JPH0636824B2 - Infusion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an infusion device for injecting various chemicals or blood into a human body by using a syringe type injection pump.

[0002]

2. Description of the Related Art Conventionally, there has been known an infusion device in which a syringe sucking up a drug solution is attached to a syringe type pump, and the sucker of the syringe is pressed at a constant speed by a slider to automatically infuse the solution. ing. This infusion device is disclosed in Japanese Unexamined Patent Publication (Kokai) No. 48-62289 and Japanese Unexamined Utility Model Publication No. 57-
It is disclosed in Japanese Patent Publication No. 76637 and Japanese Patent Publication No. 63-44390.

[0003] In this type of pump, it is important that the drug solution be infused into the patient without difficulty. Therefore, the upper limit of the pressure at the portion of the needle immediately before the drug solution is injected into the patient is determined, the pressing force on the sucker of the syringe when reaching this upper limit value is calculated, and an alarm is issued when this pressing force is reached. Alternatively, there is provided an infusion device in which the operation of the pump is stopped.

[0004]

However, in this method, even if the pressing force against the sucker exceeds the upper limit value and an alarm is issued, no abnormality may occur. This is because it does not take into consideration that the injection pressure varies depending on the viscosity of the drug solution, the gauge or size of the injection needle, and the injection site (vein / artery / muscle) of the patient. That is, since the upper limit value is set in accordance with the low-viscosity drug solution, it does not correspond to the high-viscosity high-calorie drug solution, which has recently received attention. Further, the upper limit value does not correspond to the repulsive force with respect to the injection pressure that is affected by the blood pressure such as when using an injection needle with a small gauge having a large pressure drop or in the case of arterial injection. In the worst case,
When the blood pressure rose due to a sudden change in the patient, the infusion could stop due to an alarm.

In view of the above circumstances, the present invention is directed to
Needle gauge, patient injection site (vein / artery / muscle)
It is an object of the present invention to provide an infusion device in which the alarm level of the injection pressure can be switched in a plurality of stages in consideration of the repulsive force due to.

[0006]

The infusion device according to the present invention comprises a syringe in which a drug solution is stored, a drive mechanism for pressing a sucker in the syringe at a constant speed, and a pressure for detecting a pressing force applied to the sucker. A sensor, a comparison circuit to which the detection output of the pressure sensor can be input, an upper limit coefficient unit and a lower limit coefficient unit input to this comparison circuit, and a selection switch for selecting upper and lower limit values from these upper limit and lower limit coefficient units. Is equipped with. The detection output of the pressure sensor is A / D converted into, for example, an 8-bit digital signal in the pressure conversion circuit.

[0007] According to another aspect, a learning function for updating the upper and lower limit values corresponding to an alarm generated within a predetermined time after the start of infusion may be further provided.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows an infusion device 1 according to an embodiment of the present invention.
Is shown. The case 2 of the infusion device 1 includes an operation unit 4 for monitoring the infusion operation of the syringe 3 and the infusion state.
And a mounting part 5 to which the syringe 3 can be mounted. First, the syringe 3 has, for example, a total volume of 10 depending on the application.
Standard products of mm, 20 mm, 30 mm and 50 mm are used, and therefore have an outer diameter corresponding to the standard. Even if the syringe 3 is a standard product of, for example, 50 mm, the manufacturer has a different friction coefficient with the sucker and a different pressing force per unit flow rate. However, syringes of the same manufacturer with the same standard have almost no variation in the friction coefficient, and therefore the friction coefficient is substantially constant.

Further, the operating section 4 includes a capacity indicator 6 for displaying the size of the mounted syringe 3 by means of, for example, an LED.
Centralized indicator 7 for displaying various operating states, infusion start indicator 8, infusion stop indicator 9, flow rate during infusion, cumulative flow rate or one-shot flow rate of ml / hr (hour) or ml A 4-digit numerical display 10 for displaying in units is arranged.

Therefore, the centralized display 7 is an alarm level automatic setting display which lights up for a predetermined time after the start of the infusion to instruct the updating of the upper and lower limit values for the alarm, and an abnormality such as a blockage during the infusion after the elapse of the predetermined time. Or a blockage / open indicator that lights up when the injection needle comes off, a low-voltage indicator that indicates that the built-in secondary battery has reached the limit of use, and an operation forgetting indicator that indicates a mistake in the operating procedure. An infusion completion indicator that indicates the completion of infusion and a standby indicator that indicates 1 minute before the completion of infusion are provided.

The operation portion 4 is further provided with a one-shot button 1 capable of sending a larger amount of infusion liquid than a normal infusion amount in an emergency.
1, an infusion amount button 12 for selecting the display content of the numerical display 10, an infusion start / stop button 13, a fast-forward button 14, and a power button 15 are arranged. Furthermore, the numerical display 10
Above and below the flow rate setting button 1 that can set the flow rate digit by digit
6 are arranged. These flow rate setting buttons 16 can be set between 0.0 and 199.9 ml per hour. Further, the sucker in the empty syringe 3 is pressed at a constant speed, the pressing force at this time is regarded as the pressing force loss value, and the learning function setting button 17 or the buzzer stop button ( (Not shown) is also arranged.

The mounting portion 5 has a mounting portion 22 on which an outer cylinder 21 of the syringe 3 is mounted, a slider 24 capable of pressing a sucker 23 slidably moving inside the syringe 3, and a slider 24 as shown in FIG. And a drive mechanism 25 for driving the slider 24 in the direction of the mounting portion 22 (direction of arrow a) while supporting the slider 24. First, the mounting part 22 is provided with a holding part 26 for fixing the mounted syringe 3 from above, and a syringe diameter detector 27 arranged under the holding part 26. Also,
For the slider 24, the drive mechanism 25 is released and the slider 2
A release button 28 for returning 4 to the original position is provided, and a part of the drive mechanism 25 is covered with a bellows 29 so that the inside cannot be seen.

Therefore, in the pump having the syringe 3 and the sucker 23, the syringe 3 is held by the holding portion 26 and the sucker 2 is held.
The rear end of the slider 3 is brought into contact with the slider 24. A flexible infusion pipe (not shown) communicating with the injection needle is connected to the tip of the syringe 3. Therefore, the syringe 3 is mounted on the mounting portion 22.
When the slider 24 is pushed by the drive mechanism 25 in the direction of arrow a at a predetermined speed, the drug solution in the syringe 3 is pushed out at a predetermined flow rate and is passed through the infusion pipe and the injection needle. Injected into the patient.

This drive mechanism 25, as shown in FIG.
The spindle 30 slidably supported by the mounting portion 5, and the mounting portion 5
And a release shaft which is slidably supported on the main shaft 30 and is arranged in parallel with the main shaft 30. The main shaft 30 has one end fixed to the slider 24 and the other end fixed to the engaging member 32. On the other hand, the release shaft is arranged on the opposite side of the main shaft 30 and is not visible, but one end vicinity is pivotally supported by the slider 24, the other end vicinity is pivotally supported by the engaging member 32, and one end is released via the arm. And the other end is fixed to an engaging claw (not shown) of the engaging member.

Like the slider 24, the engaging member 32 is slidably supported in the mounting portion 5 and is reciprocally moved by the feed screw 34 that can engage with the engaging claw. That is, each of the engagement members 32 has the main shaft 3 within the mounting portion 5.
0 and guide rod and feed screw 3 arranged parallel to the release axis
4 is slidably attached. The feed screw 34 is axially supported by the mounting portion 5 and is supported so as to be slightly movable in the axial direction. Although the guide rod is arranged on the front side of the feed screw 34, the illustration thereof is omitted.

Further, the syringe diameter detector 27 has a holding portion 2.
A shield plate that moves up and down in conjunction with the knob 6 and a three-stage photo interrupter that crosses between the light emitting portion and the light receiving portion are provided. This shield is provided with a notch,
Regarding the width of the notch, when the syringe 3 is not mounted, all the light receiving parts are shielded, when the total amount of 10 mm of the syringe 3 is mounted, only the lower part of the light receiving part (001) is exposed, and when the 20 mm syringe 3 is mounted, the interruption and the lower part The light receiving part (011) is shielded, and 30
It is set so that all the light receiving parts (111) are exposed when the mm syringe 3 is mounted, and only the lower light receiving part (110) is shielded when the 50 mm syringe 3 is mounted. Therefore, the syringe diameter detector 27 receives a digital signal with a 3-bit width from the three-stage light receiving section, and these digital signals have a 1-bit diameter indicating the presence or absence of a syringe and a 2-bit diameter indicating the type of syringe. A decoder for decoding the signal R and outputting the signal R is provided.

On the other hand, as shown in FIG. 2, the feed screw 34 has a pressure sensor 40 attached to one end 34a and a large gear 41 of a reduction gear mechanism fixed to the other end. The motor 42 in which a small gear that meshes with the large gear is fixed to the rotary shaft is shown in FIG.
As shown in FIG. 3, under the control of the motor control circuit 43, the flow rate signal and the diameter signal R from the flow rate setting button 16 are rotationally driven at a predetermined speed. The flow rate signal and the diameter signal R are stored in the memory.

The pressure signal output from the pressure sensor 40 is amplified by an amplifier and then amplified by the pressure conversion circuit 4.
4 is input. After the A / D conversion, the pressure conversion circuit 44 converts the pressure difference due to the difference in the syringe diameter based on the 2-bit diameter signal R to obtain the pressure per unit area of the chemical liquid, and the output thereof is the subtractor 45. Entered in.

The subtractor 45 includes a syringe 3 and a sucker 2.
The output of the pressure loss coefficient device 46, which outputs the pressure loss value based on the friction coefficient between the pressure loss coefficient and the pressure coefficient of 3, is also input. This pressure loss coefficient device 46
Includes a ROM 49 to which a manufacturer signal M of, for example, 3 bits from a syringe type selection switch 48 that can be selected by several manufacturers of syringes is input. This ROM4
A 2-bit diameter signal R corresponding to, for example, four types of syringe diameters is input to 9 to subtract a pressure loss value corresponding to a syringe of a specific diameter of a specific manufacturer currently in use, from the subtracter 45.
To enter. Therefore, the value related to the friction coefficient stored in the ROM 49 is determined based on the standard of the syringe 3 and the specification of the manufacturer.

Instead of this, the pressure loss coefficient device 46 presses the sucker 23 in the empty syringe 3 at a constant speed and stores a RAM or a register 50 for a learning function for storing the pressing force value at this time. You may prepare.

On the other hand, in the comparison circuit 47, the output of the upper limit coefficient device 51 for detecting occlusion, which indicates whether or not the infusion needle of the infusion solution is normally inserted into the blood vessel or the muscle of the patient, and the needle or the needle. The output of the lower limit coefficient unit 52 for opening detection, which indicates whether or not the infusion pipe has come off due to an external factor such as turning over, is input and compared with the net pressing force signal.

These upper limit coefficient unit 51 and lower limit coefficient unit 52
Is a ROM or RAM selected by the closing pressure level selection switch 53 or a selection register. The occlusion pressure level selection switch 53 outputs appropriate upper and lower limit values stored in the upper limit coefficient unit and the lower limit coefficient unit according to the viscosity of the infusion solution, and is incorporated in the main body so as not to be easily operated normally. . The selection switch 53 controls the viscosity of the infusion solution,
Depending on the gauge of the needle and the injection site of the patient, for example, 16 alarm levels can be manually selected, eg by a nurse.

According to another embodiment, when the injection needle is correctly inserted into the injection site of the patient, the infusion solution is injected within a predetermined time, for example, within 1 minute after the injection of the infusion solution is started. It is possible to automatically set the alarm level by utilizing the fact that the injection of s. In this case, when the output of the comparison circuit 47 reaches the alarm level within a predetermined time after the start of infusion, the upper limit coefficient unit 51 and the lower limit coefficient unit 52.
The contents of the register for are updated and the next alarm level is selected. Of course, it is important for the learning function to update the upper and lower limit values corresponding to the alarm that may occur within a predetermined time after the start of infusion, to monitor the condition of the patient during sufficient infusion after the elapse of a predetermined time. .

Further, the comparison circuit 47 detects a corresponding abnormal state when the pressing force signal exceeds the upper and lower limit values, and inputs an alarm signal to the alarm circuit 54. The alarm circuit 54 displays the stop signal ST on the motor control circuit 4 while displaying the block / open indicator 7 in FIG. 1 according to the abnormal state.
3 to stop the motor. Therefore, the infusion status can be constantly monitored.

The alarm circuit 54 outputs an alarm signal having various contents. For example, syringe 3 for which infusion has been completed
Is replaced with a syringe 3 containing a new drug solution, the previously stored diameter of the previous syringe 3 is compared with the diameter of the next syringe 3, and an alarm is issued if the comparison result is different. . Of course, the alarm may change the display state by sound, light, etc. according to the content thereof.

The block circuit shown in FIG.
A U, ROM, RAM, I / O device, a one-chip microcomputer system having an A / D conversion function and a D / A conversion function, or an ordinary microcomputer system can be used, but it may be composed of an analog circuit. You can
Further, a pulse motor may be used as the motor.

[0027]

As described above, the infusion device according to the present invention provides an alarm for the injection pressure in consideration of the viscosity of the drug solution, the gauge of the injection needle, and the repulsive force due to the injection site (vein / artery / muscle) of the patient. Since I changed the level to multiple levels,
It is possible to set alarm levels corresponding to infusions with various viscosities, and based on this, it is possible to accurately detect abnormalities such as needle dropouts, tube disconnections, and needle jams during infusions, and always perform infusions safely. .

[Brief description of drawings]

FIG. 1 is an external perspective view of an infusion device according to an embodiment of the present invention.

FIG. 2 is a partially cutaway front view of the infusion device of FIG.

FIG. 3 is a block diagram schematically showing an infusion control circuit according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Infusion device 3 Syringe 25 Drive mechanism 40 Pressure sensor 47 Comparison circuit 51 Upper limit coefficient unit 52 Lower limit coefficient unit 53 Selection switch

Claims (2)

[Claims] 1. A syringe containing a liquid medicine, a drive mechanism for pressing a sucker in the syringe at a constant speed, a pressure sensor for detecting a pressing force against the sucker, and a detection output of the pressure sensor is input. And a lower limit coefficient unit input to the comparison circuit, and a selection switch for selecting upper and lower limit values from the upper limit coefficient unit and the lower limit coefficient unit. 2. The infusion device according to claim 1, further comprising a learning function for updating the upper and lower limit values corresponding to an alarm generated within a predetermined time after the start of infusion.