Patent Application
20170023516
Field of the Invention
The present invention relates, in general, to medical devices and, in particular, to hand-held test meters and related methods.
Description of Related Art
The determination (e.g., detection and/or concentration measurement) of an analyte in, or characteristic of, a bodily 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, haematocrit 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 a hand-held test meter in combination with analytical test strips (e.g., electrochemical-based analytical test strips).
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, hand-held test meters for use with an analytical test strip (e.g., an electrochemical-based analytical test strip) in the determination of an analyte (such as glucose) in a bodily fluid sample (such as for example, a whole blood sample) according to embodiments of the present invention include a housing, a strip port connector disposed at least partially within the housing, a micro-controller disposed in the housing, a voltage supply disposed in the housing (e.g., a 3V voltage supply), and a fluid ingress detection circuit block disposed in the housing that includes at least one paired signal trace and ground trace, and a ground-reference.
In hand-held test meter according to embodiments of the present invention, a portion of the paired signal trace and ground trace are separated by a predetermined distance (for example, a distance of 1 mm or less). In addition, the signal trace is electrically connected to the voltage supply and to the micro-controller and the ground trace is electrically connected to the ground-reference. Moreover, in the absence of ingress fluid, the signal trace is electrically isolated from the ground trace. In such a configuration, the fluid ingress detection circuit block generates an output signal to the micro-controller that is dependent on fluid ingress into the meter housing, thus providing for detection of fluid ingress.
Once apprised of the present disclosure, one skilled in the art will recognize that the term “paired” as used with respect to the paired signal trace and ground trace refers to a signal trace and ground trace that operate in concert to signal the detection of fluid ingress when such fluid forms a conducting bridge between the signal trace and the ground trace.
The ingress of fluids, such as water and cleaning solutions, into a hand-held test meter's housing can damage electrical components therein, create electrical leakage paths that drain batteries within the hand-held test meter and potentially lead over the course of time to the generation of inaccurate analyte determinations. Hand-held test meters according to embodiments of the present invention are beneficial in that the fluid ingress detection circuit block is configured to generate an output signal that varies with the presence or absence of fluid ingress. Such an output signal can be monitored by, for example, the micro-controller and a warning message displayed to a user when fluid ingress has been detected.
In addition, fluid ingress detection circuit blocks employed in embodiments of inventions according to the present invention cost effective in that they can include only relatively inexpensive components (for example, signal traces, ground traces and a low cost resistor).
Referring to
Display 102 can be, for example, a liquid crystal display or a bi-stable display configured to show a screen image. An example of a screen image during the determination of an analyte in a bodily fluid sample may include a glucose concentration, a date and time, an error message, and a user interface for instructing a user how to perform a test. Examples of screen images during use of the operating range test strip simulation circuit block may be an image reporting that a hand-held test meter operating range test passed, or an image reporting that the hand-held test meter operating range test has resulted in an error.
Strip port connector 106 is configured to operatively interface with an electrochemical-based analytical test strip TS, such as an electrochemical-based analytical test strip configured for the determination of hematocrit and/or glucose in a whole blood sample. Therefore, the electrochemical-based analytical test strip is configured for operative insertion into strip port connector 106 and to operatively interface with micro-controller block 112 via, for example, suitable electrical contacts, wires, electrical interconnects or other structures known to one skilled in the art.
USB Interface 108 can be any suitable interface known to one skilled in the art. USB Interface 108 is an electrical component that is configured to power and provide a data line to hand-held test meter 100.
Micro-controller block 112 also includes a memory sub-block that stores suitable algorithms for the determination of an analyte based on the electrochemical response of an analytical test strip and to also determine a characteristic (e.g., hematocrit) of the introduced bodily fluid sample. Micro-controller block 112 is disposed within housing 110 and can include any suitable micro-controller and/or micro-processer known to those skilled in the art. Suitable micro-controllers include, but are not limited to, micro-controllers available commercially from Texas Instruments (Dallas, Tex., USA) under the MSP430 series of part numbers; from ST MicroElectronics (Geneva, Switzerland) under the STM32F and STM32L series of part numbers; and Atmel Corporation (San Jose, Calif., USA) under the SAM4L series of part numbers). Micro-controller block 112 is in communication with fluid ingress detection circuit 116 via, for example, a digital input port of micro-controller block 112 that is configured to receive an output signal from fluid ingress detection circuit block 116. Such as signal is denoted by an arrow in
Ground reference 118 of hand-held test meter 100 can be any suitable meter ground reference known to one skilled in the art. For example, a meter ground-reference can be a ground reference employed by the hand-held test meter's power supply such as a battery's negative terminal.
Referring, in particular, to
In the embodiment of
In the absence of fluid ingress that bridges signal trace 122 and ground trace 124, the output signal from fluid ingress detection circuit block 116 is, for example, a first predetermined value such as 3V (see
The paired signal trace 122 and ground trace 124 can be formed using any suitable technique including, for example, being formed on a printed circuit board (PCB) disposed within housing 110. Signal trace 122 and ground trace 124 can be, for example, formed of electro less nickel with gold plating. Moreover, paired signal and ground traces employed in embodiments of the present invention can be disposed within hand-held test meter housing in any suitable configuration and are not limited to the configurations depicted in
Once apprised of the present disclosure, one skilled in the art will recognize that fluid ingress detection circuit blocks employed in embodiments of the present invention can take various forms and are not limited to the embodiment depicted in
Method 600 includes, at step 610, activating a fluid ingress detection circuit block disposed within a housing of the hand-held test meter. Such activation can involve, for example, powering on the hand-held test meter and/or activation of a predetermined step in software controlling the hand-held test meter. The activated fluid ingress detection circuit block can be, for example, the fluid circuit detection block described herein with respect to hand-held test meter 100 or described herein with respect to any other embodiment of the present hand-held test meter invention.
At step 610, the fluid ingress detection circuit block of the hand-held test meter is employed to detect the presence of fluid ingress into the housing of the hand-held test meter. Such detection step can, for example, include applying a predetermined voltage to a signal trace of a paired signal and ground trace of the fluid ingress detection circuit block. An example of such application is depicted in, and described with respect to,
Step 620 results in the fluid ingress detection circuit block generating an output signal (see step 630). In step 630, the output signal is a first predetermined output signal in the absence of fluid ingress (see, for example, the 3V output signal depicted in
If desired, detection of fluid ingress via steps 610, 620 and 630 can be employed to display a warning message to a user via a display of the hand-held test meter (see step 640 of FIG.).
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 hand-held test meters according to embodiments of the present invention and described herein.
Once apprised of the present disclosure, one skilled in the art will recognize that the meters and methods according to embodiments of the present invention, including method 600, can employ any suitable electrochemical techniques, including those based on Cottrell current measurements, coulometry, amperometry, chronoamperometry, potentiometry, and chronopotentiometry.
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.
