Abstract:
A lancing device comprising: a cover section, a part of which is provided with an opening; a main body held on the cover section and configured to be movable in a predetermined direction from the opening relative to the cover section; a lancing unit which is launched in the predetermined direction; and an operating section configured to launch the lancing unit when the operating section is pushed by applying a force in the predetermined direction, wherein the lancing unit is launched when the force is applied to the operating section in the predetermined direction with regulating a movement of the main body in the predetermined direction, and the main body moves, instead of pushing the operating section, by applying the force in the predetermined direction without regulating the movement of the main body in the predetermined direction is disclosed.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2013-041223 filed on Mar. 1, 2013, the entire content of which is hereby incorporated by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention relates to a lancing device for forming pores for body fluid extraction in the body of a subject. 
       BACKGROUND OF THE INVENTION 
       [0003]    There are well known lancing devices for puncturing the body of a subject with needles to form pores in the skin to extract bodily fluids to be used for measuring components such as glucose in the body fluid of the subject (for example, refer to U.S. Patent Application Publication No. 2009/0054920 and Japanese Patent Application Publication No. 2011/177523). 
         [0004]    U.S. Patent Application Publication No. 2009/0054920 discloses a lancing device provided with an end cap at one end of a tubular housing, and a lancet opening in the end cap, whereby a needle-like lance can advance and retract through the lancet opening. This lancing device has structural elements which are user accessible on the side surface of the housing, and is configured so that a spring exerts a force on the lance causing the lance to extend from the lancet opening when the user presses the user accessible structural element on the side of the housing. 
         [0005]    Japanese Patent Application Publication No. 2011/177523 discloses a lancing device having a cover section at one end of a cylindrical housing and an operating cap at the other end, and further having a through-hole provided in the cover so that a lancet set needle unit can advance and retract from the through-hole. The lancing device has an operating cap which is slidable in the axial direction of the housing, and is configured so that the sporing exerts a force on the lancet set when the operating cap is pushed on the side of the housing causing the needle unit of the lancet set to protrude from the through-hole of the cover section in the lancing direction. 
         [0006]    The lancing device disclosed in U.S. Patent Application Publication No. 2009/0054920 has caused concern that the user accessible structural element may inadvertently operate when the user holds the housing because the direction in which the user holds the housing is the same as the direction of operation of the user accessible structural element. The lancing device disclosed in Japanese Patent Application Publication No. 2011/177523 has caused concern that the user may inadvertently expose the sharp lancet set needle unit from the end of the cover section when the user operates the operating cap while the cover section is not abutting the body of the user (subject) since the direction in which the user holds the housing is different from the operating direction of the operating cap. 
       SUMMARY OF THE INVENTION 
       [0007]    The scope of the present invention is defined solely by the appended claims, and is not affected to any degree by the statements within this summary. 
         [0008]    A first aspect of the present invention is a lancing device comprising:
       a cover section, a part of which is provided with an opening;   a main body held on the cover section and configured to be movable in a predetermined direction from the opening relative to the cover section;   a lancing unit which is launched in the predetermined direction; and   an operating section configured to launch the lancing unit when the operating section is pushed by applying a force in the predetermined direction,   wherein the lancing unit is launched when the force is applied to the operating section in the predetermined direction with regulating a movement of the main body in the predetermined direction, and   the main body moves, instead of pushing the operating section, by applying the force in the predetermined direction without regulating the movement of the main body in the predetermined direction.       
 
         [0015]    A second aspect of the present invention is a lancing device comprising:
       a main body comprising a housing, a biasing unit provided inside the housing and configured to launch a lancing unit in a predetermined direction, and a button for launching the lancing unit via the biasing unit when the button is pushed in the predetermined direction with a predetermined force; and   a cover section to be held by a user when the user pushes the button, and which can hold the main body, with a force that is less than the predetermined force, so that at least part is covered by the housing, wherein   the main body is movable in the predetermined direction relative to the cover section which holds the main body.       
 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0019]      FIG. 1  is a perspective view of the external structure of a lancing device with the cover section closed; 
           [0020]      FIG. 2  is a perspective view of the external structure of a lancing device with the cover section opened; 
           [0021]      FIG. 3  is a perspective view of the external structure of the main body with the cover section removed; 
           [0022]      FIG. 4  is a frontal view showing the exterior of the lancing device in the closed condition; 
           [0023]      FIG. 5  is a front sectional view showing the interior of the lancing device in the closed condition; 
           [0024]      FIG. 6  is a side sectional view on the A-A line of  FIG. 4 ; 
           [0025]      FIG. 7  is a frontal view showing the exterior of the lancing device in the open condition; 
           [0026]      FIG. 8  is a front sectional view showing the interior of the lancing device in the open condition; 
           [0027]      FIG. 9  is a side sectional view on the B-B line of  FIG. 7 ; 
           [0028]      FIG. 10  is a front sectional view showing the interior of the lancing device with the cover section closed when the mounting member is in an energized state; and 
           [0029]      FIG. 11  is a front sectional view showing the interior of the lancing device in the operational condition. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0030]    The preferred embodiments of the present invention are described hereinafter with reference to the drawings. 
         [0031]    The lancing device  1  of the present embodiment forms body fluid extraction holes (micropores) in the skin of a subject by installing a sterilized fine needle tip  6  so that the needles of the fine needle tip  6  abut the skin of the subject. The body fluid (interstitial fluid) exuded from the micropores formed in the skin of the subject by the lancing device  1  and the fine needle tip  6  is collected in an extraction medium, the glucose concentration in the interstitial fluid is calculated by measuring the extraction medium by a glucose analyzer (not shown in the drawing) and estimating the AUC based on this calculated value so that a diabetic patient can, herself, monitor the estimated AUC to manage her condition. 
       Lancing Device Structure 
       [0032]    The lancing device  1  forms a plurality of minute extraction pores through the stratum corneum of the epidermal layer of the skin but does not reach the vascular plexus in the dermis to extract interstitial fluid from the micropores.  FIGS. 1 and 2  are perspective views showing the exterior structure of the lancing device of the present embodiment. The lancing device  1  is configured by a main body section  2  and a cover section  3  which covers the main body section  2 , and is substantially cylindrical overall. The cover section  3  is capable of sliding in the longitudinal direction relative to the main body section  2 . That is, the main body section  2  and the cover section  3  are relatively slidable in the longitudinal direction so that the main body section  2  can be pulled from the cover section  3  and the main body section  2  can be housed within the cover section  3 .  FIG. 1  shows the main body section  2  entirely housed within the cover section  3 , whereas  FIG. 2  shows the main body section  2  pulled from the cover section  3 . 
         [0033]    The main body section  2  has a cylindrical base  21 . A cylindrical step portion  22  extends from the base  21  and has a diameter that is coaxial and slightly smaller than the diameter of the base  21 , and a cylindrical ejecting portion  23  ultimately extends from the step portion  22  and has a diameter that is coaxial and slightly smaller than the diameter of the step portion  22 . An ejection aperture  23   a  is provided in the ejecting portion  23 , to allow the fine needle tip which forms micropores in the skin of the subject to be launched from the ejection aperture  23   a.    
         [0034]    A cylindrical inner housing portion  24 , which has a diameter that is coaxial and smaller than the diameter of the base  21 , extends from the base  21  from the side opposite the step portion  22 . A mechanism for ejecting the fine needle tip is accommodated within the inner housing portion  24 . 
         [0035]    The cover section  3  is cylindrical with the same diameter as the base  21 , and is mounted on the main body section  2  so as to cover the inner housing portion  24 . The cover section  3  has an inner diameter that is slightly larger than the outer diameter of the inner housing portion  24 , and is slidable in the longitudinal direction relative to the inner housing portion  24 . In other words, the main body section  2  is slidable in the longitudinal direction relative to the cover section  3 . When the inner housing portion  24  is entirely covered by the cover section  3  (the condition shown in  FIG. 1  is hereinafter referred to as “closed condition”), the end of the cover section  3  abuts the base portion  21  (at this time, the position of the main body section  2  relative to the cover section  3  is hereinafter referred to as “first position”). A part of the inner housing portion  24  is exposed when the cover section  3  is moved relative to the main body section  2  in a direction that separates the base  21  and the cover section  3  from the closed condition. This condition (hereinafter referred to as “open condition”) is shown in  FIG. 2 . 
         [0036]    The cover section  3  is a part which the user holds when using the lancing device  1 . The cover section  3  is cylindrical in shape as described above to be easy to hold by the user. The cover section  3  has an overall length of 100 mm and an external diameter of 30 mm so as to be easy to hold for the average adult. Note that the size and shape of the cover section  3  is not specifically limited to these dimensions, and preferably will be cylindrical with a length of 90 mm or more and less than 110 mm for ease of grasping in a hand of the user. When the cover section  3  is cylindrical, the major diameter is preferably 10 mm or more and less than 50 mm. 
         [0037]      FIG. 3  is a perspective view of the external structure of the main body section  2  with the cover section  3  removed. An operating section  4  is provided at the end of the main body section  2  on the opposite side from the ejecting portion  23 . The operating section  4  may be, for example, a button. The main body section  2  is described below with the ejecting portion  23  side referred to as the downstream side and the operating section  4  side as the upstream side. 
         [0038]    As shown in  FIG. 3 , the inner housing portion  24  is provided with a long slide hole in the longitudinal direction, that is, the vertical direction, of the inner housing portion  24 . As shown in  FIGS. 2 and 3 , a pressing member  51  is provided within the inner housing portion  24 . The pressing member  51  has a screw hole  51   a,  and a screw  31  for connecting the cover section  3  and the pressing member  51  is screwed into the screw hole  51   a  through a slide hole  25 . The pressing member  51  is provided with a protrusion  51   b  which protrudes to the outside, and the protrusion  51   b  is inserted in the slide hole  25 . That is, the screw  31  and the protrusion  51   b  are movable along the slide hole  25 , thereby regulating the movement direction of the cover section  3  which is connected to the pressing member  51  in the vertical direction. 
         [0039]      FIG. 4  is a frontal view of the exterior of the lancing device in the closed condition, and  FIG. 5  is a front sectional view showing the interior of the lancing device in the closed condition. The protrusion  51   b  is provided below the bottom end of the cover section  3 . That is, the bottom end of the cover section  3  abuts the top end of the base  21  and the protrusion  51   b  intrudes to the inner side of the base  21  when the cover section  3  is in the closed condition. 
         [0040]    The bottom end of the pressing member  51  is bent in an L-shape to form a contact portion  51   c.  A mounting member  52  for mounting the fine needle tip  6  is arranged inside the inner housing portion  24 , and a compression spring  54  for exerting a force on the mounting member  52  is arranged above the mounting member  52 . 
         [0041]    The condition shown in  FIG. 5  is a condition in which the compression spring  54  exerts a force on the mounting member  52  (referred to below as “de-energized condition”). That is, the position of the mounting member shown in  FIG. 5  is the bottom limit position, and the length is the natural length such that a load is not exerted by the compression spring  54  when the mounting member  52  is at the bottom limit position. 
         [0042]    The mounting member  52  has two protrusions  52   a  and  52   b,  as shown in  FIG. 5 . When the cover section  3  is lifted upward and the lancing device  1  transitions from the closed condition to the opened condition, the contact portion  51   c  of the pressing member  51  comes into contact with the protrusion  52   a  on the bottom side of the mounting member  52 . The mounting member  52  is pressed by the pressing member  51  and moves upward when the cover section  3  is lifted. When the mounting member  52  moves upward, the compression spring  54  is compressed by the bottom end of the compression spring  54  being pressed upward by the mounting member  52 . Thus, the compression spring  54  exerts a downward force on the mounting member  52 . 
         [0043]    Two opposed guide parts  55  are provided on the inner wall of the inner housing portion  24 .  FIG. 5  shows only one of the two guide parts  55 . A gap extending in the vertical direction is formed between the two guide parts  55 , and the mounting member  52  is arranged between the two guide parts  55 . The movement direction of the mounting member  52  is regulated in the vertical direction by the gap between the two guide parts  55 . 
         [0044]    A locking member  53  is provided above the mounting member  52 , as shown in  FIG. 5 . The locking member  53  is rotatable on an axis  53   d  which extends in the front-to-back direction. A hook  53   a  is provided on the locking member  53 , and the locking member  53  exerts a force via a spring (not shown in the drawing) so that the hook  53   a  is positioned on the bottom side in the natural position. 
         [0045]      FIG. 6  is a side sectional view on the A-A line of  FIG. 4 ; when the lancing device  1  is in the closed condition, the bottom end of the cover section  3  and the top end of the base  21  are in contact or very near contact, as shown in  FIG. 6 . In this condition, the protrusion  51   b  of the pressing member  51  intrudes to the inner side of the base  21  as described above. A concavity  21   a  is formed on the inner side of the base  21 , and the protrusion  51   b  engages the concavity  21   a  at this time. A convexity  21   b  is provided at the top side of the concavity  21   a,  such that the protrusion  51   b  must override the convexity  21   b  and move upward when the engagement is released from the condition of the protrusion  51   b  engages in the concavity  21   a.  That is, the protrusion  51   b  must override the convexity  21   b  for the lancing device  1  to transition from the closed condition to the opened condition. The force required to accomplish this override is 3 N in the present embodiment. Note that the force required to release the engagement of the main body section  2  and the cover section  3  of the lancing device  1  is not limited to 3 N, but preferably is 2 N or greater but less than 5 N. 
         [0046]      FIG. 7  is a frontal view of the exterior of the lancing device in the opened condition, and  FIG. 8  is a front sectional view showing the interior of the lancing device in the opened condition.  FIG. 9  is a side sectional view on the B-B line of  FIG. 7 . When the cover section  3  is lifted upward relative to the main body section  2  with a force of 3 N or greater, the protrusion  51   b  which is engaged in the concavity  21   a  overrides the convexity  21   b,  and the engagement of the cover section  3  and the main body section  2  is released (refer to  FIG. 9 ). When the cover section  3  is lifted upward, the bottom end of the cover section  3  separates from the top end of the base  21  and the inner housing portion  24  is exposed (refer to  FIG. 7 ). At this time, the pressing member  51  also moves upward together with the cover section  3  relative to the main body section  2 , and the protrusion  51   b  is exposed from the slide hole  25  of the inner housing portion  24 . The mounting member  52  is lifted upward when the cover section  3  is lifted upward while the contact portion  51   c  of the pressing member  51  contacts the protrusion  52   a  on the bottom side of the mounting member  52 , as mentioned above. 
         [0047]    An inclined portion  53   b  is provided on the bottom side of the hook  53   a  of the locking member  53 . When the mounting member  52  moves upward within the inner housing portion  24 , the mounting member  52  approaches the locking member  53  and the protrusion  52   b  on the top side of the mounting member  52  comes into contact with the inclined portion  53   b  of the locking member  53 . Then, when the ascent of the mounting member  52  continues, the inclined portion  53   b  is pressed by the protrusion  52   b  and the locking member  53  is rotated on the pivot shaft  53   d  against the exerted force. Hence, when the protrusion  52   b  overrides the inclined surface  53   b,  the locking member  53  is rotated in the opposite direction by the exerted force and returned to the natural condition. The protrusion  52   b  therefore engages the hook  53   a  of the locking member  53  (refer to  FIG. 8 ). 
         [0048]    As shown in  FIG. 7 , when the cover section  3  is lifted upward relative to the main body section  2  until the screw  31  connecting the cover section  3  and the pressing member  51  is positioned near the top end of the slide hole  25  (at this time the position of the main body section  2  relative to the cover section  3  is referred to as “second position” below), the protrusion  52   b  of the mounting member  52  therefore engages the hook  53   a  of the locking member  53 . At this time the mounting member  52  receives the force exerted by the compression spring  54  (referred to as “energized condition” below). 
         [0049]    When the mounting member  52  is in the energized condition, the main body section  2  is movable between the first position and the second position.  FIG. 10  is a front sectional view showing the interior of the lancing device  1  with the cover section  3  closed when the mounting member  52  is in the energized condition. When the main body section  2  is moved upward from the second position while the mounting member  52  is energized and the energized condition is locked by the locking member  53 , the contact portion  51   c  of the pressing member  51  separates from the protrusion  52   a  of the mounting member  52  and moves downward relative to the protrusion  52   a  (the protrusion  52   a  moves upward relative to the contact portion  51   c ). That is, the cover section  3  is closed with the mounting member  52  in the energized condition. 
         [0050]    The main body section  2  moves upward accurately relative to the cover section  3  because the pressing member  51  and the movement of the cover section  3  are regulated in the vertical direction by the slide hole  25  at this time. The upward movement of the main body section  2  causes the protrusion  51   b  of the pressing member  51  to override the convexity  21   b  provided on the inner side of the base  21 , the protrusion  51   b  then engages the concavity  21   a  and the main body section  2  arrives at the first position. Hence, the condition shown in  FIG. 8  transitions to the condition shown in  FIG. 10 . 
         [0051]    When the mounting member  52  is in the energized condition and the main body section  2  is at the first position, the lancing device  1  enters the operational condition in which the device can be operated by the user. When the operating section  4  is operated downward while the lancing device  1  is in the operational condition (operating section  4  is pressed down), the lock held by the locking member  53  is released, the mounting member  52  is actuated by the force exerted by the compression spring  54 , and the fine needle tip  6  is launched downward.  FIG. 11  is a front sectional view showing the interior of the lancing device in the operational condition. 
         [0052]    The operating section  4  is mounted on the inner housing portion  25  and moves in vertical directions. A support panel  56  which extends laterally is fixedly attached to the inner wall of the inner housing portion  25  at a position below the operating section  4 . A vertical panel portion  41  is provided at the bottom of the operating section  4 , and the panel portion  41  extends below the support panel  56 . 
         [0053]    A protrusion  42  is provided on the panel portion  41 . An inclined portion  53   c  is provided on the surface of the locking member  53  which faces the panel portion  41 . The inclined portion  53   c  of the locking member  53  comes into contact with the protrusion  42  of the panel portion  41 . The operating section  4  is usually protrudes from the main body section  2  because the locking portion  53  receives an upward force via a spring through the protrusion  42  and the inclined portion  53   c.  When the operating section  4  is pressed downward, the panel portion  41  moves downward relative to the support panel  56 , the inclined portion  53   c  is pressed down by the protrusion  42 , and the locking member  53  is rotated on the pivot shaft  53   d  against the exerted force. 
         [0054]    The force required to operate the operating section  4  in the downward direction, that is, the force necessary to press down the operating section  4  against the force exerted by the locking portion  53 , is 6 N in the present embodiment. Note that the force required to press down the operating section  4  is not limited to 6 N, and such force is preferably 5 N or greater but less than 10 N inasmuch as the force necessary is at least greater than the force required to release the engagement between the main body section  2  and the cover section  3  of the lancing device  1  (a force of 3 N in the present embodiment). 
         [0055]    When the operating section  4  is pressed down and the panel portion  41  moves downward, the panel portion  41  opposes the top part of the locking member  53 . Then, when the descent of the operating section  4  continues, the inclined portion  53   c  is pressed by the protrusion  42  and the locking member  53  is rotated on the pivot shaft  53   d  against the exerted force. Hence, the engagement is released between the protrusion  52   b  of the mounting member  52  and the hook  53   a  of the locking member  53 , the mounting member  52  with the fine needle top  6  mounted thereon is forced downward by the compression spring  54 , and the fine needle tip  6  is launched. 
       Lancing Device Operation 
       [0056]    The operation of the lancing device  1  is described below. The subject first mounts the fine needle tip  6  on the mounting member  52  from the ejection aperture  23   a.    
         [0057]    The subject then shifts the lancing device  1  from the de-energized condition to the energized condition. That is, the subject holds the cover section  4  of the lancing device  1  in the hand (for example, the right hand) and grasps the base  21  of the main body section  2  with the other hand (for example, the left hand), then moves the cover section  3  relative to the base  21  so as to pull the closed cover section  3  from the base  21 . The main body section  2  is thus moved from the first position to the second position. 
         [0058]    While the main body section  2  moves from the first position to the second position, the pressing member  51  moves upward inside the inner housing portion  24 , the contact portion  51   c  comes into contact with the protrusion  52   a  of the mounting member  52 , and the mounting member  52  is pressed upward by the pressing member  51 . The compression spring  54  is therefore compressed, and the mounting member  52  is ultimately pulled up against the force exerted by the compression spring  54 . The protrusion  52   b  on the top side of the mounting member  52  comes into contact with the inclined portion  53   b  of the locking member  53 , the inclined portion  53   b  is pressed by the protrusion  52   b,  and the locking member  53  is rotated on the pivot shaft  53   d.  When the protrusion  52   b  overrides the inclined portion  53   b,  the locking member  53  returns to the natural condition and the protrusion  52   b  engages the hook  53   a  of the locking member  53 . Hence, the mounting member  52  becomes energized. 
         [0059]    The subject then moves the main body section  2  from the second position to the first position relative to the cover section  3  so as to close the cover section  3  of the energized lancing device  1 . That is, the subject moves the cover section  3  with one hand to bring it near the base  21  which is held in the other hand so that there is contact or near contact between the bottom end of the cover section  3  and the top end of the base  21 . Hence, the lancing device  1  becomes operational. 
         [0060]    When the lancing device  1  becomes operational, the subject holds the cover section  3  in one hand (for example, the right hand), and presses the bottom end of the lancing device  1 , that is, the end provided with the ejection aperture  23   a  of the ejecting portion  23 , against the body (for example, the left arm) of the subject. Thus, the main body  2  of the lancing device  1  is pressed upward, that is, the mounting member  52  (fine needle tip  6 ) is pressed in the opposite direction to the direction in which the force is exerted by the compression spring  54 , and the downward movement of the main body section  2  is regulated. 
         [0061]    As described above, the operating section  4  is operated by the thumb of the hand in which the subject holds the cover section  3  when the main body section  2  is pushed upward. When a downward force is applied to the operating section  4 , this force is transmitted to the main body section  2  through the support panel  56 . That is, the downward force on the main body section  2  functions as a force in the direction of separation from the cover section  3 . However, since the main body section  2  is pressed against the body of the subject at this time, a reaction force to the downward force is generated, and the main body section  2  does not move relative to the cover section  3  so as to remain stationary at the first position. 
         [0062]    As described above, a force of 6 N is required to operate the operating section  4 . Therefore, when a downward force of 6 N or greater is applied to the operating section  4 , the locking member  53  rotates on the pivot shaft  53   d.  This action releases the lock of the locking member  53 , the mounting member  52  is actuated by the force exerted by the compression spring  54 , and the fine needle tip  6  is launched downward. A plurality of fine needles protrude from the bottom surface (the surface facing the skin, referred to as “micropore forming surface” below) of the fine needle tip  6 . The fine needles of the fine needle tip  6  have a length (for example 0.3 mm) sufficient to pass through the stratum corneum of the epidermal skin but not reach the vascular plexus in the dermis. The micropore forming surface of the fine needle tip  6  abuts (impacts) the skin of the subject and forms a plurality of micropores in the skin of the subject. 
         [0063]    The operation of the lancing device  1  is described below when a force is applied downward on the operating section  4  while the bottom end of the operational lancing device  1  is not pressed against the body of the subject, that is, the downward movement of the main body section  2  is not regulated. When a downward force is applied to the operating section  4  due to the subject trying to operate the operating section  4  or inadvertently touching the operating section  4  when the main body section  2  of the lancing device  1  is not being pressed upward, this force is transmitted to the main body section  2  through the support panel  56 . That is, the downward force on the main body section  2  functions as a force in the direction of separation from the cover section  3 . 
         [0064]    At this time a force of 3 N is required to release the engagement between the base  21  and the protrusion  51   b  of the pressing member  51 ; since a force of 6 N is required to operate the operating section  4 , the operating section  4  does not operate when a downward force of 3 N or greater is applied to the operating section  4 , and the engagement between the base  21  and the protrusion  51   b  is not released. Therefore, the main body section  2  moves from the first position to the second position relative to the cover section  3 , and the lancing device  1  is opened. At this time the fine needle tip  6  is not launched because the operating section  4  does not operate. That is, according to the lancing device  1  of the present embodiment, when the bottom end of the lancing device  1  is not pressed against the body of the subject, the mechanism which launches fine needle tip  6  of the lancing device  1  will not operate even when a downward force is applied to the operating section  4  due to misuse or the like, and the main body section  2  and the cover section  3  are pulled apart. The user inadvertently launching the fine needle tip  6  is therefore prevented. 
       (Other Embodiments) 
       [0065]    Note that although the embodiment described above is configured with the operating section  4  provided at the end on the opposite side from the ejection aperture  23   a  of the lancing device  1 , the present invention is not limited to this configuration. The position of the operating section is discretionary insofar as it is operational in the same direction as the direction of separation of the main body section  2  from the cover section  3 . For example, the operating section may be provided on a side surface of the cover section  3 . 
         [0066]    Although the drive source of the mounting member  52  and the fine needle tip  6  mounted thereon is a compression spring  54  in the above embodiment, the present invention is not limited to this configuration. An elastic body other than a compression spring, such as rubber, tension spring, air spring or the like also may be used as the drive source of the mounting member  52  and the fine needle tip  6 . Furthermore, a power generator such as a pneumatic cylinder or more may be used, rather than an elastic body, as the drive source of the mounting member  52  and the fine needle tip  6 , wherein the power generator generates a drive force in response to the operation of the operating section  4  to drive the mounting member  52  and the fine needle tip  6 . 
         [0067]    Although a force of 3 N is required to release the engagement between the cover section  3  and the main body section  2 , and a force of 6 N is required to operate the operating section  4  in the embodiment described above, the present invention is not limited to this configuration. However, it is preferable that the difference between the force required to operate the operating section  4  and the force required to release the engagement between the cover section  3  and the main body section  2  is 1 N or greater but less than 6 N. When a downward force is applied to the operating section  4  while the main body section  2  of the operational lancing device  1  is not being pressed upward, the mechanism which launches the fine needle tip  6  of the lancing device  1  is reliably prevented from operating and the main body section  2  and the cover section  3  can be pulled apart by because the difference between the force required to operate the operating section  4  and the force required to release the engagement between the cover section  3  and the main body section  2  is 1 N or greater. Furthermore, handling complexity is caused by an extreme difference between the force required to operate the operating section  4  and the force required to release the engagement between the cover section  3  and the main body section  2  can be avoided because difference between the force required to operate the operating section  4  and the force required to release the engagement between the cover section  3  and the main body section  2  is less than 6 N. 
         [0068]    Although the above embodiment has been described in terms of piercing the skin of a subject by a fine needle tip  6 , the present invention is not limited to this configuration. A configuration which lances by mounting a lancing unit with a conventional needle may also be applied. 
         [0069]    Although the above embodiment is described in terms of operation by the subject herself, the present invention is not limited to this configuration. The lancing device also may be operated by a person other than the subject.