JP3378054B2 - Drive control method for peristaltic infusion pump - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drive stop control method of a peristaltic infusion pump for injecting a liquid to be transported stored in a liquid storage container. The present invention relates to a drive control method for a peristaltic infusion pump that infuses a nutrient solution or a drug solution stored in an infusion bag to administer the solution into a living body. [0002] For example, in the medical field, nutrient solutions,
In order to administer a parenteral liquid such as a drug solution or a saline solution into a living body, a medical infusion system for injecting such a liquid has been used. FIG. 12 shows an example of this infusion system, which includes an infusion bag 54 for storing a nutrient solution and the like, and an infusion pump 51 for infusing the nutrient solution and the like. As this infusion pump 51, as disclosed in Japanese Patent Publication No. 61-55,393, a peristaltic (peristaltic finger) infusion pump is known, and an infusion bag is provided in front of a main body 51a. A tube mounting portion 53 to which a flexible tube 55 connected to the like is mounted is provided. The tube mounting portion 53 is provided with a pump portion 57 for closing and injecting the liquid passing through the tube 55 by peristaltic movement of the finger so as to sequentially move the crushed position of the liquid feeding tube 53 and injecting the liquid. A door 52 opposite to 57 is attached to be openable and closable. A back plate 58 that presses the tube 55 with a predetermined pressure in a direction toward the pump unit 57 is provided on the door inner surface 52a facing the pump unit 57. A spring is provided between the back plate 58 and the door inner surface 52a to urge the back plate 58 toward the pump unit 57. The pump section 57 of the infusion pump 51 is driven by a stepping motor or the like. By controlling the rotation speed of this motor, the flow rate per unit time (for example, one hour) can be set within a predetermined range. It has become. Also, since the amount of infusion per rotation of the motor drive shaft is known in advance, by counting the number of rotations of the motor drive shaft, the integrated amount of infusion after starting the infusion is calculated. . Further, the infusion pump 51
Also has the function of setting the planned infusion volume. If the scheduled infusion volume and infusion flow rate are set, the infusion can be automatically performed for a long time (about 24 hours) while detecting with the infusion sensor 59. [0004] This type of infusion pump 51 incorporates an infusion amount monitoring device that indicates completion of infusion, and the conventional infusion amount monitoring device calculates by counting the number of rotations of a motor drive shaft. When the infusion integrated amount or the infusion integrated amount calculated by counting the number of drops of the drug solution or the like matches the preset infusion scheduled amount, the infusion is performed by turning on a lamp or emitting a buzzer sound. It indicates that it has been completed. [0005] However, when an infusion is performed for a long time or when a plurality of types of infusions are performed using a plurality of infusion pumps, the patient's noise due to the driving noise of the motor causes the patient to suffer from the noise. There is a problem that hinders the resting state. The present invention has been made to improve the above-mentioned problems of the conventional peristaltic infusion pump,
Drive control of peristaltic infusion pump with reduced noise during operation
An object of the present invention is to provide an METHODS. Means for Solving the Problems [0007] The present invention for achieving the above object provides a peristaltic infusion pump for transferring a drug solution in an infusion tube by sequentially pressing the infusion tube with a plurality of fingers. A drive control method, comprising the steps of: setting an infusion flow rate at an input unit; applying a pulse excited based on a start instruction input to a motor drive circuit to drive a peristaltic pump unit; and The predetermined time comprises a step of adding a voltage obtained by adding a predetermined amount to the predetermined voltage, and a step of performing infusion at an infusion flow rate by driving the peristaltic pump unit, so as to reduce noise during operation of the peristaltic pump unit. , So that the rotor moves less
When two-phase excitation to the motor drive circuit is performed
A drive control method of the peristaltic infusion pump, further comprising a step of performing control so as to perform three-phase excitation . The transported liquid stored in the liquid storage container is infused at a set infusion flow rate. Then, the noise during the operation of the infusion pump is reduced by the brake pulse generation circuit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a peristaltic infusion pump according to an embodiment will be described in detail with reference to the accompanying drawings. FIG. 1 shows a peristaltic infusion pump 1 according to the present invention.
FIG. Referring to FIG. 1, reference numeral 2 denotes an LED or the like for notifying an abnormality of the peristaltic infusion pump 1 or the like.
When air bubbles are detected in a tube (not shown) mounted on the peristaltic infusion pump 1 on the display section of the above, when blockage of the tube mounted on the peristaltic infusion pump 1 is detected, the peristaltic infusion pump is detected. 1. When the flow rate of the liquid in the tube attached to 1 is not within the predetermined set flow rate, when there is no liquid in the tube attached to the peristaltic infusion pump 1, the door 12 of the peristaltic infusion pump 1 is open. Alternatively, the display unit indicates an abnormality such as a case where the infusion is not completely closed, a case where the infusion is completed, and the like. These may be separately displayed on the display unit. Reference numeral 3 denotes a second display unit for digitally displaying an integrated amount of infusion, an infusion flow rate, an estimated infusion amount, and the like. The integrated amount is obtained by calculating the total infusion amount from the start of the infusion to the present time from the flow rate per unit time based on a table stored in advance and displaying the calculated amount. Reference numeral 4 denotes a changeover switch for switching between the display of the flow rate and the planned quantity on the second display unit 3;
Is an integration clear key for clearing the integration amount, and 6 is a key for setting the number of droplets. A reference numeral 7a designates a rough adjustment key (two digits) for setting an infusion flow rate (infusion time per unit time, for example, one hour) and an estimated infusion amount, and 7b sets an infusion flow rate and an estimated infusion amount. Fine adjustment key (single digit)
In the upper keys 7a and 7b, each digit is incremented by +10 and +1 each time the key is pressed, and in the lower keys 7a and 7b, each digit is incremented by -10 and -1 each time the key is pressed once. The flow rate setting is 7a,
When an input is made with the key 7b, a pulse having a pulse frequency corresponding to the set flow rate is given to the motor drive circuit, and the rotation speed of the motor drive shaft is controlled. 8
Is a power key. When the power source is a battery, an indication to that effect is displayed, and when the voltage drops below a predetermined value, it flashes.
9 is infused at a predetermined flow rate while the fast-forward key is pressed. Numeral 10 is a key for starting and stopping the infusion, which also has a function of a mute key for an alarm buzzer. Reference numeral 11 denotes a knob for opening and closing the door 12, and reference numeral 13 denotes a grip. The medical infusion system shown in FIG. 2 is used for injecting a drug solution (infusion agent) into a living body, performing automatic infusion, and the like, and includes an infusion bag 14 containing a drug solution. And a peristaltic infusion pump 1. The infusion bag 14 contains a nutrient solution, a drug solution,
A predetermined amount of a parenteral liquid (corresponding to a liquid to be transported) such as a physiological saline solution is filled and locked on an upper portion of a stand (not shown). A drip tube 21 is provided at the lower end of the infusion bag 14.
Is connected to one end of the flexible tube 15A. The drip tube 21 is provided with a droplet detection sensor 20 for detecting a drop of a drug solution or the like falling from the infusion bag 14. The droplet detection sensor 20 includes an optical sensor 22. The optical sensor 22 includes a light emitting element (for example, an infrared light L).
ED) 22a and light receiving element (eg, phototransistor)
22b, and is provided so that the light from the light emitting element 22a is blocked by the drop. Infusion bag 1
4, the light from the light emitting element 22a is blocked or passed by the dropped liquid as the chemical solution falls,
The light receiving element 22b outputs, for example, an off signal when receiving the light from the light emitting element 22a, and outputs an on signal that is equal to or less than a preset threshold value when the light is blocked by the droplet. By counting this ON signal, the number of drops of the chemical solution or the like is detected. In addition, the drip tube 21 is configured such that 15 drops
The number of drops per unit volume (for example, 1 cc) is predetermined, such as 1 cc for 19 drops, 1 cc for 19 drops, and 1 cc for 60 drops. Therefore, by counting the number of drops of the liquid medicine or the like, that is, the ON signal from the light receiving element 22b, and dividing this by the number of drops per unit volume, the infusion integrated amount can be calculated. This integrated amount is displayed on the second display unit. If the dropping of the drug solution or the like is not detected even after the lapse of a predetermined time, that is, if the ON signal from the light receiving element 22b is not detected during the predetermined time, it is determined that the drug solution or the like stored in the infusion bag 14 has run out. Can be determined. The infusion pump 1 is provided with a tube mounting portion 15 to which a flexible tube 15A connected to the infusion bag 14 or the like is mounted. The tube mounting portion 15 has a peristaltic pump portion 17 for moving a drug solution passing through the tube 15A.
And a door 12 facing the peristaltic pump unit 17 is attached so as to be openable and closable. As shown in FIG. 2, the door inner surface 12a facing the pump portion 17 is also provided.
Is provided with a back plate 18 that presses the tube 15A along the direction toward the peristaltic pump section 17. Between the back plate 18 and the door inner surface 12a, an urging member 20 such as a spring for urging an elastic force for pressing the back plate 18 toward the peristaltic pump unit 17 with a predetermined pressing force is attached. ing. Further, the peristaltic pump section 17 is covered with a waterproof sheet member to prevent the chemical solution from entering the peristaltic pump section 17. As shown in FIG. 3, the peristaltic pump section 17 includes a plurality of (for example, six) fingers 25 movable forward and backward with respect to the mounted tube 15A, and slidably move each of these fingers. And a casing 26 for holding. The casing 26 is composed of a pair of casing members 27 that are abutted against each other.
A holding groove 28 that slidably holds each finger 25 is formed in the shelf 6 in a shelf shape. In the casing 26, a support shaft 29 is rotatably mounted via a bearing 30, and a plurality of (for example, six) eccentric cams 31 are shifted on the support shaft 29 by a predetermined angle. Is fixed. Note that the support shaft 29 has a substantially D-shaped cross section in order to prevent a displacement from occurring with a timing pulley 60 described later due to rotation. Finger 25
Has a substantially plate-like shape, and has a cam hole 32 with which the eccentric cam 31 slides. The portion of the support shaft 29 fitted to the eccentric cam 31 may have an ordinary circular cross section other than the D-shaped cross section. As shown in FIG. 3, one end of the support shaft 29 protruding from the casing 26 is connected to a rotation driving unit including a timing pulley 60, a timing belt 61, a motor (not shown), and the like. When the motor is actuated to rotate the support shaft 29, each of the eccentric cams 31 fixed to the support shaft 29 with the phase shifted is provided on the inner peripheral surface of the cam hole 32 of the corresponding finger 25. It rotates while sliding. As a result of this cam action, each finger 25 starts moving forward from the upper part while sliding in the holding groove 28 as a tube pressing means.
The tube 15A is pressed against the back plate 18 to close the flow path of the tube 15A. Further, the finger 25 that has moved to the forward limit moves toward the backward limit as the support shaft 29 further rotates, and the blockage is released. In this way, by repeating the operation of sequentially moving the fingers 25 located above to the forward limit, the tube 15A
Is closed, ie, the closing point 15a sequentially moves downward along the longitudinal direction of the tube 18, so that the liquid in the tube 15A is infused from the suction side to the discharge side. Further, in order to prevent pulsation, the phase at which the lowermost finger 25 moves to the forward limit and the uppermost finger 25 starts to advance is advanced by a predetermined time using the encoder 47. This eliminates the need to provide a finger for pulsation correction. As is well known, the stepping motor can control the rotation speed of the motor drive shaft by controlling the pulse frequency of the pulse applied to the motor drive circuit. Therefore, the peristaltic pump unit 17 controls the frequency of the pulse applied to the stepping motor, so that the infusion rate per unit time is set within a predetermined range. The transport liquid amount integrating means 45 for integrating the amount of liquid infused by the infusion pump 1 is provided with a timing pulley 60 connected to the support shaft 29 as shown in FIGS.
And an optical sensor 48. The outer peripheral flange of the timing pulley 60 is an encoder 47 in which one slit 47a is formed. As shown in FIG. 5, the optical sensor 48 includes a light emitting element (for example, an infrared LED) 48a and a light receiving element (for example, a phototransistor) 48b, and is provided so that light from the light emitting element 48a passes through the slit 47a. ing. As described above, by forming the conventional encoder unit provided separately from the pulley integrally with the timing pulley 60, the outer dimensions of the infusion pump 1 can be reduced. Further, the center hole 60a of the pulley 60 into which the support shaft 29 is inserted is formed in a D-shape.
Is non-circular, no displacement (slip) occurs between the pulley 60 and the support shaft 29, and the rotation speed of the support shaft 29 can be accurately detected by the encoder 47.
It should be noted that the present invention does not hinder a pump having an encoder of another component. In addition, the shape and the like of the encoder are not limited to these. The drive of the motor is transmitted to the timing belt 61, the timing pulley 60 and the support shaft 29. When the encoder 47 rotates together with the timing pulley 60, light from the light emitting element 47a is blocked or passes through the slit 47a. The light receiving element 48b outputs, for example, an ON signal when receiving the light from the light emitting element 48a, and outputs an OFF signal when the light is blocked. By counting the ON signal, the number of rotations of the support shaft 29 is detected.
The infusion amount per rotation of the support shaft 29 is known in advance. Therefore, the rotation speed of the support shaft 29, that is, the light receiving element 48b
Is counted, and this signal is multiplied by the amount of infusion per rotation of the support shaft 29 to calculate the integrated amount of infusion. As described above, since the integrated amount of liquid infusion can be calculated based on the number of drops detected by the droplet detection sensor 20, the transport liquid amount integrating means 45 may be configured by the droplet detection sensor 20. The second display section 3 is preferably constituted by an LED or an LCD having seven segments. Alternatively, the LEDs may be arranged in a row, and a predetermined display may be indicated by turning on, off, or blinking the LEDs. Further, an error display can be performed using this segment. In addition, a buzzer may be provided in the time display section to indicate an infusion completion alarm or the like, and various alarms may be identified by making the buzzer sound an intermittent sound or a continuous sound. Further, the display unit 3 and the buzzer may be connected to a so-called nurse call system, and a predetermined display based on the calculation result may be displayed at the nurse center. Next, the operation of the infusion pump 1 will be described with reference to the flowcharts shown in FIGS. 1 and 6, and the block diagram shown in FIG. When the program starts, various variables are initialized, and the scheduled infusion volume Q is set by the setting keys 7a and 7b of the key input unit 77, which is stored in the storage unit 76 and is displayed on the first display unit. 3 is displayed (step S1). Next, the infusion flow rate V is set on the setting keys 7a and 7
b, and this is also stored in the storage unit 76 and displayed on the first display unit 3 (step S2). It is determined that input by double or triple pressing of keys other than the simultaneous pressing of the switching key 4 and the fine adjustment key 7b is invalid. In addition, the switching key can be input during the infusion operation, but interrupt processing is prohibited for the setting of the scheduled infusion amount Q and the setting of the infusion flow rate V. When the switch 10 is operated and the start of infusion is instructed by the output from the control unit 74 (S3), the buzzer / nurse call output unit 73 indicating the start of infusion sounds and the infusion flow rate V set in step S2. A pulse having a pulse frequency corresponding to is given to the motor drive circuit (S4),
The rotation speed of the motor drive shaft is controlled by the storage unit 76 and the control unit 74, and the peristaltic pump unit 17 is driven by the rotation of the motor 78 via the timing belt 61 to cause the tube 1 to rotate.
5A are sequentially pressed, and infusion is started from the infusion bag 14 at a desired infusion flow rate (S5). Normally, the drip signal from the drop sensor 22 is compared with a target drip interval (S6), and the control unit 74 controls the motor speed so that the drip interval corresponds to the set infusion flow rate V. I do. The various sensors 75 detect the air bubbles in the tube 15AA, detect the open state of the door, detect the voltage drop, and complete the infusion. If any of these occurs, the motor is immediately stopped, and the buzzer / nurse call is performed. 73, etc. (S7,
S8, S9). With respect to the motor drive circuit, the following measures have been taken. At the start of rotation of the motor, a predetermined time (for example, about 0.2 seconds) after the start of infusion is set in the low-speed range in the high-speed range to compensate for the torque reduction in the high-speed range (for example, 1000 pps or more) of the motor. To drive the motor so that the rotation is set at a high speed. In addition, a voltage obtained by adding a predetermined amount to a predetermined voltage is applied to the motor drive circuit for a predetermined time after the start of infusion. The optimum voltage corresponding to the set flow rate is changed stepwise and applied to the motor drive circuit for reducing noise and power consumption. To reduce noise, brake pulses are applied to the motor drive circuit as shown in FIG. 9A or 9B. The power supply 71 is a power supply for the whole peristaltic infusion pump, and may be a battery such as a nickel cadmium battery which can be charged from an external power supply. By using a rechargeable battery, automatic switching means is provided for power supply from the battery even in the case of a power failure or the like, so that safety is improved. Also, by using a DC battery for an automobile, it can be easily used as a power source even in an ambulance. Next, a normal rotation method in the case of two-phase excitation will be described with reference to FIGS. [0030] In step S _1, A phase and B 'phase is the point X of the rotor 70 of the by Figure 10 energized (·) is stationary at the position of. (Where B 'is the inverse phase B) Step S ₂ in A, B moves when excited rotor position. Similarly, as the process proceeds to steps S ₃ and S ₄ , the rotor also moves →, and if pulses are continuously applied as in S _{1 to} S ₄ , the rotor continues to rotate in synchronism therewith. The stepping motor rotates one step at a time according to the input pulse. The one-step response has a damped oscillation waveform as shown in FIG. When the frequency of the input pulse matches the natural frequency of the rotating system, a resonance phenomenon occurs. When resonance occurs, the noise and vibration of the motor itself increase, and when the amplitude exceeds the stable region, reverse rotation or misstep occurs. By inputting a pulse as shown in FIG. 9 to the motor in order to reduce noise and vibration, the pulse shown in FIG.
As described above, the amplitude of the damped vibration is reduced, and as a result, resonance and noise of the motor can be suppressed. Next, the operation will be described with reference to FIG. 9 as an example of a brake pulse. [0035] In step _{S 1 A, A ', B} ' ( where A 'is the inverse phase A) is in this case the rotor is a three-phase excitation at the same time to rest in the position of FIG. 10. Rotor moves from this state to the step S ₂ is followed by step S ₃ in →→
The rotor rotates like →→→→. In the case of a simple two-phase excitation as shown in FIG. 8, the moving angle rotates at a step angle unique to the motor as shown by →→→→ . Since the amount is reduced, the overshoot and undershoot described above are reduced, and the resonance is reduced. The above pulse train is merely an example, and the technique for reducing the resonance is not limited to this. Further, by controlling the voltage in synchronization with the control pulse, the motor resonance can be more effectively reduced. Further, this control pulse may be constituted by either hardware or software. When it is determined that the infusion integrated amount i has reached the scheduled infusion Q and the infusion is completed, an infusion completion alarm is issued. This infusion completion warning is also given to an operator or the like by turning on a lamp or emitting a buzzer sound. In the case where the liquid medicine or the like stored in the liquid container (infusion bag) 14 is exhausted during the infusion operation, the empty liquid display section of the first display section 2 is displayed, and the replacement operation of the infusion bag 14 is performed. Required by workers and others. In addition, each display unit 2
If you connect 3 or buzzer to the nurse call system,
Since various information and alarms associated with the infusion work can be collectively grasped at the nurse center, there is no need for the nurse to look in advance about the operating states of the plurality of infusion pumps. In the embodiment, an example is shown in which a motor excitation means for generating a brake pulse is applied to a peristaltic infusion pump. However, a roller pump having a plurality of rollers as a tube pressing means using a stepping motor may be used. Can be applied. As described above, according to the drive control method of the peristaltic infusion pump for transferring the medicinal solution in the infusion tube by sequentially pressing the infusion tube with the plurality of fingers according to the present invention, the infusion flow rate is input. Setting step, a pulse excited based on a start instruction input is given to a motor drive circuit, and a step of driving a peristaltic pump unit. a step of adding a voltage, by driving the peristaltic pump unit consists of a step of performing a transfusion in infusion rate, to reduce noise during operation of the peristaltic pump unit, the low
To the motor drive circuit so that the
A method for controlling the drive of a peristaltic infusion pump, characterized in that the method further comprises the step of performing a three-phase excitation at the same time when performing the phase excitation. When the infusion is performed or a plurality of types of infusions are performed using a plurality of infusion pumps, the driving sound of the motor does not disturb the patient's resting state.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a front view of a peristaltic infusion pump according to the present invention. FIG. 2 is a schematic configuration diagram showing an infusion system using a peristaltic infusion pump according to the present invention. FIG. 3 is a sectional view showing a pump section shown in FIG. 1; FIG. 4 is a perspective view showing a pump unit shown in FIG. 1; FIG. 5 is a perspective view showing an example of an infusion amount integrating means shown in FIG. 1; FIG. 6 is a flowchart showing an operation procedure of an infusion operation. FIG. 7 is a block diagram illustrating a processing circuit according to the present embodiment. FIG. 8 is a diagram showing two-phase normal excitation of the present embodiment. FIG. 9 is a diagram illustrating excitation of a two-phase brake pulse according to the present embodiment. FIG. 10 is a diagram illustrating a motor rotation operation of the present embodiment. FIG. 11 is a diagram illustrating a one-step response of the stepping motor according to the present embodiment. FIG. 12 is a schematic configuration diagram showing an example of a medical infusion system. [Description of Signs] 1, 51a Infusion pump (infusion means) 7a, 7b Setting keys 22, 59 Droplet detection sensors 14, 54 Infusion bag (supply source) 45 Infusion amount integrating means 74 CPU (control) Part)

Claims (1)

(57) Claims 1. A drive control method of a peristaltic infusion pump for transferring a drug solution in an infusion tube by sequentially pressing the infusion tube with a plurality of fingers, comprising: A step of setting the flow rate at the input unit; a step of applying a pulse excited based on the start instruction input to the motor drive circuit to drive the peristaltic pump unit; a step of adding a voltage was quantified addition, by driving the該蠕dynamic pump unit consists of a step of performing a transfusion in該輸fluid flow rate, to reduce noise during operation of該蠕dynamic pump unit, the rotor
To the motor drive circuit so that the amount of movement of
A method for controlling the drive of a peristaltic infusion pump, further comprising the step of performing a three-phase excitation at the same time when performing the phase excitation.