JPH085713Y2 - Automatic chemical injection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a chemical liquid injector.

[Prior Art] In recent years, with the progress of treatment methods, it has become necessary to inject a fixed amount of a medicinal solution into a human body over a long period of time, and an automatic medicinal solution injecting device for stabilizing the injecting rate has rapidly spread. .

As this type of automatic liquid medicine injecting device, there has been proposed a device that specifies how much liquid medicine to inject per unit time and simply performs the injection and ends. Further, as for overload detection in which a tube for supplying a drug solution is bent and the pressure inside the syringe rises, there is also proposed a method of detecting the injection pressure of the injector to give a warning and automatically stopping the drug solution injector.

[Problems to be Solved by the Invention] However, in the above-described conventional automatic liquid injector, the overload detection is performed by detecting that the injection pressure of the syringe has reached a predetermined pressure that requires a warning. There was a problem of lack of sex.

In view of the above, the present invention aims to improve the responsiveness of abnormality detection in a syringe by performing overload detection based on information on the moving distance of the syringe piston during injection.

[Means for solving the problem]

In order to achieve the above-mentioned object, the present invention, in a chemical liquid automatic injection device that drives a transmission mechanism by a drive source to press a piston of an injector to quantitatively supply a chemical liquid, provides reference movement information of the piston at predetermined time intervals. Preliminarily stored storage means, a position detection sensor that interlocks with the drive of the transmission mechanism and detects the actual movement position of the moved piston, and actual movement information of the piston at predetermined time intervals based on the detection signal of this position detection sensor. It is a gist to provide an arithmetic control unit for sequentially calculating the above and detecting overload of the syringe based on the comparison result of the actual movement information and the reference movement information stored in the storage unit.

[Action]

That is, when the transmission mechanism is driven by the drive source, the piston of the syringe starts to move in order to supply the drug solution in a fixed amount. Then, the actual movement position of the piston is detected by the position detection sensor, and the actual movement information of the piston at predetermined time intervals is sequentially calculated based on the detection signal. Then, based on the comparison result between the calculated actual movement information and the reference movement information stored in the storage means in advance, the arithmetic control means detects the overload in the syringe.

[Embodiment] An embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 2, reference numeral 1 is a front panel of the automatic drug solution injecting device, and 2 is a support base fixed to the panel 1, which supports and fixes the syringe 3. That is, the recess 4 is formed in the support base 2 in the horizontal direction in FIG. 2, and the syringe 3 is supported and fixed in the horizontal direction. Reference numeral 5 is a lock member formed in a substantially L shape in a plane, and is provided on the upper right side of the support base 2 so as to be rotatable by a shaft 6. When the locking member 5 is locked at the position indicated by the chain double-dashed line in FIG. 2, the syringe 3 is sandwiched between the tip of the locking member 5 and the recess 4 and is fixed to the support base 2 (see FIG. 1). .

7 is a long hole formed in the horizontal direction of the panel 1,
The sliding member 8 slides along the elongated hole 7. A longitudinal slit 9 is formed on the outer side surface of the sliding member 8, and a flange 11 is formed in the slit 9 on the proximal end portion of the piston 10 of the syringe 3 as shown in FIG. It can be inserted. As a result, when the sliding member 8 slides along the elongated hole 7 (leftward in FIG. 2), the piston 10 is driven and the drug solution in the syringe 3 is delivered to the outside.

Reference numeral 12 is an engagement groove formed in one side of the support base 2 in the vertical direction, and a flange 15 formed to project at the base end of the syringe 3 is engaged. Reference numeral 13 denotes a pair of through holes provided in the support base 2 near the upper and lower ends of the engagement groove 12, and is formed in a horizontally long shape so as to extend between the engagement groove 12 and the side surface of the support base 2. Reference numeral 14 denotes a locking rod arranged in the pair of through holes 13, which is movable in the longitudinal direction of the through hole 13. When the flange 15 of the injector 3 is fitted in the fitting groove 12, it is arranged on the right side of the locking rod 14 in FIG.

Reference numeral 16 denotes an operation unit provided on the lower right side of the panel 1, which includes a start switch for supplying the liquid medicine in the syringe 3, a setting switch for setting the injection amount of the liquid medicine, a stop switch for stopping the supply of the liquid medicine, and an alarm for an abnormality. LED 43 and the like are provided. Reference numeral 18 denotes a display unit provided on the left side of the operation unit 16 for displaying the setting of the injection amount of the chemical liquid, the injection amount of the chemical liquid, and the remaining injection amount (remaining amount).

As shown in FIG. 1, 19a and 19b are support members fixed to both sides in the horizontal direction on the back surface of the panel 1. A pair of rail members 20 is provided between the support members 19a and 19b.
Has been erected. The inner end of the sliding member 8 is projected inward through the elongated hole 7 of the panel 1, and the pair of rail members 20 are inserted through the inner end. And
The sliding member 8 is slidably supported along the rail member 20.

Reference numeral 21 denotes a rack, one end of which is fixed to the sliding member 8. A rack support member 22 supports and fixes the other end of the rack, and is inserted and supported by the pair of rail members 20. Therefore, the rack support member 22 is slidable with respect to the rail member 20.

Reference numeral 23 is a stepping motor as a drive source, and a pinion 24 provided on the stepping motor 23 can be meshed with the rack 21 by a mounting structure described later. Therefore, when the stepping motor 23 is driven, the piston 10 is horizontally pushed rightward in FIG. 1 via the rack 21 and the sliding member 8. In addition,
The sliding member 8 and the rack 21 constitute a transmission mechanism.

Reference numeral 25 is a potentiometer as a position detection sensor provided adjacent to the stepping motor 23, and a pinion 26 provided on an actuator of the potentiometer 25 can be meshed with the rack 21 by a mounting structure described later. Therefore, when the rack 21 is moved by driving the stepping motor 23, the pinion 26 of the potentiometer 25 rotates, and the amount of rotation (rotation speed) causes the piston to move.
It is designed to detect 10 moving distances.

As shown in FIG. 6, 27a and 27b are a pair of guide members vertically provided on the back surface of the panel 1 with the long hole 7 interposed therebetween, and the guide holes 28a and 28b are horizontal to the respective guide members 27a and 27b. It is transparently installed in the direction. 29a and 29b are the guide members 27
The moving member is inserted in the guide holes 28a, 28b of the a, 27b.
30 connects the base ends of the moving members 29a, 29b,
A connecting member that connects the base ends of the pair of locking bars 14.

Further, the one moving member 29b is formed longer than the other moving member 29a, and a spring 31 is interposed at a tip protruding from the guide member 27b, and the spring 31 is fixed by a bolt 32. Therefore, the moving member 29b is always pulled in the leftward direction in FIG. 6 by the urging force of the spring 31,
The connecting member 30 is adapted to abut one end surface of the guide members 27a, 27b.

Reference numeral 33 denotes a micro switch disposed on the right side of the connecting member 30 on the back surface of the panel 1. The micro switch 33 is turned on to detect an overload of the syringe 3. That is, when the syringe 3 moves, the flange 15 pushes the locking rod 14 against the bias of the spring 31, and the connecting member 30 moves slightly to the right to move the microswitch.
The actuator 34 of 33 is pressed to turn on the micro switch 33.

Next, a mounting structure of the stepping motor 23 and the potentiometer 25 will be described.

As shown in FIGS. 3 and 4, 35a and 35b are four support pieces which are projected and supported at four positions on the back surface of the panel 1 in the vertical and horizontal directions (in the direction orthogonal to the paper surface in FIG. 4). Reference numeral 36 is a pair of poles provided at the tips of the support pieces 35a and 35b and connecting the upper and lower support pieces 35a and 35b, respectively. 37 is the pole
Reference numeral 38 is a spring interposed in the lower portion of 36, and 38 is a pair of loose insertion members that are inserted in and supported by the upper portion of the spring 37 so as to be freely insertable.

Reference numeral 39 denotes a support plate that connects the pair of loose insertion members 38 to each other, and the stepping motor 23 and the potentiometer 25 are attached and fixed to the support plate 39. Reference numeral 40 denotes a regulation plate that is installed between the support pieces 35a arranged on the upper part, and is fixed to the upper surface of the support piece 35a. The shaft 6 of the lock member 5 is arranged between the upper portion of the support plate 39 and the regulation plate 40. In addition, the support plate 39 and the regulation plate 40
A cutout portion 6a is formed on the outer periphery of the shaft 6 disposed between and.

Therefore, when the lock member 5 is in the unlocked position shown in FIG. 3, the notch 6a of the shaft 6 contacts the upper side of the support plate 39. At this time, the urging force of the spring 37 pushes the loose insertion member 38 upward and makes contact with the lower surface of the support piece 35a. As a result, the support plate 39, the stepping motor 23, and the potentiometer 25 are moved upward, and the engagement between the pinions 24 and 26 and the rack 21 is released.

Further, when the lock member 5 is rotated to the lock position shown by the chain double-dashed line in FIG. 2 in order to set the syringe 3 on the support base 2, the notch 6a of the shaft 6 is leftward as shown in FIG. Located towards. As a result, the support plate 39 is moved downward by the shaft 6 against the urging force of the spring 37.
39 moves downward, and the stepping motor 23 and the pinions 24 and 26 of the potentiometer 25 are meshed with the rack 21.

Next, an electric circuit for driving and controlling the chemical liquid injector will be described.

As shown in FIG. 5, 46 is an input / output interface. 41 is a controller that is connected to the input / output interface 46 and controls the rotation of the stepping motor 23;
Is an A / D converter that is connected to the input / output interface 46 and converts the displacement signal of the potentiometer 25 into a digital signal. The LED 43 blinks to indicate a warning such as overload. Reference numeral 44 denotes a speaker, which is adapted to generate a sound to indicate a warning such as overload. Reference numeral 45 is a switch for driving the automatic drug solution injecting device.

47 is a central control processing unit (hereinafter,
It is called a CPU) and controls the drive of the stepping motor 23, calculates the amount of the chemical solution supplied by the injector 3, and controls the output devices. Reference numeral 48 is a ROM as a storage means, in which the control data of the chemical liquid automatic injection device is stored in advance. Reference numeral 49 denotes a RAM, which temporarily stores the result calculated by the CPU 47. 50 is a timer circuit, and this timer circuit 50
Based on the above, the moving distance of the piston 10 is detected, and the chemical solution is quantitatively supplied per unit time.

The operation of the automatic drug solution injector configured as described above will be described.

First, after sucking the drug solution into the syringe 3, the syringe 3
Is set in the automatic liquid injector. That is, as shown by the solid line in FIG. 2, the syringe 3 with the lock member 5 moved upwards.
Is disposed in the recess 4, and the flange 15 of the syringe 3 is disposed between the locking rod 14 and the engagement groove 12. On the other hand, by sliding the sliding member 8 to an arbitrary position, the flange 11 of the piston 10 is slit 9
Get involved in.

Then, when the lock member 5 is rotated to the lock position shown by the chain double-dashed line in FIG. 2, the shaft 6 moves the support plate 39 downward against the biasing force of the spring 37. Then, as shown in FIG. 4, the stepping motor 23 and the pinions 24 and 26 of the potentiometer 25 mesh with the rack 21.

Next, the power switch 45 is turned on to drive the automatic chemical injection device. Then, the supply amount of the chemical liquid is set by operating the operation unit 16 while looking at the display unit 18. here,
In this example, 50 ml / h was set.

When a start switch (not shown) of the operation unit 16 is turned on, the CPU 47 detects the start position of the sliding member 8 based on the potentiometer 25 via the A / D converter 42 and the input / output interface 46 and stores it in the RAM 49. ,
The stepping motor 23 is rotationally controlled via the controller 41.

Then, the stepping motor 2 is controlled by the CPU 47 drive control.
The pinion 24 of 3 rotates, and the rack 21 slides to the right in FIG. Then, since the sliding member 8 also moves to the right side due to the movement of the rack 21, the piston 10 is pressed to supply the liquid medicine inside the syringe 3 to the outside. When the supply of the prescribed chemical liquid is completed, the CPU 47 causes the stepping motor 2
Stop rotation control of 3.

 Next, overload detection by the CPU 47 will be described.

Inputs the detection signal from the potentiometer 25 at every predetermined time, the position at the start on the basis of the detection signal (distance) distance as a real movement information slide member 8 is moved from _{X 0 (X 1, X 2} ... X _n ) is sequentially calculated. Then, the distance X that the sliding member 8 has moved is subtracted from the predetermined distance A, which is the reference movement information that the sliding member 8 is stored in advance in the ROM 48 and that moves every predetermined time. That is, for example, the moving distance X _n of the piston 10 from the start is calculated every 10 seconds, and the predetermined distance A corresponding to each time is subtracted from the distance X _n . If the result is smaller than the movement allowable error value B of the sliding member 8, the CPU 47 makes a first judgment that the syringe 3 is not overloaded.

However, the result is the movement allowable error value B of the sliding member 8.
When it becomes larger than this, the CPU 47 determines that the injector 3 is overloaded, and stops the drive control of the stepping motor 23. Furthermore, the LED 4 provided on the operation unit 16
3 is controlled to blink via the input / output interface 46, and a warning sound is generated from the speaker 44 via the input / output interface 46 to notify the abnormality.

Further, the CPU 47, after the first judgment, the potentiometer 2
Based on the detection signal from 5, the moving distance ΔX as the actual moving information of the sliding member 8 per unit time (for example, every 10 seconds) is calculated, and the sliding member 8 stored in advance in the ROM 48 is stored per unit time. Predetermined distance ΔA as reference movement information for movement
Is subtracted from the moving distance ΔX. If this calculation result is smaller than the movement allowable error value C of the piston 10 per unit time, the CPU 47 makes a second determination that the syringe 3 is not overloaded, and continuously supplies the drug solution to the outside.

However, when it becomes larger than the movement allowable error value C of the piston 10 per unit time, the CPU 47 determines that the syringe 3 is overloaded and stops the drive control of the stepping motor 23. Further, the LED 43 provided in the operation unit 16 is controlled to blink through the input / output interface 46, and the input / output interface 46 is also used.
A warning sound is generated from the speaker 44 via the to notify the abnormality.

If the CPU 47 no longer detects an overload, the flange 15 of the injector 3 pushes the locking rod 14 to the right against the biasing force of the spring 31 in FIG. . As a result, the connecting member 30 provided at the base end of the locking rod 14 presses the actuator 34 of the micro switch 33, so that the CPU 47 causes the micro switch 33 to operate.
The stepping motor 23 is stopped by detecting that an overload has occurred in the syringe 3 based on the ON operation of the.

On the other hand, the CPU 47 subtracts the supply amount from the preset injection amount and displays the remaining amount of the liquid medicine injected on the display unit 18. That is, the moving distance of the sliding member 8, that is, the moving distance of the piston 10 is calculated based on the rotation speed of the potentiometer 25 to calculate the amount of the supplied chemical liquid. The supplied amount is subtracted from the set amount, and the calculation result is displayed on the display unit 18.

At this time, the CPU 47 determines whether or not the piston 10 has reached the position indicating that the chemical liquid is insufficient, and when the piston 10 has reached that position, the rotation control of the stepping motor 23 is stopped. Then, the CPU 47 controls the blinking of the LED 43 and generates a warning sound from the speaker 44 to notify it.

Further, when the CPU 47 detects that the piston 10 has reached the position where the chemical liquid supply is completed based on the potentiometer 25, C
PU47 stops the rotation control of stepping motor 23, LED4
3 is controlled by blinking, and a warning sound is generated from the speaker 44 to notify it.

As described above, in this embodiment, the movement distance Xn (actual movement information) of the piston 10 from the start time is calculated every predetermined time, and the movement distance A (previously stored for each predetermined time) from the movement distance Xn is calculated. (Reference movement information) is subtracted, the first judgment is made as to whether or not an overload has occurred based on the magnitude relationship between the result and the movement allowable error value B, and the movement of the sliding member 8 per unit time. Whether or not an overload has occurred depending on the magnitude relationship between the result obtained by subtracting the previously stored movement distance ΔA (reference movement information) from the distance ΔX (actual movement information) and the movement allowable error value C. The second decision is made.

Therefore, the overload can be detected before the injection pressure of the syringe 3 becomes excessive, and the responsiveness is improved as compared with the conventional automatic liquid injector for detecting the injection pressure of the syringe 3 to detect the overload. Can be made. Further, since the potentiometer 25 always detects the moving distance of the piston 10 at every predetermined time, it is possible to improve the detection accuracy of the moving distance of the piston 10.

Also, since the potentiometer 25 can be easily attached,
The structure can be simplified. Furthermore, since the remaining amount is detected and the remaining amount is displayed on the display unit 18, it is possible to grasp the remaining amount supplied at a glance by looking at the display unit 18.

Although the rotary potentiometer 25 is used in the present embodiment, it is naturally possible to provide a cylinder type sliding potentiometer 25 as shown in FIG. 7 to detect overload and residual amount.

The present invention is not limited to the above-mentioned embodiment, and can be arbitrarily modified within a range not departing from the gist of the present invention.

[Effects of the Invention] As described in detail above, according to the present invention, the comparison result of the actual movement information of the piston based on the detection signal from the position detection sensor during injection and the reference movement information stored in advance in the storage means is obtained. On the basis of this, since overload detection can be performed before the actual injection pressure becomes excessive, there is an effect that the responsiveness in abnormality detection of the syringe can be improved.

[Brief description of drawings]

FIG. 1 is a plan view of a potentiometer provided on the automatic drug injector, FIG. 2 is a front view of the automatic drug injector, and FIG. 3 is a rear view showing a state where the stepping motor and potentiometer are separated from the transmission mechanism. Fig. 4 is a rear view showing a state in which a stepping motor and a potentiometer are meshed with a transmission mechanism, Fig. 5 is an electric circuit diagram for controlling the chemical liquid injector, and Fig. 6 is an overload of the chemical liquid injector. FIG. 7 is a rear view showing the detection mechanism, and FIG. 7 is a plan view showing another example in which a potentiometer is provided in the chemical liquid automatic injection device. 3 ... Syringe, 8 ... Sliding member, 21 ... Rack, 23 ... Stepping motor as drive source, 25 ... Potentiometer as position detection sensor, 47 ... CPU as arithmetic control means, 4
8 ... ROM as storage means

Claims (1)

[Scope of utility model registration request] 1. A drug solution automatic injection device that drives a transmission mechanism by a drive source to press a piston of an injector to supply a drug solution in a fixed amount, and a storage unit that stores in advance reference movement information of the piston at predetermined time intervals. A position detection sensor that detects the actual movement position of the moved piston in conjunction with the drive of the transmission mechanism, and sequentially calculates the actual movement information of the piston at predetermined time intervals based on the detection signal of this position detection sensor, and An automatic drug injector according to claim 1, further comprising arithmetic control means for detecting an overload of a syringe based on a comparison result of movement information and reference movement information stored in the storage means.