JP2002257782A - Electrochemical sensor measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrochemical sensor measuring device dispensing with the judgment of a measuring electrode and a calibration electrode and capable of precisely measuring the concentration of a specified material in a sample electrolytic solution by judging various electrodes by a CPU without erroneous recognition. SOLUTION: In this device, the mode is transferred to a measurement mode after the installation of an electrochemical sensor 5 is judged by the CPU 16 from the input of a load detection signal from a sensor detecting circuit 15, a voltage is applied by a potential control circuit 12 so as to keep the working electrode 2 and reference electrode 4 of the electrochemical sensor 5 in a constant potential, and the current value depending on the concentration of the specified material in the sample electrolytic solution generated between the working electrode 2 and a counter electrode 3 is detected by a current detecting circuit 13. In the CPU 16, the current value shown by a digital signal from an A/D converter 14 is read and stored in a RAM 18, the concentration of the specified material is calculated and measured according to the relational expression between the current value preliminarily stored in a ROM 17 and the concentration of the specified material, and the result is displayed in an LCD 19.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrochemical sensor mainly used for measuring the concentration of a specific substance contained in a sample electrolyte solution, and more particularly to an electrode group provided on an insulating substrate in an electrochemical sensor. TECHNICAL FIELD The present invention relates to an electrochemical sensor measurement device capable of measuring a current value in a reaction product by utilizing an electrochemical reaction generated in an electrode group when a sample is exposed to a sample electrolyte solution.

[0002]

2. Description of the Related Art Conventionally, as this type of electrochemical sensor measuring apparatus, for example, Japanese Patent Application Laid-Open No. Hei 4-357452 (Japanese Patent Publication No. 8-204) is suitable for measuring a blood glucose level.
No. 12), a quantitative analysis method and apparatus using a disposable sensor, a data management method in a simple blood glucose meter disclosed in Japanese Patent Application Laid-Open No. 7-128338, and a simple blood glucose meter using the data management method Is mentioned.

[0003] An electrochemical sensor measuring apparatus applied by these techniques, for example, referring to a circuit block diagram of the basic structure shown in FIG. 8, shows an electrode group 7 provided on an insulating substrate.
9 is comprised of a measurement electrode or a calibration electrode and a simple blood glucose meter 80.

[0006] Of these electrodes, the measuring electrode in the electrode group 79 is composed of a measuring electrode and a counter electrode, and the calibration electrode is mounted with various resistances having unique resistance values (kΩ) and different calibration curves No.
Are classified so as to identify and select those corresponding to. For example, the calibration electrode No. 0 is the resistance value 27 (kΩ) and the calibration curve N
o. F-0, the calibration electrode No. 1 is a resistance value of 30
(KΩ) and the calibration curve No. F-1 corresponding to calibration electrode N
o. No. 2 has a resistance value of 33 (kΩ) and a calibration curve No. F-2, the calibration electrode No. No. 3 has a resistance value of 36 (kΩ) and a calibration curve No. F-3, the calibration electrode No. 4 is the resistance value 39
(KΩ) and the calibration curve No. F-4 corresponding to calibration electrode N
o. 5 is a resistance value 43 (kΩ) and is a calibration curve No. 5; F-5, the calibration electrode No. 6 has a resistance value of 47 (kΩ) and a calibration curve No. 6; F-6, the calibration electrode No. 7 is a resistance value 51
(KΩ) and the calibration curve No. F-7, calibration electrode N
o. 8 is a resistance value 56 (kΩ) and is a calibration curve No. F-8, the calibration electrode No. 9 has a resistance value of 62 (kΩ) and a calibration curve No. 9; It is a condition corresponding to F-9.

On the other hand, the simple blood glucose meter 80 includes a connector 81 connected to the electrodes of the electrode group 79, an electrode insertion detection switch 82 connected to the connector 81, and a current / voltage converter 83 connected to the connector 81. , Current / voltage converter 83
, An A / D converter 84, a CPU 87 connected to an electrode insertion detection switch 82 and an A / D converter 84, and also connected to an EEPROM 85 and a RAM 86 as a storage device, and a CPU 87 and a current / voltage converter. Table 8
3 and an LCD 89 which is a display connected to the CPU 87.

In the case of this electrochemical sensor measuring apparatus, for example, when a measuring electrode is attached to the connector 81 as an electrode of the electrode group 79, the electrode insertion detecting switch 8
2 detects that any of the electrodes has been mounted, and transmits an electrode detection signal indicating the result to the CPU 87. CPU8
In 7, upon recognizing that the measurement electrode is mounted on the basis of the electrode detection signal, the control signal indicating that a voltage should be applied to the measurement electrode is transmitted to the reaction voltage setting circuit 88. As a result, a current based on the electrode reaction is generated at the measurement electrode, and this current is converted into a voltage by the current / voltage converter 83, and further, A
After being converted into a digital voltage signal by the / D converter 41, C
Transmit to PU87. Therefore, the CPU 87 determines and determines the blood glucose level of the measurement electrode based on the change value of the current value indicated by the digital voltage signal.
The blood glucose level is measured by reading out and calculating from the OM 85 (or the RAM 86), and the result is displayed on the LCD 8.
9 is displayed.

When a calibration electrode is attached to the connector 81 as an electrode of the electrode group 79, the simple blood glucose meter 80 uses the electrode insertion detection switch 82 to detect which electrode is attached, and outputs an electrode detection signal indicating the result. It is transmitted to the CPU 87. When the CPU 87 recognizes that the calibration electrode has been mounted based on the electrode detection signal, the CPU 87 transmits a control signal to the reaction voltage setting circuit 88 to apply a voltage to the calibration electrode. As a result, a current corresponding to the specific resistance is generated at the calibration electrode, and this current is converted into a voltage by the current / voltage converter 83, further converted into a digital voltage signal by the A / D converter 41, and then sent to the CPU 87. Transmit. So, CPU
At 87, an EEP in which a blood glucose level corresponding to the change value of the current value indicated in advance is stored based on the change value of the current value as a judgment and identification of the calibration electrode based on the change value of the current value indicated by the digital voltage signal.
The blood glucose level is measured by reading and calculating from the ROM 85 (or the RAM 86), and the result is displayed on an LCD.
89 is displayed. However, when the CPU 87 here recognizes that the electrode is a calibration electrode based on the electrode detection signal from the electrode insertion detection switch 82, the calibration curve N stored in advance in the EEPROM 85 (or the RAM 86) may be used.
o. , A calibration curve corresponding to each resistance value is identified and selected, and at the time of measurement, the selected calibration curve No. is used. Calculate the blood sugar level for.

[0008] Incidentally, as other well-known techniques relating to these electrochemical sensor measuring devices suitable for blood sugar level measurement, for example, an electrochemical gas sensor disclosed in JP-A-6-18477 and JP-A-7-209247 are disclosed. Patent Document 1: Gas sensing device with temperature compensation function for electrochemical gas sensor disclosed in Japanese Patent Application Laid-Open Publication No. 8-94569;
For example, there is a blood sugar level measuring device disclosed in Japanese Patent No. 4022, a biosensing meter which detects connection of an appropriate electrode disclosed in Japanese Patent No. 2704046 and discriminates between a sample piece and a check piece.

[0009]

In the case of the above-described electrochemical sensor measuring apparatus, an electrode insertion detection switch (or a similar detection circuit) is provided for discriminating the type of the electrode in the electrode group, and the electrode group is mounted. The type of each electrode in is determined based on their electrical connection state (resistance value or current value) to detect (or detect) whether it is a measurement electrode or a calibration electrode, and the result is used as an electrode. It is transmitted to the CPU as a detection signal (or electrode detection signal),
Actually, the current value and the resistance value of the electrode to be detected (or detected) are easily changed and unstable, so that the type of the electrode cannot be accurately determined only from the mounting state of the electrode. There is a drawback that the CPU is likely to cause erroneous recognition when identifying the measurement electrode or the calibration electrode, and as a result, it is not possible to accurately and accurately measure the concentration of the specific substance in the sample electrolyte solution.

The present invention has been made to solve such a problem. The technical problem of the present invention is that it is not necessary to discriminate each electrode in the electrode group, and the CPU judges each electrode without erroneous recognition. An object of the present invention is to provide an electrochemical sensor measuring device capable of accurately and accurately measuring the concentration of a specific substance in an electrolyte solution.

Another technical object of the present invention is to provide an electrochemical sensor measuring apparatus capable of easily performing correction adjustment for measurement in the entire apparatus.

[0012]

According to the present invention, there is provided an electrochemical sensor which is used for measuring the concentration of a specific substance contained in a sample electrolyte solution and has an electrode group provided on an insulating substrate. And a measuring device including a CPU capable of detecting a state in which the electrochemical sensor is mounted, and a measuring device including a CPU capable of detecting a state in which the electrochemical sensor is mounted. The measuring device has a three-electrode configuration including a counter electrode and a reference electrode. The measuring device is connected to a predetermined portion of the electrochemical sensor when the electrochemical sensor is mounted, and detects an electric load obtained when a predetermined voltage value is applied. A sensor detection circuit that outputs a load detection signal indicating the result of the operation, and a potential control circuit that applies a predetermined voltage by performing potential control so as to keep the potential difference between the working electrode and the reference electrode constant. A current detection signal indicating a result of detecting a current value in a reaction product generated by an electrochemical reaction generated between the working electrode and the counter electrode when the three electrodes are exposed to the sample electrolyte solution under the condition of potential control. An output of a current detecting means circuit is provided, and an electrochemical sensor measuring device is provided in which the CPU determines the mounting state of the electrochemical sensor by inputting a load detection signal.

Further, according to the present invention, in the electrochemical sensor measuring device, the CPU determines the specific substance in the sample electrolyte solution based on the current value indicated in the current detection signal as a measurement mode after the recognition of the mounting of the electrochemical sensor. The measurement device is a read-only memory in which a relational expression between the current value required for measuring the concentration of the specific substance in the sample electrolyte solution by the CPU and the concentration of the specific substance is stored in advance. A storage device, a readable and writable storage device for storing a current value calculated by the CPU based on the current detection signal, and a CP
An indicator for displaying the measurement result of the concentration of the specific substance in the sample electrolyte solution by U is obtained.

On the other hand, according to the present invention, there is provided a measurement sensor which is used for measuring the concentration of a specific substance contained in a sample electrolyte solution and includes an electrochemical sensor in which an electrode group is provided on an insulating substrate. And a measuring device including a CPU capable of detecting a state in which the measuring sensor is mounted, and a measuring device including a CPU capable of detecting a state in which the measuring sensor is mounted, wherein the measuring sensor measures a temperature near the electrochemical sensor. A temperature sensor that outputs a temperature measurement signal indicating the result is provided, and the electrode group in the electrochemical sensor has a three-electrode configuration including a working electrode, a counter electrode, and a reference electrode.
The measurement device is connected to the temperature sensor when the measurement sensor is mounted, and includes a temperature detection circuit that outputs a temperature detection signal indicating a result of temperature detection based on the temperature measurement signal. An electrochemical sensor measurement device that determines a state by inputting a temperature detection signal is obtained.

According to the present invention, in the electrochemical sensor measuring device, the measuring device performs a potential control so as to keep the potential difference between the working electrode and the reference electrode constant, and applies a predetermined voltage. And a current detection showing a result of detecting a current value in a reaction product generated by an electrochemical reaction generated between the working electrode and the counter electrode when the three electrodes are exposed to the sample electrolyte solution under the condition of potential control. An electrochemical sensor measurement device including a current detection circuit for outputting a signal is obtained.

Further, according to the present invention, in the electrochemical sensor measuring device, the CPU determines the specific substance in the sample electrolyte solution based on the current value indicated in the current detection signal as the measurement mode after the recognition of the mounting of the measurement sensor. The concentration is quantified and measured, and the concentration of the specific substance is corrected in accordance with the result of calculating the temperature of the sample electrolyte solution based on the detected temperature value indicated in the temperature measurement signal.
U is a relational expression between the current value required for measuring the concentration of the specific substance in the sample electrolyte solution and the concentration of the specific substance, and the voltage of the sample electrolyte solution corresponding to the voltage value required for calculating the temperature of the sample electrolyte solution. A read-only storage device in which a relational expression necessary for correcting the concentration of the specific substance according to the temperature and the temperature of the sample electrolyte solution is stored in advance, and the current value and the temperature calculated by the CPU based on the current detection signal. A readable / writable storage device for storing the voltage value calculated by the CPU based on the detection signal, and a measurement result of the concentration of the specific substance in the sample electrolyte solution by the CPU or a calculation result of the temperature of the sample electrolyte solution. And an indicator for displaying the measurement result of the concentration of the specific substance in the sample electrolyte solution corrected by the above method.

In addition, according to the present invention, in any one of the above electrochemical sensor measuring devices, the measuring sensor is connected to the electrochemical sensor and the temperature sensor in a state where the electrochemical sensor and the temperature sensor are provided. A printed circuit board on which a plurality of wiring portions are disposed, and the printed circuit board is housed in a cartridge. The cartridge is an opening for exposing three electrodes of the electrochemical sensor to the outside in a state where the printed circuit board is housed. Is provided at one end and the other end is an open end for inserting a printed circuit board.

On the other hand, according to the present invention, in the above-mentioned electrochemical sensor measuring device, the CPU is used in place of a measuring sensor detachable from the measuring device, and a counter electrode and a counter electrode are formed on a printed circuit board provided with the electrochemical sensor. A reference resistance having a predetermined resistance value is interposed between the working electrode, the counter electrode, and the reference electrode by short-circuiting between the reference electrodes, and a detection resistance having a predetermined resistance value is provided at a location separated from the reference resistance. Can be detected, and the potential control circuit controls the potential so as to keep the potential difference constant with respect to the reference resistance between the working electrode and the counter electrode and the reference electrode in the check sensor. The control circuit applies a predetermined voltage, and the current detection means circuit outputs a reference current detection signal indicating a result of detecting a reference current value flowing through the reference resistor under the condition of the potential control. The temperature detection circuit is connected to the detection resistor when the check sensor is mounted, and outputs a temperature detection signal indicating a result of temperature detection based on a resistance value signal obtained from the detection resistor. And
The CPU obtains an electrochemical sensor measurement device that determines the mounting state of the check sensor by inputting a temperature detection signal.

Further, according to the present invention, in the electrochemical sensor measuring apparatus, after the recognition of the mounting of the check sensor, the CPU determines the sample in the measurement mode based on the reference current value indicated in the reference current detection signal as the check mode. Calculates the current value at the time of quantification measurement of the concentration of the specific substance in the electrolyte solution to perform measurement correction of the entire circuit,
The read-only storage device includes, as characteristics of a check sensor required for calculation of a current value by the CPU, a voltage value of a temperature detection signal corresponding to a predetermined resistance value of the detection resistor and a reference value corresponding to a predetermined resistance value of the reference resistance. The reference current value of the current detection signal is stored in advance, and the readable and writable storage device is C
An electrochemical sensor measurement device that stores the reference current value calculated by the PU and displays the calculation result of the current value by the CPU is obtained as the display.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention will be described below in detail with reference to the drawings.

First, the technical background introduced into the electrochemical sensor measuring device of the present invention will be described. In the case of this electrochemical sensor measuring device, the electrochemical sensor used is
It is used to measure the concentration of a specific substance contained in a sample electrolyte solution. As a basic configuration, an electrode group provided on an insulating substrate has a three-electrode configuration including a working electrode, a counter electrode, and a reference electrode. Also, in the measuring device attached to the electrochemical sensor, the three electrodes are placed in the sample electrolyte solution under the condition that the potential is controlled by the potential control means so as to keep the potential difference between the working electrode and the reference electrode constant, and the voltage is applied. The current value in the reaction product generated by the electrochemical reaction generated between the working electrode and the counter electrode when exposed is detected by the current detection means, and the concentration of the specific substance in the sample electrolyte solution is quantified and measured. I do.

The principle of operation of this electrochemical sensor is that, for example, hydrogen peroxide (H) is used as a specific substance in a sample electrolyte solution.
_When measuring the concentration of ₂ O ₂ ), a constant potential (400 mV) is applied between the working electrode and the reference electrode by the potential control means of the measuring device.
When the three electrodes are exposed to the sample electrolyte solution under the condition that a predetermined voltage is applied by controlling the potential so as to maintain the hydrogen peroxide (H ₂ O ₂ ) in the sample electrolyte solution. Is anodized on the working electrode, and as a result, an oxidation current is generated between the working electrode and the counter electrode, that is, the electrolyzed free electrons 2e represented by the reaction formula of H ₂ O ₂ → 2H ⁺ + O ₂ + 2e ^{−. -Has} an oxidation current value of Therefore, if the oxidation current value due to the free electrons 2e ^{− is} detected by the current detection means of the measuring device, the concentration of hydrogen peroxide (H ₂ O ₂ ) in the sample electrolyte solution can be quantified and measured.

FIG. 1 is a plan view showing an electrochemical sensor provided in an electrochemical sensor measuring apparatus according to one embodiment of the present invention. This electrochemical sensor includes a working electrode 2, a counter electrode 3, and a reference electrode 4 as an electrode group provided on the insulating substrate 1.
The working electrode 2 has a lead portion 2a and a contact portion 2b extending and connected thereto, and the counter electrode 3 also has a lead portion 3a and a contact portion 3b extending and connected thereto. Similarly, the lead portion 4a and the contact portion 4b extend and are connected.

Specifically, the size of the insulating substrate 1 is 6 m in width.
m × 9 mm in height, and a working electrode 2 of 1.2 mm in width (width) × 2.0 mm in length (length), 0.4 mm in width (width) ×
Counter electrode 3, 2.0 mm long (length), 0.4 mm wide (width)
A reference electrode 4 having a length (length) of 2.0 mm is provided, and the lead portions 2a, 3a, 4a of each electrode are set to a width (width) of 0.2 mm × a height (length) of 2.8 mm). Contact part 2
b, 3b, 4b are 0.8 mm in width (width) × length (length).
6 can be exemplified.

FIG. 2 is a side sectional view of each electrode taken along the line AA 'in FIG. Here, a platinum layer 2β is laminated on a titanium layer 2α disposed on an insulating substrate 1 to which a silicon oxide film is formed on silicon, a glass substrate, a quartz or polyimide substrate, a polycarbonate substrate, a glass epoxy substrate, or the like. And the working electrode 2 is formed,
Similarly, a counter electrode 3 is formed by laminating a platinum layer 3β on a titanium layer 3α disposed on the insulating substrate 1, and further laminating a silver chloride layer 4β on a silver layer 4α disposed on the insulating substrate 1. Reference pole 4
Are formed.

The platinum layer 2 of the working electrode 2 and the counter electrode 3
As the electrode material for β and 3β, carbon, gold, iridium, or the like can be used in addition to platinum. The working electrode 2 and the counter electrode 3 can be formed by a vapor deposition method, a sputtering method, screen printing, plating, or the like. When formed by the sputtering method, the thickness of the titanium layers 2α and 3α is 0.02 μm.
m to 0.2 μm, and the thickness of the platinum layers 2β and 3β is 0.1
It is preferable to set it to about μm to 1.0 μm.

The reference electrode 4 is formed by disposing a silver layer 4α on the insulating substrate 1, treating the surface of the silver layer 4α, and then laminating a silver chloride layer 4β. Titanium, platinum, or the like may be laminated on the underlayer of the silver layer 4α in order to improve the adhesion to the insulating substrate 1. When the reference electrode 4 is formed by a sputtering method, it is preferable that the thickness of the silver layer 4α be about 0.1 μm to 1.0 μm. The silver chloride layer 4β can be formed by a method of treating with an aqueous solution of iron (III) chloride or chromium (III) chloride, or a method of performing electrolysis in an aqueous solution of chloride.

Here, a description will be given of a manufacturing process when each electrode is formed by a sputtering method.
Titanium layers 2α, 3α and platinum layers 2β, 3β are formed and patterned by sputtering on a 70 mm long insulating substrate base material plate to form a predetermined number of working electrodes 2 and counter electrodes 3, and
A predetermined number of silver layers 4α are formed and patterned on the insulating substrate base material plate by sputtering. Next, the lead portions 2a, 3 are respectively applied to a predetermined number of the working electrode 2, the counter electrode 3, and the reference electrode 4 (only the silver layer 4α at this stage) by photolithography.
a, 4a and contact portions 2b, 3b, 4b are formed. Further, a predetermined number of reference electrodes 4 are formed by treating the base plate of the insulating substrate in an aqueous solution of iron (III) chloride to form a silver chloride layer 4β on the surface of the predetermined number of silver layers 4α. Finally.
Each of the insulating substrate base material plates has a width of 6 mm ×
A predetermined number of insulating substrates 1 are obtained by dividing and cutting into a size of 9 mm in length.

FIG. 3 is a plan view showing a main configuration of a measurement sensor constituted by using the above-described electrochemical sensor 5. The main part of the measurement sensor is a plurality (five in this case) of a plurality of (in this case, five) thermistors 7 serving as temperature sensors that output a temperature measurement signal indicating a result of measuring the temperature in the vicinity of the electrochemical sensor 5. The wiring portion 8 is disposed on the printed circuit board 6 on which the electrochemical sensor 5 and the thermistor 7 are connected to the wiring portion 8 in this state.

As described above, by mounting the electrochemical sensor 5 and the thermistor 7 on the printed circuit board 6, electrical connection with the circuit section of the main body of the measuring apparatus becomes possible. Specifically, the electrochemical sensor 5 is mounted on one end side of the printed circuit board 6 and disposed on the printed circuit board 6 with each of the contact portions 2b, 3b, 4b by wire bonding, soldering, anisotropic conductive resin or the like. A part of the wiring portion 8 is electrically connected. The other part of the wiring section 8 on the printed board 6 is for connecting the thermistor 7, and the thermistor 7 is mounted at the center on the printed board 6 by soldering or the like. The other end of the wiring section 8 of the printed circuit board 6 is used for connection with a connector of the measuring apparatus main body.

FIG. 4 shows an external configuration of a measurement sensor manufactured by mounting a main part of the above-described measurement sensor (the printed circuit board 6 on which the electrochemical sensor 5 and the thermistor 7 are mounted) in the cartridge 9. (A) relates to a plan view from the top direction, (b) relates to a side view in the longitudinal direction, and (c) relates to a side sectional view in the longitudinal direction.

Here, a state in which the measurement sensor is manufactured by mounting the printed circuit board 6 on which the above-described electrochemical sensor 5 and the thermistor 7 are mounted in the cartridge 9 is shown. However, the cartridge 9 has an opening 9a at one end for exposing the three electrodes (the working electrode 2, the counter electrode 3, and the reference electrode 4) of the electrochemical sensor 5 to the outside while the printed circuit board 6 is housed. The other end is an open end 9b for inserting the printed circuit board 6.

As described above, in the measurement sensor, the printed circuit board 6 on which the electrochemical sensor 5 and the thermistor 7 are mounted is housed in the cartridge 9 and mounted, thereby ensuring waterproofness and facilitating the handling. Only the working electrode 2, the counter electrode 3, and the reference electrode 4 of the electrochemical sensor 5 are in contact with the sample electrolyte solution by the opening 9a provided in the cartridge 9, and the other parts are not in contact with the sample electrolyte solution. Note that a seal member 10 is provided around the opening in order to improve waterproofness. The seal member 10 is fitted to the main body of the measuring device by an opening end 9 a provided in the cartridge 9. In this state, electrical connection with the circuit section of the measuring device main body becomes possible.

FIG. 5 is a circuit block diagram showing the basic configuration of an electrochemical sensor measuring apparatus according to one embodiment of the present invention, showing the basic configuration of the measuring apparatus 11 with the above-described electrochemical sensor 5 mounted. It is.

The measuring device 11 includes a potential control circuit 12 for performing a potential control so as to keep a potential difference between the working electrode 2 and the reference electrode 4 in the electrochemical sensor 5 constant and applying a predetermined voltage, and a condition based on the potential control. A current value in a reaction product generated by an electrochemical reaction between the working electrode 2 and the counter electrode 3 when the three electrodes (working electrode 2, counter electrode 3, and reference electrode 4) are exposed to the sample electrolyte solution below. A current detection means circuit 13 for outputting a current detection signal indicating a result of detecting the current, an A / D converter 14 for converting the current detection signal into a digital signal,
A load detection signal which is formed of a circuit including a resistor to which a voltage of 3 V is applied, and which is connected to a predetermined portion of the electrochemical sensor 5 and indicates a result of detecting an electric load obtained when a predetermined voltage value is applied. Sensor detection circuit 15 that outputs
And the mounting state of the electrochemical sensor 5 is determined by the sensor detection circuit 15.
And by inputting the load detection signal from
After recognition of the wearing of the electrochemical sensor 5, A /
A CPU 16 for quantifying and measuring the concentration of a specific substance in the sample electrolyte solution based on a digital signal indicating a current detection value from the D converter 14, and a current required for measuring the concentration of the specific substance in the sample electrolyte solution by the CPU 16 A ROM 17 in which a relational expression between the value and the concentration of the specific substance is stored in advance, a RAM 18 in which a current value calculated by the CPU 16 indicated by a digital signal of the current detection signal is stored, and a concentration of the specific substance in the sample electrolyte solution by the CPU 16 And an LCD 19 for displaying the measurement results.

Here, as an example, a case where the concentration of hydrogen peroxide in the sample electrolyte solution is measured by the measuring device 11 equipped with the electrochemical sensor 5 will be described. In the measuring device 11, the mounting state of the electrochemical sensor 5 is determined by the CPU 16.
Is determined by inputting a load detection signal from the sensor detection circuit 15, and the mode shifts to the measurement mode after recognition of the mounting of the electrochemical sensor 5.

In the measurement mode, when the working electrode 2 and the reference electrode 4 of the electrochemical sensor 5 are controlled by the potential control circuit 12 so as to maintain a constant potential (range of 400 mV to 700 mV) and a predetermined voltage is applied. Since a current depending on the concentration of hydrogen peroxide in the sample electrolyte solution is generated between the working electrode 2 and the counter electrode 3, this current value is detected by the current detection circuit 13 to output a current detection signal. Since the current at this time flows between the working electrode 2 and the counter electrode 3, the current detection circuit 1
3 may be provided on either the working electrode 2 side or the counter electrode 3 side. The current detection signal is converted into a digital signal by the A / D converter 14 and transmitted to the CPU 16. In the CPU 16, RO
In accordance with the firmware stored in M17, the detected current value indicated by the digital signal is fetched and stored in RAM1.
8, the concentration of hydrogen peroxide is calculated and measured according to the relational expression between the current value and the concentration of hydrogen peroxide stored in the ROM 17 in advance, and the result is displayed on the LCD 19.

Incidentally, here, as an example for explaining the operation of the electrochemical sensor 5, the case where the concentration of hydrogen peroxide is measured has been described. However, an enzyme or the like is placed on three electrodes (sensor elements) of the electrochemical sensor 5. It is also possible to measure a reactant such as glucose (glucose) in a sample electrolyte solution after forming an organic functional film containing.

In the case of this electrochemical sensor measuring device, the CPU 16 is used for the electrode group (three electrodes) as in the conventional device.
Is not configured to detect the electrical connection state, and when the electrochemical sensor 5 is mounted on the measuring device 11, the sensor detection circuit 15 in the measuring device 11 is connected to a predetermined portion of the electrochemical sensor 5 and outputs a load detection signal. However, since the CPU 16 that has received the load detection signal recognizes the mounting state of the electrochemical sensor 5, it is not necessary to determine the electrode group (three electrodes), and the CPU 16 identifies various electrodes without erroneous recognition. The concentration of the specified substance can be measured accurately and accurately,
Moreover, the entire structure is simple.

FIG. 6 is a circuit diagram showing the basic configuration of an electrochemical sensor measuring apparatus according to another embodiment of the present invention, showing the basic configuration of the measuring apparatus 11 'with the above-mentioned measuring sensor 20 mounted. FIG.

This measuring device 11 'performs potential control so as to keep the potential difference between the working electrode 2 and the reference electrode 4 in the electrochemical sensor 5 of the measurement sensor 20 constant (500 mV), and applies a predetermined voltage. Generated by a circuit 12 and an electrochemical reaction that occurs between the working electrode 2 and the counter electrode 3 when the three electrodes (working electrode 2, counter electrode 3, and reference electrode 4) are exposed to the sample electrolyte solution under the conditions of potential control. A current detection means circuit 13 for outputting a current detection signal indicating a result of detecting a current value in the reaction product to be detected, a resistor of 27 kΩ is connected to apply a voltage of 3 V, and the measurement sensor 20
A temperature detection circuit 21 that is connected to the thermistor 7 at the time of mounting and outputs a temperature detection signal indicating a result of temperature detection based on a temperature measurement signal from the thermistor 7;
An A / D converter 14 'for converting the current detection signal and the temperature detection signal into a digital signal; a mounting state of the measurement sensor 20 determined by inputting a temperature detection signal from the temperature detection circuit 21; After the recognition of the wearing of the sample 20, the concentration of the specific substance in the sample electrolyte solution is quantified and measured based on the digital signal indicating the current detection value from the A / D converter 14 'as a measurement mode, and the A / D converter 14' CPU 16 'for correcting the concentration of a specific substance according to the result of calculating the temperature of the sample electrolyte solution based on a digital signal indicating the detected temperature value from the CPU, and measuring the concentration of the specific substance in the sample electrolyte solution by the CPU 16' The relational expression between the required current value and the concentration of the specific substance, the temperature of the sample electrolyte solution corresponding to the voltage value required to calculate the temperature of the sample electrolyte solution, and the C represented by the digital signal of the ROM 17 'which previously stores relations required for correction of the concentration of a specific substance, a current value calculated in CPU16 represented by the digital signal of the current detection signal and the temperature detection signal corresponding to the time
RAM 18 'for storing the voltage value calculated by PU16
And an LCD 19 for displaying the measurement result of the concentration of the specific substance in the sample electrolyte solution by the CPU 16 'or the measurement result of the concentration of the specific substance in the sample electrolyte solution corrected based on the calculation result of the temperature of the sample electrolyte solution. It is comprised including.

In this measuring device 11 ', the measuring sensor 20
When measuring the concentration of a specific substance in the sample electrolyte solution with the sensor 1 attached, the CPU 1
6 'determines by inputting the temperature detection signal from the temperature detection circuit 21, and then shifts to the measurement mode after recognition of the mounting of the measurement sensor 20.

In the measurement mode, when the working electrode 2 and the reference electrode 4 of the electrochemical sensor 5 in the measurement sensor 20 are controlled by the potential control circuit 12 so as to maintain a constant potential (500 mV) and a predetermined voltage is applied. The current depending on the concentration of the specific substance in the sample electrolyte solution is the working electrode 2 and the counter electrode 3
The current value is detected by the current detection circuit 13 and a current detection signal is output. Since the current at this time flows between the working electrode 2 and the counter electrode 3, the current detection circuit 13 may be provided on either the working electrode 2 side or the counter electrode 3 side. The current detection signal is converted into a digital signal by the A / D converter 14 'and transmitted to the CPU 16'. Further, the temperature detection signal from the temperature detection circuit 21 is also transmitted to the A / D converter 1.
At 4 ', the signal is converted into a digital signal and transmitted to the CPU 16'.

In accordance with the firmware stored in the ROM 17 ', the CPU 16' takes in the detected current value indicated by the digital signal and the voltage value of the temperature detection signal and stores them in the RAM 18 ', and further stores them in the ROM 17' in advance. The result of calculating and measuring the concentration of the specific substance in accordance with the relational expression between the current value and the concentration of the specific substance is stored in the RAM 18 '(the result at this time may be displayed on the LCD 19), and furthermore, the ROM 17'. The temperature of the sample electrolyte solution corresponding to the voltage value is calculated with reference to the table stored in the RAM 18 ', and the specific value stored in the RAM 18' is calculated according to the relational expression necessary for correcting the concentration of the specific substance according to the calculation result. The concentration of the substance is corrected, and the result is displayed on the LCD 19.

More specifically, as the temperature characteristics of the thermistor 7, the temperature is 0 ° C., the resistance is 9.541 kΩ, and the temperature is 2
A resistor having a resistance of 3.000 kΩ at 5 ° C. and a resistance of 1.109 kΩ at a temperature of 50 ° C. is used. Under these conditions, the voltage values of the temperature detection signals output from the temperature detection circuit 21 are 2.217 V and 2 .700V and 2.822V.

When the measurement sensor 20 is not mounted,
The voltage value of the temperature detection signal output from the temperature detection circuit 21 is 0V. When the measurement sensor 20 is mounted, when the thermistor 7 is connected to the temperature detection circuit 21, the temperature detection circuit 21 outputs a temperature detection signal having a voltage value according to the temperature measurement signal from the thermistor 7. Usually, since the measurement sensor 20 is used in a temperature range of 0 ° C. to 50 ° C., the voltage value of the temperature detection signal output from the temperature detection circuit 21 is 2.217.
V to 2.822V. The output of the temperature detection signal is input to the I / O of the CPU 16 'to activate the CPU 16' in the sleep state.

Therefore, in the CPU 16 ', the output of the temperature detection signal from the temperature detection circuit 21 is input as a digital signal via the A / D converter 14', and the range of the voltage value of the digital signal is from 2.217V to 2.217V. Since the voltage is 2.822 V, it is recognized that the measurement sensor 20 is mounted, and the measurement mode is executed.

In the measurement mode, a predetermined voltage is applied to the working electrode 2 and the reference electrode 4 of the electrochemical sensor 5 of the measurement sensor 20 by the potential control circuit 12 so as to have a constant potential (500 mV). After a current value generated between the working electrode 2 and the counter electrode 3 in the sensor 5 is detected by the current detection circuit 13, the current value is converted into a digital signal by the A / D converter 14 'and is taken into the CPU 16'.
Stored in M18 '. Further, the CPU 16 'has the ROM 1
7 ′, the concentration of the specific substance is calculated according to the relational expression between the current value and the concentration of the specific substance stored in advance, and the result is expressed as R
Store in AM18 '. Here, as a relational expression stored in the ROM 17 'in advance, when K is a calibration coefficient 1,
Examples can be given of those expressed by the following relationship: concentration (mM) = K × current value (μA).

On the other hand, the temperature measurement signal output from the thermistor 7 is input to the temperature detection circuit 21 and then output here as a temperature detection signal.
The voltage value of the temperature detection signal ranges from 2.217 to 2.822 V. The temperature detection signal of this voltage value is supplied to the A / D converter 1
After being converted into a digital signal at 4 ', it is taken into the CPU 16' and stored in the RAM 18 '. By the way, A /
The input of the D converter 14 'is 10 bits, and the input range is 0 to
3V. Further, the CPU 16 'calculates the temperature of the sample electrolyte solution from the relation of the temperature of the sample electrolyte solution corresponding to the voltage value with reference to a table stored in the ROM 17' in advance. In the above example, when the voltage value of the temperature detection signal output from the temperature detection circuit 21 is 2.217 V, it is 0 ° C., when it is 2.700 V, it is 25 ° C.
When the voltage is 2.822V, the temperature is 50 ° C. Finally, R
A relational expression for correcting the concentration of a specific substance in the sample electrolyte solution stored in advance in AM18 ', that is, T is the temperature (° C.) of the sample electrolyte solution, and Tk is 0.05 as the temperature coefficient of the sample electrolyte solution. , Corrected concentration (mM) = concentration (mM)
/ [1 + Tk × (T-25)], the concentration of the specific substance is corrected in accordance with a relational expression expressed by the relation
This is displayed at D19.

In the case of this electrochemical sensor measuring apparatus, the CPU 1 is used for the electrode group (three electrodes) as in the conventional apparatus.
When the measuring sensor 20 is mounted on the measuring device 11 ′, the measuring sensor 20
A temperature detecting circuit 21 in the measuring device 11 'is connected to the thermistor 7, and the temperature detecting circuit 21 uses a temperature measuring signal output from the thermistor 7 as a temperature detecting signal.
16 ', and the CPU which has input the temperature detection signal.
16 'recognizes the mounting state of the measurement sensor 20, so that it is not necessary to determine the electrode group (three electrodes) as in the case of the apparatus of the embodiment, and the CPU 16' discriminates various electrodes without erroneous recognition before the sample electrolyte. The concentration of the specific substance in the solution can be measured accurately and accurately. That is, here, the measurement sensor 20
The thermistor 7 mounted inside the sensor and the temperature detecting circuit 21 in the measuring device 11 'are connected, and the mounting state of the measuring sensor 20 can be recognized by the CPU 16'. There is no need to provide it, and the entire structure is simple.

FIG. 7 shows a basic configuration of an electrochemical sensor measuring apparatus according to another embodiment of the present invention. The check sensor 22 is obtained by changing the detailed configuration of the measuring sensor 20 described above.
FIG. 9 is a circuit block diagram showing a basic configuration of a measuring device 11 ″ with the device mounted thereon.

The check sensor 22 here corresponds to FIG.
6 can be substituted for the measurement sensor 20 shown in FIG. 6 by changing the main part (not including the cartridge 9) of the measurement sensor 20 in which the electrochemical sensor 5 and the thermistor 7 are mounted on the printed circuit board 6 shown in FIG. Specifically, the electrochemical sensor 5 in the main part of the measurement sensor 20
The working electrode 2, the counter electrode 3, and the reference electrode 4
Above, the reference electrode 3 and the reference electrode 4 are short-circuited, a reference resistance R1 of 500Ω is interposed between the working electrode 2 and the counter electrode 3 and the reference electrode 4, and is separated from the reference resistance R1 instead of the thermistor 7. The configuration is such that a detection resistor R2 of 500Ω is mounted at a location.

On the other hand, in the measuring device 11 ″, the potential control circuit 12 ′ keeps the potential difference constant (500 mV) with respect to the reference resistance R 1 between the working electrode 2 and the counter electrode 3 and the reference electrode 4 in the check sensor 22. A predetermined voltage is applied by performing potential control so as to maintain the reference current, and the current detection means circuit 13 'detects the reference current flowing through the reference resistor R1 under the condition of the potential control. It is designed to output a signal.

The temperature detecting circuit 21 ′ is connected to a resistor of 27 kΩ and applied with a voltage of 3 V, and is connected to the detecting resistor R 2 when the check sensor 22 is mounted, and is connected to the detecting resistor R 2. A temperature detection signal indicating the result of temperature detection based on the value signal is output.

Further, the A / D converter 14 ″ converts the reference current detection signal and the temperature detection signal into digital signals,
The PU 16 ″ determines the mounting state of the check sensor 22 by inputting a temperature detection signal from the temperature detection circuit 21 ′, and sets the check mode after the recognition of the mounting of the check sensor 22 as a check mode from the A / D converter 14 ″. The entire circuit is corrected by calculating a current value for quantifying and measuring the concentration of the specific substance in the sample electrolyte solution obtained in the measurement mode based on the digital signal indicating the current detection value.

For this reason, the ROM 17 "is stored in the CPU 16".
As a characteristic of the check sensor 22 necessary for calculating the current value according to the above, the voltage value of the temperature detection signal output from the temperature detection circuit 21 'corresponding to the resistance value of the detection resistor R2 and the current corresponding to the resistance value of the reference resistor R1 The reference current value of the reference current detection signal detected by the detection circuit 13 'is stored in advance, and the RAM 18 "stores the reference current value calculated by the CPU 16" indicated by the digital signal of the reference current detection signal. The LCD 19 'displays the result of the correction (calculation of the current value) of the entire circuit by the CPU 16 ".

In this measuring apparatus 11 ", when correcting the entire circuit with the check sensor 22 mounted, the CPU 16" inputs the temperature detection signal from the temperature detecting circuit 21 'to the mounted state of the check sensor 22. Therefore, after the recognition of the mounting of the check sensor 22, the mode is shifted to the check mode.

In the check mode, the check sensor 22
And a predetermined voltage is applied to the reference resistance R1 between the working electrode 2 and the counter electrode 3 and the reference electrode 4 by the potential control circuit 12 'so as to keep the potential difference constant (500 mV). After the reference current value flowing through the reference resistor R1 is detected by the current detection circuit 13, the A / D converter 1
The digital signal is converted into a digital signal at 4 ", taken into the CPU 16" and stored in the RAM 18 ".
6 "is a characteristic of the check sensor 22 stored in the ROM 17" in advance as a voltage value of the temperature detection signal output from the temperature detection circuit 21 'corresponding to the resistance value of the detection resistor R2 and a resistance value of the reference resistor R1. Corresponding current detection circuit 1
Reference of the reference current value of the reference current detection signal detected at 3 'and correction of the entire circuit by calculating the current value detected in the measurement mode based on the reference current value,
The result is displayed on the LCD 19 '.

Specifically, a 0.5 kΩ detection resistor R 2 is mounted on the check sensor 22 instead of the thermistor 7, and the voltage value of the temperature detection signal output from the temperature detection circuit 21 is 2. 945V. The temperature characteristics of the thermistor 7 described above are such that the temperature is 0 ° C. and the resistance is 9.541.
kΩ, temperature 25 ° C, resistance 3.000 kΩ, temperature 5
A resistor having a resistance of 1.109 kΩ at 0 ° C. is used. Under these conditions, the voltage values of the temperature detection signals output from the temperature detection circuit 21 are 2.217 V, 2.700 V, and 2.8, respectively.
However, the resistance of the check sensor 22 under these conditions is 0.500 kΩ, and the voltage value of the temperature detection signal output from the temperature detection circuit 21 is 2.
945V.

When the check sensor 22 is not mounted, the voltage value of the temperature detection signal output from the temperature detection circuit 21 'is 0V. When the check sensor 22 is attached, the resistance value of 0.5 kΩ of the detection resistor R2 is connected to the temperature detection circuit 21 ', and outputs a temperature detection signal of 2.945V. The output of this temperature detection signal is sent to the I / O
To activate the CPU 16 ″ in the sleep state. By the way, the input of the A / D converter 14 ″ is 10
Bit and input range are 0-3V.

Therefore, in the CPU 16 ", the output of the temperature detection signal from the temperature detection circuit 21 'is output to the A / D converter 14".
, And the voltage value of the digital signal is 2.945 V, so that it is recognized that the check sensor 22 is mounted, and the check mode is started.

In the check mode, the check sensor 22
Potential control circuit 12 'for the 500Ω reference resistor R1.
A predetermined voltage is applied so as to attain a constant potential (500 mV), whereby a reference current value (1 mA) flowing through the reference resistor R1 is detected by the current detection circuit 13 '.
Is converted into a digital signal by the / D converter 14 "
16 "and stored in the RAM 18". However, in this current detection circuit 13 ', the reference current value 1 mA is set to 1
The voltage is converted to a current detection signal of V.

By the way, it is expected that the voltage value a taken into the CPU 16 ″ deviates from 1 V due to the offset voltage, the bias current or the variation of the resistance of the operational amplifier used in the current detection circuit 21 ′. Is a relational expression defining 1 mA = a in RAM 18 ″.
If the current value detected in the measurement mode is calculated based on this relational expression, the correction in the entire circuit of the measurement device 11 ″ can be automatically executed. The characteristics of the sensor 22
OM17 ". The characteristic of the check sensor 22 is that the resistance value of the detection resistor R2 is 0.5.
When the voltage value of the temperature detection signal output from the temperature detection circuit 21 'is 2.945V when the resistance value is 00kΩ, and the current detection circuit 13' detects the voltage value when the resistance value of the reference resistor R1 is 0.500kΩ. The case where the reference current value of the reference current detection signal is 1.000 mA can be exemplified. The result of the correction (calculation of the current value) of the entire circuit in the measuring device 11 ″ is displayed on the LCD 19.

Incidentally, the correction of the entire circuit in the measuring device 11 ″ is performed by setting the detection resistor R2 to a range of different resistance values (for example, 0.1 kΩ to 1.0 kΩ) and the reference resistor R2.
If 1 is combined as a range of different resistance values (for example, 1 kΩ to 50 kΩ) and executed a plurality of times, the accuracy can be further improved.

In such an electrochemical sensor measuring device, when the check sensor 22 is mounted on the measuring device 11 ″, the temperature detecting circuit 21 ′ in the measuring device 11 ″ is connected to the detecting resistor R 2 of the check sensor 22. Then, the temperature detection circuit 21 'transfers the resistance signal output from the detection resistor R2 to the CPU 16 "as a temperature detection signal, and the CPU 16" that has input the temperature detection signal recognizes the mounting state of the check sensor 22, After the CPU 16 "in the measuring device 11" recognizes the attachment of the check sensor 22, the mode shifts to the check mode, and the reference current value flowing in the reference resistor R1 is stored in the RAM 18 ", and the current value detected in the measurement mode is stored. Wiring and circuit specially for check sensor identification to automatically correct the entire circuit by calculating based on the value There is no need to provide a switch or the like, yet not on the need to perform manual gain adjustment and offset adjustment in which a variable resistor or the like, the whole can automatically perform configuration has been overall circuit adjustment simpler.

[0066]

As described above, according to the electrochemical sensor measuring apparatus of the present invention, the electrode group of the electrochemical sensor has a three-pole structure including a working electrode, a counter electrode, and a reference electrode, and furthermore, the electrochemical sensor is used. In addition to forming a measurement sensor that is mounted on a printed circuit board in combination with a temperature sensor, when mounting an electrochemical sensor or a measurement sensor on the measurement device side, an electrical load or After detecting temperature and recognizing the attachment of the electrochemical sensor or measurement sensor by the CPU, the measurement mode is executed to measure the concentration of the specific substance in the sample electrolyte solution. Unlike the device, it is not necessary to distinguish each electrode in the electrode group, and the CPU determines various electrodes without erroneous recognition and then accurately and accurately measures the concentration of a specific substance in the sample electrolyte solution. So as you can be in. Also, by changing the detailed configuration of the measurement sensor, the working electrode, the counter electrode,
The reference electrode is short-circuited on the printed circuit board between the counter electrode and the reference electrode, a reference resistance having a predetermined resistance value is interposed between the working electrode and the counter electrode and the reference electrode, and the reference resistance is used instead of the temperature sensor. A check sensor with a configuration in which a resistance for detection of a predetermined resistance value is mounted at a separated location. Similarly, on the measurement device side, the detail function is changed without changing the basic configuration, and the space is irrelevant to the electrode group. After checking the mounting of the check sensor by the CPU at the specified location, the check mode is executed to make it possible to easily perform correction adjustment for measurement in the entire device, making maintenance and inspection of the entire device easier than ever before And can be performed with high reliability.

[Brief description of the drawings]

FIG. 1 is a plan view showing an electrochemical sensor provided in an electrochemical sensor measuring device according to one embodiment of the present invention.

FIG. 2 is a side sectional view of each electrode taken along the line AA ′ in FIG.

FIG. 3 is a plan view showing a main configuration of a measurement sensor configured using the electrochemical sensor shown in FIG. 1 or FIG. 2;

4A and 4B show an external configuration of a measurement sensor manufactured by mounting a main part configuration of the measurement sensor shown in FIG. 3 on a cartridge, wherein FIG.
(B) relates to the side view in the longitudinal direction, (c)
Is related to a side sectional view in the longitudinal direction.

FIG. 5 is a circuit block diagram showing a basic configuration of the electrochemical sensor measuring device according to one embodiment of the present invention, showing a basic configuration of the measuring device with the electrochemical sensor shown in FIG. 1 or FIG. It is.

FIG. 6 shows a basic configuration of an electrochemical sensor measurement device according to another embodiment of the present invention, showing a basic configuration of the measurement device in a state where the measurement sensors shown in FIGS. 4 (a) to (c) are mounted. FIG. 3 is a circuit block diagram illustrating the configuration.

FIG. 7 shows a basic configuration of an electrochemical sensor measuring apparatus according to another embodiment of the present invention, in which a check sensor having a detailed configuration of the measuring sensor shown in FIGS. 4 (a) to 4 (c) is mounted. FIG. 2 is a circuit block diagram showing a basic configuration of the measurement device in a state where the measurement is performed.

FIG. 8 is a circuit block diagram showing a basic configuration of a conventional electrochemical sensor measuring device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Insulating substrate 2 Working electrode 2a, 3a, 4a Lead part 2b, 3b, 4b Contact part 2α, 3α Titanium layer 2β, 3β Platinum layer 3 Counter electrode 4 Reference electrode 4α Silver layer 4β Silver chloride layer 5 Electrochemical sensor 6 Printed circuit board 7 Thermistor 8 Wiring section 9 Cartridge 9a Opening 9b Open end 10 Sealing material 11, 11 ', 11 "Measuring device 12 Potential control circuit 13 Current detecting circuit 14, 14', 14", 84 A / D converter 15 Sensor detecting circuit 16, 16 ', 16 ", 87 CPU 17, 17', 17" ROM 18, 18 ', 18 ", 86 RAM 19, 19', 89 LCD 20 Measurement sensor 21, 21 'Temperature detection circuit 22 Check sensor 79 Electrode Group 80 simple blood glucose meter 81 connector 82 electrode insertion detection switch 83 current / voltage converter 85 EEPROM 88 Response voltage setting circuit R1 Reference resistance R2 Detection resistance

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Soichi Saito 5-7-1 Shiba, Minato-ku, Tokyo Inside NEC Corporation (72) Inventor Satoru Satoru 2-1-25-1 Nakane, Meguro-ku, Tokyo Tama Electric Industry Co., Ltd.

Claims (8)

[The claims] 1. An electrochemical sensor which is used for measuring the concentration of a specific substance contained in a sample electrolyte solution and has an electrode group provided on an insulating substrate, and wherein the electrochemical sensor is detachable. And a measuring device including a CPU capable of detecting a state in which the electrochemical sensor is mounted. In the electrochemical sensor measuring device, the electrochemical sensor divides the electrode group into a working electrode, a counter electrode, and a reference electrode. An electrode configuration, wherein the measuring device is connected to a predetermined portion of the electrochemical sensor when the electrochemical sensor is mounted, and a load indicating a result of detecting an electric load obtained when a predetermined voltage value is applied. A sensor detection circuit that outputs a detection signal, a potential control circuit that performs a potential control so as to keep the potential difference between the working electrode and the reference electrode constant, and applies a predetermined voltage; When the three electrodes are exposed to the sample electrolyte solution under the condition of the potential control, the result of detecting a current value in a reaction product generated by an electrochemical reaction generated between the working electrode and the counter electrode is shown. A current detection circuit for outputting a current detection signal indicated by the CPU.
Is characterized in that the mounting state of the electrochemical sensor is determined by inputting the load detection signal. 2. The electrochemical sensor measurement device according to claim 1, wherein the CPU is configured to execute the measurement in the sample electrolyte solution based on the current value indicated in the current detection signal as a measurement mode after the mounting of the electrochemical sensor is recognized. The concentration of the specific substance, and the measuring device comprises the CP
A read-only storage device in which a relational expression between a current value required for measuring the concentration of the specific substance in the sample electrolyte solution and the concentration of the specific substance by U is stored in advance, and the CPU based on the current detection signal. An electrochemical sensor, comprising: a readable and writable storage device for storing the current value calculated in the step (a), and a display for displaying a measurement result of the concentration of the specific substance in the sample electrolyte solution by the CPU. measuring device. 3. A measurement sensor, which is used for measuring the concentration of a specific substance contained in a sample electrolyte solution and includes an electrochemical sensor in which an electrode group is provided on an insulating substrate, and the measurement sensor is attached and detached. A measurement device including a CPU capable of detecting a state in which the measurement sensor is mounted and a measurement device including a CPU, wherein the measurement sensor indicates a result of measuring a temperature near the electrochemical sensor. A temperature sensor that outputs a temperature measurement signal, and the electrode group in the electrochemical sensor has a three-electrode configuration including a working electrode, a counter electrode, and a reference electrode;
The measurement device is connected to the temperature sensor when the measurement sensor is mounted, and includes a temperature detection circuit that outputs a temperature detection signal indicating a result of temperature detection based on the temperature measurement signal. And an attachment state of the measurement sensor is determined by inputting the temperature detection signal. 4. The electrochemical sensor measuring device according to claim 3, wherein the measuring device performs a potential control so as to keep a potential difference between the working electrode and the reference electrode constant, and applies a predetermined voltage. A circuit and detecting a current value in a reaction product generated by an electrochemical reaction generated between the working electrode and the counter electrode when the three electrodes are exposed to the sample electrolyte solution under the conditions of the potential control. And a current detection means circuit for outputting a current detection signal indicating the result of the measurement. 5. The electrochemical sensor measurement device according to claim 4, wherein the CPU is configured to execute the measurement in the sample electrolyte solution based on a current value indicated in the current detection signal as a measurement mode after the mounting of the measurement sensor. Quantifying and measuring the concentration of the specific substance, and correcting the concentration of the specific substance according to the result of calculating the temperature of the sample electrolyte solution based on the detected temperature value shown in the temperature measurement signal, The measuring device is configured to calculate the relational expression between the current value required for measuring the concentration of the specific substance in the sample electrolyte solution and the concentration of the specific substance by the CPU, and the voltage value required for calculating the temperature of the sample electrolyte solution. A read-only storage device which stores in advance a corresponding temperature of the sample electrolyte solution and a relational expression necessary for correcting the concentration of the specific substance in accordance with the temperature of the sample electrolyte solution; A readable / writable storage device for storing a current value calculated by the CPU based on the output signal and a voltage value calculated by the CPU based on the temperature detection signal, and the CPU in the sample electrolyte solution by the CPU. An indicator for displaying the measurement result of the concentration of the specific substance, or the measurement result of the concentration of the specific substance in the sample electrolyte solution corrected based on the calculation result of the temperature of the sample electrolyte solution. Electrochemical sensor measurement device. 6. The electrochemical sensor measurement device according to claim 3, wherein the measurement sensor includes the electrochemical sensor and the temperature sensor in a state where the electrochemical sensor and the temperature sensor are provided. A printed circuit board provided with a plurality of wiring portions connected to a sensor is accommodated in a cartridge, and the cartridge is accommodated in the electrochemical sensor in a state where the printed board is accommodated.
An electrochemical sensor measurement device having an opening for exposing electrodes to the outside at one end, and the other end serving as an opening end for inserting the printed circuit board. 7. The electrochemical sensor measurement device according to claim 5, wherein the CPU is used in place of the measurement sensor detachable from the measurement device, and on a printed circuit board provided with the electrochemical sensor. A short circuit is established between the counter electrode and the reference electrode, a reference resistance having a predetermined resistance value is interposed between the working electrode, the counter electrode, and the reference electrode, and a predetermined resistance is provided at a location separated from the reference resistance. It is possible to detect a state in which a check sensor comprising a value detection resistor is mounted, and the potential control circuit is configured to control the reference resistance between the working electrode, the counter electrode, and the reference electrode in the check sensor. A predetermined voltage is applied by performing potential control so as to keep the potential difference constant, and the current detection means circuit detects a reference current value flowing through the reference resistor under the condition of the potential control. The temperature detection circuit outputs a reference current detection signal indicating a detection result, and the temperature detection circuit is connected to the detection resistor when the check sensor is mounted, and based on a resistance value signal obtained from the detection resistor. A temperature detection signal indicating a result of the temperature detection performed by the CPU, and further, the CPU determines the mounting state of the check sensor by inputting the temperature detection signal. Sensor measuring device. 8. The electrochemical sensor measurement device according to claim 7, wherein the CPU performs the measurement mode based on the reference current value indicated in the reference current detection signal as a check mode after the recognition of the mounting of the check sensor. Compensating the measurement of the entire circuit by calculating the current value at the time of quantification measurement of the concentration of the specific substance in the sample electrolyte solution in, the read-only storage device,
The characteristics of the check sensor required for the calculation of the current value by the CPU correspond to the voltage value of the temperature detection signal corresponding to the predetermined resistance value of the detection resistor and the predetermined resistance value of the reference resistor. The reference current value of the reference current detection signal is stored in advance, and the readable and writable storage device stores the reference current value calculated by the CPU. An electrochemical sensor measurement device for displaying a calculation result of the current value.