Optical Microprobe for Neurology

Abstract

An imaging system for a patient includes an imaging probe. The imaging probe includes: a slender shaft for insertion into the patient's body, the slender shaft including a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion; a rotatable optical core including a proximal end and a distal end, the rotatable optical core being configured to be optically and mechanically connected to an interface unit; a probe connector located at the proximal end of the slender shaft and surrounding at least a portion of the rotatable optical core; and an optical assembly located near the distal portion of the slender shaft and the distal end of the rotatable optical core, the optical assembly being configured to direct light to tissue and collect reflected light from the tissue. A shear-thinning fluid may be provided between the slender shaft and the rotatable optical core, for example to reduce undesired rotational variations of the rotatable optical core.

Description

[0001] Related Application Data

[0002] This application claims priority to the following patent applications: U.S. Patent Provisional Application Serial No. 62 / 322,182, entitled "Miniature Light Probes for Neurology", filed on April 13, 2016; U.S. Patent Provisional Application Serial No. 62 / 148,355, entitled "Miniature Light Probes for Neurology", filed on April 16, 2015; the contents of which are hereby incorporated by reference herein for all purposes. This application is related to: U.S. Provisional Application Serial No. 62 / 212,173, entitled "Imaging System Comprising an Imaging Probe and Delivery Device", filed on August 31, 2015; the contents of which are hereby incorporated by reference herein for all purposes. Field of the Invention

[0003] The inventive concept generally relates to imaging systems, and more particularly to neuroimaging systems including an imaging probe, an imaging console, and a delivery device. Background of the Invention

[0004] Imaging probes have been commercialized for imaging various internal locations of a patient, such as intravascular probes for imaging a patient's heart. Due to their size and stiffness, the ability of current imaging probes to reach certain anatomical locations is limited. Current imaging probes are inserted through a guide wire, which can compromise the placement of the imaging probe and limit the use of one or more delivery catheters through which the imaging probe is inserted. There is a need for imaging systems including probes with reduced diameter, high flexibility, and the ability to advance to a patient site without a guide wire, and also for systems having one or more delivery devices compatible with these improved imaging probes. Summary of the Invention

[0005] In accordance with one aspect of the inventive concept, an imaging system for a patient includes: an imaging probe configured to generate an image of the patient. The imaging probe includes: an elongate shaft for insertion into the patient, the elongate shaft including a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion; a rotatable optical core including a proximal end and a distal end, the rotatable optical core being configured to be optically and mechanically connected to an interface unit; a probe connector located at the proximal end of the elongate shaft and surrounding at least a portion of the rotatable optical core; and an optical assembly located near the distal portion of the elongate shaft and the distal end of the rotatable optical core, the optical assembly being configured to direct light to tissue and collect reflected light from the tissue.

[0006] In some embodiments, the imaging probe includes a shear-thinning fluid located in the distal portion of the elongate shaft, such as a shear-thinning fluid configured to reduce undesired rotational variations of a rotatable optical core (such as and the attached optical component 130) while avoiding placing an excessive load on the rotatable optical core.

[0007] In some embodiments, the imaging probe further includes at least one space-reducing element located between the elongate shaft and the rotatable optical core, and wherein the at least one space-reducing element is configured to reduce rotational speed variations of the rotatable optical core. The at least one space-reducing element may be located in at least a portion of the distal portion of the elongate shaft. The at least one space-reducing element may be configured to reduce rotational speed variations by increasing the shear thinning of the shear-thinning fluid.

[0008] In some embodiments, the imaging probe further includes an inertial assembly configured to reduce rotational speed variations of the rotatable optical core.

[0009] In some embodiments, the imaging probe further includes an impeller connected to the rotatable optical core and configured to resist rotation of the rotatable optical core during retraction of the rotatable optical core.

[0010] In some embodiments, the imaging probe further includes a reinforcing element embedded in the elongate shaft, the reinforcing element being configured to resist flexure of the elongate shaft and including an optically transparent portion.

[0011] In some embodiments, the imaging probe further includes a reduced inner diameter portion of the elongate shaft, wherein the reduced inner diameter portion is configured to reduce rotational speed variations of the rotatable optical core.

[0012] In some embodiments, the imaging system is configured to generate a three-dimensional image by retracting the elongate shaft.

[0013] In some embodiments, the imaging system is configured to detect and / or quantify misalignment of a flow diverter implanted in a patient.

[0014] In some embodiments, the imaging system is configured to provide quantitative and / or qualitative information for determining the size of a flow diverter implanted in a patient and / or for positioning the flow diverter in the patient. The quantitative and / or qualitative information includes information related to parameters selected from: perforator location; perforator geometry; neck size; flow diverter mesh density; and combinations thereof.

[0015] In some embodiments, the imaging system is configured to image a stent retriever at least partially located within a thrombus of a patient. The imaging system may be configured to image at least one of the following thrombi: a thrombus not engaged with the stent retriever or a thrombus not removed by the stent retriever.

[0016] In some embodiments, the imaging system is configured to quantify the volume of a thrombus within a patient. The thrombi to be quantified include thrombi selected from the group consisting of: residual thrombi of an acute stroke; thrombi remaining after a thrombus removal operation; thrombi present after implantation of a flow diverter; and combinations thereof.

[0017] In some embodiments, the imaging system is configured to provide implant location information, and the implant location information is used to select a specific implantable device to be implanted within a patient. The system may further include an implantable device implanted within the patient, and the implantable device may include a device selected from the group consisting of: a stent; a flow diverter; and combinations thereof. The implantable device may be selected based on implantable device parameters selected from: porosity; length; diameter; and combinations thereof.

[0018] In some embodiments, the imaging system is configured to provide porosity information of a device implanted within a patient. The porosity information includes the porosity of a portion of the implanted device that will be located near a side branch of the blood vessel in which the implanted device is located. The system may be configured to provide the porosity information based on the wire diameter of the implanted device. The system may further include an implanted device, and the implanted device may include a device selected from the group consisting of: a stent; a flow diverter; and combinations thereof. The imaging system may further be configured to provide information related to implanting a second device within the patient. The first implanted device may include a stent, and the second implanted device may include a flow diverter. The first implanted device may include a flow diverter, and the second implanted device may include a flow diverter. The imaging system may further be configured to provide an image during deployment of the implantable device. The imaging system may further be configured to allow modification of the implantable device while the optical component is located near the implantable device. The modification may include modification of the porosity of the implantable device. The system may further include a balloon catheter configured to perform the porosity modification.

[0019] In some embodiments, the imaging system is configured to image at least one perforating artery of a patient. The at least one perforating artery may have a diameter of at least 50 μm. The system may further include a treatment device. The treatment device may include a device selected from the group consisting of: a stent retriever; an embolization coil; an embolization coil delivery catheter; a stent; a covered stent; a stent delivery device; an aneurysm treatment implant; an aneurysm treatment implant delivery device; a flow diverter; a balloon catheter; and combinations thereof.

[0020] In some embodiments, the system further includes at least one guiding catheter. The at least one guiding catheter may include a microcatheter. The microcatheter may include an inner diameter of 0.0165″ to 0.027″. The microcatheter may include an inner diameter of 0.021″ to 0.027″.

[0021] In some embodiments, the imaging probe is configured and arranged to access a blood vessel of a human.

[0022] In some embodiments, the imaging probe is configured to access a blood vessel of the brain.

[0023] In some embodiments, the elongate shaft includes a material selected from the group consisting of: FEP; PTFE; Pebax; PEEK; polyimide; nylon; and combinations thereof.

[0024] In some embodiments, the elongate shaft includes a material selected from the group consisting of: stainless steel; nitinol; and combinations thereof.

[0025] In some embodiments, the elongate shaft includes: a first portion including a metal tube and a second portion including a braided shaft.

[0026] In some embodiments, the elongate shaft includes a hydrophobic material configured to reduce a change in length of the elongate shaft during exposure of the elongate shaft to fluid.

[0027] In some embodiments, the elongate shaft includes an outer diameter that varies along the length of the elongate shaft.

[0028] In some embodiments, the elongate shaft includes an inner diameter that varies along the length of the elongate shaft.

[0029] In some embodiments, the elongate shaft includes an outer diameter of 0.006″ to 0.022″.

[0030] In some embodiments, the elongate shaft includes an outer diameter of approximately 0.0134″.

[0031] In some embodiments, the elongate shaft includes an inner diameter of 0.004″ to 0.012″. The elongate shaft may include a wall thickness of approximately 0.003″.

[0032] In some embodiments, the elongate shaft includes an outer diameter of less than or equal to 500μm.

[0033] In some embodiments, the elongate shaft includes an outer diameter of less than or equal to 1mm.

[0034] In some embodiments, the elongate shaft includes an outer diameter of approximately 0.016″. At least the outermost 30 cm of the elongate shaft may include an outer diameter of less than or equal to 0.016″.

[0035] In some embodiments, the elongate shaft may include an outer diameter of approximately 0.014″. The elongate shaft may be configured to advance through the vasculature without a guidewire or delivery device. At least the most distal 30 cm of the elongate shaft may include an outer diameter that is less than or equal to 0.014″.

[0036] In some embodiments, the elongate shaft includes an intermediate portion proximal to the distal portion, and the distal portion includes a larger outer diameter than the intermediate portion. The distal portion of the elongate shaft may include an inner diameter that is larger than the inner diameter of the intermediate portion. The larger outer diameter of the distal portion may surround the optical component.

[0037] In some embodiments, the elongate shaft includes a length of at least 100 cm. The elongate shaft may include a length of no more than 350 cm.

[0038] In some embodiments, the elongate shaft includes a length of at least 200 cm. The elongate shaft may include a length of at least 220 cm. The elongate shaft may include a length of at least 240 cm. The elongate shaft may include a length of approximately 250 cm.

[0039] In some embodiments, the elongate shaft further includes an intermediate portion, and the distal portion of the elongate shaft includes an inner diameter that is larger than the inner diameter of the intermediate portion of the elongate shaft. The inner diameter of the distal portion of the elongate shaft may be at least 0.002″ larger than the inner diameter of the intermediate portion of the elongate shaft. The distal portion of the elongate shaft may include an outer diameter that is approximately the same as the outer diameter of the intermediate portion of the elongate shaft. The distal portion of the elongate shaft may include an outer diameter that is larger than the outer diameter of the intermediate portion of the elongate shaft. The outer diameter of the distal portion of the elongate shaft may be at least 0.001″ larger than the outer diameter of the intermediate portion of the elongate shaft. The distal portion of the elongate shaft may include a wall thickness that is less than the wall thickness of the intermediate portion of the elongate shaft. The distal portion of the elongate shaft may include a material that is harder than the intermediate portion of the elongate shaft. The distal portion of the elongate shaft may include a reinforcing element.

[0040] In some embodiments, the distal portion of the elongate shaft includes a rapid exchange guidewire lumen. The guidewire lumen may include a length that is less than or equal to 150 mm. The guidewire lumen may include a length of at least 15 mm. The guidewire lumen may include a length of at least 25 mm.

[0041] In some embodiments, the distal portion of the elongate shaft includes an optically transparent window, and the optical assembly is located within the optically transparent window. The optically transparent window may include a length of less than 20 mm or less than 15 mm. The optically transparent window may include a material selected from the group consisting of: Pebax; Pebax 7233; PEEK; amorphous PEEK; polyimide; glass; sapphire; nylon 12; nylon 66; and combinations thereof. The elongate shaft may at least include a first portion located near the optically transparent window, and the first portion may include a braided shaft. The elongate shaft may further include a second portion proximal to the first portion, and the second portion may include a metal tube. The optically transparent window may include a length of 1 mm to 100 mm. The optically transparent window may include a length of approximately 3 mm. The optically transparent window may include a material selected from the group consisting of: nylon; nylon 12; nylon 66; and combinations thereof.

[0042] In some embodiments, the elongate shaft includes a strengthening element. The strengthening element may be located at least in the distal portion of the elongate shaft. The strengthening element may be constructed and arranged to resist rotation of the distal portion of the elongate shaft during rotation of the rotatable optical core. The strengthening element may terminate proximal to the optical assembly. The strengthening element may include a coil. The strengthening element may include a metal coil wound around PTFE. The strengthening element may include a coil wound in a direction such that rotation of the rotatable optical core tightens the metal coil. The imaging probe may further include a fluid located between the rotatable optical core and the elongate shaft, and the metal coil may be configured to reduce torsion of the elongate shaft caused by the torque applied by the fluid.

[0043] In some embodiments, the elongate shaft includes a distal end, and the imaging probe includes a spring tip connected to the distal end of the elongate shaft. The spring tip may include a radiation-impermeable portion. The spring tip may include a length of 2 cm to 3 cm.

[0044] In some embodiments, the elongate shaft includes a proximal portion configured and arranged to be located in a service loop, and the proximal portion of the elongate shaft has a different configuration from the rest of the elongate shaft. The different configuration may include a larger outer diameter. The different configuration may include a thicker wall.

[0045] In some embodiments, the system further includes a fluid located within the lumen of the elongate shaft, and a fluid interaction element located in the distal portion of the lumen of the elongate shaft, and the fluid interaction element is configured to interact with the fluid to increase the load on the rotatable optical core during rotation of the rotatable optical core. The fluid interaction element may include a coil located within the lumen of the elongate shaft. The fluid interaction element may include a non-circular cross-section of the lumen. The non-circular cross-section may include a geometry selected from the group consisting of: a polygonal cross-section of the lumen of the elongate shaft; a protrusion entering the lumen of the elongate shaft; a recess in the inner diameter of the elongate shaft; and combinations thereof. The fluid may include a low-viscosity fluid. The fluid may include a viscosity of 1000 Cp or less.

[0046] In some embodiments, the imaging probe further includes a first sealing element located within the lumen of the elongate shaft, the sealing element being located between the rotatable optical core and the elongate shaft and configured to slidably engage the rotatable optical core and resist the flow of fluid around the sealing element (e.g., provide a seal when rotating the rotatable optical core). The first sealing element may be located in the distal portion of the elongate shaft. The imaging probe further includes a first liquid near the optical assembly and a second fluid near the rotatable optical core, and the first sealing element may be located between the first liquid and the second liquid. The first liquid includes a first viscosity, while the second liquid includes a second viscosity higher than the first viscosity. The first sealing element may be further configured to resist the rotation of the rotatable optical core. The first sealing element may include a hydrogel. The first sealing element may include an adhesive bonded to the elongate shaft. The first sealing element may include an ultraviolet-curable adhesive bonded to the elongate shaft. The rotatable optical core may include a material that does not bond to the adhesive. The first sealing element may include a flexible material. The flexible material may include silicone resin. The imaging system may further include a second sealing element located between the rotatable optical core and the elongate shaft, and the second sealing element may be configured to slidably engage the rotatable optical core and may also be configured to resist the flow of fluid around the second sealing element, and the imaging probe may further include a fluid located between the first sealing element and the second sealing element. The first sealing element and the second sealing element may be separated by a distance of 1 mm to 20 mm. The fluid located between the first sealing element and the second sealing element may include a viscosity of 10 Cp to 100 Cp. The first sealing element may be located proximal and near the optical assembly, and the second sealing element may be located distal to the first sealing element.

[0047] In some embodiments, the imaging probe includes a sealing element near the proximal end of the elongate shaft. The sealing element may be located between the elongate shaft and the probe connector.

[0048] In some embodiments, the rotatable optical core includes a single-mode glass fiber having an outer diameter of 40 μm to 175 μm.

[0049] In some embodiments, the rotatable optical core includes a single-mode glass fiber having an outer diameter of 80 μm to 125 μm.

[0050] In some embodiments, the rotatable optical core includes a polyimide coating.

[0051] In some embodiments, the rotatable optical core includes an outer diameter of 60 μm to 175 μm. The rotatable optical core may include an outer diameter of about 110 μm.

[0052] In some embodiments, the rotatable optical core includes a material selected from the group consisting of silica glass; plastic; polycarbonate; and combinations thereof.

[0053] In some embodiments, the rotatable optical core includes a numerical aperture of about 0.11.

[0054] In some embodiments, the rotatable optical core includes a numerical aperture of at least 0.11.

[0055] In some embodiments, the rotatable optical core includes a numerical aperture of about 0.16.

[0056] In some embodiments, the rotatable optical core includes a numerical aperture of about 0.20.

[0057] In some embodiments, the rotatable optical core is configured and arranged to rotate in a single direction.

[0058] In some embodiments, the rotatable optical core is configured and arranged to rotate in two directions.

[0059] In some embodiments, the rotatable optical core is configured to retract within the elongate shaft. The system may further include a purge medium introduced between the rotatable optical core and the elongate shaft. The purge medium may provide a function selected from the group consisting of matching the refractive index; lubrication; removing air bubbles; and combinations thereof.

[0060] In some embodiments, the optical component includes an outer diameter of 80 μm to 500 μm. The optical component may include an outer diameter of about 150 μm.

[0061] In some embodiments, the optical component includes an outer diameter of at least 125 μm.

[0062] In some embodiments, the optical component includes a length of 200 μm to 3000 μm. The optical component may include a length of about 1000 μm.

[0063] In some embodiments, the optical component includes a lens. The lens may include a GRIN lens. The lens may have a focal length of from 0.5 mm to 10.0 mm. The lens may have a focal length of about 2.0 mm. The lens may include a spherical lens.

[0064] In some embodiments, the optical component includes a reflective element.

[0065] In some embodiments, the optical component includes a lens, a reflective element, and a connecting element, and the connecting element positions the reflective element relative to the lens. The connecting element includes an element selected from the group consisting of: a tube; a flexible tube; a heat shrink tube; an optically transparent arm; and combinations thereof. The connecting element may position the reflective element at a distance from the lens of from 0.01 mm to 3.0 mm. The connecting element may position the reflective element at a distance from the lens of from 0.01 mm to 1.0 mm. The reflective element may include a split portion of a larger assembly. The reflective element may include a segment of a wire. The wire may include a gold wire. The lens may include a GRIN lens. The lens may have at least one of an outer diameter of 150 μm or a length of 1000 μm. The lens may further include a coreless lens located proximal to the GRIN lens and optically connected to the GRIN lens.

[0066] In some embodiments, the imaging probe includes an inertial component, and the inertial component is located near the optical component.

[0067] In some embodiments, the imaging probe includes an inertial component, and the imaging probe further includes a wound hollow core cable having a proximal end and a distal end, the distal end of the wound hollow core cable being fixed to a rotatable optical core at a position proximal to the optical component, and the proximal end of the wound hollow core cable not being connected to the optical core.

[0068] In some embodiments, the imaging probe includes an inertial component, the inertial component including a fluid within the lumen of an elongate shaft and a mechanical resistance element located on a distal portion of the optical core, and the mechanical resistance element being in contact with the fluid and configured to resist rotation of the rotatable optical core.

[0069] In some embodiments, the imaging probe includes an inertial component, and the inertial component is constructed and arranged to provide inertial damping that increases with rotational speed.

[0070] In some embodiments, the imaging probe includes an inertial component, and the inertial component includes a protrusion from the rotatable optical core. The protrusion may be constructed and arranged to frictionally engage the elongate shaft. The protrusion may be constructed and arranged to cause a shear force that places a load on the rotatable optical core during rotation.

[0071] In some embodiments, the imaging probe includes an inertial component, and the inertial component includes a protrusion from the elongate shaft. The protrusion may be configured and arranged to frictionally engage with the rotatable optical core. The protrusion may be configured and arranged to cause a shear force that applies a load to the rotatable optical core during rotation. The protrusion may be formed by heat treatment of the elongate shaft.

[0072] In some embodiments, the imaging probe includes an inertial component, and the inertial component includes a compressed portion from the elongate shaft. The system may further include at least one band configured to curl the elongate shaft to form the compressed portion.

[0073] In some embodiments, the imaging probe includes an inertial component, and the inertial component includes an impeller.

[0074] In some embodiments, the imaging probe includes an impeller, and the impeller is configured and arranged to cause a wind-up loading on the rotatable optical core during rotation.

[0075] In some embodiments, the imaging probe includes an impeller and the imaging probe further includes a fluid in the lumen, and the impeller is configured to engage the fluid during rotation of the rotatable optical core.

[0076] In some embodiments, the imaging probe includes an impeller, and the impeller includes a turbine.

[0077] In some embodiments, the imaging probe includes an impeller, and the impeller is configured to frictionally engage the elongate shaft during rotation of the rotatable optical core.

[0078] In some embodiments, the imaging probe includes an impeller, and the impeller includes vane-type microstructures.

[0079] In some embodiments, the imaging probe includes an impeller, and the impeller includes a flywheel.

[0080] In some embodiments, the imaging probe includes a strengthening element.

[0081] In some embodiments, the imaging probe includes a strengthening element, and the strengthening element includes a coil embedded in the elongate shaft, and the geometry of the wire helix mates with the pull-back helical rotation pattern of the optical assembly, but is offset by approximately half of the wire helix such that the imaging beam of the optical assembly passes between the wire helices during pull-back.

[0082] In some embodiments, the imaging probe includes a strengthening element, and the strengthening element includes a winding wire formed on the rotatable optical core.

[0083] In some embodiments, the imaging probe includes a reinforcement element, and the reinforcement element includes a reinforcing member embedded in the elongate shaft, and the geometry of the reinforcing member cooperates with the retraction spiral pattern of the optical assembly, but is offset by approximately half of a line spiral such that the imaging beam of the optical assembly passes between the line spirals during retraction.

[0084] In some embodiments, the imaging probe includes a reduced portion of the elongate shaft. The imaging probe may include at least one band that curls around the elongate shaft and constricts the elongate shaft to form the reduced portion of the elongate shaft. At least one band may provide a seal formed between the rotatable core and the elongate shaft. The reduced portion of the elongate shaft may include a heat-treated portion of the elongate shaft.

[0085] In some embodiments, the imaging probe further includes a fluid within the lumen of the elongate shaft. The fluid may be configured and arranged to reduce variations in the rotational speed of the rotatable optical core. The system may further include a seal element located near the proximal end of the elongate shaft, and the seal may be configured to retain the fluid within the lumen. The fluid may include a first fluid surrounding the optical assembly and a second fluid surrounding the rotatable optical core. The first fluid may include a first viscosity and the second fluid may include a second viscosity higher than the first viscosity. The second fluid may be configured and arranged to reduce variations in the rotational speed of the rotatable optical core. The system may further include a seal element between the first fluid and the second fluid. The fluid may include a gel. The fluid may include a shear-thinning fluid. The fluid may include a shear-thinning gel. The fluid may be configured to provide lubrication. The fluid may be constructed such that the rotatable optical core tends to remain centered within the elongate shaft during rotation of the rotatable optical core. The first fluid may include a viscosity of 10 Pa·s to 100,000 Pa·s. The first fluid may be configured to reduce the viscosity to a level of approximately 3 Pa·s at a shear rate of 100 s -1 The fluid may include a lubricant configured to reduce friction between the rotatable optical core and the elongate shaft. The fluid may include a first fluid and a second fluid, and the second fluid may be within the elongate shaft near the optical assembly, and the first fluid may be within the elongate shaft proximal to the second fluid. The imaging probe may further include a seal element between the first fluid and the second fluid. The seal element may be located at a position 1 mm to 20 mm from the optical assembly. The seal element may be located at a position approximately 3 mm from the optical assembly. The first fluid may include a viscosity of 10 Pa·s to 100,000 Pa·s. The first fluid includes a shear-thinning fluid. The first fluid may be configured to reduce the viscosity to a level of approximately 3 Pa·s at a shear rate of 100 s -1The shear rate reduces the viscosity to a level of about 3 Pa - S. The first fluid material may include a fluid selected from the group consisting of: hydrocarbon - based materials; silicone resins; and combinations thereof. The second fluid may have a viscosity of from 1 Pa - S to 100 Pa - S. The second fluid may have a viscosity of about 10 Pa - S. The second fluid may include a fluid selected from the group consisting of: mineral oil; silicone resins; and combinations thereof. The imaging system may be configured to pressurize the fluid in the lumen. The imaging system may be constructed and arranged to perform pressurization of the fluid to reduce bubble formation and / or bubble growth. The imaging system may be configured to pressurize the fluid in the lumen to a pressure of at least 100 psi. The imaging system may include a pressurization assembly configured to perform pressurization of the fluid. The pressurization assembly may include a check valve. The fluid may include a lubricant. The lubricant may be configured to reduce the friction between the rotatable optical core and the elongate shaft when at least a portion of the elongate shaft is near and distal to the carotid artery. The fluid may include a high - viscosity fluid. The elongate shaft may be constructed and arranged to expand when the fluid is pressurized. The elongate shaft may be constructed and arranged to expand to a first inner diameter when the fluid is at a first pressure. The elongate shaft may be constructed and arranged to expand to a second inner diameter when the fluid is at a second pressure. The elongate shaft may be constructed and arranged to become stiffer when the fluid is pressurized. The elongate shaft may be constructed and arranged to increase the space between the rotatable optical core and the elongate shaft during expansion caused by the pressurized fluid. The elongate shaft may be constructed and arranged to maintain at least partial expansion when the fluid pressure decreases.

[0086] In some embodiments, the imaging probe further includes a torque shaft having a proximal end and a distal end, and the torque shaft may be fixedly connected to the rotatable optical core such that rotation of the torque shaft rotates the rotatable optical core. The torque shaft may include stainless steel. The torque shaft may have an outer diameter of from 0.02″ to 0.09″. The torque shaft may have an outer diameter of about 0.025″. The torque shaft may have a length of about 49 cm. The torque shaft may include dimensions selected from the group consisting of: an inner diameter of about 0.015″; an outer diameter of about 0.025″; and combinations thereof. The torque shaft may have a wall thickness of from 0.003″ to 0.020″. The torque shaft may have a wall thickness of about 0.005″. The distal end of the torque shaft may be within 60 cm of the optical connector. The distal end of the torque shaft may be within 50 cm of the optical connector. The distal end of the torque shaft may be located at a position at least 50 cm from the optical component. The distal end of the torque shaft may be located at a position at least 100 cm from the optical component. The imaging system may further include a retraction assembly configured to retract at least one of the rotatable optical core or the elongate shaft, and the distal end of the torque shaft may be proximal to the retraction assembly. The imaging probe may further include a fixed tube located between the torque shaft and the rotatable optical core. The fixed tube may be adhesively connected to at least one of the torque shaft or the rotatable optical core.

[0087] In some embodiments, the imaging system further includes a visualization marker configured and arranged to identify the position of the optical component on a second image generated by a separate imaging device. The separate imaging device may include a device selected from the group consisting of: a fluoroscope; an ultrasound imager; an MRI; and combinations thereof. The visualization marker may be located on the optical component. The visualization marker may be located at a fixed distance from the optical component. The imaging system may further include a connecting element that connects the visualization marker to the optical component.

[0088] In some embodiments, the imaging probe may include a plurality of markers configured and arranged to provide regular functions. At least one of the plurality of markers may include at least one of a sealing element or a rotational damper. The plurality of markers may include two or more markers selected from the group consisting of: a radiation-impermeable marker; an ultrasound reflection marker; a magnetic marker; and combinations thereof. The plurality of markers may be located on a rotatable optical core. The plurality of markers may be located on an elongate shaft.

[0089] In some embodiments, the imaging system further includes a console including components selected from the group consisting of: a rotation assembly; a retraction assembly; an imaging assembly; an algorithm; and combinations thereof.

[0090] In some embodiments, the imaging system further includes a rotation assembly configured and arranged to rotate a rotatable optical core. The rotation assembly may include a motor. The imaging system may further include a retraction assembly configured and arranged to retract at least one of the rotatable optical core or the elongate shaft. The imaging system may further include a translatable slider, and the rotation assembly may be located on the translatable slider. The rotation assembly may be configured and arranged to be located at a position independent of the retraction assembly. The retraction assembly may be configured and arranged to be closer to the patient than the rotation assembly. The rotation assembly may provide power to the retraction assembly. The rotation assembly may include a drive cable that provides power to the retraction assembly. The elongate shaft may be configured and arranged to be retracted by the retraction assembly. The elongate shaft may include a proximal portion configured and arranged to provide a service loop during retraction by the retraction assembly. The rotation assembly may rotate the rotatable optical core at a rate of 20 rps to 2500 rps. The rotation assembly may rotate the rotatable optical core at a rate of about 250 rps. The rotatable assembly may rotate the rotatable optical core at a rate of up to 25,000 rps. The rotation assembly may be configured and arranged to rotate the rotatable optical core at a variable rotation rate. The imaging system may further include a sensor configured to generate a signal, and the rotation rate may vary based on the sensor signal. The sensor signal represents a parameter selected from the group consisting of: tortuosity of a blood vessel; narrowing of a blood vessel; presence of a clot; presence of an implanted device; and combinations thereof. The rotation assembly may be configured to allow an operator to change the rotation speed. The rotation assembly may be configured to automatically change the rotation speed. The rotation assembly may be configured to increase the rotation speed when collecting image data from a target region.

[0091] In some embodiments, the imaging system further includes a retraction assembly configured and arranged to retract at least one of the rotatable optical core or the elongate shaft. The retraction assembly may be configured and arranged to retract the rotatable optical core without retracting the elongate shaft. The retraction assembly may be configured and arranged to retract both the rotatable optical core and the elongate shaft. The retraction assembly may be configured and arranged to simultaneously retract the rotatable optical core and the elongate shaft. The retraction assembly is configured and arranged to consistently retract the rotatable optical core and the elongate shaft. The imaging probe may include a fluid between the rotatable optical core and the elongate shaft, and the retraction assembly may be configured and arranged to perform the retraction while minimizing the formation of air bubbles in the fluid. The distal portion of the elongate shaft may include an optically transparent window, and the optical assembly may be located within the optically transparent window. The optically transparent window may include a length that is less than or equal to 6 mm, less than or equal to 15 mm, or less than or equal to 20 mm. The optically transparent window may include a length of 5 mm to 50 mm. The optically transparent window may include a length of approximately 10 mm or approximately 12 mm. The optically transparent window may include a length that is less than or equal to 4 mm. The optically transparent window may include a length of approximately 3 mm. The elongate shaft may include an outer diameter that is less than or equal to 0.025″. The elongate shaft may include an outer diameter that is less than or equal to 0.016″. The elongate shaft may include an outer diameter that is less than or equal to 0.014″. The retraction assembly may be configured and arranged to retract the elongate shaft. The elongate shaft may include a proximal portion configured and arranged to provide a service loop during retraction by the retraction assembly. The retraction assembly may include a telescoping retraction assembly. The telescoping retraction assembly may include a disposable motor. The imaging probe may include a Tuohy valve, and the retraction assembly may be operably engaged with the Tuohy valve during retraction. The retraction assembly may be configured to perform the retraction over a time period of 0.1 to 10 seconds. The retraction assembly may be configured to perform the retraction over a time period of approximately 4 seconds. The retraction assembly may be configured and arranged to retract at least one of the rotatable optical core or the elongate shaft by a distance of approximately 50 mm. The retraction assembly may be configured and arranged to retract at least one of the rotatable optical core or the elongate shaft by a distance of approximately 75 mm. The retraction assembly may be configured and arranged to retract at least one of the rotatable optical core or the elongate shaft by a distance of 20 mm to 150 mm. The retraction assembly may be configured and arranged to have a retraction distance selected by an operator of the system. The retraction assembly may be configured to perform the retraction at a rate of 3 mm / sec to 500 mm / sec. The retraction assembly may be configured to perform the retraction at a rate of approximately 50 mm / sec. The retraction assembly may be configured and arranged to retract at least one of the rotatable optical core or the elongate shaft at a variable retraction rate. The imaging system may further include a sensor configured to generate a signal, and the retraction rate may vary based on the sensor signal. The sensor signal may represent a parameter selected from the group consisting of: tortuosity of a blood vessel; narrowing of a blood vessel; presence of a clot; presence of an implanted device; and combinations thereof.The retraction assembly may be configured to allow an operator to vary the retraction rate. The retraction assembly may be configured to automatically vary the retraction rate. The retraction assembly may be configured to reduce the retraction rate when visualizing a target area. The imaging system may also include a catheter device that includes at least one of a vascular introducer or a guide catheter through which a slender shaft may be inserted, and the retraction assembly may be connected to the catheter device. The imaging system may also include a catheter device that includes at least one of a vascular introducer or a guide catheter through which a slender shaft may be inserted, and the retraction assembly may be constructed and arranged to be located within 20 cm of the catheter device.

[0092] In some embodiments, the imaging system further includes an imaging assembly configured to provide light to and collect light from a rotatable optical core. The imaging assembly may include a light source configured to provide light to the rotatable optical core. The imaging assembly may include an optical fiber rotary joint that includes an optical core and is configured to transmit light to and receive light from the rotatable optical core. The rotatable optical core may include fibers having a first numerical aperture, and the imaging assembly may include an imaging assembly optical core having a second numerical aperture that is different from the first numerical aperture. The first numerical aperture may be approximately 0.16, and the second numerical aperture may be approximately 0.11. The imaging system may also include an adapter configured to connect an imaging probe to the imaging assembly. The adapter may include a lens assembly configured to mate with different numerical apertures. The adapter may be configured to be used in a plurality of clinical procedures but in fewer procedures than the imaging assembly. The adapter may include fibers having a numerical aperture selected to minimize coupling losses between the imaging probe and the imaging assembly. The numerical aperture of the adapter fibers may be approximately equal to the geometric mean of the numerical aperture of the rotatable optical core and the numerical aperture of the imaging assembly. The numerical aperture of the adapter fibers may be approximately equal to the arithmetic mean of the numerical aperture of the rotatable optical core and the numerical aperture of the imaging assembly.

[0093] In some embodiments, the imaging system further includes an algorithm. The imaging system also includes a sensor configured to generate a signal, and the algorithm may be configured to analyze the sensor signal. The sensor signal may represent light collected from tissue. The sensor signal may represent parameters related to the following group: tortuosity of blood vessels; narrowing of blood vessels; presence of a clot; presence of an implanted device; and combinations thereof.

[0094] In some embodiments, the imaging system further includes at least one guiding catheter configured to slidably receive an imaging probe. The imaging system may also include a flush fluid delivery assembly configured to deliver a flush fluid between the at least one guiding catheter and the imaging probe. The flush fluid may include saline and / or a contrast agent (e.g., a radiopaque contrast agent). The flush fluid delivery assembly may be configured to deliver the flush fluid at a rate of about 6 ml / sec. The imaging system may also include a flush fluid, and the flush fluid may include an iodinated contrast agent having an iodine concentration of 50 mg / ml to 500 mg / ml. The flush fluid may include a fluid having a viscosity of 1.0 Cp to 20 Cp at a temperature of about 37°C. The at least one guiding catheter may include: a first guiding catheter including an optically transparent window, and an optical assembly is constructed and arranged to be located within the optically transparent window. The first guiding catheter may include a microcatheter having an inner diameter of 0.021″ to 0.027″. The first guiding catheter may include a microcatheter having an inner diameter of 0.0165″ to 0.027″. The at least one guiding catheter may further include a second guiding catheter configured to slidably receive the first guiding catheter.

[0095] In some embodiments, the imaging system further includes a torque tool constructed and arranged to operably engage an elongate shaft and subsequently apply a torsional force to the elongate shaft.

[0096] According to another aspect of the inventive concept, a method of using the imaging system described herein is provided.

[0097] Reference Citation

[0098] All publications, patents, and patent applications provided in this specification are hereby incorporated herein by reference as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated herein by reference. BRIEF DESCRIPTION OF THE DRAWINGS

[0099] The foregoing and other objects, features, and advantages of embodiments of the present invention will be apparent from a more particular description of the preferred embodiments as illustrated in the drawings, in which like reference numerals represent like or similar elements. The drawings are not necessarily to scale, with emphasis being placed on illustrating the principles of the preferred embodiments.

[0100] Figure 1 is a schematic diagram of an imaging system including an imaging probe, an imaging console, and one or more delivery devices, in accordance with the inventive concept.

[0101] Figure 1A is Figure 1 an enlarged view of a distal portion of the shaft of the imaging probe of, in accordance with the inventive concept.

[0102] Figure 2 Is a perspective view of an imaging probe, the imaging probe including a metal coil in the distal portion of its shaft, in accordance with the concepts of the present invention.

[0103] Figure 3 Is a graph showing non-uniform rotational deformation.

[0104] Figure 4 Is a side cross-sectional view of the distal portion of an imaging probe, the distal portion including a thin-walled section around the axis of an optical assembly, in accordance with the concepts of the present invention.

[0105] Figure 5 Is a side cross-sectional view of the distal portion of an imaging probe, the distal portion including two fluids within the shaft of the imaging probe, in accordance with the concepts of the present invention.

[0106] Figure 6 Is a perspective view of an impeller and a side cross-sectional view of the distal portion of an imaging probe, the distal portion including the impeller, in accordance with the concepts of the present invention.

[0107] Figure 7 Is a side cross-sectional view of the proximal portion of an imaging probe, the proximal portion including a pressurizing element, in accordance with the concepts of the present invention.

[0108] Figure 8 Is a side anatomical view of a system, the system including a guiding catheter, an imaging probe, and a treatment device, each of which is placed into a patient's blood vessel, in accordance with the concepts of the present invention.

[0109] Figure 9 Is Figure 8 A side anatomical view of the system shown after partial retraction of the guiding catheter, in accordance with the concepts of the present invention.

[0110] Figure 10 Is Figure 8 A side anatomical view of the system shown after the imaging probe is advanced through the treatment device, in accordance with the concepts of the present invention.

[0111] Figure 11 Is Figure 8 A side anatomical view of the system shown when the imaging probe is retracted through the treatment device, in accordance with the concepts of the present invention.

[0112] Figure 12 Is a side anatomical view of a system, the system including an imaging probe and a treatment device, in accordance with the concepts of the present invention.

[0113] Figure 13 Is a side cross-sectional view of an imaging probe, the imaging probe including a precise spacing between a rotatable optical core and a shaft, the spacing being configured to provide capillary action to a fluid, in accordance with the concepts of the present invention.

[0114] Figure 14 is a partial assembly view of an imaging probe, the imaging probe including a shaft, a rotatable optical core, and a torque shaft, in accordance with the concepts of the present invention.

[0115] Figure 15A Through C are side cross-sectional views of the imaging probe as its shaft undergoes a series of expansion steps through internal fluid, in accordance with the concepts of the present invention.

[0116] Figure 16 is a side cross-sectional view of the distal portion of an imaging probe, the distal portion including a distal marker positioned relative to an optical assembly, in accordance with the concepts of the present invention.

[0117] Figure 17 is a side cross-sectional view of the distal portion of an imaging probe, the distal portion including two sealing elements, in accordance with the concepts of the present invention.

[0118] Figure 18 is a side cross-sectional view of the distal portion of an imaging device, the distal portion including a lens and a deflector, the lens and the deflector being separated and connected by a protrusion, in accordance with the concepts of the present invention. DETAILED DESCRIPTION

[0119] The terms used herein are merely for the purpose of describing particular embodiments and are not intended to limit the concepts of the present invention. Moreover, embodiments of the present invention concepts may include a number of novel features, none of which is the sole reason for its desired attributes or essential for practicing the invention concepts described herein. As used herein, the singular forms "a" and "the" are intended to also include the plural forms unless the context clearly indicates otherwise.

[0120] It will be further understood that when used herein, the words "comprises" (and any form thereof), "has" (and any form thereof), "includes" (and any form thereof) or "contains" (and any form thereof) specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0121] However, it should be understood that although the terms first, second, third, etc. may be used herein to describe various limitations, elements, components, regions, layers, and / or parts, these limitations, elements, components, regions, layers, and / or parts should not be limited by these terms. These terms are only used to distinguish one limitation, element, component, region, layer, or part from another limitation, element, component, region, layer, or part. Thus, the first limitation, element, component, region, layer, or part discussed below may be referred to as a second limitation, element, component, region, layer, or part without departing from the teachings of this application.

[0122] It should be further understood that when an element is referred to as being "on" or "attached to" or "connected to" or "coupled to" another element, it can be directly on or above the other element, or connected or coupled to the other element, or there can be one or more intervening elements. In contrast, when an element is referred to as being "directly on" or "directly attached to" or "directly connected to" or "directly coupled to" another element, there are no intervening elements. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" versus "directly between", "adjacent" versus "directly adjacent", etc.).

[0123] It should be further understood that when a first element is referred to as being "in" or "on" and / or "within" a second element, the first element can be located: within the interior space of the second element, within a portion of the second element (e.g., within the wall of the second element); on the outer surface and / or inner surface of the second element; and combinations of one or more of them.

[0124] Spatial relationship terms, such as "beneath", "below", "lower", "above", "upper", etc., may be used to describe the relationship of one element and / or feature to another element and / or feature, as illustrated, for example, in the figures. It will be understood that, in addition to the orientation depicted in the figures, the spatial relationship terms are intended to encompass different orientations of the device in use and / or operation. For example, if the device in the figures is turned over, an element or feature described as "below" and / or "beneath" another element or feature will be oriented "above" the other element or feature. The device may be otherwise oriented (e.g., rotated 90 degrees or in other directions), and the spatial relationship terms used herein are to be interpreted accordingly.

[0125] As used herein, the term "and / or" refers to a particular disclosure of each of two specific features or components, which may include or exclude the other specific feature or component. For example, "A and / or B" refers to the following particular disclosures of each: (i) A, (ii) B, and (iii) A and B, as each is presented separately herein.

[0126] As described herein, "room pressure" refers to the pressure of the environment of the systems and devices surrounding the concepts of the present invention. Positive pressure includes a pressure that is higher than room pressure, or simply greater than another pressure, such as a positive differential pressure across a fluid passage component such as a valve. Negative pressure includes a pressure that is lower than room pressure, or less than another pressure, such as a negative differential pressure across a fluid passage component such as a valve. Negative pressure can include a vacuum, but does not mean the pressure under vacuum. As used herein, the term "vacuum" can be used to refer to a complete or partial vacuum, or any negative pressure as described above.

[0127] As used herein, the term "diameter" for describing a non-circular geometry refers to the diameter of an imaginary circle that approximates the described geometry. For example, when describing a cross-section, such as the cross-section of a component, the term "diameter" is applied to denote the diameter of an imaginary circle having the same cross-sectional area as the cross-section of the described component. The axis of the concepts of the present invention, such as a hollow tube axis including a lumen and a wall, includes an inner diameter (ID) equal to the diameter of the lumen, and an outer diameter (OD) defined by the outer surface of the axis.

[0128] As used herein, the terms "major axis" and "minor axis" of a component are respectively the length and diameter of the smallest volume imaginary cylinder that can completely enclose the component.

[0129] As used herein, the term "transducer" refers to any component or combination of components that includes receiving energy or any input and generating an output. For example, a transducer can include electrodes that receive electrical energy and distribute the electrical energy to tissue (e.g., based on the size of the electrodes). In some configurations, the transducer converts an electrical signal into any output, such as light (e.g., a transducer including a light-emitting diode or a light bulb), sound (e.g., a transducer including a piezoelectric crystal configured to deliver ultrasonic energy), pressure, thermal energy, cryogenic energy, chemical energy; mechanical energy (e.g., a transducer including an electric motor or a solenoid), magnetic energy, and / or a different electrical signal (e.g., a Bluetooth or other wireless communication element). Alternatively or additionally, the transducer can convert a physical quantity (e.g., a change in a physical quantity) into an electrical signal. The transducer can include any component that delivers energy and / or a medicament to tissue, such as a transducer configured to deliver one or more of the following to tissue: electrical energy to tissue (e.g., a transducer including one or more electrodes); light energy to tissue (e.g., a transducer including a laser, a light-emitting diode, and / or an optical element such as a lens or a prism); mechanical energy to tissue (e.g., a transducer including a tissue manipulation element); acoustic energy to tissue (e.g., a transducer including a piezoelectric crystal); chemical energy; electromagnetic energy; magnetic energy; and combinations of one or more thereof.

[0130] As used herein, the term "patient site" refers to a location within a patient, such as a bodily conduit (e.g., an artery and a vein) such as a blood vessel or a portion of the gastrointestinal tract (e.g., the esophagus, stomach, or intestine), or a location with an organ. A "patient site" can refer to a location in the spine, such as within the epidural space or intrathecal space of the spine. A patient site can include a location that includes one or more of the following: an aneurysm; a stenosis; a thrombus and / or an implant.

[0131] As described herein, the term "nerve site" refers to a patient site located near the brain, such as a location in the neck, head, or brain of the patient. A nerve site can include a location near the brain that includes one or more of the following: an aneurysm; a stenosis; a thrombus and / or an implant.

[0132] As used herein, the term "near" shall include relatively close to, on, in, or within the referenced component or other location.

[0133] As used herein, the terms "transparent" and "optically transparent" refer to a property of a material that is relatively transparent (e.g., not opaque) to light (e.g., to collect image data of a patient site) transmitted and / or collected by one or more components or probes of the imaging system of the inventive concept.

[0134] It will be understood that, for clarity, specific features of the inventive concept described in the context of separate embodiments can also be provided in combination with a separate embodiment. Conversely, for brevity, the various features of the inventive concept described in the context of separate embodiments can also be provided separately or in any suitable sub-combination. For example, it will be understood that all features recited in any claim (whether an independent claim or a dependent claim) can be combined in any given manner.

[0135] The concepts of the present invention include an imaging probe, and the imaging system includes an imaging probe and one or more delivery devices, such as a delivery catheter and / or a guide wire. The imaging probe can be configured to be located near a patient site and collect image data from the patient site, such as a nerve site, a spinal site, and / or other patient sites defined above. The imaging probe includes an elongated shaft having a lumen. In some embodiments, a rotatable optical core and a distally located optical assembly are located within the lumen of the shaft of the probe. A probe connector can be located at the proximal end of the elongated shaft, and the connector surrounds at least a portion of the rotatable optical core (such as the proximal end of the rotatable optical core). The concepts of the present invention also include a method of using one or more delivery devices, such as a delivery catheter and / or a guide wire, to introduce the imaging probe into a patient site, such as a nerve site. In some embodiments, the imaging probe is advanced to the patient site through a delivery catheter and not over a guide wire.

[0136] In some embodiments, the imaging probe includes an inertial assembly configured to reduce variations in the rotational speed of the rotatable optical core. In some embodiments, the imaging probe includes an impeller connected to the rotatable optical core and configured to resist the rotation of the rotatable optical core, for example, during retraction of the rotatable optical core.

[0137] In some embodiments, the imaging probe includes a reinforcement assembly embedded in the elongated shaft. The reinforcement assembly is configured to resist flexure of the elongated shaft and can include an optically transparent portion.

[0138] In some embodiments, the imaging probe includes an elongated shaft, wherein at least a portion of the shaft includes a reduced inner diameter or alternatively includes a portion where the gap between the elongated shaft and the rotatable optical core is reduced. The reduced gap portion can be configured to reduce variations in the rotational speed of the rotatable optical core. In some embodiments, the reduced gap portion frictionally engages the elongated shaft with the rotatable optical core, providing a damping force configured to reduce undesired variations in the speed of the rotatable optical core (e.g., to avoid undesired variations in rotational speed in the connected optical assembly 130). Alternatively or additionally, a fluid can be located in the reduced gap portion (or other locations between the elongated shaft and the rotatable optical core), for example, to similarly reduce undesired variations in the speed of the rotatable optical core. The fluid can include a shear-thinning fluid configured to avoid overloading the rotatable optical core (e.g., to prevent breakage of the rotatable optical core during high-speed rotation).

[0139] The systems, devices, and methods of the present inventive concept can be used to diagnose and / or treat a stroke. A stroke is the fourth leading cause of death in the United States and results in all conditions related to the cost of disability. A stroke is the result of a vascular disease and has two main forms: ischemic, in which the blood supply to the brain is interrupted; and hemorrhagic, in which a ruptured blood vessel leaks blood directly into the brain tissue. Both forms have associated high morbidity and mortality rates, making improved diagnosis and treatment have a significant impact on healthcare costs.

[0140] When planning and applying treatments such as: thrombolytic drugs or stent retrievers for removing clots (ischemic stroke); or coils, flow diverters, and other devices for repairing aneurysms (hemorrhagic stroke), imaging of blood vessels is the primary diagnostic tool. The main imaging techniques used are external, non-invasive imaging techniques such as X-rays, angiography, or MRI, but these techniques provide limited information such as blood vessel size and shape information with medium resolution (e.g., a resolution of approximately 200 μm). This level of resolution does not allow imaging of smaller important perforating blood vessels in the vasculature. The inability to adequately image these blood vessels limits pretreatment planning as well as the acute assessment of treatment outcomes. These imaging techniques are further limited in their effectiveness due to obscuration and local image disappearance that can be produced by the treatment itself (e.g., in the case of implanting one or more coils). Therefore, there is also a need to perform intravascular imaging to examine the detailed morphology of the internal blood vessel 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, but they are only approved for use in coronary arteries. IVUS is used in larger peripheral vasculature systems. Currently, intravascular imaging has not been extended to neurovasculature other than larger carotid arteries. Limitations of current technologies involve: neurovascular sizes can become very small, with diameters of 1 mm or less, and the vascular tortuosity becomes quite high (e.g., if attempting to navigate the tortuous carotid sinus to reach and image the middle cranial artery and its upper branches and segments).

[0141] Due to the limitations based on ultrasound resolution, especially the inevitable beam expansion when using small transducers, optical techniques are more suitable. In particular, with the emergence of new light sources such as broadband SLEDs, visible wavelength laser diodes, and compact swept-source light sources, all of which are compatible with single-mode fibers and interferometric imaging such as OCT, the use of optical techniques is very advantageous both in terms of clinical performance and commercial perspectives. Using single-mode fibers allows for small-diameter imaging catheters.

[0142] Now refer to Figure 1, which shows a schematic diagram of an imaging system including an imaging probe and one or more delivery devices, in line with the concept of the present invention. System 10 is constructed and arranged to collect image data and generate an image based on the recorded data, such as when system 10 includes an optical coherence tomography (OCT) imaging system. System 10 includes an imaging probe 100, and at least one delivery device, such as at least one delivery catheter 50 and / or at least one guide wire 60. System 10 may also include an imaging console: console 200, which is configured to be operably connected to the imaging probe 100. System 10 may also include a fluid syringe, such as syringe 300, 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 shown injectant 305. System 10 may also include an implant, such as implant 85, which may be implanted into a patient through an implant delivery device 80. System 10 may also include a device configured to treat a patient: treatment device 91, which may be configured to dilate a stenotic site, remove stenotic material (e.g., a thrombus) and / or otherwise treat a patient's disease or disorder. System 10 may also include a second imaging device, such as the shown imaging device 92.

[0143] The imaging probe 100 includes an elongate shaft: shaft 110, which includes a proximal end 111, a distal end 119, a proximal portion 111a, an intermediate portion (intermediate portion 115), and a distal portion 119a. An optical connector, connector 102, is located on the proximal end 111 of the shaft 110, such as a connector configured to operably connect the probe 100 to the console 200. The imaging probe 100 is configured to provide a patient image, such as a three-dimensional (3D) image generated when retracting the shaft 110 of the imaging probe 100. In some embodiments, the imaging probe 100 and / or another component of the system 10 has a construction and arrangement of similar components similar to those described in U.S. Provisional Application Serial No. 62 / 148,355, filed on April 29, 2015, and co-pending with the applicant, entitled "Low Light Probe for Neurology", the content of which is incorporated herein by reference for all purposes.

[0144] Imaging system 10 may include one or more imaging probes 100, each adapted to image highly tortuous body cavities such as the middle cerebral artery, various peripheral arteries, and endocrine system ducts such as the hepatic (biliary) and pancreatic ducts. Each imaging probe 100 may include a very small cross-section, typically with an OD of less than 1 mm, and include a rotatable optical core: core 120, which includes a single fiber optically connected to optical component 130 at its distal end. The rotatable core 120 is rotated to produce a high-fidelity image of the wall of the cavity into which the probe 100 is inserted. The imaging probe 100 and other components of the imaging system 10 may be configured to facilitate a uniform rotational speed of the core 120 as the imaging probe 100 traverses difficult sites. The imaging system 10 may include a plurality of imaging probes 100 provided in a kit configuration, such as when two or more probes 100 include different characteristics (e.g., different lengths, diameters, and / or flexibilities).

[0145] Imaging probe 100 is constructed and arranged to collect image data from a patient site. The distal portion 119a can be configured to pass through a patient site, such as a patient site that includes occlusive material such as a thrombus, or a patient site that includes an implant. In some embodiments, the probe 100 is constructed and arranged to collect image data from a nerve site, such as a nerve site selected from the group consisting of: an artery in a patient's neck; a vein in a patient's neck; an artery in a patient's head; a vein in a patient's head; an artery in a patient's brain; a vein in a patient's brain; and a combination of one or more thereof. In some embodiments, the probe 100 is constructed and arranged to collect image data from one or more locations along or near a patient's spine. In some embodiments, the probe 100 is constructed and arranged to collect image data from tissue selected from the group consisting of: wall tissue of a blood vessel in a patient site; a thrombus near a patient site; occlusive material near a patient site; a blood vessel outside the blood vessel where the optical assembly 130 is located; tissue outside the blood vessel where the optical assembly 130 is located; extracellular deposits outside the lumen of the blood vessel where the optical assembly 130 is located (e.g., within and / or outside the blood vessel wall); and a combination of one or more thereof. Alternatively or additionally, the optical assembly 130 can be constructed and arranged to collect image data from an implanted device (such as a temporary or chronic implanted device), such as the implant 85 described below or a device previously implanted in a patient. In some embodiments, the optical assembly 130 is constructed and arranged to collect image data regarding the placement procedure of implanting an implant in a patient (such as real-time data collected during placement). The optical assembly 130 can be constructed and arranged to collect implant data, which includes position and / or extension data related to the placement of an implant and other treatment devices, such as devices selected from the group consisting of: a stent retriever (also known as a stentriever); an embolization device, such as an embolization coil; an embolization coil delivery catheter; an occlusion device; a stent; a covered stent; a stent delivery device; a flow diverter; an aneurysm treatment device; an aneurysm delivery device; a balloon catheter; and a combination of one or more thereof. In some embodiments, the optical assembly 130 is constructed and arranged to collect data related to the position of the implant 85 or other devices that include a stimulation element, such as an electrode located near the brain or other stimulation elements (such as an electrode located in the deep brain or other brain locations), or a stimulation element located near the spine (such as a stimulation element configured to treat pain by stimulating spinal tissue). The implantation of the implant 85 can be performed based on an analysis of the collected image data (such as the analysis of the collected image data by algorithm 240).The analysis can be used to modify implant parameters selected from the group consisting of: selection of an implantable device (e.g., selection of implant 85); selection of the porosity of the implantable device; selection of the metal coverage of the implantable device; selection of the pore density of the implantable device; selection of the diameter of the implantable device; selection of the length of the implantable device; selection of the location for implanting the implantable device; dilation parameters for expanding the implantable device after implantation; repositioning of the implantable device after implantation; selection of a second implantable device to be implanted; and combinations thereof. The adjustment of the implant can be performed based on one or more issues identified in the analysis, such as issues selected from the group consisting of: misalignment of the implanted device; insufficient deployment of the implanted device; presence of air bubbles; and combinations thereof.

[0146] In some embodiments, the optical assembly 130 is configured and arranged to collect data related to the position of the treatment device during patient treatment, such as treatment device 91 described below.

[0147] The delivery catheter 50 may include one or more delivery catheters, such as the illustrated delivery catheters 50a, 50b, 50c to 50n. The delivery catheter 50 may include a vascular introducer, such as Figure 1 The illustrated delivery catheter 50a includes a vascular introducer delivery catheter 50 引入 when. After the vascular introducer is positioned through the patient's skin, the other delivery catheters 50 may be inserted into the patient through the delivery catheter 50 引入 Two or more delivery catheters 50 may collectively include a set of inner diameter (ID) and outer diameter (OD) such that a first delivery catheter 50 slidably receives a second delivery catheter 50 (e.g., the OD of the second delivery catheter is less than or equal to the ID of the first delivery catheter), and the second delivery catheter 50 slidably receives a third delivery catheter 50 (e.g., the OD of the third delivery catheter is less than or equal to the ID of the second delivery catheter), and so on. In these configurations, the first delivery catheter 50 may be advanced to a first anatomical location, the second delivery catheter 50 may be advanced through the first delivery catheter to a second anatomical location distal to or away from (hereinafter "distal") the first anatomical location, and smaller diameter delivery catheters 50 may be used in a suitable order as such.

[0148] Each delivery catheter 50 includes a shaft 51 (such as shafts 51a, 51b, 51c, and 51n as shown), each having a distal end 59 (such as distal ends 59a, 59b, 59c, and 59n as shown). A connector 55 (such as connectors 55a, 55b, 55c, and 55n as shown) is located on the proximal end of each shaft 51. Each connector 55 may include a Tuohy or other valved connector, such as a valved connector configured to prevent fluid from flowing out of the associated catheter 50 (with and / or without a separate shaft located within the connector 55). For example, connector 55 may include ports 54 as shown on delivery catheters 50b, 50c, and 50n, such as ports constructed and arranged to allow fluid to be introduced into the associated delivery catheter 50 and / or for removing fluid from the associated delivery catheter 50. In some embodiments, as described below, a flushing fluid is introduced through one or more ports 54, such as to remove blood or other undesirable materials from a location near the optical assembly 130. The port 54 may be located on one side of the connector 55 and may include a Luer fitting and a cap and / or valve. The shaft 51, connector 55, and port 54 may each include standard materials and have a structure similar to commercially available introducers, guide catheters, diagnostic catheters, intermediate catheters, and microcatheters for interventional procedures.

[0149] Each delivery catheter 50 includes a lumen 52 (for clarity of illustration, reference numeral 52 is shown on delivery catheter 50a but not on the remaining delivery catheters 50), the lumen 52 extending from the connector 55 to the distal end 59 of the shaft 51. The diameter of each lumen 52 defines the ID of the associated delivery catheter 50. Each delivery catheter 50 may be advanced over a guide wire (such as guide wire 60) through the lumen 52. In some embodiments, the delivery catheter 50 is configured for rapid exchange advancement and retraction over a guide wire, such as by a sidecar with a rapid exchange (Rx) guide wire lumen known to those skilled in the art. In some embodiments, the probe 100 and at least one delivery catheter 50 are jointly constructed and arranged such that the delivery catheter 50 advances through a tube such as a blood vessel, and the probe 100 is slidably received by the delivery catheter 50 and advanced through the delivery catheter 50 to a location near the patient site PS to be imaged (such as just distal to the patient site PS to be imaged, within the patient site PS, and / or just adjacent to the patient site PS). In some embodiments, a second delivery catheter 50 is slidably received by the first delivery catheter 50, and the probe 100 is advanced through the second delivery catheter 50 to a location near the patient site PS to be imaged. In other embodiments, three or more delivery catheters 50 are inserted coaxially with each other, and the probe 100 is advanced through the innermost delivery catheter 50 to a location near the patient site PS to be imaged. In some embodiments, the probe 100 is advanced through (such as through and beyond) one or more delivery catheters 50 without using a guide wire.

[0150] The delivery catheter 50 may include one or more delivery catheters selected from the group consisting of: introducers; vascular introducers; introducers with an ID of 7Fr to 9Fr; delivery catheters (also referred to as guiding catheters) for positioning through the aortic arch (e.g., such that its distal end is just distal or near the aortic arch), such as delivery catheters with an ID of 5Fr to 7Fr or an ID of approximately 6.5Fr; delivery catheters (also referred to as intermediate catheters) for insertion through a larger, previously placed delivery catheter, such as an intermediate delivery catheter with an ID of 0.053″ to 0.070″; delivery catheters with an ID of 0.0165″ to 0.027″ (also referred to as microcatheters); and combinations of one or more of them. In some embodiments, the delivery catheter 50 includes a first delivery catheter 50 引入 , which includes an introducer, such as a guide with an ID of 7Fr to 9Fr or an ID of approximately 8Fr. The delivery catheter 50 may also include a second delivery catheter 50 configured and arranged to be inserted into the first delivery catheter 50, such as the second delivery catheter 50 导引 , which is configured and arranged to be positioned through the aortic arch and has an ID of 5Fr to 7Fr or an ID of approximately 6Fr. The delivery catheter 50 may include a third delivery catheter 50 configured and arranged to be inserted through the first delivery catheter 50 引入 and / or the second delivery catheter 50 导引 , such as a third delivery catheter 50 with an ID of 0.053″ to 0.070″ 中间 (e.g., an intermediate catheter). The delivery catheter 50 may include a fourth delivery catheter 50 configured and arranged to be inserted through the first delivery catheter 50, the second delivery catheter 50, and / or the third delivery catheter 50 微 , such as a fourth delivery catheter 50 with an ID of 0.0165″ to 0.027″ 微 . The imaging probe 100 may be configured and arranged to be inserted through the first delivery catheter 50, the second delivery catheter 50, the third delivery catheter 50, and / or the fourth delivery catheter 50, such as when the OD of the imaging probe 100 is less than 0.070″, such as when the OD of at least the distal portion of the imaging probe 100 is less than or equal to 0.025″, 0.022″, 0.018″, 0.016″, 0.015″, or 0.014″. In some embodiments, the ID of at least the distal portion of the imaging probe 100 is approximately 0.014″ (e.g., an ID of 0.012″ to 0.016″). In some embodiments, the system 10 includes the probe 100 and one or more delivery catheters 50.

[0151] Each delivery catheter 50 may include an optically transparent section, such as a section that is relatively transparent to light transmitted and / or received by the optical assembly 130, such as the transparent section 57 shown on delivery catheter 50n and described herein. The transparent section 57 may include a length of up to 50 cm, such as a length of 1 cm to 15 cm, or a length of up to 2 cm or up to 5 cm. The transparent section 57 may be part of a delivery catheter 50 that includes a microcatheter with an ID of 0.0165″ to 0.027″ or 0.021″ to 0.027″. The system 10 may include a first delivery catheter 50 that slidably receives the probe 100 and includes the transparent section 57, and a second delivery catheter 50 that slidably receives the first delivery catheter 50.

[0152] Each delivery catheter 50 may include a spring tip, not shown herein, but as described herein the spring tip 104 is connected to the shaft 110 of the probe 100.

[0153] The guidewire 60 may include one or more guidewires, such as the guidewires 60a, 60b to 60n shown. The guidewire 60 may include one or more guidewires that are constructed and arranged to support the advancement (e.g., intravascular advancement) of the probe 100 (e.g., through a rapid exchange lumen in the distal portion 119a of the shaft 110) and / or the delivery catheter 50 into a patient site PS such as a nerve site. The guidewire 60 may include one or more guidewires selected from the group consisting of: guidewires with an OD of 0.035″ to 0.038″; guidewires with an OD of 0.010″ to 0.018″; access length guidewires, such as guidewires with a length of approximately 200 cm; exchange length guidewires, such as guidewires with a length of approximately 300 cm; guidewires with a length of 175 cm to 190 cm; guidewires with a length of 200 cm to 300 cm and / or an OD of 0.014″ to 0.016″; hydrophilic guidewires; Stryker Synchro TM guidewires; Terumo guidewires, such as the Terumo Glidewire TM guidewires; Terumo Traxcess TM guidewires; X-Celerator TM guidewires; X-Pedion TM guidewires; Agility TM guidewires; Bentson TM guidewires; Coon TM guidewires; Amplatz TM guidewires; and combinations of one or more of them. In some embodiments, the system 10 includes the probe 100 and one or more guidewires 60. The guidewire 60 may include one or more visualization portions, such as one or more radiopaque or ultrasound-reflective portions.

[0154] System 10 may include various combinations and configurations of delivery catheter 50 and guidewire 60. In some embodiments, delivery catheter 50 includes a first delivery catheter 50 including an introducer (e.g., a vascular introducer) 引入 , and at least two delivery catheters 50 inserted through delivery catheter 50 引入 . These catheters include respective sets of different IDs and ODs, e.g., to sequentially insert each delivery catheter 50 through lumen 52 of a previously placed delivery catheter 50, as detailed herein. In some embodiments, the first delivery catheter 50 is advanced over a first guidewire 60, and a delivery catheter 50 with a smaller OD is subsequently advanced over a guidewire 60 with a smaller OD (e.g., after removing the first guidewire 60 from the first delivery catheter 50 and replacing it with a second guidewire 60). In some embodiments, after imaging probe 100 located within the delivery catheter has collected image data (e.g., after retraction for collecting image data), imaging probe 100 is removed and replaced with a guidewire 60, and additional devices (e.g., other delivery catheters 50, treatment device 91, implant delivery device 80, or other devices) may be placed over the guidewire 60. In some embodiments, probe 100, one or more delivery catheters 50, and / or one or more guidewires 60 are inserted, advanced, and / or retracted as described herein.

[0155] Probe 100, one or more delivery catheters 50, and / or one or more guidewires 60 may be advanced through one or more blood vessels to patient site PS (e.g., one or more delivery catheters 50 are advanced over a guidewire 60 through one or more arteries or veins). Alternatively and additionally, probe 100, one or more delivery catheters 50, and / or one or more guidewires 60 may be advanced to patient site PS through a non-vascular lumen or through another body cavity or space (e.g., may also be performed over a guidewire 60), such as the epidural space and / or intrathecal space of the spine.

[0156] In some embodiments, one or more delivery catheters 50 include functional elements 53 (e.g., functional elements 53a, 53b, 53c, and 53n as shown). Each functional element 53 may include one or more functional elements, such as one or more sensors, transducers, and / or other functional elements as detailed below. In some embodiments, the length of shaft 110 is at least 100 cm, at least 200 cm, at least 240 cm. In some embodiments, the length of shaft 110 is about 250 cm. In some embodiments, the length of shaft 110 is less than or equal to 350 cm, less than or equal to 250 cm, or less than or equal to 220 cm.

[0157] In some embodiments, the shaft 110 includes an outer diameter (OD) of 0.005″ to 0.022″ along at least a portion of its length (e.g., at least a portion of the distal portion 119a). In some embodiments, the shaft 110 includes an OD of approximately 0.0134″, an OD of 0.014″ or less, or an OD of 0.016″ or less along at least a portion of its length (e.g., along a portion surrounding the core 120 and / or the optical assembly 130, and / or along at least the most distal 10 cm, 20 cm, or 30 cm of the shaft 110). In these embodiments, the imaging probe 100 may be configured to advance and / or retract without a guide wire or delivery catheter (such as when consistently retracting the optical assembly 130 and the shaft 110 during collection of image data). In some embodiments, the shaft 110 includes an OD of less than 1 mm or less than 500 μm along at least a portion of its length. In some embodiments, the shaft 110 includes an OD that varies along its length. In some embodiments, the OD of the distal portion 119a is greater than the OD of the intermediate portion 115, such as when the OD of the portion of the distal portion 119a surrounding the optical assembly 130 is greater than the OD of the intermediate portion 115. In these embodiments, the ID of the distal portion 119a may be greater than or similar to the ID of the intermediate portion 115.

[0158] In some embodiments, the shaft 110 includes an inner diameter (ID) of 0.004″ to 0.012″ along at least a portion of its length. In some embodiments, the shaft 110 includes an ID of approximately 0.0074″ along at least a portion of its length (e.g., along a portion surrounding the core 120 and / or the optical assembly 130). In some embodiments, the shaft 110 includes an ID that varies along its length. In some embodiments, the ID of the distal portion 119a is greater than the ID of the intermediate portion 115, such as when the ID of the portion of the distal portion 119a surrounding the optical assembly 130 is greater than the ID of the intermediate portion 115.

[0159] In some embodiments, the shaft 110 includes a wall thickness of 0.001″ to 0.005″, or approximately 0.003″, along at least a portion of its length (e.g., along a portion surrounding the optical assembly 130). In some embodiments, the shaft 110 includes a thinner wall surrounding at least a portion of the optical assembly 130 (e.g., thinner than the portion surrounding the core 120).

[0160] In some embodiments, the distal portion 119a of the shaft 110 has a larger ID than the intermediate portion 115 of the shaft 110, such as when the intermediate portion 115 has an ID that is at least 0.002″ larger than the ID of the distal portion 119a. In these embodiments, the OD of the intermediate portion 115 and the OD of the distal portion 119a may have similar sizes. Alternatively, the OD of the intermediate portion 115 may be different from the OD of the distal portion 119a (e.g., the OD of the distal portion 119a may be greater than the OD of the intermediate portion 115, such as when the distal portion 119a is at least 0.001″ larger).

[0161] In some embodiments, the imaging probe 100 includes a reinforcing portion, such as when the imaging probe 100 includes a reinforcing element 118. The reinforcing element 118 is located in at least a portion of the shaft 110, within at least a portion of the shaft 110 and / or positioned along at least a portion of the shaft 110. In some embodiments, the reinforcing element 118 is located within the shaft 110 or on the inner surface of its wall. In some embodiments, the reinforcing element 118 includes a wire wound around a core 120. In some embodiments, the reinforcing element 118 terminates proximal to the optical assembly 130. Alternatively, the reinforcing element 118 may laterally move to and / or potentially extend beyond the optical assembly 130, such as when portions of the reinforcing element 118 include one or more optically transparent materials.

[0162] In some embodiments, the distal portion 119a includes a wall thickness that is less than the wall thickness of the intermediate portion 115. In some embodiments, the distal portion 119a includes a material that is harder than the material of the intermediate portion 115, and / or the distal portion 119a includes a reinforcing element (e.g., the reinforcing element 118a shown below) Figure 13 when the distal portion 119a includes a wall thickness that is less than the wall thickness of the intermediate portion 115.

[0163] In some embodiments, the probe 100 includes a guide wire lumen, such as a rapid exchange guide wire lumen located in the Figure 1 sidecar 105 shown. The sidecar 105 may include a length of less than 150 mm. The sidecar 105 may include a length of at least 15 mm, such as a length of approximately 25 mm.

[0164] In some embodiments, the proximal portion 111a of the shaft 110 is configured to be located in a service loop. The proximal portion 111a of the shaft 110 may include a configuration that is different from the intermediate portion 115 or different from the distal portion 119a. For example, the proximal portion 111a may include a larger OD or a thicker wall than the intermediate portion 115.

[0165] In some embodiments, the shaft 110 includes an outer shaft and an inner "torque" shaft, and the inner "torque" shaft may be shorter than the outer shaft, as described below with reference to Figure 14As described. In some embodiments, the torque shaft terminates before the portion of the probe 100 that enters the patient.

[0166] In some embodiments, the system 10 includes a torque tool 320 that frictionally engages the shaft 110 of the probe 100 (e.g., laterally from a position along the proximal portion 111a) and allows an operator to apply a torsional force to the shaft 110.

[0167] Additionally referring Figure 1A , an enlarged view of the distal portion 119a is shown, in accordance with the concepts of the present invention. The lumen 112 extends from the proximal end 111 of the shaft 110 to the distal portion 119a and ends at a position proximal to the distal end 119. Located within the lumen 112 is a rotatable optical core: the core 120. An optical assembly the optical assembly 130 is located on the distal end of the core 120. The optical assembly 130 includes a lens 131 and a reflective surface: a reflector 132. The optical assembly 130 is located within the optically semi-transparent and / or effectively transparent window portion viewing portion 117 of the shaft 110. The optical assembly 130 is constructed and arranged to collect image data through at least a portion of the shaft 110. In some embodiments, the optical assembly 130 is also constructed and arranged to collect image data through at least a portion of an additional device, such as at least a portion of the shaft of the delivery catheter 50 (e.g., the optically transparent portion of the delivery catheter 50, such as the transparent segment 57 described herein). In Figure 1A For clarity of illustration, the optional sidecar 105 and the reinforcement element 118 have been removed.

[0168] In some embodiments, a fluid 190 is included in the lumen 112 (e.g., in the space not occupied by the core 120 and the optical assembly 130), such as Figure 1AThe illustrated fluids 190a and 190b, where fluid 190b is located around the optical assembly 130 and fluid 190a is located around the core 120 and proximal to the optical assembly 130. Fluid 190 (e.g., fluid 190b) can include an optically transparent fluid. In some embodiments, fluids 190a and 190b include similar materials. Alternatively or additionally, fluids 190a and 190b can include different materials. In some embodiments, fluid 190a includes a more viscous fluid than fluid 190b. Fluids 190a and / or 190b (individually or collectively referred to as fluid 190) can be configured and arranged to limit undesirable variations in the rotational speed of the core 120 and / or the optical assembly 130. In some embodiments, fluid 190 includes a gel. In some embodiments, fluid 190 includes a non-Newtonian fluid (e.g., a shear-thinning fluid) or other fluid whose viscosity varies with shear. Alternatively or additionally, fluid 190 can include a lubricant (e.g., to provide lubrication between the core 120 and the shaft 110). In some embodiments, fluid 190 includes a shear-thinning fluid and the core 120 rotates at a rate higher than 50 Hz, such as higher than 100 Hz or 200 Hz. At higher rotational rates, if fluid 190 includes a high-viscosity Newtonian fluid, the viscous drag generated during rotation of the core 120 will create a torsional load on the core 120 that will break the core 120 before high rotation speeds can be achieved. However, a fluid 190 including a low-viscosity Newtonian fluid is also not desirable because it does not provide sufficient damping (e.g., will not provide sufficient rotational speed control), such as during low-speed ("idle mode") imaging. For these reasons, the probe 100 can include a fluid 190 that is a shear-thinning (non-Newtonian) fluid with a relatively high viscosity, which provides sufficient load during low-speed rotation of the core 120 and, due to its varying viscosity, avoids excessive load during high-speed rotation of the core 120. In some embodiments, fluid 190 includes a shear-thinning fluid whose viscosity varies non-linearly (e.g., its viscosity rapidly decreases as the shear rate increases). In some embodiments, the probe 100 includes a reduced gap between the shaft 110 and the core 120 along at least a portion of the shaft 110 (e.g., the portion of the shaft 110 proximal to the optical assembly 130), such as by referring to Figure 16The space reducing element described above. The gap can be from 20 μm to 200 μm (e.g., a constant or varying gap from 20 μm to 200 μm). The fluid 190 (e.g., a high viscosity, shear thinning fluid) can be (at least) located in the reduced gap portion of the shaft 110. In this configuration, the force applied to the core 120 to reduce rotational variations is directly proportional to the shear stress and the length of the shaft 110 where the fluid 190 interacts with the shaft 110 ("interaction length"). Positioning this interaction length relatively close to the optical assembly 130 optimizes the reduction of undesired rotational speed variations of the optical assembly 130 (e.g., since the core 120 can have a low torsional stiffness, damping that is far enough away from the optical assembly 130 will not provide the desired effect on the optical assembly 130).

[0169] In some embodiments, the optical assembly 130 includes a lens 131, and the OD of the lens 131 is larger than the diameter of the lumen 112 of the shaft 110 (e.g., larger than the diameter of at least a portion of the lumen 112 on the distal side of the optical assembly 130). The OD of the lens 131 being larger than the diameter of the lumen 112 prevents the optical assembly 130 from translating within the lumen 112. For example, the lens 131 can include an aperture lens with a relatively large diameter, e.g., to provide a small spot size while collecting a large amount of light (e.g., a lens 131 having an OD of nearly up to 350 μm). The lumen 112 can be smaller than this diameter (e.g., less than 350 μm), e.g., to allow for a reduced OD of the shaft 110 on the proximal side of the optical assembly 130 (e.g., Figure 4 、 5 、6, 12, 13, and 16 as shown). In embodiments where the OD of the optical assembly 130 is larger than the diameter of the lumen 112 at the position on the proximal side of the optical assembly 130, the portion of the shaft 110 surrounding the optical assembly 130 has a larger OD and / or ID than the portion of the shaft 110 on the proximal side of the optical assembly 130. In these embodiments, since the lumen 112 has too small a diameter to accommodate the translation of the optical assembly 130, both the shaft 110 and the optical assembly 130 are retracted simultaneously during image data collection.

[0170] In some embodiments, the fluid 190 (e.g., fluid 190a) includes a fluid with a viscosity of 10 Pa·s to 100,000 Pa·s. In these embodiments, the fluid 190 can be configured to be at about 100 s -1to a shear rate of thinning to about 3 Pa - S. In some embodiments, the fluid 190 (such as fluid 190b) includes a viscosity of 1 Pa - S to 100 Pa - S, such as a viscosity of about 10 Pa - S. In some embodiments, the fluid 190 is configured such that the core 120 tends to remain centered within the lumen 112 of the shaft 110 during rotation (such as due to the shear - thinning property of the fluid 190). In some embodiments, the fluid 190a includes a hydrocarbon - based material and / or a silicone resin. In some embodiments, the fluid 190b includes a mineral oil and / or a silicone resin. In some embodiments, the probe 100 includes one or more fluids 190 in at least the outermost 20 cm of the shaft 110.

[0171] In some embodiments, the lumen 112 includes a seal: a sealing element 116, which is constructed and arranged to provide a seal between the core 120 and the wall of the shaft 110 (such as when located within the distal portion 119a). The sealing element 116 may allow rotation of the core 120 while permitting mixing and / or migration of the fluids 190a and / or 190b (such as by resisting flow around the seal 116). In some embodiments, the sealing element 116 is located at a position 1 to 200 mm from the optical assembly 130, such as when the sealing element 116 is located at a position about 3 mm from the optical assembly 130. In some embodiments, the sealing element 116 includes two or more sealing elements, such as two or more sealing elements 116 that slidably engage the core 120 and / or the optical assembly 130. In some embodiments, the probe 100 includes a sealing element located in the proximal portion of the shaft 110 (such as within or near the connector 102), such as the sealing element 151 described below with reference to Figure 7 the sealing element 151 as described.

[0172] The sealing element 116 and / or 151 may include elements selected from the group consisting of: a hydrogel material; a flexible material; a silicone resin; and combinations of one or more of them. In some embodiments, the sealing element 116 and / or 151 may include a material adhered to the shaft 110 with an adhesive, or purely the adhesive itself on the shaft 110 (such as an ultraviolet - curable adhesive or an adhesive configured not to adhere to the core 120).

[0173] In some embodiments, the fluid 190 is configured to be pressurized, as described herein with reference to Figure 7 described, for example to reduce bubble formation and / or bubble growth within the fluid 190.

[0174] The shaft 110 may include one or more materials and may include at least a portion that is braided and / or includes one or more liners such as a polyimide or PTFE liner. In some embodiments, at least the distal portion 119a of the shaft 110 includes an OD less than or equal to 0.025", for example, an OD less than or equal to 0.022", 0.018", 0.016", 0.015", or 0.014". In some embodiments, the shaft 110 includes a material selected from the group consisting of: polyetheretherketone (PEEK); polyimide; nylon; fluorinated ethylene propylene (FEP); polytetrafluoroethylene (PTFE); polyether block amide (Pebax); and combinations of one or more thereof. In some embodiments, the shaft 110 includes at least a portion including a braided portion comprising stainless steel and / or nickel-titanium alloy, for example, a shaft 110 including a braided portion located on a thin-walled FEP or PTF. The braided portion may be coated with Pebax or other flexible material. In some embodiments, the shaft 110 includes at least a portion (e.g., a proximal portion) that is metal, such as a metal hypotube comprising stainless steel and / or nickel titanium alloy. In some embodiments, the shaft 110 includes a first portion that is a metal tube, and a second portion distal to the first portion that includes a braided shaft. In some embodiments, the shaft 110 includes at least a portion that includes a hydrophobic material or other material configured to reduce changes (e.g., changes in length) when exposed to a fluid.

[0175] The observation portion 117 of the shaft 110 may include one or more materials and may include similar or different materials than different portions of the shaft 110. The observation portion 117 may include an ID and / or OD similar to one or more other portions of the shaft 110. In some embodiments, the ID and / or OD of the observation portion 117 is greater than the ID and / or OD of the shaft 110 at the middle portion 115 of the shaft 110. The observation portion 117 may include a flexibility similar or different than one or more other portions of the shaft 110. The observation portion 117 may include one or more optically transparent materials selected from the following group: Pebax; Pebax 7233; PEEK; amorphous PEEK; polyimide; glass; sapphire; nylon 12; nylon 66; and combinations of one or more thereof.

[0176] In some embodiments, a flexible tip portion is located on the distal end of the shaft 110, such as the spring tip 104 shown. The spring tip 104 may include a length of 0.5 cm to 5 cm, such as a length of about 1 cm, 2 cm, or 3 cm, or a length of 2 cm to 3 cm. At least a portion of the spring tip 104 may be visible to an imaging device, such as by including a radiopaque material such as platinum or other material visible to an X-ray imaging device. The spring tip 104 may include a core including a material such as stainless steel.

[0177] In some embodiments, the probe 100 and / or other components of the system 10 include one or more markers (such as radiation-opaque or other visual markers), sensors, transducers, or other functional elements, such as: functional elements 53a to n of the delivery catheter 50; functional elements 83 of the implant delivery device 80; functional elements 93 of the treatment device 91; functional elements 113a and 113b of the shaft 110 (individually or collectively referred to as functional elements 113, as described below); functional elements 123 of the core 120; functional elements 133 of the optical assembly 130; functional elements 203 of the console 200; and functional elements 303 of the syringe 300.

[0178] In some embodiments, the core 120 includes single-mode glass fibers, such as fibers with an OD of 40 μm to 175 μm, fibers with an OD of 80 μm to 125 μm, fibers with an OD of 60 μm to 175 μm, or fibers with an OD of approximately 110 μm. The core 120 may include materials selected from the group consisting of: silica glass; plastics; polycarbonate; and combinations of one or more of them. The core 120 may include fibers with a coating, such as a polyimide coating. The core 120 may include a cladding material and / or coating around the fiber, such as those known to those skilled in the art. The core 120 may include a numerical aperture (NA) of 0.11 or greater, such as an NA of approximately 0.16 or 0.20. In some embodiments, the core 120 may include an NA (such as an NA of 0.16 to 0.20) to significantly reduce losses caused by bending, such as those encountered in tortuous sections. The system 10 may be configured to rotate the core 120 in a single direction (unidirectional rotation) or in multiple directions (bidirectional rotation).

[0179] In some embodiments, the probe 100 and other components of the system 10 are configured to retract the core 120 within the shaft 110. In these embodiments, the probe 100 may be configured such that a material (such as fluid 190) is introduced into the shaft 110 and within the shaft 110 (such as between the core 120 and the shaft 110). The introduced material may be configured to provide functions selected from the group consisting of: matching the refractive index; lubrication; bubble removal; and combinations of one or more of them.

[0180] In some embodiments, the optical assembly 130 includes an OD of 80 μm to 500 μm, such as an OD of at least 125 μm, or an OD of approximately 150 μm. In some embodiments, the optical assembly 130 includes a length of 200 μm to 3000 μm, such as a length of approximately 1000 μm. The optical assembly 130 may include one or more lenses, such as the lens 131 shown, such as a GRIN lens and / or a spherical lens. The optical assembly 130 may include a GRIN lens with a focal length of 0.5 mm to 10.0, such as a focal length of approximately 2.0 mm. The optical assembly 130 may include one or more reflective elements, such as the reflective element 132 shown.

[0181] In some embodiments, the optical assembly 130 includes a lens 131 and a reflective element 132, and the reflective element 132 is offset from the lens 131 by one or more connecting elements 137, as Figure 18 shown. The connecting element 137 may include a tube (such as a heat shrink tube) surrounding at least a portion of the lens 131 and the reflective element 132. The connecting element 137 may include one or more elements selected from the group consisting of: a tube; a flexible tube; a heat shrink tube; an optically transparent arm; and combinations of one or more of them. The connecting element 137 may position the reflective element 132 at a distance of 0.01 mm to 3.0 mm, for example 0.01 mm to 1.0 mm, from the lens 131. The reflective element 132 may include a local portion of a larger component, and the local portion is cut or otherwise separated (such as split) from the larger component during the manufacturing process for manufacturing the optical assembly 130. Using the larger component may simplify the operations during manufacturing. In some embodiments, the resulting reflective element 132 includes a reflector with an optimized shape. The reflective element 132 may include a segment of wire, such as a gold wire. In some embodiments, the lens 131 may include a GRIN lens, such as a lens with an OD of about 150 μm and / or a length of about 1000 μm. In some embodiments, the lens 131 further includes a second lens, such as a coreless lens located proximal to the GRIN lens and optically connected to the GRIN lens.

[0182] In some embodiments, the imaging probe 100 includes a reduced diameter portion (such as a reduced outer diameter and / or inner diameter portion) at a position proximal to the optical assembly 130 along the axis 110, as Figure 4 , 5 , 6, 12, 13, and 16 shown. In these embodiments, the optical assembly 130 may include an OD greater than the lumen 112 of the axis 110 (such as at a position proximal to the optical assembly 130), for example to provide a larger lens 131 to improve imaging capabilities. In some embodiments, the probe 100 includes a space reducing element between the axis 110 and the core 120, such as the element 122 described below with reference to Figure 16 . The functional elements 113 and / or 123 may include space reducing elements (such as protrusions from the axis 110 and / or the core 120 respectively).

[0183] The console 200 may include components: a rotation component 210 that is constructed and arranged to rotate at least the core 120. The rotation component 210 may include one or more motors configured to provide rotation, such as motors selected from the group consisting of: a direct current motor; an alternating current motor; a stepper motor; a synchronous motor; and combinations of one or more of them. The console 200 may include components: a retraction component 220 that is constructed and arranged to retract at least the shaft 110. The retraction component 220 may include one or more motors or linear drive elements configured to provide retraction, such as components selected from the group consisting of: a direct current motor; an alternating current motor; a stepper motor; a synchronous motor; a gear mechanism, a linear drive mechanism; a magnetic drive mechanism; a piston; a pneumatic drive mechanism; a hydraulic drive mechanism; and combinations of one or more of them. The rotation component 210 and / or the retraction component 220 may have a construction and arrangement similar to that described in the applicant's co-pending U.S. Provisional Application Serial No. 62 / 148,355, entitled "Optical Microprobes for Neurology", filed on April 29, 2015: the content of which is hereby incorporated by reference herein for all purposes.

[0184] The console 200 may include an imaging assembly 230 configured to provide light to the optical assembly 130 (e.g., via the core 120) and collect light from the optical assembly 130 (e.g., via the core 120). The imaging assembly 230 may include a light source 231. The light source 231 may include one or more light sources, including one or more light sources configured to provide light of one or more wavelengths to the optical assembly 130 via the core 120. The light source 231 is configured to provide light (via the core 120) to the optical assembly 130 such that image data can be collected, including cross-sectional, longitudinal, and / or volumetric information related to the patient site PS being imaged or the implanted device. The light source 231 may be configured to provide light such that the collected image data includes characteristics of tissue within the patient site PS being imaged, e.g., to provide information related to a patient disease or disorder present within the patient site PS being imaged, either quantitatively, qualitatively, or otherwise. The light source 231 may be configured to deliver broadband light and have a center wavelength in the range of 800 nm to 1700 nm. The bandwidth of the light source 231 may be selected to achieve a desired resolution, which may vary depending on the needs of the intended use of the system 10. In some embodiments, the bandwidth is about 5% to 15% of the center wavelength, which allows a resolution of 20 μm to 5 μm, respectively. The light source 231 may be configured to deliver light at a power level that reaches the ANSI Class 1 ("eye safe") limit, although higher power levels may be used. In some embodiments, the light source 231 delivers light at a power level of about 20 mW in the 1.3 μm band. As the center wavelength of the delivered light increases, tissue light scattering decreases, but water absorption also increases. The light source 231 may deliver light with a wavelength close to 1300 nm to balance these two effects. The light source 231 may be configured to deliver light of a shorter wavelength (e.g., light of about 800 nm) to pass through a patient site to be imaged that includes a large amount of fluid. Alternatively or additionally, the light source 231 may be configured to deliver light of a longer wavelength (e.g., light of about 1700 nm), e.g., to reduce high levels of scattering within the patient site to be imaged.

[0185] The imaging assembly 230 (or another component of the console 200) may include a fiber optic rotary joint (FORJ) configured to deliver light from a light source 231 to the core 120 and receive light from the core 120. In some embodiments, the core 120 includes a fiber having a first numerical aperture (NA), and the imaging assembly 230 may include an imaging assembly optical core having a second NA that is different from the first NA. For example, the first NA (the NA of the core 120) may include an NA of about 0.16, while the second NA (the NA of the optical core of the imaging assembly) may include an NA of about 0.11. In some embodiments, the system 10 includes an adapter 310 configured to optically couple the probe 100 to the imaging assembly 230 (e.g., a single-use or limited-use disposable adapter that is used for fewer procedures than the imaging assembly 230). The adapter 310 may include a lens assembly configured to "optically match" (e.g., to minimize coupling loss) different numerical apertures (e.g., the first NA and the second NA described above). In some embodiments, the adapter 310 includes a fiber having an NA that is the geometric mean of the two different NAs. In some embodiments, the adapter 310 includes a fiber having an NA that is the arithmetic mean of the two different NAs.

[0186] The rotation assembly 210 can be configured to rotate the core 120 (and subsequently one or more components of the optical assembly 130) at a rotational speed of about 250 rps or at rotational speeds between 40 rps and 1000 rps. The rotation assembly 210 can be configured to rotate the core 120 at a rate between 20 rps and 2500 rps. In some embodiments, the rotation assembly 210 can be configured to rotate the core 120 at a rate of up to 25,000 rps. In some embodiments, the rotational speed provided by the rotation assembly 210 is variable, e.g., the rotational speed varies based on a signal provided by a sensor of the system 10, e.g., one or more of the functional elements 53, 83, 93, 113, 123, 133, 203, and / or 303 include sensors, and the algorithm 240 is used to analyze one or more signals from one or more sensors. In some embodiments, the signal of the sensor represents the amount of light collected from tissue or other targets. In some embodiments, the system 10 is configured to change the rotational speed provided by the rotation assembly 210 when the signal of the sensor is related to a parameter selected from the following group: the tortuosity of the blood vessel in which the probe 100 is placed; the narrowing of the blood vessel in which the probe 100 is placed; the presence of a clot near the optical assembly 130; the presence of an implanted device near the optical assembly 130; and combinations thereof. In some embodiments, the rotational speed provided by the rotation assembly 210 is changed by an operator (e.g., a clinician) of the system 10. Alternatively or additionally, the system 10 can automatically or at least semi-automatically (referred to herein as "automatically") change the rotational speed provided by the rotation assembly 210, e.g., an automatic change in the rotational speed determined by one or more signals from one or more of the above sensors. In some embodiments, the rotation of the rotation assembly 210 is increased (manually or automatically) when the optical assembly 130 collects image data from the target area.

[0187] In some embodiments, the rotation assembly 210 is constructed and arranged to rotate the core 120 at one speed (e.g., at least 150 rps or about 250 rps) during the collection of image data (i.e., "imaging mode"), and to rotate the core 120 at a different rate (e.g., a slower rate, e.g., at a rate between 30 rps and 150 rps) during "preview mode". During preview mode, a "positioning operation" can be performed, where the optical assembly 130 is linearly positioned and / or a flushing process can be initiated. The positioning operation can be configured to visualize bright reflections (e.g., via one or more implants, such as implantable stents, deflectors, and / or coils). Alternatively or additionally, the preview mode can be configured to allow an operator (e.g., a clinician) to confirm that the optical assembly 130 has exited the distal end 59 of the surrounding delivery catheter 50. The preview mode can be configured to reduce the time and acceleration forces associated with rotating the core 120 at a certain speed (e.g., at least 150 rps or about 250 rps) to accommodate image data collection.

[0188] The retraction assembly 220 can be constructed and arranged to retract the optical assembly 130 (e.g., via the core 120 and / or the retraction shaft 100) at a retraction rate of approximately 40 mm / sec, e.g., a retraction rate of 3 mm / sec to 500 mm / sec (e.g., 5 mm / sec to 60 mm / sec, or approximately 50 mm / sec). The retraction assembly 220 can be constructed and arranged to perform a retraction of 20 mm to 150 mm (e.g., a retraction of approximately 50 mm or 75 mm), e.g., a retraction performed over a time period of 0.1 seconds to 15.0 seconds, e.g., a time period of 0.1 to 10 seconds, or approximately 4 seconds. In some embodiments, the retraction distance and / or retraction rate is operator-selectable and / or variable (e.g., manually or automatically). In some embodiments, the retraction distance and / or retraction rate provided by the retraction assembly 220 is variable, e.g., the retraction distance and / or retraction rate varies based on signals provided by sensors of the system 10, e.g., one or more of the functional elements 53, 83, 93, 113, 133, 203, and / or 303 include sensors, and an algorithm 240 is used to analyze one or more signals from one or more sensors. In some embodiments, the signals of the sensors represent the amount of light collected from tissue or other targets. In some embodiments, the system 10 is configured to change the retraction distance and / or retraction rate provided by the retraction assembly 220 when the signals of the sensors are related to a parameter selected from the group consisting of: the tortuosity of the blood vessel in which the probe 100 is placed; the narrowing of the blood vessel in which the probe 100 is placed; the presence of a clot near the optical assembly 130; the presence of an implanted device near the optical assembly 130; and combinations thereof. In some embodiments, the retraction distance and / or retraction rate provided by the retraction assembly 220 is changed by an operator (e.g., a clinician) of the system 10. Alternatively or additionally, the system 10 can automatically or at least semi-automatically (referred to herein as "automatically") change the retraction distance and / or retraction rate provided by the retraction assembly 210, e.g., an automatic change in the retraction distance and / or retraction rate determined by one or more signals from one or more of the above sensors. In some embodiments, the retraction distance and / or retraction rate of the retraction assembly 220 is changed (increased or decreased, manually or automatically) while the optical assembly 130 is collecting image data from the target area.

[0189] In some embodiments, the retraction assembly 220 and the probe 100 are configured such that during image data collection, the retraction assembly 220 retracts the core 120 without causing translation of the shaft 110 (e.g., the core 120 retracts within the lumen 112 of the shaft 110).

[0190] In some embodiments, the retraction assembly 220 and the probe 100 may be configured such that during image data collection, the retraction assembly 220 consistently retracts the core 120 and the shaft 110. In these embodiments, since the optical assembly 130 does not translate within the shaft 110, the shaft 110 may include a relatively short viewing window: a viewing portion 117 that surrounds the optical assembly 130. For example, in these embodiments, the length of the viewing portion 117 may be less than or equal to 20 mm, less than or equal to 15 mm, less than or equal to 6 mm, or less than or equal to 4 mm, such as when the length of the viewing portion 117 is approximately 3 mm. In some embodiments, the viewing portion 117 includes a length of 5 mm to 50 mm, such as a length of approximately 10 mm or approximately 12 mm. In embodiments where the optical assembly 130 does not translate within the shaft 110, the diameter (ID and / or OD) of the shaft 110 may be reduced at a location proximal to the viewing portion 117. For example, the OD of the shaft 110 (at least the portion of the shaft 110 that surrounds and is adjacent to the optical assembly) includes a diameter of less than or equal to 0.025″, 0.016″, or 0.014″. Alternatively or additionally, in these embodiments where the optical assembly 130 does not translate within the shaft 110, the portion of the shaft proximal to the optical assembly 130 (e.g., proximal to the viewing portion 117) may include an opaque construction, such as a braided construction or a construction using a material such as a metal tube (e.g., a nitinol or stainless steel hypotube), for example to improve the pushability of the probe 100.

[0191] The retraction assembly 220 may be configured to minimize the formation of air bubbles within any fluid (e.g., fluid 190) within the shaft 110, such as by consistently retracting the shaft 110 and the core 120, or by retracting the core 120 at an exact rate to avoid air bubble formation. When retracting the shaft 110, the proximal portion 111a may be configured to be located within the service loop. The retraction assembly 220 may include a translatable slider, and the rotation assembly 210 may be located on the translatable slider.

[0192] The retraction assembly 220 may include a telescoping retraction assembly. The retraction assembly 220 may include a motor, such as a single-use or multi-use disposable motor, for example the disposable motor is part of the telescoping retraction assembly.

[0193] In some embodiments, the rotation assembly 210 may be located at a position independent of the retraction assembly 220. In some embodiments, the retraction assembly 220 is configured to be located closer to the patient than the position where the rotation assembly 210 is located (e.g., the retraction assembly 220 is located within 20 cm of the vascular introducer or other patient introduction device into which the probe 100 is inserted). In some embodiments, the retraction assembly 220 is configured to be removably connected to the patient introduction device, such as to connect to a Tuohy connector of the vascular introducer into which the probe 100 is inserted, such as the delivery catheter 50 described herein.

[0194] In some embodiments, the retraction assembly 220 receives "power" from the console 200, for example, via a drive shaft 211 that may be operably connected to Figure 1 the rotary assembly 210 as shown.

[0195] The console 200 may include a display 250, such as a display configured to provide one or more images (e.g., videos) based on the collected image data. The imaging assembly 230 may be configured to provide images on the display 250 at an updated frame rate of up to about 250 frames per second (e.g., similar to the rotational rate of the core 120). The display 250 may provide 2-D and / or 3-D representations of 2-D and / or 3-D data.

[0196] The console 200 may include one or more functional elements, such as Figure 1 the functional element 203 as shown. Each functional element 203 may include one or more functional elements, such as one or more sensors, transducers, and / or other functional elements detailed below.

[0197] The console 200 may include algorithms, such as the illustrated algorithm 240, which may be configured to adjust (e.g., automatically and / or semi-automatically adjust) one or more operating parameters of the system 10, such as operating parameters of the console 200, the probe 100, and / or the delivery catheter 50. Alternatively and additionally, the algorithm 240 may be configured to adjust operating parameters of individual devices, such as the syringe 300 or the implant delivery device 80 described below. In some embodiments, the algorithm 240 is configured to adjust operating parameters based on one or more sensor signals, such as sensor signals provided by the sensor-based functional elements of the inventive concepts described herein (e.g., signals provided by one or more of the functional elements 53, 83, 93, 113, 123, 203, and / or 303). The algorithm 240 may be configured to adjust operating parameters selected from the group consisting of: rotational parameters, such as the rotational rate of the core 120 and / or the optical assembly 130; retraction parameters of the shaft 110 and / or the optical assembly 130, such as retraction rate, distance, start position, end position, and / or retraction initiation time (e.g., when to initiate retraction); position parameters, such as the position of the optical assembly 130; line spacing parameters, such as lines per frame; image display parameters, such as the ratio of display size to vessel diameter; probe 100 configuration parameters; injection 305 parameters, such as the ratio of saline to contrast agent, which is configured to determine a suitable refractive index; light source 231 parameters, such as the delivered power and / or the frequency of the delivered light; and combinations of one or more of them. In some embodiments, the algorithm 240 is configured to adjust retraction parameters, such as parameters that trigger the initiation of a pullback, such as a pullback initiated based on parameters selected from the group consisting of: lumen emptying; syringe 300 signal; change in the collected image data (e.g., change in the image associated with proper blood evacuation around the optical assembly 130 based on the collected image data); and combinations of one or more of them. In some embodiments, the algorithm 240 is configured to adjust probe 100 configuration parameters, such as the algorithm 240 identifies (e.g., automatically identifies via RF or other embedded ID) the connected probe 100 and adjusts parameters such as arm path length and / or other parameters listed above.

[0198] Syringe 300 may include a power syringe, syringe pump, peristaltic pump, or other fluid delivery device configured to inject a contrast agent, such as a radiopaque contrast agent, and / or other fluids. In some embodiments, syringe 300 is configured to deliver a contrast agent and / or other fluids (e.g., contrast agent, saline, and / or dextran). In some embodiments, syringe 300 delivers fluid during a flush procedure as described below. In some embodiments, syringe 300 delivers the contrast agent or other fluid through delivery catheter 50 having an ID of 5F to 9Fr, delivery catheter 50 having an ID of 0.53″ to 0.70″, or delivery catheter 50 having an ID of 0.0165″ to 0.027″. In some embodiments, the contrast agent or other fluid is delivered through a delivery catheter as small as 4Fr (e.g., for distal injection). In some embodiments, syringe 300 delivers the contrast agent and / or other fluid through the lumen of one or more delivery catheters 50 while one or more smaller delivery catheters 50 are also located within lumen 52. In some embodiments, syringe 300 is configured to deliver two different fluids simultaneously and / or sequentially, such as a first fluid delivered from a first reservoir and including a contrast agent at a first concentration, and a second fluid delivered from a second reservoir and including less or no contrast agent. Syringe 300 includes one or more functional elements, such as Figure 1 the functional element 303 shown. The functional element 303 may include one or more functional elements, such as one or more sensors, transducers, and / or other functional elements detailed below.

[0199] Implant 85 may include one or more implants for treating vascular occlusions or aneurysms (e.g., temporary or chronic implants). In some embodiments, implant 85 includes one or more implants selected from the group consisting of: flow diverters; Pipeline TM flow diverters; Surpass TM flow diverters; embolization coils; stents; Wingspan TM stents; covered stents; aneurysm treatment implants; and combinations of one or more thereof. Delivery device 80 may include a catheter or other tool for delivering implant 85, such as implant 85 including a self-expanding or balloon-expandable portion. The implant delivery device 80 may include functional elements, such as Figure 1The functional element 83 shown. The functional element 83 may include one or more functional elements, such as one or more sensors, transducers, and / or other functional elements detailed below. In some embodiments, the system 10 includes a probe 100, one or more implants 85, and / or one or more implant delivery devices 80, as described in the co-pending U.S. Provisional Application Serial No. 62 / 212,173, entitled "Imaging System Comprising an Imaging Probe and Delivery Device," filed on August 31, 2015; the content of which is incorporated herein by reference for all purposes. In some embodiments, the probe 100 is configured to collect data related to the implant 85 and / or the implant delivery device 80 (e.g., the anatomical location, orientation, and / or other configuration data of the implant 85 and / or the implant delivery device 80) after the implant 85 and / or the implant delivery device 80 have been inserted into a patient's body.

[0200] The treatment device 91 may include an occlusion treatment or other treatment devices selected from the group consisting of: a balloon catheter configured and arranged to dilate a stenosis or other narrowing of a blood vessel; a drug-eluting balloon; an aspiration catheter; an ultrasonic fragmentation device; an atherectomy device; a thrombus removal device, such as a stent retrieval device; Trevo TM Stent retriever; Solitaire TM Stent retriever; Revive TM Stent retriever; Eric TM Stent retriever; Lazarus TM Stent retriever; stent delivery catheter; microbraided implant; embolization system; WEB TM Embolization system; Luna TM Embolization system; Medina TM Embolization system; and combinations of one or more of them. In some embodiments, the treatment device 91 includes treatment devices selected from the group consisting of: a stent retriever; an embolization coil; an embolization coil delivery catheter; a stent; a covered stent; a stent delivery device; an aneurysm treatment implant; an aneurysm treatment implant delivery device; a flow diverter; a balloon catheter; and combinations of them. In some embodiments, the probe 100 is configured to collect data related to the treatment device 91 (e.g., the location, orientation, and / or other configuration data of the treatment device 91) after the treatment device 91 has been inserted into a patient's body. The treatment device 91 may include functional elements, such as Figure 1 The functional element 93 shown.

[0201] The second imaging device 92 may include one or more imaging devices such as selected from the group consisting of: X-ray; fluoroscope, such as a single-plane or bi-plane fluoroscope; CT scanner; MRI; PET scanner; ultrasonic imager; and combinations of one or more of them.

[0202] The functional elements 53, 83, 93, 113, 123, 133, 203, and / or 303 may each include one or more sensors, transducers, and / or other functional elements as detailed below.

[0203] In some embodiments, the functional element 113 is located near the optical assembly 130 (e.g., the functional element 113b is located Figure 1A distal to the optical assembly 130 as shown, at the same axial position as the optical assembly 130 and / or proximal to the optical assembly 130). In some embodiments, the imaging probe 100 includes Figure 1 the functional element 113a as shown. The functional element 113 is shown located proximal to the shaft 110, however it may be located at another position of the probe 100, such as on, in, and / or within the connector 102. The functional element 113a and / or 113b (individually or collectively referred to as the functional element 113) may each include one or more functional elements, such as one or more sensors, transducers, and / or other functional elements as detailed below.

[0204] In some embodiments, the functional elements 53, 83, 93, 113, 123, 133, 203, and / or 303 include sensors, such as sensors configured to provide signals related to parameters of the components of system 10 and / or sensors configured to provide signals related to patient parameters. The functional elements 53, 83, 93, 113, 123, 133, 203, and / or 303 may include one or more sensors selected from the group consisting of: physiological sensors; pressure sensors; strain gauges; position sensors; GPS sensors; accelerometers; 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 of one or more of them. In some embodiments, the functional elements 53, 83, 93, 113, 123, 133, 203, and / or 303 may include one or more physiological sensors selected from the group consisting of: pressure sensors, such as blood pressure sensors; blood gas sensors; flow sensors, such as blood flow sensors; temperature sensors, such as blood or other tissue temperature sensors; and combinations of one or more of them. In some embodiments, the algorithm 240 is configured to process the signals received by the sensors, such as the signals provided by the sensors described herein. In some embodiments, the functional elements 53, 83, 93, 113, 123, and / or 133 include position sensors configured to provide signals related to a vascular path (such as a vascular lumen path) in three dimensions. In some embodiments, the functional elements 53, 83, 93, 113, 123, and / or 133 include magnetic sensors configured to provide signals for positioning the optical assembly 130 relative to one or more implanted devices (such as one or more implants 85 including ferrous or other magnetic portions described herein). In some embodiments, the functional elements 53, 83, 93, 113, 123, and / or 133 include flow sensors, such as flow sensors configured to provide signals related to blood flowing through a blood vessel in the patient site PS (such as blood flowing through a stenosis or other local occlusive segment of a blood vessel). In these embodiments, the algorithm 240 may be configured to evaluate blood flow (such as evaluating the significance of an occlusion), such as to provide information to a clinician regarding potential treatments for the occlusion. In some embodiments, the optical assembly 130 includes the functional element 113 when the optical assembly 130 is constructed and arranged as a sensor configured to provide signals related to blood flow. In some embodiments, the functional elements 53, 83, 93, 113, 123, and / or 133 include flow sensors configured to provide signals for co-registering vascular anatomy data to flow data, which is used to provide pre- and post-intervention modeling of flow (such as aneurysm flow), assess the risk of an intervention, and / or otherwise evaluate the appropriateness of an intervention.In some embodiments, the functional elements 53, 83, 93, 113, 123, and / or 133 include an ultrasonic sensor configured to provide a signal (e.g., an image or frequency data) that can be co-registered with the information derived from near-field optics provided by the optical assembly 130. In some embodiments, the functional elements 53, 83, 93, and / or 113 are configured to be deployed by their associated devices, e.g., to implant the functional elements (e.g., sensor-based functional elements) into a patient. The implantable functional elements 53, 83, 93, and / or 113 may include microchips and / or MEMS components. The implantable functional elements 53, 83, 93, and / or 113 may include at least a portion configured to be visualized (e.g., image data collected by the probe 100 and / or a separate imaging device such as the second imaging device 92).

[0205] In some embodiments, the functional elements 53, 83, 93, 113, 123, 133, 203, and / or 303 include one or more transducers selected from the group consisting of: heating elements, e.g., heating elements configured to deliver sufficient heat to ablate tissue; cooling elements, e.g., cooling elements configured to deliver cryogenic energy to ablate tissue; acoustic transducers, e.g., ultrasonic transducers; vibration transducers; and combinations of one or more of them.

[0206] In some embodiments, the functional elements 53, 83, 93, and / or 113 include a pressure relief valve configured to prevent excessive pressure buildup in the associated device. In some embodiments, the functional elements 53, 83, 93, and / or 113 include one or more side holes, e.g., one or more side holes for delivering fluid during the flushing process described herein.

[0207] In some embodiments, the functional elements 53, 83, 93, 113, 123, 133, 203, and / or 303 include visualization markers, such as when the functional elements 53, 83, 93, and / or 113 include markers selected from the group consisting of: radiation-impermeable markers; ultrasonic reflection markers; magnetic markers; ferromagnetic materials; and combinations of one or more of them.

[0208] The probe 100 is configured to collect image data, e.g., image data collected during rotation and / or retraction of the optical assembly 130. The optical assembly 130 can be rotated by the rotating core 120. The optical assembly 130 can be retracted by the retraction shaft 110. The optical assembly 130 can collect image data when a portion of the shaft of the delivery catheter 50 is around it (e.g., within the transparent section 57 of the delivery catheter) and / or when no section of the catheter 50 is around the optical assembly 130 (e.g., when the optical assembly 130 has advanced beyond the distal end 59 of all delivery catheters 50 into which the probe 100 is inserted).

[0209] During collection of image data, a flushing process may be performed, for example, by delivering one or more fluids: an injectate 305 (e.g., propelled by a syringe 300 or other fluid delivery device), to remove blood or other somewhat opaque materials (hereinafter referred to as non-transparent materials) near the optical assembly 130 (e.g., to remove non-transparent materials between the optical assembly 130 and the delivery catheter and / or between the optical assembly 130 and the vessel wall), e.g., to allow light distributed from the optical assembly 130 to reach all tissues and other objects to be imaged and to be reflected back from all tissues and other objects to be imaged. In these flushing embodiments, the injectate 305 may include an optically translucent material, such as saline. The injectate 305 may include one or more visualization materials, as described below. The injectate 305 may be delivered by the syringe 300 described below.

[0210] The flushing rate required to provide clearance around the optical assembly 130 may be inversely proportional to the viscosity of the flushing medium. This mathematical relationship may be driven by the downstream drainage of the flushing medium in the capillary bed. If the capillary bed drains slowly, it is easier to maintain the upstream flushing at or slightly above the pressure of natural blood pressure, such that fresh blood does not enter the vessel being imaged (e.g., the location near the optical assembly 130). Conversely, if the capillary bed drains quickly, the flushing rate needs to be increased accordingly. Since the viscosity of saline (a standard flushing medium) is about 1 / 3 of the viscosity of blood (e.g., 1 Cp vs 3.3 Cp), approximately three times the normal flow rate will be required to clear the vessel (in the area near the optical assembly 130), and such a flow rate may pose a risk to the integrity of the vessel. As an alternative, a contrast agent medium (e.g., a radiopaque contrast agent medium) may be used for flushing. The contrast agent material has a high viscosity (due to its high iodine concentration, typically at a concentration of about 300 mg / ml). The system 10 may include a flushing fluid including a contrast agent, such as a contrast agent having an iodine concentration of 50 mg / ml to 500 mg / ml (e.g., associated with a viscosity of about 2 to 5 times that of blood viscosity). The system 10 may include a flushing fluid (e.g., a radiopaque or other visualization flushing fluid) having a viscosity of 1.0 Cp to 20 Cp (e.g., at a temperature of about 37°C).

[0211] Alternative or in addition to its use in the flushing process, the injectate 305 may include materials configured to be observed by a second imaging device 92, e.g., the injectate 305 includes a contrast agent material configured to be observed by a second imaging device 92 including a fluoroscope or other X-ray device; an ultrasound reflective material configured to be observed by a second imaging device 92 including an ultrasound imager; and / or a magnetic material configured to be observed by a second imaging device 92 including an MRI.

[0212] The injectate 305 may be delivered by one or more delivery catheters 50 (e.g., in the space between a first delivery catheter 50 and an inserted delivery catheter 50, or in the space between a delivery catheter 50 and an inserted probe 100). The injectate 305 delivered during the flushing process (or other injectate 305 delivery process) may be delivered out of the distal end 59 of the delivery catheter 50 (e.g., the distal end 59 proximal to the optical assembly 130), as described in co-pending U.S. Provisional Application Serial No. 62 / 212,173, entitled "Imaging System Comprising an Imaging Probe and a Delivery Device," filed on August 31, 2015, the content of which is hereby incorporated by reference herein for all purposes. Alternatively or additionally, any delivery catheter 50 may include one or more side holes passing through a portion of the associated shaft 51, such as the side hole 58 shown in the distal portion of the delivery catheter 50c. In some embodiments, the delivery catheter 50 comprises a microcatheter, which includes a side hole 58 in the distal portion, such as a microcatheter having an ID less than 0.027″ (e.g., a microcatheter having an ID of 0.016″ to 0.027″ or an ID of 0.021″ to 0.027″). In some embodiments, the flushing fluid is delivered to the optical assembly 130 from both the side hole 58 and the distal end 59 of the delivery catheter 50. The side hole 58 may be configured and arranged to allow the flushing fluid to pass through the side hole 58 from within the shaft 51, such as when a separate shaft is inserted into the delivery catheter 50 (e.g., the shaft 51 of an additional delivery catheter 50 or the shaft 110 of the probe 100). Delivery of the flushing fluid through the side hole 58 and / or the distal end of the delivery catheter 50 may be performed to clear blood from the region surrounding the cavity section of the optical assembly 130, such as during image data collection.

[0213] In some embodiments, the injectate 305 is delivered during the flushing process based on parameters selected from the following group: a predetermined volume of the injectate to be delivered; a predetermined time for delivering the injectate; a time of delivery, including a time extending before retraction of the shaft 110, which continues until image data has been collected (e.g., completion of retraction of the shaft 110); and combinations of one or more thereof. In some embodiments, the syringe 300 delivers a fluid during the flushing process having a substantially flow profile selected from the following group: contrast agent (e.g., 20% to 100% contrast agent may be mixed with saline) flowing at 5 ml / second for 6 seconds (e.g., for imaging the carotid artery, including 4 seconds for collecting image data); contrast agent (e.g., 20% to 100% contrast agent may be mixed with saline) flowing at 4 ml / second for 6 seconds (e.g., for imaging the vertebral artery, including 4 seconds for collecting image data); and combinations of one or more thereof. In some embodiments, the flushing process includes delivery of the injectate 305 for 2 seconds to 8 seconds (e.g., via one or more delivery catheters 50), such as delivery of the injectate for about 4 seconds (e.g., to clear blood or other non-transparent fluid from the lumen segment or other regions of the blood vessel surrounding the optical assembly 130 during collection of image data from the patient site PS). In a similar flushing process, the injectate 305 may be delivered at a rate of 3 ml / second to 9 ml / second (e.g., at 6 ml / sec via one or more delivery catheters 50) to clear non-transparent material.

[0214] During these flushing processes, the injectate 305 may include a translucent fluid selected from the following group: saline; contrast agent; dextran; and combinations of one or more thereof. In some embodiments, the volume of the injectate 305 delivered during the flushing process and / or the time for delivering the injectate 305 is determined by parameters selected from the following group: the type of procedure performed; the diameter of the blood vessel in which the optical assembly 130 is located; the length of retraction; the duration of retraction; and combinations of one or more thereof. In some embodiments, the injectate 305 is delivered during the flushing process by a delivery catheter having an ID greater than 0.027″ (e.g., a first delivery catheter 50 whose distal end 59 is more proximal than a second delivery catheter 50 inserted into the first delivery catheter 50). In some embodiments, the injectate 305 is delivered into a plurality of delivery catheters 50 through associated lumens 52 (e.g., in the space between two or more pairs of delivery catheters 50 arranged to slidably receive one another in a sequential manner).

[0215] In some embodiments, the injectate includes a first fluid (e.g., a fluid including saline and / or a fluid excluding or including minimal contrast agent) delivered during a first portion of the flushing process, and a second fluid including a contrast agent (e.g., a second fluid including saline and a contrast agent), e.g., to limit the amount of contrast agent delivered to the patient during the flushing process. In these embodiments, syringe 300 may include two reservoirs (as described above), e.g., a first reservoir for supplying the first fluid and a second reservoir for supplying the second fluid. When consisting of two reservoirs, syringe 300 may be configured to deliver the fluids in each reservoir at different rates, e.g., to achieve different pressures and / or provide flushing through different catheters having different IDs.

[0216] As described herein, the optical assembly 130 may be rotated (e.g., by rotation of the core 120) and retracted (e.g., by retracting the shaft 110 by the retraction assembly 220) during collection of image data such that the rotation is combined with the retraction to produce a 3D image of the patient site PS. In some embodiments, the optical assembly 130 is rotated at a speed of 40 rps to 1000 rps, e.g., at a rate of about 250 rps. In some embodiments, the optical assembly 130 rotates at a first rate during the imaging mode and at a second rate during the preview mode (the imaging mode and the preview mode are each as described above). In some embodiments, the optical assembly 130 retracts a distance of 1 cm to 15 cm, e.g., a retraction of about 4 cm. In some embodiments, the optical assembly 130 retracts at a rate of 1 mm / sec to 60 mm / sec. In some embodiments, the retraction of the optical assembly 130 includes a retraction of retracting about 7.5 cm in 4 seconds and / or a retraction rate of about 20 mm / sec. In some embodiments, the retraction of the optical assembly 130 includes an axial resolution of 5 μm to 20 μm and / or a longitudinal resolution of 20 μm to 100 μm. The longitudinal resolution is controlled by two factors: the spot size (beam cross-section) at the surface of the tissue being imaged and the spacing between successive rotations of the optical assembly 130 during retraction. For a rotation rate of 100 rps and a pull-back rate of 22 mm / sec, this results in a pitch of 200 μm between rotations. In these configurations, a spot size of 20 μm to 40 μm results in collection of image data that under-samples the object being imaged. System 10 may be configured to more closely match the spot size to the pitch, e.g., by correlating the spot size to the rotation rate and / or the pull-back rate.

[0217] In some embodiments, the imaging system 10 is constructed, arranged, and operative to produce images as described in U.S. Provisional Application Serial No. 62 / 212,173, jointly pending by the applicant, titled "Imaging System Comprising an Imaging Probe and Delivery Device," filed on August 31, 2015; the content of which is hereby incorporated by reference herein for all purposes.

[0218] In some embodiments, system 10 is configured to assist in the selection, placement, and / or use of a treatment device 91. The treatment device 91 may include a stent retriever configured to remove a thrombus or other occlusive material from a patient. For example, an imaging probe 100 images the site and / or the treatment device 91 to generate anatomical information (e.g., for selecting the size or other geometry of the stent retriever), visualizes the stent retriever at the occluded site (e.g., to position the treatment device 91), and / or visualizes occlusive material (e.g., thrombus) that is engaged with and / or not removed by the treatment device 91. In some embodiments, system 10 is configured to quantify the thrombus volume, such as the thrombus removed by the treatment device 91. The thrombus visualized by system 10 includes thrombi selected from the group consisting of: residual thrombi from an acute stroke; thrombi remaining after a thrombus removal procedure; thrombi present after implantation of a flow diverter; and combinations thereof.

[0219] In some embodiments, system 10 is configured to provide anatomical information for selecting an implantation site and / or to select a specific implantable device to be implanted in a patient, such as implant 85 of system 10 described above. System 10 may be configured to image at least one perforating artery of a patient, such as to image one, two, or more perforating arteries having a diameter of at least 50 μm. Implant 85 may be implanted in a patient via an implant delivery device 80, such as when implant 85 includes a stent and / or a flow diverter. System 10 may be configured to perform functions selected from the group consisting of: detecting and / or quantifying attachment of implant 85 (such as stent or flow diverter misalignment); providing quantitative and / or qualitative information regarding the size and / or location of implant 85 to be implanted in a patient, such as information related to perforator location; perforator geometry, neck size, and / or flow diverter mesh density; and combinations of one or more thereof. System 10 may be configured to provide information related to implant 85 parameters selected from the group consisting of: porosity; length; diameter; and combinations thereof. System 10 may be configured to provide porosity information of implant 85, which includes the porosity of one or more portions of implant 85, such as a portion located near a side branch of the blood vessel in which implant 85 is implanted. System 10 may be configured to provide porosity information based on the wire diameter of implant 85. System 10 may be configured to provide information related to a second implant 85 to be implanted in a patient (such as implantation site or device information). In these embodiments using two implant devices 85, the first implant device and the second implant device may include similar or different devices (such as a stent and a flow diverter, two stents, or two flow diverters). System 10 may be configured to collect image data during deployment of one or more implants 85. System 10 may be configured to collect image data for modifying an implant device (such as during and / or after implantation), such as to modify the porosity of implant 85 (such as via a treatment device 91 including a balloon catheter for adjusting the porosity of a partially implanted or fully implanted implant 85).

[0220] For decades, dedicated catheters have been used to image conventionally inaccessible body regions such as coronary arteries, neurovascular arteries, the endocrine system, pulmonary airways, etc. Even so, products for these applications are still widely developed because technological advancements allow for higher resolution, new modalities (such as spatially resolved spectroscopy), and lower-cost probes. The limitations and other issues of current catheters are described below. Since imaging catheters with reduced diameters generally prevent the use of conventional optics or so-called coherent fiber bundles, such imaging catheters typically utilize the high-speed rotation of distally positioned optics to form cross-sectional views of body cavities. The rotating optics do not produce a conventional "snapshot" of multiple pixels, but rather build up an image by scanning a single imaging point, one or two pixels at a time, similar to the raster scan employed by older CRTs. This rotation can be combined with longitudinal movement ("pullback") to produce a helical scan of an artery or lumen, which can be presented as a 3D image. Most currently available imaging catheters have distally positioned imaging elements that are optically or electrically connected to the proximal end. The imaging elements are connected to a mechanical transmission that provides rotation and pullback. Recently, advancements in micromotor technology can replace the mechanical transmission for distally positioned actuation, but still require pullback. However, these motors are expensive and relatively large (existing designs do not allow for the construction of probes with an OD below 1 mm).

[0221] "Torque shafts" are commercially available, which are small wire-wound tubes for transmitting torque along a long and flexible shaft. These devices are now commonly used in intravascular ultrasound (IVUS) procedures as well as OCT procedures. Imaging probes combined with torque shafts perform rotational scans, for example, in the coronary arteries. However, typically the OD of these devices is about 0.8 to 1.3 mm (2.4 Fr to ~4 Fr) and are thus 2 to 4 times larger than the devices required for nerve applications. Currently, these torque wires cannot be scaled down to the dimensions required for the construction of a scanning imaging catheter with an OD less than 0.7 mm.

[0222] Since optical imaging in arteries requires clearing the obscuring blood, typically with a flushing fluid, the diameter of the imaging catheter is very important in smaller or occluded vessels (e.g., because of the use of a smaller guide). Since it is often the diseased or occluded vessels that need to be imaged for diagnosis and treatment, the imaging probe 100 can be designed to have a smaller diameter (e.g., an OD less than or equal to 0.025″, 0.016″, or 0.014″).

[0223] As previously disclosed (U.S. Patent 6,891,984 to Peterson et al. ['984 patent]; U.S. Patent 6,165,127 to Crowley ['127 patent], the contents of which are incorporated herein by reference for all purposes), a viscous fluid is provided for the distal region of the imaging catheter to prevent torsion.

[0224] Achieving uniform rotational scanning at the distal tip of a single fiber imaging catheter while maintaining an outer diameter (OD) of the entire device less than 500 μm is a significant challenge. Since it is currently not feasible to add a motor on the distal tip with a size of OD less than 1 mm (see Tsung-Han Tsai, Benjamin Potsaid, Yuankai K. Tao, Vijaysekhar Jayaraman, James Jiang, Peter J. S. Heim, Martin F. Kraus, Chao Zhou, Joachim Hornegger, Hiroshi Mashimo, Alex E. Cable, and James G. Fujimoto; "Ultrahigh-Speed Endoscopic Optical Coherence Tomography Using a Micro-Motorized Imaging Catheter and VCSEL Technology", Biomed Opt Express. July 1, 2013; 4(7):1119-1132) plus the accompanying line and size issues, a method must be found to apply torque to the proximal end and transmit the torque to the distal tip (which can be up to 3 meters apart in some clinical applications) while maintaining a uniform rotational speed. A uniform speed is extremely important for image fidelity because non-uniform rotation can lead to image smear and severe distortion (see Figure 3 ). Considering the extremely low inherent rotational stiffness of the glass fiber, the problem of uniformly rotating the distal tip by driving the proximal end can be understood. Uniform rotation is critically important in endoscopic techniques to obtain accurate circumferential images. The term "NURD" (Non-Uniform Rotational Deformation) has been coined in the industry to describe these detrimental effects.

[0225] Figure 3 An example of distortion caused by Non-Uniform Rotational Deformation (NURD) is shown. The solid curve is a simulated perfect circular artery with a diameter of 4 mm. The curve with square data points is an image of the same arterial wall with NURD. In this case, the catheter rotation was slowed down by 50% on a small part of the cycle and sped up by 50% on another part, such that the average distal rotational speed matched the proximal rotational speed (as it must, otherwise rapidly accumulating torsion would cause the core 120 to break). It can be seen that this NURD can lead to significant measurement errors. The imaging probe 100 and other components of the system 10 are configured to reduce these types of distortions.

[0226] The '127 patent discloses the use of a viscous fluid located within the lumen of an ultrasound catheter. The purpose of the fluid is to provide a load on the torque line such that the line enters a state of high torsional stiffness at a moderate rotational speed. As described in the '127 patent, the fluid is contained within a separate lumen formed within the main catheter, increasing the overall size of the device. The fluid does not contact the imaging tip, and ultrasonic energy does not propagate through the fluid. The method also requires the use of a torque line, limiting the achievable reduction in the desired size. In the imaging probe of the present inventive concept, one or more viscous fluids (e.g., one or more fluids 190) can be provided to deliberately cause torsion (i.e., winding) of the core 120. The torsion can include dynamic torsion that varies with the total (i.e., end-to-end) frictional load (torque) of the probe 100, resulting in a relatively constant rotational rate. The probe 100 can be configured such that the amount of torsion during retraction of one or more portions of the probe 100 (e.g., retraction of the core 120 and / or retraction of the core 120 and the shaft 110) varies.

[0227] The '984 patent utilizes a viscous fluid having a high refractive index to simultaneously reduce the refractive effect at the boundary of the bending sheath and to provide a viscous load to allow the optical fiber to become a torque transmitter. This configuration allows for a certain reduction in size. However, the '984 patent fails to describe or disclose a mechanism for confining the fluid at the distal tip within geometric constraints; the inevitable migration of the fluid during transportation and storage will result in an inevitable loss of performance. Similarly, the '984 patent fails to address the problems that can be caused during retraction of the internal fiber that results in the formation of voids within the viscous fluid, where these voids cause a large optical effect (so-called "bubble-artifacts" see, e.g., "Expert Review of Methods, Terminology, and Clinical Applications of Optical Coherence Tomography: Physical Principles, Methods of Image Acquisition, and Clinical Applications for the Assessment of Coronary Arteries and Atherosclerosis", Francisco Prati et al., European Heart Journal, November 4, 2009). In some embodiments, the probe 100 is configured to rotate the core 120 in a single direction (i.e., unidirectionally) during use. In some embodiments, the probe 100 includes a torque shaft within the shaft 110 that frictionally engages the core 120, such as the torque shaft 110b described below. The torque shaft 110b can extend from the proximal end of the probe 100 to a position proximal to the optical assembly 130, such as a torque shaft having a distal end that is at least 5 cm from the optical assembly 130, or a torque shaft having a distal end that is proximal to the most proximal position of the shaft 110 within the patient.

[0228] The liquid, gel, or other fluid-filled (e.g., and sealed) imaging probe 100 has the advantage of not requiring purging (e.g., removing air bubbles). The fluid 190a or 190b can be configured as a lubricating oil to reduce the friction between the core 120 and the shaft 110. In embodiments where the core 120 is relatively pulled back into the shaft 110 to obtain an image, a void is formed at the end of the core 120 that can be filled with a liquid, gel, or other fluid (e.g., fluid 190).

[0229] Since the fluid must be provided from the proximal end of the shaft 110 and travel the length of the core 120, it is difficult to "fill" the fluid into this area. Bubbles may form here due to the low pressure that can be generated. In embodiments of the present inventive concept, the entire imaging probe 100 is pulled back during image data collection (i.e., the core 120 and the shaft 110 retract together without relative axial movement between the two), rather than the core 120 retracting within the shaft 110. Since the shaft 110 moves with the core 120, the presence of the low-pressure region at the end of the imaging core is eliminated or at least reduced.

[0230] As Figure 4 shown, since relative movement between the optical component 130 and the shaft 110 is avoided, this "mutual" movement of the shaft 110 and the core 120 allows the shaft 110 to have a larger diameter around the optical component 130. A larger-diameter optical component 130 (e.g., a lens with a larger diameter of the optical component 130) provides more light collection, which can be associated with a brighter image. This configuration can also provide a lens of the optical component 130 that has a focal length away from the OD (e.g., outer surface) of the shaft 110 around the optical component 130, improving the distal image quality. Alternatively and additionally, as also Figure 4 shown, the optical component 130 can include an OD that is larger than the ID of at least a portion of the shaft 110 proximal to the optical component 130. In these embodiments, the optical component 130 and the shaft 110 can be retracted simultaneously during image data collection from the target area.

[0231] In some embodiments, the wall of shaft 110 is relatively thick over most of its length, as compared to the thinner wall of shaft 110 at its distal portion (e.g., the portion of shaft 110 adjacent to optical assembly 130 is thinner). Such a configuration allows for improved longitudinal and torsional control for positioning imaging probe 100. In some embodiments, shaft 110 may include a reinforcing portion surrounding optical assembly 130, such as a reinforcing section of shaft 110 including: a different (stiffer) wall material; a braided shaft portion; and / or a reinforcing element (e.g., a wire embedded in the wall of shaft 110). The reinforced distal portion of shaft 110 may be associated with the thinner wall, which in turn is associated with optical assembly 130 including larger optical components (e.g., one or more larger diameter lenses), such as without increasing the OD of shaft 110 around optical assembly 130. In some embodiments, shaft 110 has mechanical properties that vary along its length (e.g., a reinforcing proximal section for "pushing ability") and a stiffness that gradually decreases distally (e.g., to improve delivery ability and safety in advancing into tortuous sites).

[0232] Similarly as Figure 4 shown, optical assembly 130 may include lens 131 and a reflective element 132 (e.g., to "steer" light). Reflective element 132 is configured such that optical assembly 130 is asymmetric. In some cases, when optical assembly 130 rotates at high speed, the presence of a viscous liquid or other viscous fluid in the optical path around optical assembly 130 can cause cavitation in the region behind reflector 132. As Figure 5 shown, in some embodiments, probe 100 includes a first fluid, fluid 190a surrounding core 120, and a second, different fluid surrounding optical assembly 130: fluid 190b, such that fluid 190a can be configured to provide a first function (e.g., preventing or at least reducing undesired rotational variations of core 120), while fluid 190b provides a second function (e.g., preventing or at least cavitation around optical assembly 130). In some embodiments, the viscosity of fluid 190b may be selected to be a relatively low viscosity, e.g., to minimize cavitation, while the viscosity of fluid 190a may be selected to be relatively high (e.g., at least more viscous than fluid 190b) to optimize the uniformity of rotational speed.

[0233] In nerve placement, the imaging probe 100 is typically placed in the femoral vessels of a patient. Starting from the carotid artery of the aorta, there is significant tortuosity in the vasculature near the nerve imaging region. In some embodiments, using a highly viscous fluid 190a in the middle portion and / or proximal portion of the imaging probe 100 allows the fluid 190a to provide an additional function of lubricating the rotating core 120 in the shaft 110 (e.g., lubrication facilitates placement of the imaging probe 100 in the highly tortuous region). The resulting reduced friction reduces the stress on the core 120 and allows for smoother movement at any discontinuities in the shaft 110 or core 120. The fluid 190 can be configured to provide sufficient lubrication or other favorable parameters to eliminate or at least reduce (as used herein "reduce") the adverse effects when the probe 100 is located in a tortuous site (e.g., when the distal portion 119a is near and distal to the carotid artery). In these embodiments, the fluid 190 can include a highly viscous fluid.

[0234] Additionally, the presence of the highly viscous fluid 190a helps to retain the lower viscosity fluid 190b in the distal end of the shaft 110 prior to use, as the higher viscosity fluid 190a in the shaft 110 acts as a barrier and reduces the likelihood of the fluid 190b migrating from the imaging region around the optical component 130 prior to use (e.g., during sterilization and shipping of the imaging probe 100). In some embodiments, a sealing element such as the sealing element 116 is located between two or more different fluids 190. Alternatively, a separating element may not be present, e.g., one or more of the fluids 190 includes a gel configured not to mix with the adjacent fluid 190.

[0235] In some embodiments, the imaging probe 100 includes an inertial assembly that includes an impeller, a thruster, or other inertia-based element configured to reduce undesired variations in the rotational speed of the optical component 130, as Figure 6 shown. The imaging probe 100 includes an impeller 182 connected to the core 120. The drag on the impeller 182 "winds up" the core 120 and reduces unintentional or other undesired variations in the rotational speed of the fiber. The impeller 182 is used to rotate the fluid 190 between the shaft 110 and the optical component 130. The blades of the impeller 182 form a drag that remains uniform during rotation due to its symmetry about its axis of rotation. In some embodiments, the radially extending ends of the impeller 182 intentionally contact the inner wall of the shaft 110 to optionally or increasingly provide drag. The impeller 182 can include one or more protrusions from the core 120, such as protrusions that frictionally engage the shaft 110 and / or otherwise cause shear forces that impose a load on the core 120 during rotation. The impeller 182 can include one or more protrusions from the shaft 110, such as protrusions that frictionally engage the core 120 and / or otherwise cause shear forces that impose a load on the core 120 during rotation.

[0236] The impeller 182 can be configured to cause a winding load on the core 120. The impeller 182 can be configured to frictionally engage the fluid 190 and / or the shaft 110 during rotation of the core 120. The impeller 182 can include components selected from the group consisting of: turbines; vane-type microstructures; flywheels; and combinations of one or more thereof.

[0237] Liquids, gels, or other fluids located within the shaft 110 can have a tendency to form bubbles. If these bubbles are in the optical path, they will reduce light transmission. In some embodiments, the fluid 190a and / or the fluid 190b (individually or collectively referred to as the fluid 190) can be pressurized (e.g., to a pressure of 100 psi or greater) to prevent or at least reduce the size of any bubbles in the shaft 110, as described herein with reference to Figure 7 that.

[0238] Small tire inflators are typically used to inflate bicycle tires. They can be less than 1 inch in size and are suitable for this application. These and similarly configured inflators can provide pressures up to and exceeding 100 psi, which, when applied to the fluid 190, can significantly reduce the size of the bubbles. Assuming a bubble size of 0.1 μL at atmospheric pressure, the bubble size at 100 psi can be calculated as:

[0239] V p = V a P a / P p

[0240] Where:

[0241] V p = Bubble volume at pressure

[0242] V a = Bubble volume at atmospheric pressure (e.g., 0.1 μL)

[0243] P a = Atmospheric pressure (14.7 PSI)

[0244] P p = Pressure of the pressurizing device (e.g., 100 psi)

[0245] Under pressure, the bubble volume is reduced from 0.1 μL to 0.0147 μL. The corresponding bubble diameter is reduced from 0.022″ to 0.011″, which will mitigate or eliminate the harmful effects on the light beam.

[0246] Figure 7 is a cross-sectional view of an imaging probe including a pressurization system, in accordance with the concepts of the present invention. The imaging probe 100 includes a shaft 110 having a proximal end 111, a lumen 112, a core 120, and an optical connector 102, each of which can have a similar configuration to that described herein with reference to Figure 1The construction and arrangement described. The imaging probe 100 may include a pressurization assembly 183 (such as a pressurized gas tank), which may be fluidly connected to the lumen 112 through a valve 184 (such as a one-way check valve). In some embodiments, each imaging probe 100 has a pressurization assembly 183. Alternatively, a single pressurization assembly 183 may be reused (such as having been used on an imaging probe 100 in multiple clinical procedures). In some embodiments, the pressurization assembly 183 may be pre-connected to the shaft 110 or may be separate and connectable. In some embodiments, the pressurization assembly 183 may be operably connected and / or activated prior to the clinical use of the imaging probe 100, such as to pressurize the fluid within the lumen 112 or other internal locations of the imaging probe 100, such as to reduce the size of one or more air bubbles in a fluid such as the fluid 190 described herein.

[0247] In some embodiments, at a location near the proximal end 111 of the shaft 110, a sealing element 151 (such as a compressible O-ring) is located between the core 120 and the shaft 110. The shaft 110 and the sealing element 151 may be constructed and arranged to maintain relative sealing when the lumen 112 is pressurized (such as as described above), while allowing the core 120 to rotate within the shaft 110 and the sealing element 151. The sealing element 151 may provide a seal during rotation of the core 120 within the shaft 110. As described herein, retracting both the shaft 110 and the core 120 simultaneously during imaging simplifies the design of the sealing element 151. In some alternative embodiments, the core 120 retracts within the shaft 110, and the sealing element 151 is configured to maintain a seal during this retraction.

[0248] In some embodiments, at least a portion of the shaft 110 is configured to radially expand when the fluid 190 is pressurized, such as Figure 15A as shown in FIGS. C. The pressurization assembly 183 is connected to the connector 102 such that the fluid 190 can be introduced into and / or pressurized within and / or in the shaft 110. In Figure 15A FIG., the proximal portion 111a of the shaft 110 is expanded (such as the lumen 112 is expanded in the region of the proximal portion 111a). In Figure 15B FIG., the proximal portion 111a and the intermediate portion 115 of the shaft 110 are expanded. In Figure 15C FIG., the proximal portion 111a, the intermediate portion 115, and the distal portion 119a are expanded. In these embodiments, the system 10 may be configured such that the shaft 110 is as in Figure 15CThe fully extended and rotated core 120 is shown. The extension of the shaft 110 can create and / or increase the space between the core 120 and the inner wall of the shaft 110. In some embodiments, the shaft 110 maintains at least partial extension (e.g., the shaft 110 has been plastically deformed) when the pressure of the fluid 190 is reduced (e.g., reduced to atmospheric pressure). The shaft 110 can be configured to expand to a first diameter (ID and / or OD) when the fluid 190 is pressurized to a first pressure and to expand to a second, larger diameter when the fluid 190 is pressurized to a second, higher pressure. In some embodiments, the shaft 110 is configured to become stiffer when the pressure of the fluid 190 increases.

[0249] The imaging probe 100 and the non-disposable components of the system 10 can have two connectors (e.g., a disposable catheter). One is connected to the shaft 110 (non-rotating shaft) and the other is connected to the core 120. The connectors of the imaging probe 100 to the console 200 can include two functional connectors. One connector includes the connection of the shaft 110 to a retraction assembly, such as the retraction assembly 220 described herein, such that the shaft 110 (and the optical assembly 130) can be retracted during the collection of image data. The other connector includes connecting the core 120 to a rotation assembly, such as the rotation assembly 210, such that the core 120 can be rotated during the collection of image data. The two connectors can be retracted together during the collection of image data. The connector of the core 120 creates an optical connection between the core 120 and the imaging assembly (e.g., the imaging assembly 230 described herein) and can provide power to the rotating core 120 (e.g., the connector of the rotation assembly 210).

[0250] The imaging system and associated imaging probe of the present inventive concept provide enhanced compatibility with conventional treatment catheters, such as those used in neurosurgery as described herein.

[0251] Stent retriever devices (also referred to as "stent retrievers") are used for endovascular recanalization. Although the success rate of revascularization is high, multiple passes of the stent retriever device are often required to completely remove the clot, increasing the number of procedures and the likelihood of complications. Adding imaging to stent retrieval procedures has the potential to reduce procedure time and complications. In Figures 8 to 11In this case, system 10 includes an imaging probe 100 and a treatment device: treatment device 91. Although treatment device 91 is shown as a stent retriever, other treatment devices are also applicable, such as treatment devices 91 selected from the group consisting of: stent retrievers; embolization coils; embolization coil delivery catheters; stents; covered stents; stent delivery devices; aneurysm treatment implants; aneurysm treatment implant delivery devices; flow diverters; balloon catheters; and combinations thereof. Imaging probe 100 and treatment device 91 have been placed in a blood vessel, such as a blood vessel in the neck or head. Imaging probe 100 and treatment device 91 can be inserted into a single catheter, such as the delivery catheter 50d shown.

[0252] The positioning of the optical assembly 130 and the resulting images ensure the correct placement of the treatment device 91 (e.g., the positioning of the stent retriever distal to the thrombus) and also ensure that the treatment is successfully completed (e.g., sufficient thrombus has been removed), reducing both the number of procedures and improving clinical outcomes.

[0253] In some embodiments, system 10 includes a delivery catheter 50a (not shown, but e.g., a 6 to 8Fr guiding catheter) that can be placed in a target blood vessel (e.g., an artery), such as by using transfemoral access. In some embodiments, delivery catheter 50a includes a standard balloon guiding catheter, e.g., to prevent distal thrombus migration and enhance aspiration during thrombus removal. System 10 may also include a delivery catheter 50b (not shown, but e.g., a flexible 5 to 6Fr catheter) that serves as an intermediate catheter and is advanced through delivery catheter 50a to obtain distal access near the occluded portion of the blood vessel. System 10 may include the third delivery catheter 50c shown, e.g., a 0.021″ to 0.027″ microcatheter, which is used to cross the thrombus or otherwise provide access to the target site to be treated and / or imaged. An angiography run can be performed through delivery catheter 50c to angiographically evaluate the correct position of the tip of delivery catheter 50C (e.g., the position of the tip proximal to the thrombus and to estimate the length of the clot). The treatment device 91 (e.g., the stent retriever shown) is then released by pulling back delivery catheter 50c while keeping treatment device 91 in place. In some embodiments, treatment device 91 should cover the entire occluded length to achieve flow restoration (e.g., when the stent is partially opened).

[0254] In Figure 8 this case, the distal portion of delivery catheter 50c is located within the blood vessel (e.g., within the blood vessel location including the thrombus). The stent portion of treatment device 91 remains undeployed and is captured within the distal portion of delivery catheter 50c. In Figure 9Retract the delivery catheter 50c such that the stent portion of the treatment device 91 is deployed (e.g., to engage a thrombus, not shown). In Figure 10 Advance the imaging probe 100 through the deployed stent portion of the treatment device 91. Image data may be collected during the advancement. In Figure 11 Retract the imaging probe 100 (with the optical assembly 130 passing through the stent portion of the treatment device 91) while collecting image data, e.g., to perform the procedural evaluations described herein.

[0255] In some embodiments, the system 10 is configured and arranged to provide proximally applied torque (e.g., to the core 120) and distally applied rotational speed control (e.g., to the core 120 and / or the optical assembly 130). This configuration has several advantages including, but not limited to: small size; low cost; and independence from tortuous paths at the distal tip of the imaging probe 100.

[0256] In some embodiments, the system 10 is configured to provide precise rotational control through inertial damping (e.g., to avoid undesired changes in rotational speed of the core 120 and / or the optical assembly 130), e.g., inertial damping that increases with rotational speed. This control may be achieved by: viscous fluid in contact with the core 120 and / or the optical assembly 130 (e.g., the fluids 190a and / or 190b described herein); fluid in contact with a mechanical load such as vane-type microstructures; a mechanical load acting as a flywheel; and combinations thereof.

[0257] In some embodiments, the imaging probe 100 includes a guide wire independent design that includes a shaft 110 with an OD of 0.016″ or less (e.g., about 0.014″) and is configured such that its shaft 110, core 120, and optical assembly 130 are consistently retracted by using an external pullback (e.g., the retraction assembly 220 described herein).

[0258] In some embodiments, the imaging probe 100 is configured to advance through a blood vessel to a target site with or without the use of a microcatheter.

[0259] In some embodiments, the imaging probe 100 is configured such that the core 120 and the optical assembly 130 are configured to retract within the shaft 110 during image data collection, e.g., using an internal pullback of a purge medium (e.g., the fluid 190 or other purge medium introduced between the core 120 and the shaft 110). In some embodiments, the introduced material is configured to provide a function selected from the group consisting of: matching refractive index; lubrication; bubble removal; and combinations thereof.

[0260] In some embodiments, the imaging probe 100 includes an Rx tip. In these embodiments, the imaging probe 100 may be configured such that the core 120 and the optical assembly 130 are configured to retract within the shaft 110 during image data collection.

[0261] In some embodiments, the imaging probe 100 includes a highly deliverable probe with a very small cross-section. In some embodiments, the shaft 110 includes one or more optically transparent materials that provide an optically transparent window within the distal portion 119a of the shaft 110: the viewing portion 117. The viewing portion 117 may include a length of from 1 mm to 100 mm, such as a length of about 3 mm. In some embodiments, the viewing portion 117 may include a length of less than 50 mm, such as less than 20 mm or less than 15 mm (e.g., a relatively short window in embodiments where the shaft 110 and the optical assembly 130 are simultaneously retracted during the collection of image data). The viewing portion 117 may include materials selected from the group consisting of: nylon; nylon 12; nylon 66; and combinations of one or more of them. In some embodiments, at least a portion of the shaft 110 includes a reinforcing portion, such as a reinforcing portion including a reinforcing element (e.g., Figure 1 the reinforcing element 118 shown). In some embodiments, the reinforcing element 118 terminates proximal to the optical assembly 130 (e.g., proximal to the viewing portion 117 of the shaft 110). Alternatively, the reinforcing element 118 may extend beyond the optical assembly 130, such as as Figure 2 shown, and the pull-back geometry may be coordinated such that the optical paths to and from the optical assembly 130 avoid the reinforcing element 118. A reinforcing element 118 may be included to resist torsion of the distal portion 119a, such as during rotation of the core 120. For example, the reinforcing element 118 may include elements selected from the group consisting of: coils; metal coils; metal coils wound around a plastic such as PTFE; tubes; metal tubes; metal and / or plastic braids located within the wall of the shaft 110; and combinations thereof. In some embodiments, the shaft 110 includes a reinforcing element 118 including a coil wound in a direction such that rotation of the core 120 tends to tighten the coil (e.g., to resist torsion of the shaft 110). In some embodiments, one or more portions of the reinforcing element 118 are in contact with a fluid (e.g., the fluid 190 described herein) retained within the shaft 110 such that torsion of the shaft 110 is reduced by the torque force applied to the reinforcing element 118 by the fluid.

[0262] In some embodiments, the system 10 includes the integration of the imaging probe 100 with one or more treatment devices (e.g., one or more treatment devices 91). For example, the treatment device 91 may include a stent retriever, and the system 10 may provide real-time simultaneous visualization of one or more of the following: the patient's site (e.g., the patient's vessel wall and other tissues); the treatment device 91 (e.g., one or more struts of the treatment device 91); and / or thrombus or other occlusive material. The simultaneous visualization may be associated with reduced operative time and improved efficacy.

[0263] In some embodiments, system 10 is configured to apply a proximal pressure to imaging probe 100, such as to keep the distal portion bubble-free or at least mitigate the generation of bubbles within one or more fluids 190 of imaging probe 100.

[0264] As described herein, imaging probe 100 includes a core 120 that includes fine fibers, which may be optically coupled at its distal end to an optical assembly 130 that includes a lens assembly. In some embodiments, a fluid interaction element (such as a coil or length of wound wire, but not necessarily a torque wire) may be located just proximal to optical assembly 130 (such as embedded in the wall of shaft 110 or within shaft 110). In some embodiments, shaft 110 may be filled with a low-viscosity fluid 190, such as to interact with the fluid interaction element and create drag. Contrary to traditional torque wires, coils or other fluid interaction elements are not wound to produce high-fidelity transmission of torque, but rather add viscous drag. Fluid 190 may be of low viscosity (such as having a viscosity of 1000 Cp or less) to allow for easier filling and will reduce bubble artifacts in high-viscosity solutions. The fluid interaction element may include an impeller, such as impeller 182 described herein. The fluid interaction element includes a non-circular cross-sectional portion of a portion of shaft 110, such as a cross-section having a geometry selected from the group consisting of: a polygonal cross-section of the lumen of shaft 110; a protrusion entering the lumen of shaft 110; a depression in the inner diameter (i.e., inner wall) of shaft 110; and combinations of one or more of them.

[0265] In some embodiments, imaging probe 100 includes an element formed to create viscous drag, such as impeller 182 described herein. The element may have various shapes designed to maximize interaction with internal fluid 190.

[0266] In some embodiments, imaging probe 100 is constructed and arranged such that mechanical friction between a portion rigidly coupled to core 120 and a portion in tight contact with the wall of shaft 110 creates viscous drag. The friction may be created by shear forces of a narrow ring between a mechanical element and shaft 110, such as when shaft 110 is filled with fluid 190.

[0267] In some embodiments, imaging probe 100 includes at least one fluid 190 contained by at least one seal element 116 (such as seal element 116 and / or seal element 151 described herein). Seal element 116 and / or 151 may be constructed and arranged to allow core 120 to rotate within the sealed area while preventing (viscous) fluid 190 from passing through the seal. In some embodiments, two seal elements 116a and 116b are included, such as one just proximal to optical assembly 130 and one located more distally, as Figure 17As shown. In these embodiments, the separation distance between the two sealing elements 116 and / or the viscosity of the captured fluid 190 can be selected to generate sufficient torsional load when the core 120 rotates. In some embodiments, the two sealing elements 116a and 116b are separated by a distance of 1 mm to 20 mm. In some embodiments, the fluid 190 has a viscosity of 10 Cp to 100 Cp.

[0268] In some embodiments, the system 10 includes an imaging probe 100 and a console 200. The imaging probe 100 includes: a proximal end 111 and a distal end 119, and at least one lumen 112 extending between the proximal end 111 and the distal end 119. A core 120 is located within the lumen 112. The proximal end of the core 120 is in optical and mechanical communication with the console 200, and the distal end of the core 120 is in optical communication with an optical component configured to collect image data within a body cavity.

[0269] In some embodiments, the imaging probe 100 includes an optical component 130 located at the distal end of the core 120. The optical component 130 is in mechanical and optical communication with the core 120. The optical component 130 directs light to a target to be imaged (such as a thrombus, blood vessel wall, tissue, and / or implant), and collects light returning from the imaged target. The imaging probe 100 may also include an inertial system (such as an impeller 182) located near the distal end of the core 120, wherein the inertial system reduces unwanted rotational speed variations that occur during rotation of the core 120. The inertial system may include a (predetermined) length of coiled hollow-core cable, the distal end of which is fixed to the core 120 just proximal to the optical component 130, and the proximal end is not connected (such as not connected to the core 120). The inertial system may include a mechanical resistance element located in the distal region of the core 120 and may contact a fluid 190 defined within the lumen 112 of the shaft 110, with mechanical resistance being generated during rotation within the fluid 190.

[0270] In some embodiments, the imaging probe 100 includes a sealing element, such as the sealing element 151 described herein, which is located within the lumen 112 of the shaft 110. The sealing element 151 may be configured to allow rotation of the core 120 during formation of a substantially liquid-tight seal around the core 120 and the inner wall of the shaft 110. In some embodiments, the sealing element 151 is also configured as a mechanical resistance element. In some embodiments, the sealing element 151 is formed of a hydrogel. In some embodiments, the sealing element 151 is formed of an adhesive (such as an ultraviolet-curable adhesive) that adheres to the inner wall of the shaft 110 rather than the surface of the core 120. In some embodiments, the surface of the core 120 is configured to prevent adhesion to the adhesive (such as a UV adhesive). In some embodiments, the sealing element 151 is formed of a flexible material such as silicone resin.

[0271] In some embodiments, the imaging system includes an imaging probe 100 and an imaging console: console 200. The imaging probe 100 includes a proximal end 111, a distal end 119, and at least one lumen 112 extending between the proximal end 111 and the distal end 119. The imaging probe further includes a core 120 contained within the lumen 112 of the shaft 110, a proximal end of the core 120 in optical and mechanical communication with the console 200, and a distal end optically connected to an optical assembly 130 configured to collect image data within a body cavity. The optical assembly 130 is located at the distal end of the core 120 and is configured to direct light to a target to be imaged (such as a thrombus, blood vessel wall, tissue, and / or implant), and to collect light returning from the imaged target.

[0272] In some embodiments, the imaging probe 100 includes a core 120 and one, two, or more inertial elements, such as the impeller 182 described herein, which are connected to the optical assembly 130 and / or the core 120 (such as connected to the distal portion of the core 120). The impeller 182 can be configured such that when the core 120 retracts (such as in the presence of a liquid, gel, or gaseous medium, such as fluid 190), the impeller 182 applies a rotational force to the core 120, such as to reduce undesired rotational speed variations. The impeller 182 can include a turbine-like structure.

[0273] In some embodiments, the system 10 includes an imaging probe 100 and an imaging console: console 200. The imaging probe 100 includes a proximal end 111, a distal end 119, and at least one lumen 112 extending between the proximal end 111 and the distal end 119. The imaging probe 100 may further include a rotatable optical core: core 120, which is contained within the lumen 112 of the shaft 110, the proximal end of the core 120 being in optical and mechanical communication with the console 200, and the distal end being configured to collect image data from a body cavity.

[0274] As described herein, the imaging probe 100 includes an optical assembly 130 located at the distal end of the core 120. The optical assembly 130 is in mechanical and optical communication with the core 120 and is configured to direct light to a target to be imaged, and to collect light returning from the imaged target. The imaging probe 100 may further include a reinforcing or other strengthening element (such as the strengthening element 118 described herein) embedded within the shaft 110, which creates an improved stiffness but an effective optically transparent window for rotational and pullback scanning. The strengthening element 118 may include embedded wires and / or strengthening members (including plastic strengthening members) within the shaft 110. The strengthening element 118 may include a helical geometry. As described above, the helical geometry of the strengthening element 118 cooperates with the pullback helical rotation pattern of the optical assembly 130, but is offset by approximately half of the helix of the strengthening element 118 such that the imaging beam of the optical assembly 130 passes between the strengthening 118 helices during the pullback of the optical assembly 130.

[0275] Now referring toFigure 12 , a side cross-sectional view of the distal portion of the probe 100 is shown, which is inserted into a blood vessel such that the optical assembly 130 is located within a treatment device 91 (such as a stent deployment device, a stent retrieval device, or other treatment device), in accordance with the concepts of the present invention. The probe 100 includes a shaft 110, a core 120, an optical assembly 130, a lens 131, and a reflector 132, and these and other components of the probe 100 may have a construction and arrangement similar to those described above. In some embodiments, the distal end 119 includes a geometry and / or stiffness to enhance the advancement of the distal end 119 through the blood vessel and / or one or more devices located within the blood vessel. For example, the distal end 119 may include Figure 12 the bullet-shaped profile shown. Alternatively or additionally, the treatment device 91 may include a proximal portion (such as the proximal end 91a shown), which may enhance the delivery of the distal end 119 through the proximal end 91a. In some embodiments, the probe 100 includes a spring tip, such as the spring tip 104 described above.

[0276] The probe 100 and other components of the system 10 may be configured to allow a clinician or other operator to "observe" (e.g., in real time) the collection of a thrombus or other occlusive material into the treatment device 91, such as to determine when to remove the treatment device 91 and / or how to operate the treatment device 91 (e.g., maneuvers to remove the treatment device 91 and / or reposition the treatment device 91 to enhance treatment). The ability to observe the treatment can avoid unnecessary waiting times and other delays, as well as improve the efficacy of the procedure (e.g., enhance the removal of the thrombus).

[0277] Now referring to Figure 13 , a side cross-sectional view of the distal portion of the probe 100 is shown, in accordance with the concepts of the present invention. The probe 100 includes a shaft 110, a lumen 112, a core 120, an optical assembly 130, a lens 131, and a reflector 132, and these and other components of the probe 100 may have a construction and arrangement similar to those described above. In some embodiments, the distal portion 119a of the shaft 110 includes a reinforcing element: Figure 13The reinforcing element 118a shown. Inclusion of the reinforcing element 118a may permit the wall surrounding the axis 110 of the optical assembly 130 to be thin (e.g., thinner than the wall of the more proximal portion of the axis 110). The reinforcing element 118a may comprise an optically transparent material as described herein. The reinforcing element 118a may be configured to provide strut and / or torsional strength to the axis 110. In some embodiments, the probe 100 includes a lumen narrowing structure such that the tube 114 shown is located within the lumen 112 of the axis 110. The tube 114 may be adhesively or at least frictionally engaged with the inner wall of the axis 110 or the outer surface of the core 120. In some embodiments, the tube 114 is merely a protrusion (e.g., a portion of the axis 110) from the inner wall of the axis 110. The tube 114 may be configured to provide a function selected from the group consisting of: increasing the torsional strength of the axis 110; increasing the strut strength of the axis 110; providing capillary action between fluids around the core 120 and / or the optical assembly 130; and combinations thereof. In some embodiments, the probe 100 includes the fluids 190a and / or 190b shown, as described above. The fluids 190a and 190b may include similar or different fluids. In some embodiments, the fluid 190a and / or 190b includes the low viscosity fluid described above. In some embodiments, the fluid 190a and / or 190b includes the shear thinning fluid described above.

[0278] Now referring to Figure 14 , a schematic illustration of an imaging probe is shown, depicted in a partially assembled state and in accordance with the concepts of the present invention. The probe 100 may include a first portion that includes a connector 102a, an outer shaft 110a, and a spring tip 104, as Figure 14 shown in the construction and arrangement. The probe 100 may also include a second portion, a connector 102b, a torque shaft 110b, a core 120, and an optical assembly 130. The outer shaft 110a, the spring tip 104, the core 120, the optical assembly 130, and other components of the probe 100 may have a construction and arrangement similar to those described above. The connector 102b may have a construction and arrangement similar to the connector 102 described above, e.g., to optically connect the probe 100 to the console 200. The connector 102a may be configured to surround and mechanically engage the connector 102b such that the connector 102a and / or 102b is mechanically connected to the console 200.

[0279] The torque shaft 110b frictionally engages the core 120 at least at the distal portion of the torque shaft 110b (e.g., by an adhesive). The torque shaft 110b may be connected to the connector 102b via an adhesive or other mechanical engagement (e.g., via a metal tube not shown, but a tube pressed into the connector 102b). In some embodiments, a strain relief: tube 121 is provided at the end of the torque shaft 110b shown. The tube 121 may be configured to reduce kinking and / or increase the fixation between the torque shaft 110b and the core 120. The tube 121 and the torque shaft 110b may have similar ID and / or OD.

[0280] During the assembly process, the torque shaft 110b, the optical assembly 130, and the core 120 are located within the shaft 110a. The connector 102a may be engaged with the connector 102b to maintain the relative positioning of the two components.

[0281] The torque shaft 110b may include one or more plastic or metallic materials, e.g., the torque shaft 110b includes a braided torque shaft (e.g., a braided portion including at least stainless steel). The torque shaft 110b may include a length such that the distal end of the torque shaft 110b terminates at a minimum distance from the optical assembly 130, e.g., a length of about 49 cm. In some embodiments, the torque shaft 110b includes a length such that the torque shaft 110b does not enter or enters only a small portion into the patient. In these embodiments, the retraction assembly 220 may be located at a position distal to the distal end of the retraction assembly 220 and engage the shaft 110 at this position.

[0282] Now referring Figure 15A to C, a series of side - view cross - sectional views of the imaging probe in a series of expansion steps in which its shaft passes through internal fluid, in accordance with the concepts of the present invention. The probe 100 includes a connector 102, a shaft 110, a core 120, and an optical assembly 130, and these and other components of the probe 100 may have a construction and arrangement similar to those described above. The shaft 110 includes a proximal portion 111a, an intermediate portion 115, and a distal portion 119a. The probe 100 also includes a pressurization assembly 183, which may include a valve 184, each having a similar construction to that referred to above Figure 7The construction and arrangement of the similar components described. The probe 100 can be configured such that fluid is introduced into the lumen 112 and / or the pressure of the fluid within the lumen 112 is increased, causing the shaft 110 to expand. For example, a first introduction of fluid 190 into the lumen 112 and / or a first increase in the pressure of the fluid 190 within the lumen 112 (e.g., via the pressurization assembly 183) can be performed such that the proximal portion 111a of the shaft 110 expands as shown in FIG. 15a. Subsequently, a second introduction of fluid 190 into the lumen 112 and / or a second increase in the pressure of the fluid 190 within the lumen 112 can be performed such that the intermediate portion 115 of the shaft 110 expands as shown in FIG. 15b. Subsequently, a third introduction of fluid 190 into the lumen 112 and / or a third increase in the pressure of the fluid 190 within the lumen 112 can be performed such that the distal portion 119a of the shaft 110 expands as Figure 15C shown. In some embodiments, the shaft 110 is expanded to create a space between the inner wall of the shaft 110 and the core 120 and / or to create a space between the inner wall of the shaft 110 and the optical assembly 130.

[0283] Now referring to Figure 16, showing a side cross-sectional view of the distal marker of the imaging probe, the distal portion including a distal marker positioned relative to the optical assembly, in accordance with the concepts of the present invention. Probe 100 includes shaft 110, core 120, optical assembly 130, lens 131, and reflector 132, and these and other components of probe 100 may have a construction and arrangement similar to those described above. Shaft 110 includes a proximal portion 111a (not shown), a distal portion 119a, and a distal end 119. Probe 100 may include a functional element 133a, which may be located on or positioned relative to optical assembly 130 (e.g., located on optical assembly 130 or at a desired and / or known distance from optical assembly 130). Functional element 133a is shown located distally of optical assembly 130 and at a fixed distance determined by connecting element tube 134 (e.g., a heat shrink tube or other plastic tube). In some embodiments, functional element 133a includes a sensor, transducer, or other functional element described herein. In some embodiments, functional element 133a includes a visualization element, such as a radiation-impervious element, an ultrasound-visible element, and / or a magnetically visible element. In some embodiments, functional element 133a includes a visualization element for identifying the position of optical assembly 130 on an image generated by an imaging device (e.g., a fluoroscope, an ultrasound imager, or an MRI), and the fixed position of functional element 133a relative to optical assembly 130 avoids registration problems, such as those encountered when functional element 133a is located on shaft 110 or other components of probe 100, the size or other position of which relative to optical assembly 130 may change over time (e.g., due to expansion or contraction caused by temperature offsets). In some embodiments, functional element 133a is connected to optical assembly 130 by a connecting element, such as tube 134 described above, and tube 134 or other connecting elements (e.g., connecting element 137 described herein) are configured to avoid dimensional changes (e.g., being minimally affected by changes in temperature). In some embodiments, probe 100 includes a fixing element 136 (e.g., an adhesive such as a UV curable adhesive), which is located just distally of functional element 133a as Figure 16 shown and is configured to hold the position of functional element 133a.

[0284] Probe 100 may include one or more elements that cause a frictional engagement between shaft 110 and core 120 and / or simply reduce the space between shaft 110 and core 120, such as Figure 16One or more of the illustrated elements 122a, 122b, and 122c, for example, reduce undesired variations in the rotational rate as described above. In some embodiments, the probe 100 includes a compression element: a band 122a that is located near and / or within the shaft 110 and causes frictional engagement of a portion of the inner wall of the shaft 110 with the core 120. Alternatively or additionally, the shaft 110 may include one or more protrusions 122b (such as annular protrusions) that extend to frictionally engage the core 120. Alternatively or additionally, the core 120 may include one or more protrusions 122c, each extending to frictionally engage the shaft 110. One or more of the elements 122a, 122b, and / or 122c may be included, and each may be configured to generate a shear force that applies a load to the core 120 during rotation of the core 120. In some embodiments, a fluid 190 is located between the shaft 110 and the core 120, such as a shear-thinning fluid as described herein. In these embodiments, one or more of the elements 122a, 122b, and / or 122c may include a space-reducing element that is configured to increase the shear thinning of the fluid 190 during rotation of the core 120 (i.e., by interacting with the fluid 190 to increase the amount of thinning that occurs in the absence of one or more space-reducing elements 122).

[0285] Now referring to Figure 17 , a side cross-sectional view of a distal portion of an imaging probe is shown, the distal portion including two sealing elements, in accordance with the concepts of the present invention. The probe 100 includes a shaft 110, a core 120, and an optical assembly 130, a lens 131, a reflector 132, and an observation portion 117, and these and other components of the probe 100 may have a construction and arrangement similar to those described above. The shaft 110 includes a lumen 112, a proximal portion 111a (not shown), a distal portion 119a, and a distal end 119. The probe 100 may also include a spring tip 104. The probe 100 includes the illustrated functional element 113, or other functional elements described herein. Figure 17 The probe 100 of

[0286] Now referring to Figure 18, showing a side cross-sectional view of the distal portion of the imaging probe, the distal portion including a reflective element offset from a lens and a plurality of visualization markers, in accordance with the concepts of the present invention. Probe 100 includes a shaft 110, a core 120, an optical assembly 130, a lens 131, and a reflector 132, and these and other components of probe 100 may have a construction and arrangement similar to those described above. Shaft 110 includes a lumen 112, a proximal portion 111a (not shown), a distal portion 119a, and a distal end 119.

[0287] In some embodiments, reflector 132 may be located distally of lens 131 and connected by a connecting element 137, as Figure 18 shown and described above.

[0288] In some embodiments, probe 100 includes a plurality of visualization markers, such as Figure 18 the four functional elements 123a shown, which may be configured to provide a "regular function" when visualized by a separate imaging device such as a fluoroscope, an ultrasound imager, or an MRI (e.g., when the functional elements 123a include radiation-impermeable markers; ultrasound reflector markers; or magnetic markers, respectively). The functional elements 123a may include one or more visualization bands (e.g., one or more compressible bands and / or wire coils) that frictionally engage with core 120. Alternatively or additionally, one or more functional elements 123a may be located on the wall of shaft 110, within the wall of shaft 110, and / or on the inner surface of shaft 110. The functional elements 123a may be located at equidistantly spaced positions and / or at positions with a known spacing distance. In some embodiments, one or more functional elements 123a may also be configured as a sealing element (e.g., to provide a seal for the contained fluid, such as one or more of the fluids 190 described herein) and / or a rotational damper, which is configured to reduce undesired changes in the rotational speed of core 120 and / or optical assembly 130.

[0289] Although the preferred embodiments of the devices and methods have been described with reference to the environments in which they were developed, they merely illustrate the principles of the inventive concept. Modifications or combinations of the above components, other embodiments, constructions, and methods for implementing the inventive concept, and variations of aspects of the inventive concept that are obvious to those skilled in the art are intended to be included within the scope of the claims. Additionally, although the steps of a method or process have been listed in a particular order in this invention, it is possible to change the order of execution of some steps or even, in some cases, it is advantageous, and the particular steps of the method or process presented below should not be considered in a particular order unless such order specificity is explicitly stated in the claims.

Claims

1. An imaging system for a patient, comprising: An imaging probe, comprising: An elongate shaft for insertion into a patient, including a proximal end, a distal portion, and a lumen extending between the proximal end and the distal portion; A rotatable optical core including a proximal end and a distal end, the rotatable optical core being configured to be optically and mechanically connected to a console; A probe connector located at the proximal end of the elongate shaft and surrounding at least a portion of the rotatable optical core; An optical assembly located near the distal portion of the elongate shaft and the distal end of the rotatable optical core, the optical assembly being configured to direct light to tissue and collect reflected light from the tissue; and A shear-thinning fluid contained in the distal portion of the elongate shaft, the viscosity of which decreases as the rotational speed of the rotatable optical core increases.

2. The imaging system according to claim 1, wherein the shear-thinning fluid is configured to reduce undesired rotational variations of the rotatable optical core.

3. The imaging system according to claim 2, wherein the shear-thinning fluid is configured to avoid placing an excessive load on the rotatable optical core.

4. The imaging system according to claim 1, wherein the imaging probe is configured to access blood vessels of the brain.

5. The imaging system according to claim 1, wherein the imaging probe further comprises at least one space-reducing element located between the elongate shaft and the rotatable optical core.

6. The imaging system according to claim 5, wherein the at least one space-reducing element is configured to reduce rotational speed variations of the rotatable optical core.

7. The imaging system according to claim 6, wherein the at least one space-reducing element is configured to reduce the rotational speed variations by increasing the shear-thinning of the shear-thinning fluid.

8. The imaging system according to claim 1, wherein the optical assembly includes an outer diameter that is greater than an inner diameter of at least a portion of the elongate shaft proximal to the optical assembly.

9. The imaging system according to claim 1, wherein the imaging system is configured to generate a three-dimensional image by retracting the elongate shaft.

10. The imaging system according to claim 1, wherein a distal portion of the elongate shaft includes an optically transparent window, and wherein the optical assembly is located within the optically transparent window.

11. The imaging system according to claim 10, wherein the optically transparent window includes a length of less than 20 mm.

12. The imaging system according to claim 11, wherein the optically transparent window includes a length of less than 15 mm.

13. The imaging system according to claim 10, wherein the optically transparent window includes a material selected from the group consisting of: Pebax registered trademark; Pebax 7233; PEEK; amorphous PEEK; polyimide; glass; sapphire; nylon 12; nylon 66; and combinations thereof.

14. The imaging system according to claim 10, wherein the elongated shaft includes at least a first portion near the optically transparent window, and wherein the first portion includes a braided shaft.

15. The imaging system according to claim 10, wherein the elongated shaft further includes a metal tube proximal to the optically transparent window.

16. The imaging system according to claim 1, further comprising a fluid interaction element at the distal portion, wherein the fluid interaction element is configured to interact with the shear-thinning fluid to increase the load on the rotatable optical core during rotation of the rotatable optical core.

17. The imaging system according to claim 1, wherein the rotatable optical core is constructed and arranged to rotate in a single direction.

18. The imaging system according to claim 1, wherein the optical assembly has an outer diameter of 80 μm to 500 μm.

19. The imaging system according to claim 1, further comprising a retraction assembly configured and arranged to retract the elongated shaft and the optical assembly simultaneously while the imaging probe collects data from the target area.

20. The imaging system according to claim 1, wherein the imaging system is configured to provide quantitative or qualitative information for determining the size of a flow diverter to be implanted in a patient or for positioning a flow diverter in a patient.

21. The imaging system according to claim 20, wherein the quantitative and / or qualitative information includes information related to parameters selected from the group consisting of: perforator location; perforator geometry; neck size; flow diverter mesh density; and combinations thereof.

22. The imaging system according to claim 1, wherein the imaging system is configured to provide implantation location information, and wherein the implantation location information is used to select a specific implantable device to be implanted in a patient.

23. The imaging system according to claim 22, further comprising an implantable device implanted in a patient, wherein the implantable device includes a device selected from the group consisting of: a stent; a flow diverter; and combinations thereof.

24. The imaging system according to claim 23, wherein the implantable device is selected based on implantable device parameters selected from: porosity; length; diameter; and combinations thereof.

25. The imaging system according to claim 1, further comprising at least one guiding catheter.

26. The imaging system according to claim 25, wherein the at least one guiding catheter has an inner diameter of 0.0165″ to 0.027″.

27. The imaging system according to claim 1, wherein the elongated shaft includes an inner diameter that varies along the length of the elongated shaft.

28. The imaging system according to claim 1, wherein the elongated shaft has an outer diameter of 0.006″ to 0.022″.

29. The imaging system according to claim 1, wherein the elongated shaft further includes an intermediate portion, and wherein the distal portion of the elongated shaft has an inner diameter greater than the inner diameter of the intermediate portion of the elongated shaft.

30. The imaging system according to claim 29, wherein the distal portion of the elongated shaft has a wall thickness less than the wall thickness of the intermediate portion of the elongated shaft.

31. The imaging system according to claim 1, wherein the imaging probe further includes a torque shaft having a proximal end and a distal end, and wherein the torque shaft is fixedly connected to the rotatable optical core such that rotation of the torque shaft rotates the rotatable optical core.

32. The imaging system according to claim 31, further comprising a retraction assembly configured and arranged to retract at least one of the rotatable optical core or the elongated shaft.

33. The imaging system according to claim 1, further comprising a rotation assembly configured and arranged to rotate the rotatable optical core.

34. The imaging system according to claim 1, wherein the console includes: A rotation assembly configured and arranged to rotate the rotatable optical core; And A retraction assembly configured and arranged to retract at least one of the rotatable optical core or the elongate shaft.

35. The imaging system according to claim 1, wherein the shear-thinning fluid has a viscosity of 10 Pa·s to 100,000 Pa·s.

36. The imaging system according to claim 1, wherein the shear-thinning fluid is configured to reduce the viscosity to a level of about 3 Pa·s.

37. The imaging system according to claim 1, wherein the shear-thinning fluid is configured to reduce the viscosity to a level of about 3 Pa·s at a shear rate of 100 s -1 -1.

38. The imaging system according to claim 1, wherein the shear-thinning fluid includes a hydrocarbon-based material.

39. The imaging system according to claim 1, wherein the shear-thinning fluid includes a silicone resin.

40. The imaging system according to claim 1, wherein the shear-thinning fluid includes a fluid selected from the group consisting of: a hydrocarbon-based material; a silicone resin; and combinations thereof.

41. The imaging system according to claim 1, wherein the shear-thinning fluid includes: A first liquid located near the optical assembly, the first liquid having a first viscosity, and A second liquid located near the rotatable optical core, the second liquid having a second viscosity higher than the first viscosity.

42. The imaging system according to claim 1, wherein the shear-thinning fluid is contained in the distal portion of the elongated shaft, and wherein the shear-thinning fluid has a viscosity that decreases as the rotational speed of the rotatable optical core increases.

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