JPS6241027B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a heparin injection device that is attached to an artificial dialysis machine that performs artificial dialysis of blood and continuously injects heparin into a blood circuit through which blood flows.

Conventionally, a pulse motor has been used in such heparin injection devices, but since the heparin injection flow rate is as low as about 1 to 5 c.c./hour, the driving pulse of the pulse motor is
A low repetition frequency of less than 1 pps was required. However, if a substantially direct current drive voltage is applied to the pulse motor in order to satisfy the drive pulse conditions, the power consumption in the pulse motor will increase and the amount of heat generated will be significantly large, and ultimately, not only the pulse motor but also the heparin This has the disadvantage that the functionality of the injection device is significantly reduced and reliability is lost. In addition, a light emitting diode (hereinafter referred to as "LED") is used in the heparin injection device to externally display the heparin injection status, but one of the four drive lines for the pulse motor is The LED is connected to and blinks, and the on/off period of the LED corresponds to the pulse width supplied to the drive line, for example, for each on/off period of 2 seconds or more. Therefore, if the amount of heparin injected is halved by driving the pulse motor,
Another drawback was that the on-off cycle of the LED doubled, reducing the blinking frequency by half, and it became difficult to recognize the state of heparin injection due to the blinking of the LED.

The present invention has been made in view of these drawbacks, and its object is to provide a heparin infusion device that is attached to an artificial dialysis machine that performs artificial dialysis of blood and continuously injects heparin into a blood circuit through which blood flows. It is an object of the present invention to provide a heparin injection device that improves reliability by eliminating all of the drawbacks of the invention and makes it easy to recognize the state of heparin injection.

The features of the present invention include a volume for setting the heparin injection flow rate to a desired value in a heparin injection device installed in an artificial dialysis machine, and a volume setting value that is A/D converted and then subjected to predetermined arithmetic processing. a programmable frequency divider that sets the frequency division data calculated by the programmable frequency divider; and a component that divides the first output signal of the programmable frequency divider by two to generate second to fifth output signals having different phases. a monostable multivibrator that receives the first output signal and generates a sixth output signal having a predetermined pulse width synchronized with the first output signal; A driver is provided which generates a signal for driving a pulse motor for heparin injection only during the period when the output signal is generated.

Hereinafter, the present invention will be described in detail using figures. FIG. 1 is a block circuit diagram of an embodiment of the present invention, in which 1 is a volume for setting the heparin injection flow rate to a desired value, 2 is an A/D converter, and 3
is the central processing unit (hereinafter referred to as "CPU"), and 4 is the central processing unit (hereinafter referred to as "CPU").
A programmable frequency divider whose frequency division data is set by the output signal of the CPU 3 and divides the clock output from the CPU 3 using the frequency division data; 5 is the output signal from the programmable frequency divider 4 (hereinafter referred to as " A frequency divider 6 receives the first signal and divides the frequency of the first signal by two to generate and output second to fifth signals having different phases. A monostable multivibrator 7 generates a sixth signal having a predetermined pulse width (for example, a pulse width of a short period τ) in synchronization with the first signal; 7 is the first to fourth AND circuits 7a to 7d and the first to A driver having fourth output transistors 7'a to 7'd, 8 a pulse motor for injecting heparin, 8a connected at one end to the collector of the first output transistor 7'a and at the other end to the second output transistor. A first excitation coil 8b is connected to the collector of the third output transistor 7'b, and a second excitation coil 8b has one end connected to the collector of the third output transistor 7'c and the other end connected to the collector of the fourth output transistor 7'd. coil,
9 has one end connected to the first and second excitation coils 8a, 8.
b, and the other end is connected to the collector of the third output transistor 7'c (or the collector of the fourth output transistor 7'd) via the resistor R and the diode _D2 (or _D1 ). This is an LED that is connected to the LED and emits light to indicate the status of heparin injection to the outside. Furthermore, the diode
D ₁ and D ₂ are connected not to the respective collectors of the third and fourth output transistors 7'c and 7'd, but to the respective collectors of the first and second output transistors 7'a and 7'b. may be used. Also, +
V is a drive power supply voltage for the pulse motor 8, and is, for example, 24V.

The operation of the embodiment of the present invention having the above configuration will be described below. FIG. 2 is a time chart for explaining the operation of the embodiment of the present invention. , OFF) state. Further, T is a long period time of about 1 second or more (for example, 2 seconds), and τ is a time indicating the short-term pulse width. In FIG. 1, Volume 1 can be set to any value between 0 and 5 c.c./hour for the heparin injection flow rate, and the heparin injection flow rate is set to a desired value by Volume 1. . The set value is converted into a digital quantity by the A/D converter 2, and then inputted to the CPU 3, where predetermined arithmetic processing is performed to obtain frequency-divided data corresponding to the desired value. The frequency division data is input and set to the programmable frequency divider 4 as an output signal of the CPU 3, and the clock signal (for example, several M) supplied from the CPU 3 to the programmable frequency divider 4 is set.
Hz) is also frequency-divided by the frequency division data, and the first waveform of about 1 pps, for example, as shown in the waveform diagram in Figure 2A.
A signal is now output from the programmable frequency divider 4. The first signal is input to the frequency divider 5 and
The frequency is divided and output from the frequency divider 5 as second to fifth signals having different phases as shown in the waveform diagrams shown in FIG. The first to fourth AND circuits 7a to 7d of
are input respectively. The first signal is also input to the monostable multivibrator 6, and in synchronization with the falling edge of the first signal, a sixth signal having a pulse width of, for example, a short period τ is input to the monostable multivibrator 6. 6 to the first in the driver 7
The signals are input to fourth AND circuits 7a to 7d, respectively.
Therefore, the first to fourth AND circuits 7a to 7d perform an AND operation on the second to fifth signals and the sixth signal, respectively, and only the periods indicated by diagonal lines in FIG. The first or second exciting coil 8a, 8b is excited, and the pulse motor 8 performs an advance operation only during that period. Also, the diode in Figure 1
By using D ₁ and D ₂ , the signals whose phases are inverted with each other, such as between the signals showing the respective waveforms in Figure 2 B and C, or between the signals showing the respective waveforms in Figure 2 D and E, can be OR operation is performed, and LED 9 in Figure 1 blinks (ON,
OFF). Furthermore, the short period τ mentioned above
The selection of is limited to the upper limit of the response frequency of the pulse motor 8, but considering the discrimination limit of the human visual acuity that can recognize the blinking of the LED 9, it is appropriate to select a frequency of several tens of milliseconds, and the above response is possible. The frequency is below the upper limit. Further, the value of the period τ can be changed in various ways within the range below the above upper limit.

According to the embodiment of the present invention as described in detail above, unlike the conventional method in which the pulse motor was driven by signals with waveforms as shown in FIG.
Since the configuration allows the pulse motor to advance only during the periods indicated by diagonal lines in Figures 7-8, power consumption in the pulse motor can be saved during periods other than the above-mentioned diagonally shaded periods, and ultimately the pulse motor and heparin injection device It has the advantage of improving reliability. Also, as is clear from comparing Figure 2 Ro~Ho and Figure 2F, in the case of blinking the LED 9 in Figure 1 with any signal in Figure 2 Ro~Ho (conventional method) Compared to the above, the LED 9 blinks four times more frequently in the embodiment of the present invention, which also has the advantage that it is much easier to recognize the heparin injection status than in the conventional case. Furthermore, embodiments of the present invention have the advantage that they can be applied to any device where the pulse motor moves very slowly and the holding torque of the pulse motor itself is not required.

[Brief explanation of the drawing]

Figure 1 is a block circuit diagram of an embodiment of the present invention, Figure 2 is a block circuit diagram of an embodiment of the present invention.
The figure is a time chart explaining the operation of the embodiment of the present invention. 1...Volume, 2...A/D converter, 3...
...CPU, 4...Programmable frequency divider, 5...
Frequency divider, 6... Monostable multivibrator, 7...
...Driver, 8...Pulse motor, 8a, 8b...
...Exciting coil, 9...LED.

Claims (1)

[Claims] 1 In a heparin injection device that is attached to an artificial dialysis machine that performs artificial dialysis of blood and continuously injects heparin into a blood circuit through which blood flows, there is a volume for setting the heparin injection flow rate to a desired value, and a volume setting value A for setting the heparin injection flow rate to a desired value. A program frequency divider that sets frequency division data calculated by performing /D conversion and predetermined arithmetic processing, and a first output signal from the program frequency divider is divided by two and the respective phases are determined. a frequency divider that generates second to fifth output signals having different values;
a monostable multivibrator that receives the first output signal and generates a sixth output signal having a predetermined pulse width synchronized with the first output signal; and first to fourth ANDs.
and first to fourth output transistors connected in series to the AND circuits, respectively, and the second to fifth output transistors are connected to the first to fourth AND circuits, respectively.
receiving the output signal of the sixth output signal and the sixth output signal.
a dry bat that generates a signal for driving a pulse motor for heparin injection only during the period when the output signal is generated; and a dry bat that has one end connected to the first output transistor and the other end connected to the second output transistor. a second excitation coil having one end connected to the third output transistor and the other end connected to the fourth output transistor, and one end connected to the neutral point of each of the first and second excitation coils; A heparin injection device comprising a light emitting diode which is connected to the third or fourth output transistor and whose other end is connected to the third or fourth output transistor, and which blinks to externally display the state of heparin injection.