WO2008054423A1

WO2008054423A1 - Magnetically controllable elongate device, systems and methods

Info

Publication number: WO2008054423A1
Application number: PCT/US2006/060395
Authority: WO
Inventors: Charles D. Melville
Original assignee: University Of Washington
Priority date: 2006-10-31
Filing date: 2006-10-31
Publication date: 2008-05-08

Abstract

The present invention provides improved systems, methods and devices having a flexible elongate body with magnetic elements distributed along a proximal portion to help magnetically control positioning or movement of a proximal portion of the device within a patient's body lumen. A device includes a flexible elongate body having a flexible distal portion and a proximal portion, and one or more magnetic elements distributed along the proximal portion that generate, in response to an applied magnetic field, a force or torque along the proximal portion sufficient to help control positioning or movement of the proximal portion within the patient's body lumen.

Description

MAGNETICALLY CONTROLLABLE ELONGATE DEVICE, SYSTEMS

AND METHODS

BACKGROUND OF THE INVENTION

[000 IJ The present invention relates generally to for insertion and navigation of devices through a body lumen of a patient. More particularly, the present invention provides improved systems, methods and devices having a flexible elongate body with magnetic elements distributed thereon to help magnetically control positioning or movement of the device within a patient's body lumen.

[0002] Small sized sensors and end effectors that are developed for use in medical applications often need to be positioned and moved in three dimensions, including navigation through tortuous spaces and lumens of a patient's body including, for example, a vasculature, esophageal, bronchial, gastrointestinal passageways, and the like. Since many body lumens or passageways are small, there are increasing efforts to develop smaller and more appropriately sized devices, as well as methods for positioning and translation through a body lumen.

[0003] An improved scanning beam system has been under development at the University of Washington to more fully meet the needs for micro-optical image acquisition systems. This improved scanning beam system is typically much smaller than conventional devices, and makes use of a cantilevered optical fiber that can be scanned in one or two dimensions. Light is projected out of the end of the optical fiber, through a lens system, and onto a target area of a surface. To acquire an image, a time series of backscattered reflected light is captured with one or more light detector(s) of the system. More specifically, signals from one or more photodetector(s) correspond to the brightness of the small portion of the image illuminated by the fiber at that point in time. As the motion of the optical fiber is predictable and repeatable, the reflected backscattered light intensity measured at the detector(s) can be sequentially correlated with known positions of the optical fiber. This allows a two- dimensional image to be generated one pixel at a time. Some exemplary scanning fiber devices are described in U.S. Patent Nos. 6,294,775Bl (Seibel) and 6,563,105B2 (Seibel), and in U.S. Patent Application Publication Nos. 2001/0055462A1 (Seibel) and 2002/006434 IAl (Seibel), the complete disclosures of which are incorporated herein by reference.

[0004] At present, larger devices, such as larger endoscopes, are typically manipulated and advanced through a patient's body lumen by pushing and twisting on a part of the endoscope that is external, or proximal, to the end or portion of the endoscope inserted into the patient's body lumen. Body lumens often include a tortuous and convoluted path, and considerable manipulation of the endoscope is often necessary to advance the endoscope through the patient's body lumen, making the procedure more difficult and time consuming and adding to the potential for complications and damage to the interior walls of the lumen. Mechanically steerable devices have been devised to facilitate navigation through passageways including, for example, internal wires running the length of the device that are used to bend the distal end to "point" in the desired direction. Such components, however, add to the overall size and complexity of the devices and are difficult to navigate through certain passageways, including those of greater length. [0005] Furthermore, conventional methods and techniques of advancing larger devices through a passageway are marginal at best when applied to smaller devices (e.g., scanning beam devices) and, in some cases, ineffective. For example, smaller devices, such as scanning beam devices, have a high aspect ratio making it difficult, if not impossible, to advance or position the device though a passageway and to a desired location by the conventional means primarily including application of mechanical compression or tension force to the proximal end of the device. Even once a smaller device is successfully positioned in a passageway, withdrawal of the device can be equally or more problematic due, for example, to the combination of friction and high aspect ratio which can cause damage and/or slicing through the lumen tissue as the device is removed. [0006] Therefore, what is needed are devices that able to be more easily and effectively positioned and/or navigated through convoluted or tortuous passageways of a patient's body lumen.

BRIEF SUMMARY OF THE INVENTION [0007] In one aspect, the present invention provides a device for insertion and navigation through a patient's body lumen. The device includes a flexible elongate body having a flexible distal portion and a proximal portion, and one or more magnetic elements distributed along the proximal portion that generate, in response to an applied magnetic field, a force or torque along the proximal portion sufficient to help control positioning or movement of the proximal portion within the patient's body lumen.

[0008] The one or more magnetic elements can be distributed along a portion of the device proximal to the distal end of the device. Both the orientation of the magnetic elements and the pattern of distribution along the portion or shaft can vary, for example, based on the intended use of the device. The magnetic elements can be densely or more sparsely distributed over a relatively short segment of the device or can be populated over a longer portion including, for example, up to the entire length of the proximal portion of the device. Magnetic elements can be distributed axially along the length of the device or, for example, distributed laterally along the length. Additionally, various compositions and configurations of magnetic materials will be suitable for use according to the present invention and magnetic elements can include, for example, various permanent and non-permanent magnet compositions, ferromagnetic materials, electromagnets (e.g., electromagnetic coils, solenoids, etc.), and the like.

[0009] As magnetic elements are distributed along a portion of the device, application of the magnetic field can be used to generate a force or torque along the flexible elongate body having magnetic elements distributed thereon (e.g., proximal portion) and, thereby, control positioning and/or movement of the device, particularly the proximal portion of the device. The device can be advanced or moved through a lumen by application of a mechanical compression or tension force to the proximal end of the device and/or by application of a magnetic field to the magnetic elements of the device so as to generate a force that magnetically advances or pulls the device in the desired direction. As will be recognized, the force or torque along the flexible elongate body, and therefore the positioning and/or movement of the device, will be at least partially dependent on the nature (e.g., strength, magnitude, direction, etc.) of the selected applied magnetic field. Thus, the positioning/movement of the device can at least partially be controlled via selection of the applied magnetic field. In embodiments where the magnetic elements distributed along the proximal portion comprise an electromagnetic coil, selective energization of electromagnetic coils adds an addition means for effecting the positioning or movement of the device. For example, the electromagnetic coil can be selectively energized as to effect the interaction between the electromagnetic coil and the applied magnetic filed, thereby effecting positioning or movement of the proximal portion of the device. [0010] In another aspect of the present invention, a system for navigating a device of the invention in a patient's body lumen is provided. The system includes a processor, a magnetic field generator assembly coupled to the processor, for generating, with the one or more magnetic elements, a torque or force along the proximal portion of the device within a patient's body lumen; and a data storage device coupled to the processor and storing instructions operable to cause the processor to apply the torque or force to control positioning or movement of the device within the patient's body lumen.

[0011] Systems and methods of the invention can include a tracking means or system that allows visualization and/or identification of the location of at least a portion of the device within a patient's body lumen. The system can include identification of device location at a given time as well as movement and location history that will allow tracking of device movement and progression through a lumen. Various known means for tracking the location of a device in a patient's body are known in the art, including markers (e.g., radiopaque markers), contrast media, transmitting units and the like, and can be included in the systems and methods of the present invention. For example, the tracking system can include a positioning unit or plurality thereof that communicates, for example to a remote receiver, a signal comprising information about the location of the device. A positioning unit can be located, for example, in the distal portion or at the distal end of the elongate body or elsewhere on the device. In one embodiment of the present invention, a positioning unit can include a detector coil that receives an electrical or magnetic fields (e.g., pulsed magnetic field). A detector coil can be mounted, for example, on the elongate device, such as at the distal portion, and signal relayed to a remote receiver for device location and tracking. Various other known tracking means will be suitable for use in the systems and methods of the present invention. [0012] In another aspect, the present invention provides a method of positioning or moving a device in a body lumen of a patient. The method includes introducing a device into a body lumen of a patient, for example, through a natural orifice or through an incision. The device typically includes a flexible elongate body having a distal portion, a proximal portion, and a magnetic element or plurality of magnetic elements distributed along the proximal portion. The method further includes advancing the device along a path through the patient's body lumen while flexing the distal portion, and applying a magnetic field to the magnetic element sufficient to generate a force or torque along the proximal portion and to help control positioning or movement of the advancing device. [0013] Thus, in one embodiment of the present invention, application of the magnetic field allows the positioning and shape of the device while in a body lumen of a patient, including where the device is statically positioned in the body lumen or as the device is advanced through the lumen (or withdrawn). For example, the magnetic field can be applied to the device such that a length of the elongate body (e.g., proximal portion) assumes a desired or selected shape that is determined or controlled by the applied magnetic field. Typically, the selected shape will conform to or approximate a shape of a portion of the patient's body lumen, and can include the approximate path of the distal portion as advanced through the patient's body lumen. The selected shape of the device and/or shape of a portion of the patient's body lumen can be determined in a variety of methods, including by use of known medical imaging technologies and techniques, as well as by tracking the path of the distal portion as the device is advanced through the patient's body lumen. As the device translates through the patient's body lumen, the selected shape is propagated along the length of the device. For example, the selected shape propagates proximally along the proximate portion as the device is advanced through the lumen, and the selected shape propagates distally along the proximate portion as the device is retracted or withdrawn from the lumen. Such translation of the device creates a serpentine motion along the elongate body as the device is advanced, and allows navigation and negotiation of tortuous or curving paths of a patient's body lumen while reducing undesired contact and/or friction between the device the lumen walls.

[0014] As set forth above, methods of the present invention include flexing of the distal portion of the elongate body while advancing the device along a path through the patient's body lumen. In one embodiment, flexing of the distal portion of the device can be passive or primarily incident to movement of the device through the lumen. For example, flexing of the distal portion can be at least partially due to contact between the distal portion (distal end) and a wall of the lumen as the device is advanced and maneuvered through the lumen. Since the distal portion is flexible, it will bend or flex when the distal end of the device is pushed against a surface, such as an interior wall of a lumen. Additionally or alternatively, the distal portion of the device can be controllable or selectively steerable, and devised to facilitate direction and/or orientation of the distal portion of the device and selection of the desired path through the lumen along which the device is advanced. In one embodiment, the distal portion includes a magnetic element for facilitating the positioning and/or movement of the distal portion of the device. In such an embodiment, the distal portion of the device including one or more magnetic elements can be controlled by applying a magnetic field sufficient to control positioning or movement of the distal portion of the device having the magnetic elements, similar to the controlling of the proximal portion of the device discussed above. Thus, in addition to controlling the positioning or movement of the proximal portion of the device, the distal portion can be flexed by application of a magnetic field to point or steer the distal end of the device as the device is advanced along a path through the patient's body lumen.

[0015] In certain embodiments of the present invention, it may be desirable to reduce friction between the device and a body lumen of the patient including, for example, generating vibrational motion or movement along a portion of the device so as to reduce static friction. Devices having a long shaft or elongate body can have difficulties moving in and around objects, such as through a patient's lumen and around the various twists, turns, bends, etc. of the lumen, which can be at least partially due, for example, to device stiffness and/or friction between the device and portions (e.g. walls) of the lumen. Friction can include, for example, static friction and/or kinetic friction. Kinetic friction is the friction of one object sliding along or past another object. This kinetic friction requires more work to be performed by the mechanism moving the device compared to the absence of friction forces. Static friction typically exists between two objects at rest. Static friction is usually higher than kinetic friction between two objects. As such, typically once static friction is overcome with a force, the device slides along with less force requirements.

[0016] One way to overcome static friction between objects (e.g. device and lumen wall) is to vibrate an object or oscillate an applied force or torque. In another aspect a method of the present invention includes introducing a device in a body lumen of a patient, the device comprising a flexible elongate body having a distal portion, a proximal portion, and a plurality of magnetic elements distributed along the proximal portion; applying a magnetic field to the plurality of magnetic elements of the device so as to generate a force or torque along the proximal portion; and advancing the device within the patient's body lumen. The method further includes periodically oscillating the force or torque so as to reduce friction between the body lumen and the advancing device. [0017] Thus, in one embodiment, reduction of friction between the device and the body lumen of the patient can be accomplished by periodically oscillating the force or torque generated by application of a magnetic field to the plurality of magnetic elements of a device of the invention. In one embodiment, periodically oscillating the force or torque includes oscillating the applied magnetic field. Where the applied magnetic filed is at least partially generated by an electromagnet, oscillating the applied magnetic field can include oscillating the current applied to an electromagnet generating the magnetic field, for example, by applying an alternating current to the electromagnet or by pulsing a current (e.g., direct current) applied to the electromagnet. In another embodiment, periodically oscillating the force or torque includes oscillating a current applied to one or more electromagnetic elements distributed along the proximal portion. Similar to above, oscillating the current applied to an electromagnetic element on the device can include applying an alternating current or pulsing a current (e.g., direct current) applied to the electromagnetic element. Thus, systems and methods of the present invention can include an oscillation control system for generating vibrational movement and/or reducing friction along the length of the device, including the proximal portion of the flexible elongate body.

[0018] For a fuller understanding of the nature and advantages of the present invention, reference should be made to the ensuing detailed description and accompanying drawings. Other aspects, objects and advantages of the invention will be apparent from the drawings and detailed description that follows.

BRIEF DESCRIPTION OF THE DRAWINGS [0019J FIG. 1 shows a device according to an embodiment of the present invention.

[0020] FIG. 2 illustrates a system according to an embodiment of the present invention.

[0021] FIGS. 3A and 3B show a conceptual illustration of application of a magnetic field to a magnetic element, according to an embodiment of the present invention.

[0022] FIG. 4 shows a magnetic field generator assembly according on an exemplary embodiment of the present invention.

[0023] FIG. 5 illustrates a device with electromagnetic elements and driver chips according to an embodiment of the present invention.

[0024] FIG. 6 shows a device of the invention positioned in a patient's body lumen, according to an embodiment of the present invention. [0025] FIG. 7 is a block diagram of a simplified method encompassed by the present invention.

[0026] FIG. 8 is a block diagram of a simplified method encompassed by the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0027] FIG. 1 illustrates a device according to an embodiment of the invention. The device 10 includes a flexible elongate body 12 having a distal portion 14 and a proximal portion 16, and one or more magnetic elements 18 distributed along the proximal portion 16. The distal portion 14 includes a length of the elongate body 12 or shaft of the device 10 that extends distally beyond the magnetic element 18. The proximal portion 16 refers to a portion of the elongate body 12 including the one or more magnetic element 18 and is proximate to the distal portion 14 of the device 10. The proximal portion 16 can include any portion of the elongate body 12 proximal to the distal end of the device 10. The distal portion 14 can vary in length and will depend at least partially upon the placement of magnetic elements 18 along the proximal portion 16 and the desired use of the device 10. As illustrated, the distal portion 14 is flexible and will be capable of bending or flexing in numerous directions and at various angles consistent with the desired use of the device 10 and navigation through tortuous paths of a patient's body lumen. Similarly, the body 12 of the device 10, including the proximal portion 16, is highly flexible so that it is able to be advanced through tortuous paths and curves without bending, kinking, or otherwise compromising the structural integrity and/or functionality of the device 10. The device further includes a proximal end 20 including a handle or hub 22 that can be optionally coupled with other components or systems.

[0028] A device according to the present invention may take on a variety of forms, but are typically in the form of a flexible endoscope, catheter, fiberscope, surgical tool and instrument, microscope, horoscope, and the like. The devices of the present invention can be a limited use device (e.g., disposable device) or a multiple-use device. ^"Where appropriate for certain medical uses, the device of the present invention will generally be sterile, either being sterilizable or provided in heretically sealed package for use. [0029] In one embodiment, the device includes a scanning beam device, such as a scanning beam endoscope. The scanning beam systems suitable for use in the present invention will often include a scanning beam device or probe and a base station for controlling the scanning beam device. The scanning beam devices or probes will often include a scanner for spatially scanning a beam of light over a target area of a target surface. The scanner preferably comprises a single, cantilevered optical fiber. While these scanning beam systems and scanning fiber systems generally encompass systems used for image acquisition, alternative embodiments may be used at least in part (or even primarily) for image display. Scanning beam and scanning fiber display systems may, for example, selectively project illuminating light from the end of the scanning fiber so as to generate an image on the target surface. The scanning element of the device typically comprises a single, cantilevered optical fiber, but alternate beam scanning mechanisms may also be employed. For example, mirror beam scanning systems and/or micro electro-mechanical systems (MEMS) beam scanning mechanisms may be suitable for effecting the scanning of the beam in some embodiments. A more complete description of suitable scanning beam systems and devices may be found in the following commonly owned U.S. patents and patent applications: U.S. Patent Application Serial No. 10/956,241, entitled "Remapping Methods to Reduce Distortions in Images," filed October 1 , 2004, U.S. Patent Application Serial No. 10/956,473, entitled "Configuration

Memory for a Scanning Beam Device," filed October 1, 2004, U.S. Patent Application Serial No. 11/021,981, entitled "Methods of Driving a Scanning Beam Device to Achieve High Frame Rates," filed on December 23, 2004, U.S. Patent Application Serial No. 11/021,981 , entitled "Methods of Driving a Scanning Beam Device to Achieve High Frame Rates, filed on December 23 , 2004, and U.S. Patent Application Serial No. 11/065,224, entitled

"Scanning Beam Device with Detector Assembly," filed on February 23, 2005, the complete disclosures of which are incorporated herein by reference., the complete disclosures of which are incorporated herein by reference.

[0030] FIG. 2 shows a system 30 including an elongate device 10 for insertion and navigation through a patient's body lumen according to an embodiment of the present invention. As in the embodiment of FIG. 1, the device 10 includes a flexible elongate body 12 having a distal portion 14 and a proximal portion 16. One or more magnetic elements 18 are distributed along the proximal portion 16 of the device 10. The system 30 further includes a magnetic field generator 32 that is capable of generating a magnetic field 34 of selected direction and strength to control movement and/or positioning of the device 10, for example, within a body lumen of a patient. The system 30 includes a control unit 36 for controlling and/or coordination various components of the system 30, including the magnetic field generator 32. The system may optionally include a tracking system to provide visualization and/or identification of the location of at least a portion of the device 10, e.g., as positioned within a patient's body lumen. In the illustrated embodiment, the tracking system can include a positioning unit 38 and a receiver 40. In one embodiment, a system 30 of the invention can further include an oscillation control system 42 for generating vibrational movement and/or reducing friction along the length of the device 10, including the proximal portion 16 of the flexible elongate body 12. The oscillation control system 42 may be coupled or integrated with the control unit 36, as illustrated in FIG. 2, or can include an another arrangement, such as integration with the device or component thereof.

[0031] As magnetic elements are distributed along a portion of the device (e.g., proximal portion), application of the magnetic field can be used to generate a force or torque along the flexible elongate body and control positioning or movement of the device. An applied magnetic field will be generated by a magnetic field generator, typically including one or more pairs of electromagnetic coils. Certain interactions between a magnetic element and an applied magnetic filed generated by electromagnetic coils are described generally with reference to FIGS. 3 A and 3B.

[0032] FIG. 3A shows an opposite coil pair and illustrative magnetic flux lines. The magnetic fluxes generated when the two coils are equally energized combine to form a relatively uniform magnetic field inside the coils. The north ("N") and south ("S") magnetic poles of a permanent magnet are shown for illustrative purposes, though it will be recognized that the foregoing description can include electromagnetic elements having a magnetic field. When a magnetic element (e.g., magnetic element of a device) is introduced into this uniform magnetic field, a force is generated and the magnetic element will align according to the poles (e.g., or magnetic field of an electromagnetic element) and those of the field of the magnetic coils. A magnetic gradient may be selected by applying a larger electric current to one coil compared to the other. Applying a gradient to a magnetic element will generate a force on the magnetic element directed toward the coil with the higher current and the larger magnetic field.

[0033] FIG. 3B shows two coils arranged in a 90 degree configuration, and one illustrative magnetic flux line. The magnetic flux line, in the region of interest is now rotated about 45 degrees compared to the arrangement illustrated in FIG. 3 A. An orientation of a magnetic element in the magnetic field is shown. Orientation of the magnetic element can be reversed, for example, by reversing the direction of the current. Coils of the assembly or those energized are not limited to any particular number. As will be recognized, by selectively energizing coils of the assembly, the positioning, orientation, and/or movement of a magnetic element, and thus the proximal portion of the device, can be controlled. Where the magnetic element is an electromagnetic element, selective energization of the electromagnetic coils can add an additional control parameter. .

[0034] Thus, an external magnetic field generator is capable of generating a magnetic field of selected magnitude, strength, and/or direction so as to control positioning or movement of a device of the invention within the patient's body lumen according to the methods of the present invention. Assemblies typically, but not necessarily, include one or more pairs of electromagnetic coils that are selectively energized to control positioning and/or movement of a magnetic element and, therefore, a device on which the element is positioned. Magnetic coils may be stationary or may move or rotate with respect to the patient.

[0035] Referring to FIG. 4, an exemplary magnetic field generator assembly 50 of six magnetic coils 52 is provided. The assembly 50 includes independently addressable electromagnetic coils 52 configured for positioning the assembly 50 external to the patient's body, and a patient 54 can be introduced to an area 56 within the assembly 50. The assembly 50 includes three pairs of coils 52, with each pair including a first coil positioned oppositely to a second coil, and the coils 52 can be selectively energized, typically in pairs. It will be recognized that a magnetic field generator assembly of the invention is not limited to any particular arrangement or configuration, including those illustrated.

[0036] Parameters of the applied magnetic field produced by the magnetic field generator can be controlled, for example, by controlling the currents applied to electromagnetic coils comprising the system. Thus, the system 30 further includes a control unit 36, as illustrated in FIG. 2, for controlling and/or coordinating operation and interaction between components of the system 30 of the invention including, for example, the device 10 and the magnetic field generator 32. The system control unit 36 can include, for example, a computer, a graphical interface (not shown), and one or more input devices (not shown), which can be coupled with the control unit 36 and/or device 10, to allow a user (e.g., physician, technician, etc.) to operate one or more components of the system 30. The control unit 36 can include, for example, a wide variety of proprietary or commercially available computers or systems having one or more processing structures, a personal computer, mainframe, or the like, with such systems often comprising data processing hardware and/or software configured to implement any one (or combination of) the method steps described herein, including, for example, controlling positioning and movement, as well as reducing friction in a device in a body lumen of a patient. Any software will typically comprise machine readable code of programming instructions and/or algorithms to control a system of the present invention which provides appropriate magnetic field parameters (e.g., strength, magnitude, direction, etc.) and interaction with a device of the invention to achieve a selected torque or force to control positioning or movement of the device within the patient's body lumen. Such instructions can be embodied in a tangible media such as memory, a digital or optical recording media, optical, electrical, or wireless telemetry signals, of the like, and any one or more of these structures may also be used to transmit data and information between components of the system in any of a wide variety of distributed or centralized signal processing architectures.

[0037] Various known or proprietary systems, including magnetic field generator assemblies and associated control apparatus (e.g., control unit), for magnetically controlling/navigating magnetic elements in a patient can be included in systems and methods of the present invention. For example, magnetic navigation systems are currently commercially available from Stereotaxis, Inc., St. Louis, MO (see, e.g., the world wide web, at the url "stereotaxis.com")- A more complete description of magnetic navigation systems, magnetic field generators and assemblies, and associated control apparatus may be found, for example, in the following U.S. Patents and Patent publications: U.S. Patent No. 6,902,528;

U.S. Patent No. 6,015,414; U.S. Patent No. 6,630,879; U.S. Patent No. 6,786,219; U.S. Patent No. 6,834,201; U.S. Patent No. 6,817,364; U.S. Patent No. 6,241,671; U.S. Patent No. 5,125,888, each of which is incorporated herein by reference.

[0038] As illustrated in FIG. 2, according to one embodiment, a system of the present invention can further include an oscillation control system 42. An oscillation control system 42 may coordinate with other components of the system 30 and will be capable of periodically oscillating the force or torque generated by application of a magnetic field to the magnetic elements 18 of the device 10 of the invention so as to produce vibrational movement and/or reducing friction along the length of the device 10, including the proximal portion 16 of the flexible elongate body 12. Periodically oscillating the force or torque can include oscillating the applied magnetic field 34. In certain embodiments where the applied magnetic filed is at least partially generated by an electromagnet, oscillating the applied magnetic field can include oscillating the current applied to an electromagnet generating the magnetic field, for example, by applying an alternating current to the electromagnet or by pulsing a current (e.g., direct current) applied to the electromagnet. Periodically oscillating the force or torque can further or alternatively include oscillating a current applied to one or more electromagnetic elements distributed along the proximal portion. Similar to above, oscillating the current applied to an electromagnetic element on the device can include applying an alternating current or pulsing a current (e.g., direct current) applied to the electromagnetic element. The oscillation control system 42 can include, for example, software or programming instructions on a computer readable medium that may integrated with a component of the system (e.g., device, control unit, etc.) or separate from the device (e.g., CD, DVD, floppy disk, etc.), and can be used in combination with electronic hardware and/or one or more software programs of the system.

[0039] A system of the invention will typically include a tracking system that allows visualization and/or identification of the location of at least a portion of the device within a patient's body lumen. The system can include identification of device location at a given time as well as movement and location history that will allow tracking of device movement and progression through a lumen. Various known means for tracking the location of a device in a patient's body are known in the art, including markers (e.g., radiopaque markers), contrast media, transmitting units and the like, and can be included in the systems and methods of the present invention. For example, the tracking system can include a positioning unit or plurality thereof that communicates, for example to a remote receiver, a signal comprising information about the location of the device. As illustrated in FIG. 2^ a positioning unit 3 S can be located, for example, in the distal portion 14 or at the distal end of the elongate body 12 or elsewhere on the device 10. In one embodiment of the present invention, a positioning unit 38 can include a detector coil mat receives an electrical or magnetic fields (e.g., pulsed magnetic field). A detector coil can be mounted, for example, on the elongate device 10, such as at the distal portion 14, and signal relayed to a remote receiver 40 for device location and tracking. Various other known tracking means will be suitable for use in the systems and methods of the present invention. The information generated by the tracking system can provide feedback to a system or method of the invention and effect subsequent steps or further actions. For example, the magnitude or direction of the applied magnetic field may be modified as to achieve movement of the device from an actual position to a desired position, for example, for advancement of the device or positioning in a patient's body lumen. [0040] As illustrated in FIG. 1 and FIG.2, the one or more magnetic elements 18 can be distributed along a portion of the device proximal to the distal end of the device 10. Both the orientation of the magnetic elements 18 and the pattern of distribution along the portion or shaft can vary, for example, based on the intended use of the device 10. The magnetic elements 18 can be densely or more sparsely distributed over a relatively short segment of the device 10 or can be populated over a longer portion including, for example up to the entire length of the proximal portion 16 of the device 10. Magnetic elements 18 can be distributed axially along the length of the device 10 or, for example, distributed laterally along the length. Additionally, various compositions and configurations of magnetic materials will be suitable for use according to the present invention and magnetic elements can include, for example ferromagnetic materials, electromagnetic coils, solenoids, and the like.

[0041] Referring now to FIG. 5, distribution of magnetic elements along a shaft or proximal portion of a device according to one embodiment of the invention is illustrated. The device includes an electromagnetic coil 60 axially positioned or distributed along the shaft and electromagnetic coils 62 positioned laterally along the device. The coils 60, 62 are shown as helically patterned coils for illustrative purposes, but can include any configuration suitable for use according to the present invention. It will be understood that direction and strength of the magnetic field generated by an electromagnetic coil can be selected, for example, by the positioning of the coil and application of current (e.g., direction of current through coils), and the amount of current applied, respectively. For example, energizing an axially distributed coil will generate a magnetic field that is generally parallel to the longitudinal axis of the device shaft, while energizing a laterally distributed coil will generate a magnetic field generally perpendicular to the longitudinal axis. The coils 60, 62 can be disposed on a substrate 64 that is typically flexible and includes circuitry, electrical components, etc. coupled with the coils 60, 62 for applying current (e.g., alternating current, direct current, etc.) to the coils 60, 62. The coils 60, 62 can include, for example, a conductive material printed or otherwise deposited on the substrate 64. The device can further include coil drivers 66 or microchips. The drivers 66 can include components (e.g., microprocessor, storage media, etc.) for controlling the activating or selective energizing of the coils 60, 62. The drivers 66 and/or coils 60, 62 distributed along the elongate body can be operably coupled with a control unit 36 as shown in the embodiment of FIG. 2 for selectively energizing the coils 60, 62 and/or coordinating the energizing with other components of the system 30 (e.g., magnetic field generator). In one embodiment, an oscillation control system may be integral to one or more drivers 66 of the device.

[0042] Use of a device and system according to the present invention is described referring to FIG. 6. As in the embodiment of FIGS. 1 and 2, the device 10 includes a flexible elongate body 12 with a distal portion 14 and a proximal portion 16, and a plurality of magnetic elements 18 distributed along the proximal portion 16. The device 10 can introduced into a body lumen 70 of a patient, through a natural orifice or through an incision and advanced along a path through the patient's body lumen 70 and a magnetic field 72 is applied. The device 10 can be advanced or moved through the lumen 70 by application of a mechanical compression or tension force to the proximal end of the device and/or by application of a magnetic field 72 to the magnetic elements 18 of the device 10 so as to generate a force that magnetically pulls the device 10 in the desired direction. Application of the magnetic field 72 can be used to generate a force or torque along the flexible elongate body 12 having magnetic elements 18 distributed thereon (e.g., proximal portion). [0043] In one embodiment, the force/torque generated by the applied magnetic field 72 may be used to control the position the device 10 in the lumen 70, either as the device 10 is held statically within the lumen 70 or for negotiating the paths of the lumen 70 as the device 10 is advanced therethrough. The magnetic field 72 is applied to the device 10 in the lumen 70 so that at least a portion of the device 10, such as the proximal portion 16, assumes a selected shape that is controlled or determined by the interaction between the magnetic elements 18 and the applied magnetic field 72. The selected shape will typically approximate the shape of a portion of a path through the lumen 70. The selected shape can be maintained as the device 10 translates through the patient's body lumen 70. For example, as the device 10 is advanced through the lumen 70 while applying the magnetic field 72, the selected shape propagates proximally along the flexible elongate body 12. Likewise, as the device 10 is retracted or withdrawn from the lumen 70, the selected shape propagates distally along the flexible elongate body 12. As illustrated, the distal portion 14 can be flexed as the device 10 is positioned or advanced in the lumen 70. The distal portion 14 can optionally include one or more magnetic elements 76 so that the distal portion 14 is magnetically controllable or steerable. In such an embodiment, the distal portion 14 of the device 10 including one or more magnetic elements 76 is controlled by applying a magnetic field 72 sufficient to control positioning or movement of the distal portion 14, similar to the controlling of the proximal portion 16 of the device as described herein. The force or torque generated by application of a magnetic field 72 to the magnetic element so the device 10 can be periodically oscillated, as discussed above, so as to reduce friction between the device 10 and the lumen 70.

[0044] FIG. 7 and FIG. 8 schematically illustrate methods encompassed by the present invention. As shown in. FIG. 7, a device of the invention is introduced into the body lumen of a patient (Step 80). The method includes advancing the device along a path through the patient's body lumen while flexing the distal portion of the device (Step 82). A magnetic field is applied externally with respect to the patient (Step 84). The magnetic field is applied to the magnetic element of the device and will be sufficient to generate a force or torque along the proximal portion of the device and help control positioning or movement of the proximal portion of the advancing device. The method can optionally include detecting a position of the device or generating information about the position and/or location of the device within the patient (Step 86). The information about the position/location of the device can be generated at any one or more step (e.g., each step). The information generated regarding the device position/location at any step can provide feedback to a system or method of the invention and effect subsequent actions or steps. For example, the magnitude or direction of the applied magnetic field may be modified as to achieve movement of the device from an actual position to a desired position.

[0045] As shown in FIG. 8, a method of the invention can include a reduction of friction (e.g., static friction) between a device and the patient's lumen. A device of the invention is introduced into a patient's body lumen (Step 90). Next, a magnetic field is applied to the plurality of magnetic elements of the device so as to generate a force or torque along the proximal portion (Step 92). The device is then advanced within the patient's body lumen (Step 94). Then, the force or torque is periodically oscillated so as to reduce friction between the body lumen and the advancing device (Step 96). The method may include detecting a position of the device, for example, by generating information about the position and/or location of the device within the lumen (Step 98). The information about the position/location of the device can be generated at any one or more step and may provide feedback to a system or method of the invention and effect subsequent actions or steps.

[0046] The present invention can further include a kit. The kit may include a device 10 of the invention as illustrated in FIG. I, instructions for use, and at least one package.

Optionally, the kit may include a computer readable medium that may be integral with the device (such as non-volatile memory) or separate from the device (e.g., CD, DVD, floppy disk, etc.).

[0047] It is understood that the examples and embodiments described herein are for illustrative purposes only and that various modifications or changes in light thereof will be suggested to persons skilled in the art and are to be included within the spirit and purview of this application and the scope of the appended claims. Numerous different combinations are possible, and such combinations are considered to be part of the present invention.

Claims

WHAT IS CLAIMED IS:

1. A method, comprising: introducing a device into a body lumen of a patient, the device comprising a flexible elongate body having a distal portion, a proximal portion, and a magnetic element distributed along the proximal portion; advancing the device along a path through the patient's body lumen while flexing the distal portion; and applying a magnetic field to the magnetic element sufficient to generate a force or torque along the proximal portion and to help control positioning or movement of the proximal portion of the advancing device.

2. The method of 1, wherein a length of the proximal portion of the device assumes a selected shape determined by the applied magnetic field.

3. The method of 2, wherein the selected shape is propagated along the length of the proximal portion as the device is advanced through the patient's body lumen.

4. The method of 2, wherein the selected shape approximates a shape of a portion of the patient's body lumen.

5. The method of 2, wherein the selected shape comprises a path of the distal portion through the patient's body lumen.

6. The method of 1, wherein the magnetic element comprises an electromagnetic coil selectively energized as to effect an interaction between the electromagnetic coil and the applied magnetic field, thereby effecting positioning or movement of the proximal portion of the advancing device.

7. The method of I₅ wherein the distal portion comprises a magnetic element.

8. The method of 7, further comprising applying a magnetic field sufficient to control positioning or movement of the distal portion of the device.

9. The method of 1, further comprising detecting a position of the device within the patient's body lumen.

10. The method of 9, further comprising modifying the magnitude or direction of the applied magnetic field as to achieve movement of the device from an actual position to a desired position.

11. The method of 1 , further comprising periodically oscillating the force or torque so as to reduce friction between the body lumen and the advancing device.

12. The method of 1 , wherein the device comprises a plurality of magnetic elements distributed along the proximal portion.

13. A method, comprising: introducing a device in body lumen of a patient, the device comprising a flexible elongate body having a distal portion, a proximal portion, and a plurality of magnetic elements distributed along the proximal portion; applying a magnetic field to the plurality of magnetic elements of the device so as to generate a force or torque along the proximal portion; advancing the device within the patient's body lumen; and periodically oscillating the force or torque so as to reduce friction between the body lumen and the advancing device.

14. The method of claim 13, wherein the periodically oscillating the force or torque comprises oscillating the applied magnetic field.

15. The method of claim 14, wherein the oscillating the applied magnetic field comprises oscillating a current applied to an electromagnet generating the magnetic field.

16. The method of claim 15, wherein oscillating the current comprises applying an alternating current to the electromagnet.

17. The method of claim 15, wherein oscillating the current comprises pulsing a direct current applied to the electromagnet.

18. The method of claim 13, wherein the periodically oscillating the force or torque comprises oscillating a current applied to an electromagnetic element distributed along the proximal portion.

19. A device for insertion and navigation through a patient's body lumen, comprising: a flexible elongate body having a flexible distal portion and a proximal portion; and one or more magnetic elements distributed along the proximal portion that generate, in response to an applied magnetic field, a force or torque along the proximal portion sufficient to help control positioning or movement of the proximal portion within the patient's body lumen.

20. The device of 19, wherein magnetic elements are distributed axially or laterally along the length of the proximal portion.

21. The device of 19, wherein at least one of the magnetic elements comprises a ferromagnetic material.

22. The device of 19, wherein at least one of the magnetic elements comprise a electromagnetic element.

23. The device of 22 further comprising an oscillation control system programmed to selectively control activation of the electromagnetic element.

24. The device of 23, wherein the oscillation control system comprises a driver chip positioned on the elongate body and adapted to address and activate a plurality of electromagnetic elements.

25. The device of 19, wherein the distal portion further comprises a magnetic element.

26. The device of 19, further comprising a positioning unit that communicates, to a remote receiver, information about the location of the device.

27. The device of 26, wherein the positioning unit comprises a detector coil that receives an electrical and magnetic field and the location of the device is based on the magnitude of the received signal.

28. The device of 27, wherein the positioning unit is positioned at the distal portion.

29. The device of 19, wherein the device is a scanning beam device.

30. A system for navigating a device in a patient's body lumen, the device comprising a flexible elongate body having a flexible distal portion and a proximal portion with one or more magnetic elements distributed along the proximal portion, the system comprising: a processor; a magnetic field generator assembly coupled to the processor, for generating, with the one or more magnetic elements, a torque or force along the proximal portion of the device within a patient's body lumen; and a data storage device coupled to the processor and storing instructions operable to cause the processor to: apply the torque or force to control positioning or movement of the device within the patient's body lumen.

31. The system of 30, wherein the magnetic field generator assembly comprises a plurality of independently addressable electromagnetic coils configured for positioning the assembly external to the patient's body lumen.

32. The system of 31, wherein applying the torque or force to control positioning or movement of the device comprises selectively energizing electromagnetic coils of the assembly.

33. The system of 30, wherein applying the torque or force to control positioning or movement of the device comprises selectively energizing an electromagnetic element distributed along the length of the device.

34. The system of 33, wherein the data storage device further comprises instructions operable to cause the processor to periodically oscillate the force or torque so as to reduce friction between the body lumen and the device as advanced along a path through the patient's body lumen.

35. The system of 34, wherein the periodically oscillating the force or torque comprises oscillating an applied magnetic field or oscillating a current applied to an electromagnetic element distributed along the device.

36. The system of 35, wherein the device further comprises a magnetic element in the distal portion and the data storage device and instructions operable to cause the processor to apply a torque or force to control positioning or movement of the distal portion of the device.

37. The system of 30, wherein the device further comprises a positioning unit that communicates, to a remote receiver, a signal comprising information about the location of the device.

38. The system of 37, wherein the applying the torque or force to control positioning or movement of the device comprises receiving information about the location of the device and modifying the magnitude or direction of an applied magnetic field as to achieve movement of the device from an actual position to a desired position.