Patent Application
20150330937
1. Field of the Invention
The present invention relates, in general, to medical devices and, in particular, to hand-held test meters and related methods.
2. 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.
In general, hand-held test meters for use an analytical test strip (such as, for example, an electrochemical-based analytical test strip) in the determination of an analyte (e.g., glucose) in, and/or a characteristic (such as hematocrit) of, a bodily fluid sample (for example, a whole blood sample) according to embodiments of the present invention include a housing, a micro-controller disposed in the housing, a body portion proximity sensor module disposed at least partially in the housing, and a strip port connector configured to operationally receive an analytical test strip. The body portion proximity sensor module of the analytical test strip is configured to sense presence of a user's body portion (such as a user's finger, user's forearm, user's palm or other body portion suitable for expressing a bodily fluid sample) within a predetermined distance of the strip port connector and, upon sensing the presence of such a user's bodily portion, transmit a signal to the micro-controller indicating the presence of such a user's bodily portion.
The body portion proximity sensor module can be based on, for example, capacitance sensing. Once apprised of the present disclosure, one skilled in the art will recognize that body portion finger proximity sensor modules employed in embodiments of the present invention and/or associated algorithms employed by the micro-controller can, if desired, be tuned to reliably sense characteristics of a particular body portion at a predetermined distance via routine experimentation.
Hand-held test meters according to embodiments of the present invention are beneficial in that the sensing of a user's body portion (such as a user's finger) within a predetermined distance (e.g., a distance of less than or equal to 10 mm or less than or equal to 5 mm) of the strip port connector in combination with the presence of an analytical test strip inserted into the strip port connector is an indication that a bodily fluid sample (typically a whole blood sample expressed from the user's fingertip or other suitable body portion) is about to be applied to the analytical test strip. This indication can be employed by the micro-controller to switch the hand-held test meter from a low-power stand-by state to a high-power activated state, thus beneficially saving battery power prior to the sensing of the user's finger. For example, once an analytical test strip is inserted into the test meter, the test meter can enter a low-power stand-by state wherein essentially only the body portion proximity sensor module, the micro-controller module and a display module of the test meter are powered. Subsequently, once a body portion is sensed at a predetermined distance, the high-power activated state can entered wherein the remainder of the test meter's electrical circuits (such as analog and digital electrical circuitry blocks employed in the determination of an analyte in an applied bodily fluid sample) are fully powered and, if desired, the body portion proximity sensor module de-powered (i.e., deactivated).
Once one skilled in the art is apprised of the present disclosure, he or she will recognize that an example of a hand-held test meter that can be readily modified as a hand-hand test meter according to the present invention is the commercially available OneTouch® Ultra® 2 glucose meter from LifeScan Inc. (Milpitas, Calif.). Additional examples of hand-held test meters that can also be modified are found in U.S. Patent Application Publications No's. 2007/0084734 (published on Apr. 19, 2007) and 2007/0087397 (published on Apr. 19, 2007) and in International Publication Number WO2010/049669 (published on May 6, 2010), each of which is hereby incorporated herein in full by reference.
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.
Strip port connector 106 is configured to operatively interface with an 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 and analog electrical circuitry block 114 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 can also include a suitable algorithm(s) for assessing a signal(s) from body portion proximity sensor 107 to ascertain if such signals are representative of a user's body portion being present within the predetermined distance. Once apprised of the present disclosure, such suitable algorithms will be apparent to one skilled in the art can include, for example, suitable algorithms that compare the signal magnitude versus a threshold(s) and/or that employ signal characteristics such as the rate-of-change of the signal. Micro-controller block 112 is disposed within housing 110 and can include any suitable micro-controller and/or micro-processer known to those of skill 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).
In the embodiment of
Upon a user's body portion (such as a user's finger) coming in close proximity to the strip port connector and thus in close proximity to the inserted analytical test strip, the finger proximity detection module senses the presence of the user's body portion and sends a command signal to the micro-controller. Upon receiving this command, the micro-controller turns on its ADC and starts sampling in the normal manner, and the body portion proximity detection module is put into a low power sleep mode.
Analog electrical circuitry block 114 can be any suitable analog electrical circuitry block known to those of skill in the art and is configured to provide excitation voltage and current waveforms to an inserted electrochemical-based analytical test strip and to provide signal conditioning and buffering during the receipt by an Analog-to-Digital (ADC) sub-block of the micro-controller of the resulting currents and voltages.
Digital electrical circuitry block 116 can be any suitable digital electrical circuitry block known to those of skill in the art and configured to provide a logical interface to the micro-controller and to provide for control and configuration via software commands.
Referring to
The square wave of
As describe above, the schematic of
Method 500 includes operably inserting an analytical test strip into a hand-held test meter in a low-power stand-by state (see step 510 of
At step 530 of method 500, upon sensing of the user's body portion within the predetermined distance, electrical circuitry of the hand-held test meter is switched from the low-power stand-by state to a high-power active state upon sensing the presence of the user's body portion (for example, the user's finger, forearm or palm) within the predetermined distance.
Once apprised of the present disclosure, one skilled in the art will recognize that methods according to embodiments of the present invention, including method 500, 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.
