JPH07111988A - Apparatus for preventing back-flow of biofluid from occurring - Google Patents

Abstract

PURPOSE:To prevent back-flow of a biofluid from occurring when the biofluid is collected for measurement of a blood-sugar level. CONSTITUTION:In a blood-sugar level measuring apparatus wherein a suction cell 30 is tightly adhered on the skin of a subject to be examined and a switch valve 31 by which this suction cell 30 is made vacuum to collect quantitatively a tissue fluid is provided, an apparatus for preventing back-flow of a biofluid from occurring wherein a pressing piece 7 arranged between the suction cell 30 and the switch valve 31 and pressing a tube Ta connecting them and a motor M pressing this pressing piece 7 on the tube Ta or retreating it from the tube Ta are provided, is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing backflow of biological fluid suitable for use in a blood glucose level measuring device.

[0002]

2. Description of the Related Art Conventionally, when measuring a blood glucose level with a blood glucose level measuring device, a part of the stratum corneum of the skin at a predetermined site of a subject is removed to expose the epidermis, and a suction cell is adhered to this part. When aspirating through a suction pump etc., the biological fluid leaks out,
This biological fluid was collected, the glucose level was measured, and the blood glucose level was determined.

As such a blood glucose level measuring device, there has been proposed a device for reducing the generation of bubbles contained in the biological fluid when the biological fluid is sampled and the glucose level is measured (Japanese Patent Application No. 2).
-259573). This device was constructed as shown schematically in FIG. That is, the suction cell 30 is brought into close contact with the skin S from which the stratum corneum Sa has been removed. The suction cell 30 is connected to the lower opening of the switching valve 31 via the tube Ta, and the upper opening of the switching valve 31 is connected to the pressure gauge 32, the three-way valve 33 and the suction pump 34 via the tube Ta. . The switching valve 31 has a fixed capacity in the internal liquid passage, and thus can quantitatively collect the biological fluid.

In addition, when the glucose level is measured, the switching valve 3
1 is switched to supply the diluting liquid 36 filled in the diluting liquid tank 35 from the left side opening via the liquid feeding pump 37 and the tube Tb, and the diluting / stirring section 38 is connected to the right side opening by the tube Tc. Via the biological fluid G and the diluent 36
Is discharged and stirred to dilute. The diluted biological fluid G is supplied to the measurement unit 39 via the tube Td, and the calibration / measurement / display recording unit 40 displays or records the calibrated measurement value. The diluting liquid measured by the measuring unit 39 is discharged as a waste liquid to the drain tank 41 via the tube Te,
The measuring unit 39 and the diluting / stirring unit 38 are configured to be cleaned with the cleaning liquid 43 in the cleaning tank 42 via the liquid feed pump 44 and the tubes Tf and Td.

In such a structure, the suction cell 30 is attached to a predetermined part of the living body, the suction pump 34 makes a negative pressure to suck the biological fluid G, and the switching valve 31 quantitatively collects the biological fluid G. However, since the collected biological fluid G in the switching valve 31 contains bubbles, the three-way valve 33 is switched to the atmospheric pressure side to increase the pressure to reduce the bubbles, and then the dilution / stirring unit 38.
Is diluted and sent to the measuring unit 39 to measure the glucose value. Therefore, it is possible to accurately measure the blood glucose level by eliminating or reducing the influence of bubbles on the collected biological fluid G.

In the above proposal, as another example, in order to reduce air bubbles in the biological fluid, the internal pressure is forcibly increased when the biological fluid is collected by the pressure increasing means instead of opening to the atmospheric pressure. Such a configuration is also disclosed.

[0007]

However, in the above-mentioned conventional structure, it is possible to reduce the bubbles in the collected biological fluid, but in the switching valve when the biological fluid is opened to the atmospheric pressure or when the pressure is forcibly increased. There was a case in which the biological fluid was pushed back to the suction cell side, and the biological fluid could not be collected or decreased, making it difficult to measure the blood glucose level.

Therefore, in view of the above points, it is an object of the present invention to provide a biological fluid backflow prevention device in a blood glucose level measuring device which prevents the biological fluid from flowing back when bubbles of the biological fluid in the switching valve are removed. To do.

[0009]

In the device for preventing backflow of biological fluid according to the present invention, as shown in FIG. 1, for example, a suction cell 30 is brought into close contact with the skin of a subject, and the pressure inside the suction cell 30 is reduced to reduce the tissue fluid. In the blood glucose level measuring device having the switching valve 31 for quantitatively collecting blood pressure, the pressing piece 7 that is arranged between the suction cell 30 and the switching valve 31 and presses the tube Ta that connects them.
And a driving means M for pressing the pressing piece 7 against the tube Ta or retracting it from the tube Ta.

[0010]

[Function] At the time of collecting a fixed amount of the biological fluid in the switching valve at the time of collecting the biological fluid, the backflow prevention device disposed between the switching valve and the suction cell is driven to press the tube so that the biological fluid is directed toward the suction cell. To prevent regurgitation. Next, the biological fluid is released to atmospheric pressure to increase the pressure, or the pressure is forcibly increased to reduce the bubbles contained in the biological fluid. Therefore, the biological fluid can be collected in a state where air bubbles are reduced without flowing backward in the direction of the suction cell,
An accurate blood glucose level can be measured without being affected by bubbles or by reducing the number of bubbles.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the biological fluid backflow prevention device of the present invention will be described below with reference to FIGS. The parts corresponding to those of the conventional example in FIG. 3 are designated by the same reference numerals.

In FIG. 1, the backflow preventive device includes a base 1,
It is composed of a shaft 2 that is movable back and forth by rotation and a motor M that drives the shaft 2.

The pedestal 1 has a through hole 3 into which the tube Ta can be inserted, bearings 4 and 5 for supporting the front and rear end portions of the shaft 2 are formed, and a screw portion with which the shaft 2 is screwed near the center. 6 is formed.

A pressing piece 7 for pressing the tube Ta is attached to one end of the shaft 2 and a gear 8 is attached to the other end.
Is fixed. Further, a screw portion 9 that is screwed into the screw portion 6 of the pedestal 1 is formed in the middle portion of the shaft 2. The shaft 2 advances to the tube Ta side when it is rotated clockwise, for example, and retracts when it is rotated counterclockwise.

Since the tube Ta is usually made of flexible plastic, it is crushed by advancing and pressing the pressing piece 7, but when the pressing piece 7 is retracted, it returns to its original state due to its elasticity. Therefore, the tube Ta
Biological fluid inside can be blocked or passed.

A gear 10 for driving the gear 8 of the shaft 2 is attached to the motor M. In this case, since the shaft 2 moves to the left and right (in the direction of the arrow), the gear 10 of the motor M is made wider than the width of the gear 8 of the shaft 2 so that the gear 8 moves forward or backward with rotation. It does not come off from the gear 10 of the motor M.

In the above-mentioned structure, when the blood glucose level measuring device is operated to aspirate the biological fluid, the motor M is rotated counterclockwise to retract the pressing piece 7 of the shaft 2 and the tube Ta.
Is opened and the switching valve 31 is set to the suction cell 3
Set to 0 side. Therefore, the biological fluid sucked by the suction cell 30 reaches the switching valve 31 via the tube Ta, and a fixed amount of biological fluid flows into the switching valve 31.

When the switching valve 31 is filled with the biological fluid, the motor M of the backflow prevention device is driven to rotate the shaft 2 in the clockwise direction to move the pressing piece 7 forward and press the tube Ta to squeeze the switching valve. The biological fluid in 31 is blocked so as not to flow back into the suction cell 30. Next, set the three-way valve 33 to the pressure gauge 3
2 and the atmosphere side are switched to increase the pressure to reduce the bubbles in the biological fluid in the switching valve 31.

When the bubbles of the biological fluid in the switching valve 31 disappear or decrease due to the increased pressure, the switching valve 31 is switched to the liquid feed pump 37 and the dilution / stirring section 38 to dilute / stir, and then sent to the measuring section 9. The glucose level contained in the collected biological fluid is measured to measure the blood glucose level.

After the blood glucose level is measured, the shaft 2 of the backflow preventing device is rotated counterclockwise through the washing process described above with reference to FIG.
Is released and the above-described biological fluid suction measurement process is repeated.

As described above, the biological fluid can be prevented from flowing back to the suction cell side in a state where the biological fluid is collected and the bubbles in the biological fluid are reduced at the time of measurement, so that the blood glucose level can be measured quickly and Can be done accurately.

FIG. 2 is a schematic configuration diagram showing another embodiment. In this example, instead of the motor-driven backflow prevention device shown in FIG. 1, a spring and a ball constitute a backflow prevention device. That is, in FIG. 2, reference numeral 20 denotes a case, which has openings h1 and h2 at which the tube Ta is sealed and fitted, and a spring 21 and a ball 22 are arranged between the upper and lower openings h1 and h2. The spring 21 acts to constantly press the ball 22 against the opening h2. The lower opening h2 is formed, for example, in a truncated cone shape so that the inner side thereof widens toward the ball 22. Therefore, the ball 22 is reliably placed inside the opening h2 so that the biological fluid does not flow back into the tube Ta during a predetermined operation.

In the above structure, the opening h2 can be shielded without the spring 21, but when the switching valve 31 is switched to the atmosphere side, the spring 21 is provided so that the pressing force and the action at the time of increasing the pressure can be obtained. As a result, the ball 22 can rapidly and surely block the opening h2.

In this structure, since the suction cell 30 and the inside of the tube Ta have a negative pressure when the biological fluid is sucked, the ball 22 in the case 2 resists the pressing force of the spring 21 by the biological fluid flowing from the opening h2. And pushed up,
When the three-way valve 33 is switched to the atmosphere side in order to reduce bubbles, the pressure rapidly increases and the ball 22 closes the opening h2.

Therefore, it is possible to prevent backflow of the biological fluid sucked at the time of opening to the atmospheric pressure to the suction cell 30 side, and it is possible to eliminate or reduce the bubbles in the biological fluid.

Further, the present invention is not limited to the above-mentioned embodiments, and it goes without saying that various other configurations can be adopted without departing from the gist of the present invention.

[0027]

As described above, according to the present invention, the backflow of the biological fluid is prevented between the switching valve and the suction cell when the biological fluid is sucked to reduce the bubbles inside the blood glucose level. Therefore, it is possible to accurately and promptly collect the biological fluid and measure the blood glucose level with high accuracy without being affected by the bubbles or reducing the influence of the bubbles.

Further, since the attachment portion of the suction cell can be maintained at a negative pressure, the sampled state can be kept constant and an excessive burden on the subject can be prevented.

Furthermore, since the suction cell can be maintained at a negative pressure except when the atmosphere is open to the atmosphere or when the pressure is increased, it is possible to reduce the power consumption of the suction pump or to reduce the size of the suction pump.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a configuration of a biological fluid backflow prevention device of the present invention.

FIG. 2 is a schematic diagram showing the configuration of another embodiment.

FIG. 3 is a block diagram showing a configuration of a blood glucose level measuring device used for explaining a conventional example and the present invention.

[Explanation of symbols]

 7 Pressing piece M Motor 30 Suction cell 31 Switching valve Ta tube

Claims (1)

[Claims] 1. A blood glucose measuring device having a switching valve for bringing a suction cell into close contact with the skin of a subject, and decompressing the inside of the suction cell to quantitatively collect tissue fluid. A backflow prevention device for biological fluid, comprising: a pressing piece which is arranged between the pressing pieces and presses a tube connecting the connecting pieces; and a driving means which presses the pressing piece against the tube or retracts the tube from the tube.