Arthroscopic devices and methods

Abstract

To provide an arthroscopic device and method.SOLUTION: An arthroscopic cutting probe includes an outer sleeve and an outer cutting window at its distal end. An inner sleeve is rotationally disposed in a bore of the outer sleeve, and the inner sleeve has a distal end, a proximal end, a longitudinal passageway, and an inner cutting window distal to it. An active electrode sleeve is disposed on an outer surface of the inner sleeve in a position opposed to the inner cutting window. Rotation of the inner sleeve causes the inner cutting window to rotate past the outer cutting window to resect a tissue as the cutting windows pass each other. A high frequency current can be applied to an active electrode to enhance tissue cutting to rotate the cutting windows, or to cauterize tissue when the cutting windows are held stationary with the active electrode.SELECTED DRAWING: Figure 18

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to U.S. Patent Application No. 16 / 397,742 (Attorney Docket No. 41879-741.201), filed April 29, 2019, which claims the benefit of U.S. Provisional Application No. 62 / 664,692 (Attorney Docket No. 41879-741.101), filed April 30, 2018, the complete disclosure of which is incorporated herein by reference.

[0002] The present invention relates to a medical system that includes a variation of a motor-driven tubular cutter or arthroscopic shaver configured for both mechanical and electrosurgical cutting, ablation and coagulation procedures.

[0003] Endoscopic and other surgical procedures, including subacromial decompression, anterior cruciate ligament reconstruction including notch plasty, and arthroscopic resection of the acromioclavicular joint, require the cutting and removal of bone and soft tissue. Currently, surgeons use arthroscopic shavers and burrs with rotating cutting surfaces to remove hard tissue in such procedures.

[0004] To promote efficiency, some endoscopic tool systems include a reusable handpiece and a selection of interchangeable tool probes with different working ends. Because each of these working ends can have two or more functions, such as soft tissue removal and hard tissue resection, these tool systems can offer multiple specific functions and provide great flexibility. While offering great flexibility, the wide variety of surgical procedures and anatomical differences necessitate multiple specific tool functions.

[0005] It is therefore an object of the present invention to provide additional interchangeable other tool probes and methods for their use, such as improved arthroscopic tissue cutting probes and removal systems in which a motor-driven electrosurgical device is provided for selectively cutting and removing bone or soft tissue from a joint or other site. It is a further object of the invention to provide a single arthroscopic cutting probe or other handheld device capable of both mechanically and electrosurgically enhanced cutting of both soft and hard tissue. At least some of these objects will be met by the inventions described herein. [Background technology]

[0006] Related commonly owned patents and published applications include: U.S. Patent Nos. 8,221,404; 8,323,280; 9,204,918; 9,277,954; 9,247,983; 9,592,085; 9,585,675; 9,603,656; and 9,681,913. ; 9,855,675; 10,028,767; 10,052,149; 9,795,434; and 10,022,140; and U.S. Patent Application Publication Nos. 2016-0113706; 2016-0157916; 2017-0128083; 2017-0172648; 2017-0 No. 258519; No. 2017-0258512; No. 2017-0290602; No. 2017-0303990; No. 2017-0252099; No. 2018 No. -0000534; No. 2018-0161088; No. 2018-0008334; No. 2018-0093391; No. 2019-0015151; No. 20 18-0263649; 2019-0083121; 2019-0008538; 2018-0303509; 2018-0317957; 2019-0021788; 2019-0059983; and 2019-0008541, the complete disclosures of which are incorporated herein by reference. Summary of the Invention

[0007] The present invention provides improved devices and methods for resecting tissue in arthroscopy and other surgical procedures. In particular, the present invention provides a single tool, typically in the form of an arthroscopic cutting probe, capable of resecting tissue with both mechanical and electrosurgical enhancement. The tool preferably consists of a tubular cutter with an outer sleeve and a rotating inner sleeve, each sleeve typically having a cutting window formed at or near its distal end. An active electrode is typically located on the distal outer surface of the inner sleeve or tubular cutter and allows application of electrosurgical current to tissue when aligned with the outer cutting window of the outer tubular sleeve. A return electrode is typically provided along at least a portion of the outer surface of the outer sleeve (bipolar designs), although in other instances it may be provided separately from the cutting probe or other tool, typically in the form of a grounding pad placed outside the patient's body, typically on the lower back (monopolar designs).

[0008] In a first aspect of the present invention, an arthroscopic cutting probe includes an outer sleeve having a longitudinal bore and an outer cutting window at a distal end of the outer sleeve. An inner sleeve is rotationally disposed within the longitudinal bore of the outer sleeve, the inner sleeve having a distal end, a proximal end, a longitudinal passage, and an inner cutting window disposed through the cylindrical wall of the inner sleeve near its distal end. Both the outer sleeve and the inner sleeve typically include concentric tubular sleeves coaxially aligned along a central axis. The tubular sleeves are typically at least partially constructed of metal or other electrically conductive material, as described in more detail below, and typically connect to a proximal hub that can interface with a motor drive unit, also described in more detail below.

[0009] The arthroscopic cutting probe of the present invention also typically includes an active electrode located on the outer surface of the inner sleeve, typically near the distal end of the cylindrical wall. Rotation of the inner sleeve relative to the outer sleeve rotates the inner cutting window past the outer cutting window, cutting tissue received through the cutting windows as they pass each other. The active electrode is positioned on the inner sleeve such that as the inner sleeve rotates, the active electrode also passes the outer cutting window. Furthermore, the active electrode can be selectively aligned within the outer cutting window by stopping rotation of the inner sleeve at a particular rotational orientation, as described below.

[0010] In certain embodiments, the active electrode has a curved surface that matches the curvature of the cylindrical wall of the inner sleeve. In certain instances, the active electrode is surrounded by a dielectric insert that electrically insulates the active electrode from the inner sleeve, particularly the metallic portion of the inner sleeve that conducts the applied current. In some embodiments, the outer surface of the active electrode is flush with the cylindrical envelope of the distal end of the inner sleeve. In other embodiments, the outer surface of the active electrode may be fully or partially recessed within the cylindrical envelope of the distal end of the inner sleeve.

[0011] In yet another specific embodiment, the aperture is disposed through at least one of the active electrode and a region of the cylindrical wall of the inner sleeve adjacent to the active electrode. The distal end of the inner sleeve is typically sealed except for the inner cutting window and the aperture, such that negative pressure applied to the proximal end of the longitudinal passage of the inner sleeve can be drawn through either the inner cutting window or the aperture, depending on which is aligned with the outer cutting window. When the inner cutting window is aligned with the outer cutting window, it is understood that the aperture is typically positioned against the inner wall of the outer sleeve and is shielded from suction. Conversely, when the aperture is exposed through the outer cutting window, at least a portion of the inner cutting window is covered by the wall of the outer sleeve, blocking suction.

[0012] In certain examples, the dielectric insert may include any one of a ceramic material, a glass material, a polymer, or a combination thereof. The active electrode and the dielectric insert may be disposed on a side of the cylindrical wall of the inner sleeve opposite the inner cutting window, and the outer sleeve may include a metallic body that can provide a return electrode that functions in conjunction with the active electrode.

[0013] In yet another specific embodiment of the present invention, the longitudinal passage of the inner sleeve may be configured to be coupled to a negative pressure source, such that suction can be applied through either the inner cutting window or the opening when the inner cutting window or opening is aligned with the outer cutting window.

[0014] In yet another specific example, the outer sleeve can have a bullet-shaped distal end with a spherical distal tip. The outer cutting window can be formed on the spherical distal tip. Similarly, the distal end of the inner sleeve can have a bullet shape with an inner cutting window formed thereon. In this manner, the inner cutting window can nest within the outer cutting window when they are aligned. Similarly, the active electrode can nest within the outer cutting window when the active electrodes are aligned.

[0015] In a second aspect of the present invention, an arthroscopic cutting system includes an arthroscopic cutting probe, generally as described above. The arthroscopic cutting system further includes at least a motor drive unit and a radio frequency (RF) power source. The motor drive unit is configured to be coupled to the inner sleeve of the arthroscopic cutting probe so as to rotate the inner sleeve relative to the outer sleeve. In this manner, the inner and outer cutting sleeves can be rotated relative to one another to ablate tissue received in the cutting window as they move in and out of alignment. The RF power source is configured to be coupled to an active electrode and a return electrode, which can be formed as a dispersive pad external to the cutting probe or placed on the patient's skin, such as on the lower back.

[0016] The arthroscopic cutting system of the present invention typically further includes a controller that can be used to operate the arthroscopic cutting system in any one of at least three different operating modes. First, the controller can be pre-programmed or programmable to activate the motor drive unit to rotate the inner cutting window past the outer cutting window while the RF power source is not activated. In this manner, the arthroscopic cutter can resect tissue in a purely mechanical manner by shearing.

[0017] In a second mode of operation, the controller may be pre-programmed or programmable to combine mechanical shearing with electrosurgical enhancement in the arthroscopic cutting probe by supplying current from the RF power source to the active electrode to provide an enhanced cutting, ablation, or coagulation current.

[0018] In a third mode of operation, the controller may be pre-programmed or programmable to hold the motor drive stationary while supplying RF current to the active electrode, which is exposed through the outer cutting window and can selectively deliver either a cutting current, an ablation current, or a coagulation current to tissue in the absence of mechanical shear.

[0019] The arthroscopic cutting system of the present invention typically further includes a negative pressure source coupled to the longitudinal passage of the inner sleeve and capable of drawing tissue through the cutting window as they pass each other when operating in either the first or second modes described above. Alternatively, negative pressure can be applied through the opening when the cutting system is operating in the third mode. Typically, the controller can be pre-programmed or programmable to coordinate the delivery of negative pressure from the negative pressure source with the rotation of the inner sleeve and the delivery of RF current in any one of the combinations described herein.

[0020] In a third aspect of the present invention, a method for resecting tissue includes providing an arthroscopic cutting probe generally as described above. The outer cutting window of the arthroscopic cutting probe is engaged against tissue, and rotation of the inner sleeve and supply of current to the active electrode are independently controlled to achieve one of at least three different operational cutting and tissue processing modes. In a first mode, the inner cutting window is rotated past the outer cutting window while the outer cutting window is engaged against tissue without supplying radio frequency (RF) current to the active electrode, resecting tissue received through the outer cutting window as they pass each other. In a second mode of operation, the cutting window operates as just described with simultaneous supply of RF current to the active electrode to achieve a combination of both mechanical shearing and electrosurgical treatment. In a third mode of operation, the inner sleeve is held stationary relative to the outer sleeve, and RF current is supplied to the active electrode to achieve at least one of cutting, ablation, and tissue cauterization.

[0021] In certain embodiments of the methods herein, the inner cutting window can be rotated during at least some periods without application of RF current to the active electrode in a first mechanical ablation mode. In other examples, the inner cutting window can be rotated during at least other periods while RF current is applied to the electrode in a second electrosurgical mode of operation. In yet other examples, the inner cutting window can be held stationary while RF current is applied to the active electrode in a third electrosurgical mode of operation.

[0022] In yet another example, the method of the present invention further includes applying negative pressure to the longitudinal passages of the inner sleeve to draw tissue through the cutting windows as they pass each other, or applying negative pressure to the longitudinal passages of the inner sleeve to draw tissue through the openings while the inner sleeve is stationary. [Brief explanation of the drawings]

[0023] Various embodiments of the present invention will now be described with reference to the accompanying drawings, it being understood that the drawings depict only typical embodiments of the invention and therefore should not be considered limiting of scope.

[0024] [Figure 1] FIG. 1 is a perspective view of an arthroscopic cutting system including a reusable handpiece with a motor drive and a detachable disposable cutting probe, the cutting probe shown in two orientations when coupled to the handpiece, with the probe and working end facing up or down relative to the handpiece, and the handpiece including an LCD screen for displaying operating parameters of the system in use along with control actuators on the handpiece.

[0025] [Figure 2A] 2A is an enlarged longitudinal cross-sectional view of the hub of the probe of FIG. 1 (where the hub and probe face upward relative to the handpiece) taken along line 2A-2A of FIG. 1, further showing a Hall effect sensor carried by the handpiece for probe orientation and positioning of the probe's motor-driven components relative to the handpiece, and multiple magnets carried by the probe hub for device identification.

[0026] [Figure 2B] 2B is a cross-sectional view of the hub of FIG. 1 taken along line 2B-2B of FIG. 1, where the hub and probe face downward relative to the handpiece, showing the magnet and Hall effect sensor in a different orientation than in FIG. 2A.

[0027] [Figure 3A] 2 is an enlarged perspective view of the working end of the probe of FIG. 1 facing upward, where the rotatable cutting sleeve is in a first position relative to the outer sleeve and the window of the cutting sleeve is aligned with the outer sleeve window;

[0028] [Figure 3B] 2 is a perspective view of the working end of FIG. 1 facing downward, where the rotatable cutting sleeve is in a second position relative to the outer sleeve and the electrode carried by the cutting sleeve is aligned with the centerline of the window in the outer sleeve.

[0029] [Figure 4] FIG. 2 is a perspective view of the working end of a variation of a probe that may be removably coupled to the handpiece of FIG. 1, where the working end includes a bone burr extending distally from an outer sleeve.

[0030] [Figure 5] 2 is a perspective view of a working end of a variation of a probe that may be removably coupled to the handpiece of FIG. 1, where the working end has a reciprocating electrode.

[0031] [Figure 6] FIG. 2 is a perspective view of the working end of another variation of a probe that may be removably coupled to the handpiece of FIG. 1, where the working end has a hook electrode having an extended position and a non-extended position.

[0032] [Figure 7] FIG. 2 is a perspective view of the working end of yet another variation of a probe that may be removably coupled to the handpiece of FIG. 1, where the working end has an openable and closable jaw structure for cutting tissue.

[0033] [Figure 8] 3B is a chart of set speeds for a probe with a rotating cutting sleeve as in FIGS. 1 and 3A , and schematically illustrates the method used by the controller algorithm to stop the rotation of the cutting sleeve at a selected default position.

[0034] [Figure 9A]FIG. 9A is a longitudinal cross-sectional view of a probe hub similar to that of FIG. 2A (except that the hub in FIG. 9A has an internal cam mechanism, like the working end of FIG. 5, that converts rotary motion into linear motion to reciprocate the electrode axially). Here, FIG. 9A shows the hub and drive coupling magnets as in FIG. 2A, with the hub in an upward position relative to the handpiece.

[0035] [Figure 9B] 9B is a cross-sectional view of the hub of FIG. 9A rotated 180 degrees in a downward position relative to the handpiece.

[0036] [Figure 10] FIG. 10 is a perspective view of another variation of the probe showing a motor-driven rotating inner cutting sleeve containing the electrode and an outer sleeve that holds the distal dielectric housing.

[0037] [Figure 11A] 11 is a perspective view of the working end of the outer sleeve of the probe of FIG. 10 separated from the inner sleeve.

[0038] [Figure 11B] 11 is a perspective view of the working end of the inner sleeve of the probe of FIG. 10, with the inner sleeve window facing upward.

[0039] [Figure 11C] FIG. 11C is a perspective view of the working end of the inner sleeve of FIG. 11B, with the inner sleeve window facing downward.

[0040] [Figure 12] FIG. 11B is a perspective view of the dielectric housing of FIG. 11A.

[0041] [Figure 13] 13 is a cross-sectional view of the working end of FIG. 10 taken along line 13-13 of FIG. 10.

[0042] [Figure 14]FIG. 10 is a perspective view of another variation of the probe showing a motor-driven rotating inner cutting sleeve including an electrode with an insulating coating that rotates within a metal outer sleeve.

[0043] [Figure 15] 11B and 11C, showing a perspective view of the working end of a motor-driven rotating inner sleeve with an abrasive cutting function for grinding bone.

[0044] [Figure 16] FIG. 10 is a perspective view of the working end of another variation of the probe, showing a motor-driven reciprocating inner sleeve containing an electrode that reciprocates within a dielectric housing carried by an outer sleeve.

[0045] [Figure 17] FIG. 10 is a perspective view of the working end of another variation of the probe, showing a reciprocating inner sleeve with a ceramic or glass cutting edge surrounding an electrode sleeve that reciprocates within a metal outer sleeve.

[0046] [Figure 18] FIG. 10 is a perspective view of another variation of a probe having a windowed inner sleeve that rotates within a concentric windowed outer sleeve, the window ends of both sleeves being metal and adapted to cut tissue with an active electrode held in a dielectric insert within the dielectric insert.

[0047] [Figure 19A] FIG. 19 is an enlarged view of the working end of FIG. 18 in the window closed position showing the active electrode and dielectric insert.

[0048] [Figure 19B] FIG. 19B is a view of the working end of FIG. 19A with the window in an open position. DETAILED DESCRIPTION OF THE INVENTION

[0049] The present invention relates to bone cutting and tissue removal devices and related methods of use. Several variations of the present invention will now be described to provide a general understanding of the principles of form, function, and use of the devices disclosed herein. Generally, the present disclosure provides variations of arthroscopic tools adapted for cutting bone, soft tissue, meniscal tissue, and for RF ablation and coagulation. The arthroscopic tools are typically disposable and configured for removable coupling to a non-disposable handpiece carrying the motor-driven components. This description of the general principles of the present invention is not intended to limit the inventive concepts in the appended claims.

[0050] 1 , an arthroscopic system 100 of the present invention provides a handpiece 104 with a motor drive 105 and a disposable shaver assembly or probe 110 with a proximal hub 120 that can be received by a receiver or bore 122 of the handpiece 104. In one embodiment, the probe 110 has a working end 112 that carries a high-speed rotary cutter configured for use in many arthroscopic surgical applications, including, but not limited to, treatment of bones of the shoulder, knee, hip, wrist, ankle, and spine.

[0051] 1, 2A, and 3A, probe 110 has a shaft 125 extending along a longitudinal axis 128, which includes an outer sleeve 140 and an inner sleeve 142 rotatably disposed therein, the inner sleeve 142 carrying a distal ceramic cutting sleeve 145 (FIG. 3A). Shaft 125 extends from a proximal hub 120, where outer sleeve 140 is coupled in a fixed manner to hub 120, which may be, for example, injection-molded plastic with an outer sleeve 140 insert molded therein. Inner sleeve 142 is a drive coupling 150 configured to couple to a rotating motor shaft 151 of motor drive unit 105; more specifically, a rotatable cutting sleeve 145 fabricated of a ceramic material with sharp cutting edges 152a and 152b opposite a window 154 for cutting soft tissue. A motor drive 105 is operably coupled to the ceramic cutter to rotate the cutting sleeve at speeds ranging from 1000 rpm to 20,000 rpm. Referring to FIG. 3B, it can be seen that the cutting sleeve 145 also carries an RF electrode 155 on a surface opposite a window 154. The cutting sleeve 145 rotates and shears tissue at a toothed opening or window 158 (FIG. 3A) in the outer sleeve 140. Probes of the type shown in FIG. 1 are described in further detail in co-pending and co-owned patent application Ser. No. 15 / 421,264, filed Jan. 31, 2017, entitled "ARTHROSCOPIC APPARATUS AND METHODS," (Attorney Docket No. 41879-714.201), which is incorporated herein by reference in its entirety.

[0052] As shown in FIG. 1 , the probe 110 is shown in two orientations for removably coupling to the handpiece 104. More specifically, the hub 120 can be coupled to the handpiece 104 in an upward orientation, indicated by "UP," and a downward orientation, indicated by "DN," where the orientations are 180° opposite each other. It can be appreciated that the upward and downward orientations are necessary to orient the working end 112 upward or downward relative to the handpiece 104 so that the cutting sleeve 145 can interface with the target tissue in all directions without the physician having to manipulate the handpiece 360° to access the tissue.

[0053] Referring to FIG. 1, it can be seen that the handle 104 is operatively coupled by an electrical cable 160 to a controller 165 that controls the motor drive unit 105. Actuator buttons 166a, 166b, or 166c on the handle 104 can be used to select an operating mode, such as various rotation modes of the ceramic cutting sleeve 145. In one variation, a joystick 168 can be moved back and forth to adjust the rotational speed of the ceramic cutting sleeve 145. The cutter rotational speed can be continuously adjustable or incrementally adjustable up to 20,000 rpm. An LCD screen 170 is provided on the handpiece to display operating parameters such as cutting sleeve RPM, operating mode, etc.

[0054] Referring to FIG. 1, it can be seen that the system 100 and handpiece 104 are adapted for use with a variety of disposable probes that can be designed for a variety of different functions and procedures. For example, FIG. 4 shows a different variation of a probe working end 200A, similar to the working end 112 of the probe 110 of FIGS. 3A and 3B, except that a ceramic cutting sleeve 205 extends distally from an outer sleeve 206, and the cutting sleeve has a burr edge 208 for cutting bone. The probe of FIG. 4 is described in more detail in co-pending and commonly owned patent application Ser. No. 15 / 271,184, filed September 20, 2016, entitled "ARTHROSCOPIC APPARATUS AND METHODS" (Attorney Docket No. 41879-728.201). Figure 5 shows a different variation of a probe working tip 200B with a reciprocating electrode 210 in a probe of the type described in detail in co-pending and commonly owned patent application Ser. No. 15 / 410,723 (Attorney Docket No. 41879-713.201), entitled "ARTHROSCOPIC DEVICE AND METHODS," filed Jan. 19, 2017. In another example, Figure 6 shows a further variation of a probe working tip 200C with an extendable-retractable hook electrode 210 in a probe of the type described in more detail in co-pending and commonly owned patent application Ser. No. 15 / 454,342 (Attorney Docket No. 41879-715.201), entitled "ARTHROSCOPIC DEVICE AND METHODS," filed Mar. 9, 2017. In yet another example, FIG. 7 shows a variation of a probe-type working end 200D having an openable / closable jaw structure 215 actuated by a reciprocating sleeve 218 for trimming meniscus or other tissue, as described in more detail in co-pending and commonly owned patent application Ser. No. 15 / 483,940, filed April 10, 2017, entitled "Arthroscopic Apparatus and Method" (Attorney Docket No. 41879-721.201). All of the probes in FIGS. 4-7 can have a hub similar to hub 120 of probe 110 in FIG. 1 for coupling to the same handpiece 104 in FIG. 1. However, some probes (see FIGS. 5-7) have a hub mechanism for converting rotational motion to linear motion. All patent applications identified in this paragraph are incorporated herein by this reference.

[0055] 1 further shows that system 100 also includes a negative pressure source 220 coupled to a suction tube 222 that communicates with a flow path 224 in handpiece 104 and that can cooperate with any of probes 110, 200A, 200B, or 200C of FIGS. 1-3B, 4, 5, and 6. Referring to FIG. 1, it can also be seen that system 100 includes an RF source 225 that can be connected to the electrode configuration of any of probes 110, 200A, 200B, or 200C of FIGS. 1-3B, 4, 5, and 6. Controller 165 and a microprocessor therein, along with control algorithms, are provided to operate and control all functions, including control of motor drive 105 for moving the motor-driven components of any probe working end 110, 200A, 200B, or 200C, and control of negative pressure source 220 and RF source 225, which can aspirate fluid and tissue debris into collection reservoir 230.

[0056] As can be seen from the above description of system 100 and handpiece 104, controller 165 and controller algorithms must be configured to perform and automate many tasks to provide system functionality. In a first embodiment, the controller algorithm is required for device identification, so that when any of the different probe types 110, 200A, 200B, 200C, or 200D of FIGS. 1 and 4-7 are coupled to handpiece 104, controller 165 recognizes the probe type and then selects algorithms for operating motor drive 105, RF source 225, and negative pressure source 220 as required for the particular probe. In a second embodiment, the controller is configured with algorithms that identify whether the probe is coupled to handpiece 104 in an up-facing or down-facing orientation relative to the handpiece, with each orientation requiring a different subset of operating algorithms. In another embodiment, the controller has separate control algorithms for each probe type, with some probes having rotatable cutters and others having reciprocating electrodes or jaw structures. In another aspect, most, if not all, probes 110, 200A, 200B, 200C, and 200D (FIGS. 1, 4-7) require a default "park" position where the motor-driven components are parked in a particular orientation within the working end. For example, a rotatable cutter 145 with electrode 155 requires the electrode to be centered within outer sleeve window 158 in the default position as shown in FIG. 3B. Some of these systems, algorithms, and methods of use are now described.

[0057] As shown in FIGS. 1, 2A, and 2B, the handpiece 104 is seen to carry a first Hall Effect sensor 240 in a distal region of the handpiece 104 adjacent the receiving passage 122 that receives the hub 120 of the probe 110. FIG. 2A corresponds to the probe 110 and working end 112 of FIG. 1 in an upward position, designated "UP." FIG. 2B corresponds to the probe 110 and working end 112 of FIG. 1 in a downward position, designated "DN." The handpiece 104 carries a second Hall Effect sensor 245 adjacent the rotatable drive coupling 150 of the probe 110. The probe 110 carries a plurality of magnets, described below, that interact with the Hall Effect sensors 240, 245 to provide a number of control functions in cooperation with a controller algorithm, including (i) identification of the type of probe coupled to the handpiece, (ii) the upward or downward orientation of the probe hub 120 relative to the handpiece 104, and (iii) the rotational speed and velocity of the rotary drive collar 150, which can determine the position of a rotating or reciprocating motor-driven component.

[0058] The cross-sectional views of FIGS. 2A and 2B show that the hub 120 of the probe 110 holds first and second magnets 250a and 250b on its surface. The Hall sensor 240 of the handpiece 104 is axially aligned with either magnet 250a or 250b when the probe hub 120 is coupled to the handpiece 104 facing up (FIGS. 1 and 2A) or down (FIGS. 1 and 2B). In one embodiment outlined above, the combination of magnets 250a and 250b and the Hall sensor 240 can be used to identify probe types. For example, a product portfolio may have two to ten or more types of probes, such as those shown in FIGS. 1, 4-7. Each such probe type can hold magnets 250a, 250b with specific, different magnetic field strengths. The Hall sensor 240 and controller algorithm can then be adapted to read the magnetic field strength of a particular magnet within the probe, which can be compared to a library of magnetic field strengths corresponding to specific probe types. A Hall identification signal can then be generated or otherwise provided to controller 165 to select a controller algorithm for operating the identified probe, which may include parameters for operating motor drive 105, vacuum source 220, and / or RF source 225 that may be required for the probe type. As shown in FIGS. 1, 2A, and 2B, probe hub 120 may be coupled to handpiece 104 in an up-and-down orientation, in which the north (N) and south (S) poles of magnets 250a, 250b are reversed relative to probe axis 128. Thus, Hall sensor 240 and associated algorithms look for magnetic field strength regardless of polarity to identify probe type.

[0059] 1, 2A, 2B, 3A, and 3B, first and second magnets 250a and 250b, each having a different orientation of north (N) and south (S) poles relative to the longitudinal axis 128 of the hub 120, are also used to identify the upward or downward orientation of the hub 120 and working end 112. In use, as described above, a physician can couple the probe 110 to the receiving channel 122 of the handpiece with the working end 112 facing upward or downward based on their preference and the target tissue. It can be appreciated that the controller algorithm adapted to stop the rotation of the cutting sleeve 145 within the window 158 of the outer sleeve 104 of the working end 112 must "learn" whether the working end is facing upward or downward due to the 180° difference in orientation or rotation of the cutting sleeve 145 relative to the handpiece and the Hall sensor 240. The Hall sensor 240, together with a controller algorithm, can determine an up or down DN by sensing whether the north (N) or south (S) pole of either magnet 250a or 250b is facing up and in close proximity to the Hall sensor 240.

[0060] In another aspect of the invention, in probe 110 (FIG. 1) and other probes, motor-driven components at the working end, such as the rotary cutter 145 at the working end 112 of FIGS. 1, 3A, and 3B, must stop at a selected rotational position relative to the notched opening or window 158 in the outer sleeve 140. Other probe types may have reciprocating sleeve or jaw structures as described above, which also require controller algorithms to stop the movement of the moving components at selected positions, such as the jaw structure of FIG. 7 and the axially moving electrode of FIGS. 5 and 6. In all probes, the motor drive 105 is coupled to a rotating drive coupling 150; therefore, sensing the rotational position of the drive coupling 150 can be used to determine the orientation of the motor-driven components at the working end. More specifically, in FIGS. 1, 2A, and 2B, the drive coupling 150 holds third and fourth magnets 255a and 255b, whose north and south poles are inverted relative to the probe axis 128. Thus, the Hall sensors 245 sense each magnet as it rotates past them, thereby determining the exact rotational position of the drive coupling 150 twice in each of its revolutions (once for each magnet 255a, 255b). A controller tachometer algorithm using the clock can then determine and optionally display the RPM of the drive coupling 150, e.g., cutting sleeve 145 in FIG. 3A.

[0061] In another embodiment of the invention, the Hall sensor 245 and magnets 255a and 255b (FIGS. 1 and 2A) are used in a set of controller algorithms to stop the rotation of an end-of-operation motor-driven component, such as the cutting sleeve 145 of FIGS. 1, 3A, and 3B, at a preselected rotational position. In FIG. 3A, it can be seen that the inner sleeve 142 and the "first side" of the cutting sleeve 145 and window 154 therein are stopped and centered over the window 158 of the outer sleeve 140. The rest position of the cutting sleeve 145 and window 154 of FIG. 3A can be used for cleaning or flushing the workspace to allow for large fluid outflow through the probe.

[0062] FIG. 3B shows the inner sleeve 142 and the "second side" of the cutting sleeve 145 positioned around the centerline of the window 158 of the outer sleeve 140. The rest or stop position of the cutting sleeve 145 in FIG. 3B is necessary to ablate or coagulate tissue using the RF electrode 155. Because the outer sleeve 140 typically includes a return electrode 260, it is important that the electrode 155 remain aligned with the centerline of the outer sleeve window 158. The position of the electrode 155 in FIG. 3B is referred to herein as the "centerline default position." If the cutting sleeve 145 and electrode 155 were rotated closer to the edge 262a or 262b of the window 158 of the outer sleeve 140, RF current could arc between the electrodes 155 and 260, potentially causing a short circuit that would disable the probe. Therefore, a robust and reliable stop mechanism, described next, is required.

[0063] As shown in FIGS. 1, 2A, and 2B, the controller 165 can constantly determine the rotational position of the drive coupling 150 in real time, thereby determining the angle or rotational position of the ceramic cutting sleeve 145 and the electrode 155. As the Hall sensor 245 detects whether the magnet 255a or 255b in the drive coupling 150 rotates the electrode 155 away from its default centerline position, the controller algorithm can further calculate the angle of rotation of the electrode 155 away from its default centerline position. Each magnet has a specified, known strength, and the algorithm can use a lookup table to list the field strength corresponding to the angle of rotation from the default position. Therefore, if the Hall signal responsive to the rotational position of the magnet 255a or 255b drops by a specified amount from its known peak value at its default centerline position, it means that the electrode 155 has moved away from the center of the window 158. In one variation, if the electrode 155 moves a selected rotational angle from the centerline position during RF energy delivery to the electrode, the algorithm immediately turns off the RF current and alerts the physician via an audible and / or visual signal, such as a warning on the LCD screen 170 of the handpiece 104 and / or on a screen of the controller console (not shown). Thus, termination of RF current delivery prevents the potential for electrical arcing between the electrode 155 and the outer sleeve electrode 260.

[0064] During use, when the electrode 155 is in the position shown in FIG. 3B , a physician can move the energized electrode over tissue to ablate or coagulate the tissue. During such use, the cutting sleeve 145 and electrode 155 can engage or snag on tissue, inadvertently rotating the electrode 155 from its default centerline position. Therefore, the system provides a controller algorithm, referred to herein as an “active electrode monitoring” algorithm, in which the controller continuously monitors the position signal generated by the Hall sensor 245 during RF energy delivery in both ablation and coagulation modes to determine whether the electrode 155 and inner sleeve 142 have deviated from their centerline position. In another variation, the controller algorithm can then be configured to reactivate the motor drive 105 to return the inner sleeve 142 and electrode 155 to their default centerline position if the electrode 155 has deviated from its centerline position. In another variation, the controller algorithm can be configured to automatically re-apply RF current to the RF electrode 155 when the RF electrode 155 is returned to its default centerline position. Alternatively, the controller 165 can request that the physician manually resume the delivery of RF current to the RF electrode 155 when the RF electrode 155 is returned to the centerline position. In one aspect of the invention, the drive coupling 150, i.e., the magnets 255a and 255b, are mounted to the inner sleeve 142 and the cutting sleeve 145 at a predetermined angular relationship relative to the longitudinal axis 128 so that the Hall sensors generate signals responsive to the magnets 255a, 255b that are the same for all probes within a probe type, allowing the controller algorithm to function properly.

[0065] Turning now to the stopping mechanism or algorithm for stopping the motion of the motor-driven components of the working end 112, FIG. 8 schematically illustrates the algorithm and steps of the stopping mechanism. In one variation, as shown in FIG. 8, a stopping mechanism consistent with the present invention (i) uses a dynamic braking method and algorithm to stop the rotation of the inner sleeve 142 and cutting sleeve 145 (FIGS. 1, 3A, and 3B) at an initial position, and then (ii) a secondary check algorithm is used to check the initial stop position achieved by the dynamic braking algorithm, and if necessary, the stopping algorithm can reactivate the motor drive 105 to slightly reverse (or advance) the rotation of the inner sleeve 142 and drive coupling 150 to the extent necessary to position the cutting sleeve 145 and electrode 155 within the centerline position or within 0° to 5° of the target centerline default position. Dynamic braking is further described below. FIG. 8 schematically illustrates various aspects of a controller algorithm for controlling the rotational speed of the cutting sleeve and stopping the cutting sleeve 145 at the default centerline position.

[0066] Referring to FIG. 8, it can be seen that the controller 165 operates the probe 110 of FIGS. 1, 3A, and 3B at a "set speed." This set speed can be a PID-controlled, unidirectional, continuous rotation mode, or an oscillatory mode in which the motor drive 105 rotates the cutting sleeve 145 in one direction and then reverses the rotation, as is known in the art. At higher rotational speeds, such as 1,000 RPM to 20,000 RPM, it is not practical or feasible to obtain a signal from the Hall sensor 245 indicating the position of the magnets 255a or 255b in the drive coupling 150 in order to apply a stopping algorithm. As shown in FIG. 8, when the physician stops cutting with the probe 110 by releasing the actuator button or foot pedal actuation, the current to the motor drive 105 is turned off. The controller algorithm then uses the Hall sensor 245 to monitor the deceleration of the rotation of the drive coupling 150 and inner sleeve 142 until a slower RPM is reached. The deceleration period can be from 10 milliseconds to 1 second, and is typically about 100 milliseconds. Once an appropriate slower RPM, referred to herein as the "search speed" (see FIG. 8), is reached, the controller 165 restarts the motor drive 105, rotating the drive coupling at a slower speed ranging from 10 RPM to 1,000 RPM (in one variation, between 50 RPM and 250 RPM). An initial "search delay" period ranging from 50 milliseconds to 500 milliseconds is provided to allow the PID controller to stabilize the RPM at the selected search speed. The controller algorithm then monitors the Hall position signal for magnet strength, and when the magnet parameter reaches a predetermined threshold—for example, when the rotational position of the electrode 155 and drive coupling 150 corresponds to the default position of the centerline of 3B—the control algorithm applies dynamic braking to immediately stop the rotation of the motor drive shaft 151, drive coupling 150, and motor-driven components of the probe. FIG. 8 further illustrates that the controller can check the position of the magnet / drive coupling 150 after the braking and stopping steps.If the Hall position signal indicates that the motor-driven component is out of its target default position, the motor drive 105 can be restarted to move the motor-driven component, after which the brakes can be reapplied as described above.

[0067] 8 can typically stop rotation of the drive coupling 150 at approximately a 0°-15° variance of the target stop position, but this can vary depending on whether different types of tissue are cut and impede rotation of the cutting sleeve 145, and whether the physician fully disengages the cutting sleeve from the tissue interface when the motor drive is deactivated. Therefore, dynamic braking alone may not guarantee that the default or stop position is within the desired variance.

[0068] For background, the concept of dynamic braking is described in the following publications: https: / / www.ab.com / support / abdrives / documentation / techpapers / RegenOverview01.pdf and http: / / literature.rockwellautomation.com / idc / groups / literature / documents / wp / drives-wp004_-en-p.pdf. Essentially, a dynamic braking system provides a chopper transistor on the DC bus of an AC PWM drive that feeds a power resistor that converts regenerative electrical energy into thermal energy. The thermal energy is dissipated into the local environment. This process is commonly referred to as dynamic braking, with the chopper transistor and associated control and components, called a chopper module, and a power resistor, called a dynamic braking resistor. The entire assembly of the chopper module with the dynamic braking resistor is sometimes referred to as a dynamic braking module. The dynamic braking resistor allows the magnetic energy stored in the parasitic inductance of its circuit to be safely dissipated during the turn-off of the chopper transistor.

[0069] This method is called dynamic braking because the amount of braking torque you can apply changes dynamically as the load decelerates. In other words, braking energy is a function of the kinetic energy of the rotating mass, and as that decreases, so does your braking ability. So the faster you're rotating or the more inertia you have, the harder it is to brake, but as you slow down, you hit the law of diminishing returns and at some point there's no braking power left.

[0070] In another aspect of the present invention, a method was developed to improve the accuracy of the stopping mechanism, a component of the positioning algorithm described above. It was recognized that each magnet in a single-use probe may vary slightly from its specified strength. As described above, the positioning algorithm uses Hall effect sensor 245 to continuously monitor the magnetic field strength of magnets 255a and 255b as drive coupling 150 rotates, and the algorithm determines the rotational position of the magnet and drive coupling based on the magnetic field strength. As the magnet rotates past the Hall effect sensor, the field strength rises and falls. Therefore, it is important for the algorithm to have a library of field strengths that accurately correspond to the degree of rotation away from the peak Hall signal when the magnet is adjacent to sensor 245. For this reason, the first step of the positioning algorithm includes a "learning" step that enables the controller to learn the actual magnetic field strength of magnets 255a and 255b. Note that the actual magnetic field strength of magnets 255a and 255b may differ from the specified strength. After a new single-use probe 110 (FIG. 1) is coupled to the handpiece 104 and the motor drive 105 is actuated, the positioning algorithm rotates the drive coupling at least 180°, and more frequently at least 360°. During this time, the Hall sensors 245 quantify the magnetic field strength of the particular probe's magnets 255a and 255b. The positioning algorithm then stores the large and small Hall signals (corresponding to the north and south poles) and calibrates a library of field strengths corresponding to various rotation angles away from the Hall small-large signal position when the magnet is adjacent to the Hall sensor.

[0071] Generally, a method of use relating to the learning algorithm includes providing a handpiece with a motor drive, a controller, and a probe having a proximal hub configured for removably coupling to the handpiece, the motor drive configured to couple to a rotating drive coupling in the hub, the drive coupling holding first and second magnets with north and south poles at different positions relative to said axis, coupling the hub to the handpiece, actuating the motor drive to rotate the drive coupling and magnets at least 180 degrees, detecting the strength of each magnet using a handpiece sensor, and using the detected magnet strengths to calibrate a positioning algorithm responsive to the sensors detecting different strengths of the magnets during rotation, thereby increasing accuracy in calculating the rotational position of the drive coupling 150.

[0072] Another aspect of the present invention relates to an expanded method of use using a probe working end with an electrode, such as the working end 112 of FIGS. 1 and 3B. As described above, a positioning algorithm is used to stop rotation of the electrode 155 at the default centerline position of FIG. 3B. An additional "slight oscillation" algorithm is used to activate the motor drive 105 simultaneously with RF current to the electrode 155, specifically an RF cutting waveform for tissue ablation. The slight oscillation thus provides a form of oscillating RF ablation. The slight oscillation algorithm rotates the electrode 155 in one direction a predetermined degree of rotation, which the controller algorithm determines from the Hall position signal. The algorithm then reverses the direction of the motor drive and rotates in the opposite direction until the Hall position signal indicates that a predetermined angle of rotation has been achieved in the opposite direction away from the electrode's default centerline position. The predetermined degree of angular movement can be any appropriate rotation appropriate for the dimensions of the outer sleeve window, and in one variation is 1° to 30° in each direction away from the centerline default position. Often, the predetermined degree of angular movement is 5° to 15° in each direction away from the centerline default. The slight vibration algorithm can use an appropriate PID control of the motor shaft speed, and in one variation, the motor shaft speed is 50 RPM to 5,000 RPM, and often 100 RPM to 1,000 RPM. In other words, the oscillation frequency is 20 Hz to 2,000 Hz, and typically 40 Hz to 400 Hz.

[0073] While the above description of the slight vibration algorithm is provided with reference to the electrode 155 on the rotating cutting sleeve 145 of Figure 3B, it should be understood that the slight vibration operates on a reciprocating electrode 212 such as that shown at the working end 200C of Figure 6. In other words, the hook-shaped electrode 212 of Figure 6 can be provided with a vibration frequency in the range of 20 Hz to 2000 Hz, typically in the range of 40 Hz to 400 Hz.

[0074] 9A and 9B are longitudinal cross-sectional views of a probe hub 120' corresponding to the working end 200B of FIG. 5 having a reciprocating electrode 210. In FIGS. 9A and 9B, the handpiece 104 and Hall effect sensors 240 and 245 are, of course, the same as above, since there are no changes to the handpiece 104 for different types of probes. The probe hub 120' of FIGS. 9A and 9B is very similar to the hub 120 of FIGS. 2A and 2B. Here, the first and second identification / orientation magnets 250a and 250b are the same. The third and fourth rotational position magnets 255a and 255b are also the same and are carried by the drive coupling 150'. The probe hub 120' of FIGS. 9A and 9B differs only in that the drive coupling 150 rotates with a cam mechanism operably coupled to the inner sleeve 142' to convert rotational motion into linear motion to reciprocate the electrode 210 within the working end 200B of FIG. 5. Similar hubs for converting rotary motion to linear motion are provided at working ends 200C and 200D in Figures 6 and 7. Working ends C and 200D each have a reciprocating component (212, 218) at the working end.

[0075] 10, 11A-11C show another variation of an arthroscopic shaver or resection probe 400 somewhat similar to that of FIGS. 1, 3A, and 3B, including a tubular cutter having a proximal hub 402 coupled to an elongated shaft assembly 405. The shaft assembly includes an outer sleeve 410 and a concentric inner sleeve 415 extending along an axis 418 to a working end 420. The hub 402 is also adapted to couple to a motor drive and handpiece operated by a controller and controller algorithm having features as described in the previous embodiment for rotating the inner sleeve 415 and stopping the inner sleeve 415 at a selected rotational position, such as a window-closed position or a window-open position. The working end 420 also has an outer sleeve window 422 that cooperates with the inner sleeve window 425 to engage and resect tissue.

[0076] In the variations shown in FIGS. 10 and 11A-11C, the shaft assembly 405 differs in that the outer sleeve 410 has a distal end portion that includes a dielectric or housing 440 in which the outer window 422 is disposed. In one variation, the inner and proximal portions 426b and 426a of the outer sleeve 410 extending from the hub 402 comprise a thin-walled, conductive metal tube 428, such as stainless steel. As described further below, the proximal or inner portion of the metal tube functions as an electrode, shown at 430 in FIG. 10 . In a typical variation, the dielectric housing 440 comprises a ceramic material, a glass material, a polymer material, or a combination thereof. In some variations, the dielectric housing 440 can be mounted within a metal support portion 442 of the metal outer tube 428 that extends under or partially around the dielectric housing 440.

[0077] 11A shows the working end 436 of the outer sleeve 410 with the outer window 422 separated from the inner sleeve 415. A passageway or bore 444 can be seen extending through the dielectric housing 440 and outer sleeve 410 within which the concentric inner sleeve 415 is rotationally disposed.

[0078] FIG. 11B shows the working end 438 of the inner sleeve 415 separated from the outer sleeve 410 of FIG. 11A in a first position. In the first position, the inner sleeve window 425 faces upward. FIG. 11C shows the same inner sleeve 415 rotated 180 degrees so that the inner sleeve window 425 faces downward. As shown in FIGS. 11B and 11C, the inner sleeve 415 comprises a thin-walled metal tube of a conductive material, such as stainless steel, which can function as an electrode, indicated at 450. Thus, the working end 438 of the inner sleeve 415, which holds the inner window 425, comprises the electrode 450 configured for a tight, rotational fit into the bore 444 of the dielectric housing 440, such that the inner window edge 456, with optional teeth, and the outer sleeve window edge 458 function like scissors to mechanically or electrosurgically shear or excise tissue, as described further below. As shown in FIGS. 11A and 11B, inner sleeve 415 is a thin layer 470 of insulating polymer, such as heat shrink tubing or a parylene coating, that electrically insulates the outer surface of inner sleeve 415 from the inner surface of metal outer sleeve 428.

[0079] In another embodiment of the invention, as shown in Figures 10 and 11C, the backside 472 of the inner sleeve 415 opposite the inner sleeve window 425 has at least one opening 475 provided for fluid to exit therethrough when the inner sleeve 415 is rotated relative to the outer sleeve 410 to a position in which the window is closed (see Figure 1).

[0080] 12 shows the dielectric or ceramic housing 440 with outer sleeve 415 in a phantom view. The dielectric housing 440 can be seen to have a recess 476 where the distal end 477 of the outer sleeve 415 surrounds and supports the dielectric housing 440. The wall thickness of the dielectric housing around the window 422 can range from approximately 0.05 inches to 0.20 inches.

[0081] Figure 13 is a longitudinal cross-sectional view of the working end 420 of the probe of Figures 10-11C, showing the window of the working end 420 in a closed position. It can be seen that the working end 438 of the inner sleeve 415 is in close tolerance with the bore 444 of the outer sleeve and dielectric housing 440, so that rotation of the inner sleeve 415 can shear tissue engaged by the windows 422, 425 of the inner and outer sleeves. Figure 13 further shows the support portion 442 of the metal outer sleeve 428, which extends below the ceramic housing 440. Figure 13 also shows the thin insulating layer 470, which surrounds the inner sleeve 415 and electrically insulates it from the metal outer sleeve 428.

[0082] As shown in FIG. 13 , an RF source 480 is coupled to both the inner sleeve 410 and the outer sleeve 415 to provide electrosurgical functionality. The RF source 480 can provide an average of at least 100 W, or at least 200 W, or at least 300 W, or at least 400 W to enable ignition of a plasma on the exposed outer surface or outer surface 482 of the inner sleeve 415 in the window closed position as shown in FIG. 10 . Typically, the outer surface 482 of the inner sleeve 415 in the window closed position is less than 15 mm², less than 10 mm², or less than 8 mm². Thus, it can be appreciated that during operation, rotation of the inner sleeve 415 about the outer sleeve 410 in a first operating mode can mechanically shear tissue engaged by the windows 422 and 425, or electrosurgically ablate tissue in a second operating mode. That is, the inner sleeve can rotate and simultaneously shear the tissue while the RF source 480 supplies a cutting current to the inner sleeve to generate a plasma that shears the tissue or to energize the edge of the inner sleeve window 425 that can assist in shearing the tissue.

[0083] In general, an ablation probe or treatment device according to the present invention includes a shaft assembly 405 having an outer sleeve 410 and a rotatable inner sleeve 415 coaxially received in a bore 444 of the outer sleeve, the inner and outer sleeves having respective inner and outer cutting windows 422 and 425 and cooperating cutting edges at their distal portions, the distal portion of the outer sleeve holding the cutting window 422 comprising a dielectric housing 440, and the distal working end 438 of the inner sleeve 415 holding the inner cutting window 425 comprising an RF electrode 450.

[0084] In this variation, the dielectric material of the dielectric housing can include at least one of a ceramic, a glass, and a polymer. For example, the ceramic material can be selected from the group consisting of alumina, zirconia, silicon nitride, yttria-stabilized zirconia, magnesia-stabilized zirconia, ceria-stabilized zirconia, and zirconia-toughened alumina.

[0085] 10 includes a motor configured to selectively rotate within the inner sleeve in first and second rotational directions, with a radio frequency (RF) source 480 coupled to the electrode, and a controller operably coupled to the motor and the RF source.

[0086] Typically, the controller includes an algorithm for stopping the motor and positioning the inner sleeve in a window-closed position or a window-open position. The controller is further configured to selectively operate in (i) a first mode in which the motor rotates or vibrates the inner sleeve with the RF electrode de-energized to mechanically cut tissue; (ii) a second mode in which the motor rotates or vibrates the inner sleeve with the RF electrode energized to electrosurgically cut tissue; (iii) a third mode in which the inner sleeve is stationary in the window-closed position and the RF electrode is energized to apply coagulation or ablation energy to tissue; or (iv) a fourth mode in which the inner sleeve is stationary in the window-open position and the RF electrode is energized to apply coagulation or ablation energy to tissue.

[0087] FIG. 14 shows another variation of a working end 500, including an outer sleeve 505 and an inner sleeve 510 adapted to rotate within a bore 512 of the outer sleeve. In this variation, the outer sleeve 505 comprises a conductive metal tube without a ceramic housing, as in the previous variations of FIGS. 10 and 11A. In this variation, the dielectric components separating the conductive inner sleeve 510 from the conductive outer sleeve include a dielectric coating or layer 520 on the distal end 522 of the inner sleeve 510 and a polymer coating 528 on the proximal and inner portions of the inner sleeve 510. The dielectric material 520 on the distal end 522 of the inner sleeve may be a ceramic or glass material that can be configured with a sharp edge 532 to provide a sharp and durable edge 532 for cooperation with an edge 534 of an outer sleeve window 535. In all other respects, the variation of FIG. 14 can operate in the same manner as the variations described in FIGS. 10-13.

[0088] 11B and 11C , but now with an abrasive cutting feature or sharp edge 536 for abrading bone. Thus, another mode of operation may be to rotate the inner sleeve at high speeds to cut or abrade bone using the abrasive feature 536, typically without RF current being applied to the electrode surface. In some methods, RF current may be applied to the electrode surface while abrading or cauterizing hard tissue.

[0089] FIG. 16 illustrates another variation of the working end 540 that operates under similar principles to the variation of FIG. 10 . Here, an outer sleeve 545 holds a distal dielectric or ceramic housing 550, and a concentric inner sleeve 555 with a cutting edge 556 is adapted to move relative to an outer sleeve window 560 within the dielectric housing 550. In this variation, however, the inner sleeve 555 reciprocates rather than rotates. Otherwise, the cutting edge 556 of the inner sleeve 555 is configured to fit snugly within a bore 564 of the dielectric housing 550, such that the inner sleeve cutting edge 556 and the edge 568 of the outer sleeve window 560 shear tissue engaged by the window 560. As described in the previous embodiment, an RF source 480 is operably coupled to both the inner and outer sleeves 545 and 555 to enable electrosurgical cutting. Thus, during use, the reciprocating motion of the inner sleeve can resect tissue mechanically or electrosurgically, as described above.

[0090] FIG. 17 shows another variation of a working end 580 similar to that of FIGS. 14 and 15. In this variation, an outer sleeve 585 comprises a thin-walled conductive metal with a window 588 therein. An inner sleeve 590 comprises a metal sleeve encased in an insulating polymer 592 and a distal ceramic or glass portion 595 that functions as an electrical insulator and provides a cutting edge 596. In this variation, the inner sleeve 590 is again adapted for reciprocating motion. Again, an RF source 480 is operably coupled to both the inner sleeve 585 and the outer sleeves 585 and 590 to enable electrosurgical cutting. During use, reciprocating motion of the inner sleeve can thus resect tissue mechanically or electrosurgically as described above.

[0091] As shown in FIGS. 18, 19A, and 19B, another variation of an arthroscopic shaver or resection probe according to the present invention includes a tubular cutter 600 having a proximal hub 602 coupled to an elongated shaft assembly 605 having an active end 608, as shown in FIG. 18. The shaft assembly 605 includes a first or inner sleeve 610 and a second or outer sleeve 615. The sleeves 105 and 110 extend concentrically or coaxially on a longitudinal axis 618 from the hub 602 to the active end 608. The proximal hub 602 may be similar to or identical to the type of hub shown in FIG. 10 and is typically adapted for coupling to a handpiece and motor drive operated by a controller and controller algorithm having the features described in the previous embodiment for rotating the inner sleeve 610 and stopping the inner sleeve 610 at a selected rotational position (e.g., a window-closed position as shown in FIG. 19A or a window-open position as shown in FIG. 19B). Working end 608 has a first or inner sleeve window 622 that rotates into and out of alignment with a second or outer sleeve window 625 to engage and cut tissue. In the embodiment of Figures 18, 19A, and 19B, both inner sleeve 610 and outer sleeve 615 are electrically conductive, typically formed all or in part of metal, and generally configured to provide a working end similar to that of a commercially available arthroscopic shaver.

[0092] 19A and 19B, elongate shaft assembly 605 and working end 608 differ from previous embodiments described herein in that inner sleeve 610 includes a thin-walled conductive sleeve 632 having an internal lumen 652 and a dielectric insert 635 that holds an active electrode 640 disposed in the wall of the thin-walled conductive sleeve at or near its distal end. An electrical lead 644 (FIG. 19A) extends from an RF source 650 through the internal lumen 652 of inner sleeve 610 (FIG. 19B) to the active electrode 640.

[0093] In one variation, the return electrode 655 may be formed on or as an integral part of the elongate shaft assembly 605. In some cases, the outer sleeve 615 may be insulated from the inner sleeve 610, and the outer surface of the outer sleeve may provide the return electrode, as shown in Figures 19A and 19B. In other examples, the inner sleeve 610 and the outer sleeve 615 may be electrically coupled and may include the return electrode 655.

[0094] 19A , one or more openings 658 may be formed adjacent to or partially below the active electrode 640. Such openings 658 are adapted to allow saline to flow continuously through the working end 608 of the probe regardless of the rotational orientation of the inner sleeve window 622 relative to the outer sleeve window 625. That is, even when the inner sleeve 610 is rotated to close both the outer sleeve window 625 and the inner sleeve window 622, as shown in FIG. 19A , the openings 658 still allow saline to flow into the internal lumen 652 within the internal sleeve 610 when negative pressure is applied to the proximal end of the internal lumen, as described below.

[0095] Thus, the probe can be used in a first mode of operation in which inner sleeve 610 rotates within outer sleeve 615, rotating inner and outer sleeve windows 622, 625 past each other to mechanically cut tissue without supplying RF current. Optionally, the inner sleeve window can be configured with cutting teeth or other cutting elements 623 formed on at least an axially oriented portion of its periphery. Such cutting elements can shear against a peripheral surface 626 formed around the periphery of outer window 625.

[0096] In a second mode of operation, inner sleeve 610 can be rotated with RF source 650 activated to energize active electrode 640 and enhance tissue cutting. That is, the mechanical shearing of tissue caused by rotation of inner and outer windows 622 and 625 continues and is enhanced by the application of RF tissue, typically cutting or ablating current. In another example, RF coagulation current can be applied through electrode 640 while rotating inner and outer windows 622 and 625 to provide simultaneous mechanical ablation and electrosurgical coagulation.

[0097] In a third mode of operation, the controller and controller algorithm can be used to stop rotation of the inner sleeve 610 at the window closed position of Figure 19A and the electrode 640 can be activated to coagulate or ablate tissue without simultaneous mechanical shearing. Ablation of tissue can be performed by applying an RF cutting or ablation current, and coagulation can be performed by applying an RF coagulation current.

[0098] While specific embodiments of the present invention have been described in detail above, it will be understood that this description is for illustrative purposes only and that the above description of the present invention is not exhaustive. Certain features of the present invention are shown in some drawings and not in others; this is for convenience, and any feature may be combined with other features in accordance with the present invention. Certain variations and alternatives will be apparent to those skilled in the art. Such alternatives and variations are intended to be encompassed within the scope of the claims. Certain features presented in dependent claims may be combined and fall within the scope of the present invention. The present invention also encompasses embodiments as if dependent claims were alternatively written in multiple dependent claim format with reference to other independent claims.

[0099] Other variations are within the spirit of the invention. Accordingly, while the invention is susceptible to various modifications and alternative constructions, specific illustrated embodiments thereof are shown in the drawings and have been described above in detail. It is to be understood, however, that there is no intention to limit the invention to the particular forms disclosed, but the intention is to cover all modifications, alternative constructions, and equivalents which are within the spirit and scope of the invention as defined by the appended claims.

[0100] Use of the terms "a," "an," "the," and similar referents in the context of describing the present invention (particularly in the context of the claims that follow) should be construed to include both the singular and the singular unless otherwise stated herein or clearly contradicted by context. The terms "comprise," "have," "comprise," and "contain" should be construed as open-ended terms (i.e., meaning "including, but not limited to") unless otherwise indicated. The term "connected" should be construed as partially or wholly contained within, connected to, or coupled to, even if there is something intervening. Recitation of ranges of values ​​herein is merely intended to serve as a shorthand method of individually referring to each individual value falling within the range, unless otherwise stated herein, and each individual value is incorporated into the specification as if it were individually set forth herein. All methods described herein can be performed in any suitable order unless otherwise indicated herein or clearly contradicted by context. Any and all examples provided herein, or the use of exemplary language (e.g., "etc.") are intended merely to better clarify embodiments of the invention and do not impose limitations on the scope of the invention unless otherwise claimed. No language in the specification should be construed as indicating any non-claimed element as essential to the practice of the invention.

[0101] Preferred embodiments of the present invention are described herein, including the best mode known to the inventors for carrying out the invention. Variations of those preferred embodiments may become apparent to those skilled in the art upon reading the foregoing description. The inventors expect that such variations will be utilized by those skilled in the art, and the inventors intend to practice the invention otherwise than as specifically described herein. Accordingly, this invention includes all modifications and equivalents of the subject matter recited in the claims appended hereto as permitted by applicable law. Moreover, any combination of the above-described elements in all possible variations thereof is included in the invention unless otherwise indicated herein or clearly contradicted by context.

[0102] All references cited in this specification, including publications, patent applications, and patents, are herein incorporated by reference to the same extent as if each reference was individually and specifically indicated to be incorporated by reference and was set forth in its entirety herein. [Explanation of symbols]

[0103] 602 Proximal Hub 605 Shaft Assembly 608 Working End 610 Inner sleeve 615 Outer sleeve 618 Longitudinal Axis 622 Inner Sleeve Window 625 Outer Sleeve Window 635 Dielectric Insert 640 Active Electrodes 650 RF source 655 Return Electrode

Claims

1. 1. An arthroscopic cutting probe, comprising: an outer sleeve having a longitudinal bore and an outer cutting window at a distal end, the outer sleeve comprising a metal that functions as a return electrode; an inner sleeve rotatably disposed within the longitudinal bore of the outer sleeve, the inner sleeve having a distal end, a proximal end, a longitudinal passageway, and an inner cutting window disposed through a cylindrical wall of the inner sleeve near its distal end, the inner sleeve comprising a first portion being a thin-walled conductive sleeve member and a second portion being a dielectric insert disposed within the wall of the thin-walled conductive sleeve member at or near the distal end of the inner sleeve, the dielectric insert holding the active electrode surrounded by the dielectric insert so as to electrically insulate the active electrode from the thin-walled conductive sleeve member; Equipped with the inner sleeve is coupled to a drive coupling configured to couple to a motor drive unit to rotate the inner sleeve relative to the outer sleeve, rotate the inner cutting window past the outer cutting window, and cut tissue received through the cutting windows as they pass one another; the active electrode may be selectively positioned within the outer cutting window as the inner sleeve rotates within the outer sleeve; An arthroscopic cutting probe, wherein an aperture is disposed through at least one of the active electrode and the cylindrical wall of the inner sleeve adjacent the active electrode.

2. The arthroscopic cutting probe of claim 1 , wherein the longitudinal passage of the inner sleeve is configured to be coupled to a source of negative pressure.

3. 3. The arthroscopic cutting probe of claim 2, wherein the distal end of the inner sleeve is sealed except for the inner cutting window and the opening, such that negative pressure applied to the proximal end of the longitudinal passage can be drawn through either the inner cutting window or the opening, depending on which is aligned with the outer cutting window.

4. An arthroscopic cutting probe as described in claim 1, wherein the dielectric insert is positioned on the side of the cylindrical wall of the inner sleeve opposite the inner cutting window.

5. The arthroscopic cutting probe of claim 1 , wherein the active electrode has a curved surface that matches the curvature of the cylindrical wall of the inner sleeve.

6. The arthroscopic cutting probe of claim 1 , wherein the dielectric insert comprises a ceramic material, a glass material, a polymer, or a combination thereof.

7. An arthroscopic cutting probe as described in claim 1, wherein the inner sleeve has a bullet-shaped distal end on which the inner cutting window is provided.

8. An arthroscopic cutting probe as described in claim 7, wherein the bullet-shaped distal end of the inner sleeve comprises metal.

9. The arthroscopic cutting probe of claim 1 , wherein the outer sleeve has a bullet-shaped distal end with the outer cutting window disposed thereon.

10. The arthroscopic cutting probe of claim 1 , wherein the inner cutting window nests within the outer cutting window when the inner and outer cutting windows are aligned.

11. The arthroscopic cutting probe of claim 1 , wherein the active electrode nests within the outer cutting window when the active electrode and the outer cutting window are aligned.

12. 1. An arthroscopic cutting system comprising: An arthroscopic cutting probe according to any one of claims 1 to 11; a motor drive unit coupled to the inner sleeve and configured to rotate the inner sleeve relative to the outer sleeve; a radio frequency (RF) power source configured to be coupled to the active electrode and the return electrode; a controller configured to control the motor drive unit and the RF power supply; 1. An arthroscopic cutting system comprising:

13. The controller a first mode of mechanical tissue cutting, wherein the motor drive is activated to rotate the inner cutting window past the outer cutting window and the RF power source is not activated; a second mode for combined mechanical and electrosurgical tissue cutting, wherein the motor drive is activated to rotate the inner cutting window past the outer cutting window and the RF power source is activated to supply cutting, ablation, or coagulation current to the active electrode; and a third mode, wherein the motor drive holds the active electrode stationary within the outer cutting window and activates the RF power source to supply a cutting, ablation, or coagulation current to the active electrode; 13. The arthroscopic cutting system of claim 12, configured to operate the motor drive and the RF power source in each of

14. 14. The arthroscopic cutting system of claim 13, further comprising a negative pressure source configured to couple to the longitudinal passage of the inner sleeve to draw suction through the cutting windows as they pass each other when operating in either the first mode or the second mode, or to draw suction through the opening when operating in the third mode.

15. The arthroscopic cutting system of claim 14 , wherein the controller is configured to activate the negative pressure source.

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