MXPA05007009A - Apparatus for extracting bodily fluid. - Google Patents

Abstract

An apparatus for extracting bodily fluid (e.g., whole blood) from a user's finger includes a housing with a lancing mechanism and a clamping mechanism attached to thereto. The clamping mechanism includes a lower arm assembly and an upper arm assembly. The upper and lower arm assemblies are operatively connected such that when a user's finger applies a user force to the lower arm assembly and displaces the lower arm assembly from a first to a second position, the upper and lower arm assemblies cooperate to engage the user's finger with a compressive force that is greater than the user force. In addition, the lancing mechanism is configured to lance a target site on the user's finger while the upper and lower arm assemblies are cooperating to engage the user's finger. Thereafter, the compressive force serves to extract a bodily fluid sample from the lanced target site.

Description

APPARATUS FOR EXTRACTING BODY FLUID BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates, in general, to a fluid extraction apparatus and, in particular, to an apparatus for extracting body fluid and associated methods.

DESCRIPTION OF THE RELATED ART A variety of medical conditions, such as diabetes, require the monitoring of a concentration of analytes, (for example, the concentration of glucose) in an interstitial fluid, blood or other body fluid sample. Typically, such monitoring requires the removal of a sample of body fluid from a target site (e.g., a target site of dermal tissue) on a user's finger. Extraction (also referred to as "expression") of a blood sample from a user's finger generally involves penetrating the target site of dermal tissue and applying pressure in the vicinity of the penetrated site to extract the blood sample. In the event that the target site of dermal tissue is on the user's finger, it is known that the extraction of the blood sample is carried out by using a fluid extraction device with a pressure ring. The pressure ring is used to apply pressure against the target site of dermal tissue either before and / or after the perforation. To reduce the user's pain or discomfort during drilling, it is advisable to penetrate the target site to a shallow depth of penetration (such as a penetration depth on the 0.5 mm to 1.0 mm scale). However, the removal of a sample of body fluid from a target site that has been drilled at a relatively shallow depth of penetration requires a higher amount of applied pressure compared to the extraction of a target site that has been drilled to a relatively deep penetration depth. The strength and dexterity required to apply the required pressure (for example, an applied pressure of 15 N or more around the target site of dermal tissue at the end of a finger) is not available to all users. It is known to use various extraction devices during drilling that help in the application of pressure. However, these apparatuses are usually problematic and complicated to operate (for example, they require using both hands for their operation), they operate in a non-intuitive manner, and / or they use expensive and bulky motorized components. Therefore, there is still a need for an apparatus for extracting body fluid from a target site that facilitates the application of pressure to the target site and that its operation is still simple and intuitive. In addition, the device must be compact and not require the use of expensive and bulky motorized components. A procedure is also needed to extract a sample of body fluid that is simple and intuitive.

BRIEF DESCRIPTION OF THE INVENTION The apparatus for removing body fluid according to exemplary embodiments of the present invention facilitates the application of pressure to a target site, and even its operation is simple and intuitive. In addition, the apparatus is compact and does not require the use of expensive and bulky motorized components. Certain modalities can be operated with one hand and without requiring separate activation of motors or other bulky components. An apparatus for removing body fluid according to an exemplary embodiment of the present invention includes a housing, a lancet mechanism attached to the housing and a fastening mechanism attached to the housing. The fixing mechanism includes an upper arm assembly and a lower arm assembly. The upper and lower arm assemblies are operatively connected in such a way that when a user's finger applies a predetermined user force to the lower arm assembly and moves the lower arm assembly from a first position to a second position, the upper arm assembly and the lower arm assembly cooperate to couple the user's finger with a compressive force that is greater than the user's predetermined force. In addition, the lancet mechanism is configured to penetrate a target site on the user's finger while the upper arm assembly and the lower arm assembly cooperate to engage the user's finger. Subsequently, the compressive force serves to extract a sample of body fluid from the perforated target site. The upper and lower arm assemblies can be operatively connected by, for example, one or more articulated mechanisms employing the mechanical advantage of coupling the user's predetermined force with the compressive force. Due to the mechanical advantage of the articulated mechanism, the compressive force is greater than the user's predetermined force. Exemplary embodiments of apparatus for removing body fluid according to the present invention may optionally include force limiting means (such as a force limiting spring) that prevent the compressive force from exceeding a predetermined level.

BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the aspects and advantages of the present invention will be obtained by reference to the following detailed description which sets forth illustrative modalities, wherein the principles of the invention are used, and the accompanying drawings (wherein similar numbers represent similar elements) of which: Figure 1 is a simplified perspective view of an apparatus for removing body fluid according to an exemplary embodiment of the present invention; Figure 2A is a simplified perspective view of a portion of the apparatus illustrated in Figure 1; Figure 2B is a simplified cross-sectional view of the portion illustrated in Figure 2A; Figure 2C is a simplified side view of the fluid portion shown in Figures 2A and 2B with a user's finger engaged therein; Figures 3A and 3B are simplified transverse representations of a user's finger coupled only with a lower arm assembly and with the upper compression surface and a lower arm assembly, respectively; Figure 4 is a simplified side view of the apparatus of the figure 1 with a user's finger coupled thereto and the upper and lower arm assemblies in a second position; Figures 5A and 5B are simplified side views of the apparatus shown in Figure 1 with the upper arm assembly rotated fully counterclockwise with a finger of the user coupled with the lower arm assembly and with a finger of the user by depressing the lower arm assembly, respectively; Figures 6A and 6B are a side view and a terminal view respectively, of the embodiment shown in Figure 1 in a storage configuration; Figures 7A to 7C are schematic side views showing a sequence of steps in the operation of the apparatus of Figure 1; Figures 8A and 8B are simplified perspective views of an apparatus for removing body fluid according to another exemplary embodiment of the present invention; Figure 8C is a simplified cross-sectional view of the apparatus of Figures 9A and 9B; Figure 9 is a simplified schematic cross-sectional view of an apparatus for removing body fluid in accordance with yet another exemplary embodiment of the present invention; Figure 10 is a simplified schematic cross-sectional view of an apparatus for removing body fluid according to yet another exemplary embodiment of the present invention; Fig. 11 is a flow chart depicting a sequence of steps in a method according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION Figures 1, 2A, 2B, 2C and 4 are various representations of an apparatus 100 for extracting body fluid (e.g., whole blood) from a target site (such as a target site of dermal tissue on a user's finger) in accordance to the present invention. The apparatus 100 includes a housing 102, a lancet mechanism 104 attached to the housing 102 and a locking mechanism 106 that is also attached to the housing 102. The locking mechanism 106 includes a lower arm assembly 108 and a lower arm assembly 110. The lancet mechanism 104 may include means for measuring, analyzing and displaying an analyte concentration of a sample of body fluid drawn by the apparatus 100. However, once the present invention has been assessed, those skilled in the art will recognize that the embodiments of the present invention can also be used to extract a sample of body fluid for further analysis by a separate analysis system. Any suitable lancet mechanism can be employed in the apparatus according to the present invention. An example of a suitable lancet mechanism is described in the US patent. No. 6,197,040, which is incorporated, therefore in the present totally for reference. In the embodiment of figures 1, 2A-2C and 4, the lancet mechanism 104 includes a skin probe 112 and a dermal tissue penetration element (not shown). The skin probe 112 is configured to limit the depth at which the dermal tissue penetration element can penetrate a target site (eg, a target site of dermal tissue) when the apparatus 100 is employed to extract a fluid sample. bodily. Any suitable skin probe known to those skilled in the art may be employed in the embodiments of the present invention. A non-limiting example of a suitable skin probe is described in the patent application of E.U.A. co-pending No. 10 / 690,083. In addition, the skin probe 112 may be movable or fixed relative to the housing 102. The dermal tissue penetration elements employed in the embodiments of the present invention may be a conventional lancet, as is known to those skilled in the art, or can be part of an integrated medical device that includes a dermal tissue penetration element and a test strip, of which the examples are described in the international application No. PCT / GB 01/05634 (published as WO 02/49507 on June 27, 2002) and the US patent application No. 10 / 143,399, both of which are incorporated herein in their entirety for reference. As will be explained below in detail, the upper and lower arm assemblies 110 and 108 are operatively connected in such a way that when a user's finger applies a predetermined user force to the lower arm assembly 108 and moves the arm assembly bottom 108 from a first position to a second position (shown in figure 2C), the upper arm assembly 110 and the lower arm assembly 108 cooperate to couple the user's finger with a compressive force that is greater than the predetermined force of the user. In addition, the lancet mechanism 104 is configured to penetrate a target site in the user's finger while the upper arm assembly 0 and the lower arm assembly 108 cooperate to engage the user's finger. Then, the compressive force serves to extract a sample of body fluid from the penetrated target site. In the embodiment of FIGS. 1, 2A, 2B, 2C and 4, the fixing mechanism 106 is pivotally connected to the housing 102 and is configured to allow the operation operated with one hand of the apparatus 100 to be performed with a user force relatively easy while facilitating the removal of a sample of body fluid (eg, a blood sample) out of a penetrated target site (such as a target site of penetrated dermal tissue) without manipulation (e.g., tightening and / or milking) of the target site after penetration. Indeed, as will be described hereinafter, the fixing mechanism 106 is configured in such a way that a predetermined force applied by a user's finger is sufficient to operate the apparatus 100. With particular reference to FIGS. 2A, 2B, and 2C, the lower arm assembly 108 includes a body 114 with a proximal end 116, a distal end 118, a body upper surface 120 and a lower body surface 122. The distal end 118 is configured to accommodate the shape of the lancet mechanism 104 and may have , for example, a stepped shape in its cross section. The distal end 118 includes a lower flange 124 and a pressure ring 126 for coupling a target site (eg, a target site of dermal tissue of a finger F of the user as depicted in Figure 2C). The pressure ring 126 includes a flange 128 surrounding an opening 130 for the skin probe 112 that extends directly. The tab 128 may be, for example, planar, in highlight and / or with a profile to accommodate different target sites. The opening 130 can be any suitable shape including, but not limited to, circular, oval, square, triangular, hexagonal and octagonal. The pressure ring 126 can be removable or permanently attached to the body 114. Non-limiting examples of pressure rings that can be employed in the embodiments of the present invention are described in the patent application of E.U.A. Nos. 09/877514 (published as US 2002/0016606 on February 7, 2002) and 10 / 653,023, both of which are therefore fully incorporated for reference. The pressure ring 126 may be formed of relatively rigid plastic material including, but not limited to, polystyrene, polycarbonate and polyester, or of relatively elastically deformable material including, but not limited to, elastomeric materials, polymeric materials, polyurethane materials , latex materials, silicone materials and any combination thereof. The proximal end 116 of the lower arm assembly includes means for limiting the compressive force applied to the user's finger F, ie an arm limiting the force 132 and a spring limiting the force 134 which are operatively connected to limit the force. compressive strength The force limiting arm 132 is engaged within the body 114 and extends from the proximal end 16 of the lower arm assembly to approximately the center of the body 114. The force limiting arm 132 and the lower arm assembly 108 are pivoted to the housing 102 in the axis of the lower pivot 136. The limiting arm 132 is also pivoted to approximately the center of the upper arm assembly 110. The spring limiting the force 134 is attached to the boundary arm the force 132 by a screw 140 or other suitable means such as by welding or an adhesive. The body 114 and the limiting force arm 132 can be formed, for example, from rigid materials including polycarbonate, polystyrene or a metal. The angle α formed between the lower arm assembly 108 and the plane P (see, for example, in Figure 2B) can vary from about 0 to about 45 degrees during operation of the apparatus 100. The distal end 18 of the lower arm assembly makes contact with housing 102 when a is approximately 0 degrees. With reference to Figure 2B, the force limiting spring 134 extends from near the center of the arm which limits the force 132 internally through the body 1 14 of the inner arm assembly 108 and exits the body 114 at the flange lower 124 such that when a is close to 0 degrees and a user's F finger is engaged (see Figure 2C), the limiting force arm 132 rotates counterclockwise about the pivot axis lower 136, causing the spring limiting the force 134 to deviate against the lower flange 124. The spring limiting the force 134, therefore, beneficially limits the amount of compressive force applied to a finger F of the coupled user in the fixing mechanism 106. In such a circumstance, the angle ß is formed between the arm limiting the force 132 and the body of the lower arm assembly 114 (see Figure 2C). The angle ß can vary from, for example, about 0 degrees to 20 degrees. In general terms, the purpose of the spring limiting the force 134 (or other suitable means for limiting the compressive force as known to those skilled in the art once the description of the present is assessed) is to limit the applied constrictive force by the assemblies of upper and lower arm to a finger of the user. This can be done, for example, by providing the upper and lower arm assemblies to deform and / or deflect in such a way that the compressive force that would otherwise be present in a fully rigid fixing mechanism is mitigated. The upper arm assembly 110 includes substantially parallel upper arms 142A and 142B and an upper compression surface 144 (see, for example, Figure 2A). The upper arms 142A and 142B each include a cam portion 146 and are each pivotally attached to the arm which limits the force 132 on the upper pivot shaft 148. An angle? formed between the lower arm assembly 108 and the upper arms 42A, 142B (shown in Figure 2B) can vary from about 0 degrees to 180 degrees during the operation of the apparatus 100. The cam portions 146 are in contact with the surfaces slides 150 of the housing 102. When the upper arms 142A, 142B rotate about the upper pivot shafts 148, the cam portions 146 slide along the sliding surfaces 150. The upper compression surface 144 applies pressure against the finger F of the user when the finger F of the user is coupled with the fixation mechanism 106 and thus aids in the removal of body fluid from the user's F finger. The upper compression surface 144 can be any suitable upper compression surface including, but not limited to, a curved upper compression surface, a superior angled compression surface, a superior compression surface with multiple sides or the surface of two cylindrical sleeves. In addition, the upper compression surface 144 can be formed of flexible material including, but not limited to, leather, artificial leather, upper, nylon band, rubber, or a semi-rigid plastic such as vinyl or polypropylene. In the embodiment shown in Figures 1, 2A, 2B, and 2C, the upper compression surface 134 is removably attached to the upper arms 142A, 142B by screws 152. The upper compression surface 144 can also be adhered to the upper compression surfaces 144A, 142B. upper arms 142A, 142B using techniques known to those skilled in the art, including double-sided hot-sealing sizing or double-sided pressure-sensitive adhesion. The upper compression surface 144 can also be sewn or riveted onto the upper arms 142A, 142B. It is postulated, without being linked, that the manner in which the compressive force is applied by the apparatus according to exemplary embodiments of the present invention can be explained by the following description, with reference to Figures 3A and 3B. With reference to Figure 3A, because the user's F finger is forced towards the pressure ring 126, a downward force F1 is created by the finger bone FB of the user's finger F. The flange 128 of the pressure ring reacts with an equal and opposite Fe force against the bottom side of the user's finger F. Because F1 is increased, a protrusion of the pressurized skin B can be created. Applying a compressive force F2 across the upper compression surface 144 to the top of the user's F finger allows the force F1 to be reduced while maintaining the compressive force Fe and the protrusion of skin B, as shown in Figure 4B. In this way, the amount of user force that must be applied by the user's F finger to maintain the protrusion of the skin B is beneficially reduced through the application of the compressive force F2 through the compression surface. top 144, thus reducing the hassle, and the effort required by a user. Now referring to Figure 4, the compressive force F2 generated by the upper compression surface of the upper arm assembly can be defined by the following equations: Fe = F1 + F2 and F2 = Fc * (L2 / L1) * (L3) / L4) where: Fe is the compressive force is a user's finger that results from the cooperation of the upper arm assembly and the lower arm assembly; L1 is the distance of the lower pivot axis 136 to the upper pivot axis 148; L2 is the distance of the lower pivot axis 136 to the center line of the pressure ring 126 (wherein Figure 5 is operatively aligned with the upper compression surface 144); L3 is the distance of the cam portion 146 to the upper pivot shaft 148; and L4 is the distance of the cam portions 146 to the center line of the pressure ring. The distances L1, L2, L3 and L4 can be, for example, from about 15 mm to 32 mm, 30 mm to 60 mm, 8 mm to 16 mm and 22 mm to 44 mm, respectively. In an exemplary embodiment where L1 = 32 mm, L2 = 60 mm, L3 = 16 mm and L4 = 44 mm, 68% of the compressive force Fe is generated by the upper compression surface 144 of the fixing mechanism 106 (ie , F2) and 32% of the compressive force Fe is generated by the user's finger F (ie, F1). In general terms, the apparatus for the extraction of body fluid according to the embodiments of the present invention is configured in such a way that the movement of the lower arm assembly from a first position to a second position is translated in the movement of the assembly of upper arm in the same direction as the lower arm assembly such that the distance between the upper and lower arm assemblies is decreased. In addition, a mechanical advantage is provided when this configuration is provided for a portion of Fe provided by F2. The compressive force Fe required to successfully extract a body fluid sample from a target dermal tissue site of a user's finger may be as high as approximately 18N. A user may experience discomfort when applying a force F1 that is greater than 10N. From the previous example, the force required by the user's finger for the exemplary embodiment may be up to about 6N, which is less than the force at which a user typically experiences discomfort. In this way, the apparatus 100 beneficially decreases the amount of force required by a user to successfully remove body fluid. Figures 5A and 5B depict side views of the apparatus 100 with upper arms 142A and 142B rotated counterclockwise (in the direction of the open arrow of Figure 5A) around the upper pivot axis 148. In FIG. the configuration of Figures 5A and 5B, the upper arms 142A and 142B contact the stop surface 160 in the housing 102. In Figure 5A, the lower arm assembly 108 is raised slightly above the skin probe 112. it requires additional force from the user's finger F to rotate the lower arm assembly 108 clockwise to fully engage the skin probe 112 with the dermal tissue of the user's finger F, as shown in Figure 5B. In the configuration of Figures 5A and 5B, the arm limiting the force 132 is stationary and the force required to press the lower arm assembly 108 onto the skin probe 112 is equal to a displacement force created by the spring that Limits the force 134. The operation of the apparatus 100 in the manner shown in Figures 5A and 5B does not involve the application of force to a user's finger by the upper compression surface 144. However, with the upper arms 142A and 142B in the position of FIGS. 5A and 5B, the apparatus 100 can be used to extract body fluid from different target sites to a target site of a user's finger. Figures 6A and 6B show the side and end views, respectively, of the apparatus 100 in a storage configuration. In Figures 6A and 6B, the upper arm assembly 110 is fully rotated clockwise about the upper pivot shaft 148 and the lower arm assembly 108 is fully rotated clockwise about the axis lower pivot 136. In such configuration, the apparatus 100 is compact and can be adjusted, for example, in the palm of a user's hand. Normal non-limiting dimensions shown in Figures 6A and 6B are a X dimension of 77 mm, a Y dimension of 53 mm and a Z dimension of 22 mm. Figures 7A through 7C are schematic side views showing a sequence of steps in the operation of the apparatus 100 of Figure 1. Figure 7A depicts the upper and lower arm assemblies 110 and 108 in a first position with a user's finger. F contacting the pressure ring 126 of the lower arm assembly 108 but without applying any significant force. The upper and lower arm assemblies can be maintained in the first position by, for example, the user's finger, nominal friction (as compared to F1) about the lower pivot axis 136, or nominal spring (as compared to F1) that it moves against the lower arm assembly 108. Figure 7B depicts the lower arm assembly 108 that rotates clockwise under a force applied by the user's finger F. As the lower arm assembly 108 rotates, the upper arm assembly 110 engages the finger of user F (see Figure 7B). Once the user's finger F has applied a predetermined force, the upper and lower arm assemblies 108 and 110 achieve a second position described in figure 7C. In this second position, the upper compression surface 144 and the pressure ring 126 cooperate to exert a compressive force on the user's finger F. The compressive force applied is the sum of the forces applied by the upper compression surface 144 and the The user's strength is predetermined and typically lies on the scale of, for example, close to 9N to 18N. Typically, the compressive force applied by the compression surface 144 (ie, F2) is greater than or equal to the predetermined force applied by the user's finger F (i.e., F1). F2 however, does not need to be greater than F1 in order to provide benefits as described here. For the example described above, about 68% of the total compressive force (Fe) is contributed by the upper compression surface 144 (ie, F2), while about 32% of the total force is contributed by the force of the default user (that is, F1). Figures 8A to 8C depict several views of the apparatus 200 for removing body fluid according to another exemplary embodiment of the present invention. The apparatus 200 includes a housing 202, a lancet mechanism 204 and a locking mechanism 206. The attachment mechanism 206 includes a lower arm assembly 208, an upper arm mechanism 210 and a hinge rod 212. The arm assembly upper 210 and lower arm assembly 208 are pivotally connected to a housing 202 by the upper pivot shaft 214 and a lower pivot shaft 216, respectively. The angle <; j > formed between the lower arm assembly 208 and the housing 202 may vary from about 0 degrees to about 45 degrees during the operation of the apparatus 200. The angle? formed between the upper arm assembly 210 and the lower arm assembly 208 may vary from about 0 degrees to about 30 degrees during the operation of the apparatus 200. The lower arm assembly 208 includes a pressure ring 218 and an axle 218. lower pivot of a link rod 220. The lower link assembly 208 is pivotally attached to the link rod 212 on the lower pivot shaft of the link rod 220. The upper link assembly 210 includes two upper compression surfaces in cylindrical form 222 and an upper pivot axis of hinge rod 224, as illustrated in Figure 8B. The upper arm assembly 210 is pivotally attached to the hinge bar 212 on the upper pivot axis of the hinge bar 224. In the embodiment of FIGS. 8A, 8B and 8C, the upper compression surfaces 222 are surfaces of removable cylindrical sleeves 226. In addition, the compression surfaces 222 are configured to engage the upper part of the user's finger F. Referring to FIG. 8C, the articulation bar 212 includes an adjusting screw 228 in contact with a spring that limits the force 230. The hinge bar 212 is located distal to the upper pivot shaft 214 and the lower pivot shaft 216. The adjusting screw 228 extends internally from the upper part of the hinge bar 212 and contacts the limiting spring. the force 230. The force limiting spring 230 is also in contact with the upper pivot axis of the hinge rod 224. In the configuration of the 8A-8C, the compressive force experienced by the user's finger F is limited by the use of the adjusting screw 228, the spring limiting the force 230, and the upper pivot axis of the hinge bar 224. The axis of The upper pivot of the hinge bar 224 can move reversibly and linearly against the spring limiting the force 230 when the force against the upper pivot axis of the hinge rod 324 exceeds a preload displacement established by the spring limiting force 230 The adjusting screw 228 also allows the aforementioned preload displacement to be adjusted by varying the amount of compression between the adjusting screw 228 and the upper pivot axis of the hinge bar 224. Although a limitation means of force is optional in the apparatus for the extraction of body fluid according to embodiments of the present invention, said means limiting The force may be useful to ensure that an optimum compressive force is applied to various sizes of the user's fingers. In addition, the use of a means that limits the force within its operating limits may serve to limit the total compressive force to no more than, for example, 10N. The upper arm assembly 210 and the lower arm assembly 208 can be formed of suitable rigid material including, but not limited to, aluminum, stainless steel, polystyrene, polycarbonate and polyester. The upper arm assembly 210 can be constructed of flexible materials including, but not limited to, polypropylene in such a way that the upper arm assembly 210 is bent when the compression force against the user's finger F exceeds a predetermined limit. Figure 9 describes an apparatus 300 for extracting body fluid according to still another embodiment of the present invention. Apparatus 300 (as well as apparatus 400 and apparatus 500 described below) applies a compressive force to a finger of user F such that a tourniquet effect is applied to the finger of user F causing sufficient bleeding to gather at the site. of dermal tissue perforation so that the extraction of body fluid is successful. The apparatus 300 includes a housing 302, a lancet mechanism 304 and a locking mechanism 306. The housing 302 includes a means for measuring, analyzing and displaying an analyte concentration (not shown). The housing 302 also includes a lower compression surface 308. The lancet mechanism 304 is adjacent the lower compression surface 308, and includes a skin penetration member 310, a lancet spring 312 and an opening 314 for the penetration element of dermal tissue pass through it. The locking mechanism is pivotally attached to the housing 302 by a pivot shaft 316. The locking mechanism 306 includes a lever arm 318 and an inner compression surface 320. The interior compression surface 320 can be made from a compliant material which includes, for example, rubber or foam and can be contoured to fit a finger shape of the user F. The angle? formed between the inner compression surface 320 and the lower compression surface 308 may vary from about 0 degrees to about 90 degrees during the operation of the apparatus 300. The inner compression surface 320 is in opposite relation to the lower compression surface 308 of the housing 302. The lower compression surface 308 can be made, for example, of compliant material including rubber or foam and can be contoured to the finger shape of the user F. The inner compression surface 320 and the compression surface lower 308 are configured to apply a compressive force on the user's finger F (in a manner similar to a tourniquet), when the lever arm 318 and the housing 302 are tightened together (i.e. one toward the other) and the arm lever 318 rotates toward housing 302, thereby decreasing the angle? In other words, the housing and the locking mechanism are operatively connected such that a user's finger inserted between the upper compression surface and the inner compression surface is engaged with a compressive force when the lever arm and the housing are tightened together (that is, one towards another). Tightening can be performed, for example, manually by a user's hand. The tightening action is an intuitive action for the user. The locking mechanism 306 applies a compressive force on a user's finger via a mechanical advantage provided by the configuration of the locking mechanism. In the embodiment of Figure 9, the mechanical advantage is the ratio of the dimensions L1 and L2 (ie, L1 / L2). Therefore, the compressive force on a finger of the user is beneficially greater than the force exerted on the lever arm and the housing to tighten them together. The convenient mechanical ratio of L1 / L2 can be, for example, in the scale of more than 1 to 10. Figure 10 represents an apparatus 400 for the extraction of body fluid. The apparatus 400 includes a housing 402, a lancet mechanism 404 and a locking mechanism 406. The lancet mechanism 404 includes an opening (not shown), a trigger 409 and a dermal tissue penetration element 410. The fixation mechanism 406 includes an internal compression surface 414, a cavity 416, a lower compression surface 418 on a movable compression member 420, a vertical connector 422, and a lever arm 424. The lever arm 424 includes a pivot shaft 426 and a trigger release 428. The inner compression surface 414 is located within the cavity 416. The lower compression surface 418 is also located within the cavity 416 in an oppositional relationship with the inner compression surface 414. The element of compression 420 is attached to lever arm 424 by vertical connector 422. The angle i formed between lever arm 424 and housing 402 p it can vary from about 0 degrees to about 90 degrees during operation of the apparatus 400. The inner compression surface 414 and the lower compression surface 418 are configured to apply a compressive force on the user's finger F (in a similar manner to a turnstile), when the lever arm 424 and the housing 402 are pressed together and the lever arm 424 rotates towards the housing 402, thereby decreasing the angle i. The tightening action is an intuitive action of the user and also serves to activate (ie, turn on) the lancet mechanism 404 via the release of the trigger 428. Referring to FIG. 11, a method 500 for removing the body fluid from a Target site according to an exemplary embodiment of the present invention includes step 510 to provide an apparatus for the removal of body fluid that includes (i) a housing; (ii) a lancet mechanism for piercing a target site attached to the housing and (iii) a fixing mechanism attached to the housing. In addition, the attachment mechanism of the apparatus includes the upper and lower arm assemblies. Said apparatuses have been described above (for example, with respect to figures 1 and 8A). Subsequently, a predetermined force is applied to the lower arm assembly with a user's finger such that the lower arm assembly moves from a first position to a second position, as set forth in step 520 of FIG. 11. said displacement, the upper arm assembly and the lower arm assembly cooperate to couple the user's finger with a compressive force that is greater than the predetermined user's strength (as described above with respect to, for example, Figure 7C) .

Subsequently, as set forth in step 530 of figure 11, a target site of the user's finger is pierced with the lancet mechanism, while the upper arm assembly and the lower arm assembly cooperate to engage the user's finger, where after the compressive force serves to extract a sample of body fluid from the perforated target site. It should be understood that various alternatives to the embodiments of the invention described herein can be employed in the practice of the invention. It is intended that the following claims define the scope of the invention and the structures and methods within the scope of these claims and their equivalents, therefore they are covered.

Claims (14)

NOVELTY OF THE INVENTION CLAIMS

1. - An apparatus for extracting body fluid, the apparatus comprises: a housing; a lancet mechanism for penetrating a target site attached to the housing; a fixing mechanism attached to the housing, the fixing mechanism includes: a lower arm assembly; and an upper arm assembly; characterized in that the lower arm assembly and the upper arm assembly are operatively connected such that when a user's finger applies a predetermined user force to the lower arm assembly, the lower arm assembly moves from a first position to a second position and the upper arm assembly and the lower arm assembly cooperate to engage the user's finger with a compression force that is greater than the predetermined user force; and wherein the lancet mechanism is configured to penetrate a target site on the user's finger while the upper arm assembly and the lower arm assembly cooperate to engage the user's finger, henceforth the compression force serves to extract a sample of body fluid from the penetrated target site.

2. The apparatus according to claim 1, further characterized in that the lower arm assembly and the upper arm assembly cooperate by means of a mechanical advantage to couple the user's finger with the compression force.

3. The apparatus according to claim 1, further characterized in that the fixing mechanism is pivoted to the housing and is configured for one-handed operation of the apparatus.

4. - The apparatus according to claim 1, further characterized in that the lower arm assembly includes a pressure ring and the upper arm assembly includes a compression surface and wherein the pressure ring and the compression surface cooperate for Couple the user's finger with the compression force.

5. The apparatus according to claim 1, further characterized in that it also includes means for limiting the compression force.

6. - The apparatus according to claim 5, further characterized in that the means for limiting the compression force include: an arm that limits the force; and a spring limiting force, wherein the arm limiting the force and the spring limiting the force are operatively connected to limit the compression force.

7. - The apparatus according to claim 5, further characterized in that the means for limiting the compression force include: an adjusting screw; and a spring limiting force, wherein the adjusting screw and the spring limiting force are operatively connected to limit the compression force.

8. - The apparatus according to claim 1, further characterized in that the apparatus further includes an articulation arm and the mounting of the lower arm and the upper arm assembly are operatively connected by the articulation arm.

9. The apparatus according to claim 1, further characterized in that the predetermined force is less than about 6 N and the compression force is between 9 N and 18 N.

10. - An apparatus for removing body fluid, the apparatus comprises: a housing with a lower compression force; a lancet mechanism for penetrating a target site attached to the housing; a fixing mechanism attached to the housing, the fixing mechanism includes: a lever; and an inner compression surface operatively aligned with the lower compression surface; wherein the housing and the locking mechanism are operably connected such that a user's finger inserted between the upper compression surface and the inner compression surface engages a compression force when the lever and housing are tightened together .

11. - The apparatus according to claim 10, further characterized in that it includes a trigger release, wherein the trigger release is configured to activate the lancet mechanism when the lever and housing are tightened together.

12. - The apparatus according to claim 10, further characterized in that the lever arm and the housing cooperate by means of the mechanical advantage to produce the compression force.

13. - A method for extracting body fluid from a target site, the method comprising: providing an apparatus for extracting body fluid including: a housing; a lancet mechanism for penetrating a target site attached to the housing; a fixing mechanism attached to the housing, the fixing mechanism includes: a lower arm assembly; and an upper arm assembly; applying a predetermined force to the lower arm assembly with a user's finger so that the lower arm assembly moves from a first position to a second position and the upper arm assembly and lower arm assembly cooperate to engage the finger of the user with a compressive force that is greater than the force of the predetermined user; and penetrating a target site in the user's finger while the upper arm assembly and the lower arm assembly cooperate to couple the user's finger, henceforth the compression force serves to extract a body fluid sample from the penetrated target site .

14. - The method according to claim 13, further characterized in that the step of further providing includes providing an apparatus for extracting body fluid that also includes means for limiting the compression force and the step of applying also includes means for limiting the compression force that acts to limit the compression force.