Abstract:
A lancet device for obtaining a blood sample from a finger or at an alternate site of a patient. The lancet device includes a body and a lancet, the lancet being movable between a retracted position in which the lancet tip is disposed within the body and an extended position in which the lancet tip extends beyond the body. The device is cocked by compressing a U-shaped spring steel accessible on opposite sides of the body, the U-shaped spring steel being coupled to the lancet. Once cocked, a pawl retains the U-shaped spring steel in a compressed state. The device is fired by contacting the patient where sampling is to occur with one end of an actuator, the opposite end of the actuator serving to release the pawl from the U-shaped spring steel.

Description:
This application is a continuation application of Ser. No. 10/447,578, filed on May 29, 2003, now U.S. Pat. No. 7,303,573, which are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to lancet devices and relates more particularly to a novel lancet device. 
     There are many medical conditions for which it is desirable to draw a blood sample from a patient for analysis. For example, in the case of certain communicable diseases, a blood sample drawn from a patient may be analyzed for the presence of a blood borne pathogen. Alternatively, in the case of diabetes, blood samples drawn periodically from a patient may be used to monitor blood sugar levels. 
     Blood samples taken from a patient for blood sugar monitoring are typically obtained by piercing the skin of the patient using a lancet device. A lancet device typically includes a body and a lancet. The body is typically adapted to be held by the user, the lancet being coupled to the body and being adapted to pierce the skin of the patient so as to draw blood therefrom. In some lancet devices, the lancet extends from the body at all times. As can readily be appreciated, such lancet devices may inadvertently prick people and/or become contaminated with foreign objects and, therefore, pose a safety risk. Accordingly, in other lancet devices, the lancet is adapted to be moved, when actuated, from a retracted position in which the lancet tip is disposed within the body to an extended position in which the lancet tip extends beyond the body. Typically, the movement of the lancet from its retracted position to its extended position is effected with such force that contact of the moving lancet tip with the skin of a patient results in the piercing of the skin of the patient. In many such lancet devices having a movable lancet, the lancet is automatically drawn back into the body after reaching its extended position in order to minimize the risk of inadvertent lancet sticks. 
     Lancet devices having a movable lancet typically fall into one of two types. In one such type of device, the lancet is, prior to use and without any prepping by a user, maintained in an armed state, ready to be fired. The firing of a lancet in such a device is typically effected either by pressing or compressing the entire device against the skin of the patient or by depressing a movable plunger or trigger on the device while holding the remainder of the device against the skin of the patient. Examples of the aforementioned type of lancet device are disclosed in the following documents, all of which are incorporated herein by reference: U.S. Pat. No. 5,201,324, inventor Swierezek, issued Apr. 13, 1993; U.S. Pat. No. 5,540,709, inventor Ramel, issued Jul. 30, 1996; U.S. Pat. No. 5,709,699, inventor Warner, issued Jan. 20, 1998; U.S. Pat. No. 5,755,733, inventor Morita, issued May 26, 1998; U.S. Pat. No. 6,322,574, inventors Lloyd et al., issued Nov. 27, 2001; U.S. Pat. No. 6,358,265, inventors Thorne, Jr. et al., issued Mar. 19, 2002; and U.S. Patent Application Publication No. US 2002/0087180, inventors Searle et al., published Jul. 4, 2002. 
     One drawback to lancet devices of the type described above is that such devices require the user, who is typically also the patient whose skin is about to be pricked, to provide the necessary force to drive the lancet through the skin of the patient. Because most people have an aversion to being pricked, there is a natural tendency for the patient to flinch before or as the lancet is moving, with the result that a clean piercing is often not achieved. Moreover, because an inexperienced patient often will not know the appropriate amount of force necessary to drive the lancet through the skin, it is not uncommon for such a patient to fail to insert the lancet through the skin, with the result that the procedure must be repeated. 
     Another drawback to lancet devices of the type described above is that it is possible for the lancet to be fired prematurely simply by the inadvertent application of pressure to the lancet device. As can readily be appreciated, the premature firing of the lancet may result in an undesired piercing of a person and/or in the contamination of the lancet. In addition, with respect to those lancet devices that also include a safety feature for preventing the lancet from being used multiple times, the premature firing of the lancet will prevent the lancet device from later being used for its intended purpose. Furthermore, for those lancet devices that do not include a safety feature for preventing the lancet from being used multiple times, even if the lancet is not fired prematurely and is, in fact, used on its intended patient, there is a risk that subsequent handling of the lancet device by a second person may result in an inadvertent lancet stick of said second person. 
     The second type of lancet device having a movable lancet typically takes the form of a pen-shaped device comprising a spring-loaded lancet, cocking means for storing energy in the spring, and trigger means for releasing the energy stored in the spring to drive movement of the lancet. In use, the spring is cocked, the device is held against the skin of the patient, and the trigger is fired. Examples of the aforementioned type of lancet device are disclosed in the following documents, all of which are incorporated herein by reference: U.S. Pat. No. 4,462,405, inventor Ehrlich, issued Jul. 31, 1984; U.S. Pat. No. 4,503,856, inventor Cornell et al., issued Mar. 12, 1985; U.S. Reissue Pat. No. 32,922, inventors Levin et al., reissued May 16, 1989;U.S. Pat. No. 5,613,978, inventor Harding, issued Mar. 25, 1997; and U.S. Patent Application Publication No. US 2001/0027326, inventor Schraga, published Oct. 4, 2001. 
     Of the above documents, U.S. Reissue Pat. No. 32,922 is illustrative. In this patent, there is disclosed a lancet device comprising an inner tubular member and an outer tubular member, the inner tubular member being telescopically mounted within the outer tubular member. A lancet holder is slidably mounted within the inner tubular member, the lancet holder receiving at its forward end a lancet. A shaft extends rearwardly from the lancet holder, the shaft traveling through the inner tubular member and terminating within the outer tubular member. A spring is mounted on the shaft within the inner tubular member, the spring biasing the lancet holder forwardly. A finger formed on the lancet holder is adapted to extend radially outwardly through a transverse opening in the inner tubular member. A trigger mounted externally to the inner tubular member is adapted to engage the lancet holder finger and to push said finger into the inner tubular member through the transverse opening. To cock the device, the outer tubular member is pulled away from the inner tubular member and then released. The pulling away of the outer tubular member causes the shaft to be pulled rearwardly and the spring to be compressed. In addition, the pulling away of the outer tubular member causes the finger on the lancet holder to be drawn into the transverse opening in the inner tubular member, thereby retaining the spring in its compressed state. To fire the device, the trigger is depressed. Depression of the trigger causes the finger to be pushed back into the inner tubular member, thereby releasing the spring. Said release of the spring results in the lancet being driven forwardly through the end of the inner tubular member. After firing, a second spring, which is located in the outer tubular member surrounding the rear end of the shaft, draws the lancet back into the inner tubular member. 
     One drawback to the aforementioned lancet device is that one must use two hands to cock the device, one hand to hold the inner tubular member and the other hand to pull the outer tubular member rearwardly relative to the inner tubular member. In addition, after cocking the device, one must re-position the hand that is going to be used to fire the device so that a finger is positioned over the trigger. 
     Another drawback to the aforementioned lancet device and to many of the other lancet devices described above is that such devices are intended to be used to prick the finger tip of a patient (the finger tip being highly vascularized) and then to have the patient express a drop of blood from the pricked finger tip. This can be problematic, however, since the finger tip has a high concentration of pain receptors located therein. Consequently, both the act of pricking the finger tip and the act of expressing blood therefrom can be quite painful. Moreover, this effect is magnified where the patient is diabetic, and frequent blood samples must be drawn. This problem cannot simply be avoided by using the same devices on alternate body parts, such as the forearm, the trunk, the buttocks and the upper thighs, which do not have as high a concentration of pain receptors as the finger tips, since these devices are not designed to draw an adequate amount of blood for sampling from these less vascularized body parts. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a novel lancet device. 
     It is another object of the present invention to provide a lancet device as described above that overcomes at least some of the drawbacks associated with existing lancet devices. 
     It is still another object of the present invention to provide a device as described above that can be mass-produced relatively inexpensively, that has a minimal number of parts, and that is easy to operate. 
     In furtherance of the above and other objects to be described or to become apparent from the description below, there is provided, according to one aspect of the invention, a lancet device comprising (a) a body, said body comprising an open top end and at least one side opening; (b) a spring, said spring being mounted in said body and being transformable between a cocked state of comparatively greater compression and an uncocked state of comparatively lesser compression, said spring being manually accessible for compression through said at least one side opening; and (c) a lancet, said lancet having a lancet tip, said lancet being coupled to said spring for movement between a retracted position wherein said lancet tip is positioned below said open top end of said body and an extended position wherein said lancet tip is positioned above said open top end of said body, said lancet being in said retracted position when said spring is in said cocked state and in said extended position when said spring is in said uncocked state. 
     According to another aspect of the invention, there is provided a lancet device comprising (a) a body, said body comprising an open top end; (b) a spring, said spring being mounted in said body and being reversibly transformable between a cocked state of comparatively greater compression and an uncocked state of comparatively lesser compression; (c) a lancet, said lancet having a lancet tip, said lancet being coupled to said spring for movement between a retracted position wherein said lancet tip is positioned below said open top end of said body and an extended position wherein said lancet tip is positioned above said open top end of said body, said lancet being in said retracted position when said spring is in said cocked state and in said extended position when said spring is in said uncocked state; (d) a releasable catch for retaining said spring in said cocked state; and (e) an actuator engageable with said releasable catch for releasing said releasable catch, said actuator being actuated by contact with the body part to be lanced by said lancet. 
     According to yet another aspect of the invention, there is provided a lancet device comprising (a) a body, said body comprising a tubular member terminating in an open top end; (b) a lancet, said lancet having a lancet tip, said lancet being movable from a retracted position wherein said lancet tip is positioned below said open top end of said tubular member to an extended position wherein said lancet tip is positioned above said open top end of said tubular member; (c) a spring, said spring being mounted in said body and being coupled to said lancet for moving said lancet from said retracted position to said extended position; (d) a releasable catch for retaining said lancet in said retracted position; (e) an actuator engageable with said releasable catch for releasing said releasable catch, said actuator extending through said open top end of said tubular member and being actuated by contact with the body part to be lanced by said lancet; and (f) a flexible seal for stretching the skin to be pierced by said lancet, said flexible seal being mounted on said tubular member and extending beyond said open top end. 
     According to still yet another aspect of the invention, there is provided a lancet device comprising (a) a body, said body comprising (i) a base, said base having an inner cavity and comprising a front, a back, a left side, a right side, a bottom and an open top, each of said left side and said right side including a scalloped portion having a longitudinal slot, and (ii) a hollow cover, said hollow cover being mounted on said base and comprising a bottom portion and a tubular top portion, said tubular top portion having an open top end and an open bottom end; (b) a spring, said spring being a generally U-shaped member mounted in said body and comprising a first outwardly biasing arm and a second outwardly biasing arm, said first outwardly biasing arm being accessible through said longitudinal slot in said left side of said base for compression towards said second outwardly biasing arm, said second outwardly biasing arm being accessible through said longitudinal slot in said right side of said base for compression towards said first outwardly biasing arm; (c) a lancet holder; (d) a support member, said support member being mounted in said base and comprising a cylindrical member, said cylindrical member comprising a longitudinally-extending bore aligned with said tubular top portion of said cover, said lancet holder being slidably mounted in said longitudinally-extending bore, said cylindrical member further comprising a catch, said catch being releasably engageable with said lancet holder when said spring is sufficiently compressed; (e) a lancet, said lancet being mounted in said lancet holder and having a lancet tip, said lancet being coupled to said spring for movement between a retracted position wherein said lancet tip is positioned below said open top end of said tubular top portion of said hollow cover and an extended position wherein said lancet tip is positioned above said open top end of said tubular top portion of said hollow cover, said lancet being in said retracted position when said spring is in a cocked state and in said extended position when said spring is in an uncocked state; (f) means for coupling said spring to said lancet holder; (g) means for biasing said lancet holder downwardly, said biasing means being weaker than said spring; (h) an actuator slidably mounted within said tubular top portion of said hollow cover and engageable with said catch for releasing said catch from said lancet holder, said actuator being actuated by contact with the body part to be lanced by said lancet; and (i) means for biasing said actuator away from said catch. 
     For purposes of the present specification and claims, various relational terms like “top,” “bottom,” “proximal,” “distal,” “upper,” “lower,” “front,” and “rear” are used to describe the present invention when said invention is positioned in a given orientation. It is to be understood that, by altering the orientation of the invention, certain relational terms may need to be adjusted accordingly. 
     Additional objects, as well as features and advantages, of the present invention will be set forth in part in the description which follows, and in part will be obvious from the description or may be learned by practice of the invention. In the description, reference is made to the accompanying drawings which form a part thereof and in which is shown by way of illustration an embodiment for practicing the invention. This embodiment will be described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural or mechanical changes may be made without departing from the scope of the invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is best defined by the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are hereby incorporated into and constitute a part of this specification, illustrate a preferred embodiment of the invention and, together with the description, serve to explain the principles of the invention. In the drawings wherein like reference numerals represent like parts: 
         FIG. 1  is a perspective view of one embodiment of a lancet device constructed according to the teachings of the present invention, the lancet device being shown prior to being cocked; 
         FIG. 2  is a partially exploded perspective view of the uncocked lancet device shown in  FIG. 1 ; 
         FIG. 3  is a top view of the uncocked lancet device shown in  FIG. 1 ; 
         FIG. 4  is an enlarged longitudinal section view of the uncocked lancet device taken along line  1 - 1  of  FIG. 3 ; 
         FIG. 5  is an enlarged front view of the uncocked lancet device shown in  FIG. 1 , with the front base portion and the skin not being shown; 
         FIG. 6  is an enlarged perspective view of the rear base portion of the device of  FIG. 1 ; 
         FIG. 7  is an enlarged perspective view of the front base portion of the device of  FIG. 1 ; 
         FIG. 8  is an enlarged perspective view of the cover of the device of  FIG. 1 ; 
         FIG. 9  is an enlarged perspective view of the biasing member of the device of  FIG. 1 ; 
         FIG. 10  is an enlarged perspective view of the support member of the device of  FIG. 1 ; 
         FIG. 11  is an enlarged perspective view of the lancet holder of the device of  FIG. 1 ; 
         FIG. 12  is an enlarged perspective view of the actuator of the device of  FIG. 1 ; 
         FIG. 13  is a longitudinal section view of the lancet device of  FIG. 1 , the lancet device being shown in a cocked state; 
         FIG. 14  is an enlarged fragmentary longitudinal section view of the cocked lancet device shown in  FIG. 13 , illustrating the releasable restraint of the lancet holder by the releasable pawl; and 
         FIG. 15  is a top view of the cocked lancet device shown in  FIG. 13 , with the cover, the actuating mechanism, and the seal not being shown to illustrate the releasable restraint of the lancet holder by the releasable pawl. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring now to  FIGS. 1 through 5 , there are shown various views of one embodiment of a lancet device constructed according to the teachings of the present invention, said lancet device being shown in an uncocked state and being represented generally by reference numeral  11 . 
     Device  11  includes a rear base portion  13  and a front base portion  15 . Rear base portion  13 , which is also shown separately in  FIG. 6 , is a unitary structure, preferably made of a durable molded plastic or similarly suitable material, and comprises a rear wall  17 , a pair of side walls  19 - 1  and  19 - 2 , a bottom wall  21 , an open front and an open top. Rear wall  17  is shaped to include an upwardly extending tab  23 , tab  23  terminating at its top end in a rearwardly facing pawl  25 . For reasons to become apparent below, tab  23  is adapted to be resiliently flexed forwardly. 
     A scalloped portion  27 - 1  is provided in side wall  19 - 1 , and a corresponding scalloped portion  27 - 2  is provided in side wall  19 - 2 . As will be described below, scalloped portions  27 - 1  and  27 - 2  are adapted to receive a user&#39;s thumb and forefinger, respectively (or vice versa). Scalloped portion  27 - 1  is provided with a longitudinal slot  29 - 1 , and scalloped portion  27 - 2  is provided with a corresponding longitudinal slot  29 - 2 , the functions of slots  29 - 1  and  29 - 2  to become apparent below. 
     Front base portion  15 , which is also shown separately in  FIG. 7 , is a unitary structure, preferably made of the same material as rear base portion  13 . Front base portion  15  has a shape that is substantially a mirror image of rear wall  17 . As such, front base portion  15  is shaped to include an upwardly extending resilient tab  31 , tab  31  terminating at its top end in an forwardly facing pawl  33 . Front base portion  15  is fitted together with rear base portion  13 , for example by mating peripheral edges, to jointly define a hollow base  34  having a base cavity  35 . 
     Device  11  also includes a cover  41 . Cover  41 , which is also shown separately in  FIG. 8 , is a unitary structure, preferably made of a durable molded plastic or similarly suitable material, and comprises a bottom portion  43  and a top portion  45 . Bottom portion  43 , which is generally trough-shaped and defines an interior cavity  44 , includes a front wall  47 , a rear wall  49 , an upwardly-curved intermediate wall  51  and an open bottom. Bottom portion  43  sits upon base  34 , with the bottom edge  53  of bottom portion  43  being appropriately dimensioned to substantially match the top edge  55  of base  34 . A transverse slot  57  is provided in front wall  47 , and a corresponding transverse slot  59  is provided in rear wall  49 , slot  57  receiving pawl  33  and slot  59  receiving pawl  25 . In this manner, cover  41  is secured to base  34 . To remove cover  41  from base  34 , one flexes tab  31  rearwardly to remove pawl  33  from slot  57  and/or flexes tab  23  forwardly to remove pawl  25  from slot  59 . 
     Top portion  45 , which is generally tubular in shape and open at both ends, extends upwardly from intermediate wall  51 . An external circumferential flange  61 , the purpose of which will be described below, is provided on top portion  45  a short distance below its top end  63 . 
     Base  34  and cover  41  jointly define a hollow body. 
     Device  11  additionally comprises a biasing member  71  disposed within base  34 . Biasing member  71 , which is also shown separately in  FIG. 9 , is a unitary U-shaped ribbon-type structure, made of spring steel or the like, and comprises a pair of resilient, outwardly-biasing arms  73 - 1  and  73 - 2  interconnected by a base portion  75 . Arms  73 - 1  and  73 - 2 , the free ends of which are adapted to be pivoted towards one another by a user for reasons to become apparent below, are aligned with and accessible through slots  29 - 1  and  29 - 2 , respectively. Base portion  75  is fixed to the top of bottom wall  21  of rear base portion  13  by a screw  77  and a nut  78 , screw  77  being inserted through transverse openings  79  and  81  provided in bottom wall  21  and base portion  75 , respectively. 
     Device  11  further comprises a flexible filament  85  disposed within base  34 . Filament  85 , which may be a length of string or another similarly suitable material, is a unitary structure having a first end  87  and a second end  89 . First end  87  is inserted through a transverse opening  88  formed in arm  73 - 1  proximate to its free end, first end  87  being knotted to prevent its withdrawal through opening  88 . Second end  89  is inserted through a transverse opening  90  formed in arm  73 - 2  proximate to its free end, second end  89  being knotted to prevent its withdrawal through opening  90 . For reasons to become apparent below, the length of filament  85  is such that, when the free ends of arms  73 - 1  and  73 - 2  are pivoted towards one another (i.e., when device  11  is cocked), slack is created in filament  85 , and when the free ends of arms  73 - 1  and  73 - 2  are nearly at their relaxed positions (i.e., when device  11  is uncocked), filament  85  is pulled taut. 
     It should be understood that, although biasing member  71  and filament  85  are described in the present embodiment as separate structures, biasing member  71  and filament  85  could be modified to be a unitary structure. 
     Device  11  also includes a support member  91 . Support member  91 , which is also shown separately in  FIG. 10 , is a unitary structure, made of a durable molded plastic or another similarly suitable material, and comprises a base portion  93  and a stem portion  95 . Base portion  93 , which is generally rectangular in shape, is seated on top of base portion  75  of biasing member  71 . 
     Stem portion  95 , which extends upwardly from base portion  93 , is shaped to include a pair of tabs  96 - 1  and tabs  96 - 2  and a generally cylindrical member  97 . Tabs  96 - 1  and  96 - 2  flank cylindrical member  97 , with tab  96 - 1  facing rear wall  17  of rear base portion  13  and tab  96 - 2  facing front wall  15 . For reasons to become apparent below, tab  96 - 1  is provided with a transverse opening  98 - 1 , and tab  96 - 2  is provided with a transverse opening  98 - 2 . 
     Cylindrical member  97 , which is open at its top end, is shaped to include a longitudinally-extending bore  101  and a plurality of longitudinally-extending transverse slots  103 - 1 ,  103 - 2 ,  103 - 3  and  103 - 4  communicating with bore  101 . Slots  103 - 1  and  103 - 2  are aligned with slots  29 - 1  and  29 - 2 , respectively, of rear base portion  13  and permit filament  85  to pass through cylindrical member  97 . For reasons to become apparent below, slot  103 - 3  is aligned with tab  96 - 1 , and slot  103 - 4  is aligned with tab  96 - 2 . 
     Cylindrical member  97  is also shaped to include an arm  105 , arm  105  being biased radially inwardly towards bore  101 . The top end of arm  105 , which extends just beyond the top end of bore  101 , is shaped to include a releasable catch or pawl  107 , the purpose of which will be described below. 
     Support member  91  is fixed to biasing member  71  by screw  77  and nut  78 , screw  77  being inserted through a bore  109  in support member  91  that is aligned with transverse openings  79  and  81  in bottom wall  21  and base portion  75 , respectively. (Instead of being secured to one another by screw  77  and nut  78 , support member  91  and biasing member  71  may be secured together by other means, such as by being molded together, by being coupled together by a snap feature, etc.) 
     Device  11  also includes a lancet holder  111 , lancet holder  111  being slidably mounted in cylindrical member  97  of support  91 . Lancet holder  111 , which is also shown separately in  FIG. 11 , is a unitary structure, made of a durable molded plastic or another similarly suitable material, and comprises a top portion  112  and a bottom portion  113 . Top portion  112  is a generally tubular structure having a closed bottom end  114  and an open top. Bottom portion  113 , which is generally T-shaped, includes a downwardly extending central arm  117  and a pair of laterally extending side arms  119 - 1  and  119 - 2 . Central arm  117 , which is disposed within bore  101  of cylindrical member  97 , is provided with a transverse opening  118  aligned with slots  103 - 1  and  103 - 2 . For reasons to be described below, filament  85  extends through opening  118 . 
     Side arm  119 - 1  extends through slot  103 - 3  and is provided with a transverse opening  120 - 1 . One end of an elastic strap  121  is secured to arm  119 - 1 , and the opposite end of strap  121  is secured to tab  96 - 1 . Preferably, strap  121  is formed by overmolding (or “two-shot molding”) a thermoplastic elastomeric (“TPE”) material over arm  119 - 1  and through opening  120 - 1  and by overmolding (or “two-shot molding”) the same TPE material over tab  96 - 1  and through opening  98 - 1 . (Alternatively, instead of interconnecting arm  119 - 1  and tab  96 - 1  using strap  121 , one could insert a first end of an elastic filament through opening  120 - 1  and insert a second end of said elastic filament through opening  98 - 1 , said first and second ends of said elastic filament being knotted to prevent their withdrawal through opening  120 - 1  and opening  98 - 1 , respectively.) 
     Side arm  119 - 2  extends through slot  103 - 4  and is provided with a transverse opening  120 - 2 . One end of an elastic strap  123  is secured to arm  119 - 2 , and the opposite end of strap  123  is secured to tab  96 - 2 . Preferably, strap  123  is formed by overmolding (or “two-shot molding”) a TPE material over arm  119 - 2  and through opening  120 - 2  and by overmolding (or “two-shot molding”) the same TPE material over tab  96 - 2  and through opening  98 - 2 . (Alternatively, instead of interconnecting arm  119 - 2  and tab  96 - 2  using strap  123 , one could insert a first end of an elastic filament through opening  120 - 2  and insert a second end of said elastic filament through opening  98 - 2 , said first and second ends of said filament being knotted to prevent their withdrawal through opening  120 - 2  and opening  98 - 2 , respectively.) 
     Elastic straps  121  and  123  are used to bias lancet holder  111  downwardly; however, the biasing strength of biasing member  71  is greater than the biasing strength of straps  121  and  123 . Accordingly, in the absence of a compressive or inwardly-directed force applied to biasing member  71  by a user, filament  85  is pulled taut by biasing member  71 , causing holder  111  to be positioned at a relatively high position within support  91  and stretching straps  121  and  123  well beyond their normal or relaxed lengths (but not to their rupturing points). If, however, a compressive force is applied to biasing member  71  by a user, slack is created in filament  85 , and straps  121  and  123  are permitted to contract towards their relaxed lengths, causing holder  111  to be pulled down within support  91 . Once sufficient compressive force has been applied to biasing member  71  to draw the top of holder  111  down below pawl  107 , further compressive force need not be applied to maintain biasing member  71  in a compressed state as pawl  107  pivots inwardly to engage the top of holder  111 . The energy stored in the thus compressed biasing member  71  may thereafter be released by removing pawl  107  from holder  111  in the manner to be described below. As can be appreciated, once the restraint on biasing member  71  is released, biasing member  71  expands towards its relaxed state, causing holder  111  to quickly move upwardly relative to support  91 . Elastic straps  121  and  123 , which are then highly stretched by the quick upward movement of holder  111 , provide a small degree of downward spring to holder  111 . 
     Device  11  additionally includes a lancet  131 . Lancet  131 , which may be a conventional, disposable lancet, is a unitary member, preferably made of metal or another similarly suitable material. Lancet  131  comprises a cylindrical base  133  and a stem  135 . Base  133  is removably received within top portion  112  of holder  111 . Stem  135  of lancet  131  extends upwardly from base  133  and terminates in a sharp tip  137  adapted to pierce the skin of a patient. 
     Device  11  further includes a seal  141 . Seal  141 , which may be made of silicone rubber or a similarly suitable material, is a unitary structure comprising a lower portion  143  and an upper portion  145 . Lower portion  143  is tubular in shape and is inserted over top portion  45  of cover  41 , with the bottom edge of lower portion  143  resting upon flange  61  of top portion  45 . Upper portion  145  extends beyond top portion  45  of cover  41  and flares outwardly for reasons to become apparent below. 
     Device  11  additionally includes an actuator  151 , actuator  151  being slidably mounted within top portion  45  of cover  41 . Actuator  151 , which is also shown separately in  FIG. 12 , is a unitary structure, preferably made of a durable molded plastic or another similarly suitable material. Actuator  151  is shaped to include a cylindrical portion  153 , cylindrical portion  153  having a top end  155  and a bottom end  157 . Top end  155  is positioned at approximately the top edge  141 - 1  of seal  141 , and bottom end  157  extends into bottom portion  43  of cover  41  and is aligned with and spaced a short distance above pawl  107 , as well as the remainder of cylindrical member  97  of support  91 . 
     An external circumferential flange  159  is formed on actuator  151  and is positioned a short distance from bottom end  157 . A ring  161 , which may be made of foam or a like material, is mounted on top of flange  159 . The bottom surface of ring  161  is fixed at a first point to the top of flange  159  using a suitable adhesive (not shown), and the top surface of ring  161  is fixed at a second point, approximately 180 degrees from said first point, to the bottom surface of intermediate wall  51  of cover  41 . In this manner, actuator  151  is biased upwardly by ring  161 . 
     Device  11  further includes a protective membrane or skin  171  tightly fitted over base  34  (except for the bottom portion thereof) and the exposed portions of biasing member  71 . Skin  171  is preferably made of a flexible, elastic material. 
     In use, an operator grips device  11  with the forefinger and the thumb of one hand, the forefinger being positioned against that portion of skin  171  covering scalloped portion  27 - 1  of base  34  and the thumb being positioned against that portion of skin  171  covering scalloped portion  27 - 2  of base  34  (or vice versa). At this point, prior to any cocking of device  11 , device  11  is essentially as shown in  FIGS. 1 through 5 . The operator then cocks device  11  by compressing spring  71  with the forefinger and the thumb and then by releasing pressure from spring  71  while still maintaining a hold on device  11 . As noted above, the compression of spring  71  causes the free ends of arms  73 - 1  and  73 - 2  to be pivoted towards one another and causes lancet holder  111  to be drawn down below pawl  107 . The subsequent release of compression on spring  71  by the operator then causes lancet holder  111  to come into engagement with pawl  107 , pawl  107  retaining holder  111  in place. At this point, device  11  is cocked and is essentially as seen in  FIGS. 13 through 15 . It can readily be appreciated that, with spring  71  thus restrained from returning to its relaxed state by the engagement of pawl  107  with holder  111 , a considerable amount of potential energy is stored in spring  71 . Device  11  is then used by pressing top edge  141 - 1  of seal  141  and top end  155  of actuator  151  against that portion of the patient where sampling is desired. As top edge  141 - 1  of seal  141  is pressed against the skin of the patient (and is engaged therewith), top edge  141 - 1  expands in diameter, stretching the engaged skin outwardly. Concurrently, as top end  155  of actuator  151  engages the skin of the patient, top end  155  causes distension of the skin and, at the same, causes actuator  151  to be moved downwardly. Continued movement of actuator  151  causes bottom end  157  of actuator  151  to move pawl  107  out of engagement with lancet holder  111 , thereby resulting in the release of potential energy stored by spring  71  and the firing of lancet  131  into the patient. 
     Once device  11  has been used to pierce the skin of a patient, lancet  131  should be replaced. To access a used lancet  131  disposed within the body of device  11 , a user depresses tabs  23  and/or  31  until cover  41  can be unhooked from base  34 . The used lancet  131  may then be removed from holder  111  and replaced with a new lancet  131 . After a new lancet  131  has been placed in holder  111 , cover  41  may then be re-attached to base  34 . 
     As noted above, one desirable property of device  11  is that device  11  is not limited to use on a finger but may be used on alternate sites of a patient. 
     In another embodiment (not shown), skin  171  is replaced with a rigid protective casing that encloses base  34  and the exposed portions of biasing member  71 , the device further including a pair of depressable buttons, each button having a first end coupled to a respective arm  73  of biasing member  71  and a second end extending through the protective casing. 
     The embodiments of the present invention described above are intended to be merely exemplary and those skilled in the art shall be able to make numerous variations and modifications to it without departing from the spirit of the present invention. All such variations and modifications are intended to be within the scope of the present invention as defined in the appended claims.