Systems, devices and methods for antegrade dissection and re-entry

Abstract

An exemplary catheter includes a housing having a distal catheter region configured to be disposed at least partially within the body and a proximal catheter region configured to remain at least partially outside the body. The catheter may define an imaging lumen configured to receive an imaging device, a guidewire lumen, an off-ramp, and an indicator lumen configured to receive an indicator detectable by the imaging device. The guidewire lumen is configured to receive a guidewire and includes a distal region and a proximal region. The off-ramp extends from the guidewire lumen at or near the intersection of the distal and proximal regions of the guidewire lumen. The catheter may also include one or more guidewire feeds configured to move the guidewire from the proximal section to the off-ramp.

Description

[Background technology]

[0001] (CROSS REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Provisional Patent Application No. 63 / 311,852, filed February 18, 2022, and entitled "METHODS AND SYSTEMS CONFIGURED TO DETERMINE AN ​​ORIENTATION OF A CATHETER," U.S. Provisional Patent Application No. 63,311,871, filed February 18, 2022, and entitled "ROTATIONAL IMAGING DISTORTION CORRECTION," and U.S. Provisional Patent Application No. 63 / 479,850, filed January 13, 2023, and entitled "SYSTEMS, DEVICES AND METHODS FOR ANTEGRADE DISSECTION AND REENTRY," each of which is incorporated by reference in its entirety for all purposes.

[0002] Anatomically complex chronic total occlusions (CTOs) often require exploiting extraplaque, i.e., pre-existing, “subintimal” space for successful CTO recanalization. Antegrade dissection and reentry (ADR) techniques are an important part of the hybrid approach to modern CTO percutaneous coronary intervention (PCI). However, despite the availability of dedicated reentry devices, the success rate of ADR is approximately 50-60% in large registries. This is often attributed to large extraplaque hematoma formation leading to loss of distal vessel visualization and loss of guidewire support and steerability making reentry highly challenging. Both existing ADR and antegrade wire escalation are subvisualized strategies that are premised on the lack of real-time visual guidance by angiography and their inability to provide a high degree of precision in steering and advancing the reentry device. Summary of the Invention [Means for solving the problem]

[0003] Embodiments are directed to methods and systems configured to perform intravascular imaging and / or antegrade dissection and re-entry for the treatment of chronic total occlusions of blood vessels, including the coronary vasculature and peripheral vasculature. The catheter may be configured to support and aim a steerable guidewire, for example, with guidance from simultaneous optical coherence tomography ("OCT") imaging. In some examples, the catheter may comprise a tip with radiopaque markers, a torque shaft, a catheter rotator assembly, a guidewire introducer port, an imaging drive shaft with optical fiber, an imager with a longitudinal translator, and a housing. The catheter tip further comprises two ports, one for axial loading of the guidewire and the other for radial exit of the guidewire. The catheter tip may be optically transparent in the visible to infrared light spectrum. The catheter is attached to an imaging console and a sled assembly and configured to perform OCT.

[0004] The method includes acquiring one or more images at one or more locations along the length of the catheter using an OCT imaging device. The method additionally includes detecting the location of a fixed, always-present landmark or feature, such as an indicator lumen or an eccentric edge of the catheter body, relative to the center of the OCT imaging device. The method also includes applying a template, including an off-ramp indicator, across the one or more images. The off-ramp indicator is a two-dimensional graphic or a three-dimensional augmented graphic. The off-ramp indicator appears as opaque or semi-transparent on the one or more images.

[0005] Some embodiments also relate generally to image processing, and more specifically to methods and apparatus for correction of non-uniform rotational distortion in catheter-based imaging systems.

[0006] A need exists for providing a solution for visualizing a cross-sectional view of an anatomical lumen or cavity while traversing it with clear interpretation of the surrounding anatomical structures and tissues. Accurate imaging and positioning of the imaging system can help the practitioner precisely orient an interventional instrument that stays within a desired path to a target location and / or can be steered to avoid critical structures that may be damaged during a diagnostic or therapeutic procedure.

[0007] In one embodiment, a computer-based method for correcting image distortion in an eccentric rotational imaging catheter system is provided that utilizes sinusoidal variations in the catheter wall to eliminate the distortion in the final image.

[0008] In one embodiment, a system for imaging a lumen includes an imaging catheter having a tubular body, a proximal end region, a distal end region, a middle region, imaging lumens located along the proximal, middle, and distal regions, a common guidewire lumen located along the proximal, middle, and distal regions, a side lamp lumen located in the distal end region, connected to the common guidewire lumen and having a distal opening in a side wall of the tubular body, a distal guidewire lumen located in the distal end region, connected to the common guidewire lumen and having a distal opening in an end wall of the tubular body, and at least one guidewire biasing structure having a reduced diameter region at a junction of the distal guidewire lumen and the common guidewire lumen, and a longitudinal axis of the common guidewire lumen and a longitudinal axis of the distal guidewire lumen. a proximal catheter assembly comprising a proximal optical connection interface; a tubular body comprising at least one guidewire biasing structure selected from the group consisting of: an offset distance of 0.01 mm, an angled flap at or proximal to the junction of the distal guidewire lumen and the common guidewire lumen, and a guidewire lumen ridge at or proximal to the junction of the distal guidewire lumen and the common guidewire lumen; a catheter housing coupled to a proximal end region of the tubular body; and a proximal catheter assembly comprising a proximal optical connection interface; an imaging catheter comprising a first guidewire port in fluid communication with the common guidewire lumen, an imager port in fluid communication with the imaging lumen, and an imaging optical fiber connected to the proximal optical connection interface and extending along the imaging lumen. The system may further comprise a second guidewire port in fluid communication with the common guidewire lumen, the second guidewire port having an interface different from that of the first guidewire port. The first and second guidewire ports are located in a hub distal to the catheter assembly. The catheter housing may further comprise an imager actuator engaged to the imaging optical fiber and configured to longitudinally translate the imaging optical fiber relative to the imaging lumen. The system may further comprise a catheter rotation actuator coupled to the tubular body and configured to rotate the tubular body relative to the proximal catheter housing assembly.The catheter rotation actuator may be rotatably coupled to a distal end of the catheter housing. The proximal catheter assembly may further comprise an optical cable between the catheter housing and the proximal optical connection interface. The proximal optical connection interface may be directly coupled to the catheter housing. The system may further comprise an imaging console comprising a console housing, a power supply, a laser source with an output port, a sled interconnect interface, a touch screen interconnect interface, and a large display interconnect interface. The laser source output port may comprise an imaging port and an aiming beam port. The system may further comprise a sled assembly comprising a sled housing, a catheter interconnect, a sled power actuator, and a catheter detachment actuator. The catheter interconnect may be a spring-loaded catheter interconnect and the catheter detachment actuator is a catheter ejection actuator. The sled power actuator comprises a light. The system may further comprise a touch screen with a mounting attachment. The system may further comprise a large non-touch screen display. The sled housing may comprise a distal cavity configured to receive the catheter housing.

[0009] In another embodiment, a method of preparing an imaging catheter is provided that includes attaching a first sterile drape to a sled assembly, coupling the catheter assembly and the sled assembly, activating the sled assembly, activating an aiming beam of the catheter assembly, deactivating the sled assembly, removing the catheter assembly from the sled assembly, and encapsulating a proximal end of the catheter assembly with a second sterile drape. Attaching the first sterile drape to the sled assembly includes attaching the sterile drape to the sled assembly using a mounting cap. The method may further include cutting open a folded corner of the first sterile drape to form a drape opening to be positioned between the sled assembly and the mounting cap.

[0010] In another example, a method of using an imaging catheter is provided that includes advancing the imaging catheter through a guide catheter and over a guidewire to a target site, attaching the imaging catheter to a sled assembly, activating the imaging catheter to image the target site, using a longitudinal adjustment interface on a proximal housing of the imaging catheter to longitudinally image a ramp lumen of the imaging catheter, advancing the imaging catheter toward and around a lesion at the target site, using the imaging catheter to identify a true lumen at the target site, rotating an imaging portion of the target site using a rotational actuator of the imaging catheter to orient the ramp lumen toward the true lumen at the target site, withdrawing the guidewire from a distal guidewire lumen of the imaging catheter, advancing the guidewire through the ramp lumen of the imaging catheter and into the true lumen at the target site, optionally confirming re-entry of the true lumen, and retracting the imaging catheter while maintaining the position of the guidewire within the true lumen. The method may further include using the guidewire to deliver a stent to the target site. The method may further include activating a ruler overlay of the target site imaging unit, the ruler overlay depicting distance markings, and measuring vessel size using the ruler overlay. The method may further include turning on a lamp overlay of the target site imaging unit, the lamp overlay depicting guidewire orientation markings on the target site imaging unit. The method may further include flushing the imaging catheter using a guidewire flush port of the imaging catheter. Confirming re-entry of the true lumen may be confirmed using fluoroscopy and contrast. The method may further include pre-coupling the catheter assembly and the sled assembly, and activating the sled assembly. The method may further include attaching a first sterile drape to the sled assembly. The method may further include activating an aiming beam of the catheter assembly, and deactivating the sled assembly.The method may further include removing the catheter assembly from the sled assembly and encapsulating the proximal end of the catheter assembly with a second sterile drape. Attaching the first sterile drape to the sled assembly may include attaching the sterile drape to the sled assembly using a mounting cap. The method may further include cutting open a folded corner of the first sterile drape to form a drape opening to be positioned between the sled assembly and the mounting cap.

[0011] An image-guided interventional catheter includes a housing including a distal catheter region, the distal catheter region including an imaging body and a catheter body, the distal catheter region configured to receive an imaging device, an imaging lumen and a guidewire lumen configured to receive a guidewire, the distal catheter region including a distal section, a proximal section, and one or more guidewire feeds, the one or more guidewire feeds including a ridge in the proximal section near an intersection of the distal and proximal sections, a tapered region, the distal section having a maximum lateral dimension that increases with increasing distance from the intersection. The housing defines a guidewire lumen including at least one of a section, a center of the distal section offset relative to a center of the proximal section, or an intersection of the distal and proximal sections including a thin penetrable wall, an off-ramp extending from the guidewire lumen at or near the intersection of the distal and proximal sections of the guidewire lumen, where the one or more guidewire feeds are configured to extend the guidewire from the guidewire lumen into the off-ramp, and an indicator lumen configured to receive an indicator detectable by an optical coherence tomography imaging device. The imaging device may include an optical coherence tomography imaging device. The one or more guidewire feeds may include a ridge. The one or more guidewire feeds may include a distal section including a tapered region. The tapered region may extend from the intersection of the distal and proximal sections. The one or more guidewire feeds may include a center of the distal section that is offset relative to a center of the proximal section. The one or more guidewire feeds may include an intersection of the distal and proximal sections that includes a thin penetrable wall. The one or more guidewire feeds may further include a ramp at the intersection of the distal and proximal sections. The distal catheter region may include one or more detectable structures that indicate a distance from a distal tip of the distal catheter region, the one or more detectable structures being detectable by an imaging device.The one or more detectable structures may include an annular or semi-annular base and one or more elongated arms extending from the annular or semi-annular base, at least one or more longitudinal arms being detectable by the imaging device. The one or more longitudinal arms may include a plurality of longitudinal elements, at least some of the longitudinal elements being different in length. The one or more detectable structures may include one or more holes formed in the housing at the distal catheter region. In some variations, a system is provided comprising the catheter as described above, the housing including the proximal catheter region, the housing attached to the catheter, the housing including one or more actuators configured to at least one of rotate at least a portion of the catheter relative to the housing or move the imaging device within the imaging lumen. The system may further comprise a display and a graphical user interface configured to show an image detected by the imaging device on the display, the graphical user interface including at least one icon that applies a template on the image shown on the display. The template may include an off-ramp indicator that indicates the direction in which the off-ramp extends from the guidewire lumen.

[0012] In another embodiment, a method for determining catheter orientation is provided that includes acquiring one or more images at one or more locations along the length of the catheter using an optical coherence tomography imaging device, filtering out data from the one or more images, detecting a catheter trajectory, detecting a location of a fixed, always-present catheter landmark or feature relative to a center of the optical coherence tomography imaging device, and applying a template including an off-ramp indicator across the one or more images, the off-ramp indicator including a two-dimensional graphic or a three-dimensional augmented graphic, the off-ramp appearing as opaque or semi-transparent on the one or more images. Detecting the catheter trajectory may include detecting the trajectory within a catheter edge detection range from an edge of the one or more images. The fixed, always-present catheter landmark feature may include an indicator lumen. Detecting a location of a fixed, constantly present catheter landmark or feature relative to a center of the optical coherence tomography imaging device may include at least one of detecting an indicator lumen within a lumen detection range from one or more image edges or detecting an indicator lumen within an indicator lumen angle range, the indicator lumen angle range being spaced from the detected trajectory by an angular offset. The template may include an indicator circle disposed across the indicator lumen.

[0013] In another embodiment, a non-transitory computer readable medium is provided that stores an image correction program that causes a computing device with a storage medium to perform functions including receiving frames of sequential images generated by an eccentric imaging catheter, identifying imaged wall locations in the sequential images from the sequential image period, and correcting the sequential image period by matching the imaged wall locations of the sequential images to reference wall locations of the sequential image period. Correcting the sequential image period may include deleting intervening sequential images between the sequential images and the reference wall locations. The reference wall locations may be from a sequence of reference wall locations that correspond to a reference sinusoidal pattern of wall locations. The reference sinusoidal pattern of wall locations may be derived from a geometric model of the eccentric imaging catheter. The reference sinusoidal pattern of wall locations may be determined by a calibration procedure of the eccentric imaging catheter. The frames may be selected from a series of sequential images generated by the eccentric imaging catheter. The frames of sequential images may correspond to a 360 degree rotation of the eccentric imaging catheter or a fixed number of sequential images. The non-transitory computer readable medium may further include downsampling the series or cycle of sequential images. Downsampling may include deleting sequential images from the series or cycle of sequential images. The ratio of deleted sequential images to non-deleted sequential images may be greater than or equal to 20:1. Downsampling may include cropping a fixed number of pixels or distance from the camera origin end of each of the sequential images from the series or cycle of sequential images. The non-transitory computer readable medium may further include extrapolating at least one replacement sequential image from at least some of the deleted sequential images, the at least one replacement sequential image being less in number than the number of deleted sequential images.

[0014] In another embodiment, a non-transitory computer readable medium is provided that stores an image correction program that causes a computing device having a storage medium to perform functions including receiving frames of sequential images generated by a variable wall distance imaging catheter, identifying imaged wall locations in the sequential images from a period of sequential images, and correcting the period of sequential images by matching the imaged wall locations of the sequential images to reference wall locations of the period of sequential images. The variable wall distance imaging catheter may be an eccentric imaging catheter. The variable wall distance imaging catheter may be a concentric non-circular imaging catheter.

[0015] In another embodiment, an imaging processing system for performing image processing functions is provided, the imaging processing system comprising: a receiving unit configured to receive frames of sequential images generated by an eccentric imaging catheter; an identification unit configured to identify an imaged wall location in the sequential image from the sequential image period; and a correction unit configured to correct the sequential image period by matching the imaged wall location of the sequential image to a reference wall location of the sequential image period.

[0016] In yet another embodiment, an image processing method is provided that includes receiving frames of sequential images generated by an eccentric imaging catheter, identifying imaged wall locations in the sequential images from a period of the sequential images, and correcting the period of the sequential images by matching the imaged wall locations of the sequential images to reference wall locations of the period of the sequential images.

[0017] In another embodiment, a re-entry catheter system is provided comprising an elongate catheter body having a proximal end, a distal end, a common lumen extending from a proximal location at the proximal end to a distal location proximal to the distal end and having a first central longitudinal axis, a distal lumen extending from the distal location of the common lumen to the distal end of the catheter body and having a second central longitudinal axis parallel to and offset from the first central longitudinal axis, and a side lumen extending distally from the distal location of the common lumen to a sidewall location of the catheter body, the sidewall location being a central longitudinal axis of the catheter body. A re-entry catheter system is provided comprising a catheter body comprising a side lumen proximal to the distal end and an imaging lumen extending from the proximal end of the catheter body, and a proximal catheter handle coupled to the proximal end of the catheter body, the handle comprising a catheter body rotator knob configured to rotate the catheter body relative to the proximal catheter handle, and an imaging catheter displacement knob configured to longitudinally displace an imaging catheter inserted into the catheter body relative to the catheter body. A sidewall location of the side lumen may be located proximal to a closed distal end of the imaging lumen. The distal end of the catheter body may be asymmetrically tapered cone-shaped. The catheter body may further comprise an indicator lumen. The average diameter of the indicator lumen may be smaller than the average diameter of the imaging lumen, smaller than the average diameter of the common lumen, and smaller than the average diameter of the distal lumen.

[0018] Features from any of the disclosed embodiments may be used in combination with each other, including but not limited to, In addition, other features and advantages of the present disclosure will become apparent to those skilled in the art through consideration of the following detailed description and the accompanying drawings. [Brief description of the drawings]

[0019] The drawings illustrate several embodiments of the present disclosure, with the same reference numbers referring to the same or similar elements or features in different views or embodiments shown within the drawings.

[0020] [Figure 1A]FIG. 1A is an isometric view of a portion of a catheter, according to an embodiment.

[0021] [Figure 1B] 1B and 1C are cross-sectional views of the catheter as shown in FIG. 1A taken along planes 1B-1B and 1C-1C, respectively. [Figure 1C] 1B and 1C are cross-sectional views of the catheter as shown in FIG. 1A taken along planes 1B-1B and 1C-1C, respectively.

[0022] [Diagram 2] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments. [Figure 3A] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments. [Figure 3B] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments. [Figure 4] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments. [Figure 5A] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments. [Figure 5B] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments. [Figure 6A] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments. [Figure 6B] 2-6B are cross-sectional views of catheters having different guidewire feed sections in different environments.

[0023] [Figure 7] FIG. 7 is a flowchart of an example method for providing an off-ramp indicator, according to an embodiment.

[0024] [Figure 8A] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8B] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8BB] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8C] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8D] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8DD] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8E] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8F] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8FF] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8G] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8H] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment. [Figure 8HH] 8A-8HH are schematic diagrams illustrating locations on a catheter where images can be taken, and examples of raw and lamp overlay images taken at each location, according to one embodiment.

[0025] [Figure 9] FIG. 9 is an example of a waterfall image taken at the location illustrated in FIG. 8HH, according to one embodiment.

[0026] [Figure 10A] 10A-10D are schematic diagrams illustrating how moving an OCT imaging device within the imaging lumen changes the locations of different components of the catheter relative to the center of the OCT imaging device, according to one embodiment. [Figure 10B] 10A-10D are schematic diagrams illustrating how moving an OCT imaging device within the imaging lumen changes the locations of different components of the catheter relative to the center of the OCT imaging device, according to one embodiment. [Figure 10C]10A-10D are schematic diagrams illustrating how moving an OCT imaging device within the imaging lumen changes the locations of different components of the catheter relative to the center of the OCT imaging device, according to one embodiment. [Figure 10D] 10A-10D are schematic diagrams illustrating how moving an OCT imaging device within the imaging lumen changes the locations of different components of the catheter relative to the center of the OCT imaging device, according to one embodiment.

[0027] [Figure 11] FIG. 11 is the waterfall image shown in FIG. 9 further annotated to show additional information shown thereon.

[0028] [Figure 12] FIG. 12 illustrates a template overlaid on an image, according to one embodiment.

[0029] [Figure 13] FIG. 13 is a circular image that can be used to find the trajectory of the catheter and indicator lumen, according to an embodiment.

[0030] [Figure 14] FIG. 14 is an isometric view of a detectable structure that may be disposed in or on a catheter (not shown), according to an embodiment.

[0031] [Figure 15] FIG. 15 is an isometric view of a catheter including a detectable structure, according to an embodiment.

[0032] [Figure 16A] 16A-16D are side elevation, side cross-sectional, top and top cross-sectional views of an exemplary proximal catheter assembly. [Figure 16B] 16A-16D are side elevation, side cross-sectional, top and top cross-sectional views of an exemplary proximal catheter assembly. [Figure 16C] 16A-16D are side elevation, side cross-sectional, top and top cross-sectional views of an exemplary proximal catheter assembly. [Figure 16D] 16A-16D are side elevation, side cross-sectional, top and top cross-sectional views of an exemplary proximal catheter assembly.

[0033] [Figure 16E] FIG. 16E depicts a variation of the catheter that includes a proximal cable between the catheter housing and the connector.

[0034] [Figure 17] FIG. 17 is a diagram of a system according to an embodiment.

[0035] [Figure 18A] 18A and 18B are images of an exemplary graphical user interface that may be used in conjunction with a touch screen, according to an embodiment. [Figure 18B] 18A and 18B are images of an exemplary graphical user interface that may be used in conjunction with a touch screen, according to an embodiment.

[0036] [Figure 18C] 18C and 18D depict ruler overlays of the OCT images of the touch screen and secondary display, respectively. [Figure 18D] 18C and 18D depict ruler overlays of the OCT images of the touch screen and secondary display, respectively.

[0037] [Figure 19] FIG. 19 is a flow chart of general system operation during a re-entry operation.

[0038] [Figure 20A]20A-20C depict overall, proximal, and distal planar views of another exemplary catheter system comprising a 4 French image-guided re-entry catheter. [Figure 20B] 20A-20C depict overall, proximal, and distal planar views of another exemplary catheter system comprising a 4 French image-guided re-entry catheter. [Figure 20C] 20A-20C depict overall, proximal, and distal planar views of another exemplary catheter system comprising a 4 French image-guided re-entry catheter.

[0039] [Figure 21A] 21A-21E depict fluoroscopic images of the therapeutic procedure. [Figure 21B] 21A-21E depict fluoroscopic images of the therapeutic procedure. [Figure 21C] 21A-21E depict fluoroscopic images of the therapeutic procedure. [Figure 21D] 21A-21E depict fluoroscopic images of the therapeutic procedure. [Figure 21E] 21A-21E depict fluoroscopic images of the therapeutic procedure.

[0040] [Figure 22A] 22A and 22B depict OCT images at the same anatomical location, but at different rotational orientations. [Figure 22B] 22A and 22B depict OCT images at the same anatomical location, but at different rotational orientations.

[0041] [Figure 22C] 22C and 22D depict OCT and angiogram images in the same anatomical location and similar rotational orientation as FIG. 22B, with the guidewire extending out from the side port. [Figure 22D]22C and 22D depict OCT and angiogram images in the same anatomical location and similar rotational orientation as FIG. 22B, with the guidewire extending out from the side port.

[0042] [Figure 22E] 22E and 22F are OCT and angiogram images, respectively, confirming guidewire reentry. [Figure 22F] 22E and 22F are OCT and angiogram images, respectively, confirming guidewire reentry.

[0043] [Figure 22G] FIG. 22G is an angiogram image after re-entry and stent placement.

[0044] [Figure 23A] FIG. 23A is a schematic waterfall image of a captured 2D image from a concentric rotational imaging catheter system.

[0045] [Figure 23B] FIG. 23B is a schematic circumferential reconstruction of the waterfall image from FIG. 23A.

[0046] [Figure 24A] FIG. 24A is a schematic waterfall image of a captured 2D image from a concentric rotational imaging catheter system, with distortion from rotational variations.

[0047] [Figure 24B] FIG. 24B is a schematic circumferential reconstruction of the waterfall image from FIG. 24A.

[0048] [Figure 25A] FIG. 25A is a schematic waterfall image of a captured 2D image from an eccentric rotational imaging catheter system.

[0049] [Figure 25B] FIG. 25B is a schematic circumferential reconstruction of the waterfall image from FIG. 25A.

[0050] [Figure 26A] FIG. 26A is a schematic waterfall image of a captured 2D image from an eccentric rotational imaging catheter system, with distortion from rotational variations.

[0051] [Figure 26B] FIG. 26B is a schematic circumferential reconstruction of the waterfall image from FIG. 26A.

[0052] [Figure 27] FIG. 27 is an example waterfall image from an off-centered OCT catheter system annotated with the corresponding set of imaged and predicted catheter edges and image corrections.

[0053] [Figure 28A] FIG. 28A is a schematic perspective view of an exemplary multi-lumen catheter with an eccentric imaging lumen.

[0054] [Figure 28B] 28B and 28C are various cross-sectional views of the catheter in FIG. [Figure 28C] 28B and 28C are various cross-sectional views of the catheter in FIG.

[0055] [Figure 29A] 29A and 29B are exemplary pre- and post-correction OCT images, respectively, captured from the exemplary catheter in FIG. 28A. [Figure 29B] 29A and 29B are exemplary pre- and post-correction OCT images, respectively, captured from the exemplary catheter in FIG. 28A.

[0056] [Figure 29C]FIG. 29C is a reference OCT image from the same imaging location as FIGS. 29A and 29B, with limited or no significant rotational distortion.

[0057] [Figure 30A] 30A-30C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A. [Figure 30B] 30A-30C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A. [Figure 30C] 30A-30C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A.

[0058] [Figure 31A] 31A-31C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A. [Figure 31B] 31A-31C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A. [Figure 31C] 31A-31C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A.

[0059] [Figure 32A] 32A-32C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A. [Figure 32B] 32A-32C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A. [Figure 32C] 32A-32C are exemplary pre-correction, post-correction, and baseline OCT images captured from the exemplary catheter in FIG. 28A.

[0060] [Figure 33A] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33B] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33C] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33D] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33E] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33F] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33G] 33A-33M depict example preparation steps for using an OCT imaging system. [Fig. 33H] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33I] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33J] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33K] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33L] 33A-33M depict example preparation steps for using an OCT imaging system. [Figure 33M] 33A-33M depict example preparation steps for using an OCT imaging system.

[0061] [Figure 34A] 34A-34F depict exemplary OCT images obtained during use of the OCT imaging system. [Figure 34B] 34A-34F depict exemplary OCT images obtained during use of the OCT imaging system. [Figure 34C] 34A-34F depict exemplary OCT images obtained during use of the OCT imaging system. [Fig. 34D] 34A-34F depict exemplary OCT images obtained during use of the OCT imaging system. [Figure 34E] 34A-34F depict exemplary OCT images obtained during use of the OCT imaging system. [Fig. 34F] 34A-34F depict exemplary OCT images obtained during use of the OCT imaging system.

[0062] [Figure 34G] FIG. 34G depicts a ruler overlay on the OCT image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0063] Detailed Description Embodiments are directed to systems, devices, and methods for antegrade dissection and re-entry. Such systems, devices, and methods may include image-guided interventional catheters ("catheters"), systems including same, and methods of using same. An exemplary catheter includes a housing having a distal catheter region configured to be positioned at least partially within the body and a proximal catheter region configured to remain at least partially outside the body. The distal catheter region includes an imaging body and a catheter body. The distal catheter region defines multiple lumens. The multiple lumens may include an imaging lumen, a guidewire lumen, an off-ramp, and an indicator lumen. The imaging lumen is configured to receive an imaging device (e.g., an optical coherence tomography imaging device). The guidewire lumen is configured to receive a guidewire and includes a distal region and a proximal region. The off-ramp extends from the guidewire lumen at or near the intersection of the distal and proximal regions of the guidewire lumen. The indicator lumen is configured to receive an indicator that is detectable by an imaging device and a software algorithm. The catheter may also include one or more guidewire feeds. The guidewire feeds are configured to move the guidewire from the proximal section to the off-ramp. Examples of guidewire feeds may include a distal section that includes a ridge, a tapered region, the centers of the distal and proximal sections of the guidewire lumen being offset, or an intersection of the distal and proximal sections that includes a thin penetrable wall.

[0064] A catheter may be used to guide a guidewire into the body. For example, the distal end of the guidewire may be inserted into the body. The lumen in which the guidewire is disposed may be blocked (e.g., due to a chronic total occlusion) and / or may branch into one or more additional lumens (e.g., the true lumen). In such a situation, the proximal end of the guidewire may be disposed into the guidewire lumen through an opening formed on the distal catheter region of the catheter. The catheter may be moved into the body along the guidewire until the catheter reaches a desired location (e.g., in the blocked portion of the lumen or where an additional lumen branches from it). At this point, the guidewire is disposed in both the distal and proximal regions of the guidewire lumen. Once the catheter reaches the desired location, the guidewire may be retracted into the catheter until the guidewire is no longer in the distal region of the catheter. The guidewire may then be advanced into the catheter, which causes the distal guidewire tip to interact with the guidewire feed. The interaction between the guidewire and the guidewire feed causes the guidewire to move into the off-ramp instead of back into the distal section of the guidewire lumen. The guidewire may exit the catheter via the off-ramp at a different angle relative to the catheter than when the guidewire exited the catheter via the distal section of the guidewire lumen.

[0065] During use, it may be difficult to determine the orientation of the off-ramp relative to the body. The orientation of the off-ramp may need to be known to prevent the guidewire exiting the off-ramp from puncturing the lumen of the body or blood vessel or moving in an improper direction. The imaging device in conjunction with other elements of the catheter may be used to determine the orientation of the off-ramp at any given time. For example, a system including the catheter may be capable of detecting one or more elements of the catheter (e.g., an indicator disposed within an indicator lumen). The orientation of the off-ramp may then be determined based on a known positional relationship between the imaging device and one or more detected elements, and a known positional relationship between the imaging device, the detected elements, and the off-ramp.

[0066] FIG. 1A is an isometric view of a portion of a catheter 100, according to an embodiment. FIGs. 1B and 1C are cross-sectional views of the catheter 100 taken along planes 1B-1B and 1C-1C, respectively, as shown in FIG. 1A. The catheter 100 includes a housing 102. The housing 102 includes a distal catheter region (part of that shown in FIG. 1A) and a proximal catheter region (shown in FIG. 16A). The distal catheter region includes at least a portion of the housing 102 that is disposed within the body, while the proximal catheter region includes at least a portion of the housing 102 that is not disposed within the body. For illustrative purposes, the distal catheter region of the housing 102 includes an imaging body 104 that facilitates imaging of structures and / or tissues surrounding the catheter 100 and the catheter body 106. The imaging body 104 may include a material that is at least partially transparent (e.g., at least partially optically transparent) to a stimulus emitted and / or detected by the imaging device 109 (e.g., an optical coherence tomography imaging device ("OCT") or ultrasound) to reduce imaging opacity to the imaging device 109. The catheter body 106 may be opaque to the imaging device 109. However, it should be noted that the imaging body 104 may be opaque and / or the catheter body 106 may be at least partially transparent to the imaging device 109. The imaging body 104 may be integrally formed with or distinct from the catheter body 106.

[0067] In some embodiments, the catheter 100 is an over-the-wire support or extender catheter to aid in the placement and positioning of a guidewire within a blood vessel. In another embodiment, the catheter 100 is an over-the-wire OCT-guided support or extender catheter to facilitate the placement and positioning of a guidewire with real-time visualization within a blood vessel. In some embodiments, the catheter 100 is an over-the-wire OCT-guided re-entry catheter that may be used in conjunction with a guidewire. The catheter 100 may be 2.5 French, 3 French, 4 French, 5 French, 6 French, 7 French, 8 French, 9 French, or 10 French, may be 50-130 cm, 90-130 cm, 90-110 cm, 50-135 cm, or 90-135 cm long, with or without a radiopaque tip, with or without an inflatable or collapsible balloon at the distal end of the catheter 104 on the opposite side of the off-ramp exit 114, may optionally include a hydrophilic coating, and may be straight or angled. The balloon may be at least partially transparent to the imaging device 109 .

[0068] The housing 102 of the catheter 100 may define multiple lumens. For example, the housing 102 may define an imaging lumen 108, a guidewire lumen 110, an indicator lumen 112 (FIGS. 1C and 8A), and an off-ramp 114. One or more of the imaging lumen 108, the guidewire lumen 110, or the indicator lumen 112 may extend generally parallel to the longitudinal axis of the catheter 100. Meanwhile, the off-ramp 114 is a lumen that extends from the guidewire lumen 110 to a lateral edge 116 of the housing 102. In other words, at least a portion of the off-ramp 114 extends at a non-parallel angle relative to the longitudinal axis of the catheter 100.

[0069] The imaging lumen 108 may be configured to receive an imaging device 109 (shown in FIG. 1A ). The imaging device 109 may include any suitable device capable of imaging the catheter 100 and / or the environment (e.g., an artery) about it. In an embodiment, the imaging device 109 may include at least one of an OCT, an ultrasound transceiver, or another imaging device. The imaging lumen 108 may extend into the imaging body 104 of the housing 102, thereby enabling the imaging device 109 to image the environment about the catheter 100.

[0070] Guidewire lumen 110 may be configured to receive a guidewire (not shown). Guidewire lumen 110 may extend to a distal end 111 of housing 102 and form an opening 113 in housing 102, thereby allowing a guidewire to extend out of catheter 100. Guidewire lumen 100 includes a distal section 119 and a proximal section 120 (FIG. 1B). Distal section 119 extends from the distal end 111 of housing 102 to proximal section 120. Proximal section 120 extends from distal section 119 toward (e.g., to) a proximal catheter region. In an embodiment, all or a majority of the distal section 119 (e.g., 80% or more or 90% or more of its length) is within the imaging body 104 of the housing 102, and all or a majority of the proximal section 120 (e.g., 90% or more or 95% or more of its length) is within the catheter body 106. In such an embodiment, the intersection 122 of the distal section 119 and the proximal section 120 is at or near the intersection of the imaging body 104 and the catheter body 106. Locating all or a majority of the distal section 119 within the imaging body 104 allows the of-ramp 114 and the environment in which it positions the guidewire to be imaged by the imaging device 109.

[0071] In some embodiments, catheter 100 may be an OCT-guided re-entry catheter over a wire that may be used in conjunction with a guiding catheter and a guidewire. In such embodiments, guidewire lumen 110 may be configured to receive a guidewire. The guidewire may be a 0.014 inch guidewire, but in some other variations may be a 0.009 inch or 0.010 inch guidewire, with or without a tapered tip. The guidewire may be provided with a hydrophobic or hydrophilic coating in more and more areas, and may have a length in the range of 150-300 cm, 150-200 cm.

[0072] The indicator lumen 112 may be configured to receive a material that may be detectable by the imaging device 109. In certain examples, the material received by the indicator lumen 112 may be more easily detectable by the imaging device 109 than the guidewire and / or imaging body 104. For example, the material received by the indicator lumen 112 may be more opaque or reflective to the stimuli emitted and / or detected by the imaging device 109 than the guidewire and / or imaging body 104. Additionally or alternatively, the indicator lumen 112 may provide a material discontinuity or interface between the medium inside the lumen and its surroundings, resulting in a difference in optical index of refraction and partial reflectance whose interference signal is detectable by the imaging device 109 and used as a fixed landmark. In certain embodiments, the indicator lumen 112 may also be used for other functions, including, but not limited to, flushing blood to improve imaging clarity or injecting diagnostic or therapeutic agents into the surrounding tissue. In such embodiments, the indicator lumen 112 may also form an opening (not shown) in the housing 102 through which flushing fluid and / or diagnostic or therapeutic agents may be dispensed from the housing 102 .

[0073] As discussed above, the off-ramp 114 extends from the guidewire lumen 110 to a lateral edge 116 of the housing 102 (e.g., a lateral edge of the imaging body 104). Thus, diverting the guidewire from the guidewire lumen 110 into the off-ramp 114 causes the guidewire to extend at an angle relative to the longitudinal axis of the catheter 100. The off-ramp 114 may extend from the guidewire lumen 110 at a location at or near the intersection 122 between the distal section 119 and the proximal section 120. Such a location of the off-ramp 114 allows the guidewire to be diverted into the off-ramp 114 as the guidewire is retracted from the distal section 119. The off-ramp 114 may extend at an angle between about 10° and about 45° relative to the central axis of the guidewire lumen 100, such as within the range of about 10° to about 20°, about 15° to about 25°, about 20° to about 30°, about 25° to about 35°, about 30° to about 40°, or about 35° to about 45°.

[0074] Guidewire lumen 110 and off-ramp 114 are configured to receive a guidewire. Thus, guidewire lumen 110 and off-ramp 114 exhibit a cross-sectional size (e.g., diameter or other maximum lateral dimension) that is sufficiently large to receive a guidewire. In an embodiment, at least a portion of guidewire lumen 110 extending from distal end 111 and a portion of off-ramp 114 extending from intersection 122 exhibit a cross-sectional size that is significantly larger (e.g., up to 5%, 10%, 20%, 25%, 50%, 75%, 100%, 150%, or 200% larger) than the cross-sectional size of the guidewire. The significantly larger cross-sectional size of guidewire lumen 110 and off-ramp 114 facilitates insertion of a guidewire into guidewire lumen 110 and off-ramp 114. Additionally, the cross-sectional size of guidewire lumen 110 and / or off-ramp 114 may decrease along at least a portion of their length. For example, the cross-sectional size of guidewire lumen 110 may be reduced at locations away from distal end 111 and / or proximate intersection 122 and / or at the exit of off-ramp 114. As will be discussed in more detail below, the reduced cross-sectional size of guidewire lumen 110 may facilitate redirecting the guidewire from guidewire lumen 110 (e.g., proximal section 120) into the off-ramp 114. The reduced cross-sectional size of guidewire lumen 110 and / or off-ramp 114 also reduces guidewire migration therein and minimizes backflow of fluids from the body into guidewire lumen 110.

[0075] During use, the guidewire may be inserted into a body lumen, such as an artery in the human body. In some cases, the body lumen may be obstructed, for example, by plaque or atherosclerotic plaque. Generally, the guidewire may be used to move, disrupt, or otherwise remove the obstruction. In certain embodiments, the guidewire may be unable to move, disrupt, or otherwise remove the obstruction, such as when the obstruction is caused by a chronic total occlusion. When the guidewire encounters an obstruction that cannot be moved, disrupted, or otherwise removed, the guidewire may be positioned within the guidewire lumen 110 (if not already positioned within the guidewire lumen 110), thereby allowing the guidewire to guide the catheter 100 through the body. When catheter 100 is at or near an obstruction that cannot be dislodged, broken, or otherwise removed, the guidewire may be retracted into guidewire lumen 110 until the distal tip of the guidewire is spaced farther from the distal end 111 of catheter 100 than the entrance to the off-ramp 114 (i.e., the opening of the off-ramp 114 adjacent to the guidewire lumen 110). For example, the distal tip of the guidewire may be retracted until the distal tip of the guidewire is positioned proximal to the bifurcation junction between the guidewire lumen 110 and the off-ramp 114. The guidewire may then be advanced into the off-ramp 114. Advancing the guidewire into the off-ramp 114 changes the direction in which the guidewire extends, thereby allowing the guidewire to advance around or through the obstruction in the direction of the true lumen, which in turn allows catheter 100 to advance around the obstruction. For example, after the guidewire has been extended out of the off-ramp 114, the catheter 100 may be removed and, with the guidewire backloaded into the catheter 100 at the distal tip 111, the catheter 100 is reinserted into the lumen, following the guidewire and advancing around the obstruction.

[0076] As discussed above, catheter 100 may include one or more guidewire feeds. The guidewire feeds are configured to redirect the guidewire within proximal section 120 toward off-ramp 114 instead of distal section 119 as the guidewire is advanced from proximal section 120 toward distal section 119. Catheter 100 may include any number of guidewire feeds, such as one guidewire feed, two guidewire feeds, three guidewire feeds, four guidewire feeds, or five or more guidewire feeds. In the embodiment illustrated in FIG. 1B, catheter 100 includes three guidewire feeds. However, it should be noted that catheter 100 may include guidewire feeds other than or in addition to the guidewire feeds illustrated in FIG. 1B.

[0077] In an embodiment, the guidewire feed may include a ridge 124. The ridge 124 is a protrusion that extends from the housing 102 into the guidewire lumen 110. The ridge 124 may assume any suitable shape, such as a generally spherical, cylindrical, or wedge-like shaped portion. The ridge 124 may be located at the intersection 122 or in the proximal section 120 at a location that is slightly (e.g., about 5 mm or less, about 3 mm or less, or about 1 mm or less) spaced from the intersection 122. The ridge 124 may be opposite the entrance to the off-ramp 114. The ridge 124 may form an obstacle that causes the guidewire to detour into the off-ramp 114 instead of the distal section 119. For example, as discussed above, the guidewire may be retracted into the catheter 100 until the guidewire is no longer disposed within the distal section 119, or in other words, until the distal tip of the guidewire is disposed within the proximal section 120. Advancing the guidewire toward the distal tip 111 causes the distal tip of the guidewire to contact the ridge 124. Contacting the guidewire against the ridge 124 causes the guidewire to be diverted toward the off-ramp 114 instead of the distal section 119. The ridge 124 may be an improvement over conventional means for diverting the guidewire between two paths. For example, the ridge 124 does not need to move to divert the guidewire, thus avoiding problems associated with at least some conventional means for diverting the guidewire, such as the conventional means breaking or becoming stuck.

[0078] In an embodiment, the guidewire feed may include a tapered region 126 formed in the distal section 119. The tapered section 126 includes a region of the distal section 120 where the lateral dimension (e.g., diameter) of the distal section 119 decreases. The lateral dimension of the tapered section 126 may decrease with increasing proximity to the intersection 122. The tapered section 126 may decrease the lateral dimension of the distal section 119 until the lateral dimension of the distal section 119 is only slightly larger than the lateral dimension of the guidewire. The tapered section 126 may be spaced from the distal tip 111 such that the reduced lateral dimension of the tapered section 127 does not inhibit the insertion of the guidewire into the guidewire lumen 110. For example, as shown, the tapered region 126 may extend from or near the intersection 122. Tapered region 126 reduces the lateral dimension of distal section 119 at intersection 120 such that the lateral dimension of distal section 119 is less than the lateral dimension of the entrance to off-ramp 114. The reduced lateral dimension of distal section 119 at intersection 122 relative to the lateral dimension of the entrance to off-ramp 114 reduces the likelihood that advancing the guidewire will cause the guidewire to enter distal section 119 and increases the likelihood that advancing the guidewire will cause the guidewire to enter off-ramp 114. Again, tapered region 126 may be an improvement over conventional means for diverting the guidewire between two passageways because tapered region 126 does not need to move to divert the guidewire. Also, as discussed above, the reduced lateral dimension of guidewire lumen 110 caused by tapered region 126 inhibits fluid from flowing up to guidewire lumen 110.

[0079] In an embodiment, the guidewire feed includes offsetting the distal and proximal sections 119, 120 relative to one another. For example, the distal section 119 may exhibit a distal central axis 128 and the proximal section 120 may exhibit a proximal central axis 130. The distal central axis 128 may be offset relative to the proximal central axis 130. In other words, the distal central axis 128 and the proximal central axis 130 are not aligned. The distal and proximal central axes 128, 130 may be positioned such that the proximal central axis 130 is closer to the off-ramp 114 than the distal central axis 128. The offset between the distal and proximal axes 128, 130 increases the likelihood that advancing the guidewire from the proximal section toward the distal tip 111 will cause the guidewire to enter the off-ramp 114 instead of the distal section 119.

[0080] The catheter 100 may include one or more additional features, such as augmenting structures 118, that reinforce the guidewire lumen 110 or another portion of the catheter 100. The catheter 100 may also include a helical reinforcement or a side-slotted tube.

[0081] The catheters disclosed herein may include guidewire feeds other than the guidewire feed shown in FIG. 1B. FIGS. 2-6B are cross-sectional views of catheters having different guidewire feeds according to different environments. Except as otherwise disclosed herein, the catheters shown in FIGS. 2-6B may be identical to or substantially similar to any of the catheters disclosed herein. For example, the catheter may include a housing defining multiple lumens. The multiple lumens may include a guidewire lumen and an off-ramp. The guidewire lumen may include a distal section and a proximal section. It is noted that the guidewire feeds illustrated in FIGS. 2-6B may be used in any of the catheter embodiments disclosed herein. Additionally, it is noted that any of the guidewire feeds illustrated in FIGS. 2-6B may be used in conjunction with one or more of any other guidewire feeds disclosed herein.

[0082] 2, the guidewire feed section of catheter 200 may include a thin penetrable wall ("thin wall") 232. Thin wall 232 may be positioned at or near intersection 222 of distal section 219 and proximal section 220 of guidewire lumen 210. Thin wall 232 is configured to be penetrable by a guidewire to form a hole therein. The hole formed in thin wall 232 may exhibit a size that corresponds to the size of the guidewire. In other words, penetrating thin wall 232 with a guidewire causes thin wall 232 to exhibit a hole, which may be as small as possible to fit the guidewire therethrough. The small size of the hole reduces the likelihood that advancing a guidewire from proximal section 220 toward distal tip 211 will move the guidewire back through thin wall 232.

[0083] Thin wall 232 may be formed from any suitable material. In some embodiments, thin wall 232 may be formed from the same material as the portion of housing 202 defining intersection 222, which may facilitate manufacturing of thin wall 232 than if thin wall 232 were formed from a different material than the portion of housing 222 defining intersection 222. In some embodiments, thin wall 232 formed from a different material than the portion of housing 202 forming intersection 222 may allow thin wall 232 to be formed from a material that is at least one of more easily penetrable, stronger, more easily manufactured as a thin film, or otherwise more beneficial than the material forming housing 202.

[0084] In an embodiment, the thin wall 232 is about 1 μm or more, about 5 μm or more, about 10 μm or more, about 25 μm or more, about 50 μm or more, about 100 μm or more, about 150 μm or more, about 200 μm or more, about 300 μm or more, about 400 μm or more, about 500 μm or more, about 600 μm or more, about 700 μm or more, about 800 μm or more, about 1 mm or more, about 1.25 mm or more, about 1.5 mm or more, about 2 mm or more. or greater than about 1 μm to about 10 μm, about 5 μm to about 25 μm, about 10 μm to about 50 μm, about 25 μm to about 100 μm, about 50 μm to about 150 μm, about 100 μm to about 200 μm, about 150 μm to about 300 μm, about 200 μm to about 400 μm, about 300 μm to about 500 μm, about 400 μm to about 600 μm, about 500 μm The guidewire lumen 210 exhibits a minimum thickness, measured parallel to one or more central axes, that is within the range of about 700 μm, about 600 μm to about 800 μm, about 700 μm to about 900 μm, about 800 μm to about 1 mm, about 900 μm to about 1.25 mm, about 1 mm to about 1.5 mm, or about 1.25 mm to about 2 mm.

[0085] Thin wall 232 is configured to be easily penetrable. Whether thin wall 232 is easily penetrable depends on the material forming thin wall 232 and the minimum thickness of thin wall 232. In an embodiment, thin wall 232 does not include holes therein. In such an embodiment, a device (e.g., a needle or probe) may be inserted into guidewire lumen 210 via the proximal or distal guidewire lumen. A device inserted into guidewire lumen 210 may puncture or otherwise penetrate thin wall 232 and form a small hole therein. The small hole may exhibit a lateral dimension (e.g., diameter) substantially equal to, or more preferably smaller than, the lateral dimension of the guidewire. The device may then be removed from guidewire lumen 210, and a guidewire may then be inserted into guidewire lumen 210. The guidewire may extend through a small hole formed in thin wall 232. After the guidewire is extended through the small hole, the small hole exhibits a lateral dimension substantially similar to the lateral dimension of the guidewire. In an embodiment, the thin wall 232 includes a small hole formed therein prior to use. In such an embodiment, the thin wall 232 does not need to be penetrated by the device. However, forming a small hole in the thin wall 232 prior to use may prevent the catheter 200 from being used with a guidewire that exhibits a lateral dimension smaller than the lateral dimension of the small hole. In an embodiment, the thin wall 232 does not include a hole formed therein. In such an embodiment, the guidewire itself may be used to form a small hole in the thin wall 232 instead of using the device to form a hole prior to insertion of the guidewire.

[0086] 3A and 3B, the catheter 300 includes a housing 302. The housing 302 defines a guidewire lumen 310 including a distal section 319 and a proximal section 320. The housing 302 defines a side opening 334 that extends from a lateral edge 316 to the guidewire lumen 310 at an intersection 322 of the distal and proximal sections 319, 320. The housing 302 also includes a biased section 336 that assumes a tubular shape that extends partially across the side opening 334. In other words, the biased section 336 forms the intersection 322. When unrestricted, the biased section 336 assumes a curved shape that allows the biased section 336 to extend through the side opening 334. As shown in Figure 3A, the portion of the guidewire lumen 310 defined by the biased section 336 may be urged into alignment with the distal and proximal sections 319, 320 of the guidewire lumen 310 when the guidewire 338 is disposed within the proximal and distal sections 319, 320 of the guidewire lumen 310. As shown in Figure 3B, retracting the guidewire 338 from the proximal section 319 allows the biased section 336 to assume its curved shape, which in turn allows the biased section 336 to form an off-ramp of the catheter 300. Advancing the guidewire 338 towards the distal tip 311 causes the guidewire 338 to follow the curved shape of the distal section 336. The curved shape of 336 may extend at an angle between about 10° and about 45° relative to the central axis of guidewire lumen 310, such as within the range of about 10° to about 20°, about 15° to about 25°, about 20° to about 30°, about 25° to about 35°, about 30° to about 40°, or about 35° to about 45°.

[0087] 4, the catheter 400 includes a housing 402. The housing 402 defines a guidewire lumen 410 including a distal section 419 and a proximal section 420. The housing defines a side opening 434 that extends from a lateral edge 416 to the guidewire lumen 410 at the intersection of the distal and proximal sections 419, 420. The catheter 400 also includes a ramp 440 that extends at least partially across the side opening 434. The ramp 440 may be distinct from the housing 402 (e.g., the housing 402 may be formed from a polymer and / or the ramp 440 may be formed from Nitinol) or may be integrally formed with the housing 402 (e.g., the housing 402 and the ramp 440 may be formed from the same material and exhibit a single piece construction). The ramp 440 may be configured to rotate or bend at or near where the ramp 440 meets the housing 402. The ramp 440 may toggle between a first state and a second state. The ramp 440 may extend generally parallel to a central axis of the guidewire lumen 410 when the ramp 440 is in the first state. The ramp 440 may assume the first state when a guidewire (not shown) is positioned within the distal and proximal sections 419, 420. Removing the guidewire from the distal section 419 allows the ramp 440 to move toward a surface of the guidewire lumen 410 opposite the side opening 434. The ramp 440 may move toward the opposing surface of the guidewire lumen 410 because the ramp 440 is biased or due to gravity. The ramp 440 is in the second state when the ramp 440 is allowed to move toward a surface of the guidewire lumen 410 opposite the side opening 434. When ramp 440 exhibits the second state, advancing the guidewire toward distal tip 411 causes the guidewire to exit guidewire lumen 410 at side opening 436. In other words, ramp 440 forms at least a portion of an off-ramp of catheter 400. It should be noted that housing 402 may include a tapered surface 442 extending from or near ramp 440 when ramp 440 does not extend to lateral edge 416 of housing 402.

[0088] 5A and 5B, the catheter 500 includes a housing 502. The housing 502 defines a guidewire lumen 510 including a distal section 519 and a proximal section 520. The housing 502 defines a lateral opening 534 extending from a lateral edge 516 to the guidewire lumen 510 at an intersection 522 of the distal and proximal sections 519, 520. The housing 502 also includes a hypotube 544 disposed within the guidewire lumen 510. The hypotube 544 is movable (e.g., slidable) relative to the guidewire lumen 510. The hypotube 544 is biased such that at least a portion of the hypotube 544 assumes a curved shape when the hypotube 544 is unrestricted. The hypotube 544 may be switchable between a first state and a second state. When in the first state, the hypotube 544 may be positioned within the distal and proximal sections 519, 520 (as shown in FIG. 5A ) and extend across the side opening 536. The hypotube 544 may assume a shape that corresponds to the shape of the proximal and distal sections 519, 520 of the guidewire lumen 510 when the hypotube 544 is in the first state. The hypotube 544 may be switched from the first state to the second state by retracting the hypotube 544 and the guidewire (not shown) such that the hypotube 544 and the guidewire are no longer within the distal section 519 of the guidewire lumen 510. When the hypotube 544 is in the second state, the portion of the hypotube 544 adjacent the side opening 534 may bend to assume its curved shape, thereby allowing the hypotube 544 to extend through at least a portion of the side opening 534. The curved shape of the hypotube 544 allows the hypotube 544 to form an off-ramp for the catheter 500. Thus, advancing the guidewire toward the distal end 511 when the hypotube 544 is in the second state causes the guidewire to exit the catheter 500 and out the side opening 534.In another embodiment, the hypotube 544 may be retracted further proximal to the side opening 534 so that it extends straight within the guidewire lumen 510, and the hypotube 544 is then rotated 180 degrees and re-advanced towards the distal end of the guidewire lumen 510. Doing so keeps the hypotube straight within the guidewire lumen 510 while the hypotube 544 is urged against the opposing inner walls of the side opening 534. The hypotube 544 can then be repositioned to its original state as in FIG. 5A to allow the guidewire to be advanced to the distal end of the guidewire lumen 510.

[0089] 6A and 6B, the catheter 600 includes a housing 602. The housing 602 defines a guidewire lumen 610 including a distal section 619 and a proximal section 620. The housing 602 defines a side opening 654 that extends from a side edge 616 to the guidewire lumen 610 at an intersection 622 of the distal and proximal sections 619, 620. The catheter 600 also includes a biasing member 646 attached to at least a portion of the side edge 616 opposite the portion of the housing 602 that defines the intersection 622. When a guidewire is disposed within the distal and proximal sections 610, 620 of the guidewire lumen 610, the distal catheter region of the catheter 600 may be generally straight (as shown in FIG. 6A). Retracting the guidewire 638 from the distal section 619 of the guidewire lumen 610 causes the biasing member 646 to bend a portion of the distal catheter region of the housing 602 (as shown in FIG. 6B ). Advancing the catheter toward the distal tip 611 after the biasing member 646 has bent the housing 602 causes the distal section 619 to bend the guidewire 638, thereby changing the direction in which the guidewire 638 extends. In other words, the biasing member 646 causes the distal section 619 to form an off-ramp of the catheter 600.

[0090] 1A-6B illustrate various guidewire feeds. It should be noted that any of the catheters disclosed herein may include one or more of the guidewire feeds disclosed above or any other conventional guidewire feeds, including combinations of any of the aforementioned guidewire feeds.

[0091] Figures 7-8HH and the accompanying description illustrate an exemplary method of using the catheter. For simplicity and clarity, the catheter 100 illustrated in Figures 1A-1C will be referenced during the discussion of the method of using the catheter. However, it should be noted that the method of using the catheter discussed below may be used with any suitable catheter, including any of the catheters discussed herein or any conventional catheter.

[0092] An individual (e.g., a surgeon) using catheter 100 may use OCT imaging device 109 to facilitate using off-ramp 114 to change the direction in which the guidewire extends. In certain embodiments, an individual using catheter 100 may position catheter 100 so that off-ramp 114 faces away from the adventitia of the lumen (e.g., the outermost tissue layer of the arterial wall) because perforation of the adventitia may cause bleeding into the pericardium. Such positioning of catheter 100 allows off-ramp 114 to be aligned with the direction of the true lumen in which the individual desires to push the guidewire. However, it may be difficult for an individual using catheter 100 to determine the direction in which off-ramp 114 is oriented using OCT imaging device 109.

[0093] Thus, the methods and systems disclosed herein are configured to provide an off-ramp indicator 1202 (shown in FIG. 12) that indicates the general direction in which the off-ramp 114 is oriented. The off-ramp indicator 121 assists an individual in identifying the direction towards which the off-ramp 114 is pointing and the direction through which the user will push the guidewire out, in this case the direction of the true lumen or artery. The off-ramp indicator 121 is configured to be precise and distinct enough to avoid confusing an individual using the catheter 100.

[0094] 7 is a flowchart of an example method 700 for providing an off-ramp indicator, according to an embodiment. Method 700 may include one or more operations, functions, or actions as illustrated by one or more of blocks 705, 710, 715, 720, or 725. The operations described in blocks 705-725 may be performed (or caused to be performed) in response to execution of computer-executable instructions stored on non-transitory memory.

[0095] The method 700 includes block 705, which includes acquiring one or more images using the OCT imaging device 109 at one or more locations along the length of the catheter 100. The method 700 may include block 710, which includes filtering out data from one or more images. The method 700 may include block 715, which includes detecting a trajectory of the catheter 100. The method 700 may include block 720, which includes detecting a location of a landmark or feature that is fixed and always present relative to the center of the OCT imaging device 109. The method 700 may include detecting a trajectory using block 715 and detecting a landmark or feature that is fixed and always present relative to the center of the OCT imaging device 109 using block 720 over one or more iterations in a forward or reverse order, which may be predetermined by an algorithm. The method 700 may include block 725, which includes applying a template, including an off-ramp indicator, over one or more images (as shown in FIG. 13).

[0096] The blocks included in method 700 are for illustrative purposes. In some embodiments, the blocks may be performed in the order listed or in a different order. In some embodiments, one or more of blocks 705-725 may be omitted, split into multiple blocks, modified, or supplemented. In some embodiments, two or more of blocks 705-725 may be combined into a single block. In some embodiments, method 700 may include one or more additional blocks, such as modifying or otherwise editing one or more images (e.g., changing the brightness or contrast of an image).

[0097] Block 705 includes acquiring one or more images using OCT imaging device 109 at one or more locations along the length of catheter 100. OCT imaging device 109 may take 1D images. Each 1D image may include hundreds to thousands of data points (i.e., pixels). OCT imaging device 109 may take multiple 1D images to generate a 2D image. The 2D image generated by OCT imaging device 109 may be a waterfall image (as shown in FIGS. 9 and 11) or a non-waterfall image of a sector (as shown in FIGS. 8D, 8DD, 8F, 8FF, 8H, 8HH, 12, and 13).

[0098] In an embodiment, the OCT imaging device may capture a single 2D image at a location along the length of the catheter 100, or may take multiple 2D images at various locations along the length of the catheter 100. FIGS. 8A-8HH are examples of various locations on the catheter 100 and examples of circular non-waterfall images (sector views) taken at each of the locations. FIG. 8A illustrates that a first image may be taken at a location where the off-ramp 114 begins to branch off from the guidewire lumen 110, and FIG. 8B is an example of a first image in an unannotated form. To facilitate review of the first image, FIG. 8BB includes circles superimposed thereon indicating the edge of the catheter 100 (larger circle) and the indicator lumen 112 (smaller circle). Note that subsequent images include similar edges superimposed thereon. FIG. 8C illustrates that a second image may be taken closer to the distal end 111 than the first image (FIG. 8A) where the of-ramp 114 is distinct from the guidewire lumen 110, and FIGS. 8D and 8DD are examples of the second image in unannotated and annotated configurations, respectively. FIG. 8E illustrates that a third image may be taken closer to the distal end 111 than the second image (FIG. 8C) where the of-ramp 114 meets the lateral edge 116, and FIGS. 8F and 8FF are examples of the third image in unannotated and annotated configurations, respectively. FIG. 8G illustrates that a fourth image may be taken closer to the distal end 111 than the third image (FIG. 8E) between the of-ramp 114 and the distal end 111, and FIGS. 8H and 8HH are examples of the fourth image in unannotated and annotated configurations, respectively. It should be noted that the locations discussed above are provided only as examples, and that block 705 may include capturing 2D images at more or fewer locations and / or may include capturing 2D images at different locations on the catheter 100.

[0099] 8B, 8D, 8F, and 8H, it is difficult or impossible to determine the orientation of catheter 100. For example, it is difficult or impossible to determine the direction in which off-ramp 114 extends from guidewire lumen 110 or the direction in which a guidewire would extend from off-ramp 114. Thus, it is important to find the orientation of catheter 100, and in particular the direction in which off-ramp 114 extends from guidewire lumen 110, as provided by off-ramp indicator 1202 (shown in FIG. 12).

[0100] Block 710 includes filtering out data from one or more images. The information contained within the images is highly redundant and, in some locations, highly unlikely to provide useful information in determining the orientation of the catheter 100. Thus, dropping data from one or more images may reduce the redundancy, noise, and amount of data being analyzed. The reduced redundancy, noise, and data may make it quicker to determine the orientation of the catheter 100, such that the orientation of the catheter 100 may be determined in real time (from the perspective of the individual using the catheter 100), and may make it more accurate to determine the orientation of the catheter 100 by reducing the likelihood that the computer system will misidentify features of the catheter 100.

[0101] Block 710 may include analyzing the waterfall image. FIG. 9 is an example of a waterfall image 900 taken at a location of the catheter 100 between the distal tip 111 and the off-ramp 114, according to an embodiment. The waterfall image 900 includes multiple 1D images taken by the OCT imaging device 109. Each of the 1D images (or A-lines in OCT, A-mode lines in ultrasound imaging) may be arranged as a row in the waterfall image. That is, the waterfall image may be arranged in a horizontal direction over a time interval (or B-scan). This exemplary waterfall image 900 is also annotated to indicate a catheter edge detection range 904 from the imager origin 902 where detection of the lateral edges 116 of the catheter 100 is performed and thus used to detect the peaks 906 of the sinusoids defined by the lateral edges 116 of the catheter 100. It has been found that in some applications, the peaks 906 may be the most easily and / or reliably detected feature of the catheter 100. Also depicted is a lumen detection range 908 within which detection of indicator lumen 112 is performed. Lumen detection range 908 reduces the likelihood that other features similar to indicator lumen 112 will be unintentionally detected and identified as indicator lumen 112. Note that while the waterfall image shown in FIG. 9 may include 5,000 1D images, the waterfall image detected by OCT imaging device 109 may include more or less than 5,000 1D images. Block 710 may include reducing the number of 1D images in the waterfall image due to redundant information contained in the 1D images. For example, block 710 may include excluding all but 1 in 10 to 1 in 35 (e.g., 1 in 27) 1D images from the waterfall image. In certain embodiments, block 710 may include reducing the number of 1D images to approximately 180 images.

[0102] Components of the catheter 100 are likely to be within a threshold distance from the OCT imaging device 109, while anything else that is farther away from the OCT imaging device 109 than the threshold distance is likely to be a lumen or part of a body. Thus, only data that falls within a threshold distance from the top of the waterfall image is likely to contain data related to components of the catheter 100. Block 710 may include excluding data that is more than a threshold distance away from the top of the waterfall image, since such data is unlikely to contain information about components of the catheter 100. In other words, block 710 may include retaining data that is within a threshold distance of the top of the image. In the particular example illustrated in FIG. 9, block 710 may include excluding all data that is more than 200 data points (i.e., pixels) from the top of the image, since such data is unlikely to contain information about components of the catheter 100.

[0103] As will be discussed in more detail below, blocks 715 and 720 include determining the location (e.g., distance and / or angle) of certain components, edges, or interfaces of the catheter 100 relative to the center of the OCT imaging device 109. Note that the location of these components of the catheter 100 relative to the center of the OCT imaging device 109 may vary for a variety of reasons. In certain examples, the location of these components of the catheter 100 relative to the center of the OCT imaging device 109 may depend on the particular catheter 100. In certain examples, the OCT imaging device 109 may move within the imaging lumen 108, which may change the location of the components of the catheter 100 relative to the center of the OCT imaging device 109. FIGS. 10A-10D are cross-sectional views of the catheter 100 illustrating how moving the OCT imaging device 109 within the imaging lumen 108 changes the location of different components of the catheter 100 relative to the center of the OCT imaging device 109, according to an embodiment. In particular, Figures 10A-10D illustrate OCT imaging devices 109 located at the top, bottom, left, and right regions of the imaging lumen 108, respectively. Depending on the location of the OCT imaging device 109 within the imaging lumen 108, the distance from the center of the OCT imaging device 109 and the trajectory of the catheter 100 (i.e., the lateral edge 116 of the catheter 100 that is closest to the center of the OCT imaging device 109) will vary. Also, depending on the location of the OCT imaging device 109 within the imaging lumen 108, the angle measured between the shortest line extending from the center of the OCT imaging device 109 to the trajectory of the catheter 100 and the line extending from the center of the OCT imaging lumen 108 to the center of the indicator lumen 112 will vary. It should be noted that the location of the components of the catheter 100 relative to the center of the OCT imaging device 109 may also vary due to compressive forces applied to the catheter 100 from the lumen, bending of the catheter 100, and / or manufacturing imperfections. Blocks 715 and 720 will use ranges, instead of exact positions, to find components of catheter 100 to accommodate for these variations.

[0104] Block 715 includes detecting the trajectory of the catheter 100. As discussed above, the trajectory of the catheter 100 is the lateral edge 116 of the catheter 100 that is closest to the center of the OCT imaging device 109. Referring back to FIG. 9, the OCT imaging device 109 may not be located within the center of the catheter 100, and thus the distance from the center of the OCT imaging device 109 to the lateral edge 116 of the catheter 100 may vary. Varying the distance between the center of the OCT imaging device 109 and the lateral edge 116 causes the lateral edge 116 to appear as a sine wave in the waterfall image. The sine wave is superimposed on the image of FIG. 9 to more clearly show the lateral edge 116 of the catheter 100. The approximate distance from the center of the OCT imaging device 109 and the trajectory of the catheter 100 is known, with any uncertainty, primarily due to the OCT imaging device 109 not being centered within the imaging lumen 108. Two horizontally extending lines are used to limit the area of ​​the waterfall image where the trajectory of the catheter 100 may be located. The two lines correspond to the approximate distance from the center of the OCT imaging device 109 to the trajectory of the catheter 100, with the space between the two annular portions accommodating variations in the distance between the center of the OCT imaging device 109 and the trajectory for reasons discussed above. The system may limit or at least focus the search for the trajectory of the catheter 100 within the space between the two lines. Note that limiting or focusing the search for the trajectory of the catheter 100 between the two lines prevents or at least inhibits false positives. The trajectory of the catheter 100 is the portion of the sinusoid closest to the top of the waterfall image (i.e., the lateral edges 116 of the catheter 100). Figure 11 is the waterfall image shown in Figure 9 with further annotated to show additional information shown thereon, including showing the trajectory angle 920 of the catheter 100, which is the axis between the imager origin 902 and the closest distance to the catheter edge (e.g., the peak 906 of the sine wave). As will be discussed in more detail below, Figure 11 also depicts the indicator lumen angle 906, which is the axis between the imager origin 902 and the center of the detected indicator lumen 112.Detection of the indicator lumen 112 is facilitated by constraining the search based on a distance range 908 from the imager origin 902, but may also be constrained by an indicator lumen angle range 924. The angular distance 924 is based on the slope characteristic of a sine wave. Once the indicator lumen angle 906 is identified, the angular offset between the trajectory angle 920 and the indicator lumen angle 906 may be determined.

[0105] In one embodiment, the search for the trajectory of the catheter 100 is performed using an independent template search. The independent template search searches for the trajectory of the catheter 100 between two lines, as discussed above. The template search uses a template extracted from a typical reduced waterfall image that has been processed by Gaussian blurring and then rescaled. The template search involves the squared difference between the template and the patch of the search area (the template is slid across the search area), and the results are then normalized. The result of the template search is a certainty image that indicates a high probability of a hotspot feature being present at that location.

[0106] Block 720 includes detecting the location of a fixed, always-present landmark or feature relative to the center of the OCT imaging device 109. The fixed, always-present landmark or feature may be always-present along at least a portion of the length of the catheter 100. For simplicity, the indicator lumen 112 will be discussed as being a fixed, always-present landmark feature. However, it should be noted that other components, edges, or interfaces of the catheter 100 may be fixed, always-present landmark features instead of or in addition to the indicator lumen 112.

[0107] In an embodiment, block 720 includes detecting the trajectory of the indicator lumen 112 relative to the center of the OCT imaging device 109. The trajectory of the indicator lumen 112 may refer to the portion of the indicator lumen 112 that is closest to and / or farthest from the center of the OCT imaging device 109. The approximate distance from the center of the OCT imaging device 109 (top of the waterfall image) and the trajectory of the indicator lumen 112 is known, and any uncertainty therein is primarily due to the OCT imaging device 109 not being centered within the imaging lumen 108. The distance from the center of the OCT imaging device 109 to the trajectory of the indicator lumen 112 may be known, determined experimentally or empirically (e.g., using the OCT image), or calculated based on the geometry of the particular catheter. Referring to FIG. 11, one or more sets of two horizontally extending lines 908 are used to limit the area of ​​the waterfall image in which the trajectory of the indicator lumen 112 may be located. One or more sets of two lines correspond to the approximate distance from the center of the OCT imaging device 109 to the trajectory of the indicator lumen 112, with a space between the two lines to accommodate variations in the distance between the center of the OCT imaging device 109 and the trajectory of the indicator lumen 112, for reasons explained above. In Figures 9 and 11, two sets of two horizontally extending lines 908 are used, one to limit or focus the search for the trajectory of the indicator lumen 112 that is closest to the center of the OCT imaging device 109, and the other to limit or focus the search for the trajectory of the indicator lumen 112 that is furthest from the center of the OCT imaging device 109. It should be noted that the two lines 904 used to limit or focus the search for the trajectory of the indicator lumen 112 closest to the center of the OCT imaging device 109 are identical to the two lines 908 used to find the trajectory of the catheter 100, although these two sets of lines need not be identical depending on the geometry of the catheter 100. It should be noted that limiting or focusing the search for the indicator lumen 112 between the two lines 908 prevents or at least inhibits false positives.To facilitate inspection, indicator lumen 112 is illustrated in Figures 3 and 5 using superimposed circles.

[0108] In an embodiment, the location of the trajectory of the catheter 100, as detected during block 715, may be used to detect the location of the indicator lumen 112 relative to the center of the OCT imaging device 109. For example, an approximate angle is known between a line extending from the center of the OCT imaging device 109 to the trajectory of the catheter 100 and a line extending from the center of the OCT imaging device 109 to the center of the indicator lumen 112 (hereinafter referred to as the "trajectory / indicator angle"), and the uncertainty in the trajectory / indicator angle is primarily due to the OCT imaging device 109 not being centered within the imaging lumen 108. The trajectory / indicator angle may be known, experimentally or empirically determined (e.g., using OCT images), or calculated based on the geometry of a particular catheter. With reference to FIG. 11, the angle offset 926 is the distance on the waterfall image that corresponds to the minimum approximate trajectory / indicator angle. An indicator lumen angle range 924, which corresponds to the uncertainty in the trajectory / indicator angle, extends from the angle offset 926. At least a portion of the indicator lumens 112 (e.g., the trajectory of the indicator lumens 112) is expected to lie within the indicator lumen angle range 924. Thus, the search for the indicator lumens 112 may be limited or focused within the indicator lumen angle range 924. In certain examples, the search for the indicator lumens 112 may be limited or focused within the overlap between the indicator lumen angle range 924 and between one or more sets of two lines 908. It is noted that limiting or focusing the search for the indicator lumens 112 within the indicator lumen angle range 924 prevents or at least inhibits false positives.

[0109] Block 720 may detect the center of indicator lumen 112 (shown using reference numeral 922 on FIG. 11) using the trajectory of indicator lumen 112 or other information detected during block 720.

[0110] In one embodiment, the search for fixed, consistent landmarks or features is performed using an independent template search. The independent template search searches for fixed, consistent landmarks or features between two lines, as discussed above. The template search uses a template extracted from a typical reduced waterfall image that has been processed by Gaussian blurring and then rescaled. The template search involves squared differences between the template and patches of the search area (the template slides across the search area), and the results are then normalized. The result of the template search is a certainty image that indicates the high probability of a feature being at that location, which is a hotspot.

[0111] Generally, the trajectory of the catheter 100 is more reliably found in the waterfall image than the indicator lumen 112. Thus, the trajectory of the catheter 100 may be used to detect the trajectory / indicator angle. However, in some embodiments, the indicator lumen 112 may be found with greater certainty (e.g., more reliably detected than the trajectory of the catheter 100). In such embodiments, the indicator lumen 112 may be used to detect the trajectory of the catheter 100 using the techniques discussed above. For example, the location of the indicator lumen 112 and the known approximate trajectory / indicator angle may be used to restrict or at least focus the search of the trajectory of the catheter 100 to an area (i.e., an angular offset may be measured from the center of the indicator lumen 112, and an angular range extending from the angular offset is used to restrict or focus the search).

[0112] In an embodiment, block 705 may include detecting multiple images at different locations along the length of catheter 100, as discussed above. In such an embodiment, blocks 710-720 may be performed for only one, some, or all of the multiple images. A certainty value may be detected for each of the images for which blocks 710-720 are performed. Only the image with the highest certainty value or an image with a certainty value above a threshold (if applicable) is used to determine the orientation of catheter 100 and the direction in which off-ramp 114 extends from the remainder of catheter 100.

[0113] Block 725 includes applying a template 1200 (shown in FIG. 12 ), including an off-ramp indicator 1202, across one or more images. Preferably, block 725 applies the template 1200 to one or more images in substantially real time, thereby allowing an individual using the catheter 100 to know the orientation of the catheter 100 and the direction in which the off-ramp 114 extends at any given time. As used herein, “substantially real time” refers to a period of time that is short enough that an individual using the catheter 100 is unable to detect any delay or that any delay is unlikely to adversely affect the operation of the catheter 100. For example, “substantially real time” may allow for a delay of about 5 seconds or less, more preferably about 1 second or less, or even more preferably about 0.5 seconds or less, or about 0.1 seconds or less.

[0114] The template 1200 includes the imaging lumen 108, guidewire lumen 110, indicator lumen 112, the orientation of the off-ramp 114 (indicated using the off-ramp indicator 1202), and the location (e.g., the angle between them) and relative distance between the lateral edge 116 of the catheter 100. The template 1200 may be known, experimentally or empirically determined (e.g., using OCT images), or calculated on a catheter-by-catheter basis. For example, three parameters of the template 1200 that may be known, determined, or calculated include the angle between the centers of the guidewire lumen 110 and indicator lumen 112, the radial distance between the centers of the imaging lumen 108 and guidewire lumen 110, and the off-ramp angle direction relative to a vector from the center of the imaging lumen 108 and the center of the guidewire lumen 110. Template 120 may also make one or more assumptions about the diameter of catheter 100, the diameter of imaging lumen 108, the diameter of guidewire lumen 110, the diameter of indicator lumen 112, the relative angles of the centers of the three lumens, the relative positions of the three lumens within catheter 100, etc. Template 1200 may be aligned on the image such that characteristics of catheter 100 detected between blocks 715 and 720 are aligned with corresponding portions of template 1200.

[0115] The template 1200 is a visual template. That is, when the template 1200 is overlaid over an image, it adds one or more visual indications. FIG. 12 illustrates the template 1200 overlaid on an image, according to an embodiment. The template 1200 includes an off-ramp indicator 1202. The off-ramp indicator 1202 indicates the angular direction in which the off-ramp 114 extends relative to the catheter 100 (e.g., relative to the guidewire lumen 110). The off-ramp indicator 1202 also indicates the orientation of the catheter 100. In an embodiment, the off-ramp indicator 1202 may include a line that indicates the general angular direction in which the off-ramp 114 extends relative to the remainder of the catheter 100. In an embodiment, the off-ramp indicator 1202 may be a triangle, two lines extending from a point, a single line with an arrow, or other indicator that indicates the general angular direction in which the off-ramp 114 extends relative to the remainder of the catheter 100, in addition to any uncertainty. In one embodiment, as shown, the off-ramp indicator 1202 may include a line and an indicator (eg, a triangle) that indicates uncertainty.

[0116] In an embodiment, the template 1200 may include at least one of an imaging circle 1204, a guidewire circle 1206, an indicator circle 1208, or a catheter edge circle 1210, which are shown when the template 1200 is overlaid on an image. The imaging circle 1204 may correspond to the location, size, and shape of the imaging lumen 108. The guidewire lumen 1206 may correspond to the location, size, and shape of the guidewire lumen 110. The indicator lumen 1208 may correspond to the location, size, and shape of the indicator lumen 112. The indicator lumen 112 provides the user of the catheter 100 with direct and real-time visual feedback of the accuracy with which the off-ramp indicator 1202 is predicting the guidewire exit trajectory. For example, if the indicator lumen 112 is misaligned from the indicator lumen, the user can thus infer the deviation at which the guidewire will exit the off-ramp indicator 1202. The catheter edge circle 1210 corresponds to the location, size, and shape of the lateral edge 116 of the catheter 100. The imaging circle 1204, the guidewire circle 1206, the indicator circle 1208, and / or the catheter edge circle 1210 provide a visual indication to the individual using the catheter 100 to facilitate the individual interpreting what is shown in the image. The imaging circle 1204, the guidewire circle 1206, the indicator circle 1208, and / or the catheter edge circle 1210 also help indicate the orientation of the catheter 100 to the individual using the catheter 100. In an embodiment, the imaging circle 1204, the guidewire circle 1206, the indicator circle 1208, and / or the catheter edge circle 1210 may be selectively displayed. It should be noted that the imaging circle 1204, the guidewire circle 1206, the indicator circle 1208, and / or the catheter edge circle 1210 may be slightly apart on the image due to, for example, compression of the catheter 100 during use or manufacturing imperfections. The display of any element of the off-ramp indicator 1202 or template may be of any color or suitable form or shape that is easy for a user to identify. Not all elements 1202, 1204, 1206, 1208, and 1210 need to be displayed.An off-ramp indicator 1202 displayed using an indicator circle 1208 would meet the need to indicate the direction or trajectory of a guidewire exiting the off-ramp 114, for example, using a reference (indicator circle) indicator relative to the position of a fixed landmark (indicator lumen 112), allowing a user to determine whether the off-ramp indicator 1202 is displaying correctly.

[0117] Method 700 may include one or more additional blocks other than blocks 705-725. In an example, method 700 may include generating a template 1200 that is customized for each catheter. Calibrating and generating the template 1200 for each catheter may be tedious. Thus, software may be used to capture the variations for each catheter 100. The software may include generating various images of the catheter 100. The software may analyze the images and calibrate the template 1200 based on the various images. For example, the software may detect one or more features of the catheter 100 and calibrate the template 1200 based on the detected features. In an embodiment, a user of the catheter 100 may review the images to determine if the software accurately represents the features and may allow the user to modify the template to accommodate errors in detecting the features.

[0118] In certain embodiments, method 700 includes an optional block of duplicating a portion of the waterfall image prior to blocks 715 and 720. For example, the algorithms disclosed herein may have difficulty detecting the trajectory of catheter 100 and / or indicator lumen 112, as discussed in blocks 715 and 720, when the trajectory of catheter 100 and / or indicator lumen 112 is located at least partially at or near a lateral edge (e.g., left or right edge) of the waterfall image. Thus, method 700 may include duplicating a column of one edge of the waterfall image (either the right or left side) and adding the duplicated column to the other edge of the waterfall image. The duplicated column may include 5-30% (e.g., 15-25%) of the waterfall image. In certain embodiments, when an image includes 180 1D images, the first 40 1D images on the right side may be duplicated and added to the left side such that the waterfall image now has 220 1D images. Duplicating the columns of the waterfall image and adding the columns to opposing edges of the waterfall image ensures that the trajectories of the catheter 100 and indicator lumen 112 are not located at or near the lateral edges of the waterfall image.

[0119] In one embodiment, method 700 includes an optional block of detecting a certainty value of the trajectory of catheter 100 and indicator lumen 112 detected during blocks 715 and 720 and determining whether sufficient certainty exists to warrant displaying off-ramp indicator 121. In such an embodiment, off-ramp indicator 121 may be displayed when the certainty value exceeds a predetermined threshold. Detecting a certainty value of the trajectory of catheter 100 and indicator lumen 112 detected during blocks 715 and 720 prevents erroneous results from being displayed to an individual using catheter 100 that may confuse the individual.

[0120] In one embodiment, method 700 includes an optional block of editing the image. For example, method 700 may include adjusting the brightness of the image, adjusting the contrast of the image, or otherwise editing the image. Editing the image may facilitate detecting the trajectory of catheter 100 and / or detecting indicator lumen 112. Editing the image may also make it easier for an individual using catheter 100 to understand and interpret the OCT image.

[0121] In one embodiment, the method 700 includes displaying the detected image to the individual as a catheter-centered view of the catheter 100, as opposed to the OCT imaging device 109 being the center of the image. In such an embodiment, the template 120 may be catheter-centered.

[0122] It should be noted that instead of a waterfall image, a circular image may be used to find the trajectory of the catheter 100 and / or the indicator lumen 112. For example, FIG. 13 is a circular image that may be used to find the trajectory of the catheter 100 and the indicator lumen 112, according to an embodiment. Because FIG. 13 is not a waterfall image, circular lines are added to the image instead of horizontal lines. The outer two lines 1352 may indicate the space where the trajectory of the catheter 100 may be found. Line 1354 indicates the location of the trajectory of the catheter 100. The inner two circular lines 1356 indicate the space where the trajectory of the indicator lumen 112 is expected to be found. The angled lines 1358 are the indicator lumen angle range. A line 1360 within the angled lines 1358 indicates the center of the indicator lumen 112.

[0123] In other embodiments, indicator lumen 112 may be located outside of detection range 304, completely decoupling it from track edge detection. Indicator lumen 112 may also be any shape other than circular and sized within the physical constraints of catheter 100 such that it distinguishes it from other features in the cross-section of catheter 100.

[0124] In other embodiments, the lateral edges 116 of the catheter 100 may include fixed features along the extent of travel of the imaging device 109 within the catheter 100. Such features may include placement and bonding of small clear or impermeable elongated objects or grooves along the extent of travel of the imaging device 109.

[0125] As discussed above, the imaging device of the catheters disclosed herein may detect images of the catheter at one or more locations along the length of the housing. For example, the imaging device may detect one or more images by physically moving the imaging device along the length of the housing. During use, it may be difficult for a user of the catheter to know the location of the imaging device and the location of the catheter and the environment around the catheter being imaged by the imaging device at any given time. Thus, any of the catheters disclosed herein may include a detectable structure configured to indicate the location of the imaging device along the length of the housing. FIG. 14 is an isometric view of a detectable structure 1450 that may be disposed in or on a catheter (not shown) according to an embodiment. The detectable structure 1450 is configured to be disposed in or on the housing 102.

[0126] The detectable structures 1450 are configured to be detectable by the imaging device 109. Thus, the detectable structures 1450 are formed from a material that is easily detectable by the imaging device. For example, the detectable structures 1450 may be formed from a material that is at least partially opaque to or reflective of a stimulus emitted or received by the imaging device. In an embodiment, when the imaging device is an OCT imaging device, the detectable structures 1450 may be formed from a material that is at least partially opaque (e.g., more opaque than the surrounding housing) or reflective to light. In an embodiment, when the imaging device is an ultrasound device, the detectable structures 1450 may be formed from a material that is at least partially opaque (e.g., more opaque than the surrounding housing) or reflective to ultrasound wavelengths.

[0127] The detectable structure 1450 is configured to indicate the location of the imaging device relative to the housing. For example, the detectable structure 1450 may indicate the distance from the distal tip, the intersection of the distal and proximal sections of the guidewire lumen, and / or the distance from the intersection of the catheter body and the imaging body of the housing. The detectable structure 1450 indicates the location of the imaging device relative to the housing because the detectable structure 1450 has a known location on the housing.

[0128] The detectable structure 1450 includes a base 1452. The base 1452 may have an annular or semi-annular shape since the housing 102 has a generally circular cross-sectional shape. The annular or semi-annular shape of the base 1452 also allows the lumen of the catheter to pass through the base 1452. In certain embodiments, the base may have a semi-annular shape that allows the imaging device to detect at least a portion of the environment centered around the catheter when the imaging device is at least partially surrounded by the annular base 1452. The detectable structure 1450 also includes one or more extension arms 1454 extending from the base 1452. The detectable base 1452 and the one or more extension arms 1454 may be used to determine the position of the imaging device 109. For example, the imaging device may detect the base 1452 when the imaging device is adjacent to or within at least a portion of a volume defined by the base 1452, thereby indicating a location of the imaging device. Similarly, the imaging device may detect one or more extension arms 1454 when the imaging device is adjacent to the one or more extension arms 1454, thereby indicating a location of the imaging device. In an embodiment, as shown, the detectable structure 1450 includes multiple extension arms 1454 extending from the base 1452. Each of the multiple extension arms 1454 may extend a different length from the base 1452. The location of the imaging device 109 may be determined based on the number of extension arms 1454 detected by the imaging device 109. For example, using the particular detectable structure 1450 illustrated in FIG. 14, the imaging device 109 is positioned between the base 1452 and the end of the shortest extension arm 1454 when the imaging device 109 detects four extension arms 1454, and the imaging device 109 is positioned between the end of the second longest extension arm 1454 and the end of the longest extension arm 1454 when the imaging device 109 detects one extension arm 1454.

[0129] Catheters disclosed herein may include detectable structures other than the detectable structure 1450 illustrated in FIG. 14. For example, FIG. 15 is an isometric view of a catheter 1500 including a detectable structure 1550, according to an embodiment. Except as otherwise disclosed herein, the catheter 1500 may be identical to or substantially similar to any of the catheters disclosed herein. The catheter 1500 includes a housing 1502. To facilitate illustration, the lumen defined by the housing 1502 is not illustrated. The housing 1502 defines one or more holes and / or depressions. The holes and / or depressions may be spaced apart along a longitudinal axis of the housing 1502. The relative positions of each of the holes and / or depressions on the housing 1502 may be known. The holes and / or depressions may be detectable by an imaging device. Thus, the holes and / or depressions form the detectable structure 1550. The position of the imaging device within the housing 1502 may be determined by counting the number of holes and / or depressions that the imaging device passes through as it moves within the housing 1502.

[0130] FIG. 16A is a side view of a catheter 1600, according to an embodiment. Except as otherwise disclosed herein, the catheter 1600 may be the same as or substantially similar to any of the catheters disclosed herein. For example, the catheter 1600 includes a distal catheter region 1656 and a proximal catheter region 1658. The distal catheter region 1656 may be the same as or substantially similar to the catheter shown in FIGS. 1A-6B. The overall length of the catheter 1600 from the end of the distal catheter region 1656 to the proximal catheter region 1658 may be about 1 m to about 3 m. The portions of the catheter 1600 formed in the distal catheter region 1656 and the proximal catheter region 1658 may be of any suitable size, such as 4 French or smaller.

[0131] The catheter 1600 may include a hub 1660 attached to a terminal end of the proximal catheter region 1658. The hub 1660 may optionally be tapered in a distal direction, as depicted in FIG. 16A. The hub 1660 may be attached to the proximal catheter region 1658 using any suitable technique. For example, a portion of the proximal catheter region 1658 adjacent its terminal end may be disposed within the distal end of the hub 1660 attached thereto using an interference fit, or the proximal catheter region 1658 may be integrally formed with the hub 1660. The hub 1660 may include one or more openings therein that allow access to one or more of the lumens of the distal connector of the catheter 1600. For example, the distal connector 1660 may include a guidewire flush port 1662 configured to allow one or more fluids to flow into the guidewire lumen. The hub 1660 may also optionally include a guidewire introducer port 1664 to allow a guidewire to be introduced into the catheter and / or for the distal end of a guidewire to extend out of the catheter 1600.

[0132] The catheter 1600 also includes a housing 1666. The housing 1666 is configured to be gripped and manipulated by a user of the catheter 1600. The housing 1666 may include one or more actuators that may be manipulated by a user of the catheter 1600, thereby allowing the user to operate the catheter 1600. For example, the housing 1666 may include a first actuator 1668 and a second actuator 1670, and one or more flanges 1676 and / or recesses 1678 to facilitate engagement or releasable attachment to other components, such as a sled assembly, an interconnect or handle socket for the housing 1666 or a sterile cover. The first and second actuators 1668, 1670 may include knobs (e.g., rotatable knobs) or any other suitable actuators. The first and second actuators 1668, 1670 may be configured to control one or more operations of the catheter 1600. In an embodiment, the first actuator 1668 may be used to adjust the longitudinal position of an imaging device inserted into and / or engaged with the housing 1666. In such an embodiment, the first actuator 1668 may comprise a rotatable knob utilizing a helically threaded interface to advance or retract an imaging device engaged with the interface. In other variations, the first actuator 1668 may comprise a mechanical slide or rack and pinion assembly for moving the imaging device. In an embodiment, the second actuator 1670 is a catheter body rotation interface or adapter that facilitates rotation of the distal and proximal catheter regions 1656, 1658 without requiring rotation of the entire catheter 1600 and / or housing 1666. Thus, rotation of the catheter off-ramp of the distal catheter region 1656 does not result in rotation of all catheter structures.When the actuator is configured to rotate a portion of the catheter 1600, the housing 1666 may include a fiber optic rotary junction, such as those manufactured by Spinner (Munich, Germany), Princetel (Hamilton, NJ), or Moog (Elma, NY).

[0133] The housing 1666 may also include an optical connector 1672 (e.g., a standard 2.5 mm optical connector) provided at a proximal end of the housing 1666 for connecting the catheter 1600 to a standard superluminescent diode (SLED) light source or swept laser source of an OCT system. Any of a variety of known ophthalmic or medical OCT control systems or components may be used, such as Zeiss CIRRUS (Carl Zeiss Meditec USA, Inc., Dublin, Calif.) and EnFocus (Leica Microsystems Inc., Deerfield, Ill.). The housing 1666 may also include one or more ports, for example, the housing 1666 may include an image flushing port 1672 configured to allow one or more fluids to be flowed into the imaging lumen.

[0134] FIG. 16E depicts another embodiment of a catheter 1680 similar to the catheter 1600 in FIGS. 16A-16D, except that a fiber optic cable 1682 is provided between the catheter housing 1666 and the fiber optic connector 1674. In this embodiment, the catheter housing 1666 is manipulated by the user as a proximal catheter handle, as the catheter 1600 in FIG. 16A was configured to do, rather than a combined catheter / sled assembly, as depicted in FIGS. 33A-33M. This cabled catheter 1680 also allows the system to transition the boundary proximally away from the catheter housing 1666 between sterile and non-sterile environments, which may simplify the connection between the catheter connector 1674 and the sled such that a sterile drape is not required at the junction of the connector 1674 and the sled. The length of the cable 1682 may be within a range of, for example, 6 inches to 6 feet, or 12 inches to 4 feet, or 1 foot to 3 feet, or 18 inches to 3 feet. In FIG. 16A, the permanent portion of the imaging drive / sled assembly is at the proximal end and a handle or housing socket is at the distal end where it connects to the catheter 1600.

[0135] 17 is a diagram of a system 1780, according to an embodiment. The system 1780 includes a catheter 1700. The catheter 1700 may include any of the catheters disclosed herein. The system 1780 may also be configured to perform any of the methods disclosed herein.

[0136] The system 1780 includes one or more components that facilitate the operation of the catheter 1700. For example, the system 1780 may include a bed 1782 or other structure on which a patient of the catheter 1700 may rest. The system 1780 may also include an external imaging device 1784 configured to image tissue within the patient's body and the catheter 1700. The external imaging device 1784 may include, for example, a projection radiography device (e.g., an X-ray machine), a magnetic resonance imaging (MRI) machine, a computed structural characteristic machine (e.g., a CT scanner), and an ultrasound device, or any other external imaging device. The system 1780 may also include an imaging display 1786 configured to provide data to a user (e.g., a physician) of the system 1780. The imaging display 1786 may display, for example, images detected by the imaging device of the catheter 1700 and / or images detected by the external imaging device 1784.

[0137] The system 1780 may include one or more components configured to operate and / or use data acquired by the catheter 1700. For example, the system 1780 may include an imaging driver 1788. The imaging driver 1788 may be configured to connect to the catheter 1700, e.g., an image interconnect 1674, such as a DMI fiber optic connector (Diamond SA, Losone, Switzerland). The imaging driver 1788 may also include software that enables the imaging device of the catheter 1700 to communicate with other components of the system 1780, such as at least one of the imaging display 1786, the console 1790, or the touch screen 1792. The imaging driver 1788 may be physically attached to the touch screen 1792, or the imaging driver 1788 may be separately mounted on an operating table inside or outside the sterile field.

[0138] The system 1780 may also include a console 1790 connected or connectable to the catheter 1700. The console 1790 is configured to facilitate operation of the catheter 1700. In an embodiment, the console 1790 may provide at least one of power to the catheter 1700 and / or light or other stimuli (e.g., via an optical cable) to the catheter 1700 when the imaging device requests light or other stimuli. In an embodiment, the console 1790 may also provide control of one or more operations of the catheter 1700 and analyze any data generated by the catheter. In such an embodiment, the console 1790 may further include a housing with a SLED light source or swept laser source output, a graphics processing unit (GPU) for generating output to a touch screen and an optional larger non-touch screen display, and corresponding connecting cable interfaces for the laser source output and the GPU output. The SLED light source or swept laser source output may include an imaging source interconnect and an interconnect for an optional aiming beam as described elsewhere herein. The console 1790 may also include one or more power switches, a locking mechanism (key or keyless), and an emergency stop button or actuator.

[0139] As discussed above, the system 1780 may include a touch screen 1792 (e.g., a tablet). The touch screen 1792 may enable the system 1780 to provide information or control options to a user of the system 1780 and allow the user to at least partially control the operation of the system 1780. The touch screen 1792 (i.e., a device configured to provide images to and receive input from the touch screen 1792) may include a graphical user interface that provides information to the user and allows the user to input commands to the system 1780. Figures 18A and 18B are images of an exemplary graphical user interface 1800 that may be used in conjunction with a touch screen, according to an embodiment. The user interface 1800 includes a command area 1802 that allows a user to interact with the user interface 1800 (e.g., input commands into the user interface 1800) and a display portion 1804 that is configured to provide data or images to the user. For example, the display portion 1804 may provide images generated by an imaging device in the catheter, using the methods discussed above.

[0140] 18A, the command area 1802 may include one or more icons displayed thereon that, when pressed by a user, change the image provided in the display portion 1804. Typically, the command area 1802 is displayed on the touch screen 1792 and the display portion 1804 is displayed on the imaging display 1786. In one embodiment, the icons may include a pause icon 1806 that, when pressed by a user, causes the image provided in the display portion 1804 to show a live feed or a still frame of the live feed of the image detected by the imaging device. In one embodiment, the icons may include one or more rotate icons 1808a and 1808b that, when pressed, rotate the image provided in the display portion 1804. The icons may also include a brightness icon 1810 and a contrast icon 1812 that are configured to change the brightness and contrast of the image, respectively, when manipulated by a user. The icons may include a flash play icon 1813 that, when pressed by a user, causes the display portion 1804 to show a playback of what was previously shown. The icons may also include an expansion icon 1814. Referring to FIG. 18B, the expansion icon 1814 may cause the graphical user interface 1800 to display an expansion box 1816 when pressed. The expansion box 1816 may include one or more additional icons (e.g., selectable circles). For example, the expansion box 1816 may include a lamp overlay icon 1818. When pressed, the lamp overlay icon 1818 may overlay a template on the image. The template may include any of the templates disclosed herein, for example, illustrating an off-ramp indicator 1820 (as shown) and an indicator circle 1822. The expansion box 1816 may also include a ruler icon 1824 that, when pressed, causes a scale to be overlaid on the image.18C and 18D depict an exemplary ruler overlay 1840 that may be provided on the touch screen and secondary display, respectively, comprising intersecting X- and Y-axis rulers with 0.5 and / or 1 mm incremental markings. In this particular example, the rings are each 1 mm apart, while the axis marks are 0.5 mm apart. In use, in addition to turning the ruler overlay 1840 on and off via the user interface icon 1824, the user interface may also be movable relative to the OCT image using the touch screen or an input device (e.g., keyboard, mouse, gesture tracker), which may facilitate measurement of the lumen or other anatomical structure when the catheter is not in a central location of the lumen or anatomical structure. The expansion box 1816 may also include a background subtraction icon 1826 that subtracts or at least reduces the background detected by the imaging device. 18A, the graphic user interface 1800 may optionally include additional control icons, including, but not limited to, a start / stop video recording icon 1828, a play / reloop icon 1830 that plays the last segment of the current video to allow the user to review the procedure, and brightness and contrast icon controls 1832 and 1834. The interface may also include an icon 1836 for turning on and off the aiming beam 3326, depicted in FIG. 33H, which may be used to verify the functionality of the catheter, the light source, and the optical coupling therebetween prior to insertion of the catheter into the patient.

[0141] 17, the system 1780 may include one or more input and output devices other than or in addition to the touch screen 1788. In one embodiment, as shown, the system 1780 may include an imaging display 1786. In one embodiment, the system 1780 may include a keyboard, mouse, joystick, or other input device that allows a user to modify the image detected by the imaging device.

[0142] The catheter systems disclosed herein are typically used in conjunction with the coronary arteries and other peripheral vasculature, including the arterial and venous vasculature, although in other variations, re-entry may be used in conjunction with other non-vascular body lumens, such as the lymphatic system, biliary tree, etc., and brain or neurovascular structures. The catheter system includes an imaging device, such as OCT or ultrasound, although the system may also be used in conjunction with an external visualization or imaging system, such as a fluoroscopy system in a catheterization procedure room or interventional radiology suite.

[0143] In one embodiment, a method of using a re-entry catheter system, as depicted in FIG. 19, is provided. Generally, the method 1900 includes console preparation 1902, sled preparation 1904, touch screen preparation 1906, and catheter preparation 1908. The catheter is then navigated to the lesion under fluoroscopic guidance (1910). Using the catheter's imaging system, including the imager position knob and catheter rotation adapter (1912), the surrounding anatomical structures are visualized. The catheter is advanced (1914) closer to the chronic total occlusion ("CTO"). The catheter is flushed (1916) with saline, if necessary or desired, which is visible on OCT imaging. The catheter is then advanced (1918) into the subintimal space, to and around the CTO. Once passed to the CTO, OCT imaging is used to identify true lumen pulsating regions and adventitial fibrous / honeycomb layer regions (1920). Using the imaging overlay, the guidewire lamp indicator is then rotated (1922) toward the true lumen and away from the pericardium or epicardium to avoid risk of perforation. Before advancing the guidewire, the overlay extension of the flush lumen circle is verified to be concentric with the OCT image of the flush lumen (1924). The guidewire can then be advanced and re-entry into the true lumen is verified by OCT imaging (1926). Once the guidewire is positioned, the catheter is retracted (1928) while maintaining the position of the guidewire. Once the catheter is removed, the imaging system is turned off (1930). A stent is then deployed over the guidewire or other procedures may be performed (1932).

[0144] Example detailed procedure The patient and procedure area are prepped and draped in the usual sterile fashion. A clear / transparent sterile drape may also be provided over the console's non-sterile touch screen. The touch screen drape may include a silicone adhesive, hook-and-loop interface, or snap buttons to facilitate attachment. The drape may also be used to grip the touch screen in a sterile fashion for repositioning or attachment to the procedure bed or fluoroscopy system rails.

[0145] The catheter 3300 is inspected for damage and using sterile techniques, removed from its packaging, and transported to a sterile field for further inspection. A protective cap 3302 covering the proximal fiber optic connector 3304 of the catheter housing 3306 is removed (FIGS. 33A and 33B). The proximal fiber optic connector 3304 may be a standard 2.5 mm ferrule. The catheter housing 3306 and connector 3304 are then inserted through the cap 3308 into the thread 3310 (FIG. 33C) until the catheter housing is fully attached via the circumferential recess 3312 (FIG. 33D). The interface between the catheter housing 3306 and the thread 3310 may be configured to provide visual, audible, and / or tactile feedback to indicate engagement, for example, via a surface marking, a latch, or a change in resistance. The catheter shaft is then hydrated in sterile saline for a period of time, e.g., 20 seconds to 120 seconds, 30 seconds to 60 seconds, or 30 seconds to 45 seconds. Using a syringe (e.g., 5 cc or 10 cc), the catheter 3300 may be flushed with sterile heparinized saline using the guidewire lumen flush port 3314 while blocking the guidewire introducer port 3316 and verifying patency with saline out of the distal end of the catheter 3320. Blocking the guidewire introducer port 3318 may be performed using the user's finger. Hemostatic valves may optionally be attached to the guidewire lumen flush port and / or introducer port to block or resist leakage. The syringe 3318 is then attached to the imaging lumen port 3320 to verify that fluid is present at the distal tip as well (FIG. 33E).

[0146] After reconfirming that the console is turned on, the catheter is then tested by selecting and entering case information on the touch screen. This may include catheter specific information such as a catheter identifier or serial number. The catheter user interface then becomes available. Various medical record information, e.g., patient ID, case ID, site ID, catheter serial number, etc., may be entered and edited on the data entry screen. After this data entry, the catheter user interface may then change to a catheter control screen (FIG. 18A) with various exemplary catheter control elements as described elsewhere herein. The various catheter controls and interface elements are tested and / or configured prior to beginning the procedure. To begin imaging, an actuator on the sled 3310, e.g., button 3322, may be activated (FIG. 33F) and the rotation of the imager within the catheter 3300 is confirmed via a sector view on the system display. In some variations, an indicator light is provided on the system or on the actuator button, which may glow a first color (e.g., white or green) if working properly, or provide a warning (red or flashing) if a problem with the imager rotation is detected by the sensor and / or by the image output itself. If a problem is detected, the catheter 3300 can be detached from the sled 3310 by actuating the removal latch or buttons 3324a and 3324b (FIG. 33G), released, and then reattached to retry and confirm proper loading and function. Tactile and / or audible feedback may be confirmed to ensure proper loading, and then imager activation can be resumed. Image quality and continuity of the light source to the end region of the catheter 3300 can be tested and confirmed by turning on the aiming beam 3322 (FIG. 33H) via the aiming beam icon 1826 of the user interface (FIG. 18A) and checked for visible light emission from the end region of the catheter 3300. The catheter 3300 may need to be replaced if the aiming beam 1826 is not visible or is very dim.

[0147] Prior to inserting the catheter 3300 into the patient, the sled 3310 and catheter 3300 should be turned off by reactivating the sled button 3318 (FIG. 33F). The light on the sled button 3318 should be turned off and the rotation mechanism in the sled should stop turning. The catheter 3300 is then detached from the sled 3310 via the removal buttons 3320a / 3320b. The exposed connector 3304 should be recapped using a protective cap 3302. Because the proximal end of the catheter 3300 has been in contact with the sled 3310 and is no longer sterile, the catheter 3300 will need to be covered to maintain or protect the sterile field. In FIGS. 33I-33K, a sterile probe cover package 3328 is opened, containing a plastic cover 3330 and an elastic or rubber band 3332. The sterile end 3334 of the cover 3330 is held and the cover 3330 is pushed over the proximal end of the catheter 3300 (FIG. 33J). The cover 3330 is then secured to the catheter 3300 via a rubber band 3332 around the recess of the catheter 3300 (FIG. 33K).

[0148] The catheter is then advanced under visual guidance, e.g., fluoroscopy, through the inserted sheath and over the guidewire into the patient to the target lesion site. The guidewire lumen of the catheter is configured to accommodate a standard 0.014 inch guidewire, although in other variations, other guidewire sizes may be accommodated. In this example, the guidewire has a minimum length of 180 cm and will be used with a 6 French to 8 French trapper, a 7 French sheath, and a 7 French guiding catheter (minimum 0.081 inch). In another example, if the guidewire is paired with a guide dilation catheter, e.g., a TRAPLINER guide dilation catheter (Teleflex, Morrisville, NC), the 8 French TRAPLINER catheter should be used in addition to the 8 French sheath and 8 French guiding catheter. If no trapper or TRAPLINER guide dilation catheter is used, a 300 cm guidewire should be used to ensure guidewire position.

[0149] The tip of the catheter is visually observed via fluoroscopy as it is advanced within the guiding catheter where it is inserted into the patient. Advancement is stopped when the catheter tip is located directly adjacent the end of the guiding catheter. The sterile cover 3330 and protective cap 3302 are then removed from the connector 3304 so that the catheter 3300 can be reattached to the sled 3310 as depicted in FIG. 33F. The system is reactivated via the sled button 3322 and record icon 1828 on the user interface (FIG. 18A). Imaging is used to visualize the vasculature during the procedure on either a touch screen or a secondary display connected to the system. The imager knob 3336 of the catheter 3300 in FIG. 33L can be used to adjust the longitudinal position of the imager along the nosecone relative to the ramps around the catheter's side port. The imager knob 3336 may also be used to advance or retract the imager to visualize the ramps and / or guidewire lumen. A rotation knob or adapter 3338 on the catheter 3300 may also be used to rotate the catheter clockwise or counterclockwise to orient the guidewire and guidewire lamp toward the true lumen.

[0150] The catheter is then advanced over the guidewire toward the target CTO lesion. Some palpable resistance may be felt or detected by the user as the guidewire is advanced into the subintimal space. Fluoroscopic visualization is used during advancement to confirm the catheter position and the end of the guidewire relative to the CTO lesion. Once the distal end of the catheter reaches the vicinity of the CTO lesion, it should also be proximate to the distal end of the guidewire. The proximal end of the guidewire 3340 should protrude through the introducer port 3342 in the proximal region of the catheter 3300, as illustrated in FIG. 33M. Localized flushing of the imaging area can be performed through the guidewire lumen flush port 3344, adjacent to the guidewire introducer port 3342. Larger volume flushing can also be performed through the flush port of the guiding catheter, for example, when required in larger vessels. FIG. 34A depicts an example OCT image with blood in the field of view, which acts as an optical scattering medium at the operating wavelength of the OCT imaging system, thus exhibiting a general haze, fog, or mist in the image. FIG. 34B depicts an example OCT image with a reduced amount of blood in the field of view resulting from a saline flush through the guidewire lumen flush port. The vasculature surrounding the catheter is more visible. The saline flush itself can be seen via a star-like region 3360 in the OCT image, resulting from the fluid dynamics around the catheter 3300. FIG. 34B also depicts the subintimal anatomy from the catheter, where the true lumen 3362 appears as a flattened pancake shape extending from the 5-9 o'clock region of the image.

[0151] The catheter is advanced toward the lesion site to re-enter the true lumen from the subintimal space. The catheter tip / ramp orientation is visually confirmed prior to advancing the catheter. The user confirms the location of the true lumen and identifies the desired re-entry location or path based on the OCT images. Referring to FIG. 34C, once the true lumen 3362 location is identified, the catheter 3300 is rotated using the rotating adapter to aim the guidewire ramp 3364 toward the true lumen 3362 and away from the pericardium 3366 and adventitia 3368 of the vessel. The direction of the guidewire trajectory 3370 can be determined by the axis between the guidewire lumen 3372 and the guidewire ramp 3364. This can also be confirmed based on its relative orientation to other visualized structures of the catheter 3320, such as the indicator lumen or flash lumen 3376, and by its orientation as the guidewire 3377 is advanced through the ramp 3364.

[0152] The lamp indicator overlay 3374 and the circular indicator 3376 of the flush lumen 3378 or indicator lumen (FIGS. 34D and 34E) can be turned on and off via the lamp indicator icon 1818 (FIG. 18B) of the extension menu 1816. When turned on, three potential conditions can arise: If the system is not confident in identifying the catheter orientation, no overlay graphics will be provided. If the system is confident in its determination of the catheter orientation, the circle indicator 3376 and the frustum-shaped lamp indicator overlay 3374 will appear on the OCT image (FIGS. 34D and 34E). However, as shown in Fig. 34D, the system is confident in indicating the expected trajectory of the guidewire ramp / guidewire trajectory as exhibited by the offset between the circular indicator 3376 and the flash or indicator lumen 3378, but may still be in error, whereas Fig. 34E depicts greater alignment between the circular indicator 3376 and the flash lumen 3378, and thus the ramp indicator 3374 in Fig. 34E is more likely to be accurate. When using or relying on the ramp indicator 3374, the user should verify alignment between the circular indicator 3376 and the flash lumen 3378, and also make a final and independent assessment of the guidewire trajectory prior to and during guidewire advancement.

[0153] Once the user makes the decision to deploy or advance the guidewire toward the true lumen, the guidewire is retracted until the distal end of the guidewire is located in the common lumen of the catheter, proximal to the ramp lumen, and then advanced through the ramp lumen into the true lumen. FIG. 34F depicts an OCT image of successful re-entry of the guidewire 3380 from the subintimal space into the true lumen 3362, where the guidewire 3380 is visible within the true lumen 3362. The user should confirm the re-entry via fluoroscopy with contrast injection under fluoroscopy, indicating arterial or side branch revascularization. Once the site and direction of re-entry is determined, the user may also substitute or replace the existing guidewire via the guidewire introducer port 3342 in FIG. 33M, depending on the user's decision as to whether a different type and / or stiffness guidewire is appropriate. If the guidewire becomes stuck within the catheter during advancement or retraction, the guidewire lumen may be flushed through the guidewire lumen flush port 3344. During pullback or retraction of the guidewire back into the catheter, the user should stop if any resistance is encountered and assess the cause of the resistance. If the guidewire cannot be freed with flushing of heparinized saline through the guidewire lumen flush port 3344, or if the guidewire appears to have herniated or kinked, the guidewire should not be pulled back; instead, the guidewire and catheter should be slowly and gently withdrawn together under fluoroscopic guidance as a single unit or assembly.

[0154] Upon proper placement of the guidewire, the catheter should be retracted while leaving the guidewire in place using standard catheter placement laboratory procedures for catheter removal or exchange. Once the catheter has been withdrawn from the body, the activation button 3322 on the sled 3310 is deactivated, stopping imaging and turning off the motor, per FIG. 33F, and the catheter 3300 is disconnected by activating the release latch or button 3324a / 3324b, per FIG. 33G. The catheter is then discarded according to standard disposal techniques once the catheter has been removed from the sterile field. Alternatively, the practitioner may choose to deactivate the imaging and motor and disconnect the catheter from the sled 3310 before retracting the catheter while holding the guidewire in place.

[0155] As shown, to size the artery or lumen during the procedure, the ruler overlay 1840, depicted in Figs. 18C, 18D, and 34G, may be turned on by selecting the ruler icon 1824, depicted in Fig. 18B. Fig. 23G depicts a mesh pattern overlaying the OCT image with 0.5 mm accuracy in a water / saline environment. As described above, the ruler overlay 1840 comprises ring indicators spaced 1 mm apart and axis markings in 0.5 mm increments. In a particular embodiment depicted in Fig. 34G, the ruler overlay 1840 has an imager field of view with a radius / diameter of over 3.5 mm and 7 mm, respectively. Generally, arteries are filled with optically scattering media such as blood, which obscures the OCT signal beyond the catheter cross section. Imaging resolution may be improved by transiently or temporarily displacing the surrounding blood by flushing an optically clear fluid, preferably with 50 / 50 saline / contrast, through the guiding catheter flush port and / or the guidewire lumen flush port to expose the surrounding arterial structures. By flushing, image resolution may be improved, which may make it easier to measure the inner diameter of the artery or lumen with the aid of the ruler overlay 1840.

[0156] Case Report The first human case of successful contemporary ADR using an exemplary OCT-guided re-entry catheter was performed, utilizing real-time high-resolution visualization with image enhancement and precision steering and advancement of the guidewire. Figures 20A-20C depict a catheter 2000 comprising a proximal housing 2066 and a catheter body 2002 with a distal end 2011. With reference to Figure 10B, the proximal housing 2066 includes an imager position adjustment knob or actuator 2068, a flush port 2072, a catheter orientation knob or controller 2070, and a guidewire introducer 2064 into which a guidewire 2038 is inserted. At the distal end 2011 of the catheter body 2002 depicted in Figure 10C, the guidewire 2038 is depicted extending out of a side port 2014 with the imaging device 2009 visible within the imaging lumen 1222. The easily steerable and torquable imaging catheter facilitates the practitioner to steer and aim a 0.014 inch guidewire out of the side port in any continuous orientation with an accuracy of better than 5 degrees.

[0157] A 74-year-old male presented with CSS class III angina in the setting of a left anterior descending artery (LAD) CTO. Dual coronary angiography showed a mid-LAD ​​CTO with a tapered proximal cap adjacent to the diagonal branch (Figure 21A), an occlusion length of >20 mm, and calcification within the CTO segment (J-CTO score of 2) (Figure 21B). An AWE strategy was used initially, but the polymer-coated guidewire was found to be present within the extraplaque space (Figure 21C), so an ADR technique was performed using an exemplary ADR catheter (Figure 21D). The catheter was advanced over a MIRACLEBROS 12 guidewire (Asahi Intecc USA, Irvine, CA) past the distal cap to the re-entry zone within the extraplaque space (Figure 21E). Retrograde contrast injection showed poor distal target visualization due to extraplaque hematoma formation.

[0158] Using extended real-time OCT image guidance, a pulsating artery with blood flow was visualized from the extraplaque space beyond the distal cap of the CTO at 5 o'clock in the OCT image / clip (FIG. 22A). The ramp overlay extension is depicted by a protruding line indicating a side port orientation from which guidewire advancement would lie between the two protruding lines. In FIG. 22A, the ramp overlay is oriented toward the adventitia as marked by an area identifying the fibrous / honeycomb layer structure. The catheter was then torqued / rotated to redirect the exit ramp overlay extension away from the adventitia (from 10 o'clock to 1 o'clock in the OCT image) and toward the true lumen at 5 o'clock in the OCT image / clip (FIG. 22B). An ASTATO XS20 wire (Asahi Intecc USA) was then advanced through the dedicated re-entry port off-ramp (FIGS. 22C and 22D) and successfully re-entered the true lumen in the mid-LAD. Guidewire position within the true lumen was confirmed by angiography and OCT imaging (Figures 22E and 22F). Figure 22G shows the final angiographic results and restoration of flow following stent deployment, depicting complete recanalization of the LAD after stent placement.

[0159] The ADR catheter provided real-time OCT-based enhancements with catheter orientation information relative to displayed vessel morphology (e.g., true lumen, adventitia, calcified nodule, etc.) that allowed the user to directionally control the coronary guidewire for re-entry. This real-time image-guided re-entry helps overcome the challenges posed by extraplaque hematoma formation and subsequent loss of distal vessel visualization. The high resolution provides clear morphological detail along with software enhancements for ease of use that represent a significant advancement over current device-based re-entry approaches and IVUS-guided techniques.

[0160] Some imaging systems utilize an array of imaging elements and capture a complete 2D image, while others may use an image capture sensor that may be moved during image capture to obtain a sequence or series of images at different locations. These images may then be aggregated into a single 2D or 3D image or model. Examples of such imaging systems include A-line images captured by OCT imaging systems, or A-mode linear images captured by ultrasound imaging systems. This type of imaging is particularly useful in miniaturized, elongated imaging systems, for example found in catheter-based or endoscopy-based imaging systems, where space constraints do not allow a fixed array of imaging elements to capture a complete image. In catheter-based imaging systems, the imaging elements may be rotated to capture sequential or successive images at different angular orientations of the imaging elements. These images may then be aggregated to provide a two-dimensional representation of the structure surrounding the imaging catheter. Such imaging catheters may be inserted directly into a patient for imaging, or may be inserted into the lumen of another catheter, for example, so that other functions or procedures may be provided by the catheter.

[0161] 23A diagrammatically illustrates a composite set of successive line images, known as waterfall images 2300a, on the horizontal axis and on the vertical axis arranged in a time sequence in a parallel fashion, such as generated from an imaging catheter located within a larger catheter, e.g., a guide catheter or interventional catheter. The topmost line 2302a in image 2300a corresponds to the imager origin or starting location of the imaging element, followed by a rectangular interior area 2304a of the larger catheter, followed by an outer wall 2306a of the larger catheter. Beyond the wall, various structures 2308a, 2310a, and 2312a within the surrounding tissue or environment can be visualized. In this particular example, because the imaging catheter is located within a concentric lumen of another catheter, the distance from the imaging source to the outer wall of the other catheter is nominally a constant distance such that in the waterfall image 2300a, the outer wall 2306a has a generally linear shape.

[0162] Referring to FIG. 23B, the same composite set of successive line images may also be arranged in a radial manner in a time sequence to generate a circumferential image 2300b (i.e., a sector view) around the imaging catheter. Because of this radial arrangement of linear images, the starting location of the imaging element is a circle or point 2302b, rather than a line 2302a, as depicted in FIG. 23A. Similarly, the interior region 2304b of the larger catheter is now an annular region, which is more indicative of the actual geometry of the larger catheter, as is the outer wall 2306b, which is depicted here as a circle, rather than the linear line 106a in FIG. 1A. Various structures 2308a, 2310a, and 2312a are now depicted at different positions and orientations 2308b, 2310b, and 2312b, respectively, surrounding the reference point 2302b of the imager origin.

[0163] One potential challenge with waterfall or radial image reconstruction is that ideally the movement or rotation rate of the imaging element is nominally uniform or constant so that simple aggregation of linear images into waterfall or radial images can be uniformly aligned. However, if the movement or rotation rate is variable, this can result in oversampling or undersampling in some image orientations, which when aggregated will result in image distortion. This is commonly known as non-uniform rotational distortion (NURD) of the image. This can result from frictional rotational resistance, which can result in excess speed after the resistance is overcome or reduced.

[0164] Figures 24A and 24B graphically depict some of the distortions that may occur. If the imaging element is maintained at a constant rotation rate during scanning of the structures 2408a / 2408b, the composite image of the structures 2408a / 2408b may be relatively accurate and undistorted compared to the structures 2308a / 2308b in Figures 23A and 23B. However, if the rotation rate or scanning speed is higher than expected, certain regions may be undersampled, resulting in a compressed appearance as depicted by the structures 2410a / 2410b in Figures 24A and 24B, which may appear as compressed ellipses compared to the circles 2310a / 2310b in Figures 23A and 23B. If the rotation rate or scan speed is slower than expected in a particular region, this may result in a horizontal or circumferentially elongated appearance, as depicted by structures 2412a / 2412b in Figures 24A and 24B, which are oversampled and appear as rectangular rather than the square appearance of structures 2312a / 2312b in Figures 23A and 23B. Notably, however, the wall lines and wall circles 2406a / 2406b may appear undistorted due to the absence of effect of scan speed or rotation rate on the distance from imager origin 2402a / 2402b to outer wall 2406a / 2406b, where the imaging catheters are concentrically located within the other catheter.

[0165] To correct such distortions, some imaging catheters will utilize sensors (such as encoders) and / or fiducials on the catheter to detect speed variations and correct them. As an example, sensors need to be present at the distal end at the point of signal collection and at the proximal end of the catheter or endoscope from which the imaging element is rotated. Presumably, the proximal end is well controlled with a uniform or constant rotational speed, while the imaging element at the distal end, which collects the incoming signal, experiences unpredictable and non-uniform friction along the axis of rotation. If the differential angular displacement or rotational speed between these two ends can be measured, the distorted images caused by NURD can be corrected. Other image correction algorithms may rely on external fiducials such as struts of a stent loaded into the catheter or deployed in the vessel by catheter or conventional procedures. Others may still analyze the degree of inhomogeneity of successive line images to detect oversampling and remove the line images causing distortion. However, it can be difficult to distinguish an oversampled line image from an anatomical region that lacks anatomical variability along some sectors of the image. In other words, correcting for image distortion requires the ability to detect known periodicity, uniformity, or predictability of external objects in all orientations that is lacking within biological tissue anatomy, or the integration of perceptual means within the catheter or endoscope construct.

[0166] However, referring to Figures 25A and 25B, if the imaging catheter is located in an imaging lumen of a catheter where the imaging lumen and imaging element are eccentrically located, the catheter wall 2506a in the waterfall image 2500a will have a sinusoidal appearance, with the amplitude of the sine wave being proportional to the degree of eccentricity. For a perfectly cylindrical (circular cross-section) catheter with an eccentrically located imaging element, the catheter wall appearance in the waterfall diagram is necessarily a perfect and single cycle sine wave. On the radial image 2500b, the outer wall 2506b will still have a circular appearance in a circular catheter, but the outer wall 306b will be offset from the imager origin 2502b. If a uniform translation or rotation rate / speed is maintained, the structures 2508a / b, 2510a / b, and 2512a / b will be largely unaffected by the eccentric location of the imaging catheter if the catheter material is generally transparent for OCT imaging.

[0167] If the rotation rate varies during image acquisition, the resulting images from an eccentric imaging catheter will generally exhibit deviations from the sinusoidal pattern of the outer wall of the larger catheter that are not seen in the wall line images of a concentric imaging catheter system. Figures 26A and 26B, for example, depict distant structures 2608a / b, 2610a / b, and 2612a / b imaged with the same rotation rate variations as in Figures 24A and 24B. However, here the outer wall line 2606a deviates from the expected sinusoidal pattern 2614 on the waterfall image 2600a and may have more of a turbulent wave pattern 2616 or a flatter sinusoidal pattern depending on the type of variation that occurs. On the radial image 2600b, instead of an offset circular shape, the outer wall 2606b may have an irregular closed or oval shape.

[0168] However, by utilizing the predicted or reference shape or line of the outer wall of a larger catheter, the outer wall location of the actual line image obtained is adjusted to conform to the predicted or reference shape or line of the outer wall, thereby compensating for the image distortion caused by the uniform allocation of the non-uniform line image in the waterfall image, which can then be used to construct a radial image with little distortion.

[0169] FIG. 27 depicts an exemplary waterfall image 2700 acquired from an OCT imaging catheter inserted into the imaging lumen of a multi-lumen catheter. The solid line 2702 represents the identified or detected outer wall of the multi-lumen catheter from the acquired series of line images that make up the waterfall image from one 360 ​​degree set of acquired line images. The dashed line 2704 represents one period of a reference sinusoidal line pattern that would be expected to cause the imaging catheter to maintain a uniform rotational speed. To correct for variations in rotational speed, one or more line images may be removed from the waterfall image and the wall locations of the remaining line images may be shifted horizontally or in time to a relative location within the line image period or time interval that matches the reference wall location in the reference sinusoidal line pattern. This horizontal shift is depicted by arrow 2706. This deletion of the line image to conform to a reference sinusoidal line pattern corrects the relative distortion without significant loss of image detail because the density of A-lines is typically much higher than the pixel density of high-resolution displays.

[0170] In one embodiment, to minimize processing time so that corrected OCT images can be displayed during the procedure with minimal time delay, only line image deletion from the acquired images is performed to reduce image distortion. However, in other variations, interpolation is applied to the undersampled regions to restore some of the lost data and maintain overall image resolution. However, this may result in additional processing time that may result in lags or delays in displaying the corrected images.

[0171] In another embodiment, the catheter wall edge locations along each A-line in the waterfall plot are located and the resulting edge deviations are compared to a template sine wave that is aligned to a peak, valley, or any reference point along the template, and all A-lines are then realigned and shifted so that the edge locations are aligned to the template. The catheter walls and reference points can be detected through the use of existing methodologies, including traditional image processing and neural networks. The A-line adjustments can be done through a variety of methods, including brute force pick-and-place or matrix transformations. When reconstructed in the sector view, the image is now undistorted and corrected.

[0172] In another embodiment, a model characterizing the NURD is generated, a remapping matrix to reverse the distortion is produced, and the matrix is ​​applied to the distorted waterfall image to produce a corrected waterfall image. Model constants can be inferred in real time by leveraging the catheter wall detection method described above, including properties such as the acceleration and velocity of the imaging element. Alternatively, one or more fixed models can be used where the observed NURD can be generalized across devices, reducing computational costs and minimizing processing time by slightly sacrificing quality.

[0173] 28A-28C are various schematic diagrams of a multi-lumen catheter 2800 used to capture the OCT images in FIGS. 27 and 29A-32C. The catheter 2800 includes a housing 2802. For illustrative purposes, the housing 2802 includes an imaging section 2804 located at a distal end of a catheter body 2806, which facilitates imaging of structures and / or tissues surrounding the catheter 2800. The imaging section 2804 may be made of a material that is optically transparent to reduce imaging opacity to a selected imaging modality, e.g., OCT or ultrasound. However, it should be noted that the imaging section 2804 may be opaque, transparent, or partially transparent. For example, with respect to an optical imaging modality such as OCT, the imaging section 2804 may be optically transparent or partially transparent, and with respect to an ultrasound imaging modality, the imaging section may be transparent, partially transparent, or opaque, so long as the material provides acoustic coupling of ultrasound. The change in optical index between the outer wall 2816 of the imaging section 2804 and the surrounding biological fluids and tissue will enhance the visibility of the outer wall 2816 on the images, as depicted in Figures 29A-32C.

[0174] The imaging body 2804 may be integrally formed with or distinct from the catheter body 2806. The catheter 2800 includes an imaging lumen 2808 and a guidewire lumen 2810. The imaging lumen 2808 and the guidewire lumen 2810 may extend generally parallel to a longitudinal axis of the catheter 2800. The imaging lumen 608 may be configured to receive an optical coherence tomography ("OCT") imaging device. The guidewire lumen 2810 may be configured to receive a guidewire (not shown). The guidewire lumen 2810 may extend to a distal end 2814 of the catheter 2800, thereby allowing the guidewire to extend out of the catheter 2800. The catheter 2800 may also include an indicator lumen 2812 (partially obscured by the guidewire lumen 2810). The indicator lumen 2812 may be configured to receive a material that may be detectable by an OCT imaging device. In certain embodiments, the material received by indicator lumen 2812 may be more easily or reliably detectable by an OCT imaging device and may be used as a base point for performing further image processing or distortion correction. Indicator lumen 2812 may also be used for other functions, including, but not limited to, flushing blood to improve imaging clarity or injecting diagnostic or therapeutic agents into the surrounding tissue.

[0175] Structures of the multi-lumen catheter 2800, such as guidewire lumen 2810 and indicator lumen 2812, are visible on the image of FIG. 27, in addition to the outer wall 2702. FIGS. 29A, 30A, 31A, and 32A depict other exemplary raw OCT image captures via an OCT imaging catheter located within catheter 2800. FIGS. 29B, 30B, 31B, and 32B depict corresponding processed images with distortion correction described above. FIGS. 29C, 30C, 31C, and 32C are reference images representing a generally ideal image with minimal inherent distortion taken with catheter 600 at locations corresponding to the distorted and processed images.

[0176] If a uniform rotation rate can be maintained, the size and shape of the sinusoidal pattern can be predicted or derived from the model geometry of the imaging lumen of the larger catheter. However, this reference sinusoidal pattern may be subject to additional variations other than rotation rate variability. For example, if the imaging catheter is smaller than the inner diameter of the imaging lumen of the larger catheter, there may be additional dispersion in the imager origin location, which may also change during the imaging procedure as the imaging catheter and / or the larger catheter are bent or torqued. Alternatively, the reference sinusoidal pattern may be obtained by acquiring a reference calibration image from a catheter assembly under ideal conditions that may minimize rotation rate variations, for example, the catheter is in a straight configuration without any bending and / or in a reduced friction liquid.

[0177] The image correction described herein may be used in conjunction with OCT catheters, and endoscopic systems, ultrasound catheter systems, and may be used for imaging of various anatomical structures, lumens, or transport ducts, including, but not limited to, vascular cavities such as arteries and veins, lymphatic vessels, nasal cavities, outer ear, inner ear, esophagus, stomach, duodenum, small intestine, large intestine, rectum, bronchi, urethra, ureters, and the like, in humans, mammals, and non-mammals. Applications are not limited to biological imaging, but may also be used for industrial and other applications.

[0178] Various aspects and embodiments have been disclosed herein, and other aspects and embodiments are contemplated. The various aspects and embodiments disclosed herein are for purposes of illustration and are not intended to be limiting.

[0179] Terms of degree (e.g., "about," "substantially," "generally," etc.) indicate variations that are not structurally or functionally significant. In some embodiments, when a term of degree is included with a term of quantity, the term of degree is interpreted to mean ±10%, ±5%, or +2% of the term of quantity. In some embodiments, when a term of degree is used to modify a shape, the term of degree indicates that the shape modified by the term of degree has the general appearance of the disclosed shape. For example, the term of degree may be used to indicate that the shape may have rounded corners instead of sharp corners, may have curved edges instead of straight edges, may have one or more protrusions extending therefrom, is oval, is identical to the disclosed shapes, etc.

Claims

1. 1. A system for imaging a lumen, the system comprising: an imaging catheter, the imaging catheter comprising: A tubular body, a proximal end region; and a distal end region; and An intermediate region; an imaging lumen located along the proximal, intermediate, and distal regions; a common guidewire lumen located along the proximal, intermediate, and distal regions; a side lamp lumen located within the distal end region, connected to the common guidewire lumen, the side lamp lumen having a distal opening in a side wall of the tubular body; a distal guidewire lumen located within the distal end region, connected to the common guidewire lumen, the distal guidewire lumen having a distal opening in an end wall of the tubular body; at least one guidewire biasing structure, said at least one guidewire biasing structure comprising: a reduced diameter region at the junction of the distal guidewire lumen and the common guidewire lumen; an offset distance between a longitudinal axis of the common guidewire lumen and a longitudinal axis of the distal guidewire lumen; an angled flap at or proximal to the junction of the distal guidewire lumen and the common guidewire lumen; a guidewire lumen ridge at or proximal to the junction of the distal guidewire lumen and the common guidewire lumen; at least one guidewire biasing structure selected from the group consisting of: a tubular body comprising: a proximal catheter assembly including a catheter housing coupled to the proximal end region of the tubular body and a proximal optical connection interface; a first guidewire port in fluid communication with the common guidewire lumen; an imager port in fluid communication with the imaging lumen; an imaging optical fiber connected to the proximal optical connection interface and extending along the imaging lumen; A system comprising:

2. The system of claim 1 , further comprising a second guidewire port in fluid communication with the common guidewire lumen, the second guidewire port having an interface different from an interface of the first guidewire port.

3. The system of claim 2 , wherein the first and second guidewire ports are located in a hub distal to the catheter assembly.

4. 10. The system of claim 1, wherein the catheter housing further comprises an imager actuator engaged to the imaging optical fiber and configured to longitudinally translate the imaging optical fiber relative to the imaging lumen.

5. The system of claim 1 , further comprising a catheter rotation actuator coupled to the tubular body and configured to rotate the tubular body relative to the proximal catheter housing assembly.

6. The system of claim 5 , wherein the catheter rotation actuator is rotatably coupled to a distal end of the catheter housing.

7. The system of claim 2 , wherein the proximal catheter assembly further comprises an optical cable between the catheter housing and the proximal optical connection interface.

8. The system of claim 2 , wherein the proximal optical connection interface is directly coupled to the catheter housing.

9. further comprising an imaging console, the console comprising: The console housing and a power supply source; a laser source having an output port; a thread interconnect interface; a touch screen interconnection interface; Large display interconnection interface and The system of claim 1 , comprising:

10. The system described in claim 9, wherein the laser source output port comprises an imaging port and an aiming beam port.

11. Further comprising a sled assembly, the sled assembly comprising: A threaded housing; a catheter interconnect; a sled power actuator; Catheter removal actuator The system of claim 9, comprising:

12. 12. The system of claim 11, wherein the catheter interconnect is a spring-loaded catheter interconnect and the catheter removal actuator is a catheter ejection actuator.

13. The system of claim 11 , wherein the sled power actuator comprises a light.

14. The system of claim 9 further comprising a touch screen with a mounting mount.

15. The system of claim 11 , wherein the sled housing comprises a distal cavity configured to receive the catheter housing.

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