Abstract:
A surgical instrument handle includes adaptations for improved ergonomics, such as broad, rounded hand-contacting surfaces and physiologic range of motion for instrument actuation. The handle may be mostly enclosed by the hand in use, and may be stabilized by the palm, ring finger, and little finger. One example includes a ratchet mechanism and release button.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of: 
         [0002]    U.S. Application No. 61/595,209, filed Feb. 6, 2012, entitled ERGONOMIC HANDLE FOR SURGICAL INSTRUMENT, Attorney&#39;s docket no. MLI-107 PROV, which is pending. 
         [0003]    The above-referenced document is hereby incorporated by reference in its entirety. 
     
    
     BACKGROUND 
       [0004]    The present disclosure relates to instrument handle designs for improved ergonomics. Specifically, the described embodiments may be incorporated into surgical instruments, such as rongeurs, graspers, cutters, and the like. It will be appreciated that the disclosed embodiment may have application to other instruments or tools for surgical, medical, or non-medical uses. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]    While exemplary embodiments of the present technology have been shown and described in detail below, it will be clear to the person skilled in the art that variations, changes and modifications may be made without departing from its scope. As such, that which is set forth in the following description and accompanying drawings is offered by way of illustration only and not as a limitation. The actual scope of the invention is intended to be defined by the following claims, along with the full range of equivalents to which such claims are entitled. 
           [0006]    In the following Detailed Description, various features are grouped together in several embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that exemplary embodiments of the technology require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. 
           [0007]    Identical reference numerals do not necessarily indicate an identical structure. Rather, the same reference numeral may be used to indicate a similar feature or a feature with similar functionality. Not every feature of each embodiment is labeled in every figure in which that embodiment appears, in order to keep the figures clear. Similar reference numbers (e.g., those that are identical except for the first numeral) are used to indicate similar features in different embodiments. 
           [0008]      FIG. 1  is a side view of a prior art surgical instrument; 
           [0009]      FIG. 2A  is a side view of a surgical instrument in a first position; and  FIG. 2B  is a side view of the surgical instrument of  FIG. 2A  in a second position; 
           [0010]      FIG. 3A  is a side view of another surgical instrument in a first position; and  FIG. 3B  is a side view of the surgical instrument of  FIG. 3A  in a second position; 
           [0011]      FIG. 4  is a side cross section view of a handle portion of the surgical instrument of  FIG. 3A  in the first position; 
           [0012]      FIG. 5  is a side cross section view of the handle portion of the surgical instrument of  FIG. 3A  in the second position; 
           [0013]      FIG. 6A  is a side isometric view of an actuation linkage of the handle portion of the surgical instrument of  FIG. 3A  in the first position; and  FIG. 6B  is a side isometric view of the actuation linkage of  FIG. 6B  in the second position; 
           [0014]      FIG. 7  is a side isometric view of a handle body of the handle portion of the surgical instrument of  FIG. 3A ; and 
           [0015]      FIG. 8  is a side isometric view of a lever of the handle portion of the surgical instrument of  FIG. 3A ; 
           [0016]      FIG. 9  is a side view of the prior art surgical instrument of  FIG. 1  held by a user in a fingertip grip; and 
           [0017]      FIG. 10  is a side view of the prior art surgical instrument of  FIG. 1  held by a user in a palm grip. 
       
    
    
     DETAILED DESCRIPTION 
       [0018]    Standard medical planes of reference and descriptive terminology are employed in this specification. A sagittal plane divides a body into right and left portions. A mid-sagittal plane divides the body into bilaterally symmetric right and left halves. A coronal plane divides a body into anterior and posterior portions. A transverse plane divides a body into superior and inferior portions. Anterior means toward the front of the body. Posterior means toward the back of the body. Superior means toward the head. Inferior means toward the feet. Medial means toward the midline of the body. Lateral means away from the midline of the body. Axial means toward a central axis of the body. Abaxial means away from a central axis of the body. 
         [0019]    The following disclosure is made in the context of a manual arthroscopic instrument for the purposes of illustration. The principles of the disclosed technology are applicable to a variety of other tools and instruments outside the scope of manual arthroscopic instruments. 
         [0020]    Referring to  FIG. 1 , a surgical instrument  10  includes a working portion  12  and a handle portion  14 . The working portion  12  in this example includes a pair of opposed jaws  16 ,  18  for grasping or biting a substance such as tissue. Other working portions and/or end effectors may be substituted: rongeurs, scissors, suture graspers, suture passers, knot tiers, implant manipulators, implant actuators, and the like. The handle portion  14  includes a handle body  20  and a lever  22  mounted to the handle body  20 . The handle body  20  includes a finger loop  24 . The lever  22  includes a finger loop  26  and a finger rest  28 . 
         [0021]    The working portion  12  is operatively assembled to the handle portion  14  so that movement of the lever  22  relative to the handle body  20  causes actuation of the working portion  12 . In this example, the working portion  12  is carried by, or supported by, the handle body  20 . The lever  22  is pivotally mounted to the handle body  20 , and is connected to at least one sub-component of the working portion  12 , as will be discussed in more detail below. As the lever  22  pivots relative to the handle body  20 , the working portion  12  is actuated. In this example, the jaws  16 ,  18  open and close as the lever  22  pivots relative to the handle body  20 . The jaws  16 ,  18  may be said to move between a first state and a second state as the lever  22  pivots relative to the handle body  20 . In other examples, a different working portion may perform a different action in response to movement of the lever  22 . Some examples of basic actions are opening, sliding, rotating, protruding, locking, cutting, vibrating, oscillating, reciprocating, heating, electrifying, magnetizing, illuminating, imaging, and the like. Each action and its opposite action may be considered a pair of first and second states. It will be appreciated that, in some examples, multiple actions may occur in response to movement of the lever  22  in one direction, and their opposites may occur in response to movement of the lever  22  in an opposite second direction. 
         [0022]    In one specific example, a stationary jaw, such as jaw  18 , may be coupled to a first end  31  of a tube  30 . An opposite second end  33  of the tube  30  may be coupled to a first end  21  of the handle body  20 . A movable jaw, such as jaw  16 , may be opposably hinged to the stationary jaw  18 , and may also be connected to a first end of a shaft  32  (not shown), the first end of the shaft  32  adjacent the first end  31  of the tube  30 . The shaft  32  may be slidably and/or rotatably received within the tube  30 . An opposite second end of the shaft  32  may be connected to the lever  22 , the second end of the shaft  32  adjacent the first end  21  of the handle body  20 . The lever  22  may be pivotally mounted to the handle body  20 . In this example, when the lever  22  is pivoted toward the handle body  20  as shown in  FIG. 1 , the jaws  16 ,  18  close. When the lever  22  is pivoted away from the handle body  20  (not shown), the jaws  16 ,  18  open. 
         [0023]    The arrangement of the handle portion  14  may permit one or more of a user&#39;s digits (fingers) to be inserted into the finger loops of the handle body  20  and lever  22 , as shown in  FIG. 9 . For example, an index finger  990  may be inserted into the lever finger loop  26 , a middle finger  992  may contact the finger rest  28 , and a thumb  998  may be inserted into the handle body finger loop  24 . While some users may find this “fingertip grip” to be satisfactory in terms of comfort, instrument control, mechanical advantage, efficiency, and the like, other users may find the fingertip grip to be unsatisfactory for continual use, or unsatisfactory right from the start. 
         [0024]    It has been observed that some users avoid inserting their digits into the finger loops. Instead, these users may support the handle body  20  in the palm of the hand, with one or more fingers resting on the lever  22 . In other words, the hand wraps around the outside of the handle portion  14 . This “palm grip” may be preferred, at least by some users, because the wrist remains in an ergonomically neutral position, the instrument  10  tends to sit lower in the hand, the instrument  10  feels more stable, the fingers are unconfined by the finger loops  24 ,  26 , and/or the instrument  10  is supported by portions of the hand other than the index and/or middle fingers  990 ,  992 , so that support is independent of instrument actuation by these fingers. 
         [0025]    The following disclosure sets forth examples of instrument handle portions that may be adapted for the palm grip. The example handle portions are also adapted for actuation by the index and/or middle fingers, which are the so-called power fingers of the hand. The examples may be perceived by users as being better balanced than fingertip grip designs. The examples illustrate that the handle portion may be oriented relative to the working portion so that the user&#39;s wrist remains in an ergonomically neutral position as the instruments are being used. An example with a ratchet mechanism is disclosed. The examples may be cost competitive relative to existing fingertip grip instruments. 
         [0026]    Referring to  FIGS. 2A-2B , a surgical instrument  40  includes a working portion  42  and a handle portion  44 . The working portion  42  in this example includes a pair of opposed jaws  46 ,  48  for grasping or biting a substance such as tissue. Other working portions and/or end effectors may be substituted: rongeurs, scissors, suture graspers, suture passers, knot tiers, implant manipulators, implant actuators, and the like. The handle portion  44  includes a handle body  50  and a lever  52  mounted to the handle body  50 . The instrument  40  includes a tube  60  between the working portion  42  and the handle portion  44 , and a shaft  62  (not shown) inside the tube. The surgical instrument  40  of  FIGS. 2A-2B  may share some of the characteristics set forth below for the surgical instrument  70  of  FIGS. 3A-3B . 
         [0027]    The following description for instrument  70  also applies to instrument  40  of  FIGS. 2A-2B , except as noted with regard to the ratchet link  100 , button  102 , button hole  85 , and pin hole  88 . 
         [0028]    Referring to  FIGS. 3A-3B , another surgical instrument  70  includes a working portion  72  and a handle portion  74 . The working portion  72  in this example includes a pair of opposed jaws  76 ,  78  for grasping or biting a substance such as tissue. Other working portions and/or end effectors may be substituted: rongeurs, scissors, suture graspers, suture passers, knot tiers, implant manipulators, implant actuators, and the like. The handle portion  74  includes a handle body  80  and a lever  82  mounted to the handle body  80 . The instrument  70  includes a tube  90  between the working portion  72  and the handle portion  74 , and a shaft  92  ( FIG. 4 ) inside the tube. The surgical instrument  70  of  FIGS. 3A-3B  may share some or all of the characteristics set forth above for the surgical instrument  40  of  FIGS. 2A-2B . Unlike the surgical instrument of  FIGS. 2A-2B , the example of  FIGS. 3A-3B  includes a ratchet link  100  and a button  102 . 
         [0029]    In the examples of  FIGS. 2A-3B , the working portion is operatively assembled to the handle portion so that movement of the lever relative to the handle body causes actuation of the working portion. In these examples, the working portion is carried by, or supported by, the handle body. The lever may be pivotally mounted to the handle body, and may be connected to at least one sub-component of the working portion. As the lever pivots relative to the handle body, the working portion is actuated. In these examples, the jaws open and close as the lever pivots relative to the handle body. In other examples, the working portion may perform some other action, as listed above, in response to movement of the lever. 
         [0030]    In the example of  FIGS. 3A-3B , a stationary jaw, such as jaw  78 , may be coupled to a first end  91  of a tube  90 . An opposite second end  93  of the tube  90  may be coupled to a first end  81  of the handle body  80 . In this example, the second end  93  is fixed in a hole  84  of the handle body; thus tube  90  may be described as a stationary shaft. A movable jaw, such as jaw  76 , may be opposably hinged to the stationary jaw  78 , and may also be connected to a first end (not shown) of a shaft  92  ( FIG. 4 ), where the first end of the shaft  92  is adjacent the first end  91  of the tube  90 . The shaft  92  may be slidably and/or rotatably received within the tube  90 ; thus shaft  92  may be described as a movable shaft. An opposite second end  94  ( FIG. 4 ) of the shaft  92  may be connected to the lever  82 , where the second end  94  of the shaft  92  is adjacent the first end  81  of the handle body  80 . In this example, the second end  94  of the shaft  92  is coupled to the lever  82  by a series of links, as will be discussed in more detail below. 
         [0031]    In another example of the present technology, an outer tube may be the movable shaft and an inner shaft may be the stationary shaft. In yet another example, the stationary and movable shafts may both be tubes. In yet another example, the stationary and movable shafts may lie side by side, and may be solid or tubular. A solid shaft may have one or more inclusions, such as an inner conductive core surrounded by insulation. In further examples, multiple stationary and/or movable shafts may be included. 
         [0032]    The handle portion  74  may be shaped and sized to substantially fill the user&#39;s palm. The size of the handle portion  74  may take into account published anthropometric data and human factors recommendations for grip span. As one example, the handle portion  74  may have a grip span of 5.5 cm at the lever pivot point (pin  99 ,  FIG. 3A ), 7 cm at the center of the lever  82 , and 6.5 cm at the lever tip  83 . Other grip span dimensions are contemplated in order to fit the natural distribution of hand sizes in the human population. The handle portion  74  may be shaped and sized so that the palm and the lesser two fingers, and optionally the thumb, are used to hold the handle portion  74 , leaving the index and middle fingers free to actuate the lever  82 . 
         [0033]    The lever  82  may be pivotally mounted to the handle body  80 , such as by pin  99  as shown in  FIG. 3A . Pin  99  may be referred to as a lever pivot point  99 . Pin  99  is transversely offset from a central longitudinal axis of the tube  90  by about a handbreadth. The transverse offset may be between 6 cm and 10 cm; other transverse offset dimensions are contemplated in order to fit the natural distribution of hand sizes in the human population, and in order to accommodate different design intents with regard to the amount of handle portion  74  covered by a user&#39;s hand. When the lever  82  is pivoted away from the handle body  80 , the jaws  76 ,  78  may be open, as shown in  FIG. 3A . When the lever  82  is pivoted close to the handle body  80 , the jaws  76 ,  78  may be closed, as shown in  FIG. 3B . 
         [0034]    The instrument  70  of  FIGS. 3A-3B  may include a multi-link mechanism which cooperates with the handle body  80 , lever  82 , and pin  99  to provide the desired actuation stroke length and force magnification, also known as mechanical advantage. By positioning the lever pivot point  99  at a distance from the central longitudinal axis of the tube  90 , each finger moves through an anatomically and ergonomically appropriate actuation stroke length. The longer, stronger index and middle fingers can move farther than the smaller, weaker ring and little fingers. 
         [0035]    Referring to  FIGS. 4-5 , the handle portion  74  of the surgical instrument  70  of  FIGS. 3A-3B  has been cross sectioned along a plane of bilateral symmetry, also known as a center plane, mid-plane, or mid-sagittal plane.  FIG. 4  shows the instrument  70  in the open, resting, or non-actuated position and  FIG. 5  shows the instrument in the closed, active, or actuated position. While the following description points out specific characteristics of individual component parts, one of skill in the art will recognize that at least some of these characteristics may be altered, varied, or omitted without sacrificing the salient principles of the technology. 
         [0036]    Referring to  FIGS. 4-5  and  7 , the handle body  80  may be a thin-walled, hollow component that may be the primary structural element of the instrument. An aperture  96  may extend through the handle body  80 ; this example includes three apertures  96  of various shapes and sizes. The handle body  80  may present broad, rounded surfaces for contact with the palm of the hand. The palm-contacting surfaces, or backstrap, may be textured or may include high friction inserts to improve grip security. An extension, tang, or beavertail  95  may be present. The handle body  80  may be economically manufactured using a casting process, as one example. Secondary operations may be performed, for example after casting, to form a shaft hole  84  and pin holes  98 ,  101 ,  103 ,  104 ,  105 . The handle body  80  may be simplified as a triangle, with apices at the center points of holes  98 ,  101 ,  103 , and line segments connecting the points. The center point of hole  98  may be referred to as a main pivot point because it forms a main pivot joint in combination with point  89  of the lever  82 . 
         [0037]    With reference to  FIGS. 4-5  and  8 , the lever  82  may be a thin-walled, hollow component that is the location where the user applies actuation forces to the instrument  70 . The lever  82  may house a ratchet mechanism, as may be seen in  FIGS. 3A-5 . The lever  82  may present broad, rounded surfaces for contact with the fingers of the hand. The lever  82  may be manufactured using a casting process, as one example. Secondary operations may be performed, for example after casting, to form a button hole  85  and pin holes  87 ,  88 ,  89 . The lever  82  may be hinged to the handle body  80  by a pin through holes  89  and  98 . The lever  82  may be simplified as a line segment extending between the center points of holes  87  and  89 . 
         [0038]    The lever  52  of the surgical instrument  40  of  FIGS. 2A-2B  may be similar to lever  82 , but may lack the button hole  85  and/or pin hole  88 . 
         [0039]    With reference to  FIGS. 4-5 , a main spring  86  may bias the instrument in the open position, although in other examples, the main spring  86  may bias the instrument in a closed position. The main spring  86  may be free-floating within the hollow sections of the handle body  80  and lever  82 . The position of the main spring  86  may be constrained in the handle body  80  and lever  82  by a retention pin  97  in each component. 
         [0040]    Referring to  FIGS. 4-6B , the first link  110  may be a connecting link. The first link  110  connects the lever  82  to the second link  112 , described below. The first link  110  may include an aperture  111 , and pin holes  117 ,  119  in opposite ends of the first link  110  for connection to the lever  82  and second link  112 , respectively. The first link  110  may be hinged to the lever  82  at a first joint by a pin through holes  87  and  117 . The first link  110  may be simplified as a line segment extending between the center points of holes  117 ,  119 . 
         [0041]    The second link  112  may be the force magnification link. The second link  112  receives input forces from the first link  110  and transfers the forces to the third link  114 . The magnitude of the force magnification, or mechanical advantage, can vary with the motion of the mechanism and/or the dimensions of the second link  112 . The magnification can increase as the mechanism moves from the open to the closed position. The second link  112  includes holes  120 ,  123 ,  124  for connection to the first link  112 , the handle body  80 , and the third link  114 , respectively. The second link  112  may be hinged to the first link  110  at a second joint by a pin through holes  119  and  120 , and hinged to the handle body  80  at a third joint by a pin through holes  101  and  123 . The second link  112  may also provide a connection point, or hole  122  for the ratchet link  100  as well as features to constrain the overall range of motion, such as a pin in slot  115  and hole  104 , which may form a sliding joint. The second link  112  may include an aperture  113 ; this example includes two apertures  113 . The second link  112  may also include a hole  121  for a drag plug (not shown). 
         [0042]    The second link  112  may be simplified as a triangle, with apices at the center points of holes  120 ,  123 , and  124 , and line segments connecting the points. The mechanical advantage of the second link  112  may be at least partially determined by dividing the length of the line segment between points  123  and  120  by the length of the line segment between points  123  and  124 . 
         [0043]    The third link  114  may be another connecting link. The third link  114  connects the second link  112  to the jaw drawbar, or shaft  92 . The third link  114  may include pin holes  125 ,  126  in opposite ends of the third link  114  for connection to the second link  112  and shaft  92 , respectively. The third link  114  may be hinged to the second link  112  at a fourth joint by a pin through holes  124  and  125 . The third link  114  may be simplified as a line segment extending between the center points of holes  125 ,  126 . 
         [0044]    The fourth link  116  may be a control link that modulates, adjusts, or aligns the force vector from the third link  114  to match or align with the center longitudinal axis of the drawbar  92 , or a center longitudinal axis of the hole  84  through which the drawbar  92  passes. This may minimize load-induced deflections in the mechanism. The fourth link  116  may include pin holes  127 ,  128  in opposite ends of the fourth link  116  for connection to the third link  114  and handle body  80 , respectively. The fourth link  116  may be hinged to the third link  114  at a fifth joint by a pin through holes  126  and  127 , and hinged to the handle body  80  at a sixth joint by a pin through holes  103  and  128 . The fourth link  116  may be simplified as a line segment extending between the center points of holes  127 ,  128 . 
         [0045]    The actuation linkage is shown in the open position in  FIGS. 4 and 6A , and in the closed position in  FIGS. 5 and 6B . As the lever  82  rotates toward the handle body  80 , the center point of hole  126  of the third link  114  moves away from the first end  81  of the handle body  80 . The center point of hole  126  of the third link  114  moves along an arcuate path controlled by the fourth link  116 . The arcuate path includes a linear component acting along the center longitudinal axis of the hole  84  in the handle body  80  which receives the second end  93  of the tube  90  and/or the second end  94  of the shaft  92 , or other instrument components suitable for rongeurs, scissors, suture graspers, suture passers, knot tiers, implant manipulators, implant actuators, and the like. The arcuate path also includes a transverse component acting normal to the center longitudinal axis of the hole  84  in the handle body  80 ; this transverse component may be a small percentage of the linear component, and in some examples may be zero. 
         [0046]    The lever  82  receives an input force/rotation from the hand of a user, and by means of the linkage, transforms the user input to an output force/displacement at the center point of hole  126  of the third link  114 . In the example illustrated, the output is primarily a linear force/translation along the center longitudinal axis of the hole  84  in the handle body  80 , and secondarily a force/motion acting transverse to the center longitudinal axis of the hole  84 . The center point/axis of hole  126  of the third link  114  may be referred to as an actuation point, a drive point, or an output point of the handle portion  74 . The center longitudinal axis of the hole  84  may be referred to as an actuation axis, a drive axis, or an output axis of the handle portion  74 . 
         [0047]    The components of the actuation linkage may be manufactured using traditional machining processes or formed by casting with minimal secondary operations to the pin holes and clevis widths. 
         [0048]    Alternate examples of the multi-link mechanism will now be discussed. These alternatives are contemplated for instruments  40  and  70 . 
         [0049]    The first link  110  may be replaced with a sliding connection between the lever  82  and the second link  112 . In this arrangement, lever  82  and second link  112  may be directly connected. The sliding connection may be a pin-in-slot arrangement, as illustrated elsewhere in the mechanism above, or it may be a shaft-in-collar arrangement, or the like. In one example, lever  82  may be modified to include a fixed extension with a forked end for engagement with a pin in hole  120  of the second link  112 . The orientation and extent of the fork may be selected to guide the pin in hole  120  along a path between the open and closed positions. The path may be similar or identical to a path between the open and closed positions followed by a pin through holes  119  and  120  in the mechanism of  FIGS. 3A-5 . 
         [0050]    The third link  114  may be replaced with two or more individual links. This arrangement may be useful in situations where the linkage detours around an obstacle, such as another component in the handle portion  74 . Some or all of the individual links which replace the third link  114  may be hinged together, or may include sliding connections, or they may bear against an internal part of the handle portion  74 , or they may be constrained by one or more control links similar to the fourth link  116 . 
         [0051]    The fourth link  116  may be replaced with a sliding connection between the third link  114  and the handle body  80 . The sliding connection may be like the ones described previously. 
         [0052]    The handle portion  74  may also be modified to include a transducer to convert the planar (arcuate, quasi-linear, linear, etc.) motion of the center point of hole  126  of the third link  114  (the output point of the handle portion  74 ) to rotational movement of a shaft, such as shaft  92 . In one example, motion of the output point may be mechanically converted to rotational motion by modifying the handle portion  74  to include an intermediate shaft between the third link  114  and the shaft  92 . In this arrangement, the shaft  92  may be proportionately shortened. A first end of the intermediate shaft may be hinged to the third link  114  at hole  126 , and optionally hinged to the fourth link  116 , if present, at hole  128 . An opposite second end of the intermediate shaft may include one or more transverse protrusions, such as posts, tabs, ears, bosses, and the like. The second end  94  of the shaft  92  may be modified to include a socket shaped and sized to receive the second end of the intermediate shaft. The interior of the socket may include one or more helical grooves shaped, sized, and positioned to receive the one or more transverse protrusions; the number of grooves is equal to or greater than the number of transverse protrusions. As the center point of hole  126  of the third link  114  moves along its path in response to movement of the lever  82 , the intermediate shaft moves accordingly. The transverse protrusions interact with the helical grooves to force the socket, and therefore shaft  92 , to turn. This example provides alternating rotational motion as the handle portion moves between the open and closed positions. 
         [0053]    In a further development of this example, a clutch and/or flywheel may be added so that the shaft  92  may be driven in a single rotational direction, and may build up speed with each actuation of the lever  82 . 
         [0054]    Returning to  FIGS. 3A-5 , the ratchet link  100  may connect to the second link  112  in the same general area as the first link  110 . Hole  130  of the ratchet link  100  is shown connected to hole  122  of the second link  112  by a hinge pin, forming a joint. This connection location exhibits the largest displacement during actuation in this example. The ratchet link  100  may be tied to, or connected to, the ratchet button  102  via a sliding connection of a pin in slot  129  and hole  136  of the ratchet button  102 . The ratchet link  100  may include a friction zone  132  with teeth, serrations, grooves, ridges, coating, or other high friction means for discrete or infinitely variable engagement with the button  102 , as will be discussed below. 
         [0055]    Hole  134  of the ratchet button  102  may be rotationally pinned to hole  88  of the lever  82  at a joint. Hole  136  of the ratchet button  102  may carry a pin for connection to the ratchet link  100  via sliding joint with slot  129 . The button  102  may include a friction zone  138  with teeth, serrations, grooves, ridges, coating, or other high friction means for discrete or infinitely variable engagement with the ratchet link  100 . The button  102  may be spring biased to protrude out from the front of the lever  82  through hole  85 . As the button  102  is depressed, the pin in the sliding joint pushes the ratchet link  100  away from the button  102 , separating the friction zones  132 ,  138 , which are mating tooth patterns in this example. 
         [0056]    When the handle portion  74  is grasped by a hand of a user, the output axis is adjacent a thumb of the hand, the main pivot joint is adjacent a small finger of the hand, and a finger of the hand may rest on the button. This is similar to the palm grip illustrated in  FIG. 10 . With reference to  FIG. 3A , it will be appreciated that a ring finger of a hand may be positioned to rest on the button  102  when the hand grips the handle normally. However, in other examples, a button may be positioned for normal contact by the index, middle, ring, and/or small finger. 
         [0057]    Because the ratchet button  102  may be located in the normal finger contact area of the lever  82 , the ratchet mechanism may be selectively overridden using a normal grip. As a result, no separate ratchet lockout feature is included in this example, although a ratchet lockout feature may be included in other examples. 
         [0058]    A ratchet spring  118  may be captured in a slip fit keyway in the ratchet button  102 . The ratchet spring  118  may be maintained in its position by the internal walls of the lever  82 . The ratchet spring  118  may bias the button  102  to protrude through hole  85  of the lever  82 , and at the same time may bias the button friction zone  138  to engage the ratchet link friction zone so that the ratchet mechanism is normally engaged. 
         [0059]    The ratchet link  100  can function as an automatic one-way brake or locking device to hold the instrument  70  in a closed or partially closed position without user effort. The ratchet link  100  may resist the action of a biasing member, such as spring  86 , which may tend to urge the instrument  70  to an open position. The button  102  can function to temporarily disengage the ratchet link  100  so that the instrument  70  can move toward the open position. 
         [0060]    The components disclosed herein may be fabricated from metals, alloys, polymers, plastics, ceramics, glasses, composite materials, or combinations thereof, including but not limited to: PEEK, titanium, titanium alloys, commercially pure titanium grade 2, ASTM F67, Nitinol, cobalt chrome, stainless steel, ultra high molecular weight polyethylene (UHMWPE), biocompatible materials, and biodegradable materials, among others. Different materials may be used for different parts. Different materials may be used within a single part. Any component disclosed herein may be colored, coded or otherwise marked to make it easier for a user to identify the type and size of the component, the setting, the function(s) of the component, and the like. 
         [0061]    It should be understood that the present systems, kits, apparatuses, and methods are not intended to be limited to the particular forms disclosed. Rather, they are to cover all combinations, modifications, equivalents, and alternatives falling within the scope of the claims. 
         [0062]    The claims are not to be interpreted as including means-plus- or step-plus-function limitations, unless such a limitation is explicitly recited in a given claim using the phrase(s) “means for” or “step for,” respectively. 
         [0063]    The term “coupled” is defined as connected, although not necessarily directly, and not necessarily mechanically. 
         [0064]    The use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and/or the specification may mean “one,” but it is also consistent with the meaning of “one or more” or “at least one.” The term “about” means, in general, the stated value plus or minus 5%. The use of the term “or” in the claims is used to mean “and/or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and/or.” 
         [0065]    The terms “comprise” (and any form of comprise, such as “comprises” and “comprising”), “have” (and any form of have, such as “has” and “having”), “include” (and any form of include, such as “includes” and “including”) and “contain” (and any form of contain, such as “contains” and “containing”) are open-ended linking verbs. As a result, a method or device that “comprises,” “has,” “includes” or “contains” one or more steps or elements, possesses those one or more steps or elements, but is not limited to possessing only those one or more elements. Likewise, a step of a method or an element of a device that “comprises,” “has,” “includes” or “contains” one or more features, possesses those one or more features, but is not limited to possessing only those one or more features. Furthermore, a device or structure that is configured in a certain way is configured in at least that way, but may also be configured in ways that are not listed. 
         [0066]    In the foregoing Detailed Description, various features are grouped together in several embodiments for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment.