The present invention relates generally to the field of lancets, and more particularly to disposable lancet having a conical polymeric tip for piercing the skin to obtain a sample of blood as in blood glucose testing or blood typing analysis.
Samples of blood must sometimes be collected from a human or animal subject. For example, many diabetics periodically monitor their blood glucose level by collecting a small blood sample from their fingertip, forearm, or other body part. In addition, small blood samples are also commonly collected prior to accepting blood from a donor at blood drives or blood banks, to determine the donor's blood type and/or to screen potential donors for anemia, diseases, or other conditions.
Generally, lancing devices are commonly used to pierce the skin of a subject to obtain a sampling of blood, interstitial fluid, and/or other bodily fluids. Typically, a lancing device incorporates a spring-driven carrier for holding a disposable lancet and some type of triggering mechanism to release energy stored in the spring to drive the sharp edge/point of the lancet to penetrate the subject's skin. Commercially-available lancets typically resemble the device depicted in
A desired effect of using lancets is to draw an amount of blood sufficient to perform medical tests. Different subjects or different testing sites on the same subject may generate differing sample sizes resulting from a lancing procedure that pricks the skin at a specified penetration depth and/or transverse dimension. For example, different test subjects may have differing capillary bed depths and/or differing blood flow responses from similar skin pricks. Similarly, a sample site on a subject's fingertip may generate a greater sample size, whereas a forearm or other alternate sample site may generate a lesser sample size, for the same subject. These differences in sampling response can necessitate a lancet penetration that is shallower/deeper or narrower/wider in some sampling applications than in others. For this reason, lancets with sharp tips of various thicknesses are available. Commercially available lancet thicknesses are commonly measured or specified by numerical gauge or wire thickness. Example gauge formats include 25, 28 and 33 gauge. The gauge scale is numerically arranged with larger numbers signifying thinner tips and smaller gauge numbers signifying thicker tips. For a given penetration depth, a larger gauge lancet will typically produce a smaller skin prick and lesser sample size, and a smaller gauge lancet will typically produce a larger skin prick and a greater sample size.
The provision of lancets of varying gauges for different sampling needs can lead to inefficiencies in use resulting from selection of an incorrect lancet gauge. For example, selection and use of too small a lancet may result in inadequate sample size, necessitating multiple lancing procedures. Alternatively, use of too large a lancet may result in too large a sample than needed and greater perception of pain by the subject, potentially reducing compliance with a prescribed testing regimen. The manufacturing and stocking of multiple lancet gauges may also increase costs and required shelf space.
Thus it can be seen that needs exist for improvements to lancets for blood sampling. It is to the provision of an improved lancet meeting these and other needs that the present invention is primarily directed.
In example embodiments, the present invention provides a conical polymeric lancet tip that incorporates multiple gauge numbers within a single body. The change in gauge number depends on the position along the conical body and is equivalent to the change of position depth.
In one aspect, the invention relates to a lancet with a body that has a tapered surface extending between a sharp tip and a wide base. The tapered surface is configured to define a plurality of different lancet gauge levels corresponding with a plurality of different penetration depths.
In another aspect, the invention relates to a lancet with a sharp tip that has a polymeric material. The sharp tip has an acutely-angled tapering outer surface and a base with a surface area that is larger than the sharp tip. The lancet also has a lancet body that is integrally formed with the sharp tip.
In a further aspect, the invention relates to a method of controlling penetration depth of a lancet. The method includes configuring a lancet tip to have a tapered surface with a point and a base. The tapered surface includes a plurality of different lancet gauge numbers corresponding to a plurality of different penetration depth increments. The method also includes securing the lancet tip to a support body.
In another aspect, the invention relates to a lancet including a lancet body and a sharp lancet tip extending from said lancet body. The sharp lancet tip preferably has a conical geometry having circular base at its point of connection with the lancet body, a point defining an included angle at a distal end thereof, and a tip height defined between the base and the point.
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 the invention 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 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,
As depicted, the sharp tip 22 has an inverted circular-circumference conical shape with a wide base and a narrow pointed tip, defining a tip height between the base and the tip of, for example, between about 2 mm-6 mm, or more preferably between about 3 mm-5 mm, or between about 3 mm-4 mm. Alternative shapes can include an inverted cone or pyramid with three sides forming a triangular base or an inverted cone or pyramid with four sides forming a square or rectangular base, or a generally conical element defining a sharp tip and concave or convex sides. Additional alternative shapes can include five or more sides forming a prismatic or faceted point or edge.
The tip 22 preferably has a point or edge that is sharp enough to prick the skin of a human or animal subject with minimal trauma and perception of pain, to generate a blood sample. The apex, edge or point of the sharp tip 22 preferably defines an acute angle of, for example, between about 2°-10°, or more preferably between about 3°-7°. This acute angle can continue to define the circumferential surface of the tip 22 from the point to the base, so that the tip is progressively tapered or stepped to vary and/or regulate the penetration depth of the tip into flesh, and thereby the size of the skin prick generated. Alternatively, the angle between diametrically-opposing) (180°) locations on the circumferential surface of the tip can vary between the point and the base. For example, at a certain vertical position between the point and the base, the angle can be smaller or larger than the acute angle of the point. In this manner, a single lancet format can be used universally in place of any of a range of standard lancet gauge formats, for differing sampling needs and/or for use at different sample sites. As particularly shown in
The lancet of the present invention may be particularly suited for adaptation and use with adjustable depth lancing devices of various forms. For example, in a method of use with a direct-link depth control lancing device, the penetration depth of the tip 22 of the lancet 20 is controlled, and the size of the skin prick is thereby varied depending on the desired sampling result. Incrementally increasing or decreasing the lancing depth correspondingly increases or decreases the dimension of the skin prick in the direction along the surface of the skin, thereby generating a larger or smaller sample size.
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 benefit of U.S. Provisional Patent Application Ser. No. 61/592,178 filed Jan. 30, 2012, the entirety of which is hereby incorporated herein by reference for all purposes.
Number | Date | Country | |
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61592178 | Jan 2012 | US |