JPH04338458A - Blood sampler - Google Patents

Abstract

PURPOSE:To enable the sampling of a very small amount of blood with automatic detection of a blood vessel by a method wherein an internal space of a blood sampling needle is made negative in pressure and when a blood sampling needle is pierced into a blood vessel of an organism by the moving operation of a driver, a pressure detector detects a change in pressure to stop or control the driver immediately with a controller. CONSTITUTION:When a starting button 54 of a controller 50 is depressed, a vacuum pump 32 is started to generate a negative pressure in a blood sampling needle 10. Then, the blood sampling needle 10 starts to be driven forward and when the tip thereof is pierced into a blood vessel, blood begins to flow into the blood sampling needle 10 and a pressure in the needle rises. The pressure in the blood sampling needle 10 is always measured with a pressure sensor 40 simultaneously with the starting of the blood sampler and as a rise in the pressure exceeds a fixed value, the controller 50 stops a motor immediately and the blood sampling needle 10 is stopped and held to suck blood. After a fixed time passes, the controller 50 stops the vacuum pump 32 while opening a solenoid valve 36 so that the pressure in the blood sampling needle 10 is equal to the atmospheric pressure. Thus, the suction of the blood is stopped and the blood sampled is held.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to a device for collecting blood from a living body, and more particularly to a blood collecting device that allows blood to be collected by the person receiving the blood collection, such as a patient, and that significantly reduces the pain associated with blood collection. It is something.

0002

BACKGROUND OF THE INVENTION Testing of blood components has become an extremely effective means for diagnosing and monitoring various diseases, and a simple means for collecting blood from a living body is desired.

[0003] As such a means for collecting blood, as is well known, a method is mainly used in which a needle is inserted into a blood vessel and the blood is collected by suction using a syringe or the like.

[0004] However, this method has the disadvantage that it can only be used by doctors or persons specially trained in blood sampling techniques.

[0005] Therefore, as a means by which anyone can easily collect blood, a needle (lancet) with a diameter of about 0.8 mm and a sharpened tip is used to instantly collect small blood vessels using a spring. A known method (spring lancet) involves puncturing and pulling out a densely packed fingertip to injure small blood vessels as well as the skin and tissue, and then collect blood from the wound groove. This method is in practical use as a method that allows patients with diabetes, who require frequent blood tests over a long period of time, to collect and measure their own blood.

However, in this method, if a thin needle is used, it may not hit the blood vessel or the puncture mark may become occluded, making it impossible to collect blood.To ensure blood collection, it is necessary to use a thick needle at the tip of a finger, which is densely packed with small blood vessels. It is necessary to puncture the area. However, since there are many painful points distributed on the fingertip where blood vessels are densely packed, this method causes pain to collect blood, and blood is collected by squeezing blood from the puncture mark rather than inserting the tip of a hollow needle into the blood vessel. This has the disadvantage that tissue fluid may be mixed into the collected blood, causing errors in testing.

[0007]

[Problems to be Solved by the Invention] The present invention was made in view of the above-mentioned conventional problems as well as the recent miniaturization of biological substance detectors (sensors), which has made it possible to miniaturize the amount of specimen required. The purpose of this system is to make it possible to automatically collect blood from a living body without depending on the technique of the person collecting the blood, to avoid contamination with body fluids other than blood, and to eliminate the pain associated with blood collection. It is an object of the present invention to provide a blood sampling device that can be significantly reduced in cost.

[0008]

[Means for Solving the Problems] The blood sampling device of the present invention includes a hollow blood sampling needle for inserting one end into a living body and collecting blood, and an inner part of the blood sampling needle connected to the other end of the blood sampling needle. a pressure reducing device for generating negative pressure in a space; a drive device connected to the blood sampling needle for moving the blood sampling needle; a pressure detection device for detecting the pressure in the internal space of the blood sampling needle; and the pressure detection device. The control device includes a control device that controls the drive device based on an output signal of the device and also controls the pressure reducing device.

[0009] The blood sampling needle in the above structure is inserted into a living body and guides blood in a blood vessel inside the living body to outside the living body. The material of the blood collection needle should be one that is highly rigid and has little toxicity to living organisms. Specifically, glass or carbon fiber is suitable. Alternatively, it may be made of metal. The shape of the blood collection needle is hollow, and the outer diameter is 20μm to 60μm.
It is better to set it to m. The main blood vessels from which blood is collected by the blood sampling device of the present invention have an outer diameter of 20 μm to 60 μm. Therefore, if the outer diameter of the blood collection needle is 20 μm or less,
The amount of blood collected decreases, and blood collection is not performed efficiently.
If it is 60 μm or more, the blood sampling needle will destroy the blood vessel. Note that the tip of the blood collection needle is sharp so that it can be easily inserted into arterioles, venules, and the like.

The pressure reducing device of the present invention is connected to a blood sampling needle, generates negative pressure in the internal space of the blood sampling needle, and maintains the blood sampling needle in a state capable of sucking blood. Furthermore, after a certain amount of blood has been suctioned, the suction is stopped and the pressure is controlled so that the collected blood is retained.

The drive device according to the present invention moves the blood sampling needle based on an output signal from a pressure detection device communicating with the blood sampling needle, and inserts the tip of the blood sampling needle into a blood vessel.

[0012] In the pressure detection device according to the present invention, the pressure sensing portion thereof is connected in communication with the internal space of the blood sampling needle, and detects the pressure within the blood sampling needle. Then, based on the obtained pressure change signal, it is determined whether the blood sampling needle has been inserted into the blood vessel, whether blood is being aspirated, etc.

The control device according to the present invention controls the drive device based on the output signal from the pressure detection device,
In particular, the drive device moves the blood collection needle intermittently at high speed, performs an operation of causing the blood collection needle to search for a blood vessel, and when the blood collection needle penetrates into a blood vessel, performs aspiration of blood for a certain period of time; Thereafter, a signal is given to the decompression device to stop suction and stop blood collection.

[0014]

[Operation] The operation of the blood sampling device according to the present invention constructed as described above will be explained.

When the blood sampling device according to the present invention is attached to the skin of a living body and the control device is activated, the drive device punctures the living body with the blood sampling needle, moves the tip of the blood sampling needle intermittently under the skin at high speed, and at the same time The pressure reducing device is activated to make the internal space of the blood collection needle negative pressure (pressure lower than atmospheric pressure). When the tip of the blood collection needle is inserted into a blood vessel in the living body by moving the drive device, blood flows into the blood collection needle, so that the pressure inside the blood collection needle changes (the pressure increases). This pressure increase signal causes
The tip of the blood collection needle is inserted into a blood vessel, and it can be detected that blood has begun to be drawn into the blood collection needle. When the pressure detection device detects this pressure change, the control device immediately stops the drive device to stop and hold the blood sampling needle with its tip inserted into the blood vessel, and the negative pressure inside the blood sampling needle causes the blood to be drawn. Aspirate it into the blood collection needle and collect blood. In this state, the pressure inside the blood collection needle is maintained at negative pressure for a predetermined period of time, and during that time, blood is drawn from the blood vessel into the blood collection needle to perform blood collection. The collected blood is temporarily held within the blood collection needle, and is discharged from the blood collection needle as needed.

[0016] If the control device controls the drive device to drive the blood sampling needle subcutaneously and advance it a predetermined distance, but the pressure detection device does not detect an increase in pressure within the blood sampling needle, It is assumed that the blood sampling needle did not hit a blood vessel. At this time, the drive device moves the blood collection needle backward until its tip comes close to the surface of the skin, changes the insertion angle at that position, and inserts the blood collection needle again. This is then repeated until the tip of the blood collection needle touches the blood vessel. Blood vessels are searched in this way. Therefore, the person collecting blood does not have to remove the blood sampling device from the blood sampling site such as the arm, reattach it to a different position, and repeat the blood sampling operation, and can efficiently collect blood. When a predetermined amount of blood has been collected, the drive device removes the blood collection needle and blood collection is completed.

[0017] The blood sampling device according to the present invention can be used not only from humans but also from animals.

[0018]

[Effects of the Invention] As detailed above, according to the present invention,
The user can automatically collect blood by simply attaching the device to the blood collection site, and the diameter of the blood collection needle can be made finer depending on the amount of blood collected, preventing damage to living tissue during blood collection and puncture marks. It is possible to reduce the risk of infection by bacteria, etc., and to significantly reduce the pain associated with blood collection.

In particular, in the blood sampling device according to the present invention, as described above, the blood sampling needle is moved intermittently at high speed, so that the tip of the blood sampling needle is inserted into the blood vessel, and the drive device is controlled by the control device. Due to the time delay between receiving the stop signal and stopping, there is no risk of the blood sampling needle tip penetrating the blood vessel, and it also prevents the blood vessel wall from curving when the blood sampling needle tip hits the blood vessel wall. , it becomes possible to smoothly insert the blood collection needle.

Further, in the drive device for the blood sampling apparatus according to the present invention, since the blood sampling needle is driven in a sector-like manner, it is possible to efficiently search for a blood vessel.

[0021]

Embodiments Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 shows the basic configuration of an embodiment of the apparatus of the present invention. The blood sampling device of this embodiment includes a hollow blood sampling needle 1 for inserting one end into a living body and collecting blood.
0, a pressure reducing device 30 connected to the other end of the blood sampling needle for generating negative pressure in the internal space of the blood sampling needle, a drive device 20 connected to the blood sampling needle for moving the blood sampling needle, Pressure detection device 4 that detects the pressure in the internal space of the blood collection needle 10
0, and a control device 50 that controls the drive device 20 based on the output signal of the pressure detection device 40 and also controls the pressure reduction device 30.

FIG. 2 shows the configuration of an embodiment of the present invention in more detail than in FIG. 1.

[0024] The blood collection needle 10 is made of Pyrex glass,
The distal end has an outer diameter of 50 μm and an inner diameter of 30 μm, and is sharp to facilitate insertion into arterioles, venules, etc., and the rear end is connected to and held by a drive device 20. Note that the inner surface of the blood collection needle is preferably coated with an anticoagulant such as heparin to prevent blood from coagulating.

As shown in FIG. 2, the pressure reducing device 30 includes a vacuum pump 32 that generates negative pressure in the inner space of the blood sampling needle 10, a throttle valve 34 for adjusting the negative pressure, and a solenoid valve 36.
It consists of. The throttle valve 34 maintains the inside of the blood collection needle at a negative pressure that allows blood to be aspirated during blood suction, and also maintains the pressure when the tip opening of the blood collection needle 10 is occluded by living tissue and when puncturing into a blood vessel. There is a difference between the state where the blood is flowing and the state where blood is flowing, and the pressure detection device 40 is adjusted so that the difference can be determined. Furthermore, the solenoid valve 36 is closed during blood suction based on the control signal from the control device 50 to maintain a negative pressure inside the blood collection needle, and when the blood suction is completed,
When removing the blood collection needle from the living body, the inside of the blood collection needle is opened to atmospheric pressure.

The drive device 20 includes a blood collection needle mount 210 that holds the blood collection needle 10, a drive mechanism 230 that drives the blood collection needle mount 210, and a drive circuit 220 that supplies a driving pulse current to the drive mechanism 230. .

An internal cross-section of the blood collection needle mount 210 is shown in FIG. The rear end of the blood collection needle is fitted and held in a fixed tube 212 with a rubber seal 214 for preventing air leakage interposed therebetween. Further, the inside of the blood collection needle is branched into two parts within the fixed cylinder 212, one end of which is connected to the pressure detection device 40, and the other end is connected to the pressure reduction device 30.

FIG. 4 shows details of the drive mechanism 230 connected to the blood collection needle mount 210. The drive mechanism 230 is a mechanism that drives the tip of the blood collection needle 10 in a sector shape via the blood collection needle mount 210. That is, its configuration includes three linear pulse motors (hereinafter abbreviated as motors) 235, 236, and 237, which are drive sources, and a shaft 231.
, two bearings 232 and 233, and joint 23
4, drive shafts 240, 241, and 242, drive plate 23
8, and an installation box 239 for storing all of them and stably placing the front surface on the skin of the living body.

One end of the shaft 231 is directly fixed to the blood collection needle mount 210, and the other end is fixed to the joint 23.
4, it is integrally connected to the drive shaft 240 of the motor 235. Moreover, the shaft 231 and the drive shaft 240 are
Since it is structured so that it can be fitted into the bearings 232 and 233 and freely moved in the axial direction (in the left-right direction in FIG. 4), it can be driven in the axial direction by the motor 235.

The bearings 232, 233 and the motor 235 are fixed to a drive plate 238, and the drive plate 238 connects the drive shafts 241 of the motors 236, 237 with universal joints (not shown) at the bases of the bearings 232 and 233. 242, respectively. The drive plate 238 is integrated with the blood collection needle 10, the blood collection needle mount 210, and the shaft 231, and is driven by motors 236 and 237 fixed to the installation box 239 in a direction perpendicular to the central axis of the blood collection needle (vertical direction in FIG. 4). It has a structure that allows it to be driven.

[0031] The drive plate 238 also connects the motors 236, 2
By driving 37 and 235 in synchronization as described below, the direction of the axis of the blood collection needle relative to the installation box 239 can be adjusted while the tip of the blood collection needle is held on the front surface of the installation box 239 (i.e., on the skin surface of the living body). It is designed to rotate around its tip. That is, the drive device 20 drives the motors 236 and 237 synchronously at a speed proportional to the distance from the tip of the blood collection needle 10 to the base of the bearings 232 and 233, and corrects the axial deviation using the motor 235. (When tilting the blood collection needle from a direction perpendicular to the skin surface, move the blood collection needle forward (left direction in Figure 4).
In the opposite case, the shaft 231 and the drive shaft 240 of the motor 235 are driven in an arc centered on the tip of the blood collection needle 10.

Note that the motors 235, 236, and 23
7 uses a linear pulse motor as described above, so the blood collection needle 10 can be driven intermittently and in steps at high speed. In particular, in motor 235,
A device that is movable with a moving distance of about 10 μm per step is used.

The drive circuit 220 is an electric circuit that supplies pulse current to operate the motors 235, 236, and 237 of the drive mechanism 230, and is controlled by the control device 50 to drive the blood collection needle 10 as described above. Generates a pulse current corresponding to the signal.

In this embodiment, the pressure detection device 40 uses a semiconductor pressure sensor, and its pressure detection portion is connected to the internal space of the blood sampling needle 10 via the blood sampling needle mount 210 to measure the internal pressure of the blood sampling needle. Detect.

As shown in FIG. 2, the control device 50 controls the drive device 20 and the pressure reducing device 30 based on the output signal of the pressure detection device 40, and manages and executes the blood sampling operation. It consists of an amplifier 52 for amplifying the output signal of the sensor, a start button 54 with which the user instructs the blood sampling device to start a blood sampling operation, and a control computer 56 that centrally controls all blood sampling operations.

All control functions by the control computer 56 are written as programs in the memory built into the computer 56, and include the following functions. (1) Blood sampling operation is started by the operation signal of the start button 54. (2) Drive the motor 235 to move the blood collection needle 10 forward or backward. (3) While the blood collection needle 10 is being driven forward, the position where the output signal of the pressure detection device 40 rapidly decreases (the pressure decreases) is stored as the number of current pulses applied to the motor 235. (4) Before the blood sampling operation, a criterion regarding the pressure increase in the blood sampling needle 10 for determining whether the tip opening of the blood sampling needle 10 is in a closed state or in a state where it is inserted into a blood vessel is stored in advance. (5) While the blood collection needle 10 is being driven forward, when the rise in the output signal of the pressure detection device 40 reaches the criterion described in (4),
Immediately stop the motor 235 and keep the blood collection needle 10 stopped. (6) After performing the stop operation described in (5), after a preset time has elapsed depending on the required amount of blood to be collected, the vacuum pump 32 is stopped, the solenoid valve 36 is opened, and then the motor 235 is driven to move the blood collection needle 10 backward, returning it to its initial state, and completing the blood collection operation. (7) If a pressure increase reaching the criterion described in (4) is not detected even if the blood collection needle 10 is advanced 1 mm from the position described in (3), the motor 235 is driven to move the blood collection needle 10 to the position described in (3). The blood collecting needle 10 is returned to the position described in 1, and the motors 236, 237, and 235 are driven to rotate the direction of the blood collecting needle 10 by a certain angle around its tip. (8) When the rotation operation described in (7) reaches a preset limit angle, the vacuum pump 32 is stopped, the solenoid valve 36 is opened, and the motor 235 is subsequently driven to remove the blood collection needle 10. Retract it to return to the initial state and stop the blood collection operation.

The effects of the blood sampling device of this embodiment constructed as described above will be explained below.

FIG. 5 shows a blood sampling procedure using the blood sampling apparatus configured as described above using a time chart. When the blood sampling device is not in use, the blood sampling needle 10 is recessed into the installation box 239, and in this state, the user attaches the installation box 239 to the blood sampling site, such as the arm, and fixes it with a band or the like.

Thereafter, when the user presses the start button 54 of the control device 50, the vacuum pump 32 is started (see FIG. 5).
Point O), negative pressure is generated within the blood collection needle 10.

Next, the blood sampling needle 10 starts to move forward (point P), and when the needle tip penetrates the skin, the tip opening is blocked by living tissue, and the pressure inside the needle decreases rapidly ( Same Q point). Then, the blood collection needle 10 is driven further forward, and when the tip punctures a blood vessel, blood begins to flow into the blood collection needle 10, and the pressure inside the needle increases (point R).

The pressure inside the blood sampling needle 10 is constantly measured by the pressure sensor 40 at the same time as the blood sampling device is activated, and when the pressure rise exceeds a certain value (the tip of the needle has completely penetrated into the blood vessel). The control device 50 immediately stops the motor 235, holds the blood sampling needle 10 stopped (point S), and aspirates blood. After a certain period of time has passed in this state, the control device 50 stops the vacuum pump 32 and opens the solenoid valve 36 to bring the inside of the blood collection needle 10 to atmospheric pressure, stops blood suction, and holds the collected blood. (same T point).

[0042] Thereafter, the control device 50 drives the motor 235 in the opposite direction to that described above, removes the blood sampling needle 10 from the skin, returns it to the position before use, and stops it (points U to V in the same figure), and resumes the blood sampling operation. finish.

[0043] In the above blood sampling operation, the blood sampling needle 10
Blood collection needle 1 from the position where the tip punctures the skin (point Q)
If the pressure inside the needle does not increase even if the needle is driven forward by 1 mm (that is, if the blood collection needle does not hit the blood vessel), the control device 50 first drives the motor 235 so that the tip slightly punctures the skin. Blood sampling needle 10 to the position (same Q point)
to retreat. Next, the control device 50 controls the motor 236,
237 and 235 are driven and controlled to rotate the direction of the blood collection needle 10 by a certain angle around its tip, and then the blood collection needle 10 is again driven forward by the motor 235.

In this way, the control device 50 controls the blood sampling needle 1.
The above operation is repeated until the pressure inside the blood collection needle 10 rises, and the tip of the blood collection needle 10 is driven in a sector-like manner.

Furthermore, if the mounting method of the installation box 239 is not appropriate and the pressure inside the needle does not increase even if the above operation is repeated up to the limit angle set in advance in the control device 50 (if no blood vessel is found), The drive device 20 removes the blood collection needle 10 from the skin and stops the blood collection operation.

In this embodiment, by sweeping the tip of the blood sampling needle 10 subcutaneously while detecting the pressure inside the blood sampling needle 10, it is possible to automatically locate blood vessels and collect blood. It is.

[0047] Furthermore, in this blood sampling device, the diameter of the blood sampling needle 10 can be made to be several tens of micrometers, which is comparable to the small blood vessels (arterioles and venules) that are distributed at high density under the skin of living organisms. Since blood can be collected from such a blood vessel, blood can be collected from any site that is safe for the living body. The blood collection needle is punctured only shallowly under the skin, and the damage to blood vessels and living tissues is extremely small compared to conventional methods. Therefore,
By simply attaching and fixing the device to a blood sampling site such as the arm, the user can collect blood safely and with significantly reduced pain.

[0048] In this embodiment, a blood sampling device suitable for collecting a small amount of blood is shown, but the present invention is not limited to this, and it is also possible to collect a larger amount of blood. In that case, by using a blood collection needle with a diameter that corresponds to the required amount of blood, and by attaching a setting box in advance so that the tip of the blood collection needle is placed on the blood vessel suitable for blood collection, the procedure will be carried out in exactly the same way as in this example. Blood can be collected by operation.

In this example, a blood collection needle made of Pyrex glass, which is easy to manufacture, was used; however, when the blood collection device of the present invention is used particularly in hardened areas of the skin, hollow carbon needles, which are fine and have high strength, may be used. It is also possible to use a fiber or hollow metal blood collection needle.

[Brief explanation of drawings]

[Fig. 1] Block diagram showing the basic configuration of the present invention

[Figure 2]
A block diagram showing the configuration of an embodiment of the present invention

FIG. 3 is a cross-sectional view of a blood collection needle mount according to an embodiment of the present invention.

FIG. 4 is a configuration diagram showing an overview of the drive mechanism according to the embodiment of the present invention.

FIG. 5 is an explanatory diagram of a blood sampling operation according to an embodiment of the present invention.

[Explanation of symbols]

10　　　　Blood collection needle 20 Drive device 30　　　　　Pressure reduction device 40 Pressure detection device 50 Control device

Claims (1)

[Claims] Claims: 1. A hollow blood collection needle with one end inserted into a living body to collect blood, and a reduced pressure connected to the other end of the blood collection needle to generate negative pressure in the internal space of the blood collection needle. a drive device connected to the blood collection needle to move the blood collection needle, a pressure detection device that detects the pressure in the internal space of the blood collection needle, and the drive device based on an output signal of the pressure detection device. and a control device that controls the pressure reducing device.