Powered surgical handpiece, holder and cutting accessory

Abstract

A motorized surgical handpiece having a collet is disclosed. Within the collet is a clamping member that releasably retains the shaft of a cutting accessory to the drive shaft so that the cutting accessory rotates upon motor actuation. The collet includes a ring having an opening through which the cutting accessory is inserted. The opening is non-circular in shape. When the shaft of an accessory having a cross-sectional shape that matches the opening shape is inserted into the opening, the shaft of the accessory is properly aligned with the collet clamping member.

Description

[0001] This application is a divisional application of a patent application filed on July 27, 2015, with application number 202010096011.X, entitled "Electric Surgical Handpiece, Holder and Cutting Attachment", which in turn is a divisional application of a patent application filed on July 27, 2015, with application number 201580050298.X, entitled "Electric Surgical Handpiece with Holder for Easy Alignment of Cutting Attachment to Tool". Technical Field

[0002] This invention generally relates to a surgical tool system with selectively attached cutting attachments. More specifically, this invention relates to a surgical tool system having cutting attachments configured to facilitate alignment of the attachments with a holder that holds the attachments to a tool handpiece. Background Technology

[0003] In modern surgery, one of the most important instruments available to medical personnel is the power surgical tool. Typically, such a tool includes a handheld unit that houses a motor. Attached to the handheld unit is a cutting attachment. The cutting attachment is designed to be applied to the patient's surgical site to accomplish specific medical tasks. Some power surgical tools are equipped with drills or small drills for making holes in hard tissue or for selectively removing hard and soft tissue. Other power surgical tools also include a saw blade as a cutting attachment. These tools are used to separate large segments of hard and / or soft tissue. The ability to use power surgical tools on patients reduces physical strain on physicians and other medical personnel when performing procedures on patients. Moreover, most surgical procedures can be performed faster and more accurately using power surgical tools than with the manual surgical tools that preceded them.

[0004] By reference to U.S. Patent No. 5,888,200, entitled "MULTI-PURPOSE SURGICALTOOL SYSTEM," published March 30, 1999, a surgical tool system designed for a variety of different applications is disclosed. This tool system includes a handpiece in which a motor is housed. The handpiece also includes a first coupling assembly for selectively coupling an attachment shaft to the motor shaft. The handpiece also includes a second coupling assembly for selectively securing an attachment to the front end of the handpiece. This attachment may include its own drive shaft and attachment coupling assembly. These attachments are elongated attachments, angled attachments, and / or capable of actuating a saw blade. Therefore, the advantage of providing this type of tool system is that a single handpiece can be used to drive multiple different cutting attachments and assist in positioning the attachments at the surgical site in a manner required or desired for a particular surgical procedure.

[0005] A variation of this tool system is disclosed in U.S. Patent No. 6,562,055, published May 13, 2003, entitled "CUTTING ATTACHMENT FOR ASURGICAL HANDPIECE DESIGNED TO BE SELECTIVELY COUPLED TO THE HANDPIECE," the contents of which are expressly incorporated herein by reference. This document discloses a surgical tool with a drive shaft having an elongated bore. The drive shaft bore is sized to the proximal end of a shaft for receiving an accessory. A chuck is mounted to the drive shaft to rotate with it. The chuck has a foot projecting into the drive shaft bore. This assembly is also designed to allow the accessory shaft to be selectively longitudinally positioned relative to the chuck foot. The accessory is formed with several retaining features arranged longitudinally along the length of the drive shaft. These features allow the physician to selectively set the extent to which the accessory shaft extends forward of the handpiece. In particular, the physician may want to set the distal end of the accessory shaft to extend a relatively short distance forward of the handpiece shaft, the distal end of which is the end to which a tissue manipulation member is attached. The attachment is positioned such that the distal positioning retaining feature engages with the chuck foot. Alternatively, the physician can reposition the cutting attachment so that the tissue manipulation component is positioned relatively far from the handpiece. For this system configuration, the axis is set longitudinally relative to the chuck, such that the proximal positioning retaining feature is a retaining feature engaged with the chuck foot.

[0006] The advantage of the above structure is that a single cutting attachment can be positioned such that the attachment head is positioned at different distances from the handpiece. This eliminates the need to provide several cutting attachments configured such that the distance between only two different attachments is the overall length of the attachment shaft.

[0007] The above types of surgical tool systems work well when the attachments have a rigid axis.

[0008] However, many different surgical tool systems are equipped with cutting attachments having relatively thin and / or flexible axes. One type of surgical tool system equipped with this type of thin, flexible cutting attachment axis is the minimally invasive surgery (MIS) tool system. MIS tool systems, as their name suggests, are designed to be applied to the surgical site in the patient through a relatively small opening formed in the patient, called a gate. The goal behind performing a MIS procedure is to minimize the size of the incision formed in the patient to be close to the internal part of the patient to be operated on. One reason this goal is desired is that it reduces the extent to which patient tissues need to return to their initial state and heal after surgery. Another advantage of performing a MIS procedure is that, in contrast to procedures that form larger incisions, MIS procedures reduce the degree to which internal tissues and organs are exposed to the surrounding environment. By extension, this reduces the degree to which patient tissues are exposed to infection.

[0009] Many tools designed to perform MIS procedures have a relatively small cross-sectional width. This facilitates the fitting of the tool into the relatively small diameter opening formed in the patient. Some MIS tools are designed to insert into circular openings with a diameter of 2 cm or less. These tools themselves may have a cross-sectional diameter of 0.5 cm or less.

[0010] There exists an electric surgical tool that includes a cutting attachment designed to sit within small-diameter holes. Typically, this type of tool system has a front attachment designed to be releasably attached to a handpiece. The cutting attachment is rotated by a handpiece motor and within the attachment. Some of these attachments have a longitudinal axis with bends. The attachment axis is flexible so that as the axis bends, the attachment is bent or angled.

[0011] For accessory shafts to be bent or flexed, or to be fitted into small-diameter attachments, their diameters are typically designed to be relatively small. Some accessory shafts have flexible sections with a diameter of 2 mm or less.

[0012] Problems arise due to the small size and flexibility of these accessory shafts. These shafts can bend or rotate when inserted into the handpiece. This bending is generally away from the longitudinal axis passing through the shaft. Rotation is generally around the longitudinal axis. Bending can occur during the process of inserting the accessory into the handpiece. When bending occurs, it may be necessary to rotate the shaft to position it in a position where the retaining feature is aligned with the complementary retaining feature integrated into the holder. This action must be taken, which increases the overall time required to perform the surgical procedure. Increasing the time required to perform this task is detrimental to one of the goals of modern surgery. In particular, the goal of modern surgery is to perform procedures as quickly as possible to minimize the time the patient is held under anesthesia and the time the patient's body is open and exposed to the surrounding environment.

[0013] Undesirable rotation of the accessory shaft can occur during the procedure when the handpiece is actuated. Specifically, when the handpiece rotates, the entire accessory shaft should rotate at the same speed. However, due to the different forces applied to different parts of the accessory and the flexible nature of the accessory shaft, some twisting may exist within the accessory shaft about its longitudinal axis. Due to this twisting and the natural tendency of the material forming the shaft to twist back to an untwisted state, the proximal end of the accessory shaft, i.e., one end of the shaft arranged integrally with the drive shaft of the handpiece, may want to rotate within the drive shaft. This rotation of the shaft can cause the shaft retaining feature to rotate out of engagement with the chuck feet or other clamping retaining features that hold the shaft in place. If this type of movement of the accessory shaft relative to the drive shaft occurs, the accessory shaft may not be securely held in place by the drive shaft. Summary of the Invention

[0014] This invention relates to a novel and useful surgical tool system. The surgical tool system of the present invention includes a powered surgical handpiece and a cutting attachment rotated by the handpiece. The system of the present invention includes a retainer having a locking member integrally formed with the handpiece. The system also includes a retaining feature integrally formed with the cutting attachment. The retainer locking member is designed to engage the attachment retaining feature such that, due to this engagement, the attachment rotates with rotation of the locking member. The system of the present invention is also designed such that the handpiece and the cutting attachment have complementary features that, when the cutting attachment is assembled to the handpiece, align the attachment retaining feature with the retainer locking member. These features also inhibit relative rotation of the attachment relative to the handpiece locking member.

[0015] In some configurations of the invention, the retainer includes an alignment ring. The alignment ring is positioned distally at the front of the locking member. The alignment ring has a non-circular opening. The accessory shaft is shaped such that at least a proximal section of the shaft is non-circular. More specifically, the accessory shaft is shaped to slide snugly fit into the opening in the alignment ring.

[0016] The alignment ring opening is positioned relative to the locking element of the clamp. The retaining feature on the accessory shaft is in the corresponding position along the shaft.

[0017] As part of the process of preparing the tool system of the present invention for use, the accessory shaft is inserted into the aligning ring of the clamping device. To assemble the accessory shaft in this way, it is generally necessary to rotate the shaft so that the non-circular portion of the shaft aligns with the non-circular hole in the aligning ring. Once this alignment process is completed, it is simple to slide the shaft through the ring. Due to the alignment of the accessory shaft with the aligning ring of the clamping device, the shaft retaining feature is aligned with the clamping device locking element.

[0018] The clamping ring rotates with the rotation of the handpiece output shaft. Due to the tight fit of the accessory shaft in the ring's hole, the accessory shaft is forced to rotate with the ring. This suppresses twisting of the relatively short section of the accessory shaft located near the ring. The elimination of this twisting also eliminates twisting that could cause the accessory shaft to disengage from the clamping locking element.

[0019] In some embodiments of the invention, the clamp includes a gripper having a spring, similar to a foot used as a locking element for a handpiece.

[0020] In some embodiments of the invention, the holder is removably attached to a housing containing a handheld motor. Attached Figure Description

[0021] The invention is characterized by the claims. The above and other features and benefits of the invention are understood through the following detailed description given in conjunction with the accompanying drawings. Unless otherwise stated, the relative dimensions of the components shown in the figures are generally understood to be the relative dimensions of the components with respect to each other. In the drawings:

[0022] Figure 1 This is a plan view of the surgical tool system of the present invention;

[0023] Figure 2 yes Figure 1 An exploded diagram of the system's basic components;

[0024] Figure 3 This is a plan view of the removable card holder of this system;

[0025] Figure 4 This is a cross-sectional view of the card holder;

[0026] Figure 5 This is an exploded view of the card holder;

[0027] Figure 6 This is a perspective view of the card holder body;

[0028] Figure 7 This is a cross-sectional view of the card holder body;

[0029] Figure 8 is an alternative perspective view of the card holder body;

[0030] Figure 9 This is a perspective view of the card holder cover;

[0031] Figure 10 This is a cross-sectional view of the card holder cover;

[0032] Figure 11 is a perspective view of the clamp spring coil;

[0033] Figure 12 is a perspective view of the drive shaft inside the card holder;

[0034] Figure 13 is a sectional view of the drive shaft;

[0035] Figure 14 is a perspective view of the clamp;

[0036] Figure 15 is an exploded view of the chuck, alignment ring, and drive pin;

[0037] Figure 15A It describes how the distal end of the clamp sits in the alignment ring;

[0038] Figure 16 It is a perspective view of the alignment ring;

[0039] Figure 17 It is a planar view of the far end of the alignment ring;

[0040] Figure 18 It is a cross-sectional view of the alignment ring;

[0041] Figure 19 This is a perspective view of the locking ring of the card holder;

[0042] Figure 20 This is a perspective view of the actuator inside the card holder;

[0043] Figure 21 This is a cross-sectional view of the actuator;

[0044] Figure 22 This is a perspective view of the transmission rod inside the clamp;

[0045] Figure 23 This is a perspective view of the torque loop inside the clamp;

[0046] Figure 24 This is a sectional view of the nose from the perspective of a surgical tool system.

[0047] Figure 25 is a perspective view of the distal end of the cut accessory shaft;

[0048] Figure 26 is a plan view of the proximal end of the cut attachment viewed from the far forward side; and

[0049] Figure 27 is a planar view of the proximal end of the cut accessory shaft, in which the side edges of the retaining feature are visible. Detailed Implementation

[0050] The basic components of the surgical tool system 40 of the present invention are referenced. Figure 1 and Figure 2 As can be seen, system 40 includes a handheld component 42. The handheld component 42 has a cylindrical body 44. Inside the handheld component body 44 is a motor 46, depicted by a shaded rectangle. The motor 46 rotates a drive spindle 48, depicted by a second shaded rectangle. A clasp 60 is removably attached to the distal end of the handheld component body 44. ("Distal" is understood to mean away from the physician holding the handheld component 42 and towards the surgical site to be performed. "Proximal" is understood to mean towards the physician holding the handheld component 42 and away from the surgical site to be performed.) A nose portion 302 is removably attached to the distal end of the clasp 60 and extends forward from the distal end of the clasp. A cutting attachment 320 is disposed inside the nose portion 302. The cutting attachment 320 is coupled to the clasp 60 and extends through and out of the distal end of the nose portion 302. A tissue manipulation member 338 positioned at the anterior portion of the nose portion 302 forms the distal end of the cutting attachment.

[0051] Inside the holder 60 is a drive shaft 134 (Figure 12). The proximal end of the drive shaft is configured to engage and be rotated by the handpiece spindle 48. The components inside the holder 60, described below, releasably hold the cutting attachment 320 to the drive shaft 134. Actuation of the motor 46 thus causes rotation of the cutting attachment 320.

[0052] The handheld component 42 is formed such that the main body 44 is approximately cylindrical. The distal end of the main body 44 is as follows: Figure 2 The dotted opening 45 in the figure depicts the opening. This allows the proximal end of the holder 60 to be seated in the body 44. The drive spindle 48 extends into the open distal end of the handpiece.

[0053] The handheld motor 46 is any suitable motor for actuating the cutting attachment. Motor 46 is typically an electro-hydraulic or hydraulically driven motor. Cable 43 is visible extending from the proximal end of the handheld body 44. Cable 43 represents energy, gas, or water for driving the motor sourced from a control panel independent of the system 40 of this invention. Such a motor, which can be incorporated into the handheld part 42, is disclosed in the applicant's U.S. Patent No. 8,597,316, published December 2, 2013, entitled "CUTTING ACCESSORY FOR FOR USE WITH A MEDICAL / SURGICAL POWERED HANDPIECE, THE ACCESSORYHAVING FEATURES THAT FACILITATE THE FINE OR COARSE ADJUSTMENT OF THE EXTENSION OF THE ACCESSORY SHAFT," the contents of which are incorporated herein by reference. A control console capable of supplying electrical power to an electric drive motor is disclosed in the applicant's U.S. Patent No. 7,422,582, granted on September 9, 2008, which states that "CONTROL CONSOLE TO WHICH POWERED SURGICAL HANDPIECES ARE CONECTED, THE CONSOLE CONFIGURED TO SIMULTANEOUSLYE NERGIZE MORE THAN ONE AND LESS THAN ALLOF THE HANDPIECES," the contents of which are incorporated herein by reference. Again, it should be understood that the structure of the handheld motor 46 and the components for supplying power to the motor are not part of this invention.

[0054] The drive spindle 48 is rotatably mounted in the body 44 by a bearing (not shown and not part of the invention). The drive spindle 48 can be accessed through the open end 45 of the handheld body 44. The drive spindle is formed with a rectangular closed end hole 49 that opens from the distal end of the spindle and extends proximally from the distal end of the spindle.

[0055] Card holder 60 is configured to have in Figures 3-5 The visible housing 62 and cover 104 integrate to form the body of the holder's outer shell. Figure 6 - The shell 62, best visible in Figure 8, is formed from a single metal piece having multiple distinct cylindrical segments. One proximal cylindrical segment is the foot 64. The foot 64 has two recesses extending inward from the outer surface of the foot and circumferentially around the foot. The first of these recesses is an annular notch 66. The second recess is a groove 68. In cross-section, both the notch 66 and the groove 68 are rectangular in shape. The shell 62 is formed such that the groove 68 is forward-spaced from the notch 66 and is shorter in length than the notch. Figure 5 A centrally visible hole 69 extends inward from the outer surface of the foot. The hole 69 is positioned distally at the front of the groove 68. The housing 62 has a ring 70 at the front of the foot 64. The ring 70 has an outer diameter larger than the outer diameter of the foot 64. In the depicted embodiment of the invention, the outer diameter of the ring 70 is tapered. The diameter of the ring decreases slightly distally from its proximal end.

[0056] The housing 62 has a head 72 at the front of the ring 70. The head 72 generally has a diameter approximately equal to that of the foot 64. The front portion of the head 72 proximal to the front end is formed with a helical groove 74. The groove 74 is symmetrical about a longitudinal axis passing through the proximal to distal side of the housing 62. The housing 62 is also formed such that a stop 76 (one visible in FIG. 8) is present adjacent to each groove 74. At the front portion of the groove 74 present in the head 72, the head is formed with a circumferentially extending notch 78. In the portion of the head 72 in front of the notch 78, a hole 80 extends laterally through the head.

[0057] The lip 84 extends forward from the head 72 and forms the farthest portion of the housing 62. The lip 84 has an outer diameter smaller than the outer diameter of the head 72. The lip 84 is formed with threads (not shown).

[0058] The housing 62 is formed having a plurality of continuous holes that form a longitudinally extending channel through the housing. A first hole, namely hole 88, extends distally forward from the proximal end of the housing. Hole 88 is thus positioned within the housing foot 64. The housing 62 is also formed such that the inner wall defining hole 88 has a notch 90 extending circumferentially outward from hole 88. The notch 90 is continuous with hole 88 and positioned approximately in the middle of the hole. The notch 90 extends circumferentially around hole 88.

[0059] A hole 92 extends distally forward from the distal end of a hole 88. The housing 62 is formed such that the hole 92 is positioned within a housing annulus 70. The hole 92 has a diameter smaller than that of the hole 88. The distal end of the hole 92 opens into a hole 96. The hole 96 has a diameter smaller than that of the hole 88 but larger than that of the hole 96. The housing 62 is also formed to define a groove 94 in the inner wall of the defining hole 96 of the housing. The groove 94 extends outwardly from the proximal end of the hole 96 where the hole 88 opens into the hole 96. The groove 94 extends circumferentially around the outer side of the hole 96. A hole 98 extends from the distal end of the hole 96 to the distal end of the housing 62. The hole 98 has a diameter larger than that of the housing hole 88. The housing 62 is formed such that the hole 98 extends through both the housing head 72 and the distal lip 84.

[0060] Now for reference Figure 9 and Figure 10 The described cover 104 has a base 106. The cross-section of the base 106 is generally circular. The cover 104 is also formed such that the outer diameter of the base decreases slightly as it extends distally. The cover has an annulus 110 at the front of the base 106. The annulus 110 is generally cylindrical and has a diameter smaller than that of the base. The cover 104 is also formed such that the portion of the annulus 110 immediately adjacent to the front of the base 106 has a notch 108. The notch 108 extends circumferentially around the annulus 110.

[0061] The neck 112 extends forward and distally from the cover ring 110. The neck 112 has a curved outer surface with a diameter smaller than that of the ring 110. The outer surface of the neck 112 is not perfectly cylindrical. In fact, the neck 112 is formed with two parallel flat portions 114 that are opposite in diameter. The flat portions 114 are located inside the connecting outer curved section of the neck 112.

[0062] A cylindrical head 116 extends forward from the ring 110. The head 116 has a diameter smaller than the distance through the flat portion 114 of the neck. At a short distance of approximately 4 mm from the anterior portion of the proximal end of the head, a hole 118 extends laterally through the head. The hole 118 extends into the hole 117 described below. A rim 120 is present at the distal end of the head 116. The rim 120 projects radially outward from the head 116.

[0063] A hole 105 extends distally forward from the proximal end of the cover base 106. The hole 105 has a diameter larger than the diameter of the housing head 72. The distal end of the hole 105 opens into a hole 107. The hole 107 has a diameter smaller than the diameter of the hole 105. The inner cylindrical wall of the cover 104 defining the hole 107 is threaded (not shown). More specifically, the cover hole 107 is sized to fit the housing lip 84 such that complementary threads around the housing lip 84 engage with the hole. A hole 109 extends forward from the hole 107. The hole 109 has a diameter smaller than the diameter of the hole 107. The not shown area is the cut between holes 107 and 109. The hole 109 is tapered. Therefore, the diameter of the hole 109 decreases as it extends distally from the hole 107.

[0064] The distal end of hole 109 opens into hole 111. Hole 111 is cylindrical in shape and has the same diameter as the distal end of hole 109. Hole 111 opens into hole 115. Hole 115 has a smaller diameter than that of hole 111. Cutout 113 is located between holes 111 and 115.

[0065] A hole 117 extends through the cover head 116 at the front of the hole 115. The hole 117 has a section with varying diameter. The cover head 116, including the hole 117, is formed to receive a component 308 inside the nose 302, the component being used to releasably retain the nose to the holder 60.

[0066] Pin 119 is seated in the cover hole 118. Pin 119 ( Figure 4 It cooperates with the nose connection feature 308 to hold the nose 302 to the holder 60.

[0067] In Figure 11, the flexible spring coil 124, best visible, snaps into a recess 66 formed in the foot 64 of the housing. The spring coil 124 is generally in the form of a cylindrical sleeve with an intermittent portion 126 extending the length of the ring. The spring coil is formed such that the corresponding outer surfaces 128 and 130 of the ring taper inward at the proximal and distal ends. The components of the forming system 40 are sized such that when the ring 124 is seated on the foot 64 of the holder, the main outer annular surface 129 of the spring coil 124 protrudes outward from the foot. This assists in the snap-fit ​​of the ring into and out of an opening 45 inside the handheld body 44. Structural features abutting the spring coil 124 inside the handheld body 44 are not shown. These surfaces are surfaces that constrain the movement of the spring to assist in the releasable attachment of the holder 60 to the handheld part 42.

[0068] exist Figure 5An O-ring 125, visible in the image, is seated in and extends out of a recess 68 in the housing. The O-ring 125 dampens vibrations of the retainer 60 relative to the handpiece. A pin 127 is seated in and extends out of a bore 69 in the housing. The pin 127 cooperates with a component inside the handpiece body 44 to prevent rotation of the retainer 60 relative to the handpiece 42. The component inside the handpiece body that engages the pin 127 is not part of the present invention.

[0069] As best seen in Figures 12 and 13, the gripper drive shaft 134 is a one-piece unit. The drive shaft is formed with a leg 136 at its proximal end. The leg 136 is generally cylindrical. At the proximal end of the shaft 134, the leg 136 is formed such that two parallel flat portions 138 (one visible) extend forward from the proximal end of the leg. The proximal portion of the leg, i.e., the portion where the flat portion 138 is presented, is dimensioned for sliding fit in the handgrip drive spindle hole 49, so that there is a minimum clearance between the spindle 48 and the drive shaft leg. Not shown but visible in Figures 12 and 13 is a hole extending distally forward from the proximal end of the drive shaft 134. This hole is not part of the present invention.

[0070] The drive shaft has a waist section 139 at the front of the leg 136. The waist section 139 is cylindrical in shape and has a diameter larger than that of the leg 136. The drive shaft has a torso 142 at the front of the waist section. The torso 142 is cylindrical in shape and has a diameter larger than that of the waist section 139. A cut 144, for manufacturing purposes, separates the waist section 139 and the torso 142. A cut 140, also for manufacturing purposes, separates the leg 136 from the waist section 139. The torso 142 has two symmetrical, opposite elliptical openings 146 at the front of the cut 144. The torso 142 is shaped such that the main axis of the openings 146 is parallel to the proximal to distal longitudinal axis passing through the drive shaft 134.

[0071] The drive shaft 134 is also configured to have a neck 150 located immediately anteriorly at the distal end of the torso 142. The neck 150 extends radially outward from the torso 142. An incision, not shown, is located proximally in the torso 142 immediately adjacent to the neck 150. The neck 150 has a proximal outer surface 152.

[0072] The drive shaft 134 has a head 158 at the front of the neck 150. The head 158 is cylindrical in shape. The head 158 has a diameter equal to or smaller than the diameter of the shaft body 142.

[0073] A bore 162 extends proximally from the distal shaft head 158. The bore 162 extends through the shaft head 158 and neck 150 and partially through the body 142. The proximal end of the bore 162 opens into a bore 166. The bore 166 is coaxial with the bore 162 and is smaller in diameter than the bore 162. A step 164 at the proximal end of the bore 162 defines the transition between the bore 162 and the bore 166. The bore 166 terminates at a position anterior to the proximal end of the shaft body 142. An opening 146 in the body opens into the bore 166.

[0074] exist Figure 4 and Figure 5 Two bearing assemblies 170, visible in the image, rotatably hold the drive shaft 134 to the holder housing. (Not specifically shown are the inner and outer sleeves of the bearing assembly 170. The inner sleeve, positioned proximal to the bearing assembly 170, is arranged above the waist section 139 of the drive shaft 134. The outer sleeve, also positioned proximal to the bearing assembly 170, sits against the inner wall of the housing 62 defining the bore 96. Wave-shaped washer 172 ( Figure 5 The wave washer 172 is positioned proximally adjacent to the proximal end of the proximal bearing assembly 170. The outer periphery of the wave washer 172 is seated in the housing recess 94. The inner periphery of the wave washer is seated in the drive shaft recess 140. The wave washer 172 abuts against the drive shaft 134 to push the drive shaft forward distally.

[0075] The inner sleeve of the distal bearing assembly 170 is seated around the drive shaft head 158. The outer surface of the bearing assembly is arranged against the inner cylindrical wall of the cover 106 defining the bore 111. The component forming the retainer 60 is sized such that the distal end of the drive shaft is spaced behind the cutout 113 inside the cover 106.

[0076] The chuck 178, now described with reference to Figures 14 and 15, is slidably arranged in the drive shaft 136. The chuck 178 releasably holds the cutting attachment 320 to the drive shaft. The chuck 178 is a one-piece component including a base 182. The base 182 is cylindrical and sized to be slidably fitted within the drive shaft bore 166 with minimal lateral movement. A crown 180 extends proximally from the proximal end of the chuck base 182 a short distance forward. The crown 180 is tapered such that the diameter of the outer surface of the crown decreases as it extends proximally from the base 182. A bore 184 extends longitudinally through the crown and base 182. The bore 184 is present for manufacturing reasons. The presence of the bore 184 also assists in the deflection of the chuck leg 192, discussed below. A bore 186 extends laterally through the chuck base 182 from side to side. Boreholes 184 and 186 intersect. The chuck 172 is formed such that the groove 188 extends forward and distally from the hole 188. The groove 188 is positioned on a plane extending from the proximal to the distal side, and the longitudinal central axis of the chuck 178 lies in said plane.

[0077] Two legs 192 extend forward from the clamp base 182. The legs 192 are arched. A circle defined by the outer surface of the leg has a diameter smaller than that of the base 182. A circle defined by the inner surface of the opposite face of the leg defines a gap 193, the distal end of which is indicated in FIG. 14. In a cross-section in a plane perpendicular to the longitudinal axis, the gap 193 is approximately circular in shape.

[0078] Ankle 194 and foot 196 are located distal to each leg 192. Each ankle 194 has an outer surface flush with the outer surface of the leg, from which the foot extends. As discussed below, foot 196 has an outer surface extending radially outward from the outer surface of ankle 194. Each ankle 194 and foot 196 has a pair of opposite sides 198. Ankle 194 and foot 196 are shaped such that the sides 198 taper relative to the proximal to distal longitudinal axis passing through the ankle and foot. Therefore, the distance between opposite sides 198 is relatively short, smaller than the distance across the leg, immediately adjacent to the ankle 194 extending from it. The distance between the sides 198 of a single foot 196 increases as it extends distally. Thus, on each side of clamp 178, the adjacent side surface of the opposite ankle and foot defines a recess 202, one of which is indicated in Figure 14. Each recess 202 has a shape such that the width through the recess decreases distally along the recess. The recess 202 can be considered to have a curved wedge shape.

[0079] Each foot 196 has four arched outer surfaces. A first outer surface, surface 204, extending distally from the ankle, tapers outwards as it extends distally, the surface being approximately perpendicular to the longitudinal axis passing through the chuck 178. A second surface, surface 206, has a radius of curvature that is substantially constant along its length. A third surface, surface 208, extending distally, tapers slightly outwards from surface 206. Surface 208 tapers to a fourth surface, surface 210. Surface 210 has a constant diameter. A circle defined by the opposite surface 210 has a diameter approximately 0.12 mm smaller than the diameter of the drive shaft bore 162. This sizing allows the chuck legs 192, ankle 194, and foot 196 to flex outwards away from the longitudinal axis extending through the drive shaft 136.

[0080] Each foot 196 protrudes inward toward the longitudinal axis of the clamp 178 and opposite feet 196. The innermost surface of each foot is considered to be the head surface 211. The head surface 211 is convex in shape.

[0081] The reference is also slidably arranged in the drive shaft 136. Figures 16-18The alignment ring 212 is described. The alignment ring 212 has a cylindrical head 230. More specifically, the head 230 is sized to move longitudinally within a drive shaft bore 192. A waist 228 is positioned proximally rearward from the head 230. The waist 228 is shaped to taper inwardly extending proximally from the head 230. A pair of opposing feet 226 extend outwardly from the waist 228. The feet 226 and waist 228 are combined to define a recess 229 extending distally from the proximal end of the ring 212. The recess 229 is sized to receive opposing clamp ankles 194 and feet 196.

[0082] The alignment ring 212 is also formed with an opening 232 extending proximally from the distal end of the ring. The opening 232 is tapered. As the opening 232 extends proximally from the distal end of the head 230, its diameter decreases. The opening 232 terminates at a cylindrical hole 234. The proximal end of the hole 234 opens into a hole 236. In cross-section, in a plane perpendicular to the longitudinal axis passing through the alignment ring 212, the hole 236 is a flattened ellipse. More specifically, the hole 236 has two opposing parallel sides. Two curved ends connect the parallel sides. Each curved end faces an arc of approximately 120°. Only... Figure 18 As indicated in the diagram, two stepped portions at the base of hole 234 define the transition between hole 234 and hole 236. Hole 236 occupies approximately two-thirds of the total length of the ring head 232. Hole 236 opens into recess 229.

[0083] When the clamp 60 is assembled, the base and legs of the chuck 178 are seated in the drive shaft hole 166. The chuck ankle 194 and foot 196 are arranged in the annular recess 229. Also arranged in the chuck hole 162 is the alignment ring 212. Each chuck ankle 194 and associated foot 196 is arranged in one end of the alignment ring recess 229, as shown in Figure 15 and... Figure 15A As can be seen in. For example, in Figure 15A As best seen, the chuck 178 and alignment ring 212 are also configured such that when the chuck, ankle 194, and foot 196 are seated in the ring recess 229, the ankle and foot are separated from adjacent recesses away from the defining surfaces. A narrow separation exists between the chuck side surface 198 and the adjacent surface of the alignment ring 212. A wider gap exists between the distal surface of the chuck foot 196 and the adjacent surface of the alignment ring. The gap depicted is enlarged for illustrative purposes. It should be understood that the chuck foot 196 is capable of laterally flexing relative to the alignment ring foot 226.

[0084] Multiple components of the clamp cooperate to move the chuck 178 and the alignment ring 212 longitudinally within the drive shaft. One of these components is now referenced. Figure 19The locking ring 240 is described. The locking ring 240 is sleeve-shaped. The locking ring 240 has an inner diameter that allows the ring to slide and rotate over the housing head 72. The outer surface of the locking ring 240 is formed with knurled portions 242 to allow easy rotation of the ring by the thumb and fingers. The knurled portions 242 extend approximately four-fifths of the ring's closest side. The furthest fifth of the ring is smooth.

[0085] The locking ring 240 is also formed such that two grooves 244 extend inward from the inner wall of the ring and longitudinally along the inner wall of the ring. The grooves 244 are symmetrical with respect to the longitudinal axis passing through the proximal to distal side of the ring 240. In cross-section, i.e. in a plane perpendicular to the longitudinal axis passing through the locking ring, the shape of the grooves 244 is curved.

[0086] exist Figure 20 and Figure 21 The actuator 246, best visible in the center, is the second component and is part of the assembly of the longitudinal shifting chuck 178 and the alignment ring 212. The actuator 246 has a sleeve-shaped body 248. The outer diameter of the actuator body 248 is sized to allow the actuator to engage in a tight longitudinal sliding assembly movement within the housing bore 98. At the distal end of the body 248, the actuator 246 has a lip 250 extending radially inward from the body. The actuator 246 is also sized such that the inner diameter of the lip, approximately 2.5 mm, is larger than the outer diameter of the drive shaft body 142.

[0087] The actuator 246 also has two symmetrically opposite cut-off portions 252. Each cut-off portion 252 is a small segment of void space in the form of a sphere. Each cut-off portion 252 is shown as an opening into the interior of the actuator 246. This opening exists for manufacturing reasons.

[0088] When the holder 60 is assembled, the actuator 246 is seated in the housing bore 98. Figure 5 The most visible ball bearing 256 is seated in each of the spiral grooves 74 of the housing. The ball bearing 256 is sized to protrude outward from both the outer and inner surfaces of the housing head 72. The portion of each ball bearing 256 protruding outward from the housing head is seated in one of the locking ring grooves 244. The portion of each ball bearing 256 protruding inward from the bore 98 defining the inner surface of the housing is seated in one of the cut-off portions 252. Therefore, rotation of the locking ring causes the ball bearing 256 to move longitudinally along the housing within the grooves 244. This longitudinal movement of the ball bearing 256 causes the actuator 246 to move longitudinally within the housing bore 98.

[0089] exist Figure 22The drive rod 258, as best seen, is also slidably arranged in the housing bore 98. The drive rod 258 has a tubular body 260. The outer surface of the body 260 has a diameter smaller than the inner diameter of the actuator lip 250. The inner surface of the body 260 has a diameter sufficiently large than the diameter of the drive shaft body 142, allowing the drive rod to move freely longitudinally over the drive shaft 134.

[0090] The drive rod 258 has an edge 262 extending radially outward from the body 260. The edge 262 is positioned at the distal end of the body 260. The drive rod 258 is also formed with two coaxial holes 264. The holes 264 are positioned at the front of the proximal end of the body. The holes 264 are centered around a common axis that intersects a longitudinal axis passing through the proximal to distal side of the drive rod 258.

[0091] A drive rod 258 is arranged on the drive shaft body 142 for movement over the body. The drive rod 258 is positioned such that the drive rod edge 262 is positioned immediately distal to the front of the actuator lip 250. The component forming the retainer is dimensioned such that the drive rod edge 262 protrudes over the actuator lip 250.

[0092] The components forming the clamp 60 are also configured such that the drive shaft opening 146, the chuck hole 186, and the transmission rod hole 264 are aligned. Figure 5 The drive pin 266, as shown in Figure 15, extends through these gaps. The drive pin 266 fits snugly in the chuck hole 186 and the drive rod hole 264. The drive pin 266 is movable proximally and distally within the drive shaft opening 146. The drive pin 266 transmits the rotational motion of the drive shaft 134 to the chuck 178. The drive pin 266 also longitudinally transmits the movement of the drive rod 258 to the chuck 178, so that the chuck moves in unison with the drive rod.

[0093] exist Figure 4 and Figure 5 Two coil springs, 268 and 270, visible in the image, are arranged around the drive shaft body 142. The first spring, 268, is positioned radially closest to the outer cylindrical surface of the body 142. The proximal end of spring 268 abuts against the edge 262 of the drive rod 258. The distal end of spring 268 abuts against the annular proximal surface 152 of the drive shaft journal 150. Spring 268 is under compression. Spring 268 thus typically exerts a force that holds the drive rod 258 proximally away from the drive shaft journal 150. The force exerted by spring 268 can be overcome by a manual force that causes longitudinal displacement of the drive rod.

[0094] Spring 270 is located outside and around spring 268. The proximal end of spring 270 is arranged against an annular portion and points distally toward the surface of actuator 246. The opposite distal end of spring 270 is arranged against an annular stepped portion inside cover 104, the stepped portion being the transition between holes 107 and 109.

[0095] Also arranged inside the bushing is... Figure 23 The stop ring 274 is visible in the image. As its name suggests, the stop ring 274 is annular. The stop ring 274 is formed with multiple segments having a flat outer surface 276. One outer surface 276 has an opening 278 extending through the ring toward the center of the ring 274. The stop ring 274 is also formed to have a closed end hole 280 extending proximally from the distal to proximal face of the ring.

[0096] A retaining ring 274 is fixedly disposed in the retainer 60 above the portion of the notch 78 at the front of the housing head 72. A pin 282 extends through the locking ring opening 278 into the housing bore 80. Figure 5 Keep the retaining ring fixed to the housing 62.

[0097] exist Figure 4 and Figure 5 The visible coil spring 284 is positioned proximally adjacent to the stop ring 274. The spring 284 has two opposing legs (not shown). The first leg extends proximally and is disposed in a hole (not visible) formed in the locking ring 240. The second leg extends distally and extends into the stop ring hole 280. The spring 284 is positioned on the locking ring 240 to counteract the force that causes the locking ring to rotate. The force exerted by the spring 284 on the locking ring 240 can be overcome by a finger force applied to the locking ring 240, thereby rotating the locking ring.

[0098] As in Figure 2 and Figure 24 The nose portion 302, visible in the image, includes a base 304. The base 304 is generally tapered in shape, as its diameter decreases as it extends proximally from the outer surface. A portion 304 of the base has a constant diameter. A gap 306 and a connecting feature 308 are provided inside the base 304. The gap 306 and the connecting feature 308 are designed to facilitate a releasable connection of the nose base 304 over the cover head 116 and neck 112. Specific means of connecting the nose to the holder 60 are not part of this invention. Therefore, the gap 306 and the connecting feature 308 are not described further.

[0099] A constant-diameter tube 310 is mounted to the nose base 302 and extends distally at the front of the nose base 302. A cavity 312 inside the tube opens distally into a base gap 304. A bearing assembly 314 is located inside the cavity 312. The bearing assembly 314 rotatably holds a shaft 322, integrally formed with the cutting attachment, within the tube cavity 312.

[0100] Although tube 310 is depicted as straight, it should be understood that the invention is not so limited. In an alternative embodiment of the invention, the tube is curved, with its longitudinal axis bent from proximal to distal. This allows the physician to use the system to position the distal end of the tube and the attached tissue manipulation member 338 radially away from a line transfer that forms an extension of the proximal to distal longitudinal axis passing through the handpiece 42. This positioning assists in arranging the tissue manipulation member against one side of a gate in the defined patient tissue into which the nasal tube 310 is inserted.

[0101] refer to Figure 2 The structure of the cutting attachment 320 is understood in conjunction with Figures 25-27. The cutting attachment includes an elongated shaft 322. A tissue manipulation member 338 is attached to the distal end of the shaft 322. The tissue manipulation member is designed to perform a procedure on living tissue, applied against said living tissue. The depicted tissue manipulation member 338 is a bur (the cutting groove of the bur is not shown). The specific structure of the tissue manipulation member 338 is not part of the invention. In an alternative embodiment of the invention, the tissue manipulation member may be a bur with a head having a non-spherical shape. Alternatively, the tissue manipulation member may be a drill bit.

[0102] The accessory shaft 322 is generally in the form of a cylindrical rod. In some embodiments of the invention, the shaft 32 is formed of M42 tool steel or 440A stainless steel. Adjacent to the tissue operating member 338, the shaft 322 has a relatively rigid distal section 334. The distal section 334 has a length between 1 and 3 cm. Proximal to the distal section 334, the shaft 322 has a proximal section 332. The proximal section 332 is smaller in diameter than the distal section 330. This reduced diameter of the proximal section 332 allows it to flex when inserted into a curved or angled nasal cannula. The proximal section 332 has a diameter of 2 mm or less, and often 1.6 mm or less.

[0103] The accessory shaft 322 is also formed such that a tapered portion 323 exists at the proximal end of the shaft. Therefore, the diameter of the shaft increases as it extends distally from the proximal end of the shaft 322. The shaft 322 is also formed with a plurality of facets 324 on opposite sides of the shaft's diameter. The facets 324 are arranged longitudinally along the shaft and extend forward from the tapered section of the shaft. In the illustrated embodiment of the invention, each facet is recessed. Each facet 324 is arched and curves inwardly from the outer cylindrical surface of the proximal section 332 of the shaft. Two incomplete facets exist at the proximal end. Each facet 324 curves outwardly toward the adjacent distally positioned facet extending distally from the proximal end. A peak 326 exists at the location where two longitudinally adjacent facets abut, one of which is indicated in each of Figures 25 and 27. The peak 326 appears as a line.

[0104] On each side of shaft 322, a set of faces is presented like a row of faces. The accessory shaft 322 is also formed such that, at the front of the farthest side portion 324, a flat portion 328 exists in each row of faces. Each flat portion 328 is rectangular and recessed relative to the outer cylindrical surface of the shaft. The flat portion 328 is planar. The plane in which the flat portion 328 is positioned is parallel to the longitudinal axis passing through shaft 322. Each flat portion 328 is positioned a distance away from the longitudinal axis of the shaft, said distance being equal to the distance between the peak and the shaft. A stepped portion 329 defines the transition of each flat portion 328 from its proximal extension 332 of the shaft to its distal extension. The stepped portion 329 lies in a plane substantially perpendicular to the longitudinal axis passing through shaft 322.

[0105] The components forming system 40 are shaped such that the radius of curvature of shaft 322 is generally between 0.01 and 0.02 mm, smaller than the radius of the circle defined by the curved side of the alignment annular hole 236. The radius of curvature of the shaft is also understood to be approximately 0.2 to 0.4 mm, smaller than the radius of the center of the gap 193 surrounding the interior of the collet 178. The distance through the shaft flat portion 328 is 0.02 to 0.05 mm, smaller than the distance through the parallel side of the annular hole 236. The shaft face portion 324 is shaped such that each face portion can receive an outwardly curved face portion of one of the collet finger head surfaces 211.

[0106] The system 40 of the present invention is prepared for use by first connecting the card holder 60 to the handheld part 42. This results in the card holder drive shaft 134 being coupled to the handheld part spindle 48. The nose 302 is fitted onto the card holder cover 104.

[0107] To attach the cutting attachment 320 to the remainder of system 40, locking ring 240 is rotated to place the clamp in a loaded state. More specifically, locking ring 240 is rotated to cause a distal displacement movement of actuator 246. Movement of actuator lip 250 against edge 262 of drive rod 258 causes the same distal movement of drive rod. Distal displacement of drive rod 258 causes the same distal movement of chuck 178, such that chuck foot 196 is positioned in front of drive shaft step 164. When chuck 178 is thus positioned, chuck foot 196 is free to bend outward. System 40 is in a loaded state.

[0108] At this point, system 30 is in a condition to receive cutting attachment 320. The proximal end of the cutting attachment is inserted into the nose 302 and the holder. When the proximal end of the cutting attachment enters the alignment ring 212, the attachment may not be aligned with the ring hole 236. In this case, the proximal end of the attachment shaft 322 impacts the truncated tapered forming surface of the alignment ring 212 that defines the ring opening 232. Due to the presence of the tapered portion of the ring surface defining the opening 232 and the tapered portion 323 of the shaft, continued insertion of the attachment shaft 322 causes the proximal end of the attachment to shift laterally toward the hole 234. When the proximal end of the shaft enters the ring hole 234, the shaft may not be aligned with the adjacent attachment hole 236. For these two components to be aligned, the attachment peak 326 should be positioned in a plane parallel to the plane of the parallel side surface of the hole 236. In the case that these components are not so aligned, further advance of the attachment is stopped by the step portion of the attachment surrounding the ring between holes 234 and 236. This obstruction in the movement of the attachment serves as a tactile cue to the individual performing the process of aligning the attachment 320 with the holder 60. This alignment is easily performed by rotating the shaft, allowing it to pass through the annular hole 236. Since the proximal end of the shaft is seated in the hole 234, the possibility of the shaft moving out of the hole 234 by itself due to this rotation is virtually nonexistent.

[0109] Once the shaft 322 is correctly aligned, it is inserted into the hole 236. The proximal section 332 of the shaft first travels into the space between the finger surfaces 211 of the chuck and enters the chuck gap 193. This movement is possible because the chuck foot 196 freely bends outward as the shaft peak 326 pushes against the finger surface 211. Again, there is a gap between the distal end of the chuck foot 196 and the adjacent proximal finger surface of the alignment ring 212 defining the recess 229. The presence of this gap ensures that as the chuck foot 196 bends, the bending is not blocked by the foot abutting against the alignment ring. As the shaft 322 moves proximal, the finger surface moves in and out of engagement with the adjacent chuck face 324. Each time the chuck foot rides over the pair of chuck peaks 326 as it bends outward, there is a slight variation in the resistance to shaft insertion. This variation in resistance provides tactile feedback on the shaft entering and disengaging from engagement with the chuck foot 196.

[0110] The cutting attachment 320 is inserted into the holder 60 until the tissue manipulation member 338 is positioned forward at the distal end of the nose 302 to the distance desired by the physician. At this point, the chuck finger head surface 211 abuts against a pair of opposing shaft surfaces 324. The shaft is locked in place by rotating the locking ring 240 in the opposite direction to the direction in which the ring is rotated to place the holder in a loaded state. This opposing rotation of the ring 240 causes the ring actuator 246 to shift proximally. The spring 268 then freely pushes the drive rod 258 proximally. The proximal shift of the drive rod 258 causes the same proximal movement in the chuck 178. More specifically, the chuck 178 shifts proximally until the chuck surface 206 abuts against the stepped portion 164 inside the drive shaft. This abutment causes the chuck foot 196 to move inward against the adjacent surface 196 of the cutting attachment 302. The holder 60 is thus in a locked or operational state.

[0111] Due to the proximal movement of the chuck, the chuck abuts against the angled side surface of the alignment ring defining the recess 229. The alignment ring 212 moves proximally together with the chuck 178.

[0112] If necessary, cable 43 is connected to a control panel that provides power to the handheld motor 46.

[0113] The system 40 is used via a starter motor 46. The rotational torque of the handpiece drive spindle 48 is transmitted to the chuck drive shaft 134. Pin 266 transmits this rotational movement to the chuck 178. Since the attachment shaft 320 is clamped between the chuck feet 196, the attachment 320 undergoes the same rotation. The rotating tissue manipulation member 332 compresses the tissue to perform the desired surgical procedure.

[0114] As the cutting attachment 320 rotates, the peak 328 or flat portion 328 presses against the adjacent planar surface of the alignment ring defining the hole 236 along one side of the shaft 322. This surface-to-surface contact causes the alignment ring 212 to rotate together with the attachment shaft 322. This also means that there is a slight lag between the rotation of the chuck 178 and the rotation of the alignment ring 212. As described above, the components forming the clamp 60 are assembled such that there is a slight gap between the sides 198 of the chuck ankle 194 and foot 196 and the adjacent surface of the alignment ring. This gap prevents these surfaces from making contact when there is a lead or lag in the rotation of the chuck 178 relative to the ring 212. This lead and lag occur when the system is turned on, the system is stopped, or when the attachment is driven back and forth in an oscillating mode. Preventing this contact reduces wear that the chuck and alignment ring would otherwise suffer.

[0115] The components forming the system 40 of the present invention are therefore designed to facilitate easy attachment of the accessory 320 to other components of the system. If the accessory shaft 322 is not aligned with the chuck foot 198, the shape of the shaft and the alignment ring forces the shaft to be further inserted into the holder, and the shaft is rotated until the components are aligned. The shape of these components guides the setting system so that the user can rotate the accessory shaft 322 in this way.

[0116] Another feature of the invention is that the components are configured such that the attachment can be set such that the distance at which the tissue manipulation member 338 is positioned anteriorly at the distal end of the nose 302 can be selectively set. This eliminates the need to provide several different tissue manipulation members, the only difference between which is a slight difference in the length of their axes.

[0117] If the physician wishes to position the attachment so that the tissue manipulation component 338 is as close as possible to the nose 302, the shaft is arranged in the holder such that the shaft flat portion 328 sits in the alignment ring hole 236. Furthermore, if the user attempts to over-insert the shaft into the chuck, the stepped portion 329 immediately preceding the shaft flat portion 328 abuts against the alignment ring stepped portion 235 around the hole 236. This abutment of the stepped portion prevents the shaft from being inserted beyond its useful depth in the holder 60.

[0118] The flat portion 328 provides another advantage when present in some cutting attachments of the present invention. Some cutting attachments 320 have a tissue manipulation member 338 that is subjected to significant resistance from the tissue when compressing it. One type of cutting attachment subjected to these loads is a cutting attachment where the tissue manipulation member is a small drill bit with a diameter of 4 mm or greater. The concave shape of the shaft face 324 inevitably reduces the structural strength of the proximal section 332 of the shaft. If the resistance load for a rotating attachment is so large, the reduced strength of this portion of the shaft will lead to shaft breakage, at which point these faces compress the wall of the alignment chuck 212 of the defining hole 236.

[0119] This type of cutting attachment 324 actually has relatively few faces 324. This ensures that when the shaft is assembled to the holder, a small section of the flat portion 328 of the shaft sits in the annular hole 236. The cross-sectional width of this small section of the shaft 322 is larger than that of the section with the recessed face. In other words, the flat portion 328 is further away from the longitudinal axis of the shaft than the shallow portion of the face 324 is from this axis. Alternatively, it can be stated that the face 324 extends inward relative to the flat portion 328. The small section of the shaft 322 with the flat portion 328, due to its increased thickness, is better able to withstand the stress of the shaft abutting against the annular ring when the attachment is subjected to significant resistance. This ability of this section of the shaft to withstand such stress reduces the possibility that the portion of the shaft arranged in the chuck 212 will fatigue to the point of fracture due to this resistance.

[0120] Another feature of the invention is that advantages are provided to systems with components having relatively small cross-sectional dimensions. The diameter of the nasal tube 310 is typically 0.3 cm or less, and often 0.15 cm or less. As discussed above, the accessory shaft has a relatively small diameter to facilitate insertion and bending of the shaft within the nose having the curved tube 310. Therefore, the system 40 of the present invention is designed to perform minimally invasive surgical (MIS) procedures.

[0121] The foregoing describes one specific embodiment of the present invention. It should be understood that other embodiments of the present invention may have different features than those described.

[0122] For example, none of the embodiments of the invention require that the retainer 60 in the housing be separate from the handheld component 42 and removable from said handheld component. In some embodiments of the invention, the retainer is built into the body of the handheld component. Moreover, in some embodiments of the invention, a removable nose may not be present. In some embodiments of the invention where a nose is present, the nose may be built into the handheld component like the retainer. In still other embodiments of the invention, the nose and the retainer may be a one-piece assembly removably attached to the handheld component.

[0123] In some embodiments of the invention, the handheld component may have a transmission mechanism between the motor and the gripper drive shaft. One such transmission mechanism is characterized by typically reducing the rotational torque so that the gripper drive shaft rotates at a speed lower than the speed of the rotor inside the motor.

[0124] It is not required that all embodiments of the present invention have a cutting attachment shaft sized and formed from a material that allows shaft flexibility. Alternative systems 40 of the present invention may include a cutting attachment formed with a rigid shaft.

[0125] Similarly, the clamping assembly that releasably holds the accessory shaft to the drive shaft is not always a chuck with two legs. In other embodiments of the invention, the chuck may have three or more legs that clamp against the accessory shaft 322. Moreover, in some embodiments of the invention, the clamping assembly may not include a chuck. One such alternative clamping assembly is a ball in a hole assembly. This type of clamping assembly typically includes several clamping balls. Each ball protrudes into a hole in the drive shaft. The hole receives the accessory shaft. When this type of clamp is in the locked state, the ball is held in the shaft hole. The ball engages complementary fastening features on the accessory shaft to clamp the accessory shaft for rotation relative to the drive shaft. When the clamp is in the loaded state, the ball is able to move radially into and out of the drive shaft hole. This allows the accessory shaft to be removed from the clamp. In some embodiments of the invention, this also allows the longitudinal position of the accessory 320 to be selectively reset. In some embodiments of the invention, a single clamping member may be present to hold the accessory shaft to the clamp drive shaft.

[0126] As described above, variations exist in the geometry of the cutting and retaining features integral with the accessory shaft 320 of the present invention. It is not required that these features always be recessed. For example, in some embodiments of the invention, these features may be convex. Alternatively, the features may be flat portions separated by laterally extending ridges. In other embodiments of the invention, these features may be flat portions formed with pockets or recesses. The pockets or recesses (or multiple pockets and recesses) are formed such that each retaining feature can receive complementary male features of the retainer locking member. Similarly, it is apparent from the above that it is not required that the accessory shaft 322 form two rows of symmetrically aligned retaining features in all embodiments of the invention. In alternative embodiments of the invention, the accessory shaft 322 may have one, three, or more rows of retaining features. In these embodiments of the invention, there may be flat portions associated with only a single row of retaining features. In embodiments of the invention with several flat portions, the flat portions may not be symmetrically arranged about the longitudinal axis of the 322 shaft. Alternatively, in some designs, the flat sections adjacent to the arches may not be separated from each other by arches.

[0127] In some embodiments of the invention, each flat portion 324 may not be aligned with a row of retaining feature portions 324. In such embodiments of the system of the invention, the corresponding alignment ring face may not be aligned with one of the clamping members of the holder.

[0128] Assuming the clamping assembly and shaft retaining features differ from those already described, the alignment ring 212 inherently need not be as described above. Generally, the non-circular hole or opening of the alignment ring will have a shape adapted to the non-circular cross-sectional shape of the proximal end of the accessory shaft. This shape need not always be elliptical. The shape can be a truncated circle, a polygon, or a circle with a recess.

[0129] Furthermore, the alignment ring is not always a separate component from the other parts of the clamping device. In some embodiments of the invention, where the clamping assembly has a locking element with a ball in a hole, the alignment ring can be integrally formed with the drive shaft. In these embodiments of the invention, the alignment ring thus defines a non-circular opening inside the drive shaft that creates a gap, in which the accessory shaft is arranged and the locking ball moves in and out of the non-circular opening.

[0130] The dimensions listed above are for describing one aspect of the invention. Unless explicitly stated in the claims, these dimensions should not be construed as limiting the scope of the claims.

[0131] Therefore, the purpose of the appended claims is to include all such variations and modifications that cover the essential scope and spirit of the invention.

Claims

1. A cutting attachment (320) for use with a power surgical handpiece (42) and a retainer, the retainer for holding the cutting attachment on the handpiece, the retainer including an alignment ring for receiving an axis, the cutting attachment comprising: The slender shaft (322) has a proximal end and a distal end opposite to each other, and also has a longitudinal axis and an outer surface; Tissue manipulation member (338), which is attached to the distal end of the shaft, is designed to perform a procedure on living tissue, and the tissue manipulation member is applied against the living tissue; A proximal section (332) extending from the distal end to the proximal end has a plurality of faces (324) extending inward from the outer surface of the shaft, each face having at least one shallow portion and being shaped to receive a clamping member (210) that holds the shaft in a handheld member, wherein at least two faces are provided, the at least two faces being arranged in a straight line and extending from the proximal end to the distal end along the proximal section (332) of the shaft; The shaft is further shaped to have a flat portion (328) that extends distally in front of the farthest side portion (324), the distance between the flat portion and the longitudinal axis of the shaft being greater than the distance between the shallow portion of the face and the longitudinal axis, and less than the distance between the outer surface of the shaft (322) and the longitudinal axis, wherein the flat portion is designed to surface-contact with the surface of the alignment ring when the shaft is received in the alignment ring of the holder.

2. The cutting attachment as claimed in claim 1, wherein the flat portion (328) and the face portion (324) are aligned in a straight line.

3. The cutting attachment as claimed in claim 1, wherein the shaft is formed with two rows of face surfaces (324), and the flat portion (328) extends in front of each row of face surfaces.

4. The cutting attachment as claimed in claim 3, wherein the two rows of faces (324) are opposite to each other.

5. The cutting attachment as claimed in claim 3, wherein each flat portion (328) is opposite to the other.

6. The cutting attachment as claimed in claim 3, wherein each flat portion is located in a plane parallel to the longitudinal axis.

7. The cutting attachment as claimed in any one of claims 1 to 6, wherein each face (324) is recessed.

8. The cutting attachment as claimed in any one of claims 1 to 6, wherein adjacent face portions (324) abut against the peak portion (326).

9. The cutting attachment as claimed in claim 8, wherein the distance between the flat portion (328) and the longitudinal axis is equal to the distance between the peak portion (326) and the longitudinal axis.

10. The cutting attachment as claimed in any one of claims 1 to 6, wherein the shaft (322) is further formed as having a radially extending stepped portion (329), which is a transition surface between the distal end of the flat portion (328) and the outer surface of the shaft (322) located on the distal side of the flat portion.

11. The cutting attachment as claimed in any one of claims 1 to 6, wherein the shaft (322) is formed having a distal segment (334) extending proximally from the tissue operation member and a proximal segment (332) extending proximally from the distal segment, and the diameter of the distal segment is greater than the diameter of the proximal segment.

12. The cutting attachment as claimed in any one of claims 1 to 6, wherein the tissue operation member (338) is a small drill or drill bit.

13. The cutting attachment as claimed in any one of claims 1 to 6, wherein a tapered portion (323) is provided at the proximal end of the shaft (322).

14. The cutting attachment as claimed in any one of claims 1 to 6, wherein the proximal end of the shaft (322) has a non-circular cross-sectional shape.

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