Imaging probe with rotatable core

Abstract

This disclosure provides an imaging probe with a rotatable core that allows rotation of an imaging component with a diameter larger than the lumen in which the rotatable core is located, and a method for constructing the probe. The imaging probe is a grossly long, flexible imaging catheter used in cardiovascular surgery. It allows for a smaller lumen to accommodate the rotatable core, simplifies the inclusion of other functional components in the catheter, and improves the quality of the resulting images.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Application No. 62 / 300,583, filed February 26, 2016, entitled “Imaging Probe with Rotatable Core”, the entire contents of which are incorporated herein by reference. background

[0003] This disclosure generally relates to the field of imaging probes for imaging mammalian tissues and structures using high-resolution imaging, including high-frequency ultrasound and optical coherence tomography.

[0004] Minimally invasive imaging of the body is used for a variety of purposes, including, for example, any of the following: i) assessing tissue and anatomical structures; ii) planning and / or guiding interventions in localized areas of the body; and iii) evaluating the outcomes of interventions that alter the structure, composition, or other properties of a localized area. Minimally invasive imaging can refer to, for example, ultrasound and optical imaging methods. Minimally invasive ultrasound is particularly useful for endovascular and cardiac procedures. For these applications, ultrasound transducers are incorporated into catheters or other devices that can be inserted into the body. For example, two exemplary embodiments of minimally invasive ultrasound are intravascular ultrasound (IVUS) for imaging blood vessels and intracardiac echocardiography (ICE) for imaging cardiac chambers. Both ICE and IVUS are minimally invasive and involve placing one or more ultrasound transducers within blood vessels or cardiac chambers to obtain high-quality images of these structures.

[0005] Optical imaging methods based on fiber optic technology used in the medical field include optical coherence tomography (OCT), angiography, near-infrared spectroscopy, Raman spectroscopy, and fluorescence spectroscopy. These modalities typically require one or more optical fibers to transmit light energy along an axis between the imaging site and the imaging detector. OCT is an optical simulation of ultrasound and provides imaging resolution of approximately 1 to 30 micrometers, but in most cases does not penetrate tissue as deeply as ultrasound. Fiber optics can also be used to transmit energy for therapeutic procedures such as laser ablation of tissue and photodynamic therapy. Additional forms of imaging related to this disclosure include angiography, endoscopy, and other similar imaging techniques involving the use of probes to image sites within a patient's body, obtaining images based on the reflection of light in the visible or infrared range of the spectrum. Other additional forms of high-resolution imaging may use acoustic energy to create light energy (sonoluminescence imaging) or use light energy to create acoustic energy (photoacoustic imaging).

[0006] Numerous methods have been employed to perform minimally invasive imaging to assess several distinct regions of mammalian anatomy, including the gastrointestinal system, cardiovascular system (including the coronary, peripheral, and neurovascular systems), skin, eyes (including the retina), genitourinary system, mammary tissue, liver tissue, and many other regions. For example, imaging of the cardiovascular system using high-frequency ultrasound or optical coherence tomography has been developed to assess the structure and composition of arterial plaques. High-resolution imaging has been used to measure the geometry of blood vessels or plaques, blood flow through diseased arteries, and the impact of interventions on arterial plaques (such as through plaque resection, angioplasty, and / or stenting). Attempts have also been made to use high-resolution imaging to identify vascular injuries that have not yet caused clinical symptoms but have ruptured or eroded, increasing the risk of acute myocardial infarction. These so-called “vulnerable plaques” are areas of strong interest because the prospect of treating such plaques to preemptively prevent adverse clinical events is conceptually attractive. However, no specific imaging modality has yet demonstrated efficacy in this regard.

[0007] A growing area of ​​interest is the use of image-guided techniques in surgical and electrophysiological procedures for structural heart disease. This often requires placing catheters in specific locations within the heart chambers to perform therapeutic procedures such as device implantation (e.g., closure devices for patent foramen ovale, valve repair or replacement devices, left atrial appendage closure devices) or placement of therapeutic catheters (e.g., ablation or cryotherapy catheters). Guiding intermediate steps during surgery, such as crossing the atrial septum of the heart, may also be necessary. Minimally invasive imaging can be helpful in these steps.

[0008] The center frequency of minimally invasive ultrasound typically ranges from 3 MHz to 100 MHz. Higher frequencies result in higher resolution but lead to reduced signal penetration and thus a smaller field of view. Penetration depth can range from less than one millimeter to several centimeters, depending on several parameters, such as the transducer's center frequency and geometry, the transducer's sensitivity, the attenuation of the medium through which it is imaged, and specific specifications of the embodiment that affect the system's signal-to-noise ratio.

[0009] Optical coherence tomography (OCT) generally offers higher resolution than ultrasound and may be better able to identify certain structures or components in blood vessels and other tissues. It may also penetrate certain tissue components, such as calcified tissue, better than ultrasound. For example, OCT can better distinguish the thickness of fibrous caps or the presence of inflammatory or necrotic areas near the arterial surface. However, in most biological media, OCT is limited by its reduced penetration depth (approximately 500 to 3000 micrometers). Most of these media are not optically transparent.

[0010] Angiography, endoscopy, bronchoscopy, and many other imaging devices have been described, which allow visualization of internal tubes and structures in the mammalian body (such as blood vessels, the gastrointestinal tract, and the pulmonary system) based on the principle of illuminating a region near the distal end of a rigid or flexible shaft within the body. Images are then created by placing a photodetector array (such as a CCD array) near the end of the shaft or by using a bundle of optical fibers to transmit the received light from the distal end of the shaft to the proximal end. The photodetector array or other system allows the operator to generate or view an image representing the illuminated area. Fiber bundles are bulky, reduce the flexibility of the shaft, and have other disadvantages.

[0011] Many of these imaging probes and flexible catheters rely on a rotatable conduit extending through a lumen. The rotatable conduit is rotated by a rotational drive mechanism that is mechanically connected to or attached to its proximal end. One or more imaging components are attached to the rotatable conduit at a point remote from its proximal end, such that the imaging components rotate in tandem with the rotatable conduit. The imaging components may include transmitters and / or receivers of imaging energy, such as ultrasound transducers or light transmitters / receivers.

[0012] Minimally invasive devices typically have a long segment designed to be advanced into the body. This long segment is designed with a small maximum cross-sectional area to minimize the size of any surgical entry point or opening through which the long segment is advanced. This tends to minimize the risks of bleeding, discomfort, trauma, and other aspects associated with device insertion into the body.

[0013] Catheters are used for diagnostic and / or therapeutic purposes and have various sensors and actuators mounted on them and / or embedded in their lumens. Catheters may be equipped with imaging devices employing imaging modalities such as optical imaging, optical spectroscopy, fluorescence, infrared cardiac endoscopy, acoustic imaging, photoacoustic imaging, thermal imaging, and magnetic resonance imaging. For example, ultrasound or optical imaging devices can be used to locate and diagnose diseased parts of the body, such as narrowed areas of arteries. Catheters may also contain therapeutic devices, such as those used to perform interventional techniques including balloon angioplasty, laser ablation, rotational atherectomy, pacing, and targeted plaque resection. Additionally, catheters may be equipped with sensors such as electromagnetic position / orientation tracking sensors, temperature sensors, and force measurement sensors.

[0014] Intravascular catheters need to be compactly configured to enable delivery into the vascular system. For example, current catheters used for intravascular ultrasound and intracardiac echocardiography are approximately 0.8 mm to 4 mm in diameter, where smaller probes can be delivered further within the vascular tree of the coronary anatomy due to gradually decreasing vessel diameters or stenosis in diseased vessels. However, catheters equipped with imaging components are also constrained in how small and compact they can be constructed, thus limiting the inner diameter of the distal end of the catheter.

[0015] The outer sheath section of the catheter is typically made of one or more layers of biocompatible material (usually plastic) and may or may not be reinforced with metal or other braided materials. Most intravascular imaging catheters that rely on rotatable tubing (such as flexible torque cables) are assembled with an imaging core and an outer sheath. The distal end of the outer sheath may be closed or more often has small openings to allow air bubbles or other media to drain when flushing the inner core with a medium that allows imaging energy to radiate from the catheter (such as saline), where loss and / or deformation are reduced. During assembly, the imaging assembly and the distal end of the rotatable tubing are advanced into the main lumen of the outer sheath in a proximal-to-distal manner. The imaging core comprises the rotatable tubing and the imaging assembly. The housing is coupled to the proximal end of the imaging core and mechanically coupled to the proximal end of the outer sheath in a manner consistent with this.

[0016] This assembly method restricts the sheath to a sufficiently large internal cross-sectional area along the portion of the sheath extending from the proximal entry point of its cavity to the final position where the imaging assembly is destined to reside during operation, along the long axis of the sheath. This, in turn, restricts the size of the imaging assembly and the ultrasonic aperture to be small enough to fit within the cavity of the sheath in which the rotatable tube resides.

[0017] The size of the lumen is limited to the external dimension (i.e., typically the outer diameter of a conduit with a circular cross-section) minus the portion of the cross-section occupied by the sheathing wall. The wall must have a suitable thickness to provide the necessary mechanical properties for the conduit and possess torsion flexibility, maneuverability, resistance to rupture when a pressure difference exists between the lumen and the surrounding environment (e.g., during flushing), and other similar mechanical characteristics. The wall can be reinforced using reinforcing materials such as metal braided materials or other materials known in the art.

[0018] Several methods exist in the art for joining catheters and other minimally invasive devices, including thermal bonding, laser welding, the use of adhesives (including UV-cured adhesives), ultrasonic welding, press-fitting, fastening, the use of connectors, and many other methods. Each method has its own advantages and disadvantages. Among the techniques used for joining catheter segments (such as extrusion of thermoplastic polymers (nylon, Pebax, polyethylene, etc.), one preferred technique is thermal bonding. Thermally bonding two segments of a catheter typically involves inserting a mandrel into some or all of the lumens of the two catheter segments while placing a heat-shrinkable polymer tube over the catheter segments to be joined. Heat is then applied to the catheter so that the heat-shrinkable tube shrinks as the polymer material of the catheter segment softens and reflows, ultimately resulting in the two segments joining together. The mandrel protects the integrity of those lumens that undergo deformation during the reflow process. The lumen liner may also have a lining, such as a PTFE liner. Summary of the Invention

[0019] This disclosure provides an imaging probe with a rotatable core, the rotatable core allowing rotation of an imaging component with a diameter larger than the lumen in which the rotatable core is located, and a method for constructing the probe. The imaging probe is a grossly long, flexible imaging catheter for use in cardiovascular surgery. It allows for a smaller lumen to accommodate the rotatable core, simplifies the inclusion of other functional components in the catheter, and improves the quality of the resulting images.

[0020] In a first aspect, a method for assembling an imaging probe is provided, the method comprising:

[0021] A long sheath is provided, which has an inner cavity and a distal opening;

[0022] A rotatable tube having an imaging assembly connected to the distal end of the rotatable tube is inserted through the distal opening of the elongated sheath, wherein the lateral span of the imaging assembly is greater than the diameter of the inner cavity of the elongated sheath, such that the imaging assembly extends from the distal opening of the elongated sheath after the rotatable tube is inserted into the inner cavity.

[0023] Provides a distal end, which has a distal end and an open proximal end;

[0024] The distal end is inserted above the imaging assembly such that the proximal portion of the distal end contacts the elongated sheath in the contact area, and preferably overlaps with the elongated sheath in the contact area; and

[0025] The distal end is joined to the long sheath, wherein the joining is performed by locally applying heat to the contact area.

[0026] On the other hand, an imaging probe is provided, which includes:

[0027] Long sheath with an inner cavity and a distal opening;

[0028] A rotatable conduit extending through the inner cavity, the rotatable conduit having an imaging assembly connected to its distal end, wherein the lateral span of the imaging assembly is greater than the diameter of the inner cavity of the elongated sheath, such that the imaging assembly extends from the distal opening of the elongated sheath.

[0029] The distal end houses the imaging component, wherein the proximal portion of the distal end is engaged with the distal region of the elongated sheath and preferably overlaps with the distal region of the elongated sheath.

[0030] A further understanding of the functionality and advantages of this disclosure can be achieved by referring to the following detailed description and accompanying drawings. Attached Figure Description

[0031] The implementation will now be described by way of example only with reference to the accompanying drawings, in which:

[0032] Figure 1 The image shows a component of the sheath of an exemplary medical probe.

[0033] Figure 2A Show Figure 1 The longitudinal cross-sectional view of the probe sheath shown illustrates where joints are formed when different parts of the probe sheath are joined.

[0034] Figure 2B Show Figure 1 The diagram shows a cross-sectional view of the probe sheath, where the section is taken through the long proximal end portion of the sheath.

[0035] Figure 2C Show Figure 1 The diagram shows a cross-sectional view of the probe sheath, where the section is taken through the soft distal end portion of the sheath.

[0036] Figure 2D Show Figure 1 The diagram shows a cross-sectional view of the probe sheath, where the section is taken through the distal end portion of the sheath.

[0037] Figure 3A Shown after the components of the coupling sheath, Figure 1 The image shows a longitudinal cross-sectional view of the probe sheath.

[0038] Figure 3B Show Figure 1 The longitudinal cross-sectional view of the probe sheath shown illustrates the introduction of the imaging assembly and imaging conduit from the proximal end direction / region.

[0039] Figure 3C Show Figure 1The longitudinal cross-sectional view of the probe sheath shown illustrates the imaging component located at or near the distal end.

[0040] Figure 4 An exemplary embodiment of the imaging probe is shown, wherein the radial span of the distal imaging assembly is greater than the inner diameter of the elongated proximal sheath, and wherein the distal end is engaged to the elongated proximal sheath while being mechanically supported by a rigid reinforcing member.

[0041] Figure 5 This illustrates the use of a mandrel when engaging a long proximal sheath to a rigid support member prior to engaging the distal end.

[0042] Figure 6A An exemplary embodiment of the imaging probe is shown, wherein the radial span of the distal imaging component is greater than the inner radius of the elongated proximal sheath, and wherein the elongated proximal sheath includes an attitude sensor and an optical fiber for optical communication with a rotary encoder interface.

[0043] Figure 6B Showing through Figure 6A The cross section of line EE is shown in the figure.

[0044] Figure 7 An exemplary rotary encoder substrate is shown.

[0045] Figure 8 An exemplary embodiment of an imaging probe is shown, wherein the radial span of the distal imaging component is greater than the inner radius of the elongated proximal sheath, and wherein the elongated proximal sheath includes conductive wiring.

[0046] Figure 9 An exemplary embodiment of an imaging probe is shown, wherein the radial span of the distal imaging component is greater than the inner diameter of the elongated proximal sheath, and wherein the elongated proximal sheath includes conductive wiring capable of generating a magnetic field to actuate a tiltable transducer to which a magnet is attached.

[0047] Figure 10 The flowchart illustrates an exemplary method in which a 3D image is selectively updated using a calculated angle of incidence and / or proximity associated with image data.

[0048] Figure 11 This is a schematic diagram of an exemplary imaging system used for ultrasound imaging, optical imaging, or both. Detailed Implementation

[0049] Various embodiments and aspects of this disclosure will be described with reference to the details discussed below. The following description and accompanying drawings are illustrative of this disclosure and should not be construed as limiting it. Numerous specific details are described to provide a comprehensive understanding of various embodiments of this disclosure. However, in some cases, well-known or conventional details have not been described in order to provide a concise discussion of embodiments of this disclosure.

[0050] As used herein, the terms “comprise” and “comprising” should be interpreted as inclusive and open-ended, not exclusive. Specifically, when used in the specification and claims, the terms “comprise” and “comprising” and their variations mean to include the specified features, steps, or components. These terms should not be construed as excluding the presence of other features, steps, or components.

[0051] As used herein, the term “exemplary” means “used as an example, instance or illustration” and should not be construed as a preferred or superior configuration to other configurations disclosed herein.

[0052] As used herein, the terms “about” and “approximately” refer to variations that may exist within the upper and lower limits of the numerical range, such as variations in properties, parameters, and dimensions. Unless otherwise stated, the terms “about” and “approximately” mean plus or minus 25% or less.

[0053] It should be understood that, unless otherwise stated, any designated scope or group is a shorthand for referring to a single scope or group and each possible subscope or subgroup covered therein, and similarly for each member of any subscope or subgroup therein. Unless otherwise stated, this disclosure relates to and expressly incorporates every specific member and combination of a subscope or subgroup.

[0054] As used herein, when used in conjunction with a quantity or parameter, the term “approximately” refers to a range spanning roughly one-tenth to ten times the specified quantity or parameter.

[0055] This disclosure provides various exemplary embodiments of a medical probe with a sheath having a distal portion with a larger inner diameter extending to a central lumen with a smaller inner diameter. The segment with the larger inner diameter is located away from the proximal end of the sheath. In several exemplary embodiments, this design is made possible by laser welding the distal end to the distal end of the sheath or by using localized thermal bonding and heat-shrink reflow processes, and by incorporating rigid reinforcing members in the catheter.

[0056] Figure 1An exploded perspective view of several sections of the sheath of an exemplary imaging probe 100 (e.g., a catheter) is shown, the imaging probe 100 having a closed, dome-shaped distal end and a deflectable distal end. An elongated proximal section 110 has a main lumen 115, walls, and a generally circular cross-section. A separate lumen 125 for a drawstring 120 is present, as is known in the art, which can be constructed by including a single piece of thin-walled tubing (such as a polyimide tube or a multi-cavity extrusion). A soft distal section 130 (relative to the proximal section 110) having a generally soft material also has a main lumen 135 and a lumen for the drawstring 120. It also includes a draw ring 138, which is typically made of metal and can be included in the soft section by forging or other processes known in the art. The pull cord 120 extends from the proximal end of the sheath through the pull cord cavity 125 of the proximal section 110, through the pull cord cavity of the flexible section 130, and is attached to the pull ring 138, for example by laser welding.

[0057] The distal end 140 terminates at the distal dome 142 and is formed of a material having properties suitable for allowing imaging energy transmission through the walls of the distal end 140.

[0058] The distal end 140 can be formed, for example, by an end-forming process, a hot air station, or via injection molding. The material used for the distal end 140 can be selected based on its properties, such as mechanical strength, sound attenuation, light transmittance, and other properties. Similar considerations can be taken into account when designing the wall thickness of the distal end 140.

[0059] Figure 2A Show Figure 1 The image shows a longitudinal cross-sectional view of the walls of the components of the sheath of the imaging probe 100 (i.e., the elongated proximal section 110, the soft section 130, and the distal end 140). Figure 2B The cross-section of the elongated proximal segment 110 is shown, while Figure 2C A cross-section of the portion where the pull ring 138 of the soft distal section 130 is located is shown, and Figure 2D A cross-section of the proximal portion of the distal end 140 is shown.

[0060] The segments can then be joined together by placing heat shrink tubing around the assembly using a mandrel occupying the main cavity of the three segments (including the hollow portion at the distal end 140), applying heat in a controlled manner, and then removing the mandrel and heat shrink tubing. Figure 2AThe diagram shows a butt joint 150 between the long proximal segment 110 and the soft segment 130. An overlap joint 155 between the soft segment 130 and the distal end 140 is also shown. Other operational sequences are possible during catheter construction, such as joining the proximal segment 110, soft segment 130, and distal end segment 140 in discrete steps, merging the draw lumen 125 after joining the proximal segment 110 and soft segment 130, or adding and weaving an outer sheath to the proximal segment 110 and soft segment 130.

[0061] Figure 3A This shows the distal portion of the outer sheath, with distal end 140 and pull cord 120, after the long proximal section, flexible section, and distal end have been joined together at connectors 155 and 150. If a user pulls the proximal end of pull cord 120 relative to the sheath, the side of the sheath containing pull cord 120 will shorten and the flexible section will deflect in that direction.

[0062] Figure 3B The illustration shows the advancement of a rotatable imaging conduit 160 (preferably a flexible torque cable) advancing from the proximal end of the sheath toward the distal end, and a distal imaging assembly 170 (such as an ultrasonic transducer). An example of an imaging conduit with a rotatable imaging conduit can be found in U.S. Patent No. 20090264768, the contents of which are incorporated herein by reference in their entirety.

[0063] Figure 3C The position of the rotatable imaging conduit 170 is shown when the imaging assembly 170 is aligned with the distal end 140. The rotatable imaging conduit acts as an imaging window through which imaging energy, such as ultrasound or light, travels between the imaging assembly 170 and the region outside the distal end 140 of the conduit.

[0064] While minimizing the cross-sectional area of ​​long sections is desirable for minimally invasive procedures, in many cases, maximizing the size of functional components within the device, such as ultrasonic transducers, is desirable. Larger aperture ultrasonic transducers tend to be more sensitive than smaller aperture transducers. Furthermore, with larger aperture sizes, the ultrasonic beam from the transducer tends to be better focused over a longer axial distance (i.e., along the propagation axis of the ultrasonic wave).

[0065] Furthermore, when joining conduit components together using thermal processes such as laser welding, ultrasonic welding, or by applying heat via convection, conduction, or radiation, it is important to avoid causing unnecessary damage to nearby components of the conduit. In imaging conduits with complex scanning mechanisms, such as those disclosed in U.S. Patent Publication No. 20090264768, several components of the imaging assembly can be sensitive to excessive heat, such as insulation on electrical conductors, coatings, plastic housing components, epoxy resins, imaging ends that typically have thin walls, or other bonding agents used in components such as the scanning mechanism.

[0066] Figure 4 An exemplary embodiment of an imaging conduit with imaging components that address these problems is shown. For example... Figure 4 As shown, the imaging assembly 170 is larger than the proximal segment and is included at the end of the catheter, the imaging assembly having a diameter larger than the main lumen 115 to which the proximal segment 110 is attached. It should be noted that... Figure 4 The exemplary embodiment shown illustrates an elongated proximal portion 110 engaged to the distal end 140. It will be understood that this distal end may alternatively be engaged to an intermediate sheath portion, such as... Figure 2C and Figures 3A to 3C The soft intermediate sheath portion is shown in the diagram. The proximal sheath portion 110 and the distal end 140 may be made of polyethylene extrusion, although any other medical-grade plastic may be used alternatively, provided that the two plastic extrusions are compatible with each other and can form a strong bond. The imaging assembly may be fully or partially rotatable.

[0067] During assembly Figure 4 In one exemplary method of the imaging catheter shown, before attaching the distal end 140, the imaging assembly 170 and the rotatable imaging conduit 160, along with electrical leads, optical fibers, flushing chambers, and other components housed within a portion of the rotatable imaging conduit 160, are inserted from the distal end of the sheath. The distal end 140 is then placed on the proximal sheath portion 110, and two plastic pieces are engaged on an overlapping section 175 atop a rigid reinforcement member 180. In some exemplary embodiments, the rigid reinforcement member 180 may serve a dual purpose in the catheter design, such as a marker band and / or a pull ring for a deflection mechanism.

[0068] In one exemplary embodiment, the distal end 140 is joined to the proximal sheath portion 110 using heat shrinkage and locally applied heat. The rigid reinforcing member 180 functions in a manner similar to a mandrel by providing an external radial force in region 175, wherein the distal end 140 and the proximal sheath portion 110 are compressed together by a heat shrink member that provides an internal radial force. The rigid reinforcing member 180 may be a separate hollow cylinder provided for this purpose. Low-temperature heat shrink members may be used, wherein the low-temperature heat shrink member has a component that shrinks at a temperature lower than the melting point of the plastic material forming the proximal sheath portion 110. For example, a polyolefin heat shrink tube can be activated at approximately 90°C compared to the melting point of Pebax 7233, which has a melting point of approximately 175°C. The heat shrink member provides sufficient pressure to hold the entire assembly together. This process is not limited to the use of heat shrink members. Other instruments may be used, such as, but not limited to, radial bands, precision clips, or other clamps. Transparent materials that transmit laser energy may be used. Alternatively, other methods of joining the regions may be employed. Areas can be joined using adhesives such as cyanoacrylate or various epoxy resins. Areas can also be joined using mechanical methods such as press fitting, locating pins, or clamps.

[0069] Alternatively, the overlapping areas of the distal end 140 and the proximal sheath portion 110 can be laser-welded together, thereby directing the laser energy to the joint region 175 so as not to cause indirect damage to adjacent portions of the catheter. In one exemplary embodiment involving laser welding, the distal end is at least partially transparent, and a light-absorbing material can be applied between the distal end 140 and the portions of the proximal sheath portion 110 to be joined to enhance the localization of light absorption and thus localize the generated heat. In one exemplary embodiment, the dome end 140 is held in contact with the distal end of the sheath by a heat-shrinkable insert that allows laser energy to pass through. The process is not limited to the use of heat-shrinkable inserts, but other instruments can be used, such as transparent radial bands, precision transparent clips made of glass or laser-energy-compatible polymers, or other fixation devices that allow laser energy to pass through.

[0070] For example, in an exemplary embodiment where an optically transparent polyethylene extrusion is used to form the proximal sheath portion 110 and the distal end 140, a light-absorbing material (Clearweld) can be used. The Solution Pen LD220C absorbs laser radiation from the YAG laser beam passing through the top transparent plastic layer and generates heat at the intersection of the two plastic parts, thereby locally melting the plastic and joining the two sections together. Although the exemplary manufacturing method described above uses a YAG welding laser, this exemplary process is not limited to using only a laser welding machine. Other methods for joining joints with different inner diameters include, for example, using a concentrated hot air station that does not diffuse much heat along the sheath, or using a soldering iron or other types of lasers such as diode lasers.

[0071] Other exemplary alternatives to the above method include using colored thermoplastic extrusions, or using additives or pigments suitable for transparent plastics, such as carbon black.

[0072] If the laser welding method does not sufficiently localize the generated heat, a rigid reinforcing member 180 can be used to provide structural support. Alternatively, if the applied heat is sufficiently localized at the interface between the distal 140 and the proximal sheath portion 110, the laser welding method can be performed without a rigid reinforcing member.

[0073] Figure 5 An exemplary embodiment is shown in which a rigid reinforcing member 180 is positioned above a mandrel 50, and one end of a plastic extrusion is positioned above the rigid reinforcing member 180. According to an exemplary joining method, a heat-shrinkable member is then placed on top of the assembly. A hot air station is used to melt the plastic extrusion 110 on top of the rigid reinforcing member 180. This results in a thin plastic layer covering a portion of the rigid reinforcing member 180 and holding the rigid reinforcing member 180 in place at the distal end of the sheath. The heat-shrinkable member is then peeled off and the mandrel 50 is removed.

[0074] Then the light is absorbed (e.g., Clearweld). A solution is applied to the inner surface of the portion of the plastic sheath 110 located on the rigid reinforcing member 180. Allow a few minutes for the solution to dry. Then, the proximal end of the distal end 140 is placed on top of the rigid reinforcing member 180 and the distal end of the extrusion member 110, such that the overlapping section of the sheath 110 and the distal end 140 fully overlaps with the applied light-absorbing solution. Alternatively, overlap bonding can be achieved by having the distal end of the proximal section 110 on the outer layer and the proximal end of the distal end 140 inside the distal end of the proximal section 110. Laser radiation is directed onto the overlapping section to bond the two layers. The laser beam passes through the first transparent layer and is absorbed at the intersection of the joint components, thereby generating localized heat and forming an effective and reliable thermal bond. In one exemplary embodiment, the overlapping section of the two plastic layers is positioned in or near the middle of the rigid reinforcing member 180, because directing the laser to the edge of the rigid reinforcing member 180 may cause the plastic sections not supported by the rigid reinforcing member 180 to melt and deform.

[0075] In one exemplary embodiment, this example process facilitates the manufacture of a catheter with a rotatable imaging conduit supporting an imaging assembly, wherein the imaging assembly is housed at or near the distal end of the catheter, and wherein the imaging assembly has a cross-sectional shape and size larger than the cross-sectional shape and size that the sheath's lumen will additionally accommodate by inserting the imaging assembly into the catheter sheath in a proximal-to-distal manner. By making the attachment of the distal end to the sheath possible after the imaging assembly and rotatable conduit are positioned in their functional positions within the portion of the sheath to be inserted into the body (i.e., the portion where the cross-sectional area is minimized to minimize trauma to the body), the imaging assembly can have a size larger than it would have under a conventional proximal-to-distal insertion method.

[0076] In another exemplary embodiment, the proximal wall of the sheath at the distal end can be made thicker, and thus can be made to include more functional components, as will be described later.

[0077] In one exemplary embodiment, the distal section of the sheath may not require a separate rigid reinforcement member because the sheath may have a wall thickness sufficient to withstand any inward radial force applied by the heat shrink member, and may also be thick enough to dissipate any localized heat used to form a thermal bond between the distal end and the section of the sheath 110, thereby preventing heat from deforming or otherwise damaging the catheter or its internal components.

[0078] exist Figure 1 , Figures 2A to 2D and Figures 3A to 3CIn the illustrated example, a drawstring and a loop are included as components of the catheter to demonstrate that features including a drawstring lumen, such as a long portion along the catheter, require space within the overall area of ​​the cross-section of the long portion, thereby limiting the size of the main lumen and consequently limiting the radial span (size and shape) of the imaging assembly housed within the main lumen. However, many exemplary embodiments of this disclosure do not constrain the radial span of the imaging assembly, even when a drawstring lumen is present. For example, by making the wall thickness in the distal end thinner than the wall around the main lumen (for better imaging properties), the cross-section of the imaging portion at the distal end can be designed to be larger than the cross-section of the main lumen to facilitate the manufacture, cost, and / or structural integrity of the long portions of the catheter (such as the proximal long portion and the flexible portion as in the exemplary embodiments).

[0079] As previously mentioned, it may be desirable for the imaging assembly to have the largest possible diameter (radial span; size and shape) to improve functionality and / or image quality. In the case of ultrasound imaging, the imaging assembly may include more than one ultrasound transducer. For example, the ultrasound transducer may be mounted on a housing and pivot assembly that allows the ultrasound transducer to pivot about a tilting channel to achieve 3D imaging, as disclosed in U.S. Patent Publication No. 20090264768. The 3D forward-looking scanning mechanism may benefit from the additional space in the distal end of the catheter for the imaging assembly, where the additional space can be used, for example, to accommodate a larger imaging assembly, which can then be used to make room for more components of the imaging assembly, including, but not limited to, ultrasound transducers that may be larger than the ultrasound transducers that can be additionally accommodated. The 3D scanning mechanism will preferably, but not necessarily, be positioned near the distal end of the catheter so that a relatively unobstructed line of sight passes freely through the dome-shaped imaging window, especially when the beam is emitted in a more forward direction.

[0080] The exemplary method of this disclosure, which allows the imaging assembly to be inserted from the distal end, allows the catheter to be configured to have a smaller central lumen along its sheath. Such a smaller central lumen will allow for a thicker wall diameter. This extra space can be used, for example, to add an off-center lumen within the sheath.

[0081] An exemplary use of the additional side lumen is to incorporate an additional suture, which allows for better catheter manipulation. Catheter maneuverability is particularly important for ablation procedures, where the catheter is used to cauterize specific abnormal cardiac tissue at the site of arrhythmia in the atria and ventricles. In the case of imaging catheters, this additional maneuverability allows for greater control of the field of view. Another use of the side lumen is the ability to add one or more flushing lumens and / or one or more other fluid delivery lumens to the catheter.

[0082] The additional cross-sectional space in the sheath, obtainable by employing a central lumen with a diameter smaller than the lateral span of the imaging components (or other distal functional devices or elements), can also be used, or alternatively, to insert or otherwise incorporate additional sensors into the catheter, isolated from the central lumen, such as, but not limited to, temperature sensors, electromagnetic sensors for electroanatomical mapping, optical fibers for rotary encoders (specifically in conjunction, as the reduced diameter of the torque cable makes the imaging system more susceptible to NURD), or through-insulation wires attached to electrodes for sensing intracardiac electrograms and / or cardiac pacing.

[0083] Therefore, additional functionality can be added to 2D or 3D imaging catheters by including at least a portion of one or more of the following functional enhancement components in the catheter sheath:

[0084] 1. Add one or more attitude sensors or transmitters, such as those provided by Northern Digital (NDI) or Ascencion Technology, to provide the ability to sense the position and / or orientation of the distal segment of the duct;

[0085] 2. Add a rotary encoder (such as one or more of those rotary encoders described in U.S. Patent No. 8,712,506, which is incorporated herein by reference in its entirety);

[0086] 3. Add one or more fiber optic-based sensors, such as Bragg gratings, optical pressure sensors, or optical temperature sensors;

[0087] 4. Add one or more pacing or electrocardiogram (ECG) electrodes;

[0088] 5. One or more deflection mechanisms (e.g., pull cords) to make the sheath more maneuverable, such as bidirectional steering;

[0089] 6. Add an accessory lumen having a proximal outlet for delivery to deliver fluid or a separate device (such as a thread) to the anatomical area surrounding the distal portion of the catheter;

[0090] 7. Additional flushing or draining chambers that are in fluid communication with the internal region of the conduit to help improve image quality, such as by removing air from the distal region that may interfere with imaging; and / or

[0091] 8. Add wiring to include an electromagnetic winding near the end, such as an electromagnetic winding for enhancing the tilting performance of a magnet-based scanning mechanism or for sensing electromagnetic signals (such as electromagnetic (EM) noise that may interfere with image quality).

[0092] It should be noted that if the most distal portion of the functional enhancement component is positioned proximal to the imaging assembly along the long axis (longitudinal axis) of the catheter, it is preferable to add multiple of these functional enhancement components. For example, if they intersect with the field of view of the imaging assembly, the wiring, optical fibers, and / or cavities used to implement the functions of these components may, to a minimum or significant degree, interfere with the imaging performed by the imaging assembly. For example, wiring can cause shadows in ultrasound imaging; therefore, the above-described embodiment is preferred for ultrasound applications, but the pacing electrode and its associated wiring do not necessarily need to be positioned proximal to the imaging assembly.

[0093] As an example, Figure 6A and Figure 6B The distal section of the conduit is shown, including an attitude sensor 200 within the wall of a sheath 110, a wired conductive conduit 205, a torque cable (rotatable imaging conduit) 160, a distal imaging end 140, an imaging assembly 170, and a structural rigid member 180. Figure 6A and Figure 6B In the illustration, the structural rigid member 180 is shown as embedded in the sheath 110, but in other exemplary embodiments (e.g., see [reference needed]), the rigid member 180 is shown as embedded in the sheath 110. Figure 4 The structural rigid member 180 is accessible to the inner surface of the sheath 110. It also includes the following to provide rotational encoding capability: an encoding substrate 220, an optical fiber 210 incorporated in the sheath, an optional imaging pad 212, and an optional lens 214, wherein the encoding substrate rotates in conjunction with rotating components such as the imaging assembly 170. Figure 7 The image shows a perspective view of the coding substrate 220. Figure 6B The central circle in the diagram shows the electrical coaxial cable 172 used to transmit ultrasound signals to and from the imaging assembly 170.

[0094] It should be noted that a synergistic effect can be achieved by combining a smaller torque cable with a rotary encoder for detecting rotational motion. A smaller main cavity and a smaller torque cable typically negatively impact the rotational performance of the torque cable in terms of how closely rotation at the proximal end of the torque cable is converted into an equivalent rotation at the distal end. However, the rotary encoder reduces the need for one-to-one transmission along the length of the torque cable. This alleviates several design constraints on rotary conduits and allows for smaller and / or simpler designs of the torque cable, or even the use of simpler structures such as hollow polymer extrusions to replace the torque cable. Therefore, the rotary encoder enables smaller diameters and potentially simpler torque transmission methods, thereby providing space within the conduit wall for the rotary encoder to be included in the conduit design.

[0095] The attitude sensor 200 (or attitude transmitter) can be one of those known in the art, such as those supplied by NDI, Ascension Technology, or found in Carto Systems (Biosense Webster). The advantages of including an attitude sensor / transmitter in an imaging catheter are well known in the art because it provides coordinates about where to collect images within a reference coordinate system (typically a coordinate system relative to the center of the patient or the worktable where the patient lies). For example, U.S. Patent No. 6,443,894 provides an example of an imaging catheter including an attitude sensor.

[0096] Attitude sensors have previously been incorporated into array-based intracardiac echocardiography (ICE) catheters, which do not involve rotating torque cables or rotary motors. Furthermore, the position and orientation of the image relative to the attitude sensor are more easily determined using array-based imaging catheters because there is a fairly fixed geometric relationship between the attitude sensor and the imaging array transducer. In mechano-imaging catheters, the imaging transducer changes its position or orientation relative to the attitude sensor. Therefore, a method for detecting the position and / or orientation of the imaging transducer is more helpful in mapping images from the imaging assembly onto the attitude sensor reference frame. In its simplest form, a rotary encoder positioned outside the patient and coupled to the proximal portion of the torque cable (such as a rotary encoder in a patient interface module) provides some information about the rotational position of the imaging assembly. However, the accuracy of the external rotary encoder's orientation relative to the actual rotational orientation within the sheath may be inaccurate due to the imprecise torque transmission provided by the torque cable, which is a long and imperfect component susceptible to human intervention such as non-uniform rotational deformation. Additionally, in some embodiments of the imaging catheter, the sheath incorporating the attitude sensor may be able to rotate freely relative to rotating components within the catheter. Furthermore, in some embodiments such as 3D imaging conduits, the imaging component may be configured such that the angle at which the emitted imaging beam is tilted more toward the forward or side view, and may have a tilt angle encoder provided, such as those described in U.S. Patent Application Publication No. 20120197113.

[0097] To enhance the ability to map imaging data (such as complete image frames, imaging vectors, or imaging pixel samples) from the image coordinate system to the attitude sensor reference coordinate system, it may be desirable to incorporate the rotary encoder 220 between the imaging assembly and the sheath, such as... Figure 6A As included in [the document]. Similarly, it is desirable to incorporate tilt angle encoders within the imaging assembly or sheath, such as those described in U.S. Patent Application Publication No. 20120197113 and U.S. Patent No. 8,712,506.

[0098] A magnet-based attitude transmitter positioned on a rotating IVUS catheter has been constructed by Mediguide (part of St. Jude), in which a small magnet is placed at the end of the IVUS catheter to sense the position of the IVUS catheter end. The Mediguide magnet does not require wiring along the length of the catheter and therefore does not produce imaging artifacts from any wiring typically associated with several other implementations of attitude sensors or transmitters when the Mediguide magnet is added to the catheter end.

[0099] NDI supplies attitude sensors with a diameter less than 1 mm and a length less than 1 cm, capable of detecting position and orientation in 5 or 6 degrees of freedom. Such attitude sensors can detect 3D position within a reference coordinate system (e.g., x, y, z) and two or three angular orientations of the sensor. The roll axis of orientation (e.g., rotational orientation about an axis of the sensor (such as the major axis of the sensor) is provided by a 6-DOF sensor instead of a 5-DOF sensor.

[0100] NDI systems operate by placing a field generator near the patient, which generates an electromagnetic field above the patient. The sensor includes one or more coils and associated wiring that detects the localized electromagnetic field and transmits a signal along the associated wiring to a console to determine the sensor's position and / or orientation. The field can be a static magnetic field or a time-varying electromagnetic field. Commonly used systems employ time-varying electromagnetic fields for position and orientation sensing.

[0101] Another form of position sensing involves using impedance measurements across the body to triangulate the position of electrodes in contact with anatomical structures. This system typically has two or more (usually at least three) reference electrodes or electrode pads attached to the body, thereby triangulating or otherwise estimating the position of the catheter electrodes.

[0102] It is also possible to use two impedance-based position sensors along the length of the conduit (i.e., the electrode) to obtain two sets of xyz coordinates, which can be used to provide information about the orientation of the two degrees.

[0103] Similarly, two sensors can be used, one with five degrees of freedom (DOF) sensing and the other with position sensing at least at approximately the same longitudinal location on the catheter, to provide the information needed to determine the sixth degree of freedom (rolling) given that the two sensors are positioned relative to each other in a known configuration. The advantage of using two sensors to provide six degrees of freedom positioning and orientation, rather than a single six-DOF sensor, is that both sensors (which are themselves smaller than six-DOF) can each be smaller than a six-DOF sensor. Furthermore, if the center of the main lumen is desired to be near the center of the catheter, a larger single sensor can force the main lumen to be smaller than the lumen that two smaller sensors placed in two different locations around the main lumen might require.

[0104] The advantage of electrode-based sensing is that the electrodes can be used for other purposes (pacing, ECG sensing), and the same setup can be used to determine the location of any catheter electrode in the body. Electromagnetic sensors may be more accurate and precise than simple electrodes.

[0105] Adding an attitude sensor to an imaging catheter for mechanical scanning offers several advantages. It makes it easier for the user to understand the relationship between manipulations applied to the catheter (by the user or actuators of a robotic mechanism such as those external to the body) and its position and orientation relative to a reference frame. It allows imaging data to be mapped to 3D or 4D (3D + time, such as ECG-gated time windows) datasets, and, if Doppler is enabled, to 5D datasets (3D + time + flow). Furthermore, the image quality of an imaging catheter depends on several aspects of the catheter. Imaging data acquired in preferred regions where the imaging beam is more concentrated (such as in the near field of a single element of a unitary ultrasound transducer (as opposed to an array transducer) generally has better quality than imaging data acquired outside of that region. Therefore, by moving the distal portion of the imaging catheter within the body, some imaging data will have better quality as the catheter moves closer to the tissue of interest.

[0106] In one exemplary implementation, 3D or 4D imaging data obtained outside a preferred region can be updated using imaging data subsequently obtained within the preferred or optimal region to improve the overall quality of the dataset.

[0107] Furthermore, the quality of ultrasound images may depend slightly on the angle of incidence between the ultrasound beam and the imaged structure. Therefore, in some exemplary embodiments, images of the same structure can be obtained from multiple viewpoints, and a piecewise algorithm known in the art can be used to estimate an approximate angle of incidence. For example, typically the optimal imaging signal is perpendicular incidence. In some cases, reflection artifacts exist under perpendicular incidence and are preferably near but slightly off-center from perpendicular incidence (approximately 3 to 10 degrees). Imaging data collected using the most preferred angle of incidence can be used to create 3D or 4D composite imaging datasets.

[0108] Furthermore, the quality of ultrasound images can depend slightly on the distance between the ultrasound transducer and the structure being imaged. For example, if the transducer is a focused transducer, optimal imaging will occur within the focal region. The focal region is typically defined as the full width at half maximum (FWHM) area along the depth direction of a given A-scan line. In the case of an unfocused transducer, the sound beam... Approximate distances can be estimated using segmentation algorithms known in the art. Imaging data collected using the optimal distance can be used to create 3D or 4D composite imaging datasets.

[0109] Now for reference Figure 10 A flowchart illustrating such an exemplary method is shown, in which a 3D image is selectively updated using calculated incident angles and / or proximity associated with image data. As shown at 400, a 3D or 4D image dataset is initially obtained, and as shown at 410, a 3D representation is reconstructed from the dataset using information provided by an attitude sensor. As shown at 420, additional incremental imaging data, which may be 2D, 3D, or 4D, is then obtained. As shown at 430, the incremental image data is processed using attitude information to determine whether it at least partially corresponds to previously obtained image data. The attitude information is then used at step 440 to determine incident angle and / or proximity information associated with the incremental imaging data. Then at step 450, it is determined whether the incremental imaging data and its associated incident angle and / or proximity information represent preferred imaging data (e.g., based on a pre-selected threshold, or, for example, based on a comparison with a lookup table containing preferred ranges). In the absence of identification of preferred imaging data, steps 420 through 440 may optionally be repeated. If preferred image data is identified, the preferred imaging data can be used to reconstruct a 3D representation, as shown at 460.

[0110] Typically, in the field of minimally invasive imaging probes, the insertable portion is configured to be flexible, especially when advanced into a vascular system, where the system causes the portion to bend. Therefore, if the rigid reinforcement 180 is too long, it will create undesirable local stiffness. In some exemplary embodiments, the length of the rigid member may be less than 20 times, 10 times, 5 times, 3 times, or 1 times the outer diameter of the probe.

[0111] Figure 8 An exemplary embodiment is shown in which the distal region of the conduit sheath merges with a winding 240 surrounding the main lumen. This winding can be electrically communicated with external electronics via a conductive conduit 245.

[0112] Figure 8 The exemplary windings shown can be used in several applications, such as, but not limited to:

[0113] 1) It acts as an attitude sensor or transmitter;

[0114] 2) To generate a local magnetic field that actuates the movement within the duct;

[0115] 3) To generate a localized magnetic field to attract magnetic components outside the catheter; and

[0116] 4) Generate electromagnetic signals within the body, including those that may have introduced artifacts into the imaging signals from the imaging components.

[0117] Provide surrounding main cavity 115 (e.g.) Figure 8 (in the middle) rather than the adjacent main cavity 115 (e.g.) Figure 6A A potential advantage of using an attitude sensor in the middle (of the image) is that such a configuration can accommodate more than Figure 6A The implementation method has a larger main cavity and allows for a more radially symmetrical design.

[0118] An exemplary embodiment in which the winding 240 can actuate movement within the probe involves incorporating a magnet into the backing of a tiltable transducer. Examples of such embodiments are... Figure 9 As shown, a tiltable transducer 260 is tilted about a pivot axis 265 and pivotally mounted to a housing 270, wherein the tiltable transducer 260 has a magnet 280 attached thereto, recessed therein, or otherwise mechanically supported. The ultrasonic transducer 260 is connected via a conductive spring (not shown) to one or more electrical signal conduits (not shown) within a torque cable. A magnetic field is generated by applying current to the winding 240 through the proximal winding conductor 245, which tilts the tiltable transducer 260 via an attractive / repulsive force between the transducer magnet 280 and the winding 240. In other exemplary embodiments, the magnet 280 does not necessarily need to be directly attached to the transducer 260. For example, the magnet may be attached to a push rod or shaft to tilt or translate the transducer within the imaging assembly.

[0119] The winding conduits 245 are typically electrically insulated from each other and are either provided with insulation or insulated by incorporation into the conduit wall. The winding conduits 245 may be incorporated into the reinforcing braid within the sheath to reduce the cross-sectional area used along the main portion of the sheath.

[0120] In another exemplary embodiment, the distal end region may be configured to include a plurality of transducers supported by one or more imaging components, wherein the imaging components and / or transducers have a lateral span greater than the inner diameter of the main lumen of the catheter.

[0121] While the foregoing exemplary embodiments have illustrated various aspects of this disclosure by relating to imaging probes / catheters having imaging components, it should be understood that the exemplary embodiments disclosed herein may be suitable for use with medical probes having non-imaging rotatable devices that replace or supplement imaging components.

[0122] It should be understood that the distal end, including a distal dome-shaped profile, described and illustrated herein provides a non-limiting example of a distal end configuration, and other distal end geometries and profiles may be employed without departing from the intent of this disclosure. Furthermore, although the foregoing exemplary embodiments illustrate a closed distal end, it should be understood that the distal end may include one or more openings or ports.

[0123] Now for reference Figure 11 An imaging system is shown at point 10, which includes an imaging probe 44 connected to an image processing and display system 49 via a patient interface module 36. The image processing and display system 49 includes hardware supporting one or more imaging modes, such as ultrasound, optical coherence tomography, angiography, infrared imaging, near-infrared imaging, Raman spectroscopy-based imaging, or fluorescence imaging. Specific embodiments of ultrasound imaging probes and combined ultrasound and optical imaging probes are disclosed in the following patents: U.S. Patent No. 20080177183, filed January 22, 2008, entitled "Imaging Probe with Combined Ultrasounds and Optical Means of Imaging," filed by Courtney et al.; U.S. Patent No. 20080177138, filed January 22, 2008, entitled "Scanning Mechanisms for Imaging Probe"; and U.S. Patent No. 20090264768, filed March 27, 2009, entitled "Scanning Mechanisms for Imaging Probe," each of which is incorporated herein by reference in its entirety.

[0124] The controller and processing unit 34 is used to facilitate the coordinated activities of the various functional units of the system and may include some or all of the components shown in the accompanying drawings and listed herein. The controller and processing unit 34, or a separate computing device or system, may also be used to implement... Figure 10The flowchart shown is associated with the method. An operator interacts with system 50 via a display and / or user interface 38. System 10 may also include electrode sensors 40 to acquire electrocardiogram (ECG) signals from the body of the patient being imaged. In situations where cardiac motion may affect image quality, the ECG signals can be used to time the acquisition of imaging data. The ECG can also act as a trigger for when to begin an acquisition sequence, such as when to begin changing the rotational speed of a motor to activate a desired scanning pattern. For example, ECG-triggered initiation of an imaging sequence enables image acquisition during specific phases of the cardiac cycle, such as systole or diastole. If the optical subsystem 30 is included in a specific embodiment of the imaging system, it may include any or all of the following components: interferometer components, one or more optical reference arms, optical multiplexers, optical demultiplexers, light sources, photodetectors, spectrometers, polarization filters, polarization controllers, timing circuitry, analog-to-digital converters, parallel processing arrays, and other components known to contribute to any of these optical imaging techniques. The ultrasound subsystem 32 may include any or all of the following components: a pulse generator, an electronic filter, an analog-to-digital converter, a parallel processing array, an envelope detector, an amplifier (including a time-gain-compensated amplifier), and other components known to be helpful for acoustic imaging techniques.

[0125] If the controller and processing unit 34 are included in a specific embodiment of the imaging system, then the controller and processing unit 34 serve multiple purposes. Those skilled in the art will understand that the specific components required depend on the needs of the particular type of imaging system. For example, the controller and processing unit may include any combination of the following: a motor drive controller, data storage components (such as memory, hard disk drive, removable storage device), readers and recorders for media (such as CDs, DVDs, and Bluray™ discs), position sensing circuitry and / or software, angle detection circuitry and / or software, timing circuitry and / or software, cardiac gating functions, a volumetric imaging processor, a scan converter, and others. As described above, the display and user interface 38 may also optionally be provided for real-time data display or for displaying data after the time of acquisition of the imaging data.

[0126] It should be understood that the patient interface module 36 and the controller and processing unit 34 are merely exemplary illustrations of the selection and organization of hardware subsystems, and many other implementations are possible. For example, the patient interface module 36 may be housed within the processing and display system 49 along with the controller and processing unit 34.

[0127] An exemplary imaging probe 44 includes an imaging assembly 50, an optional imaging conduit 46 along most of the length of the imaging probe, and a connector 48 at the proximal end 47 of the imaging probe. The imaging assembly 50 is located near the distal end 41 of the imaging probe 44. The imaging assembly 50 generally refers to a component of the imaging probe 44 from which signals (acoustic signals, optical signals, or both) are collected for imaging of an area near the imaging assembly 50. The imaging assembly 50 may house transducers for emitting and / or receiving imaging radiation. The transmitter and receiver may be a single component, as is typically the case in the case of a piezoelectric transducer.

[0128] In the case of optical imaging, imaging assembly 50 typically includes the distal end of an optical fiber and a combination of optical components such as lenses (e.g., spherical lenses or GRIN lenses). Mirrors and / or prisms may be included for beam transmission and / or collection. Optionally, an optical detector such as a CCD array or an optical light source such as one or more LEDs may be directly incorporated into the imaging assembly, eliminating the need for one or more optical fibers in the optical imaging probe. Imaging probe 44 may include ports at one or more points along its length to facilitate flushing. Furthermore, imaging assembly 50, connector 48, and / or imaging conduit 46 may be filled with and / or surrounded by a fluid such as saline solution and may be flushed. In applications involving optical imaging, imaging probe 44 may be filled with a gas. The gas may include carbon dioxide or another readily soluble gas with minimal biotoxicity. Alternatively, in the case of a multimodal optical / acoustic imaging system, imaging assembly 50 may be partitioned to include at least one gas-filled compartment or cavity for optical imaging and at least one fluid-filled compartment or cavity for acoustic imaging.

[0129] Imaging conduit 46 includes at least one wire (optionally two or more) connecting the transmitter and / or receiver to an adapter (referred to herein as patient interface module 36) via a connection. Imaging conduit 46 may include, for example, an optical fiber wrapped with two layers of wire electrically insulated from each other. Imaging conduit 46 may also be reinforced by other structural features, such as spiral-wound wires or other designs used to construct imaging torque cables for rotating the scanning mechanism. Alternatively, imaging conduit 46 may include electrical conductors, and the rotation mechanism may be positioned away from the proximal end to apply rotational motion to the imaging assembly. An exemplary mechanism includes a micromotor and a slip ring near the imaging assembly.

[0130] Optionally, the imaging probe 44 may include a memory, such as an EEPROM for storing information including calibration information, sequence information, probe design information, desired filter information, and any other probe-specific information. This memory may be located in the connector 48.

[0131] The patient interface module 36 facilitates the transmission of signals within any fiber optic and / or wiring connections to a suitable image processing unit. It may include a motor drive unit for applying rotational motion to components of the imaging mechanism. Additional sensors, such as motion sensing circuitry, may be incorporated as part of the patient interface module 36, for example, to sense the rotation angle of rotating components within the imaging probe 44 and / or to detect the deflection angle of a component at the distal end 41 of the imaging probe 44. Additionally, the patient interface module 36 may include amplifiers to improve the transmission of electrical signals or power between the imaging probe 44 and the rest of the system.

[0132] The specific embodiments described above have been illustrated by way of example; however, it should be understood that these embodiments may have various modifications and alternatives. It should also be understood that the claims are not intended to limit the specific forms disclosed, but rather to cover all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure.

Claims

1. An imaging probe, comprising: An elongated sheath includes an inner surface and an outer surface, the inner surface defining a main cavity; A rotatable conduit extends within the main cavity, wherein the proximal end of the rotatable conduit can be connected to a rotary drive mechanism for imparting rotation to the rotatable conduit. An imaging assembly is mechanically coupled to the rotatable conduit at a location remote from the proximal end of the rotatable conduit, and the imaging assembly is connectable to external control and image processing hardware via an imaging signal transmission conduit extending through the rotatable conduit. An attitude detection component, wherein at least a portion of the attitude detection component is located within the elongated sheath between the inner surface and the outer surface; and A rotary encoder, including a remote rotary encoder interface configured to facilitate determining the angular orientation of the imaging component relative to the elongated sheath, the rotary encoder being connectable to external control and image processing hardware via a rotary encoder signal transmission channel. Wherein, the lateral extension of the imaging component exceeds the diameter of the main cavity of the elongated sheath, such that the imaging component is located distal to the distal end of the elongated sheath. The imaging probe further includes a distal tip that accommodates the imaging component, wherein the proximal portion of the distal tip is coupled to and overlaps with the distal portion of the elongated sheath. The remote rotary encoder interface is located between the distal end of the long sheath and the proximal end of the imaging component.

2. The imaging probe according to claim 1, wherein, The remote rotary encoder interface is fixed to the imaging assembly and rotates in unison with the imaging assembly, wherein the sensing mechanism of the rotary encoder is embedded within the elongated sheath.

3. The imaging probe according to claim 1 further includes a rigid reinforcing member located within the elongated sheath, such that the rigid reinforcing member contacts the inner surface of the elongated sheath or is embedded within the elongated sheath, and such that the rigid reinforcing member has a longitudinal extension in the distal region of the elongated sheath.

4. The imaging probe according to claim 1, wherein, The rotary encoder signal transmission conduit is located between the inner surface and the outer surface of the elongated sheath.

5. The imaging probe according to claim 4, wherein, The rotary encoder signal transmission channel is located inside the side cavity of the long sheath.

6. The imaging probe according to claim 1, wherein, The attitude detection component includes an electromagnetic attitude sensor, which is connected to the external control and image processing hardware via an attitude detection signal transmission channel located between the inner and outer surfaces of the elongated sheath.

7. The imaging probe according to claim 6, wherein, The attitude detection signal transmission channel is located inside the side cavity of the long sheath.

8. The imaging probe according to claim 6, wherein, The electromagnetic attitude sensor includes a conductive winding surrounding the main cavity, wherein the attitude detection signal transmission conduit is electrically connected to the conductive winding.

9. The imaging probe according to claim 1, wherein, The attitude detection component includes an electromagnetic transmitter configured to generate an electromagnetic field for attitude detection by an external attitude detection circuit, wherein the electromagnetic transmitter is connectable to the external control and image processing hardware via an attitude transmitter conduit located between the inner and outer surfaces of the elongated sheath.

10. The imaging probe according to claim 9, wherein, The electromagnetic field is a time-varying electromagnetic field.

11. The imaging probe according to claim 9, wherein, The electromagnetic field is a static magnetic field.

12. The imaging probe according to claim 9, wherein, The electromagnetic transmitter includes a conductive winding surrounding the main cavity, wherein the attitude transmitter conduit is electrically connected to the conductive winding.

13. The imaging probe according to claim 1, wherein, The attitude detection component includes a magnet.

14. The imaging probe according to claim 1, wherein, The attitude detection component includes multiple electrodes for impedance-based attitude sensing.

15. An imaging system, comprising: The imaging probe according to any one of claims 1 to 14, wherein the imaging probe is operatively connectable to the external control and image processing hardware; The external control and image processing hardware is configured to perform the following operations: Control the imaging component to acquire an image dataset including three-dimensional image data; Receives a corresponding attitude detection signal generated or detected by the attitude detection component, and receives a corresponding rotary encoder signal from the rotary encoder; and The attitude detection signal, the rotary encoder signal, and the image dataset are processed to generate a three-dimensional representation of the structure.

16. The imaging system according to claim 15, wherein, The image dataset comprises multiple subsets of image data, each subset representing the structure according to a different incident angle, wherein the external control and image processing hardware is further configured to perform additional operations including: The plurality of image data subsets are processed to estimate the corresponding incident angle for each image data subset; and When generating the three-dimensional representation of the structure, image data corresponding to one or more incident angles is used.

17. The imaging system according to claim 15, wherein, The image dataset comprises multiple subsets of image data, each subset representing the structure based on different distances between the imaging component and the structure. The external control and image processing hardware is further configured to perform additional operations including: The plurality of image data subsets are processed to estimate the corresponding distance between the imaging component and the structure for each image data subset; and When generating the three-dimensional representation of the structure, image data corresponding to one or more distances is used.

18. A method for controlling an image probe to generate a three-dimensional image of a structure, the method comprising: Sending a control signal to an imaging probe, which is provided according to any one of claims 1 to 14, to perform operations including: Acquire image datasets including 3D image data; and Receive the corresponding attitude detection signal generated or detected by the attitude detection component, and receive the corresponding rotary encoder signal from the rotary encoder; as well as The attitude detection signal, the rotary encoder signal, and the image dataset are processed to generate a three-dimensional representation of the structure.

19. The method according to claim 18, wherein, The image dataset includes multiple image data subsets, each of which represents the structure according to a different incident angle. The method further includes: The plurality of image data subsets are processed to estimate the corresponding incident angle for each image data subset; and When generating the three-dimensional representation of the structure, image data corresponding to one or more incident angles is used.

20. The method according to claim 18, wherein, The image dataset includes multiple image data subsets, each of which characterizes the structure based on different distances between the imaging component and the structure. The method further includes: The plurality of image data subsets are processed to estimate the corresponding distance between the imaging component and the structure for each image data subset; and When generating the three-dimensional representation of the structure, image data corresponding to one or more distances is used.

Images