System and method for registering optical sensor reference frames

Abstract

According to one aspect, a medical device can include a proximal end, a distal end, and a shaft extending between the proximal end and the distal end. The medical device can also include a magnetic sensor assembly that can include a magnetic coupling, a first magnetic sensor, and a second magnetic sensor, where the magnetic coupling is located at the distal end of the medical device and rigidly secured to an inner surface of the shaft. The medical device can also include an optical fiber comprised of a plurality of optical fiber cores extending along a length of the shaft, where one or more of the plurality of optical fiber cores includes an optical sensor located at a position along the optical fiber, where the optical fiber is rigidly supported within the shaft proximate to the optical sensor.

Description

[0001] Cross-reference with related applications

[0002] This application claims the benefit and priority of U.S. Provisional Application 62 / 990,154, filed March 16, 2020, entitled “System and Method for Registering Optical Sensor Reference Systems,” the contents of which are incorporated herein by reference. Technical Field

[0003] This invention generally relates to a system for positioning a medical device within a patient's body, and more particularly to the use of optical sensors in conjunction with one or more other positioning systems. Background Technology

[0004] Positioning systems are used to allow surgeons / technicians to visually observe the position and / or orientation of medical devices relative to patient-associated imaging. For example, electrophysiological catheters are used in various diagnostic, therapeutic, and / or mapping procedures, as well as ablation procedures for heart disease, to diagnose and / or correct conditions such as atrial arrhythmias, including ectopic atrial tachycardia, atrial fibrillation, and atrial flutter. During the procedure, the catheter or catheter sheath is deployed and manipulated via the patient's blood vessels to the desired site, such as within the patient's heart. To improve the overall procedure and outcome, the operator needs to know the catheter's position and orientation as it navigates within the patient to minimize physical damage to surrounding tissues and ensure the device reaches its intended target.

[0005] Some common methods for positioning medical devices within a patient's body use opaque markers, such as metal coils or polymers containing a specific proportion of barium sulfate (BaSO4) detected using X-ray fluoroscopy. However, it would be beneficial to limit patient exposure to X-rays and thus reduce and / or eliminate reliance on X-ray fluoroscopy. Other techniques for positioning medical devices include one or more of magnetic, electrical, and / or ultrasound techniques. For example, one type of positioning system is based on impedance, comprising one or more pairs of surface electrodes (such as patches) located outside the patient's body, a reference sensor (e.g., another patch) attached to the patient's body, and one or more sensors (such as electrodes) attached to the medical device. These pairs of electrodes may be arranged adjacently and linearly, or associated with corresponding axis lines of a reference frame used for this positioning system. The system can determine position and / or orientation by applying a current across the pairs of electrodes, measuring the corresponding voltage sensed by the device at the device electrodes (i.e., relative to the reference sensor), and then processing the measured voltage / impedance to determine the position of the device electrodes within the reference frame defined by the external electrodes.

[0006] Another system is known as a magnetic field-based system. This type of system typically includes one or more magnetic field generators attached to or placed near other components of the patient's bed or surgical environment, and one or more magnetic field detection coils coupled to a medical device. The generator provides a controlled, low-intensity alternating magnetic field within a target area (i.e., the anatomical region). In response to the magnetic field, the detection coils generate signals indicating one or more characteristics of the sensed field. The system then processes these signals to generate one or more position and / or orientation readings associated with the coils (and therefore with the medical device). The position and / or orientation readings are typically read relative to the field generator, thus the field generator serves as the actual "origin" of the reference frame for the magnetic field-based positioning system. Summary of the Invention

[0007] According to one aspect, the medical device may include a proximal end, a distal end, and a shaft extending between the proximal and distal ends. The medical device may also include a magnetic sensor assembly, which may include a magnetic coupler, a first magnetic sensor, and a second magnetic sensor, wherein the magnetic coupler is located at the distal end of the medical device and rigidly fixed to the inner surface of the shaft. The medical device may also include an optical fiber consisting of a plurality of optical fiber cores extending along the length of the shaft, wherein one or more of the plurality of optical fiber cores include optical sensors located along the length of the optical fiber, wherein the optical fiber is rigidly supported within the shaft near the location of the optical sensors.

[0008] According to another aspect, the positioning system may include a medical device having a proximal end and a distal end, wherein the distal end may include at least a first positioning sensor and an optical sensor, wherein the first positioning sensor and the optical sensor may be rigidly fixed within the distal end of the medical device. The positioning system may also include a computer system configured to receive feedback from the first positioning sensor and optical feedback from the optical sensor, wherein the computer system may be used to determine the position of the distal end of the medical device in a first reference frame based on the received feedback, and may determine the shape of the distal end of the medical device in a second reference frame based on the optical feedback, wherein the computer system may transform the shape of the distal end of the medical device from the second reference frame to the first reference frame at least partially based on the position of the distal end of the medical device. The output generated by the computer system may include the position and shape of the distal end of the medical device represented in the first reference frame.

[0009] According to another aspect, a method for positioning a medical device within a patient's body may include receiving feedback from a first positioning sensor and receiving optical feedback from an optical sensor. The method may further include calculating the position of the first positioning sensor based on the received feedback, wherein the position is provided relative to a first reference frame defined by the first positioning sensor. The method may further include calculating the shape of the optical sensor based on optical feedback from the optical sensor, wherein the shape is provided relative to a second reference frame defined about the optical sensor. The method may further include transforming the shape of the optical sensor from the second reference frame to the first reference frame based on the position of the first positioning sensor and stored transformation coefficients. The method may further include displaying the position and shape of the medical device relative to the first reference frame.

[0010] According to another aspect, a method for calibrating an optical sensor using a magnetic positioning sensor located at the distal end of a medical device may include placing the distal end of the medical device within a magnetic field and positioning the distal end of the medical device in a first position, wherein the first position causes a deflection of the optical sensor. The method may further include recording first magnetic position data provided by the magnetic positioning sensor and first optical data provided by the optical sensor, and storing the recorded data as a first reference pair, wherein the first magnetic position data is provided within a magnetic reference frame, and the first optical data is provided within an optical reference frame. The method may further include placing the distal end of the medical device in a second position, wherein the second position causes a deflection of the optical sensor, and recording second magnetic position data provided by the magnetic positioning sensor and second optical data provided by the optical sensor, and storing the recorded data as a second reference pair, wherein the magnetic position data is provided within a magnetic reference frame, and the optical data is provided within an optical reference frame. The method may further include calculating a transformation based on the first and second reference pairs to transform optical shape data from the optical reference frame to the magnetic reference frame, and storing the calculated transformation.

[0011] According to another aspect, the medical device may include a proximal end, a distal end, a handle connected to the proximal end, and a shaft extending between the proximal and distal ends. The medical device may also include first and second magnetic sensors located within the handle, and an optical fiber consisting of multiple optical fiber cores extending from the handle to the distal end of the medical device. The optical fiber may consist of one or more optical fiber cores, one or more of which include multiple fiber Bragg grating (FBG) sensors arranged substantially adjacent to each other from the handle to the distal end of the medical device. Attached Figure Description

[0012] Figure 1 It is an isometric view of a positioning system that combines a first medical positioning system (e.g., a magnetic field-based system) with an optical system according to some embodiments.

[0013] Figure 2This is an equiaxed view of the distal end of a catheter with a transparent outer shaft, according to some embodiments, to show the positions of the optical fiber and magnetic sensor within the distal end of the catheter.

[0014] Figure 3 This is an equiaxed cross-sectional view of the distal end of a catheter according to some embodiments, showing the location of optical and magnetic sensors within the distal end of the catheter.

[0015] Figure 4 This is an equiaxed rod cross-sectional view of a multi-core optical fiber according to some embodiments.

[0016] Figure 5 It is an isometric view of an optical sensor and a magnetic sensor, and a reference frame associated with each sensor, according to some embodiments.

[0017] Figure 6 This is a block diagram of a registration system for registering optical sensors using a first medical positioning system, according to some embodiments.

[0018] Figure 7 This is a flowchart illustrating a method for registering an optical sensor with a first medical positioning system, according to some embodiments.

[0019] Figure 8 This is an isometric view of the handle assembly of a magnetic sensor according to some embodiments. Detailed Implementation

[0020] This invention provides a system and method for correlated / displayed shape information received from (multiple) optical sensors within a reference frame associated with a first positioning system. In this way, the shape of a medical device can be displayed within the reference frame of the first positioning system. The medical device (such as an interventional or surgical catheter, catheter sheath, and other elongated medical devices) is equipped with one or more sensors for the first positioning system (such as a magnetic, impedance, and / or ultrasound-based system) to position the medical device within a patient's body. Furthermore, the medical device is equipped with one or more optical sensing technologies, such as fiber Bragg grating (FBG) sensors and / or optical interferometer distal force sensors, for detecting shape and / or force applied to the medical device or at least a portion of the medical device including the optical sensors. Generally, the optical sensors located on the medical device are configured to receive optical input via optical fibers, multi-core optical fibers, etc., capable of transmitting optical signals, wherein information regarding the position, orientation, and / or shape of the optical sensors is determined by the light reflected from the sensors. This invention provides a system and method for correlated / displayed shape information received from (multiple) optical sensors within a reference frame associated with a first positioning system.

[0021] Figure 1This is an isometric view of system 100, used for performing medical procedures on patient P. Figure 1 In the illustrated embodiment, system 100 includes a medical device, such as Figure 1 The catheter 102, catheter sheath, or other surgical device, at least partially located within the patient P, is shown. The catheter 102 includes a proximal end 104, a distal end 106, and a handle 108. During surgery, the distal end 106 is placed in a target area within the patient's body (e.g., within a blood vessel) and is navigated to the desired location within the body by the surgeon / technician via a controller located on the handle 108. As described in more detail below, sensor feedback received from one or more sensors located on the catheter 102 (e.g., at the distal end 106 of the catheter 102) allows the computer system 116 to determine the position, orientation, and / or shape of the catheter 102 and display this information to the surgeon / technician via a display 124. In some embodiments, the position, orientation, and / or shape of the catheter 102 are displayed relative to a patient image (e.g., an MRI image, geometry created from a mapping catheter, ultrasound catheter, etc.). For example, in Figure 1 In the illustrated embodiment, a C-ARM component 126 is shown, which can be used to generate X-ray images of patient P. However, in other embodiments, the catheter 102 can be used without an external imaging device such as the C-ARM 126.

[0022] In some embodiments, the catheter 102 includes a magnetic sensor ( Figure 2-5 Figures 210a and 210b are shown, which are used within a magnetically based positioning system to detect the position and / or orientation of the distal end 106 of catheter 102 within a patient's body. In some embodiments, the magnetic sensor is located at the distal end 106 of catheter 102 (e.g., as shown in Figure 210b). Figure 2 , 3 (as shown in Figure 5). In other embodiments, the magnetic sensor is located within the handle 108 (e.g., Figure 8(See handle 808 shown). In embodiments employing a magnetic-based positioning system, a magnetic field must be generated to interact with the magnetic sensor. For example, in some embodiments, a magnetic emitter assembly 127 is mounted to the underside of a tabletop 129 to generate the magnetic field required for interaction with the magnetic sensor. In embodiments where the magnetic sensor is located within the handle 108 of the catheter 102, the handle 108 must operate within the area where the magnetic field is generated (i.e., the area near the patient). In some embodiments, the magnetic emitter assembly 127 generates a low-energy magnetic field. One or more magnetic sensors located within the catheter 102 (e.g., distal end 106, handle 108, etc.) interact with the low-energy magnetic field and generate a response feedback that can be used to determine the position and / or orientation of the magnetic sensor within the area defined by the magnetic field. The feedback generated by the magnetic sensor is provided via a magnetic sensor cable 114 to a computer system 116, which interprets and displays the received data, allowing the surgeon / technician to observe the position and orientation of the catheter 102 within an image of the patient's body via a display 124. In some embodiments, an external magnetic field (generated by the magnetic transmitter assembly 127) provides a reference for positioning the magnetic sensor within the patient image and provides this information to the display 124. In other embodiments, other types of well-known positioning systems (e.g., impedance-based systems, ultrasound-based systems, etc.) may be utilized.

[0023] In addition, one or more optical sensors provide feedback to computer system 116 via fiber optic cable 112. As described in more detail below, the optical feedback is used to determine the position, orientation, shape, and / or temperature of catheter 102. In particular, the shape information provided by the optical sensors provides information not provided by a magnetically based positioning system. However, the optical feedback received from the optical sensors does not reference any external field (it only references itself). To utilize the shape information provided by the optical sensors, the position, orientation, and / or shape information determined by the optical feedback is transformed into a reference frame adopted by the first positioning system (e.g., a magnetically based system). As described in more detail below, in some embodiments, the magnetic reference frame associated with the optical sensors is registered with a reference frame adopted by the magnetic sensors (or other sensor types), allowing the optical feedback to take advantage of the reference frame defined by the magnetically based positioning system. In this way, the position, orientation, and / or shape information provided by the optical sensors is transformed (i.e., referenced) into a reference frame capable of displaying the position, orientation, and shape of catheter 102 within the scope of patient image data.

[0024] In some embodiments, the computer system 116 includes an electronic control unit (ECU) 118, a memory / repository 120, an input / output device 122, and a display 124. The memory / repository 120 stores instructions executable by the processor 118 to perform one or more modules, including a magnetic positioning module 130 and an optical positioning module 132. In another embodiment, other positioning systems may be used instead of or in combination with the magnetic positioning system, including impedance-based systems, ultrasonic systems, and one or more other well-known positioning systems.

[0025] Magnetic positioning module 130 receives feedback from a magnetic sensor located at the distal end 106 of conduit 102. The feedback provided by the magnetic sensor is the result of the interaction between one or more magnetic sensors and a low-energy magnetic field generated by the magnetic emitter assembly 127. In some embodiments, the position of the magnetic sensor is determined within a three-dimensional (3D) reference frame, referred to herein as the magnetic reference frame. The output provided by magnetic positioning module 130 is the position and / or orientation of the magnetic sensor within a magnetic coordinate frame. Optical sensor data received from one or more optical sensors located within conduit 102 is provided to optical positioning module 132. In some embodiments, one or more optical sensors are located at the distal end 106 of conduit 102. In other embodiments, the optical sensors may be located at multiple locations associated with conduit 102 and positioned adjacent or nearly adjacent to each other along the length of conduit 102 (i.e., from the distal end 106 toward the proximal end 104, and in some cases along the entire length to the handle 108). Furthermore, optical positioning module 132 receives input regarding the position of the magnetic sensor within the magnetic coordinate frame and stored transformation coefficients. In some embodiments, a registration process is used to register an optical sensor with a magnetic sensor and generate transformation coefficients for transforming the position from a magnetic reference frame to another magnetic reference frame. Based on the optical sensor data, the position of the magnetic sensor within the magnetic reference frame, and the stored transformation coefficients, the optical positioning module 132 generates an output providing the position, orientation, and / or shape of the optical sensor within the magnetic reference frame. In this way, the positioning outputs provided with respect to both the magnetic sensor and the optical sensor represent location within the magnetic reference frame and can be positioned with respect to patient imaging data provided to the display 124. As described in more detail below, the position of the magnetic sensor can determine the number and location of the optical sensors required to represent the position, orientation, and / or shape of the optical sensors relative to the magnetic reference frame.

[0026] Reference Figure 2-5 And 8, based on one or more magnetic sensors (e.g., Figure 2 The magnetic sensors 210a and 210b shown Figure 8The magnetic sensors 810a and 810b shown in the figure receive input from one or more optical sensors (e.g., Figure 3 The optical sensors 300a, 300b, and 300c shown in the figure receive inputs (such as fiber Bragg gratings (FBGs)) in a magnetic reference frame 312. Figure 3 The location, orientation, and shape of the medical device are determined within the (shown) field. As described in more detail below, the magnetic reference system is based on magnetic sensors 210a, 210b (or 810a, 810b, as shown below). Figure 8 (Shown) the interaction with an externally generated magnetic field. Therefore, the position and orientation of the magnetic sensors 210a, 210b within the magnetic reference frame are known and can be located without additional input. Conversely, the magnetic reference frame 314 is referenced only to the optical sensors themselves, not to any external magnetic field (or, in the case of impedance-based positioning, to a surface electrode placed on the patient). To compensate for the lack of an external reference point for the magnetic reference frame 314, it is registered with a magnetic reference frame 312. In some embodiments, the output of the registration process is a set of transformation coefficients unique to the registered medical device, which are used to transform feedback received from one or more optical sensors 300a, 300b, 300c from the magnetic reference frame 314 to the magnetic reference frame 312. As discussed in more detail below, magnetic reference 314, which is registered to one or more optical sensors 300a, 300b, 300c using magnetic reference 312, includes a magnetic reference 314 that allows position / shape information provided by one or more optical sensors (e.g., multiple fiber Bragg gratings (FBGs) 300a, 300b, 300c) to be displayed within magnetic reference 312 for positioning catheter 102 within a patient image.

[0027] exist Figure 3In the illustrated embodiment, a plurality of optical sensors 300a, 300b, 300c are arranged longitudinally along a portion of a multi-core optical fiber 206, wherein one or more cores within the multi-core optical fiber 206 may include one or more optical sensors 300a, 300b, 300c. In some embodiments, the one or more optical sensors 300a, 300b, 300c are fiber Bragg grating (FBG) sensors, which are optical sensors capable of detecting applied force, strain, and / or temperature changes. In some embodiments, a single core in the multi-core optical fiber 206 includes each of the plurality of optical sensors 300a, 300b, 300c. Furthermore, one or more optical sensors can be used for a variety of different functions. For example, one optical sensor 300a may be used for shape sensing, while another optical sensor may be used for temperature sensing. As described above, in some embodiments, other optical sensors may be positioned along the length of the conduit 102 (from the distal end 106 toward the proximal end 104, and in some cases extending to the handle 108), wherein feedback received from the plurality of sensors allows the calculation of the shape of a conduit of a given length. In other embodiments, each of a plurality of optical sensors 300a, 300b, 300c in a sensing shape may be applied, wherein the plurality of optical sensors extend from the distal end 106 of the catheter 102 to the proximal end 104 of the catheter 102, or to the handle 108 of the catheter 102. In this way, the position and / or orientation of the ablation tip 202 and the shaft 204 can be determined.

[0028] As described above, in some embodiments, one or more optical sensors 300a, 300b, 300c are fiber Bragg grating sensors—a distributed Bragg reflector comprising an optical fiber core with a periodically varying refractive index. The interface at each refractive index variation forms a reflection of the incident light. Most reflections are relatively weak, and light at these wavelengths mostly propagates through the fiber Bragg grating. However, light at a certain resonant wavelength related to the periodically varying refractive index is reflected by the fiber Bragg grating. The relationship between the reflected light and the periodic variation of the refractive index of the fiber core is defined as:

[0029] λ β =2n eff Λ (1)

[0030] Where Λ is the period of the grating, n eff It is the effective refractive index of the fiber core, λ β This is the Bragg wavelength at which resonance occurs. In this way, the optical signal transmitted along the fiber core to the fiber Bragg grating will result in the resonant wavelength λ. βThe reflection of light is related to the periodic variation of the fiber Bragg grating. Force, strain, and / or temperature changes applied to the fiber Bragg grating will cause periodic variations in the grating, which in turn cause variations in the wavelength of the reflected light. By detecting the wavelength variation reflected by the fiber Bragg grating, information about the force, strain, and / or temperature changes applied to the sensor and / or the shape (i.e., bending) of the sensor can be detected. In this invention, the focus is on detecting the force and / or shape applied to the conduit 102, although in some embodiments, temperature changes can also be detected using one or more fiber cores. Force detection can include forces applied to the ablation tip along the conduit axis and deflection forces that cause bending of the conduit 102. Depending on the location of one or more fiber Bragg gratings (FBGs), shape information about a specific portion of the conduit 102 (e.g., the distal end 106 of the conduit as shown by the arrangement of one or more fiber Bragg gratings (FBGs) 300a, 300b, 300c) or along a certain length of the conduit 102 can be acquired. For example, multiple fiber Bragg gratings (FBGs) can be positioned along a certain length of the conduit 102—from the proximal end 104 or even from the handle 108 to the distal end 106.

[0031] When a axial force or deflection force is applied to a fiber Bragg grating, both the grating's period and the fiber's effective refractive index change accordingly, thus altering the Bragg wavelength (e.g., the wavelength of the reflected light). By measuring the shift in the Bragg wavelength, fiber Bragg gratings (FBGs) can be used for force and shape sensing (as well as temperature sensing). One advantage stems from the absolute nature of the information encoded in the wavelength change measurement, which makes the sensor unaffected by fluctuating optical power or interface losses. The shift in the Bragg wavelength can be obtained by applying a strain ε and a change in ambient temperature dT, as shown in Equation 2:

[0032]

[0033] in, It is the photoelastic constant, ρ e =0.22 indicates pure silicon glass. It is the linear expansion coefficient. dT is the thermo-optic coefficient, while dT is the temperature change. For a grating with a wavelength of 1550 nm, the wavelength change typically corresponds to strain on the order of ~1 pm / με, while the temperature change corresponds to strain on the order of 10 pm / ℃.

[0034] Young's modulus E is defined as:

[0035]

[0036] Where F is the force, A0 is the area of ​​the fiber cross-section, L0 is the fiber length, and ΔL is the tension length caused by the applied force. The force can be derived from formula (3):

[0037] F=EA0ε (2)

[0038] Where ε=ΔL / L0 is the strain. For a single-mode optical fiber with a diameter of 125 nm, the Young's modulus of the glass material is 70×10⁻⁶. 9 N / m 2 Therefore, the force relative to the strain of the optical fiber can be obtained as:

[0039] F=859ε(N) (5)

[0040] When the ambient temperature remains constant at dT = 0, for pure glass ρ e =0.22, according to Formula 5 and Formula 2, the force applied corresponding to the offset of the Bragg wavelength is obtained:

[0041] F≈1101dλ / λ B (3)

[0042] The decomposition of the 0.01 nm Bragg wavelength shift within the 1550 nm wavelength range, given by Equation 6, yields a force decomposition of 0.7 g. According to Equations 4 and 2, the Bragg wavelength shift corresponding to the applied force and temperature change is expressed as:

[0043]

[0044] Where Δλ is the Bragg wavelength shift, ΔT is the temperature change, F is the applied force, E is Young's modulus, A0 is the area of ​​the fiber cross-section, and ρ... e α is the photoelastic constant, α is the linear expansion coefficient, and ξ is the thermo-optical coefficient.

[0045] To sense the deflection force in three dimensions, multiple independent optical sensors can be used in one embodiment. For example, refer to Figure 4 The multi-core fiber 206 comprises multiple (e.g., seven) independent fiber cores, as shown and labeled 402a-402g, each fiber core including at least one fiber Bragg grating (FBG). Figure 4 (Not shown). In some embodiments, at least a first plurality of fiber cores (e.g., fiber cores 400a-400f) are equidistantly arranged along the outer periphery of the multi-core fiber 206. A deflection force applied to the multi-core fiber causes some fibers to elongate and some to compress, so the feedback provided by some of the fiber Bragg gratings (FBGs) will show a change in wavelength corresponding to the compression (i.e., shortening) of the FBG, and at least some of the FBGs will show a change in wavelength corresponding to the elongation of the FBG. Based on the feedback, the amount and shape of the deflection can be determined. Although Figure 4Seven individual fiber cores are shown, but fewer individual fiber cores may be required in other embodiments. For example, in some embodiments, force and shape sensing is achieved by three individual fiber cores positioned along the outer periphery of the multi-core fiber 206 and arranged equidistantly from each other (e.g., 120° apart). Alternatively, more than seven fiber cores within the multi-core fiber 206 may also be considered.

[0046] In some embodiments, multiple fiber cores 400a-400f arranged around the outer periphery are used to detect deflection forces applied to a fiber Bragg grating (FBG). In other embodiments, a first set of multiple fiber cores (e.g., fiber cores 400a, 400c, and 400e) arranged around the outer periphery are used for shape sensing, while a second set of multiple fiber cores (e.g., fiber cores 400b, 400d, and 400f) arranged around the outer periphery are used for axial force sensing. Generally, it is desirable for the multiple cores to be equidistantly distributed around the outer periphery of the multi-core fiber to provide maximum quantity information related to the sensor shape. In some embodiments, the central fiber core 400g is also used to detect forces—including axial forces and / or deflection forces. In other embodiments, the central fiber core 400g is used for temperature compensation / internal strain monitoring. Various other configurations can be used to detect deflection forces, axial forces, and / or temperature changes.

[0047] As described above, in some embodiments, one or more optical sensors 300a, 300b, 300c (e.g., fiber Bragg gratings (FBGs)) are not arranged at specific locations along a certain length of the multi-core fiber—for example, as… Figure 2 and Figure 3The portion of the ablation tip 202 shown—one or more fiber cores 402a-402g—may include multiple fiber Bragg gratings (FBGs) arranged along the axial length of the fiber core. For example, fiber core 400a may include multiple fiber Bragg gratings (FBGs), each defined by a unique grating period. In some embodiments, the multiple fiber Bragg gratings (FBGs) are adjacent to each other (e.g., stacked end-to-end), with little or no gap between adjacent multiple fiber Bragg gratings (FBGs). Each fiber Bragg grating (FBG) provides feedback on the force applied to the fiber Bragg grating (FBG), wherein the end-to-end stacking of multiple fiber Bragg gratings (FBGs) can provide shape information for a longer length of conduit 102. In some embodiments, shape information related to the axial length of conduit 102 can be collected by placing multiple fiber Bragg gratings (FBGs) back-to-back. In some embodiments, a plurality of fiber Bragg gratings (FBGs) may extend from the distal end 106 of the conduit 102 toward the handle 108—in some embodiments, all the way from the distal end 106 of the conduit 102 to the handle 108. In some embodiments, in order to distinguish the reflections provided by each of the plurality of fiber Bragg gratings (FBGs) connected along the same fiber core, each fiber Bragg grating (FBG) must be characterized by a different grating period, so that reflections received on the same fiber can be deterministically assigned to one of the plurality of fiber Bragg gratings (FBGs). In this way, the optical sensor 300 provides feedback for determining the shape of the optical sensor 300.

[0048] Figure 3 It is along Figure 2 The diagram shows a cross-sectional view of the distal end 106 of the conduit 102, taken along line 3-3. In some embodiments, the magnetic sensor assembly includes a magnetic coupler 208, a first magnetic sensor, and second magnetic sensors 210a and 210b. The magnetic coupler 208 is rigidly fixed to the inner surface of the shaft 204. The first and second magnetic sensors 210a and 210b are fixed to the magnetic coupler 208, wherein the magnetic coupler 208 holds the magnetic sensors 210a and 210b in a fixed position relative to the shaft 204 and relative to each other. Although not shown in this view, the magnetic signals detected by the first and second magnetic sensors 210a and 210b are transmitted through the magnetic sensor cable 114 (… Figure 1 (As shown) Communication is transmitted to computer system 116. Based on the rigid connection of magnetic sensors 210a and 210b located within the distal end 106 of catheter 102 and the rigid positioning of magnetic sensors 210a and 210b relative to each other, the position and orientation of the distal end 106 of catheter 102 relative to magnetic reference frame 312 are known. Figure 3In the illustrated embodiment, the magnetic reference frame 312 is defined by coordinate axes (e.g., mX, mY, mZ), with directions about these axes (e.g., yaw, pitch, roll) denoted as θ. Based on feedback provided by magnetic sensors 210a, 210b, the absolute position and / or orientation of the distal end 106 of the conduit is known within the magnetic reference frame 312.

[0049] In some embodiments, the optical fiber 206 extends within the outer shaft 204 toward the distal end 106 of the conduit 102. In some embodiments, the optical fiber 206 is a multi-core optical fiber comprising multiple fiber cores (e.g., Figure 4 (As shown). The optical fiber 206 is rigidly fixed within the distal end 106 of the conduit 102 by optical fiber tubes (here shown as a first optical fiber tube support 304, a second optical fiber tube support 306, and a third optical fiber tube support 308). In some embodiments, the first optical fiber tube support 304, the second optical fiber tube support 306, and the third optical fiber tube support are integral (i.e., a single tube). In other embodiments, the first, second, and third optical fiber tube supports are separate from each other. In some embodiments, the first optical fiber tube support 304, the second optical fiber tube support 306, and the third optical fiber tube support 308 serve to rigidly fix the optical fiber 206 within the distal end 106 of the conduit 102. Figure 3 In the illustrated embodiment, the first fiber optic tube support 304, the second fiber optic tube support 306, and the third fiber optic tube support 308 serve to support the fiber optic cable 206 in a generally central position within the distal end 106 of the conduit 102. In other embodiments, the fiber optic cable 206 may be retained in a non-central position within the conduit 102, provided that the position of the fiber optic cable 206 remains fixed relative to the conduit 102.

[0050] Within the ablation tip 202, a flexible tip wall 316 and a spring 302 allow the ablation tip 202 to be compressed along the axial direction. In some embodiments, the flexible tip wall 316 and spring 302 also allow the ablation tip 202 to deflect (e.g., bend) in a non-axial direction. In some embodiments, the flexible tip wall 316 may be employed without the spring 302. First, second, and third fiber optic supports 304, 306, and 308 rigidly secure the fiber optic cable 206 to the conduit 102, forcing the fiber optic cable 206, particularly the optical sensor 300, to conform to the orientation / shape of the ablation tip 202. Furthermore, in some embodiments, to ensure rigidity between the fiber optic cable 206 and the conduit 102, the fiber optic cable 206 is coupled to one or more of the first fiber optic support 304, the second fiber optic support 306, and / or the third fiber optic support 308 to ensure a rigid connection of the optical sensor within the axial 204. Therefore, the optical fiber 206 follows the movement and shape of the catheter 102, so that the optical feedback received from the optical sensor 300 characterizes the shape and / or geometry of the catheter 102.

[0051] In some embodiments, multiple individual optical sensors 300a, 300b, 300c (e.g., fiber Bragg gratings (FBGs)) may be employed within one or more associated with each of the plurality of cores. Figure 3 In the illustrated embodiment, optical sensor 300a is located at the farthest end of optical fiber 206, optical sensor 300b is located near optical sensor 300a, and optical sensor 300c is located near optical sensor 300b. In some embodiments, one or more of optical sensors 300a, 300b, or 300c can be used to sense shape or sense force. For example, in some embodiments, optical sensor 300a can be used for force sensing, while optical sensors 300b and 300c are used for shape sensing. In other embodiments, each of optical sensors 300a, 300b, and 300c is used for shape sensing. In embodiments where each optical sensor 300a, 300b, and 300c is located within the same fiber core, each of the plurality of fiber Bragg gratings (FBGs) can be designed to operate at different wavelengths, thereby enabling them to provide feedback related to the sensed strain / force. In some embodiments, optical sensors 300a-300c may not be confined to the area within or near the ablation tip 202. For example, in some embodiments, multiple optical sensors or multiple fiber Bragg gratings (FBGs) may be arranged end-to-end along one or more fiber cores from the ablation tip 202 to the magnetic sensors 210a, 210b (e.g., Figure 5 In the illustrated embodiment, multiple optical sensors 300a, 300b, 300c, 300d, and 300e extend from the distal tip of catheter 300a to the region near magnetic sensors 210a and 210b. In other embodiments, multiple optical sensors (e.g., fiber Bragg grating (FBG) sensors) may be arranged end-to-end along one or more fiber cores from the ablation tip 202 along the length of catheter 102 to the handle 10. Regarding... Figure 5 In the illustrated embodiment, each of the plurality of fiber Bragg gratings (FBGs) 300a-300e (if operating on the same fiber core) can operate at different wavelengths from each other, thereby providing light reflections that can be distinguished from the other fiber Bragg gratings (FBGs) by the strain / force sensed by each of the plurality of fiber Bragg gratings (FBGs). In this way, the feedback provided by the fiber Bragg gratings (FBGs) can be used to determine shape information from the magnetic sensors 210a, 210b to the tip of the conduit.

[0052] By registering one or more optical sensors 300a-300c with magnetic reference frame 312, the shape and / or position information obtained from optical sensor 300 (relative to magnetic reference frame 314) is transformed into magnetic reference frame 312. In some embodiments, since magnetic sensors 210a, 210b are rigidly fixed to the distal end 106 of catheter 102, magnetic sensors 210a, 210b and thus magnetic reference frame 312 are forced to follow the movement of catheter 102. Therefore, the position / orientation (but not the shape) of catheter 102 can be obtained from magnetic sensors 210a, 210b and represented relative to magnetic reference frame 312. Similarly, one or more optical sensors 300a-300c are rigidly fixed to the distal end 106 of catheter 102, and optical sensors 300a-300c are also forced to follow the movement of catheter 102. Registering one or more optical sensors 300a-300c relative to a magnetic reference frame 312 allows the magnetic reference frame 312 to be used as a reference point for one or more optical sensors 300a-300c. That is, the position, shape, and orientation of one or more optical sensors 300a-300c relative to the position and orientation of magnetic sensors 210a, 210b are known.

[0053] exist Figure 3 In the illustrated embodiment, magnetic sensors 210a and 210b are located at the distal end 106 of the conduit 102. In other embodiments, such as Figure 8 In the illustrated embodiment, magnetic sensors 810a and 810b are located within the handle 808 of the catheter. In this embodiment, the magnetic reference frame is based on the position of the handle 808. The position and / or orientation of the distal end of the catheter can be determined based on multiple deployed optical sensors (e.g., fiber Bragg gratings (FBGs)) arranged along a length of the catheter between the handle 808 and the distal end. As described above, each adjacent FBG sensor will operate at a different wavelength, allowing each sensor to provide feedback. In particular, referencing the shape data provided by the multiple optical sensors to the magnetic reference frame defined by the magnetic sensors located within the handle 108 allows the position and orientation of the distal end 106 of the catheter 102 to be determined.

[0054] Reference Figure 6 and Figure 7 The document describes a registration process for associating magnetic reference frame 314 with magnetic reference frame 312. Although magnetic reference frame 312 is referenced, other positioning systems and corresponding reference frames may be utilized in other embodiments. In some embodiments, the registration process is performed during manufacturing. In other embodiments, if the registration process is performed before each use, then magnetic reference frame 314 can be recalibrated with magnetic reference frame 312. In particular, Figure 6This is a block diagram illustrating a system 600 for registering an optical sensor 606 according to some embodiments, and Figure 7 This is a flowchart illustrating the steps used in the registration process according to some embodiments.

[0055] System 600 includes a computer system 610 with a processor 612 and a memory 614. The memory 614 is configured to store instructions executable by the processor 612 to implement a registration module 616. The computer system 610 is configured to receive feedback from a medical device 602, which includes a magnetic sensor 604, an optical sensor 606, and a non-volatile memory 608. In some embodiments, the magnetic sensor 604 provides feedback for determining the position and / or orientation of the medical device 602 in response to the medical device 602 being placed in a magnetic field. Similarly, the optical sensor 606 generates feedback for determining the position, orientation, and / or shape of the optical sensor 606. (As stated above regarding...) Figure 2-5 The feedback received from the magnetic sensor 604 is provided based on the applied external magnetic field and is represented with reference to a magnetic reference frame (mX, mY, mZ). The feedback received from the optical sensor 606 is provided only with reference to itself and is represented with reference to a magnetic reference frame (oX, oY, oZ). The registration module 616, implemented by the computer system 610, collects position and orientation data (mX, mY, mZ) from the magnetic sensor 604. i mY i mZ i mθ i And it collects position, orientation, and shape information (oX) from the optical sensor 606. i oY i oZ i 、oθ i Furthermore, the collected data was used to determine the transformation data from the magnetic reference frame to the magnetic reference frame.

[0056] Reference Figure 7 This illustrates the registration process of the optical positioning / shape sensor 606 within a reference frame adopted by the first positioning sensor 604. In some embodiments, the position / shape of the optical sensor 606 is changed relative to the first positioning sensor 604 (e.g., a magnetic sensor), and feedback from both sensors is stored as a reference pair. This data can be collected using various methods, although the purpose of this discussion is to hold the medical device within a clamp that keeps the first positioning sensor 604 relatively fixed and to change the position / shape of the optical sensor 606 relative to the first positioning sensor 604. In other embodiments, the optical sensor 606 may remain relatively fixed, and the first positioning sensor 604 may be changed relative to the optical sensor.

[0057] In step 702, the medical device 602 is placed in a clamp (not shown), and the clamp is placed in a magnetic field (assuming the first positioning sensor includes a magnetic sensor).

[0058] In step 704, the portion of the medical device including the optical sensor 606 (e.g., Figure 2-5 The distal end 106 of the catheter 102 shown is positioned relative to the first positioning sensor 604 in a first position. In a subsequent step, the position of a portion of the medical device 602, including the optical sensor 606, relative to the first positioning sensor 604 is changed to collect additional data points describing the relationship between the magnetic reference frame and the magnetic reference frame. This can be achieved by keeping the first positioning sensor 604 substantially stationary while changing the position of the optical sensor 602. In one embodiment, a force is applied to the portion of the medical device 602 that houses one or more optical sensors 606 (e.g., in...). Figure 2-5 In the example shown, the distal end 106 of the catheter 102 is used to cause this portion of the medical device to deflect relative to the first positioning sensor. For example, in one embodiment, weight can be attached to the distal end of the medical device to generate the desired force. In other embodiments, other methods can be used to deflect the desired portion of the medical device 602. It is desirable to deflect the medical device 602 to subject the optical sensor 606 to compression / strain to help align the magnetic reference frame with the first reference frame.

[0059] In step 706, the position and / or orientation (mX1, mY1, mZ1, mθ1) of the first positioning sensor 604 within a first reference frame (e.g., a magnetic reference frame) is determined using feedback received from the first positioning sensor 604. Additionally, in step 706, the position, orientation, and / or shape (oX, oY1, oZ1, oθ1) of the optical sensor 606 within the magnetic reference frame is determined using feedback received from the optical sensor 606. (As stated above regarding...) Figure 2-5 In some embodiments, multiple fiber cores are utilized, wherein the force applied to the fiber core is detected by compression / strain using optical sensors (e.g., fiber Bragg gratings) located within each of the multiple fiber cores. A magnetic reference frame can be centered along one of the multiple fiber cores, for example... Figure 4 The centrally located fiber core 400g is shown in the figure. In other embodiments, the magnetic reference frame is centered relative to one of a plurality of fiber cores (e.g., fiber core 400a) located on the outer periphery of the optical guide tube.

[0060] In step 707, the position data (mX1, mY1, mZ1, mθ1) and the optically based shape / position data (oX1, oY1, oZ1, oθ1) are stored as a reference pair.

[0061] In step 708, it is determined whether a sufficient number of reference pairs have been collected. In some embodiments, this may include comparing the number of stored reference pairs with a threshold to determine if additional reference pairs are needed. In other embodiments, multiple locations need to be set, and the process continues until reference pairs have been collected from each required location. In some embodiments, a predetermined threshold number of reference pairs are collected (collected at sufficiently different locations). For example, if the medical device rotates approximately 90 degrees between measurements, then four reference pairs of data are collected. In other embodiments, the medical device rotates 45 degrees, and eight reference pairs are collected. In other embodiments, fewer or more reference pairs are collected.

[0062] If a sufficient number of reference pairs have been collected, the method proceeds to step 712, where the transformation from the magnetic reference frame to the first reference frame (e.g., the magnetic reference frame) is calculated using multiple reference pairs. If a sufficient number of reference pairs have not been collected, the method proceeds to step 710.

[0063] In step 710, the position change relative to the first positioning sensor 604 (e.g., a magnetic sensor) includes changes in position from optical sensors (e.g., Figure 2-5 The position of a portion of the medical device 602 (distal 106) in the illustrated embodiment. In some embodiments, the change of position includes rotating the position of the medical device 602 by a known amount (e.g., 90 degrees), which causes rotation of both the optical sensor 606 and the first positioning sensor 604. In some embodiments, the medical device 602 rotates within a clamp, while in other embodiments, the entire clamp of the medical device 602 is kept rotated. A force is again applied to the portion of the medical device 602 including the optical sensor 606 to cause a deflection relative to the first positioning sensor 604 within the optical sensor 606. In some embodiments, the same force is applied at this position as at the previous position, causing the medical device 606 to deflect substantially equally at each position. For example, in embodiments where weight is attached to the distal end of the medical device 606 to provide the desired deflection force, the same weight applied at the first position is applied to the second position. In other embodiments, the applied force may be different, as long as some force is applied to achieve at least some deflection of the optical sensor 606 relative to the first positioning sensor 604. In other embodiments, a portion of the medical device 602, including the optical sensor 606, is moved to a new position relative to the first positioning sensor 604.

[0064] After the position of the medical device is changed in step 710, the position and / or orientation (e.g., mX2, mY2, mZ2, mθ2) of the first positioning sensor 604 is determined in step 706 using feedback received from the first positioning sensor 604. Similarly, the position, orientation, and / or shape (e.g., oX2, oY2, oZ2, oθ2) of the optical sensor 606 is determined using feedback received from the optical sensor 606, and these are stored as another reference pair. The process of changing the position of the optical sensor relative to the magnetic sensor and measuring the position of each optical sensor continues until several reference point pairs are collected.

[0065] In step 712, a transformation required to represent the position, orientation, and / or shape information collected from the optical sensor 606 within a first reference frame (e.g., mX, mY, mZ) is determined based on multiple reference pairs. In some embodiments, in addition to multiple reference pairs, other information may be used to determine the transformation from the magnetic reference frame (e.g., oX, oY, oZ) to the first reference frame (e.g., mX, mY, mZ). For example, in some embodiments, the distance d between the magnetic sensor (210a, 210b) and the optical sensor (in...) is utilized in the transformation. Figure 5 (As shown) to determine the position of the optical sensor relative to a magnetic reference frame. In this way, the position / shape information collected by the optical sensor 606 can be expressed within a first reference frame (e.g., a magnetic reference frame).

[0066] In step 714, the calculated transformation based on multiple benchmarks is stored in medical device 602. In some embodiments, medical device 602 includes non-volatile memory 608 for storing the transformation. During operation of medical device 602, the transformation data stored in non-volatile memory 608 can be downloaded or otherwise provided to a computer system (e.g., Figure 1 The computer system 116 shown is used by the computer system to transform the position / shape information provided by the optical sensor 606 to a first reference frame (e.g., a magnetic reference frame), so that the position, orientation and / or shape of the optical sensor are accurately displayed in the first reference frame.

[0067] Reference Figure 8 The diagram illustrates a handle assembly 808 including magnetic sensors 810a, 810b according to some embodiments. As briefly described above, in some embodiments, the magnetic sensors 810a, 810b may be located within the handle assembly 808 at the distal end for guiding a conduit (not shown). In this embodiment, the handle assembly 808 must be located within a magnetic field—for example, within a field formed by... Figure 1Within the magnetic field generated by the magnetic transmitter assembly 127 shown. Based on feedback provided by magnetic sensors 810a, 810b, the position and / or orientation of the handle 808 can be determined within the magnetic field (i.e., within a magnetic reference frame). In other embodiments, the position of the handle assembly 808 can be determined using one or more other types of positioning systems (rather than magnetic sensors).

[0068] In some embodiments, the fiber core 806 extends from the handle 808 along the length of the shaft from the proximal end to the distal end (e.g., ...). Figure 1 (Illustrated). In some embodiments, the multi-core fiber 806 includes multiple fiber cores, one or more of which may include one or more optical sensors. For example, in one embodiment, fiber Bragg grating (FBG) sensors are arranged adjacent to each other along the length of the shaft from the handle 808 to the distal end of the conduit. Feedback received from the multiple FBG sensors allows the shape of the shaft from the handle 808 to the distal end to be calculated. As described above, the position and shape information provided by the multiple FBGs can be transformed from the FBG reference frame (i.e., the magnetic reference frame) to the magnetic reference frame of the handle assembly 808. In this way, the position, shape, and / or orientation of the conduit from the handle to the distal end is known and displayed within the magnetic reference frame.

[0069] Discussion of possible embodiments

[0070] The following is a non-exclusive description of possible embodiments of the present invention.

[0071] According to one aspect, the included medical device may include a proximal end, a distal end, and a shaft extending between the proximal and distal ends. The medical device may also include a magnetic sensor assembly, which may include a magnetic coupler, a first magnetic sensor, and a second magnetic sensor, wherein the magnetic coupler is located at the distal end of the medical device and rigidly fixed to the inner surface of the shaft. The medical device may also include an optical fiber composed of multiple optical fiber cores extending along the length of the shaft, wherein one or more of the multiple optical fiber cores include an optical sensor located at a position along a certain length of the optical fiber, wherein the optical fiber is rigidly supported within the shaft near the optical sensor.

[0072] The medical device described in the preceding paragraph may optionally include (in addition and / or alternatively) any one or more of the following features, configurations and / or other components.

[0073] For example, in some aspects, the medical device may also include an optical fiber support having a central opening for housing and supporting the optical fiber within a shaft, wherein the optical fiber support is adjacent to the optical sensor.

[0074] In some respects, the optical fiber can be integrated with an optical fiber support to rigidly secure a portion of the optical fiber, including the optical sensor, to the shaft via the optical fiber support.

[0075] In some respects, a medical device can be a catheter with a flexible tip located at the distal end.

[0076] In some respects, optical sensors may include fiber Bragg gratings, wherein at least some of the multiple fiber cores include at least one fiber Bragg grating.

[0077] In some aspects, at least one of the multiple fiber cores may include a plurality of fiber Bragg gratings extending along a certain length of the fiber core, wherein each fiber Bragg grating associated with a particular fiber core is defined by a unique grating period relative to other fiber Bragg gratings located in the same fiber core.

[0078] According to another aspect, the positioning system may include a medical device having a proximal end and a distal end, wherein the distal end may include at least a first positioning sensor and an optical sensor, wherein the first positioning sensor and the optical sensor may be rigidly fixed within the distal end of the medical device. The positioning system may also include a computer system configured to receive feedback from the first positioning sensor and optical feedback from the optical sensor, wherein the computer system may be used to determine the position of the distal end of the medical device within a first reference frame based on the received feedback, and may determine the shape of the distal end of the medical device within a second reference frame based on the optical feedback. The computer system may transform the shape of the distal end of the medical device from the second reference frame to the first reference frame, at least partially based on the position of the distal end of the medical device. The output generated by the computer system includes the position and shape of the distal end of the medical device represented within the first reference frame.

[0079] The medical device described in the preceding paragraph may optionally include (in addition and / or alternatively) any one or more of the following features, configurations and / or other components.

[0080] For example, in one aspect, the computer system may additionally transform the shape of the distal end of the medical device from the second reference frame to the first reference frame based on a transformation that associates the second reference frame with the first reference frame.

[0081] In another aspect, the positioning system may include a non-volatile memory for storing transformation coefficients, wherein the transformation coefficients are specifically determined during the registration stage to correlate the position of the optical sensor with the position of the first positioning sensor.

[0082] In another aspect, the optical sensor may include one or more fiber Bragg gratings, the fiber of which is arranged along a portion of the fiber extending a certain length along the medical device.

[0083] In another aspect, the first positioning sensor may be a magnetic sensor housed within a magnetic coupling rigidly fixed to the distal end of the medical device.

[0084] According to another aspect, a method of placing a medical device inside a patient's body may include receiving feedback from a first positioning sensor and receiving optical feedback from an optical sensor. The method may further include calculating the position of the first positioning sensor based on the received feedback, wherein the position is provided with reference to a first reference frame defined by the first positioning sensor. The method may further include calculating the shape of the optical sensor based on optical feedback from the optical sensor, wherein the shape is provided with reference to a second reference frame defined about the optical sensor. The method may further include transforming the shape of the optical sensor from the second reference frame to the first reference frame based on the position of the first positioning sensor and stored transformation coefficients. The method may further include displaying the position and shape of the medical device with respect to the first reference frame.

[0085] The medical device described in the preceding paragraph may optionally include (in addition and / or alternatively) any one or more of the following features, configurations and / or other components.

[0086] For example, in one aspect, the step of displaying the position and shape of a medical device may include displaying the position and shape of the medical device relative to an image of a patient.

[0087] According to another aspect, a method for calibrating an optical sensor using a magnetic positioning sensor within the distal end of a medical device may include placing the distal end of the medical device within a magnetic field and positioning the distal end of the medical device in a first position, wherein the first position causes a deflection of the optical sensor. The method may further include recording first magnetic position data provided by the magnetic positioning sensor and first optical data provided by the optical sensor, and storing the recorded data as a first reference pair, wherein the first magnetic position data is provided in a magnetic reference frame and the first optical data is provided in an optical reference frame. The method may further include placing the distal end of the medical device in a second position, wherein the second position causes a deflection of the optical sensor, and recording second magnetic position data provided by the magnetic positioning sensor and second optical data provided by the optical sensor, and storing the recorded data as a second reference pair, wherein the magnetic position data is provided in a magnetic reference frame and the optical data is provided in an optical reference frame. The method may further include calculating a transformation based on the first and second reference pairs to transform optical shape data from the optical reference frame to the magnetic reference frame, and storing the calculated transformation.

[0088] The medical device described in the preceding paragraph may optionally include (in addition and / or alternatively) any one or more of the following features, configurations and / or other components.

[0089] For example, in one aspect, positioning the distal end of a medical device in a first position may include applying a first force to the distal end of the medical device to cause a displacement within the distal end.

[0090] In another aspect, applying the first force to the distal end of the medical device may include applying weight to the distal end of the medical device.

[0091] In another aspect, placing the distal end of the medical device in the second position may include applying a second force to the distal end of the medical device, wherein the direction of application of the second force is different from that of the first force.

[0092] In another aspect, storing computational transformations may include storing the computational transformations to non-volatile memory included on a medical device.

[0093] According to another aspect, the medical device may include a proximal end, a distal end, a handle connected to the proximal end, and a shaft extending between the proximal and distal ends. The medical device may also include first and second magnetic sensors located within the handle, and an optical fiber consisting of multiple optical fiber cores extending from the handle to the distal end of the medical device. The optical fiber may consist of one or more optical fiber cores, one or more of which include multiple fiber Bragg grating (FBG) sensors that are nearly adjacent to each other from the handle to the distal end of the medical device.

[0094] The medical device described in the preceding paragraph may optionally include (in addition and / or alternatively) any one or more of the following features, configurations and / or other components.

[0095] For example, on the one hand, each of the multiple FBG sensors located along the same fiber core is defined by a unique grating period relative to other fiber Bragg gratings located in the same fiber core.

Claims

1. A positioning system, comprising: A medical device having a proximal end and a distal end, wherein the distal end includes at least a first positioning sensor and an optical sensor, wherein the first positioning sensor and the optical sensor are rigidly fixed within the distal end of the medical device; and The computer system is configured as follows: Receive feedback from the first positioning sensor; Receive optical feedback from the optical sensor; The position of the first positioning sensor is calculated based on the received feedback, wherein the position is provided with respect to a first magnetic reference frame defined by the first positioning sensor; The shape of the optical sensor is calculated based on optical feedback from the optical sensor, wherein the shape is provided with respect to a second optical reference frame defined by the optical sensor; Record the first magnetic position data provided by the first positioning sensor and the first optical data provided by the optical sensor; The recorded data is stored as a first reference pair, wherein first magnetic position data is provided in a first magnetic reference frame and first optical data is provided in a second optical reference frame; The distal end of the medical device is placed in a second position, where the second position causes the optical sensor to deflect. Record the second magnetic position data provided by the first positioning sensor and the second optical data provided by the optical sensor, and store the recorded data as a second reference pair; Transformation is calculated based on the first reference pair and the second reference pair to transform the optical shape data from the second optical reference system to the first magnetic reference system, thereby transforming the shape of the optical sensor from the second optical reference system to the first magnetic reference system; The position and shape of the medical device are shown with respect to the first magnetic reference frame.

2. The positioning system of claim 1, wherein the computer system further transforms the shape of the distal end of the medical device from the second optical reference frame to the first magnetic reference frame based on a transformation that associates the second optical reference frame with the first magnetic reference frame.

3. The positioning system of claim 1, wherein the medical device includes a non-volatile memory for storing transformation coefficients, wherein the transformation coefficients are uniquely determined during the registration phase to correlate the position of the optical sensor with the position of the first positioning sensor.

4. The positioning system of claim 1, wherein the optical sensor comprises one or more fiber Bragg gratings arranged along a portion of an optical fiber extending along a length of the medical device.

5. The positioning system of claim 1, wherein the first positioning sensor is a magnetic sensor housed within a magnetic coupling member rigidly fixed to the distal end of the medical device.

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