Patent Publication Number: US-2022226033-A1

Title: Linear electric surgical hammer impact tool

Description:
PRIORITY CLAM 
     The present application claims priority to U.S. Provisional Application No. 63/140,071, entitled “Linear Electric Hammer Impact Tool,” filed on Jan. 21, 2021; the contents of which are hereby incorporated by reference in their entirety. 
    
    
     FIELD OF THE DISCLOSURE 
     The present disclosure relates generally to surgical instruments and use thereof. More specifically, the present disclosure relates to an electric surgical impact tool and methods of use thereof. 
     BACKGROUND 
     Orthopedic surgeons commonly utilize tools for cutting or carving bone that require a hammer or mallet to transmit an impaction force to the tool. An example is a broach tool used to prepare the proximal end of a femur to receive the stem of a hip implant. Such broaches can be used with a hammer wielded by the physician or with a pneumatic “jackhammer” like tool. However, striking a broach tool with a hammer can be tiresome and can cause high stresses on the physician&#39;s own joints, such as the shoulder joint. Furthermore, pneumatic impact tools require connection to an air hose, which can he inconvenient and can potentially limit the physician&#39;s ability to orient the tool in the desired manner. 
     SUMMARY 
     The following, non-limiting examples, detail certain aspects of the present subject matter to solve the challenges and provide the benefits discussed herein, among others. 
     Example 1 is a linear electric surgical hammer impact tool comprising: a housing defining a cavity extending along a longitudinal axis of the housing; a slider located inside the cavity and arranged along the longitudinal axis of the housing; a shuttle located inside the cavity and arranged along the longitudinal axis of the housing, the shuttle comprising a first set of collars and a second set of collars; a motor configured to drive the slider along the longitudinal axis in a first direction and a second direction; and a tool holder connected to the shuttle, wherein motion of the slider in the first direction causes the slider to contact the first set of collars and motion of the slider in the second direction causes the slider to contact the second set of collars. 
     In Example 2, the subject matter of Example I optionally includes Wherein the slider comprises a slider flange that contacts the first and second set of collars during motion of the slider. 
     In Example 3, the subject matter of any one or more of Examples 1-2 optionally include wherein the motor is a tube motor and a slider shaft passes at least partially through the tube motor. 
     In Example 4, the subject matter of any one or more of Examples 1-3 optionally include wherein the shuttle comprises: a shuttle flange; a first rod extending from the shuttle flange, a first collar from the first and second set of collars attached to the first rod; and a second rod extending from the shuttle flange a second collar from the first and second set of collars attached to the second rod. 
     In Example 5, the subject matter of any one or more of Examples 1-4 optionally include wherein the shuttle comprises a biasing element configured to bias the shuttle in the first direction. 
     In Example 6, the subject matter of any one or more of Examples 1-5 optionally include a sensor arrange to detect a position of the slider within the cavity. 
     In Example 7, the subject matter of any one or more of Examples 1-6 optionally include a controller operative to perform operations comprising: determining an estimate of a hone quality; and increasing or decreasing an impact force generated by the linear electric surgical hammer impact tool based on the estimate of the bone quality. 
     In Example 8, the subject matter of any one or more of Examples 1-7 optionally include a controller operative to perform operations comprising: determining a displacement of a tool attached to the tool holder; and increasing or decreasing an impact force generated by the linear electric surgical hammer impact tool based on the displacement of the tool. 
     In Example 9, the subject matter of any one or more of Examples 1-8 optionally include a handle that defines a cavity sized to receive electronics and the motor. 
     In Example 10, the subject matter of Example 9 optionally includes wherein the handle comprises: a first trigger operative to cause the slider to move in the first direction; and a second trigger operative to cause the slider to move in the second direction. 
     Example 11 is a linear electric surgical hammer impact tool comprising: a housing defining a cavity extending along a longitudinal axis of the housing; a slider comprising a slider shaft located inside the cavity and arranged along the longitudinal axis of the housing; a shuttle located inside the cavity and arranged along the longitudinal axis of the housing, the shuttle comprising: a shuttle flange, a first rod extending from the shuttle flange, a first collar and a second collar attached to the first rod, and a second rod extending from the shuttle flange, a third collar and a fourth collar attached to the second rod, the first collar, the second collar, the third collar, and the fourth collar defining a stroke of the slider; a tube motor defining a through hole sized to receive the slider shaft, the tube motor configured to drive the slider along the longitudinal axis in a first direction and a second direction; and a tool holder connected to the shuttle, wherein motion of the slider in the first direction causes the slider to contact the first collar and the third collar and motion of the slider in the second direction causes the slider to contact the second collar and the fourth collar. 
     In Example 12, the subject matter of Example 11 optionally includes wherein the shuttle comprises a biasing element configured to bias the shuttle in the first direction. 
     in Example 13, the subject matter of any one or more of Examples 11-12 optionally include a sensor arrange to detect a position of the slider within the housing, 
     In Example 14, the subject matter of any one or more of Examples 11-13 optionally include a controller operative to perform operations comprising: determining an estimate of a bone quality; and increasing or decreasing an impact force generated by the linear electric surgical hammer impact tool based on the estimate of the bone quality. 
     in Example 15, the subject matter of any one or more of Examples 11-14 optionally include a controller operative to perform operations comprising: determining a displacement of a tool attached to the tool holder; and increasing or decreasing an impact force generated by the linear electric surgical hammer impact tool based on the displacement of the tool. 
     In Example 16, the subject matter of any one or more of Examples 11-15 optionally include a handle that defines a cavity sized to receive electronics and the motor; a first trigger operative to cause the slider to move in the first direction; and a second trigger operative to cause the slider to move in the second direction. 
     Example 17 is a linear electric surgical hammer impact tool comprising: a processor; and a memory storing instructions that, when executed by the processor, cause the processor to perform operations comprising: receiving an estimate of a bone quality, receiving feedback during a surgical procedure, determining an updated estimate of the bone quality, and increasing or decreasing an impact force generated by the linear electric surgical hammer impact tool based on the updated estimate of the bone quality. 
     In Example 18, the subject matter of Example 17 optionally includes wherein determining the updated estimate of the bone quality includes determining a displacement of a tool attached to a tool holder of the linear electric surgical hammer impact tool. 
     In Example 19, the subject matter of any one or more of Examples 17-18 optionally include wherein receiving the estimate of the bone quality include receiving patient data related to a bone to be rasped. 
     In Example 20, the subject matter of any one or more of Examples 17-19 optionally include a Hall effect sensor, wherein the operations further comprise determining a position of a slider located within a housing of the linear electric surgical hammer impact tool based on a signal received from the Flail effect sensor. 
     in Example 21, the surgical impact tools, systems, and/or methods of any one or any combination of Examples 1-20 can optionally be configured such that all elements or options recited are available to use or select from. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       In the drawings, which are not necessarily drawn to scale, like numerals can describe similar components in different views. Like numerals having different letter suffixes can represent different instances of similar components. The drawings illustrate generally, by way of example, but not by way of limitation, various embodiments discussed in the present document. 
         FIG. 1  shows an isometric view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 2  shows a side section view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 3  shows a side section cutaway view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 4A  shows a detail side section view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 4B  shows a detail side section view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 4C  shows a detail side section view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 4D  shows a detail side section view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 5  shows a detail side section view of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 6A  shows a partial cross section of a mounting of a handle and housing of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 6B  shows a detail partial cross section of the mounting of the handle and housing of  FIG. 6A  consistent with at least one example of this disclosure; 
         FIG. 7  shows a cross section of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 8A  shows a tube motor for use in a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 8B  shows a cross section of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIG. 8C  shows a detail cross section of a proximal region of a linear electric surgical hammer impact tool consistent with at least one example of this disclosure; 
         FIGS. 9A and 9B  show a linear electric surgical hammer impact tool in accordance with at least one example of this disclosure. 
         FIGS. 10A, 10B, and 10C  show options for bone quality assessment consistent with at least one example of this disclosure; 
         FIG. 11  shows a flowchart of logic usable for controlling a linear electric surgical hammer impact tool consistent with at least one example of this disclosure 
         FIG. 12  shows a schematic of a controller consistent with at least one example of his disclosure 
     
    
    
     Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate exemplary embodiments of the disclosure, and such exemplifications are not to be construed as limiting the scope of the disclosure in any manner. 
     DETAILED DESCRIPTION 
     As an alternative to a pneumatic piston driven system, disclosed herein are electrically driven systems. Specifically, the linear electric surgical hammer impact tools disclosed herein can include impact elements, sometimes called sliders that can impact shuttles, tool holding elements, etc. to generate impact forces. 
     An electric motor can be configured to drive the impact elements to create the impact forces. For example, motion of a slider in a first direction can cause the slider to contact a first set of collars and motion of the slider in a second direction can cause the slider to contact a second set of collars. The contact between the collars and the slider can generate the impact forces to drive a rasp and/or broach into a canal of a bone and extract the rasp and/or broach from the canal. 
     As disclosed herein, one or more sensors, such as Hall effect sensors can be used to determine the position of the impact elements within the linear electric surgical hammer impact tools. Based on the position, the impact force generated can be determined. Also, a controller can be operative to determining an estimate of a bone quality and increasing or decreasing an impact force generated by the linear electric surgical hammer impact tool based on the estimate of the bone quality. 
     The above discussion is intended to provide an overview of subject matter of the present patent application. It is not intended to provide an exclusive or exhaustive explanation of the invention. The description below is included to provide further information about the present patent application. 
     Turning now to the figures,  FIG. 1  shows an example of a linear electric surgical hammer impact tool  100  consistent with at least one example of this disclosure. As disclosed herein, linear electric surgical hammer impact tool  100  can provide a simple, efficient, and robust battery powered handheld linear electric surgical hammer impact tool for use in surgical procedures. The linear electric surgical hammer impact tool  100  can include a distal end cap  102  and a proximal end cap  104  on opposite ends of a tool body  106 . As shown in  FIG. 2 , a tool holding element  202  with tool holder  108  emanates from the proximal end of the tool body  106 . With continued reference to  FIG. 1 , a handle  110  is secured to the tool body  106  and has a grip portion  112  which internally contains a battery pack  204  and controller  206 , sometimes called control electronics, controlled by a trigger  114 . Alternatively, or in addition, a voice control and response is enabled with use of a speaker/microphone  116 . 
       FIGS. 2, 3, 4A, 4B, 4C, 4D, and 5  show internal details of the linear electric surgical hammer impact tool  100  where tool body  106  contains a tubular electromagnetic linear motor with a coil structure  208  fixed inside the tool body  106 . The coil structure  208  actuates a magnetic or ferromagnetic mechanical impact motion element  210 . The impact motion element  210  may be supported by low friction bearings  502 A and  502 B (collectively bearings  502  shown in  FIG. 5 ) on a centrally located rod-like tool holder element  202  which is supported by low friction bearings  212 A and  212 B (collectively bearings  212  shown in  FIG. 2 ) in the proximal end cap  104  and distal end cap  102  respectively located at the ends of the tool body  106 . These bearings  212  and  502  may be simple plain bushing type bearings made from a material such as Rulon, which has a low coefficient of friction against polished stainless steel of the shaft  214 , and since the radial loads are very low, essentially radial parasitic magnetic forces from the motor, the energy loss due to friction will be less than a few percent of the energy delivered to the impact surface. If, however, longer life, less particles, and lower friction is desired, since the speeds are high, several meters per second, self-acting aerodynamic bearing features can be formed in the bearings&#39; inside diameters that act in either direction of motion. Furthermore, because a user may exert large radial loads on the tool when working on certain types of patients, and hence on the tool holder, the bearing  212 A can be a rolling element type such as a ball bearing cage bushing a die set bushing) bearing or a recirculating ball bushing, or as discussed below in the context of  FIGS. 4B, 4C and 4D , a diaphragm flexure type bearing. 
     The coil structure  208  can contain sensing elements  216  to determine a position of the impact motion element  210 . The sensed position can be used by the controller  206 , disposed in region  218 , to control current from the battery pack  204  to the coil structure  208  to thus control a position, a velocity, and an acceleration of the impact motion element  210 . The impact motion element  210  can thus be controlled to deliver the desired impact energy to a flange  220  of the tool holder element  202  with a desired cycle time. Accordingly, the impact motion element  210  can cause a force on a tool, held by the tool holder element  202  and tool holder  108 , to be able to do useful work such as cutting bone, where the mass of the impact motion element  210  on the low end may be about ¼ of the mass of the tool holder element  202  and the attached tooling (e.g., a chuck, tool adapter, tool holder  108 , etc.) and up to about two to four times that of the tool holder element  202  and attached tooling. 
       FIG. 2  shows a side section view of the linear electric surgical hammer impact tool  100  in the ready to be activated position where the coil structure  208  have caused the impact motion element  210  to move until it almost touches a rear impact flange  222 , sometimes called a distal flange, used for retracting the tool. Here the rear impact flange  222  is of the bolt-on collar type to enable assembly of the system, but it could also be shrunk fit on once the impact motion element  210  is placed over the shaft  214 . The user can push a tool (not shown), such as a broach attached to tool holder  108 , forward into the object to be cut, which can push the tool holder element  202  backwards into the tool body  106 . The flange  220  of the tool holder element  202  is now located at a proper impact position and its position is sensed by a sensor  224 A. The rear impact flange  222  position is sensed by sensor  224 B. Sensor  224 A and sensor  224 B are collectively referred to as sensors  224 . 
     The position of the impact motion element  210  may also be sensed, such as with sensing element  216 , such as a magnetic sensor, in the coil structure  208 . Based on the energy to be delivered, the controller  206  can command current (and voltage) to the coil structure  208  to accelerate the impact motion element  210  forward to reach a velocity needed, in the space that has been sensed, in order to deliver an impact of the desired energy.  FIG. 3  shows a side section cutaway view of the linear electric surgical hammer impact tool  100  at the moment of impact between the impact motion element  210  and the flange  220 . 
     Simplicity of design can be achieved by minimizing the number of parts and moving interfaces. As disclosed herein, concentric elements can enable minimal energy loss and wear of moving elements. The tool holder element  202  can rest in linear bearings  212 , which may be sliding bearings or rolling element bearings or flexural bearings, at the proximal and distal ends respectively. Rulon, a PTFE based bearing, is an example sliding contact beating material because it can be steam sterilized and has very low friction even when not additionally lubricated. Each of the bearings  212  can be press-fit into their respective end caps  102  and  104 , but here snap rings  226  (labeled individually as snap rings  226 A,  226 B, and  226 C) are shown to provide additional reliability for holding the bearings  212  in place in this impact device. In addition, a lip seal  228  can be held in place by a snap ring  230 . Alternatively, the lip seal  228  and snap ring  230  can be replaced by a simple O-ring or a Quad-ring in a groove where the lip seal  228  resides. The lip seal  228  can have lower friction, but it can be more complex to clean out. Still consistent with embodiments disclosed herein, a bellows seal can be used that can allow for effectively unrestrained axial motion, or a metal bellows can provide a slight spring bias, while providing a hermetic seal. A bellows, advantageously for sterilization purposes, can allow gas inside the tool to expand and push out as needed the tool holder element  202  by deflecting the bellows. The distal end bearing and mating shaft segment may be hexagonal to prevent rotation of the tool holding element  202 , and the hexagonal bearing in the enclosed distal end of the tool does not need to be seated. 
       FIG. 4B  shows where the proximal bearing  212 A can be replaced with diaphragm flexure bearing  402  that can provide sealing by the diaphragm at the proximal end as well as internal expansion of gases. Other elements can remain the same as described with respect to  FIGS. 4A, 4C, and 4D . The diaphragm flexures bearings  402  can be made from electroformed nickel alloy, for example, so it can also provide a nominal spring return force to the tool holder element  202  to keep it centered. The distal bearing  212 B can remain as a sliding bearing or it can also be made from a similar flexural bearing. 
     The impact flanges  220  and  222  can be centered about the coil structure  208 , and their positions may be sensed by sensors  224 , so the proper motion profile of the impact motion element  210  can be controlled to impact the tool holder element  202  to either drive in or retract a tool. As shown, the tool holder  108  can fit over the front cylindrical portion  404  of the diaphragm flexure bearings  402 . This can be a shrink-fit or it may be bonded with an adhesive, such as Loctite. A flexing element  406  can be the actual flexing diaphragm, which can also provide radial stiffness to support the tool holder element  202  shaft  214 . A conical portion  408  of the diaphragm flexure bearings  402  can fit over a front tapered portion  410  of the proximal end cap  104  and can act to center the shaft  214  with respect to the proximal end cap  104  and the coils. 
       FIG. 4B  shows a simple diaphragm flexure  412  but it is understood that a convoluted (or corrugated) diaphragm based proximal end cap can also be used, as shown in  FIG. 4C . The convoluted diaphragm flexure  412  can be made by electroforming for example and, because the features are circular about the center axis, can have good radial load capacity and stiffness but also greater range of motion and can be very compliant axially, although they may be more expensive to manufacture. A convoluted diaphragm in this system could provide greater range of motion, up to 10 mm vs 2 mm, to enable the device to “dry fire” with less chance of over-flexing the flexure were it a simple drumhead like diaphragm. Here, the diaphragm flexure  412  can be made nominally planar and then sandwiched between elements at its inside diameter (ID) and outside diameter (OD). At the OD it can be held in a structure  414 , which can be brazed, bonded, press fit, or even threaded into tool body  106 , where it can be seen ring  416  can also fit inside the structure  414  and push the outer flange of diaphragm flexure  412  against a step of the structure  414 . At its ID, diaphragm flexure  412  can engage the shaft  214  to radially center the shaft  214  in the proximal end cap  104 , and is sandwiched between flange  418 , which may have deadblow hammer like characteristics as discussed herein with respect to  FIG. 8 , and the tool holder  108 , which can be extended to create a strong axial clamping effect and can be bonded, shrunk-fit, or clamped in place. 
     In  FIG. 4D , a proximal end cap  420  can have two convoluted diaphragms  422  (labeled individually as diaphragms  422 A and  422 B) spaced about four rod diameters apart with ring spacers  424  (labeled individually as ring spacers  424 A and  424 B) between them. This can provide good moment support to a rod held by the flexures. Ring  426  can lock the flexures axially in place at the OD. The ring spacers  424  can be identical and have projecting internal annular flanges  428  (labeled individually as flanges  428 A and  428 B). At the ID, a spacer  430  can be compressed when a rod inserted through and as with the single flexure of  FIG. 4C , may be sandwiched between the rod flange  220  and tool holder  108 . In  FIG. 4D , the spacer  430  can have a radially projecting flange  432  that can limit the distal and proximal travel of the flexures by hitting either of flanges  428  thereby preventing damage to the flexures. In all instances of use of flexures, the distal cap  102  can be the same as the proximal cap  104  so the tool holding element  202  can be completely supported by flexures. 
     The proximal end cap  104  for use with sliding bearing  212 A is shown as a sliding fit into the tool body  106 , but this can be a threaded connection with mating tapers to ensure concentricity. It can also be permanently attached by shrink-fit, soldering, brazing, adhesion or even welding as it is closest to the surgical operation and bears greatest stress and should be free of spaces in which biological materials could infiltrate. With the proximal end cap  104  effectively permanently attached to the tool body  106 , the distal end cap  102  can be removable and this can be by a threaded connection between the distal end cap  102  and the tool body  106 . In the distal end cap  102  can be the rear sliding bearing  212 B held in place by press-fit or the snap ring  226 C as disclosed herein. The shaft  214  of the tool holder element  202  can be supported at each end and due to the concentric nature of the system, it can exert only radial parasitic loads from the cutting operation requiring guidance from the surgeon holding the tool  100 . The distal end cap  102  can be closed. In other words, there can be no need for the shaft  214  to be able to protrude from the distal end cap  102 . 
     As shown in  FIG. 5 , the impact motion element  210  can slide along the smooth shaft  214  on the same size and type of Rulon bearings as used to support the shaft  214 . Smooth bore bearings, or bearings with grooves to promote the formation of a dynamic supporting air film when the speed rises, typically about 0.5 m/second, to reduce friction and wear and increase efficiency even further. Bearings  502  in the proximal and distal ends of the impact motion element  210  central ferromagnetic core structure  504  are retained by snap rings  506  (labeled individually as snap rings  506 A and  506 B). Here a magnetic member is shown to interact with the coil structure  208  as a Lorentz force actuator. Magnets  510  (labeled individually as magnets  510 A,  510 B,  510 C,  510 D,  510 E,  510 F,  510 G,  510 H, and  510 I) may be radially polarized and shown spaced with spacers  512  (labeled individually as spacers  512 A,  512 B,  512 C,  512 D,  512 E,  512 F,  512 G, and  512 H) such that a magnetic field can project radially from the north of one magnet, through the current carrying coils and back into a south of an adjacent magnet. As the magnetic field crosses the circumferentially wound current carrying coils, a force by the right-hand rule is created axially to move the impact motion element  210 . The Lorentz force affect can move mass to create an impact inertia and a long stroke. Alternatively, every other magnet of magnets  510  can be axially polarized so the magnets  510  can be arranged to form a N-S:S-N:N-S . . . array or a Halbach array to give a somewhat stronger field effect at the potential expense of somewhat more elaborate manufacturing. 
     As disclosed herein, the impact motion element  210  can be supported within the coil structure  208  by linear bearings, which may be self-acting aerostatic bearings. This radially decouples the impact motion element  210  from the tool holding element  202 . This can provide a high level of concentricity and efficiency for the electric motor. 
     Linear electric motors disclosed herein can be a Lorentz force motor, but variable reluctance and hysteresis motors can also be used, although more difficult to control, and may be larger, the mechanical structure simpler and hence could have cost advantages. For a variable reluctance motor, the magnetic material of the impact motion element  210  can consist of soft magnetic material, such as laminated silicon steel, with multiple projections acting as magnetic poles. For a hysteresis motor, the magnetic material of the impact motion element  210  may be a smooth cylinder of hard chrome or cobalt steel with large hysteresis loop properties. 
     The impact motion element  210  can have the core structure  504  with one end solid as shown and the other end has a washer  514  held in place with a snap ring  516 . The entire magnet assembly of the impact motion element  210  can be epoxied together. A thin, on the order of ½ to 1 mm thick, non-magnetic stainless steel tube can encapsulate the entire assembly to ensure no magnet chips would short the motor in case of a fracture. As disclosed herein, this element can be made from a resilient material in which case it can project to also be the impact surface thereby creating a lower peak but longer duration impact force akin to using a dead blow hammer. For a fast hard crisp blow though, hard steel on hard steel can be used. The opposite end of the impact motion element  210  can be used for retraction. 
     To drive a tool forward for cutting, the user pushes the linear electric surgical hammer impact tool  100  forward and the surface  232  of the tool holder  108  can come to rest on the front snap ring (or surface)  230  of the proximal end cap  104 . The controller  206  can control the coil to retract the impact motion element  210  and then drive it forward to achieve the speed needed to generate the energy of impact desired. The flange  220  of the tool holder element  202  can thus be impacted by the proximal end of the impact motion element  210 . To retract a tool, the user pulls back on the linear electric surgical hammer impact tool  100 , which can cause the flange  220  to come to rest against the inside surface  236  of end cap  104  and bring the rear impact flange  222  into the range of the impact motion element  210  to be accelerated from the proximal end to the distal end of the coil structure  208  from a ready position near the proximal end of the linear electric surgical hammer impact tool  100 . The speed of the impact controls the energy and hence the force delivered upon impact. 
     The microphone  116  can be connected to the controller  206 , which can be a microprocessor controller, for control of current to the coil structure  208  to hear the user speak commands as they are using the linear electric surgical hammer impact tool  100 . As an example, a surgeon, as he or she is observing the impact, can speak “less force,” “more force,” “faster,” “slower,” etc. and it will be understood that the linear electric surgical hammer impact tool  100  can be controlled by the user to meet their needs and style of use using his or her voice. The controller  206  can learn to respond to a particular user. 
     For the controller  206  to obtain less force it can control the distance of acceleration and current to the coil structure  208  to vary the force and hence the acceleration of the impact motion element  210 . The impact force can be proportional to energy, which is the product of one half the mass of the impact motion element  210  and its velocity squared. “Faster” can mean that the controller  206  would then, after impact, bring the mass back faster to a starting point for the next impact, and then accelerate the impact motion element  210 . The controller  206  can operate in current control mode, to generate the desired force, and the voltage follows according to the speed as the impact motion element  210  accelerates. This Lorentz force actuator has the moving element travel further than the pitch between magnets, and hence the sensing elements  216 , such as Hall effect sensors, can be dispersed in the coil structure  209  to sense the polarity of the magnets beneath them, and switch the current direction to the coil  208  to ensure that the force is always in the proper direction as the impact motion element  210  accelerates. This type of longer-range motion linear electric actuator can have three independently controllable coils, which are switched in a sinusoidal fashion to give smooth motion of the moving magnet member (e.g., the impact motion element  210 ). 
     As the impact motion element  210  is accelerated, there is an equal and opposite force on the coil structure  208 , which the user can feel, although it can be absorbed somewhat by the mass of the system.  FIG. 6A  shows a partial cross section of a mounting of the handle  602 , which can have a top portion  604  so that it can contain circumferential internal grooves  606  (labeled individually as grooves  606 A and  606 B) for accepting dampening elements  608  (labeled individually as dampening elements  608 A and  608 B), such as “quad rings” to secure housing  118 . The housing  118  can have corresponding external grooves  612  (labeled individually as grooves  612 A and  612 B) as shown in FIG. GB, where an inner diameter lobes of the dampening element  608 B engage the sides of the groove  606 B, while the outer diameter lobes of the dampening element  608 B engage the sides of grooves  612  in the housing  118 . While  FIGS. 6A and 6B  show square dampening elements, circular O-rings can be used. 
       FIG. 7  shows a cross section of a linear electric surgical hammer impact tool  700  consistent with at least one example of this disclosure. The linear electric surgical hammer impact tool  700  can include a tool holder element  702  that can have a proximal impact flange  704  for driving a tool secured to tool holder  108  and distal impact flange  706  for retracting the tool. Proximal impact flange  704  and distal impact flange  706  can be separate elements threaded onto a rod  708 . The impact flanges  704  and  706  can have cavities for resilient polymer elements  710  (labeled individually as resilient polymer elements  710 A and  710 B) to provide the linear electric surgical hammer impact tool  700  with more of a deadblow hammer performance as disclosed herein. The distal end  712  of the rod  708  can have a hex shape machined into it to slide into a hex bushing  714 . If a diaphragm type beating is used, then the rod  708  and diaphragm bearing can be designed to properly engage one another. 
     As disclosed herein, in order to deliver a longer duration lower force, a resilient low loss polymer, such as hard cast polyurethane, can be incorporated into the contact surface of the impact motion element  210 , or as a washer placed around the shaft  214  of the tool holder element  702  at the impact surfaces of the flanges  220  and  222  (as shown in at least  FIG. 2 ). 
       FIGS. 8A, 8B, and 8C  show a linear electric surgical hammer impact tool  800  consistent with at least one example of this disclosure. The linear electric surgical hammer impact tool  800  can include a tube motor  802 . As disclosed herein, the tube motor  802  can be mounted inside a housing  804  and a core  806  can move back and forth within the motor stator  808 . A rod impactor  810 , shown in tubular form, can be attached to an end of the moving core  806  by a threaded stud  812  threaded into the end of the core  806  and a distal flange  814  of the rod impactor  810 . A cylindrical space  816  within the rod impactor  810  can receive a flared end  818  of a tool holding element  820  and this flared end  818  can be what is impacted to drive the tool holding element  820  in the proximal or distal direction to drive a tool forward or to retract the tool. It is understood that while shown here as a tubular structure, rod impactor  810  can also be planar, as in the body of a turnbuckle so its sides are open and is thus one piece and the tool holder element  820  inserted thereby negating the need for end  822  to be a separately attachable element. 
     The axial motion space in the rod impactor&#39;s internal cavity, e.g., cylindrical space  816 , can be equal to the stroke of the moving core needed to generate the desired maximum impact energy. This stroke distance can be determined by a maximum attainable force and speed of the tube motor  802  and the combined mass of the moving core  806  and the tubular rod impactor  810 . The motor force-speed curve can be used in conjunction with the total moving mass to determine the acceleration as a function of speed and hence the distance travelled to compute the stroke required and this stroke plus the thickness of the flared end  818  gives the total length of the cavity  816 .  FIG. 9B  shows the linear electric surgical hammer impact tool  800  in a retracted mode where the user can be pushing the linear electric surgical hammer impact tool  800  forward to engage an operation tool (e.g., a broach not shown but held in the tool holder  108 ) with the object to be operated on (e.g., a femur) by the tool. Hence the distal end of tool holder  108  can be touching the proximal face of the proximal end cap  824  and a motion limiting flange  826  of the tool holding element  820  can be spaced distally rearward from the end cap  824 . The moving core  806  can be ready to be accelerated forward until the proximal face of flange  814  impacts the distal face of flared end  818  transferring the kinetic energy of the core  806  and rod impactor  810  to the tool holder element  820 . This can send a stress wave down a shaft  828  where it then is transferred to the tool holder  108  and on into an operating tool to do work on an object, such as driving a reamer into bone. 
     To retract the operation tool, the user pulls back on the linear electric surgical hammer impact tool  800  and the motion limiting flange  826  of the tool holding element  820  can contact the end cap  824  (or a snap ring  830 ) while the core  806  is moved all the way forward by a system controller, such as controller  206 . It then accelerates distally and the distal inside surface of impactor end cap  822  impacts proximal surface of flared end  818  imparting energy to retract the operating tool. 
     The tool holding element  820  can be supported by a bearing system that can withstand radial and moment loads and ensure efficient accurate axial motion so the flared end  818  does not contact the bore  816 . Bore  816  is not pressurized, as clearance, such as 1 mm radially, can exists between the relative moving elements to allow for essentially unrestricted airflow to ensure energy is not lost to pumping air through a restriction. For example, two bearings  832  (labeled individually as bearings  832 A and  832 B) can be separated by at least 3 or more, such as 5, diameters of the shaft  828 . In addition, the distance of the flange  818  from the bearing  832 A can be about equal to the spacing between the bearings. In this way, radial motion of the flared end  818  can be on the order of radial clearance between the bearings and the shaft  828 , which can be about 0.1 mm, and hence ensure the flared end  818  does not contact the inside of the bore  816 . As disclosed herein, the linear motion bearings  832  can be sliding or rolling element or flexural element bearings chosen for the type of application and performance desired. 
     The linear electric surgical hammer impact tool  800  can include a handle  834  with grip  836  and trigger  838 . Within the handle  838  and a base  840  can be control circuits, such as controller  206 , and a removable and rechargeable battery  842 , which slides into place. The top of the handle  834  can be connected to the mounting block  810 . A dampening interface between the two may also be used as disclosed herein. A speaker/microphone  844  can enable voice control of the linear electric surgical hammer impact tool  800  to make it respond to user commands and speak back to the user about the state of the device as disclosed herein. 
     Any embodiments disclosed herein can enable advanced control where, for the tool used and the state of the patient and the operation, the linear electric surgical hammer impact tools can automatically adjust the impact energy and frequency. To achieve intelligent control of the tools as an operation progresses, sensors such as sensors  224 , can be used to monitor a position of the tool holding elements, such as tool holding elements  202 ,  702 , and  820 , with respect to a tool&#39;s position, or the position sensor included in commercial tube motors may be used. In addition, an accelerometer in the tool (or its adaptor element that enables its proper positioning with respect to the tool holder  108 ) can also provide additional feedback to enable ascertaining the progress of the tool into the bone. Consistent with embodiments disclosed herein, a camera can look upon the operation to also monitor progress of the tool into the bone with each impact, and information from the camera and the accelerometer can be sent to control electronics, such as controller  206 , by wireless link. 
       FIGS. 9A and 9B  show a linear electric surgical hammer impact tool  900  in accordance with at least one example of this disclosure. The linear electric surgical hammer impact tool  900  can include a housing  902  having a rear cap  904  and a front cap  906 . A rear flange  908  and a front flange  910  can be secured to housing  902  proximate the rear cap  904  and the front cap  906 , respectively, using bolts  912 . The housing  902  can define a cavity  903  that extends along a longitudinal axis of the housing  902 . 
     A shuttle  914  can be located at least partially inside the housing  902  and include rods  916  (labeled individually as rods  916 A and  916 B). During operation, the shuttle  914  can translate along the longitudinal axis of the housing  902 . Collars  918  (labeled individually as collars  918 A,  918 B,  918 C, and  918 D) can be connected to the rods  916  and define a travel space  920 . Stated another way, the collars  918  can limit movement of the shuttle  914  to a predefined range of stroke. The position of the collars  918  can be adjusted to increase or decrease the stroke length for the shuttle  914 . 
     The shuttle  914  can include masses  922  (labeled individually as masses  922 A and  922 ) and springs  924  (labeled individually as springs  924 A and  924 B). The masses  922  and the springs  924  can press against the rear flange  908  to bias the shuttle  914  towards a front end (sometimes referred to as a proximal end) of the linear electric surgical hammer impact tool  900 . The position of the collars  918 A and  918 B can be changes do adjust the amount of biasing force generated by the spring  924 . Thus, the masses  922  and the springs  924  can act as a biasing element. 
     The linear electric surgical hammer impact tool  900  can include a slider  926  that translates back and forth along the longitudinal axis of and within the cavity  903  defined by the housing  902 . The slider  926  can include a slider flange  928  that defines holes  930  (labeled individually as holes  930 A and  930 B). The rods  916  can pass through the holes  930  and the slider flange  928  can be position in between the collars  918  to limit a range of motion of the slider  926  relative to the shuttle  914 . The slider flange  928  can also be located in between the collars  918 C and  918 D and a shuttle flange  932 . 
     During an impact stroke, the slider flange  928  can impact the collars  918 C and  918 D to drive the shuttle  914 , and a tool (e.g., a broach) attached to the shuttle  914 , forward. During a retraction stroke, the slider flange  928  can impact the collars  918 A and  918 B to drive the shuttle  914 , and the tool attached to the shuttle  914  reward. 
     Movement of the slider  926  can be controlled by a controller  934  that can control a motor  936 . As disclosed herein, a slider shaft  938  can pass though a through hole  940  defined by the motor  936 . The slider shaft  938  can also include one or more magnets as disclosed herein to cooperate with the motor  936  to cause the slider  926  to oscillate back and forth to generate impact forces. The controller  934  can be a programmable controller or other circuitry as disclosed herein. The motor  936  can be a tube motor or other motor as disclosed herein. Sensors, such as Hall effect sensors, as disclosed herein, can be used to monitor the position of the slider  926  as disclosed herein with respect to impact motion element  210 . Sensors and magnets are not shown in  FIG. 9  for clarity, but can be any configuration as disclosed herein. 
     The controller  934  and the motor  936  can be contained in a cavity  942  defined by a handle  944 . The handle  944  can include triggers  946  (labeled individually as triggers  946 A and  946 B). During use, a surgeon can press one of triggers (e.g., the trigger  946 A) to cause the linear electric surgical hammer impact tool  900  to generate an impact force (sometimes called a driving force) needed to drive a tool forward. Pressing the other trigger (e.g., the trigger  946 B) can cause the linear electric surgical hammer impact tool  900  to generate an impact force (sometimes called a retraction force) to extract the tool from bone. 
       FIGS. 10A, 10B, and 10C  show options for bone quality assessment consistent with at least one embodiment of this invention. Input into a controller of an initial assessment by a surgeon of the bone quality (e.g., the surgeon inputting the bone quality into a tool or some user interface, or some outside assessment of bone quality via X-ray or CT), which the surgeon can speak to the tool and a microphone, receives the words. Using a wireless link, the controller of the tool can access an external computer, which could process the information and a control plan can downloaded to the tool and used to better control the tool for the operation at hand. 
     As shown in  FIG. 10A , the various linear electric surgical hammer impact tools disclosed herein can provide feedback as to displacement of tools ( 1002 ). Based on the displacement, a bone quality can be determined. For example, large displacements can mean poor quality as the tool easily displaces bone. Small displacement may be higher bone quality since the tool is not able to displace as much bone for a given setting. Once an estimation of the bone quality is made, the value can be displayed to the surgeon ( 1004 ). 
     As shown in  FIG. 10B , tomography scan, x-rays, or other scan data can he used to form an estimation of bone quality ( 1006 ). For example, if x-rays are faint, then bone density may be low and low bone density can be equated to poor bone quality. Dark and/or clear x-rays may indicate dense bone having a higher bone quality. Once an estimation of the bone quality is made, the value can be displayed to the surgeon ( 1008 ). 
     As shown in  FIG. 10C , a surgeon can enter various factors for a patient, such as age, gender, race, data from pre-operative scans, etc. ( 1010 ). Using the various data, a computing system can use lookup tables, actuarial tables, anonymized data from other patients, etc. to formulate an estimate of bone quality. Based on the various factors, the estimated bone quality can be determined and displayed to the surgeon ( 1012 ). 
       FIG. 11  shows a method for controlling a linear electric surgical hammer impact tool consistent with at least one example of this disclose. Once the bone quality is assessed and entered into a controller ( 1102 ), the operation may commence ( 1104 ). For example, bone quality scores can range from 1, poor quality bone, to 5 for high quality bone. Depending on the bone quality the tool may be set to deliver a predetermine impact force. For example, for low bone quality a low impact force can be set. For a higher bone quality, a higher impact force can be set. 
     During the operation, the bone quality can be updated ( 1106 ), using the tool position sensor sensing, based on how quick the tool is moving into the bone on the first few broaches. For example, if the broach is sliding in faster than expected due to weak cancellous bone (e.g., osteoporosis), the bone quality can be updated. The goal of the initial bone quality assessment can be to modulate the starting force (initial impact) and adjust the amount of subsequent impact modulation as the tool progresses into the bone ( 1108 ). As the tool keeps impacting as broaches are increased in size, for example, the energy is monitored and remains unchanged when there is “maximum” broach movement down the femur canal (as measured by the position sensor) for example. 
     Updating the bone quality can be a continuous process. For example, as the position sensor notes that the broach or implant is not advancing forward as much (“medium movement forward”), which can indicate the end of travel. Continuing to impact the bone harder may damage the bone so the tool can automatically modulate the force down a specific percentage a more significant decrease for weaker bone, less significant for stronger bone, etc. 
       FIG. 12  shows an example schematic of controller  1200 , such as the controllers  206  and  934 , in accordance with at least one example of this disclosure. As shown in  FIG. 12 , controller  1200  can include a processor  1202  and a memory  1204 . The memory unit  1204  can include a software module  1206  and bone data  1208 . While executing on the processor  1202 , the software module  1206  can perform processes receiving displacement data, determining bone quality, adjusting an impact force of a tool, etc., including, for example, one or more stages included in the methods described below with respect to  FIGS. 10 and 11 . As disclosed herein, bone data  1208  can include formulas, lookup tables, actuarial tables, patient data, etc. that can be used to determine bone quality as disclosed herein. Bone data  1208  can also include data for correlating impact forces desirable for given bone qualities and for various sizing of tools, such as rasps and/or broaches. Controller  1200  can also include a user interface  1210 , a communications port  1212 , and an input/output ( 110 ) device  1214 . 
     The user interface  1210  can include any number of devices that allow a user to interface with the controller  1200 . Non-limiting examples of the user interface  1210  can include a keypad, such as buttons located on a housing of a linear electric surgical hammer impact tool, a microphone, a display (touchscreen or otherwise and connected to controller via a wired or wireless connection), etc. 
     The communications port  1212  may allow the controller  1200  to communicate with various information sources and devices, such as, but not limited to, remote computing devices such as servers or other remote computers. For example, remote computing devices may maintain data, such as patient scan data, that can be retrieved by the controller  1200  using the communications port  1212 . Non-limiting examples of the communications port  1212  can include, Ethernet cards (wireless or wired), Bluetooth® transmitters and receivers, near-field communications modules, etc. 
     The I/O device  1214  can allow the controller  1200  to receive and output information. Non-limiting examples of the I/O device  1214  can include, sensors, such as Hall effect sensors, a camera (still or video), a microphone, etc. For example, the I/O device  1214  can allow the controller  1200  to directly receive patient data from a CT scanning device, x-ray machine, etc. As another example, the I/O device  1214  can include a Hall effect sensor that transmits one or more signals received by the processor  1202 . The processor  1202  can then determine a position of a slider and/or an impact force to be generated by the slider based on the position of the slider. 
     NOTES 
     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 can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein. 
     In the event of inconsistent usages between this document and any documents so incorporated by reference, the usage in this document controls. 
     In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more,” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects. 
     The above description is intended to be illustrative, and not restrictive. For example, the above-described. examples (or one or more aspects thereof) can be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted 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 can be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter can lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated 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 appended claims, along with the full scope of equivalents to which such m s are entitled.