JPS628763A - Infusion apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an infusion device used in an automatic infusion device or the like.

[Conventional technology]

Conventionally, peristaltic finger pumps have been known as infusion devices used in automatic drip devices (for example, Japanese Patent Application Laid-Open No. 1983-1999).
No. 165868). This type of finger pump is configured to transfer a fixed amount of liquid by squeezing an elastic infusion tube in the liquid feeding direction by the movement of a large number of finger members. When the discharge side flow rate of a pump configured in this way is measured, a substantially trapezoidal discharge waveform and a substantially V-shaped backflow waveform that occurs when the finger member releases the pressure on the infusion tube are repeated ( (See Figure 6). As described above, in the conventional finger pump, since the discharge side flow rate is not constant, there is a problem in using it as an automatic drip infusion device.

From this point of view, various proposals have been made for making the discharge side flow rate constant in screw pumps for this type of use. For example, the point in time when the pushing body of a screw pump releases the completely occluded state of the infusion tube by rotational movement is detected, and based on this detection signal, the drive motor of the drive pump is operated at a higher speed than during steady rotation for a predetermined period of time. Rotate it with
An infusion device has been proposed that prevents backflow by replenishing the backflow from the suction side in a short period of time.
No. 463). However, when the infusion device according to the above proposal is used as a driving finger pump, as shown in FIG.
Therefore, the finger pump drive motor is rotated at a higher speed than during steady rotation.

Although it is true that the amount of time spent regurgitating has decreased,
Still, the discharge flow rate stops even temporarily, and this time cannot be ignored, especially when the pump is driven at a low speed, so this remains a problem as an automatic drip infusion device.

[Problem that the invention seeks to solve]

However, since automatic drip infusion devices are used for the purpose of injecting medicinal solutions into the patient's body, the pump discharge flow rate characteristics are such that accurate injection can be performed at a stable flow rate from a low flow rate range to a high flow rate range. required. In particular, when used for premature infants, critically ill patients, etc., stability of the flow rate in the low flow range is strongly desired. For example, in a peristaltic finger pump,
When the discharge side flow rate is measured, it has a substantially trapezoidal discharge waveform and a substantially ■-shaped backflow waveform that occurs when the finger member releases the suppression blockage of the infusion tube, and the flow rate characteristics are not constant. Therefore, in order to keep the discharge flow rate constant in this type of pump, the approximately trapezoidal discharge waveform described above is required.

It is necessary to perform pump drive control that can bring the flow rate increase region and flow rate decrease region closer to the set flow rate and also bring the backflow waveform closer to the set flow rate.

[Means for solving problems]

Therefore, in the present invention, as shown in FIG. 6, in the conventional smooth-acting finger pump, in the characteristics of the flow rate discharged from the infusion tube due to the spiral movement of the finger member, the flow rate is flat with a substantially trapezoidal discharge waveform. It was found that the point at which the flow rate changes from the region to the flow rate decreasing region (point P) almost coincides with the point at which the most downstream finger member starts pressing and closing the infusion tube, and from this point (point P), the next period begins. Stabilization of the discharge side flow rate characteristics is realized by driving the pump at a speed faster than the set speed in the section up to the point (point B) where the flow rate plateau of the substantially trapezoidal discharge waveform starts.

Therefore, the infusion device according to the present invention includes a pump portion configured to sequentially press and close the infusion tube with a plurality of peristaltic finger members to transfer liquid, and a finger member on the most downstream side of the pump portion to close the infusion tube. The present invention is characterized in that it includes a detection section that detects a time point at which a cut-off starts and generates a detection signal, and a drive control section that inputs the detection signal and drives the pump section to rotate at a higher speed than the set rotation speed in a predetermined period.

In the above-mentioned infusion device, the speed setting for driving the pump unit to rotate at a higher speed than the set rotation speed can be set to accelerate and decelerate in multiple stages, so that the actual discharge flow rate characteristic of the pump unit can be made approximately constant. .

Note that it is preferable that the point in time when the most downstream finger member of the pump section starts closing off the infusion tube is detected by a rotational position detector provided on the rotation shaft that drives the finger member.

[Effect]

In the present invention, by properly detecting the point at which the most downstream finger member of the pump section starts closing off the infusion tube, the drive control section, which operates based on this detection signal, issues a high-speed rotation drive command to the pump section. If done properly, it is possible to effectively prevent pulsations occurring in the flow rate characteristics on the discharge side of the infusion tube, and to obtain stable characteristics even in particular, minute flow characteristics. In addition, by adjusting the operating range and speed settings of the high-speed rotation drive according to the capacity of the pump and the amount of liquid delivered, it is easy to improve safety and performance when used as an automatic drip device. can be realized.

〔Example〕

Next, the actual 1ff of the infusion device according to the present invention! Examples will now be described in detail with reference to the accompanying drawings.

FIG. 1 is a system diagram showing one embodiment of the infusion device of the present invention. However, the infusion device of this embodiment has a pump part 1α,
It basically consists of a detection section 12 and a drive control section 14.

First, as the details of the pump section 10 are shown in FIGS. 2 to 4, the pump part 10 includes an elastic infusion tube 16 made of vinyl chloride, silicone, etc. A plurality of driven finger members 18 that sequentially close and open the finger members 1
8 and a fixing press plate 20 that fixes the other side of the infusion tube 16. The finger members 18 are held by a holder 22, and each finger member 18 has an elongated hole 24, and an eccentric cam 26 is positioned in the elongated hole 24. 2
By inserting and arranging the finger member 8, the finger member 18 is configured to generate the required drive. In this case, with respect to the adjacent upstream eccentric cam 26 fixed to the rotating shaft 28,
By configuring and arranging the device so as to have a delay angle of 360°/number of cams, the rotational movement of the eccentric cam 26 is converted into a linear movement of the finger member 18, and the liquid in the infusion tube 16 is transferred while being pressed. I can do it. One end of the rotating shaft 28 is connected to a pulse motor 3 via a transmission mechanism 30.
It is coupled to the drive shaft 34 of No. 2. On the other hand, a rotation detecting disk 36 is attached to the other end of the rotating shaft 28, and a rotation position detector 38 constituting the detecting section 12 is provided to this disk 36.

Infusion tube 1 of the pump section 10 configured in this way
6, a drug vial 42 is connected to the upstream side thereof via a drip barrel 40, and an injection needle 44 is connected to the downstream side thereof.

The detection unit 12 includes the rotational position detector 38 and the detection circuit 46.
It consists of The rotational position detector 38 is, for example, a photoelectric detection device consisting of a pair of light emitting diodes and a phototransistor for detecting a detection notch 48 (see FIG. 4) provided on a part of the outer periphery of the rotation detection circumferential circle ifi, 36. It can be composed of a container. The detection circuit 46 is configured to generate a predetermined operation signal based on the detection signal detected by the photoelectric detector. Further, this detection unit 12 detects a point E at one end of the detection notch 48 of the rotation detection disc 36, so that the finger member 18 on the most downstream side can detect the point at which the infusion tube 16 starts to close. (See Figure 5).

The drive control section 14 controls the rotation of the pulse motor 32 of the pump section 1o in the section where the signal detected by the detection section 12 is output at a higher speed than the steady rotation. For this reason, the drive control unit 14 includes a pulse oscillator 50,
It is composed of a frequency division switching circuit 52 and a pulse motor drive circuit 54. When there is no signal from the detection circuit 46, the frequency division switching circuit 52 divides the frequency of the signal supplied from the pulse oscillator 50 so that the rotation of the pulse motor 32 becomes steady rotation, and sends it to the pulse motor drive circuit 54. On the other hand, when there is a continuous signal from the detection circuit 46 (while the photoelectric detector 38 is sensing the detection notch 48), the frequency from the pulse oscillator 50 is divided so that the pulse motor 32 rotates at high speed. and is applied to the pulse motor drive circuit 54.

In this case, the point E at one end of the detection notch 48 of the disk 36 is set at a position equal to the point (point P) at which the flow rate flat area of the substantially trapezoidal discharge waveform transitions to the flow rate decreasing area. Further, the other end of the detection notch 48 is approximately equal to the point at which the flow rate plateau of the substantially trapezoidal discharge waveform of the next cycle starts.

Therefore, the actual ejection characteristics of the infusion device configured as described above is the curve shown in FIG. 8.

FIG. 10 is a system diagram showing another embodiment of the infusion device according to the present invention. The basic configuration of this embodiment is the same as that of the embodiment shown in FIG. Therefore, for convenience of explanation, the same reference numerals are given to the same components as in the embodiment shown in FIG. 1, and detailed explanation thereof will be omitted. That is, in FIG. 10, the detection section 12 includes two detection circuits 46a and 46b.
These first and second detection circuits 46a, 46b
As shown in FIG. 11, first and second rotational position detectors 3 are provided at a predetermined angle apart from the rotation detection disc 36.
8a and 33b. Therefore, for example, the first rotational position detector 3 connected to the first detection circuit 46a
8a is a photoelectric detector for detecting a detection hole 48a provided in a part of the outer circumference of the rotation detection disc 36, and a second rotation position detector connected to the second detection circuit 46b. Reference numeral 38b is a photoelectric detector for detecting 24 detection holes 48b provided in the rotation detection disk 36 at equal intervals slightly inner than the detection holes 48a.

However, in this embodiment, the first detection circuit 46
The point in time when a detects the detection hole 48a every rotation of the rotation detection disk 36 is set so that it coincides with the point in time when the most downstream finger member 18 starts closing the infusion tube 16 (point P).

On the other hand, the second detection circuit 46b detects one of the rotation detection discs 36.
The detection hole 48b is detected every /24 revolutions, and this detection signal is supplied to the frequency division switching circuit 52. Starting from the detection signal supplied from the first detection circuit 46a, the pulse oscillator 50 generates a signal for each input signal. The frequency of the supplied signal is divided and sent to the pulse motor drive circuit 54. In this case, the frequency division ratio in the frequency division switching circuit 52 is set based on the ejection waveform shown in FIG. 6, for example, as shown in FIG. 12.
The steady rotational speed of the pulse motor 32 is assumed to be 1, and a required speed multiplier is set for each divided section. In addition, the 12th
In the figure, the maximum speed indicates the maximum speed at which the pulse motor 32 can rotate. Therefore, the actual ejection characteristics of the infusion device configured as described above is the curve shown in FIG. 9. As is clear from FIG. 9, it can be seen that this embodiment is improved compared to the actual ejection characteristics (see FIG. 8) according to the embodiment shown in FIG. 1.

〔Effect of the invention〕

As is clear from the various embodiments described above, according to the present invention, the infusion tube is pressed and closed by a plurality of spiral finger members without deforming the envelope line at the distal end into a substantially sinusoidal shape, and the most downstream By increasing the drive speed of the pump section at the point when the finger member on the side begins to close the infusion tube, the required infusion fluid is replenished from the suction side, thereby effectively preventing the occurrence of pulsation in the flow rate on the discharge side of the pump section. I can do it. Further, by changing the speed in multiple stages in a required high-speed rotation section, the actual discharge flow rate characteristics can be further stabilized.

In particular, compared to conventional devices, the infusion device of the present invention exhibits the above-mentioned stable pump characteristics when performing microinfusions by driving the pump section at low speed, so it is extremely suitable for use as an automatic infusion device. It is for government use.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. For example, in the case of a single detection circuit, the frequency division switching circuit is operated to set the frequency division ratio to Within the scope of the spirit of the present invention, it is possible to set the signal to be converted in multiple stages, or to arbitrarily set the number of division intervals for switching the frequency division ratio even when multiple detection circuits are provided. Of course, various design changes can be made.

[Brief explanation of drawings]

FIG. 1 is a system diagram showing an embodiment of the infusion device according to the present invention, FIGS. 2 to 4 show the configuration of the pump section in FIG. 1, and FIG. 2 is a partially sectional side view. Figure 13 is a sectional view of the main part taken along line m-m in Fig. 2, Fig. 4 is a side view of the main part seen from the ■ direction in Fig. 2, and Fig. 5 is a section V in Fig. 2. , FIGS. 6 and 7 are waveform diagrams showing the infusion characteristics of the conventional device, FIGS. 8 and 9 are waveform diagrams showing the infusion characteristics of the inventive device, and FIG. 10 is a waveform diagram showing the infusion characteristics of the inventive device. A system diagram showing another embodiment.
The figure is a waveform diagram showing a speed magnification set for each divided section by dividing one period of the ejection waveform in the apparatus shown in FIG. 10 into a plurality of sections. io,,, pump section 12. ,,detection section 14,,
, drive control section 16. ,, Infusion tube 1B, ,,
Finger member 20. ,,Fixed presser plate 22),,Holder 24. ,,long 26,,,eccentric cam
2B, Rotating shaft 30, Transmission mechanism 32.
,,pulse motor 34,,,drive shaft 36. ,
, rotation detection disc 38, , rotation position detector 40. ,
, drip barrel 42), medicine bottle 44. ,,syringe needle 46,,detection circuit 48. ,,detection notch 50,
,,pulse oscillator 52. , , frequency division switching circuit 54 , ,
, pulse motor drive circuit IGi FIG, 5 FIG, 6

Claims (3)

[Claims] (1) A pump section configured to sequentially press and close an infusion tube with a plurality of peristaltic finger members to send fluid;
A detection unit that detects the start point of closing of the infusion tube by the finger member on the most downstream side of the pump unit and generates a detection signal; and a detection unit that inputs the detection signal to drive the pump unit to rotate at a higher speed than the set rotation speed for a predetermined period. An infusion device characterized by comprising a drive control section that performs the following steps. (2) In the infusion device according to claim 1,
An infusion device in which the speed is set to accelerate and decelerate in multiple stages in order to drive the pump part to rotate at a higher speed than the set rotation speed. (3) In the infusion device according to claim 1,
An infusion device in which the point at which the most downstream finger member of the pump section starts closing off the infusion tube is detected by a rotational position detector provided with respect to a rotating shaft that drives the finger member.