JPS6344389B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an infusion device for injecting various medicinal solutions, blood, etc. into a human body using a syringe-type infusion pump.

BACKGROUND ART Infusion devices that automatically perform infusion 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. The capacities of syringes used in such infusion devices are currently 1, 5, 10, 20, 30,
Available in 50ml and various types. These syringes have a limited length so that they can be held and used as a so-called syringe, so the diameter of the syringe is changed depending on the capacity. When the diameter of the syringe is changed in the above-mentioned infusion device, it is necessary to change the feeding speed of the syringe suction in order to inject the liquid at the same flow rate, but if this is done incorrectly, serious consequences may occur. become. for example
There is about twice the difference in inner diameter area between a 20ml syringe and a 50ml syringe, so if you accidentally set the suction speed of the 50ml syringe to the same as that of the 20ml syringe, the injection will be about twice as long. This is extremely dangerous. Such a situation is likely to occur, for example, when one syringe is replaced with a syringe of the wrong size after infusion has been completed. Measures also need to be taken in case the syringe comes off during infusion.

The present invention provides an infusion device for solving the above problems.

FIG. 1 shows the appearance of an infusion device 1 according to the present invention, in which a case 2 includes an operating section 3 and a pump mounting section 4.
and 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 five functions according to the 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.

(5) Detect when a syringe of the wrong size is attached or removed.

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. Therefore, from this potentiometer 33, a signal S _P1 representing the position of the slider 18, that is, the position of the sucker 25 is obtained.

This signal S _P1 is applied to a suction position detection circuit 35, which applies a suction position detection signal S _P2 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 S _P2 , 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 S _P2.
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.

Next, a pressure sensor 39 for detecting the fluid pressure inside 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 no liquid is 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 comparator circuit 43 is supplied with reference values indicating pressure abnormalities from a closed value generating circuit 44 and an open value generating circuit 45, and is compared with the signal S _PS . The above closing value is a reference value when the motor load becomes heavy, such as when a needle is jammed, and the above opening value is a reference value when the motor load becomes light, such as when a needle is pulled out or a tube is dislocated, etc. . 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 having different syringe diameters. That is, the signal S R is compared with the reference voltages A, B, and C for identifying the A syringe, the B syringe, and the C syringe, respectively, and _{an identification signal S D is} output. The motor control circuit 32 uses this signal S _D and the injection speed setting circuit 30.
The speed of the motor 28 is controlled based on the injection speed set in . The signal S _D is applied to a storage circuit 48 and stored as the size of the syringe currently in use. This memory circuit 48 stores and holds a reference voltage corresponding to the size of the syringe and applies this to the syringe detection circuit 49. As the reference voltage to be stored and held, a voltage substantially equal to the reference voltages A, B, and C is used. The syringe detection circuit 49 detects the reference voltage A or B stored above.
Or compare C with the above signal S _R. Now, for example, syringe A is being used and the memory circuit 48 is receiving the signal S _D
It is assumed that a reference voltage A is stored and held based on the reference voltage A, and this reference voltage A is applied to the syringe detection circuit 49. Assume that the syringe 24 is replaced in this state and, for example, syringe C is used. At this time, the signal S _R changes immediately, but since the memory circuit 48 holds the reference voltage A, the syringe detection circuit 49
can detect that syringe A has changed to syringe C. In this way, the syringe detection circuit 49 outputs a detection signal S _C and applies it to the alarm signal generation circuit 38 when the syringe 24 comes off or is mistakenly replaced with a syringe of another size. This provides an appropriate display and also stops the motor 28. According to the above, the diameter of the syringe is automatically detected and the motor 2
In addition to determining the speed of item 8, it is also possible to detect incorrect attachment of a syringe, and the functions of items 4 and 5 above can be achieved.

The alarm signal generating circuit 38 outputs alarm signals having various contents, and it goes without saying that the display state of the alarm by sound, 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 Delcalin resin or the like is provided in an opening 51 at one end of the frame 50 via a packing 52. This frame 50 further includes a plate spring 53 made of stainless steel or the like.
A pair of strain gauges 54 and 55 are provided on the leaf spring 53. A hard protrusion 56 is embedded in the pressing portion 22, and this protrusion 5
6 is in contact with substantially the center of the leaf 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 syringe diameter detector 21 will be described with reference to FIG.

In the figure, a pair of rotating arms 59, 60 each having a detector 57, 58 are fixed at their lower portions to rotating shafts 61, 62. Gears 63 and 64 are fixed to these 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 with respect to the detection element 67, and the detection element 67 outputs a voltage corresponding to the diameter of the syringe to the signal S _R Output as . Figure 5 shows the output characteristics of the Hall element, and linear characteristics are obtained in the range of S. For example,
The output shown is obtained for each syringe A, B, and C.

As described above, the present invention detects the syringe diameter and stores it, and also compares the stored syringe diameter with the currently detected syringe diameter. When a syringe of the wrong size is attached or a syringe falls off, this can be reliably detected, and the safety of infusion can be improved.

[Brief explanation of the drawing]

1 to 5 show embodiments of the present invention, in which FIG. 1 is an external perspective view of an infusion device, FIG. 2 is a block diagram of a drive device, and FIG. 3 is a sectional side view of essential parts of a 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, 18...Slider, 21...Syringe diameter detector, 22...Pushing part, 24...Syringe, 25...Suck, 26...Pump, 48...Storage circuit, 49...Syringe detection circuit .

Claims (1)

[Scope of Claims] 1. In a device that performs infusion by pressing and moving the sucker of a syringe pump with a slider, the device includes: a means for detecting the diameter of the syringe used; and a value detected by the detecting means. storage means; means for comparing the stored detection value with a current detection value obtained from the detection means and outputting a signal when the stored detection value differs from the current detection value; An infusion device characterized by being provided with.