1. Field of the Invention
The present invention relates, in general, to medical devices and, in particular, to analytical test strip and test meter combinations and related methods.
2. Description of Related Art
The determination (e.g., detection and/or concentration measurement) of an analyte in a fluid sample is of particular interest in the medical field. For example, it can be desirable to determine glucose, ketone bodies, cholesterol, lipoproteins, triglycerides, acetaminophen and/or HbA1c concentrations in a sample of a bodily fluid such as urine, blood, plasma or interstitial fluid. Such determinations can be achieved using an analytical test strip and test meter combination.
The novel features of the invention are set forth with particularity in the appended claims. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings, in which like numerals indicate like elements, of which:
The following detailed description should be read with reference to the drawings, in which like elements in different drawings are identically numbered. The drawings, which are not necessarily to scale, depict exemplary embodiments for the purpose of explanation only and are not intended to limit the scope of the invention. The detailed description illustrates by way of example, not by way of limitation, the principles of the invention. This description will clearly enable one skilled in the art to make and use the invention, and describes several embodiments, adaptations, variations, alternatives and uses of the invention, including what is presently believed to be the best mode of carrying out the invention.
As used herein, the terms “about” or “approximately” for any numerical values or ranges indicate a suitable dimensional tolerance that allows the part or collection of components to function for its intended purpose as described herein.
In general, analytical test strip and test meter combinations for use in the determination of an analyte (such as glucose) in a bodily fluid sample (e.g., a whole blood sample) according to embodiments of the present invention include an analytical test strip and a test meter. The analytical test strip has at least one electrode, a first electrical contact pad that is in electrical communication with the electrode and configured to communicate an electrical response of the electrode to the test meter, and a second electrical contact pad that is in electrical communication with the electrode and is configured to communicate an electrical response of the electrode to the test meter should the test meter be in electrical communication with the second electrical contact pad. In addition, the second electrical contact pad has electrical continuity with the first electrical contact pad and the first and second electrical contact pads are disposed in either of first and second predetermined spatial relationships to one another. For example, and as described further herein, the first predetermined spatial relationship can be an aligned spatial relationship while the second predetermined spatial relationship can be a staggered spatial relationship.
The test meter has, in general, a test strip receiving module, with first and second electrical connector pins, and a signal processing module configured to distinguish the predetermined spatial relationship of the first and second electrical contact pads of an analytical test strip inserted into the test strip receiving module. Such distinguishing is accomplished by the signal processing module sensing one of electrical continuity between the first and second electrical connector pins via the first and second electrical contact pads and electrical discontinuity between the first and second electrical connector pins via the first electrical contact pad and, thereby, distinguishing the inserted analytical test strip as having either the first or second predetermined spatial relationship.
Such an analytical test strip and test meter “combination” can be considered an analytical test strip and test meter “set” or analytical test strip and test meter “pairing” and the test meter is considered an associated test meter with respect to the analytical test strip. Moreover, since analytical test strips having either the first or the second predetermined spatial relationships can be distinguished (i.e., differentiated) from one another, such analytical test strips are also referred to as differentiable analytical test strips.
Analytical test strip and test meter combinations according to embodiments of the present invention are beneficial in that the analytical test strips can be readily identified as suitable or unsuitable for use by the test meter based on whether the signal processing module senses an electrical continuity or an electrical discontinuity. Such identification beneficially enables the test meter to proceed with analyte determination only when appropriate, thus avoiding potentially improper, erroneous or inaccurate analyte determinations based on the use of unsuitable analytical test strips.
It is envisioned that various commercial markets can be supplied with analytical test strip and meter combinations according to embodiments of the present invention. For example, commercial market “A” can be supplied with analytical test strips that have a predetermined aligned spatial relationship that results in the sensing of electrical continuity, while commercial market “B” can be supplied with analytical test strips that have a predetermined staggered spatial relationship that results in the sensing of electrical discontinuity. In such a scenario, signal processing modules of test meters supplied to users in markets “A” and “B” would be programmed to identify analyte test strips with the appropriate electrical continuity or discontinuity as suitable for use and analyte test strips with inappropriate electrical continuity or discontinuity as unsuitable for use. If an analytical test strip configured for market A where to be inadvertently employed in market B, a market B test meter would determine that the analytical test strip was unsuitable for use and, if desired, display an appropriate message to a user on a display module of the test meter.
Referring to
First electrically conductive layer 108 includes a first electrode 114, first electrical contact pad 116 and second electrical contact pad 118. Analytical test strip 102 also includes connection track 120 that provide electrical communication between first and second electrical contact pads 116 and 118 and first electrode 114. First electrical contact pad 116 and second electrical contact pad 118 are in either of a first predetermined spatial relationship or a second predetermined spatial relationships to one another. Moreover, first electrical contact pads 116 and second electrical contact pad 118 are in electrical continuity due to connection track 120.
Analytical test strip 102 also includes a patterned spacer layer 124 positioned between second electrically conductive layer 112 and first electrically conductive layer 108. Patterned spacer layer 124 defines a sample-receiving chamber 126 therein. Analytical test strip 102 also includes a reagent layer 128 and second electrically conductive layer 112 includes a second electrode 130, as depicted in
First insulating layer 106 and second insulating layer 112 can be formed, for example, of a plastic (e.g., PET, PETG, polyimide, polycarbonate, polystyrene), silicon, ceramic, or glass material. For example, the first and second insulating layers can be formed from a 7 mil polyester substrate.
First electrode 114, along with second electrode 130 of second electrically conductive layer 112, are configured to electrochemically determine analyte concentration in a bodily fluid sample (such as glucose in a whole blood sample) using any suitable electrochemical-based technique known to one skilled in the art. First electrode 114 can be configured, for example, as a working electrode while second electrode 130 can, for example, be configured as a counter/reference electrode such that analyte test strip 102 is configured as an electrochemical-based analyte test strip.
The first and second conductive layers, 108 and 112 respectively, can be formed of any suitable conductive material such as, for example, gold, palladium, carbon, silver, platinum, tin oxide, iridium, indium, or combinations thereof (e.g., indium doped tin oxide). Moreover, any suitable technique can be employed to form the first and second conductive layers including, for example, sputtering, evaporation, electro-less plating, screen-printing, contact printing, or gravure printing. For example, first conductive layer 108 can be a sputtered palladium layer and second conductive layer 112 can be a sputtered gold layer. A typical but non-limiting thickness for the first and second conductive layers is in the range of 5 nm to 100 nm.
Patterned spacer layer 124 serves to bind together first insulating layer 106 (with conductive layer 108 thereon) and second insulating layer 110 (with second electrically conductive layer 112 thereon), as illustrated in
Reagent layer 128 can be any suitable mixture of reagents that selectively react with an analyte such as, for example glucose, in a bodily fluid sample to form an electroactive species, which can then be quantitatively measured at an electrode of analyte test strips according to embodiments of the present invention. Therefore, reagent layer 128 can include at least a mediator and an enzyme. Examples of suitable mediators include ferricyanide, ferrocene, ferrocene derivatives, osmium bipyridyl complexes, and quinone derivatives. Examples of suitable enzymes include glucose oxidase, glucose dehydrogenase (GDH) using a pyrroloquinoline quinone (PQQ) co-factor, GDH using a nicotinamide adenine dinucleotide (NAD) co-factor, and GDH using a flavin adenine dinucleotide (FAD) co-factor. Reagent layer 128 can be formed using any suitable technique.
Test meter 104 includes a display 152, a housing 154, a plurality of user interface buttons 156, an optional soft key 158 and a test strip receiving module 160. Test meter 104 further includes electronic circuitry modules (described with respect to
Referring again to
Second electrical connector pin 164 is configured to contact second electrical contact pad 118 for the predetermined spatial relationship of
Once apprised of the present disclosure, one skilled in the art will recognize that embodiments of the present invention can employ more than one electrical connector pin for making electrical contact with electrical contact pad 116. Moreover, embodiments of the present invention can employ more than one electrical connector pin for making electrical contact with electrical contact pad 118 for the predetermined spatial relationship of
Signal processing module 166 is configured to module is configured to distinguish the predetermined spatial relationship of the first electrical contact pad and the second electrical contact pad of an analytical test strip inserted into the test strip receiving module by sensing one of electrical continuity between the first electrical connector pin and the second electrical connector pins via the first electrical contact pad and second electrical contact pad (as in
In the embodiment of
Memory unit 174 of test meter 104 includes a suitable algorithm that determines an analyte based on the electrochemical response of analytical test strip 102. The algorithm, therefore, accommodates the electrochemical response of the electrodes within electrochemical-based analytical test strip 10.
At step 620, a signal processing module of the test meter is used to sense one of (i) electrical continuity between a first electrical connector pin of the test strip receiving module and a second electrical connector pin of the test strip receiving module via a first electrical contact pad and a second electrical contact pad of the analytical test strip and (ii) electrical discontinuity between the first electrical connector pin and the second electrical connector pins via the first electrical contact pad.
The signal processing module is used, at step 630 of method 600, to distinguish the inserted analytical test strip as having a first predetermined spatial relationship of the first electrical contact pad and the second electrical contact pad or a second predetermined spatial relationship of the first electrical contact pad and the second electrical contact pad. Non-limiting examples of such first and second predetermined spatial relationships are depicted in
Method 600 also includes ascertaining suitability of the analytical test strip based on the distinguishing step (see step 640) and determining, based on analytical test strip suitability, an analyte in a bodily fluid sample applied to the analytical test strip (see step 650).
Once apprised of the present disclosure, one skilled in the art will recognize that methods according to embodiments of the present invention including method 600 can be readily modified to incorporate any of the techniques, benefits and characteristics of analytical test strip and test meter combinations according to embodiments of the present invention and described herein.
While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. It should be understood that various alternatives to the embodiments of the invention described herein may be employed in practicing the invention. It is intended that the following claims define the scope of the invention and that devices and methods within the scope of these claims and their equivalents be covered thereby.