Imaging probe with fluid pressurization element

Abstract

An imaging system for a patient includes an imaging probe. The imaging probe includes an elongated shaft inserted into the patient's body, a rotatable optical core, an optical assembly, a damping fluid, and a fluid pressurizing element. The elongated shaft includes a proximal end, a distal end, and a lumen extending between the proximal and distal ends. The rotatable optical core includes the proximal and distal ends. At least a portion of the rotatable optical core is disposed within the lumen of the elongated shaft. The optical assembly is disposed proximate to the distal end of the rotatable optical core and configured to direct light to tissue and collect reflected light from the tissue. The damping fluid is disposed between the elongated shaft and the rotatable optical core and configured to reduce non-uniform rotation of the optical assembly. The fluid pressurizing element is configured to increase the pressure of the damping fluid to reduce the presence of air bubbles proximate the optical assembly.

Description

[Technical Field] 【0001】 The concept of the present invention generally relates to an imaging system, and more particularly to an intravascular imaging system including an imaging probe and a delivery device. [Background technology] 【0002】 Imaging probes for imaging various locations within a patient's body, such as intravascular probes for imaging the patient's heart, are commercially available. Current imaging probes have limitations in their ability to reach specific anatomical sites due to their size and rigidity. Because current imaging probes are inserted over a guidewire, probe placement and the use of one or more delivery catheters into which the imaging probe is inserted may be restricted. Therefore, there is a need for imaging systems that include probes with smaller diameters and greater flexibility, and systems that have one or more delivery devices to accommodate these improved imaging probes. [Overview of the project] 【0003】 According to one aspect of the concept of the present invention, a patient imaging system comprises an imaging probe. The imaging probe comprises an elongated shaft including a proximal end, a distal end, and a lumen extending between the proximal and distal ends; a rotatable optical core including the proximal and distal ends, wherein at least a portion of the rotatable optical core is located within the lumen of the elongated shaft and positioned close to the distal end of the rotatable optical core, configured to guide light to tissue and collect reflected light from the tissue; a damping fluid positioned between the elongated shaft and the rotatable optical core and configured to reduce uneven rotation of the optical assembly; a fluid pressurizing element configured to increase the pressure of the damping fluid to reduce the presence of bubbles near the optical assembly; and an imaging assembly configured and positioned to optically couple with the imaging probe and configured to irradiate the imaging probe with light and receive reflected light collected by the optical assembly. 【0004】 In some embodiments, the fluid pressurizing element is configured to reduce the formation of bubbles. 【0005】 In some embodiments, the fluid pressurizing element is configured to reduce the growth of one or more bubbles. 【0006】 In some embodiments, the fluid pressurizing element is configured to reduce the size of one or more bubbles. 【0007】 In some embodiments, the system includes an optical beam path, and the fluid pressurizing element is configured to propel one or more bubbles away from the optical beam path. 【0008】 In some embodiments, the fluid pressurizing element is configured to generate a pressure gradient within the damping fluid. 【0009】 In some embodiments, the fluid pressurizing element is configured to increase the pressure of the damping fluid for a limited period of time. 【0010】 In some embodiments, the fluid pressurizing element is configured to intermittently increase the pressure of the damping fluid. The fluid pressurizing element can be configured to increase the pressure of the damping fluid only when imaging is possible. The fluid pressurizing element can be configured to increase the pressure of the damping fluid only when a rotatable optical core rotates. The fluid pressurizing element can be configured to increase the pressure of the damping fluid for discrete times of two minutes or less. The fluid pressurizing element can be configured to increase the pressure of the damping fluid for discrete times of 30 seconds or less. The fluid pressurizing element can be configured to increase the pressure of the damping fluid for discrete times of 5 seconds or less. 【0011】 In some embodiments, the fluid pressurizing element is configured to generate a damping fluid pressure of at least 3.6 psi, 5.0 psi, 10 psi, 15 psi, 20 psi, 30 psi, and / or 40 psi. 【0012】 In some embodiments, the fluid pressurizing element is configured to generate a damping fluid pressure of at least 75 psi, 100 psi, 125 psi, and / or 150 psi. 【0013】 In some embodiments, the fluid pressurizing element is configured to generate high-pressure and low-pressure regions within the damping fluid. 【0014】 In some embodiments, the fluid pressurizing element comprises a pressurizing source. The pressurizing source may comprise a pump. The fluid pressurizing element may further comprise a valve configured to allow the passage of gas while restricting the passage of damping fluid. 【0015】 In some embodiments, the fluid pressurizing element is configured to increase the pressure of the damping fluid as the rotatable optical core rotates. The fluid pressurizing element may include at least one projection extending radially from the rotatable optical core. The at least one projection may include a plurality of projections, each extending radially from the rotatable optical core. The fluid pressurizing element may include a helical projection extending radially from the rotatable optical core. The fluid pressurizing element may comprise a helical coil surrounding the rotatable optical core. The helical coil may have a uniform pitch. The fluid pressurizing element may comprise an element having a propeller-like structure. The fluid pressurizing element may comprise a spring-type element. 【0016】 In some embodiments, the fluid pressurizing element comprises a first fluid pressurizing element and a second fluid pressurizing element, the second fluid pressurizing element being positioned proximal to the first fluid pressurizing element. The second fluid pressurizing element may be configured to prime the first fluid pressurizing element when rotated. 【0017】 In some embodiments, the fluid pressurizing element is adhesively attached to a rotatable optical core. 【0018】 In some embodiments, the fluid pressurizing element is molded on and / or together with the rotatable optical core. 【0019】 In some embodiments, the fluid pressurizing element is integrated into a rotatable optical core. 【0020】 In some embodiments, the fluid pressurized element is formed on a rotatable optical core. This system can be formed on the rotatable optical core via vapor deposition and / or three-dimensional (3D) printing. 【0021】 In some embodiments, the fluid pressurizing element comprises a material selected from the group consisting of metal, plastic, stainless steel, nickel-titanium alloy, nylon, polyetheretherketone, polyimide, and combinations thereof. 【0022】 In some embodiments, the rotatable optical core has a diameter D1, the elongated shaft lumen has a diameter D2, and the fluid pressurizing element extends radially from the rotatable optical core at a height H1, where H1 is at least 5% and / or 95% of half the difference between D1 and D2. 【0023】 In some embodiments, the rotatable optical core has a diameter D1, the elongated shaft lumen has a diameter D2, the fluid pressurizing element extends radially from the rotatable optical core at a height H1, the clearance C1 has a value obtained by subtracting H1 from half the difference between D1 and D2, and the clearance C1 has a length of 100 μm or less and / or 75 μm or less. 【0024】 In some embodiments, the fluid pressurized element is provided with a covering. The covering may comprise elements selected from a group consisting of sheaths, heat-shrinkable tubing, painted coatings, sprayed coatings, and combinations thereof. 【0025】 In some embodiments, the fluid pressurizing element is further configured to generate a driving force, which is configured to translate a rotatable optical core. The fluid pressurizing element can be configured to advance the rotatable optical core when rotated in a first direction, and to retract the rotatable optical core when rotated in a second direction opposite to the first direction. 【0026】 In some embodiments, the damping fluid comprises a non-Newtonian fluid. 【0027】 In some embodiments, the damping fluid comprises a shear-reducing fluid. 【0028】 In some embodiments, the damping fluid has a static viscosity of at least 500 centipoise. The damping fluid may have a shear viscosity lower than its static viscosity. The damping fluid may have a ratio of static viscosity to shear viscosity of at least 1.2:1 and / or 100:1 or less. 【0029】 In some embodiments, the damping fluid comprises a first fluid and a second fluid. The first fluid may be a low-viscosity fluid, and the second fluid may be a high-viscosity fluid. 【0030】 In some embodiments, the damping fluid comprises a low-viscosity fluid configured to reduce bubble formation. The damping fluid may comprise a fluid having a viscosity of 1000 centipoise or less. 【0031】 In some embodiments, the damping fluid comprises a fluid having high surface tension configured to reduce bubble formation. The damping fluid may comprise a fluid having a surface tension of at least 40 dynes / cm. 【0032】 In some embodiments, the imaging probe includes a distal portion having a diameter of 0.020 inches or less. The distal portion of the imaging probe may have a diameter of 0.016 inches or less. 【0033】 In some embodiments, the imaging probe further includes a sealing element at the distal end of an elongated shaft. 【0034】 According to another aspect of the concept of the present invention, the imaging probe comprises an elongated shaft having a proximal end, a distal end, and a lumen extending between the proximal and distal ends; a rotatable optical core having a proximal end and a distal end, wherein at least a portion of the rotatable optical core is positioned within the lumen of the elongated shaft and close to the distal end of the rotatable optical core, and is configured to guide light to tissue and collect reflected light from the tissue, and an optical assembly. The shaft comprises a proximal shaft and a distal shaft attached thereto. The proximal shaft comprises a first tubular member having a first lumen. The distal shaft comprises a second tubular member having a second lumen. The shaft further comprises a third tubular member extending into the first lumen and the second lumen. The shaft further comprises a fourth tubular member having a proximal portion surrounding the distal portion of the first tubular member and a distal portion located between the proximal portion of the second tubular member and the third tubular member. 【0035】 In some embodiments, the first tubular member comprises a spirally cut hypotube. 【0036】 In some embodiments, the second tubular member is made of a transparent material. 【0037】 In some embodiments, the third tubular member has a larger outer diameter than the first lumen. 【0038】 In some embodiments, the fourth tubular member comprises a heat-shrinkable material. 【0039】 In some embodiments, the imaging probe further comprises adhesives disposed between two or more of a first tubular member, a second tubular member, a third tubular member, and / or a fourth tubular member. 【0040】 In some embodiments, the imaging probe further comprises a fluid propulsion element having a diameter D1, and the third tubular member comprises a lumen having a diameter smaller than D1. 【0041】 In some embodiments, the second tubular member is provided with a projection extending toward the third tubular member. 【0042】 In some embodiments, the second tubular member has a maximum diameter close to that of the third tubular member, and the fourth tubular member has a maximum diameter close to that of the third tubular member, with each maximum diameter not exceeding 0.02 inches, 0.0175 inches, and / or 0.0155 inches. 【0043】 In some embodiments, the fluid pressurizing element comprises a first fluid pressurizing element and a second fluid pressurizing element. The first and second pressurizing elements can create opposite pressure gradients when rotated. 【0044】 According to another measurement of the present invention, a method for manufacturing a fluid propulsion element for an optical probe comprises providing a tube into which a mandrel is inserted, forming two or more helical channels along the length of the tube, removing a first fluid propulsion element from the mandrel, and removing a second fluid propulsion element from the mandrel. 【0045】 In some embodiments, the method further comprises generating a first optical probe using at least a first fluid propulsion element. The method may further comprise generating a second optical probe using a second fluid propulsion element. 【0046】 The technology described herein, along with its characteristics and associated advantages, is best understood by referring to the following detailed description in conjunction with the attached drawings, which illustrate typical embodiments. 【0047】 <Import by reference> All publications, patents, and patent applications described herein are incorporated herein by reference to the same extent as any individual publication, patent, or patent application is explicitly and individually indicated to be incorporated by reference. For all purposes, the entirety of all publications, patents, and patent applications mentioned herein is incorporated herein by reference. 【0048】 <Related applications> This application claims the interests of U.S. Provisional Application No. 62 / 840,450, filed on April 30, 2019, entitled “Imaging Probe with Fluid Pressurization Element,” the contents of which are incorporated in their entirety by reference. 【0049】 This application claims the interests of U.S. Provisional Application No. 63 / 017,258, titled "Imaging System," filed on 29 April 2020, the contents of which are incorporated in their entirety by reference. 【0050】 This application claims the benefits of U.S. Provisional Application No. 62 / 850,945, titled "OCT-Guided Treatment of a Patient," filed on 21 May 2019, the contents of which are incorporated in their entirety by reference. 【0051】 This application claims the benefits of U.S. Provisional Application No. 62 / 906,353, titled "OCT-Guided Treatment of a Patient," filed on 26 September 2019, the contents of which are incorporated in their entirety by reference. 【0052】 This application relates to the U.S. Provisional Application No. 62 / 148,355, titled "Micro-Optic Probes for Neurology," filed on April 16, 2015, the contents of which are incorporated in their entirety by reference. 【0053】 This application relates to the U.S. Provisional Application No. 62 / 322,182, titled "Micro-Optic Probes for Neurology," filed on April 13, 2016, the contents of which are incorporated in their entirety by reference. 【0054】 This application relates to the international PCT patent application titled "Micro-Optic Probes for Neurology," serial number PCT / US2016 / 027764, filed on 15 April 2016, and publication number WO 2016 / 168605, published on 20 October 2016, the contents of which are incorporated in their entirety by reference. 【0055】 This application relates to the U.S. Patent Application No. 15 / 566,041, titled "Micro-Optic Probes for Neurology," filed on 12 October 2017, and U.S. Publication No. 2018-0125372, published on 10 May 2018, the contents of which are incorporated in their entirety by reference. 【0056】 This application relates to U.S. Provisional Application No. 62 / 212,173, titled "Imaging System Includes Imaging Probe and Delivery Devices," filed on 31 August 2015, the contents of which are incorporated in their entirety by reference. 【0057】 This application relates to the U.S. Provisional Application No. 62 / 368,387, titled "Imaging System Includes Imaging Probe and Delivery Devices," filed on 29 July 2016, the contents of which are incorporated in their entirety by reference. 【0058】 This application relates to the international PCT patent application titled "Imaging System Includes Imaging Probe and Delivery Devices," serial number PCT / US2016 / 049415, filed on 30 August 2016, and publication number WO 2017 / 040484, published on 9 March 2017, the contents of which are incorporated in their entirety by reference. 【0059】 This application relates to U.S. Patent Application No. 10,631,718, issued on April 28, 2020, entitled “Imaging System Includes Imaging Probe and Delivery Devices,” serial number 15 / 751,570, filed on February 9, 2018, the contents of which are incorporated in their entirety by reference. 【0060】 This application relates to the U.S. Provisional Application No. 62 / 591,403, titled "Imaging System," filed on 28 November 2017, the contents of which are incorporated in their entirety by reference. 【0061】 This application relates to the U.S. Provisional Application No. 62 / 671,142, titled "Imaging System," filed on 14 May 2018, the contents of which are incorporated in their entirety by reference. 【0062】 This application relates to the international PCT patent application titled "Imaging System," serial number PCT / US2018 / 062766, filed on 28 November 2018, and publication number WO2019 / 108598, published on 6 June 2019, the contents of which are incorporated in their entirety by reference. 【0063】 This application relates to the U.S. Provisional Application No. 62 / 732,114, titled "Imaging System with Optical Pathway," filed on 17 September 2018, the contents of which are incorporated in their entirety by reference. 【0064】 This application relates to the international PCT patent application titled "Imaging System with Optical Pathway," serial number PCT / US2019 / 051447, filed on 17 September 2019, and publication number WO 2020 / 0611001, published on 26 March 2020, the contents of which are incorporated in their entirety by reference. [Brief explanation of the drawing] 【0065】 [Figure 1] This is a schematic diagram of an imaging system equipped with an imaging probe having a fluid pressurizing element, which is consistent with the concept of the present invention. [Figure 1A] This is an enlarged view of the components within circle M1 in Figure 1, which is consistent with the concept of the present invention. [Figure 2]This is a schematic diagram of the distal portion of an imaging probe and a delivery catheter, consistent with the concept of the present invention. [Figure 2A] This is an enlarged view of the components within circle M2, which are consistent with the concept of the present invention. [Figure 2B] This is a schematic diagram of the distal portion of an imaging probe showing a fluid flow pattern, consistent with the concept of the present invention. [Figure 2C] This document demonstrates a fluid flow simulation that aligns with the concept of the present invention. [Figure 3A] This is a schematic diagram of the distal portion of an imaging probe that conforms to the concept of the present invention. [Figure 3B] This is a schematic diagram of the distal portion of an imaging probe that conforms to the concept of the present invention. [Figure 4] This is a schematic diagram of the distal portion of an imaging probe and a delivery catheter, consistent with the concept of the present invention. [Figure 4A] This is an enlarged view of the components within circle M3 that are consistent with the concept of the present invention. [Figure 5] This is a schematic diagram of the distal portion of an imaging probe and a delivery catheter, consistent with the concept of the present invention. [Figure 5A] This is an enlarged view of the components within circle M4 that are consistent with the concept of the present invention. [Figure 6A] This is a schematic diagram of the distal portion of an optical probe that is consistent with the concept of the present invention. [Figure 6B] This is a schematic diagram of the distal portion of an optical probe that is consistent with the concept of the present invention. [Figure 6C] This is a schematic diagram of the distal portion of an optical probe that is consistent with the concept of the present invention. [Figure 7] This is a cross-sectional view showing a segment of an imaging probe having a shaft with a multi-component structure that conforms to the concept of the present invention. [Figure 8] This is a cross-sectional view showing a part of an imaging probe equipped with a bidirectional fluid propulsion element that conforms to the concept of the present invention. [Figure 9A] This is a perspective view of the four steps of a process for manufacturing a fluid propulsion element, consistent with the concept of the present invention. [Figure 9B]This is a perspective view of the four steps of a process for manufacturing a fluid propulsion element, consistent with the concept of the present invention. [Figure 9C] This is a perspective view of the four steps of a process for manufacturing a fluid propulsion element, consistent with the concept of the present invention. [Figure 9D] This is a perspective view of the four steps of a process for manufacturing a fluid propulsion element, consistent with the concept of the present invention. [Modes for carrying out the invention] 【0066】 The following describes embodiments of the present technology in detail, with examples shown in the accompanying drawings. Similar reference numerals may be used to refer to similar components. However, this description is not intended to limit the disclosure to any particular embodiment, but should be interpreted as including various modifications, equivalents, and / or substitutes of the embodiments described herein. 【0067】 In this specification, the terms “comprising” (and any form of “comprising,” such as “comprise” or “comprises”), “having” (and any form of “having,” such as “have” or “has”), “including” (and any form of “including,” such as “includes” or “include”), or “containing” (and any form of “containing,” such as “contains” or “contain”) are understood to be used in this specification. When used herein, these terms specify the existence of a described feature, integer, step, operation, element, and / or component, but do not preclude the existence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. 【0068】 Furthermore, while terms such as first, second, third, etc. may be used in this specification to describe various limitations, elements, components, areas, layers, and / or sections, it should be understood that these limitations, elements, components, areas, layers, and / or sections should not be limited by these terms. These terms are used solely to distinguish one limitation, element, component, area, layer, or section from another limitation, element, component, area, layer, or section. Accordingly, the first limitation, element, component, area, layer, or section described below may be referred to as the second limitation, element, component, area, layer, or section without departing from the teachings of this application. 【0069】 Further understanding is that when an element is described as "on," "attached," "connected," or "coupled" to another element, it means that the element is directly on top of or above the other element, or is connected to or coupled to the other element, or that one or more intervening elements may be present. On the other hand, when an element is described as "directly on," "directly attached," "directly connected," or "directly coupled" to another element, there are no intervening elements. Other words used to describe relationships between elements should be interpreted similarly (e.g., "between" vs. "direct between," "adjacent" vs. "direct adjacent," etc.). 【0070】 Furthermore, when the first element is said to be "inside," "on top of," and / or "inside" the second element, it is understood that the first element can be located within the internal space of the second element, as part of the second element (e.g., inside the walls of the second element), on the outer surface and / or interior surface of the second element, and in one or more combinations thereof. 【0071】 In this specification, the term “proximity” used to describe the proximity of a first component or location to a second component or location should be interpreted to include not only one or more locations that are near the second component or location, but also locations that are in, above, and / or within the second component or location. For example, a component located in proximity to an anatomical site (e.g., the location of a target tissue) includes not only components located in proximity to the anatomical site, but also components located in, above, and / or within the anatomical site. 【0072】 Spatially relative terms such as "down," "below," "bottom," "up," and "top" can be used to describe the relationship between one element and / or function and another, as shown in the diagram, for example. Furthermore, it is understood that spatially relative terms are intended to encompass different orientations of the device during use and operation, in addition to the orientation depicted in the diagram. For example, if the device in the diagram is turned over, elements described as "below" and / or "below" other elements and features will be oriented "up" of those other elements and features. The device can be oriented in other ways (e.g., rotated 90 degrees or in other orientations), and the spatially relative descriptors used here are interpreted accordingly. 【0073】 As used herein, terms such as “reduce,” “reducing,” and “reduction” include reductions in quantity, including reductions to zero. Reducing the likelihood of occurrence includes prevention of occurrence. Correspondingly, the terms “prevent,” “preventing,” and “prevention” include the actions of “reduce,” “reduction,” and “reduction,” respectively. 【0074】 As used herein, the term "and / or" is to be considered to be specifically disclosed for each of two designated features or components, either together with or without the other. For example, "A and / or B" is to be considered to be specifically disclosed for each of (i) A, (ii) B, and (iii) A and B, as if each were described separately herein. 【0075】 As used herein, the term "one or more" can mean any number, including one, two, three, four, five, six, seven, eight, nine, ten, or more. 【0076】 The terms “and combinations thereof” and “and combinations thereof” may be used in this specification after a list of items that should be included individually or collectively. For example, components, processes, and / or other items selected from a group consisting of: For example, components, processes, and / or other items selected from a group consisting of A; B; C; and combinations thereof shall include one or more sets of components consisting of one, two, three or more of item A, one, two, three or more of item B, and / or one, two, three or more of item C. 【0077】 In this specification, unless otherwise specified, “and” may mean “or,” and “or” may mean “and.” For example, if a feature is described as having A, B, or C, that feature may have A, B, and C, or any combination of A, B, and C; similarly, if a feature is described as having A, B, and C, that feature may have only one or two of A, B, or C. 【0078】 The expression "configured (or set up)" as used in this disclosure can be replaced with expressions such as "suitable for," "capable of," "designed to," "adapted to," "made," or "capable," depending on the context. Furthermore, the expression "configured (or set up)" does not only mean "specifically designed to" in terms of hardware. Alternatively, depending on the context, the expression "device configured to" may mean that the device "is capable" of working together with other devices or components. 【0079】 In this specification, the term “threshold” means a maximum level, a minimum level, and / or a range of values ​​related to a desired or undesirable state. In some embodiments, system parameters are maintained above a minimum threshold, below a maximum threshold, within a threshold range, and / or outside a threshold range to produce a desired effect (e.g., effective treatment) and / or to prevent or otherwise reduce undesirable events (e.g., device and / or clinical adverse events) (hereinafter, “prevention”). In some embodiments, system parameters are 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, taking into account patient variability, system variability, tolerance range, etc. In this specification, “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. 【0080】 In this specification, “room pressure” means the pressure of the environment surrounding the system and apparatus of the concept of the present invention. Positive pressure includes pressures higher than room temperature, or simply pressures higher than other pressures, such as positive differential pressure across a fluid path component, such as a valve. Negative pressure includes pressures lower than the room pressure, or pressures lower than other pressures, such as negative differential pressure across a fluid component's path, such as a valve. Negative pressure can include a vacuum, but does not mean pressure below a vacuum. In this specification, the term “vacuum” can be used to refer to a complete or partial vacuum, or any negative pressure as described above. 【0081】 In this specification, the term “diameter” used to describe non-circular shapes is considered to be the diameter of a hypothetical circle that approximates the shape being described. For example, when describing a cross-section, such as the cross-section of a part, the term “diameter” shall represent the diameter of a hypothetical circle having the same cross-sectional area as the cross-section of the part being described. 【0082】 In this context, the "major axis" and "minor axis" of a part refer to the length and diameter of the smallest possible volume of a hypothetical cylinder that can completely enclose that part. 【0083】 In this specification, the term “functional element” is understood to include one or more elements constructed and arranged to perform a certain function. Functional elements may include sensors and / or transducers. In some embodiments, a functional element is configured to supply energy and / or treat tissue (e.g., a functional element configured as a therapeutic element). Alternatively or additionally, a functional element (e.g., a functional element consisting of sensors) may be configured to record one or more parameters, such as a patient’s physiological parameters, a patient’s anatomical parameters (e.g., tissue morphology parameters), a patient’s environmental parameters, and / or system parameters. In some embodiments, a sensor or other functional element is configured to perform a diagnostic function (e.g., to collect data used to perform a diagnosis). In some embodiments, a functional element is configured to perform a therapeutic function (e.g., to provide therapeutic energy and / or therapeutic agents). In some embodiments, a functional element consists of one or more elements configured and arranged to perform functions selected from a group consisting of energy supply, energy extraction (e.g., cooling of components), supply of drugs, manipulation of system components or patient tissue, recording or otherwise sensing parameters such as patient physiological parameters or system parameters, and one or more combinations thereof. The functional element comprises a fluid and / or a fluid supply system. The functional element may include a reservoir such as an expandable balloon or other fluid-holding reservoir. A "functional assembly" may comprise an assembly constructed and arranged to perform functions such as diagnostic and / or therapeutic functions. A functional assembly may include an expandable assembly. A functional assembly may include one or more functional elements. 【0084】 As used herein, the term “transducer” is interpreted to include any component or combination of components that receive energy or any input and produce an output. For example, a transducer may include electrodes that receive electrical energy and distribute that electrical energy to tissue (for example, based on the size of the electrodes). In some configurations, a transducer converts an electrical signal into any output such as light (e.g., a transducer consisting of a light-emitting diode or a light bulb), sound (e.g., a transducer consisting of a piezoelectric crystal configured to supply ultrasonic energy), pressure, thermal energy, cryogenic energy, chemical energy, mechanical energy (e.g., a transducer consisting of a motor or a solenoid), magnetic energy, and / or another electrical signal (e.g., Bluetooth or other wireless communication element). Selectively or additionally, a transducer may convert a physical quantity (such as a change in a physical quantity) into an electrical signal. A transducer may include any components that deliver energy and / or agents to tissue. For example, a transducer is configured to transmit one or more of the following to tissue: electrical energy (e.g., a transducer including one or more electrodes), light energy (e.g., a transducer consisting of optical components such as lasers, light-emitting diodes, lenses, and prisms), mechanical energy (e.g., a transducer with tissue manipulation elements), sound energy (e.g., a transducer with a piezoelectric crystal), chemical energy, electromagnetic energy, magnetic energy, and one or more combinations thereof. 【0085】 In this specification, the term “fluid” means a liquid, gas, gel, or any fluid material, such as a material that can be propelled through a lumen and / or opening. 【0086】 For clarity, it should be understood that certain features of the concept of the present invention described in the context of separate embodiments may also be provided in combination in a single embodiment. Conversely, for brevity, various features of the concept of the present invention described in the context of a single embodiment may also be provided separately or in any suitable subcombination. For example, it will be understood that all features described in any of the claims (whether independent or dependent) can be combined in any way. 【0087】 At least some of the figures and descriptions of the concept of the present invention have been simplified to focus on elements relevant to a clear understanding of the concept of the invention, while, for the purpose of clarity, other elements that would be understood by those skilled in the art may also constitute part of the concept of the invention. However, since such elements are well known in the art and do not necessarily facilitate a better understanding of the invention, such elements are not described herein. 【0088】 The terms defined herein are used solely to describe specific embodiments of the disclosure and are not intended to limit the scope of the disclosure. Terms provided in the singular form are intended to include the plural form unless the context clearly indicates otherwise. All terms used herein, including technical or scientific terms, have the same meaning as those generally understood by those skilled in the art unless otherwise specifically defined herein. Terms defined in commonly used dictionaries should be construed to have the same or similar meaning in the context of the art, and not an ideal or exaggerated meaning, unless expressly defined herein. In some cases, terms defined herein should not be construed to exclude embodiments of the disclosure. 【0089】 This specification provides an imaging system for a patient, comprising an imaging probe and an imaging assembly optically coupled to the imaging probe. The probe comprises an elongated shaft, a rotatable optical core, and an optical assembly. The rotatable optical core is located within the lumen of the elongated shaft. The optical assembly is positioned close to the distal end of the optical core and is configured to direct light into tissue and collect reflected light from the tissue. When optically coupled to the imaging probe, the imaging assembly is configured to illuminate the imaging probe and receive reflected light collected by the optical assembly, providing images of, for example, blood vessels and devices placed within the blood vessels. The probe may include a damping fluid positioned between the elongated shaft and the rotatable optical core, which may be configured to reduce uneven rotation of the optical assembly and, as a result, reduce undesirable distortion of the images produced by the system. The probe may further include a fluid pressurizing element configured to increase the pressure of the damping fluid to reduce the presence of bubbles close to the optical assembly (e.g., bubbles that limit or degrade the quality of images produced by the system). 【0090】 Vascular imaging is a primary diagnostic tool when planning and applying treatments such as thrombolytic agents and stent retrievers for thrombectomy (e.g., ischemic stroke), or coils and flow diverters for aneurysm repair (e.g., hemorrhagic stroke). While external, non-invasive imaging techniques such as X-ray angiography and magnetic resonance imaging (MRI) are the main imaging technologies, these techniques only provide information about the size and shape of vessels and have moderate resolution (~0.2 mm or 200 μm). Such resolutions are insufficient to capture important small features present within the vessels. Failure to adequately image these vessels limits preoperative planning and acute evaluation of treatment outcomes. When coils are used, the effectiveness of these imaging techniques is further limited by shadows and localized image loss caused by the treatment. Therefore, there is a desire to perform intravascular imaging of the present invention to examine the detailed morphology of the vascular wall and / or to better plan and evaluate the results of catheter-based interventions. Currently, intravascular imaging techniques such as intravascular ultrasound (IVUS) and intravascular optical coherence tomography (OCT) have been developed and approved for use in coronary arteries. IVUS is also used in peripheral blood vessels. However, intravascular imaging has not been extended to neurovascular vessels, except for the large carotid arteries. This limitation is mainly due to two reasons: the size of neurovascular vessels is very small, less than 1 mm in diameter, and the curvature of the vessels is very high. Therefore, smaller and more flexible imaging probes are needed. For example, probes that can safely and effectively navigate the winding carotid sinus to reach and image the middle cranial artery and its more distal branches and segments. 【0091】 Ultrasound has fundamental limitations in resolution, and beam spreading is unavoidable, especially when using small transducers, making optical techniques preferable. The emergence of new light sources, such as broadband superluminescent light-emitting diodes (SLEDs), supercontinuum lasers, small sweep sources, micro-optical systems, and optical coherence tomography (OCT), including those compatible with single-mode fibers, has made the use of optical techniques highly advantageous from both a clinical performance and commercial standpoint. Furthermore, the use of single-mode fibers allows for the consideration of the smallest possible imaging probes. 【0092】 Generally, to create a three-dimensional (3D) image of the vascular wall, light emitted by an imaging optical system located distal to the inserted probe can be swept across the lumen surface by simultaneously moving ("pulling back") and rotating the fiber connected to the optical system in the axial direction. For accurate and distortion-free images, uniform rotation speed at the distal end is desirable. Due to size and cost considerations, the drive motor causing the rotation is located proximal, outside the patient, and separate from the imaging probe (e.g., configured in a reusable configuration for use with multiple imaging probes). The fiber of the imaging probe has a natural tendency to "whip" at its distal end, a phenomenon called NURD (Non-Uniform Rotational Distortion). To overcome this undesirable effect, a tightly wound, spring-like coil called a torque wire is used, with the fiber positioned at the center of the coil to reduce the non-uniform rotation of the distal optical system. These torque wires are costly and prone to recurrence of NURD if the catheter size is increased (e.g., diameter increases) or if the labyrinthine limits are exceeded. Furthermore, the torque wire is sensitive to the total curvature accumulated along the length of the catheter, and since the torque wire must be attached to a proximal drive source, this accumulated total curvature can be large (for example, causing NURD to reappear). Since uniform rotation is required only for the distal tip optics, the rotation of the proximal components of the distal optics does not need to be controlled as much. In other words, as long as the rotation speed of the distal optics is relatively constant, the fiber can be twisted or not twisted in the proximal region in response to changes in labyrinthineness without generating NURD. Thus, a configuration that uniformly controls the rotation of the distal optics without using a torque wire avoids many limitations while offering many advantages. 【0093】 To overcome the limitations of torque wires and control changes in rotational speed, damping fluids have been used. For example, U.S. Patent No. 6,891,984 ('984 Patent) describes using a viscous fluid to "rewind" the fibers and store rotational energy. Furthermore, since the rewinding speed is determined by the viscosity of the fluid, it can provide an effective feedback mechanism for rotational control. The fluid covering the lens must satisfy the desired optical properties, in particular, an optical index within an acceptable range to minimize cylindrical distortion and low absorption at the operating wavelength. Since the selected liquid is temporarily placed inside the body, it can be a biocompatible liquid. If biocompatible, an additional protective layer can be added to protect against undesirable single-fault conditions (e.g., leak conditions). 【0094】 The conceptual system of the present invention may include non-Newtonian fluids and / or shear thin-walled fluids that can handle high-speed rotation, as described in the U.S. Patent Application No. 15 / 566,041, co-filed by the applicant, entitled "Micro-Optic Probes for Neurology," filed on 12 October 2017. 【0095】 Fluid-based rotation control solutions (e.g., fluid damping solutions) all suffer from the problem of bubble formation within the fluid. Generally, bubbles have little effect on mechanical performance, but it is easy to understand that bubbles located in the light transmission and reception paths ("light beam paths") can have a significant negative impact on image quality. Bubble formation is a phenomenon inherent to rotating bodies in fluids, such as cavitation. Bubbles can also form in fluids at the fluid-solid interface due to nucleation, but cavitation is usually dominant at high rotational speeds. Because the light beam needs to be orthogonal relative to the probe axis, some asymmetry exists in the distal optical system (e.g., a lens assembly with a chamfered distal end configured to guide light at 90° from the axis of the distal end of the attached fiber), and as a result, a tendency to create low-pressure regions generally occurs at high rotational speeds. 【0096】 Cavitation is the presence of small, vapor-filled regions ("bubbles") that occur when a liquid is subjected to abrupt pressure changes, forming cavities in areas of relatively low pressure. The system of the present invention has several general characteristics that can be optimized to minimize cavitation and the associated bubble formation. For example, the geometric shape of the imaging probe (e.g., the space in which the damping fluid is placed) can be constructed and positioned to minimize bubble formation. The viscosity of the damping fluid included can be selected to limit bubble formation. The damping fluid can comprise a fluid having a low vapor pressure and / or low levels of dissolved gas (or gas). The damping fluid can comprise a fluid having high surface tension (e.g., prone to causing bubbles to collapse). The damping fluid can comprise a fluid with low surface tension (e.g., when bubble formation is induced via nucleation), such as a wetting agent. While low viscosity fluids tend to reduce bubble formation, this alone may not be sufficient to effectively control NURD. A combination of two or more fluids (e.g., a stacked arrangement) can be used, for example, when one or more sealing elements are included to keep the fluids separated. The low-viscosity fluid is placed above the distal optics (e.g., above the distal optics only), and the high-viscosity fluid is placed proximal to the low-viscosity fluid and can extend over a relatively long segment of the imaging probe. In some embodiments, one or more damping fluids are used, and the one or more damping fluids include viscosity, low vapor pressure, low levels of dissolved gas, low surface tension, and / or high surface tension, selected to reduce bubble formation. 【0097】 In some embodiments, the pressure of the contained damping fluid (or other fluid) can be increased to produce an effect selected from the group consisting of: reduced bubble formation, reduced growth of one or more bubbles (e.g., one or more existing bubbles), reduced size of one or more bubbles (e.g., one or more existing bubbles), propulsion of one or more bubbles away from the light beam path, and a combination thereof. Increased pressurization of the damping fluid can be performed for a limited time, as prolonged pressurization may cause the fluid to adsorb additional gases and lead to the establishment of new vapor pressures. The pressurizing elements of the concept of the present invention can be small in size (e.g., compact) so as to fit within a probe. These pressurizing elements can be activated (e.g., generate increased pressure in the damping fluid) only when actual imaging is occurring (e.g., when the fiber and distal optics are rotating at high speed) to avoid the establishment of undesirable equilibrium states caused by prolonged pressurization. 【0098】 All of the above bubble reduction configurations can be applied individually and / or in combination to prevent, limit, and / or reduce bubble formation near the distal optical system of the probe. 【0099】 A system of the concept of the present invention may include a probe having a fluid pressurizing element configured to "minimize bubble effects" (e.g., reduce the presence of bubbles in one or more locations), which includes preventing, limiting, and / or reducing the formation of one or more bubbles, limiting and / or reducing the expansion of one or more bubbles, reducing the size of one or more bubbles, and / or keeping one or more bubbles away from the light beam path (e.g., keeping one or more bubbles away from optical assemblies that transmit light to and / or from tissue). 【0100】 Referring to Figure 1, a schematic diagram of an imaging system comprising an imaging probe having a fluid pressurized element, consistent with the concept of the present invention, is illustrated. Referring further to Figure 1A, an enlarged view of the components within circle M1, consistent with the concept of the present invention, is illustrated. The imaging system 10 is constructed and arranged to collect image data and generate one or more images based on the recorded data, for example, if the imaging system 10 comprises an optical coherence tomography (OCT) imaging system constructed and arranged to collect image data of an imaging location (e.g., a segment of a blood vessel, such as during a pullback procedure). The imaging system 10 comprises an imaging probe 100, which is a catheter-based probe, and a rotating assembly 500 and a retracting assembly 800, which can be operably attached to the imaging probe 100, respectively. The imaging system 10 may further comprise a console 50, configured to be operably connected to the imaging probe 100, such as via the rotating assembly 500 and / or the retracting assembly 800. The imaging probe 100 can be introduced into a patient's conduit, such as a patient's blood vessel or conduit, via one or more delivery catheters, for example, the indicated delivery catheter 80. Alternatively, the imaging probe 100 can be introduced via an introducer device such as an endoscope, arthroscope, or balloon dilator. In some embodiments, the imaging probe 100 is configured to be introduced into a conduit selected from the group consisting of: arteries, veins, intracardiac or adjacent arteries, intracardiac or adjacent veins, intracerebral or adjacent arteries, intracerebral or adjacent veins, peripheral arteries, peripheral veins, via a natural orifice into a conduit such as the esophagus, via a surgically created orifice into a body cavity such as the abdomen, and one or more combinations thereof. The imaging system 10 may further include additional imaging devices, such as a second imaging device 15 shown. The imaging system 10 may further include a treatment device 16 configured to treat a patient.The imaging system 10 may further include a fluid injector such as an injector 20, which may be configured to inject one or more fluids, such as a flushing fluid, an imaging contrast agent (e.g., a radiopaque contrast agent, hereinafter referred to as "contrast agent"), and / or other fluids such as the indicated injector 21. The imaging system 10 may further include an implant such as an implant 31, which may be implanted in a patient via a delivery device such as an implant delivery device 30 and / or a delivery catheter 80. 【0101】 In some embodiments, the imaging probe 100 and / or other components of the imaging system 10 may have a similar structure and arrangement to similar components described in the jointly filed U.S. Patent Application No. 15 / 566,041, titled "Micro-Optic Probes for Neurology," filed October 12, 2017, and / or the jointly filed U.S. Provisional Patent Application No. 62 / 732,114, titled "Imaging System with Optical Pathway," filed September 17, 2018. The imaging probe 100 may be constructed and positioned to collect image data from patient sites, such as intravascular cardiac sites, intracranial sites, or other sites accessible via the patient's vascular system. In some embodiments, the imaging system 10 may have a similar structure and arrangement to a similar system and method of use described in the applicant's jointly pending U.S. Patent Application No. 15 / 751,570, titled "Imaging System includes Imaging Probe and Delivery Devices," filed on February 9, 2018. 【0102】 The delivery catheter 80 comprises a shaft 81 which is an elongated shaft, a lumen 84 located therein, and a connector 82 located at its proximal end. The connector 82 may include a Touhy or other valved connector, such as a valved connector configured to prevent fluid leakage from the associated delivery catheter 80 (with and / or without a separate shaft located within the connector 82). The connector 82 may include a port 83, such as a port configured and positioned to allow the introduction of fluid into and / or the removal of fluid from the delivery catheter 80. In some embodiments, a lavage fluid is introduced through one or more ports 83, as described below, to remove blood or other undesirable material from a location close to the optical assembly (e.g., from a location close to the optical assembly to a location distal to the optical assembly, e.g., the optical assembly 115 described below). The ports 83 may be located on the side of the connector 82 and may include a Luer fitting and a cap and / or valve. The shaft 81, connector 82, and port 83 may each be made of standard materials and may have a structure similar to commercially available introducers, guide catheters, diagnostic catheters, intermediate catheters, and microcatheters used in interventional procedures. The delivery catheter 80 may include a catheter configured to deliver the imaging probe 100 (via the lumen 84) to a location in the brain, a location in the heart, and / or another location in the patient. 【0103】 The imaging system 10 may comprise two or more delivery catheters 80, for example, three or more delivery catheters 80. The multiple delivery catheters 80 may comprise at least a vascular introducer and other delivery catheters 80 that can be inserted into the patient from there after the vascular introducer has been positioned through the patient's skin. The two or more delivery catheters 80 may collectively comprise a set of inner diameters (ID) and outer diameters (OD), such that a first delivery catheter 80 slidably accepts a second delivery catheter 80 (e.g., the OD of the second delivery catheter is less than or equal to the ID of the first delivery catheter), and a second delivery catheter 80 slidably accepts a third delivery catheter 80 (e.g., the OD of the third delivery catheter is less than or equal to the ID of the second delivery catheter). In these configurations, the first delivery catheter 80 can be advanced to a first anatomical location, and the second delivery catheter 80 can be advanced via the first delivery catheter to a second anatomical location distal to or otherwise separated from the first anatomical location (hereinafter, "distal"), which can be appropriately done using delivery catheters 80 of progressively smaller diameters. The probe 100 can be advanced through and / or alongside one or more of the delivery catheters 80 (e.g., through the lumen of the smallest delivery catheter 80). In some embodiments, the delivery catheter 80 can have a similar structure and arrangement to similar components described in the applicant's jointly pending U.S. Patent Application No. 15 / 751,570, titled "Imaging System includes Imaging Probe and Delivery Devices," filed February 9, 2018. 【0104】 The imaging probe 100 has an elongated body consisting of one or more elongated shafts and / or other tubes, which in this specification has an elongated shaft 120. The shaft 120 comprises a proximal end 1201, a distal end 1209, and a lumen 1205 extending between them. In some embodiments, the lumen 1205 comprises multiple coaxial lumens within one or more elongated shafts 120, for example, one or more lumens adjacent to one another defining 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 comprises a braided structure. The shaft 120 operably surrounds a rotatable optical fiber, an optical core 110 (for example, the optical core 110 is located within the lumen 1205), which has a proximal end 1101 and a distal end 1109 (the proximal end 1101 is not shown but is close to the proximal end 1201 of the shaft 120). The optical core 110 may comprise dispersion-shift fibers, such as depressurized cladding dispersion-shift fibers. The shaft 120 further comprises a distal portion 1208, which includes a transparent window 130 (for example, a window that is transparent to light of one or more frequencies that passes through the optical core 110). The window 130 may comprise the entire circumference of the distal portion 1208 of the shaft 120. An optical assembly 115, which is an optical assembly, is operably mounted to the distal end 1109 of the optical core 110 (for example, so that the optical assembly 115 rotates integrally with the optical core 110). The optical assembly 115 is positioned within the window 130 of the shaft 120. A connector assembly 150, which is a connector assembly, is positioned at the proximal end of the shaft 120. The connector assembly 150 operably mounts the imaging probe 100 to a rotating assembly 500, which is operably mounted to the optical core 110. The rotating assembly 500 can be configured to rotate the optical core 110 within the shaft 120, as described herein.The connector assembly 150 may have a similar structure and arrangement to similar components described in the international PCT patent application, serial number PCT / US2018 / 062766, jointly filed by the applicants, titled “Imaging System,” filed on 28 November 2018, and in the U.S. provisional patent application, serial number 62 / 732,114, jointly filed by the applicants, titled “Imaging System with Optical Pathway.” A second connector, a pullback connector 858, is positioned on the shaft 120. The connector 858 may be detachably mounted and / or adjustable along the length of the shaft 120. The connector 858 may be positioned along the shaft 120 by an operator or the like, close to the proximal end of the delivery catheter 80 (for example, close to the connector 82 of the delivery catheter 80), after the imaging probe 100 has been inserted into the patient via the delivery catheter 80. The shaft 120 may include a portion that accommodates slack in the shaft 120 between the position of the connector assembly 150 and the connector 858, a proximal portion of the shaft 120 (for example, the proximal portion of the imaging probe 100), and a service loop 185. 【0105】 The imaging probe 100 may include one or more visible markers along its length (e.g., along the shaft 120), markers 131a-b are shown (mark 131 in this specification). Marker 131 may comprise markers selected from the group consisting of radiopaque markers; ultrasonic reflective markers; magnetic markers; iron markers; visible markers; and one or more combinations thereof. In some embodiments, marker 131 comprises markers positioned (e.g., within and / or at least near the distal portion 1208) to assist the operator of the imaging system 10 in performing a pullback procedure (e.g., a pullback procedure using fluoroscopy and / or external ultrasound imaging). For example, after the pullback is completed, the distal end 1209 of the shaft 120 is positioned distal to the proximal end of the implant (e.g., so that the imaging probe 100 can be safely advanced through the implant after the pullback). 【0106】 In some embodiments, the imaging probe 100 includes a gel 180, which is a viscous damping fluid or other damping material, positioned within the lumen 1205 of the shaft 120 and configured to reduce the non-uniform rotation of the optical assembly 115. The gel 180 may surround at least the distal portion of the optical core 110. The gel 180 may further surround the optical assembly 115. The gel 180 may comprise a non-Newtonian fluid, such as a shear thin-walled fluid. In some embodiments, the gel 180 comprises a static viscosity of at least 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 180 may be between 1.2:1 and 100:1. Gel 180 may comprise a gel as described with reference to the applicant's jointly filed U.S. Patent Application No. 15 / 566,041, entitled "Micro-Optic Probes for Neurology," filed on 12 October 2017, and the applicant's jointly filed International PCT Patent Application No. 2018 / 062766, entitled "Imaging System," filed on 28 November 2018. 【0107】 The imaging probe 100 may include a distal tip 119, which is a distal tip. In some embodiments, the distal tip 119 includes, for example, a spring tip configured to improve the "navigability" of the imaging probe 100 in a winding path (e.g., in the blood vessels of the brain or heart that have a winding path) (e.g., to improve the "trackability" and / or "maneuverability" of the imaging probe 100). In some embodiments, the tip 119 has a length between 5 mm and 100 mm (e.g., a spring having a length between 5 mm and 100 mm). Alternatively or additionally, the tip 119 may include a cap, plug, or other element configured to seal the distal opening of the window 130. In some embodiments, the tip 119 includes a radiopaque marker configured to improve the visibility of the imaging probe 100 under X-ray or fluorescent light. In some embodiments, the tip 119 includes a relatively short lumen guidewire path to enable "rapid replacement" translation of the imaging probe 100. 【0108】 In some embodiments, at least the distal portion of the imaging probe 100 (for example, the distal portion of the shaft 120 surrounding the optical assembly 115) has an outer diameter of 0.020 inches or less, or 0.016 inches or less. 【0109】 In some embodiments, the imaging probe 100 is configured and positioned for use in intravascular nerve procedures (e.g., procedures to visualize blood, vascular systems, and other tissues adjacent to the brain, and / or procedures to visualize devices temporarily or permanently placed in close proximity to the brain). An imaging probe 100 configured for use in nerve procedures may have an overall length of at least 150 cm, for example, about 300 cm. 【0110】 Alternatively or additionally, the imaging probe 100 may be constructed and configured for use in intravascular cardiac procedures (e.g., procedures to visualize blood, vascular systems, and other tissues adjacent to the heart, and / or devices temporarily or permanently placed in close proximity to the heart). An imaging probe 100 configured for use in cardiovascular procedures may have an overall length of at least 120 cm, for example, about 280 cm. In some embodiments, the imaging probe 100 has a length of at least 260 cm and / or up to 320 cm. 【0111】 The rotating assembly 500 is operably mounted to the connector 150 of the imaging probe 100. The rotating assembly 500 may comprise one or more rotary joints, optical connectors, rotational energy sources, and / or linkages configured to operably mount and rotate the optical core 110. The connector 150 is detachably mounted to the rotating assembly 500 and may be configured and arranged to enable a rotational connection between the proximal end 1101 and a rotating optical fiber joint (such as an optical fiber rotary joint or FORJ). The rotating assembly 500 may have a similar structure and arrangement to similar components described in the applicant's jointly filed international PCT patent application, serial number PCT / US2018 / 062766, titled “Imaging System,” filed November 28, 2018, and the applicant's jointly filed U.S. provisional patent application, serial number 62 / 732,114, titled “Imaging System with Optical Pathway,” filed September 17, 2018. The rotating assembly 500 can be configured to rotate the optical core 110 at a speed of at least 100 revolutions per second, for example, at least 200 revolutions per second or 250 revolutions per second, or between 20 revolutions per second and 1000 revolutions per second. The rotating assembly 500 can include a rotational energy source selected from the group consisting of a motor, a servo, a stepping motor (e.g., a stepping motor including a gearbox), a linear actuator, a hollow core motor, and combinations thereof. In some embodiments, the rotating assembly 500 is configured to rotate the optical assembly 115 and the optical core 110 as a single unit. 【0112】 The retraction assembly 800 is operably attached to the imaging probe 100 to retract the imaging probe 100 toward the patient's access site. The retraction element 850 can be operably attached to the retraction assembly 800 and the imaging probe 100 to transmit retraction force from the retraction assembly 800 to the imaging probe 100. The retraction element 850 may comprise a conduit 855 surrounding a coupling 856 slidably received therein. The retraction element 850 may comprise a connector 852 that is operably attached to the retraction assembly 800 so that the retraction assembly 800 can retract the linkage 856 toward the conduit 855. In some embodiments, the conduit 855 comprises a connector 857 that is operably attached to a reference point near the patient's access site, for example, to a connector 82 of a delivery catheter 80, to establish a reference point for the retraction of the imaging probe 100 toward the patient. The connector 857 can be attached to a reference point, such as a patient transport device, operating table, and / or other fixed or semi-fixed reference point. The linkage 856 can be releasably attached to the connector 858 of the imaging probe 100. The retraction assembly 800 retracts at least a portion of the imaging probe 100 (e.g., the portion of the imaging probe 100 distal to the attached connector 858) relative to an established reference point by retracting the linkage 856 relative to the conduit 855 (e.g., retracting the portion of the linkage 856 emerging from a portion of the conduit 855, as shown). In some embodiments, the retraction assembly 800 is configured to retract at least a portion of the imaging probe 100 (e.g., at least a portion of the optical assembly 115 and shaft 120) at a speed between 5 mm / sec and 200 mm / sec, or between 5 mm / sec and 100 mm / sec, for example, about 60 mm / sec. Additionally or alternatively, the pullback procedure can be performed over a period of time ranging from 0.5 seconds to 25 seconds, for example, approximately 20 seconds (for example, over a distance of 100 mm at 5 mm / sec).The service loop 185 of the imaging probe 100 can be positioned between the connector 857 and the rotating assembly 500, allowing the imaging probe 100 to be retracted relative to the patient while the rotating assembly 500 remains stationary (for example, attached to part of the operating table and / or console 50). 【0113】 The retraction assembly 800 further comprises a motivating element configured to retract the linkage 856. In some embodiments, the motivating element comprises a linear actuator, a worm drive operably mounted to a motor, a pulley system, and / or other linear force transmission mechanisms. The linkage 856 can be operably mounted to the motivating element via one or more linkages and / or connectors. The retraction assembly 800 may have a similar structure and arrangement to similar components described in the applicant's jointly pending international PCT patent application, serial number PCT / US2018 / 062766, titled “Imaging System,” filed November 28, 2018. 【0114】 In some embodiments, the imaging system 10 includes a patient interface unit 200. The patient interface unit 200 may comprise a single housing that includes both the rotating assembly 500 and the retraction assembly 800. Alternatively or additionally, the patient interface unit 200 may comprise two or more housings, such as separate housings for each of the rotating assembly 500 and the retraction assembly 800. In some embodiments, the connector 150, service loop 185, retraction element 850, and connector 852 are housed in a single housing that is configured to operably attach to both the rotating assembly 500 and the retraction assembly 800 (for example, when the rotating assembly 500 and the retraction assembly 800 are housed in a single housing). 【0115】 The console 50 comprises an imaging assembly 300, a user interface 55, a processor 52, and one or more algorithms 51. The imaging assembly 300 may be configured to supply light to the optical assembly 115 (e.g., via the optical core 110) and to 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 comprise one or more light sources, such as one or more light sources configured to supply light of one or more wavelengths to the optical assembly 115 via the optical core 110. The light source 310 is configured to supply light to the optical assembly 115 (via the optical core 110) so that image data comprising cross-sectional, longitudinal, and / or volumetric information relating to the patient site being imaged or the implanted device can be collected. The light source 310 can be configured to provide light such that the acquired image data includes characteristics of the tissue within the patient area being imaged, and can provide, for example, information related to the patient's disease or disorder present within the patient area being imaged, in a quantifiable, qualitative, or otherwise manner. The light source 310 can be configured to emit broadband light, having a center wavelength in the range of 350 nm to 2500 nm, 800 nm to 1700 nm, 1280 nm to 1310 nm, or about 1300 nm (e.g., light emitted with a sweep range of 1250 nm to 1350 nm). The bandwidth of the light source 310 can be selected to achieve a desired resolution, which may vary depending on the needs of the intended use of the imaging system 10. In some embodiments, the bandwidth is about 5% to 15% of the center wavelength, which enables a resolution between 20 μm and 5 μm. The light source 310 can be configured to supply light at a power level that meets the ANSI Class 1 ("eye-safe") limits, but higher power levels can also be employed. In some embodiments, the light source 310 emits light in the 1.3 μm band at a power level of approximately 20 mW. As the central wavelength of the emitted light increases, light scattering in the tissue decreases, but water absorption increases. To balance these two effects, the light source 310 can emit light with a wavelength close to 1300 nm.The light source 310 may be configured to emit shorter wavelength light (e.g., light of about 800 nm) to traverse the patient area being imaged, which contains a large amount of fluid. Alternatively or additionally, the light source 310 may be configured to emit longer wavelength light (e.g., light of about 1700 nm) to reduce high levels of scattering within the patient area 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 changes repeatedly over time) and / or 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). The imaging assembly 300 may have a similar structure and arrangement to similar components described in the applicant's jointly pending U.S. Provisional Patent Application, serial number 62 / 732,114, titled “Imaging System with Optical Pathway,” filed September 17, 2018. 【0116】 The console 50 may comprise one or more algorithms, such as algorithm 51 shown in the illustration, configured to adjust (e.g., automatically and / or semi-automatically) one or more operating parameters of the imaging system 10, such as the operating parameters of the console 50, the imaging probe 100, and / or the delivery catheter 80. The console 50 may further comprise a processing assembly, processor 52, configured to execute algorithm 51 and / or perform any type of data processing, such as digital signal processing, as described below with reference to Figure 4. Additionally or alternatively, algorithm 51 may be configured to adjust the operating parameters of another device, such as the injector 20 or implant delivery device 30, as described below. In some embodiments, algorithm 51 is configured to adjust the operating parameters based on one or more sensor signals, such as sensor signals provided by sensor-based functional elements of the concept of the present invention described herein. The algorithm 51 can be configured to adjust operating parameters selected from the group consisting of rotational parameters such as the rotational speed of the optical core 110 and / or optical assembly 115, retraction parameters such as the retraction speed, distance, start position, end position and / or retraction start timing (e.g., when retraction is started) of the shaft 120 and / or optical assembly 115, positional parameters such as the position of the optical assembly 115, line spacing parameters such as the number of lines per frame, image display parameters such as scaling of the display size relative to the vessel diameter, configuration parameters of the imaging probe 100, injector 21 parameters such as the ratio of saline to contrast configured to determine an appropriate refractive index, light source 310 parameters such as the power and / or frequency of the irradiated light, and one or more combinations thereof.In some embodiments, algorithm 51 is configured to adjust pullback parameters such as a parameter that triggers the start of a pullback, such as a pullback initiated based on a parameter selected from the group consisting of: lumen flushing (that the lumen adjacent to the optical assembly 115 is sufficiently cleared of blood or other material interfering with image formation), receiving an indicator signal from the injector 20 (e.g., a signal indicating that sufficient flushing fluid has been delivered), changes in the acquired image data (e.g., based on the acquired image data, a change in the image is detected that correlates to the blood being properly drained from around the optical assembly 115), and one or more combinations thereof. In some embodiments, algorithm 51 is configured to adjust configuration parameters of the imaging system 10 related to the imaging probe 100, such as when algorithm 51 identifies the mounted imaging probe 100 (e.g., automatically identifies it via RF or other embedded ID) and adjusts parameters of the imaging system 10, such as an arm path length parameter, a dispersion parameter, and / or other parameters as described above. 【0117】 The imaging system 10 may include one or more interconnecting cables (shown as bus 58). Bus 58 may operably connect the rotating assembly 500 to the console 50, the retraction assembly 800 to the console 50, and / or the assembly 500 to the retraction assembly 800 (for example, by connecting the patient interface unit 200 to the console 50). Bus 58 may include one or more optical transmission fibers, electrical transmission cables, fluid conduits, and one or more combinations thereof. In some embodiments, bus 58 includes at least an optical transmission fiber that optically couples the rotating assembly 500 to the imaging assembly 300 of the console 50. Additionally or alternatively, bus 58 may include at least a power and / or data transmission cable that transmits power and / or motivational information to the retraction assembly 800. 【0118】 The user interface 55 may include outputs 56 and inputs 57. Outputs 56 may include one or more outputs selected from a group consisting of output signals such as a screen, indicator lights, tactile transducers such as vibration transducers, speakers, and wireless signals received by external devices, and combinations thereof. Inputs 57 may include inputs selected from a group consisting of input signals such as buttons, two or more buttons, touchscreens, mice, and wireless signals received from external devices, and combinations thereof. In some embodiments, outputs 56 and / or inputs 57 are integrated into the patient interface unit 200 and / or either or both of the rotational assembly 500 and the retraction assembly 800. 【0119】 The second imaging device 15 may include one or more imaging devices selected from the group consisting of X-ray, fluoroscopy such as single- or double-sided fluoroscopy, CT scanner, MRI, PET scanner, ultrasound imaging device, and one or more combinations thereof. In some embodiments, the second imaging device 15 includes a device configured to perform rotational angiography. 【0120】 The treatment device 16 may include occlusive therapy or other treatment devices selected from the group consisting of: balloon catheters configured and positioned to dilate narrowed blood vessels; drug-eluting balloons; suction catheters; sonolysis devices; atherectomy devices; stent retriever devices and other thrombectomy devices; Trevo® stent retriever; Solitaire® stent retriever; Revive® stent retriever; Eric® stent retriever; Lazarus® stent retriever; stent retriever catheters; microblade implants; embolization systems; WEB® embolization systems; Luna® embolization systems; Medina® embolization systems; and one or more combinations thereof. 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 has been inserted into the patient. 【0121】 The injector 20 may include a power injector, syringe pump, peristaltic pump, or other fluid delivery device configured to inject contrast agents and / or other fluids, such as radiopaque contrast agents. 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 the fluid in a flushing procedure as described below. In some embodiments, the injector 20 delivers the contrast agent or other fluid via a delivery catheter 80 having an ID between 5 Fr and 9 Fr, a delivery catheter 80 having an ID between 0.53 inches and 0.70 inches, or a delivery catheter 80 having an ID between 0.0165 inches and 0.027 inches. In some embodiments, the contrast agent or other fluid is delivered via a small delivery catheter of about 4 Fr (e.g., for distal injection). In some embodiments, the injector 20 delivers contrast agent and / or other fluids through the lumen of one or more delivery catheters 80, while one or more smaller delivery catheters 80 are also present in the lumen. In some embodiments, the injector 20 is configured to deliver two different fluids simultaneously and / or sequentially, such as a first fluid delivered from a first reservoir containing a first concentration of contrast agent, and a second fluid delivered from a second reservoir containing less or no contrast agent. 【0122】 The injectable fluid 21 may comprise a fluid selected from the group consisting of optically transparent materials, saline solution, visible materials, contrast agents, dextran, ultrasound-reflective materials, magnetic materials, and combinations thereof. The injectable fluid 21 may contain a contrast agent and saline solution. The injectable fluid 21 may comprise at least 20% contrast agent. For example, a flushing procedure can be performed during image acquisition by delivering, for example, one or more fluids, the injectable fluid 21 (for example, propelled by an injector 20 or other fluid delivery device) to remove blood or other somewhat opaque materials (hereinafter referred to as impermeable materials) in the vicinity of the optical assembly 115 (e.g., impermeable materials between the optical assembly 115 and the delivery catheter, and / or impermeable materials between the optical assembly 115 and the blood vessel wall) so that the light distributed from the optical assembly 115 reaches all tissues and other objects to be imaged and reflects back. In these embodiments of flushing, the injectable fluid 21 may comprise an optically transparent material such as saline solution. The injector 21 may comprise one or more visible materials, as described below. 【0123】 In lieu of, or in addition to, use in the flushing procedure, the injector 21 may comprise a material configured to be visible in the second imaging device 15, for example, a contrast agent configured to be visible in the second imaging device 15 comprising a fluoroscope or other X-ray apparatus, an ultrasonically reflective material configured to be visible in the second imaging device 15 comprising an ultrasonic imager, and / or a magnetic material configured to be visible in the second imaging device 15 comprising an MRI. 【0124】 The implant 31 may comprise implants (e.g., temporary or chronic implants) for treating one or more vascular occlusions or aneurysms. In some embodiments, the implant 31 comprises one or more implants selected from the group consisting of flow diverters, Pipeline® flow diverters, Surpass® flow diverters, embolization coils, stents, Wingspan® stents, covered stents, aneurysm treatment implants, and one or more combinations thereof. 【0125】 The implant delivery device 30 may include a catheter or other tool used to deliver the implant 31, such as when the implant 31 has a self-expanding or balloon-expanding 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., 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 have been inserted into the patient. 【0126】 In some embodiments, one or more system components, such as a console 50, a delivery catheter 80, an imaging probe 100, a patient interface unit 200, a rotating assembly 500, a retraction assembly 800, a treatment device 16, an injector 20, and / or an implant delivery device 30, each further comprises one or more functional elements (hereinafter referred to as "functional elements"), such as functional elements 59, 89, 199, 299, 599, 899, 99a, 99b, and / or 99c as shown in the illustration. Each functional element may comprise at least two functional elements. Each functional element may comprise one or more elements selected from the group consisting of sensors; transducers; and combinations thereof. A functional element may comprise a sensor configured to generate a signal. The functional elements may include sensors selected from the group consisting of physiological sensors, pressure sensors, strain gauges, position sensors, GPS sensors, acceleration sensors, temperature sensors, magnetic sensors, chemical sensors, biochemical sensors, protein sensors, flow sensors such as ultrasonic flow sensors, gas detection sensors such as ultrasonic bubble detectors, sound sensors such as ultrasonic sensors, and combinations thereof. The sensors may include physiological sensors selected from the group consisting of pressure sensors such as blood pressure sensors, flow sensors such as blood gas sensors and blood flow sensors, temperature sensors such as blood or other tissue temperature sensors, and combinations thereof. The sensors may include position sensors configured to generate signals related to the shape of a vascular pathway (e.g., the shape of a 2D or 3D vascular pathway). The sensors may include magnetic sensors. The sensors may include flow sensors. The system may further include algorithms configured to process signals generated by the sensor-based functional elements. Each functional element may include one or more transducers.Each functional element may include one or more transducers selected from a group consisting of a heater such as a heating element configured to provide sufficient heat to excise tissue, a cooler such as a cooling element configured to provide cryogenic energy to excise tissue, a sound transducer such as an ultrasonic transducer, a vibration transducer, and combinations thereof. 【0127】 In some embodiments, the imaging probe 100 includes a “bubble handling” mechanism, such as a fluid pressurizing element (FPE) 1500 shown in the illustration, for preventing or at least reducing the presence of bubbles in close proximity to the optical assembly 115, as described in detail herein. The FPE 1500 may be configured to generate a pressure difference within the volume of the gel 180 and / or otherwise increase the pressure in one or more volumes of the gel 180. The FPE 1500 may include a distal end positioned relatively close to the proximal end of the optical assembly 115. In some embodiments, the FPE 1500 is configured to increase the pressure in the volume of the gel 180 in close proximity to the optical assembly 115 and / or generate a pressure difference. Additionally or alternatively, the FPE 1500 may generate a flow of the gel 180 (e.g., a flow of the gel 180 containing one or more bubbles, such as to keep bubbles away from the optical assembly 115). The FPE1500 may include projections extending from the optical core 110 that increase the pressure of the gel 180 when the FPE1500 rotates (via the rotation of the optical core 110). Alternatively or additionally, the FPE1500 may include a pump, pressurized vessel, and / or other pressurized source ("pump" as herein) fluidly mounted in one or more lumens (e.g., lumen 1205 of shaft 120) to increase the pressure of the gel 180 (e.g., intermittently, as required by system 10). 【0128】 As shown in Figure 1A, one or more bubbles B may be present in the gel 180. For example, when the optical core 110 and optical assembly 115 rotate within the gel 180, bubbles B may form, such as through cavitation and / or other bubble formation anomalies as described above. Additionally or alternatively, one or more bubbles B may (already) be present in the gel 180, such as as a result of the manufacturing process of the imaging probe 100. In operation, bubbles B close to the optical assembly 115 may cause undesirable imaging artifacts and / or other imaging problems. The FPE 1500 can be configured and positioned to prevent or at least reduce the formation of bubbles B, reduce the expansion of one or more bubbles B, reduce the size of one or more bubbles B, and / or keep one or more bubbles away from the optical assembly 115. In the initial startup state (for example, when the FPE1500 has just started rotating), the pressure in the gel 180 distal to the FPE1500 increases, causing bubbles distal to the FPE1500 to move distally and be compressed due to the rising pressure, while bubbles proximal to the FPE1500 initially move toward the FPE1500 (as the fluid moves to fill the space created by the compressed bubbles), but then stop moving when an equilibrium pressure gradient is reached. In some embodiments, the FPE1500 is configured to manipulate (e.g., propel) the gel 180 to generate a high-pressure region HP surrounding the optical assembly 115 (e.g., the volume of gel 180 adjacent to the optical assembly 115) and a low-pressure region LP adjacent to the FPE1500 (e.g., the volume of gel 180 adjacent to the optical assembly 115). 【0129】 In some embodiments, one or more bubbles B may be trapped in the distal part of the high-pressure area HP, but the FPE 1500 is configured and positioned to operate the gel 180 proximal to the optical assembly 115 so as to prevent bubbles B from being trapped proximal to the assembly 115 (e.g., bubbles B trapped distally do not move toward the optical assembly 115). Additionally or alternatively, the increased pressure of the high-pressure area HP can cause a reduction in the size of any existing bubbles B adjacent to the optical assembly 115 (e.g., compression of any bubbles B in the high-pressure area HP), and / or the increased pressure can prevent new bubbles B from forming. In some embodiments, the high-pressure area HP generated by the FPE 1500 has a pressure of at least 3.6 psi (e.g., at least about 0.25 atmospheres), e.g., at least 5 psi, at least 10 psi, at least 15 psi, at least 20 psi, at least 30 psi, and / or at least 40 psi. In some embodiments, the FPE1500 generates pressures of at least 75 psi, at least 100 psi, at least 125 psi, and / or at least 150 psi in area HP. In some embodiments, the high-pressure area HP has a pressure at least 5 psi higher than the pressure in the low-pressure area LP, for example, at least 10 psi, at least 20 psi, and / or at least 30 psi higher. In some embodiments, each bubble B is compressed to 2 or 3 times its original size (i.e., 1 / 2 or 1 / 3 of its original size) under the high-pressure conditions of the high-pressure area HP. 【0130】 In some embodiments, the gel 180 comprises a low-viscosity fluid, such as a shear-reducing fluid with a low initial viscosity, which reduces the likelihood of bubble B formation. For example, the gel 180 may have a viscosity of 1000 centipoise or less. Additionally or alternatively, the gel 180 may have a high surface tension, for example, a surface tension of at least 40 dynes / cm, which reduces the likelihood of bubble B formation. 【0131】 In some embodiments, for example, when the lumen 1205 is pressurized, the gel 180 is pressurized by a pump (intermittently pressurized to a pressure above atmospheric pressure) via a pump (e.g., the FPE 1500 is external but has this pump fluidically connected to the lumen 1205) located within the console 50 or patient interface unit 200. In some embodiments, the gel 180 is pressurized by an external source, and the FPE 1500 is configured and positioned to create a pressure difference within the gel 180 in addition to the pressure applied by a separate pump (e.g., when rotated). Intermittent pressurization (e.g., via an external pump or via rotation of the FPE 1500) can offer numerous advantages, such as preventing an increase in dissolved gases within the gel 180 due to a constant applied pressure, as described herein. 【0132】 In some embodiments, the FPE1500 includes a radially extending spiral projection from the optical core 110, configured to increase the pressure in the gel 180 and / or create a pressure difference within the gel 180 when the optical core 110 rotates, as described below with reference to Figure 2. In some embodiments, the FPE1500 includes one or more radially extending projections from the optical core 110, configured to generate a pressure difference within the gel 180 when the optical core 110 rotates, as described herein, for example with reference to Figure 3. In some embodiments, the FPE1500 includes a pump, a pressurized vessel, and / or other pressurizing source (hereinafter referred to as "pump"), for example, a fluid conduit that is fluidly attached to the pump at its proximal end and exits to the lumen 1205 adjacent to the optical assembly 115. 【0133】 In some embodiments, the FPE 1500 is configured to operate intermittently, thereby intermittently increasing the pressure in the gel 180 to intermittently generate a pressure difference within the gel 180. For example, the FPE 1500 may include one or more radially extending projections from the optical core 110, configured to generate a pressure difference within the gel 180 only when the optical core 110 is rotating, as described below with reference to Figure 4A. In these embodiments, while the FPE 1500 is not operating (e.g., not rotating), the pressure in the gel 180 can be normalized to a pressure lower than the pressure in the high-pressure region HP while the FPE 1500 is operating (e.g., rotating). Intermittent pressurization can be used to prevent an increase in dissolved gases within the gel 180. In some embodiments, the FPE1500 is configured to operate continuously only for limited time periods, such as 2 minutes or less at a time, for example, 30 seconds or less, or discrete time periods of 5 seconds or less (for example, intermittently pressurizing the gel 180 to prevent undesirable dissolution gases within the gel 180). 【0134】 Referring here to Figures 2 and 2A, schematic diagrams of the distal portions of the imaging probe and delivery catheter, and enlarged views of the components within circle M2, respectively, are shown, consistent with the concept of the present invention. The imaging probe 100 and delivery catheter 80 can have a similar structure and arrangement to the imaging probe 100 and delivery catheter 80 described above, referring to Figures 1 and 1A. In the embodiments shown in Figures 2-2A, the shown FPE1500s, which is a fluid pressurization mechanism, comprises a helical projection extending radially from the optical core 110. During operation, as the optical core 110 rotates, the FPE1500s rotate together, generating a fluid flow in the vicinity of the FPE1500s and creating a pressure gradient within the gel 180 (e.g., across the FPE1500s). An example of modeling the fluid flow dynamics is described below with reference to Figures 2B-C. 【0135】 In some embodiments, the FPE1500s comprises a helical coil, such as a spring or other winding, attached along a portion of the length of the optical core 110 (e.g., surrounding the core 110). The FPE1500s can be attached to the optical core 110 via an adhesive or other tacky material. In some embodiments, the FPE1500s are manufactured by being molded on and / or together with the core 110, formed within the core 110 (e.g., via a material removal process), fused onto the core 110, and / or otherwise attached to or together with the core 110. In some embodiments, the FPE1500s comprises a material selected from the group consisting of metal; plastic; stainless steel; nickel-titanium alloy; nylon; polyetheretherketone (PEEK); polyimide; and combinations thereof. In some embodiments, the FPE1500s can be formed directly on the optical core 110 using vapor deposition and / or 3D printing techniques. In some embodiments, a selectively curable material is applied to the optical core 110 and cured in a helical pattern to form the FPE1500s. For example, a high-strength UV-curable adhesive can be applied to the surface of the optical core 110 and selectively cured using a rotating, focused UV beam. In some embodiments, the FPE1500s may include a material selected to minimize deformation of the FPE1500s while a pressure gradient is applied. For example, during rotation, a pressure gradient is generated over the length of the FPE1500s, and to prevent deformation, shorter FPE1500s require a harder material than longer FPE1500s configured to generate the same pressure gradient. 【0136】 The FPE1500s has a radial height, height H1, which is the distance from the surface of the optical core 110 to the outer edge of the FPE1500s. The optical core 110 has a diameter D1. The lumen 1205 of the shaft 120 has an inner diameter D2. In some embodiments, the diameters D1 and D2 vary along the length of the probe 100, and the following dimensions relate to segments of the probe 100, such as the distal segment shown in Figure 2A (e.g., the proximal and near segments of the optical assembly 115). The probe 100 may have a clearance C1 between the FPE1500s (e.g., the outer diameter of the FPE1500s) and the inner wall of the shaft 120. The clearance C1 relates to both the difference between the diameters D1 and D2 and the height H1 of the FPE1500s, such that C1 is equal to half the difference between D1 and D2 minus H1. In some embodiments, the clearance C1 has a clearance of 100 μm or less, 75 μm or less, for example, between 10 μm and 75 μm. In some embodiments, the height H1 has a height of 5% to 95% of half the difference between D1 and D2 (for example, a height H1 that occupies at least 5% and / or 95% or less of the space between the outer surface of the core 110 and the inner wall of the shaft 120). In some embodiments, the optimal height H1 depends on factors such as the viscosity of the damping fluid (e.g., the viscosity of the gel 180), the desired rotational speed of the optical core 110, the desired pressure gradient, and / or the clearance between the FPE 1500s and the inner wall of the shaft 120 (e.g., a tighter clearance produces higher pressure). In some embodiments, the coil profile of the FPE 1500s has a width W1 as shown. The width W1 can have a width of 1% to 95% of the diameter D1. The FPE1500s may also have a pitch P1 as shown in the figure. The pitch P1 may be such that the gap between adjacent coils is 0.5 to 20 times the diameter D1. In some embodiments, adjacent coils do not touch each other. In some embodiments, the pitch P1 is uniform along the length of the FPE1500s.In some embodiments, the pitch P1 can have a pitch between 0.2 mm and 1.2 mm, for example, a pitch of about 0.5 mm or 1 mm. In some embodiments, the length and / or pitch P1 of the FPE1500s can be selected to achieve a desired pressure generated when the optical core 110 rotates. 【0137】 In some embodiments, the gel 180 comprises a high-viscosity shear-thinning fluid, as described with reference to Figure 1 above. In some embodiments, the maximum functional clearance C1 (e.g., the maximum acceptable clearance C1 such that the rotation of the FPE 1500s generates sufficient fluid pressure within the lumen 1205) is proportional to the viscosity of the gel 180. For example, the higher the viscosity of the gel 180, the larger the maximum clearance C1. In some embodiments, the clearance C1 is proportional to the pressure difference that can be generated within the gel 180 by rotating the FPE 1500s, as described herein. For example, the smaller the clearance C1, the larger the pressure difference that can be generated. In some embodiments, the clearance C1 and height H1 are minimized to restrict turbulence, recirculation, and / or the flow of other unwanted fluids in close proximity to the optical core 110. In some embodiments, the gel 180 comprises a Newtonian fluid (non-shear-thinning). Dimensions C1, H1, D1, and D2 can be optimized for different properties of gel 180. 【0138】 In some embodiments, the FPE1500s is provided with a covering (not shown). The covering may comprise a sheath such as a heat-shrinkable tube and / or a painted or sprayed coating. The covering may be configured to improve the coupling of the FPE1500s to the optical core 110 and / or to control the dimensions of the FPE1500s (e.g., to firmly hold the FPE1500s to the optical core 110 to limit undesirable variations in height H1). Additionally or alternatively, the covering may be configured to modify the surface properties of either or both the optical core 110 and the FPE1500s. In some embodiments, the covering has a thickness that does not significantly affect the fluid propulsion and / or other fluid pressurization (hereinafter "fluid pressurization") performance of the FPE1500s. Alternatively or additionally, the FPE1500s may be configured and positioned such that the dimensions C1, H1, and D1 are optimized after the application of the covering. 【0139】 In some embodiments, the pressure on the gel 180 within the lumen 1205 caused by the rotation of the FPE 1500s exerts a functional torsional shear force on the inner wall of the lumen 1205. The shaft 120 can have a torsional resistance greater than the functional torsional shear force exerted by the gel 180. In some embodiments, the gel 180 exerts a torque of about 0.004 N·cm, and the shaft 120 has a torsional resistance of at least 0.01 N·cm, e.g., 0.03 N·cm. Additionally or alternatively, the FPE 1500s can exert a "winding" stress on the optical core 110 when the optical core 110 is rotated, allowing the FPE 1500s to be driven within the gel 180. The optical core 110 can be configured and positioned so as not to be adversely affected (e.g., not to break or otherwise fail) by shear stress induced by the rotation of the core 110 and FPE 1500s within the gel 180, as well as by shear stress induced by pullback motion within the gel 180. In some embodiments, the additional winding stress on the optical core 110 caused by the FPE 1500s functions as a NURD reduction mechanism, as well as NURD reduction caused by the gel 180, as described in the international PCT patent application serial number PCT / US2018 / 062766 in the joint application of the applicant entitled “Imaging System,” filed November 28, 2018. 【0140】 Referring further to Figures 2B and 2C, schematic diagrams of the distal portion of the imaging probe showing a fluid flow pattern consistent with the concept of the present invention and a fluid flow simulation are shown, respectively. The movement of gel 180 is shown by the fluid flow arrow FF in Figure 2B and the path FP in Figure 2C. P and FP DThe optical core 110 and FPE1500s are depicted as rotating with the upper end of the FPE1500s rotating within the page. Along with the illustrated axial motion, the fluid flow also includes a rotational component, as shown in Figure 2C. The distal tip 1209 and / or at least the distal portion of the shaft 120 can be sealed, such as when the distal tip 119 is equipped with a cap or plug configured as a sealing element, plug 1209a as shown in Figure 2B. As the FPE1500s rotates as illustrated, the fluid close to the optical core 110 flows distally toward the high-pressure region HP. As the pressure in the high-pressure region HP increases to match the pressure of the distal fluid flow, a closed-loop recirculation pattern appears, as shown. The fluid propelled distally by the FPE1500s encounters the pressure in the high-pressure area HP and is redirected proximal along the surface of the lumen 1205 (e.g., along the path of least resistance). This fluid flow pattern creates a “deadhead” pressure profile (e.g., no net fluid flow) and maintains a pressure gradient from the low-pressure area LP to the high-pressure area HP along FPE1500s. As shown in Figure 2C, the fluid path FP D This depicts the fluid flow adjacent to the optical core 110 and toward the distal high-pressure region HP. Fluid path FP P This depicts a fluid flow that is close to the surface of lumen 1205 and proximal to the low-pressure area LP. 【0141】 Referring here to Figures 3A and 3B, schematic diagrams of the distal portions of two imaging probes including a fluid propulsion element, consistent with the concept of the present invention, are shown. Figure 3A shows the rapidly replaceable distal tip 119 RX The distal portion of the imaging probe 100a, including the spring tip 119, is shown. Figure 3B shows the spring tip 119. SIllustrates the distal portion of the imaging probe 100b, including. The imaging probes 100a and 100b of FIGS. 3A and 3B can include similar components and have the same structure and arrangement as the imaging probe 100 of FIGS. 1 and 1A described herein. The optical assembly 115 can include a lens assembly, assembly 1151, optically and physically coupled to the distal end of the optical core 110. The lens assembly 1151 can include a GRIN lens with a beveled distal end. The beveled distal end of the lens assembly 1151 can include a total internal reflection surface. The tube 1154, which is an elongated tube, surrounds at least the distal portion of the optical core 110, the lens assembly 1151, and the plug 1153, which is a sealing element (e.g., a sealing element similar to the plug 1209a of FIG. 2B). The tube 1154 can include a heat-shrinkable material. The tube 1154 can have PET. At least a portion of the tube 1154 can be adhered or otherwise fixed to at least a portion of the lens assembly 1151, the optical core 110, and / or the plug 1153. The plug 1153 is configured to prevent and / or restrict the outflow of the gel 180 into the cavity (the illustrated space 1152) created 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 (e.g., provide a glass-air interface). The optical core 110 can include a support element 1102. The support element 1102 can include a torque wire disposed proximal to the optical assembly 115. The support element 1102 can be configured to reinforce the distal portion of the optical core 110, such as by providing rotational reinforcement to the optical core 110. 【0142】 In some embodiments, the FPE 1500, as shown in FIGS. 3A and 3B, is the FPE 1500 S1 and 1500 S2 such as, includes two fluid propulsion elements. The distal FPE 1500 S1It may be configured to generate a pressure gradient across the optical assembly 115, as described herein. Furthermore, the proximal FPE1500 S2 This is because gel 180 is proximal (for example, FPE1500) S2 To prevent it from moving beyond (or to minimize it otherwise), and / or FPE1500 S1 To prevent cavitation in the vicinity of (for example, FPE1500) S1 To prevent bubble formation in the proximal region, use gel 180 with FPE1500. S1 It can be configured to "prime" the FPE1500. S2 It may be positioned close to the proximal end of the gel 180 (for example, close to a position within the shaft 120 into which the gel 180 is inserted from the distal end of the shaft 120 during manufacturing). 【0143】 Referring here to Figures 4 and 4A, schematic diagrams of the distal portion of the imaging probe and delivery catheter, and enlarged views of the components within circle M3, respectively, are shown, consistent with the concept of the present invention. The imaging probe 100 in Figures 4 and 4A has similar components to the imaging probe 100 in Figure 1 described herein, and can have a similar structure and arrangement. The imaging probe 100 in Figures 4 and 4A has a pressurizing element with a propeller-like structure, FPE1500 P It contains FPE1500. P It may include one or more radial projections 1501 extending from the optical core 110. The projections 1501 have a profile configured to propel fluid when the optical core 110 rotates, and are similar to propeller blades. FPE1500 P As described above, it can be configured to create a pressure gradient within the gel 180. 【0144】 Referring here to Figures 5 and 5A, schematic diagrams of the distal portion of the imaging probe and delivery catheter, and enlarged views of the components within circle M4, respectively, are shown, consistent with the concept of the present invention. The imaging probe 100 in Figures 5 and 5A may consist of similar components, and have a similar structure and arrangement, as described herein for the imaging probe 100 in Figure 1. The imaging probe 100 in Figures 5 and 5A is connected to the pump FPE1500. PS It is equipped with a pressurizing element. FPE1500 PS It may include a fluid lumen 1502 having an outlet port 1503 that exits into a lumen 1205 located proximal to the optical assembly 115. Lumen 1205 may be fluidically connected to a pump, such as a pump in console 50 in Figure 1, although not shown. The pump is used before, during, and / or after the imaging procedure for the FPE 1500. PS It can be configured to apply pressure to gel 180 via FPE1500. PS The fluid limiting element may further include a valve 1504. The valve 1504 is shown to be located proximal to the outlet port 1503 in the lumen 1205. The valve 1504 is FPE1500 PS Within the lumen 1205, the flow of the fluid (e.g., gel 180) may be configured to restrict the flow to the proximal position so that an increased pressure in the gel 180 can be generated distal to the valve 1504. The valve 1504 may be configured to allow the passage of air and / or other gases (e.g., bubble B as described herein) while restricting the passage of gel 180 (e.g., due to the viscosity and / or molecular size of gel 180). FPE1500 PS It can be configured to generate a pressure gradient within the gel 180, as described herein with reference to Figures 1 and 1A. 【0145】 Referring here to Figures 6A, 6B, and 6C, cross-sectional views of the distal portion of the optical probe are shown, consistent with the concept of the present invention. The imaging probe 100 can have a similar structure and arrangement to the imaging probe 100 described above with reference to Figures 1 and 1A. In some embodiments, the optical core 110 is configured to retract and advance within the shaft 120, as shown in Figures 6A-C. The optical core 110 can be retracted via a linkage 856 operably attached to the proximal portion of the optical core 110 (as shown here in Figure 1). The fluid pressurizing element optically coupled to the optical core 110 is a spring-type element, FPE1500, as described here with reference to Figures 2-3B. S It can include FPE1500 S This can be configured to generate a pressure gradient from a low-pressure area LP to a high-pressure area HP within the gel 180, as described herein. In some embodiments, when the optical core 110 is housed in the shaft 120, the housing may cause voids (e.g., one or more bubbles formed due to the pressure drop caused by the housing of the optical core 110) to form within the gel 180. FPE1500 S It can be configured to minimize the formation of these voids by creating a pressure gradient within the gel 180 while the optical core 110 rotates and retracts. Additionally or alternatively, FPE1500 S It can be configured to generate a driving force that drives at least the distal end of the optical core 110 longitudinally (e.g., proximal and / or distal) within the lumen 1205 of the shaft 120. 【0146】 FPE1500 S As shown in Figures 6A-C, it can be configured to generate both a driving force and a pressure gradient within the gel 180, triggering one or more resulting scenarios. In Figure 6A, the optical core 110 is (FPE1500 S However, when rotated in the first direction (to propel the gel 180 distally), an attractive force F is exerted on the optical core 110. RThis creates a pressure gradient from the low-pressure area LP to the high-pressure area HP. The optical core 110 is subjected to a holding force F, such as the force exerted from the retraction assembly 800, as described above with reference to Figure 1. H It can be held in place by this mechanism. In this state, the optical core 110 does not move longitudinally (e.g., proximal and / or distal) within the shaft 120. 【0147】 As shown in Figure 6B, the holding force F H When removed, force F R It acts to retract at least the distal portion of the optical core 110 into the shaft 120. In some embodiments, the retraction assembly 800 also applies a retraction force F to the optical core 110. R This can be configured to assist in the retraction of the optical core 110 within the shaft 120, thereby limiting the stress applied to the optical core 110 while a retraction force is applied from the proximal portion. 【0148】 In some embodiments, as shown in Figure 6C, the optical core 110 (and FPE1500) S ) is FPE1500 S This drives the gel 180 in the proximal direction, and a forward force F is applied to the optical core 110. A It can be rotated in a second direction (for example, opposite to the first direction) to apply force F. In some embodiments, the retraction assembly 800 can apply a forward force F to the proximal portion of the optical core 110. A While the retraction assembly 800 applies a force that presses against the proximal portion, force F A By applying a (tensile force) to the distal portion of the optical core 110, it can be configured to limit and / or prevent kinking of the optical core 110 within the shaft 120. 【0149】 Referring here to Figure 7, a cross-sectional view of a segment of an imaging probe having a multi-component shaft structure consistent with the concept of the present invention is shown. The imaging probe 100 of the concept of the present invention may include a shaft having multiple components, such as the components of the shaft 120 shown in Figure 7. The shaft 120 may include a tube 121, which is at least a first (proximal) portion, fixedly attached to a window 130, which is a second (distal) portion, via a joint 125. The tube 121 may comprise an elongated hollow member, such as a hypotube (for example, a metal tube that may have one or more engineering features along its length). In some embodiments, the tube 121 comprises a hypotube with a helical cut along at least a portion of its length. In some embodiments, the tube 121 comprises a nickel-titanium alloy (e.g., nitinol). In some embodiments, the tube 121 comprises a plastic material such as polyimide or PEEK. In some embodiments, the window 130 comprises a transparent elongated hollow member, as described above with reference to Figure 1. 【0150】 The joint 125 may comprise at least a distal portion of the tube 121 and at least a proximal portion of the window 130. The distal portion of the tube 121 may comprise a tapered portion 1211, which is a narrowing portion. The tapered portion 1211 may be configured such that the outer diameter of the tube 121 decreases from the proximal end of the tapered portion 1211 toward the distal end of the tapered portion 1211. The tube 121 comprises a lumen 1215 through which it passes. An elongated segment of the tube 123 is partially inserted into the lumen 1215 of the tube 121. The tube 123 may have an outer diameter approximately equal to the diameter of the lumen 1215. In some embodiments, tube 123 has an outer diameter slightly larger than the diameter of lumen 1215 (e.g., so that tube 123 can be press-fitted into lumen 1215), or tube 123 has a diameter equal to or slightly smaller than the diameter of lumen 1215 (e.g., so that space for adhesive is provided between tube 125 and tube 121). Tube 123 contains a lumen 1235. In some embodiments, lumen 1235 has a diameter larger than the outer diameter of the optical core 110 (e.g., so that the optical core 110 can be slidably positioned within it). Additionally or selectively, lumen 1235 is FPE1500 S To prevent it from translating proximal to tube 123 (for example, FPE1500) S Due to the proximal translation of FPE1500 S The end of tube 123 comes into contact with FPE1500 S (To prevent it from entering 1235 lumens), FPE1500 S It can have a diameter smaller than the outer diameter (for example, tube 123 constitutes the inner diameter). 【0151】 The joint 125 may further include an overtube 122 configured to surround at least the distal portion of tube 121 and at least a portion of tube 123 (e.g., at least a portion of tube 123 extending distally from lumen 1215). The overtube 122 may comprise a “heat-shrinkable” material (e.g., a material configured to shrink when heat is applied). In these embodiments, the overtube 122 may have a first diameter (e.g., a pre-shrinkable diameter) greater than or equal to the outer diameter of tube 121 so that tube 121 is slidably received within the overtube 122. After the overtube 122 is positioned relative to tubes 121, 123, heat may be applied to the overtube 122 so that it shrinks and conforms to the outer profiles of tubes 121, 123. Additionally or selectively, the overtube 122 may comprise an elastic material. In some embodiments, the overtube 122 may be made of an elastic material and have an inner diameter less than or equal to the outer diameter of the tube 123. In these embodiments, the overtube 122 can be positioned relative to the tubes 121 and 123 by stretching the overtube 122 to slidably receive the tubes 121 and 123, and after positioning, the overtube 122 contracts to conform to the outer profile of the tubes 121 and 123. In some embodiments, the overtube 122 can be "rolled" over the tubes 121 and 123, and the overtube 122 stretches and deforms simultaneously when rolled over the tubes 121 and 123. The overtube 122 may be made of PET. 【0152】 The proximal portion of the window 130 may be provided with inwardly facing radial projections 1302. The radial projections 1302 may have an inner diameter configured and positioned to match the outer diameter of the tubes 123, 122 (e.g., the outer diameter of tube 122 when compressed relative to tube 123). In some embodiments, the window 130 does not include radial projections 1302, and the inner diameter of the window 130 is configured and positioned to match the outer diameter of the tubes 123, 122. In some embodiments, the proximal portion of the window 130 slidably receives the distal portions of the tubes 122, 123. The proximal portion of the window 130 may further slidably receive at least the distal portion of the taper 1211 of tube 121. The window 130 can be fixedly attached to the tubes 121, 122, and / or 123 via compression and / or adhesive. In some embodiments, the outer surface of the overtube 122 can be prepared (e.g., mechanically or chemically) for adhesion to the window 130, for example, via a chemical primer. In some embodiments, the proximal end of the window 130 is "compressed" over the tubes 121, 122, and / or 123 to provide a compression fit. In some embodiments, the window 130 comprises a material configured to contract when tension is applied (e.g., when the window 130 is pulled away from the tube 121 intentionally or unintentionally), and the window 130 is compressed over the tubes 121, 122, and / or 123 to reinforce the joint 125 when tension is applied. In these embodiments, the tubes 121, 122, and / or 123 may have a lower modulus of elasticity than the window 130, and the window 130 will be compressed more under equal tension than one or more of the tubes 121, 122, and / or 123. 【0153】 In some embodiments, the joint 125 has a maximum outer diameter of 0.02 inches or less, for example, 0.0175 inches or less, for example, 0.0155 inches or less. In some embodiments, the joint 125 has a tensile strength of at least 2N, for example, at least 2.6N, for example, at least 5.5N, for example, at least 6N. In some embodiments, the distal portion of the imaging probe 100 (including the joint 125 and at least the distal segment of the tube 121, for example, the distal 30 cm of the imaging probe 100) has a minimum bending radius of 5 mm or less, for example, 4 mm or less, 3 mm or less, or 2.5 mm or less. 【0154】 In some embodiments, the optical core 110 may comprise two or more layers, such as a core 1105, which may be surrounded by a cladding 1106 that is one or more layers of cladding (e.g., two or more concentric layers). 【0155】 Referring now to Figure 8, a partial cross-sectional view of an imaging probe including a bidirectional fluid propulsion element, consistent with the concept of the present invention, is shown. The imaging probe 100 in Figure 8 has similar components to the imaging probe 100 of Figure 1 described herein, and can have a similar structure and arrangement. The imaging probe 100 in Figure 8 has two fluid propulsion elements, FPE1500 F and 1500 R It is equipped with. In some embodiments, FPE1500 F As shown in Figure 8, FPE1500 R It can be positioned near the FPE1500. F When the optical core 110 is rotated in the first direction as described herein, the gel 180 is moved to the FPE1500 R It can be configured to propel distally toward the [object]. FPE1500 R When the optical core 110 is also rotated in the first direction, the gel 180 is moved to the FPE1500. F It can be configured to propel proximally toward (for example, FPE1500) F and 1500R However, when rotated in the same direction, they propel the gel 180 in opposite directions. In this way, FPE1500 F and 1500 R The elements are configured to maintain the gel 180 between them (for example, to create a confined region of pressurized gel 180 between the two elements). In some embodiments, as the optical core 110 moves forward and / or backward within the shaft 120, the FPE 1500 F and 1500 R This propels the gel 180 and translates it together with the optical core 110 (for example, when these FPEs translate together with the optical core 110, FPE 1500 F and 1500 R It is configured to remain in between. In some embodiments, the rotation of the optical core 110 is reversed, and the FPE1500 F and 1500 R Gel 180 can be at least partially evacuated from the area between them. 【0156】 Referring now to Figures 9A-9, perspective views are shown of four steps in a process for manufacturing a fluid propulsion element consistent with the concept of the present invention. Figure 9A shows a tube 1510 (e.g., a polyimide tube) surrounding a mandrel 1520. The helical channel is cut (e.g., laser cut) into the tube 1510 (e.g., after the mandrel 1520 has been inserted into the tube 1510). In Figure 9B, the mandrel 1520 is rotated 180°, and a second helical channel is cut, separating the tube 1510 into a first fluid propulsion element FPE1 and a second fluid propulsion element FPE2, each surrounding the mandrel 1520 (e.g., two similar or different FPE1500s). In Figure 9C, FPE2 is removed from the mandrel 1520, for example, FPE2 is peeled off the mandrel 1520. In Figure 9D, FPE1 is also removed from the mandrel 1520 (e.g., peeled off or slid from the mandrel 1520). The illustrated process provides two fluid propulsion elements of the concept of the present invention, for use in a single optical probe 100 comprising two FPE1500s, and / or for use in two optical probes 100, each comprising a single FPE1500. In this process, each of FPE1 and FPE2 can have matching dimensions, for example, when the coil spacing is equal to the coil width of each FPE. In some embodiments, three or more slits can be made in the tube 1510 to produce three or more FPE1500s. 【0157】 The embodiments described above should be understood to be for illustrative purposes only, and further embodiments are anticipated. Any feature described herein in relation to any one embodiment may be used alone or in combination with other features described, or in combination with one or more features of any other embodiment, or in combination with any other embodiment. Furthermore, equivalents and modifications not described above may be adopted without departing from the scope of the concept of the invention as defined in the appended claims.

Claims

[Claim 1] Imaging probe and It includes an imaging assembly, The imaging probe is A long, slender shaft having a proximal end, a distal end, and a lumen extending between the proximal end and the distal end, A rotatable optical core having a proximal end and a distal end, wherein at least a portion of the rotatable optical core is located within the lumen of the elongated shaft, An optical assembly positioned close to the distal end of the rotatable optical core and configured to irradiate tissue with light and collect reflected light from the tissue, A damping fluid is disposed between the elongated shaft and the rotatable optical core, and is configured to reduce the uneven rotation of the optical assembly. It comprises a fluid pressurizing element located within the lumen of the elongated shaft and configured to increase the pressure of the damping fluid and reduce the presence of bubbles near the optical assembly, The fluid pressurizing element comprises a spiral projection extending radially from the rotatable optical core, and is configured to increase the pressure of the damping fluid when the rotatable optical core rotates. The aforementioned spiral projections are formed such that gaps are provided between adjacent portions in the axial direction of the optical core. The aforementioned imaging assembly is It is configured and positioned to be optically coupled with the imaging probe, and is configured to emit light to the imaging probe and receive the reflected light collected by the optical assembly, A patient imaging system. [Claim 2] The aforementioned fluid pressurizing element is It is configured to reduce bubble formation. The system according to claim 1. [Claim 3] The aforementioned fluid pressurizing element is It is configured to reduce the size of one or more bubbles. The system according to claim 1. [Claim 4] It is equipped with an optical beam path, The aforementioned fluid pressurizing element is It is configured to propel one or more bubbles to a location away from the optical beam path. The system according to claim 1. [Claim 5] The aforementioned fluid pressurizing element is The damping fluid is configured to form a pressure gradient, The system according to claim 1. [Claim 6] The aforementioned fluid pressurizing element is The damping fluid is configured to intermittently increase its pressure. The system according to claim 1. [Claim 7] The aforementioned fluid pressurizing element is It is configured to increase the pressure of the damping fluid for a discrete time of 5 seconds or less. The system according to claim 6. [Claim 8] The aforementioned fluid pressurizing element is It is configured to generate a damping fluid pressure of at least 3.6 psi, The system according to claim 1. [Claim 9] The aforementioned fluid pressurizing element is It comprises a first fluid pressurizing element and a second fluid pressurizing element, The second fluid pressurizing element is Located proximal to the first fluid pressurizing element, The system according to claim 1. [Claim 10] The second fluid pressurizing element is The damping fluid is configured to prevent it from moving from the distal to the proximal side of the second fluid pressurizing element when it rotates. The system according to claim 9. [Claim 11] The aforementioned fluid pressurizing element is The rotatable optical core is adhesively attached to the following: The system according to claim 1. [Claim 12] The aforementioned fluid pressurizing element is Formed on the rotatable optical core, The system according to claim 1. [Claim 13] The aforementioned fluid pressurizing element is Formed on the rotatable optical core by vapor deposition and / or three-dimensional (3D) printing, The system according to claim 12. [Claim 14] The aforementioned fluid pressurizing element is The material comprises a material selected from the group consisting of metals, plastics, stainless steel, nickel-titanium alloys, nylon, polyetheretherketones, polyimides, and combinations thereof. The system according to claim 1. [Claim 15] The rotatable optical core is Having a diameter D1, The lumens of the aforementioned elongated shaft are Having a diameter D2, The aforementioned fluid pressurizing element is It extends radially from the rotatable optical core with a height H1, The aforementioned height H1 is, It is at least 5% of half the difference between the diameter D1 and the diameter D2. The system according to claim 1. [Claim 16] The rotatable optical core is Having a diameter D1, The lumens of the aforementioned elongated shaft are Having a diameter D2, The aforementioned fluid pressurizing element is Extending radially from the rotatable optical core with a height H1, Clearance C1 is, It has the value obtained by subtracting the height H1 from half the difference between the diameter D1 and the diameter D2, The aforementioned clearance C1 is Having a length of 100 μm or less, The system according to claim 1. [Claim 17] The damping fluid is, Equipped with a shear-reducing viscosity fluid, The system according to claim 1. [Claim 18] The damping fluid is, Having a static viscosity of at least 500 centipoise, The system according to claim 1. [Claim 19] The damping fluid is, The ratio of the static viscosity to the shear viscosity is at least 1.2:

1. The system according to claim 18. [Claim 20] The damping fluid is, A fluid with a viscosity configured to reduce bubble formation, The system according to claim 1. [Claim 21] The damping fluid is, The fluid comprises a fluid having a viscosity of 1000 centipoise or less. The system according to claim 20. [Claim 22] The damping fluid is, A fluid having high surface tension configured to reduce bubble formation, The system according to claim 1. [Claim 23] The damping fluid is, The fluid comprises a fluid having a surface tension of at least 40 dynes / cm. The system according to claim 22. [Claim 24] The imaging probe is It has a distal portion having a diameter of 0.020 inches or less, The system according to claim 1. [Claim 25] The distal portion of the imaging probe is Having a diameter of 0.016 inches or less, The system according to claim 24. [Claim 26] The imaging probe is The distal end of the elongated shaft further includes a sealing element. The system according to claim 1.