JPH0636825B2 - 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, this method has a drawback in that an alarm is issued before the pressing force against the sucker reaches a prescribed upper limit and the pump in operation is stopped. This is because it does not take into account the coefficient of friction between the syringe and the sucker. That is, in order to determine the net infusion amount of infusion by the pressing force against the sucker,
It is essential to take into account the coefficient of friction between the syringe and the sucker slidably mounted within the syringe. Moreover, this friction coefficient varies depending on the specifications of syringes of various diameters and manufacturers.

In view of the above circumstances, it is an object of the present invention to provide an infusion device for obtaining a net infusion pressure for infusion from the pressing force of the syringe in consideration of the friction coefficient between the syringe and the sucker. And

[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 pressure conversion circuit connected to a signal from this pressure sensor, a pressure loss coefficient device that outputs a pressing force loss value based on a friction coefficient between the syringe and the suction member, and from the pressure conversion circuit. And a subtractor for subtracting the pressing force loss value from the output detected pressing force value to obtain a net pressing force. The signal from the pressure sensor is A / D converted into an 8-bit decoder signal in the pressure conversion circuit.

According to another aspect, the sucker in the empty syringe is pressed at a constant speed, and the pressing force at this time is regarded as the pressing force loss value and stored in the pressure loss coefficient unit. You may further have a learning function. The coefficient of friction is determined based on the syringe specifications and manufacturer specifications, and thus each value is stored in ROM.

[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 has a built-in self-diagnosis indicator for instructing that the self-diagnosis program is in operation, and an occlusion / open indicator for lighting up when an abnormality occurs during transfusion, for example, occlusion or detachment of the injection needle. A low voltage indicator that indicates that the secondary battery has reached the limit of use, an operation forgetting indicator that indicates a mistake in the operating procedure, and an infusion completion indicator that indicates infusion completion.
A standby indicator for indicating one minute before the completion of infusion is 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. In addition, the guide rod includes the main shaft 30, the release shaft, and the feed screw 34, and the engaging member 32
Since the slider 24 is slidably supported by the mounting portion 5, it may not be used.

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. 4, 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 set 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 unit 46 that outputs the pressing force 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 4
6 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 syringe manufacturers is input. This ROM
A 2-bit diameter signal R corresponding to, for example, four types of syringe diameters is input to 49, and a pressing force loss value corresponding to a syringe of a specific diameter of a specific manufacturer currently in use is input to the subtractor 45. input. 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.

In another embodiment, the learning function of pressing the sucker 23 in the empty syringe 3 at a constant speed, regarding the pressing force at this time as a pressing force loss value, and storing it in the pressure loss coefficient unit 46. Is equipped with. In this case, the pressure loss coefficient device 46 includes a RAM or a register 50 that stores an initial pressure value that depends on the friction coefficient when the suction member 23 in the syringe 3 is pressed in a normally empty state.

Such a learning function is usually used by the hospital side using the syringe 3 of a specific designated manufacturer, and when the syringe 3 of another manufacturer has to be used in an emergency or due to an inventory management error. Is effective for. Therefore, this learning function is performed at the time of factory shipment when the delivery destination hospital side knows in advance or when the designated manufacturer is changed at the hospital side.

The output of the pressure loss coefficient device 46 is also the subtractor 45.
Is input to and subtracted from the pressing force value at the time of injection to obtain the net pressing force, and this net pressing force signal is output to the comparison circuit 47 to determine the friction coefficient of the sucker 23 in the syringe 3. It prevents the impact.

In the comparison circuit 47, an upper limit value 51 for detecting occlusion indicating whether or not an injection needle for infusion is normally inserted into a blood vessel or muscle of a patient, and this injection needle or infusion pipe is turned over. A lower limit value 52 for detecting the opening indicating whether or not it is deviated due to an external factor such as is inputted and compared with the net pressing force signal. In the case of digital signals, these upper limit values and lower limit values are supplied by a dip switch or ROM by the closing pressure level selection switch 53, and are changed according to the diameter signal R and the viscosity of the infusion solution.

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 diameter of the previous syringe 3 stored in advance is compared with the diameter of the next syringe 3, and if the comparison result is different, an alarm is issued. To be Of course, the alarm sounds according to its content,
You may change the display state by light etc. See also FIG.
Each circuit can be configured with an analog circuit, and a pulse motor may be used as the motor.

[0026]

As described above, since the infusion device according to the present invention uses the pressure drop coefficient device or the learning function in consideration of the friction coefficient between the syringe and the sucker, an accurate net pressing force can be obtained. It is possible to detect accurately, and based on this, it is possible to accurately detect the infusion volume, accurately detect abnormalities such as needle loss during infusion, tube dislocation, needle clogging, etc., and always perform safe infusion.

[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 sectional view of the infusion device of FIG.

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

[Explanation of symbols]

 1 Infusion Device 3 Syringe 25 Drive Mechanism 40 Pressure Sensor 44 Pressure Conversion Circuit 45 Subtractor 46 Pressure Loss Coefficient Unit

Claims (3)

[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 signal from the pressure sensor. A pressure conversion circuit, a pressure loss coefficient device that outputs a pressing force loss value based on a friction coefficient between the syringe and the sucker, and a pressing force from the detected pressing force value output from the pressure conversion circuit. An infusion device comprising: a subtractor that subtracts a loss value to obtain a net pressing force. 2. An empty sucker in the syringe is pressed at a constant speed, and the pressing force at this time is regarded as the pressure loss value,
The infusion device according to claim 1, further comprising a learning function that is stored in the pressure drop coefficient device. 3. The infusion device according to claim 1, wherein the friction coefficient is determined based on a standard and a specification of the syringe.