Patent Publication Number: US-2020289172-A1

Title: Surgical depth instrument

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of, and priority to, U.S. Provisional Application No. 62/937,530, filed on Nov. 19, 2019, U.S. Provisional Application No. 62/901,905, filed on Sep. 18, 2019, and U.S. Provisional Application No. 62/816,536, filed on Mar. 11, 2019, the contents of each are incorporated by reference herein in their entireties. 
    
    
     FIELD 
     The present disclosure relates generally to medical devices, and, more particularly, to a measuring instrument for use in a bone implant fixation procedure, the measuring instrument including a combination of a bone probe allowing for physical examination of a hole drilled in a bone and a depth gauge member for determining a depth of the hole and providing a digital measurement of the depth. 
     BACKGROUND 
     Orthopedics is a medical specialty concerned with the correction of deformities or functional impairments of the skeletal system, especially the extremities and the spine, and associated structures, such as muscles and ligaments. Some orthopedic surgical procedures require surgeons to secure a device to one or more bones of a patient. For example, in some procedures, the surgeon may span and secures one or more bones, or pieces of a single bone, using a bone plate and one or more fasteners, such as screws. Other bone-related surgical procedures, however, may not require a bone plate and may instead solely rely on the use of one or more screws (e.g., securing a transplanted tendon). 
     In such bone-related surgical procedures, before an implant or plate, or simply the screw itself, can be attached to bone, an opening is typically drilled into the bone to accommodate the screw. With a hole in place, the surgeon can more easily select a screw of the appropriate length. However, selecting a screw of appropriate length is critical. For example, if the selected screw is too long, the distal end of the screw may pass through the end of the drilled hole and cause damage to the bone and/or protrude entirely through the bone, which can have deleterious effects, such as damage to surrounding tissue and/or pain and discomfort, or more serious complications, for the patient. For example, in some instances, the bone may abut against soft tissues that may be harmed if the screw is too long and may result in irritation of or damage to the soft parts. Additionally, a screw that protrudes through the bone may be tactilely felt by the patient, may prevent soft tissues (e.g., tendons, ligaments, or muscles) from moving over the bone surface as intended, or may even pierce the skin, which can lead to serious infection and complications. 
     The selection of an appropriate length screw is particularly important in spinal fixation procedures, such as lumbar sacral fusion and the correction of spinal deformities such as scoliotic curves. As an example, a screw mounted in the pedicle portion of the human spine should not extend to a point where the screw contacts the spinal cord itself, an event that can cause irreparable nervous system damage including paralysis. Accordingly, the determination of a length of the hole is important for choosing the appropriate length screw. 
     During drilling, the surgeon is typically capable of recognizing the resistance on the drill in order to determine when the drill has penetrated through the bone. Because the simple act of drilling does not provide an exact measurement of the depth of the bone itself, a depth gauge is commonly employed for directly measuring the depth of the hole from the top, drilling side to the bottom, opposite side of the hole. 
     Currently, many designs are known and utilized for measuring the depth of a hole or bore in a portion of a bone. Generally speaking, these designs utilize a central probe member having a barb at a distal end, and a sleeve or channel member. The probe member is inserted into the pilot hole while the surgeon attempts to find the surface with the barb. More specifically, the probe member is inserted to a depth greater than the depth of the pilot hole so that the barb is beyond the opposite side, at which point the surgeon finds the surface by hooking the barb to the opposite side. 
     The probe member is received in the sleeve or channel member and may reciprocate relative thereto. The channel member has graduated markings along a portion of its length, typically in inches and/or millimeters. A marker is laterally secured to the probe member such that, as the probe member shifts relative to the channel member, the marker indicates the relative shift between the probe member and the channel member. Accordingly, once the probe member has been secured to the opposite side of the bone, the channel member is shifted relative to the probe member and toward the bone until the channel member abuts the surface of the bone. The depth gauge is then read by examining graduated markings indicated by the probe member marker. 
     A number of problems are experienced with this depth gauge. As an initial point, the components are typically made with surgical-grade stainless steel, and the graduated markings are embossed therein. Therefore, the brightness of the operating room lights on the highly reflective surface can make the markings difficult to read. The markings are commonly in small increments, such as millimeters, and surgeons often have trouble differentiating between the markings, or noting partial increments. Reading these gauges, then, often requires carefully holding the depth gauge as the reading is taken, and a surgeon&#39;s effort to closely examine the reading may result in a loss of securement or purchase of the barb on the bone, thus necessitating a re-measurement and a loss of time. 
     Furthermore, proper reading of the markings requires a surgeon&#39;s eyes to be properly aligned with the markings. That is, a proper view of the measurement requires the surgeon to view the gauge from a lateral point of view so that the view of the probe marker aligned with the graduated markings is proper not distorted by the surgeon&#39;s elevated, standing perspective. Therefore, it is often necessary for the surgeon to bend over while using these gauges to view an accurate reading. If the depth gauge is tilted in order to make the reading, the sleeve will shift relative to the probe, thus making the measurement inaccurate and possibly causing the barb to become unsecured, as described above. In addition, removal of the depth gauge often causes the measurement to be lost. As the bone is essentially clamped, by light pressure, between the distal end of the channel member and the distal barb of the probe member, it is often necessary to retract the channel member from the bone surface in order to extract the probe from the pilot hole. 
     SUMMARY 
     The present disclosure is a medical device for use in a bone implant fixation procedure. The device is configured to provide a faster and more accurate measure of depth. In particular, the device includes a combination of a bone probe allowing for physical examination of a hole drilled in a bone and a depth gauge member for determining a depth of the hole and providing a digital measurement of the depth. Accordingly, the device of the present disclosure is capable of digitally measuring the depth of an opening in a bone during the same surgical step that a surgeon probes and inspects the interior of the opening. 
     In certain aspects, this disclosure relates to a device for the examination and measurement of a hole formed into a bone. According to some embodiments, the device includes a handle with a bone probe extending form a distal end. The bone probe has a shaft with a distal end defining a probing tip including a portion with an engagement surface shaped so as to establish purchase with an exterior surface of bone adjacent to the hole. The device includes a depth gauge cylinder slidably mounted to a portion of the handle. The depth gauge cylinder comprises a hollow body with a lumen in which a portion of the handle and the bone probe shaft are received, such that the depth gauge cylinder is operable to slide along a longitudinal axis of the handle. The device further includes a tip member attachable to a distal end of the depth gauge cylinder and operable to correspondingly slide with the depth gauge cylinder. The tip member includes an opening through which the bone probe shaft is received. 
     According to certain aspects, the device further includes a sensor with a pressure sensitive strip. The sensor is coupled to a portion of the handle that is received by the hollow body of the depth gauge cylinder and is configured to generate an electronic signal that varies in relation to distance traveled by the depth gauge cylinder relative to the handle and is indicative of a depth of the hole. 
     In some instances, the device provides a measurement of the depth of a hole that is drilled into a bone, wherein the measurement is determined by a distance traveled by the depth gauge cylinder relative to the handle of the device. More particularly, the measurement is based, at least in part, on a comparison between a first location of contact, made by a member protruding from an interior surface of the depth gauge cylinder, onto the pressure sensitive strip, and a second location of contact between the member and the pressure sensitive strip, wherein the distance between the two contact locations is indicative of the depth of the hold in the bone. 
     During a bone-related procedure involving placement of a screw, or other fastener, it may be desirable to determine whether drilling of the hole resulted in any cracks or openings, either along an interior side wall of the hole or at the base of the hole. Ensuring the integrity of the drilled hole is important because unintended cracks, openings, or irregularities can increase the risk that the screw will either not securely attach itself within the hole or may result in chipping or fragmenting of bone during fastening of the screw within the hole. It is generally not possible for a surgeon to visual examine the integrity of the drilled hole due to a limited field of view within the hole (drilled holes can be relatively small in width, such as 5 mm or less in some instances). 
     The device of the present disclosure includes a bone probe that allows for a surgeon to feel the interior side walls of the hole to locate any cracks or other unintended openings or irregularities along the interior of the hole and to further determine the exit point of the hole (i.e., for a hole that has been drilled entirely through the bone for subsequent placement of a bicortical screw or other fastener). The bone probe generally includes an elongated shaft slidably mounted within a body of the device serving as a handle adapted for manual manipulation. The elongated shaft of the probe includes a distal end configured to extend from the body of the device during use. The distal end includes a probing tip for contacting an interior portion of the hole. At least a portion of the elongated shaft may be substantially flexible or semi-rigid to provide a proper “feel” to the surgeon during examination of the hole in the bone. For example, the shaft of the bone probe may be substantially non-elastic such that the surgeon can apply pressure against the interior wall of the hole to feel for irregularities or the base of the hole via tactile feedback provided by the shaft. In some embodiments, the shaft may be tapered such that the shaft narrows in width or thickness in a direction towards the probing distal tip. In this manner, the flexibility of the shaft may increase along the shaft in a direction toward the probing tip. 
     The probing tip may include at least a first portion having a shape or contour that aids the surgeon in detecting surface irregularities (e.g., cracks, crevices, openings, etc.) on the interior surface of the hole. For example, in some embodiments the first portion may have a substantially arcuate or curved shape. The arcuate or curved portion may also aid the surgeon in locating the exit point (i.e., second opening) the hole so as to allow for the probing tip to be accurately placed and secured along an edge of the exit point so that the hole can be measured via the depth gauge member. The arcuate or curved shape of the first portion of the probing tip may generally lessen risk of tissue irritation that may otherwise occur along the interior surface of the hole, which is usually soft and easily penetrable with less curved and more abrupt surfaces (with sharp or distinct edges). In some embodiments, the first portion may have a general spherical shape. In other embodiments, the first portion may be substantially planar with rounded edges. 
     The probing tip also includes a second portion positioned opposite the first portion, wherein the second portion includes an engagement surface configured to pierce or otherwise establish purchase with an exterior portion of bone immediately adjacent to the exit point of the hole (i.e., along the edge of the hole). In particular, upon locating the exit point or second opening of the hole, the surgeon may then extend the probing tip through the exit point and then position the bone probe shaft against the interior surface of hole and pull back on the bone probe shaft so as to draw the probing tip, specifically the engagement surface, back towards, and into engagement with, the exterior surface of the bone along the edge of the exit point of the hole. Upon sufficient application of pressure (i.e., sufficient retraction of the bone probe shaft), the engagement surface of the probing tip engages and establishes purchase with the bone immediately adjacent the hole. Upon establishing engagement, the medical device may be stabilized in position, at which point, the depth gauge member can be used for measuring the depth of the hole. In some embodiments, the engagement surface may include surface texturing to enhance friction between the engagement surface and a portion of bone. For example, in some procedures in which a plate or implants is to be secured with screws through a bicortical drill hole, the probing tip may extend entirely through the hole (from one side of the bone to the other), at which point the surgeon may pull the bone probe back towards the hole such that the engagement surface of the second portion of the probing tip establishes purchase with one side of the bone, and the surface texturing enhances friction between the engagement surface and bone to reduce risk of slippage. 
     The bone probe is generally fixed to a handle of the device. The handle may include, for example, a proximal end including a grip portion to provide a surgeon with a means for applying a pulling force so as to draw the engagement surface of the probing tip of the bone probe into engagement with an exterior surface of bone immediately adjacent to a bicortical hole in the bone. 
     The depth gauge member is a cylinder that generally includes a hollow elongated body slidably mounted to a portion of the handle. The depth gauge cylinder includes a lumen in which at least a portion of the handle and the bone probe shaft are received within. The depth gauge cylinder is operable to slide along a longitudinal axis of the handle from an initial default position and an extended position relative to the handle. A tip member is releasably coupled to a distal end of the depth gauge cylinder and operable to correspondingly slide with the depth gauge cylinder during movement of the cylinder. The tip member includes an opening through which at least the bone probe shaft is received. The tip member further includes a distal end including a profile corresponding to an opening in a bone plate through which a screw is to be received. More specifically, the tip member of the present disclosure is particularly useful in procedures in which a depth measurement is to be obtained with a bone plate in place (i.e., positioned where it would be mounted). As generally understood, it is preferable to countersink a screw when performing a bone implant fixation procedure so as to avoid any potential complications as a result of a screw head extending from a surface of bone or a bone plate. There are known generally geometries of a countersink in a bone plate hole (for receiving the screw), which include at least a mini, small, and large fragment, wherein the mini-frag is the most common. The profile of the distal end of the tip member comprises a stepped profile including multiple distinct and separate stepped portions, wherein each stepped portion has a different diameter. Each of the separate stepped portions has a respective shape and/or diameter corresponding to a shapes and/or diameter of common countersink sizes provided in bone plates. The device further includes at least one sensor configured to generate an electronic signal indicative of a depth of the hole as a result of sensing a distance traveled by the depth gauge cylinder relative to the handle and bone probe 
     For example, in one embodiment, upon establishing purchase with an exterior surface of bone generally providing an edge of the exit point of the drilled (or otherwise pierced hole) via the probing tip, a surgeon need only continue pulling back on the handle to thereby maintain engagement of the bone probe with the exterior surface of bone and then slide the depth gauge cylinder in a direction towards the bone. Upon sliding the depth gauge member towards the bone, at least a portion of the tip member will pass through an opening in the bone plate corresponding to the drilled hole until a portion of the stepped profile of the tip member makes contact with and engages a countersink portion of the opening in the bone plate. When the tip member is correctly positioned in the countersink of the bone plate, the most distal edge of the tip member will be aligned along the same plane as the bone-facing surface of the bone plate. The sensor is configured to generate an electronic signal based on the distance that the depth gauge cylinder traveled relative to the handle and bone probe, wherein the electronic signal is indicative of at least a depth of the hole. In particular, the sensor may include inductive or capacitive elements or assemblies configured to sense the location of a distal end of the depth gauge cylinder, for example, relative to a specific point along the handle, and, as a result, generate an electronic signal representing the distance there between as a result of movement (i.e., sliding) of the depth gauge cylinder. For example, the depth gauge cylinder may generally slide relative to the handle and bone probe between a most-proximal position and a most-distal position and a plurality of positions therebetween. As such, the depth gauge cylinder may be in the most-proximal position when in the default, initial position when depth measurement has not yet begun. Upon establishing engagement between the bone probe tip and the bone, the depth gauge cylinder may then be advanced in a direction towards the bone from the default, initial position until the tip member, specifically the stepped profile, makes contact with a countersink in the bone plate opening. The sensed distance traveled by the depth gauge cylinder is then used to calculate the depth of the hole. In particular, the device may include logic for determining hole depth based on known variables. For example, the length of the bone probe shaft extending from the distal end of the tip member when the depth gauge cylinder is in the initial, default position (i.e., the most-proximal position relative to the handle) may be known and programmed into the logic. As such, the sensed distance traveled by the depth gauge cylinder from the initial, default position until the tip member, specifically the stepped profile, makes contact with a countersink in the bone plate opening, may simply be subtracted from the known length of the bone probe shaft to thereby provide the depth of the hole. 
     Accordingly, the digital sensing of the hole depth provides a much more accurate measurement than conventional analog depth gauges and also requiring very little, if any, input or interpretation from the surgeon. Accordingly, by providing a much more accurate measurement of a hole depth, the surgeon is able to select the correct length screw for any given hole so as to improve the chances of a successful surgery. 
     In some embodiments, the device may further include a display provided on either the handle or the depth gauge cylinder and configured to visually provide a digital readout of a depth measurement of the hole based on the electronic signal from the sensor. In other embodiments, the device may be configured to wirelessly communicate and exchange data with a separate display or computing device, such as, for example, a monitor or panel display, a PC, a notebook, a tablet computer, a smartphone, or other wireless computing device. 
     Upon receiving the electronic signal from the sensor, the separate display or computing device may be configured to visually provide the depth measurement of the hole based on the electronic signal from the sensor. Furthermore, in some embodiments, the computing device may include a specific software application that may be directed to maintaining a record of the hole measurements and/or provide an interactive user interface in which multiple holes can be mapped to a particular plate or implant and the depth of each hole (including the thickness of the plate or implant) can be included and stored for records. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Features and advantages of the claimed subject matter will be apparent from the following detailed description of embodiments consistent therewith, which description should be considered with reference to the accompanying drawings. 
         FIG. 1  is top view of one embodiment of a medical device consistent with the present disclosure. 
         FIG. 2  is a cross-sectional view of the medical device of  FIG. 1  illustrating the hollow interior of the handle and arrangement of the bone probe and depth gauge member relative to one another. 
         FIGS. 3A and 3B  are enlarged front and side views, respectively, of one embodiment of a probing tip defined on the distal end of the bone probe shaft. 
         FIGS. 3C and 3D  are enlarged front and side views, respectively, of another embodiment of a probing tip defined on the distal end of the bone probe shaft. 
         FIG. 4  is a perspective view of another embodiment of a bone probe compatible for use with the medical device of  FIG. 1 , illustrating another embodiment of a probing tip defined on a distal end of the bone probe shaft. 
         FIGS. 5 and 6  are front and side views, respectively, of the bone probe of  FIG. 4 . 
         FIG. 7  is an enlarged side view of the probing tip of  FIG. 4 . 
         FIGS. 8 and 9  are enlarged perspective views of the probing tip of  FIG. 4 . 
         FIGS. 10A and 10B  illustrate retraction of the bone probe within the handle member and subsequent compression of a spring assembly upon movement of the handle towards the bone when the probing tip of the distal end of the bone probe shaft is in contact with the bottom of the drilled hole in the bone. 
         FIG. 11  is a side view of the medical device of  FIG. 1  including a strain sensor sensing strain upon the bone probe shaft and providing an electronic signal indicative of the strain to an audio or visual component for providing an audible or visual alert. 
         FIGS. 12A-12F  illustrate a series of steps for performing a procedure of probing a drilled hole and subsequently obtaining a depth measurement using another embodiment of a medical device consistent with the present disclosure. 
         FIGS. 13A-13C  illustrate a series of steps for performing a procedure of probing a fully drilled hole (i.e., a hole extending entirely through a bone for receipt of a bicortical bone screw) with the bone probe of  FIG. 4  and further establishing purchase of the probing tip of the bone probe with a side of the bone adjacent to the bicortical drilled hole to secure the bone probe in place and allow the depth gauge member to be used for measuring the depth of the bicortical drilled hole. 
         FIG. 14  is another embodiment of a medical device consistent with the present disclosure having a display for providing a digital readout of a depth measurement of the hole. 
         FIG. 15  is another embodiment of a medical device consistent with the present disclosure configured to wirelessly communicate with and transmit depth measurement data to a wireless computing device to record, store, and/or visually display measured depths. 
         FIGS. 16 and 17  illustrate the compatibility of a medical device of the present disclosure with other medical devices so as to provide additional features, in additional bone probing and depth measurement, such as energy emission ( FIG. 16 ) and sensing capabilities ( FIG. 17 ). 
         FIG. 18  is a perspective view of a medical device consistent with the present disclosure and having a neuromonitoring port configured to receive a corresponding input connector from a nerve sensing/nerve stimulation device and provide an electrical pathway to the bone probe. 
         FIG. 19  is a side view, partly in section, of the medical device of  FIG. 18  illustrating the configuration of the bone probe shaft to carry electrical signals to and from the nerve sensing/nerve stimulation device. 
         FIGS. 20A, 20B, 20C  illustrate the transmission of a signal from bone probe to a screw positioned within a hole in a vertebra for neuromonitoring capabilities. 
         FIG. 21  illustrates an angle guide for use with the medical device of the present disclosure. 
         FIG. 22  is a perspective view of another embodiment of a medical device consistent with the present disclosure. 
         FIG. 23  is a perspective, exploded view of the medical device of  FIG. 22 . 
         FIG. 24  is a top view of the medical device of  FIG. 22  illustrating the depth gauge cylinder in the initial, default position relative to the handle and bone probe. 
         FIG. 25  is a cross-sectional view of the medical device taken along lines  25 - 25  of  FIG. 24 . 
         FIG. 26  is a side view of the medical device of  FIG. 22 . 
         FIG. 27  is a perspective view of the medical device of  FIG. 22  illustrating movement of the depth gauge cylinder relative to the handle and bone probe. 
         FIG. 28  is a perspective view of another embodiment of the medical device of  FIG. 22  illustrating the user-operated control mechanism provided on the handle. 
         FIGS. 29A, 29B, and 29C  are enlarged side views of the tip member illustrating various dimensions of the stepped profile. 
         FIG. 30  is a side view of another embodiment of a medical device of  FIG. 22  including a single body construction and  FIG. 31  is an enlarged side view of the tip member. 
         FIGS. 32 and 33  are perspective views of another medical device consistent with the present disclosure illustrating custom grip portions on portions thereof. 
         FIG. 34  is a perspective, exploded view of another embodiment of a medical device consistent with the present disclosure. 
         FIG. 35  is a perspective view of the medical device of  FIG. 34  in an assembled state and illustrating movement of the depth gauge cylinder relative to the handle and bone probe. 
         FIG. 36  is a top view of the medical device of  FIG. 34  illustrating the depth gauge cylinder in a distal-most position relative to the handle and bone probe. 
         FIG. 37  is a cross-sectional view of the medical device taken along lines  37 - 37  of  FIG. 36 . 
         FIG. 38  is a side view of the medical device of  FIG. 34 . 
         FIG. 39  is a perspective view of another embodiment of a medical device consistent with the present disclosure. 
         FIG. 40  is a perspective, exploded view of the medical device of  FIG. 39 . 
         FIG. 41  is a top view of the medical device of  FIG. 39  illustrating the depth gauge cylinder in the initial, default position relative to the handle and bone probe. 
         FIG. 42  is a cross-sectional view of the medical device taken along lines  42 - 42  of  FIG. 41 . 
         FIG. 43  is a side view of the medical device of  FIG. 39 . 
         FIGS. 44A-44E  illustrate a series of steps for performing a procedure of probing a fully drilled hole (i.e., a hole extending entirely through a bone for receipt of a bicortical bone screw) with a bone probe (similar to the bone probe of  FIG. 4 ) and further establishing purchase of the probing tip of the bone probe with a side of the bone adjacent to the bicortical drilled hole to secure the bone probe in place and subsequently obtaining a depth measurement using the embodiment of a medical device consistent with the present disclosure. 
         FIGS. 45 and 46  are perspective views of another embodiment of a medical device consistent with this disclosure. 
         FIG. 47  is an exploded view of the medical device shown in  FIGS. 45 and 46 . 
         FIG. 48  is a bottom view of the sensor depicted in  FIG. 47 , illustrating a pressure sensitive strip. 
         FIG. 49  is a perspective view of a bottom handle portion of the medical device. 
         FIGS. 50 and 51  are cross-sectional views of the medical device illustrating the depth gauge cylinder in different positions relative to the handle. 
         FIG. 52  is an enlarged cross-sectional view of the depth gauge cylinder and handle, illustrating one embodiment of a member associated with the depth gauge cylinder engaging with the pressure sensitive strip consistent with the present disclosure. 
         FIG. 53  is an enlarged cross-sectional view of a portion of the depth gauge cylinder and handle coupled to one another, illustrating of another embodiment of a member associated with the depth gauge cylinder engaging with the pressure sensitive strip consistent with the present disclosure. 
         FIGS. 54 and 55  are enlarged cross-sectional views of a portion of the depth gauge cylinder and handle coupled to one another, illustrating an interlocking assembly for retaining the depth gauge cylinder and handle to one another in which the interlocking assembly transitions between at least a first configuration ( FIG. 54 ) and a second configuration ( FIG. 55 ). 
         FIG. 56  is an exploded view of the medical device illustrating another embodiment of a member associated with the depth gauge cylinder engaging with the pressure sensitive strip consistent with the present disclosure. 
         FIG. 57  is an enlarged cross-sectional view of a portion of the depth gauge cylinder and the handle of the device of  FIG. 56 , illustrating the member engaged with the pressure sensitive strip. 
         FIG. 58  is a side perspective of a tip member consistent with the present disclosure. 
         FIG. 59  is a cross-sectional view of the tip member taken along lines A-A of  FIG. 58 . 
     
    
    
     For a thorough understanding of the present disclosure, reference should be made to the following detailed description, including the appended claims, in connection with the above-described drawings. Although the present disclosure is described in connection with exemplary embodiments, the disclosure is not intended to be limited to the specific forms set forth herein. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient. 
     DETAILED DESCRIPTION 
     By way of overview, the present disclosure is generally directed to a medical device for use in a bone implant fixation procedure and configured to provide a faster and more accurate measure of depth. In particular, the device includes a combination of a bone probe allowing for physical examination of a hole drilled in a bone and a depth gauge member for determining a depth of the hole and providing a digital measurement of the depth. Accordingly, the device of the present disclosure is capable of digitally measuring the depth of an opening in a bone during the same surgical step that a surgeon probes and inspects the interior of the opening. 
       FIG. 1  is top view of one embodiment of a medical device  100  consistent with the present disclosure and  FIG. 2  provides a cross-sectional view of the medical device  100 . As shown, the medical device  100  includes a body  102  having a first end  104  and an opposing second end  106  and is generally hollow. The body  102  is configured as a handle and generally adapted for manual manipulation. Accordingly, the body will be referred to a “handle  102 ” hereinafter for ease of explanation. 
     The device  100  further includes a bone probe  108  slidably mounted within the handle  102 . The bone probe  108  includes a shaft  110  having a distal end  112  configured to extend from, and retract towards, the first end  104  of the handle  102  during use, as will be described in greater detail herein. The distal end  112  further includes a probing tip  114 , which is useful for examination and inspection of interior surfaces of a drilled hole in bone, as will be described in  FIGS. 3A and 3B . 
     The device  100  further includes a depth gauge member  116  slidably mounted within the handle  102 . The depth gauge member  116  generally includes a hollow elongated body  118  having a distal end  120  configured to extend from, and retract towards, the first end of the handle  102  during use, similar to the bone probe shaft  110 , as will be described herein. The hollow elongated body  118  has a lumen in which at least a portion of the bone probe shaft  110  is received such that the bone probe  108  and depth gauge member  116  are independently slidable relative to one another and the handle  102 . The device  100  further includes one or more depth measurement sensors  122  configured to generate an electronic signal indicative of a depth of at least the hole, wherein the electronic signal varies in relation to a distance between the first end  104  of the handle  102  and the distal end  120  of the depth gauge member  116 , as will be described in greater detail herein. 
     The bone probe  108  and depth gauge member  116  may each be coupled to separate slider members for allowing a surgeon to manually control movement of the bone probe  108  and depth gauge member  116  independent of one another. For example, as shown in  FIG. 1 , a first slider  124  may be coupled to at least the bone probe shaft  110  and is slidable along a longitudinal axis of the handle  102 , which such movement of the first slider  124  causes corresponding movement of the bone probe shaft  110 . Although not shown in  FIGS. 1 and 2 , a second slider may be coupled to the depth gauge member  116  and is similarly slidable along the longitudinal axis of the handle  102 , such that movement of the second slider causes corresponding movement of the depth gauge member  116 . 
     The device  100  may further include a spring assembly  126  coupled to at least one of the bone probe  108  and depth gauge member  116 . The spring assembly  126  may be configured to provide a biasing force upon at least one of the bone probe  108  and depth gauge member  116  so as to maintain either the bone probe  108  or depth gauge member  116  in a default extended position. For example, as shown in  FIGS. 1 and 2 , the bone probe  108  is generally positioned in an extended configuration (probing tip  114  extended out of first end  104  of handle  102 ), in which a surgeon may now examine an interior surface of a drilled hole, as is shown in  FIGS. 10A and 10B . 
     During a bone-related procedure involving placement of a screw, or other fastener, it may be desirable to determine whether drilling of the hole resulted in any cracks or openings, either along an interior side wall of the hole or at the base of the hole. Ensuring the integrity of the drilled hole is important because unintended cracks, openings, or irregularities can increase the risk that the screw will either not securely attach itself within the hole or may result in chipping or fragmenting of bone during fastening of the screw within the hole. It is generally not possible for a surgeon to visual examine the integrity of the drilled hole due to a limited field of view within the hole (drilled holes can be relatively small in width, such as 5 mm or less in some instances). 
     The bone probe  108  allows for a surgeon to feel the interior side walls and bottom of a drilled hole so as to locate any cracks or other unintended openings or irregularities along the interior of the hole. For example, probing tip  114  is configured for contacting an interior portion of the hole and at least a portion of the elongated shaft  110  may be substantially flexible or semi-rigid to provide a proper “feel” to the surgeon during examination of the hole in the bone. For example, the shaft  110  of the bone probe  108  may be substantially non-elastic such that the surgeon can apply pressure against the interior wall of the hole to feel for irregularities or the base of the hole via tactile feedback provided by the shaft  110 . In some embodiments, the shaft  110  may be tapered such that the shaft narrows in width or thickness in a direction towards the probing distal tip. In this manner, the flexibility of the shaft may increase along the shaft in a direction toward the probing tip  114 . 
       FIGS. 3A and 3B  are enlarged front and side views, respectively, of one embodiment of a probing tip  114   a  defined on the distal end  112  of the bone probe shaft  110 . As shown, the probing tip  114   a  may include an arcuate first portion  128  shaped and configured to contact an interior surface of the hole with little or no resistance and provide tactile feedback of the interior surface to the surgeon. For example, as shown, the first portion  128  is substantially curved or spherical so as to prevent or minimize the risk that the probing tip  114   a  would penetrate or otherwise engage of portion of the interior surface of the hole. Rather, the first portion  128  is shaped so as to glide or easily slide along the interior surface, while still allowing sufficient contact to provide tactile feedback to the surgeon. Accordingly, the arcuate first portion  128  may lessen or eliminate tissue irritation that may otherwise occur when a sharper object is used to probe the bone opening. 
     The probing tip  114   a  further includes a second portion  130  having an engagement surface shaped and configured to establish purchase with a portion of the interior surface of the hole and associated with a bottom of the hole upon sufficient application of force to the shaft. The engagement surface may be a substantially abrupt edge of the probing tip  114 , in which the transition between the first portion  128  and second portion  130  is sudden (e.g., sharp corner or edge). Accordingly, upon sufficient pressure, the engagement surface is configured to pierce or establish purchase with tissue in the interior of the hole. Thus, the probing tip  114   a  is multifunctional in that the first portion  128  allows for probing of the interior surfaces to provide a surgeon with a “feel” for examination purposes and to further locate the bottom of the hole and the second portion  130  allows for the surgeon to establish purchase at the desired site (i.e., the bottom of the hole) so as to stabilize the bone probe in the desired position, at which point, the depth gauge member can be used for measuring the depth of the hole. 
     In some embodiments, the engagement surface of the second portion  130  may include surface texturing to enhance friction between the engagement surface and a portion of bone. For example, in some procedures in which a plate or implants is to be secured with screws through a bicortical drill hole, the probing tip may extend entirely through the hole (from one side of the bone to the other), at which point the surgeon may pull the bone probe back towards the hole such that the engagement surface of the second portion of the probing tip establishes purchase with one side of the bone, and the surface texturing enhances friction between the engagement surface and bone to reduce risk of slippage. 
       FIGS. 3C and 3D  are enlarged front and side views, respectively, of another embodiment of a probing tip  114   b  defined on the distal end  112  of the bone probe shaft  110 . As shown, the probing tip  114   b  may include a first portion  129  shaped and configured to contact an interior surface of the hole with little or no resistance and provide tactile feedback of the interior surface to the surgeon. For example, as shown, the first portion  129  has a substantially planar or flat surface with rounded edges so as to prevent or minimize the risk that the probing tip  114   b  would penetrate or otherwise engage of portion of the interior surface of the hole. Rather, the rounded edges of the first portion  129  are shaped so as to glide or easily slide along the interior surface, while still allowing sufficient contact to provide tactile feedback to the surgeon. The substantially planar surface may yield a more accurate depth measurement than a full radius bottom in that, in some circumstances, the flat surface may provide better engagement and sit more flush with the bottom of the hole than the full radius first portion  128  of probing tip  114   a  (in  FIGS. 3A and 3B ). It should be noted, however, that the round edges may still provide enough edge to serve as an engagement surface for establishing purchase with a portion of the interior surface of the hole and associated with a bottom of the hole upon sufficient application of force to the shaft. The second portion  131  of probing tip  114   b  may be substantially curved or spherical. 
       FIG. 4  is a perspective view of another embodiment of a bone probe  208  compatible for use with the medical device  100  consistent with the present disclosure. Similar to the bone probe  108  previously described herein, the bone probe  208  allows for a surgeon to feel the interior side walls of a hole to locate any cracks or other unintended openings or irregularities along the interior of the hole and, in combination with the depth gauge member  116 , the bone probe  208  further allows for depth measurements of the hole. In particular, as described in greater detail herein, the bone probe  208  is configured for assisting in measuring of a drilled hole extending entirely through a bone (i.e., a bicortical drilled hole) in which a bicortical screw or other bicortical fastener is to be placed. Accordingly, unlike the bone probe  108 , which has a bone probing tip generally configured to locate the base or bottom of a drilled hole in bone that does not extend entirely through the bone, the bone probe  208  includes a bone probing tip specifically configured to be extended entirely through a drilled hole (from one side of the bone to the other), at which point the surgeon may pull the bone probe back towards the hole such that an engagement surface of the bone probing tip establishes purchase with one side of the bone, thereby anchoring or securing the bone probe  208  in place and allowing subsequent depth measurement of the hole via the depth gauge member in a manner described previously herein. 
     The bone probe  208  includes a shaft  210  having a proximal end  211  and an opposing distal end  212  configured to extend from, and retract towards, the first end  104  of the handle  102  during use, as will be described in greater detail herein. The proximal end  211  may further include a cut out portion (or notch)  213  allowing for the bone probe shaft  210  to be physically coupled to a control mechanism or the like (e.g., the slider  124 ) for extending/retracting the shaft  210 . The distal end  212  includes a probing tip  214 , which is useful for examination and inspection of interior surfaces of a drilled hole in bone in a similar manner as the probing tip  114 . 
     The bone probe  208  allows for a surgeon to feel the interior side walls of a drilled hole so as to locate any cracks or other unintended openings or irregularities along the interior of the hole. For example, probing tip  214  is configured for contacting an interior portion of the hole and at least a portion of the elongated shaft  210  may be substantially flexible or semi-rigid to provide a proper “feel” to the surgeon during examination of the hole in the bone. For example, the shaft  210  of the bone probe  208  may be substantially non-elastic such that the surgeon can apply pressure against the interior wall of the hole to feel for irregularities or the base of the hole via tactile feedback provided by the shaft  210 . 
     In some embodiments, the shaft  210  may be tapered such that the shaft narrows in width or thickness in a direction towards the probing distal tip  214 . In this manner, the flexibility of the shaft may increase along the shaft  210  in a direction toward the probing tip  214 . For example, in the illustrated embodiment, the shaft  210  may have a generally cylindrical geometry along a majority of its length and may include a substantially planar portion formed along a length thereof and tapered in a direction towards the distal end  212 . For the purposes of discussion, and ease of description, the following description refers to the shaft  210  as having a first side  216  including the cylindrical shape and a second side  218  that is substantially planar and extends along length of the shaft  210 , the shaft tapering in thickness (i.e., transitioning from greater thickness to less thickness along length of the shaft  210 ) from the proximal end  211  to the distal end  212 , as illustrated in  FIGS. 5 and 6 . 
     In particular,  FIG. 5  is a front view (i.e., facing in a direction towards the second side  218  of the shaft) of the bone probe  208  and  FIG. 6  is a side view of the bone probe  208 . As shown in  FIG. 5 , the overall width of the shaft  210  remains relatively constant from the proximal end  211  to the distal end  212 , while the thickness of the shaft  210  tapers from the proximal end  211  towards the distal end  212 , as shown in  FIG. 6 . For example, the bone probe  208  may be formed from a single cylindrical piece of medical grade material (e.g., a rod of a metal such as stainless steel, nitinol, or aluminum). The second side  218  may be formed by way of a subtractive manufacturing process, such as grinding, milling, or the like, to thereby remove material from the shaft  210  to form the substantially planar surface of the second side  218 . Furthermore, the probing tip  214  is further formed by way of grinding, milling, or other technique for removing material from the shaft  210  so as to form the hook-like design, as will be described with reference to  FIGS. 7, 8, and 9  in greater detail herein. Accordingly, as shown in  FIG. 5 , the width W 1  at the proximal end  211  is approximately equal to the width W 2  at the distal end  212  and the probing tip  214 . As shown in  FIG. 6 , the thickness T 1  at the proximal end  211  is greater than the thickness T 2  at the distal end  212 , while thickness T 1  is approximately equal to the thickness T 3  at the probing tip  214 . Accordingly, the tapering in thickness of the shaft  210  occurs along the substantially planar second side  218  as a result of the formation of the second side  218  (i.e., machining to remove shaft material and create the substantially planar surface). 
       FIG. 7  is an enlarged side view of the probing tip  214  and  FIGS. 8 and 9  are enlarged perspective views of the probing tip  214 . As shown, the probing tip  214  may generally resemble a hook or the like extending from the distal end  212  of the probe shaft  210  and oriented at an angle relative to the shaft  210 , wherein such angle may be approximately perpendicular to the longitudinal axis of the shaft  210 . However, it should be noted that the probing tip  214  may be oriented at obtuse angle or an acute angle relative to the longitudinal axis of the shaft  210 . The probing tip  214  may include a base portion  220  shaped and configured to contact an interior surface of the hole with little or no resistance and provide tactile feedback of the interior surface to the surgeon. For example, as shown, the base portion  220  may have substantially curved or arcuate edges so as to prevent or minimize the risk that the probing tip  214  would penetrate or otherwise engage of portion of the interior surface of the hole. Rather, the base portion  220  may be shaped so as to glide or easily slide along the interior surface, while still allowing sufficient contact to provide tactile feedback to the surgeon. Accordingly, the base portion  220  may lessen or eliminate tissue irritation that may otherwise occur when a sharper object is used to probe the bone opening. 
     The probing tip  214  further includes a top portion  222  having a substantially planar surface that is oriented at a first angle θ 1  relative to a longitudinal axis A of the shaft  210  and further oriented at a second angle θ 2  relative to a plane  221  along which the base portion  220  is substantially parallel to. In some embodiments, the surface of the top portion  222  may be substantially perpendicular to axis A, and thus the angle θ 1  may be approximately 90 degrees. However, in some embodiments, the surface of the top portion  222  may be oriented at an angle offset relative to axis A. For example, as shown in  FIGS. 7-9 , the angle θ 1  may be acute (i.e., less than 90 degrees). In some embodiments, the angle  74   1  may be between 1 and 89 degrees. In some embodiments, the angle θ 1  may be between 5 and 25 degrees. However, in some embodiments, the angle θ 1  may be obtuse (i.e., greater than 90 degrees). In some embodiments, the angle θ 1  may be between 91 and 179 degrees. In some embodiments, the angle θ 1  may be between 95 and 115 degrees. With reference to second angle θ 2 , in some embodiments, the surface of the top portion  222  may be substantially parallel to the plane  221 , and thus the angle θ 2  is approximately 0 degrees. However, in some embodiments, the surface of the top portion  222  may be oriented at an angle offset relative to plane  221 . For example, as shown in  FIGS. 7-9 , the surface of the top portion  222  may be offset relative to the plane  221  and thus the angle θ 2  may be between approximately 1 and 89 degrees. In some embodiments, the angle θ 2  is may be between approximately 5 and 25 degrees. 
     The probing tip  214  further includes a groove or notch  224  formed adjacent to the distal end  212  of the probe shaft  210 , thereby resulting in less shaft material present at the junction between the probing tip  214  and the distal end  212  of the shaft  210 , which allows for increased deflection of the tip  214  relative to the shaft  210  for improving the purchasing the tip  214  with a portion of the bone, as will be described in greater detail herein. The probing tip  214  further includes an engagement surface  226 , in the form of an edge, defined along the perimeter of the top portion  222 . The engagement surface  226  is shaped and configured to establish purchase with a portion of the bone, specifically a side of the bone immediately adjacent to an opening of the drilled hole through which the probing tip has passed. In particular, as will be described in greater detail herein, upon an operator extending the probing tip  214  entirely through a bicortical drilled hole (i.e., a drilled hole extending entirely from one side of the bone through to the opposing side of the bone), the engagement surface  226  is shaped and configured to establish purchase with a portion of the opposing side of the bone immediately adjacent to the opening of the drilled hole in response to manipulation from the surgeon. The engagement surface  226  may be a substantially abrupt edge of the probing tip  214 , in which the transition between the base portion  220  and the top portion  222  is sudden (e.g., sharp corner or edge). Accordingly, upon sufficient pressure, the engagement surface  226  is configured to pierce or establish purchase with a portion of the opposing side of bone, thereby securing the bone probe shaft  210  in place for subsequent depth measurements. 
     Thus, the probing tip  214  is multifunctional in that the base portion  220  allows for probing of the interior surfaces to provide a surgeon with a “feel” for examination purposes and to further locate the opposing side of the bone and the top portion  222  allows for the surgeon to establish purchase at the desired site (i.e., portion of the opposing side of the bone adjacent to the opening of the drilled hole) so as to stabilize the bone probe in the desired position, at which point, the depth gauge member can be used for measuring the entire depth of the hole. In some embodiments, the engagement surface  226  of the top portion  222  may include surface texturing to enhance friction between the engagement surface  226  and the portion of bone to reduce risk of slippage during bicortical depth measurements. 
     Furthermore, as previously described, the groove  224  present at the junction between the distal end  212  of the probe shaft  210  and the probing tip  214  allows for increased deflection of the tip  214  relative to the shaft  210  for improving the purchasing of the portion of bone adjacent to the hole opening with the tip  214 . For example, upon advancing the probing tip  214  entirely through the hole, the surgeon may then position the substantially planar second side  218  against the interior surface of the drilled hole and then retract (i.e., pull back) the probe shaft  210  such that the top portion  222  of the probing tip  214  comes into contact with a portion of the opposing side of the bone immediately adjacent to the opening of the hole. As the surgeon is pulling the bone probe shaft  210  back towards the hole, the groove  224  will allow for additional flexing of the probing tip  214  relative to the remainder of the probe shaft  210  due to less material at the junction between the shaft  210  and the tip  214  at the groove  224 , which will improve the purchasing or grabbing of the opposing side of the bone with the engagement surface  226  of the top portion  222  of the probing tip. Furthermore, the tapered thickness of the shaft  210 , provided by the substantially planar second side  218 , allows for deflection or bending of the shaft  210  on one axis, such that, if the probing tip  214  is substantially perpendicular to shaft  210 , as generally shown, application of pressure upon the shaft  210  results in deflection of the probing tip  214 , particularly the engagement surface  226 , to become angled upward, thereby enabling a superior purchase or gripping of the outer surface of the opposing side of the bone. 
     It should be noted that the bone probe  208  may also be used for obtaining depths of drilled holes that are not bicortical (i.e., that do not extend entirely through the bone from one side to the other side). For example, the engagement surface  226  may establish purchase with a portion of the interior surface of the hole and associated with a bottom of the hole upon sufficient application of force to the shaft  210  and subsequently the tip  214 . The engagement surface  226  may be a substantially abrupt edge of the probing tip  114 , in which the transition between the base portion  220  and the top portion  222  is sudden (e.g., sharp corner or edge). Accordingly, upon sufficient pressure, the engagement surface  226  is configured to pierce or establish purchase with tissue in the interior of the hole. Accordingly, upon placement of force against the probing tip  214 , such as when a surgeon presses the probing tip  214  against an interior portion of the hole, the groove  224  will allow for additional flexing of the probing tip  214  relative to the remainder of the probe shaft  210  due to less material at the junction between the shaft  210  and the tip  214  at the groove  224 , which will improve the purchasing or grabbing of a surface of the hole via the engagement surface  226 . Furthermore, the tapered thickness of the shaft  210 , provided by the substantially planar second side  218 , allows for deflection or bending of the shaft  210  on one axis, such that, if the probing tip  214  is substantially perpendicular to shaft  210 , as generally shown, application of pressure upon the shaft  210  results in deflection of the probing tip  214 , particularly the engagement surface  226 , to become angled upward, thereby enabling a superior purchase or gripping of the interior surface of the hole. 
       FIGS. 10A and 10B  illustrate an initial process of examining, via the bone probe  108 , a drilled hole  134  in a bone  132 . For example, as previously described herein, the biasing force from the spring assembly  126  may be sufficient so as to maintain the bone probe  108  in the extended position while the surgeon probes an interior surface  136  of the drilled hole  134  and locates the bottom  138  of the hole  134 . However, as shown in  FIG. 10B , the biasing force may be overcome upon a surgeon moving the handle  102  in a direction towards the hole  134  once the desired target site is located, such as locating the bottom  138  of the hole  134 . The surgeon can move the handle  102  until the first end  104  of the handle  102  abuts either the surface of the bone  132  or a surface of a plate or implant  140 , as indicated by arrow  142 , thereby resulting in compression of the spring assembly  126  while maintaining placement of the probing tip  114  at the bottom  138  of the hole  134 , as indicated by arrow  144 . At this point, the depth gauge member  116  can be advanced in a direction towards the hole  134 , such that the hollow shaft  118  slides over the bone probe shaft  110 , wherein the bone probe shaft  110  generally acts as a guide and holding position as a result of the engagement surface of the second portion  130  of the probing tip  114  having established purchase with the bottom  138  of the hole  134 . The depth gauge member  116  can be extended down into the hole  134  until the distal end  120  of the depth gauge member  116  abuts the bottom  138  of the hole  134 . Accordingly, the one or more depth measurement sensors  122  can then generate an electronic signal in relation to a distance between the first end  104  of the handle  102  and the distal end  120  of the depth gauge member  116 , wherein the electronic signal is indicative of the depth of the hole  134  and the thickness of the plate or implant  140 . 
     The device  100  of the present disclosure may include a variety of different sensing devices suitable for determining a length or depth of the drilled hole or bore to be measured. For example, the one or more depth measurement sensors  122  may include, but are not limited to, an electromechanical or electronic sensor, such as a linear encoder, and may employ any one or more of acoustic, ultrasound, capacitive, electric field, inductive, electromagnetic (e.g., Hall effect-type) and optical components for determining relative or absolute distance measurements. In some embodiments, the sensors  122  may be configured to measure, sense, discriminate, or otherwise determine a length or distance between at least the first end  104  of the handle  102  and the distal end  120  of the depth gauge member  116 . 
     For example, in one embodiment, as shown in  FIGS. 10A and 10B , at least a first sensor element  122   a  is positioned proximate to the first end  104  of the handle  102  and a second sensor element  122   b  is positioned on the depth gauge shaft  118  proximate the distal end  120 . The sensor elements  122   a,    122   b  are configured to measure at least one of relative, absolute and incremental movement (e.g., distance, speed, etc.) of the depth gauge shaft  118  with respect to the first end  104  of the handle  102  during a measurement procedure. For example, in one embodiment, the sensor elements  122   a,    122   b  may be used for measure an absolute distance that the depth gauge  116  distal end  120  is moved relative to the fixed reference point such as, for example the first end  104  of the handle  102 . 
     The first sensor element  122   a  may be an active inductive, capacitive or optical element that is in communication with circuitry (e.g., a controller) of a user interface portion of the device (e.g., a GUI display or the like with user inputs). The first sensor element  122   a  may include one or more longitudinally-extending conductors that are wires, cables or traces on a printed circuit board such as, for example, a flex-circuit or the like. Furthermore, the first sensor element  122   a  may further include a plurality of inductive, capacitive or optical elements that may be coupled with and disposed on the longitudinally-extending conductors. The second sensor element  122   b  may be configured on the depth gauge shaft  118  in manner so as to cooperate with the first sensor element  122   a  proximate the first end  104  of the handle  102 . For example, the second sensor element  122   b  may be a generally passive element such as a permanent magnet, optical element (e.g., indicia) or the like that is configured to cooperate, communicate or otherwise interact with the first sensor element  122   a.  For example, during a measurement procedure, movement of the depth gauge  116  out of the device handle  102  results in interaction between the first and second sensor elements  122   a,    122   b.  In particular, as the depth gauge  116  extends from the device handle  102 , the first and second sensor elements  122   a,    122   b  move relative to one another (i.e., second sensor element  122   b  moves past first sensor element  122   a  and, in combination with one another, provide signals (e.g., pulses, etc.) to the circuitry, which processes the signals and displays a distance measurement on a display and/or transmits the signals to separate computing devices. 
     In various embodiments of the present invention, the one or more sensors  122  may be connected with a microprocessor and/or other digital electronic device in order to produce an output for an electronic display, such as a liquid crystal display or light-emitting diode display, and or for wireless/wired transmission of electronic signals, comprising the measurement data, to a wireless compatible computing device. For example, in some embodiments, the microprocessor or other digital electronic device may be connected to a wireless transmitter for wireless transmission of electronic signals. In some embodiments, a signal conditioning circuit may interpose the inductive or capacitive elements of the electronic sensor and the microprocessor or other digital electronic device used to drive the display, thus ensuring that correct input current and voltage levels are provided to the various components. The device may further include a power source, such as a primary or secondary battery, may be connected to the signal conditioning circuit or to the microprocessor directly. 
     It should be noted that the device  100  of the present disclosure may include a variety of different electronic sensor and circuitry assemblies for determining and transmitting depth measurements, including the sensors and systems discussed in U.S. Pat. Nos. 7,165,336; 7,444,756; 7,493,703; 7,607,238; 7,676,943; 7,685,735; 7,730,629; 7,895,762; 7,895,767, the contents of each of which are hereby incorporated by reference in their entirety. 
       FIG. 11  is a side view of the medical device  100  including a strain sensor  146  for sensing strain upon the bone probe shaft  110  as a result of probing the interior surface of a drilled hole. The sensor  146  may include a strain gauge or the like configured to determine a strain of the bone probe shaft  110 , which may be useful for alerting the surgeon of an amount of resistance that the distal probing tip  114  is encountering during probing of the interior of the hole. For example, while a surgeon may be able to “feel” the interior surface and further have a sense of when the probing tip  114  actually makes contact with the bottom of the hole, the strain sensor  146  may further generate an electronic signal based on a sensed strain of the shaft  110  which may then be used to provide an audible and/or visual alert, via a device  148  (i.e., speaker or lights) to the surgeon indicating that the probing tip  116  is in fact positioned at the bottom of the hole. 
     For example, the resistance encountered when the probing tip  116  engages the bottom of the hole may have a certain strain value (i.e., above a certain threshold) which may be different than a resistance encountered with the sidewalls of the hole (which may have a softer, spongier tissue). Accordingly, the audible and/or visual alert may confirm to a surgeon whether they are in fact positioned at the bottom of the hole or if too much pressure is being placed against the interior surface such that they risk possibly inadvertently piercing the interior surface. 
       FIGS. 12A-12F  illustrate a series of steps for performing a procedure of probing a drilled hole and subsequently obtaining a depth measurement using another embodiment of a medical device  300  consistent with the present disclosure. As shown, the device  300  may be similarly configured as device  100  previously described herein. However, as shown in  FIG. 12A , both the bone probe  108  and depth gauge member  116  may both be completely withdrawn into the handle  102  until either a first slider  324  is moved, resulting in corresponding movement of the bone probe  108 , or a second slider  350  is moved, resulting in corresponding movement of the depth gauge member  116 , as shown in  FIG. 12E . 
     In addition to including sliders for allowing independent movement of the bone probe and depth gauge member, the device  300  further includes a locking member  352  for locking a position of at least the bone probe  108 . As shown, the locking member  352  is coupled to the first end  104  of the handle  102  and is associated with at least the bone probe  108  in such as manner so as to allow/prevent movement of the bone probe  108 . For example, the locking member  352  has an unlocked configuration and a locked configuration, wherein, in the unlocked configuration, the locking member  352  allows the bone probe  108  to freely move and, when in the locked configuration, the locking member  352  prevents movement of the bone probe  108 . 
     For example, upon extending the bone probe  108 , a surgeon may then place the locking member  352  in a locked configuration, as shown in  FIG. 12C , in which the locking member  352  is configured to provide sufficient contact with the bone probe shaft  110  so as to prevent, or make difficult, the movement of the bone probe shaft  110  relative to the first end  104  of the handle  102 , thereby providing an amount of rigidity to the probe shaft  110 . Accordingly, a surgeon may now perform examination of a drilled hole without concern of the bone probe  108  withdrawing back into the handle  102  or being loose. 
     Upon locating the base or bottom of the hole, the surgeon may then apply sufficient force upon the bone probe shaft  110  so that the engagement surface of the second portion of the probing tip engages and establishes purchase with the bottom of the hole, or a sidewall immediately adjacent to the bottom, as shown in  FIG. 12D . Upon establishing engagement, the surgeon may then place the locking member  352  in an unlocked configuration, now that the bone probe shaft  110  is in a stabilized in position. The surgeon may then move the handle in a directions towards the bone until the first end of the handle abuts the surface of the bone or the surface of the plate/implant, as shown in  FIG. 12E , at which point, the depth gauge member  116  can be used for measuring the depth of the hole. As shown in  FIG. 12F , the surgeon may then advance the depth gauge member  116  towards hole, via the second slider  350 , such that the distal end  120  of the depth gauge member shaft  118  extends from the first end of the device handle and advances into the hole, sliding over the bone probe  108 . While the bone probe  108  is maintained in engagement with the bottom of the hole via the probing tip, the depth gauge member may be advanced in a direction towards the bottom of the hole until the distal end of the depth gauge member makes contact with the bottom of the hole. The bone probe essentially acts as a guide upon which the depth gauge member slide over when advancing to the bottom of the hole. 
     The sensor is configured to generate an electronic signal based on a distance between the first end of the body and the distal end of the depth gauge member, wherein the electronic signal is indicative of at least a depth of the hole. In particular, the sensor may include inductive or capacitive elements or assemblies configured to sense the location of the distal end of the depth gauge member relative to the first end of the device body, and, as a result, generate an electronic signal representing the distance there between. Accordingly, the sensed distance between the first end of the device handle (when abutting the bone surface) and the distal end of the depth gauge member (when abutting the bottom of the hole) is the depth of the hole. 
     It should be noted that the device may include logic or allow for adjustment to the sensing capabilities so as to program the sensor to account for other variables when sensing the depth of the hole. For example, in some embodiments, certain procedures require fixing a plate or implant to the bone via screws. Accordingly, the screw length must not only be sufficient to fill the hole but also long enough to account for the thickness of a plate or implant through which it passes when engaging the hole. Accordingly, in some embodiments, the sensor may be programmed so as to account for the thickness of the plate or implant and will further include that thickness in the electronic signal produced, such that the electronic signal is indicative of the total depth that a corresponding screw length will need to cover, including the depth of the hole in the bone in addition to the thickness of the plate or implant through which the screw will pass through and the screw head will engage. 
     Furthermore, in some instances, first end of the device handle will be directly abutting a surface of the plate or implant, as shown in  FIG. 12F , which is directly abutting the surface of the bone, when the surgeon is measuring the depth. Thus, in this case, the sensor is still able to sense a distance between the first end of the device handle and the distal end of the depth gauge member, which will provide an overall depth, rather than just a depth of the hole in the bone. 
       FIGS. 13A-13C  illustrate a series of steps for performing a procedure of probing a fully drilled hole (i.e., a hole extending entirely through a bone for receipt of a bicortical bone screw) with the bone probe  208  and further establishing purchase of the probing tip  212  of the bone probe  208  with a side of the bone adjacent to the bicortical drilled hole to secure the bone probe  208  in place and allow the depth gauge member to be used for measuring the depth of the bicortical drilled hole. It should be noted that the bone probe  208  of  FIGS. 4-9  is compatible for use with either of devices  100  and  300  and may be extended and retracted, and otherwise manipulated for subsequent probing and depth measurements, therefrom in a similar manner as bone probe  108  previously described herein. 
     As shown in  FIGS. 13A-13C , the hole is drilled entirely through the bone (i.e., bicortical drill hole), and thus a surgeon will need to not only probe the interior surface of the hole, and possible obtain neuromonitoring data (i.e., determine whether there are any nearby nerves which may be affected by placement of a screw within the hole), but further obtain an accurate measurement of the depth of the entire hole. 
     As shown in  FIG. 13A , a surgeon may first perform examination of the drilled hole with the probing tip  214  by advancing the bone probe  208  into the drilled hole. The surgeon may simply apply slight pressure such that the base portion  220  of the probing tip  214  contacts an interior surface of the hole and, in return, provides tactile feedback of the interior surface to the surgeon. The base portion  220  is shaped so as to glide or easily slide along the interior surface, while still allowing sufficient contact to provide tactile feedback to the surgeon. The surgeon may then advance the probing tip  214  entirely through the hole, at which point, the base portion  220  will cease contact with the interior surface and the surgeon will sense (via tactile feedback) that the end of the hole has been reached (shown in  FIG. 13B ). 
     At this point, upon the surgeon extending the probing tip  214  entirely through a bicortical drilled hole, the surgeon can then establish purchase between the top portion  222  of the probing tip  214  and a portion of an opposing side of bone so as to secure the bone probe shaft  210  in place for subsequent depth measurements with the depth gauge member. For example, as shown in  FIG. 13C , the surgeon may simply position the substantially planar second side  218  against the interior surface of the drilled hole and then retract (i.e., pull back) the probe shaft  210  such that the engagement surface  226  of the top portion  222  of the probing tip  214  comes into contact with a portion of the opposing side of the bone immediately adjacent to the opening of the hole. The engagement surface  226  may be a substantially abrupt edge of the probing tip  214 , in which the transition between the base portion  220  and the top portion  222  is sudden (e.g., sharp corner or edge). Accordingly, as the surgeon is pulling the bone probe shaft  210  back towards the hole, the engagement surface  226  will begin to contact the bone. In some embodiments, the engagement surface  226  may include surface texturing to enhance friction between the engagement surface  226  and the portion of bone to reduce risk of slippage during bicortical depth measurements. Furthermore, groove  224  (present at the junction between the distal end  212  of the probe shaft  210  and the probing tip  214 ) will allow for additional flexing of the probing tip  214  relative to the remainder of the probe shaft  210  due to less material at the junction between the shaft  210  and the tip  214  at the groove  224 , which will improve the purchasing or grabbing of the opposing side of the bone with the engagement surface  226  of the top portion  222  of the probing tip. Furthermore, the tapered thickness of the shaft  210 , provided by the substantially planar second side  218 , allows for deflection or bending of the shaft  210  on one axis, such that, if the probing tip  214  is substantially perpendicular to shaft  210 , as generally shown, application of pressure upon the shaft  210  results in deflection of the probing tip  214 , particularly the engagement surface  226 , to become angled upward, thereby enabling a superior purchase or gripping of the outer surface of the opposing side of the bone. Upon securing the bone probe  208  in place, depth measurements may take place with the depth gauge member in a manner similar to that of bone probe  108  previously described herein. 
       FIG. 14  is another embodiment of a medical device  400  consistent with the present disclosure having a display  454  for providing a digital readout of a depth measurement of the hole based on the electronic signal from the sensor. The display  454  may include a liquid crystal display or an LED display, for example. 
       FIG. 15  is another embodiment of a medical device  500  consistent with the present disclosure configured to wirelessly communicate with and transmit depth measurement data to a wireless computing device  600  over a network, to record, store, and/or visually display measured depths based on electronic signals from the sensor for determining depth of drilled holes. For example, the device  500  may include a wireless transmitter  556  configured to wireless communicate and exchange information, including the electronic signal, with a wireless display or computing device  600  for at least visually providing a depth measurement of the hole based on the electronic signal from the sensor. The separate display or computing device  600  may include, but is not limited to, a monitor or panel display, a PC, a notebook, a tablet computer, a smartphone, or other computing device configured to wirelessly communicate with the wireless transmitter  556 . 
     The network may be any network that carries data. Non-limiting examples of suitable networks that may be used as network include WiFi wireless data communication technology, the internet, private networks, virtual private networks (VPN), public switch telephone networks (PSTN), integrated services digital networks (ISDN), digital subscriber link networks (DSL), various second generation (2G), third generation (3G), fourth generation (4G) cellular-based data communication technologies, Bluetooth radio, Near Field Communication (NFC), the most recently published versions of IEEE 802.11 transmission protocol standards, other networks capable of carrying data, and combinations thereof. 
     Furthermore, in some embodiments, the computing device  600  may include a specific software application that may be directed to maintaining a record of the hole measurements and/or provide an interactive user interface (GUI) in which multiple holes can be mapped to a particular plate or implant and the depth of each hole (including the thickness of the plate or implant) can be included and stored for records. 
       FIGS. 16 and 17  illustrate the compatibility of a medical device of the present disclosure with other medical devices so as to provide additional features, in additional bone probing and depth measurement, such as energy emission ( FIG. 16 ) and sensing capabilities ( FIG. 17 ). For example, in some embodiments, the bone probe shaft  110 ,  210  may include an electrically conductive material (e.g., a metal such as stainless steel, nitinol, or aluminum), wherein a portion of the bone probe shaft  110 ,  210  may be exposed, or otherwise accessible, along a portion of the device handle. In particular, the device handle may include an access region  158  that may be in the form of an aperture, window, or the like, that provides access to an interior of the handle, particularly providing access to an exposed portion of the bone probe shaft. Thus, in some embodiments, an electrical current from a separate device  700 ,  800  may be supplied to the bone probe shaft via the access region  158  (e.g., slide a working tip  702  of an electrocautery device  700  into the access region  158  to make contact with bone probe shaft  110 ,  210 ). Accordingly, as a result of being made from a conductive material, the bone probe shaft  110 ,  210  may carry the electrical current to the distal probe tip, which may then be used to deliver energy to a desired target (e.g., interior surface of hole of the bone) as a result of the electrical current applied thereto. Similarly, a separate nerve sensing/stimulation device  800  (shown in  FIG. 17 ) may be coupled to the conductive bone probe shaft via the access region (i.e., slide a working tip  802  of the device  800  into the access region  158 ), such that the distal probe tip essentially acts as an extension to the nerve sensing/stimulation device and may be used to sense/stimulate nerves within the bone. The separate sensing/nerve stimulation device or system  800  may include, for example, existing capital equipment or a handheld battery-powered neuromonitoring device. 
       FIG. 18  is a perspective view of a medical device  100  having a port  160  provided on the proximal, or second end  106 , of the device body  102 . The port  160  is configured to receive a corresponding input connector from a nerve sensing/nerve stimulation device  800 . The port  160  (hereinafter referred to as “neuromonitoring port  160 ”) is coupled to the bone probe shaft  110 ,  210  and is configured to provide an electrical pathway from the nerve sensing/nerve stimulation device  700  to the bone probe  108 ,  208  upon insertion of the input connector into the neuromonitoring port  160 . As previously described, the bone probe shaft  110 ,  210  may include an electrically conductive material (e.g., a metal such as stainless steel, nitinol, or aluminum) and thus may carry an electrical signal. Thus, in some embodiments, an electrical signal from the nerve sensing/nerve stimulation device  800  may be supplied to the bone probe shaft  110 ,  210  via the neuromonitoring port  160 . Accordingly, as a result of being made from a conductive material, the bone probe shaft  110 ,  210  may carry the electrical signal to the distal probe tip  114 ,  214 , which may then be used to sense/stimulate nerves adjacent or in close proximity to the drilled hole in the bone, either when the bone probe  108 ,  208  is directly placed within the drilled hole or when the bone probe  108 ,  208  is in contact with a screw placed within the drilled hole. 
       FIG. 19  is a side view, partly in section, of the medical device  100  of  FIG. 18  illustrating the configuration of the bone probe shaft  110  for carrying electrical signals to and from the nerve sensing/nerve stimulation device. It should be noted that bone probe shaft  210  is also compatible with the nerve sensing/nerve stimulation device and can function in a similar manner as bone probe shaft  110  described herein. Upon insertion of the electrical connector into the neuromonitoring port  160 , a pathway is provided between the nerve sensing/nerve stimulation device  700  and the bone probe  108 . The bone probe shaft  108  generally includes a soft coil portion  162  configured to allow conduction of an electrical signal provided by the nerve sensing/stimulation device  800  while the shaft  110  moves between fully retracted and fully extended positions and intermediate positions there between, particularly when measuring the depth of the drilled hole  134 . In some embodiments, a portion of the distal end  112  of the bone probe  108 , particularly the exposed portion of the shaft  110  extendable outside of device body  102  may include an insulating material  164 , while the distal probing tip  114  is free of insulating material. 
       FIGS. 20A, 20B, and 20C  illustrate the transmission of a signal from bone probe  108  to a screw positioned within a hole in a vertebra for neuromonitoring capabilities. As shown in  FIG. 20A , upon coupling the nerve sensing/nerve stimulation device  700  to the medical device  100  (e.g., inserting the electrical connector into the neuromonitoring port  160 ), a surgeon can begin a neuromonitoring procedure to determine whether there are any critical neurological structures adjacent to or within an unsafe proximity to the drilled hole and screw. In particular, a surgeon can perform neuromonitoring procedure by placing the bone probe  108  directly within the drilled hole prior to screw placement, in which the distal probing tip  114  can be placed in direct contact with the interior of the hole and transmit the electrical signal from the nerve sensing/nerve stimulation device  800  to the bone tissue and will subsequently receive a response signal to then be carried back to the nerve sensing/nerve stimulation device  700  for processing. In another method, as shown in  FIGS. 20A, 20B, and 20C , the surgeon is performing the neuromonitoring procedure once the screw is already in place (e.g., already fitted within the drilled hole) by placing the distal probing tip  114  in direct contact with the screw, which, in turn, will act as a conduit and carry electrical signals to and from the distal probing tip  114  and the nerve sensing/nerve stimulation device  900 . 
     Accordingly, the medical device consistent with the present disclosure is a three-in-one single use device designed to more accurately and safely measure the screw hole pathway. For example, the probing tip of the bone probe provides a user (e.g., surgeon) with superior tactile feedback to assist the surgeon in confirming a safe pathway within the bone. The electronic measurement/digital sensing is designed to provide more accurate depth measurement for the screw pathway. The neuromonitoring feature is used to stimulate the pathway and/or screw, ensuring the screw is safely positioned away from any critical neurological structures. Overall, the medical device of the present disclosure is a faster, safer, more accurate and user-friendly solution for surgeons when placing bone screws, particularly pedicle screws during spinal fusion surgery, thereby minimizing spine surgery complications and reducing overall healthcare costs. 
       FIG. 21  illustrates an angle guide  900  for use with the medical device of the present disclosure. In some instances, holes may be drilled into bone at an angle. Accordingly, the angle guide may be useful in providing a surgeon with a visual guide as to the correct angle at which to position the device when attempting to examine the hole and further locate the bottom of the hole to carry out the depth measurements. 
       FIG. 22  is a perspective view of another embodiment of a medical device  1000  consistent with the present disclosure.  FIG. 23  is a perspective, exploded view of the medical device  1000 . The device  1000  is configured to provide a faster and more accurate measure of depth. In particular, the device  1000  includes a combination of a bone probe allowing for physical examination of a hole drilled in a bone and a depth gauge member for determining a depth of the hole and providing a digital measurement of the depth. The device  1000  generally includes a handle  1002  which includes a bone probe fixed thereto, a depth gauge cylinder  1004  slidably mounted over a portion of the handle  1002  and configured to slide along a length thereof, and a tip member  1006  releasably coupled to a distal end of the depth gauge cylinder  1004 . As illustrated, the bone probe may generally include the bone probe  208  previously described herein with respect to at least  FIGS. 4-9 . The device  1000  further includes a least a user-operated activation mechanism  1008  (which may be in the form of a button or other actuatable input mechanism) which may activate and deactivate the depth measurement function of the device  1000 , as well as other functions. As illustrated, the device  1000  further includes a display  1010  provided on the handle  1002  configured to visually provide a digital readout of a depth measurement of a hole in bone. 
     As shown, the depth gauge cylinder  1004  includes a hollow body including a lumen in which at least a portion of the handle  1002  and the bone probe  208  are received. In particular, the handle  1002  may generally include an elongate body  1012  extending from a proximal grip portion of the handle  1002 . The depth gauge cylinder  1004  is operable to slide along a longitudinal axis of the handle body  1012  from an initial, default position (most-proximal position relative to the grip portion of the handle  1002 ), as shown in  FIG. 22 , to a most-distal position (relative to the grip portion of the handle  1002 ) and a plurality of positions therebetween. As further illustrated, the depth gauge cylinder  1004  comprises a one-piece, unitary construction. The tip member  1006  further includes a one-piece, unitary construction. Accordingly, the depth gauge cylinder  1004  and tip member  1006  provide a much more rigid and durable design in comparison to currently available depth measurement devices which rely on a two-piece construction. In particular, the one-piece cylindrical body of the depth gauge cylinder and tip member obviates the problem that current devices face, notably the splitting of the two-piece handles when an associated bone probe is pivoted within the hole and applies pressure to the handle. 
     The tip member  1006  is releasably coupled to a distal end of the depth gauge cylinder  1004 , which may include a threaded engagement type coupling (i.e., the tip member  1006  can be screwed onto the distal end of the depth gauge cylinder  1004 ), a snap-fit coupling, a press-fit coupling, or the like. Once coupled to the depth gauge cylinder  1004 , the tip member  1006  is operable to correspondingly slide with the depth gauge cylinder  1004 . The tip member  1006  further includes an opening through which at least the bone probe  208  is received and travels during movement of the tip member  1006  and depth gauge cylinder  1004 . The tip member  1006  further comprises a distal end including a profile corresponding to an opening in a bone plate through which a screw is to be received, as will be described in greater detail herein. In particular, as described in greater detail herein, tip member may be considered universal in that the profile may allow for the tip member  1006  to fit most shapes, sizes, and geometries of screw sockets and bone plate openings with precision and accuracy. It should be noted that the distal end of the depth gauge cylinder  1004  is operable to receive and releasably retain one of a plurality of interchangeable tip members. As such, the tip member may be swappable with any number of tip members, each having a different size, shape, geometry, profile, or the like depending on the specific implant or bone plate to be used. Accordingly, only the tip member need be changed, while the remaining device is sufficient for the intended procedure. 
     The device  1000  further includes a sensor configured to generate an electronic signal indicative of a depth of the hole, wherein the electronic signal varies in relation to distance traveled by the depth gauge cylinder  1004  relative to the handle  1002  and bone probe  208 . In particular, the sensor may include inductive or capacitive elements or assemblies configured to sense the location of a distal end of the depth gauge cylinder  1004 , for example, relative to a specific point along the handle body  1012 , and, as a result, generate an electronic signal representing the distance therebetween as a result of movement (i.e., sliding) of the depth gauge cylinder  1004 . The sensor is in communication with depth gauge electronics and/or circuitry provided on a printed circuit board (PCB) (not shown) which may be provided within the depth gauge cylinder  1004 . For example, the inductive or capacitive elements may include resistive stripes within the depth gauge cylinder  1004 , while a copper brush spring  1016  may be provided along a portion of the handle body  112  (retained in place via a protrusion  114 ). The spring  1016  may provide some form of friction with the depth gauge cylinder  1004 . 
       FIG. 24  is a top view of the medical device  1000  illustrating the depth gauge cylinder  1004  in the initial, default position relative to the handle  1002  and bone probe  208 .  FIG. 25  is a cross-sectional view of the medical device  1000  taken along lines  25 - 25  of  FIG. 24 .  FIG. 26  is a side view of the medical device of  FIG. 22 . As illustrated in at least  FIG. 25 , a dowel pin  1018  may be provided extending through a portion of the depth gauge cylinder  1004  and into engagement with a portion of the handle body  1012  to assist in retaining the depth gauge cylinder  1004  and handle body  1012  to one another (i.e., preventing the depth gauge cylinder  1004  from completely sliding off of the handle body  1012  when moving towards the bone probe tip. 
       FIG. 27  is a perspective view of the medical device  1000  illustrating movement of the depth gauge cylinder  1004  relative to the handle  1002  and bone probe  208 . As will be described in greater detail herein, the sensor is configured to generate an electronic signal based on the distance that the depth gauge cylinder  1004  travels relative to the handle  1002  and bone probe  208 , wherein the electronic signal is indicative of at least a depth of the hole. In particular, the sensor may include inductive or capacitive elements or assemblies configured to sense the location of a distal end of the depth gauge cylinder  1004 , for example, relative to a specific point along the handle body  112 , and, as a result, generate an electronic signal representing the distance therebetween as a result of movement (i.e., sliding) of the depth gauge cylinder  1004 . For example, the depth gauge cylinder may generally slide relative to the handle and bone probe between a most-proximal position and a most-distal position and a plurality of positions therebetween. As such, the depth gauge cylinder may be in the most-proximal position when in the default, initial position when depth measurement has not yet begun and, upon traveling a distance from the initial, default position (i.e., the most-proximal position), the traveled distance is then used to determine the depth of a hole having undergone the depth measurement with the device  1000 , as will be described in greater detail herein. 
       FIG. 28  is a perspective view of another embodiment of the medical device  1000  of  FIG. 22  illustrating the user-operated control mechanism  1008  provided on the handle  1002  as opposed to the depth gauge cylinder  1004 . 
       FIGS. 29A, 29B, and 29C  are enlarged side views of the tip member  1006  illustrating various dimensions of the stepped profile. As previously described, the tip member  1006  includes a distal end including a profile corresponding to an opening in a bone plate through which a screw is to be received. More specifically, the tip member  1006  of the present disclosure is particularly useful in procedures in which a depth measurement is to be obtained with a bone plate in place (i.e., positioned where it would be mounted). As generally understood, it is preferable to countersink a screw when performing a bone implant fixation procedure so as to avoid any potential complications as a result of a screw head extending from a surface of bone or a bone plate. There are known generally geometries of a countersink in a bone plate hole (for receiving the screw), which include at least a mini, small, and large fragment, wherein the mini-frag is the most common. The profile of the distal end of the tip member  1006  comprises a stepped profile including multiple distinct and separate stepped portions, wherein each stepped portion has a different diameter (as illustrated in  FIGS. 29A, 29B , and  29 C) and tapers in diameter from a proximal position on the tip member towards a distal position of the tip member. Each of the separate stepped portions has a respective shape and/or diameter that corresponds to shapes and/or diameter of common countersink sizes provided in bone plates. Accordingly, the tip member  1006  may be considered universal in that the profile may allow for the tip member  1006  to fit most shapes, sizes, and geometries of screw sockets and bone plate openings with precision and accuracy. For example, the diameter at each stepped portion may correspond to a diameter of one of the typical geometries of the countersink (e.g., first diameter corresponds to large frag, second diameter corresponds to small frag, third diameter corresponds to mini-frag, etc.). 
       FIG. 30  is a side view of another embodiment of a medical device  1000   a  including a single body construction and  FIG. 31  is an enlarged side view of the tip member  1006 , illustrating various dimensions of the tip member profile. 
       FIGS. 32 and 33  are perspective views of another medical device  1100  consistent with the present disclosure illustrating custom grip portions on portions thereof. In particular, the medical device  1100  is similar in features as medical device  1000 , thus like features comprise like reference numerals. For example, medical device  1100  includes a handle  1102  which includes a bone probe  208  fixed thereto, a depth gauge cylinder  1104  slidably mounted over a portion of the handle  1102 , specifically a handle body  1112 , and configured to slide along a length thereof, and a tip member  1106  releasably coupled to a distal end of the depth gauge cylinder  1104 . The device  1100  further includes a display  1110  provided on the handle  1102  configured to visually provide a digital readout of a depth measurement of a hole in bone. The device  1100  further includes grip portions  1105   a,    1105   b  provided on the depth gauge cylinder  1104  which may provide improved grip for the operator during a procedure, notably during depth measuring procedures. 
       FIG. 34  is a perspective, exploded view of another embodiment of a medical device  1200  consistent with the present disclosure.  FIG. 35  is a perspective view of the medical device  1200  in an assembled state. The medical device  1100  is similar in features as medical device  1000 , thus like features comprise like reference numerals. For example, medical device  1200  includes a handle  1202  which includes a bone probe  208  fixed thereto, a depth gauge cylinder  1204  slidably mounted over a portion of the handle  1202 , specifically a handle body  1212 , and configured to slide along a length thereof, and a tip member  1206  releasably coupled to a distal end of the depth gauge cylinder  1204 . The tip member  1206  may further include radiopaque and/or echogenic markings, and, as such, may be viewed under various medical imaging procedures, including, but not limited to, fluoroscopy, direct visualization, and ultrasound (e.g., endoscopic ultrasound). For example, as illustrated, the tip member  1206  may include a radiopaque ring  1207  proximate the distal end thereof. 
     The device  1200  further includes a display  1210  provided on the handle  1202  configured to visually provide a digital readout of a depth measurement of a hole in bone. As illustrated, the depth gauge cylinder  1204  may generally slide along a track  1213  or rail assembly defined along the handle body  1212  generally corresponding to a portion  1205  of the depth gauge cylinder  1204 . The depth gauge cylinder  1204  may further include an exterior surface comprising a plurality of grip portions defined thereon. The grip portions may either be protrusions or depressions either formed in the body of the depth gauge member  1204  or comprised of a separate material. 
       FIG. 36  is a top view of the medical device  1200  illustrating the depth gauge cylinder  1204  in a distal-most position relative to the handle  1202  and bone probe  208 .  FIG. 37  is a cross-sectional view of the medical device  1200  taken along lines  37 - 37  of  FIG. 36 .  FIG. 38  is a side view of the medical device  1200 . As illustrated in at least  FIG. 25 , a set screw  1218  may be provided extending through a portion of the depth gauge cylinder  1204  and into engagement with a portion of the handle body  1212  to assist in retaining the depth gauge cylinder  1204  and handle body  1212  to one another (i.e., preventing the depth gauge cylinder  1204  from completely sliding off of the handle body  1212  when moving towards the bone probe tip. 
       FIG. 39  is a perspective view of another embodiment of a medical device  1300  consistent with the present disclosure.  FIG. 40  is a perspective, exploded view of the medical device  1300 . While medical device  1300  may share some similar in features as medical device  1000 , the medical device  1300  is generally arranged in a different manner than those medical devices  1000 ,  1100 , and  1200  previously described herein. For example, as shown, medical device  1300  includes a portion of a handle  1302  which includes a bone probe  208  fixed thereto, a depth gauge cylinder  1304 , which generally forms most of the device  1300 , slidably mounted over a portion of the handle  1302 , specifically a handle body, and configured to slide along a length thereof, and a tip member  1306  releasably coupled to a distal end of the depth gauge cylinder  1304 . The tip member  1306  may further include a radiopaque ring  1307  on a distal end. 
     The device  1300  further includes a display  1314  provided on the depth gauge cylinder  1304  configured to visually provide a digital readout of a depth measurement of a hole in bone. As illustrated, the depth gauge cylinder  1304  includes an elongate, hollow body which forms a majority of the device  1300 , the portion of the handle  1302  is positioned along an underside of the depth gauge cylinder  1304 . The device  1300  further includes a retaining cap  1308  for covering an open proximal end of the depth gauge cylinder  1304 . The depth gauge cylinder  1304  further includes a repositionable thumb rest  1310  along a topside of the depth gauge cylinder  1304 . The thumb rest  1310  may be repositioned at various positions along a length of the depth gauge cylinder  1304  via retaining tabs  1312 . 
       FIG. 41  is a top view of the medical device  1300  illustrating the depth gauge cylinder  1304  in the initial, default position relative to the handle  1302  and bone probe  208 .  FIG. 42  is a cross-sectional view of the medical device taken along lines  42 - 42  of  FIG. 41 .  FIG. 43  is a side view of the medical device  1300 . 
       FIGS. 44A-44E  illustrate a series of steps for performing a procedure of probing a fully drilled hole (i.e., a hole extending entirely through a bone for receipt of a bicortical bone screw) with a bone probe (similar to the bone probe of  FIG. 4 ) and further establishing purchase of the probing tip of the bone probe with a side of the bone adjacent to the bicortical drilled hole to secure the bone probe in place and subsequently obtaining a depth measurement using one embodiment of a medical device, such as medical device  1000 , consistent with the present disclosure. 
     As shown, the hole is drilled entirely through the bone (i.e., bicortical drill hole), and thus a surgeon will need to not only probe the interior surface of the hole, but further obtain an accurate measurement of the depth of the entire hole. Furthermore, a bone plate is positioned upon the bone which will require a tool to determine hole depth while accounting for a thickness of the bone plate. 
     As shown in  FIG. 44A , a surgeon may first perform examination of the drilled hole with the probing tip  214  by advancing the bone probe  208  into the drilled hole. The surgeon may simply apply slight pressure such that a base portion of the probing tip contacts an interior surface of the hole and, in return, provides tactile feedback of the interior surface to the surgeon. The base portion is shaped so as to glide or easily slide along the interior surface, while still allowing sufficient contact to provide tactile feedback to the surgeon. The surgeon may then advance the probing tip  214  entirely through the hole, at which point, the base portion will cease contact with the interior surface and the surgeon will sense (via tactile feedback) that the end of the hole has been reached (shown in  FIG. 44B ). 
     At this point, upon the surgeon extending the probing tip  214  entirely through a bicortical drilled hole, the surgeon can then establish purchase between the top portion of the probing tip  214  and a portion of an opposing side of bone so as to secure the bone probe shaft  210  in place for subsequent depth measurements with the depth gauge cylinder  1004  and tip member  1006 . For example, as shown in  FIG. 44C , the surgeon may simply position the substantially planar second side of the bone probe tip against the interior surface of the drilled hole and then retract (i.e., pull back) the probe shaft  210  such that the engagement surface of the top portion of the probing tip  214  comes into contact with a portion of the opposing side of the bone immediately adjacent to the opening of the hole. The engagement surface may be a substantially abrupt edge of the probing tip  214 , in which the transition between the base portion and the top portion is sudden (e.g., sharp corner or edge). Accordingly, as the surgeon is pulling the bone probe shaft  210  back towards the hole, the engagement surface will begin to contact the bone. Upon securing the bone probe  208  in place, depth measurements may take place with the depth gauge cylinder  1004  and tip member  1006 . 
     For example, with reference to medical device  1000 , the bone probe  208  is generally fixed to the handle  1002  of the device  1000 . The handle  1002  may include, for example, a proximal end including a grip portion to provide a surgeon with a means for applying a pulling force so as to draw the engagement surface of the probing tip of the bone probe into engagement with an exterior surface of bone immediately adjacent to a bicortical hole in the bone. 
     Accordingly, upon establishing purchase with an exterior surface of bone generally providing an edge of the exit point of the drilled (or otherwise pierced hole) via the probing tip, a surgeon need only continue pulling back on the handle to thereby maintain engagement of the bone probe with the exterior surface of bone and then slide the depth gauge cylinder  1004  in a direction towards the bone, as illustrated in  FIG. 44D . 
     As illustrated in  FIG. 44E , upon sliding the depth gauge cylinder  1004  towards the bone, at least a portion of the tip member  1006  will pass through an opening in the bone plate corresponding to the drilled hole until a portion of the stepped profile of the tip member  1006  makes contact with and engages a countersink portion of the opening in the bone plate. When the tip member  1006  is correctly positioned in the countersink of the bone plate, the most distal edge of the tip member  1006  will be aligned along the same plane as the bone-facing surface of the bone plate. For example, as previously described, the tip member  1006  includes a distal end including a profile corresponding to an opening in a bone plate through which a screw is to be received. More specifically, the tip member  1006  of the present disclosure is particularly useful in procedures in which a depth measurement is to be obtained with a bone plate in place (i.e., positioned where it would be mounted). As generally understood, it is preferable to countersink a screw when performing a bone implant fixation procedure so as to avoid any potential complications as a result of a screw head extending from a surface of bone or a bone plate. There are known generally geometries of a countersink in a bone plate hole (for receiving the screw), which include at least a mini, small, and large fragment, wherein the mini-frag is the most common. The profile of the distal end of the tip member  1006  comprises a stepped profile including multiple distinct and separate stepped portions, wherein each stepped portion has a different diameter (as illustrated in  FIGS. 29A, 29B, and 29C ) and tapers in diameter from a proximal position on the tip member towards a distal position of the tip member. Each of the separate stepped portions has a respective shape and/or diameter that corresponds to shapes and/or diameter of common countersink sizes provided in bone plates. Accordingly, the tip member  1006  may be considered universal in that the profile may allow for the tip member  1006  to fit most shapes, sizes, and geometries of screw sockets and bone plate openings with precision and accuracy. For example, the diameter at each stepped portion may correspond to a diameter of one of the typical geometries of the countersink (e.g., first diameter corresponds to large frag, second diameter corresponds to small frag, third diameter corresponds to mini-frag, etc.). 
     The sensor is then configured to generate an electronic signal based on the distance that the depth gauge cylinder  1004  traveled relative to the handle and bone probe, wherein the electronic signal is indicative of at least a depth of the hole. In particular, the sensor may include inductive or capacitive elements or assemblies configured to sense the location of a distal end of the depth gauge cylinder, for example, relative to a specific point along the handle, and, as a result, generate an electronic signal representing the distance there between as a result of movement (i.e., sliding) of the depth gauge cylinder. For example, the depth gauge cylinder may generally slide relative to the handle and bone probe between a most-proximal position and a most-distal position and a plurality of positions therebetween. As such, the depth gauge cylinder may be in the most-proximal position when in the default, initial position when depth measurement has not yet begun. Upon establishing engagement between the bone probe tip and the bone, the depth gauge cylinder may then be advanced in a direction towards the bone from the default, initial position until the tip member, specifically the stepped profile, makes contact with a countersink in the bone plate opening. The sensed distance traveled by the depth gauge cylinder is then used to calculate the depth of the hole. In particular, the device may include logic for determining hole depth based on known variables. For example, the length of the bone probe shaft extending from the distal end of the tip member when the depth gauge cylinder is in the initial, default position (i.e., the most-proximal position relative to the handle) may be known and programmed into the logic. As such, the sensed distance traveled by the depth gauge cylinder from the initial, default position until the tip member, specifically the stepped profile, makes contact with a countersink in the bone plate opening, may simply be subtracted from the known length of the bone probe shaft to thereby provide the depth of the hole. 
       FIGS. 45 and 46  are perspective views of another embodiment of a medical device  4500  consistent with this disclosure. The medical device  4500  includes a handle  4510  with a bone probe  208 . The medical device  4500  further includes a depth gauge cylinder  4520  slidably mounted over a portion of the handle  4510 , and in particular, slidably mounted over a handle body  4530  shaped to be received by the depth gauge cylinder  4520 . The depth gauge cylinder  4520  is configured to slide along a length of the handle body  4530  between a most-proximal position (depicted by  FIG. 45 ) and a most distal position (depicted by  FIG. 46 ) and a plurality of positions therebetween. At the most-proximal position, the bone probe  208  is maximally exposed and a proximal end of the depth gauge cylinder  4520  abuts a portion of the handle comprising a display. When the depth gauge cylinder  4520  is slid to the most-distal position, the bone probe  208 , is minimally exposed, if at all, and an interlocking assembly (discussed below) of the depth gauge cylinder  4520  and handle  4510  are engaged with one another to prevent the depth gauge cylinder  4520  from sliding off of the handle body  4530 , the interlocking assembly thereby establishing the most-distal position. 
     In certain embodiments the medical device comprises a handle body  4530  that is substantially cylindrical. The handle body  4530  may comprise a rigid material, such as a plastic, and may be shaped to be received by a depth gauge cylinder  4520 , providing a surface onto which the depth gauge cylinder  4520  may slide. As discussed below, the cylindrical handle body  4530  is further configured to prevent a user&#39;s hands or fingers from contacting a sensor, which is at least partially enclosed within the handle body  4530 , during operation. 
       FIG. 47  is an exploded view of the medical device  4500  shown in  FIGS. 45 and 46 . The medical device  4500  comprises a handle  4510  with a two-piece construction. The two piece construction of the handle  4510  comprising of a first body member  4000  coupled to a second body member  4010 , wherein the first body member  4000  defines approximately a first half of the handle  4510  and the second body member  4010  defines a corresponding second half of the handle  4510  relative to a median plane bisecting the medical device  4500  along a longitudinal axis thereof. The first and second body member  4000 ,  4010 , may be coupled together by tabs or projections, such as press-fit or snap-fit tabs, or other similar fasteners. 
     At least partially enclosed by the first and second body members  4000 ,  4010  is a sensor  4020 . The sensor  4020  configured to determine a position of the depth gauge cylinder  4520 , along a length of the handle body  4530  during operation. The position of the depth gauge cylinder  4520  is determined by the sensor  4020  at least partially based on a point of contact made by a member  4030  protruding from an interior surface of the depth gauge cylinder  4520 , wherein the member  4030  is biased to exert a pressure onto the sensor  4020 . For example, when the depth gauge cylinder  4520  is at a most post-proximal position along the handle body  4530 , the point of contact made by the member  4030  is at a proximal position on the sensor  4020 . When the depth gauge cylinder  4520  is slid to a most-distal position, the point of contact made by the member  4030  is at a distal position of the sensor  4020 , etc., such that the sensor  4020  is configured to detect each position of the depth gauge cylinder  4520  along the handle body  4530 , between and including the most-proximal position and most-distal position. The member  4030  may be fastened, molded, or fixed, to the interior surface of the depth gauge cylinder  4520 . The member may, for example, comprise a projection or tab, for example, a tab in the shape of a wiper arm, or may comprise one of a ball and spring plunger, a ball detent, or other similar mechanical arrangement. 
     The sensor  4020  comprises a pressure sensitive strip  4100 , which is sensitive to contact by the member  4030  based on an applied force or pressure. The sensor  4020  generates a signal as a function of the location of contact based on where the force and/or pressure is applied along the pressure sensitive strip  4100 . The sensor  4020  may, for example, comprise a pressure sensitive strip like the one sold under Trade Names Tescan Inc., or SpectraSensor. The pressure sensitive strip  4100  may comprise a width between approximately 2 mm-7 mm. The pressure sensitive strip  4100  may comprise a length between approximately 25 mm-100 mm. The pressure sensitive strip  4100  may be configured to detect a force within a range of about 0.05N-5N. 
     The sensor  4020  may be operably coupled to a printed circuit board (PCB) comprising a processor  4040  and/or other digital electronic devices that function to produce an output for an electronic display  4050 , such as a liquid crystal display. The output relating to a measure of a depth of a hole drilled into a bone as described above. The measurement is determined by a distance traveled by the depth gauge cylinder  4520  relative to the handle  4510 . More particularly, the measurement may be based, at least in part, on a comparison between at least a first location of contact between the member  4030  and the pressure sensitive strip  4100  (also referred to herein as “first contact location”) and a second location of contact between the member  4030  and the pressure sensitive strip  4100  (also referred to herein as “second contact location”), wherein the distance between the two contact locations is indicative of the depth of the hole in the bone. 
     The medical device  4500  further comprises a bone probe and distal tip member. The bone probe and distal tip member may be substantially similar to bone probes and distal tip members previously described herein. As such, like parts have like reference numerals (i.e., bone probe  208  and distal tip member  1006 ). In some embodiments the distal tip member  1006  is a universal tip, comprising a stepped profile to fit with a variety of shapes, sizes, and geometries of bone plate openings. The tip member  1106  may be releasably coupled to a distal end of the depth gauge cylinder  4520 . 
       FIG. 48  is a bottom view of the sensor  4020  depicted in  FIG. 47 , illustrating a pressure sensitive strip  4100 . In particular,  FIG. 48  shows a pressure sensitive strip  4100 , extending along a length of the sensor  4020  within the handle body  4530 . The sensor  4020  may be shaped to fit, and be retained by, a body member of the handle  4510 . For instance, the a body member of the handle  4510  may comprise tabs, projections, or fasteners, e.g., snap-fit tabs, which secure the sensor  4020  and accompanying electronics to the first body member  4000 . 
       FIG. 49  is a perspective view of a bottom handle portion of the medical device  4500 . The second body member  4010  includes a channel running a length of the handle body  4530 . The channel  4900  allows for the member  4030  that is protruding from an interior surface of the depth gauge cylinder  4520 , slidably mounted over the handle body  4530 , to contact the pressure sensitive strip  4100 . This configuration is beneficial because it allows the member  4030  and pressure sensitive strip  4100  to remain in operable communication with each other, while also preventing a user&#39;s hands or fingers from contacting the pressure sensitive strip  4100 , which would interfere with its measurement. 
       FIGS. 50 and 51  are cross-sectional views of the medical device  4500  illustrating the depth gauge cylinder  4520  in different positions relative to the handle  4510 . In particular,  FIG. 50  shows the depth gauge cylinder  4520  in a most-proximal position relative to the handle  4510 . In the most proximal position, the member  4030  contacts a proximal location of the pressure sensitive strip  4100 . The member  4030  may comprise a projection or tab, in the shape of a wiper arm, and biased to exert a pressure or force on the pressure sensitive strip  4100 .  FIG. 51  shows a cross-sectional view of a medical device  4500 , depicting the depth gauge cylinder  4520  in a most-distal position. In the most-distal position, the member  4030  contacts a distal location on the pressure sensitive strip  4100 . 
       FIG. 52  is an enlarged cross-sectional view of a portion of the depth gauge cylinder  4520  and handle  4510 , illustrating one embodiment of a member associated with the depth gauge cylinder  4520  with the pressure sensitive strip  4100 , consistent with the present disclosure. In particular,  FIG. 52  shows the member  4030  fastened to an interior surface  4080  of the depth gauge cylinder  4520 . The member  4030  is shown in the shape of a wiper arm, biased towards, and exerting a pressure onto, the pressure sensitive strip  4100 , according to one embodiment of this disclosure.  FIG. 53  is an enlarged a cross-sectional view of a portion of the handle  4510 , illustrating another embodiment of a member  4030  associated with the depth gauge cylinder  4520  engaging with the pressure sensitive strip  4100  consistent with the present disclosure. In particular,  FIG. 53  shows a member  4030 , wherein the member  4030  and depth gauge cylinder  4520  are a single piece of material, i.e., the member  4030  is formed from, or a part of, the depth gauge cylinder  4520 , and protrudes therefrom. 
       FIGS. 54 and 55  are enlarged cross-sectional views of a portion of the depth gauge cylinder  4520  and handle  4510  coupled to one another, illustrating an interlocking assembly  5300  for retaining the depth gauge cylinder  4520  and handle  4510  to one another in which the interlocking assembly  5300  transitions between at least a first configuration ( FIG. 54 ) and a second configuration ( FIG. 55 ). The interlocking assembly  5300  comprises a portion of the depth gauge cylinder  4520  and handle body  4530 , wherein the handle body  4530  comprises at least a first and second set of projections or tabs  5000 ,  5010 , and the depth gauge cylinder  4530  comprises a corresponding projection or tab  5050 , opposing in direction to the first and second set of tabs  5000 ,  5010 , of the handle body  4530 . Each of the first and second set of tabs  5000 ,  5010 , configured to engage with the corresponding tabs  5050  of the depth gauge cylinder  4520 , and when engaged, inhibit movement of the depth gauge cylinder  4520 . In particular, the first set of tabs  5000  are configured to retain the depth gauge cylinder  4520  in a position wherein the member  4030  of the depth gauge cylinder  4520  is not in contact with the pressure sensitive strip  4100 . This configuration is beneficial when shipping the medical device  4500 , because by keeping the member  4030  out of contact with the pressure sensitive strip  4100 , it reduces wear and tear, and reduces the risk of the member  4030  damaging the sensor during transportation when the device is prone to being bumped or dropped.  FIG. 55  shows a cross-sectional view of the interlocking assembly  5300  in the second configuration, wherein the second set of tabs  5010 , which is proximal to the first set of tabs  5000 , is engaged with the corresponding tabs  5050  of the depth gauge cylinder  4520 . In this configuration, the interlocking assembly  5300  is configured to prevent the depth gauge cylinder  4520  from sliding off of the handle  4510  of the medical device  4500 , when the depth gauge cylinder is slid distally over the handle body  4530 . 
       FIG. 56  is an exploded view of the medical device  4500  illustrating another embodiment of a member  4030  associated with the depth gauge cylinder  4520  engaging with the pressure sensitive strip  4100  consistent with the present disclosure. The medical device  4500  includes a handle  4510  with a two-piece construction, as discussed above, wherein a first body member  4000  is coupled to a second body member  4010 . The first body member  4000  defining approximately a first half of the handle  4510  and the second body member  4010  defining a corresponding second half of the handle  4510  relative to a median plane bisecting the medical device  4500  along a longitudinal axis. The first and second body member  4000 ,  4010 , may be coupled together by one of projections, tabs, such as snap-fit tabs, or other similar fasteners. 
     The first and second body members  4000 ,  4010 , may be coupled around a sensor  4020 , partially enclosing the sensor  4020  within the handle  4510 . The sensor  4020  configured to determine a position of the depth gauge cylinder  4520 , along a length of the handle body  4530  during operation. The position of the depth gauge cylinder  4520  may be determined by the sensor  4020  at least partially based on a location of contact made by a member  4600  protruding through a surface of the depth gauge cylinder  4520 . In particular, the member  4600  is configured to attach to the depth gauge cylinder  4520  by way of a chamber  5500 . The chamber  5500  may protrude through a surface of, and be substantially perpendicular to, the depth gauge cylinder  4520 . The chamber  5500  is configured to maintain a connection between the member  4600  and the depth gauge cylinder  4520 , while also facilitating an association between the member  4600  and the pressure sensitive strip  4100  of the sensor  4020 . The member  4600  may comprise a ball and spring plunger (shown in  FIGS. 56 &amp; 57 ), or a similar mechanical arrangement used to hold a moving part in a temporarily fixed position relative to another moving part. 
       FIG. 58  is a side perspective view of a tip member  1006  consistent with the present disclosure. The tip member is a universal tip  1006 , shaped to fit a variety of bone plates. The profile of the universal tip  1006  comprises a stepped profile including at least two or more distinct and separate stepped portions  5700 , wherein each stepped portion comprises a different diameter. The diameters of at least two or more stepped portions decrease from a most proximal stepped portion to a most distal stepped portion. In some embodiments the regions between the stepped portions may comprise a sloped portion  5710  for a more precise and accurate fit into a bone plate.  FIG. 59  is a cross-sectional view of the tip member  1006  taken along lines A-A of  FIG. 58 .  FIG. 59  depicts the relative diameters of the stepped portions  5700  according to an embodiment of the present disclosure. 
     Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. 
     The terms and expressions which have been employed herein are used as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding any equivalents of the features shown and described (or portions thereof), and it is recognized that various modifications are possible within the scope of the claims. Accordingly, the claims are intended to cover all such equivalents.