 130 is intentionally or unintentionally pulled away from tube 121), thereby compressing window 130 on tube 121 and / or tube 123 and increasing the holding force of joint 125 when tension is applied.In these embodiments, tube 121 and / or tube 123 may have a lower modulus than window 130 such that, under equal tension, window 130 is more compressed than one or more of tubes 121 and / or 123. In some embodiments, joint 125 has a similar configuration and arrangement to joint 125 described in commonly-owned, co-pending International Patent Application No. PCT / US2020 / 030616, filed April 30, 2020, entitled "Imaging Probe with Fluid Pressurizing Element," the contents of which are incorporated herein by reference in their entirety.

[0183] In some embodiments, marker 131 is positioned between tube 123 and window 130. In some embodiments, marker 131 is positioned at least 0.5 mm from taper 1211, which can prevent a stiff portion of shaft 120 from forming within joint 125. Marker 131 may include a radiopaque marker configured to be imaged using fluoroscopy or other X-ray-based imaging. Marker 131 may include an outer diameter of 0.25 mm or less. In some embodiments, marker 131 is positioned a distance DP from the distal end of spring tip 119 (as shown in FIG. 10B ). In some embodiments, distance DP includes at least the maximum pullback distance allowed by system 10. In some embodiments, distance DP includes a length of approximately 49 mm. This placement may be selected so that the marker 131 allows an operator of the system 10 to know the position of the distal end of the spring tip 119 after the pullback process is performed before the pullback process is performed (this may, for example, prevent the distal end of the spring tip 119 from being positioned in an undesirable proximal or other undesirable position after the pullback process).

[0184] 11A-11E, five displays of luminal image data consistent with the concepts of the present invention are shown. System 10 may display images including graphical depictions of OCT image data and / or other image data (e.g., angiography image data, MRI image data, etc.) collected by and / or input to system 10. The images shown in FIGS. 11A-11E include images generated by the imaging probe and other components of an imaging system of the concepts of the present invention. The images shown in FIGS. 11A-11E may be displayed to an operator (e.g., on display 56 of system 10 described herein). In FIG. 11A, an oblique depiction of luminal image data (e.g., a cross-sectional view in which an observer is looking at the vessel from an oblique angle on the outside of the vessel) is displayed. In this view, half of the imaged vessel is cut away, and the interior of the vessel may be viewed from this oblique angle. In FIG. 11B, the image displayed in FIG. 11A is zoomed in, e.g., at approximately 50% magnification. FIG. 11C shows a transitional display. The image is displayed by transitioning from an oblique cross-sectional representation of the image data to a "fly-through" representation. This means that the image is displayed as if the observer were looking from the inside along the vessel (e.g., from the center of the vessel). In FIG. 11D, the image data is displayed in a fly-through representation from a first axial position of the imaged lumen, and in FIG. 11E, the image data is displayed in a fly-through representation from a second axial position of the imaged lumen. In some embodiments, the axial position at which the vessel is displayed in the fly-through representation is linked to the position shown in other views simultaneously displayed on display 56, for example, when a B-mode or L-mode view (e.g., as known in the art) is simultaneously displayed. In some embodiments, system 10 provides a zoom function, and the display automatically transitions from a cross-sectional representation to a fly-through representation (e.g., as shown in FIG. 11C) when the operator zooms in beyond a threshold, such as 70% magnification.Alternatively or additionally, the operator may selectively zoom (e.g., by selecting a keyboard modifier key such as the shift key) to transition between the two display modes. In some embodiments, the operator can “virtually move” through the lumen by advancing the perspective location of the fly-through image. In some embodiments, the same operator input (e.g., provided via a user input with a single degree of freedom, such as a mouse wheel) controls both the cross-sectional zoom and the fly-through progression, e.g., using a keyboard modifier key. In some embodiments, the zoom function is performed by system 10 in the oblique view, e.g., by “dollying” (moving) the camera (e.g., the point from which the observer is viewing the vessel) toward and / or away from the center of a selected axial location of the displayed vessel. As the oblique view zoom is increased beyond a threshold, the camera begins to translate toward the fly-through direction (e.g., the oblique angle decreases) until the camera (e.g., the observer's viewpoint) is positioned along the centerline of the lumen oriented along the longitudinal axis of the vessel. As the oblique angle decreases, the cut-out portion of the vessel also appears more opaque, for example, becoming completely opaque when the camera reaches the centerline of the vessel. In some embodiments, zooming out produces the opposite effect.

[0185] It should be understood that the above-described embodiments are merely illustrative examples, and further embodiments are contemplated. Any feature described herein in connection with any one embodiment may be used alone or in combination with other features described, or may be used in combination with one or more features of any other embodiment, or in any combination of any other embodiment. Furthermore, equivalents and modifications not described above may be employed without departing from the scope of the invention as defined in the appended claims.

Claims

1. 1. An imaging system for use with a patient, comprising: the imaging system comprising an imaging probe and an imaging assembly constructed and arranged to be optically coupled to the imaging probe; the imaging probe comprises an elongate shaft, a rotatable optical core, and an optical assembly; the shaft having a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion; the optical core having a proximal end and a distal end; at least a portion of the optical core is disposed within the lumen of the shaft; the optical assembly is positioned proximate the distal end of the optical core; the optical assembly is configured to direct light toward tissue to be imaged and collect reflected light from the tissue to be imaged; the imaging assembly is configured to emit light into the imaging probe and receive the reflected light collected by the optical assembly; the imaging system is configured to perform a pullback process on the vessel being imaged; the pullback process is initiated based on cardiac motion data obtained from angiographic images provided by an angiography system; the imaging system performs an analysis of a plurality of angiographic image frames to detect relative motion between a portion of the imaging probe and one or more stable features, and initiates the pullback process when the relative motion is determined to be minimal based on the analysis. Imaging system.

2. The imaging system of claim 1 , configured to initiate the pullback process during a relatively low motion portion of the patient's cardiac cycle.

3. the imaging probe comprises a radiographic marker; The imaging system of claim 2 , wherein the imaging system is configured to determine a relatively low motion portion of the patient's cardiac cycle based on an analysis of the motion of the radiographic markers.

4. 4. The imaging system of claim 1, wherein the imaging system is configured to stop the pullback process for no more than half a cardiac cycle.

5. The imaging system comprising: a clock configured to register a first time frame of a calibration pullback of the imaging probe; the angiography system is configured to register a first image frame capturing an initial movement of the calibration pullback of the imaging probe; 5. The imaging system of claim 1, wherein the imaging system is configured to initiate the pullback process further based on the time from when the first time frame is registered by the clock to when the first image frame is registered by the angiography system.

6. the imaging system is configured to initiate injection of a flushing material to remove blood from a target region of a blood vessel being imaged; The imaging system of claim 1 , wherein the injection of the flushing material continues over multiple cardiac cycles.

7. 7. The imaging system of claim 1, wherein the imaging system is configured to initiate the pullback process further based on determining that transparency of the blood vessel has been achieved.

8. 3. The imaging system of claim 2, wherein the imaging system is configured to generate a metronome that generates an output representative of the patient's cardiac rhythm to identify a relatively low motion portion of the patient's cardiac cycle.

9. The imaging system of claim 1 , wherein the pullback process is performed at a pullback speed of at least 50 mm / sec.

10. The imaging system of claim 1 , wherein the imaging system is configured to initiate the pullback process further based on detection of a T wave.

11. The imaging system of claim 1 , wherein the blood vessels imaged include blood vessels of the heart.

Images