AU2012201370B2

AU2012201370B2 - Electrochemical Biosensor Measuring System

Info

Publication number: AU2012201370B2
Application number: AU2012201370A
Authority: AU
Inventors: Geun Sig Cha; Gang Cui; Keun Ki Kim; Moon Hwan Kim; Hakhyun Nam; Jae Hyun Yoo
Original assignee: i Sens Inc
Current assignee: i Sens Inc
Priority date: 2007-03-02
Filing date: 2012-03-07
Publication date: 2013-10-03
Anticipated expiration: 2028-02-26
Also published as: AU2012201370A1

Abstract

Abstract There is provided a biosensor measuring method for detecting a target component in biological samples using a biosensor encoded with product lot information and the s product lot information sensing unit having light emitter/detector pairs by irradiating on the product lot information markings with the light emitted from a bank of light emitters and by reading the transmitted or reflected lights from the product lot information markings with the detectors paired with the light emitters, the method comprising: checking malfunction of the production lot information sensing unit; alerting the io malfunction in the product lot information sensing unit; decoding the production lot information read through the production lot information sensing unit when the production lot information sensing unit normally operates; and analytically determining a target component in a sample from the response of the biosensor strip in combination with the decoded production lot information. 3199224_1 (GHMatters) P89758 AU 7/03/12 600 flo 01, I-- L"G 500: 702 Ito

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicant(s): i-SENS, Inc. Invention Title: Electrochemical Biosensor Measuring System The following statement is a full description of this invention, including the best method for performing it known to me/us: -2 ELECTROCHEMICAL BIOSENSOR MEASURING SYSTEM Related Application 5 This application is a divisional application of Australian application no. 2008221803 the disclosure of which is incorporated herein by reference. Most of the disclosure of that application is also included herein, however, reference may be made to the specification of application no. 2008221803 as filed or accepted to gain further understanding of the invention claimed herein. 10 Technical Field The present invention relates to an electrochemical biosensor measuring device. Background Art is For the diagnosis and prophylaxis of diabetes mellitus, the importance of periodically monitoring blood glucose levels is increasingly emphasized. Nowadays, strip-type biosensors designed to be used in hand-held reading devices allow individuals to readily monitor glucose levels in the blood. Many various commercialized biosensors measure the blood glucose content of 20 blood samples using an electrochemical technique. The principle of the electrochemical technique is based on the following Reaction 1. [Reaction 1] Glucose + GOx-FAD -- gluconic acid + GOx-FADH 2 GOx-FADH 2 + Mox -- GOx-FAD + Mred 25 wherein, GOx represents glucose oxidase; GOx-FAD and GOx-FADH 2 respectively represent an oxidized and a reduced state of glucose-associated FAD (flavin adenine dinucleotide), a cofactor required for the catalysis of glucose oxidase; and Mox and Mred denote the oxidized and reduced states, respectively, of an electron transfer mediator. 30 The electrochemical biosensor uses as electron transfer mediators organic electron transfer materials, such as ferrocenes or derivatives thereof, quinines or derivatives thereof, organic or inorganic materials containing transition metals (hexamine ruthenium, polymers containing osmium, potassium ferricyanide and the like), organic conducting salts, and viologens. 35 The principle by which blood glucose is measured using the biosensor is as follows. Glucose in the blood is oxidized to gluconic acid by the catalytic activity of glucose oxidase, with the cofactor FAD reduced to FADH 2 . Then, the reduced cofactor FADH 2 transfers electrons to the mediator, SO that FADH 2 returns to its oxidized state; that is, 31992241 (GHMatters) P89758.AU 7/03/12 -3 FAD and the mediator are reduced. The reduced mediator is diffused to the surface of the electrodes. The series of reaction cycles is driven by the anodic potential applied at the working electrode, and redox current proportional to the level of glucose is measured. Compared to biosensors based on colorimetry, electrochemical biosensors s (that is, based on electrochemistry) have the advantages of not being influenced by the turbidity or color of the samples and allowing the use of wider range of samples, even cloudy ones, without pretreatment thereof. Although this electrochemical biosensor is generally convenient when used to monitor and control the amount of blood glucose, its accuracy is greatly dependent on io lot-to-lot variation between respective mass-produced lots in which the biosensors are produced. In order to eliminate such variation, most of the commercialized biosensors are designed such that a user directly inputs calibration curve information, which is predetermined at the factory, into a measuring device capable of reading the biosensor. However, this method inconveniences the user a great deal and causes the 15 user to make input errors, thus leading to inaccurate results. In order to solve this problem, a method by which the resistance of each electrode can be adjusted such that the variations in mass production is corrected (US 20060144704 Al), a method in which a connection to a resistor bank is made (WO 2007011569 A2), and a method by which information is read by varying resistance 20 through the adjustment of the length or the thickness of each electrode (US 20050279647 Al) have been proposed. The methods proposed for the electrochemical biosensors are all based on a technique in which electrical variation is read. Furthermore, a method for distinguishing production lot information by reading the resistivity of a conductor marked on a strip using an electrical method (US 4714874) 25 has been proposed. However, these methods function to accurately adjust resistance, and require a process of mass-producing the sensors first, measuring the statistical characteristics of the sensors, and post-processing the measured information again using a method of adjusting the resistance marked on the sensors. However, the process of accurately 30 adjusting the resistance, marked in large quantities, through the post-processing is very inconvenient, and is difficult to use in practical applications. Methods in which colored marks are used with a spectral system capable of discriminating colors to realize a colorimetric method (US 3907503, US 5597532, US 6168957), and a method capable of reading bar codes (EP 00075223 B1, WO 35 02088739 Al) have been proposed. These methods using color or bar codes are favorable for a colorimetric method-based sensor using the spectrum system, but they have technical and economic difficulties when applied to a system using an electrochemical measurement mechanism. For example, the size and structure of the area where the electrochemical sensor strip is inserted into the measuring device for 31992241 (GHMatters) P89758.AU 7/03/12 -4 the purpose of electrical connection, that is, the connection space of the sensor strip, is very limited when constructing a device and circuit for spectroscopically identifying a structure into which the production lot information is input, which results in a great increase in system construction expense. 5 Furthermore, instead of the methods of marking the production lot information on the sensor strip, a method of recording information on a container or pack containing a sensor and allowing the information to be read by the measuring device has been proposed. However, this method also has a possibility of causing the user to make an error. 10 For conventional methods developed in order for users to measure the blood glucose levels thereof using disposable electrochemical biosensor strips without the need to manually input accurate calibration curve information about biosensors, which differs from one production lot to another into a measuring device, the sensors require a long period of time for the preparation thereof, and also require post-processing, in is which errors are likely to be made. Also, conventional devices for reading hue marks using a filter or a monochromator for the wavelength of a light source encounter great spatial limitations and pose problems in the construction of small-sized systems. Thus, there is a need for a biosensor that has a mark which is simple and can be 20 easily marked within a short time period, such as hue marks, which are convenient to print on a small area of a biosensor, or hole marks, which can be easily prepared simultaneously when the final press process for mass production is performed, thereby allowing the biosensor to be produced on a mass scale. Also, there is a need for a biosensor that has production lot information recorded on the mark through which the 25 production lot information can be thus inputted to an insulation plate of the biosensor, so that when the biosensor is inserted into a measuring device, the production lot information is automatically identified without a mistake being made by a user, thus enabling blood glucose to be conveniently and accurately measured and being economical. 30 Leading to the present invention, intensive and thorough research into electrochemical biosensors. conducted by the present inventors, aiming to maintain economic efficiency in the construction of' the measuring device in which the production lot information thereof can be easily and accurately input into the measuring device and which removes the risk of mistakes being made by the user, thus providing 35 an accurate measurement value, resulted in the finding that, when the production lot information is recorded in the form of hue marks or hole marks on the electrochemical biosensor strip, and when various connectors are connected with a small-sized emitter detector system to automatically read the production lot information, there is no need 31992241 (GHMatters) P89758.AU 7/03112 -5 for a user to manually input the production lot information of a biosensor, and thus accurate measurement values can be conveniently obtained. Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art. 5 Summary of the Invention In a first aspect, the present invention provides a biosensor measuring method for detecting a target component in biological samples using a biosensor encoded with product lot information and the product lot information sensing unit having light io emitter/detector pairs by irradiating on the product lot information markings with the light emitted from a bank of light emitters and by reading the transmitted or reflected lights from the product lot information markings with the detectors paired with the light emitters, the method comprising: checking malfunction of the production lot information sensing unit; 15 alerting the malfunction in the product lot information sensing unit; decoding the production lot information read through the production lot information sensing unit when the production lot information sensing unit normally operates; and analytically determining a target component in a sample from the response of 20 the biosensor strip in combination with the decoded production lot information. In a second aspect, the present invention provides a biosensor measuring device for detecting a component of a sample through a biosensor strip having a production lot information identification unit that includes at least one production lot information mark, the biosensor measuring device comprising: 25 a production lot information sensing unit including a plurality of paired light emitters and detectors that reads a production lot information by emitting the light onto and detecting the absorbed or reflected light from the production lot information identification unit; and a biosensor strip measuring module that decodes the production lot information 30 and uses the decoded production lot information for analytical determination of a target component in samples, wherein the measuring module comprises at least one processor that is activated by a predetermined program, and the predetermined program comprises a series of commands for performing the above measuring method. 35 In the specification, the term "biosensor" is used to have the same meaning as the term "biosensor strip". 3199224_1 (GHMatters) P89758.AU 7/03/12 -6 Brief Description of the Drawings Objects, features and advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which: 5 FIG. 1 is a schematic perspective view of a connector having a transparent body installed in a measuring device in accordance with an embodiment of the present invention: FIG. 2 is a schematic perspective view of a connector provided with a transmission window in one side thereof, which is used in a measuring device in accordance with an io embodiment of the present invention; FIG. 3 is a schematic perspective view of a connector constructed to have a sliding structure, which is used in a measuring device in accordance with an embodiment of the present invention; FIG. 4 is a schematic perspective view of a connector comprising a light emitter, a is detector and an electrical connection portion in an integrated structure therein, which is used in a measuring device in accordance with an embodiment of the present invention; FIG. 5 is a schematic perspective view of a connector comprising a light emitter, a detector system and an electrical connection portion in an integrated structure therein, 20 which is used in a measuring device in accordance with an embodiment of the present invention; FIG. 6 is a schematic perspective view of a connector comprising an image signal identification device and an electrical connection portion in an integrated structure, which is used in a measuring device in accordance with an embodiment of the present 25 invention; FIG. 7 is a schematic sectional view showing the insertion of a biosensor to a connector in a measuring device according to an embodiment of the present invention; and FIG. 8 is a flow chart showing a measuring process using a biosensor measuring 30 device in accordance with the present invention. Brief Description of the Mark of Drawings 104: electrode 110: biosensor strip 3s 500: production lot information identification portion 700: sensor connector 700a: connector body 700b: sliding structure of connector 702: light emitter 3199224_1 (GHMatters) P89758.AU 7/03/12 -7 703: detector 704: printed circuit board 705: electrical connection portion 706: transmission window 5 707: image signal identification device Detailed Description The electrodes of the electrochemical biosensor used in the electrochemical biosensor measuring device according to the present invention may be formed on one io or both of at least two planar insulating plates. That is, (1) a single working electrode and a single auxiliary electrode (or reference electrode) may be formed on the same planar insulating plate, or (2) may he formed on two planar insulating plates facing each other [parallel electrodes; reference: E. K. Bauman et al.. Analytical Chemistry. vol 37, p 1378. 1965: K. B. Oldham in "Microelectrodes: Theory and Applications," is Kluwer Academic Publishers, 1991; J. F. Cassidy et al., Analyst, vol 118, p 415]. In addition, the electrodes of the electrochemical biosensor used in the electrochemical biosensor measuring device according to the present invention may further include a sample fluidity determining electrode, which is disposed behind the working electrode and is capable of measuring the fluidity of whole blood samples on a 20 lower planar insulating plate. The biosensor is described in greater detail taking parallel electrodes as an example. In the case where the electrochemical biosensor used for the electrochemical biosensor measuring device according to the present invention is constructed using the 25 parallel electrodes, the biosensor may have a structure in which the working electrode and the auxiliary electrode are spaced apart from each other by a pressure-adhesive spacer which is 50-250 pm thick, and are aligned or not aligned with each other and facing each other. In the thin spacer, a capillary sample cell on the microliter volume scale is 30 provided for injecting a bio-sample in a measurement space defined by the working electrode and the auxiliary electrode and retaining the sample therein. The capillary sample cell includes a sample introducing portion and a micro-path. In the thin spacer, a sample fluidity determining electrode is placed preferably at a predetermined distance from the working electrode or the auxiliary electrode so that 35 fluorinated blood having a corpuscle volume of 40% can reach the working electrode (or the auxiliary electrode) along a micro-path 0.5-2 mm wide and 50-250 Prm high within about 600 ms, and more preferably at a predetermined distance from the working electrode or the auxiliary electrode such that non-fluorinated blood can reach 31992241 (GHMalters) P69758.AU 7/03/12 -8 the electrode along the micro-path 0.5-2 mm wide and 50-250 pm high within 300 ms, and still more preferably within 200 ms. Functioning to introduce a blood sample into one end of the biosensor, the sample introducing portion is preferably formed in a "1" shape so as to allow the rapid, s accurate and convenient introduction of a blood sample from the fore end of the biosensor strip. The sample introducing portion is structured such that an allowance space is formed the a location at which a sample introducing path and an air vent cross each other. By the term "cross", as used herein, it is meant that the sample-introducing path and the air vent are not arranged parallel to each other, but intersect each other at 10 a predetermined point. During measurement, the allowance space helps maintain a constant and accurate volume of the blood sample within the path while discharging the excess sample through the air vent. Also, the allowance space may he used as the place where the sample fluidity determining electrode is disposed. When introduced into the sample introducing portion, a blood sample moves to the electrodes through is the micro-path. In the electrochemical biosensor used in the electrochemical biosensor measuring device according to the present invention, the reaction reagent layer may be formed merely by applying a reagent solution only to the working electrode, or to both the working electrode and the sample fluidity determining electrode. The reaction reagent 20 layer includes an enzyme, such as a glucose oxidase or a lactate oxidase, an electron transfer mediator, a water-soluble polymer, such as a cellulose acetate, a polyvinyl alcohol or a polypyrrol, a fatty acid having 4 to 20 carbon atoms as a reagent for reducing a hematocrit effect, and a hydrophilic quaternary ammonium salt. In the electrochemical biosensor according to the present invention, electrode 2s connection portions at which the biosensor and the measuring device are electrically connected are designed to exist in the same plane in which the working electrode and auxiliary electrode are connected via connection lines. The level of blood glucose that is measured by the biosensor of the present invention from the results of an electrochemical reaction is provided to the measuring device through the electrode 30 connection portions, and thus can be numerically converted into a precise blood glucose value. The electrochemical biosensor according to the present invention includes a production lot information identification portion 500 for providing calibration curve information about various concentrations of liquid samples, which is used for 35 respective production lots at the time of manufacturing the biosensor, along with biosensor production lot information, to a user. The production lot information identification portion 500 may include at least one mark selected from the group consisting of hue marks, hole marks, and light transmitting film-covered hole marks. 3199224_1 (GHMatters) P89758.AU 7/03112 -9 In the electrochemical biosensor measuring device according to the present invention, the production lot information encoded by the hue mark, the hole mark or the light-transmitting film-covered hole mark can be identified using various methods including an optical method, an imaging method, and an IR beam method. The s operational principle by which the production lot information identification portion in the measuring device is identified is described in detail below. In the measuring device, at least two light emitters, for examples, photodiodes, are integrated within a small space. Photodiodes useful in the present invention are preferably three-component light emitting diodes emitting red, blue and green colors, or 10 four-component light emitting diodes emitting white, red, blue and blue colors, but are not limited thereto. The light emitter may use an infrared light source. Using the light emitted from the photodiodes or the infrared light source, the information encoded by the hue mark, the hole mark or the light-transmitting film-covered hole mark marked in the production lot information identification portion of the biosensor is detected. 15 The hue mark may display the information about differences between production lots according to differences in color, brightness, or chroma. The hole mark may encode the information about differences between production lots as a combination of close and open holes. As for the light-transmitting film-covered hole mark, its information about differences between production lots can be indicated by varying the 20 degree of transmission of the film covering the hole mark. It is preferred that the number of hue marks or hole marks be adjusted to fall within the range of 1 to 10. The light sensed by the production lot information identification portion is transmitted therethrough or reflected therefrom, and experiences a change in intensity or wavelength. The transmitted or reflected light is detected by a detector 703, such as 25 an optical identifier, placed at a location between the light emitters 702. The change in the intensity and wavelength of light, as detected by the detector 703, is delivered to a calculation system (not shown) from which the change appears as the production lot information of the biosensor. The light emitter 702 and the detector 703 may be constructed in a separated or 30 integrated structure. The detector 703 may be located in the same plane as the light emitter 702 when it is adapted to detect the light reflected from the hue marks, the hole marks or the light-transmitting film-covered hole marks, and may be located in a plane opposite the light emitter 702 when it is adapted to detect the transmitted light. With regard to the hue marks, the differences in the image made by their 35 combinations correspond to differences in the information about production lots. The images of the marks are detected by an image signal identification device 707, such as a CCD camera, and are transmitted to a calculation system (not shown) from which the image signal appears as the production lot information of the biosensor. 31992241 (GHMatters) P89758.AU 7/03112 - 10 The production lot information identification portion 500, adapted for the electrochemical biosensor, which is used for the electrochemical biosensor measuring device according to the present invention, is not limited to a parallel type electrochemical biosensor, and may also be applied to a plane type electrochemical 5 biosensor, which is implemented such that the working electrode and the auxiliary electrode are formed in the same plate and are thus operated, and to a differential type electrochemical biosensor, which is implemented such that the parallel type electrochemical biosensor and the plane type electrochemical biosensor process signals differently. 10 A connector used in the electrochemical biosensor measuring device according to the present invention preferably has a structure in which one or more absorption or ref lection path(s) comprising a light emitter-production lot information identification portion-detector can be realized, thereby identifying the production lot information marked on the biosensor. is As shown in FIG. 1, the connector 700, for example, may be formed of a body made of transparent material, such as transparent acrylic or plastic. Furthermore, the connector 700, as shown in FIG. 2, may be provided with a transmission window 706 in one side thereof so that infrared rays absorbed or reflected via the light emitter-production lot information identification portion-detector 700 are 20 passed therethrough. Accordingly, even when the connector is made of opaque material, or even when the body of the connector is colored, the light beams radiated by the light emitters 702 can easily reach the production lot information identification portion of the biosensor through the transmission window 706, and thus the production lot information can be identified. 2S Furthermore, in order to pass the light beams, which are absorbed or reflected via the light emitter-production lot information identification portion-detector, through the connector 700, the connector 700 may be manufactured such that one side thereof has a sliding door structure 700b. In greater detail, when a biosensor is inserted into the connector, the sliding door structure 700b of the connector is pushed along with the 30 biosensor in the insertion direction of the biosensor, thus realizing the path along which the light beams can reach the production lot information identification portion of the biosensor. In this case, the sliding door structure 700b may be connected to a device that can passively or automatically remove the biosensor, and thus the biosensor can he easily separated and removed from the biosensor measuring device using the 35 removing device (not shown) after the use of the biosensor. As shown in FIGS. 4 to 6, the connector may comprise the light emitters 702, the detector 703 and electrical connection portions 705 in an integrated structure within the body thereof. For example, the connector of FIG. 4 employs a three-color diode as a light emitter 702 and an optical identifier as a detector in an integrate structure, by 31992241 (GHMatters) P89758 AU 7/03/12 - 11 which differences in the color, brightness or chroma of the production lot information identification portion of the biosensor are detected to thus identify the production lot information. The connector of FIG. 5 employs an infrared light source 703 as a light emitter 702 and an optical identifier as a detector 703 in an integrated structure in s order to discriminate the differences in the color, brightness or chroma of the production lot information identification portion of the biosensor, thereby identifying production lot information. FIG. 6 shows a connector 700 which employs an image signal identification device 707 as a detector by which the image encoded by the hue mark of the production lot information identification portion is detected so as to identify 1o the production lot information. Preferably, the image signal identification device may be a charge coupled device (CCD) camera. It may be generally difficult or uneconomical to construct a system in which a hue or hole mark identification circuit of a photospectrometer system is installed in combination with a circuit and device for measuring the biosensor of an i5 electrochemical system. With the recent development of small-sized light emitting device, detecting device and circuit design technologies, however, a system, the constitution of which was considered unfeasible in the past due to incompatibility between constitutional components, can be easily and economically implemented in a small circuit space at minimal cost. 20 Conventional devices for reading hue marks using a filter or a monochromator to determine the wavelength of a light source encounter great spatial limitations and pose problems in the construction of small-sized systems. In the recognition of production lot information, in contrast, the biosensor according to the present invention can readily identify hue marks and allows the construction of an economical system because it 25 uses small-sized three-component light emitting diodes emitting red, blue and green colors at the same time and detects overall variation in the light reflected from or transmitted through the hue marks with a small-sized optical identification device. The advantage of such electrochemical measurement is combined with the advantages of recent small-sized spectral device technologies obtained by the development of 30 technology, and thus a biosensor that is economical and provides precise measurement values can be provided. Furthermore, the present invention provides a measuring method using the electrochemical biosensor measuring device, comprising: inserting a biosensor provided with a production lot identification portion containing 35 production lot information into the connector port of the biosensor measuring device to activate its power (step 1); identifying the production lot information of the biosensor inserted at Step 1 (step 2); 31992241 (GHMatters) P89758.AU 7/03/12 - 12 activating measurement and operation processes of the biosensor measuring device in conformity with the production lot information identified at Step 2 (step 3); and introducing a liquid sample to the sample inlet of the biosensor to result in quantitative electrochemical information about the sample, quantifying a specific 5 component of the liquid sample, and displaying quantification results (step 4). The measuring method using the biosensor measuring device of the present invention is described stepwise in detail below. In step 1, a biosensor provided with a production lot identification portion containing production lot information into the connector port of the biosensor io measuring device is inserted to activate its power. As shown in FIG. 7, the biosensor is inserted into the connector 700 of the measuring device through a sensor injection hole. Upon insertion, the electrodes 104 of the biosensor 110 are electrically connected to the electrical connection portions 705 of the connector to allow electric current to how, therefore operating the measuring is device. Next, Step 2 serves to identify the production lot information of the biosensor which is inserted at step 1. As shown in FIG. 7, the insertion of the biosensor 110 into the connector 700 electrically connects the biosensor to the measuring device through the connector 700 20 to activate the light emitter 702-detector 703 system in the measuring device, thereby identifying the production lot information of the biosensor using the activated light emitter 702-detector 703 system. In this regard, the identification of the production lot information is implemented by the recognition of at least one mark selected from the group comprising a hue mark, a 25 hole mark and a light-transmitting film-covered hole mark. The hue mark may display the information about differences between production lots by differences in the color, brightness, or chroma of a plurality of color images. The hole mark may encode the information about differences between production lots in the form of a combination of holes which are independently open or closed. As for the 30 light-transmitting film-covered hole mark, its information about differences between production lots can be displayed by varying the degree of transmission of films covering open holes. It is preferred that the number of hue marks or hole marks be adjusted to fall within the range of 1 to 10. The identification of the production lot information can be achieved as follows. 35 For instance, light beams are emitted sequentially from three-component photodiodes of red, green and blue colors or four-component photodiodes of white, red, green and blue colors to detect the hue marks, hole marks or light-transmitting film-covered hole marks of the production lot information identification portion. Variations in wavelength, color, brightness and chroma depending on the degrees of 31992241 (GHMatters) P89758.AU 7/03112 - 13 reflection or transmission of detected light beams are detected by an optical identification device, so that the production lot information of the biosensor can be identified. In another example, image signals are detected from the hue marks of the 5 production lot information identification portion, thereby identifying the production lot information of the biosensor. In Step 3, measurement and operation processes of the biosensor measuring device are activated in conformity with the production lot information identified at Step 2. 10 Following the identification of the production lot information at Step 2, in greater detail; the measuring device has measurement and operation processes activated in conformity with the identified production lot information, and enters a standby state for sample measurement. Finally, Step 4 serves to introduce a liquid sample to the sample inlet of the 15 biosensor to result in quantitative electrochemical information about the sample, quantify a specific component of the liquid sample, and display the quantified results. In greater detail, the introduction of a liquid sample into the biosensor strip inserted into the measuring device (step a) creates a predetermined potential difference between the working electrode and the auxiliary electrode and between the sample 20 fluidity determining electrode and the auxiliary electrode (step b), the sample flowing into the sample introducing portion of the strip causes primary electrical variation between the working electrode and the auxiliary electrode to adjust the voltages between the electrodes to the same value (step c). The sample fluidity determining electrode senses the flow of the sample to cause secondary electrical variation, and 25 the voltage between the auxiliary electrode and the sample fluidity determining electrode is adjusted to be the same, thus providing information about the time difference with the electrical variation primarily sensed by the working electrode (step d). When a liquid sample is sufficiently mixed with a reagent applied to the working electrode, voltage is applied again between the working electrode and the auxiliary 30 electrode to cause a cyclic reaction in a parallel-type thin layer electrochemical cell, and the stationary current value thus reached is read (step e). The amount of the substrate present in the sample is analyzed using the time information obtained in step d and the stationary current value obtained in step e to determine the level of a specific component, such as blood glucose, and the result is displayed in a window. 35 As described hitherto, the electrochemical biosensor measuring device according to the present invention automatically identities the production lot information of the biosensor without a mistake being made by a user upon the insertion of an electrochemical biosensor into a measuring device, thus enabling blood glucose to be conveniently and accurately measured. 31992241 (GHMatters) P89758.AU 7/03/12 - 14 Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. 5 It is to be understood that any reference to prior art made herein does not constitute an admission that the prior art formed or forms a part of the common general knowledge in the art, in Australia or any other country. In the claims which follow and in the preceding description of the invention, except where the context requires otherwise due to express language or necessary io implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e. to specify the presence of the stated features but not to preclude the presence or addition of further features in various embodiments of the invention. 3199224_1 (GHMatters) P89758.AU 7/03/12

Claims

1. A biosensor measuring method for detecting a target component in biological samples using a biosensor encoded with product lot information and the product lot 5 information sensing unit having light emitter/detector pairs by irradiating on the product lot information markings with the light emitted from a bank of light emitters and by reading the transmitted or reflected lights from the product lot information markings with the detectors paired with the light emitters, the method comprising: checking malfunction of the production lot information sensing unit; 10 alerting the malfunction in the product lot information sensing unit; decoding the production lot information read through the production lot information sensing unit when the production lot information sensing unit normally operates; and analytically determining a target component in a sample from the response of is the biosensor strip in combination with the decoded production lot information.

2. A biosensor measuring method as claimed in claim 1, wherein the checking of malfunction in the production lot information sensing unit comprises: determining malfunction of the detection unit; and 20 determining malfunction of the light emission unit, and the production lot information sensing unit is determined to be malfunctioning if any of the detection unit and the light emission unit malfunctions.

3. A biosensor measuring method as claimed in claim 2, wherein the 25 determinination of malfunction in the detection unit is based on a sensing value from the detection unit while the paired light emission unit is off.

4. A biosensor measuring method as claimed in claim 2, wherein the detection unit comprises a plurality of detectors and the malfunction in detection unit is 30 determined by sequentially activating each detector in the pluarality of detectors and reading the light-off sensing value of each detector.

5. A biosensor measuring method as claimed in claim 2, wherein the detection unit comprises a plurality of detectors and the malfunction in the detection unit is 35 determined by respective sensing values read from the plurality of detectors and the values obtained from the mathematical operation of the sensing values of the plurality of detectors. 31992241 (GHMatters) P89758.AU 7/03/12 - 16

6. A biosensor measuring method as claimed in claim 2, wherein the malfunction in detection unit is determined when the biosensor strip is placed into the device unit where the production lot sensing unit can be activated and the biosensor strip measurement sequence begins. 5

7. A biosensor measuring method as claimed in claim 2, wherein the malfunction in the detection unit is determined without biosensor strip, the result of malfunction determination is recorded in a memory of biosensor measuring device, and the biosensor measuring device alerts the malfunction in the production lot information io sensing unit.

8. A biosensor measuring method as claimed in claim 2, wherein the malfunction in the light emission unit is determined when the detection unit is determined to be normally functioning. 15

9. A biosensor measuring method as claimed in claim 8, wherein the light emission unit comprises a plurality of light emitters, and the malfunction in the light emission unit is determined by sequentially activating the plurality of light emitters and reading the light-on sensing value of each detector paired with the corresponding 20 emitter.

10. A biosensor measuring method as claimed in claim 8, wherein the light emission unit comprises a plurality of light emitters, and the malfunction in the light emission unit is determined by the light-on sensing values of respective detectors 25 when the plurality of light emitters are sequentially activated and the values obtained from the mathematical operation of the light-on sensing values of a plurality of detectors.

11. A biosensor measuring method as claimed in any one of claim 1 to claim 10, 30 wherein at least one production lot information mark comprises a hue mark, and the decoding of the production lot information is based on a difference in light absorption or reflection, color, brightness, chroma, or an image of the mark.

12. A biosensor measuring method as claimed in any one of claim 1 to claim 10, 35 wherein the at least one production lot information comprises a hole mark, and the decoding of the production lot information is based on determining differences in a combination of a plurality of open and closed holes. 3199224_1 (GHMatters) P89758.AU 7/03/12 - 17

13. A biosensor measuring method as claimed in any one of claim 1 to claim 10, wherein the at least one production lot information mark comprises a light-transmitting film-covered hole mark, and the decoding of the production lot information is made by the degree of transmission through films covering the holes. 5

14. A biosensor measuring method as claimed in any one of claim 1 to claim 10, wherein the light emitter is formed of three-component light emitting diodes that emit red, green, and blue colors, four-component light emitting diodes that emit white, red, green and blue colors, or an infrared ray source that emits infrared rays. 10

15. A biosensor measuring device for detecting a component of a sample through a biosensor strip having a production lot information identification unit that includes at least one production lot information mark, the biosensor measuring device comprising: a production lot information sensing unit including a plurality of paired light 15 emitters and detectors that reads a production lot information by emitting the light onto and detecting the absorbed or reflected light from the production lot information identification unit; and a biosensor strip measuring module that decodes the production lot information and uses the decoded production lot information for analytical determination of a target 20 component in samples, wherein the measuring module comprises at least one processor that is activated by a predetermined program, and the predetermined program comprises a series of commands for performing the measuring method of any one of claim 1 to claim 10. 25

16. A biosensor measuring device as claimed in claim 15 wherein the at least one production lot information comprises a hue mark, and the decoding of the production lot information is based on a difference in at least one of light absorption or reflection, color, brightness, chroma, and an image of the hue mark. 30

17. A biosensor measuring device as claimed in claim 15, wherein the at least one production lot information comprises a hole mark, and the decoding of the production lot information is performed by differences in a combination of a plurality of open and closed holes. 35

18. A biosensor measuring device as claimed in claim 15, wherein the at least one production lot information comprises a light-transmitting film-covered hole mark, and the decoding of the production lot information is made by the degree of transmission through films covering the hole mark. 31992241 (GHMatters) P89758.AU 7/03/12 - 18

19. A biosensor measuring device as claimed in claim 15, wherein the light emitter is formed of three-component light emitting diodes that emit red, green, and blue colors, four-components light emitting diodes that emit white, red, green, and blue 5 colors, or an infrared ray source that emits infrared rays.

20. A biosensor measuring method or a biosensor measuring device, substantially as herein described with reference to the accompanying drawings. 31992241 (GHMatters) PB9758 AU 7/03/12