Robotic surgical instrument and methods using bragg fiber sensors
A positionable medical instrument assembly, e.g., a robotic instrument driver configured to maneuver an elongate medical instrument, includes a first member coupled to a second member by a movable joint, with a Bragg fiber sensor coupled to the first and second members, such that relative movement of the first and second members about the movable joint causes a bending of at least a portion of the Bragg fiber sensor. The Bragg fiber sensor has a proximal end operatively coupled to a controller configured to receive signals from the Bragg fiber sensor indicative of a bending thereof, the controller configured to analyze the signals to determine a relative position of the first and second members about the movable joint.
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The present application claims the benefit under 35 U.S.C. § 119 to U.S. Provisional Patent Application Ser. Nos. 60/899,048, filed on Feb. 2, 2007, and 60/900,584, filed on Feb. 8, 2007. The foregoing applications are hereby incorporated by reference into the present application in its entirety.
FIELD OF INVENTIONThe invention relates generally to medical instruments having multiple jointed devices, including for example telerobotic surgical systems, and more particularly to a method, system, and apparatus for sensing or measuring the position, temperature and/or stress and strain at one or more positions along the multiple jointed device.
BACKGROUNDRobotic interventional systems and devices are well suited for use in performing minimally invasive medical procedures, as opposed to conventional techniques wherein the patient's body cavity is open to permit the surgeon's hands access to internal organs. For example, there is a need for a highly controllable yet minimally sized system to facilitate imaging, diagnosis, and treatment of tissues which may lie deep within a patient, and which may be accessed via naturally-occurring pathways such as blood vessels, other lumens, via surgically-created wounds of minimized size, or combinations thereof.
SUMMARY OF THE INVENTIONIn one embodiment, a positionable medical instrument assembly, e.g., a robotic instrument driver configured to maneuver an elongate medical instrument, includes a first member coupled to a second member by a movable joint, with a Bragg fiber sensor coupled to the first and second members, such that relative movement of the first and second members about the movable joint causes a bending of at least a portion of the Bragg fiber sensor. The Bragg fiber sensor has a proximal end operatively coupled to a controller configured to receive signals from the Bragg fiber sensor indicative of a bending thereof, the controller configured to analyze the signals to determine a relative position of the first and second members about the movable joint. By way of non-limiting example, the movable joint may allow for pivotal motion of the second member relative to the first member in a single plane, and wherein the determined relative position of the first and second members about the movable joint comprises an angular displacement of the second member relative to the first member. Alternatively, the movable joint may allow for movement of the second member relative to the first member in at least three degrees of freedom.
In another embodiment, a positionable medical instrument assembly includes a plurality of positionable members, including a first member coupled to a second member by a first movable joint, and a third member coupled to the second member by a second movable joint. One or more Bragg fiber sensors are provided, each coupled to at least two of the first, second and third members, such that relative movement of the first and second members about the first movable joint causes a corresponding bending of at least one Bragg fiber sensor, and a relative movement of the second and third members about the second movable joint causes a corresponding bending of at least one Bragg fiber sensor. Each of the one or more Bragg fiber sensors having a proximal end operatively coupled to a controller configured to receive signals therefrom indicative of a bending of one or more portions thereof, the controller configured to analyze the signals to determine a relative position of the first, second and third members about the respective first and second movable joints. By way of non-limiting examples, the first movable joint may allow for movement of the second member relative to the first member in at least three degrees of freedom, and the second movable joint may allow for movement of the third member relative to the second member in at least three degrees of freedom.
In one such embodiment, the one or more Brag fiber sensors include a first Bragg fiber sensor coupled to the first, second and third members, such that relative movement of the first and second members about the first movable joint, and relative movement of the second and third members about the second movable joint causes a bending of at least first and second respective portions of the first Bragg fiber sensor. In this embodiment, the controller is configured to analyze signals received from the first Bragg fiber sensor to determine a relative position of the first, second and third members about the respective first and second movable joints.
In another such embodiment, the one or more Brag fiber sensors include a first Bragg fiber sensor coupled to the first and second members, such that relative movement of the first and second members about the first movable joint causes a bending of at least a portion of the first Bragg fiber sensor, and a second Bragg fiber sensor coupled to the second and third members, such that relative movement of the second and third members about the second movable joint causes a bending of at least a portion of the second Bragg fiber sensor, wherein the controller is configured to analyze respective signals received from the first and second Bragg fiber sensors to determine a relative position of the first, second and third members about the respective first and second movable joints.
In yet another embodiment, a positionable medical instrument assembly includes a first member coupled to a second member by a movable joint, with a plurality of Bragg fiber sensors coupled to the first and second members, such that relative movement of the first and second members about the movable joint causes a bending of at least a portion of each of the plurality of the Bragg fiber sensors. The Bragg fiber sensors have respective proximal ends operatively coupled to a controller configured to receive signals from each of the Bragg fiber sensors indicative of a respective bending thereof. The controller is configured to analyze the signals to determine a relative position of the first and second members about the movable joint. By way of example, the movable joint may allow for pivotal motion of the second member relative to the first member in a single plane, wherein the determined relative position of the first and second members about the movable joint comprises an angular displacement of the second member relative to the first member. By way of another example, the movable joint may allow for movement of the second member relative to the first member in at least three degrees of freedom. In various embodiments, the assembly comprises a robotic instrument driver configured to maneuver an elongate medical instrument movably coupled to the second member.
In still another embodiment, a medical instrument system is provided, the system including an instrument driver, a sterile barrier, an elongate flexible instrument body operatively coupled to the instrument driver through the sterile barrier, and a Bragg fiber sensor coupled to the elongate instrument body, such that relative bending of the instrument body causes a corresponding bending of at least a portion of the Bragg fiber sensor. The Bragg fiber sensor has a proximal end operatively coupled to a position sensor controller located on a sterile field side of the sterile barrier and configured to receive signals from the Bragg fiber sensor indicative of a bending thereof, the sensor controller configured to analyze the signals to determine a relative position of the instrument. In one such embodiment, the position sensor controller transmits wireless signals to an instrument driver controller located outside the sterile field to communicate to the instrument driver a relative position of the instrument.
The drawings illustrate the design and utility of illustrated embodiments of the invention, in which similar elements are referred to by common reference numerals.
The present invention is directed to various interventional medical instruments, such as jointed positioning instruments, catheters and endoscopic devices, with Bragg fiberoptic grating guidance systems. Advantageously, each of the embodiments of the present invention described herein may be utilized with robotic catheter systems, which can control the positioning of the devices within a patients body, and may also control the operation of other functions of the devices, such as imaging devices, ablation devices, cutting tools, or other end effectors. The devices may be controlled using a closed-loop servo control in which an instrument is moved in response to a command, and then the determined position may be utilized to further adjust the position; or an open loop control in which an instrument is moved in response to a user command, the determined position is then displayed to the user, and the user can then input another command based on the displayed position.
In addition, by determining the strain or deflection of various portions of an instrument and utilizing kinematics and mechanics of materials relationships pertinent to the structures of the instrument, applied loads (preferably including magnitude and vector) may be estimated. In other words, by utilizing a kinematic model of an instrument fitted with one or more Bragg fiber sensor(s), and a mechanics model of how the instrument should deflect or strain under load, a comparison may be made between the expected position of the instrument, as determined utilizing the kinematic and/or mechanics relationships, and the actual position of the instrument, determined utilizing the Bragg fiber sensor data. The difference between actual and expected may then be analyzed utilizing the kinematic and/or mechanics relationships to determine what kind of load must have been applied to cause the difference between actual and expected—and thereby the load may be characterized. For example, taking a two-link instrument wherein the distal link is basically a flexible polymeric cylinder; a kinematic model can be used to predict how the cylinder should move relative to the more proximal pieces when actuated, and it should retain its original shape unless it is subjected to an external load; if the Bragg fiber sensor data indicates that the cylinder is bending, then the applied load can be calculated (e.g. a formula relating the bending to the load can be determined, or a lookup table of predetermined empirical data could be used). Thus, by using the Bragg fiber sensor to measure deflections or strains in different parts of the instrument, forces on the instrument and stresses within the instrument may be determined.
Examples of robotic catheter systems and their components and functions have been previously described in the following U.S. patent applications, which are incorporated herein by reference in their entirety: U.S. patent application Ser. Nos. 10/923,660, filed Aug. 20, 2004; 10/949,032, filed Sep. 24, 2005; 11/073,363, filed Mar. 4, 2005; 11/173,812, filed Jul. 1, 2005; 11/176,954, filed Jul. 6, 2005; 11/179,007, filed Jul. 6, 2005; 11/202,925, filed Aug. 12, 2005; 11/331,576, filed Jan. 13, 2006; 60/785,001, filed Mar. 22, 2006; 60/788,176, filed Mar. 31, 2006; 11/418,398, filed May 3, 2006; 11/481,433, filed Jul. 3, 2006; 11/637,951, filed Dec. 11, 2006; 11/640,099, filed Dec. 14, 2006; 60/833,624, filed Jul. 26, 2006 and 60/835,592, filed Aug. 3, 2006.
All of the following technologies may be utilized with manually or robotically steerable instruments, such as those described in the aforementioned patent application, U.S. Ser. No. 11/481,433. In addition, all of the following technologies may be utilized with the robotic catheter systems and methods described in the U.S. patent applications listed above, and incorporated by reference herein.
For clarity, the sheath and guide catheter instruments described in the exemplary embodiments below may be described as having a single lumen/tool/end-effector, etc. However, it is contemplated that alternative embodiments of catheter instruments may have a plurality of lumens/tools/end-effectors/ports, etc. Furthermore, it is contemplated that in some embodiments, multiple catheter instruments may be delivered to a surgical site via a single multi-lumen sheath, each of which is robotically driven and controlled via an instrument driver. Some of the catheter instruments described herein are noted as flexible. It is contemplated that different embodiments of flexible catheters may be designed to have varying degrees of flexibility and control. For example, one catheter embodiment may have controlled flexibility throughout its entire length whereas another embodiment may have little or no flexibility in a first portion and controlled flexibility in a second portion. Similarly, different embodiments of these catheters may be implemented with varying degrees of freedom.
With reference to the figures, the implementation of fiberoptic Bragg grating sensing to various interventional medical devices will be described. Fiberoptic Bragg grating sensing can be implemented onto interventional medical devices to determine the location of various parts of the device by positioning the fiberoptic bundle longitudinally along the device and calculating the deflection of the fiberoptic bundle. The determination of the deflections of portions of a Fiberoptic Bragg grating sensor is known in the relevant art, but the integration of strains or deflections associated with various portions of a multi-part or articulated medical instrument utilizing one or more Fiberoptic Bragg grating sensors to predict the position of multi-part medical instrument in space.
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It is contemplated that various medical systems for minimally invasive surgery may utilize alternative embodiments of catheters including fiberoptic Bragg grating fibers and associated sensors for measuring strain and determining positions along an elongated instrument similar to those described in detail in U.S. Provisional Patent Applications Nos. 60/785,001 (filed Mar. 22, 2006) and 60/788,176 (filed Mar. 31, 2006), both incorporated by reference herein in their entirety.
For example, one or more Bragg sensing fibers may be included with each of the arms of a “da Vinci Surgical System” available from Intuitive Surgical Inc. of Sunnyvale, Calif.
It is desirable to minimize (or even eliminate) the need to pass instruments through sterile barrier (or drape). Thus, the devices located on one side of the sterile barrier may use a wireless communication link to communicate with devices located on the other side of the sterile barrier. To this end, the position determining system may be configured to be placed within the sterile barrier and communicate wirelessly with the control station. Alternatively, as depicted in
Referring to
Another surgical system that can benefit from accurate position information is the NIOBE Magnetic Navigation System and associated Magnetic GentleTouch Catheters, all available from Stereotaxis, Inc. of St. Louis, Mo. Stereotaxis provides products for magnetically-assisted surgery.
Another surgical system that may benefit from position information during a surgical procedure is the Mako Haptic Guidance System from Mako Surgical, Inc. of Ft. Lauderdale, Fla. Mako produces a robotic system for orthopedic surgical procedures. A haptic guidance system provides sensory feedback (e.g. tactile and/or visual and/or acoustic) to the operator to assist in performing a procedure.
Yet another surgical system that can use accurate position information is the CyberKnife robotic radiosurgery system manufactured by Accuray Inc. of Sunnyvale, Calif. The CyberKnife system provided therapeutic treatment to moving target regions in a patient's anatomy by creating radiosurgical lesions. The technique includes determining a pulsating motion of a patient separately from determining a respiratory motion, and directing a radiosurgical beam, from a radiosurgical beam source, to a target in the patient based on the determination of the pulsating motion. Directing the radiosurgical beam to the target may include creating a lesion in the heart to inhibit atrial fibrillation. Due to the nature of the treatment and the radiation involved, it is desirable to have accurate positioning of the target sites. For example, the system may have to take into account the respiratory motion of the patient, and compensate for movement of the target due to the respiratory motion and the pulsating motion of the patient.
From the discussions thus far, the fiberoptic Bragg grating position determining method and apparatus has been employed in the context of robotic surgical systems and/or their associated catheter devices or beaming devices. It is also contemplated that the position determination techniques using Bragg fibers may also be employed with endoscopic instruments and endoscopic medical procedures. For example, one or more Bragg fiber sensors may be built into or located within a steerable endoscope device such as that produced by NeoGuide Systems Inc. of Los Gatos, Calif.
In the descriptions of the various embodiments of surgical systems equipped with one or more Bragg fiber sensors (also referred to as Bragg grating fibers) and associated position sensing instrumentation, the Bragg fiber sensor has been described as being disposed on, coupled to or located on a robotic arm, instrument, catheter, and/or tool. In addition, it is contemplated that in some embodiments, the Bragg fiber or fiber bundles may be mounted to or installed on the exterior surface or housing of the robotic instrument. For example, one or more Bragg grating fibers may be routed on the external housing of a robotic arm of the Intuitive Surgical da Vinci system, the Mako system, or the Accuray system. Similarly, one or more Bragg fibers may be fastened on the outer surface of the instrument of the Intuitive Surgical, Stereotaxis, or NeoGuide system or apparatus. Furthermore, a Bragg fiber may be attached to a tool instrument or end-effector which may be operably coupled with the distal end of an instrument.
It is further contemplated that in alternative embodiments, the Bragg fiber sensors may be installed within or integrated into the robotic instrument itself. For example, one or more Bragg fiber sensors may be routed internally to the robotic arm of the Intuitive Surgical da Vinci system, the Mako system, or the Accuray system. Similarly, one or more Bragg fiber sensors may be located within the catheter instrument of the Intuitive Surgical catheter, Stereotaxis catheter, or NeoGuide catheter. Furthermore, a Bragg fiber may be built into a tool instrument or end-effector at the distal end of a catheter instrument. Accordingly, as used herein, the term “disposed on” shall include without limitation all of these described methods of providing the described structure with a fiber sensor, and shall not be limited to any particular mounting method or location relative to the structure.
In the descriptions above, it has also been disclosed that position data sensing/analysis logic system (referred to generically as the “position determining system” or “sensor module”) may be located either separated from the robotic system or alternatively on the robotic system itself. In some embodiments, the position determining system may be integrated with the control system of the Intuitive Surgical/Mako/Accuray/NeoGuide/Stereotaxis surgical system. In other embodiments, the position determining system may be stand-alone or part of another computer system. Because of these different implementations, data communication between the Bragg fiber sensors, the position determining system, and/or the control system for the robotic device may be accomplished in a variety of ways. In the embodiments described above, the communication may be conducted via physical cables, wireless transmissions, infrared, optically, or other suitable means. Although the examples described herein are in the context of one Bragg fiber sensor or fiber bundle for clarity, it is contemplated that a plurality of optical fibers or fiber bundles may be deployed on each robotic arm, catheter, or tool device, thus providing additional position data and redundancy if so desired.
While multiple embodiments and variations of the invention have been disclosed and described herein, such disclosure is provided for purposes of illustration and not limitation. It will be apparent to those skilled in the art that many combinations and permutations of the disclosed embodiments are possible, for example, depending upon the medical application. Thus, the invention is to be limited only by the appended claims and their equivalents.
Claims
1. A positionable medical instrument assembly, comprising:
- a first member;
- a second member coupled to the first member by a movable joint; and
- a Bragg sensor optical fiber coupled to the first and second members, such that relative movement of the first and second members about the movable joint causes a bending of at least a portion of the Bragg sensor optical fiber,
- the Bragg sensor optical fiber having a proximal end operatively coupled to a controller configured to receive signals from respective Bragg gratings on a fiber core of the Bragg sensor optical fiber indicative of a bending thereof, the controller configured to analyze the signals to determine a relative position of the first and second members about the movable joint.
2. The instrument assembly of claim 1, wherein the movable joint allows for pivotal motion of the second member relative to the first member in a single plane, and wherein the determined relative position of the first and second members about the movable joint comprises an angular displacement of the second member relative to the first member.
3. The instrument assembly of claim 1, wherein the movable joint allows for movement of the second member relative to the first member in at least three degrees of freedom.
4. The instrument assembly of claim 1, wherein the assembly comprises a robotic instrument driver configured to maneuver an elongate medical instrument movably coupled to the second member.
5. A positionable medical instrument assembly, comprising:
- a plurality of positionable members, including a first member coupled to a second member by a first movable joint, and a third member coupled to the second member by a second movable joint; and
- one or more Bragg sensor optical fibers, each coupled to at least two of the first, second and third members such that relative movement of the first and second members about the first movable joint causes a corresponding bending of at least one Bragg sensor optical fiber, and a relative movement of the second and third members about the second movable joint causes a corresponding bending of a same or different at least one Bragg sensor optical fiber, each of the one or more Bragg sensor optical fibers having a proximal end operatively coupled to a controller configured to receive signals therefrom indicative of a bending of one or more portions thereof, the controller configured to analyze the signals to determine a relative position of the first, second and third members about the respective first and second movable joints.
6. The instrument assembly of claim 5, wherein the first movable joint allows for movement of the second member relative to the first member in at least three degrees of freedom, and wherein the second movable joint allows for movement of the third member relative to the second member in at least three degrees of freedom.
7. The instrument assembly of claim 6, the one or more Bragg sensor optical fibers including a first Bragg sensor optical fiber coupled to the first, second and third members, such that relative movement of the first and second members about the first movable joint, and relative movement of the second and third members about the second movable joint causes a bending of at least first and second respective portions of the first Bragg sensor optical fiber, and wherein the controller is configured to analyze signals received from the first Bragg sensor optical fiber to determine a relative position of the first, second and third members about the respective first and second movable joints.
8. The instrument assembly of claim 6, the one or more Bragg sensor optical fibers including
- a first Bragg sensor optical fiber coupled to the first and second members, such that relative movement of the first and second members about the first movable joint causes a bending of at least a portion of the first Bragg sensor optical fiber, and
- a second Bragg sensor optical fiber coupled to the second and third members, such that relative movement of the second and third members about the second movable joint causes a bending of at least a portion of the second Bragg sensor optical fiber,
- wherein the controller is configured to analyze respective signals received from the first and second Bragg sensor optical fibers to determine a relative position of the first, second and third members about the respective first and second movable joints.
9. The instrument assembly of claim 5, further comprising an elongate medical instrument movably coupled to the second member.
10. A positionable medical instrument assembly, comprising:
- a first member;
- a second member coupled to the first member by a movable joint; and
- a plurality of Bragg sensor optical fibers coupled to the first and second members, such that relative movement of the first and second members about the movable joint causes a bending of at least a portion of each of the Bragg sensor optical fibers,
- the Bragg sensor optical fibers having respective proximal ends operatively coupled to a controller configured to receive signals from respective Bragg gratings located on the Bragg sensor optical fibers and indicative of a respective bending thereof, the controller configured to analyze the signals to determine a relative position of the first and second members about the movable joint.
11. The instrument assembly of claim 10, wherein the movable joint allows for pivotal motion of the second member relative to the first member in a single plane, and wherein the determined relative position of the first and second members about the movable joint comprises an angular displacement of the second member relative to the first member.
12. The instrument assembly of claim 10, wherein the movable joint allows for movement of the second member relative to the first member in at least three degrees of freedom.
13. The instrument assembly of claim 10, wherein the assembly comprises a robotic instrument driver configured to maneuver an elongate medical instrument movably coupled to the second member.
14. A medical instrument system, comprising:
- an instrument driver;
- a sterile barrier;
- an elongate flexible instrument body operatively coupled to the instrument driver through the sterile barrier;
- a Bragg sensor optical fiber coupled to the elongate instrument body, such that relative bending of the instrument body causes a corresponding bending of at least a portion of the Bragg sensor optical fiber, the Bragg sensor optical fiber having a proximal end operatively coupled to a position sensor controller located on a sterile field side of the sterile barrier and configured to receive signals from respective Bragg gratings located on at least one fiber core of the Bragg sensor optical fiber and indicative of a bending thereof, the sensor controller configured to analyze the signals to determine a relative position of the instrument.
15. The medical instrument system of claim 14, wherein the position sensor controller transmits wireless signals to an instrument driver controller located outside the sterile field to communicate to the instrument driver a relative position of the instrument.
Type: Application
Filed: Feb 1, 2008
Publication Date: Sep 11, 2008
Applicant: Hansen Medical, Inc. (Mountain View, CA)
Inventors: Frederic H. Moll (San Francisco, CA), Randall L. Schlesinger (San Mateo, CA)
Application Number: 12/012,795
International Classification: G01B 11/14 (20060101);