Patent Application
20120220895
The present invention relates generally to cartridge-based devices, and more particularly, to mechanisms for precisely aligning medical items to be sequentially advanced for use in, or dispensing from, cartridges or other dispensers.
Cartridge-based devices can be utilized to dispense or apply certain medical items, such as medicine, lancets, sutures, needles, surgical staples, etc., or other medical or other items. For example, a replaceable cartridge containing a plurality of items for sequential use may be loaded into a tool or other device. Such devices can be manufactured to interface with humans directly or with machines utilizing the items therein. For example, many medical procedures require puncturing of the skin, and sometimes underlying tissues, of an animal or human subject. A sharp lancet tip is commonly used to puncture the subject's skin at a lancing site to obtain a sample of blood, interstitial fluid, or other body fluid, as for example in blood-glucose monitoring by diabetics and in blood-typing and blood-screening applications.
In some situations, a person must periodically sample their blood for multiple testing throughout the day or week. This is typically done using a lancing device of some sort. Because re-use of a lancet can result in infection or spread of blood-borne contaminants, persons requiring repeated testing often must carry multiple lancets with them, with each lancet separately loaded into the lancing device for each sampling. This can be inconvenient and may lead to reduced compliance with a prescribed test regimen.
Cartridge-type lancing devices have been developed to allow the user to load cartridges into the lancing device, each cartridge holding multiple lancets for sequential use. These cartridge-type lancing devices typically operate by sequentially advancing each of the lancets in the cartridge for use, charging a drive spring, and, upon actuation of an actuator, releasing the lancet to be propelled by the discharging drive spring through a lancing stroke. The lancets are sequentially advanced into an active position for use by an advancing mechanism. However, on occasion the advancing mechanism can advance a new lancet slightly too far or not quite far enough, which can sometimes result in the device becoming jammed and inoperable until the jam is cleared. This can be a tolerances issue resulting from the advancing mechanism including mechanical parts (e.g., gears) that are manufactured precisely but with certain acceptable tolerances, or this can be the result of slippage or binding in some designs. As such, existing cartridge-type lancing devices have not proven entirely satisfactory in their ease-of-use, cost, and/or reliability.
Accordingly, it can be seen that needs exist for improvements in advancement mechanisms for cartridge-based devices. It is to the provision of an improved cartridge-based device and cartridge meeting these and other needs that the present invention is primarily directed.
The present invention relates to an improvement in cartridge-based lancing devices that promotes smooth lancet operation and prevents lancet jamming. A lancing device and a cartridge of lancets are operable to sequentially advance each lancet to an active position for use in sampling a bodily fluid. An alignment mechanism precisely aligns the lancets in the active position to promote smooth operation and prevent jamming. The alignment mechanism includes at least one register element and at least one spring-biased element movable between engaged and retracted positions. In an example embodiment, one spring-biased arm extends from the lancing-device housing and includes a protrusion, and a series of recessed register surfaces are defined in a carrier for the lancets. In the engaged position, the spring-biased protrusion fully mates with the register recess under the spring-biasing influence to precisely align the active lancet. And in the retracted position, the spring-biased protrusion is deflected from engagement with the register recess as the carrier is advanced to advance a fresh lancet into the active position.
These and other aspects, features and advantages of the invention will be understood with reference to the drawing figures and detailed description herein, and will be realized by means of the various elements and combinations particularly pointed out in the appended claims. It is to be understood that both the foregoing general description and the following brief description of the drawings and detailed description of the invention are exemplary and explanatory of preferred embodiments of the invention, and are not restrictive of the invention, as claimed.
The present invention may be understood more readily by reference to the following detailed description of example embodiments taken in connection with the accompanying drawing figures, which form a part of this disclosure. It is to be understood that this invention is not limited to the specific devices, methods, conditions or parameters described and/or shown herein, and that the terminology used herein is for the purpose of describing particular embodiments by way of example only and is not intended to be unnecessarily limiting of the claimed invention. Any and all patents and other publications identified in this specification are incorporated by reference as though fully set forth herein.
Also, as used in the specification including the appended claims, the singular forms “a,” “an,” and “the” include the plural, and reference to a particular numerical value includes at least that particular value, unless the context clearly dictates otherwise. Ranges may be expressed herein as from “about” or “approximately” one particular value and/or to “about” or “approximately” another particular value. When such a range is expressed, another embodiment includes from the one particular value and/or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment.
With reference now to the drawing figures, wherein like reference numbers represent corresponding parts throughout the several views,
It will be understood that the term “cartridge” as used herein includes carrousels, clips, and other types of dispensers of lancets or other items, whether they are replaceable cartridges used with re-useable lancing devices or whether they are integral to and disposable with the lancing devices after all the lancets have been used once, and whether the lancets or other items are rotationally advanced, linearly advanced, or otherwise configured in the cartridges. In addition, it will be understood that instead of a lancing device used with a cartridge of lancets, the herein-described assemblies and aspects of the invention can be embodied in other medical devices for using or dispensing other items, construction tools for using or dispensing fasteners or other items, firearms for using or dispensing ammunition or other items, food devices for using or dispensing candy or other food items, or other devices using cartridges holding other items that are advanced for use or dispensing. For example, the assemblies and aspects of the invention described herein can be adapted for use in medical devices that dispense sutures, needles, medicines, or surgical staples.
The components of the lancing device 10 and cartridge 50 can be fabricated from conventional materials using conventional fabrication techniques. Thus, these components can be made of plastics, metals, or other suitable materials known in the art, by molding, machining, stamping or other suitable processes known in the art.
The lancing device 10 of the depicted embodiment includes a depth-adjustment mechanism 12, an advancement mechanism 14, a lancet cap-displacement mechanism 16, a charging mechanism 18, and an actuation mechanism 20. The depth-adjustment mechanism 12 operates to provide adjustment for different puncturing depths of the lancet tip 56 into the user's skin during a lancing stroke. The advancement mechanism 14 operates to sequentially advance the lancets 52 to an active position for use. The cap-displacement mechanism 16 operates to remove the sterility caps 58 from the lancet tips 56 before the lancing stroke. The charging mechanism 18 operates to retract an active-positioned lancet 52 and charge a drive spring. And the actuation mechanism 20 operates to release the lancet from the charged position so that it can be propelled by the discharging drive spring through the lancing stroke. Details of the structure, manufacture, and operation of these mechanisms are included in the disclosure of U.S. patent application Ser. No. 12/892,324, filed Sep. 28, 2010, which is hereby incorporated by reference herein.
In various embodiments not expressly disclosed herein but included within the scope of the present invention, the lancing device and/or cartridge can be provided with additional or alternative operational mechanisms to perform the same or other basic functions required for advancing lancets or other items, they can be provided without some of these mechanisms, or they can be provided with some combination of these and/or other mechanisms. As such, included within the scope of the present invention are embodiments in which the cartridge, and the device the cartridge is used with, include operational mechanisms other than those expressly described herein.
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Even with a well-designed advancement mechanism 14, on occasion it can slightly over- or under-advance one of the lancets 52 into the active position. For example, the advancement mechanism 14 can be designed to sequentially advance the lancets 52 by 10 degrees, but on occasion over-advance one of the lancets by 0.7 degrees. To minimize jamming and other alignment problems during the rare occasions when the advancement mechanism 14 slightly over- or under-advances one of the lancets 52 into the active position, an alignment mechanism is provided. The alignment mechanism includes at least one register element and at least one spring-biased element that moves between a engaged position and a retracted position. In the engaged position, the spring-biased element matingly engages the register element to better align the active-positioned lancet relative to the cartridge housing. The spring-biased element can be designed so that, in this position, either it is in a relaxed/neutral state or it can still apply a positive biasing force to the register element. And in the retracted position, the spring-biased element does not engage the register element as the lancets are being sequentially advanced into the active position. As such, the alignment mechanism is a mechanical override of the advancement mechanism 14 that fine-tunes the alignment of the lancet 52 in the active position relative to the cartridge housing.
Referring particularly to 8-14, there is shown an alignment mechanism 80 according to an example embodiment of the present invention for use with the lancing device 10 and cartridge 50 disclosed herein. In the depicted embodiment, there are a series of fixed female register elements in the form of recesses 82 defined by the carrier 62 and one spring-biased male element in the form of a protrusion 84 extending from a resilient cantilevered arm 86 defined by the cartridge housing 60.
The recesses 82 and the protrusion 84 have generally conforming female and male shapes, respectively, when viewed from the longitudinal axis of the lancing stroke path. Their shapes are selected so that the protrusion 84 tends to bias into a precise mating engagement in precise alignment with the recess 82 being engaged when the resilient cantilevered arm 86 is in the engaged position. For example, the recesses 82 and the protrusion 84 can be generally wedge-shaped with two symmetrical sides, as in the depicted embodiment. In alternative embodiments, the recesses and the protrusion can have the shape (when viewed along the longitudinal lancing stroke path) of a dome (e.g., a semi-circle), a non-symmetrical triangle/wedge, a cone, a pyramid, a polygon (or portion thereof), or another regular or irregular shape, whether linear, curved, or otherwise shaped. Preferably, the recesses 82 each include an exit ramp surface 83 (e.g., linear, curved, or both) (see
The protrusion 84 is spring-biased toward the engaged position where it sequentially engages each of the recesses 82 of the carrier 62 (as the carrier is advanced by the advancement mechanism) to better align the active-positioned lancet 52 (see
In the depicted embodiment, the resilient cantilevered arm 86 is formed in the top wall of the cartridge housing 60 with the protrusion 84 extending downward (inward to within the housing), and the recesses 82 are formed in a top surface of the carrier 62 with each recess aligned with and on the opposite surface of the carrier from a corresponding one of the lancets 52. As each lancet 52 has a corresponding recess 82, the number of recesses included is the same as the number of lancets. In alternative embodiments, the alignment elements (e.g., the recesses) are not located so immediately adjacent their corresponding lancets and instead are formed farther away from their corresponding lancets.
In the depicted embodiment, the carrier 62 is advanced through a rotary motion to sequentially advance the radially arranged lancets 52 (for begin propelled radially outward) through the rotary motion and into the active position. As such, the recesses 82 (or other register elements) are arranged in a circular shape on the carrier 62. In alternative embodiments, the lancets 52 are generally linearly arranged (e.g., parallel in a longitudinal clip) and sequentially advanced through a generally linear motion into the active position. As such, the recesses 82 (or other register elements) are arranged in a linear arrangement within the cartridge 50 (e.g., on the carrier 62, if one is included in the desired design). In such linear embodiments (and in some rotary embodiments), the advancement mechanism can include rack-and-pinion gearing and/or spring elements for sequentially advancing the lancets to the active position.
In other alternative embodiments, the male/protrusion alignment element and the female/recessed alignment element are reversed in a vice-versa arrangement. That is, the at least one spring-biased element includes a female/recessed surface and the at least one register element is provided by a plurality of male/protrusions. Additionally or alternatively, in some embodiments the at least one spring-biased element is defined by the carrier and the at least one register element is provided by a series thereof defined by the cartridge housing. And additionally or alternatively, in some embodiments the at least one spring-biased element is provided by a series of resilient arms defined for example by the carrier and the at least one register element is provided by a plurality thereof defined by the cartridge or lancing device housing.
In yet other alternative embodiments, instead of at least one of the alignment elements being formed on the carrier, they are formed on the lancets, for example on the lancet bodies or the lancet caps. As this can lead to some frictional issues, the tolerances, spring-biasing forces, and materials for these elements can be selected to account for the longitudinal frictional issues during the lancing stroke. And the recesses can be elongated so that the protrusion does not run into the longitudinal end of the recess and impede the lancet during its lancing stroke.
In still other alternative embodiments, the cartridge does not include a lancet carrier that moves relative to the cartridge housing, and instead the cartridge (and the lancets housed therein) moves relative to the lancing device housing. In such embodiments, the register and spring-biased elements are formed on the cartridge housing (e.g., on its outer surface) and the lancing device housing (e.g., on its inner surface).
And in yet still other alternative embodiments, the alignment mechanism is designed so that it is activated when the actuator (e.g., a button or lever) of the actuation mechanism is activated (e.g., depressed). That is, the alignment elements are brought into mating engagement with each other upon the active-positioned lancet being released to traverse its lancing stroke under the influence of the discharging drive spring. In some such embodiments, the alignment mechanism is cam-operated with a cam pushing one of the alignment elements into engagement with the other one in a timed fashion. In these and related embodiments, the cam and related elements can be integrated into the advancement, charging, and/or actuation mechanism.
In some embodiments, the advancement mechanism mechanically controls the position of the lancet carrier all the way through its advancement to sequentially advance fresh lancets in the active position. In such embodiments, the alignment and/or advancement mechanism includes a release mechanism that disengages the mechanical positioning of the lancets so that they are no longer positively controlled by the advancement mechanism. In addition, persons of ordinary skill in the art will readily recognize that the alignment mechanism can be implemented in cartridge-based lancing devices having numerous other types of advancement mechanisms.
While the invention has been described with reference to preferred and example embodiments, it will be understood by those skilled in the art that a variety of modifications, additions and deletions are within the scope of the invention, as defined by the following claims.
This application claims the priority benefit of U.S. Provisional Patent Application Ser. No. 61/446,649 filed Feb. 25, 2011, the entirety of which is hereby incorporated herein by reference for all purposes.
| Number | Date | Country | |
|---|---|---|---|
| 61446649 | Feb 2011 | US |
