KR20090118314A - A apparatus and method for measuring a blood glucose using a electrophoresis phenomenon without blood gathering - Google Patents

Abstract

PURPOSE: An apparatus and a method for measuring a blood glucose using an electrophoresis without gathering blood are provided to calculate the blood glucose accurately by correcting the measurement result according to the skin resistance and skin temperature. CONSTITUTION: An apparatus for measuring a blood glucose without gathering blood includes a first extraction electrode(120), a second extraction electrode(125), an extraction electrode alternator(115), and a microprocessor. The extraction electrode alternator alternatively applies a constant current to the first and second extraction electrodes according to a control signal of a microprocessor. The microprocessor calculates an initial blood glucose of a patient based on the current inputted from an operation electrode(135) and corrects the initial blood glucose of the patient according to the skin resistance and the skin temperature. The microprocessor calculates the final blood glucose of the patient by applying the generation current, the skin resistance, and the skin temperature to the preset algorithm.

Description

A device and method for measuring a blood glucose using a electrophoresis phenomenon without blood gathering}

The present invention relates to a blood glucose measurement apparatus, and in particular, to a blood glucose measurement apparatus and method using an electrophoretic phenomenon that can measure blood glucose by extracting glucose present in the subcutaneous tissue through the epidermis using an electrophoretic phenomenon. It is about.

In general, a blood glucose measurement device collects blood directly from a human body using a syringe needle, and then measures the concentration of glucose in the blood. However, such a blood glucose measurement device is always accompanied by blood collection for measuring blood sugar can make the patient feel pain and fear. In particular, the diabetic patients who need to measure blood glucose periodically can be more burdensome.

In order to make up for the shortcomings of the conventional blood glucose measurement apparatus, a bloodless blood glucose measurement apparatus using electrophoresis has been developed. This method utilizes the movement of ions in the body fluid generated by applying a microcurrent to the skin. In particular, when a current in a certain direction is applied to the skin, glucose in the body fluid is induced / extracted. Therefore, the use of electrophoresis does not require blood collection, which is very convenient.

Referring to the operation principle of the blood-free blood glucose measurement apparatus, two extraction electrodes are brought into contact with the skin and a constant current is applied to the two extraction electrodes. Glucose derived near the electrode connected with negative voltage is extracted, and the extracted glucose is reacted with oxidase to produce hydrogen peroxide. The generated hydrogen peroxide is oxidized at the working electrode surface to generate a current, and the blood glucose level is calculated based on the generated current.

However, the conventional blood glucose measurement apparatus has a problem of shortening the life of the electrode by always applying the same polarity voltage to the same extraction electrode. That is, when a positive voltage is always applied to the first extraction electrode and a negative voltage is applied to the second extraction electrode, the current always flows only from the first extraction electrode to the second extraction electrode, and is repeated after a certain time. The lifetime of the electrode is shortened due to phosphorylation reaction or reduction reaction.

In addition, the conventional blood glucose measurement apparatus does not consider the amount of glucose extracted according to the skin resistance, there is a problem that makes the measurement results inaccurate. In other words, the skin resistance formed between different ion conductive media varies from several tens to hundreds of microwatts depending on the environment. If the skin resistance is different, the amount of glucose extracted will be different even if the same voltage is applied to the same person, resulting in inaccurate measurement results.

In addition, the conventional blood glucose measurement apparatus does not consider the difference in the reactivity of the oxidase according to the skin temperature there is a problem that makes the measurement results inaccurate. In other words, when the skin temperature is changed, the activity of glucose oxidase contained in the ion conductive medium is changed, so that even if the same amount of glucose is reacted with the same amount of glucose, the amount of hydrogen peroxide produced is incorrect, resulting in inaccurate measurement results.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a bloodless blood glucose measurement apparatus and method using electrophoresis, which may improve electrode life by changing a direction of currents formed between different extraction electrodes at predetermined time intervals. There is.

Another technical problem to be solved by the present invention is to provide a blood-free blood glucose measurement apparatus and method using an electrophoresis phenomenon that can calculate the exact blood glucose level by correcting the measurement results based on the size difference of the skin resistance according to the environment. have.

Another technical problem to be solved by the present invention is to provide a blood-free blood glucose measurement apparatus and method using an electrophoresis phenomenon that can calculate the exact blood sugar level by correcting the measurement results based on the difference in the reactivity of the enzyme according to the skin temperature. There is.

The bloodless blood glucose measurement apparatus according to an embodiment of the present invention, in the bloodless blood glucose measurement apparatus using an electrophoretic phenomenon, two different extraction electrodes, the extraction electrode engaging portion for applying a constant current to the extraction electrode, and And a microprocessor for generating a control signal for selecting an extraction electrode to which the constant current is applied and for calculating blood sugar data based on the extracted glucose.

Preferably, the extraction electrode engagement unit alternately applies the constant current to the extraction electrode in response to the control signal.

Preferably, the extraction electrode engaging portion, at least one switch that is opened and closed in response to the control signal.

Preferably, the microprocessor corrects the blood glucose data according to the skin resistance measured by the resistance meter.

Preferably, the microprocessor corrects the blood glucose data according to the skin temperature measured by the temperature meter.

In the bloodless blood glucose measurement method according to an embodiment of the present invention, in the bloodless blood sugar measurement method using an electrophoretic phenomenon, applying a positive extraction current to the two extraction electrodes, the two extraction electrodes Applying a reverse extraction current, and calculating blood glucose data based on the extracted glucose when applying the forward extraction current.

Preferably, the bloodless blood glucose measurement method further comprises the step of measuring the skin resistance of the target patient, and correcting the blood sugar data according to the measured skin resistance.

Preferably, the bloodless blood glucose measurement method further comprises the step of measuring the skin temperature of the target patient, and correcting the blood sugar data according to the measured skin temperature.

The bloodless blood glucose measurement apparatus and measuring method using the electrophoretic phenomenon according to the present invention, by changing the direction of the constant current flowing through the extraction electrode at a predetermined time period can prevent the shortening of life due to the continuous oxidation or reduction of the extraction electrode There is an effect. In addition, since blood sugar data is calculated in consideration of the difference in extraction amount and the reactivity of skin resistance and skin temperature, there is an effect of obtaining much more accurate blood glucose data than in the related art.

In order to fully understand the present invention, the operational advantages of the present invention, and the objects attained by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and the contents described in the drawings.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In describing the present invention, if it is determined that the detailed description of the related well-known configuration or function may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted.

1 is a block diagram showing a blood-free blood glucose measurement apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the blood sugar measuring apparatus 100 according to an exemplary embodiment may include a power converter 105, a constant current generator 110, an extraction electrode engaging unit 115, and a first extraction electrode 120. ), Second extraction electrode 125, ion transfer medium 130, working electrode 135, microprocessor 140, key input unit 145, screen display unit 150, communication circuit unit 155, alarm generating unit 160, a data storage unit 165, a skin resistance measurement unit 170, and a skin temperature measurement unit 175. Hereinafter, these components will be described in detail.

The power converter 105 receives drive power from a power supply (not shown) to generate + 18V positive power and -18V negative power. The power supply may be a rechargeable 3.7V lithium ion battery and may include a power supply. The power converter 105 is preferably a DC-DC converter that converts power in a step-up manner. The power converter 105 may change the magnitude of the generated voltage under the control of the microprocessor 140.

The constant current generator 110 receives the positive power from the voltage converter 105 to generate a current having a magnitude independent of the load resistance. The constant current is preferably 0.25 to 0.5 mA as the current applied to the first extraction electrode 120 or the second extraction electrode 125. The constant current generator 110 may be a voltage distribution bias transistor circuit composed of a resistor and a transistor, and the transistor used may be an N-type or P-type bipolar junction transistor.

The extraction electrode engagement unit 115 alternately supplies the constant current supplied from the constant current generator 110 to the first extraction electrode 120 and the second extraction electrode 125 under the control of the microprocessor 140. The alternating period of the first extraction electrode 120 and the second extraction electrode 125 is preferably 10 minutes. The extraction electrode engagement unit 115 may include a plurality of contactless switches controlled according to a control signal output from the microprocessor 140.

The first extraction electrode 120 or the second extraction electrode 125 outputs the constant current supplied from the extraction electrode engagement unit 115 to the extraction electrodes 120 and 125 corresponding to each other through a current path formed in the subcutaneous tissue. The first extraction electrode 120 or / and the second extraction electrode 125 may be an electrode made of platinum, platinum / carbon, or silver / silver chloride, and a working electrode 135 and a counter electrode (not shown) around the The reference electrode may be located.

The ion transfer medium 130 may be composed of a hydrogel that is a water-soluble substance as a medium for receiving glucose derived / extracted from body fluids. The ion transport medium 130 may include a glucose oxidase that generates hydrogen peroxide when reacted with glucose extracted from the skin. The ion transfer medium 130 is in direct contact with the skin and transfers hydrogen peroxide generated from glucose to the working electrode 135 in a diffusion manner.

The working electrode 135 is positioned on the inner circumferential surface of the first extraction electrode 120 or / and the second extraction electrode 125 and is a place where hydrogen peroxide transferred from the ion transfer medium 130 is oxidized to generate a current. The working electrode 135 is applied with a relative voltage of a certain magnitude. The relative voltage is preferably less than 0.4V to ensure the accuracy of the analysis. The working electrode 135 may be an electrode made of platinum or platinum / carbon.

The microprocessor 140 performs overall control of all modules and calculates blood sugar for the patient based on the generated current input from the working electrode 135. The microprocessor 140 may display / store / analyze / transmit the calculated blood sugar data or display data by receiving a user's input. The microprocessor 140 may compare the calculated blood glucose data with a threshold and generate a warning according to the comparison result.

The microprocessor 140 may calculate the initial blood sugar by converting the generated current according to a predetermined table. The microprocessor 140 may correct the initial blood glucose calculated according to the skin resistance and / or the skin temperature input from the skin resistance measuring unit 170 and / or the skin temperature measuring unit 175. The microprocessor 140 may calculate the final blood sugar by substituting the generated current, skin resistance, and skin temperature in a predetermined algorithm.

The key input unit 145 may be a touch screen interface as a module for providing a command or an instruction or setting basic information by a medical staff or a patient. The screen display unit 150 may be an LCD or LED as a module for displaying blood sugar data or analysis data. The communication circuit unit 155 may include a RS-232 serial communication port and a communication port for Zigbee communication or Bluetooth communication as a module for transmitting or receiving data to an upper computer (including a PC or PDA).

The alarm generating unit 160 may generate an alarm when the calculated blood sugar deviates from the set threshold and may emit a warning sound or light a warning light. The threshold may be a first threshold (50 mg / dL) that is a reference for hypoglycemia and a second threshold (350 mg / dL) that is a reference for hyperglycemia. The data storage unit 165 is a module that stores the calculated blood sugar data together with the measurement time, and is preferably a nonvolatile memory.

The skin resistance measuring unit 170 measures the skin resistance and outputs it to the microprocessor 140. The skin resistance measuring unit 170 is preferably in direct contact with the first extraction electrode 170 and the second extraction electrode 175. When the skin resistance input from the skin resistance measuring unit 170 is higher than the threshold, the microprocessor 140 calculates a new blood sugar by reflecting the correction value accordingly. In particular, consider the correlation between skin resistance and glucose extract.

The skin temperature measuring unit 175 measures the skin temperature and outputs the skin temperature to the microprocessor 140. Skin temperature measuring unit 175 is preferably in direct contact with the skin for clarity of temperature measurement. When the skin temperature input from the skin temperature measuring unit 175 is higher than the first threshold value, the microprocessor 140 calculates a new blood sugar by reflecting the correction value accordingly. In particular, the correlation between skin temperature and oxidase reactivity is considered.

2 is a circuit diagram illustrating a constant current generating unit and an extracting electrode engaging unit according to an exemplary embodiment of the present invention.

Referring to FIG. 2, the constant current generator 210 according to the present invention includes first to fourth resistors R1 to R4 and a transistor Tr. 1 to 4 switches SW1 to SW4. Hereinafter, these components will be described in detail.

The constant current generator 210 is configured as a voltage distribution bias circuit using a resistor, and may use N-BJT or P-BJT as an active device for generating a constant current. The constant current generator 210 generates a current having a constant size regardless of the size of the skin resistance. Preferred constant current may be 0.25 mA. Since the current flowing in the collector terminal C is substantially the same as the current flowing in the emitter terminal E, the collector current can be expressed by the following equation.

The extraction electrode engagement unit 220 includes switches that are opened and closed according to a corresponding control signal, and outputs a constant current (extraction current) input from the constant current generator 210 to the first extraction electrode or the second extraction electrode. Each switch may be a contactless switch composed of active elements such as transistors. In order to prevent a short circuit, it is preferable that the first and third control signals and the second and fourth control signals have the same logic level.

3A is a circuit diagram illustrating an embodiment of an extracting electrode engaging unit according to an embodiment of the present invention, and FIG. 3B is a circuit diagram illustrating an embodiment of an extracting electrode engaging unit according to another exemplary embodiment of the present invention.

Referring to FIG. 3A, when the second and fourth control signals are activated, the second and fourth switches are in a closed state, and the extraction current Ic is obtained from the first extraction electrode through the current passage in the subcutaneous tissue. And eventually flows to the negative 18V power supply. Therefore, the neutral glucose molecule together with the cation is accumulated in the second extraction electrode to which the negative voltage is applied. Therefore, a reduction reaction occurs at the second extraction electrode (eg AgCl-> Ag).

Referring to FIG. 3B, when the first and third control signals are activated, the first and third switches are in a closed state, and the extraction current Ic is obtained from the second extraction electrode through the current path in the subcutaneous tissue. And eventually flows to the negative 18V power supply. Thus, the neutral glucose molecule together with the cation is accumulated in the first extraction electrode to which the negative voltage is applied. Therefore, an oxidation reaction occurs at the second extraction electrode (eg Ag-> AgCl).

As shown in FIGS. 3A and 3B, when the opening and closing of the first to fourth switches are controlled using the first to fourth control signals, the extraction current Ic flows from the first extraction electrode to the second extraction electrode. The second extraction electrode may flow from the first extraction electrode. Therefore, each of the extraction electrodes alternates between the oxidation reaction and the reduction reaction at predetermined time periods, thereby preventing the life of the extraction electrodes.

4 is a detailed flowchart illustrating a blood-free blood glucose measurement method according to an embodiment of the present invention.

An extraction current for glucose induction / extraction is applied to the first extraction electrode and a negative power source is connected to the second extraction electrode (410). The extraction current is a constant current having a constant magnitude regardless of the magnitude of the skin resistance present in the current path formed between the first extraction electrode and the second extraction electrode. The working electrode may exist on the inner circumferential surface of the first extraction electrode and / or the second extraction electrode, and the counter electrode and the reference electrode may exist on the outer circumferential surface.

The glucose accumulated in the ion transport medium is extracted (420). The extracted glucose reacts with glucose oxidase present in the ion transport medium and produces an amount of hydrogen peroxide corresponding to the amount of glucose extracted. The generated hydrogen peroxide reacts with the voltage applied between the working electrode and the reference electrode, and generates a current having a magnitude corresponding to the generated hydrogen peroxide amount. The first blood glucose for the patient is calculated based on the magnitude of the generated current (430).

The skin resistance present in the current path formed between the first extraction electrode and the second extraction electrode is measured (440). Skin resistance can range from tens to hundreds of kilowatts. If the skin resistance is close to infinity, it is judged to be a poor contact and an error message is output. The current skin temperature is measured (450). The final blood sugar with improved accuracy for the patient is calculated by reflecting the change in skin resistance and skin temperature in the calculated initial blood sugar (460).

The calculated final blood sugar is displayed through the display unit (470). When the calculated final blood glucose is out of the threshold, a warning sound or a warning light is generated through the alarm generator, and the current state is transmitted to the management system through the communication circuit. If the calculated final blood glucose does not deviate from the threshold, the set wait time is waited (480). After the waiting time has elapsed, the extraction electrode is changed to the second extraction electrode to apply the extraction current (410).

Meanwhile, the present invention can be embodied as computer readable codes on a computer readable recording medium. Computer-readable recording media include all kinds of recording devices, such as ROMs, RAMs, CD-ROMs, magnetic tapes, floppy disks, and optical disks, on which data that can be read by a computer system are stored. The computer readable recording medium can also be distributed over network coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.

The best embodiment has been disclosed in the drawings and specification. Although specific terms have been used herein, they are used only for the purpose of describing the present invention and are not used to limit the scope of the present invention as defined in the meaning or claims.

Therefore, those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a block diagram showing a blood-free blood glucose measurement apparatus according to an embodiment of the present invention.

2 is a circuit diagram illustrating a constant current generating unit and an extracting electrode engaging unit according to an exemplary embodiment of the present invention.

3A is a circuit diagram illustrating an embodiment of an extraction electrode engagement unit according to an embodiment of the present invention.

3B is a circuit diagram illustrating an embodiment of an extraction electrode engaging unit according to another exemplary embodiment of the present invention.

4 is a detailed flowchart illustrating a blood-free blood glucose measurement method according to an embodiment of the present invention.

Claims (9)

In the bloodless blood glucose measurement apparatus using the electrophoresis phenomenon, Two different extraction electrodes; An extraction electrode engaging unit configured to apply a constant current to the extraction electrode; And And a microprocessor for generating a control signal for selecting an extraction electrode to which the constant current is applied and for calculating blood sugar data based on the extracted glucose. The method of claim 1, wherein the extraction electrode engaging portion, The blood-free blood glucose measurement apparatus of claim 1, wherein the constant current is alternately applied to the extraction electrode in response to the control signal. The method of claim 2, wherein the extraction electrode engaging portion, Blood glucose measurement apparatus, characterized in that at least one switch that is opened and closed in response to the control signal. The method of claim 1, wherein the microprocessor, Bloodless blood glucose measurement apparatus, characterized in that for correcting the blood sugar data according to the skin resistance measured by a resistance meter. The method of claim 1, wherein the microprocessor, Blood glucose measurement apparatus, characterized in that for correcting the blood sugar data according to the skin temperature measured by a temperature measuring device. In the bloodless blood glucose measurement method using the electrophoresis phenomenon, Applying a forward extraction current to the two extraction electrodes; Applying a reverse extraction current to the two extraction electrodes; And And blood glucose data is calculated based on the extracted glucose when the forward extraction current is applied. According to claim 5, The blood-free blood glucose measurement method, Measuring skin resistance of the subject patient; And The blood-free blood sugar measuring device further comprises the step of correcting the blood sugar data according to the measured skin resistance. According to claim 5, The blood-free blood glucose measurement method, Measuring skin temperature of the subject patient; And Blood sugar measurement method further comprises the step of correcting the blood glucose data according to the measured skin temperature. A computer-readable recording medium having recorded thereon a computer code for executing the method of claim 6.

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