Patent Publication Number: US-11389142-B2

Title: End effector coupler for surgical arm

Description:
CROSS-REFERENCE TO RELATED PATENT DOCUMENTS 
     This application is a continuation of U.S. patent application Ser. No. 15/918,531, filed on Mar. 12, 2018, the benefit of priority of which is claimed hereby, and which is incorporated by reference herein in its entirety. 
     This patent application is also related to Jeffrey Schlosser et al., U.S. patent application Ser. No. 15/560,894 entitled “Rapidly Repositionable Powered Support Arm,” filed on Sep. 22, 2017 which is hereby incorporated by reference herein in its entirety. 
    
    
     BACKGROUND 
     The present invention relates generally to apparatus and systems for supporting surgical and other tools. Some surgical procedures include use of a variety of tools. In some of these procedures, it is required that tools, such as a retractor, be maintained in a single position for an extended period of time, such as an hour or more. During this time, other tools can be used to perform other aspects of the surgery. Because it may be difficult or undesirable to manually hold a position of a tool for such lengths of time, mechanical and/or electromechanical arms can be used to hold the position of the tool while other aspects of the procedure are performed. Some arms can be adjustable such that a position of the arm can be adjusted before or during the procedure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings, which are not necessarily drawn to scale, like numerals may describe similar components in different views. Like numerals having different letter suffixes may 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  illustrates a perspective view of a repositionable, lockable surgical arm system, in accordance with at least one example of this disclosure. 
         FIG. 2A  illustrates a perspective view of a repositionable, lockable surgical arm, in accordance with at least one example of this disclosure. 
         FIG. 2B  illustrates a perspective view of a repositionable, lockable surgical arm, in accordance with at least one example of this disclosure. 
         FIG. 3  illustrates a perspective view of a surgical system, in accordance with at least one example of this disclosure. 
         FIG. 4  illustrates a schematic view of a system, in accordance with at least one example of this disclosure. 
         FIG. 5A  illustrates an end effector coupler in a coupled condition, in accordance with at least one example of this disclosure. 
         FIG. 5B  illustrates an end effector coupler in a decoupled condition, in accordance with at least one example of this disclosure. 
         FIG. 6A  illustrates a top view of an end effector coupler, in accordance with at least one example of this disclosure. 
         FIG. 6B  illustrates a side view of an end effector coupler, in accordance with at least one example of this disclosure. 
         FIG. 7A  illustrates a perspective view of an end effector coupler, in accordance with at least one example of this disclosure. 
         FIG. 7B  illustrates a bottom perspective view of an end effector coupler, in accordance with at least one example of this disclosure. 
         FIG. 8A  illustrates a perspective view of a tool securable to an end effector coupler, in accordance with at least one example of this disclosure. 
         FIG. 8B  illustrates a side view of a tool securable to an end effector coupler, in accordance with at least one example of this disclosure. 
         FIG. 8C  illustrates an end view of a tool securable to an end effector coupler, in accordance with at least one example of this disclosure. 
         FIG. 9A  illustrates a partially exploded view of an end effector coupler from a distal perspective in a first condition, in accordance with at least one example of this disclosure. 
         FIG. 9B  illustrates a partially exploded view of an end effector coupler from a distal perspective in a second condition, in accordance with at least one example of this disclosure. 
         FIG. 9C  illustrates a perspective view of an end effector coupler in a third condition, in accordance with at least one example of this disclosure. 
         FIG. 10  illustrates a perspective view of components of an end effector, in accordance with at least one example of this disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Some surgical procedures require a variety of tools. In some cases, it is desired to hold tools, such as a retractor, in a single position for an extended period of time, such as an hour or more. In these procedures, adjustable mechanical and/or electromechanical arms are often used to hold the position of the tool while other aspects of the procedure are performed. One type of arm sometimes employed is an arm that is manually articulable when unlocked and is prevented from being moved when locked. Because these arms are made for use with tools, there is a need for tools to secure to the arm. And, because a single procedure may require multiple tools and because the arms may be used for various procedures, there is a need for a method of quickly and easily securing a variety of tools to the arm. 
     This disclosure provides a solution to these issues through the use of an end effector coupler. The coupler can be releasably or fixedly secured to the arm and can include components allowing for tools to be released quickly and easily while providing a secure connection between the tool and the arm. More specifically, the end effector coupler can include a tool lock to secure a tool stem within the end effector coupler. As part of the locking engagement between the end effector and the tool, the tool stem and end effector body can interface in a taper-to-taper arrangement to reduce play or relative movement between the end effector coupler and the tool. Similarly, the end effector body and surgical arm can interface in a taper-to-taper arrangement to reduce play or relative movement between the end effector coupler and the surgical arm. 
     The end effector can also include a keyed opening and a counterbore coaxial with a central bore of the end effector. The tool stem can also include key bits configured to pass through keyways of the keyed opening to ensure alignment with the end effector, where the key bits also engage a surface between the counter bore and the proximal side of the keyed opening to as the tool is rotated; this can draw the stem completely within the end effector to secure the tool thereto. 
     Also, the locking mechanism can include a retractable pin (operable using an actuator), where the pin can extend from the bore to engage a flange of the stem. This locking engagement can prevent unwanted relative rotation of the tool and stem relative to the end effector coupler, helping to limit unwanted release of the tool from the end effector coupler. When it is desired to remove the tool, the pin can be retracted so that the tool and stem can be rotated for removal from the end effector coupler, allowing for quick release of tools from the end effector coupler. These and other features and benefits are discussed with reference to figures in further detail below. 
     As used herein, the terms “proximal” and “distal” should be given their generally understood anatomical interpretation. The term “proximal” refers to a direction generally toward the torso of a patient or base or handle of a tool, and “distal” refers to the opposite direction of proximal, i.e., away from the torso of a patient or toward the working end of the tool. 
       FIG. 1  illustrates a perspective view of repositionable, lockable surgical arm system  100 , in accordance with at least one example of this disclosure. Lockable surgical arm system  100  can include table  102 , arm  104 , tool (or instrument)  105 , and base unit  106 . Table  102  can include rail  116 . Base unit  106  can include pole  108  and manual clamp  110 . Arm  104  can include proximal joint  111 , actuator unit  112 , distal joint  113 , proximal arm  114 , distal arm  115 , and instrument holder  118 . Also shown in  FIG. 1  are orientation indicators Proximal and Distal (shown and discussed with respect to the adjustable arm). 
     Base unit  106 , which can include power control circuit components for an electrically powered actuator (such as actuator  112 ), can be secured to rail  116  of surgical table  102  using, for example, a clamp. Manual clamp  110   a  of base unit  106  can be operated to tighten base unit  106  against railing  116  and manual clamp  110   b  can be operated for adjustment of pole  108  to set a height of arm  104  above surgical table  102 . 
     Electric actuator unit  112  of arm  104  can be located near a proximal end of arm  104  and can be coupled to pole  108  at proximal joint  111 . Electric actuator  112  can also be coupled to a proximal portion of proximal arm  114 . Proximal arm  114  can be coupled to electric actuator  112  via a joint or as an actuatable part of actuator  112  in other examples. Distal arm  115  can be coupled to a distal portion of proximal arm  114  via distal joint  113 . Instrument holder or end effector coupler  118  can connect instrument  105  to the distal end of arm  104 . In some examples, a lock/unlock button can be provided on or near end effector coupler  118 . 
     The arms of lockable surgical arm system  100  can comprise a serial linkage of arm segments joined by spherical and/or rotational joints. Each of joints  111  and  113  (and any other joints in other examples) can be pivotable and/or rotational joints allowing movement of connected components with one or more degrees of freedom. Joints  111  and  113  (and joints within actuator  112 ) can be locked and unlocked using base unit  106  and actuator  112 , which can be an electric bilateral actuator. In some examples, the joints of the arm can be locked and unlocked with a fluid system. 
     While only proximal arm  114  and distal arm  115  are shown in  FIG. 1 , additional arm segments can be provided between actuator  112  and end effector coupler  118 . Each additional arm segment may require one or more additional joints to form a repositionable, lockable support arm structure. Such additional arm segments can provide greater coverage and ability for the arm to be positioned with more degrees of freedom in the surgical field. 
     In operation of some examples, the lock/unlock button can be operable by a user to initiate power locking and unlocking of arm  104 . When the lock/unlock button is not depressed arm  104  can be in a locked state where joints  111  and  113  are locked such that proximal arm  114  and distal arm  115  cannot move relative to each other or to table  102 . When the lock/unlock button is pressed, actuator  112  can unlock joints  111  and  113  such that end effector coupler  118  can be positioned, as desired, and as guided by joints  111  and  113  and proximal arm  114  and distal arm  115 . That is, end effector coupler  118  can be moved to a desired position relative to body  50  through movement paths limited by the freedom of arm  104  to position instrument  105  to a desired position relative to body  50 . 
       FIG. 2A  illustrates a perspective view of surgical arm system  200 , in accordance with at least one example of this disclosure.  FIG. 2B  illustrates a perspective view of surgical arm  200 , in accordance with at least one example of this disclosure.  FIGS. 2A and 2B  are discussed below concurrently. 
     Surgical arm  200  can include arm  204 , tool (or instrument)  205 , base unit  206  (only shown in  FIG. 2B ), control device  207 , pole  208 , and manual clamp  210 . Arm  204  can include proximal joint  211 , actuator unit  212 , distal joint  213 , proximal arm  214 , distal arm  215 , coupler joint  217 , end effector coupler  218 , and arm coupler  219 . Control device  207  can include user interface  220  and can be connected to cable  222 . Also shown in  FIG. 2  are orientation indicators Proximal and Distal. 
     Surgical arm  200  can be similar to system  100  discussed above, except that surgical arm  200  can include different features. For example, base unit  206  can be a manually adjustable unit, where manual clamp  210  can be operable to adjust a position of base unit  206  along a rail (e.g., surgical table rail) and to adjust the height of pole  208  (and therefore arm  204 ). In this example, control device  207  can include electronic components configured to control arm  204 . For example, control device  207  can house a controller (discussed further below) and user interface  220 , which can include one or more control inputs (such as buttons and switches) and can include audible or visual indicia. Cable  222  can be coupleable to control device  207  to connect a lock/unlock button to control device  207 . 
     Surgical arm  200  can also include arm coupler  219  which can be a distal coupler of arm  204  configured to releasably secure end effector coupler  218  to coupler joint  217  (and therefore to arm  204 ). In other examples, discussed below, end effector coupler  218  can be fixedly secured to arm  204 . 
     Surgical arm  204  can operate consistently with system  100  described above, except that coupler joint  217  can offer additional range of motion of the embodiment shown in  FIG. 1 . Further, end effector coupler  218  can be used to quickly and easily remove and secure tools and instruments, such as tool  205 , to surgical arm  204 , as discussed in further detail below. 
       FIG. 3  illustrates a perspective view of surgical system  300 , in accordance with at least one example of this disclosure. End effector system  300  can include arm  302 , forceps  304 , and retractor  306 . Arm  302  can include distal arm  308 , arm coupler  310 , and end effector coupler  312 . End effector coupler  312  can include keyed opening  314 , pin release  316 , and pin  318 . Forceps  304  can include tool portion  322  and stem  324 . Retractor  306  can include tool portion  326  and stem  328 . Also shown in  FIG. 3  are orientation indicators Proximal and Distal. 
     Arm  302  can be consistent with arms  104  and  204  discussed above, however, arm  302  shows additional detail of end effector  312 , which can be releasably coupled to distal arm  308  via distal coupler  310 . End effector coupler  312  can be a coupler configured to releasably secure tools and instruments, such as forceps  304  and retractor  306 , to arm  302 . 
     Forceps  304  can be surgical forceps including stem  324  extending from tool portion  322 . Stem  324  can be coupled to tool portion  322  of forceps  304  such that stem  324  does not interfere with the operation of tool portion  322  of forceps  304 . Retractor  306  can be a substantially flat and/or malleable retractor, such as a ribbon retractor, including stem  328  extending from tool portion  326  of retractor  306 . Stem  328  can be coupled to tool portion  326  of retractor  306  such that stem  328  does not interfere with the operation of tool portion  326  of retractor  306 . Each of stems  324  and  328  can be of identical structure where each can include tapered stems configured and shaped to be inserted into end effector coupler  312  through keyed opening  314 , as discussed in further detail below. 
     Keyed opening  314  of end effector coupler  312  can include an irregular geometric shape that is sized and shaped to receive each of stems  324  and  328  therethrough to individually secure each of stems  324  and  328  within end effector  312 . That is, end effector coupler  312  can secure one stem at a time. Pin  318  of end effector can be disposed within a pin bore of end effector and can extend from a distal end of end effector coupler  312  such that pin  318  can engage a tool stem to help secure the tool stem to the end effector coupler  312 . Pin  318  can be coupled to pin release  316 , where pin release  316  can be operable to translate pin  318 . 
     In operation of some examples, either of stems  324  and  328  can be oriented for insertion into keyed opening  314 . Once inserted, the stem can be rotated so that the stem locks into end effector coupler  312  so that a tapered distal end of pin  318  engages an angled (or straight) notch of a collar of the stem to restrict rotation of the stem while within end effector coupler  312 . The tool (forceps  304 , retractor  306 , or other tools, as discussed below) can then be used in a surgical procedure while connected to end effector coupler  312 . And, when a lock/unlock button is activated (as discussed in  FIGS. 1 and 2  above), end effector coupler  312  and the tool can be positioned as desired (and repositioned) and can be guided by arm  302 . Alternatively, the tool can be positioned as desired and then connected to arm  302  when in position. 
     When the tool is in a desired position, the lock/unlock button can be de-activated (or released) to lock a position of arm  302  and therefore of end effector coupler  312  and the tool (e.g., retractor  306 ) secured to end effector coupler  312 . The tool can then be used in the desired position and repositioned at any time. When it is desired to remove or change tools, pin release  316  can be actuated to retract pin  318  so that the tool (and stem  324  or  328 ) can be rotated within end effector coupler  312  to allow for removal of the stem and tool out of keyed opening  314  and out of end effector coupler  312 . This process can be repeated, such that a new tool can be inserted and removed in the same manner. 
       FIG. 4  illustrates a schematic view of control system  400 , in accordance with at least one example of this disclosure. Control system  400  can include controller  402 , surgical arm  404 , user interface  406 , and lock/unlock button  408 . Surgical arm  404  can include actuator  410  and lock(s)  412 . 
     Controller  402  can be a programable controller, such as a single or multi-board computer, a direct digital controller (DDC), or a programable logic controller (PLC). In other examples controller  402  can be any computing device, such as a handheld computer, for example, a smart phone, a tablet, a laptop, a desktop computer, or any other computing device including a processor and wireless communication capabilities. 
     Surgical arm  404  can be similar to the arms discussed above with respect to  FIGS. 1-3  in that arm  404  can be a movable arm that is lockable in a desired position. Actuator  410  can be an electric, fluid, or gas powered actuator in communication with controller  402  and can be operable to translate or otherwise move one or more components (such as an armature) in response to a control signal. Actuator  410  can be physically coupled to locks  412  which can be mechanical or electro-mechanical locks coupled to joints or arms of arm  404 . In other examples, actuator  410  can be omitted and locks  412  can be individually operable in response to individual or shared control signals from controller  402 . 
     Control system  400  can optionally include user interface  406  that can be in communication with controller  402 . In another example, user interface  406  can be separate from control system  404  or can be communicatively coupled to control system  404 . 
     Lock/unlock button  408  can be a simple button or switch in some examples and can be in communication with controller  402 . In some examples, button  408  can be attached to a portion of arm  404 . In other examples, button  408  can be attached to other components, such as table  102  of  FIG. 1  or can be located on a floor and can be operated as a foot pedal or switch. In other examples, a controller may not be present and lock/unlock button  408  can be in direct communication with actuator  410  and/or locks  412 . 
     User interface  406  can be any display and/or input device. For example, user interface can be a monitor, keyboard, and mouse in one example. In other examples, user interface  406  can be a touch screen display. In yet another example, user interface  406  can provide lights, buttons, and/or switches. Controller  402  and user interface  406  can include machine readable medium. The terms “machine readable medium” may include any medium that is capable of storing, encoding, or carrying instructions for execution by the device and that cause the device to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non-volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. 
     In operation of some examples, a user can interact with user interface  406  to power on control system  400 . Power can be indicated by a light, for example, on user interface  406  and/or on arm  404 . The user can then operate button  408  to send an unlock signal to controller  402  to initiate power locking and unlocking of arm  404 . In response, controller  402  can send a signal to actuator  410  and/or locks  412  to unlock locks  412 . Once arm  404  is unlocked, the user can move an instrument and arm  404  to a desired location and orientation relative to a patient. When the user releases the lock/unlock button, it can send a lock signal (or can cease sending an unlock signal) to controller  402 . In response, controller  402  can send a signal (or can cease sending an unlock signal) to actuator  410  and/or locks  412  to lock the joints of arm  404 , locking arm  404  in the desired position such that the joints of arm  404  cannot articulate and the end effector of arm  404  cannot move relative to arm  404 . 
     Though the components of control system  400  are shown as being wired to controller  402 , the lines of  FIG. 4  connecting components of control system  400  can also represent wireless communication paths where each component can communicate using wireless (electromagnetic signals) through protocols such as WiFi, Bluetooth (Bluetooth LE), Near-Field Communications (NFC), and the like. 
       FIG. 5A  illustrates a perspective view of end effector coupler  500  in a coupled condition, in accordance with at least one example of this disclosure.  FIG. 5B  illustrates a perspective view of end effector coupler  500  in a decoupled condition, in accordance with at least one example of this disclosure.  FIGS. 5A and 5B  are discussed below concurrently. 
     End effector coupler  500  can include body  502 , proximal coupler  504 , and tool lock  506 . Tool lock  506  can include keyed opening  508 , pin bore  510 , pin  512  (including tapered portion  512   t ), biasing element  514 , and pin release  516 . Keyed opening  508  can include central bore  518  (or stem opening) and keyways  520   a  and  520   b . Body  502  can also include slot  522 . Also shown in  FIGS. 5A and 5B  is tool  525 , which can include stem  526 , tool portion  528 , and flange  530 . Stem  526  can include tapered portion  532  and projections  534  (or key bits  534 ). Flange  530  can include notches  536   a  and  536   b . Also shown in  FIGS. 5A and 5B  are orientation indicators Proximal and Distal and Axis A. 
     Body  502  can be a rigid or semi-rigid body comprised of materials such as metals, plastics, foams, elastomers, ceramics, composites, and combinations thereof. Body  502  can include proximal portion  502 P and an opposite distal portion  502 D including a distal end. Body  502  can be sized and shaped to be handheld and hand-positioned. For example, body  502  can be ergonomically shaped and can include ridges or crenellations to promote ergonomics and grip. Slot  522  of body  502  can be an axially extending slot along a side of body  502  adjacent pin bore  510  and can be sized to allow a portion of pin release  516  to extend through body  502  to couple to pin  512 . 
     Proximal coupler  504  can be a rigid or semi-rigid body comprised of materials such as metals, plastics, foams, elastomers, ceramics, composites, and combinations thereof. Proximal coupler  504  can have a substantially hollow cylindrical geometric shape and can be securable to distal portion  502 D of body  502 . In some examples, proximal coupler  504  can include a threaded portion configured to secure proximal coupler  504  to a surgical arm. 
     Tool lock  506  can be comprised of multiple components of end effector coupler  500  and can be configured to secure tool  525  to end effector coupler  500 . Keyed opening  508  of tool lock  506  can be a central bore  518  of keyed opening  508  configured to receive a tool stem therein. Central bore  518  can be a longitudinal bore extending into body  502  from the distal end of distal portion  502 D of body  502 . Central bore can extend into body  502  along axis A, which can be central to keyed opening  508  and central to body  502  in some examples, but can be offset from a central axis of body  502  in other examples. In some examples, central bore  518  can be sized to receive tool stem  526  in a taper-to-taper arrangement, as discussed further below. 
     Keyways  520   a  and  520   b  can be notches extending radially from central bore  518  and can be sized and shaped to receive key bits  534  of tool  525  when key bits  534  are aligned with keyways  520   a  and  520   b , but can prevent passage of key bits  534  into or out of keyways  520   a  and  520   b  (therefore preventing stem from being inserted into keyed opening  508  or being removed therefrom) when key bits  534  are not aligned with keyways  520   a  and  520   b . As discussed further below, each of keyways  520   a  and  520   b  can include a proximal face, where each proximal face is engageable with key bits  534  of tool  525 . 
     Pin bore  510  can be a longitudinal bore extending into body  502  from the distal end of distal portion  502 D of body  502 . In some examples, pin bore  510  can be adjacent (or proximate or near) central bore  518  and can extend through body  502  substantially parallel to central bore  518  and axis A, but can be not parallel to central bore  518  in other examples. 
     Pin  512  can be a rigid or semi-rigid body comprised of materials such as metals, plastics, foams, elastomers, ceramics, composites, and combinations thereof. Pin  512  can include tapered portion  512   t  at a distal termination of pin  512 . Pin  512  can be disposed within pin bore  510  such that tapered portion  512   t  extends from pin bore  510  (and therefor beyond distal portion  502 D of body  502  when pin  512  is in an extended or locked position. 
     Biasing element  514  can be a resilient element such as a spring. In some examples, biasing element  514  can be a compression coil spring. In other examples, biasing element can be other springs or resilient members, such as a wave spring or compressible and resilient members comprised of materials such as rubbers, plastic, and the like. In some examples, biasing element can be disposed within pin bore  510  to engage a proximal termination of pin bore  510  and to engage a proximal termination of pin  512 , such that biasing element  514  biases pin  512  distally relative to body  502 . Pin release  516  can be an actuator operable by hand or tool and can be coupled to pin  512  through slot  522  of body  502 . 
     Tool  525  can be a surgical tool such as forceps or a retractor (as described below), or various other surgical tools that can be adapted to include a stem. Stem  526  can be a keyed stem, shaped and sized to be inserted within end effector coupler  500  to secure tool  525  to end effector coupler  500 . Tool portion  528  can be connected to the operable tool, such as the forceps or retractor. Flange  530  can be a flange or collar extending radially outward from stem and can include notches  536   a  and  536   b  extending substantially axially therethrough (though notches  536   a  and  536   b  can extend through flange  530  at an axis not parallel with the axis of stem  526 , in some examples). 
     Stem  526  can also include tapered portion  532 , which can be sized and shaped to extend into central bore  518  of keyed opening  508 , where stem  526  can be tapered to mate with a tapered bore of body  502 . Key bits  534  of stem  526  can be projections extending radially outward from stem  526  and key bits  534  can be sized and shaped to pass through keyways  520   a  and  520   b  when key bits  534  are aligned with keyways  520   a  and  520   b . Key bits  534  can also be used to secure stem  526  within central bore  518  as discussed further below. 
     In operation of some examples, tool  525  can be separate from end effector coupler  500 , as shown in  FIG. 5B . When it is desired to secure tool  525  to end effector coupler  500 , tool stem  526  can be inserted into central bore  518  and rotated clock-wise approximately one quarter of a turn to secure tool  525  to end effector coupler  500 . In other examples, tool  525  (and stem  526 ) can be rotated greater than a quarter turn, such as a half or three-quarters turn, and can be rotated less than a quarter turn, such as a one-eighth or one-sixteenth turn. 
     More specifically, tool stem  526  can be inserted into central bore  518  until key bits engage body  502 . Key bits  534  can then be aligned with keyways  520   a  and  520   b  to allow tool stem  526  to be further inserted into central bore  518 . As discussed further below, tool stem  526  can then be rotated clockwise (from a distal perspective) to seat key bits  534  within a counterbore of central bore  518 , where contact between key bits  534  and portions of central bore  518  draw tool stem  526  completely into central bore  518  as stem  526  is rotated. In other examples, tool stem  526  can be rotated counter-clockwise to seat key bits  534  within the counterbore of central bore  518 . 
     Alternatively, tool stem  526  can be inserted into central bore  518  until key bits engage body  502 . Key bits  534  can then be aligned with keyways  520   a  and  520   b  to allow tool stem  526  to be further inserted into central bore  518  entirely until key bits  534  rest within a counter bore of central bore  518  which extends stem  526  entirely into central bore  518 . Tool stem  526  can then be rotated clockwise (from a distal perspective) to seat key bits  534  within the counterbore of central bore  518 . 
     During insertion of tool stem  526  into central bore  518 , a proximal portion of flange  530  can contact pin  512  to cause pin  512  to move proximally into pin bore  510 . As tool stem  526  is rotated, one of notches  536   a  and  536   b  will align with tapered portion  512   t  of pin  512  as key bits  534  draw tapered portion  532  into central bore  518 , allowing pin  512  to extend from pin bore  510  and into either notch  536   a  or notch  536   b . Pin  512  can automatically extend to this extended position due to being biased to extend distally from pin bore  510  by biasing element  514 . When pin  512  is in this position, pin  512  can apply a force from biasing element  514  on flange  530  to further ensure a stable connection between tool  525  and end effector coupler  500 . Also, as pin  512  engages one of notches  536   a  and  536   b , the interaction can produce a noise in addition to being visible through one of notches  536   a  or  536   b , which can provide indications to an operator that tool  525  is secured to end effector coupler  500 . 
     The taper-to taper interface of stem  526  with central bore  518  and the engagement of key bits  534  with a proximal portion of keyed opening  508  and the counterbore of central bore  518  can both help limit undesired movement of tool  525  relative to end effector coupler  502 ; and, the engagement of flange  530  with pin  512  can help limit counter-clockwise rotation of tool  525  relative to central bore  518  and body  502  to help prevent back-out of tool  525  from end effector coupler  500 , securing tool  525  to end effector coupler  502 . In some examples, during insertion of stem  526  into central bore  518 , contact between taper-to taper interface of stem  526  with central bore  518  can occur substantially simultaneously as the engagement of key bits  534  with a proximal portion of keyed opening  508  and substantially simultaneously as the engagement of flange  530  with pin  512  so that stem  526  is secured in all directions relative to end effector coupler  502  all at once. 
     Also, because tapered portion  512   t  is tapered and because notches  536   a  and  536   b  can be angled, tapered portion  512   t  can contact a large surface area of either one of notches  536   a  and  536   b . This contact can further help limit unwanted back-out of tool  525  from end effector coupler  500 . All of these features that help secure tool  525  to end effector coupler  500  can provide a wear resistant design for the application where users frequently change instruments for different procedures. 
     When it is desired to remove tool  525  from end effector coupler  500 , pin release  516  can be translated proximally, where slot  522  guides and limits translation of pin release  516 . Proximal retraction of pin release  516  can retract pin  512  into pin bore such that pin  510  is no longer engaging a notch (of notches  536   a  and  536   b ), as shown in  FIG. 6B . This allows a user to rotate tool  525 , along with stem  526  and flange  530 , counter-clockwise so that key bits  534  can be disengaged from the distal side of keyed opening  508  and can move out of the counterbore and into alignment with keyways  520   a  and  520   b  of central bore  518 , allowing stem  526  to be removed from central bore  518 . Because pin release  516  can be easily actuated by hand and rotation of stem  526  requires about a quarter turn of tool  525  with little resistance, tool  525  can be easily and quickly removed from end effector coupler  500 . 
       FIG. 6A  illustrates a top view of end effector coupler  500 , in accordance with at least one example of this disclosure.  FIG. 6B  illustrates a side view of end effector coupler  500 , in accordance with at least one example of this disclosure.  FIGS. 6A and 6B  are discussed below concurrently. 
     End effector coupler  500  of  FIGS. 6A and 6B  can be consistent with end effector coupler  500  of  FIGS. 5A and 5B ; however,  FIGS. 6A and 6B  show end effector coupler  500  from different perspectives. Also,  FIG. 6B  shows pin  512  of end effector coupler retracted into pin bore  510  where pin release  516  is translated distally relative to body  502 . When pin  512  is in this retracted position, tool  525  can be rotated relative to body  502  because tapered portion  512   t  of pin  512  is not disposed within notch  536  to restrict rotation of flange  530 , thus allowing tool  525  to be rotated relative to body  502 . 
       FIGS. 6A and 6B  also show how proximal coupler  504  of end effector coupler  500  can be secured to proximal connector  540  of a surgical arm. In some examples, coupler  504  can be threadably engaged with distal connector  540 , as discussed in further detail below. 
       FIG. 7A  illustrates a perspective view of end effector coupler  500 , in accordance with at least one example of this disclosure.  FIG. 7B  illustrates a bottom perspective view of end effector coupler  500 , in accordance with at least one example of this disclosure.  FIGS. 7A and 7B  are discussed below concurrently. 
     End effector coupler  500  of  FIGS. 7A and 7B  can be consistent with end effector coupler  500  of  FIGS. 5A-6B  above; however,  FIGS. 7A and 7B  show internal bores of end effector coupler  500 . For example,  FIG. 7A  shows pin bore  510  extending longitudinally into body substantially parallel with axis A of keyed opening  508 , where pin bore  510  is diametrically sized to retain pin  512  and biasing element  514  ( FIG. 7B ) therein and can terminate or reduce diameters near proximal end  502 D of body  502  to axially retain pin  512  and biasing element  514  in a proximal direction. 
       FIGS. 7A and 7B  also show how central bore  518  and keyways  520   a  and  520   b  extend longitudinally (axially parallel with axis A) into body  502 .  FIGS. 7A and 7B  also show counterbore  540  of central bore  518  which can extend radially outward from central bore  518  between central bore taper  544  and keyways  520   a  and  520   b . Central bore taper  544  can be a tapered portion of central bore  518  that is complimentary to tapered portion  532  of stem  526 . In some examples, tapered portion  532  and central bore taper  544  can have one consistent taper and in other examples, tapered portion  532  and central bore taper  544  can have multiple tapered portions of varying taper sizes and/or styles including Brown, Morse, Jarno, Jacobs, and the like tapers. 
       FIG. 7B  also shows stem  546  of pin release  516 , which can be a protuberance of pin release  516  that connects pin release  516  to pin  512  through slot  522  (shown in  FIG. 5B ).  FIG. 7B  additionally shows drainage bores  548  and  550 , which can be connected to central bore  518  and pin bore  510 , respectively and can be connected to each other. Drainage bores  548  and  550  can allow for fluids and other substances to drain from body  502  after a cleaning process, such as an autoclaving process, helping to make end effector coupler  500  autoclavable. The components of end effector coupler  500  can also be manufactured out of metals, such as stainless steel and titanium, that are autoclavable. 
       FIG. 7B  also shows how projections (or key bits)  534  can be clocked relative to notches  536  of flange  530 . Key bits  534  can be circumferentially placed about stem  526  relative to notch  536  so that pin  512  engages a notch  536  as projections  534  engage a proximal portion of where central bore  518  meets counterbore  540 . The engagement by projections  534  forces tapered portion  532  to translate proximally to create a taper-to-taper interface between tapered portion  532  of stem  526  and central bore taper  544 . This relative positioning of key bits  534  to notches  536  ensures that rotation prevention of stem  526  does not occur until the taper-to-taper interface is made, helping to secure tool  525  to body  502 . 
     Alternatively, in operation of some examples, key bits  534  can be aligned with keyways  520   a  and  520   b  to allow tool stem  526  to be inserted entirely into central bore  518  until key bits  534  rest within counter bore  540  so that stem  526  engages central bore  518  in a taper-to-taper engagement. Tool stem  526  can then be rotated clockwise (from a distal perspective) so that key bits  534  engage a proximal face of keyways  520   a  and  520   b  to seat key bits  534  within counterbore  540  of central bore  518 . 
       FIG. 8A  illustrates a perspective view of tool  825  securable to an end effector coupler, in accordance with at least one example of this disclosure.  FIG. 8B  illustrates a side view of tool  825  securable to an end effector coupler, in accordance with at least one example of this disclosure.  FIG. 8C  illustrates an end view of tool  825  securable to an end effector coupler, in accordance with at least one example of this disclosure.  FIGS. 8A-8C  are discussed concurrently below. 
     Tool  825  can include stem  826 , tool portion  828 , and flange  830 . Stem  826  can include stem taper  832  and projections  834  (or key bits  834 ). Flange  830  can include notches  836   a  and  836   b  (associated with angle θ 1 ). Stem taper  832  can include first stem taper  852 , second stem taper  854 , and third stem taper  856 . Tool portion  828  can include tool connection flat  858 . Key bits  834  can each include angled face  862  (associated with angle θ 2 ) ( FIG. 5B ). Also shown in  FIGS. 8A and 8B  are orientation indicators Proximal and Distal and Axes A 1 , A 2 , A 3 , and A 4 . 
     Tool  825  can be similar to tool  525  discussed above, but  FIGS. 8A-8C  show further detail of tool  825 , as discussed below. For example,  FIGS. 8A and 8B  show how stem taper  832  can include three tapered portions: first stem taper  852 , second stem taper  854 , and third stem taper  856 . In some examples, each tapered portion can have a different taper size and/or taper style including Brown, Morse, Jarno, Jacobs, and the like tapers. In some examples, some of first stem taper  852 , second stem taper  854 , and third stem taper  856  may be straight (or not tapered). For example, first stem taper  852  may be of a constant diameter along its axial length. 
       FIGS. 8A-8C  also shows how key bits  834  can be radially extending protuberances of stem  826 , which can have a substantially trapezoidial geometric shape from a top perspective, with angled face  862  facing distally (toward flange  830 ). However, key bits  834  can have other shapes in other examples. Angled face  862  can be provided at angle θ 2 , where angle θ 2  (between angled face  862  and axis A 4 ) is selected to cause notch  836  to align with a pin of an end effector coupler when stem  826  is fully seated within a tapered bore of the end effector coupler, as caused by engagement of face  862  with a proximal portion of a keyed opening of the end effector. Axis A 4  can be coaxial and/or parallel with axis A of  FIG. 5B . Also, because angled face  836  is angled in a single direction, it ensures that tool  825  is rotated in the proper (clockwise) direction, as rotation in the opposite (counter-clockwise) direction will be prevented by contact with a non-angled face of key bit  834  and a keyway and/or counterbore of the keyed opening of the end effector coupler. 
       FIGS. 8B and 8C  also shows axes A 1  and A 2 , where axis A 1  can be a central longitudinal axis of stem  826  (which may or may not be coaxial and/or parallel with axis A of  FIGS. 5A and 5B ) and axis A 2  can be parallel with axis A 1  but spaced away therefrom. Axis A 3  can be parallel with edge  864  of notch  836   a . That is, notches  836   a  and  836   b  can be formed at an angle relative to axes A 1  and A 2 .  FIG. 8B  shows θ 1  between edge  864  (along axis A 3 ) and axis A 2 . Angle θ 1  of notches  836   a  and  836   b  can be selected to be complementary with a taper of a tapered distal tip of the pin (such as tapered portion  512   t  discussed above), which can provide a large contact surface area between a pin and flange  830  to limit play between the end effector and tool  825 . 
     Tool portion  828  can include tool connection flat  858 , which can be a substantially planar surface of tool portion  828  for manufacturing purposes. For example, tool  825  can be manufactured using machining processes (such as a lathe, etc.), and can then be attached (via welding or other fastening means) to a tool that is manufactured in separate processes. This can be helpful when the tool is not manufacturable through the same processing steps as tool  825 , such as when tool  825  connects to forceps (such as forceps  304  of  FIG. 3 ). 
       FIG. 9A  illustrates a partially exploded view of end effector  900  coupler from a distal perspective in a first condition, in accordance with at least one example of this disclosure.  FIG. 9B  illustrates a partially exploded view of end effector coupler  900  from a distal perspective in a first condition, in accordance with at least one example of this disclosure.  FIG. 9C  illustrates a perspective view of end effector coupler  900  in an assembled condition, in accordance with at least one example of this disclosure.  FIGS. 9A-9C  are discussed below concurrently. 
     End effector coupler  900  can include body  902 , proximal coupler  904 , distal connector  940  of a surgical arm, and tool  925 . Body  902  can include protrusion  968 , which can include groove  970 , ring  972 , taper  974 , and flat  976 . Proximal coupler  904  can include threaded portion  978 , and counter bore  980 . Distal connector  940  can include flange  982  and threaded insert  984 . Also shown in  FIGS. 9A and 9B  are axis A 5  and orientation indicators Proximal and Distal. 
       FIG. 9A  shows body  902  separated from collar  940  and separated from distal connector  940 , where all three components are substantially in axial alignment about axis A 5 . Body  902  can be consistent with body  502 , for example, but  FIGS. 9A and 9B  show protrusion  968  extending proximally from a proximal portion of body  902 . 
     Protrusion  968  includes groove  970 , which can be a circumferential groove around protrusion  968  between body  902  and taper  974 . Groove  970  can be sized to retain collar  904  and/or ring  972  (which can retain collar  904 ). Ring  972  can be a retaining ring, such as a snap ring or retainer, in some examples, where ring  972  can be sized to be disposed in groove  970  and can be selected to retain or captivate collar  904  on protrusion  968 . 
     Taper  974  can be a tapered portion of protrusion  968  and can have multiple tapered portions of varying taper sizes and/or styles including Brown, Morse, Jarno, Jacobs, and the like tapers. Taper  974  can be shaped complementary to a tapered bore of distal connector  940 , as discussed below in  FIG. 11 . Also, taper portion  974  can include flat  976 , which can be a substantially planar surface of taper  974  configured for alignment of end effector coupler  902  and distal connector  940  as well as to prevent rotation of end effector coupler  902  to distal connector  940 , as discussed in  FIG. 11  below. In some examples, there can be two or more of flat  976  of taper portion  974 . When two of flat  976  are included, flats  976  can be located on opposite sides of taper portion  974 . 
     Proximal coupler  904  can include threaded portion  978 , which can be a female threaded portion configured to receive threaded insert  984  of distal connector  940 . Counter bore  980  of proximal coupler  904  can be sized and shaped to receive and retain flange  982  of distal connector  940  therein, in some examples, where flange  982  is a radial extension from distal connector  940  positioned at a proximal termination of threaded insert  984 . Threaded insert  984  can be a male threaded portion configured to threadably engage threaded portion  978 . 
     In assembly of some examples, collar  904  can be placed on protrusion  968  proximate body  902 . Ring  972  can then be secured to protrusion at groove  970  to retain collar  904  between ring  972  and body  902  such that collar  904  is secured to body  902 , as shown in  FIG. 9B . However, ring  972  does not firmly engage coupler  904  against body  902 , allowing proximal coupler  904  to spin or rotate independent of body  902 . 
     Then, as shown in  FIG. 9C , taper  974  can be inserted into distal connector  940  and threaded insert  984  can be inserted into threaded portion  978  of proximal coupler  904 . Proximal coupler  904  can then be rotated to threadably secure threaded insert  984  to threaded portion  978 , thereby securing body  902  to distal connector  940 . During threading of proximal coupler  904  to distal connector  940 , proximal coupler contacts a distal side of ring  972  to draw body  902  proximally toward distal connector  940 . Following a procedure, this process can be reversed to remove end effector coupler  902  for cleaning (autoclaving) allowing end effector coupler  900  to be reusable. 
       FIG. 10  illustrates a perspective view of distal connector  1040  and end effector coupler  1000  with the coupler removed, in accordance with at least one example of this disclosure. End effector coupler  1000  can include body  1002  and protrusion  1068 . Body  1002  can include pin bore  1010  and slot  1022 . Protrustion can include groove  1070 , ring  1072 , taper  1074 , and flat  1076 . Distal connector  1040  can include flange  1082  (which can include flat  1090 ), threaded insert  1084 , and protrusion tapered bore  1086  (which can include flat  1088 ). 
     End effector coupler  1000  and distal connector  1040  can be similar to those discussed above (for example, end effector coupler  900  and distal connector  940 ); however,  FIG. 10  further illustrates details of end effector coupler  1000  and distal connector  1040 . For example,  FIG. 10  shows how pin bore  1010  and slot  1022  can extend through a proximal end of body  1002 , which can simplify assembly of end effector coupler  1000 , and can help make end effector coupler  1000  autoclavable. In this configuration, the coupler (such as proximal coupler  904 ) can retain the biasing element and pin. 
       FIG. 10  also shows protrusion tapered bore  1086  including flat  1088 . Protrusion tapered bore  1086  can be tapered complementarily to taper  1074  of protrusion  1068  to provide a taper-to-taper connection between end effector coupler  1000  and distal connector  1040  (and therefore between end effector coupler  1000  and a surgical arm), helping to prevented unwanted movement of end effector coupler  1000  and the surgical arm.  FIG. 10  also shows flat  1088  of tapered bore  1086  and flat  1076  of protrusion  1068 . These flats can be used to quickly align end effector coupler  1000  relative to distal connector  1040  and the surgical arm during attachment of end effector coupler  1000 . These flats can also prevent rotation of end effector coupler  1000  relative to distal connector  1040  and the surgical arm during attachment or movement of end effector coupler  1000 . Though two flats  1088  are shown in  FIG. 10 , more or fewer flats, such as 1, 3, 4, 5, 6, and the like, can be used. 
       FIG. 10  also shows flat  1090  of flange  1082  which can be used to couple to a tool, such as a wrench for retaining distal connector  1040  during connection of distal connector  1040  to end effector coupler  1000 . 
     EXAMPLES 
     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 an end effector coupler for a surgical arm, the end effector coupler comprising: a body comprising a proximal portion and an opposite distal portion, the distal portion including a distal end; a proximal coupler connected to the proximal portion and releasably couplable to the surgical arm; a tool lock for releasably retaining a tool stem to the end effector coupler, the tool lock comprising: a keyed opening extending through the distal end proximally into the distal portion, the keyed opening configured to receive the tool stem therein; a pin bore extending through the distal end proximate to the keyed opening; a pin disposed in the pin bore and extendable from the pin bore to engage and retain the tool stem when the tool stem is inserted into the keyed opening; and a biasing element located in the pin bore and engaging the pin to bias the pin to extend from the distal end; and a pin release comprising an actuator extending beyond an external surface of the body and engaging the pin, the pin release operable to retract the pin into to the body to disengage the pin from the tool stem allowing release of the tool stem from the keyed opening. 
     In Example 2, the subject matter of Example 1 optionally includes wherein the pin limits rotation of the stem relative to the keyed opening to prevent release of the stem from the keyed opening when the pin engages the stem. 
     In Example 3, the subject matter of any one or more of Examples 1-2 optionally include wherein the body includes a tapered bore aligned along a central axis running through the keyed opening and configured to receive the tool stem therein. 
     In Example 4, the subject matter of any one or more of Examples 2-3 optionally include wherein the tapered bore is configured to receive a complimentary tapered section of the tool stem to form a taper-to-taper interface to limit relative motion between the end effector coupler and the tool stem. 
     In Example 5, the subject matter of any one or more of Examples 1-4 optionally include wherein the proximal coupler further includes a tapered protrusion coaxial with the proximal coupler and extending and engageable with a complimentary tapered bore of a distal portion of the surgical arm to form a taper-to-taper interface to limit relative motion between the surgical arm and the end effector coupler. 
     In Example 6, the subject matter of Example 5 optionally includes wherein tapered protrusion includes a flat outer surface engageable with a flat surface of the complimentary tapered bore to align the effector relative to the arm. 
     In Example 7, the subject matter of any one or more of Examples 1-6 optionally include wherein the keyed opening further comprises a keyway extending radially from a central bore of the keyed opening and sized to receive a key bit of the stem therethrough, the key bit including an angled face engageable with a proximal portion of the keyway to limit axial movement of the stem relative to the keyed opening, and wherein the tapered bore is configured to receive a complimentary tapered section of the tool stem to form a taper-to-taper interface to limit relative motion between the end effector coupler and the tool stem, wherein a distal portion of the pin is configured to engage a notch of the tool stem to limit rotation of the tool stem relative to the end effector coupler, and wherein the angled face is configured to engage the proximal portion of the keyway substantially simultaneously with the tapered bore in receipt of the complimentary tapered section of the tool stem and substantially simultaneously with the distal portion of the pin in engagement with a notch of the tool stem. 
     Example 8 is an assisted surgical system comprising: a surgical arm moveable and lockable in a position selected by a user; a tool movable with the surgical arm, the tool including a stem for coupling the tool to the surgical arm; an end effector coupler comprising: a body including a proximal portion and an opposite distal portion, the distal portion including a distal end; a proximal coupler connected to the proximal portion and releasably couplable to the surgical arm; a tool lock for releasably retaining the tool stem to the end effector coupler, the tool lock comprising: a keyed opening extending through the distal end into the distal portion, the keyed opening configured to receive the tool stem therein; a pin disposed in a pin bore adjacent the keyed opening, the pin extendable from the pin bore to engage and retain the tool stem when the tool stem is inserted into the keyed opening; a biasing element in the pin bore and engaging the pin to bias the pin to extend from the distal end; and a pin release comprising an actuator extending beyond an external surface of the body and engaging the pin, the pin release operable to retract the pin into to the body to disengage the pin from the tool stem allowing release of the tool stem from the keyed opening. 
     In Example 9, the subject matter of Example 8 optionally includes wherein the pin limits rotation of the stem relative to the keyed opening to prevent release of the stem from the keyed opening when the pin engages the stem. 
     In Example 10, the subject matter of any one or more of Examples 8-9 optionally include wherein the end effector coupler further includes a tapered bore aligned along a central axis running through the keyed opening and configured to receive the tool stem therein. 
     In Example 1, the subject matter of Example 10 optionally includes wherein the tapered bore is configured to receive a complimentary tapered section of the tool stem to form a taper-to-taper interface to limit relative motion between the end effector coupler and the tool stem. 
     In Example 12, the subject matter of any one or more of Examples 8-11 optionally include wherein the proximal coupler further includes a tapered cylindrical protrusion coaxial with the proximal coupler and extending and engageable with a complimentary tapered bore of a distal end of the surgical arm to form a taper-to-taper interface to limit relative motion between the surgical arm and the end effector coupler. 
     In Example 13, the subject matter of Example 12 optionally includes wherein tapered cylindrical protrusion includes a flat outer surface engageable with a flat surface of the complimentary tapered bore to align the effector relative to the arm. 
     In Example 14, the subject matter of any one or more of Examples 8-13 optionally include a control device in communication with the surgical arm and operable to transmit a signal to unlock the surgical arm. 
     In Example 15, the subject matter of any one or more of Examples 8-14 optionally include the stem comprising: a key bit extending radially from the stem, wherein the keyed opening includes a stem opening and a keyway, the stem opening configured to receive the stem therein, and the keyway extending radially from less than a full circumference of the stem opening, the keyway sized to receive the key bit therethrough to allow the effector to receive the stem. 
     In Example 16, the subject matter of Example 15 optionally includes the key bit further comprising: an angled face on a proximal side of the key bit. 
     In Example 17, the subject matter of Example 16 optionally includes the keyed opening further comprising: a counterbore extending radially from the stem opening, the counterbore sized to receive the key bit therein to limit axial movement of the stem relative to the keyed opening. 
     In Example 18, the subject matter of Example 17 optionally includes wherein the angled face of the key bit is configured to engage a distal portion of the keyed opening to draw the stem into the keyed opening when the stem is rotated within the keyed opening. 
     In Example 19, the subject matter of any one or more of Examples 8-18 optionally include the tool further comprising: a flange extending radially outward from the stem and engageable with the pin to translate the pin distally. 
     In Example 20, the subject matter of Example 19 optionally includes the flange of the tool further comprising: a notch sized to receive a distal tip of the pin to limit rotation of the tool relative to the end effector coupler when the pin is received within the notch. 
     In Example 21, the subject matter of Example 20 optionally includes wherein the notch extends through a radially outer portion of the flange and includes an axis not parallel to an axis of the flange to promote contact between the flange and the pin to limit rotation of the tool relative to the end effector coupler when the pin engages the notch. 
     In Example 22, the system, device, or method of any one of or any combination of Examples 1-21 is optionally configured such that all elements or options recited are available to use or select from. 
     Additional 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) may 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 may 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 may 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 claims are entitled.