JPH02286174A - Controller for flow of intravenous drip injection - Google Patents

Abstract

PURPOSE:To set the flow of fluid therapy suitable for a patient by composing a controller for flow of intravenous drip injection of a clamp to press, open a fluid therapy tube, to close and circulate the fluid therapy and a control means to transmit an opening signal which open the clamp for a time determined corresponding to the quantity of the intravenous drip based on the signal of an intravenous drip sensor. CONSTITUTION:An activation part 15 drops an intravenous drip 3a at first and when the first drop is started, the number of the intravenous drips with the continuous flow is dropped corresponding to the time width of a time pulse signal (e). When the number of the intravenous drips is extremely small, the time pulse is made short corresponding to such a state and the accuracy of the flow is lowered by the delay of a time to open a clamp 51. Accordingly, in order to avoid such a state, the signal of a detection part 11 is counted and a frequency is divided so that a count value can be a set value. Then, when the count value achieves the set number, the time pulse is transmitted. Thus, even when the number of the intravenous drips is small, the quantity of the fluid therapy can be adjusted with a sufficiently high accuracy.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an infusion flow rate control device for controlling an infusion flow rate in an infusion set.

The Birai infusion set is used to inject medicinal solutions into the human body, and is usually constructed as shown in FIG. In FIG. 3, 1 is an infusion bottle containing an infusion 1a and sealed with a stopper 1b, and the infusion set includes the infusion bottle 1, an introduction needle 2, a drip tube 3. Infusion tube 4° clamp 5, rubber tube 6. Octopus tube 7
and an infusion needle 8, each of which is connected in cascade. The infusion bottle 1 is suspended on a stand (not shown) and the infusion solution 1a is
A predetermined water head is given to the The introducer needle 2 passes through the stopper 1b and communicates with the infusion, and at the same time an air displacement needle (not shown) is inserted into the stopper 1b.
By injecting the liquid into the infusion tube 3, the liquid drips into the infusion tube 3 and flows down the infusion tube 4 as a continuous flow. The infusion tube 4 is inserted between the fixed clamp 5C of the clamp 5 and the roller 5b, and as the axis of the roller 5b moves up and down along the inclined groove 5a, it is pressed between the fixed clamp 5C and the roller 5b, and the infusion is pumped from the sealed state to the maximum. Send liquid to any flow rate equivalent to the opening area during the open state! ! ! Adjust. The infusion needle 8 is inserted into a vein and the fluid is delivered to the human body. The octopus tube 7 is for preventing air from flowing into the vein, and the air contained in the infusion is stored in the air reservoir 7a and is prevented from flowing out into the infusion needle 8. The rubber tube 6 is feeding liquid,
It serves as a flexible tube for stably holding the infusion needle 8 in the human body.

The amount of liquid delivered in the above-mentioned infusion set is a flow rate that is inversely proportional to the head difference between the head of the infusion 1a and the venous pressure and the flow path resistance of the infusion tube 4 and the like. Since the volume of the drip is constant,
When the flow rate is high, the number of infusions per unit time is large, and even the flow is continuous, but the flow rate of infusion fluid delivered to the human body is determined by the number of infusions per unit time, and the clamp is adjusted to maintain this number of infusions. 5 to adjust the flow path resistance. However, since the infusion flow rate varies depending on the water head of the infusion, the patient's venous pressure, posture, etc., the nurse has to adjust the roller 5b of the clamp 5 as appropriate to correct the infusion flow rate, which is complicated. For this reason, a technology has been proposed in which the opening area of the infusion tube is changed by detecting infusions and controlling a movable clamp (not shown) corresponding to the roller 5b of the clamp 5 so that the number of infusions per infusion becomes a set number. .

However, as mentioned above, in the conventional technology that sets the number of infusions per unit time and presses and controls the infusion tube so that the infusion reaches the set value, Since the flow rate is determined based on the number of infusions, there is a problem in accuracy in that the set infusion flow rate cannot have a resolution higher than the volume of the infusion. In addition, although the infusion tube 4 is flexible, it is not a perfect elastic body and has internal friction, so hysteresis tends to occur during the pressing operation, causing problems such as oscillation during the closed-loop control operation that drives the movable clamp. There was a point.

The second aspect of the present invention has been made in view of the above-mentioned problems, and it is possible to set an arbitrary time that is continuously determined based on a time that is determined corresponding to the flow rate of the drip, Open the clamp with a time width equal to this time to send the infusion, and set the infusion flow rate to the amount corresponding to the set time ○N 0FFffiiv4
Using simple and inexpensive 0N-OFF control,
The purpose of this device is to provide an infusion flow rate control device that delivers a continuous infusion flow rate with high precision. a tube, an infusion needle for injecting the infusion fluid flowing out from the infusion tube into the living body through the infusion tube, and a clamp that is interposed in the infusion tube and presses and opens the infusion tube to close and distribute the infusion fluid. , of the drip sensor (i
The present invention provides an intravenous drip flow rate control device comprising: control means for transmitting a release signal to open the clamp for a predetermined time according to the amount of liquid in the intravenous drip.

Figure 1 is a block diagram showing the operation of the present invention, and the components of the infusion set in the figure that are not related to the present invention are given the same reference numerals as in the prior art shown in Figure 3. I will omit the explanation. Reference numeral 31 denotes a drip tube of the present invention; 1; a light projecting section 16 that projects light from a light source (not shown); and a light receiving section 31 that receives light from a change in scene caused by blocking the light projected from the light projecting section 16 with a liquid $3a; The light is received by the part 17, and the part 16
a and 17a are light guides constituting the light projecting section 16 and the light receiving section] and 7, respectively, and the drip tube 31, the light projecting section 16, and the light receiving section 17 are integrally constructed. Reference numeral 11 denotes a detector that detects the drip as a change in the amount of light from the optical signal transmitted from the light receiving section 17 and outputs it as a pulse signal having a time width during which the drip 3a communicates with the light receiving section 17. Reference numeral 13 denotes a time pulse oscillator, which emits a pulse voltage e having a time width set by the time setter 12, and is activated by a rising signal from the detector 11. The time width from the time pulse generator 13 is determined based on the amount of droplet of the drip 38.

14 is a drive circuit that drives the clamp 51 based on the time pulse signal, and the clamp 51 is driven based on the drive signal f.
When rotated by a predetermined rotation, for example, half a rotation.

A position detection signal g of the clamp 51 is transmitted, and the drive circuit 4 is stopped by the position detection signal g. The clamp 51 is connected to the infusion tube 4 at a time driven by a time pulse signal e.
is opened and the liquid is delivered to the infusion needle 8. The clamp 51 is closed during the period when the time pulse signal e is not transmitted. 15 activates the time pulse generator 13 and opens the clamp 51 in order to drip the first drip 3a.

FIG. 2 shows an example of the clamp 51. (a) is a side view showing how the infusion tube 4 is released from pressure to infuse the infusion, and (b) is a side view when the infusion tube 4 is pressed to stop the infusion. show. In the figure, 511 is a base, and near the end of the base 511 side plates 511a and 511b are integrally formed in parallel. 512 is a motor with a built-in reduction gear and is capable of generating sufficient torque. 513 is an eccentric cam, and the eccentric cam 513 is connected to the motor shaft 51 as shown in FIG.
2a and is fixed with screws 513a. The other end of the motor shaft 512a is rotatably supported by a side plate 511b. Reference numeral 516 denotes a detection disk for detecting the rotational position of the cam 513, which is fixed to the end of the motor shaft 512a.A transmitting magnet (not shown) is embedded in the diametrically outer circumference of the sensor 515. Detected by 514 is a leaf spring,
The leaf spring 514 has trapezoidal side surfaces, openings 514a and 514b are bored in the center side, and is screwed onto the base 511 through a screw hole 514d, as shown in the perspective view of FIG. The central portion 514c is a flat plate that is in contact with the cam 513.

The infusion tube 4 is sandwiched between the base 511 and the leaf spring 514 in parallel with the motor 512 by side plates 511a and 511.
It is inserted through the through hole 511c of b. (c) The figure is
(a) This situation is shown in the AA arrow view of the figure. In addition, 51
2b and 512C are motor electrodes. (d) The figure is (,
) This is a cross section taken along line B-B in the figure, and shows the infusion tube 4 being opened upon input of the time pulse signal e and in the process of feeding liquid. The figure (e) shows the CC cross section of the figure (b), in which the infusion tube 4 is pressed via the leaf spring 514.

This indicates that the liquid supply is sealed. motor 5
12, that is, a detection signal g is transmitted from the sensor 515 every time the cam 513 makes a half rotation in the same radial direction.

Next, the operation based on the above configuration will be explained. Since the drip flow rate is determined for a specific infusion set, the clamp 51 is adjusted based on the time corresponding to this fluid volume.
to open. The number of drops of the infusion 3a depends on the water head of the infusion 1a, the human venous pressure in the infusion needle 8, and the infusion flow resistance including the infusion tube 4, but if these infusion conditions are kept constant, the number of drops depends on the time for opening the clamp 51. When attempting to double the number of infusions, the opening time of the clamp 51 may be doubled. Conversely, if the time pulse is halved, the number of infusions will also be halved.

The starting unit 15 is for first dripping the drip 3a, and when the first drip starts, the number of drips with a continuous flow rate is determined according to the time width of the time pulse signal e.If the number of drips to be dripped is extremely small, The time pulse also becomes shorter accordingly, and the flow rate accuracy decreases due to the delay in the opening time of the clamp 51. To avoid this, the signal from the detection unit 11 is counted and frequency-divided so that the count becomes the set value. By emitting a time pulse when the count value reaches a set number,
Even when the number of infusions is small, the amount of infusion can be adjusted with sufficiently high accuracy. Although the clamp 51 has been described above using the structure shown in FIG. 2, it is not limited to this, and any structure may be used as long as it can be opened and closed according to a set time.

As described above, according to the infusion flow rate control device of the present invention, in the past, the infusion flow rate was determined as the number of infusions per unit time, and only a discontinuous flow rate could be obtained with the infusion flow rate as a unit. To solve this problem, the infusion tube is turned on and off to -0FF depending on the amount of fluid in the IV drip.
It can be opened and closed, making it possible to set an infusion flow rate suitable for the patient's medical condition.

[Brief explanation of the drawing]

Fig. 1 is a principle block diagram of the infusion flow rate control device of the present invention, Fig. 2 is a diagram showing an embodiment of the clamp shown in the principle block diagram, and Fig. 3 is a diagram showing a basic infusion set. . 1... Infusion bottle, 2... Introducing needle, 3, 31... Drip tube, 4... Infusion tube, 5, 51... Clamp,
7... Octopus tube, 8... Infusion needle, 10... Control device.

Claims (1)

[Scope of Claims] 1. An infusion tube equipped with an infusion sensor that drips an infusion drawn from an infusion container and detects the dripped infusion, and injects the infusion flowing out from the infusion tube into a living body through an infusion tube. an infusion needle that dispenses liquid; a clamp that is interposed in the infusion tube and presses and opens the infusion tube to close and distribute the infusion;
An intravenous drip flow rate control device comprising: a control means for transmitting a release signal to open the clamp for a predetermined time period depending on the amount of liquid in the intravenous drip based on a signal from a drip sensor. 2. The drip flow rate control device according to claim 1, wherein the time determined according to the amount of dripped fluid is set according to the number of the plurality of drips. 3. The clamp that presses and releases the infusion tube includes an elongated substrate on which the infusion tube is placed in the longitudinal direction, an elastic thin plate whose end is fixed to the substrate and touches the infusion tube parallel to the substrate, and the elastic plate. 3. The drip flow rate control device according to claim 1, further comprising a motor that rotates an eccentric disk that presses and releases the infusion tube via the infusion tube.