JPS6132021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an infusion pump used to continuously infuse a human body or the like for a predetermined period of time.

Today, in the medical field, various types of infusion pumps are used for administration of drug solutions, extracorporeal circulation, perfusion experiments on animals for various research purposes, and the like.
However, most of these types of pumps have a constant flow rate, so in order to bring the infusion pattern closer to the hemodynamics of the living body, pulsatile infusions are used especially for extracorporeal circulation in cardiac surgery and perfusion of medicinal solutions in organ preservation. There is a growing demand for pumps with patterns.

Conventional infusion pumps with a pulsatile infusion pattern have been of the plunger type or diaphragm type, but these types of pumps have the disadvantage that the pump mechanism limits the infusion pattern and lacks versatility. There is.

The applicant has already developed a micro-liquid delivery system consisting of a pump section in which an elastic tube is wound around a rotating body having a plurality of concentrically arranged rollers, and a pulse motor for rotationally driving the rotating body. We developed a pump and filed a patent application as Japanese Patent Application No. 52-39034 (Japanese Unexamined Patent Publication No. 124306/1983). However, in the pump according to the invention, the liquid feeding amount control signal is converted into a pulse train having a frequency proportional to the signal, and the obtained pulses are converted into a pulse train necessary for driving the pulse motor. As a result of further research and improvement, the inventors were able to achieve the desired speed by driving the pulse motor in a rotation mode consisting of adjustable acceleration, constant speed, deceleration, and rest. We found that the pump can be operated with a pulsatile infusion pattern.

Therefore, an object of the present invention is to be able to programmably set a pulsatile infusion pattern to match the circulatory dynamics of the living body, and to control the pump drive motor with high precision based on the set infusion pattern. To provide an infusion pump that can be automatically controlled.

In order to achieve the above object, the present invention includes a pump section configured by winding an elastic tube around a rotating body having a plurality of rollers, and a pulse motor for rotationally driving the rotating body. ,
A control circuit is provided that adjustably drives the pulse motor in a rotation mode that approximates the circulatory dynamics of a living body, consisting of accelerated rotation, constant speed rotation, decelerated rotation, and rest,
It is characterized by being configured to perform pump operation with an adjustable pulsatile infusion pattern.

In the infusion pump described above, the control circuit includes:
An oscillator that sets the acceleration, constant speed, and deceleration times, an oscillator that sets the rotation mode cycle, a status counter that commands the operation of each oscillator, and also commands addition or subtraction operations to the addition/subtraction counter, and a status counter command. an addition/subtraction counter that adds or subtracts the signal from the oscillator; a frequency converter that converts the contents of the addition/subtraction counter into a pulse signal having a frequency proportional to the content; and a frequency converter that generates a pulse that determines the start timing of each rotation mode and the pulse. It can be constructed from a plurality of monostable multivibrators that input the signal to the state counter via an OR gate, and a pulse motor drive circuit that controls the drive of the pulse motor based on the output pulse signal of the frequency converter.

The control circuit also includes a voltage waveform generation circuit that adjustably generates a voltage waveform that sets the rotation mode consisting of acceleration, constant speed, deceleration, and rest, and converts the output voltage of this voltage waveform generation circuit into a frequency proportional to the voltage waveform. a frequency converter that converts the output frequency of the voltage-frequency converter into a pulse signal having a frequency proportional to the output frequency of the voltage-frequency converter; and a drive control of the pulse motor based on the output pulse signal of the frequency converter. It can also be constructed from a pulse motor drive circuit that performs the following.

Next, embodiments of the infusion pump according to the present invention will be described in detail below with reference to the accompanying drawings.

The infusion pump according to the present invention basically includes a pump section, a motor for driving the pump section, and a control circuit for rotationally driving the motor. A tube type pump in which an elastic tube is wound around a rotating body having a plurality of rollers is preferably used as the pump part, and a pulse motor is used as the motor to drive the rotating body of the pump part. It is suitable if

Next, the control circuit of the infusion pump of the present invention configured as described above will be explained. In FIG. 1, reference numerals 10, 12, and 14 each indicate an oscillator that determines the rotation mode of the pulse motor 16, that is, the infusion pattern of the infusion pump, 10 is an oscillator for controlling accelerated rotation, and 12 is an oscillator for controlling constant speed rotation. The oscillator 14 is an oscillator for controlling deceleration rotation, and these oscillators control the rotational drive of the pulse motor by dividing it into three regions: accelerated rotation, constant speed rotation, and deceleration rotation, and by adjusting the time of each region, The rotation mode can be set arbitrarily. Note that reference numeral 18 is an oscillator that determines the period of the infusion pattern, and 20 is an oscillator that determines the maximum amount of infusion.

First, in the initial state, the frequency dividers 22 and 24
, flip-flop 26, and status counter 28
and addition/subtraction counter 30 have all been reset. Therefore, the output of flip-flop 26 will be at a low potential and oscillators 18 and 20 will not operate.
Further, the outputs Q ₁ to _{Q 4} of the state counter 28 are all at low potential, and the oscillators 10, 12, and 14 do not operate. Further, the output D of the addition/subtraction counter 30 also becomes a low potential, the pulse motor 16 is not driven, and no pump operation is performed.

Next, when the start signal A is applied, the monostable multivibrator 32 is activated, and this output signal is
It is input as a clock to the state counter 28 through the OR gate 34 and increments the contents of the state counter 28 by one. That is, in this case, only the output _Q1 of the state counter 28 is set to a high potential. Also, the start signal A sets the flip-flop 26,
As a result, the output of flip-flop 26 goes high, activating oscillators 18 and 20.

When the output _Q1 of the status counter 28 becomes a high potential, the oscillator 10 starts operating, and the U/D input of the addition/subtraction counter 30 becomes a high potential.
The addition/subtraction counter 30 enters the addition mode and performs an addition operation in response to the signal from the oscillator 10 inputted through the OR gate 36, and continues until the content reaches the maximum. The output D of the addition/subtraction counter 30 is input to the frequency converter 38.
The oscillation frequency of the infusion amount setting oscillator 20 is converted into a pulse signal having a frequency proportional to the output D. Here, since the output D of the addition/subtraction counter 30 increases with time, the frequency converter 3
The output frequency of 8 also increases with time. Therefore,
The pulse signal increasing in this manner is input to a pulse motor drive circuit composed of a frequency smoother 40, a pulse motor drive logic circuit 42, and an amplifier circuit 44, and causes the pulse motor 16 to rotate at an accelerated rate.
The above circuit operation is the accelerated rotation mode.

When the content of addition/subtraction counter 30 reaches a maximum, counter 30 generates a carry signal C to activate monostable multivibrator 46, whose output signal is clocked to state counter 28 via OR gate 34. is input, and the contents of the state counter 28 are incremented by one. That is, in this case, the output Q ₂ of the state counter 28
is set to high potential. As a result, oscillator 1
2 is activated. The output signal of the oscillator 12 is sent to the frequency divider 2
After one cycle, the output signal is input to the monostable multivibrator 48 through the OR gate 34 to actuate it, and this output signal is input as a clock to the state counter 28 through the OR gate 34 to increment the contents of the state counter 28 by one. During this one cycle, the addition/subtraction counter 30 does not operate and its contents remain at the maximum value, so the pulse signal input to the pulse motor drive circuit via the frequency converter 38 does not change, so the pulse motor 16 rotation does not change. The above circuit operation is the constant speed rotation mode.

The state counter 28 receives the output signal from the frequency divider 22.
The status counter 28 advances by one.
Only the output _Q3 of is at high potential. This activates the oscillator 14, and the output signal of the oscillator 14 is OR
It is inputted as the clock to the addition/subtraction counter 30 via the gate 36. In this case, addition/subtraction counter 3
Since the 0 U/D input is at a low potential, the addition/subtraction counter 30 changes to subtraction mode. That is, the addition/subtraction counter 30 continues to subtract from its maximum value until it reaches zero. Therefore, the pulse signal input to the pulse motor drive circuit via the frequency converter 38 decreases in proportion to the contents of the addition/subtraction counter 30, so that the pulse motor 16 decelerates over time. The above circuit operation is the deceleration rotation mode.

As a result of the above-described operation, when the content of the addition/subtraction counter 30 becomes 0, the addition/subtraction counter 30 generates a carry output C to operate the monostable multivibrator 46, and the output signal of this monostable multivibrator 46 is passed through the OR gate 34. state counter 2
Go one step further with the contents of 8. That is, in this case, only the output _Q4 of the state counter 28 is set to a high potential. As a result, one cycle of operation of the entire circuit is completed, and the monostable multivibrator 50 is activated. Reset 30.

Therefore, the start of the next cycle's operation mode is performed by a timer consisting of the period setting oscillator 18 and the frequency divider 24. Therefore, when the timer is activated after a predetermined period of time has elapsed, the output from the frequency divider 24 activates the monostable multivibrator 54, and the output signal of the monostable multivibrator 54 is sent to the state counter 28 via the OR gate 34. Advance the content one step. That is, in this case, only the output _Q1 of the state counter 28 is set to a high potential. In this way, when the output _Q1 of the status counter 28 becomes a high potential, the circuit operation of the pulse motor resumes the aforementioned accelerated rotation mode.

Note that when the stop signal B is applied at any time during the circuit operation, the frequency dividing circuits 22, 24, flip-flop 26, status counter 28, and addition/subtraction counter 30 are all reset, and the driving of the pulse motor 16 can be stopped. can.

The pump characteristics of the pulse motor drive in each rotation mode of acceleration, constant speed, deceleration, and rest described above are
As shown in the figure. As is clear from FIG. 2, the accelerated rotation mode due to the operation of the accelerated rotation control oscillator 10 is
The maximum infusion volume Qmax continues for ₁ hour, and then the constant speed rotation mode is activated by the constant speed rotation control oscillator 12. After ₂ hours, the deceleration rotation mode is changed to t by the activation of the deceleration rotation control oscillator 14. Lasts for ₃ hours. Thereafter, the dormant state is maintained until the time T ₀ of one cycle set by the cycle setting oscillator 18 ends. Therefore, the period setting oscillator 18
When the operation enters the second period, the acceleration, constant speed,
Rotational modes of deceleration and rest are repeated.

According to the infusion pump equipped with the control circuit in this embodiment, the pulse motor adjusts each operation time t ₁ , t ₂ , t ₃ and period T for one cycle operation consisting of acceleration, constant speed, deceleration, and rest. This allows the pump to operate with an adjustable (programmable) pulsatile infusion pattern.
Therefore, adjustment of the times t ₁ , t ₂ , t ₃ and the period T ₀ is easily achieved by making only the oscillation frequency of the oscillator adjustable.

FIG. 3 is a circuit diagram showing another embodiment of the control circuit of the pump of the present invention. In this embodiment, an oscillator 20 and a frequency converter 38 determine the maximum infusion volume.
and a pulse motor drive circuit.
This is the same as the embodiment shown in the figure. However, in this embodiment, the rotation mode of the pulse motor consisting of acceleration, constant speed, deceleration, and rest is adjustable in the same way as in the previous embodiment, and the voltage waveform suitable for this rotation mode is generated by the voltage waveform generation circuit. 56, this output signal is supplied to a voltage-to-frequency converter 58 to convert it into a frequency proportional to the voltage, and this output frequency is inputted to the frequency converter 38 to convert the output signal into a frequency proportional to the output frequency. The signal is converted into a pulse signal having a certain frequency. With this configuration, adjustable (programmable) as shown in FIG.
Pump action can be achieved with a pulsatile infusion pattern.

In the infusion pump according to the present invention, the rotation mode of the pulse motor can be adjusted to include acceleration, constant speed, deceleration, and pause, making it easy to operate the pump with any pulsatile infusion pattern. can be achieved. Further, by making the maximum infusion volume and the repetition period of the rotation mode adjustable, more effective drive control as an infusion pump can be achieved.

Although the preferred embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and can be configured with various drive control circuits, and other modifications can be made without departing from the spirit of the present invention. Of course, various design changes can be made within the structure.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram showing an embodiment of the control circuit constituting the infusion pump according to the present invention, FIG. 2 is a waveform diagram of pump characteristics obtained by the circuit shown in FIG. 1, and FIG. FIG. 3 is a circuit diagram showing another embodiment of the control circuit of the pump of the present invention. 10... Oscillator for acceleration rotation control, 12... Oscillator for constant speed rotation control, 14... Oscillator for deceleration rotation control,
16...Pulse motor, 18...Period setting oscillator,
20... Maximum infusion volume setting oscillator, 22, 24... Minute period, 26... Flip-flop, 28... Status counter, 30... Addition/subtraction counter, 32, 46, 4
8, 50, 54...monostable multivibrator, 3
4, 36, 52...OR gate, 38...frequency converter, 40...frequency smoother, 42...pulse motor drive logic circuit, 44...amplifier circuit, 56...voltage waveform generation circuit, 58...voltage-frequency converter.

Claims (1)

[Scope of Claims] 1. Consists of a pump section configured by winding and stretching an elastic tube around a rotating body having a plurality of rollers, and a pulse motor for rotationally driving the rotating body,
A control circuit is provided that adjustably drives the pulse motor in a rotation mode that approximates the circulatory dynamics of the main body, consisting of accelerated rotation, constant speed rotation, decelerated rotation, and rest,
An infusion pump configured to perform pump operation with an adjustable pulsatile infusion pattern. 2. The control circuit includes an oscillator that sets the acceleration, constant speed, and deceleration times, an oscillator that sets the rotation mode cycle, and a status counter that commands the operation of each oscillator and instructs the addition or subtraction operation to the addition/subtraction counter. , an addition/subtraction counter that adds or subtracts the signal from the oscillator according to commands from the state counter, a frequency converter that converts the contents of the addition/subtraction counter into a pulse signal having a frequency proportional to the content, and a pulse that determines the start timing of each rotation mode. It consists of a plurality of monostable multivibrators that generate pulses and input these pulses to the state counter via an OR gate, and a pulse motor drive circuit that controls the drive of the pulse motor based on the output pulse signal of the frequency converter. An infusion pump according to claim 1. 3. The control circuit includes a voltage waveform generation circuit that adjustably generates a voltage waveform that sets the rotation mode consisting of acceleration, constant speed, deceleration, and rest, and converts the output voltage of this voltage waveform generation circuit into a frequency proportional to the voltage waveform. a voltage-frequency converter; a frequency converter that converts the output frequency of the voltage-frequency converter into a pulse signal having a frequency proportional to the frequency converter; and a drive control of the pulse motor based on the output pulse signal of the frequency converter. 2. The infusion pump according to claim 1, comprising a pulse motor drive circuit that performs the following steps.