JPH04357449A - Biosensor and biosensor measuring device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a biosensor and a biosensor measuring device that can quickly and easily quantify specific components in various biological samples with high precision.

0002

[Prior Art] In recent years, various biosensors that utilize the specific catalytic action of enzymes have been developed, and as attempts are being made to apply them to the clinical field, there is a need for biosensors that can measure quickly and accurately. .

[0003] Taking glucose sensors as an example, the number of diabetic patients is rapidly increasing, and in order to measure and manage blood sugar levels, it is extremely difficult to measure plasma by centrifuging blood as in the past. Since this requires a complicated procedure, there is a demand for a sensor that can measure whole blood.

[0004] The simple type is similar to the test strips used in urine tests, and has a stick-shaped support containing an enzyme that reacts only with sugar (glucose) and an enzyme that reacts only with sugar (glucose), which changes during the enzyme reaction or with the products of the enzyme reaction. Some products have a carrier containing a dye. Blood is dropped onto this carrier and changes in the pigment are measured visually or optically after a certain period of time, but the accuracy is low due to interference from colored substances in the blood.

[0005] On the other hand, a system has been proposed that allows the electrode system to be disposed of after each measurement, but although this makes the measurement operation extremely simple, it is extremely difficult to use due to the electrode materials such as platinum and the structure. It has to be expensive. Further, as a method for manufacturing the platinum electrode, a sputtering method, a vapor deposition method, etc. can be used, but these methods are expensive in terms of manufacturing.

A biosensor described in Japanese Patent Application Laid-open No. 61-294351 was proposed as a system that can make the electrode system disposable. As shown in FIG. 9, this biosensor is made of an electrode system 30 (30'), 31 (
31'), 32 (32') and an insulating layer 33, the electrode system is covered with a porous material 35 carrying an oxidoreductase and an electron acceptor, and the entire structure is covered with a holding frame 34 and a cover 36. It is integrated.

When a sample solution is dropped onto a porous material, the oxidoreductase and electron acceptor supported on the porous material are dissolved in the sample solution, and an enzymatic reaction progresses with the substrate in the sample solution to accept electrons. The body is restored. After the reaction is completed, the reduced electron acceptor is electrochemically oxidized, and the substrate concentration in the sample solution is determined from the oxidation current value obtained at this time.

In the above measurement, a predetermined voltage is supplied to the electrode system of the sensor and the value of the current flowing between the electrodes is measured.
Based on this signal, the substrate concentration in the sample solution is calculated.

[0009]

[Problems to be Solved by the Invention] In the conventional configuration as described above, unnecessary measurement operations are performed, such as when a disposable sensor is inserted in the opposite direction, or even when it is measured while being inserted in the opposite direction. There were times when I ended up losing my job.

[0010] An object of the present invention is to provide a simple sensor and an easy-to-handle biosensor measuring device for measuring a specific component in a biological sample such as blood simply, quickly, and with high precision.

[0011]

[Means for Solving the Problems] The present invention is a biosensor characterized in that a part of the sensor is provided with a support portion having a protrusion or recess for preventing reverse insertion. Further, the present invention provides a main body that removably supports a biosensor provided with a protrusion for preventing reverse insertion, such as a groove, a recess, or a protrusion that fits into the protrusion or recess only when the sensor is inserted in a predetermined direction. This is a biosensor measuring device characterized by having a fitting part. Furthermore, the present invention is a biosensor device characterized by being provided with a switch that turns on the drive power by inserting the sensor in a predetermined direction into the support portion.

0012

[Operation] In the present invention, reverse insertion of the sensor can be prevented with a simple configuration, and an error in the insertion direction can be recognized without first operating the device.

[0013]

[Examples] The details of the present invention will be described below along with examples. FIG. 1 is an exploded perspective view of the biosensor, and FIG. 2 is an external perspective view thereof. On the substrate 1, a counter electrode 4, a measurement electrode 5, leads 3, 2 connected thereto, and an insulating layer 6 are provided. Although not shown, a reaction layer containing an enzyme and a mediator (electron acceptor) is formed to cover the counter electrode and the measurement electrode. A cover 9 is fixed onto the substrate 1 with a spacer 7 interposed therebetween. 8 is a sample supply hole through which a test liquid (sample) is introduced onto the counter electrode and the measurement electrode by capillary action. As the test liquid is introduced, internal air is discharged from the air hole 10. Reference numeral 11 denotes a reverse insertion prevention protrusion, and this protrusion can prevent reverse insertion into the biosensor device main body, which will be described below.

FIG. 3 shows the sensor 29 inserted into the connector (sensor insertion port) 13 of the device main body (not shown) from the direction indicated by the arrow, and the sensor can be freely attached to and removed from the device main body. can be supported. In the figure, 12
is a switch that is connected to the drive power source provided in the fitting part.

FIG. 8 is a block diagram of the control system of the biosensor device of the present invention. The measurement procedure using this device is as follows.

First, when the sensor 29 is properly inserted into the connector of the main body, the drive power is activated by the switch 12, the insertion is detected by the detection circuit 14, and the current voltage conversion amplifier 16, A/D converter 17 and temperature are transmitted via the CPU 15. Turn on elements such as sensor 18.

Next, when the test liquid is introduced into the sensor, it is detected and measurement is started, and after a predetermined period of reaction, a voltage is applied between the measurement electrode and the counter electrode via the reaction voltage setting circuit 24.

The signal obtained in the measurement is converted into a concentration via a signal processing section composed of a CPU, etc., and displayed on the LCD display 2.
7 is displayed.

In the figure, reference numeral 25 denotes a battery which is a power source for driving the device, and the voltage is checked by a battery checker 26 and power is supplied through a voltage stabilizing circuit 23. Further, 28 is a buzzer that notifies the progress of the measurement operation;
9 is an oscillation circuit that generates a pulse that takes the operating clock of the device, and 22 is a CPU that is used when stopping measurement midway.
This is a circuit that resets the . 20 is a memory that stores correction values and the like for each device.

[0020] In the above, the wall of the sensor insertion port of the connector is at different levels, and if the sensor is inserted in the opposite direction, the reverse insertion prevention protrusion will come into contact with the uneven level, and the sensor will not be inserted into the specified position, making it difficult to see. I can clearly see the difference in insertion. Furthermore, in this case, the sensor does not press the operation switch 12, so the device does not perform any measurement operation.

Differences in insertion direction include cases where the front and back sides are reversed, or cases where insertion is attempted from the sample supply hole side opposite to the lead portion. In either case, by providing a projection or a recess in a portion of the sensor component, the device can be activated only when inserted from a predetermined direction.

Further embodiments are shown in FIGS. 4 and 5, and FIGS. 6 and 7, respectively. FIG. 4 shows a case where a recess 38 is provided at a corner of the sensor board near the lead. FIG. 5 shows a state in which the sensor is inserted into a connector provided with a fitting portion that fits into this recess.

Further, FIG. 6 shows a case where a recess 39 is provided near the center of the lead portion side of the board, and FIG. 7 shows a case where a sensor is attached to a connector having a fitting portion that fits into this recess. Indicates the inserted state.

As shown in the above embodiments, reverse insertion can be prevented by providing a protrusion or a recess in the biosensor and providing a fitting part in the main body of the biosensor device that fits into the protrusion or recess. Can be done. Furthermore, by providing a switch for turning on the drive power source in this fitting portion, the switch can be activated only when the sensor is inserted in the correct direction.

In the above embodiment, the reverse insertion prevention protrusion is provided on the side of the sensor, but the same effect can be obtained by providing the protrusion on the upper or lower surface of the sensor. Further, the position of the recess provided in the sensor is not limited to that shown in the above embodiment.

[0026]

As described above, in the present invention, even if the sensor is inserted in the wrong direction, the error can be confirmed before it starts operating with a simple configuration.

[Brief explanation of drawings]

FIG. 1: An exploded perspective view of a biosensor according to an embodiment of the present invention.

FIG. 2: External perspective view of a biosensor according to an embodiment of the present invention

FIG. 3 is a schematic cross-sectional view of a biosensor joint in the main body of a biosensor device according to an embodiment of the present invention.

FIG. 4: External perspective view of a biosensor that is a different embodiment of the present invention.

FIG. 5 is a schematic cross-sectional view of a connecting portion of a biosensor in a biosensor device main body that is a different embodiment of the present invention.

[Figure 6
] External perspective view of a biosensor which is still another embodiment of the present invention

FIG. 7 is a schematic cross-sectional view of a connecting portion between a biosensor device main body and a biosensor, which is still another embodiment of the present invention.

[Figure 8
]Block configuration diagram of a control system of a biosensor device according to an embodiment of the present invention

[Figure 9] Exploded perspective view of a conventional biosensor

[Explanation of symbols]

1 Board 2,3 Lead 4. Opposite 5 Measurement pole 8 Sample supply hole 11 Reverse insertion prevention protrusion 12 Switch 13 Connector 29 Sensor

Claims (4)

[Claims] 1. A biosensor characterized in that a position indicating portion such as a protrusion or a recess is provided on a part of a substrate having at least a measurement electrode, a counter electrode, and leads connected thereto. 2. A support part that removably supports a biosensor, the biosensor having a position indicating part provided on a part of a substrate having at least a measurement electrode, a counter electrode, and leads connected thereto; and a driving power source that supplies power to the sensor. a signal processing section for processing current from the electrodes of the sensor; a display section for displaying the output of the signal processing section; and means for detecting whether or not the sensor is inserted into the support section in a predetermined direction. , a biosensor measurement device comprising means for operating the drive source with the detection means. 3. The position indicating part of the biosensor is a recess formed in a part of the substrate, and the support part is a recess or groove that fits into the recess of the biosensor. The biosensor measuring device according to item 2. 4. The position indicating part of the biosensor is a protrusion formed on a side surface of the substrate, and the support part comes into contact with the protrusion when the biosensor is inserted in a predetermined direction,
3. The biosensor measuring device according to claim 2, further comprising a wall surface that comes into contact with the tip of the biosensor when inserted in the opposite direction.