JPH05113177A - Finger driving control device of vermicular type liquid transport pump - Google Patents

Abstract

PURPOSE:To suppress current loss in a motor to the minimum possible extent while avoiding step-out of the motor. CONSTITUTION:A plurality of fingers F1 to F8 are installed on the shaft 40 of a stepping motor 36 along axial direction with eccentric condition in which a phase is shifted little by little, and a packing plate 41 is arranged opposing to the fingers F1 to F8 group. A liquid transport tube 100 is set between the packing plate 41 and the fingers F1 to F8 group and liquid in the tube 100 is transported under pressure by a vermicular type pushing contraction of the liquid transport tube 100 by the fingers F1 to F8 group. The rotary phases of the fingers F1 to F8 group are detected by a motor rotational phase detecting circuit 37, and necessary enough driving current for coping with driving torque necessary for transport liquid under pressure by the fingers which push the tube 100 at present, is given to a stepping motor 36 by a necessary driving current selecting means (CPU 30) on the basis of the rotating phase detected by the circuit 37.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peristaltic infusion pump used as a drive source for an intravenous infusion device such as a drip, and more particularly to a drive control device for fingers in the infusion pump.

[0002]

2. Description of the Related Art FIG. 8 shows the structure of the main part of a conventional peristaltic infusion pump of this type.

In the figure, 36 is a stepping motor,
40 is a shaft of the stepping motor 36, C1 to C8
Is a first to an eighth eccentric cam F1 which is attached to the shaft 40 so as to be slightly out of phase with each other in the axial direction.
.About.F8 are first to eighth fingers attached to the eccentric cams C1 to C8, 41 is a backing plate which is arranged facing the first to eighth fingers F1 to F8 and has a built-in compression spring, and 100 is a finger. It is an infusion tube for infusion set between the F1 to F8 groups and the backing plate 41.

Along with the continuous rotation of the stepping motor 36, the first to eighth fingers F1 to F8 press the infusion tube 100 between the backing plate 41 and the infusion tube 100 sequentially from the top to the bottom to peristally squeeze. , Infusion tube 1
The infusion solution filled in 00 is pumped.

One rotation of the stepping motor 36 corresponds to one cycle of peristaltic infusion pressure feeding. In this one cycle, the driving torque of each finger F1 to F8 required for infusion fluid pressure feeding changes depending on the rotation phase. An example will be described below (see FIG. 2 of the embodiment for specific variations in the required torque).

The backing plate 41 constantly presses the infusion tube 100 with a built-in compression spring.
The maximum pressure is applied to the compression spring in the backing plate 41 when the backing plate 41 is pressed without inclination, that is, the eighth finger F8 and the first finger F1 at both axial ends simultaneously. It is when the infusion tube 100 is pressed. At this time, a large reaction force is applied to the eighth finger F8 and the first finger F1 from the backing plate 41, and a large torque is required to rotate the fingers F8 and F1 against this. For example, as shown in FIG. 9, the required torque is 3
It is 77 g · cm.

Next, a great pressure is applied to the backing plate 41 when the fourth finger F4 or the fifth finger F5 located in the center presses the infusion tube 100. When these fingers F4 and F5 press the infusion tube 100, the reaction force from the compression spring is slightly reduced due to the backing plate 41 being slightly inclined. Therefore, the torque required to rotate the fingers F4 and F5 is smaller than that in the above case.
The required torque is 272 g · cm and 266 g · cm.

Second, third, sixth or seventh finger F
When 2, F3, F6, and F7 press the infusion tube 100, the backing plate 41 tilts largely like a seesaw, so the reaction force from the compression spring is significantly reduced, and the torque required to rotate the finger is It gets smaller. The required torque for each is 151 gcm,
181 g · cm, 181 g · cm and 198 g · cm.

[0009]

As described above, in peristaltic liquid pressure feeding by a plurality of fingers F1 to F8 having different phases, the required torque fluctuates considerably within one cycle of the stepping motor 36. Nevertheless, in the conventional finger drive control device, the fingers F1 to
The drive torque generated by the stepping motor 36 is larger than the maximum torque required by the fingers (377 g · cm in the above example) to prevent the stepping motor 36 linked to F8 from being out of step. Is always large (400 g · cm in the above example),
A constant large drive current was constantly supplied to the stepping motor 36. Therefore, there is a problem that the drive current becomes excessive in the rotation phase where the required torque is small, resulting in a large power loss.

The present invention was devised in view of such circumstances, and it is necessary and sufficient to meet the required torque of each rotation phase as the drive current supplied to the motor while avoiding the step-out of the motor. By passing an electric current,
The purpose is to reduce the power loss in the motor as much as possible.

[0011]

According to the present invention, a plurality of fingers are mounted along an axial direction in an eccentric state in which a phase is gradually shifted on a shaft driven and rotated by a motor, and the fingers are arranged so as to face each other. An infusion tube is set between the backing plate and the finger group, and the finger group sequentially presses the infusion tube in peristaltic manner with the rotation of the motor to pump the infusion solution in the infusion tube. In a finger drive control device for a peristaltic infusion pump, rotational phase detecting means for detecting a rotational phase of the finger group, and a finger pressing an infusion tube corresponding to the detected rotational phase feeds the infusion liquid. A necessary drive current selecting means for selecting a necessary and sufficient drive current for supplying the drive torque necessary for It is characterized in that it comprises.

[0012]

The required drive current selecting means is necessary and sufficient for the fingers acting on the infusion tube corresponding to the rotation phase of the finger group detected by the rotation phase detecting means to generate the drive torque necessary for the infusion of liquid. Since the drive current is given to the motor, power loss in the motor can be reduced while avoiding the step-out of the motor and favorably performing the infusion pumping.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First, an outline of a peristaltic infusion pump according to an embodiment of the present invention will be described with reference to FIGS. FIG. 4 is a front view of the peristaltic infusion pump, FIG. 5 is a perspective view of a main part showing an open state of the door, and FIG. 6 is a rear view of the peristaltic infusion pump.
FIG. 7 is a block diagram showing the electrical configuration of a peristaltic infusion pump.

This peristaltic infusion pump is an electromechanical positive pressure peristaltic intravenous infusion device having two pump heads and is used with a designated infusion set. The device program is designed to be performed from the key panel. It is possible to switch from the auxiliary infusion flow rate programmed for the drug solution of the second path containing the drug to the other main infusion rate programmed for the drug solution of the first path of the same pump. Various alarm functions such as bubble detection, upstream blockage detection, and downstream blockage detection are provided to enhance patient safety.

Reference numeral 1 denotes a power switch, and when the power switch 1 is pressed, the power of the peristaltic infusion pump is turned on. When the power is turned on, a self-test is automatically performed temporarily. Press the power switch 1 again to turn off the power. The internal battery is charged regardless of whether the power switch 1 is turned on or off when the infusion pump is connected to the AC power source.

Reference numeral 2 denotes an alarm / warning indicator for displaying all alarms and warnings relating to the infusion pump. Reference numeral 3 denotes a programming display, which displays all program information relating to the infusion, such as the infusion flow rate, the planned infusion volume, and the infused volume that have been input for each of the main infusion and the auxiliary infusion. The unit of the infusion flow rate is displayed in ml / hr, and the unit of the planned infusion volume and the infused volume is in ml.

Keys 4a to 4c are main infusion keys, which are used to input the infusion flow rate, enter the expected infusion amount, and start the infusion pump when performing only one infusion, respectively. It is something. Input with these keys is possible only when the infusion pump is stopped, after the infusion is complete, and in the main infusion mode.

Reference numeral 5 is a numerical key of "0" to "9", and numerical data for all infusions are inputted by these numerical keys 5. 6 is a clear key, and when an incorrect numerical value is input during the input of the numerical value, by pressing the clear key 6, the display can be set to "0" and the numerical value can be input again.

Reference numeral 7 denotes a stop key, which is pressed when manually stopping the infusion. After the infusion pump is stopped, if no operation is performed on the infusion pump for a period of 2 minutes, a warning buzzer sounds. Reference numeral 8 is a buzzer stop key, and by pressing this key, the alarm / warning sound is temporarily stopped for 2 minutes. However, the display state of the alarm / warning indicator 2 does not change before and after pressing the buzzer stop key 8.

Keys 9a to 9c are auxiliary infusion keys, which are used for inputting the infusion flow rate, inputting the expected infusion amount, and starting the auxiliary infusion when performing the infusion, respectively. It is a thing. Reference numerals 10a to 10c are lamps for displaying the operating state. Of these, 10a
Is an alarm lamp, and a red LED is used.

The alarm lamp 10a flashes during the alarm mode to notify that appropriate treatment is required immediately. Reference numeral 10b is a transfusion lamp, which uses a green LED. The infusion lamp 10b is turned on during infusion, and is turned off when the infusion pump is stopped. 10c is a warning lamp, which uses a yellow LED. The warning lamp 10c is turned on during the warning mode to indicate a state requiring treatment. In this case, the cause is displayed on the alarm / warning indicator 2.

Reference numeral 11 denotes a reset key. When this key is pressed when the infusion pump is stopped, the infused amount (the total amount of the main infusion and the auxiliary infusion) is reset to "0". 1
2 is an infusion volume key, and when this key is pressed, the infused volume (the sum of the main infusion and the auxiliary infusion) is displayed, and then
The infusion flow rate and the planned infusion volume registered for the main infusion and the auxiliary infusion are displayed.

Reference numeral 13 denotes a back light key, and when this key is pressed while the infusion pump is operating on AC power, the back lighting of the alarm / warning indicator 2 and the programming indicator 3 is turned on. Press it again to turn off the backlight. During operation with the built-in battery, the backlight is lit only while this key is pressed.

Reference numeral 14 is a door, and 14a is a door handle for opening and closing the door 14. To open the door 14, use the door handle 1
4a is pulled up to a position in which it is sufficiently raised.

To close the door 14, the door handle 14a is closed in the lifted state and then pushed down. 15 is green L
It is a charging lamp using an ED, and lights up while the infusion pump is connected to an AC power source, indicating that the built-in battery is in a charging state.

In FIG. 5, reference numeral 16 denotes a pressure drop sensor, which detects a pressure drop state due to an abnormality (for example, filter clogging) in the infusion set between the drug solution bottle (chemical solution bag) and the infusion pump. To do. 17
Is an infusion pump mechanism section, which is a linear peristaltic infusion pump mechanism designed for a specified infusion set (which will be described later).

Reference numeral 18 denotes a pressure increase sensor, which detects a pressure increase state in the infusion tube due to an abnormality (for example, blockage) in the infusion set between the infusion pump and the patient. Reference numeral 19 denotes a bubble sensor, which detects bubbles in a prescribed amount or more in the infusion tube. Reference numeral 20 denotes a safety clamp, which is a mechanism for automatically closing the infusion tube when the door 14 is opened, and prevents spontaneous infusion of the infusion solution.

In FIG. 6, reference numeral 21 is a power cord holder. Reference numeral 22 denotes a panel lock switch. By pressing this lock switch 22, even if a person other than the operator touches various keys and switches carelessly, the operation of the infusion pump is prevented from being changed unexpectedly. It is for doing. Reference numeral 23 is a fuse holder that incorporates a designated time-lag type fuse.

Reference numeral 24 is a volume control knob for adjusting the volume of the buzzer sounding at the time of alarm / warning. 25 is 100
It is a plug of a power cord connected to a V outlet.
Reference numeral 26 is a battery unit containing a lead storage battery. 27 is a pole clamp used when attaching to a stand. Reference numeral 28 denotes a nurse call connector portion for monitoring the alarm / warning state of the infusion pump at the nurse center by using the nurse call kit. 29 is a buzzer.

In FIG. 7, 30 is a CPU and 31 is an RO.
M and 32 are RAMs. 2 is an alarm / warning indicator, 3 is a programming indicator, 10 is an operation status indicator lamp (1
0a to 10c), 16 is a pressure drop sensor, 18 is a pressure rise sensor, 19 is a bubble sensor, 20 is a safety clamp, 22 is a panel lock switch, and 29 is a buzzer.

Reference numeral 33 is a warning / warning sound buzzer drive circuit, and 3
4 includes a power switch 1, main infusion keys 4a to 4c, numerical keys 5, clear key 6, stop key 7, buzzer stop key 8, auxiliary infusion keys 9a to 9c, reset key 11 and backlight key 13. It is a key panel equipped.

The infusion pump mechanism section 17 is composed of a motor drive circuit 35, a stepping motor 36, a motor rotation phase detection circuit 37 and the like. 38 is an A / D converter,
39 is a battery voltage detection circuit.

Next, the construction of the essential parts of the finger drive control device of the peristaltic infusion pump according to the embodiment of the present invention will be described with reference to FIG.

In FIG. 1, 30 is a CPU, 35 is a motor drive circuit, and 36 is a stepping motor. CPU
The reference numeral 30 sends a control signal calculated based on the infusion flow rate and the expected infusion volume input from the key panel 34 by a doctor or nurse to the motor drive circuit 35, and the motor drive circuit 3
5 is configured to drive and control the stepping motor 36.

Reference numeral 40 denotes a shaft of the stepping motor 36, and reference numerals C1 to C8 denote first to eighth shafts C1 to C8, which are attached to the shaft 40 little by little in phase and are closely attached in the axial direction.
Eccentric cams, F1 to F8 are first to eighth fingers attached to the eccentric cams C1 to C8, and 41 is arranged facing the first to eighth finger groups F1 to F8 and has a built-in compression spring. It is a backing plate.

Reference numeral 37 is a motor rotation phase detection circuit, which is a slit plate 3 attached to the upper end of the shaft 40.
7a and the slit plate 37a, that is, the stepping motor 3
6 and a photo interrupter 37b for detecting the rotation phase. The rotation phase signal from the photo interrupter 37b is input to the CPU 30, and the rotation phase of the stepping motor 36 is constantly monitored.

Reference numeral 100 is an infusion tube for infusion set between the fingers F1 to F8 and the backing plate 41.

Next, the operation of the finger drive control device of this peristaltic infusion pump will be described.

The shaft 40 rotates in accordance with the continuous rotation of the stepping motor 36 based on the drive current supplied from the motor drive circuit 35, and the eccentric cams C1 to C8 act from the first to the lowest positions. The eighth fingers F1 to F8 sequentially press the infusion tube 100 between the backing plate 41 and the backing plate 41 downward, and perfuse the infusion solution filled in the infusion tube 100.

The CPU 30 has a motor rotation phase detection circuit 3
In accordance with the rotation phase signal from the photo interrupter 37b in FIG.
The rotation phases of the groups 1 to F8 are constantly monitored. By preliminarily associating the rotational phase of the slit plate 37a with the positions of the fingers F1 to F8, the CPU 30 allows the CPU 30 to determine which finger of the plurality of fingers F1 to F8 is present at the current time with respect to the backing plate 41. It is possible to recognize whether or not is being pressed.

In one cycle of the stepping motor 36 (peristaltic infusion pump), the drive torque of each finger F1 to F8 required for infusion of infusion fluid changes depending on the rotation phase. The change in torque required for the fingers F1 to F8 to rotate while pressing the infusion tube 100 is shown in the upper part of FIG.

Eighth finger F8 and first finger F1
While pressing the infusion tube 100 at the same time,
It requires the largest torque of 377 gcm, and the fourth finger F4 or the fifth finger F5 is the infusion tube 1
Next large torque of 272g when pressing 00
cm, 266 g · cm are required, and the second finger F2
Alternatively, the torque required when the third finger F3, the sixth finger F6, or the seventh finger F7 presses the infusion tube 100 is at the lowest level (151 g · cm, 181 g · cm, and 181 respectively).
g · cm, 198 g · cm). The details will be described below.

In the first to eighth finger groups F1 to F8, the first finger F1 and the eighth finger F8 are located at both ends of the shaft 40 in the axial direction. Therefore, from the state where the eighth finger F8 presses the infusion tube 100 to the state where both the eighth finger F8 and the first finger F1 press the infusion tube 100 as the stepping motor 36 rotates. After the transfer, the infusion tube 100 will move to the eighth finger F8 at both axial ends.
And the first finger F1 are pressed at the same time, and the infusion tube 100 is attached to the backing plate 41.
Will be pressed with almost no inclination.

In this case, the backing plate 41 gives a large reaction force to the eighth finger F8 and the first finger F1 via the infusion tube 100 by the built-in compression spring. A large torque of 377 g · cm is required to rotate the fingers F8 and F1 against this reaction force.

The same thing as this should occur when the backing plate is pressed by the finger at the center via the infusion tube, but since the number of fingers in this embodiment is an even number, it is just at the center. There is no such finger.

A situation close to this occurs when the fourth finger F4 or the fifth finger F5 presses the backing plate 41 via the liquid transfusing tube 100. At this time, the backing plate 41 slightly tilts, The reaction force from the compression spring in the backing plate 41 is slightly reduced. Therefore, the torque required to rotate the fingers F4 and F5 is smaller than that in the above case.
It may be 72 g · cm or 266 g · cm.

Second, third, sixth or seventh finger F
When 2, F3, F6, and F7 press the infusion tube 100, the backing plate 41 is largely inclined like a seesaw, so that the reaction force from the compression spring in the backing plate 41 is considerably reduced and the fingers are rotated. The torque required for the
1gcm, 181gcm, 181gcm, 198
It becomes g · cm.

Therefore, as shown in the lower part of FIG. 2, the drive current applied to the stepping motor 36 is divided into three stages in accordance with the above required torque. The first drive current I ₁ is applied to the eighth finger F8 and the first finger F1.
Is set to be necessary and sufficient to satisfy the driving torque of T ₁ = 400 g · cm, which is sufficient to cover the required torque of 377 g · cm.

The second drive current I ₂ is applied to the fourth finger F.
The required torque of T ₂ = 300 g · cm sufficient to cover the required torque of 272 g · cm of No. 4 and the required torque of 266 g · cm of the fifth finger F5 is set as necessary and sufficient.

The third drive current I ₃ is required for the second finger F2 with a required torque of 151 g · cm, the third or sixth finger F3, F6 with a required torque of 181 g · cm, and the seventh finger F7. It is set as necessary and sufficient to cover the driving torque of T ₃ = 200 g · cm, which is enough to cover the torque of 198 g · cm.

The control operation of the drive current by the CPU 30 will be described with reference to the flowchart of FIG.

In step S1, a rotation phase signal is input from the photo interrupter 37b of the motor rotation phase detection circuit 37, and in step S2, the position of the finger currently pressing the infusion tube 100 based on the input rotation phase signal is determined. Calculate In step S3, it is determined based on the calculation result which finger the infusion tube 100 is being pressed against.

If the determined finger is the eighth finger F8 or the first finger F1, step S4
Then, the first drive current I ₁ having the largest current value is set in the motor drive circuit 35. As a result, the stepping motor 36 has the largest first drive torque T
₁ = 400 g · cm is generated. This is the required torque 3
Since the stepping motor 36 is larger than 77 g · cm, the stepping motor 36 does not step out, and the backing plate 41
It is possible to reliably rotate the eighth finger F8 or the first finger F1 against the reaction force from.

When the finger determined in step S3 is the fourth finger F4 or the fifth finger F5, the process proceeds to step S5, and the second drive current I having the next largest current value in the motor drive circuit 35. Set ₂ .
This causes the stepping motor 36 to generate a _second drive torque T ₂ = 300 g · cm, which is the next largest. This is 266g · c compared to the required torque of 272g · cm.
Since it is larger than m, it is possible to reliably rotate the fourth finger F4 or the fifth finger F5 against the reaction force from the backing plate 41 without causing the stepping motor 36 to run out of step. ..

The drive current I _{2 in} this case is the maximum drive current I
3/4 of ₁ = 75% is sufficient, and power loss can be reduced.

When the finger determined in step S3 is the second finger F2, the third finger F3, the sixth finger F6 or the seventh finger F7, the process proceeds to step S6 and the motor drive circuit 35 is operated. The third drive current I ₃ having the smallest current value is set.
As a result, the smallest third driving torque T ₃ = 200 g · cm is generated in the stepping motor 36. This is the required torque 151g · cm, 181g · cm, 19
Since the stepping motor 36 is larger than any of 8 g · cm, the second finger F2 or the third finger F3 or the sixth finger F3 resists the reaction force from the backing plate 41 without causing the stepping motor 36 to be out of step. The finger F6 or the seventh finger F7 can be reliably rotated.

The drive current I _{3 in} this case is the maximum drive current I _3.
1/2 of 1 = 50% is sufficient, and the power loss can be further reduced.

As described above, according to this embodiment, while avoiding the stepping of the stepping motor 36, a necessary and sufficient current corresponding to the required torque of each rotation phase is supplied as the drive current to be supplied to the stepping motor 36. With this configuration, the power loss in the stepping motor 36 can be reduced.

Although the number of fingers is eight in the above embodiment, the present invention is not limited to this, and the number of fingers can be appropriately determined. The number may be even or odd. In the above embodiment, the drive current is divided into three stages, but it may be divided into two stages or four or more stages. The finer it is, the more the power loss can be reduced.

[0060]

As described above, according to the present invention, the finger pressing the infusion tube gives a necessary and sufficient drive current to the motor in order to generate the drive torque necessary for pressure-feeding the infusion solution. Since it is configured, it is possible to avoid out-of-step of the motor, favorably perform infusion pumping, and reduce power loss in the motor.

[Brief description of drawings]

FIG. 1 is a partially cutaway front view showing a structure of a main part of a finger drive control device of a peristaltic infusion pump according to an embodiment of the present invention.

FIG. 2 is a diagram showing changes in required torque and drive current (drive torque) of each finger in the embodiment.

FIG. 3 is a flowchart for explaining the operation of the embodiment.

FIG. 4 is a front view showing the appearance of a peristaltic infusion pump according to an embodiment.

FIG. 5 is a perspective view of essential parts showing a state in which the door is opened in the peristaltic infusion pump of the embodiment.

FIG. 6 is a rear view showing the appearance of the peristaltic infusion pump of the embodiment.

FIG. 7 is a block diagram showing an electrical configuration of a peristaltic infusion pump according to an embodiment.

FIG. 8 is a partially cutaway front view showing a structure of a main part of a conventional peristaltic infusion pump.

FIG. 9 is a diagram showing a required torque and a drive current (drive torque) of each finger in the conventional example.

[Explanation of symbols]

30 CPU 35 motor drive circuit 36 a stepping motor 37 motor rotation phase detecting circuit 37a slit plate 37b photointerrupter 40 shaft 41 the backing plate 100 infusion tube C1~C8 eccentric cam F1~F8 fingers I ₁ ~I ₃ drive current T ₁ through T ₃ Drive torque

Claims (1)

[Claims] 1. A backing plate and a finger group, each of which is provided with a plurality of fingers along an axial direction in an eccentric state in which a phase is gradually shifted by a motor and which is eccentrically shifted, and which is arranged so as to face these finger groups. And a finger drive of a peristaltic infusion pump, in which the infusion tube is set between the fingers and the finger group sequentially pushes the infusion tube by peristaltic movement in accordance with the rotation of the motor to pump the infusion solution in the infusion tube. The controller is a rotation phase detecting means for detecting a rotation phase of the finger group, and a finger pressing the infusion tube corresponding to the detected rotation phase provides a driving torque necessary for pressure-feeding the infusion solution. And a necessary drive current selecting means for selecting the necessary and sufficient drive current and applying it to the motor. N-acting infusion pump of finger drive control device.