Surgical Electric Rotary Hammer Impact Tool

Abstract

Disclosed herein is a powered surgical rotary hammer impact tool and a method of use thereof. The powered surgical rotary hammer impact tool may include a tool body, a motor disposed within the tool body, a shaft operatively coupled to the motor, a disc hammer element, and a tool holder element. The disc hammer element is connected to the shaft and may include a radial impact protrusion. The tool holder element may include a shaft configured to support an instrument at one end and a C-shaped structure spanning the disc hammer element. Axial movement within the tool body may cause the radial impact protrusion to impact the tool holder element.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 143,514, entitled "Electric Rotary Hammer Impact Tool," filed on January 29, 2021, the contents of which are incorporated by reference in their entirety into this specification.

[0002] The present disclosure relates generally to surgical instruments and their uses. More specifically, the present disclosure relates to a surgical rotary impact tool and its method of use. [Background technology]

[0003] Orthopaedic surgeons commonly use tools for cutting or scraping bone that require a hammer or mallet to transmit the force of impact to the tool. One example is a broach tool used to prepare the proximal end of the femur to receive the stem of a hip prosthesis. Such broaches can be used with a hammer or pneumatic "jackhammer" used by the surgeon. However, striking the broach tool with a hammer can be cumbersome and can create significant stress on the surgeon's own joints, such as the shoulder joint. Additionally, pneumatic impact tools must be connected to an air hose, which can be inconvenient and limit the surgeon's ability to orient the tool as desired. Summary of the Invention

[0004] The following non-limiting examples detail particular configurations of the disclosed subject matter for specifically solving the problems and providing the advantages discussed herein.

[0005] Example 1 is a powered rotary hammer impact tool for a surgical instrument comprising a tool body, an auto, a motor disposed within the tool body, a shaft operatively coupled to a motor, a disk hammer element coupled to the shaft, the disk hammer element including a radial impact protrusion, and a tool holder element comprising a shaft configured to support an instrument at one end, the tool holder element comprising a C-shaped structure including spaced apart opposing forward and rearward impact faces straddling the disk hammer element, the tool holder element configured to move axially within the tool body when the instrument is pressed against a work surface to align the forward impact face into engagement with the radial impact protrusion to provide a forward impact to the tool holder element, and the tool holder element configured to move axially within the tool body when the instrument is pulled away from the work surface to align the rearward impact face into engagement with the radial impact protrusion to provide a rearward impact to the tool holder element.

[0006] In Example 2, the subject matter of Example 1 optionally includes changing a rotation direction of a shaft connected to the motor from a first direction for providing a forward impact to a second direction for providing a rearward impact.

[0007] In Example 3, any one or more of the subject matter of Examples 1 or 2 optionally includes a bearing supporting a shaft of the tool holder element.

[0008] In Example 4, any one or more of Examples 1-3 may optionally include, wherein the motor is configured to rotate the disc hammer element a partial revolution to provide the impact.

[0009] In Example 5, any one or more of Examples 1-4 optionally include, wherein the radial impact protrusion of the disc hammer element has a metallic impact surface.

[0010] In Example 6, any one or more of Examples 1-5 optionally include, wherein the radial impact projection of the disc hammer element has a polymeric material impact surface.

[0011] In Example 7, any one or more of the contents of Examples 1-6 optionally include a sensor arranged to detect an impact on the tool holder element and a controller configured to reverse rotation of the motor to reverse rotation of the disc hammer element.

[0012] In Example 8, the subject matter of any one or more of Examples 1-7 optionally includes control electronics and a battery in electrical communication with the control electronics, the control electronics and the battery disposed within the tool body.

[0013] In Example 9, any one or more of Examples 1-8 may optionally further include a shaft of the tool holder element aligned generally perpendicular to an axis of rotation of the motor.

[0014] In Example 10, any one or more of the subject matter of Examples 1-9 optionally includes a handle extending perpendicular to the tool body.

[0015] In Example 11, the subject matter of any one or more of Examples 1-10 optionally includes a microphone disposed in the tool body and in electrical communication with the controller, the controller configured to activate the motor based on a voice command.

[0016] In Example 12, any one or more of Examples 1-11 optionally include the disc hammer element including a plurality of swing hammer elements attached thereto.

[0017] In Example 13, the content of any one or more of Examples 1-12 optionally includes a controller operable to perform operations including measuring an estimate of bone quality and increasing or decreasing an impact force generated by the surgical powered linear hammer impact tool based on the estimate of bone quality.

[0018] In Example 14, the subject matter of any one or more of Examples 1-13 optionally includes a controller operative to perform an operation including measuring a displacement of a tool attached to the tool holder and increasing or decreasing an impact force generated by the powered surgical linear hammer impact tool based on the displacement of the tool.

[0019] Example 15 is a powered rotary hammer impact tool for use in a surgical application comprising an impact wrench having an impact mechanism configured to impart a rotational impact to an output shaft, an elongated tool arm attached to the output shaft and extending perpendicular to the axis of the output shaft, and a tool instrument attached to an end of the elongated tool arm, the tool instrument extending generally perpendicular to the end of the elongated tool arm.

[0020] In Example 16, the subject matter of Example 15 optionally includes, wherein the tool implement is connected to the elongated tool arm by a pin.

[0021] Example 17 is a method of controlling a surgical powered rotary hammer impact tool for preparing bone to receive a prosthesis, the method including setting an initial impact force level of the surgical powered rotary hammer impact tool based on an estimated bone quality, actuating the surgical powered rotary hammer impact tool at the initial impact level, monitoring an advancement of the tool into the bone, and increasing or decreasing the impact force level by a preset amount based on the detected advancement of the tool into the bone.

[0022] In Example 18, the content of Example 17 optionally includes monitoring the advancement of the tool into the bone and reducing the impact force level by a preset amount based on the detected advancement of the tool into the bone.

[0023] In Example 19, the contents of any one or more of Examples 17 or 18 optionally include, wherein the bone quality is based on a bone quality score comprising at least three bone quality levels.

[0024] In Example 20, the contents of any one or more of Examples 17-19 optionally include wherein the bone quality score is measured by detecting a change in position of the broach tool within the bone upon initial actuation of the impact tool, wherein maximum movement of the broach tool indicates poor bone quality, moderate movement of the broach tool means moderate bone quality, and a minimum amount of movement of the broach tool within the bone means high bone quality.

[0025] In Example 21, the surgical impact tools, systems and / or methods of any one or any combination of Examples 1-20 can be configured to use or select any of the elements or options mentioned, as desired. [Brief description of the drawings]

[0026] In the drawings, which are not necessarily to scale, like numerals may indicate like components in different drawings. Like numerals with different suffixes may represent different instances of like components. The drawings illustrate generally, by way of example and not by way of limitation, various embodiments discussed in this document.

[0027] [Figure 1] FIG. 1 is a perspective view of a powered rotary hammer surgical impact tool in accordance with at least one embodiment of the present disclosure. [Diagram 2] FIG. 2 is a side perspective cutaway view of a powered surgical rotary hammer impact tool in accordance with at least one embodiment of the present disclosure. [Diagram 3]FIG. 3 is a side perspective view of internal elements of a powered surgical rotary hammer impact tool in accordance with at least one embodiment of the present disclosure. [Figure 4] FIG. 4 is another side perspective view of the internal elements of a powered surgical rotary hammer impact tool in accordance with at least one embodiment of the present disclosure. [Diagram 5] FIG. 5 is a front perspective cutaway view of a powered surgical rotary hammer impact tool in accordance with at least one embodiment of the present disclosure. [Figure 6] FIG. 6 is a front cutaway view of a powered surgical rotary hammer impact tool in accordance with at least one embodiment of the present disclosure. [Figure 7] FIG. 7 is a front cutaway view of a powered rotary surgical hammer impact tool in accordance with at least one embodiment of the present disclosure. [Figure 8] FIG. 8 is a front cutaway view of a powered surgical rotary hammer impact tool in accordance with at least one embodiment of the present disclosure. [Figure 9] FIG. 9 is a front cutaway view of a powered rotary surgical hammer impact tool in accordance with at least one embodiment of the present disclosure. [Figure 10A] FIG. 10A is a perspective view of a polymer torque interface element in accordance with at least one embodiment of the present disclosure. [Figure 10B] FIG. 10B is a perspective view of a polymer torque interface element in accordance with at least one embodiment of the present disclosure. [Figure 11] FIG. 11 is a perspective view of a disc hammer element in accordance with at least one embodiment of the present disclosure. [Figure 12] FIG. 12 is a perspective view of a disc hammer element in accordance with at least one embodiment of the present disclosure. [Figure 13A] FIG. 13A is a perspective view of a tool holder element in accordance with at least one embodiment of the present disclosure. [Figure 13B] FIG. 13B is a perspective view of a tool holder element in accordance with at least one embodiment of the present disclosure. [Figure 14]FIG. 14 is a perspective view of a disc hammer element in accordance with at least one embodiment of the present disclosure. [Figure 15A] FIG. 15A is a perspective view of a disc hammer element in accordance with at least one embodiment of the present disclosure. [Figure 15B] FIG. 15B is a side cutaway view of a disc hammer element in accordance with at least one embodiment of the present disclosure. [Figure 15C] FIG. 15C is a cutaway perspective view of a disc hammer element in accordance with at least one embodiment of the present disclosure. [Figure 16A] FIG. 16A illustrates a percussion center arm rotation system in accordance with at least one embodiment of the present disclosure. [Figure 16B] FIG. 16B illustrates a percussion center arm rotation system in accordance with at least one embodiment of the present disclosure. [Figure 17A] FIG. 17A illustrates options for bone quality assessment in accordance with at least one embodiment of the present disclosure. [Figure 17B] FIG. 17B illustrates an option for bone quality assessment in accordance with at least one embodiment of the present disclosure. [Figure 17C] FIG. 17C illustrates an option for bone quality assessment in accordance with at least one embodiment of the present disclosure. [Figure 18] FIG. 18 is a flow chart of logic that can be used to control a powered linear hammer surgical impact tool in accordance with at least one embodiment of the present disclosure. [Figure 19] FIG. 19 is a schematic diagram of a controller in accordance with at least one embodiment of the present disclosure.

[0028] Corresponding reference characters indicate corresponding parts throughout the drawings. The illustrations set forth herein illustrate preferred embodiments of the present disclosure, and such illustrations should not be construed in any way as limiting the scope of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0029] As an alternative to pneumatic piston drive systems, an electric drive system is disclosed herein. Specifically, the powered rotary surgical impact tool disclosed herein can include a tool body, a shaft driven by a motor, a hammer element, and a tool holder used to generate the impact force.

[0030] As disclosed herein, a powered surgical rotary hammer impact tool can include a tool body, a shaft, a disk element, and a tool holder element. A motor can be disposed within the tool body. The shaft can be driven by the motor. The disk element (sometimes referred to as a disk hammer element) can be connected to the shaft and can include a radial impact protrusion. The tool holder element can include a shaft supporting an instrument at one end. The shaft can further include a structure, such as a C-shaped structure, that spans the disk hammer element. The structure can include spaced apart, opposing forward and rearward impact faces such that when an instrument, such as a broach, is pressed against a work surface (e.g., bone), the tool holder element can move axially within the tool body to align the forward impact face and engage the radial impact protrusion to apply a forward impact to the tool holder element. When the powered surgical rotary impact tool is withdrawn from the work surface, the tool holder element can move axially within the tool body to align the rearward impact face and engage the radial impact protrusion to apply a rearward impact to the tool holder element.

[0031] The above discussion is intended to provide an overview of the contents of this application. The discussion is not intended to be an exclusive or exhaustive description of the present invention. The following description is intended to provide further information regarding this patent application.

[0032] Turning to the drawings, Figure 1 is a perspective view of a powered surgical rotary hammer impact tool 100 in accordance with at least one embodiment of the present disclosure. Looking to Figures 1 and 2, the powered surgical rotary hammer impact tool 100 can include a handle housing 102, which can house a battery pack 202 and control electronics 204 therein. As disclosed herein, the user interface can be a mechanical switch or a voice activated control as described below in connection with Figure 3. The motor housing 104 can house an electric motor stator 206 (which can be a frameless motor with coils mounted inside the housing 104) and a rotor 208 mounted on a shaft 210 that extends through a hammer head housing 106 (sometimes abbreviated as HHH) in which main bearings 212 (individually labeled 212A and 212B) are supported and in which a disc hammer element 214 (sometimes abbreviated as DHE) is disposed. Tangentially attached to the disc hammer element 214 is a tool holder element 108 (sometimes abbreviated as THE), which may include a tool post 110 having a lower post 112 and a tool holder 114 at its end for holding a tool, such as a broach (not shown).

[0033] The side handle 116 can thread into a boss 118 to allow a user to grasp and control the powered surgical rotary hammer impact tool 100. A similar boss can be located on the opposite side of the housing 120 so that a left-handed user can grasp the side handle 116 with their right hand.

[0034] FIG 2 is a side perspective cutaway view of the powered surgical rotary impact tool 100, and FIGS 3 and 4 are side perspective views of the internal elements of the powered surgical rotary hammer impact tool 100 with the outer structural housing removed. The handle housing 102 can have an outer structure 122 that houses a battery pack 202, which can be held to a circuit board 204 by a chip 216 as shown in FIG 3. The circuit board 204 can also be held to an inner surface of the structure 122 by a chip 218. An end cap 220 can be threadedly connected for attachment to an end of the outer structure 122. A microphone cover 222 can be located in the center of the end cap, which seems like a good place for voice commands from the user to be sent and received by the microphone / speaker 302 without the possibility of being blocked.

[0035] 4 shows a motor cable 402 running from the motor stator 206 to a connector 404 near the distal end of the circuit board 204 so that it can more easily snap into place during assembly. The battery pack 202 can be a stack of coin cells in a housing that has the total energy and voltage (approximately 40 volts DC) needed to enable the motor to spin up to several thousand rpm.

[0036] Different users have different hand types, and operating a power tool with gloves on in an operating room can be cumbersome, so a traditional switch or power adjustment knob may not be desirable. Therefore, voice control can be used as disclosed herein. The surgical powered rotary hammer impact tool 100 can have a microphone 302 connected to a circuit board 204, which can be used to control the current to the coil 206. It will be appreciated that the microphone 204 allows the user to communicate commands such as "less force", "more force", "faster", "slower" when using the surgical powered rotary hammer impact tool 100, and the surgical powered rotary hammer impact tool 100 can be trained by the user to suit the user's needs and usage style.

[0037] The motor housing 104 can have an outer structure 124 that can be integral with the handle structure 122, but the handle structure 122 can be located elsewhere and have a D-handle configuration. The motor stator 206 and coils 208 can be a frameless motor, so the stator 206 can be glued in place in the outer structure 124 for reliability and good heat transfer. If the motor stator 206 could get too hot, the outer surfaces of the structures 122 and 124 can be rubber coated and / or insulated with an ergonomic grip. The motor coil 208, such as a magnetic rotor for a DC brushless motor, can be glued to the shaft portion 1002 (FIG. 10B) of the shaft 210. As shown in FIGS. 2 and 11A, a magnetic encoder disk 224 can be attached to the end 1005 of the shaft 210, and a sensor on the circuit board 204 can sense the rotation of the shaft 210.

[0038] 10A and 10B show details of rotor system 1000. The rotor system can be constructed as a subassembly that is precisely balanced and prepared for insertion into housings 104 and 106. As shown in FIG. 10B, the central main shaft 210 can be manufactured as a single element, starting from hex stock held in a precision collet and then turned or ground. Starting at the distal end, which is the end closest to the handle housing 102, end 1004 can have an encoder 224, such as a magnetic encoder, attached to provide feedback to the controller 204 regarding the position of the coil 208. Snap ring groove 1006 (separately labeled snap ring grooves 1006A and 1006B) can be sized to receive snap ring 1008 (separately labeled snap ring 1008A and 1008B) to axially restrain outrigger support bearing 226, which can be radially restrained within housing 120 by end flange 228. The shaft portion 1002 may be for a motor rotor 208, which may be attached to the shaft portion 1002 with an adhesive, welding, or the like.

[0039] The shaft section 1002 for the motor rotor 208 can utilize, for example, a MOOG DB-1500-R motor that is only ¼″ diameter and can handle the torque and inertial loads while minimizing stress concentrations, so that the transition from the full shaft radius 1010 to the 0.750″ shaft diameter 1012 is supported by main support bearings 1014 (labeled bearings 1014A and 1014B, respectively). The main support bearings can absorb impact forces. The snap ring groove 1016 can be sized to receive a snap ring to axially restrain the bearing on the shaft when the bearing is installed after a spacer flange hub washer 1018 with a 0.750" bore is installed. This washer 1018 can have an outer diameter on the side facing the bearing 1014A that is equal to or less than the inner ring outer diameter of the bearing and can have a step to a larger diameter required to support the axial surface 1102 (FIG. 11) of the hexagonal torque interface element 230. The shaft section 1020 of the main shaft 210 can be hexagonal to transfer torque from the motors 206, 208 through a hexagonal hole 1104 (FIG. 11) in a central section 1106 of the elastomeric polymer hexagonal torque interface element 230 (sometimes abbreviated as TIE). The torque interface element can be axially restrained by the spacer flange washer 1018 which can prevent it from rubbing on the non-corroding outer ring of the bearing. The torque interface element 230 is manufactured by BUNA. When made from a low loss polymer such as N-rubber or cast polyurethane, it can transmit torque with some torsional compliance without energy loss. This helps reduce impact to the rotor system 208 while extending the duration of the impulse force on the tool holder element 108.

[0040] Continuing to the proximal end, the shaft may step down to a 0.750" diameter 1022 for a second spacer flange hub washer 1024 to press against the proximal face 1102 of the torque interface element 230. The next bearing 1014A may be axially held in place in groove 1028 by a snap ring 1026.

[0041] The outer structure 120 can have end caps 232 with precision holes for receiving the main bearings 212B and for the main bearings 212A. Concentricity and perpendicularity can be achieved by a tapered interface 234. The end caps 232 can be used to allow for the insertion of the disc hammer element 214. As can be seen in FIG. 5, the outer housing 120 can have tangential holes 502 for the outer housing 126 of the tool holder element 108.

[0042] Figures 5 and 7 are cutaway views of the powered surgical rotary hammer impact tool 100 in an impact tool drive position, and Figure 6 shows the powered surgical rotary hammer impact tool 100 ready to accelerate the disc hammer element 214 clockwise (as shown) to create an impact. Within the outer housing 120, the disc hammer element 214 can be held on the shaft 210 by a hexagonal torque interface element 230 as shown in Figure 11, such that when the user pushes the powered surgical rotary hammer impact tool 100 forward to engage a portion to be worked on (e.g., bone), the radial impact surface 516 impacts the surface 504 at the distal end of the shaft 112 of the tool holder element 110 to allow the tool held therein to work beneficially.

[0043] The axial location of the impact surface 516 is set by the distal shaft end of the tool holder element 110 contacting the inner surface of the cap 236, or a flange of the proximal shaft 112 can contact the outer proximal surface of the proximal end flange 128. The tool post 110 can be forged and then machined to the final shape, in which case the end shaft region 406 and shaft 112 can be ground for a precision fit and smoothness for longer bearing life.

[0044] The shaft 112 can be sealed by a simple O-ring or a quad ring such as ring 506 in a groove in the proximal end flange 128, which can be threadably connected to the outer housing 126. In accordance with embodiments disclosed herein, a bellows seal can be used that allows for effectively unrestrained axial motion, or a metal bellows can provide some spring bias while still providing an airtight seal.

[0045] The bellows for sterilization can be pushed out by expanding a gas inside the powered surgical rotary hammer impact tool 100 to deflect the bellows as needed. The shaft 112 can slide through a bearing bushing 508, which can be a dry-run, low-friction polymer such as Rulon. The proximal end flange 128 can be retained within the housing 510 and can be pressed against and captured by the flange of the bushing 508. Alternatively, a simple cylindrical bushing can be held in place with a snap ring.

[0046] 5, the distal shaft 512 is connected to the proximal end of the shaft 112 by a C-shaped structure 514 through which a radial impact surface 516 can pass to impact the surface 504 for driving the tool, or against which the tool holder element 108 can slide when the user pulls back on the powered surgical rotary hammer impact tool 100, and which can be stopped by the snap ring 408 contacting the distal end of the structure 410. When the disc hammer element 214 rotates counterclockwise, the radial impact surface 516 can abut against surface 518 to retract the tool holder element 108.

[0047] As shown in FIG. 13B, the distal shaft 1302 can have a hexagonal cross section to constrain the rotation of the tool post 1304. The distal shaft 1302 can support the distal end of the tool holder 108 so that it does not transmit the impact force and the bearings 520 and 508 can provide moment stiffness to the tool holder element 108. The core of the shaft 515 can be drilled and a bar magnet can be inserted to create north and south poles 522. The poles are sensed by a Hall effect sensor 524 so that the microcontroller on the circuit board 204 knows if the tool holder element 108 is in a proximal position for an impact drive or distal for a back strike. The north and south poles 522 and the Hall effect sensor 524 can cooperate to prevent the disk hammer element 214 from rotating and hitting the tool holder element 108 if it is in the wrong position.

[0048] 8 and 9 are cutaway views of the retraction process in which the disc hammer element 214 first rotates clockwise, and is then accelerated counterclockwise so that the radial impact surface 516 abuts the retraction impact surface 518. The user can pull the powered surgical rotary hammer impact tool 100 back distally to allow the tool holder element 108 to slide in its bearings until the snap ring 408 contacts the underside of the distal flange 410. This properly positions the retraction impact surface 518 for abutment by the radial impact surface 516 in the left rotation mode.

[0049] FIG. 10A shows a perspective view of the rotor system element assembly 1000, all of which can be assembled and dynamically balanced using the support bearings 212A, 212B and 226, including any shaft straightening required to ensure that the support bearings 212A, 212B and 226 are all concentric. FIG. 10B shows a perspective view of the shaft 210 to which the elements are attached. The rotor 208 of the motor can be attached to the rotor shaft section 1002 with high precision and can be capable of transmitting the full torque of the motor and can resist torsional impact loads. Such attachment can be by shrink fitting or via a thin film adhesive that can be used to bond the rotor 208 to the shaft 1002.

[0050] The rotational inertia of the disk hammer element 214 can be the largest, but the rotational inertia of the motor rotor 208 and shaft 1002 can also be large. These combinations can deliver energy to the impact. A low-loss hard rubber element 1030 between the disk hammer element 214 and the hex end of the rotor shaft 1002 can be installed to allow the motor rotor 208 to decelerate more slowly when an impact occurs, reducing stress on the magnets and on the smaller diameter portion of the rotor shaft 210 where the motor rotor 208 can be mounted. This can also have the advantage that the tool holder element 108 receives an initial blow with high traction. The initial spike can be followed by a period of sustained force to initiate the cutting action and further advance the tool to complete the cut.

[0051] FIG. 11 shows an elastic torque interface element 230 that fits into the hexagonal hole 1204 of the disk hammer element 214. The torque interface element 230 can be made from an elastic low-loss polymer, such as polyurethane. Polyurethane can be used because it can elastically tolerate shock loads, does not dissipate energy such as heat (i.e., has a low loss factor), and is wear-resistant under this type of combined load. The use of the torque interface element 230 can help reduce shock loads on the motor rotor 208 and the permanent magnets attached thereto. Reducing the shock loads also helps to extend the energy transfer period and generate the desired dead blow hammer effect to operate the surgical powered rotary hammer impact tool 100 more effectively for cutting operations.

[0052] As shown in FIG. 12, the disc hammer element 214 can have an outer flange 1206 (individually labeled outer flanges 1206A and 1206B) and an inner interface structure 1208 integral with the flange 1206. A hexagonal opening 1204 can be provided in the disc hammer element 214 for receiving the torque interface element 230. The disc hammer element 214 can have a semicircular outer diameter from which a radial impact surface 1202 projects radially. The radial impact surface is the structure that impinges against the impact surface of the tool holder element 108 to drive or retract the tool. The radial impact surface 1202 can be formed integral with the outer flange 1206 and the inner interface structure 1208 and can be fully supported on three sides. Since the rotational speed can be several thousand RPM, the disk hammer element 214 can be dynamically balanced and the balance sections 1210 (individually labeled balance sections 1210A and 1210B) can be machined integrally with the disk hammer element 214 structure.

[0053] FIGURE 13A is a perspective view of the tool post 110 of the tool holder element 108, whose upper (distal) shaft 1306 is rounded in the view. To prevent rotation, the shaft 1302 is hexagonal as shown in FIGURE 13B and can move in a corresponding hexagonal linear bearing bushing in the end flange 410. The upper shaft does not need to be sealed from the outside, as it is retractable. However, for a fast, hard, clean blow, hardened steel overlay can be used for the disc hammer element 214.

[0054] FIG. 14 shows a disk hammer element 214 for softening and extending the impact. FIG. 14 is a perspective view of the disk hammer element 214 with a dead blow interface element 1402 on the radial impact surface 1202. The dead blow interface element 1402 can be modular and replaceable, shown here in the form of a button that is pressed into a pocket on its surface, and can be made from a variety of materials or composites, such as hard steel to provide a very strong, sharp, short-duration impact, or a softer material such as a polymer to apply a weaker, longer-duration force similar to that provided by a dead blow hammer or lignum vitae wood hammer. The polymer can be a hard polyurethane, such as hot cast polyurethane. The particular size (e.g., diameter and length) and material selected for the dead blow interface element 1402 can be determined by experimentation until a good "feel" is achieved for the user, and can be quantified with accelerometer measurements taken and user feedback recorded while using the powered surgical rotary impact tool 100.

[0055] 15A, 15B, and 15C, the disc hammer element 1502 can have cutouts in an inner interface structure 1504 to form connections 1506 (individually labeled connections 1506A, 1506B, and 1506C) between side plates 1508 (individually labeled side plates 1508A and 1508B). The side plates can have a hexagonal central hole 1510.

[0056] The side plates may include holes for paired bushing bearings 1512 (individually labeled bushing bearings 1512A, 1512B, and 1512C), which may be made of a dry-run, low-friction, sterilizable plastic such as Rulon. A shaft 1514 (individually labeled shafts 1514A, 1514B, and 1514C) may be supported by a respective bushing set to support a swing hammer 1516 (individually labeled swing hammers 1516A, 1516B, and 1516C). The disk hammer element 1502 may be continuously rotated clockwise when driving the tool holder element 108 or counterclockwise when retracting the tool holder element 108. The disk hammer element 1502 may be coupled to the shaft 210 by a resilient torque interface element 1030.

[0057] As shown in Figures 15B and 15C, one swing hammer, such as swing hammer 1516C, can swing back as occurs after impacting the tool holder element 110. The swing hammer 1516 can have an arcuate surface, such as surface 1518 (separately labeled surfaces 1518A and 1518B), and can impart a rolling motion against the impact surfaces 504 and 518 of the tool holder element 110 to drive and retract the surgical powered rotary hammer impact tool 100, respectively. After impacting, swinging back, and clearing the tool holder element 110, the swing hammer 1516 can impact an exposed free surface of a portion of the torque interface element 230, which can aid in swinging back in a radial direction ready for the next impact due to centrifugal force. The mass and inertia of the hammer can be smaller than the disk hammer element 1502, but has a higher vibration frequency, and the hammer 1516 can be configured for this purpose. Additionally, the swing hammer 1516 can be made from a high density material such as tungsten carbide, which has approximately twice the density of steel.

[0058] As disclosed herein, the percussion center arm rotation system can generate a linear driving force by applying a small rotary motion near the distal end of the lever arm to drive a tool connected by the pivot of the percussion center of the arm, including the mass of the tool, using the principle of rotary impact, and can obtain a linear impact motion of the tool virtually without the user feeling the impact force. This can be obtained by a system 1600 that can include a battery-powered impact wrench, as shown in FIG. 16A. The mechanism can have a control system, such as the controller disclosed herein, that monitors the rotation of the square drive output shaft 1602 so that it does not rotate more than 30°. The system 1600 can be attached to a percussion center tool arm 1604. The arm can have a distal end 1606 and a proximal end 1608, and its length and mass can be proportional to the tool 1610 attachment position and mass. The tool 1610 can fit into the slot 1216 and can be held to the arm 1604 by a quick release pin 1614 that can slide through a hole 1616 in the arm 1604. The tool 1610 can have a corresponding hole in its shaft to receive the pin 1614. The slot 1612 can allow the tool 1610 to pivot about the pin 1614.

[0059] The size and mass of the arm sections 1606 and 1608 relative to the tool 1610 can allow the user to actuate the instrument 1600 when forcing the tool 1610 into bone to carve a passageway. For example, the user can resist the impact torque, most of which is absorbed by the inertia of the instrument 1600 itself, similar to a normal impact wrench. The user does not feel the linear impact force of the tool 1610 forcing into the bone, because the ratio of the arms places the impact force at the percussion center of the arm 1604. For example, when used as an impact wrench, the torque through the square drive 403 can be translated into an axial force on the tool 1610 through the pin 1614 instead of loosening a nut.

[0060] 16B shows a percussion center arm rotation system 1650 with a shorter arm 1652, where the distal end 1656 can have a hammer head shape and the proximal end 1658 can be a simple beam shape to obtain the mass and inertial balance required to keep the percussion center in the same position relative to the square drive 1654. A tool 1660 can be held in a slot 1662 with a pin 1664 that fits into a hole 1666.

[0061] Any of the embodiments disclosed herein can allow advanced control where the system can automatically adjust the impact energy and frequency for the tool being used and the patient and operating conditions. To allow intelligent control of the tool as the operation proceeds, a sensor such as sensor 524 can be used to monitor the position of the tool holding element relative to the surgical powered rotary hammer impact tool, or a position sensor included in the tube motor can be used. Additionally, an accelerometer in the tool (or an adapter element allowing proper positioning relative to the tool holder element) can also provide additional feedback to allow confirmation of the tool's progress into the bone. A camera can also view the operation to monitor its progress into the bone with each impact, and information from the camera and accelerometer can be sent by wire or wireless link to control electronics such as control electronics 204. From the position information from the sensor, velocity and acceleration information can be derived to allow intelligent control of the amount of impact and its frequency delivered to the tool holder element.

[0062] 17A, 17B, and 17C illustrate bone quality assessment options in accordance with at least one embodiment of the present invention. Input of an initial assessment of bone quality by the physician into the controller (e.g., the physician enters bone quality into the tool or into a user interface, or an external assessment of bone quality via X-ray or CT) can be done by the physician speaking into the tool, which is picked up by a microphone. Using a wireless link, the tool's controller can access an external computer, which processes the information and downloads a control plan to the tool that can be used to better control the tool for the task at hand.

[0063] As shown in FIG. 17A, various surgical powered linear hammer impact tools disclosed herein can provide feedback on tool displacement (1702). Based on the displacement, bone quality can be measured. For example, a large displacement can mean poor quality since the tool displaces bone easily. A small displacement can mean higher bone quality since the tool cannot displace bone as much for a given situation. Once an estimate of bone quality is made, the value can be displayed to the physician (1704).

[0064] As shown in FIG. 17B, cross-sectional scan, x-ray, or other scan data can be used to form an estimate of bone quality (1706). For example, a blurry x-ray may indicate low bone density, which may equate to poor bone quality. A dark and / or clear x-ray may indicate dense bone with higher bone quality. Once an estimate of bone quality has been made, the value can be displayed to the physician (1708).

[0065] As shown in Figure 17C, a physician can input various factors about the patient, such as age, sex, race, data from pre-operative scans, etc. (1710). Using the various data, a computing system can formulate an estimate of bone quality using lookup tables, records, anonymous data from other patients, etc. The estimated bone quality based on the various factors can be measured and displayed to the physician (1712).

[0066] 18 illustrates a method of controlling a surgical powered linear hammer impact tool in accordance with at least one embodiment of the present disclosure. Once the bone quality has been assessed and entered into the controller (1802), the operation can begin (1804). For example, the bone quality score can range from 1 (poor bone quality) to 5 (good bone quality). Depending on the bone quality, the tool can be set to provide a pre-set impact force. For example, for poor bone quality, a low impact force can be set. For good bone quality, a higher impact force can be set.

[0067] During surgery, the bone quality can be updated using the tool / position sensor (1806) based on how quickly the tool moves into the bone for the first few broaches. For example, the bone quality can be updated if the broach glides faster than expected due to weak cancellous bone (e.g., osteoporosis). The purpose of the initial bone quality assessment is to adjust the starting force (initial impact) and subsequent impact amounts as the tool progresses into the bone (1808). The energy is monitored as the tool impact continues, for example as the broach size is increased, and remains constant at the "maximum" broach movement (measured by the position sensor), for example, into the femoral canal.

[0068] Bone renewal can be a continuous process. For example, when the position sensor indicates that the broach or impact is not advancing much (medium advancement), this may indicate the end of the stroke. Continuing to impact the bone with more force may damage the bone, so the tool can automatically adjust to reduce the force at a specific rate (e.g., a larger reduction for weaker bone and a smaller reduction for stronger bone).

[0069] FIG. 19 is a schematic diagram of a controller 1900, such as the electronics 204, in accordance with at least one embodiment of the present disclosure. As shown in FIG. 19, the controller 1900 can include a processor 1902 and a memory 1904. The memory unit 1904 can include a software module 1906 and bone data 1908. When executed on the processor 1902, the software module 1906 can perform processes such as receiving the displacement data, measuring bone quality, adjusting the impact force of a tool, etc., including one or more stages of the method described in connection with FIGS. 17 and 18. As disclosed herein, the bone data 1908 can include formulas, lookup tables, records, patient data, etc. that can be used to measure bone quality as disclosed herein. The bone data 1908 can also include data for correlating desired impact force to a given bone quality and determining various sizes of tools, such as files and / or broaches. The controller 1900 may also include a user interface 1910 , communication ports 1912 , and input / output (I / O) devices 1914 .

[0070] The user interface 1910 can include any number of devices that allow a user to interact with the controller 1900. Non-limiting examples of the user interface 1910 can include a keypad, such as buttons located on the housing of the powered linear hammer surgical impact tool, a microphone, a display (such as a touch screen connected to the controller 1900 by a wired or wireless connection).

[0071] The communications port 1912 allows the controller 1900 to communicate with a variety of information sources and devices, including, but not limited to, a remote computing device, such as a server or other remote computer. For example, the remote computing device can store data, such as patient scan data, that can be retrieved by the controller 1900 using the communications port 1912. Non-limiting examples of the communications port 1912 can include an Ethernet card (wireless or hardwired), a Bluetooth transmitter and receiver, a near field communication module, etc.

[0072] The I / O devices 1914 allow the controller 1900 to receive and output information. Non-limiting examples of the I / O devices 1914 can include sensors such as Hall effect sensors, cameras (still or video), microphones, etc. For example, the I / O devices 1914 can allow the controller 1900 to receive patient data directly from CT scan equipment, x-ray machines, etc. As another example, the I / O devices 1914 can include Hall effect sensors that send one or more signals that are received by the processor 1902. The processor 1902 can then measure the impact force generated by the slider based on the position of the rotating element and / or the position of the slider.

[0073] [Note] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention may be practiced. These embodiments are also referred to herein as "examples." These examples may include elements in addition to those shown or described. However, the inventors also contemplate examples in which only the elements shown or described are presented. Furthermore, the inventors also contemplate examples using any combination or permutation of the elements shown or described (or one or more forms thereof) with respect to the particular example (or one or more forms thereof) or with respect to any other example (or one or more forms thereof) shown or described herein.

[0074] In the event of a conflicting usage between this document and a document incorporated by reference, the usage of this document will control.

[0075] In this document, the singular article is used to include one or more, as is common in patent documents, apart from other instances or uses of "at least one" or "one or more." In this document, "or" is used to mean non-exclusive or "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, "including" and "in which" are used as the plain English equivalents of "comprising" and "in which," respectively. Also, in the following claims, "including" and "comprising" are used without limitation, i.e., systems, apparatus, items, compositions, formulas, or processes that include elements other than those recited in the claim with this term are also considered to be within the scope of the claim. Moreover, in the following claims, "first," "second," and "third" are used as mere designators and are not intended to impose numerical requirements on their objects.

[0076] The above description is intended to be illustrative, not restrictive. For example, the above-described embodiments (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used by those skilled in the art upon reading the above description. The Abstract is submitted in accordance with 37 CFR §1.72(b) to enable the reader to quickly ascertain the nature of the technical disclosure. The Abstract is provided with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to simplify the disclosure. This should not be construed as intending that unclaimed disclosed features are essential to the claims. Rather, inventive subject matter may reside in less than all of the features of a particular disclosed embodiment. Thus, it is contemplated that the following claims are incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the claims, along with the full scope of equivalents to which the claims are entitled. According to aspect (1), there is provided an electric rotary hammer impact tool for surgery, comprising: The tool body, a motor disposed within the tool body; a shaft operatively connected to the motor; a disc hammer element connected to the shaft, the disc hammer element including a radial impact protrusion; a toolholder element comprising a shaft configured to support an instrument at one end, the shaft of the toolholder element straddling the disc hammer element and comprising a C-shaped structure including spaced apart opposing forward and rearward impact faces; Equipped with the toolholder element is configured to move axially within the tool body when the instrument is pressed against a work surface to align the forward impact face and engage the radial impact protrusion to apply a forward impact to the toolholder element; the toolholder element is configured to move axially within the tool body as the tool is pulled away from the work surface to align the rearward impact surface and engage the radial impact protrusion to apply a rearward impact to the toolholder element. A surgical powered rotary hammer impact tool. According to aspect (2), the rotation direction of the shaft connected to the motor is changed from a first direction for providing a front impact to a second direction for providing a rear impact. According to aspect (3), the tool holder further includes a bearing for supporting the shaft of the tool holder element. According to aspect (4), the motor is configured to partially rotate the disc hammer element to provide the impact. According to aspect (5), the radial impact projection of the disc hammer element has a metallic impact surface. According to aspect (6), the radial impact protrusion of the disc hammer element has a polymeric material impact surface. According to aspect (7), further, a sensor arranged to detect an impact on the tool holder element; a controller configured to reverse rotation of a motor to reverse rotation of the disc hammer element; Equipped with. According to aspect (8), the tool further includes a control electronic device and a battery electrically communicating with the control electronic device, the control electronic device and the battery being disposed within the tool body. According to aspect (9), the shaft of the tool holder element is arranged generally perpendicular to the rotation axis of the motor. According to aspect (10), the tool further comprises a handle extending perpendicular to the tool body. According to aspect (11), the tool further includes a microphone disposed within the tool body and in electrical communication with a controller, the controller being configured to activate the motor in response to voice commands. According to aspect (12), the disc hammer element includes a plurality of swing hammer elements attached thereto. According to aspect (13), further, Measuring an estimate of bone quality; increasing or decreasing an impact force generated by the powered surgical linear hammer impact tool based on the estimate of the bone quality; The controller is operable to perform operations including: According to aspect (14), further, Measuring a displacement of a tool attached to the tool holder; increasing or decreasing an impact force generated by the powered surgical linear hammer impact tool based on the displacement of the tool; The controller is operable to perform operations including: According to an aspect (15), an impact wrench having an impact mechanism configured to apply a rotational impact to an output shaft; an elongated tool arm attached to the output shaft and extending perpendicular to an axis of the output shaft; a tool implement attached to an end of the elongated tool arm, the tool implement extending generally perpendicular to the end of the elongated tool arm; A surgical powered rotary hammer impact tool comprising: According to aspect (16), the tool implement is connected to the elongated tool arm by a pin. According to aspect (17), there is provided a method of controlling a surgical powered rotary hammer impact tool for preparing a bone to receive a prosthesis, the method comprising: setting an initial impact force level of the surgical powered rotary hammer impact tool based on the estimated bone quality; activating said powered surgical rotary hammer impact tool at a set initial impact level; monitoring tool advancement into the bone; and increasing or decreasing the impact force level by a preset amount based on the detected advancement of the tool into the bone; The method includes: According to aspect (18), the method further includes monitoring tool advancement into the bone and reducing the impact force level by a preset amount based on the detected advancement of the tool into the bone. According to an embodiment (19), the bone quality is based on a bone quality score comprising at least three bone quality levels. According to aspect (20), the bone quality score is measured by detecting a change in position of a broach tool within the bone during an initial actuation of the impact tool, with a maximum movement of the broach tool indicating low bone quality, a moderate movement of the broach tool meaning medium bone quality, and a minimum movement of the broach tool within the bone meaning high bone quality.

Claims

1. 1. A surgical powered rotary hammer impact tool, comprising: The tool body, a motor disposed within the tool body; a shaft operatively connected to the motor; a disc hammer element connected to the shaft, the disc hammer element including a radial impact protrusion; a toolholder element comprising a shaft configured to support an instrument at one end, the shaft of the toolholder element straddling the disc hammer element and comprising a C-shaped structure including spaced apart opposing forward and rearward impact faces; Equipped with the tool holder element is configured to move the shaft axially within the tool body by engaging the radial impact protrusion with the forward impact surface of the shaft and applying a forward impact to the forward impact surface, thereby forcing the instrument against a work surface; the tool holder element is configured to move the shaft axially within the tool body by engaging the radial impact protrusion with the rear impact surface of the shaft and applying a rear impact to the rear impact surface, thereby pulling the instrument away from the work surface. Surgical electric rotary hammer impact tool.

2. 2. The powered surgical rotary hammer impact tool of claim 1, wherein a direction of rotation of the shaft connected to the motor is changed from a first direction for providing a forward impact to a second direction for providing a rearward impact.

3. 3. The powered surgical rotary hammer impact tool of claim 1 or 2, further comprising a bearing supporting the shaft of the tool holder element.

4. 4. The powered rotary surgical hammer impact tool of claim 1, wherein the motor is configured to partially rotate the disc hammer element to apply the forward impact or the rearward impact.

5. 5. The powered surgical rotary hammer impact tool of claim 1, wherein the radial impact projection of the disc hammer element has a metallic impact surface.

6. 6. The powered surgical rotary hammer impact tool of claim 1, wherein the radial impact projection of the disc hammer element has a polymeric material impact surface.

7. Furthermore, a sensor arranged to detect an impact on the tool holder element; a controller configured to reverse rotation of the motor to reverse rotation of the disc hammer element; 7. The powered rotary hammer impact tool for surgery according to claim 1, further comprising:

8. 8. The powered surgical rotary hammer impact tool of claim 1, further comprising control electronics and a battery in electrical communication with the control electronics, the control electronics and the battery being disposed within the tool body.

9. 9. The powered surgical rotary hammer impact tool of claim 1, wherein the shaft of the tool holder element is aligned generally perpendicular to an axis of rotation of the motor.

10. 10. The powered rotary hammer surgical impact tool of claim 1, further comprising a handle extending perpendicular to the tool body.

11. 11. The powered surgical rotary hammer impact tool of claim 1, further comprising a microphone disposed within the tool body and in electrical communication with a controller, the controller configured to activate the motor in response to a voice command.

12. 5. The powered surgical rotary hammer impact tool of claim 1, wherein the disc hammer element comprises a plurality of swing hammer elements mounted in place of the radial impact projections.

13. Furthermore, Measuring an estimate of bone quality; increasing or decreasing an impact force generated by the powered surgical rotary hammer impact tool based on the estimate of the bone quality; a controller operative to perform operations including 13. A powered surgical rotary hammer impact tool according to any one of claims 1 to 12.

14. Furthermore, Measuring a displacement of a tool attached to the tool holder element; increasing or decreasing an impact force generated by the powered surgical rotary hammer impact tool based on the displacement of the tool; a controller operative to perform operations including 13. A powered surgical rotary hammer impact tool according to any one of claims 1 to 12.

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