Catheter for manual and remote manipulation

An elongate medical device may overcome be configured both for manual manipulation by a physician and for automatic manipulation by a remote catheter guidance system. Such an elongate medical device comprises a shaft having a proximal portion and a distal portion, a pull wire disposed in the shaft and affixed to the distal portion of the shaft, and a handle coupled with the proximal portion of the catheter shaft. The handle comprises a first mechanism configured for manual actuation of the pull wire so as to deflect the distal portion of the shaft, a second mechanism configured for remote actuation of the pull wire so as to deflect the distal portion of the shaft, and a mechanical interface configured to provide a remote catheter guidance system with a functional connection to the second mechanism.

BACKGROUND OF THE INVENTION

a. Field of the Invention

The instant disclosure relates generally to elongate medical devices for use with a remote catheter guidance system (RCGS), including elongate medical devices suitable for both manual use and automated use with an RCGS.

b. Background Art

It is known to use electrophysiology (EP) catheters for a variety of diagnostic and/or therapeutic medical procedures to correct conditions such as atrial arrhythmia, including for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter. Arrhythmia can create a variety of dangerous conditions including irregular heart rates, loss of synchronous atrioventricular contractions and stasis of blood flow which can lead to a variety of ailments.

In a typical EP procedure, a physician manipulates a catheter through a patient's vasculature to, for example, a patient's heart. The catheter typically carries one or more electrodes that may be used for mapping, ablation, diagnosis, and the like. Once at the target tissue site, the physician commences diagnostic and/or therapeutic procedures, for example, ablative procedures such as radio frequency (RF), microwave, cryogenic, laser, chemical, acoustic/ultrasound or high-intensity focused ultrasound (HIFU) ablation, to name a few different sources of ablation energy. The resulting lesion may disrupt undesirable electrical pathways and thereby limit or prevent stray electrical signals that can lead to arrhythmias. Such procedures can require precise control of the catheter during navigation to and delivery of therapy to the target tissue site.

Robotic catheter systems are known to facilitate precise control. Robotic catheter systems generally carry out (as a mechanical surrogate) input commands of a clinician or other end-user to deploy, navigate and manipulate a catheter and/or an introducer or sheath for a catheter or other elongate medical instrument, for example, a robotic catheter system described, depicted, and/or claimed in U.S. patent application Ser. No. 12/347,811 entitled “ROBOTIC CATHETER SYSTEM,” hereby incorporated by reference in its entirety as though fully set forth herein. Such robotic catheter systems include a variety of actuation mechanisms, such as electric motors, for controlling translation and deflection of the catheter and associated sheath.

A variety of catheter form factors for robotic manipulation and associated robotic actuation mechanisms are known. For example, as described in the above-referenced U.S. patent application Ser. No. 12/347,811, a catheter may be provided in a cartridge specifically designed for use with a robotic system. The robotic system, in turn, may contain a manipulation structure specifically designed for use with the catheter cartridge form factor. However, such a catheter cartridge can be more difficult to guide manually than a traditional manual catheter handle. In another example, such as disclosed in U.S. Patent Application Publication No. 2007/0198008, entitled “ROBOTIC SURGICAL SYSTEM AND METHOD FOR AUTOMATED THERAPY DELIVERY,” hereby incorporated by reference in its entirety, a traditional manual catheter handle may be controlled by a robotic manipulator manipulating the same actuation mechanisms that a physician would manipulate during manual use. Although such a system allows for robotic and manual manipulation of the same catheter form factor, it can require that the robotic manipulator be specifically designed to manipulate the manual catheter steering mechanism. Because different manual catheter handles may have different types, numbers, and placements of steering mechanisms, the use of such a robotic system may be limited by the design of the manipulator mechanism.

There is therefore a need for an improved interface for coupling a catheter to a RCGS while allowing a high degree of manual manipulation of the catheter by a physician.

BRIEF SUMMARY OF THE INVENTION

An elongate medical device may overcome some disadvantages of the prior art by being configured both for manual manipulation by a physician and for automatic manipulation by a remote catheter guidance system. Such an elongate medical device comprises a shaft having a proximal portion and a distal portion, a pull wire disposed in the shaft and affixed to the distal portion of the shaft, and a handle coupled with the proximal portion of the catheter shaft. The handle comprises a first mechanism configured for manual actuation of the pull wire so as to deflect the distal portion of the shaft, a second mechanism configured for remote actuation of the pull wire so as to deflect the distal portion of the shaft, and a mechanical interface configured to provide a remote catheter guidance system with a functional connection to the second mechanism.

The second actuation mechanism—i.e., the mechanism for remote actuation—may take a number of forms in different embodiments. In an embodiment, the second mechanism is hydraulic. An embodiment of the hydraulic mechanism comprises a drive cylinder, a hydraulic fluid line, a drive shaft coupled with the drive cylinder and coupled with the pull wire through an anchor block. The hydraulic fluid line may be coupled at a first end with the drive cylinder and at a second end with the interface and can be configured to provide hydraulic fluid to the drive cylinder. In an embodiment, the first actuation mechanism may also be coupled with the anchor block. The interface may comprise a hydraulic fluid port coupled with the hydraulic fluid line and a valve configured to selectively permit said remote system access to said hydraulic fluid line or to seal said hydraulic fluid line, in an embodiment.

In a further embodiment of the elongate medical device, the medical device may further comprise a force translation mechanism configured to translate force on the second mechanism into actuation of the pull wire. In an embodiment, the second actuation mechanism can comprise a socket. In the same or another embodiment, the force translation mechanism may comprise one or more mechanisms selected from the group consisting of gears, pulleys, wires, cables, and levers.

In an embodiment including a socket as the second actuation mechanism, the pull wire may be a first pull wire configured to deflect the distal portion in a first deflection direction in response to torque on the socket in a first rotational direction, and the medical device may further comprise a second pull wire configured to deflect the distal portion in a second deflection direction opposite the first deflection direction in response to torque on the socket in a second rotational direction opposite the first rotational direction. In a further embodiment, the socket may comprise a first socket and the medical device may further comprise a third pull wire and a second socket coupled to the third pull wire. The third pull wire may be configured to deflect the distal portion in a third deflection direction, for example, substantially orthogonal to the first and second directions in response to torque on the second socket.

The elongate medical device may also include various other features. In an embodiment, the elongate medical device may comprise a sensor configured to determine the position of the pull wire. In the same or another embodiment, the medical device may further comprise an irrigation fluid pathway extending through the shaft and terminating at the mechanical interface.

Another embodiment of an elongate medical device configured for manual use and for remote manipulation may comprise a modular configuration. Such an elongate medical device may comprise a modular cartridge and a handle portion releasably coupled with the modular cartridge. The modular cartridge may comprise a housing, a shaft having a distal portion and a proximal portion, the proximal portion coupled with the housing, a pull wire extending through the shaft and coupled with the distal portion of the shaft, and an interface member movably disposed within the housing, said interface member coupled with said pull wire such that movement of said interface member results in movement of the pull wire. The handle portion can comprise a receiving member releasably coupled with the interface member, and an actuation mechanism configured for manual manipulation, coupled with the receiving member, configured to impart force to the pull wire through the receiving member so as to deflect the distal portion of the shaft.

In an embodiment, the modular cartridge may further comprise a connection interface comprising an irrigation fluid port. In a further embodiment, the modular cartridge connection interface can further comprise at least one electrical connection for electrically coupling the handle portion with a sensor disposed in the shaft. In a still further embodiment, the handle portion may further comprise a handle portion fluid interface and a handle portion electrical interface. In an embodiment, the modular cartridge housing may be substantially round. In an embodiment, the modular cartridge may further comprise a sensor configured to sense the position of said connection member.

Another embodiment of an elongate medical device configured for manual use and for remote manipulation may comprise a shaft having a proximal portion and a distal portion, a pull wire disposed in the shaft and affixed to the distal portion of the shaft, and a handle having a distal end and a proximal end, the distal end coupled with the proximal portion of the catheter shaft. The proximal end of the handle may comprise an interface for coupling with a remote catheter guidance system, the interface comprising at least one electrical connector, a fluid port, a mechanical interlock, and an apparatus for actuating the pull wire so as to deflect the distal portion of the catheter shaft. In an embodiment, the apparatus for actuating the pull wire can comprise one or more of a hydraulic fluid port and a socket.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings wherein like reference numerals are used to identify the same or substantially similar components in the various views,FIG. 1illustrates one exemplary embodiment of a robotic control and guidance system10(RCGS10) for manipulating one or more medical devices. The RCGS10can be used, for example, to manipulate the location and orientation of catheters and sheaths in a heart chamber or in another body cavity or lumen. The RCGS10thus provides the user with a similar type of control provided by a conventional manually-operated system, but allows for repeatable, precise, and dynamic movements. For example, a user such as a physician or electrophysiologist can identify locations (potentially forming a path) on a rendered computer model of the cardiac anatomy. The system can be configured to relate those digitally selected points to positions within a patient's actual/physical anatomy, and can thereafter command and control the movement of the sheath and/or catheter to the defined positions. Once at a specified target position, either the user or the system can perform the desired diagnostic or therapeutic function. The RCGS10can enable full robotic navigation/guidance and control.

As shown inFIG. 1, the RCGS10can generally include one or more monitors or displays12, a visualization, mapping, and/or navigation system14, a human input device and control system (referred to as “input control system”)100, an electronic control system200, a manipulator assembly300for operating one or more device cartridges400, and a manipulator support structure500for positioning the manipulator assembly300in proximity to a patient or a patient's bed.

The displays12can be configured to visually present a user with information regarding patient anatomy, medical device location or the like, originating from a variety of different sources. The displays12can include, for example, (1) a monitor16(coupled to system14—described more fully below) for displaying cardiac chamber geometries or models, displaying activation timing and voltage data to identify arrhythmias, and for facilitating guidance of catheter movement; (2) a fluoroscopy monitor18for displaying a real-time x-ray image or for assisting a physician with catheter movement; (3) an intra-cardiac echo (ICE) display20to provide further imaging; and/or (4) an EP recording system display22.

The visualization, navigation, and/or mapping system14may be configured to provide a number of advanced features, such as visualization, mapping, navigation support and positioning (i.e., determine a position and orientation (P&O) of a sensor-equipped medical device, for example, a P&O of a distal tip portion of a catheter). In an exemplary embodiment, the system14may comprise an impedance-based system, such as, for example, the EnSite NavX™ system commercially available from St. Jude Medical, Inc., and as generally disclosed in U.S. Pat. No. 7,263,397 entitled “Method and Apparatus for Catheter Navigation and Location and Mapping in the Heart,” the entire disclosure of which is incorporated herein by reference. In other exemplary embodiments, however, the system14may comprise other types of systems, such as, for example and without limitation: a magnetic-field based system such as the Carto™ System available from Biosense Webster, and as generally shown with reference to one or more of U.S. Pat. No. 6,498,944 entitled “Intrabody Measurement,” U.S. Pat. No. 6,788,967 entitled “Medical Diagnosis, Treatment and Imaging Systems,” and U.S. Pat. No. 6,690,963 entitled “System and Method for Determining the Location and Orientation of an Invasive Medical Instrument,” the entire disclosures of which are incorporated herein by reference, or the gMPS system from MediGuide Ltd., and as generally shown with reference to one or more of U.S. Pat. No. 6,233,476 entitled “Medical Positioning System,” U.S. Pat. No. 7,197,354 entitled “System for Determining the Position and Orientation of a Catheter,” and U.S. Pat. No. 7,386,339 entitled “Medical Imaging and Navigation System,” the entire disclosures of which are incorporated herein by reference; and a combination impedance-based and magnetic field-based system such as the Carto 3 System also available from Biosense Webster.

As briefly described above, in an exemplary embodiment, the system14involves providing one or more positioning sensors for producing signals indicative of medical device location (position and/or orientation) information. In an embodiment wherein the system14is an impedance-based system, the sensor(s) may comprise one or more electrodes. Alternatively, in an embodiment wherein the system14is a magnetic field-based system, the sensor(s) may comprise one or more magnetic sensors (e.g., coils) configured to detect one or more characteristics of a low-strength magnetic field.

The input control system100may be configured to allow a user, such as an electrophysiologist, to interact with the RCGS10, in order to control the movement and advancement/withdrawal of one or more medical devices, such as, for example, a catheter and/or a sheath (see, e.g., U.S. Patent Publication No. 2010/0256558 entitled “Robotic Catheter System,” and PCT/US2009/038597 entitled “Robotic Catheter System with Dynamic Response,” published as WO 2009/120982, the entire disclosures of which are incorporated herein by reference). Generally, several types of input devices and related controls can be employed, including, without limitation, instrumented traditional catheter/sheath handle controls, oversized catheter/sheath models, instrumented user-wearable gloves, touch screen display monitors, 2-D input devices, 3-D input devices, spatially detected styluses, and traditional joysticks. For a further description of exemplary input apparatus and related controls, see, for example, U.S. Patent Publication Nos. 2011/0015569 entitled “Robotic System Input Device” and 2009/0248042 entitled “Model Catheter Input Device,” the entire disclosures of which are incorporated herein by reference. The input devices can be configured to directly control the movement of the catheter and sheath, or can be configured, for example, to manipulate a target or cursor on an associated display.

The electronic control system200can be configured to translate (i.e., interpret) inputs (e.g., motions) of the user at an input device of the input control system100(or from another source) into a resulting movement of one or more medical devices (e.g., a catheter and/or a sheath). In this regard, the system200may include a programmed electronic control unit (ECU) in communication with a memory or other computer readable media (memory) suitable for information storage. Relevant to the present disclosure, the electronic control system200may be configured, among other things, to issue commands (i.e., actuation control signals) to the manipulator assembly300(i.e., to the actuation units—electric motors thereof, in particular) to move or deflect the medical device(s) associated therewith to prescribed positions and/or in prescribed ways, all in accordance with the received user input and/or a predetermined operating strategy programmed into the system200. In addition to the instant description, further details of a programmed electronic control system can be found in U.S. Patent Publication No. 2010/0256558, the entire disclosure of which was incorporated herein by reference above. It should be understood that although the visualization, navigation, and/or mapping system14and the electronic control system200are shown separately inFIG. 1, integration of one or more computing functions can result in a system including an ECU on which can be run both (i) various control and diagnostic logic pertaining to the RCGS10and (ii) the visualization, navigation, and/or mapping functionality of system14.

The manipulator assembly300, in response to commands issued by the electronic control system200, can be configured to maneuver the medical device(s) associated therewith (e.g., translation movement, such as advancement and withdrawal of the medical device(s)), as well as to effectuate distal end (tip) deflection and/or rotation or virtual rotation. In an embodiment, the manipulator assembly300can include actuation mechanisms/units (e.g., a plurality of electric motor and lead screw combinations, or other electric motor configurations) for linearly actuating one or more control members (e.g., steering wires) associated with the medical device(s) for achieving the above-described translation, deflection and/or rotation (or virtual rotation). In addition to the description set forth herein, further details of a manipulator assembly can be found in U.S. Patent Publication No. 2009/0247942 entitled “Robotic Catheter Manipulator Assembly,” the entire disclosure of which is incorporated herein by reference.

A device cartridge400can be provided for each medical device controlled by the RCGS10. For this exemplary description of an RCGS, and as will be described in greater detail below, one cartridge may be associated with a catheter and a second cartridge may be associated with an outer sheath. However, in other exemplary embodiments, a single medical device, and therefore, a single cartridge, or more than two medical devices, and therefore, more than two cartridges, may be used. Accordingly, embodiments wherein more or less than two cartridges are employed remain within the spirit and scope of the present disclosure. Furthermore, as will be described in detail below, medical device form factors other than cartridges400may be used with the manipulation assembly300. In any event, the cartridges (or other medical device form factor) may be coupled, generally speaking, to the RCGS10to allow for robotically-controlled movement. In addition to the description set forth herein, further details of a device cartridge can be found in U.S. Patent Publication Nos. 2009/0247943 entitled “Robotic Catheter Device Cartridge” and 2009/0247944 entitled “Robotic Catheter Rotatable Device Cartridge,” the entire disclosures of which are incorporated herein by reference.

FIG. 2is a diagrammatic side view of an exemplary catheter402and catheter manipulator mechanism302. The illustrated manipulator mechanism302is coupled to the catheter402at an interface404. The catheter402can include a shaft406with a distal portion408and a proximal portion410and a handle412with a proximal interface414and a manual pull wire actuation mechanism416.

The manipulator mechanism302can be configured to translate the catheter402generally along the central axis of the catheter402in the distal and proximal directions respectively indicated by arrows T1, T2and, in an embodiment, to rotate the catheter about the central axis of the catheter (as generally indicated by rotation line R). Unlike known robotic systems that manipulate manual catheter handles, the manipulator mechanism302may control distal deflection of the catheter by actuating a dedicated actuation mechanism driven through the interface404, not by actuating the manual pull wire mechanism416. Such a dedicated remote actuation mechanism is discussed in greater detail in conjunction withFIGS. 3-5. Because the manipulator mechanism controls the deflection of the catheter402through an interface404that may be used for many different catheters, the manipulator mechanism302is capable of use for remote control of many different types of manual catheter handles (given an appropriate configuration, e.g., an interface in the catheter handle). This presents an advantage over known systems, which require different manipulator mechanisms to control different models of catheter handles having different designs.

The catheter402can be configured both for manual manipulation by a physician and remote manipulation by the manipulation mechanism302. Accordingly, the catheter may include a manual pull wire actuation mechanism416and a dedicated remote actuation mechanism which, as noted above, is described in further detail in conjunction withFIGS. 3-5. The shape and design of the handle412, including the manual pull wire actuation mechanism416, allow a user to manually guide the catheter402to an intended location to, e.g., deliver ablation therapy. In addition, the catheter proximal interface414provides a functional connection between the catheter402and an RCGS for remote guidance and control.

Though not shown, the catheter402may include a plurality of electrical components, such as position sensors and other sensors, ablation electrodes, diagnostic electrodes, and the like. Accordingly, the shaft406and handle412may include signal transmission pathways for signals to and from those electrical components, such as wires and cables, as known in the art. Such transmission pathways may extend from each respective electrical component to the proximal interface414.

FIG. 3is a schematic and block diagram view of an exemplary embodiment of the catheter402shown inFIG. 2, designated catheter4021. Illustrated catheter4021includes a shaft4061with a distal portion4081, a proximal portion4101, a pull ring418, and four pull wires420. The catheter4021also includes two remote actuation mechanisms422coupled to two force translation mechanisms424, two manual actuation mechanisms416coupled to two additional force translation mechanisms426, and four control elements428each respectively coupled to a pull wire420.

The pull wires420, pull ring418, and control elements428are provided for deflecting the distal portion4081of the shaft4061. Each pull wire420may be coupled to a control element428such that a proximal or distal movement of the control element428results in a corresponding proximal or distal movement of the pull wire420. The movement of the pull wire420can be translated into a force on the catheter shaft4061by the pull ring418, which in turn can cause the distal portion4081of the shaft4061to deflect. In the illustrated embodiment, the four pull wires are provided as two orthogonal pairs, with each wire in a pair effecting a deflection opposite the other wire in the pair. Thus, together the pull wires420are configured to deflect the catheter in four directions that are separated by 90 degrees—i.e., the pull wire4201may effect a deflection to the left in the plane of the page, the pull wire4204may effect a deflection to the right in the plane of the page, the pull wire4203may effect a deflection into the page, and the pull wire4202may effect a deflection out of the page. Though four pull wires420are shown, any number of pull wires420may be provided in the catheter such as, for example, only two pull wires420. Additionally, though a pull ring418is shown for coupling the pull wires420with the catheter shaft4061, the pull wires420may be coupled with the catheter shaft through any other means known in the art.

The manual actuation mechanisms416can be provided for manual actuation of the pull wires420to manually deflect or steer the catheter. Each manual actuation mechanism can be configured to control an opposed pair of pull wires420—i.e., the first manual actuation mechanism4161controls the pull wires4281,4284and the second manual actuation mechanism4162controls the pull wires4282,4283. The manual actuation mechanisms416may comprise mechanisms generally known in the art, such as, for example only, deflection collars on the exterior of the catheter handle4121. Though two manual actuation mechanisms416are shown, more or fewer manual actuation mechanisms may be provided. For example, in an embodiment with only two opposed pull wires420, only one manual actuation mechanism416may be provided.

The remote actuation mechanisms422can be provided for remote actuation of the pull wires (e.g., by an RCGS) to remotely deflect or steer the catheter4021. If desired, each remote actuation mechanism422may be configured to control an opposed pair of pull wires420—i.e., the first remote actuation mechanism4221controls the pull wires4281,4284and the second remote actuation mechanism4222controls the pull wires4282,4283. The remote actuation mechanisms can be, for example, mechanical, such as sockets (shown inFIGS. 5A-B), rotating rings, or slider blocks, hydraulic (shown inFIG. 4), or another mechanism known in the art.

The force translation mechanisms424,426can be provided to translate a force on an actuation mechanism416,422into a distal or proximal movement of a control element428to control the distal deflection of the catheter shaft. The force translation mechanisms424,426may be gears, pulleys, wires, cables, levers, or any other mechanism or combination of mechanisms known in the art. In an embodiment, one or more of the force translation mechanism424,426may be a part of a remote or manual actuation mechanism. Furthermore, like the actuation mechanisms416,422, fewer or more force translation mechanisms424,426may be provided depending on the number of pull wires provided in the catheter4021. In addition, the force translation mechanisms424for the remote actuation mechanisms422and the force translation mechanisms426for the manual actuation mechanisms416may share components, or may be independent, as shown inFIG. 3.

The control elements428can be actuated in pairs—i.e., two control elements that effect deflection in directions 180 degrees opposed to each other can be actuated in tandem by a single actuation mechanism. Accordingly, a single manual actuation mechanism416and a single remote actuation mechanism422may each be coupled to opposing control elements. For example, in an embodiment, a single deflection collar4161may be coupled to opposing pull wires4201,4204via the control elements4281,4284and the force translation mechanism4261such that a clockwise turn of the collar4161results in a proximal force on the control element4281and a distal force on the other control element4284, while a counter-clockwise turn of the collar does the opposite—i.e., results in a distal force on the control element4281and a proximal force on the other control element4284. A single remote actuation mechanism4221may be similarly coupled to the control elements4281,4284to apply similar opposed forces.

In an alternate embodiment, the catheter4021may include separate sets of pull wires420for actuation by the remote actuation mechanisms422and the manual actuation mechanisms416. Corresponding separate control elements428may also be provided. In such an embodiment, the separate sets of pull wires420for manual and robotic manipulation may be substantially co-located (i.e., with two pull wires provided adjacent to each other for each deflection direction), or the two separate sets of pull wires may be substantially offset such that the manual actuation mechanisms416and the remote actuation mechanisms422deflect the catheter in different directions.

FIG. 4is a diagrammatic view of the interior of an exemplary embodiment of the catheter402ofFIG. 2, designated catheter4022. The catheter4022includes a shaft4062having a distal portion4082and a proximal portion4102, and a handle4122including a manual actuation mechanism4162(shown in phantom), an irrigation fluid pathway444(also shown in phantom), a proximal interface4142with a shunt valve436, two pull wires420, a control element428(shown as an anchor block) for each pull wire, a mechanical drive link430for each pull wire, a hydraulic system432, and a pull wire position sensor434for each pull wire. The illustrated hydraulic system432includes a hydraulic drive438for each pull wire, each hydraulic drive438including a drive shaft440, a hydraulic cylinder442, and a hydraulic fluid line446.

Each anchor block control element428may be rigidly coupled to a respective pull wire420, but can be movably disposed in the catheter4022. Thus, a movement of an anchor block control element428may result in a movement of a pull wire420and a deflection of the distal portion4082of the shaft4062. As noted above with respect toFIG. 3, the anchor block control elements428may be actuated or controlled in tandem, such that a proximal force on one anchor block may be accompanied by a distal force on the other anchor block.

The catheter4022may be designed for both manual manipulation by a user and remote manipulation with an RCGS. Accordingly, the exterior of the handle4122and the manual actuation mechanism4162can be designed for manual manipulation by a user in a fashion similar to known manual catheter handles. The manual actuation mechanism4162can be, as noted above, any manual actuation mechanism known in the art. The manual actuation mechanism4162can be coupled to each anchor block428through a mechanical link430(analogous to a force translation mechanism426shown inFIG. 3), such that rocking the manual actuation mechanism4162in a chosen direction can result in opposed respective proximal and distal forces on the two anchor blocks428(and thus, on the two pull wires420).

The hydraulic system432may be provided in the catheter as a remote mechanism for pull wire actuation by an RCGS. In the hydraulic system432, hydraulic fluid flows through the fluid lines446to actuate the drive cylinders442(i.e., to move a piston in the hydraulic cylinder442towards the proximal or distal end of the catheter handle). Each drive cylinder442can actuate a respective drive shaft440, which may be coupled to a respective anchor block control element428. Thus, a proximal or distal movement of a piston in a hydraulic drive cylinder442results in a corresponding proximal or distal force on an anchor block control element428.

The pull wire position sensors434can assist with determining the position of the pull wires420so that, for example only, a mapping and positioning system may accurately determine the degree of deflection (and, thus, the overall shape) of the distal portion4082of the catheter shaft4062. Each position sensor434is shown as a potentiometer, though other position sensing devices may be used, such as a linear variable differential transformer (LVDT), a Bragg grating, or another device based on optic methods, such as interferometry or reflectance.

Each potentiometer434includes a wiper450movable relative to a resistive track452. In an embodiment, the wiper450can be rigidly coupled to the anchor block control element428. As the anchor block control element428(and, thus, the wiper450) moves proximally or distally, the wiper's position on the resistive track452changes. As the position of the wiper450changes, so does the electrical resistance of the resistive track452. By applying an electrical signal through the resistive track452, the RCGS can measure the resistance of the resistive track452to determine the position of the anchor block control element428at any given time and estimate the shape of the shaft distal portion4082accordingly. Such an electrical signal may be carried between the interface4142and the position sensor434by a signal cable448, which may be any appropriate electrical cable or wiring known in the art.

As noted above, the catheter4022also includes a proximal interface4142that may function as the sole interface between the catheter4022and an RCGS, including mechanical, electrical, and fluid coupling. Accordingly, the proximal interface4142may include a shunt valve436that allows hydraulic fluid to circulate freely in the hydraulic system432when the catheter4022is not connected to a RCGS (and thus, prevents the pistons in the drive cylinders442from opposing forces applied through the manual actuation mechanism4162), but permits a fluidic connection between the manipulation mechanism302and the hydraulic fluid lines446so that the RCGS may drive the hydraulic system432as a remote manipulation mechanism. Thus, when the catheter4022is connected to the manipulation mechanism302via the proximal interface4142, the RCGS can drive the hydraulic system432with hydraulic elements (e.g., drive cylinders, drive shafts) included in the manipulation mechanism302or elsewhere in the RCGS. The proximal interface4142may also include electrical connections and mechanical coupling for the manipulator mechanism302, examples of which are shown inFIGS. 5A-5B.

FIG. 5Ais a partial cross-sectional view of an exemplary embodiment of an interface4043between an exemplary embodiment of a catheter4023and the manipulation mechanism302. The illustrated interface4043includes elements from a proximal interface4143of an exemplary catheter4023and elements from the connection port of the manipulation mechanism302. The proximal interface4143of the catheter4023includes a remote actuation mechanism (shown as an interior socket460), an irrigation fluid port462, and electrical connections464. The connection port of the manipulation mechanism302includes an exterior socket466and complementary components for the fluid line and electrode connections.

The irrigation fluid port462is provided for the flow of irrigation fluid from the manipulation mechanism302to the catheter4023. Irrigation fluid may be provided to the distal portion of the catheter4023to, for example, prevent the buildup of coagulum at an ablation site and/or to reduce the temperature of an ablation electrode. Irrigation fluid may be provided by a fluid pump or saline drip in the RCGS (not shown), and may flow through a fluid lumen in the catheter4023, such as, for example only, the fluid lumen444shown inFIG. 4.

The electrical connections464can provide signal pathways for signals to or from one or more sensors, electrodes, or other components disposed in the catheter4023, such as, for example, positioning sensors, ablation electrodes, mapping electrodes, and the like. Although ten electrode connections464are provided in the interface4143, not all are designated for visual clarity. More or fewer electrode connections may be provided as needed, depending on the configuration of the catheter4023.

The interior socket460may be configured both for mechanically coupling the catheter4023with the manipulation mechanism302and as a remote actuation mechanism. A clockwise turn of the exterior socket466of the manipulation mechanism302(controlled by the RCGS as described above in conjunction withFIG. 1) may impart a clockwise force on the interior socket460, which in turn may be translated into a force on the pull wires420of the catheter4023by a force translation mechanism424(not shown inFIG. 4A) to deflect or steer the distal portion of the catheter4023. As noted above, the force translation mechanism424may include gears, pulleys, wires, cables, levers, or any other mechanism or combination of mechanisms known in the art.

FIG. 5Bis a partial cross-sectional view of an exemplary embodiment of an interface4044between an exemplary embodiment of a catheter4024and the manipulation mechanism302. The interface4044includes the same fluid port462and electrical connections464as the interface4043shown inFIG. 5A. Accordingly, the description of those components set forth above may apply equally to the interface4044and the catheter4024. The interface4044may also include two socket connections, each including an interior socket460configured to interact with an exterior socket466disposed in the manipulation mechanism302.

Each of the interior sockets may be used as a remote manipulation mechanism to actuate opposing control elements and opposing pull wires (as shown inFIG. 3). Thus, each interior socket may be respectively coupled with a force translation mechanism424to control two pull wires420. With two sockets, the interface4044may be used to control the movement of a catheter with four pull wires. In an embodiment, two sockets may also be included on a catheter with only two pull wires—the first socket as an actuation means for the two pull wires, and the second socket only as a means of mechanical coupling.

A catheter with a first, manual manipulation mechanism and a second, remote manipulation mechanism as described above can provide advantages over known catheters and devices used in remote systems. First, the same catheter may be used both for manual and remote manipulation without sacrificing manual or remote control quality. Second, the same robotic manipulator may be used to control many different types of catheters, without regard for the placement and design of manual actuation mechanisms, given a proper interface on the catheter.

A second way of improving on known catheters for remote manipulation is with a modular catheter cartridge that can be coupled with an RCGS or with a manual catheter handle portion designed for use with the modular cartridge.

FIG. 6is a diagrammatic view of the interior of a modular catheter cartridge1400that can be coupled with either an RCGS or with a catheter handle portion for manual manipulation by a physician. The illustrated cartridge1400includes a catheter shaft1402having a distal portion1404and a proximal portion1406, a housing1408, two pull wires1410respectively disposed in two pull wire channels1412, an irrigation fluid lumen1414, two interface pins1416, two interface pin position sensors1418, and a proximal interface1420. The proximal portion1406of the shaft1402is coupled to the housing1408by an anchor block1422.

The pull wires1410may extend to the distal portion1404of the shaft1402and may be coupled with the shaft1402with, for example only, a pull ring, as shown inFIG. 3. As described above, each pull wire may be used to deflect the distal portion1404by applying a distal or proximal force to the pull wire.

Each pull wire1410can be coupled with a respective interface pin1416which is movably coupled with the housing1408. Each interface pin1416may act as a control element for a pull wire1412, such that proximal or distal movement of an interface pin1416results in deflection of the distal portion1404of the catheter shaft1402. As a result, the interface pins1416may be moved proximally and distally by an RCGS or by a manual catheter handle portion to deflect the distal portion1404of the catheter shaft1402. It should be understood that the interface pins1416need not take the form shown in FIG.6—e.g., the interface pins1416may extend proximally from the housing1408, as shown, or may be contained entirely within the housing1408, and may have any appropriate shape and size.

Each interface pin1416may be coupled with a respective interface pin position sensor, shown as a linear variable differential transformer (LVDT)1418. Each LVDT1418can determine the position of an interface pins1416, and thus can determine the tension on each pull wire1410to estimate the shape of the distal portion1404of the catheter shaft1402. The LVDT1418may function as known in the art. In an embodiment, a center coil of the LVDT1418may be rigidly coupled to the interface pin1416, while two secondary coils may be movable relative to the interface pin1416. A current may be driven through the center coil, and the current induced on the secondary coils by the primary coil current may be measured. The secondary coils may be wound and positioned such that, in a balanced state (i.e., when the interface pin1416is in a neutral position), the currents induced on the two secondary coils are equal and opposite. However, when the primary coil moves from a neutral position, an unequal current is induced on the two secondary coils. The position of the center coil, and thus of the interface pin, may thus be determined based on the currents in the secondary coils. Of course, other position sensing means may be used, such as a potentiometer, as described above, or another position sensor as known in the art.

The modular catheter cartridge1400may be coupled to either an RCGS for remote control (i.e., similarly to cartridges in known robotic systems) or to a manual handle for manual manipulation by a physician. Accordingly, the housing1408can be configured in size and shape to resemble the distal end of a traditional manual catheter handle. In an embodiment, the housing1408may be substantially round (i.e., may have a substantially round cross-section taken transverse to the plane of the page).

The fluid lumen1414may provide for the flow of irrigation fluid to the distal portion1404of the catheter shaft1402. As noted above, irrigation fluid may be provided to cool an ablation electrode and/or to prevent the buildup of coagulum at an ablation site.

Though not shown, the catheter shaft1402may include a plurality of electrical components, such as position sensors and other sensors, ablation electrodes, diagnostic electrodes, and the like. Accordingly, the shaft1402and housing1408may include signal transmission pathways for signals to and from those electrical components, such as wires and cables, as known in the art. Such transmission pathways may extend from each respective electrical component to the proximal interface1420. Similar transmission pathways may be provided for the interface pin position sensors1418.

FIG. 7is an end view of the proximal interface1420. The proximal interface1420may include an irrigation fluid port1424for fluid access to the fluid lumen1414, a plurality of electrical connections1426for access to the transmission pathways of the LVDTs1418as well as other sensors, electrodes, and electrical components, and mechanical interlock ports1428for securely coupling the modular cartridge1400with either a manual handle portion or with an RCGS manipulator.

FIG. 8is an enlarged view of the proximal end of an interface pin1416. The interface pin1416includes a detent1430configured for mechanical coupling with an RCGS manipulator or with a manual catheter handle portion.

It should be understood that the number of pull wires and interface pins shown for the modular catheter cartridge1400is exemplary only, and not limiting. The modular catheter cartridge1400may be provided with more or fewer pull wires and a corresponding number of interface pins such as, for example only, four pull wires and four interface pins, and remain within the spirit and scope of the present invention.

FIG. 9is a diagrammatic view of an embodiment of the interior of the modular catheter cartridge1400(with portions omitted for visual clarity) and a manual handle portion1450coupled to the modular cartridge1400. The illustrated manual handle portion1450includes a housing1452, two receiving blocks1454, an interface pin release1456, a differential lead screw1458, a manual actuation mechanism1460, two slides1462,1464, an electrical connection interface1466, and a fluid connection interface1468.

Each of the receiving blocks1454can be configured to receive a respective interface pin1416. Accordingly, each receiving block1454may include two engagement pins1470configured to engage the detent1430in the interface pin1416. The engagement pins1470can be coupled to the interface pin release1456such that depressing the interface pin release1456removes the engagement pins1470from the detent1430, and the interface pin1416can be removed.

Each receiving block1454may be rigidly coupled with a slide1462,1464and the receiving blocks1454and slides1462,1464can be movable relative to the housing1452. As a result, when the interface pins1416are coupled with the receiving blocks1454, distal and proximal translation of the receiving blocks1454can result in distal and proximal force on the pull wires1410and deflection of the distal portion1404of the catheter shaft1402.

Translational movement of the receiving blocks1454can be provided by the differential lead screw1458. The differential lead screw1458may include a first section1472, coupled with the first slide1462, with right-handed windings and a second section1474, coupled with the second slide1464, with left-handed windings. The first and second slide1462,1464have windings compatible with the lead screw sections1472,1474such that rotation of the lead screw1458translates the slides1462,1464(and, as a result, the receiving blocks1454) in opposite directions (i.e., one proximally and the other distally). A clockwise movement of the lead screw1458may translate the first slide1462in the proximal direction and the second slide1464in the distal direction. A counter-clockwise movement of the lead screw1458may translate the first slide1462in the distal direction and the second slide1464in the proximal direction.

The lead screw1458may be coupled to the manual actuation mechanism1460such that rotation of the manual actuation mechanism1460rotates the lead screw1458. As a result, the manual actuation mechanism1460can be used for manual deflection of the catheter shaft1402. In an embodiment, the manual actuation mechanism1460may be a deflection collar. In the embodiment, a clockwise turn of the deflection collar would result in a corresponding clockwise rotation of the lead screw1458and proximal and distal movement of the receiving blocks1454and deflection of the catheter shaft1402.

As noted above, irrigation fluid may be provided to the distal portion1404of the shaft1402via a fluid port1424in the modular cartridge proximal interface1420. The handle portion1450may also include a fluid lumen that extends from fluid port1424of the proximal interface1420of the catheter cartridge1400to the fluid interface1468of the handle portion1450. An irrigation fluid pump or other source of irrigation fluid may thus provide irrigation fluid for the catheter through the handle portion fluid interface1468.

Also as noted above, the modular catheter cartridge1400may include a number of electrical components, such as sensors and other electrodes. The handle portion1450may include transmission pathways extending from the electrical connections1426in the modular cartridge proximal interface1420to the handle portion electrical interface1466. Thus, one or more systems may be connected to the electrical components of the modular cartridge1400, such as, for example only, a mapping and navigation system, such as the ENSITE VELOCITY system described above, or an ablation system.

The modular catheter cartridge1400may also be coupled with an RCGS having a manipulator with components similar to those in the handle portion1450—i.e., receiving blocks, a mechanism for translating the receiving blocks, and fluid and electrical interfaces. Accordingly, the modular catheter cartridge may be controlled manually (through the use of a corresponding manual handle, such as the handle portion1450) or remotely with an RCGS.