AND FAILURE DETECTION BACKGROUND:

Technical Field

This disclosure relates to medical instruments and more particularly to systems and methods for calibrating, characterizing and detecting failures in shape sensing optical fibers. Description of the Related Art

Optical shape sensing (OSS) uses light along a multicore optical fiber for device localization and navigation during surgical intervention. The principle involved makes use of distributed strain measurement in the optical fiber using characteristic ayleigh backscatter or controlled grating patterns. The shape along the optical fiber begins at a specific point along the sensor, known as the launch or z = 0, and the subsequent shape position and orientation are relative to that point.

OSS tethers provide location and orientation information for points along optical fibers. However, when the tether is incorporated within a flexible interventional device, the mapping of tether shape measurements to instrument shape measurements needs to be accurately performed to provide useful clinical information about effectors on the medical instrument, e.g., an ablation tip, needle tip, cutting edges, etc. This relationship needs to be determined at the end of the manufacturing process after final integration of the OSS fiber within a device.

Hand-in-hand with OSS-instrument calibration during manufacturing is a failure detection and correction mechanism that assesses whether OSS instruments are suitable for clinical deployment. The integration of an optical fiber into a device can introduce issues such as pinch points, accumulated twist, and strain, which can cause degraded performance in terms of accuracy and stability. For clinical use, it is essential to rapidly and accurately characterize the performance of the shape sensing capability of an integrated instrument as it comes off the production line.

An OSS tether is comprised of bare optical fiber that is connectorized at one end, terminated at the tip to suppress reflections and contains a launch point along the tether that serves as the origin of the shape reconstruction. Each tether is calibrated for shape sensing using a straight reference and wobble reference in a spiral path plate. Following calibration the bare fiber is then integrated into a device via any number of methods (attachment, embedding, adhesion, electro/magnetic attraction or other coupling means) during a manufacturing process. This integration process can affect the robustness and accuracy of the optical shape sensing technology. In addition, following integration, a registration must be performed to determine the non-linear spatiotemporal transformation which maps the dynamic geometry of the flexible instrument to the shape sensing measurements at any instant. This could include the registration of the shape sensing coordinate system to the launch fixture/instrument coordinate system.

Currently, instrument characterization is performed manually by placing the instrument into specific configurations and comparing the known path to the shape-sensed path. Robustness of the instrument is assessed by qualitatively observing the performance of the shape during instrument manipulation and handling. These techniques are not suitable for repeatable, quantitative and high-throughput measurements. SUMMARY

In accordance with the present principles, a testing system for optical shape sensing enabled devices includes an optical shape sensing module configured to interrogate and interpret feedback from an optical shape sensing device. A flexible instrument includes the optical shape sensing device and is configured to provide optical feedback to the optical shape sensing module. A test setup includes a plurality of obstacles disposed in a known geometrical position relative to one another and is configured to hold or move the flexible instrument in a known, repeatable geometrical configuration for comparison with a reference. The plurality of obstacles is included to model one or more motions or positions corresponding to a usage of the flexible instrument.

Another testing system for optical shape sensing enabled devices includes an optical shape sensing module configured to interrogate and interpret feedback from an optical shape sensing device. A flexible instrument includes an optical shape sensing device and is configured to provide optical feedback to the optical shape sensing module. A test setup includes a plurality of obstacles disposed in a known geometrical position relative to one another and configured to hold or move the flexible instrument in a known, repeatable geometrical configuration for comparison with a reference. The plurality of obstacles is included to model one or more motions or positions corresponding to a usage of the flexible instrument. A workstation includes a processor and memory. A test application is stored in the memory and is configured to provide a graphical user interface for user interaction with the test setup such that the graphical user interface is employed to program and control the test setup to perform simulation tests in accordance with recorded conditions or user controlled conditions.

A method for testing optical shape sensing enabled devices includes providing an optical shape sensing module configured to interrogate and interpret feedback from an optical shape sensing device, a flexible instrument including the optical shape sensing device and configured to provide optical feedback to the optical shape sensing module, and a test setup including a plurality of obstacles disposed in a known geometrical position relative to one another and configured to hold or move the flexible instrument in a known, repeatable geometrical configuration; testing the flexible instrument including the optical shape sensing device by subjecting the instrument to the test setup to be manipulated or held by the plurality of obstacles; and comparing a response of the flexible instrument including the optical shape sensing device with a reference to evaluate the flexible instrument for use.

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.

BRIEF DESCRIPTION OF DRAWINGS

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

FIG. 1 is a block/flow diagram showing a shape sensing enabled device and system for testing the shape sensing enabled device in accordance with the present principles;

FIG. 2 is a schematic diagram showing an illustrative test setup for testing a shape sensing enabled device in accordance with one illustrative embodiment;

FIG. 3 is a schematic diagram showing another illustrative test setup for testing a shape sensing enabled device in accordance with another illustrative embodiment;

FIG. 4 is a diagram showing mechatronic devices configured for reshaping a shape sensing enabled device in accordance with one illustrative embodiment; and FIG. 5 is a block diagram showing an illustrative method for testing a shape sensing enabled device in accordance with illustrative embodiments.

DETAILED DESCRIPTION OF EMBODIMENTS

In accordance with the present principles, a system for mechatronic-based characterization of an integrated instrument is provided that may be employed at an end of an optical shape sensing (OSS)-enabled device production line or elsewhere. The system may be employed to generate data for evaluation of performance of devices receiving regulatory approval. In particularly useful embodiments, an automated, quantitative characterization system is provided that can be operated at the end of the manufacturing process, prior to the release of the instruments to a clinical environment.

The screening and calibration process is a control point for ensuring quality optical shape sensing technology. Without this process, a position and orientation of the OSS tether is not related in a meaningful way to a flexible clinical instrument to which the fiber is attached. This process also ensures that instruments deployed clinically meet minimum performance standards.

In accordance with one embodiment, an optical fiber is coupled to an interventional instrument and launch fixture during a manufacturing process for optical shape sensed devices. A high-throughput, automated characterization of the integrated instruments, e.g., as a final manufacturing step, is employed to detect failures in the technology due to integration, to calibrate the final integrated solution, and to map the coordinate system of the shape sensing fiber to the instrument and launch fixture. An automated integrated test device may be employed to assess the quality of the optical signal (including twist, tension, and the reconstructed shape) to identify failures in the integration process. The automated integrated test device may manipulate the OSS device through known paths using a series of moveable and stationary cells with known relationships and motion. Potential moveable cells include linear stages, rotational stages, rotational cams, torsional stages, etc. Potential stationary cells include introducers, tubing representative of vasculature, launch units, etc. By defining the motion of and position of each cell, a predictive model of the shape of the instrument (OSS device) can be derived for all points and compared with the optically reconstructed shape. This comparison provides the ability to map the coordinate system of the shape sensing fiber to the instrument, assess and calibrate for accuracy, and characterize instrument robustness in the presence of clinically-relevant curvature, positioning, and motion. The automated integrated test device may stress test the OSS device robustness through flicking, vibration, torqueing of the proximal portion; tip articulation, wall scraping, curvature of the distal portion, etc.

The output of the test device may include a pass/fail outcome on the integration quality. This can include identification of any pinch points, strain, high twist, termination failure, damaged fiber coating or low signal-to-noise ratio. The yaw, pitch, roll, and offset of the launch position in the launch fixture may also be determined. This provides the coordinate mapping of the sensor to the instrument and launch fixture. In addition, a pass/fail output and report may be provided for robustness, and/or accuracy, including correction factors for accuracy improvement.

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 devices for use in understanding complex biological or mechanical systems. In particular, the present principles are applicable to internal tracking devices for procedures in or regarding biological systems, 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 of the invention, 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 of the present invention 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.

Referring now to the drawings in which like numerals represent the same or similar elements and initially to FIG. 1 , a system 100 for calibrating, characterizing and detecting failures in shape sensing optical fibers is illustratively shown in accordance with one embodiment. System 100 may include a workstation or console 112 from which a procedure is supervised and/or managed. Workstation 112 preferably includes one or more processors 114 and memory 116 for storing programs and applications. Memory 116 may store an optical sensing module 115 (or optical shape sensing (OSS) acquisition) configured to interpret optical feedback signals from a shape sensing device or system 104. Optical sensing module 115 is configured to use the optical signal feedback to reconstruct deformations, deflections and other changes associated with a medical device or instrument 102 and/or its surrounding region. It should be understood that the optical sensing module 115 or functions thereof (e.g., OSS data processing or acquisition) may be on a separate workstation or may be a stand-alone unit with the results (shape data) transmitted to a testing interface or other interface on the workstation 112 via TCPIP or some other protocol. The medical device 102 may include a catheter, a guidewire, a probe, an endoscope, a robot, an electrode, a filter device, a balloon device, or other medical component, etc.

The shape sensing system 104 on device 102 includes one or more optical fibers 126 which are coupled to the device 102 in a set pattern or patterns. The optical fibers 126 connect to the workstation 112 through cabling 127. The cabling 127 may include fiber optics, electrical connections, other instrumentation, etc., as needed.

Shape sensing system 104 with on fiber optics may be based on fiber optic Bragg grating sensors. A fiber optic Bragg grating (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.

A fundamental principle behind the operation of a fiber Bragg grating is Fresnel reflection at each of the interfaces where the refractive index is changing. 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. In an FBG sensor, the measurand (e.g., strain) causes a shift in the Bragg wavelength.

One advantage of this technique is that various sensor elements can be distributed over the length of a fiber. Incorporating three or more cores with various sensors (gauges) along the length of a fiber that is embedded in a structure permits a three dimensional form of such a structure to be precisely determined, typically with better than 1 mm accuracy. Along the length of the fiber, at various positions, a multitude of FBG sensors can be located (e.g., 3 or more fiber sensing cores). From the strain measurement of each FBG, the curvature of the structure can be inferred at that position. From the multitude of measured positions, the total three-dimensional form is determined.

As an alternative to fiber-optic Bragg gratings, the inherent backscatter in conventional optical fiber can be exploited. One such approach is to use ayleigh 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, the 3D shape and dynamics of the surface of interest can be followed.

A test bench or setup 150 includes an obstacle course of static 152 and dynamic 154 obstacles used for calibrating, characterizing and detecting failures in shape sensing optical fibers. The setup 150 includes known geometrical relationships between obstacles 152, 154 and a launch fixture 158 such that when the shape sensing device 104 and/or medical instrument 102 are deployed within the test setup 150 a known response should be expected. Deviations from the known response can be characterized as failures or deviations and checked against a reference or criteria 156 stored in memory 116.

Workstation 112 includes a display 118 for viewing optical shapes and images generated in the test setup 150. Display 1 18 may also permit a user to interact with the workstation 112 and its components and functions, or any other element within the system 100. This is further facilitated by an interface 140 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 112.

The system 100 provides for integrated device characterization that resolves three important challenges. These include registration of the optical shape reconstruction to an instrument launch fixture 158, assessment of the quality (robustness, accuracy) of the integrated device 102 and OSS sensor 104, and device specific calibration of the integrated device 102. By performing testing using the test setup 150, the integrated device 102 with shape sensing 104 is tested to meet the requirements necessary for high-throughput at the end of a manufacturing line. The testing provides a repeatable, quantitative assessment of integrated device performance; automated testing that can be performed by an unskilled operator and non-destructive device testing.

The static 152 and dynamic 154 obstacles may include one or more of the following elements. The following list is exemplary and non-exhaustive, as additional elements may be added or substituted for those listed. In one embodiment, an integrated device 102 for testing purposes can include a shape sensed catheter, guide wire, ultrasound probe, bronchoscope, etc. The integrated device 102 will include the launch fixture 158 that maintains a fixed z = 0 position and orientation for the shape sensed fiber of the OSS 104, and the integrated device 104 will also be coupled to the launch fixture 158. In an alternate embodiment, the OSS enabled device 102 does not maintain a fixed origin position, and only a portion just proximal to the origin is fixed. In another alternate embodiment, the origin within the launch fixture 158 is not fixed but can be computed using other features, for example, a known introducer shape and the relation of the origin from the launch. The same embodiment may have the launch be repositioned (translated, rotated, etc.) in a known manner and that can be used as a method for characterizing a clinical scenario where a launch unit has been moved due to an operator error. OSS measurements are still accurately registered to the imaging space due to the correction built-in during device integration. In another embodiment, a launch base is provided where the launch fixture 158 of the integrated device 102 can be clipped in place to provide a known position. The launch fixture 158 may be the same as the launch base to be used in the clinical environment.

Another dynamic obstacle 154 includes a set of mechatronic cells (capable of controlled rotation, twist or translation) to mimic the torqueing and insertion of the device as would be performed by a clinician. Mechatronic cells include any electronically controlled actuation mechanism and may include, e.g., actuators, pneumatics, hydraulics,

electromechanical devices, etc.). The instrument 102 will be attached to these cells for manipulation in space. Another dynamic obstacle 154 may include a motor and/or associated mechanism which provides a periodic disturbance to mimic the handling of the proximal portion of the instrument 102 and to reproduce the vibrations incurred by a particular type of handling. Another static 152 or dynamic obstacle 154 may include a clamp (or motorized clamp) which may mimic the forces (such as tension and compression) that the instrument 102 may undergo while a clinician handles and grips the instrument 102. Another dynamic obstacle 154 includes a set of mechatronic cells to replicate curvature similar to that seen by the proximal portion of instrument 102 (prior to the introducer).

A static obstacle 152 may include a tube, fixture or introducer to replicate the entry of the instrument 104 into the body. Another obstacle may include a clamping or compressing unit, which may be employed to replicate the pinching of the instrument caused by insertion via the introducer or contact by another device or anatomical structure.

Another obstacle may include a set of mechatronic cells to replicate an anatomically- relevant curvature. These cells are capable of rotating and translating relative to each other and allow for the position of the instrument to be controlled in a known manner. Another obstacle may include a mechanism for controlled articulation of the tip of the instrument 102. This can either be mechanically actuated or passively actuated by pushing the distal portion of the device through a tube. This allows for verification of the mechanical robustness of the tip (e.g., the termination of the optical fiber), and the ability of the fiber to slide within a lumen of the device, if not fixed at the device tip and the lumen does not lie on the neutral bending axis of the device. The shape robustness is also stressed during articulation and wall scraping of the tip.

Another obstacle may include a thermally heated portion of the test bed to assess the effect of temperature on the accuracy and robustness of both the instrument 102 and shape sensing measurement, wherein the heating may be achieved by conduction, convection and/or radiation (e.g., heating the parts after the introducer using a heated fluid-filled tube). A periodic acceleration of the distal portion of the instrument may be provided as an obstacle to mimic physiologic motion (e.g., heart beat motion or breathing). Another obstacle may include a mechanism that permits a distal portion of the instrument 102 to be inserted into models of pre-defined anatomy (perhaps with a fluid to simulate blood in the vasculature) and performing characterization (such as device stability and accuracy) while entering the vessels on the left side versus the right side.

Another element may include a secondary tracking mechanism to assess accuracy. In the case where the kinematics introduced by the mechanical test setup 150 may not be accurately known, a secondary tracking mechanism can be introduced to localize the position of the instrument including electromagnetic tracking, optical tracking, an infrared (I ) camera, imaging/machine vision, other imaging system, etc. The test setup 150 may be controlled and configured using a test application 124. The test application 124 may be stored in memory 116 and may generate an automated user interface to collect synchronized data from both the mechatronic manipulators of the device and the optical shape

measurement. This interface (140) may provide a report to the user following the execution of the tests. The report may include pass/fail results on the device integration; identification of any unusual pinch points, strain, or twist along the device; pass/fail results on the accuracy and stability of the instrument 102 to approve it for clinical use; correction factors to improve the calibrated shape reconstruction; a set of registration parameters (transformation matrix, roll, pitch, yaw, offset, etc.) to relate the reconstructed shape to the physical instrument and launch fixture; qualitative metrics to capture the stability and the accuracy of the instrument 102 for comparison between generations, integration techniques, devices, etc. The test application 124 may be employed to configure, reconfigure, or otherwise set up or control the test setup 150. The test application 124 may be configured to provide a graphical user interface for user interaction with the test setup 150 such that the graphical user interface is employed to program and control the test setup to perform simulation tests in accordance with recorded conditions or user controlled conditions. The test application 124 may also include a plurality of use scenarios and the recorded conditions that correspond to each of the plurality of use scenarios. These scenarios may include handling, storing, operating, etc.

Another element of the test application 124 may include a mechanism 125 that permits testing and characterization of the mechanical properties of the integrated device, testing for properties such as repeatability, pushability, torqueability, etc. using the mechanisms/obstacles as described above. For example, the clamp may be used to torque the device prior to the introducer and the torqueing at the tip may be measured, either using the inherent OSS measurements or using visualization techniques like an optical camera or imaging. Another mechanism 128 of the test application 124 permits characterization of the instrument 102 under different clinical use scenarios, such as the handling, stability, accuracy and characteristics of the instrument 102 with another device within or outside it (for example, the performance of a catheter with and without a guide wire inside it and the performance of a guide wire by itself and within catheters of different lumen sizes, braidings and properties). Another mechanism 130 of the test application 124 may be employed which permits testing and characterization of more than one device at the same time, and the characterization of multiple devices simultaneously. This mechanism 130 may characterize the performance of one device with respect to the other, such as a guide wire within a catheter at the same time using the steps described above. Other mechanisms and obstacles are also contemplated.

Referring to FIG. 2, an illustrative diagram showing an integrated test setup 150 is depicted in accordance with one illustrative embodiment. The shape-sensed instrument 102, in this case a catheter or guidewire, is clipped into a launch fixture/base 202. The instrument 102 passes through a flicker stage 204 followed by a translation stage 206 that pushes the device through an introducer 208. Following the introducer 208, there is a single cam element 210 that creates curvature that mimics the shape of the iliac bifurcation. A tip of the instrument 102 pushes through a tube 212 (e.g., polytetrafluoride) that deforms the tip into a fixed path. An automated graphical user interface (GUI) 214 controls the motors of the test setup 150 and acquires data while acquiring synchronized measurements from the OSS system (104).

While the test setup 150 in this example is comprised of the launch fixture and base 202 to hold the instrument 102, the flicker motor 204 to mimic operator handling, the translation stage 206 to push the device through the introducer 208, the cam element 210 to simulate anatomically-relevant curvature, and the push-through tube 212 to articulate the tip through a defined shape and introduce wall scraping to evaluate tip robustness, the test setup 150 may be configured and reconfigured as needed to handle any number and/or type of obstacle. The test setup 150 is controlled by the workstation 112, which may include a personal computer or the like. The workstation 112 may include a test application 220 that provides motor control or dynamic devices and mechanisms, e.g., the flicker stage 204, translation stage 206, cam element 210, etc. The test application 220 also includes an automated GUI 214 that programs the motor actions while acquiring synchronized optical shape from an optical shape sensing system which may include optical shape sensing module 115, which remotely communicates with the workstation 112 or may be integrated in the workstation 112. The test application 220 may also handle all OSS acquisition functions 224. The test application 220 may be the same or similar to test application 124 (FIG. 1).

In the case of robotic or actuated devices (obstacles), the test application 220 can be enhanced to provide control of the manipulation of the instrument 102 using motor controller 222 or the like. For example, a user may through the GUI 214, program the types of motions, numbers of cycles and severity for manipulating the instrument 102. The motion may include anatomically-relevant curvatures created along the instrument 102 (e.g., by cams, translators, rotators, etc.) that can have a period, acceleration, and velocity representative of heart beat motion, respiratory motion, or other anatomically-relevant motion, etc. Such motions may be preprogrammed into memory and be selectable at the GUI 214.

In one embodiment, the test setup 150 may be employed as a destructive testing system to assess mechanical performance, optical shape sensing performance, etc. of instrument over an extended period of time. A test program may be provided to determine the types, frequency and severity of motions to be imparted to the instrument 102. Referring to FIG. 3, in accordance with the present principles, the features depicted in FIG. 2 may be modified further to include additional functionality or to test for additional hazards or potential occurrences. For example, a continuous tube 302 may be provided from the introducer 208 to a tip 301 of the instrument 102 that is sealed and contains a fluid 303 that is heated to an anatomically-relevant temperature (e.g., 37 degrees Celsius). This tube 302 is comprised of a flexible material and can be distorted over the cam 210. The translation stage 206 may be configured to push the instrument 102 through the introducer 208 may also include a rotational element 304 to introduce torqueing of the instrument 102, similar to clinical use. The translation stage 206 may also include clamping elements 306 that can include a torquer in the case of a guide wire, or a pinching element to mimic operator handling of a catheter.

The test application 220 may include a position program or algorithm 308 that employs known positions of the instrument 102 during the motion of various mechanical elements of the test setup 150 to define the yaw, pitch, roll and offset of the z = 0 position of the optical fiber with respect to the launch base 202. These defined positions can be stored and enable plug-and-play use of pre-registered devices in a clinical setting. For example, the translator stage 206 could be used to define motion along a known direction (for example, along x with respect to the launch base 202). Along with the rotation element 304, this known motion could be used to establish the orientation and position of z = 0 in the launch fixture 202. The integration of an optical fiber into a device can introduce issues such as pinch points, accumulated twist, and strain, which can cause degraded performance in terms of accuracy and stability, these issues can be avoided using the stored orientations with the pre-registered devices, which can result is rapidly and accurately characterizing the performance of the shape sensing capability of the integrated instrument. The test application 220 may include a comparison program or algorithm 310 that compares an expected position of the instrument 102 (and the embedded optical shape sensing fiber) to derive a correction for the device to improve accuracy. This could be to account for inaccuracies introduced through integration of the fiber that change the original calibration of the bare fiber. The comparison program 310 may compare a reference position or known or accepted position with the measured position of the instrument 102 to evaluate how the instrument 102 responds to the test setup 150. In addition, this can correct for the motion of the sensor 104 within the instrument 102 during changes in curvature. For example, in the case of a floating-tip device, the distance from the tip of the optical fiber to the tip of the actual instrument can be calibrated for various amounts of cumulative curvature along the instrument, or, in a simpler case of a fixed-tip instrument, the offset between the tip of the fiber and the tip of the instrument for all curvatures (tip offset). Other corrections may be related to shape error, etc.

The test setup 150 may include an additional reference or tracking system 312 to provide information about the position of the instrument 102. This may include machine vision or image processing-based tracking using a camera or point-cloud imaging technology. Alternatively, electromagnetic tracking or optical tracking could be used to track discrete points along the instrument 102. Other components may include a second shape sensing system, a scanning device, etc. The reference 312 is configured to collect additional data for comparison with the integrated device data.

Referring to FIG. 4, an example of a dynamic obstacle 154 (e.g., a mechatronic device) is shown in greater detail in accordance with the present principles. Multiple cam elements 402 are lined up in a preferred configuration to create more advanced curvatures for the instrument 102. The cam elements 402 are all synchronized and can be aligned in three- dimensional space. The cams 402 may engage blocks 404 which may be biased by a spring, gravity or other biasing force 406. The blocks 404 receive the instrument 102 therein and impart the desired geometrical motion as programmed or manipulated by a user to create a deformation to the instrument 102. The motion and control of the cams 402 is preferably electronically controlled and may be provided by one or more of the workstation 112, the test application 124, controller 202, etc.

The present principles may apply to any integration of optical shape sensing into medical devices including manual catheters, actuated catheters (both manual and robotic), guide wires, stylets, endoscopes and bronchoscopes, ultrasound probes, etc. In particularly useful embodiments, the present principles may be employed at an end of a manufacturing line of an OSS product to quality check or test the product.

Referring to FIG. 5, a method for testing optical shape sensing enabled devices is illustratively depicted in accordance with the present principles. In block 502, a test system is provided that includes an optical shape sensing module configured to interrogate and interpret feedback from an optical shape sensing device, a flexible instrument including the optical shape sensing device and being configured to provide optical feedback to the optical shape sensing module, and a test setup including a plurality of obstacles disposed in a known geometrical position relative to one another and being configured to hold or move the flexible instrument in a known, repeatable geometrical configuration.

The obstacles may include one or more mechatronic cells configured to alter a three- dimensional shape of the flexible instrument (the one or more mechatronic cells include at least one of a rotation motion, a twist motion and a translation motion and may be computer controlled). The one or more mechatronic cells may be positioned to simulate an anatomical feature or other practical scenario experienced during use. A non-exhaustive list of other obstacles may include one or more of: a tube or cavity having a known shape; a motor or flicker mechanism configured to provide a vibrational disturbance to the flexible instrument; a clamp configured to impart a known force or crimping to the flexible instrument; a thermal gradient configured to simulate temperature differences along the flexible instrument; a variable positioned launch fixture, etc.

In block 504, the flexible instrument including the optical shape sensing device is tested by subjecting the instrument to the test setup to be manipulated or held by the plurality of obstacles. The test setup may be user programmed or a mode of operation may be selected by a user that best fits the intended use of the instrument. The test setup may be programmed using a GUI interface that permits a user to select a type of test, a length of test, the number and types of obstacles, the activities of the obstacles, the testing criteria (e.g., type of reference or model), etc.

In block 506, a response of the flexible instrument including the optical shape sensing device is compared with a reference to evaluate the flexible instrument for use. The comparison may be against previously measured devices, a concurrently measured device, a different tracking system's data, etc. For example, the reference may include data collected from a second shape sensing system, an image system, optical tracking, an electromagnetic tracking device, etc. The response may be employed to evaluate the flexible instruments, to provide registration criteria for other instruments, to improve accuracy by determining error, etc.

In block 508, a report may be generated with different granularities. For example, in one embodiment, a simple pass/fail criterion may be generated. In another embodiment, a report may list each obstacle and the performance associated with that obstacle. In yet another embodiment, cumulative parameters such as loss in dB may be measured along the device to determine whether an overall loss threshold is exceeded. Other reports and criteria are also contemplated. In a manufacturing environment, the results may be employed to evaluate the suitableness of the instrument. In a design environment, the results may be employed to improve on the design of the instrument and/or its software. In a clinical environment, the results may be employed to reduce setup time using data to orient or configure instruments for different procedures. In a testing environment, the test setup may be employed to cycle the instrument in a repeatable way in a known configuration or configurations, e.g., for different procedures.

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

a) the word "comprising" does not exclude the presence of other elements or acts than those listed in a given claim;

b) the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements;

c) any reference signs in the claims do not limit their scope;

d) several "means" may be represented by the same item or hardware or software implemented structure or function; and

e) no specific sequence of acts is intended to be required unless specifically indicated.

Having described preferred embodiments for optical shape sensing device calibration, characterization and failure detection (which are intended to be illustrative and not limiting), it is noted that modifications and variations can be made by persons skilled in the art in light of the above teachings. It is therefore to be understood that changes may be made in the particular embodiments of the disclosure disclosed which are within the scope of the embodiments disclosed herein as outlined by the appended claims. Having thus described the details and particularity required by the patent laws, what is claimed and desired protected by Letters Patent is set forth in the appended claims.