Patent Description:
This disclosure relates to medical instruments and more particularly to shape sensing optical fibers in guidewires configured to conform to a profile in a hub for device navigation in medical applications.

A medical device such as a catheter, deployment system, or sheath can be enabled with shape sensing by embedding an optical fiber(s) within the device. This requires customizing a mechanical design of the device to add an additional lumen for the fiber. Adding the fiber also adds cost to the device and necessitates the use of an additional shape sensing system. Such devices are known as 'over-the-wire' devices as they are typically used in conjunction with a guidewire that travels through a lumen in the device.

Optical shape sensing (OSS) or Fiber-Optical RealShape™ (also known as "Optical Shape Sensing", "Fiber Shape Sensing", "Fiber Optical 3D Shape Sensing", "Fiber Optic Shape Sensing and Localization" or the like) employs light along an optical fiber for device localization and navigation during surgical intervention. One principle involved makes use of distributed strain measurement in the optical fiber using characteristic Rayleigh backscatter or controlled grating patterns. Multiple optical fibers can be used together to reconstruct a 3D shape, or a single optical fiber with multiple cores that may also be helixed for a lower-profile sensor. The shape along the optical fiber begins at a specific point along the sensor, known as the launch or z=<NUM>, and the subsequent shape position and orientation are relative to that point. As illustrated in <CIT>, optical shape sensing fibers can be integrated into medical devices to provide live guidance of the devices during minimally invasive procedures.

In accordance with the present invention, as defined in appended independent claim <NUM>, a hub for an optical shape sensing reference includes a hub body receiving an elongated flexible instrument with a shape sensing system coupled to the flexible instrument within a path formed in the hub body. A profile is formed in the hub body in the path to impart a hub template configured to distinguish a portion of the elongated flexible instrument within the hub body in shape sensing data. An attachment mechanism mechanism, comprising a luer lock, is formed on the hub body to detachably connect the hub body to a deployable instrument such that a change in a position of the hub body indicates a corresponding change in the deployable device. According to the present invention, one end of the path of the elongated flexible instrument formed in the hub body leads to a lumen of the deployable device via said detachable connection between the hub body and the deployable device.

Preferred embodiments are defined in the appended dependent claims.

These and other objects, features and advantages of the present disclosure will become apparent from the following detailed description of illustrative embodiments thereof, which is to be read in connection with the accompanying drawings.

This disclosure will present in detail the following description of preferred embodiments with reference to the following figures wherein:.

In accordance with the present principles, a shape sensed guidewire is provided for use in a lumen that also senses the position of any commercial over-the-wire device or component. If a catheter (or other deployable device) is employed over a shape sensed guidewire (or other flexible elongated device) then the guidewire shape also defines the catheter shape for the length over which the catheter overlaps the guidewire. To properly define the position of the catheter along the guidewire, a relationship between the catheter and the guidewire needs to be known. This can be done by using a hub device to cause the guidewire to take on a specific shape, curvature, or strain profile (shape profile) at a specific position along the catheter. A method to induce such a shape, curvature or strain profile is to employ the 'hub' with a known profile which can be stored as a template.

When a shape sensed device is inside a non-shape sensed device, the shape information from the sensed device can be used to infer information about the shape and position of the unsensed device. The registration needed may include a longitudinal translation between the two devices. This registration can be performed by using a known shape deformation of the sensed device at a specific location along the unsensed device. The shape deformation can be detected through curvature detection, axial strain (from heating or tensions), 2D or 3D shape matching, etc..

Multiple different versions of hub designs may be employed. In the case of hubs that use a shape deformation (as opposed to a strain deformation due to temperature, for example), the shape deformation will also define a plane. The same hub device can be used to track orientation of the device (e.g., roll about its longitudinal axis). Orientation of the hub at a proximal part of the device may map <NUM>-to-<NUM> to a therapeutic such as a balloon, valve, endograft, stent, etc. located in the distal portion.

The present principles describe hub designs that can be used to create a template profile. These designs may include, e.g., a Luer lock hub, an over-catheter hub, a hemostatic valve hub, among others. A hub may be defined as a component that can create a shape or curvature deformation in a shape sensed device, such as a guidewire. Such a component should be able to work in a wide range of commercially available medical devices within a clinical environment. The hub design can be employed across multiple device designs. Multiple different versions of hub designs can be used for deforming the guidewire and performing longitudinal encoding.

Once the position and orientation of the over-the-wire device is known, it can be employed to display a model of a therapeutic such as a balloon, valve, endograft, stent, etc. In endovascular aneurysm repair (EVAR), the position of the endograft needs to be known so that other catheters and endografts can be navigated with respect to an original endograft. This calls for significant amounts of fluoroscopy and contrast. If the endografts are not correctly positioned, a number of issues may arise.

EVAR replaced open surgery as the most common technique for the repair of abdominal aortic aneurysms (AAA). The procedure is usually carried out under x-ray fluoroscopy guidance and uses significant amounts of contrast to position and deploy the stent graft correctly. On average <NUM>-<NUM> of contrast dye is used during an EVAR procedure, which can result in acute renal failure in ~<NUM>% of cases. One complication from EVAR is endoleaks resulting from an insufficient seal of the stent graft to the aorta. Endoleaks involve incorrect flow around the stent (for example, flow around the stent at the proximal or distal attachment site, flow through the graft wall, retrograde flow from the branches, etc.). Another complication of EVAR involves ischemia of the aortic side branches (such as the colonic, renal, and pelvic arteries). This can occur due to misplacement of the stent graft such that the stent partially or completely covers one of the side vessels, and this is associated with a lack of high-quality imaging technology as well as the learning curve of the endovascular team.

In EVAR, stent grafts are contained within a stent-deployment system that is used to navigate the stent to the correct part of the vasculature. The deployment systems tend to be relatively large and stiff endovascular devices. They typically involve a handle or set of knobs and dials at the proximal end to control the various steps around the stent deployment. The stent lies within the distal part of the device and is only released once the device has been navigated to the appropriate location. In some cases the stent completely deploys in one step, while in other cases the stent can be partially deployed to allow for correct positioning and orientation before the final deployment step firmly attaches the stent to the vasculature (typically through the retaining/sealing ring).

The endovascular stent graft needs a sufficient amount of healthy vasculature where it can land its sealing ring. If this is not possible beneath the renal arteries, then the stent will cover those arteries, and needs to create some alternative way of maintaining flow to those vessels. This can be done with a fenestrated stent (e.g., a stent with windows for the side-branches) in a procedure known as fenestrated endovascular aneurysm repair (FEVAR). In this case, the stent has fenestrations that are lined up correctly with the side branches and additional stents are placed to connect the side vessels to the main stent.

Under x-ray guidance the stent can be visualized through x-ray visible markers that are located in key positions on the stent. In the fenestrated stent, the markers identify the locations of the fenestrations and can be used to orient the stent to appropriately align the fenestrations with the side vessels.

In accordance with the present principles, devices and methods include registering a hub to a target node of an over-the-wire device and visualizing the over-the-wire device and a model at a target node in the over-the-wire device. This permits any commercial catheter, deployment system, sheath, or other such device to be navigated using a shape sensed guidewire. In useful embodiments, devices and methods make use of a proximal hub to determine orientation of a distal portion of a device such as a commercially available catheter, deployment system, or sheath that is fitted over a shape sensing guidewire. The hub may include a shape profile that deflects the guidewire passing through it into a known shape. That shape can be detected along the fiber to know the longitudinal registration between the guidewire and the over-the-wire device. Since the hub is coupled to the over-the-wire device, the hub shape can also be used to track the rotation or position applied to the proximal part of the over-the-wire device.

In one embodiment, the rotation of the hub (and hence the entire device) can be measured by fitting a plane to the known shape profile inside the hub, and tracking the orientation of that plane over time. In one embodiment, a model of a fenestrated endograft is rotated to better align the fenestrations on the endograft with an anatomical model. The rotation of the hub shape about itself is used to map the rotation of the endograft that is housed within a distal portion of the device. This allows any commercial catheter (manual or robotic), deployment system, sheath, or other such device to be navigated using a shape sensed guidewire. This can be applied to many applications such as vascular (catheters, sheaths, deployment systems, etc.), endoluminal (endoscopes), orthopedic (k-wires & screwdrivers) as well as non-medical applications.

To provide a more efficient registration, a deformable registration device utilizing Fiber-Optical RealShape™ (FORS™ also known as "Optical Shape Sensing", "Fiber Shape Sensing", "Fiber Optical 3D Shape Sensing", "Fiber Optic Shape Sensing and Localization" or the like) may be used. A Fiber-Optical RealShape™ system is a commercial name for systems developed by Koninklijke Philips, N. As used herein, the terms FORS™ and FORS™ systems are not, however, limited to products and systems of Koninklijke Philips, N. , but refer generally to fiber optic shape sensing and fiber optic shape sensing systems, fiber optic 3D shape sensing, fiber optic 3D shape sensing systems, fiber optic shape sensing and localization and similar technologies.

It should be understood that the present invention will be described in terms of medical instruments; however, the teachings of the present invention are much broader and are applicable to any fiber optic instruments. In some embodiments, the present principles are employed in tracking or analyzing complex biological or mechanical systems. In particular, the present principles are applicable to internal tracking procedures of biological systems and procedures in all areas of the body such as the lungs, gastro-intestinal tract, excretory organs, blood vessels, etc. The elements depicted in the FIGS. may be implemented in various combinations of hardware and software and provide functions which may be combined in a single element or multiple elements.

The functions of the various elements shown in the FIGS. can be provided through the use of dedicated hardware as well as hardware capable of executing software in association with appropriate software. When provided by a processor, the functions can be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors, some of which can be shared. Moreover, explicit use of the term "processor" or "controller" should not be construed to refer exclusively to hardware capable of executing software, and can implicitly include, without limitation, digital signal processor ("DSP") hardware, read-only memory ("ROM") for storing software, random access memory ("RAM"), non-volatile storage, etc..

Moreover, all statements herein reciting principles, aspects, and embodiments, as well as specific examples thereof, are intended to encompass both structural and functional equivalents thereof. Additionally, it is intended that such equivalents include both currently known equivalents as well as equivalents developed in the future (i.e., any elements developed that perform the same function, regardless of structure). Thus, for example, it will be appreciated by those skilled in the art that the block diagrams presented herein represent conceptual views of illustrative system components and/or circuitry embodying the principles of the invention. Similarly, it will be appreciated that any flow charts, flow diagrams and the like represent various processes which may be substantially represented in computer readable storage media and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.

Furthermore, embodiments can take the form of a computer program product accessible from a computer-usable or computer-readable storage medium providing program code for use by or in connection with a computer or any instruction execution system. For the purposes of this description, a computer-usable or computer readable storage medium can be any apparatus that may include, store, communicate, propagate, or transport the program for use by or in connection with the instruction execution system, apparatus, or device. The medium can be an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system (or apparatus or device) or a propagation medium. Examples of a computer-readable medium include a semiconductor or solid state memory, magnetic tape, a removable computer diskette, a random access memory (RAM), a read-only memory (ROM), a rigid magnetic disk and an optical disk. Current examples of optical disks include compact disk - read only memory (CD-ROM), compact disk - read/write (CD-R/W), Blu-Ray™ and DVD.

Reference in the specification to "one embodiment" or "an embodiment" of the present principles, as well as other variations thereof, means that a particular feature, structure, characteristic, and so forth described in connection with the embodiment is included in at least one embodiment of the present principles. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment", as well any other variations, appearing in various places throughout the specification are not necessarily all referring to the same embodiment.

It is to be appreciated that the use of any of the following "/", "and/or", and "at least one of", for example, in the cases of "A/B", "A and/or B" and "at least one of A and B", is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of both options (A and B). As a further example, in the cases of "A, B, and/or C" and "at least one of A, B, and C", such phrasing is intended to encompass the selection of the first listed option (A) only, or the selection of the second listed option (B) only, or the selection of the third listed option (C) only, or the selection of the first and the second listed options (A and B) only, or the selection of the first and third listed options (A and C) only, or the selection of the second and third listed options (B and C) only, or the selection of all three options (A and B and C). This may be extended, as readily apparent by one of ordinary skill in this and related arts, for as many items listed.

It will also be understood that when an element such as a layer, region or material is referred to as being "on" or "over" another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" or "directly over" another element, there are no intervening elements present.

Referring now to the drawings in which like numerals represent the same or similar elements and initially to <FIG>, a system <NUM> for monitoring shape sensing enabled devices and other devices is illustratively shown in accordance with one embodiment. System <NUM> may include a workstation or console <NUM> from which a procedure is supervised and/or managed. Workstation <NUM> preferably includes one or more processors <NUM> and memory <NUM> for storing programs and applications. Memory <NUM> may store an optical sensing module <NUM> configured to interpret optical feedback signals from a shape sensing device or system <NUM> (FORS™). Optical sensing module <NUM> is configured to use the optical signal feedback (and any other feedback) to reconstruct deformations, deflections and other changes associated with shape sensed devices. In accordance with the present principles, a medical device or instrument <NUM> includes a lumen <NUM>, which receives a guidewire or other elongated flexible instrument <NUM> therein. The guidewire <NUM> is configured to receive the system <NUM> therethrough. The medical device <NUM> may include a catheter, a sheath, a probe, an endoscope, a robot, an electrode, a filter device, a balloon device, a graft, a stent or other medical component having a lumen, etc. The medical device <NUM> is considered to be an over-the-wire device or component. The medical device <NUM> includes a hub <NUM> that may be configured within the device <NUM>, applied (connected/coupled) to the device <NUM> or configured to fit within the device <NUM>.

The shape sensing system <NUM> includes one or more optical fibers which may be arranged in a set pattern or patterns. The optical fibers <NUM> connect to the workstation <NUM> through cabling. The cabling may include fiber optics, electrical connections, other instrumentation, etc., as needed.

System <NUM> with fiber optics may be based on fiber optic Bragg grating sensors, Rayleigh scattering, or other types of scattering. Inherent backscatter in conventional optical fiber can be exploited, such as Raleigh, Raman, Brillouin or fluorescence scattering. One such approach is to use Rayleigh scatter in standard single-mode communications fiber. Rayleigh scatter occurs as a result of random fluctuations of the index of refraction in the fiber core. These random fluctuations can be modeled as a Bragg grating with a random variation of amplitude and phase along the grating length. By using this effect in three or more cores running within a single length of multi-core fiber, or in multiple single-core fibers arranged together, the 3D shape and dynamics of the surface of interest can be followed.

A fiber optic Bragg grating (FBG) system may also be employed for system <NUM>. FBG is a short segment of optical fiber that reflects particular wavelengths of light and transmits all others. This is achieved by adding a periodic variation of the refractive index in the fiber core, which generates a wavelength-specific dielectric mirror. A fiber Bragg grating can therefore be used as an inline optical filter to block certain wavelengths, or as a wavelength-specific reflector.

Fresnel reflection at each of the interfaces where the refractive index is changing is measured. For some wavelengths, the reflected light of the various periods is in phase so that constructive interference exists for reflection and, consequently, destructive interference for transmission. The Bragg wavelength is sensitive to strain as well as to temperature. This means that Bragg gratings can be used as sensing elements in fiber optical sensors.

Incorporating three or more cores permits a three dimensional form of such a structure to be precisely determined. From the strain measurement, the curvature of the structure can be inferred at that position. From the multitude of measured positions, the total three-dimensional form is determined. A similar technique can be used for multiple single-core fibers configured in a known structure or geometry.

In one embodiment, workstation <NUM> is configured to receive feedback from the shape sensing device <NUM> and record accumulated position data as to where the sensing device <NUM> has been within a volume <NUM>. The shape sensing information within the space or volume <NUM> can be displayed on a display device <NUM>. Workstation <NUM> includes the display <NUM> for viewing internal images of a subject (patient) or volume <NUM> and may include shape images <NUM> as an overlay on medical images <NUM> such as x-ray images, computed tomography (CT) images, magnetic resonance images (MRI), real-time internal video images or other images as collected by an imaging system <NUM> in advance or concurrently. Display <NUM> may also permit a user to interact with the workstation <NUM> and its components and functions, or any other element within the system <NUM>. This is further facilitated by an interface <NUM> which may include a keyboard, mouse, a joystick, a haptic device, or any other peripheral or control to permit user feedback from and interaction with the workstation <NUM>.

A registration device <NUM> is stored in memory <NUM> and is configured to register the hub <NUM> to a target node(s) <NUM> in the over-the-wire device <NUM>. The target node <NUM> may include any identifying features on the device <NUM> that can be employed as a reference for the hub <NUM>. The device <NUM> and the target node <NUM> are preferably visualized in an image or images <NUM>. In addition, a virtual model <NUM> of the over-the-wire device <NUM> may be rendered using the target node <NUM> as a reference to visualize in the over-the-wire device <NUM>.

In one embodiment, the hub <NUM> is registered to the target node <NUM> in the over-the-wire device <NUM> by attaching the hub <NUM> to a proximal portion of an over-the-wire device <NUM> to enable a registration (e.g., longitudinal) between the shape sensed guidewire <NUM> and the over-the-wire device <NUM>. To create a meaningful visualization of the over-the-wire device <NUM>, the hub location may be mapped to other device nodes. Nodes <NUM> are considered to be device features of interest to the clinician. Examples may include a device tip, a position of a fenestration, start and end points of a balloon, location of an ultrasound transducer, etc..

In one embodiment, the target node <NUM> may include a tip position of the device <NUM>. This node <NUM> may be employed for positioning many devices and may be employed for safety reasons (e.g., making sure that the tip does not protrude too far into certain vessels that the tip of the device remains inside the vessel, etc.). When the hub <NUM> is attached to the over-the-wire device <NUM>, it is not possible to correctly visualize the device in space until the mapping between the tip of the device <NUM> and the hub <NUM> is known.

This mapping can be done in a plurality of ways. For example, a length of the device <NUM> may be input to an image processing module <NUM>, which renders a position and dimension(s) of the devices using visualization software. This may be provided by scanning a barcode of the device <NUM> and looking up its properties in a database, the user entering a value directly or reading values from a device package, measuring by hand, etc. In another embodiment, the device <NUM> may be recognized by the image processing module <NUM> using an x-ray image and automatically looking up the information from a database. In another embodiment, the device <NUM> may be placed and attached to the hub <NUM> in an x-ray field of view (FOV) and have its length/dimension automatically detected from the resulting image.

This can be done by automatically detecting the device tip in the x-ray image or having the user click on the device tip in an image using e.g., a mouse (<NUM>). One or more x-ray projections can be employed, and this can work for all devices. In addition, automatic detection may be performed in other ways, e.g., to know the length, just align the guidewire tip with the tip of the device and click a button, or, loop the tip of the device back onto a known feature on the hub (a divot, for example) and click a button.

In accordance with the present principles, hub <NUM> provides a straightforward attachment onto a wide range of commercial devices. The function of the guidewire <NUM> is preserved, e.g., for clinical manipulation such as translation and torqueing. The hub <NUM> provides an integrated solution for the transfer of data (e.g., hub templates, etc.). The hub <NUM> is employed to create shape deformation in the guidewire <NUM> that can be used for longitudinal registration. The hub <NUM> preferably can be retrofit to any commercial medical device (<NUM>) that runs over a guidewire <NUM> (or other elongated flexible shape sensed device). For example, the medical device <NUM> may include a catheter, sheath, introducer, endograft deployment system, valve deployment system, transseptal needle, etc. These devices have a wide range of sizes, flexibility and profiles.

Referring to <FIG>, a cylindrical Luer lock hub <NUM> deforms a guidewire <NUM> into a known shape profile <NUM>. The guidewire <NUM> includes a lumen for receiving a FORS™ system, and the guidewire <NUM> can pass through a lumen into a catheter <NUM> (device <NUM>). Many devices include a male Luer lock component <NUM> at a proximal end of the guidewire lumen in the catheter <NUM>. This Luer lock <NUM> is used to flush the device with saline prior to use, or to flush with contrast during use. The hub <NUM> has a female Luer lock <NUM> on its distal portion which can mate onto the proximal end of the catheter <NUM>. This effectively extends the guidewire lumen, and the extended portion is employed to create a known curvature change. An additional advantage of using a Luer lock system <NUM> is that clinicians are already familiar with how to use it, and it would not hinder workflow. In one embodiment, a secondary attachment or lock may be employed that can lock the hub <NUM> onto the catheter <NUM> so that during torqueing the hub does not decouple from the catheter <NUM>. The attachment (<NUM> in <FIG>) will catch the catheter <NUM> lock for torqueing in one direction, but will permit it to loosen in the other direction.

Referring to <FIG>, a schematic diagram shows a shape sensed guidewire <NUM>, a catheter <NUM> and a hub <NUM>, which deforms the guidewire shape attached to the catheter <NUM> using the Luer lock system <NUM>. Other features of the hub <NUM> may include a replicated female Luer <NUM> at the proximal portion of the hub <NUM> to permit other devices to mate thereon (as they would normally mate directly to a device). A hemostatic valve <NUM> or other device may be mounted to the female Luer <NUM> of the hub <NUM>. A secondary lock <NUM> may be provided to capture the hub <NUM> and valve <NUM> and prevent rotation or unwanted release between the devices. The secondary lock <NUM> may be split-half and may include securing features, like snaps, screws, fasteners, etc..

Referring to <FIG>, in accordance with another embodiment, a hub <NUM> suitable for use with smaller catheters includes an 'over-catheter' design. This may include split-half or clamshell portions <NUM> that a catheter <NUM> is placed into and then the hub <NUM> is closed around the catheter <NUM>. Alternatively, the catheter <NUM> may be passed through a lumen <NUM> in the hub <NUM>. The over-catheter design is desirable because it means that a guidewire (not shown) only passes through the catheter lumen. The hub <NUM> does not add any additional lumen or components that interact with the guidewire. The lumen of the device (catheter <NUM>) needs to be flexible enough to pass through the shape deformation in the hub <NUM>. This may be suitable for thinner, flexible devices like navigation catheters but may not be suitable for larger, stiffer devices, e.g., endograft deployment systems. In <FIG>, instance <NUM> shows the over-catheter hub <NUM> with the clam-shell design in an open position showing a curved path for the lumen <NUM> in part of the clam-shell <NUM>. Instance <NUM> shows the over-catheter hub <NUM> clamped over the catheter <NUM>. The catheter <NUM> includes a guidewire therein (not shown) and the guidewire includes a FORS™ system therein.

In another embodiment, a hemostatic valve (<NUM>, <FIG>) may be employed with a mating male/female connection for a catheter. The valve is opened fully and a hub's distal portion may be inserted into the valve. Then, an outer component or lock (<NUM>, <FIG>) of the hub fastens around the valve to secure the hub in place. Multiple hub designs can be considered with varying paths for the guidewire. Examples of designs in addition to those already described are illustrated in <FIG>.

Referring to <FIG>, hub designs 506a, 506b, 506c (generally hub <NUM>) may include many shapes and sizes. Different designs may include different profiles for guiding a FORS™ system within a guidewire. Features of the hubs in accordance with the present principles include some or all of the following features. An orientation feature <NUM>, such as, a color marker, divot, or raised ridge feature that identifies the orientation of the device may be provided. This can enable the user to use the hub for rotational alignment or other registration functions. The hub <NUM> may include ergonomic features <NUM> to facilitate torqueing of a device <NUM> (<FIG>). This could include a winged shape profile, a ridged profile, etc. to give users a better grip. A low-friction lumen or path (PTFE coated, hydrophilic coated, etc.) may be provided to minimize the effect on the guidewire.

Referring to <FIG>, a hub <NUM> is schematically shown in accordance with one illustrative embodiment. The hub <NUM> includes a hub body <NUM>, which may include a solid design, a split half design, etc. The hub body <NUM> includes an attachment feature <NUM> as described above, such as a Luer lock, etc. In one embodiment, the hub body <NUM> provides a deformable path that includes a mechanism <NUM> for displacing the flexible instrument to form a profile in the hub body in the deformable path to impart a hub template, when the mechanism is in a first position, to distinguish a portion of the elongated flexible instrument within the hub in shape sensing data.

The hub body <NUM> may include a biasing component (<NUM>) such as a spring returned button <NUM> to induce the shape deformation when needed. By moving a shape sensed guidewire <NUM> (or catheter or other device with the shape sensed guidewire <NUM>) in accordance with arrow "A", and locking in position to maintain a shape profile <NUM>, a reversible hub profile can be achieved. This is advantageous because it permits the guidewire <NUM> to pass straight through when not triggered, thus reducing the friction on the guidewire <NUM>. However, shape measurements are only accurate/updated when the mechanism <NUM> is triggered. Although a shape within the hub is described, that shape could alternatively be provided by a heating coil or coils <NUM> to cause a temperature profile to induce axial strain in the optical shape sensing fiber within the guidewire. The hub body <NUM> may also include a permanent shaped path. Hub body <NUM> may include any combination of path changes (e.g., permanent, heated, reversible) to form a shape profile <NUM>. The shape profile <NUM> results in a set hub profile in shape sensed data.

A registration feature <NUM> such as a divot or channel may be employed. To use this divot, a device tip may looped back onto the hub <NUM> and placed within the feature <NUM>. The user initiates registration in the software (registration module <NUM>, <FIG>), and the length of the device is computed using the known relationship between the template position and the feature <NUM>.

In one embodiment, the hub <NUM> includes a proximal Luer lock or other attachment feature <NUM> that is free to rotate and pivot to allow improved usability. In addition, the attachment feature <NUM> may include torque stops, locks or other features <NUM> to prevent removal if twisting in one direction but permit removal in the other direction.

The hub <NUM> may include radio-opaque or other such features <NUM> to permit for registration of the hub in another imaging modality (e.g., fluoroscopy/x-ray, MRI, CT, ultrasound, etc.). This could also include a radio-opaque lumen to detect a hub template. A locking mechanism <NUM> may be included to capture the shape sensed guidewire <NUM> to the hub <NUM> so that they no longer translate with respect to each other. The locking mechanism <NUM> may include a spring loaded pin, a screw, a latch, a snap, etc..

In another embodiment, the hub <NUM> may be identified using an identifier <NUM>, which may include a code, serial number, radiofrequency identifier (RFID) tag, microchip, etc. in the hub <NUM> to identify its hub template from a database or other reference. The hub <NUM> may identify itself through the use of a unique template that may be stored in the database.

The hubs in accordance with the present principles can operate with a large variety of devices. In addition to catheters, for example, hubs may be employed with endograft deployment devices, etc. Other devices that may be employed with the hubs can include sheaths, introducers, mitral clip delivery systems, mitral valve delivery systems, aortic valve delivery systems, therapeutic catheters, balloon catheters, ablation catheters, imaging catheters (intravascular ultrasound (IVUS), optical coherence tomography (OCT), etc.), infusion catheters, endoscopes, needles, etc. While the over-the-wire devices are described as being placed over shape sensed guidewires, the present principles are not limited to a guidewire as the shape sensed device. Instead, any flexible elongated device may be employed and any tool with a shape sensed fiber within it may be employed to infer a shape of another tool. Although a retrofit hub has been described, the hub could also be fully integrated into the design of the catheter or medical device (over-the wire device). All of the features remain the same, with the exception of the attachment mechanism that attaches to the medical device.

Referring to <FIG>, a curvature plot or graph <NUM> showing curvature (<NUM>/mm) versus distance along a fiber (nodes) is shown. The plot <NUM> shows a hub that has been translated from left to right as indicated by arrow "B" in two time period plots. A hub template <NUM> of the hub is shown being translated. For a hub to be used for longitudinal encoding, the template <NUM> of the hub curvature (or other shape profile) needs to be used to match against the guidewire curvature (or other shape profile). This template <NUM> can be derived in plurality of ways. These may include being selected by a user from a database of stored templates by entering an identifier that is written on the hub or hub packaging. In another example, the hub template <NUM> may be identified using a radiofrequency identifier (RFID) tag in the hub to identify its template from a database. In another example, the hub template <NUM> may be identified using a microchip in the hub that stores the hub template <NUM> completely.

A search algorithm may be employed that looks at shape sensed data along the shape sensed device and identifies the template <NUM> from within the shape data. This could be done fully automatically (e.g., a search algorithm can look along a straight guidewire and find the most likely hub candidate), with user input to confirm the automatically detected hub, or to limit the search range to find the hub, or to position the hub in two different locations (to help the algorithm find the thing that changed). This could also be done with full user input to select the hub from the shape, with x-ray (or other imaging such as optical, ultrasound, MRI, etc.) to image the hub and then detect the path, etc. The full template can be detected, or a pattern-matching algorithm could match the x-ray view of the hub to potential template matches in a database.

The hub template <NUM> may take on any usable shape including 2D or 3D profiles. The hub template <NUM> needs to be distinguishable from other shape sensing data. The use of an attachable hub is provided to cause the shape deformation of a shape sensed guidewire or tool through the visual shape representation of a device that is not enabled with shape sensing but that is being used with the shape sensed tool. This permits any commercial catheter (manual or robotic), deployment system, sheath, or other such device to be navigated using a shape sensed guidewire (or other tool). This may be applied to a plurality of useful applications, such as, e.g., vascular (catheters, sheaths, deployment systems, etc.), endoluminal (endoscopes), orthopedic (k-wires and screwdrivers) as well as non-medical applications and also applies to both manual and robotic manipulation of such devices.

Referring to <FIG>, in accordance with one embodiment, a shape-sensed guidewire <NUM> is included in a catheter <NUM> with a hub <NUM>. The hub <NUM> includes a deformable mechanism or switch <NUM> to deform a guidewire shape attached to the catheter <NUM> via a Luer lock or other device. If the catheter <NUM> (or other device) is employed over the shape sensed guidewire <NUM>, the guidewire shape also defines the catheter shape for the length over which the catheter <NUM> overlaps the guidewire <NUM>. To properly define the position of the catheter <NUM>, a relationship between the catheter <NUM> and the guidewire <NUM> needs to be known. This can be achieved by having the guidewire <NUM> with a FORS™ fiber or fibers <NUM> take on a specific shape, curvature, or strain profile at a specific position along the catheter <NUM>. One way to induce such a shape, curvature or strain profile is to use the hub <NUM>.

In some cases, it is not acceptable to have the hub <NUM> always maintain its effect on the shape. Thus, a dynamic version of the hub <NUM> can be employed that can selectively turn on and off its effect on an optical fiber employed in the shape-sensed guidewire <NUM>. This permits any commercial catheter, deployment system, sheath, or other device to be navigated using the shape sensed guidewire <NUM>. The hub <NUM> can be employed with a back-loadable shape-sensed guidewire <NUM>. The hub <NUM> is employed to create a shape deformation in the guidewire <NUM> that can be used for longitudinal registration. The hub <NUM> has a feature to enable turning on/off a curvature template. The hub <NUM> should be simple to switch between on/off states by an operator (e.g., while wearing surgical gloves, etc.). In addition, when the hub <NUM> is turned 'on', the hub <NUM> needs to create a reproducible change in the shape sensing guidewire <NUM>.

The hub <NUM> is selectively interactable with the guidewire <NUM>. For example, the hub <NUM> may introduce additional friction that could impact manipulation of the guidewire <NUM>. In this case, the user may want to have the hub <NUM> in a disabled state during gross manipulations and then turn on the hub <NUM> for finer device manipulations. In the case of a FORS™-enabled back-loadable guidewire <NUM>, there may be a region at a proximal end of the guidewire <NUM> that is completely rigid (due to optical components). If the hub <NUM> employs a curve or non-straight shape template then the hub <NUM> may be disabled when the stiff proximal section of the guidewire <NUM> passes through the hub <NUM>.

The hub <NUM> is used to create shape deformation in the guidewire <NUM> be deflecting or pressing the mechanism <NUM> to provide a change in the fiber <NUM> to be used for longitudinal registration. The hub <NUM> has a feature or mechanism <NUM> to enable turning on/off a curvature template. The hub <NUM> is easily switched between on/off states by the operator (e.g., while wearing surgical gloves) or may be controlled remotely to create a reproducible template change in the shape sensing guidewire <NUM>.

Referring to <FIG>, a lever or latching lever hub <NUM> is shown in an open position <NUM> and a closed position <NUM>. The hub <NUM> includes a hinged lever <NUM> having an engagement portion <NUM>. The hub <NUM> includes Luer lock connections <NUM> and <NUM> (or other standard connections) for engaging or connecting the hub to a catheter or other device. A shape sensing fiber (shape-sensing guidewire) is threaded through or otherwise loaded into the hub <NUM>. When the lever <NUM> is open, in position <NUM>, the fiber is disposed on a straight path <NUM> through the hub <NUM>. The lever <NUM> can now be moved in the direction of arrow "B" so that the engagement portion engages and moves the fiber to a curved path <NUM> as shown in the closed position <NUM>.

A curved template is provided with path <NUM> while also allowing for the straight path <NUM> as a default. However, the path <NUM> may be the default in some embodiments. When the lever <NUM> is pressed, the template curvature is forced down onto the guidewire or fiber inside the hub <NUM> so that the template is introduced to the sensing data signal. A latch or latching mechanism <NUM> (e.g., a clip, hook, etc.) may be employed to hold the lever <NUM> in the closed position <NUM>, thereby not requiring the user to constantly hold the lever <NUM> in the closed position <NUM>. A release <NUM> may also be employed that can be depressed to release the lever <NUM> from the closed position <NUM>. Other latching mechanisms or release mechanisms may also be employed.

Referring to <FIG>, in another embodiment, a pushbutton or latching pushbutton hub <NUM> is shown in an open position <NUM> and a closed position <NUM>. The hub <NUM> includes a push button <NUM> having an engagement portion <NUM> shown in a cross-section <NUM> of the button <NUM>. The hub <NUM> includes Luer lock connections <NUM> and <NUM> for engaging or connecting the hub <NUM> to a catheter or other device. A shape sensing fiber (shape-sensing guidewire) is threaded through or otherwise loaded into the hub <NUM>. When the button <NUM> is retracted in position <NUM>, the fiber is disposed on a straight path <NUM> through the hub <NUM>. The button <NUM> can now be moved in the direction of arrow "C" so that the engagement portion engages and moves the fiber to a curved path <NUM> as shown in the closed position <NUM> and a cross-section <NUM> of the closed position.

A curved template is provided with path <NUM> while also allowing for the straight path <NUM> as a default. However, the path <NUM> may be the default in some embodiments. When the button <NUM> is pressed, the template curvature is forced down onto the guidewire or fiber inside the hub <NUM> so that the template is introduced. A latch or latching mechanism <NUM> (e.g., a clip, hook, etc.) may be employed to hold the button <NUM> in the closed position <NUM>, thereby not requiring the user to constantly hold the button <NUM> in the closed position <NUM>. A release may also be employed that can be depressed to release the button <NUM> from the closed position <NUM>. Other latching mechanisms or release mechanisms may also be employed.

Springs or a biasing device may be employed to force the button <NUM> into its default position, e.g., to permit the guidewire to pass through unimpeded. The hub <NUM> can be sealed at all times.

Referring to <FIG>, a cross-section of cam <NUM> and a cam follower mechanism <NUM> to introduce a template are illustratively shown in accordance with another embodiment. As a knob <NUM> is turned in the direction of arrow "D", the cam follower <NUM> is forced down in the direction of arrow "E" onto a guidewire <NUM>. The cam follower <NUM> follows the contour of a surface of the cam <NUM>.

In this embodiment, the template is applied directly to the guidewire <NUM> as a rotational input using the cam <NUM>. The knob <NUM> can be added to any hub. As the knob <NUM> is turned, the cam <NUM> rotates and moves the cam follower <NUM>, which in turn forces the template curvature onto the guidewire <NUM>. This permits variable templates and may impart different levels of curvature, e.g., the more the knob <NUM> is turned, the more curvature is applied to the guidewire <NUM>.

Different types of cams may be employed. For example, a barrel cam may be employed with the cam follower attached to a bent lever. As the barrel cam is rotated, the lever arm moves up and down, thereby introducing the template. One advantage of the cam embodiments includes providing a progressive amount of curvature that can be applied depending on the amount of rotation. Stiffer guidewires may take on less curvature in a body, and may also be more sensitive to curvature in the hub (thereby inducing more friction during navigation). Different guidewires could have different pre-set rotations corresponding to differing amounts of curvature, depending on their stiffness.

Referring to <FIG>, in another embodiment, a lever <NUM> may be employed to deflect a guidewire or fiber <NUM> in a hub <NUM>. In position <NUM>, the lever <NUM> is in a neutral state and is not engaged with guide wire <NUM>. In position <NUM>, the lever <NUM> is rotated about a pivot point to engage the guidewire <NUM>. The lever <NUM> can be employed with the guidewire <NUM> to induce a deformation/offset at a point in the hub <NUM> in position <NUM>. This reduces friction because only a single point of contact is made with the guidewire <NUM>.

Referring to <FIG>, in another embodiment, the lever <NUM> may be employed to deflect the guidewire or fiber <NUM> in the hub <NUM> using a biasing member or spring <NUM>. In position <NUM>, the lever <NUM> is in a retracted state maintained by the spring <NUM> and is not engaged with guidewire <NUM>. In position <NUM>, the lever <NUM> is rotated about a pivot point to engage the guidewire <NUM>. The lever <NUM> can be employed with the guidewire <NUM> to induce a deformation/offset at a point in the hub <NUM> in position <NUM>. This reduces friction because only a single point of contact is made with the guidewire <NUM>. The bias of spring <NUM> causes the lever to return to position <NUM> when released. The lever <NUM> can be secured in either state using mechanical elements.

Alternatively, in other embodiments, the guidewire may be disposed in a tube (<NUM>) that deflects the guidewire therein when engaged with the lever <NUM> (or any other element as described herein). The tube could protect the guidewire and/or further reduce friction. In addition, the spring <NUM> could be used to create a preferred state. For example, that the hub <NUM> may have as a default, the lever <NUM> applied, and the user depresses the lever <NUM> to remove the curvature.

Referring to <FIG>, a hub <NUM> is shown in three positions <NUM>, <NUM>, and <NUM> along a guidewire <NUM>. In position <NUM>, the hub <NUM> includes an engagement portion <NUM> having a biasing device <NUM>, such as, e.g., a spring or other mechanism for applying a force against a catheter <NUM> or other device. The guidewire <NUM> includes a stiff proximal portion <NUM> that leads the guidewire <NUM> and will be passed first into the catheter <NUM> and the hub <NUM> in the direction of arrow "F".

In position <NUM>, instead of having a fixed curvature in the hub <NUM>, the biasing device <NUM> pushes a curved part onto the catheter <NUM> to create a desired curve. When the stiff proximal portion <NUM> of the guidewire <NUM> enters the hub <NUM>, the proximal portion <NUM> enters the hub <NUM> and displaces the biasing device <NUM> to permit passage of the proximal portion <NUM>. The stiff proximal portion <NUM> pushes the engagement portion <NUM> (curved portion) inside the hub to straighten it when the hub <NUM> is moved in the direction of arrow "G".

In position <NUM>, when the portion <NUM> of the guidewire <NUM> is advanced (in the direction of arrow "H") passed the hub <NUM>, the biasing device <NUM> pushes the catheter <NUM> and the guidewire <NUM> into a desired curve or template. The biasing device <NUM> may include a spring, a manual force, etc. and may be applied at different positions in the hub <NUM>.

Referring to <FIG>, a compressing hub <NUM> is depicted in accordance with another embodiment. The hub <NUM> includes an open position <NUM> where a shape-enabled guidewire <NUM> or FORS™ fiber is inserted through open ends <NUM>. The guidewire <NUM> may be placed in a protective tube. A guiding feature <NUM> is located adjacent to the tube/guidewire/fiber <NUM>. The hub <NUM> may include separable portions <NUM> and <NUM> that are separated in the open position <NUM>. The portions <NUM> and <NUM> may be guided using guides <NUM> or other mechanical features.

When the portions <NUM> and <NUM> are closed in position <NUM> the guidewire <NUM> is compressed and forms a curved shape due to the path-length change. The guiding feature <NUM> may be bowed to ensure a reproducible template.

In all designs, software (optical sensing module <NUM>, <FIG>) may be employed to detect when the hub template is present by looking for a match of a shape where the match is computed to be better than a threshold value. The visualization of the device would only happen once the hub was 'on' and the template match was detected. Alternatively, if this is not sensitive enough, the hub could have an additional feature to give input as to its on/off state. This may include an electronic signal, a mechanical switch, an RF signal or any other signal or assisting method known in the art. For example, when the hub has a lever engaged, halves closed, pressure applied, a signal is generated and the visualization of the shape is checked for by the optical sensing module <NUM> (<FIG>).

Throughout this disclosure the guidewires described included shape sensing fiber or fibers. It should be understood that the present principles are not limited to guidewires as the shape sensed devices. Any tool with a shape sensed fiber associated therewith may be employed to infer a shape of another tool. The hubs/dynamic hubs described herein may include retrofit hubs that slide over devices to provide a template. In addition, the hub may also be fully integrated into a catheter (or medical device). The features described remain the same for fully integrated hubs, but with attachment mechanisms adjusted depending on the device having the hub thereon.

In addition, the shapes depicted in some of the embodiments show a simple curve for illustrative purposes. It should be understood that the curve(s) may be more complex having multiple inflections, different cusps or arcuate shapes, multiple shapes, etc. to provide the templates for device or position identification.

The hubs and dynamic hubs described herein may be employed with any commercial catheter (manual or robotic), deployment system, sheath, or other such device to be navigated using a shape sensed guidewire or other device for any applications such as, e.g., vascular (catheters, sheaths, deployment systems, etc.), endoluminal (endoscopes), orthopedic (k-wires and screwdrivers) as well as non-medical applications.

In interpreting the appended claims, it should be understood that:.

Claim 1:
A hub (<NUM>, <NUM>) for an optical shape sensing reference, comprising:
a hub body (<NUM>) configured to receive an elongated flexible instrument (<NUM>, <NUM>) with a shape sensing system coupled to the flexible instrument within a path formed in the hub body;
a profile (<NUM>, <NUM>) formed in the hub body in the path to impart a hub template configured to distinguish a portion of the elongated flexible instrument within the hub body in shape sensing data;
an elongated flexible instrument (<NUM>), a fiber optic shape sensing system coupled to the flexible instrument, at least a part of said elongated flexible instrument (<NUM>) configured to be received within said path; and
an attachment mechanism (<NUM>) formed on the hub body comprising a luer lock (<NUM>) to detachably connect the hub body to a deployable instrument (<NUM>) such that a change in a position of the hub body indicates a corresponding change in the deployable instrument,
wherein one end of the path of the elongated flexible instrument formed in the hub body leads to a lumen of the deployable device via said detachable connection between the hub body and the deployable device.