JPH08332180A - System for continuous percutaneous measurement of blood sugar value - Google Patents

Abstract

PURPOSE: To make it possible to continuously measure a blood sugar value by integrating a series of operations including automatic collecting, weighing, measuring and washing of sucked tissue fluid having no need for blood taking. CONSTITUTION: A suction pump 5 is driven to suck a skin in the state of opening a flow passage opening and closing section 18, setting a weighing valve 13 at a direction A, setting a solenoid valve 8 for changing over flow passages at a direction A side and closing a solenoid valve 6 for opening to the atm. While the suction pressure is checked by a pressure sensor 4, the suction pump is stopped under about 1/2atm. Next, whether the measurement time is attained or not is judged. The liquid path opening and closing section 18 is closed and the solenoid valve 6 for opening to the atm. is opened for about one second to restore the atm. pressure in the suction path when the measurement time is attained. At this time, the weighing valve 13 is filled with the sucked tissue fluid. Next, the weighing valve 13 is rotated in a direction C and the sucked tissue fluid is delivered together with a diluting liquid to a sensor device 15 by a liquid feed pump 10 and thereafter, the fluid is diluted by rotating a stirring rod. The sensor signal is inputted to an A/D converter existing in a control section 1 and the sensor output is displayed on a display section 2. The sugar concn. is measured and displayed about two minutes after.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blood glucose level measuring system, and more particularly to a transcutaneous continuous blood glucose level measuring system for continuously measuring blood glucose level by collecting aspiration tissue fluid.

[0002]

2. Description of the Related Art Conventionally, a blood glucose level measurement test is performed at a hospital or the like by collecting blood intravenously, centrifuging the blood, and measuring the sugar concentration contained in plasma components in the blood with a special test device. Measure or, under the guidance of a physician, measure the capillary blood obtained by puncture with a simple blood glucose meter several times a day under the guidance of a physician. It was.

[0003]

However, the conventional blood glucose measuring methods require blood sampling, which causes pain to the patient, and if this is done several times a day, there is a risk of infection from a wound. It was Further, since it is difficult to measure continuously, there is a problem that it is not easy to know a change in blood glucose level over time.

[0004] It is an object of the present invention to provide a transcutaneous continuous blood glucose level measuring system which solves the above-mentioned problems and enables continuous measurement of blood glucose level.

[0005]

According to the present invention, a suction cell for collecting suction tissue fluid that has exuded from the skin under reduced pressure, and a tube connected to the suction cell, the suction tissue fluid is weighed and suctioned. Valve that can be rotated in three directions: the drainage direction, the liquid draining direction, and the liquid sending direction, a suction pump that vacuum-sucks the surface of the skin, a solenoid valve for opening to the atmosphere for reducing bubbles contained in the suctioned tissue fluid, A suction system consisting of a liquid path switching electromagnetic valve for switching to either one of the suction direction and the liquid draining direction, a sensor device having a glucose sensor for quantifying the sugar concentration in the suctioned tissue fluid, and the inside of the weighing valve. A liquid feed pump that sends the aspirated tissue fluid together with a diluent to the sensor device, and a drainage discharged when the glucose sensor is washed with the diluent after the measurement is completed. A liquid delivery system comprising a liquid part, a liquid path opening / closing part for maintaining a reduced pressure state of the skin surface when the air is opened to the air, a display part for displaying the measurement result of the sugar concentration, a storage part for storing and storing the measurement result, and A transdermal system comprising a control system including a weighing valve, the suction system, the liquid feeding system, a liquid path opening / closing section, the display section, and a control section for controlling the operation of the storage section. A continuous blood glucose measurement system is obtained.

Further, according to the present invention, the suction system includes:
The weighing valve further includes a sample trap connected to the weighing valve via the liquid path switching electromagnetic valve to prevent the suctioned tissue fluid and the diluent from entering the suction pump. A continuous skin glucose measurement system is obtained.

Further, according to the present invention, a rotary plate with a slit is attached to the rotary shaft of the motor of the liquid feed pump, and the liquid feed amount is controlled by reading the slit with a photo sensor. A transcutaneous continuous blood glucose level measuring system is obtained.

Further, according to the present invention, before the measurement, measurement conditions such as a measurement interval and a measurement time are input to the control unit, and the glucose sensor is calibrated. A syringe is injected from the side of the weighing valve in which the suction tube in the liquid removal direction is not connected, and is sent to the sensor device to react with the glucose sensor. After the suction tissue fluid is sent to the sensor device, stirring is performed. A transcutaneous continuous blood glucose measurement system is obtained by rotating the rod and storing the output voltage of the sensor device after a predetermined time has elapsed.

Further, according to the present invention, there is provided a percutaneous continuous blood glucose level measuring system characterized in that a polymer absorbent is provided in the drainage section and the sample trap.

[0010]

The present invention will be described below with reference to the drawings. FIG. 1 is a block diagram showing one embodiment of the present invention.
The suction cell 19 is fixed to the portion of the skin surface from which the stratum corneum has been removed with an adhesive tape. The suction cell is circular, and a circular nylon mesh 20 smaller than the suction cell is inserted between the suction cell and the skin. The nylon mesh 20 has a role of holding down the skin that rises during suction, maintaining the suction effective area, and minimizing damage to the skin. 1 mm inner diameter at the center of the suction cell 19
A suction port of less than is provided, and the suctioned tissue fluid is collected in one place. The suction cell 19 is connected to the weighing valve 13 via a tube. The weighing valve 13 is rotatable by a motor 23, and is controlled by the control unit 1 so as to stop at each position in the suction direction A, the liquid removal direction B, and the liquid feeding direction C.

The suction system includes a liquid passage switching electromagnetic valve 8, a sample trap 7, a suction pump 5, a pressure sensor 4, and an atmosphere opening electromagnetic valve 6 via a suction tube 12. The liquid path switching electromagnetic valve 8 is for switching the suction path from the weighing valve 13 to the sample trap 7 in either the suction direction A or the liquid removal direction B. The sample trap 7 is for preventing the collected suctioned tissue fluid or diluent from entering the suction pump 5. The pressure during suction can be monitored by the control unit 1 using the pressure sensor 4. Although the air release electromagnetic valve 6 normally shuts off the suction passage from the outside, when the suctioned tissue fluid is sufficiently collected by the weighing valve 13, the suction passage can be communicated with the outside and the suction passage can be set to the same pressure as the atmosphere. . Although the fluid channel opening / closing section 18 is normally open, it is closed before being opened to the atmosphere, so that the skin surface is maintained under reduced pressure even when opened to the atmosphere. This is to prevent the raised skin from lowering due to suction when the skin surface is opened to the atmosphere, thereby preventing the suctioned tissue fluid collected by the weighing valve 13 from being lost. The liquid path opening / closing section 18 converts rotation into horizontal movement by a combination of a motor and an eccentric cam, and the stop is controlled by reading a slit attached to a rotating plate of the motor with a photo sensor.

The liquid feed system includes a diluent pack 9 and a liquid feed pump 1
0, the sensor device 15, and the drainage unit 14.
The liquid sending pump 10 is of an ironing type, and is for sending the diluting liquid from the diluting liquid pack 9 to the sensor device 15. A rotary plate with a slit is installed on the rotary shaft of the motor of the liquid feed pump 10, and the liquid feed amount is controlled by reading the slit with a photo sensor. The sensor device 15 has a built-in glucose sensor 16 for measuring the sugar concentration.

The glucose sensor 16 includes an ion-sensitive field effect transistor (Ion Sensitive F).
It is an application of the Field Effect Transistor, and can be repeatedly used by washing after measurement. The suctioned tissue fluid collected by the weighing valve 13 is sent to the sensor device 15 together with the diluting solution by the solution sending pump 10, and is brought into contact with the glucose sensor 16. During the measurement, the sample is diluted by rotating the stirring rod 17 by the stirring motor 21 to obtain a specified dilution ratio. After the measurement, the glucose sensor 16 is washed with the diluent and collected in the drainage unit 14. A polymer absorbent used for a commercially available disposable diaper is provided in the drainage section 14 and the sample trap 7, and the contaminated liquid is absorbed by the polymer absorbent so that the liquid can be easily disposed.

The control system includes a control unit 1, a display unit 2, a transparent touch panel 22, and a memory card 3. The control unit 1 includes a microprocessor and various interfaces, and controls the entire apparatus. The display unit 2 is a liquid crystal display, and a transparent touch panel 22 is installed on this screen, and by pressing the displayed character portion with a finger,
This device can be operated. During aspiration, during measurement, result display,
Characters such as “washing” are displayed on the display unit 2 to inform the operator of the state. The memory card 3 is an IC memory card with a built-in battery, and after the measurement is completed, it can be removed and the data can be read by a personal computer.

FIG. 2 is a flowchart at the time of continuous measurement. Before performing continuous measurement, ID of subject's age, weight, etc.
Information and measurement conditions such as measurement intervals and measurement times are input from the transparent touch panel 22 (step S101), and the output of the glucose sensor 16 is calibrated (step S10).
2). For calibration, a glucose solution having a known concentration is injected with a syringe from the side of the weighing valve 13 in the liquid removal direction to which the suction tube 12 is not connected, and this is injected into the sensor device 15.
To react with the glucose sensor.

After feeding the sample to the sensor device 15, the sensor output voltage after about 2 minutes is stored while rotating the stirring rod. Assuming that the sensor output voltage of the calibration fluid is V _C , the concentration of the calibration fluid is C _C , and the sensor output voltage of the aspiration tissue fluid is V _S ,
The sugar concentration C _S in the suctioned tissue fluid is converted by the following equation (1).

[0017]

[Equation 1] After the calibration is completed, the measurement is automatically repeated at the measurement interval specified by the measurement condition input. First, the liquid passage opening / closing portion is opened, the weighing valve 13 is in the A direction, the liquid passage switching electromagnetic valve 8 is in the A direction side, and the atmosphere opening electromagnetic valve 6 is closed, and the suction pump 5 is driven to suck the skin ( Step S103). While checking the suction pressure with the pressure sensor 4, the suction pump is stopped at about 1/2 atm. Next, it is determined whether or not it is the measurement time (step S104), and when the measurement time is reached (Yes in step S104), the liquid passage opening / closing portion 18 is closed, the atmosphere opening solenoid valve 6 is opened for about 1 second, and suction is performed. The road is returned to atmospheric pressure (step S105). At this time, the bubbles in the aspiration tissue fluid generated under low pressure are reduced or the bubbles in the lower part of the weighing valve 13 are floated up, and the aspiration tissue fluid is filled in the weighing valve 13. Next, the weighing valve 13 is rotated in the C direction, and the sucking tissue fluid together with the diluting solution is sent to the sensor device 15 by the solution sending pump 10 (step S106). When the liquid transfer is complete, rotate the stir bar to dilute. The sensor signal is input to the A / D converter in the control unit 1, and the sensor output is displayed on the display unit 2. After about 2 minutes, the sugar concentration is measured according to the above equation 1 and displayed (step S107).

After the measurement is completed, the diluting solution is sent by the solution sending pump 10 to wash the sensor (step S108). Also at this time, the sensor output is monitored, and if the sensor output voltage returns to the level before the reaction with sugar, the washing is stopped. Next, the weighing valve 13 is set in the B direction, the air opening electromagnetic valve 6 is closed, and the liquid path switching electromagnetic valve 8 is set to the B side and suction is performed for a certain period of time. It is sent to the sample trap 7. As a result, the contamination can be prevented without mixing the aspiration tissue fluid and the diluent at the time of the next aspiration collection. Next, it is determined whether or not this measurement is the final measurement (step S110), and if it is not the final measurement (No in step S110), the next suction is performed.

The weighing valve 13 is again set in the A direction, the liquid path switching solenoid valve 8 is set to the A side, and suction is performed again. When the pressure reaches 1/2 atm, the suction pump is stopped, and the liquid path opening / closing section 18 is closed. Open and wait for the collection of aspirated tissue fluid until the next measurement time. By repeating the above, it is possible to automatically and continuously collect the suctioned tissue fluid and measure the sugar concentration.

FIG. 3 is an external view showing an embodiment of the present invention. The device is divided into a main body 24 and a suction mounting portion 25. The main body can be mounted on the waist by the main body belt 27, and the suction mounting portion 25
Is fixed to an arm or the like by a belt 28.

The main body 24 and the suction mounting section 25 are connected to a cable 26.
Connected by. The cable 26 is formed by integrating a tube and a wire, which are a suction path and a liquid supply path, and is connected by a connector 31. The key is only the power switch 29, and the operation is performed on the transparent touch panel 22 on the display unit 2. When the lid 30 is opened, the diluent pack 9 can be replaced, the polymer absorbent in the drain unit 14 and the sample trap 7 can be replaced, the IC memory card can be removed, and the battery can be replaced.

[0022]

As described above, according to the present invention,
Since a series of operations for automatically collecting, weighing, measuring, and washing the aspirated tissue fluid that does not require blood collection is integrated, it is possible to continuously measure the blood glucose level.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a transcutaneous continuous blood glucose measurement system according to the present invention.

FIG. 2 is a flowchart showing steps of continuous measurement in the continuous transcutaneous blood glucose level measurement system according to the present invention.

FIG. 3 is a schematic perspective view showing a transcutaneous continuous blood glucose level measuring system according to the present invention.

[Explanation of symbols]

 1 Control Section 2 Display Section 3 Memory Card 4 Pressure Sensor 5 Suction Pump 6 Solenoid Valve for Atmosphere Opening 7 Sample Trap 8 Solenoid Valve for Switching Liquid Path 9 Diluting Liquid Pack 10 Liquid Transfer Pump 11 Liquid Supply Tube 12 Suction Tube 13 Weighing Valve 14 Drainage part 15 Sensor device 16 Glucose sensor 17 Stirring bar 18 Liquid passage opening / closing part 19 Suction cell 20 Nylon mesh 21 Stirring motor 22 Transparent touch panel 23 Motor 24 Main body 25 Suction mounting part 26 Cable 27 Main body belt 28 Suction mounting part belt 29 Power switch 30 Lid 31 Connector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shio Murakami 5-7-1, Shiba, Minato-ku, Tokyo NEC Corporation

Claims (5)

[Claims] 1. A suction cell for collecting suctioned tissue fluid that has exuded from the skin under reduced pressure, and a suction cell connected to the suction cell via a tube, and the suctioned tissue fluid is weighed, and the suction direction, the draining direction, and the liquid feeding direction. And a weighing valve that can rotate in three directions,
A suction pump for decompressing the surface of the skin, a solenoid valve for opening to the atmosphere to reduce air bubbles contained in the suctioned tissue fluid, and a solenoid valve for switching a fluid path for switching to one of the suction direction and the drainage direction. And a sensor device having a glucose sensor for quantifying the sugar concentration in the aspirated tissue fluid, a pump for delivering the aspirated tissue fluid in the weighing valve together with a diluent to the sensor device, and a method after the measurement is completed. A liquid delivery system consisting of a drainage part for collecting drainage discharged when the glucose sensor is washed with the diluted liquid, a liquid passage opening / closing part for maintaining a depressurized state of the skin surface when exposed to the atmosphere, and a sugar concentration A display unit for displaying the measurement result, a storage unit for storing and storing the measurement result, and the weighing valve, the suction system, the liquid delivery system, the liquid passage opening / closing unit, the display unit, and the storage unit. Percutaneous continuous blood sugar measuring system characterized by being configured by including a control system comprising a control unit that performs operation control. 2. The suction system is connected to the weighing valve via the liquid path switching electromagnetic valve, and includes a sample trap for preventing the suctioned tissue fluid and the diluent from entering the suction pump. The percutaneous continuous blood glucose level measuring system according to claim 1, which has. 3. The liquid supply pump according to claim 1, wherein a rotation plate having a slit is attached to a rotation shaft of the motor of the liquid supply pump, and the amount of liquid supply is controlled by reading the slit with a photosensor. A transcutaneous continuous blood glucose measurement system. 4. Before measurement, the glucose sensor is calibrated by inputting measurement conditions such as measurement interval and measurement time to the control unit, and the calibration is performed by removing a glucose solution of known concentration from the weighing valve. Inject with a syringe from the side where the suction tube is not connected, feed this to the sensor device to react with the glucose sensor, rotate the stirring rod after feeding the suctioned tissue fluid to the sensor device, 2. The transcutaneous continuous blood glucose level measuring system according to claim 1, wherein the output voltage of the sensor device after a lapse of time is stored. 5. The continuous transcutaneous blood glucose measurement system according to claim 1, wherein a polymer absorbent is provided in the drainage section and the sample trap.