Tape transport lance sampler

A lancet-sampler system is configured to automatically remove a protective cover from a lancet and automatically unpack a test pad just prior to use. This minimizes the risk of injury and reduces the chance of cross-contamination between the lancet and the test pad. The lancet defines a capillary groove for drawing body fluid from the incision via capillary action and a sample transfer opening for collecting the fluid from the groove. A carrier tape is coupled to the lancet. The carrier tape includes a test pad for analyzing the fluid. The tape is folded around the test pad to form an airtight package. The test pad is located at a position to align with the sample transfer opening when the tape is unfolded. The protective cover covers a portion of the lancet, and when the tape is pulled, the protective cover is automatically pulled from the lancet.

BACKGROUND

The present invention generally relates to a transport system for integrated sampling devices and more specifically, but not exclusively, concerns a system in which a sterility cap is automatically removed from a lancet-sampler and a technique for manufacturing the same.

The acquisition and testing of bodily fluids is useful for many purposes and continues to grow in importance for use in medical diagnosis and treatment, such as for diabetes, and in other diverse applications. In the medical field, it is desirable for lay operators to perform tests routinely, quickly, and reproducibly outside of a laboratory setting, with rapid results and a readout of the resulting test information. Testing can be performed on various bodily fluids and, for certain applications, is particularly related to the testing of blood and/or interstitial fluid. Performing home-based testing can be difficult for many patients, especially for patients with limited hand dexterity, such as the elderly or diabetics. For example, diabetics can sometimes experience numbness or tingling in their extremities, such as their hands, which can make self-testing difficult because they are unable to accurately position a test strip to collect the blood sample. In addition, wounds for diabetics tend to heal more slowly, and as a result, there is a desire to make incisions less invasive.

Recently, lancet integrated test strips have been developed in which a test strip is integrated with a lancet or other piercing means so as to form a single disposable unit. While these integrated units have somewhat simplified the collection and testing of fluid samples, there are still a number of issues that need to be resolved before a commercial unit can be implemented. One issue concerns maintaining the sterility of the lancet so as to minimize the risk of infection. In practice, conventional plastic or syringe-type caps that are used to maintain the sterility of typical lancets cannot be incorporated with lancet integrated test strips for several reasons. With typical syringe-type caps, the cap encapsulates the lancet, and the cap is removed by pulling or twisting the cap off the lancet. As noted before, diabetics as well as the elderly can experience hand dexterity problems. Consequently, the manual removal of the cap from the lancet without destroying or damaging the integrated device can be difficult or even practically impossible. As of yet, a commercially practical system for automatically removing the cap has not been developed.

Integrated systems have been proposed that utilized closed needles that are manufactured through conventional needle drawing techniques. However, these conventional drawing techniques for needles can be rather expensive. Other systems have been proposed in which closed needles are manufactured using a semiconductor manufacturing process in which layers of semiconductor material are layered to form a closed needle. However, manufacturing a closed needle in such a way can be expensive and is not well suited for high volume production. Still yet other integrated disposables have been proposed that utilize a modified version of a conventional lancet for lancing the skin.

There is a trend to make lancets and needles smaller or thinner so as to make less traumatic or less invasive incisions, which in turn makes self-monitoring less painful as well as promotes healing of the incision. However, due to their thinner nature, lancets are more prone to bending or are susceptible to other damage, especially when protective caps are removed. Further, the pulling or twisting action during cap removal can damage the test strip, like the delicate electrodes in an electrochemical type test strip, or can even result in the lancet being separated from the test strip.

Other difficulties arise when a thinner lancet is used in integrated disposables in order to reduce pain. Some integrated disposable designs have an open capillary channel or groove formed in the lancet that is used to draw via capillary action body fluid from the incision to the test area or chamber. These open capillary groove integrated disposables experience a number of difficulties in drawing fluid via capillary action when the lancet is thin. As should be already appreciated, capillary action occurs when the adhesion of a liquid, such as body fluid, to the walls of the capillary channel is stronger than the cohesive forces between the liquid molecules. Adhesion of the liquid to the walls of the capillary channel causes the edge of the liquid to move upwards in the channel, and the surface tension acts to hold the surface of the liquid intact, so instead of just the edges moving upward, the whole liquid surface is dragged upward in the channel. However, with the open capillary groove designs, one of the walls of the capillary channel is eliminated, thereby reducing the overall contact area between the walls of the capillary channel and the surface of the body fluid. This reduction in contact area between the capillary channel and the body fluid reduces the capillary force applied to the fluid. To compensate, open capillary groove integrated disposables typically require that the capillary groove is deep so that the opposing sidewalls of the groove provide sufficient contact area with the meniscus to draw the body fluid. However, when the thickness of the lancet is reduced in order to reduce pain associated with lancing, the groove becomes too shallow to draw the body fluid via capillary action.

Integrated disposable designs have been proposed in which the entire unit is sealed within a protective packet. However, these designs require the entire disposable unit to be sterilized at the same time, which results in a whole host of difficulties. Unfortunately, sterilization techniques for lancets, such as radiation, adversely affect the chemistry of the test strip. Hence, if left uncompensated, the accuracy of the test strip can be significantly hampered. To compensate for the changes that occur during sterilization, samples from sterilized lots are taken so that an adjustment or calibration value can be calculated for the lot. Moreover, certain desirable sterilization techniques for lancets are impractical when the lancet and test strip are combined together because these techniques tend to damage or even destroy components on the test strip. In addition, undesirable cross contamination can occur between the lancet and the test strip when sealed in the same protective packet. For instance, components of the test strip, such as chemicals, biological components, adhesives, and the like, can migrate within the packet onto the lancet, thereby possibly compromising the sterility of the lancet.

Thus, needs remain for further contributions in this area of technology.

SUMMARY

One aspect concerns a tape assembly that includes a lancet and a carrier tape. The lancet includes a lancet tip configured to lance tissue. A protective cover covers at least a portion of the lancet tip. The tape is coupled to the lancet and the protective cover. The tape has a slackened section between the lancet and the protective cover for allowing removal of the protective cover from the lancet tip when the tape is pulled.

Another aspect concerns a technique for assembling a tape assembly. A lancet is provided with a portion of the lancet covered with a protective cover. A slackened section of a tape is formed. The lancet and the protective cover are attached to the tape with the slackened section located between where the lancet and the protective cover are attached to the tape.

A further aspect relates to a technique for automatically removing a protective cover from a lancet. A tape assembly includes a tape and the lancet with the protective cover covering at least a portion of the lancet. The lancet and the protective cover are attached to the tape with a slackened section of the tape located between where the lancet and the protective cover are attached to the tape. The protective cover is pulled from the lancet by applying tension to the tape.

Still yet another aspect relates to a body fluid sampling device that automatically aligns a test pad with a sample collection opening. The device includes a lancet that is configured to lance an incision in tissue. The lancet defines a capillary groove configured to draw body fluid from the incision via capillary action and the sample transfer opening configured to collect the body fluid from the capillary groove. A carrier tape is coupled to the lancet. The carrier tape includes a test pad configured to analyze the body fluid. The tape is folded around the test pad, and the test pad is located at a position to align with the sample transfer opening when the tape is unfolded.

A further aspect concerns a lancet-sampler that includes a lancet. The lancet has a body and a lancet tip extending from the body configured to cut an incision in tissue. The lancet has opposing first and second sides. The lancet defines a groove in the first side that extends from the lancet tip to the body. A cover covers at least a portion of the groove over the first side to define an enclosed capillary channel configured to draw body fluid via capillary action. The groove has at least a segment that extends completely through the lancet from the first side to the second side.

DESCRIPTION OF THE SELECTED EMBODIMENTS

For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiments illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. A number of embodiments of the invention are shown in detail, although it will be apparent to those skilled in the relevant art that some features that are not relevant to the present invention may not be shown for the sake of clarity. It should be noted that directional terms, such as “up”, “down”, “top”, “bottom”, “clockwise” and “counterclockwise”, are used herein solely for the convenience of the reader in order to aid in the reader's understanding of the illustrated embodiments, and it is not the intent that the use of these directional terms in any manner limit the described, illustrated, and/or claimed features to a specific direction or orientation.

The present invention generally concerns a tape of lancet integrated test elements (LITs) and/or semi-integrated disposables as well as a technique for manufacturing the LITs and/or semi-integrated disposables. In particular, the tape includes a plurality of flat lancets. Each lancet includes a whole and/or half-etched capillary channel that connects to a sample transfer opening and an actuator engagement keyhole that is used to actuate the lancet. The capillary channel and the sample transfer opening are covered with a hydrophilic heat sealable foil via a continuous reel-to-reel process. Enclosing the capillary channel allows the lancet sampler to draw fluid via capillary action, especially when the lancet is thin. Afterwards, the individual lancets are punched from the strip. The tip of the lancet is heat-laminated between a foil sandwich, thereby forming a removable protective cover. Two strips of adhesive tape are attached to opposite ends of the lancet, and the lancet assembly is sterilized. A reagent label or test pad configured to analyze the fluid sample is applied to a main cassette or carrier tape. The cassette tape is folded over the test pad in a fanfold fashion, and the tape is secured over the test pad via a peelable adhesive to form an airtight package. In the package, a micro-desiccant bead can be affixed adjacent the test pad. The two strips of adhesive tape are attached to two opposite flaps or sections between the fold lines. During dispensing, the tape is pulled to unfold the package. As the tape unfolds, the protective cover is automatically pulled from the lancet tip. When fully unfolded, the test pad automatically aligns with the sample transfer opening. The lancet is then actuated to lance the skin, and the fluid is drawn onto the test pad via the channel in the lancet. The alignment of the test pad with the sample transfer opening can occur before or after the lancet lances the skin and collects the fluid. In other embodiments, the sample transfer opening is optional such that the fluid transfer occurs directly from the capillary channel.

With this system, the difficulties associated with the manual removal of the protective cap are eliminated because the system provides a unique technique for automatically removing caps. A number of the difficulties associated with sterilization are reduced because the lancet can be sterilized separately from the test pad. Moreover, the risk of cross-contamination between the lancet and the test pad is reduced because the lancet and test pad are only exposed immediately prior to use. As will be understood from the discussion below, the system also helps to alleviate a number of other issues. Although the present invention will be discussed with reference to collecting blood from the skin, it should be recognized that other types of body fluids, such as interstitial fluid, can be analyzed from various types of tissues, in addition to skin.

A perspective view of a lancet30, according to one embodiment, used in the LIT is shown inFIG. 1. The lancet30in one form is made from surgical grade stainless steel, but it should be appreciated that the lancet30can made of other materials suitable for lancets. In one particular form, the lancet30is made from 76 μm thick precipitation hardening (PH) 17-7 stainless steel. As can be seen, the lancet30includes a lancet tip32that extends from a lancet body or base34. The lancet tip32is configured to cut an incision in tissue. In the illustrated embodiment, the lancet tip32has a triangular shaped cutting edge, but it should be recognized that the tip32can be shaped differently in other embodiments. The profile of the lancet30inFIG. 1is generally flat, which in turn simplifies packaging of the LIT. However, it is contemplated that the lancet30in other embodiments does not necessarily need to be flat.

Stretching from the lancet tip32to the lancet base34, the lancet30has a capillary groove36that is used to transport a body fluid sample from an incision to a sample transfer opening or pooling area38in the lancet30. In the illustrated embodiment, the capillary groove36extends partially through the lancet30, and the sample transfer opening38extends completely through the lancet30. Instead of being partially etched through the lancet30, the capillary groove36in other embodiments can be a fully-etched capillary channel that extends completely through the lancet30. As a side note, the terms “etched”, “partially etched”, and “fully etched” are being used so that the reader easily comprehend the discussed concepts, and it should be understood that the use of these terms in no way limits how the various grooves, openings, and other features are created. Although these features can be etched, it should be recognized that these features can also be created using other techniques as well, like stamping, cutting, and punching, to name a few examples. In one embodiment where the lancet30is 76 μm thick, the partially etched section of the capillary groove36has a width of approximately 250 μm and a depth of approximately 40 μm, but it should be recognized that the dimensions can vary in other embodiments. The sample transfer opening38is generally wider than the capillary groove36so as to collect the fluid from the capillary groove36for deposition onto a test pad. In the depicted embodiment, the sample transfer opening38has an oblong or elliptical shape, but the sample transfer opening38can be shaped differently in other embodiments or eliminated completely.

Between the capillary groove36and the sample transfer opening38, the lancet30has a fully-etched section39that has generally the same width as the capillary groove36, but the section39is fully etched like the sample transfer opening38. If the fluid from the capillary groove36was directly transferred to the wider and fully etched sample transfer opening38, the fluid flow might on occasion stop because fluid tends to have a higher affinity for smaller capillary channels, which in this case would be the capillary groove36. The fully-etched section39before the sample transfer opening38provides a gradual transition that allows the momentum of the body fluid to carry the fluid to the sample transfer opening38. Opposite the capillary groove36, the sample transfer opening38has a vent slot40for venting air as the sample transfer opening38fills with fluid. In the illustrated embodiment, the sample transfer opening38is wider than the vent slot40, but it is contemplated that the vent slot40can have the same width or be wider than the sample transfer opening38in other embodiments. Moreover, the vent slot40in further embodiments can be eliminated such that uncovered portions of the capillary groove36and/or the sample transfer opening38can vent air. In the base34, the lancet30has an actuator engagement opening or keyhole42to which an actuator of a lancing mechanism engages in order to fire the lancet30. In the depicted embodiment, the actuator engagement hole42includes an oblong-shaped central portion and opposing circular-shaped holes. As should be recognized, the actuator engagement hole42can be shaped differently in other embodiments.

Turning toFIGS. 2 and 3, the lancets30in one form are manufactured via a continuous reel-to-reel process in which the various features of the lancets30are formed from a continuous lancet strip44. For example, the openings38,42as well as the capillary groove36can be formed via photolithography, punching, and/or stamping techniques, to name a few examples. In one particular example, the capillary groove36is formed via photolithography by only partially etching into the lancet30. As should be recognized, other types of manufacturing processes can be used to form the lancets30. In the illustrated embodiment, the lancet strip44includes tractor openings46for indexing the lancet strip44during manufacturing, but the tractor openings46can be optional in other embodiments.

As mentioned before, it is desirable to have the lancet30as thin as possible so as to minimize pain associated with lancing. It was, however, discovered that when the thickness of the lancet30is reduced, the available depth of the opposing walls of the capillary channel36is likewise reduced. This reduced wall depth of the capillary channel36in turn reduces the capillary affinity of the channel36to such an extent that the capillary channel36would not be able to consistently draw fluid in sufficient amounts for testing purposes or practically draw any fluid up to the sample transfer opening38.

Contrary to conventional wisdom that teaches the use of lancets with open capillary channels, the capillary groove or channel36of the lancet30in the illustrated embodiment is closed. To enhance the capillary action in thinner lancets, a cover foil48is used to enclose the capillary groove36so as to increase the contact area of the meniscus of the body fluid with the capillary groove36. After the capillary groove36and sample transfer opening38are formed, the lancet strip44is laminated with the cover foil48to create an enclosed capillary channel50. Laminating the cover foil48over the lancet30provides an easy technique to create a closed capillary channel. The cover foil48in one embodiment is heat sealed to the lancet strip44, but the cover foil48in further embodiments can be secured in other manners, such as via a room temperature adhesive. In one form, the cover foil48is hydrophilic by being coated with a hydrophilic layer of material. However, it should be appreciated that the cover foil48can be made hydrophilic in other manners, and all or part of the cover foil48can be hydrophilic. The cover foil48in one form is hydrophilic before the cover foil48is attached to the lancet30. In another form, hydrophilic material is deposited on a section the cover foil48that covers the capillary groove36. Surfactants, which are typically used to make materials hydrophilic, tend to be slippery. The slippery nature of surfactants can make the attachment of the cover foil48to the lancet30, with for example an adhesive, very difficult. To address this attachment issue, the cover foil48in one embodiment is not covered with a surfactant before the foil48is attached to the lancet30. Rather, once the cover foil48is attached, a solution of alcohol and surfactant is poured, sprayed, and/or otherwise drawn into the now enclosed capillary channel50. The solution is then dried to leave surfactant in the enclosed capillary channel50. In one particular form, the cover foil48is a hydrophilic heat sealable 12 μm thick polyethylene terephthalate (PET) foil. In selected embodiments, all or part of the cover foil48can be transparent and/or semi-opaque so as to be able to detect fluid fill sufficiency.

As can be seen, most of the capillary groove36and the sample transfer opening38are covered by the cover foil48to form the enclosed capillary channel50. However, a portion of the capillary groove36at the lancet tip32is left exposed so that the capillary channel50is able to collect the fluid sample. In a similar fashion, a portion of the vent slot40is open to the outside environment to permit venting of air from the capillary channel50. In comparison to open capillary channel designs, it has been found that the enclosed capillary channel50tends to be more robust than open capillary channel systems. It is theorized that, by being enclosed, the capillary channel50can enhance the capillary action that is used to draw the fluid sample. Moreover, in contrast to open capillary channel designs that allow fluid to escape, the enclosed capillary channel50tends to reduces fluid waste, which in turn reduces the amount of body fluid needed for fluid collection. Nevertheless, it should be recognized that selected features from the system described herein can be adapted to other systems that have an open capillary channel design.

Referring toFIG. 4, subsequent to lamination of the cover foil48over the strip44, the lancet30is punched from the strip44to form a lancet-sampler52. In one form, the lancet-sampler52is punched from the strip44with a high-speed rotary male/female die system. However, it should be appreciated that the lancet-sampler52can be removed from the strip44in other manners.

Looking atFIG. 5, all or a portion of the lancet tip32is sandwich between a protective foil or film54that is laminated together to form a protective tip or cover56for preventing injury as well as for maintaining the sterility of the lancet30. In one form, the protective foil54is heat laminated together to form the protective cover56, but it should be understood that the protective foil54can be laminated together in other manners, such as with an adhesive. As will be explained in greater detail below, the protective cap is configured to be automatically pulled off the lancet tip32before use. The protective foil54in one embodiment is a polyethylene (PE) or PET foil, but it is envisioned that other materials can be used. It also should be recognized that the protective cover56can be formed before the lancet-sampler52is punched from the strip44. For instance, the lancet30can be bent or cut away from the strip and the protective foil54applied before the lancet-sampler52is punched from the strip44.

Once the protective cover56covers the lancet tip32, connector tapes58are secured at opposite ends of the lancet-sampler52to create a lancet-sampler label60, as is depicted inFIG. 6. The tape connectors58are used to secure the lancet-sampler52to a carrier or cassette tape. In the illustrated embodiment, the connector tapes58are adhesive tapes, and in one particular form, the connector tapes58include PET adhesive tape. One of the connector tapes58is secured to protective cover56, and the other connector tape58is secured to the base34of the lancet30. As viewed inFIG. 6, the connector tapes58are secured to the top side of the lancet-sampler52, but it should be appreciated that the connector tapes58can be secured elsewhere. For example, one of the connector tapes58can be secured to the top side of the lancet-sampler52, and the other can be secured to the bottom side of the lancet-sampler52. In another example, the connector tapes58can be attached along the edges of the lancet-sampler52. As should be recognized, one or more of the connector tapes58can be made integral with the lancet-sampler52or the connector tapes58can be eliminated. For instance, one of the connector tapes58can be integrally formed with the protective cover56. Once assembled, the lancet-sampler label60is then sterilized. In one form, the lancet-sampler label60is sterilized using an inline electron beam (e-beam) sterilization process. Nevertheless, the lancet30can be sterilized in other manners, such as via gamma radiation or ultraviolet sterilization techniques. Moreover, it should be appreciated that the lancet30can also be sterilized at the various assembly stages before the connector tapes58are attached to the lancet-sampler52.

As noted above, the connector tapes58are used to secure the lancet-sampler label60to a cassette tape. By being disposed on the tape, multiple lancet-samplers52can be used in a cassette or other type of device that can perform multiple tests before requiring disposal. It, however, is contemplated that features of this system can be incorporated into single use meters.FIG. 7illustrates a carrier or cassette tape62, according to one embodiment, to which one or more of the lancet-sampler labels60are secured. As depicted, one or more reagent labels or test pads64for analyzing the fluid sample is applied to the tape62. In one embodiment, the tape62is a 5 mm wide×0.012 mm thick PET cassette tape, but it is envisioned that the tape62in other embodiments can be dimensioned differently and made from other materials. For instance, the tape62in another form is 23 μm thick. The test pad64incorporates the chemistry and/or sensors used to analyze a fluid sample. In one form, the test pad64is configured for electrochemical analysis of a fluid sample. The test pad64can for example include electrodes, such as working, counter, and reference electrodes, and chemistry, like mediators and enzymes, for electrochemically analyzing a fluid sample. Any number of electrochemical techniques can be used to analyze a fluid sample, such as amperometric, potentiometric, and coulometric techniques, to name a few. In other forms, the test pad64can have chemistry for analyzing a fluid sample optically, such as through reflective and/or transmissive techniques. As should be appreciated, the test pad64can be configured to analyze the fluid sample in other manners as well.

To facilitate automatic removal of the protective cover56, the tape62has a slackened or loose section that provides enough slack so that the protective cover56is able to clear the lancet tip32when tension is applied to the tape62. The slackened section of tape62also provides enough slack so that the lancet30can be fired to form an incision. Before the lancet-sampler label60is attached, the tape62is folded in a fanfold manner (180°) over the test pad64, as is illustrated inFIG. 8. The folded section of the tape62forms a packet66for protecting the test pad64as well as provides the slack to allow the cap56to be pulled from the lancet30. The packet66in one embodiment is sealed with a vapor tight pealing adhesive, and a micro-desiccant bead is affixed adjacent to the test pad64in order to control the humidity levels within the packet66. In another embodiment, a packet66is not formed, but rather, the tape62is loosely folded in a manner to create loose loops or a slackened section of tape62around the test pad64. In this embodiment, the cassette in which the tape62is housed contains a desiccant and has seals to maintain humidity levels of the test pad64. As should be appreciated, this system can be adapted for use in non-integrated systems. For example, in still yet a further form, the tape62does not include the test pad64, but rather, the lancet30is used to only form an incision (and not to collect and analyze a fluid sample). In this case, the tape62does not have the packet66. Instead, the tape62has a slackened section between where the tape is attached to the protective cover56and the lancet30so as to facilitate the removal of the protective cover56.

Returning to theFIG. 8embodiment, a pair of fingers68of a folding mechanism70are used to fold the tape62. As can be seen, the fingers68of the folding mechanism70engage opposite sides of the tape62, and the mechanism70is rotated in a counterclockwise fashion, as indicated by arrow72inFIG. 8, in order to fold the tape62to form the packet66. The fingers68form first74and second76creases or folds with an intermediate tape section78that has the test pad64. As will be discussed in detail below, the distance between the first crease74and the test pad64is selected so that, once unfolded, the test pad64aligns with the sample transfer opening38in the lancet30. This allows the test pad64to be positioned to directly absorb the fluid sample in the sample transfer opening38. The intermediate section78with the test pad64is folded against the tape62and sealed to form the packet66. Once the tape62is folded, the fingers68are temporarily pulled away from the tape62as the tape62is indexed, and afterwards, the fingers68are reapplied to the tape62to fold the next packet66. As should be appreciated, the folding mechanism70allows the tape62to be folded in a continuous process, which in turn simplifies manufacturing. It, however, should be appreciated that the tape62in other embodiments can be folded in other manners, such as manually or with a different type of folding mechanism.

Looking atFIGS. 9 and 10, the lancet-sampler label60is attached to the tape62via the connector tapes58such that the lancet-sampler label60spans across the first crease74to form a tape assembly80. The lancet-sampler labels60can be secured to the tape62in a variety of manners, such as via an adhesive, welded, and/or bonded. In particular, the connector tape58that is secured to the base34of the lancet30is attached to a first section82of the tape62, which is upstream from the first crease74, and the connector tape58that is secured to the protective cover56is attached to a second section84of the tape62, which is downstream from the intermediate section78and the second crease76. Since the lancet-sampler label60is attached to the tape62after sterilization, the harmful effects to the test pad64from sterilization are avoided. In turn, this avoids the need for recalibration of the tape assembly80.

Once assembled, the tape assembly80in one embodiment is housed within a cassette. For example, the tape assembly80can be stored in cassettes like those illustrated and described in U.S. patent application Ser. No. 11/326,422, filed Jan. 5, 2006, entitled “Lancet Integrated Test Element Tape Dispenser”, which is hereby incorporated by reference in its entirety. In one form, an unused section of the tape assembly80is stored in a stacked manner within a supply portion of the cassette so as to reduce the chance of bending of the lancets30, which can result in damage to the lancets30. After use, the used section of the tape assembly80can be wrapped around a spool within a waste portion of the cassette because damage to the lancets30after use is not a concern. If needed, the cassette can include a desiccant and seals to maintain low humidity levels within the cassette so as to preserve the test pads as well as other components. It is envisioned that the tape assembly80can be stored in other manners. By way of non-limiting examples, the tape assembly80can be stored in magazines, discs, drums, and cartridges, to name a few.

As alluded to above, the tape assembly80is configured to automatically remove the protective cover56from the tip32of the lancet30. Referring again toFIG. 10, the lancet-sampler label60is coupled to the first82and second84tape sections with the packet66in between. Before the lancet-sampler52is used, such as when the lancet-sampler52is initially indexed from a supply portion of a cassette, tension is applied to the second section84of the tape62, as indicated by arrow86inFIG. 10. In one embodiment, the tension is applied via a spool around which the used section of tape62is wound after use. In another embodiment, the tension is applied via a tractor mechanism that is used to index the tape62. It should be appreciated that the tape62can be tensioned in other manners. As the tension is applied, the first section82of the tape62is held fixed in place via a gripper or brake mechanism88. The brake mechanism88includes opposing brake pads90that clamp against the tape62to hold the first section82in place. As should be recognized, the first section82of tape can be held in place in other manners. For instance, a spool or tractor mechanism can be used to hold the first section82in place. It is envisioned that in other embodiments tension can be applied to the tape62in other manners. For example, the first section82of the tape62can be pulled while the second section84is fixed in placed. In yet another example, both sections82,84of the tape62are pulled in opposite directions at the same time.

Turning toFIG. 11, as the tension is applied in direction86, the protective cover56is pulled from the lancet30, thereby exposing the lancet tip32. After the protective cover56is removed, the lancet30can then be used to form an incision in tissue. Once the protective cover56is removed or some time thereafter, the brake mechanism88releases the tape62so that the tape62can be indexed. To form the incision, the firing mechanism engages the actuator engagement opening42so as to be able to fire the lancet30towards the tissue. As should be appreciated, the lancet30can be fired via various lancing mechanisms, like a spring-driven lancing mechanism, an electromechanical lancing mechanism, and the like. For example, a firing mechanism like the one described and illustrated in U.S. patent application Ser. No. 10/737,660, filed Dec. 16, 2003, which is herby incorporated by reference in its entirety, can be used to fire the lancet30.

During or after the protective cover56is pulled away from the lancet30, the folds forming the packet66containing the test pad64peel away from one another, as is depicted inFIG. 11. In one form, the peelable adhesive in the packet66releases, thereby opening the packet66. In contrast to previous systems, the packet66is designed to keep the test pad64protected immediately prior to use, which in turn reduces the chance of cross-contamination between the lancet30and the test pad64. As noted before, the packet66can be sealed in other manners, such as welded shut, or not sealed at all. In these other embodiments, the folds of the packet66can separate in other manners. For instance, the packet66in other embodiments can include weakened sections or break lines that break when tension is applied so as to allow the packet66to unfold. The free loop of tape62formed by the unfolded packet66provides freedom of movement for actuating the lancet30to form the incision. Lancing can occur before or after the packet66is completely unfolded.

Once the packet66is fully unfolded, the test pad64inFIGS. 12 and 13is aligned directly underneath the sample transfer opening38so that the test pad64is able to directly receive the fluid sample from the sample transfer opening38. It is envisioned that in other embodiments the packet does not necessarily need to be fully unfolded before the test pad64is aligned with the sample transfer opening38.

The transfer of the fluid sample from the lancet30to the test pad64can occur in several ways. In one way, the lancet30first collects the fluid sample and then is subsequently moved over the test pad64as the packet66completely unfolds. For example, the incision is formed and the fluid is collected before the packet66is completely unfolded. In particular, the lancet30lances the skin or other tissue with the packet66only partially unfolded, such as in the manner illustrated inFIG. 11. Fluid collection can occur while the tip32of the lancet30is still located within the tissue (subcutaneously) or the fluid sample can be collected on the surface of the tissue. After the sample is drawn into the sample transfer opening38, the packet66is completely unfolded so as to bring the test pad64into contact with the fluid sample within the sample transfer opening38. The fluid is then transferred to the test pad64and subsequently analyzed. In another way, the packet66is completely unfolded before fluid collection occurs. For example, the packet66in one embodiment is completely unfolded, and the test pad64is positioned underneath the sample transfer opening38before the lancet30forms the incision and the fluid sample is collected with the capillary groove36. It is contemplated that the transfer of the fluid sample can occur in other ways as well.

As mentioned before, the fluid sample can be collected subcutaneously or on the surface of the tissue. Regarding collection of fluid on the surface of the tissue, a number of techniques can be used to collect the sample. For instance, after forming the incision, the lancet-sampler52is temporarily retracted from the tissue, and once a predefined period has elapsed and/or fluid is detected on the surface of the tissue, the lancet-sampler52is reapplied to the incision in order to collect a fluid sample via the capillary channel50. An electromechanical positioning system, such as disclosed in U.S. patent application Ser. No. 10/737,660, filed Dec. 16, 2003, entitled “Blood Acquisition Suspension System”, which is hereby incorporated by reference, can be used to position the lancet-sampler52. The electromechanical positioning mechanism slowly moves the lancet-sampler52towards the tissue until a fill sensor in the lancet-sampler52detects that a sufficient amount of fluid has been collected.

FIG. 14shows an example of a fluid sample that has been collected with the lancet-sampler52. As can be seen, the fluid from the lancet tip is drawn up the capillary groove36and into the sample transfer opening38. As noted before, the cover foil48over the capillary groove36tends to enhance fluid collection. Once the fluid reaches the sample transfer opening38, the fluid then can be immediately transferred to the test pad64or the lancet30can be moved so that the fluid can be transferred to the test pad64. In one embodiment, the body fluid volume needed for analysis is 100 nanoliters (nL), and the test time is approximately 1-2 seconds. However, it is contemplated that other sample volumes can be used and test times can be different in other embodiments. Once the fluid sample is analyzed, the section of tape62containing the now used lancet-sampler52is wrapped around a waste spool in the cassette for later disposal. It should be recognized that the used lancet-samplers52can be disposed of in other manners.

A lancet-sampler92according to another embodiment will be now described with reference toFIGS. 15,16, and17. As can be seen, the lancet-sampler92inFIG. 15shares several features in common with the lancet-sampler52that was previously described with reference toFIG. 4. Like the previous embodiment, the lancet-sampler92includes the lancet30with the lancet tip32extending from the lancet body34, the capillary groove36, the vent slot40, the cover foil48, and the protective cap56. For the sake of clarity as well as brevity, the commonly shared features will not be discussed at length below, but reference is made to the previous discussion of these features.

To protect the cover foil48when the protective cap56is pulled from the lancet tip32, the protective cap56has a break line94that is scored, thinned, and/or otherwise weakened so that the protective cap56detaches from the lancet30at the break line94. As should be appreciated, the break line94can be formed in any number of manners, such as by mechanically scoring the protective cap56or scoring with a laser, to name a few examples.

In the illustrated embodiment, the lancet-sampler92does not have the sample transfer opening38, but rather, the capillary groove36is used to directly deposit the sampled body fluid onto the test pads64on the tape62. As illustrated inFIG. 15, the capillary groove36is fully etched through the lancet30along the entire length of the capillary groove36. That is, the capillary groove36opens on both sides of the lancet30. By being fully etched, the capillary groove36maximizes the available volume for transporting body fluid, which is helpful especially for thin lancets. Moreover, the fully etched capillary groove36tends to simply manufacturing because it eliminates the need tightly to control depth tolerances required to form a partially etched capillary groove36. It is however envisioned that in other embodiments the capillary groove36can have sections that are partially etched. To form the enclosed capillary channel50, the lancet30is sandwiched between a pair of cover foils48, as is depicted inFIG. 17. In another variation, the capillary groove36is fully etched, but only one side of the capillary channel50is covered with a cover foil48, such as shown inFIG. 18, thereby creating an open capillary channel configuration along the entire length of the capillary channel50. The capillary channel50in still yet other embodiments can have sections that are open and other sections that are closed. Referring toFIG. 15, at the distal end of the lancet tip32, the capillary groove36is uncovered or exposed so that the capillary groove36is able to collect body fluid from the incision, and the opposite end of the capillary groove36is exposed so as to form the vent slot40.

Looking atFIG. 18, a section of the capillary groove36on the side of the lancet30that faces the test pad64is likewise not covered by the cover foil48so that the capillary groove36is able to deposit body fluid onto the test pad64. Once the lancet-sampler92is positioned over the test pad64, the lancet-sampler92and the carrier tape62(test pad64) form a fluid transfer gap96. In comparison to the capillary groove36, the fluid transfer gap96has a higher affinity for the body fluid because the fluid transfer gap96is smaller than the capillary groove36. Due to the higher affinity, the body fluid is transferred to the fluid transfer gap96such that the body fluid spreads below the lancet-sampler92and over the test pad64. As can be seen, body fluid98in the fluid transfer gap96is able to cover an area that is wider than the capillary groove36. It is contemplated that the lancet-sampler92and/or the carrier tape62can contain portions that are hydrophobic and/or hydrophilic so as to direct the fluid flow.

An electrochemical version of a lancet-sampler100according to still yet another embodiment is illustrated inFIG. 19. The lancet-sampler100inFIG. 19shares several features in common with the previous embodiments, such as the lancet30, the capillary groove36, and the test tape62. For the sake of clarity as well as brevity, the commonly shared features will not be discussed at length below, but reference is made to the previous discussions. The lancet-sampler100includes a reagent or test layer102with chemicals for electrochemically analyzing fluid samples, like enzymes and mediators. The reagent layer102is disposed on the carrier tape62and covers one or more electrodes104. The electrodes104can include working, counter, and reference electrodes as well as other types of electrodes, such as for detecting fill sufficiency. The electrodes104are disposed on the carrier tape62. All or portions of the electrodes can be disposed on the same side or on the opposite side of the carrier tape62as the reagent layer102. In the illustrated embodiment, the electrodes104and reagent layer are disposed on the same side.

A lancet-sampler cassette106according to one embodiment that is used to store and index the cassette tape62will now be described with reference toFIGS. 20 and 21. The cassette106includes a housing108that has opposing housing panels110and a storage wall112that defines a storage compartment114where an unused section of the tape62is stored. InFIGS. 20 and 21, a peripheral wall that wraps around the cassette106between the opposing panels110has been removed so that the inner workings of the cassette106can be easily viewed. It should be recognized that the cassette106can include one or more sections of the peripheral wall to protect and/or maintain the sterility of the tape62.

A spool116extends between and is rotatably coupled to the opposing housing panels110. The spool116is used to move the tape62, and the tape62, once used, is wrapped around spool116. As can be seen, the spool116has a sprocket opening118that is configured to receive a sprocket that is used to rotate the spool116. First120and second122guide pins or rollers for guiding the tape62in the cassette106are rotatably coupled to the housing108. In the illustrated embodiment, the cassette106has two guide pins120,122, but the cassette106in other embodiments can include more or less guide pins than are shown, such as no guide pins. Looking atFIG. 21, the first120and second122pins are at one end of the cassette106and form a triangular pattern with the spool116. It should be recognized that the pins120,122and the spool116can be oriented in other manners. Between the first120and second122guide pins, the tape62has an acquisition section124where the fluid sample is acquired with the lancet-sampler52and analyzed. At the acquisition section124, the opposing panels110of the housing108have one or more sensor openings126in which a sensor reader of the meter is received in order to read the test pads64on the tape62. It is contemplated that in other embodiments the sensor openings126can be omitted when the sensor reader is located elsewhere along the cassette106. Depending on the analysis technique used, the sensor reader can include an optical sensor or electrical contacts, for example.

Inside the storage compartment114, the tape62is folded in a fanfold fashion. Looking atFIG. 21, the tape62is folded with blank sections between each lancet-sampler52so that the lancet-samplers52face in the same direction. In the illustrated embodiment, the lancet-samplers52are oriented in a tail first configuration in which the lancet tip32extends opposite to the direction the tape62travels during indexing. In other words, the tail or lancet body34of the lancet-sampler52is the leading end as the lancet-sampler52is moved. With this tail first orientation, the risk of the lancet30piercing the tape62is reduced when the lancet-sampler52is wrapped around the spool116. Likewise, the risk of jamming the spool116is reduced when the tape62is wrapped around the spool116in a tail first orientation. Nevertheless, it is envisioned that in other embodiments the lancet-samplers52can be oriented in other manners, such as by having a head or lancing tip first orientation, and the tape62can be folded in other manners. For example, the tape62can omit the blank sections and have a lancet sampler on every fold. The storage compartment114can further include a desiccant128for reducing harmful humidity in the storage compartment114. The storage wall112includes a divider wall section130that separates the storage compartment114from the portion of the cassette106that contains the spool116. As will be explained below, the divider wall section130assists in pulling the protective cover from the lancet tip32.

Turning toFIGS. 22A and 22B, the divider wall section130has a slot132through which the tape62passes. On one side of the slot132, the divider wall section130has an engagement block or portion134that is biased towards the tape62by a spring136. In one form, the engagement block134is made from resilient material such that the engagement block134can act like a seal so as to prevent contamination of the storage compartment114. In the illustrated embodiment, the spring136is a leaf spring. However, it should be recognized that the spring136can include other types of springs, such as a coil spring, and/or other resilient means. For example, in another embodiment, the divider wall section130is made from springy material that substitutes for the spring136. The gap height of the slot132is sized large enough so as to allow the tape62to pass through, but the gap height of the slot132is sized small enough such that the engagement block134is able to engage the protective cover56in order to pull the cover56from the lancet tip32.

Looking atFIG. 22A, as the spool116indexes the tape in an indexing direction138, the lancet-sampler52passes through the slot132. Once the protective cover56reaches the engagement block134, the cover56engages the engagement block134because the protective cover56is too thick to readily pass through the slot132. As the spool116continues to pull on the tape62in the indexing direction138, the protective cover56is pulled from the lancet tip32(FIG. 22B). Once the protective cover56is pulled from the lancet30, the spool116keeps on pulling the tape62with sufficient force so that the engagement block134deflects and/or deforms to allow the protective cover56to pass through the slot132. Afterwards, the lancet-sampler52is positioned at the acquisition section124of the cassette106, as is depicted inFIG. 21. The spool116slackens the tape62, which in turn allows the lancet30to be fired to cut the incision. After lancing, the spool116takes up the slack, and the lancet30is disposed over the test pad64such that the collected fluid sample is deposited on the test pad64. Via the sensor openings126, the meter is able to analyze the sample on the test pad64. Once the test is completed, the spool116rotates to wrap the now used lancet-sampler52around the spool116. With the tail first orientation of the lancet30on the tape62, the risk of the lancet tip32cutting and/or breaking the tape62is reduced. Subsequently, the unused lancet-samplers52in the storage compartment114are indexed in a similar fashion.

A lancet-sampler cassette or cartridge140according to still yet another embodiment will be initially discussed with reference toFIG. 23. The cassette140includes a housing142with opposing housing walls144and a peripheral wall146that defines a storage compartment148for storing an unused section of the tape62in a fan folded fashion, as is depicted inFIG. 24A. Like the previously described embodiment, the cassette140has the spool116for moving the tape62as well as the guide pin120for guiding the tape62in the cassette140. Near the spool116, the storage compartment148has a curved wall section150that coincides with the shape to the tape62when wrapped around the spool116. Desiccant128is disposed inside the storage compartment148so as to reduce humidity inside the storage compartment148. As can be seen, the storage compartment148has an exit opening152where the tape62exits the storage compartment148. At the exit opening152, the cassette140has a seal154to maintain the humidity levels within the storage compartment148as well as reduce the chance of contamination in the storage compartment148. The housing142further has one or more sensor openings156in which a sensor reader of the meter is received in order to read the test pads64on the tape62.

Looking atFIG. 24A, the exit opening152, the guide pin120, and the spool116are oriented in a triangular relationship with one another such that the tape extends at an acute angle in relation to the guide pin120. At the guide pin120, the cassette140has an end or flip wall member158that defines a lancet opening160through which the lancets30extend during lancing. As shown, the lancet opening160is aligned with the guide pin120. Between the end wall158and the exit opening152, the cassette140has an actuation opening162where the firing or actuation mechanism of the meter engages the lancet30of the lancet-sampler52.

In the illustrated embodiment, the lancet-samplers52are aligned on the tape62in a face or lancet tip first orientation in which the lancet tip32of the lancet30extends towards the spool116on the tape62. With the tip first orientation of the lancets30, removal of the protective cover56from the lancet tip32is simplified, and likewise, actuation of the lancet30is simplified. However, as mentioned before, the tip first orientation can create complications when the tape62is wrapped around the spool116. For instance, the lancets30can cut or even break the tape62, and the spool116can become jammed with the lancets30. To address these concerns, the cassette inFIG. 24Astores and dispenses the lancet-samplers52in a tip first orientation, and then flips the lancets30on the tape62to a tail first orientation before the used section of tape62is wrapped around the spool116.

In one embodiment, after the lancet-sampler52exits the storage compartment148, the firing mechanism engages the actuator engagement hole42in the lancet30in order to hold the lancet30in place. The meter and/or the cassette140includes a clutch that allows the tape62to be only moved in the indexing direction138. The firing mechanism is then used to pull the lancet30in an opposite direction to the indexing direction, thereby pulling the protective cover56from the lancet30. It should be recognized that the protective cover56can be removed in other manners. For example, as the firing mechanism holds the lancet30in another embodiment, the spool116rotates so as to pull the protective cover56from the lancet30. Once the protective cover56is removed, as is depicted inFIG. 24A, the lancet30is fired, and the fluid sample is collected with the lancet-sampler52for analysis. Once the lancet-sampler52is used, the spool116indexes the tape62. Looking atFIG. 24B, as the tape62is indexed, the lancet30extends from the tape62because the tape62bends acutely around the guide pin120. Referring toFIG. 24C, as the spool116continues to index the tape62, the lancet30hits the wall of the lancet opening160in the flip member158, which in turn causes the lancet30to face in a tail first orientation. With the lancet30flipped in a tail first orientation, the lancet30and tape62can be safely wrapped around the spool116as the spool116rotates. It should be appreciated that in other embodiments lancing, fluid sampling, and/or analysis can occur after the lancet30is flipped. For example, in one embodiment, the lancet30lances the tissue as the lancet30is flipped (FIG. 24B), and the fluid sample is then analyzed with the lancet30in a tail first orientation.

A meter164into which the cassette140can be loaded is illustrated inFIGS. 25 and 26. InFIGS. 25 and 26, various electrical systems, such as circuit boards and wires, as well as other components have been removed so that the main systems of the meter164can be easily viewed. In the illustrated embodiment, the meter164includes a housing166in which other components of the meter164are housed. The meter164further includes a power supply168, an indexing mechanism170configured to index the cassette140, a firing mechanism172configured to fire the lancets30, and a sensor system174configured to analyze the collected fluid samples. The housing166, which is shown in phantom lines inFIGS. 25 and 26, has a rectangular shape, but the housing166can be shaped differently in other embodiments. The power supply168is used to power the various systems in the meter164, like the indexing mechanism170, the firing mechanism172, and the sensor system174. The power supply168in the depicted embodiment includes batteries, but it should be appreciated that other types of power sources can be used, such for example electrical outlets or fuel cells. As shown, the sensor system174is received inside the sensor opening156of the cassette140. In the depicted embodiment, the sensor system174includes an optical sensor, but it should be recognized that the sensor system174can be configured to analyze fluid samples in other manners, such as through electrochemical analysis. When fluid is analyzed electrochemically, the sensor system174can for example include contacts configured to electrically couple to the contacts104of the electrochemical version of the lancet-sampler100and/or can include a transceiver that wirelessly communicates with the lancet-sampler100.

The indexing mechanism170in the meter164includes an indexing motor176, which in the illustrated example is a reversible electric motor with a drive worm178. The indexing motor176is powered by the power supply168. It again should be appreciated that other types of motors can be used. The drive worm178rotates an intermediate gear180, which in turn rotates a main drive gear182. The main drive gear182includes a sprocket that is received in the sprocket opening118of the spool116. As the indexing motor176rotates the drive worm gear178, the intermediate gear180and the main drive gear182rotate, which in turn rotates the spool116, thereby indexing the tape62. It is contemplated that the indexing mechanism170can be configured differently in other embodiments.

With reference toFIGS. 25, and26, the firing mechanism172includes a firing or drive motor184, a carriage186, a lancing or actuator unit188carried on the carriage186, a transmission member190for transmitting force from the lancing unit188, a guide192that is secured to the housing166, and an actuator arm or member194that is configured to actuate the lancet30. The drive motor184in the illustrated embodiment is a reversible electric motor184, but in other embodiments, the drive motor184can include other types of motors, like a pneumatic motor and/or a nonreversible motor. When the drive motor184is only able to supply output in one direction (i.e., a nonreversible motor), the firing mechanism172can incorporate a transmission that is able to change the output. The drive motor184has a worm gear196that engages an intermediate, priming gear198that is configured to prime or cock the lancing unit188. As shown, the priming gear198is rotatably coupled to a guide shaft or rod199that is coupled to the housing166at both ends.

Looking atFIG. 26, the lancing unit188is slidably coupled to the guide shaft199. In the illustrated embodiment, the lancing unit188is mechanically driven, and in particular, the lancing unit188includes a torsion barrel type firing mechanism, like an ACCU-CHEK® SOFTCLIX or MULTICLIX brand device driver (Roche Diagnostics, Indianapolis, Ind.). For detailed examples of some types of lancing units188, please refer to U.S. Pat. Nos. Re. 35,803 to Lange et al. and U.S. Pat. No. 6,419,661 to Kuhr et al., which are hereby incorporated by reference in their entirety. It should be recognized that other types of firing mechanisms can be used as well. By way of non-limiting examples, the lancing unit188in other embodiments can include other types of mechanical drivers, electromechanical type drivers, electrical type drivers, pneumatic drivers, or some combination thereof.

Facing the priming gear198, the lancing unit188has a clutch200that is configured to engage the priming gear198, as is depicted inFIG. 27A. The clutch200is only able to rotate in one direction so as to prime the lancing unit188.FIG. 27Bshows an enlarged view of the priming gear198and clutch200when engaged. As can be seen, the clutch200has clutch fingers202that engage with clutch teeth204on the priming gear198. The clutch fingers202on the clutch200are generally resilient and extend in a radial inwards direction, towards the guide shaft199. Turning toFIGS. 27A and 27B, both the clutch fingers202and clutch teeth204have corresponding engagement surfaces206that extend in a general orthogonal direction and disengagement surfaces208that are acutely angled. As the drive motor184rotates the priming gear198in a clockwise direction210(FIG. 27B), the engagement surfaces206of the priming gear198and the clutch200engage such that the priming gear198rotates the clutch200. As the clutch200is likewise rotated in the clockwise direction210, the lancing unit188is primed by winding of the spring inside the lancing unit188. Inside the lancing unit188, the clutch has a second set of one or more fingers211(FIG. 27A) that engage notches in the lancing unit188so that the clutch200is only able to rotate in a direction that winds the spring inside the lancing unit188such that the lancing unit188is primed. Referring toFIG. 27C, when the drive motor184rotates the priming gear198in a counterclockwise direction212, due the resilient nature of the clutch fingers202, the disengagement surfaces208generally slide across one another such that the priming gear198does not rotate the clutch200. Although the clutch200is disengaged from the priming gear198, the second set of fingers211of the clutch200inside the lancing unit188prevent the spring inside the lancing unit188from unwinding, thereby leaving the lancing unit188in a primed state.

Returning toFIGS. 26 and 27A, the carriage186, which holds the lancing unit188, is operatively coupled to the priming gear198through a carriage actuation member or screw214. At one end, the carriage actuation screw214includes a gear head216that engages the priming gear198. Opposite gear head216, the carriage actuation screw214has a threaded end218that is configured to threadedly engage an internally threaded collar220on the carriage186. Between the gear head216and the threaded end218, the carriage actuation screw214has an unthreaded section222. During priming of the lancing unit188, the threaded collar220of the carriage186is positioned along the unthreaded section222of the carriage actuation screw214. As the drive motor184rotates the priming gear198in the clockwise direction210to prime the lancing unit188, the carriage actuation screw214rotates in a counterclockwise direction212. With the carriage actuation screw214rotating in a counterclockwise direction212, the threaded collar220remains over the unthreaded section222and disengaged from the threaded end218. While the threaded collar220of the carriage186remains disengaged from the threaded end218, the carriage186remains stationary.

At the end of the shaft199inFIG. 26, the meter164includes an optional button223. In one embodiment, the button223is adjustable relative to the shaft199so as to be able to adjust the penetration depth of the lancet30. In another embodiment, the button223is used to fire the lancet30. Specifically, the button223in one embodiment includes a hollow tube that is slidably disposed around the shaft199and extend to the lancing unit188. When the button223is pushed, the hollow tube releases the spring inside the lancing unit188such that an extension shaft225extends from the lancing unit188. In further embodiments, the hollow tube of the button223is not disposed around the shaft199, but rather, the hollow tube acts as a section of the shaft199. It should be appreciated that firing can be initiated manually by pressing the button223, automatically, or in some other manner. Again, the button223can be optional in other embodiments, and the button223can be also located at places other than is shown in the drawings. Moreover, the lancing unit188can be fired in other manners.

After the lancing unit188is primed and lancing is initiated by pressing the button223or in some other manner, the drive motor184in one embodiment is reversed, and the priming gear198is rotated in the counterclockwise direction212. In another embodiment, the firing mechanism172does not require the button223or some other input device to be pushed in order to reverse the output of the drive motor184. For example, after the priming gear198is rotated a predetermined number of times, the drive motor184is reversed. Upon reversal of the drive motor184, the carriage actuation screw214rotates in the clockwise direction210, and consequently, the threaded collar220of the carriage186engages the threaded end218of the carriage actuation screw214. As the carriage actuation screw214continues to rotate in the clockwise direction210, the threaded end218causes the carriage186along with the lancing unit188to move away from the priming gear198in an extension direction, as is indicated with arrow224inFIG. 27A. Eventually, as the carriage186continues to move the lancing unit188in direction224, the clutch200on the lancing unit188disengages from the priming gear198(FIG. 27C).

Opposite the clutch200, as is shown inFIG. 27A, the lancing unit188is coupled to the transmission member190that transmits the movement of the carriage186as well as the firing motion from the extension shaft225of the lancing unit188to the actuator member194. Returning toFIG. 25, the transmission member190is received inside the guide member192, and the actuator member194is similarly received inside the transmission member190. Looking atFIG. 27A, the actuator member194in the illustrated embodiment has a pair of guide pins226that extend from opposing sides of the actuator member194, but it should be recognized that the actuator member194can have more or less guide pins226. The guide pins226extend through corresponding transmission slots228in the actuator member194and into guide slots230in the guide member192. The guide member192is fixed to the housing166such that the guide member192does not move relative to the housing166. Referring toFIGS. 27A and 28, the actuator member194has an engagement blade232that is configured to engage the keyhole42in the lancet30.

As shown inFIG. 27A, the guide slots230in the guide member192are generally L-shaped, and the transmission slots228in the actuator member194are slanted or angled. The L-shaped guide slots230have first234and second236sections that extend orthogonally to one another. Depending on the desired travel path for the actuator member194, the slots228,230can be shaped differently in other embodiments. When the transmission member190slides relative to the guide member192, such as during firing of the lancing unit188and/or when the carriage186is moved, the transmission slots228cause the guide pins226to move along the L-shaped path of the guide slots230. When the guide pins226of the actuator member194move in the first sections234of the L-shaped guide slots230, the engagement blade232of the actuator member194moves into engagement with the keyhole42of the lancet30. Once the guide pins226reach the corners of the L-shaped guide slots230, the transmission slots228in the moving transmission member190push the guide pins226in direction224along the second section236of the L-shaped guide slot230. This in turn causes the lancet30to extend from a lancing cap238of the meter164in order to lance the tissue and/or collect fluid from the incision.

A technique for obtaining and analyzing a fluid sample with the cassette140and meter164will be initially described with reference toFIG. 29A. To prime the lancing unit188, the drive motor184rotates the priming gear198in the clockwise direction210, which in turn rotates the clutch200of the lancing unit188. During priming of the lancing unit188, the carriage186holding the lancing unit188remains stationary because the carriage actuation screw214rotates in the counterclockwise direction212such that threaded collar220of the carriage186remains over the unthreaded section222, disengaged from the threaded end218of the screw214. As mentioned before, the indexing motor176is used to index the tape62in the cassette140so that the lancet-sampler52is properly positioned to engage the engagement blade232of the actuator member194. In one example, the indexing motor176indexes the tape62after the lancing unit188is primed, but it should be recognized that the tape62can be indexed before, during, or after the lancing unit188is primed. During indexing of the tape62, the protective cover56over the lancet tip32of the lancet30can be removed in a similar fashion as was described above with reference to the cassette140. The firing mechanism172can be primed before or after the lancing cap238is placed against the skin or other tissue.

Turning toFIG. 29B, once the clutch200is rotated sufficiently to prime the lancing unit188, the firing mechanism172is able to be fired. Firing can be initiated manually by the user, such as by pressing the button223(FIG. 26) or automatically by the meter164. In one embodiment, firing of the lancing unit188is initiated after the actuator blade232engages the lancet30, and in another embodiment, firing of the lancing unit188occurs before the actuator blade232engages the lancet30. Upon priming the lancing unit188, the driving motor184reverses such that the priming gear198rotates in the counterclockwise direction212. As a result, the carriage actuation screw214rotates in the clockwise direction210, which in turn causes the threaded collar220of the carriage186to engage the threaded end218of the screw214. Once the collar220engages the threaded end218, the carriage186moves away from the priming gear198, as is indicated by direction arrow224. Consequently, the lancing unit188along with the carriage186slides along the guide shaft199, and the clutch200of the lancing unit188disengages from the priming gear198. Although the clutch200is disengaged from the priming gear198, the lancing unit188remains primed because the second set of fingers211(FIG. 27A) only allow the clutch200to be rotated in a priming direction, thereby preventing unwinding of the torsion spring inside the lancing unit188. With the carriage186moving in direction224, the transmission member190likewise moves in the same direction. In one embodiment, the lancing unit188does not fire when the carriage186is moved such that the movement of the carriage186is the sole source for moving the transmission member190. In an alternative embodiment where the lancing unit188is fired at the same time the carriage186is moved, both the motion of the carriage186and the extension of the extension shaft225move the transmission member190. The movement of the transmission member190as well as its transmission slots228in direction224cause the guide pins226to move along the first section234of the L-shaped guide slots230. This in turn pushes the actuator blade232of the actuation member194into the keyhole42of the lancet30, thereby engaging the lancet30to the firing mechanism172. If the keyhole42is covered with a protective covering or film, the actuator blade232can be configured to puncture the film as well.

With reference toFIG. 29C, after the actuator blade232of the firing mechanism172engages the lancet, the drive motor184stops driving the carriage186in direction224. At this point, the firing mechanism172is prepared to fire the lancet30. Once prepared, the lancing unit188is fired so that the extension shaft225extends from the lancing unit188in direction224. As noted above, the lancing unit188can be automatically fired by the meter164or manually fired by pressing the button223and/or by having the user interface with some other type of input device. As mentioned above, the lancing unit188in other embodiments can be fired at the same time the carriage186is moved in direction224. Returning to the illustrated embodiment, after the firing mechanism172engages the lancet30and the user presses the button223, the lancing unit188extends the extension shaft225. As the extension shaft225moves, the transmission slots228in the moving transmission member190cause the guide pins226of the actuator arm194to slide in the second section236of the guide slot230. Consequently, the actuator arm194extends or fires the lancet30such that the lancet tip32cuts an incision in the tissue.

After cutting the incision, the lancing unit188is configured to retract the extension shaft225in a retraction direction, as is indicated by arrow240inFIG. 29D. This in turn causes the guide pins226to move in the retraction direction240, which results in the lancet30retracting from the incision. Removing the lancet30from the incision tends to reduce pain as well as potentially enhance bleeding from the incision because the lancet tip32does not plug the incision. Afterwards, the lancet30can be reapplied so that the lancet tip32is dipped into the drop of body fluid on the tissue such that a fluid sample is drawn into the lancet-sampler52. Looking aFIG. 29E, in order to reapply the lancet tip32to the drop of fluid, the drive motor184rotates the carriage actuation screw214in the clockwise direction210, thereby moving the carriage186in the extension direction224. As the carriage186moves, the actuator arm194along with the lancet30move in direction224, towards the incision.

Looking atFIG. 29F, once the sample is collected, the drive motor184reverses to rotate the carriage actuation screw214in the counterclockwise direction240. This causes the carriage186to retract in direction240, which in turn causes the lancet30to retract from the tissue. As the drive motor184continues to retract the carriage186, the guide pins226of the actuator arm194move into the first section234of the guide slots230, which in turn disengage the actuator blade232from the keyhole42in the lancet30. Before, during or after the actuator arm194disengages from the lancet30, the sensor174in the meter164can be used to analyze the fluid sample. After the firing mechanism172disengages from the lancet30, the tape62can be indexed in the manner as described above so that the now used lancet-sampler52can be flipped and wrapped around the spool116of the cassette140, while an unused lancet-sampler52is positioned for engagement with the actuator arm194of the firing mechanism172. The drive motor184continues to retract the carriage186until the collar220disengages from the threaded end218at the unthreaded section222of the carriage screw214. Around the same time, the clutch200of the lancing unit188reengages the priming gear198so that the drive motor184is again able to prime the lancing unit188. Subsequent lancets30are then able to be fired and analyze fluid in the same fashion as described above. It should be recognized that the meters in other embodiments can be configured differently.

While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected. All publications, patents and patent applications cited in this specification are herein incorporated by reference as if each individual publication, patent, or patent application was specifically and individually indicated to be incorporated by reference as set forth in its entirety herein.