JPH0749055B2 - 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 using a microcomputer system for injecting various chemicals or blood into a human body by using a syringe type infusion pump.

[0002]

2. Description of the Related Art Conventionally, a sucker is pulled out from a syringe, a syringe sucking up a drug solution is attached to a mounting portion, and the sucker is pressed at a constant speed by a slider which converts a rotation of a motor into a linear motion. An infusion device that automatically infuses is known. This infusion device is disclosed in JP-A-48-
No. 62289, Japanese Utility Model Publication No. 57-76637, Japanese Patent Publication No. 62-44505 and Japanese Patent Publication No. 63-4439.
No. 0 publication.

Further, in an infusion device in which an infusion is controlled by a microcomputer, the microcomputer detects an abnormality in another peripheral device, stops a motor for supplying the infusion, and issues an alarm.

[0004]

In an infusion device using such a microcomputer, when an abnormality occurs in the microcomputer, one of the bits of the program code is inverted due to external noise or the like and the program runs out of control. However, the motor for infusion solution supply may not stop.

In view of the above circumstances, the present invention, in an infusion device using a microcomputer, forcibly operates a motor for supplying an infusion liquid when an abnormality occurs, in addition to the control of the microcomputer when the abnormality occurs in the microcomputer. It is an object of the present invention to provide a safety device, that is, a watchdog timer, for stopping the watch.

[0006]

An infusion device using a microcomputer system according to the present invention is a microcomputer that is reset by a first reset signal when a power switch is turned on, and a motor is controlled under the control of this microcomputer. And a motor control circuit that is reset by the first reset signal and sends a second reset signal to the microcomputer when there is no monitor signal that is periodically sent from the microcomputer and the motor. It is provided with a watchdog timer that sends a stop signal to the control circuit to forcibly stop the motor.

[0007]

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 external view of an infusion device 1 using a microcomputer according to an embodiment of the present invention. The case 2 of the infusion device 1 is provided with an operation unit 4 for monitoring the infusion operation and infusion state of the syringe 3 in which the liquid medicine is stored, and a mounting unit 5 to which the syringe 3 can be attached. First,
Syringe 3 has a total volume of 10 mm and 20 m, depending on the application.
Standard products of m, 30 mm and 50 mm are used, and therefore have an outer diameter corresponding to the standard.

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 in normal infusion 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 is provided for returning 4 to the original position. Further, the drive mechanism 25 moves the sucker 23 in the syringe 3 at a predetermined speed, and a part connected to the slider 24 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.
A main shaft 30 and a release shaft slidably supported by the mounting portion 5 are provided. 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 in parallel to the side opposite to 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. An engaging claw (not shown) fixed to the button 28 and the other end being an engaging member
Fixed to.

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 is provided with 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.

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. A small gear (not shown) of the reduction gear mechanism meshes with the large gear, and the rotation shaft of the motor 42 is fixed to the small gear. This motor 4
As shown in FIG. 3, the motor 2 is rotationally driven at a speed set by the motor control circuit 43.

FIG. 3 shows a safety control circuit provided with a watchdog timer which copes with a program runaway and enhances safety. The safety control circuit includes a microcomputer 51 that is reset by a first reset signal RST1 when the power switch 50 is turned on, a motor control circuit 43 that controls the motor 42 under the control of the microcomputer 51, and a first reset. The second reset signal RST2 is reset to the microcomputer 51 when the microcomputer 51 is reset by the signal RST1.
And a stop signal to the motor control circuit 43,
The watchdog timer 52 for forcibly stopping the motor 42 by this is provided. The motor control circuit 43 includes a motor speed control circuit 53 to which a motor speed control signal is input from the microcomputer 51, and a motor drive circuit 54 to which the output of the control circuit 53 is supplied. The motor drive circuit 54 forcibly stops the motor 42 in response to a signal from the watchdog timer 52.

That is, the microcomputer 51 has the first reset signal RS when the power switch 50 is turned on.
When T1 is received, the initial program is executed to shift to the standby state, and thereafter, when various operations are performed by, for example, a nurse or the like, the corresponding program is executed and the standby state is returned after completion. During this period, the microcomputer 51
Sends to the watchdog timer 52 a monitoring signal that can be sent periodically during normal operation.

If the system is abnormal, that is, the microcomputer 51 is abnormal or the program is out of control, the watch signal supplied to the watchdog timer 52 is stopped. At this time, the watchdog timer 52 directly supplies, for example, an abnormality occurrence signal instructing the occurrence of runaway to the motor drive circuit 54, whereby the motor drive circuit 54
Stops the motor 42.

The abnormality occurrence signal is the second reset signal R for resetting only the microcomputer 51.
ST2 is generated . The microcomputer 51 is restarted by this reset, but at the time of restart by this reset, only a warning is issued as a system error. Therefore, the drive circuit 54 of the motor 42 does not recover again by this reset, and the power switch 50 must be turned off once and restarted.

As described above, when an abnormality occurs in the microcomputer 51, the watchdog timer 52 independent of the microcomputer 51 detects the abnormality and resets the system and forcibly stops the motor 42. Further, when the system is operating normally by the microcomputer 51, the control of the motor 42 is driven by the control signal. Further, the watchdog timer 52, which monitors the system by hardware, is periodically sent a monitoring signal to ensure the normal operation of the system.

Of course, the display state of the alarm may be changed by sound, light or the like according to the content thereof. Further, a pulse motor may be used as the motor 42 shown in FIG.

[0023]

As described above, since the infusion device using the microcomputer according to the present invention uses the watchdog timer, when an abnormality occurs in the microcomputer, one of the program codes is caused by external noise or the like. Even if the bit of is reversed and the program runs out of control, the motor for supplying the infusion can be forcibly stopped and the infusion can always be performed 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 sectional view of the infusion device of FIG.

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

[Explanation of symbols]

 1 Infusion Device 3 Syringe 25 Drive Mechanism 42 Motor 43 Motor Control Circuit 50 Power Switch 51 Microcomputer 52 Watchdog Timer

Claims (1)

[Claims] 1. A microcomputer which is reset by a first reset signal when a power switch is turned on, a motor control circuit which controls a motor under the control of the microcomputer, and which is reset by the first reset signal. , The monitoring signal sent from the microcomputer regularly.
And a watchdog timer for forcibly stopping the motor by sending a stop signal to the motor control circuit at the same time as sending a second reset signal to the microcomputer when there is no signal. Infusion device.