Abstract:
The tool is an instrument including a:filament which is brought into contact with an individual to test sensory perception of the individual. When the filament resiliently buckles a standard force is applied to the individual. The filament is retractable within a housing. The filament is mounted upon a shuttle which moves relative to the housing to position the filament either in a stored position within an interior chamber of the housing or in a deployed position outside of the housing. The filament both translates and rotates to move from the stored position to the deployed position. The instrument is configured to securely hold the filament in both the stored position, where the filament is kept safe when not in use, and a deployed position, where the filament is held firm during use of the filament for sensory perception testing.

Description:
FIELD OF THE INVENTION 
       [0001]    The following invention relates to medical instruments used in evaluating the health of nerves in or near the skin. More particularly, this invention relates to neurosensory evaluation tools which utilize a filament which buckles when a predetermined force is applied so that the tool can apply a repeatable standard force (and pressure) to the skin of an individual undergoing evaluation. 
       BACKGROUND OF THE INVENTION 
       [0002]    Some medical conditions have as a symptom or detrimental effect loss or reduction of tactile sensitivity of the skin of the individual. Often such medical conditions result in loss of tactile sensory perception over a period of time rather than abrupt loss of touch sensitivity. Thus, it is beneficial to have instruments which can measure the tactile sensitivity of the individual with sufficient accuracy to be able to track the tactile sensitivity of the individual over time and compare tactile sensitivity of the individual to other individuals exhibiting the same or related conditions. 
         [0003]    One general category of tactile sensory instrument known in the art is an elongate monofilament or similar resilient elongate flexible structure which can be forced axially against the skin of the individual until the filament buckles. The filament is designed to always apply substantially the same force before the filament buckles. The filament is sufficiently elastic that when the load is removed the filament returns to its original orientation. The filament is of a type which provides a maximum force before buckling. Thus, if the user of the instrument applies the filament against the skin with too much force, it will still buckle when this maximum force is exerted on the instrument, so that the instrument never applies a force greater than this threshold force to the skin of the individual. 
         [0004]    If the individual can feel this force (also quantifiable in terms of pressure) such tactile sensitivity can be noted in the individual&#39;s file. Various different body parts, and particularly extremities of the individual can be tested in this way and records gathered. Different testing instruments having different filaments with different threshold forces before buckling can be utilized to determine the point at which the individual no longer has sufficient tactile sensitivity to feel the loads applied by the device. 
         [0005]    Examples of such prior art systems include U.S. Pat. Nos. 3,662,744 and 5,492,132. Prior art filament based tactile sensory perception monitoring tools benefit from having the filament be protected in some way when not in use. The filament can become damaged when merely placed in a pocket of a user or otherwise left exposed. Once the filament has been damaged it is no longer applying the proper force before buckling and so can lead to poor data being collected. Prior art filament based tactile sensory instruments have been provided by the inventor to provide such filament protection as well as systems for controlling an amount that the filament extends from a housing for application of a variable force (or pressure). Examples of such devices include U.S. Pat. Nos. 5,823,969, 6,196,976 and 6,234,977. While such retractable tactile sensory instruments have addressed the problem of protecting the monofilament to some extent, the filament remains in a position where it can catch on a shirt pocket or other holder when being stored because the filament is only re-positioned through a pivoting motion partially out of danger of potential contact and damage to the filament. 
         [0006]    The problem of filament damage cannot be overemphasized. Often the filament can be bent or otherwise damaged in a manner which is substantially imperceptible visually or in use of the instrument. Thus, the instrument appears to be completely functional and accurately calibrated to apply the expected force. In reality, such an instrument that has been slightly damaged can be applying an improper lower or higher force (most typically lower), leading to improper diagnosis. Accordingly, a need exists for a tactile sensory evaluation instrument which has a filament that can be retracted in a manner which provides a high reliability that the filament will remain protected while retracted. 
       SUMMARY OF THE INVENTION 
       [0007]    With this invention a retractable neurosensory evaluation tool is provided which is fully retractable so that the filament of the instrument is fully protected from inadvertent contact when in its retracted position. The instrument includes a housing which has an exterior which can be readily gripped by a user. An interior chamber is provided within the housing which contains a testing filament that can be stored therein when in a retracted position. A guide is provided within this interior chamber which has an elongate form. The filament is coupled to a body and the body includes a slide which slides along the guide from a stored position to a deployed position. Once the body is at the deployed position, the body can rotate to pivot the filament out of the interior chamber and into a position perpendicular to the long axis of the housing for use. 
         [0008]    The rotation can occur by providing the guide with a curve near one end thereof or by configuring the body to both slide within the guide and pivot within the guide. In either embodiment the filament rotates from a stored position aligned within the interior chamber of the housing to a deployed position where it is pivoted (preferably to perpendicular to the housing) to position the filament where it can be effectively utilized. 
       OBJECTS OF THE INVENTION 
       [0009]    Accordingly, a primary object of the present invention is to provide a tool for neurosensory evaluation involving bringing a filament of the tool into contact with skin of an individual. 
         [0010]    Another object of the present invention is to provide an instrument which can provide an indication of the level of tactile sensitivity of the individual. 
         [0011]    Another object of the present invention is to provide a tactile sensory instrument which is easy to use. 
         [0012]    Another object of the present invention is to provide a tactile sensory instrument which has a filament which buckles when a threshold force is applied along a long axis of the filament and which filament is retracted for protection when the instrument is not in use. 
         [0013]    Another object of the present invention is to provide a tactile sensory instrument which has a filament which is both translated linearly and rotated relative to a housing to move the filament from a stored position to a deployed position. 
         [0014]    Another object of the present invention is to provide a neurosensory evaluation instrument which applies a uniform consistent force with repeated use. 
         [0015]    Another object of the present invention is to provide a neurosensory evaluation instrument which avoids damage when stored or otherwise not in use to minimize the potential for damage to the instrument. 
         [0016]    Other further objects of the present invention will become apparent from a careful reading of the included drawing figures, the claims and detailed description of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIGS. 1-4  are perspective views of the instrument of this invention following sequential steps in transition of a filament of the instrument from a stored position ( FIG. 1 ) to a deployed position ( FIG. 4 ). 
           [0018]      FIG. 5  is a perspective view of a shuttle portion of the instrument shown alone. 
           [0019]      FIG. 6  is a side elevation view of the shuttle shown in  FIG. 5 . 
           [0020]      FIG. 7  is a top plan full sectional view of the shuttle shown in  FIG. 5 , taken along lines  7 - 7  of  FIG. 6 . 
           [0021]      FIG. 8  is a side elevation sectional view of a portion of that which is shown in  FIG. 1  to illustrate the shuttle and associated filament in a stored position within the housing. 
           [0022]      FIG. 9  is a side elevation sectional view of a portion of that which is shown in  FIG. 2 , showing the filament translated to a deployed position but before rotation thereof. 
           [0023]      FIG. 10  is a side elevation sectional view of a portion of that which is shown in  FIG. 3  and with the filament undergoing rotation toward a final deployed position. 
           [0024]      FIG. 11  is a side elevation sectional view of a portion of that which is shown in  FIG. 4  after full deployment and rotation of the filament thereof. The filament is shown both before and after (in broken lines) coming into contact with a finger of an individual and illustrating how the filament buckles when a threshold force is applied. 
           [0025]      FIGS. 12-15  are perspective views of an alternative instrument of that which is shown in  FIGS. 1-11  and illustrating the sequential steps in transition of the filament from a stored position ( FIG. 12 ) to a fully deployed position ( FIG. 15 ). 
           [0026]      FIG. 16  is a perspective view of a shuttle portion of the instrument of  FIGS. 12-15  including the body and filament separate from the housing. 
           [0027]      FIG. 17  is a side elevation view of that which is shown in  FIG. 16 . 
           [0028]      FIG. 18  is a top plan sectional view taken along line  18 - 18  of  FIG. 17 , illustrating further details of the shuttle in the embodiment of  FIGS. 12-15 . 
           [0029]      FIGS. 19-22  are side elevation full sectional views of portions of that which is shown in  FIGS. 12-15  and illustrating interior details of the shuttle including the body and the filament during transition of the instrument from having the filament in a stored position to having the filament in a fully deployed position. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0030]    Referring to the drawings, wherein like reference numerals represent like parts throughout the various drawing figures, reference numeral  10  is directed to an instrument ( FIGS. 1-4 ) for use in neurosensory evaluation. The instrument  10  has a filament  60  which buckles ( FIG. 11 ) when a threshold force is applied axially thereto. This threshold force is substantially constant so that a consistent force is applied to an individual, such as to a finger F ( FIG. 11 ) so that useful evaluation of tactile sensory perception of an individual can be provided. The filament  60  is retractable from a stored position inside an interior chamber  25  of a housing  20  to a deployed position both translating linearly out of the housing  20  and pivoting relative to the housing  20 . When the filament  60  is in the retracted position within the interior chamber  25 , the filament  60  is protected from damage. 
         [0031]    In essence, and with particular reference to  FIGS. 5-9 , basic details of the instrument  10  are described according to a preferred embodiment. The instrument  10  generally includes two parts including a housing  20  (see also  FIGS. 1-4 ) and a shuttle  40 . The shuttle  40  moves relative to the housing  20  (arrows A and B of  FIG. 9 ) to move the filament  60  from its stored position within the interior chamber  25  to its deployed position outside of the interior chamber  25 . 
         [0032]    The housing  20  includes tracks  30  within the interior chamber  25  which extend longitudinally along a long axis of the housing  20 . The shuttle  40  includes a slide  45  which translates within the tracks  30 . The shuttle  40  includes a body  50  coupled to the slide  45 . The body  50  has at least a portion thereof which extends out of the interior chamber  25  so that a finger of the user or other structure can act on the body  50  to move the shuttle  40  and associated slide  45  along the tracks  30  within the interior chamber  25  of the housing  20 . 
         [0033]    The filament  60  is coupled to the body  50 . The slide  45  is configured to allow rotation within the tracks  30 . Thus, the shuttle  40  can both translate linearly along the tracks  30  and can also pivot about the slide  45  to rotate the filament  60  (about arrow B of  FIG. 10 ) from a first position aligned with the long axis of the housing  20  to a second position preferably substantially perpendicular to the long axis of the housing  20 . 
         [0034]    An alternative embodiment instrument  110  is shown in  FIGS. 12-22 . The instrument  110  is similar to the preferred embodiment of  FIGS. 1-11  except that tracks  130  rotate about a curve at one end thereof. A slide  145  is configured to rotate about this curve following the tracks  130 , rather than pivoting about a single point. 
         [0035]    More specifically, and with particular reference to  FIGS. 1-4  and  8 - 11 , particular details of the housing  20  are described according to the first embodiment instrument  10 . The housing  20  is preferably an elongate rigid construct. The housing  20  can be formed from two separate halves that are then bonded together. Such forming can be by injection molding of a plastic (e.g. polyethylene) or other material. As an alternative, the housing  20  could be formed as a unitary mass of material. The housing  20  is preferably lightweight and substantially rigid in form. The housing  20  preferably has an elongate form similar to that of a pencil to allow it to be firmly grasped by fingers of a user. Such a size also allows for convenient storage and transport within a pocket, such as a shirt pocket of the user, when not in use. To this end, an exterior of the housing  20  preferably is substantially cylindrical in form and with optional continuous and surface details to allow for a solid finger grip of the housing  20 . 
         [0036]    The housing  20  includes a proximal end  22  and a distal end  24 . The filament  60  is configured so that it is preferably retracted and deployed at the distal end  24  with the proximal end  22  being that end closest to the area on the housing  20  typically grasped by the user. The interior chamber  25  resides within the housing  20  between the proximal end  22  and the distal end  24 . Most preferably, at least portions of the interior chamber  25  extend to the distal end  24 . 
         [0037]    The interior chamber  25  is accessed through both a front slot  26  and a rear slot  28 . The front slot  26  allows the filament  60  to pivot out of the interior chamber  25  when being transitioned by rotation (along arrow B of  FIGS. 9 and 10 ) from a stored position within the interior chamber  25  to a deployed position ready for use. The rear slot  28  provides a space through which portions of the body  50  supporting the filament  60  can pass such as to allow a finger of the user to act on the filament  60  to move the filament  60  from its retracted position within the interior chamber  25  to its deployed position. 
         [0038]    The interior chamber  25  is shown in this embodiment as a generally of constant width and this width is similar to a width of the slots  26 ,  28 . Alternatively, the interior chamber  25  can have a greater width than that of the slots  26 ,  28 . Particular contours of the interior chamber  25  and slots  26 ,  28  are shown in  FIGS. 8-11 . While such a contour for the interior chamber  25  is shown, this contour of the interior chamber  25  could be altered to accommodate design choices of one practicing this invention. 
         [0039]    With particular reference to  FIGS. 8-11 , details of the tracks  30  within the interior chamber  25  of the housing  20  are described, according to this embodiment. The tracks  30  provide a preferred form of guide for guiding the slide  45  from the stored configuration within the interior chamber  25  to a deployed configuration for the instrument  10 . A pair of these tracks  30  are preferably in the form of recesses formed in side walls of the interior chamber  25 . These recesses are preferably of substantially constant depth extending from a first end  32  closest to the proximal end  22  to a second end  34  closest to the distal end  24 . In this embodiment the tracks  30  extend linearly from the first end  32  to the second end  34 . 
         [0040]    Preferably, the first end  32  is square and the second end  34  is rounded. As can be seen in  FIGS. 8-11 , the tracks  30  support the slide  45  of the shuttle  40  moving there along. In particular, the slide  45  moves from a stored position closer to the first end  32  than to the second end  34 , but spaced somewhat from the first end  32 . When the shuttle  40  is transitioned to the deployed position, the slide  45  moves to the second end  34 . By configuring the second end  34  to have a circular cross-section, and configuring the slide  45  to have a cylindrical surface  47 , the shuttle  40  can pivot about the slide  45  (arrow B of  FIGS. 9 and 10 ) when the slide  45  is abutting the second end  34  of the tracks  30 . 
         [0041]    Most preferably, the rear slot  28  on the housing  20  includes notches  29  therein at a midpoint thereof. These notches  29  define a portion of the rear slot  28  which is slightly wider than other portions of the rear slot  28 . These notches  29  can serve various different purposes such as providing a place through which the slide  45  can be passed through the rear slot  28  to install the shuttle  40  within the interior chamber  25  of the instrument  10  during initial assembly. Also, the notches  29  provide a space through which humps  56 ,  58  on the body  50  of the shuttle  40  can pass when the shuttle  40  is rotating (about arrow B of  FIGS. 9 and 10 ). 
         [0042]    Most preferably, a first dimple  36  pair are located near the first end  32  of the tracks  30 . A second dimple pair  38  is preferably located just past the second end  34  of the tracks  30 . These dimples  36 ,  38  are preferably in the form of concave spherical recesses extending partially into the side walls of the interior chamber  25  of the housing  20 . These dimples  36 ,  38  receive the humps  56 ,  58  to hold the shuttle  40  either in the stored position with the filament  60  safely within the interior chamber  25  of the housing  20  or in the deployed position preventing accidental retraction of the shuttle  40  when the filament  60  is being applied to skin of an individual. The humps  56 ,  58  and dimples  36 ,  38  could be swapped for each other as an alternative, but most preferably have the arrangement depicted. Humps  58  are positioned such that they slide along an inside wall of the chamber  25  adjacent the rear slot  28  to prevent premature pivoting of the shuttle  40 , in a manner that might otherwise cause damage to the filament  60 . 
         [0043]    With particular reference to  FIGS. 5-7 , details of the shuttle  40  and associated structures are described, according to this preferred embodiment. The shuttle  40  defines a preferred form of second portion of the instrument  10  which moves relative to the housing  20  to move the filament  60  from this stored position within the interior chamber  25  to the deployed position ready for use outside of the housing  20  ( FIG. 11 ). The shuttle  40  thus includes the slide  45 , body  50  and filament  60 . 
         [0044]    The slide  45  is preferably in the form of a cylindrical structure with the cylindrical surface  47  and flat ends  49 . The cylindrical surface  47  preferably has a diameter similar to a width of the tracks  30 . The flat ends  49  reside within the tracks  30 . The slide  45  thus allows the shuttle  40  to both translate and rotate relative to the tracks  30 . 
         [0045]    The slide  45  is preferably rigidly formed along with the body  50  from a monolithic mass of material, such as injection moldable plastic (e.g. polyethylene). The body  50  includes a lever  52  which is positioned to reside outside of the rear slot  28  of the housing  20 . An edge  54  defines a periphery of the body  50  to which both the lever  52  and slide  45  are attached. Sides  55  define lateral sides of the body  50  and preferably are generally parallel with each other to define a constant width for the body  50 . 
         [0046]    The edge  54  of the body  50  has a contour which generally keeps the shuttle  40  from being able to rotate except when the slide  45  has been positioned adjacent the second end  34  of the tracks  30 . The lever  52  is preferably positioned most distant from the slide  45  to keep the lever  52  from interfering with the housing  20  and abutting the rear slot  28  when the shuttle  40  rotates (about arrow B of  FIGS. 9 and 10 ) to move the shuttle  40  to the deployed position. 
         [0047]    The body  50  also preferably includes a pair of the forward humps  56  and a pair of the rearward humps  58  extending laterally from the sides  55 . These humps  56 ,  58  are preferably convex spherical raised portions of the body  50  which have a diameter and size similar to that of the dimples  36 ,  38  within the interior chamber  25  of the housing  20 . The pair of rearward humps  58  reside within the pair of first dimples  36  when the shuttle  40  is in the stored position. When the shuttle  40  is slid linearly (along arrow A of  FIG. 9 ) the rearward humps  58  come out of the first dimples  36 . 
         [0048]    The pair of forward humps  56  reside outside of the housing  20  and so do not resist any motion of the shuttle  40 . When the slide  45  of the shuttle  40  has abutted the second end  34  of the tracks  30 , the shuttle  40  can be rotated (about arrow B of  FIGS. 9 and 10 ). Once this rotation is approaching 90° of rotation, the forward humps  56  pass through the rear slot  28  of the housing  20  and snap into the second dimples  38 , holding the shuttle  40  in the deployed position. The strength with which the forward humps  56  reside within the second dimples  38  is preferably greater than the threshold force at which the filament  60  buckles. In this way, the shuttle  40  remains solidly in the deployed position during use of the instrument  10 . 
         [0049]    With particular reference to FIGS.  5  and  8 - 11 , details of the filament  60  are described, according to this preferred embodiment. The filament  60  is an elongate flexible and resilient structure typically formed of a homogeneous material having well understood mechanical properties, and particularly a desirable modulus of elasticity, elastic limit, ultimate strength and other material strength and flexibility characteristics. 
         [0050]    The filament  60  has a width significantly less than a length of the filament  60 , so that the filament  60  will function as a column when considered as a structural element. Columns are those structural elements which generally will fail under compression loads by buckling before failing by having compressing forces which exceed strength characteristics of the material. The filament  60  is preferably at least ten times longer than its width, and most typically approximately fifty to one hundred times longer than its width. 
         [0051]    The filament  60  is preferably cylindrical in form with a circular cross-section that extends from a root  64  to a tip  66 . The root  64  is coupled to the body  50  through a collar  62  which preferably extends from a portion of the slide  45 . This collar  62  acts as a coupling device to secure the root  64  of the filament  60  rigidly to the shuttle  40  without rotation or translation of the filament  60  relative to the shuttle  40 . The collar  62  is also formed such that it extends from the slide  45  enough to prevent damage to the filament  60 . The form of the collar  62  and front slot  26  are also made such that the buckling of the filament  60  during operation does not interfere, in any way, with the housing  20 . The filament  60  can be formed of a fiberglass type composite material or from a metal such as nickel titanium, or from a plastic material having suitable performance characteristics. 
         [0052]    Of primary importance for the filament  60  is that it is sufficiently resilient that it can undergo buckling failure when axial loads are applied to the filament  60  greater than a threshold force, and with the filament  60  resiliently returning to an original position when these forces are removed. In particular, the filament  60  is provided from a material which has an elastic limit which is higher than the force at which the filament  60  is caused to undergo buckling failure. 
         [0053]    Furthermore, the filament  60  is preferably sufficiently flexible and elastic that the filament  60  exerts a maximum force right before buckling, and then exerts a lesser axial force after buckling. In this way, the filament  60  can be pressed against the skin (e.g. the finger F of  FIG. 11 ) and exert a maximum force immediately before buckling of the filament  60 . After such buckling of the filament  60 , forces applied to the finger F again decrease. Thus, a maximum force which can be applied by the filament  60  to the finger F is the buckling force (also called threshold force) for the filament  60 . This buckling force is the force at which the filament  60  will undergo buckling failure when an axial load of that magnitude is applied to the filament  60 . The individual thus receives a force (or pressure) matching this threshold force, each time it is used and consistent repeatable evaluation of nerve sensitivity can occur. 
         [0054]    Buckling of the filament  60  can also be referred to as bending of the filament  60 . As depicted in  FIG. 11 , such buckling typically involves the filament  60  transitioning from a linear form to a curving bent form by movement of a midportion of the filament  60  laterally (along arrow C of  FIG. 11 ). As an alternative, the filament  60  would not necessarily have to have an initial entirely linear form and could still undergo buckling failure. 
         [0055]    In use and operation, and with particular reference to  FIGS. 1-4  and  6 - 11 , details of the operation of the instrument  10  are described, according to this preferred embodiment. Initially, the shuttle  40  is positioned so that the filament  60  is retracted within the interior chamber  25  of the instrument  10  ( FIGS. 1 and 8 ). When the instrument  10  is to be used, a user engages the lever  52  of the body  50  to cause the shuttle  40  to translate linearly with the slide  45  moving along the track  30  within the interior chamber  25  of the housing  20  (along arrow A of  FIGS. 2 and 9 ). Such linear translation of the shuttle  40  continues until the slide  45  abuts the second end  34  of the tracks  30 . 
         [0056]    The shuttle  40  is then rotated (along arrow B of  FIGS. 3 ,  4 ,  9  and  10 ). Such rotation continues until the filament  60  extends substantially perpendicular to the tracks  30  and the long axis of the housing  20 , has rotated typically approximately 90°. The shuttle  40  and associated filament  60  are now in a deployed position. 
         [0057]    The instrument  10  is then brought close to skin of an individual to be tested and the tip  66  of the filament  60  is caused to touch the skin of the individual and then a force is applied axially from the housing  20  to the tip  66  axially along the filament  60  until the filament  60  buckles. Typically, the user will then ask the individual “did you feel that?” or some other query to determine whether or not the individual has sufficient sensory perception of a tactile nature to feel the force applied by the instrument  10 . The instrument  10  is then typically moved to a new site and another test is performed. 
         [0058]    When the instrument  10  is no longer needed, the shuttle  40  and associated filament  60  are retracted by reversing the step described above. The instrument  10  can then be stored without concern for damaging the filament  60  until the instrument  10  again needs to be used. 
         [0059]    With particular reference to  FIGS. 12-22 , details of an alternative second embodiment instrument  110  are described. This alternative instrument  110  defines an alternative embodiment of the instrument  10  of the preferred embodiment. This alternative instrument  110  is similar in many respects to the instrument  10  with corresponding parts generally having similar part reference numbers except with the addition of “100” to each part number. 
         [0060]    Thus, the alternative instrument  110  includes an elongate housing  120  extending from a proximal end  122  to a distal end  124 . An interior chamber  125  is located within the housing  120  which is accessed through a front slot  126  and a rear slot  128 . Notches  129  are formed in the rear slot  128 . 
         [0061]    A track  130  is formed within the interior chamber  125  of the housing  120 . This track  130  is in the form of recesses formed in side walls of the interior chamber  125 . The track  130  extends from a first end  132  to a second end  134 . Uniquely, the track  130  of the alternative instrument  110  includes a curve  135  between the first end  132  and the second end  134 , and very close to the second end  134 . This curve  135  preferably is a 90° curve. The second end  134  is also uniquely preferably squared off rather than rounded in the case of the tracks  30  of the instrument  10  of the first embodiment. The interior chamber  125  preferably also includes a first dimple pair  136  and a second dimple pair  138  similar to the dimples  36 ,  38  of the preferred embodiment. 
         [0062]    A shuttle  140  is provided with the alternative instrument  110  which includes a slide  145 , a body  150  and a filament  160 . The shuttle  140  defines a second portion of the alternative instrument  110  separate from the housing  120 . The slide  145  uniquely includes a flat face  146  on one side thereof and a cylindrical surface  147  on another side thereof. The slide  145  includes flat ends  149  on opposite lateral sides of the slide  145 . The flat face  146  is provided so that it can abut the flat second end  134  of the track  130  and help to hold the shuttle  140  and associated filament  160  without rotation, when the shuttle  140  and filament  160  are in a fully deployed position. 
         [0063]    The body  150  includes a lever  152  which preferably includes a ramp  153  on an end thereof and which is angled relative to the otherwise generally flat lever  152 . The ramp  153  helps to cause the shuttle  140  to rotate with the slide  145  passing through the curve  135  in the track  130  by the user pushing lightly on the ramp  153  when the shuttle  140  has been moved close to the deployed position for the shuttle  140  and associated filament  160 . Such pushing of the ramp  153  helps to route the slide  145  in a curving fashion along the curve  135  of the track  130  to push the shuttle  140  fully to the deployed position. 
         [0064]    The body  150  further includes a peripheral edge  154  with lateral sides  155  generally parallel and spaced from each other defining a generally constant width for the body  150 . The body  150  includes a forward hump pair  156  and rearward hump pair  158 . The humps  156 ,  158  are generally similar to the humps  56 ,  58  of the preferred embodiment and provide a similar function of holding the shuttle  140  either in the stored position or the deployed position. Positioning of the humps  156 ,  158  and dimples  136 ,  138  can be slightly adjusted as needed to accommodate differences between the instruments  10 ,  110 . 
         [0065]    The filament  160  is attached to the slide  145  through the collar  162 . The filament  160  extends from a root  164  adjacent the collar  162  to a tip  166  opposite the root  164 . The filament  160  is preferably similar to the filament  60  of the first embodiment. 
         [0066]    In use and operation, the alternative instrument  110  is generally used similar to the instrument  10  described above. Initially, the shuttle  140  and associated filament  160  are in a stored position ( FIGS. 12 and 19 ). A user then places a finger on the lever  152  of the body  150  of the shuttle  140  and applies a force linearly and longitudinally along a long axis of the housing  120 . This urges the shuttle  140  and associated slide  145  toward the distal end  124  of the housing  120  by movement of the slide  145  within the track  130  (along arrow A′ of  FIGS. 13 and 20 ). When the slide  145  reaches the curve  135 , resistance to further linear motion is encountered. The user then applies a force against the ramp  153  of the lever  152  to help cause the slide  145  to rotate around the curve  135  (arrow B′ of  FIGS. 20 and 21 ), along with rotation of the shuttle  140  and included body  150  and filament  160 . Such rotation of the shuttle  140  as the slide  145  passes about the curve  135  continues until this slide  145  abuts the second end  134  of the track  130  ( FIGS. 15 and 22 ). 
         [0067]    The shuttle  140  and associated filament  160  have thus been fully deployed. The instrument  110  is then utilized by bringing the filament  160  into contact with the individual, such as at a finger F. If the filament  160  buckles (motion along arrow C′ of  FIG. 22 ) a threshold force of standard amount has been applied. The individual is then queried to determine whether the individual could feel the force being applied. Data is then gathered as to the degree of sensory perception exhibited by the individual. When the instrument  110  is no longer to be utilized, the shuttle  140  and associated filament  160  are retracted by reversing of the steps described above until the filament  160  is again protected within the interior chamber  125  of the housing  120 . 
         [0068]    This disclosure is provided to reveal a preferred embodiment of the invention and a best mode for practicing the invention. Having thus described the invention in this way, it should be apparent that various different modifications can be made to the preferred embodiment without departing from the scope and spirit of this invention disclosure. When structures are identified as a means to perform a function, the identification is intended to include all structures which can perform the function specified. When structures of this invention are identified as being coupled together, such language should be interpreted broadly to include the structures being coupled directly together or coupled together through intervening structures. Such coupling could be permanent or temporary and either in a rigid fashion or in a fashion which allows pivoting, sliding or other relative motion while still providing some form of attachment, unless specifically restricted.