JPS6389170A - Automatic blood vessel injection and blood sampling method and apparatus - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method and apparatus for automatic injection into a blood vessel, automatic dripping, automatic blood sampling from a blood vessel, etc.

[Prior art and problems]

It is widely practiced to insert a needle such as a syringe needle into a blood vessel, inject a medicinal solution into the blood vessel, or collect blood from the blood vessel. For example, in the case of a blood test or blood donation, blood is collected, and for intravenous drip or injection into a blood vessel, a drug solution is injected. In either case, the tip of a needle, such as a syringe needle, is inserted into a blood vessel and a drug solution is injected or blood is collected through this needle, so this needle is commonly referred to as a syringe needle. Furthermore, for the sake of simplicity, in the following description, unless otherwise specified, the word injection will be used to represent injection of a drug solution or blood collection. Furthermore, the person who receives the injection is referred to as a patient, and the person who is a doctor, nurse, or has the appropriate qualifications and administers the injection is referred to as a nurse. Traditionally, when a nurse gave a patient a blood vessel injection, the nurse would hold the syringe in one hand and hold the patient's arm with the other hand while inserting the needle into the patient's blood vessel. If the blood vessel is thick and stands out, the injection needle will easily hit the blood vessel, but if the blood vessel is small or deep from the surface of the arm, it will be difficult to hit the needle with a negative turn and you will need to try again several times. is required. In extreme cases, intravascular injections may be abandoned. In such cases, the patient suffers a great deal of pain. Even if the patient's blood vessels are relatively large, an inexperienced nurse may make a mistake, and the patient always feels anxious. Furthermore, it is known that when the injection needle approaches a blood vessel, the blood vessel may be pushed away by the needle and escape, which is also thought to be a cause of failure.

[Purpose of the invention]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an automatic vascular injection method and apparatus that can reliably perform vascular injection without failure.

[Summary of the invention]

It is known that when an ultrasonic transducer is placed on the skin and an ultrasonic beam is irradiated toward blood vessels, the ultrasonic waves are reflected by blood cells in the blood. The present invention utilizes this principle to identify blood vessels and the tip of the injection needle based on the position of the ultrasonic transducer, the position of the detector that detects reflected waves, the position of the tip of the injection needle, the direction of the irradiation beam, the direction of the reflected beam, etc. This system detects the positional relationship and allows the injection needle to be inserted into a blood vessel.

A first aspect of the present invention is to irradiate an ultrasonic beam to a blood vessel from an ultrasonic transducer placed outside the skin, and use the ultrasonic beam reflected by blood in the blood vessel to be placed outside the skin. Detected by a detector, the direction of a straight line connecting the tip of the cough needle and the blood vessel is determined from the positional relationship of the ultrasonic transducer, the detector, and the tip of the injection needle, and the needle is advanced in that direction and inserted into the blood vessel. This method is characterized by

A second aspect of the present invention includes at least an ultrasound transducer, a mechanism for irradiating blood in a blood vessel with an ultrasound beam generated from the ultrasound transducer, and a detection system for detecting the ultrasound beam reflected by the blood. A device consisting of a mechanism that can attach and detach a syringe and a syringe, and a mechanism that determines the advancing direction of the needle of the syringe by detecting the direction of the irradiated ultrasound beam and the direction of the reflected ultrasound beam, and a mechanism that determines the advancing direction of the needle of the syringe by detecting the direction of the irradiated ultrasound beam and the direction of the reflected ultrasound beam. This is a device that has a mechanism that leads to

In each aspect of the present invention, the direction of the injection needle toward the blood vessel is automatically determined, but advancing the injection needle toward the blood vessel may be done manually or automatically by providing such a function. You may also do so.

Each aspect of the present invention monitors whether the injection needle is pointing in the correct direction until the tip of the injection needle is inserted into the blood vessel, that is, while the injection needle is advancing, and if the injection needle is in the wrong direction. , can include a mechanism to modify it.

Aspects of the invention can include a mechanism for confirming that the tip of the injection needle is inserted into a blood vessel.

Embodiments of the invention may include safety features to prevent the needle from being penetrated deeper or shallower than necessary, or from being traversed in the wrong direction.

Aspects of the invention may include a mechanism to detect when the injection is complete and remove the needle from the blood vessel.

Embodiments of the invention may include a mechanism to disinfect the required area of skin prior to injection.

[Specific examples of the invention]

The present invention will be explained in more detail with reference to the drawings.

1 and 2 illustrate the principle of the invention. In FIG. 1, 10 is a cross section of an arm, 11 is a cross section of a blood vessel, 12 is a couplant, and 13 is a cross section of a blood vessel.
is an ultrasonic transducer, and 14 is a reflected beam detector. 15 is an aperture of the irradiated ultrasonic beam 17 and an aperture 16
The size can be adjusted. Reference numeral 18 is a diaphragm for the reflected beam 20 so that the size of the aperture 19 can be adjusted. The apertures 16 and 19 are arranged immediately in front of the ultrasonic transducer 13 and the detector 14, respectively, and are used to adjust the thickness of the beam and at the same time to adjust the thickness of the beam in any direction in the plane perpendicular to the beam and in the direction parallel to the beam. The beam 20 reflected from the blood vessel 11 can be adjusted so that the beam 20 reflected by the blood vessel 11 is incident on the optimal part of the detector. Can be done. Furthermore, the position of the aperture 16 may be adjusted as described above, or the beam 17 may be scanned by changing the inclination of the transducer 13 so that the beam 17 is sufficiently irradiated onto the blood vessel 11. When changing the attitude of the transducer 13, the attitude of the aperture 16 may also be changed integrally. The postures of the detector 14 and the aperture 18 can be adjusted in order to make the beam 20 incident on the detector efficiently. The couplant 12 is preferably a flexible container made of rubber or plastic, filled with liquid (for example, water) to prevent leakage. 21 is a syringe with a needle 22 having a tip 23.

FIG. 2 shows the positional relationship of the main parts in FIG. A, B, O, and P represent the positions of the ultrasonic emission source of the transducer 13, the delivery part of the detector 14, the center of the blood vessel 11, and the tip of the injection needle 22, respectively. P is determined to be on the perpendicular bisector of A and B, and Q is the foot of the perpendicular line from P to straight line AB.

Let the angle between straight lines AO and AB be α, and the angle between straight lines BO and AB be β. Let R be the leg of the perpendicular line from point O to straight line AB,
Let S be the intersection of straight line AB and straight line OP. AQ=QB=
Let a, PQ=b, and 0R=c. Also, straight line OP and straight line P
Let the angle formed by Q be θ.

a, , b can be considered constants. α can be found as follows. That is, the transducer 13
and adjust the attitude of the aperture 15 so that the output of the detector 14 is maximized, and the transducer 13 and the aperture 1 at that time
The angle α is determined from the positional relationship with 6. Further, the angle β can be obtained from the positional relationship between the detector 14 and the aperture 19 at that time by adjusting the postures of the detector 14 and the aperture 18 so that the output of the detector 14 is maximized after determining the angle α. Can be done. Details of how to obtain the angles α and β will be described later.

The following equation can be obtained from the above relationship.

Tanθ=a(Tanα−Tanβ)/(b+c)
(Tanα+Tanβ)・・・・・・・・・・・・・・・
(1) OP = (b+c)/r・・・・・・・・・・・・・・・
(2) However, c = 2aTan α(Tanβ)/
(Tanα+Tanβ) If angles α and β are known, equation (1) and (
From 2), the lengths of angle θ and oP can be found. That is, the conditions for directing the injection needle toward the blood vessel are determined. It also determines the distance that the tip of the injection needle must be moved to penetrate the blood vessel.

Next, a specific example of how to find the angles α and β will be explained with reference to FIG. 2. In FIG. 2, 25.28 corresponds to the aperture 15.18 in FIG. It corresponds to 16.19. Transducer 13, detector 14, aperture 2
5. Set the initial position of 28 (position before posture adjustment) as follows. When the size of the opening 26 becomes sufficiently small, it is regarded as a point and designated as D. Similarly, let E be that of the opening 29. The angles formed by straight lines AD and AB and the angles formed by straight lines BE and AB are both 45 degrees. In this state, the position of the aperture 15 is adjusted Ta so that the beam 17 passes through the aperture 16 most effectively. FIG. 3 shows this state.

In FIG. 3, straight lines AC and BK are perpendicular to straight lines AD and BE, respectively. H is the intersection of straight lines AD and BE.

Next, while irradiating the ultrasonic beam 17, the postures of the transducer 13 and the aperture 15 are adjusted without changing their relative positional relationship, that is, the aperture 25 is rotated about point A, and the detector 14 is rotated. Maximize output. This situation is shown in FIG. 4, where the beam 17 was initially on the straight line AH, but moves to the straight line AO, and as a result, the straight line AG is rotated by an angle γ to become AG'. If the rotation angle T is measured using a known rotation angle detection mechanism, for example, a rotary encoder, the angle α can be determined from the relational expression α=45+γ.

During this measurement, it is necessary to keep the aperture of the diaphragm 28 sufficiently large. Next, the aperture 28 is rotated about B so that even if the aperture 29 of the aperture 28 is narrowed down, the output of the detector 14 is sufficiently large and becomes maximum. At this time, since straight line BK is rotated by angle δ to become BK, β can be found from the relational expression β=45+δ.

In the above example, the positional relationship between the transducer 13 and the aperture 25 and the positional relationship between the detector 14 and the aperture 28 are not changed;
I try not to change the slope of 4. On the other hand, the positions and postures of the transducer 13 and the detector 14 may be fixed, and the apertures 25 and 28 may be rotated around points A and B. First, the transducer 13 is fixed and only the diaphragm 25 is rotated around point A so that the aperture of the diaphragm 28 is made sufficiently large so that the output of the detector 14 is maximized. This is possible if the beam 17 is spread radially to some extent. Similarly, only the aperture 28 is rotated so that the output of the detector 14 becomes maximum. At this time, the angle between straight lines AO and AH is γ, and the angle between straight lines BO and BH is δ. There are other ways to find α and β, but they are omitted here.

In another embodiment of the invention, the angles α, β are constant (e.g. 4
5 degrees) and move the points A and B on the straight line AB. This principle will be explained with reference to Fig. 5. A and B are the starting positions. , while keeping the positional relationship between the transducer 13 and the aperture 25 fixed, move A on the straight line AB so that the output of the detector 14 is maximized.A at this time is designated as A'.Next, Make the aperture 28 sufficiently small and move B on the straight line AB so that the output of the detector 14 is maximized.The position of B at this time is B'
shall be. Since the blood vessel is supposed to be on the perpendicular bisector of the line segment XB', the injection needle can be advanced the required distance along this line. This distance can be easily found from the line segment ○P in FIG. For example, a linear encoder can be used to obtain the distances AA' and BB'. Alternatively, a potentiometer may be used. Determining the moving distance on a straight line is easy and can use known techniques.

FIG. 6 is a principle diagram of another specific example of the present invention. In this example, the relative positional relationship of A, B, H, and P does not change.

That is, these four points are integrally fixed. In this example, in order to direct the injection needle in the direction of the blood vessel, the apertures 25 and 28 are opened to i, move H to the vicinity of blood vessel 0, scan the vicinity in detail, and detect the detector. Find the position where the output is maximum. Next, reduce the aperture further and repeat the same operation. Furthermore, if the aperture is made sufficiently small and similar scanning is repeated, this state will be when H and 0 coincide. The above scanning may seem like a lot of trouble, but it is actually performed mechanically, so it can be completed in a very short time. Since the direction of the injection needle and the distance to the blood vessel are always fixed (the direction is fixed from the beginning and the distance is PH), all that is left is to advance the injection needle a fixed distance.

In the above explanation, for the sake of simplicity, the injection needle is inserted into the blood vessel at a right angle, but in reality, the needle is inserted into the blood vessel at an angle. FIG. 7 is a side view of the specific example shown in FIG. 1, where the same numbers as in FIG. 1 indicate the same things as in FIG. needle 2
2 is inserted diagonally at an angle φ with respect to the blood vessel.

In the above explanation, for the sake of simplicity, support mechanisms for the syringe, ultrasonic transducer, detector, couplant, etc., have not been mentioned, and a specific example thereof is shown in FIG. Figure 8a
is a sectional view, and b is a side view. In figure a, 31 is a container for storing the couplant, transducer, detector, etc., and 32 and 34 are cylindrical holders for holding the arm between them, and can rotate in a hinge shape around a shaft 33. . Reference numeral 35 denotes a fixture for fixing the holders 32 and 34, which can be rotated in a hinged manner, for example, with a shaft 36 as the rotation axis. Holder 3
4 and the container 31 are integrated. The fixture 35 is removed, the holder 34 is lifted up, the arm is placed on the holder 32, the holder 34 is lowered, and the fixture 35 is fixed. The holder 32 is integrated with the stand 37. A pad 38.40 is attached to the retainer 32, and an adjustment knob 39
and 41, the position of the pad is adjusted so that the pad can tighten the arm appropriately. Next, explanation will be given with reference to figure b. A container 42 is integrated with the container 31, and houses a syringe holder 43 for sliding the syringe 21 in the direction of the blood vessel, a control mechanism for controlling the direction of the syringe, and the like. The syringe may be configured to slide smoothly inside the holder 43, or the holder itself may be structured to slide smoothly along a suitable guide. The holder is of a cartridge type, and a cartridge containing a syringe can be loaded into the container 42 and moved along the guide.

In the above explanation, the blood vessel has been assumed to be straight, but if the needle is inserted into a curved part of the blood vessel, there is a risk that the needle tip may stick out from the blood vessel.

Therefore, it is desirable to find straight sections of blood vessels. To this end, for example, in Figure 8b, when the transducer and detector are tilted together and the ultrasound is irradiated along the direction of the blood vessel, if the ratio of angles α and β is approximately constant, then Blood vessels can be considered to be straight lines.

In one embodiment of the invention, the direction of the injection needle is determined automatically, but the needle is advanced manually. For example, Figure 8
A syringe attached to a device such as that shown in b is pushed along the guide with a finger. The nurse visually determines the speed and distance of the push. When the needle is inserted into a blood vessel, the blood enters the syringe, so you can tell that the needle has entered the blood vessel.Next, manually insert the middle barrel of the syringe (
The drug solution may be injected by pressing 30) in FIG. 1, or this part of the operation may be performed automatically. In the case of blood collection, the inner tube can be returned manually or automatically. In the case of an intravenous drip, for example, the cock of the fluid delivery vibrator is initially closed, and when blood enters the syringe, the cock is opened and the drip fluid is injected using hydraulic pressure.

In one embodiment of the invention, the syringe is automatically replaced each time. In this case, the syringe may be filled with the drug solution in advance, or the syringe may be replaced with a new empty syringe and then filled with the drug solution. As a method for automatic replacement, it is possible to use a method in which the syringe is loaded in a tape, and then automatically removed from the tape and attached to the device (the so-called tape component mounting method used in the electronic device manufacturing field). .

Also, a structure such as a turret may be used for loading bullets in a gun. The tape method is extremely effective in cases such as mass medical examinations.

In one aspect of the invention, an automatic disinfection mechanism is provided. Before inserting the needle into the skin, it is necessary to disinfect the area. You can use something like absorbent cotton, cloth, sponge, or felt soaked with disinfectant to touch the necessary areas. For example, the tape mounting method described above can be used. Rather than being pre-soaked with disinfectant, the tape-loaded cloth or sponge may be impregnated with disinfectant immediately before use. Using such a method, significant savings in disinfectant solution are possible. When a cloth or sponge containing a disinfectant comes into contact with a patient's skin, it is preferable to have a mechanism that taps the cloth or sponge from the back several times to ensure complete disinfection.

In one embodiment of the present invention, the direction of the needle tip of the syringe is automatically controlled to face the direction of the blood vessel until the needle tip of the syringe is inserted into the blood vessel. That is, while advancing the needle in the initially determined direction, the positional relationship between the needle tip and the blood vessel is constantly monitored to prevent the needle from pointing in the direction of the blood vessel for some reason. The needle is always tracked so that it points in the direction of the blood vessel. Specifically, the positional relationship between the needle tip and the blood vessel may be measured at time intervals of several to several hundred milliseconds, and the direction of the needle may be corrected each time.

In one aspect of the present invention, a mechanism is provided to confirm that the needle tip has penetrated into the blood vessel. As mentioned above, if the distance between the needle tip and the blood vessel is measured and the needle is advanced this distance, the needle tip should be inserted into the blood vessel, but for safety reasons, there is no mechanism to confirm this. It is desirable that a One way to confirm this is to confirm that blood has entered the syringe. Specifically, a nurse can visually check, or a method to check automatically is to illuminate the syringe with light from a light source and make sure that the reflected light is received by the optical sensor. It may also be possible to utilize the fact that the reflectance of light is different when it is not in the syringe and when it has entered the syringe. This situation is shown in FIG.

In the figure, 45 is a light source, and 46 is a light sensor. A light beam 47 from a light source 45 is reflected at the distal end of the syringe and a reflected beam 48 is detected by a sensor 46. Before the needle tip pierces the blood vessel, the reflected beam 4 is emitted depending on the color of the syringe.
8 spectrum is determined, but blood enters the syringe (
49) Then the spectrum changes. Therefore, by appropriately selecting the color sensitivity of the sensor 46 or the spectrum of the light source 45, the presence or absence of blood 49 can be detected. Another confirmation method may be to utilize the fact that when a needle is inserted into a blood vessel, the ultrasonic waves are reflected by the needle and the output level of the detector changes.

In one aspect of the invention, a mechanism is provided to automatically detect when the injection is complete. As a specific example of end detection, the above-mentioned photodetection mechanism can be used. It can be detected by using the fact that the reflectance of light is different depending on whether there is a middle tube or not. As another specific example, it may be determined that the process ends when the middle cylinder has advanced a predetermined distance. According to this method, it is possible to inject only a predetermined amount of the injection liquid in the syringe. Another example is when the middle barrel hits the bottom of the syringe's cylinder and can no longer be advanced, so the end is when the force required to push the middle barrel suddenly increases. Therefore, we measure the force that pushes the middle cylinder, and when it exceeds a certain value, we judge that it is finished.

In one aspect of the invention, various safety mechanisms are provided. For example, if a patient feels distressed and presses an emergency button or shouts, an emergency stop switch is activated to immediately stop the injection or remove the syringe. On the other hand, countermeasures against power outages are in place. For example, it is equipped with a spare battery so that it can be operated on this battery for a certain amount of time. Examples of other safety mechanisms include a mechanical stop that prevents the needle from advancing beyond a set distance, or a microswitch that is actuated by a part of the syringe. A mechanism for stopping the advancement of the syringe may also be provided.

In the above explanation, injection into the arm has been taken as an example, but it goes without saying that the injection can be applied not only to the arm but also to other parts.

In the present invention, an ultrasonic transducer is used in the sense of a transmitter, and an ultrasonic detector is used in the sense of a delivery device, but both are types of transducers.

The ultrasonic transducer and ultrasonic detector used in the present invention are electrical/acoustic transducers, and include quartz, barium titanate porcelain, PZT, and other piezoelectric materials. The transmitter can also serve as a delivery device. Furthermore, a split type transducer can also be used. In this case, although A and B are on the same side with respect to the straight line OP in FIG. 2, the principle of the present invention can still be applied.

The frequency of the ultrasonic waves used is desirably high in order to improve resolution, and a range of several megahertz to several tens of megahertz is practical. For example, using frequencies of 10-20 MHz, sub-millimeter resolution can be obtained. Even higher frequencies can be used if transducers are available.

The aperture used in the present invention is preferably made of a material that absorbs or reflects ultrasonic waves well, such as rubber, closed-cell sponge, hollow metal, or plastic. The aperture shape of the diaphragm may be circular, rectangular, slit-shaped, or other shapes.

Light sources that can be used in the example of FIG. 9 include tungsten lamps, LEDs, fluorescent lamps, EL, and the like. Furthermore, examples of the optical sensor include a photodiode, a phototransistor, and a photoconductor.

The method of the present invention is applicable not only to humans but also to animals. This method is particularly effective because animals have hairy hair, which makes it difficult to locate blood vessels from the outside.

The device of the present invention can be of either a portable type or a stationary type.

Various measuring devices and recorders can be connected to the device of the present invention to leave records and analyze data.

〔Effect of the invention〕

According to the present invention, injection into a blood vessel can be performed reliably even without skill, and patient anxiety can be alleviated. Furthermore, since it can be automated, it is possible to rationalize personnel and improve efficiency.

Furthermore, it has the effect of facilitating vascular injection into animals such as livestock and pets.

[Brief explanation of the drawing]

1 and 2 illustrate the principle of the invention. 3 to 6 are principle diagrams of specific examples of the present invention, FIG. 7 is a side view of FIG. 1, and FIG. 8a
and b are a sectional view and a side view of a specific example of the device of the present invention, FIG.
This is a side view of a specific example of a method for confirming that a hypodermic needle has penetrated into a blood vessel. In the figure, 10 is an arm, 11 is a blood vessel, 12 is a couplant, and 13
is an ultrasonic transducer, 14 is a detector, 15.18
．． 25.28 is an aperture, 17 is an irradiation beam, 20 is a reflected beam, 16.19.26.29 is an aperture of the aperture, 21 is a syringe, 22 is an injection needle, 23 is the tip of the injection needle, A, B. O and P are respectively an ultrasonic emission source, an ultrasonic receiver, a blood vessel,
The position of the tip of the injection needle, D and E are the positions of the opening 26.29, 4
5 is a light source, 46 is a photosensor, 47 is an incident light beam, 4
8 is a reflected light beam, 49 is blood, and 43 is a syringe holder.

Claims (2)

[Claims] (1) An ultrasound transducer placed outside the skin irradiates the blood vessel with an ultrasound beam, and a detector placed outside the skin detects the ultrasound beam reflected by the blood in the blood vessel. An automatic blood vessel characterized by determining the direction of a straight line connecting the tip of the needle and the blood vessel from the positional relationship of a transducer, a detector, and the tip of the injection needle, advancing the needle in the determined direction, and inserting the needle into the blood vessel. Injection or voting method. (2) A device consisting of at least an ultrasonic transducer, a mechanism for irradiating the ultrasonic beam generated from the ultrasonic transducer to blood in a blood vessel, a detector for detecting the ultrasonic beam reflected by the blood, and a mechanism for attaching and detaching a syringe. It is characterized by having a mechanism that determines the advancing direction of the needle of the syringe by detecting the direction of the irradiated ultrasound beam and the direction of the reflected ultrasound beam, and a mechanism that guides the tip of the needle in the direction of the blood vessel. Automatic vascular injection or blood collection device.