Abstract:
A blood sampling device designed to divert attention from the pain involved in the puncture of the skin tissue by increasing comfort when lancing the skin by affecting the sensation and perception of pain. Projections on the distal end of a skin pricker contact the skin surface to confuse the nerves in the area of the prick to make the prick less noticeable.

Description:
RELATED APPLICATION DATA  
       [0001]    This application is a continuation-in-part of U.S. application Ser. No. 09/959,262, filed Oct. 22, 2001, which is incorporated herein by reference in its entirety. 
     
    
     
       FILED OF THE INVENTION  
         [0002]    This invention relates generally to medical skin piercing devices including blood sampling devices, and more particularly to skin prickers.  
         BACKGROUND  
         [0003]    Blood sampling devices are used to draw a small drop of blood for analysis. One type of blood sampling device is a skin pricker. Such skin prickers are widely used by diabetics, for example, who need to know their sugar level. However, there are many other applications.  
           [0004]    There are many different types of skin prickers, including spring-loaded devices that fire disposable lancets. Some pricking devices are entirely disposable after a single use. Regardless of the form, the pricker punctures the skin of the user and inflicts pain. While this pain is somewhat trivial and transitory, many users would welcome its reduction.  
         SUMMARY  
         [0005]    This invention is a skin pricker designed to divert attention from the pain involved in the puncture of the skin tissue by a blood sampling device. The skin pricker of this invention increases comfort when lancing by affecting the sensation and perception of pain. Projections on the distal end of a lancing device, or skin pricker, contact the skin surface to confuse the nerves in the area of the prick to make the prick less noticeable. This approach disguises the lancing action to provide a more comfortable sample. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0006]    [0006]FIG. 1 is a perspective view of a skin pricker of this invention.  
         [0007]    [0007]FIG. 2 is an enlarged perspective view of the depth adjuster of the skin pricker of FIG. 1.  
         [0008]    [0008]FIG. 3 is an exploded perspective view of the skin pricker of FIG. 1.  
         [0009]    [0009]FIG. 4 is a side elevation view in cross-section of the skin pricker of FIG. 1.  
         [0010]    [0010]FIG. 5 is a side elevation view of the skin pricker of FIG. 1.  
         [0011]    [0011]FIG. 6 is an end view of the skin pricker of FIG. 1.  
         [0012]    [0012]FIG. 7 is a top plan view of the skin pricker of FIG. 1. 
     
    
     DETAILED DESCRIPTION  
       [0013]    A skin pricker of this invention is a lancing device  20  for firing a lancet, as shown in the Figures. As may be seen by reference to FIGS. 1 and 2, lancing device  20  includes depth adjuster  22 , which includes interior threads (not shown) adapted to engage a front clip  24 , which engages a body  26 . In the description below, distal refers to the nose or lancing end generally, while proximal indicates a direction away from the nose of the device.  
         [0014]    Lancing device  20  may be used with a suitable disposable lancet, which may be inserted into lancet holder  28  by removing the assembly of the depth adjuster  22  and front clip  24 . Dialing depth adjuster  22  relative to front clip  24  alters the distance between the front clip  24  and the depth adjuster  22 , but does not disrupt engagement between the clip  24  and adjuster  22 . Therefore dialing of the adjuster  22  controls how far the lancet tip will project beyond aperture  30  of adjuster  22 . In the embodiment shown, depth adjuster  22  includes indicia  32  that correspond to penetration depth indicator  34 , which together reflect the expected penetration level of the lancet into the skin of the patient.  
         [0015]    As may be shown by reference to FIGS. 3 and 4, depth adjuster  22  includes platform  36  and aperture  30 . Projections  38  encircle aperture  30 , and each projection  38  has a shallow conical form with a rounded tip  40 . The number and arrangement of the projections  38  may vary, as may the size and shape of the individual projections. For example, the arrangement may zigzag as it surrounds the aperture. Pyramidal projections may be used, or any other suitable shape. Alternatively, two rows of projections may encircle the aperture. The two rows may include projections having various shapes and may spaced at various distances. Projections having various shapes may also be used on the same device. The projections contact the skin surface to confuse the nerves in the area of the prick, making the prick less noticeable.  
         [0016]    As shown in FIGS. 2 and 4, lancet retention clip  42  fits into groove  44  on lancet holder  28 , retaining a lancet in lancet holder  28 . Clip  42  includes slit  48 , which allows clip  42  to expand for installation. Wings  50  of lancet holder  28  are adapted to be received in corresponding wing slots  52  on the distal portion of body  26 .  
         [0017]    Recoil spring  54  fits around lancet holder  28  between cap  56  and wings  50 , and urges lancet holder  28  in a proximal direction, or rearward, in a resting state where the lancet does not project beyond the nose. The recoil spring  54  urges the lancet back to this resting state immediately after firing and lancing. Wings  50  translate in slots  52 , and catch on wing stops  58 , preventing the lancet holder  28  from being recoiled beyond the distal portion of the body  26  after firing of the lancet.  
         [0018]    Hammer  60  is urged toward the distal end of body  26  by main spring  62 . The distal end of the main spring  62  contacts the proximal end of the hammer  60 , fitting around ring  64  that projects from the proximal end surface of the hammer  60  and that surrounds the aperture  66  of the hammer  60 . The proximal end of main spring  62  rests against inner end surface  68  of the force adjuster  70 .  
         [0019]    Body  26  includes button frame  72  adapted to receive firing button  74 . Foam pads  76  on the interior of firing button  74  contact the outer surface of body  26 , and clips (not visible) on the interior of the button  74  are received in holes (not visible) in the body  26 , securing the button  74  to the body  26  in the frame  72 . In a loaded position, finger  82  of hammer  60  translates in loading slot  86  of body  26 . Depressing firing button  74  causes button tab  88  to depress finger  82  of hammer  60 , so that main spring  62  urges hammer  60  forward, forcing finger  82  out of loading slot  86  and into firing slot  90  of body  26 . Knob  92  on the distal end of hammer  60  is adapted to fit into the proximal end of lancet holder  28 , so that the main spring  62  pushes the hammer  60  into contact with lancet holder  28 , expelling the lancet beyond the platform  36  of the depth adjuster  22  and into contact with the patient. In this manner, hammer  60  is projected toward lancet holder  28 , firing the lancet and pricking the patient.  
         [0020]    Force adjuster ring  94  fits around body  26  proximal to the button  74 . Force adjuster  70  includes longitudinal flange  96  and tab  98 . Flange  96  is adapted to translate in flange opening  100  of body  26 , while tab  98  translates in tab slot  102  of body  26 . Flange opening  100  includes detents (not visible), so that flange  96  is locatable at set positions. In one embodiment, flange opening  100  subtends approximately 80 degrees of the circumference of the body  26  in a generally spiral path and three detents in the proximal edge of opening  100  can receive flange  96  alternatively to provide three different levels of force.  
         [0021]    Flange  96  is captured between a pair of ridges  106  on the inner surface  108  of force adjuster ring  94 . Extensions  110  on either side of body  26  abut annular ring  112  on the inner surface  108  of ring  94 , maintaining the axial position of the ring  94 . Extensions  110  have the force of leaf springs that are compressed when ring  94  is pressed into position and then spring out so that their ends abut annular ring  112  and thereby capture ring  94  and retain it on the body  26 .  
         [0022]    Rotating force adjuster ring  94  causes ridges  106  to force flange  96  distally or proximally to adjust the force of main spring  62  when the lancet device  20  is triggered. Thus, the force is adjusted by turning the ring  94 , which moves the force adjuster  70  axially to adjust the compression of the main spring  62 . Force adjustment indicator  114  on body  26  may be aligned with one of the notches  116  on ring  94 , allowing the user may set the amount of force with which to deliver the lancet.  
         [0023]    Body sleeve  118  includes two semi-cylindrical halves, which fit around proximal end of body  26 , over body spring  120 , which extends between cap  122  of body  26  and internal lip  124  of sleeve  118 . Keys  126  of body sleeve  118  are received in and move axially along keyways  128  of body  26 . Body spring  120  urges sleeve  118  distally in a resting, or loading, state.  
         [0024]    Sleeve  118  includes shelf  130  having an aperture  132  adapted to receive the cap  134  of the loading rod  136  and the cap  138  of the support rod  140 . Loading rod  136  and support rod  140  each include a flat edge that abut each other, so that the two rods extend through the force adjuster  70  and the ends of the rods are received in the proximal end of hammer  60 . The use of the two part rod structure, rods  136  and  140 , permit insertion of first rod  136  through the opening  66  of hammer  60  and then rod  140 , so that combined rods  136  and  140  substantially fill opening  66  of hammer  60 . Loading rod  136  also includes a hook  142  that engages ledge  144  of hammer  60 , preventing removal.  
         [0025]    After firing, pulling sleeve  118  in the proximal direction compresses body spring  120  and draws the assembly of the sleeve  118 , the rods  136 ,  140  and the hammer  60  rearward, or distally, resetting finger  82  of hammer  60  into loading slot  86 . The lancet may then be removed, and a new lancet inserted, by removing the assembly of the depth adjuster  22  and front clip  24 .  
         [0026]    All variations of the structures illustrated in the drawings and the materials described above are within the scope and spirit of this invention and the following claims.