JPH0143079Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an infusion device for injecting various medicinal solutions, blood, etc. into the human body using a syringe-type infusion pump.

BACKGROUND ART Infusion devices that automatically infuse fluid using a syringe pump have been known. This device is equipped with a syringe-type pump containing a medicinal solution, and the infusion is performed by pressing the suction of the syringe at a constant speed with a slider. In such an infusion device, it is very important to inject a predetermined amount of the liquid in the syringe into the human body. In particular, in the case of a syringe pump, since highly concentrated chemical solutions are often used, it is necessary to take the above points into consideration. Conventional devices detect the end of infusion by detecting the position of the slider using a limit switch, etc., which poses problems with accuracy, and since the detection position is fixed, the dimensions of the syringe used cannot be changed. I was unable to respond when it happened.

The present invention provides an infusion device that solves the above problems, and embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the appearance of a transportation device 1 according to the present invention, in which a case 2 includes an operating section 3 and a pump mounting section 4.
is provided. The operation section 3 includes a syringe size display section 5, an injection abnormality display section 6, an end-of-3-minute display section 7, a driving display section 8, a stop display section 9, a digital display section 10, a flow rate setting button section 11, and an infusion fluid display section. A start button 12, a stop button 13, a fast forward button 14, an elapsed time display button 15, a feeding amount display button 16, an operation button 17, etc. are arranged. A slider 18 is provided in the pump mounting portion 4 so as to be movable along a guide 19.
A syringe holding part 20 and a syringe diameter detector 21 are provided. The slider 18 has a pressing section 2.
2 (see FIG. 3) and a lock knob 23. A pump 26 consisting of a syringe 24 and a sucker 25 is attached to the holding part 20 with the syringe 24 held therein, and the pressing part 2 is attached to the rear end of the sucker 25.
2 is brought into contact. Note that an infusion pipe 27 is connected to the tip of the syringe 24.

When the slider 18 moves at a predetermined speed in the direction of arrow a in the state shown in FIG. has been made.

Next, an embodiment of a drive device for the slider 18 including the present invention will be described with reference to FIG.

This drive device includes the following four functions according to the present invention.
It is designed to have two functions.

(1) Regardless of the injection speed of the liquid, an alarm is issued a predetermined time before the end of the infusion (3 minutes in the case of Figure 1).

(2) Always inject the set amount of liquid into the patient accurately.

(3) Monitor whether the liquid is being infused normally during infusion by detecting the pressure inside the syringe.

(4) Detects the diameter of the syringe and automatically sets the liquid injection speed according to the detection.

In FIG. 2, the slider 18 is connected to the motor 2.
The sucker 25 is sent through the pressing portion 22 by being moved in the direction of the arrow a by a feed screw 29 rotated at 8. The above motor 28
is rotated at the set speed by controlling the motor control circuit 32 by the speed signal S _S output from the injection speed generation circuit 31 according to the injection speed set by the injection speed setting circuit 30. .

A linear potentiometer 33 is arranged parallel to the feed screw 29, and a contactor 34 provided on the slider 18 is in contact with this potentiometer 33. This potentiometer 33 therefore provides a signal Sp ₁ representing the position of the slider 18, that is, the position of the sucker 25.

This signal Sp ₁ is applied to a suction position detection circuit 35, which applies a suction position detection signal Sp ₂ to a three-minute-before-end detection circuit 36 and an injection end detection circuit 37. The detection circuit 36 calculates the time 3 minutes before the end of injection based on the signal Sp ₂ , the signal S _R representing the diameter of the syringe 24 obtained from the syringe diameter detector 21, and the signal S _S , and calculates the time 3 minutes before the end of injection. When the time is up, the signal _S3 is applied to the alarm signal generation circuit 38. In response to this, this circuit 38 outputs an alarm signal, and this alarm signal causes the display section 7 in FIG.
will be displayed to notify you that there are 3 minutes before the end. According to the above, regardless of the syringe diameter and injection speed, it is possible to always receive an alarm 3 minutes before the end.
The function of item (1) above can be achieved.

Next, the injection end detection circuit 37 outputs the signal S _R and the signal Sp ₂
Detects that the injection of liquid is completed based on
A signal S _E is applied to the alarm signal generation circuit 38. In response to this, this circuit 38 is connected to the control circuit 32.
Sends a stop signal S _ST to the motor 28.
will be stopped. According to the above, a constant injection amount can always be given to the patient regardless of the syringe diameter,
The function in item (2) above can be achieved. In addition, the injection end detection circuit 37 is prepared with reference voltages of sizes corresponding to, for example, A syringe, B syringe, and C syringe, as well as a signal representing the diameter of the syringe.
One of the reference voltages is selected by S _R , and the selected reference voltage is compared with the sucker position detection signal S _R , and the signal S _R exceeds the selected reference voltage. The configuration is such that the signal S _{E is output when the signal S E} is detected.

Next, the pressure sensor 39 that detects the fluid pressure within the syringe 24 is provided on the pressing portion 22 that presses the sucker 25 . A signal S _PR indicating pressure obtained from this pressure sensor 39 is applied to an initial value storage circuit 41 and a pressure conversion circuit 42 through an amplifier 40 .
The initial value storage circuit 41 stores the pressure value when liquid is not being injected at the time of stoppage, and the pressure value when injecting is subtracted from this initial pressure value in the subsequent pressure conversion circuit 42. Therefore, temperature drift, resistance of the syringe 24, etc. are offset. The pressure conversion circuit 42 also converts the pressure difference due to the difference in syringe diameter based on the signal S _R , calculates the pressure per unit area of liquid, and sends the signal S _PS to the comparison circuit 43. The comparison circuit 43 is supplied with reference values indicating pressure abnormality from a closed value generation circuit 44, an open value generation circuit 45, and an abnormal value generation circuit 46, and is compared with the signal S _PS . The above closing value is a standard value when the motor load becomes heavy, such as when a needle is jammed, and the above opening value is a standard value when the motor load is light, such as when a needle is pulled out, a tube is dislocated, etc. . Further, the above-mentioned abnormal value is a reference value when the load fluctuates rapidly. Note that these closed values, open values, and abnormal values are changed in accordance with the signal S _R.

The comparison circuit 43 detects each of the above abnormal conditions and sends the detection signal S _A to the alarm signal generation circuit 38.
Add to. This circuit 38 displays a message corresponding to the abnormal condition on the display section 6 of FIG. 1, and also sends a signal S _ST to stop the motor 28 . According to the above, the infusion state can be constantly monitored, and the function (3) above can be achieved.

Next, the comparison circuit 47 receives the signal S _R and identifies types of syringes with different syringe diameters. That is, voltages A, B, and C for identifying the A syringe, B syringe, and C syringe are compared with the signal S _R to output the identification signal S _D. The motor control circuit 32 controls the speed of the motor 28 based on this signal S _D and the injection speed set by the injection speed setting circuit 30. The signal S _D is applied to a storage circuit 48 and stored as the size of the syringe currently in use. The stored syringe size and signal S _R are applied to the syringe detection circuit 49 and compared. As a result, when the syringe 24 comes off or is mistakenly replaced with a syringe of another size, a detection signal S _C is output and added to the alarm signal generation circuit 38 . This provides an appropriate display and also stops the motor 28. According to the above, the diameter of the syringe is automatically detected to determine the speed of the motor 28, and
It is possible to detect incorrect attachment of a syringe, and the function of item (4) above can be achieved.

Note that the alarm signal generation circuit 38 outputs alarm signals having various contents, and it goes without saying that the display state of the warning by sound and light etc. may be changed depending on the contents. Further, each circuit in FIG. 2 can be constructed with a digital circuit, and furthermore, a pulse motor may be used as the motor 28.

Next, an embodiment of the pressure sensor 39 will be described with reference to FIG.

In FIG. 3, there is a frame 5 inside the slider 18.
0, and the pressing portion 22 made of Delrin resin or the like is provided in an opening 51 at one end of the frame 50 via a packing 52. This frame 5
0 is further provided with a plate spring 53 made of stainless steel or the like, and this plate spring 53 is provided with a pair of strain gauges 54 and 55. The above pressing part 2
A hard protrusion 56 is embedded in 2, and this protrusion 56
The tip of the plate spring 53 is in contact with approximately the center of the plate spring 53.

According to the above configuration, when the slider 18 moves in the direction of the arrow a and the pressing part 22 presses the sucker 25,
The protrusion 56 presses the leaf spring 53, and the amount of deflection is converted into voltage by the strain gauges 54, 55 to obtain the signal S _PR .

Next, an embodiment of the cylinder diameter detector 21 will be described with reference to FIG. 4.

In the figure, a pair of rotating arms 59, 60 each having a detector 57, 58 are supported at their lower portions by rotating shafts 61, 62. Gears 63 and 64 are fixed to the rotating shafts 61 and 62 in mesh with each other. These rotating arms 59,
60 is a pair of detectors 57 and 58 by a spring 65.
are biased toward each other. A magnet 66 is bonded to one end of one rotating arm 59, and a magnetic field detecting element 67 such as a Hall element is fixedly disposed adjacent to the magnet 66.

According to the above configuration, when the syringes 24 having different diameters are mounted on the syringe mounting portion 4 as shown by the phantom lines, the detectors 57 and 58 come into contact with both sides of the syringe 24 as shown by the phantom lines. That is, arm 5
The rotation angles of the magnets 9 and 60 differ depending on the diameter of the syringe, thereby changing the position of the magnet 66 relative to the detection element 67, and the detection element 67 outputs a voltage according to the diameter of the syringe as the signal S _R. Output. Figure 5 shows the output characteristics of the Hall element. Linear characteristics are obtained in the range of S, for example A,
The output shown is obtained for each syringe B and C.

As described above, the present invention provides an apparatus that performs infusion by pressing and moving the sucker 25 of the syringe pump 26 with the slider 18. a first detection means for detecting the sucker position, which includes a contact 34 provided on the slider and in contact with the potentiometer; and a first detection means provided on the slider for detecting the contact pressure between the slider and the sucker; The second detection means 39
and a third detection means 21 for detecting the diameter of the syringe.
and the contact pressure S _PR detected by the second detection means
and a first reference value 44, and when the contact pressure becomes larger than the first reference value, a first abnormal signal S _A is output, and the first reference value is set to the third detection value. a fourth detection means 4 configured to be changed according to the diameter S _R of the syringe detected by the means;
4, 43, the contact pressure detected by the second detection means and the second reference value 45 are compared, and when the contact pressure becomes smaller than the second reference value, a second abnormal signal S is generated. A fifth detection means 4 configured to output _A and change the first reference value according to the diameter of the syringe detected by the third detection means.
3, 45, a sixth detection means 37 for detecting the completion of the infusion based on the detection signals SP1, S _R obtained from the first and third detection means, and the first and second detection means 37; This invention relates to an infusion device comprising means 38 and 32 for stopping the infusion when an abnormal signal is output. Therefore, according to the present invention, since the end of infusion is automatically detected according to the diameter of the syringe used, the set injection amount can always be ensured regardless of the diameter of the syringe. Regardless of the diameter of the syringe used with this, abnormalities such as needle jams, needles coming out, and tube displacements can be reliably detected to ensure safety.

[Brief explanation of the drawing]

1 to 5 show an embodiment of the present invention, in which FIG. 1 is an external perspective view of the infusion device, FIG. 2 is a block diagram of the drive device, and FIG. 3 is a cross-sectional side view of the main part of the pressure sensor. FIG. 4 is a cross-sectional front view of the main part of the syringe diameter detector, and FIG. 5 is an output characteristic diagram of the Hall element. In addition, in the symbols used in the drawings, 1...
... Infusion device, 18 ... Slider, 21 ... Syringe diameter detector, 22 ... Pressing part, 24 ... Syringe, 25 ... Suction cup, 26 ... Pump, 33 ... Linear potentiometer, 34 ... Contact, 35...
. . . suction position detection circuit, 37 . . . injection end detection circuit.

Claims (1)

[Scope of Claim for Utility Model Registration] In a device that performs infusion by pressing and moving the sucker of a syringe pump with a slider, the device comprises: a potentiometer extending in the direction of movement of the slider; a first detection means for detecting the sucker position, which is constituted by a contactor that contacts the potentiometer; and a second detection means provided on the slider and detecting the contact pressure between the slider and the sucker. and a third detection means for detecting the diameter of the syringe, and a contact pressure detected by the second detection means and a first detection means.
, and outputs a first abnormal signal when the contact pressure becomes larger than the first reference value, and the first reference value is detected by the third detection means. a fourth detection means configured to be changed according to the diameter of the second detection means; and a fourth detection means configured to change the contact pressure detected by the second detection means
, and outputs a second abnormal signal when the contact pressure becomes smaller than the second reference value, and the second reference value is detected by the third detection means. a fifth detection means configured to be changed according to the diameter of the infusion; and a sixth detection means configured to detect that the injection of the infusion is completed based on the detection signals obtained from the first and third detection means. An infusion device comprising: a detection means; and a means for stopping the infusion when the first and second abnormality signals are output.