JP2023084434A - Clamp device and instillation monitoring device - Google Patents

Abstract

To provide a clamp device and an instillation monitoring device capable of appropriately closing a transfusion tube irrespective of manufacturing variation of components.SOLUTION: A clamp device 1 includes: a DC motor 15 for driving a clamp mechanism 14; a motor current detection circuit 16; a photosensor 17 for detecting opening and closing of a transfusion tube 3b by the clamp mechanism 14; a drive control section 82 for outputting a drive signal to drive the DC motor 15, stopping the output of the drive signal to stop the drive of the DC motor 15; and a drive time setting section 81 for setting an extension time until stopping the output of the drive signal from the detection of the closure of the transfusion tube 3b, based on a current value detected by the motor current detection circuit 16. The drive control section 82 stops the drive of the DC motor 15 based on the extension time set by the drive time setting section 81 when the photosensor 17 detects the closure of the transfusion tube 3b.SELECTED DRAWING: Figure 1

Description

The present invention relates to clamping devices and drip monitoring devices.

2. Description of the Related Art Conventionally, a drip monitoring device is known that monitors droplets formed in a drip port of a drip tube of an infusion set used during infusion therapy. A drip monitoring device monitors the flow rate of droplets and the like, and medical personnel such as doctors and nurses can take appropriate measures based on the monitoring results.

Such a drip monitoring device includes a clamp device having a tube clamp and an actuator for opening or closing a tube, and the tube is closed by the tube clamp by driving the actuator (see, for example, Patent Document 1).

JP-A-2002-336350

However, due to variations in the manufacture of the component parts of the tube clamp, variations occur in the positions where the tube is closed by the tube clamp.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a clamping device capable of properly closing a tube regardless of manufacturing variations in component parts, and a drip monitoring device provided with this clamping device.

The present invention comprises a clamping mechanism for opening or closing a tube, a drive section for driving the clamping mechanism, a drive current detection section for detecting the drive current of the drive section, and a clamping mechanism for opening or closing the tube. a motion detection unit that detects the a drive time setting unit that sets an extension time from detection of clogging of the tube to stopping of output of the drive signal based on the detected current value, wherein the drive control unit performs the operation The present invention relates to a clamping device that stops driving of the driving section based on the extension time set by the driving time setting section when the detecting section detects the blockage of the tube.

Further, it is preferable that the drive time setting unit sets the extension time based on the amount of increase in the current value per unit time at a predetermined timing in the drive state of the drive unit.

Further, the drive time setting unit obtains a slope of change in the current value from an amount of increase in the current value per time at a predetermined timing in the drive state of the drive unit, and determines a slope of the change in the current value. If it is less than the threshold, a first extension time is set as the extension time, and if the slope of the change in the current value is equal to or greater than the predetermined threshold value, a second extension that is longer than the first extension time is set as the extension time. It is preferable to set the time.

Further, it is preferable that the driving time setting section sets the extension time based on the current value at a specific timing.

Further, the drive time setting unit sets the first extension time as the extension time when the current value is less than the predetermined value, and sets the extension time as the extension time when the current value is equal to or greater than the predetermined value. It is preferable to set the second extension time longer than the first extension time.

The present invention also provides a drip monitoring device for monitoring the dripping of droplets of an infusion solution in a drip tube, comprising: a droplet detection unit for detecting the dripping of droplets; In addition, the drive control unit relates to a drip monitoring device that drives the drive unit when the droplet detection unit continues to fail to detect a droplet for a predetermined period of time.

ADVANTAGE OF THE INVENTION According to this invention, the clamp device which can block|occlude a tube appropriately, and the drip monitoring apparatus provided with this clamp device can be provided, regardless of the manufacturing variation of component parts.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the outline|summary of the drip monitoring apparatus which concerns on this embodiment. FIG. 10 is a diagram showing the configuration around the clamp mechanism in a state where the infusion tube is opened; FIG. 10 is a diagram showing the configuration around the clamp mechanism when the infusion tube is closed; 4 is a diagram showing an overview of the configuration of a control unit; FIG. FIG. 10 is a diagram showing control of the clamping mechanism when closing the infusion tube; FIG. 10 is a diagram showing control of the clamping mechanism when there is variation in the output signal of the first photosensor; FIG. 10 is a diagram showing control of a clamping mechanism for eliminating variation in closed position of the pusher; It is a figure which shows the operation|movement of a pusher by the presence or absence of an infusion tube. It is a figure which shows the operation|movement of a pusher by the presence or absence of an infusion tube. FIG. 10 is a diagram showing control of the clamping mechanism when there is no infusion tube; FIG. 10 is a diagram showing control of the clamping mechanism when there is an infusion tube; FIG. 10 is a diagram showing control of the clamping mechanism when there is no infusion tube; FIG. 10 is a diagram showing control of the clamping mechanism when there is an infusion tube;

Embodiments of the present invention will be described in detail with reference to the drawings. As shown in FIG. 1, a drip monitoring device 100 is a device for monitoring drips, and is used, for example, at a medical institution during infusion therapy. The infusion solution is supplied from the infusion bag 2 to the infusion tube 3 a connected to the infusion bag 2 . The infusion tube 3 a is connected to the upper portion of the drip tube 3 and distributes the infusion from the infusion bag 2 to the drip tube 3 . An infusion tube 3b as a tube is connected to the lower portion of the drip tube 3, and the infusion supplied to the drip tube 3 is supplied to the infusion tube 3b. The drip monitoring device 100 monitors dripping of droplets D (hereinafter simply referred to as droplets) formed at the drip port of the drip tube 3 . Also, the amount of infusion is adjusted by a clamp 4 for opening and closing the middle portion of the infusion tube 3b.

The drip monitoring device 100 includes a droplet detector 20 that detects droplets D, and a clamp device 1 that operates based on the droplet interval detected by the droplet detector 20 .
The droplet detector 20 includes a light emitter 5 , a light receiver 6 and an amplifier circuit 7 . The clamp device 1 includes a control unit 8, a control circuit 9, an LED driver 10, an LED 11, an LCD driver 12, an LCD 13, a clamp mechanism 14, a DC motor 15 as a driving unit, and a driving current detection unit. a motor current detection circuit 16 and a photosensor 17 as an operation detection unit. Infusion monitoring device 100 also includes a power supply (not shown) for supplying power to each component.

The light emitting unit 5 irradiates light onto the droplets that are dropped in the drip tube 3 . The light emitted from the light emitting unit 5 may be visible light or infrared light. The light emitting unit 5 is composed of, for example, one or more LEDs.

The light-receiving section 6 is a light-receiving element configured such that the output voltage varies according to the intensity of the received light. For example, the light-receiving unit 6 increases the output voltage when the intensity of the received light is high, and decreases when the intensity of the received light is low.

The light receiving section 6 is arranged to face the light emitting section 5 . The light emitted from the light-emitting portion 5 is attenuated when passing through the droplet and is received by the light-receiving portion 6 . Since the light is attenuated, the intensity of the received light becomes weaker, and the output voltage from the light receiving section 6 becomes lower than when the droplet does not pass. Using this fact, the droplet detection unit 20 detects the dropping of droplets.

The amplifier circuit 7 amplifies the output voltage from the light receiving section 6 and outputs it to the control section 8 .

The control unit 8 is a processor such as a CPU (Central Processing Unit). The control unit 8 may include a ROM (Read Only Memory) in which the program is stored, a RAM (Random Access Memory) for storing data temporarily required when the CPU executes the program, and the like. good.
Details of the control unit 8 will be described later.

The control circuit 9 controls the light emitting section 5 according to the control signal from the control section 8 . Also, the control circuit 9 controls the clamp mechanism 14 according to the drive signal from the control section 8 .

The LED driver 10 controls the LEDs 11 according to control signals from the control section 8 .
An LED (Light Emitting Diode) 11 emits light under the control of an LED driver 10 . The LED 11 is controlled to be lit for a certain period of time, for example, when a droplet falls.

The LCD driver 12 controls an LCD (Liquid Crystal Display) 13 in accordance with a control signal from the controller 8 .
The LCD 13 displays images under the control of the LCD driver 12 . The LCD 13 is controlled to display, for example, the droplet flow rate (mL/h).

The clamp mechanism 14 has a mechanism for holding the infusion tube 3b and closes or opens the infusion tube 3b. For example, the clamp mechanism 14 opens the infusion tube 3b when the infusion is being dripped, and closes the infusion tube 3b when the dripping of the infusion is finished.
The DC motor 15 operates according to the drive signal from the control circuit 9 to drive the clamp mechanism 14 .

A motor current detection circuit 16 detects the current value of the driving current of the DC motor 15 and outputs the detected current value to the control circuit 9 .
The photo sensor 17 has a light receiving element, a light emitting element, etc., detects the open position, the intermediate position and the closed position of the clamp mechanism 14 and outputs them to the control circuit 9 .

In the drip monitoring device 100 described above, the control unit 8 detects droplets by the light emitting unit 5 and the light receiving unit 6, and determines that the infusion of the infusion bag 2 has been completed when no droplets have been detected for a certain period of time. , and outputs a drive signal for the clamping mechanism 14 to the control circuit 9 .
The control circuit 9 drives the DC motor 15 according to the drive signal, and the clamp mechanism 14 closes the infusion tube 3b. The control circuit 9 also receives the current value of the DC motor 15 detected by the motor current detection circuit 16 and outputs the current value of the DC motor 15 to the control unit 8 .

The clamping mechanism 14 takes about 2 seconds to close the infusion tube 3 b , and the clamping mechanism 14 closes the infusion tube 3 b so that the infusion remains in the drip tube 3 . Therefore, when continuing to supply the infusion solution after replacing the infusion bag 2, priming downstream of the drip tube 3 is not required.

FIG. 2 is a diagram showing the configuration around the clamp mechanism 14 when the infusion tube 3b is opened. FIG. 3 is a diagram showing the configuration around the clamp mechanism 14 when the infusion tube 3b is closed.

As shown in FIGS. 2 and 3, the clamp mechanism 14 includes a pusher 141, a wall portion 142, a light blocking plate 143, and a pusher operating mechanism 144. As shown in FIG.
The photosensor 17 has a first photosensor 171 and a second photosensor 172 .

The pusher 141 is configured to be movable forward and backward toward the infusion tube 3b by a pusher operating mechanism 144 . The tip portion of the pusher 141 has a sharp shape so as to suitably block the infusion tube 3b.

The wall portion 142 is arranged to face the pusher 141 . Without the infusion tube 3 b , the tip of the pusher 141 can reach the wall 142 . That is, the infusion tube 3b is arranged between the tip portion of the pusher 141 and the wall portion 142, and is crushed by the tip portion of the pusher 141 and the wall portion 142 to be closed.

The light blocking plate 143 is arranged on the side of the pusher 141 and blocks light from the first photosensor 171 and the second photosensor 172 as the pusher 141 moves.

The pusher operating mechanism 144 is arranged between the pusher 141 and the DC motor 15 and transmits the driving force of the DC motor 15 to the pusher 141 . The pusher actuation mechanism 144 includes, for example, a feed screw, gears, etc., converts the rotary motion of the DC motor 15 into linear motion, and transmits the driving force of the DC motor 15 to the pusher 141 . As a result, the pusher 141 advances from the open position (see FIG. 2) where the infusion tube 3b is opened to the closed position (see FIG. 3) where the infusion tube 3b is closed, and also moves from the closed position to the open position. Retractable.

The first photosensor 171 is arranged at a position where the pusher 141 detects the closed position where the infusion tube 3b is closed. The second photosensor 172 is arranged at a position for detecting the open position where the pusher 141 opens the infusion tube 3b.

As the pusher 141 moves, the light shielding plate 143 moves, thereby changing the received light outputs of the first photosensor 171 and the second photosensor 172 . Thereby, the control unit 8 can grasp the position of the pusher 141 .
In this embodiment, the control unit 8 determines that the pusher 141 is positioned at the closed position when the first photosensor 171 and the second photosensor 172 are shielded by the light shielding plate 143 and the received light output is reduced (see FIG. 3). ). Further, the control unit 8 determines that the pusher 141 is positioned at the open position when the first photosensor 171 and the second photosensor 172 are not shielded by the light shielding plate 143 and the received light output is not lowered (see FIG. 2). . Furthermore, the control unit 8 controls the pusher 141 when only the second photosensor 172 is shielded by the light shielding plate 143, the light receiving output of the second photosensor 172 decreases, and the light receiving output of the first photosensor 171 does not decrease. is positioned at the middle position.

FIG. 4 is a diagram showing an outline of the configuration of the control section 8. As shown in FIG. The control unit 8 includes a drive time setting unit 81 and a drive control unit 82 .
Based on the current value of the DC motor 15 detected by the motor current detection circuit 16, the drive time setting unit 81 causes the drive control unit 82 to output the drive signal after the photosensor 17 detects the blockage of the infusion tube 3b. set the extension time until the

Specifically, the driving time setting unit 81 sets the extension time of the DC motor 15 based on the amount of increase in the current value of the DC motor 15 per time at a predetermined timing in the driving state of the DC motor 15 . Further, the drive time setting unit 81 may set the extension time of the DC motor 15 based on the current value of the DC motor 15 at a specific timing. Details of the driving time setting unit 81 will be described later.

The drive control unit 82 drives the DC motor 15 by outputting the drive signal, and stops driving the DC motor 15 by stopping the output of the drive signal. Further, when the photosensor 17 detects that the infusion tube 3b is blocked while the DC motor 15 is being driven, the drive control unit 82 stops driving the DC motor 15 based on the extension time set by the drive time setting unit 81. . Specifically, when the photosensor 17 detects the blockage of the infusion tube 3b while the DC motor 15 is being driven, the driving time setting unit 81 turns off the DC motor 15 after the extension time set by the driving time setting unit 81 has elapsed. stop driving.

FIG. 5 is a diagram showing control of the clamping mechanism 14 when the infusion tube 3b is closed when the driving time setting unit 81 does not set the extension time. As shown in FIG. 5, the clamp mechanism 14 normally opens the infusion tube 3b, and the pusher 141 is placed in the open position to open the infusion tube 3b. At this time, neither the first photosensor 171 nor the second photosensor 172 is shielded by the light shielding plate 143, and the received light output signals of the first photosensor 171 and the second photosensor 172 both become High. ing.

When the drive control unit 82 outputs a drive signal (drive signal ON) while the pusher 141 is at the open position, the DC motor 15 starts operating to move the pusher 141 of the clamp mechanism 14 toward the infusion tube 3b. move to At this time, when the light shielding plate 143 attached to the pusher 141 shields the first photosensor 171 and the second photosensor 172, the received light output signals of the first photosensor 171 and the second photosensor 172 change from High to Low. change to

The drive control unit 82 determines that the pusher 141 has reached the closed position when the received light output signals of both the first photosensor 171 and the second photosensor 172 become Low while the drive signal is being output. After making a determination, output of the driving signal is stopped (driving signal OFF), and the operation of the clamping mechanism 14 is stopped.

That is, the DC motor 15 starts operating at the timing when the drive signal is turned ON while the light shielding plate 143 does not shield both the first photosensor 171 and the second photosensor 172, and the clamping mechanism 14 pusher 141 toward the infusion tube 3b.

When the light shielding plate 143 shields the second photosensor 172 and does not shield the first photosensor 171, the pusher 141 of the clamp mechanism 14 begins to push the infusion tube 3b, and the infusion tube 3b is partially blocked. state. The control unit 8 determines that the pusher 141 is positioned at the intermediate position in this state.

In a state in which the pusher 141 moves further toward the infusion tube 3b and the light blocking plate 143 shields both the first photosensor 171 and the second photosensor 172, the infusion tube 3b is closed by the pusher 141 of the clamp mechanism 14. . The control unit 8 determines that the pusher 141 has reached the closed position in this state. Then, the drive control unit 82 stops outputting the drive signal (OFF), and the DC motor 15 stops operating.

FIG. 6 is a diagram showing the control of the clamping mechanism 14 when there is variation in the detection timing of the change in the light receiving output signal of the first photosensor 171 when the driving time setting unit 81 does not set the extension time. is. As shown in FIG. 6, the detection timing of the change in the light reception output signal of the first photosensor 171 varies. Variations in the detection timing of changes in the light-receiving output signal are caused by manufacturing variations in the detection range of the light-receiving output signal of the first photosensor 171 .

That is, due to the influence of variations in the detection range of the light reception output signal of the first photosensor 171, the light reception output signal of the first photosensor 171 varies in the timing at which it changes from High to Low. As a result, as indicated by the dotted line in FIG. 6, the pusher 141 of the clamp mechanism 14 may stop at an intermediate position without reaching the closed position, and the infusion tube 3b may not be closed. .

7A and 7B are diagrams showing the control of the clamp mechanism 14 for eliminating variations in the closing position of the pusher 141. FIG. When there is variation in the detection range of the light receiving output signal of the first photosensor 171, the driving time setting unit 81 adjusts the variation of the light receiving output signal of the first photosensor 171 in order to eliminate the variation in the closing position of the pusher 141. An extension time is set for extending the drive of the DC motor 15 by the time ΔT corresponding to the amount of variation in the timing of . Then, when the first photosensor 171 and the second photosensor 172 detect the blockage of the infusion tube 3b (blocked position of the pusher 141), the drive control unit 82 drives after the extension time ΔT has elapsed since the blockage was detected. Stops signal output. As a result, even if there is a variation in the detection range of the light receiving output signal of the first photosensor 171 and the first photosensor 171 detects the clogging of the infusion tube 3b while the pusher 141 is positioned at the intermediate position. However, the movement of the pusher 141 is stopped after the extension time ΔT has elapsed since the blockage was detected. Therefore, even if there is variation in the detection range of the light receiving output signal of the first photosensor 171, the infusion tube 3b can be preferably closed.

8 and 9 are diagrams showing the operation of the pusher 141 depending on the presence or absence of the infusion tube 3b. As shown in FIG. 8, when the infusion tube 3b is between the pusher 141 and the wall portion 142, that is, when the infusion tube 3b is closed by the clamp mechanism 14, the pusher 141 closes the infusion tube 3b at the closed position. do. In this case, the infusion tube 3 b is interposed between the tip of the pusher 141 and the wall portion 142 .

On the other hand, when there is no infusion tube 3b between the pusher 141 and the wall portion 142 as shown in FIG. When the driving of the DC motor 15 is extended by ΔT, the pusher 141 comes into direct contact with the wall portion 142 at the closed position.

In this way, if the uniform extension time ΔT is set as shown in FIG. 7 when there is no infusion tube 3b between the pusher 141 and the wall portion 142, the tip of the pusher 141 will directly move to the wall portion 142 for the maximum time ΔT. pressed against. The tip of the pusher 141 has a sharp shape to block the infusion tube 3b. Therefore, if the tip of the pusher 141 is repeatedly pressed against the wall 142 without the infusion tube 3b, the tip of the pusher 141 is deformed, and as a result, the infusion tube 3b cannot be sufficiently closed.

Therefore, the drip monitoring device 100 (clamping device 1) according to the present embodiment focuses on the characteristic that the current value of the DC motor 15 increases when a torque load is applied to the DC motor 15, and when there is an infusion tube 3b, , the extended time for each different DC motor 15 is set. More specifically, the drive time setting unit 81 determines the presence or absence of the infusion tube 3b based on the current value of the DC motor 15 detected by the motor current detection circuit 16, and when it is determined that the infusion tube 3b is not present, A first extension time Ta is set as the extension time, and a second extension time Tb longer than the first extension time is set as the extension time when it is determined that the infusion tube 3b is present.

10 and 11 are diagrams showing control for setting the extension time based on the gradient ΔI1/ΔT1 of the change in the current value of the DC motor 15. FIG. FIG. 10 is a diagram showing control of the clamp mechanism 14 when there is no infusion tube 3b. FIG. 11 is a diagram showing control of the clamp mechanism 14 when the infusion tube 3b is present.

As shown in FIG. 10, without the infusion tube 3b, no torque load is applied to the DC motor 15 until the pusher 141 of the clamp mechanism 14 reaches the wall portion 142. As shown in FIG. Therefore, the current value detected by the motor current detection circuit 16 is constant. Here, assuming that the amount of increase in the current value per time ΔT1 is ΔI1, the slope of change in the current value ΔI1/ΔT1 is substantially zero.

When the slope ΔI1/ΔT1 of the change in the current value at a predetermined timing in the driving state of the DC motor 15 is less than the set predetermined threshold value A1, the drive time setting unit 81 sets the light receiving output signal of the first photosensor 171 to A first extension time Ta is set as an extension time from when the signal changes from High to Low until the output of the drive signal is stopped. Here, the extension time Ta is set to, for example, 0 seconds (that is, the timing at which the received light output signal of the first photosensor 171 changes from High to Low).

That is, the driving time setting unit 81 obtains the slope ΔI1/ΔT1 of the change in the current value from the amount of increase ΔI1 in the current value with respect to the time ΔT1. A short first extension time Ta including 0 as time is set. As a result, when the pusher 141 (clamp mechanism 14) moves from the open position to the closed position without the infusion tube 3b, the first photosensor 171 detects the blockage at the timing or for a very short time after detecting the blockage. , the movement of the pusher 141 is stopped. Therefore, it is possible to prevent the tip of the pusher 141 from being directly pressed against the wall portion 142 and deformed.

On the other hand, as shown in FIG. 11, when there is an infusion tube 3b, a torque load is applied to the DC motor 15 when the pusher 141 of the clamp mechanism 14 starts pushing the infusion tube 3b. Therefore, the current value detected by the motor current detection circuit 16 increases according to the torque load. Assuming that the amount of increase in the current value per time ΔT1 is ΔI1, the slope of the change in the current value is obtained by ΔI1/ΔT1.

The drive time setting unit 81 sets the output signal of the first photosensor 171 to High when the slope ΔI1/ΔT1 of the change in the current value at a predetermined timing in the driving state of the DC motor 15 is equal to or greater than the set predetermined threshold value A1. A second extension time Tb, which is longer than the first extension time Ta, is set as an extension time until the output of the drive signal is stopped after the output changes from to Low. Here, the extension time Tb is set as a time equal to or longer than the time ΔT corresponding to the variation in the timing of the change in the light receiving output signal of the first photosensor 171 .

That is, the driving time setting unit 81 obtains the slope ΔI1/ΔT1 of the change in the current value from the amount of increase ΔI1 in the current value with respect to the time ΔT1. As the time, a second extension time Tb that is equal to or longer than the time ΔT corresponding to the amount of variation in the detection range of the output signal of the first photosensor 171 is set. As a result, when the pusher 141 (clamp mechanism 14) moves from the open position to the closed position while the infusion tube 3b is present, after the first photosensor 171 detects the blockage, the pusher 141 continues to operate for the second extension time Tb. is moved, the movement of the pusher 141 is stopped. Therefore, even if there is variation in the detection range of the light receiving output signal of the first photosensor 171, the infusion tube 3b can be preferably closed.

As a predetermined timing for obtaining the gradient ΔI1/ΔT1 of the change in the current value, after the first photosensor 171 and the second photosensor 172 detect that the pusher 141 is positioned at the intermediate position, the first photosensor 171 detects the position of the pusher 141 . Preferably, the timing is just before the detection of reaching the closed position between the detection of the arrival of 141 to the closed position.

In the example shown in FIGS. 10 and 11, the driving time setting unit 81 sets the extension time based on the amount of increase in the current value of the DC motor 15 per unit time, but the driving time setting unit 81 sets a specific timing The extension time may be set based on the current value of the DC motor 15 at .

12 and 13 are diagrams showing control for setting the extension time based on the current value of the DC motor 15. FIG. FIG. 12 is a diagram showing control of the clamping mechanism 14 when there is no infusion tube 3b.

As shown in FIG. 12, without the infusion tube 3b, no torque load is applied to the DC motor 15 until the pusher 141 of the clamp mechanism 14 reaches the wall portion 142. As shown in FIG. Therefore, the current value detected by the motor current detection circuit 16 is constant.

When the current value I2 of the DC motor 15 at a specific timing T2 in the driving state of the DC motor 15 is less than the predetermined value Ia, the driving time setting unit 81 detects that the output signal of the first photosensor 171 has changed from High to Low. After that, a first extension time Ta is set as an extension time until the output of the drive signal is stopped. Here, the first extension time Ta is set to, for example, 0 seconds (that is, the timing at which the received light output signal of the first photosensor 171 changes from High to Low).

FIG. 13 is a diagram showing control of the clamp mechanism 14 when the infusion tube 3b is present. As shown in FIG. 13, when the infusion tube 3b is present, a torque load is applied to the DC motor 15 when the pusher 141 of the clamp mechanism 14 starts to push the infusion tube 3b. Therefore, the current value detected by the motor current detection circuit 16 increases according to the torque load.

When the current value I2 of the DC motor 15 at a specific timing T2 in the driving state of the DC motor 15 is equal to or greater than the predetermined value Ia, the driving time setting unit 81 determines that the output signal of the first photosensor 171 has changed from High to Low. After that, a second extension time Tb longer than the first extension time Ta is set as an extension time until the output of the drive signal is stopped. Here, the second extension time Tb is set as a time equal to or longer than the time ΔT corresponding to the amount of variation in the timing of the change in the light reception output signal of the first photosensor 171 .

As a specific timing for detecting the current value I2, after the first photosensor 171 and the second photosensor 172 detect that the pusher 141 is located at the intermediate position, the first photosensor 171 moves the pusher 141 to the closed position. It is preferable that the timing is just before the detection of the arrival at the closed position during the detection of the arrival.

As described above, according to the present embodiment, the drip monitoring device 100 including the clamp device 1 includes the clamp mechanism 14 that opens or closes the infusion tube 3b that is connected to the drip tube 3 and that circulates the infusion solution, and the clamp mechanism 14 , a motor current detection circuit 16 that detects the drive current of the DC motor 15, a photosensor 17 that detects opening or closing of the infusion tube 3b by the clamp mechanism 14, and outputting a drive signal Based on the current value detected by the drive control unit 82 that drives the DC motor 15 and stops the output of the drive signal to stop the driving of the DC motor 15 and the motor current detection circuit 16, the photosensor 17 detects the transfusion. and a drive time setting unit 81 for setting an extension time from detection of blockage of the tube 3b until the drive control unit 82 stops outputting the drive signal. 3b is detected, the drive of the DC motor 15 is stopped based on the extension time set by the drive time setting unit 81. FIG.

As a result, the drip monitoring device 100 (clamping device 1) can set the extension time of the DC motor 15 based on the current value of the DC motor 15 depending on the presence or absence of the infusion tube 3b. Therefore, the infusion tube 3b can be properly closed by the clamp mechanism 14. As shown in FIG.

Further, the driving time setting unit 81 sets the extension time based on the increase amount ΔI1 of the current value of the DC motor 15 per time ΔT1 at a predetermined timing in the driving state of the DC motor 15 . As a result, the presence or absence of the infusion tube 3b can be determined using the characteristic that the current value of the DC motor 15 increases when a torque load is applied to the DC motor 15. An extension time for the DC motor 15 can be set. Therefore, the infusion tube 3b can be properly closed by the clamp mechanism 14 regardless of manufacturing variations of the components.

Further, the drive time setting unit 81 obtains the slope of change in the current value ΔT1/ΔI1 from the amount of increase ΔI1 in the current value per time ΔT1 at a predetermined timing in the drive state of the DC motor 15, and determines the slope of the change in the current value. When ΔT1/ΔI1 is less than the predetermined threshold value A1, the first extension time Ta is set as the extension time, and when the gradient ΔT1/ΔI1 of the current value change is equal to or greater than the predetermined threshold value A1, the first extension time is set as the extension time. A second extension time Tb longer than Ta is set. Accordingly, by setting the first extension time Ta to 0 or a very short time, when the pusher 141 (clamp mechanism 14) moves from the open position to the closed position without the infusion tube 3b, the first photo The movement of the pusher 141 can be stopped at the timing when the sensor 171 detects the blockage or in a very short time after detecting the blockage. Therefore, it is possible to prevent the tip of the pusher 141 from being directly pressed against the wall portion 142 and deformed. Further, by setting the second extension time Tb to a time equal to or longer than the time ΔT corresponding to the variation in the timing of the change in the light receiving output signal of the first photosensor 171, the pusher 141 (clamping mechanism) can be 14) moves from the open position to the closed position, after detecting the blockage by the first photosensor 171, the pusher 141 is moved for the second extension time Tb, and then the movement of the pusher 141 is stopped. Therefore, the infusion tube 3b can be properly closed by the clamp mechanism 14 regardless of manufacturing variations of the components.

Further, the drive time setting unit 81 sets the extension time based on the current value of the DC motor 15 at the specific timing T2. As a result, the presence or absence of the infusion tube 3b can be determined using the characteristic that the current value of the DC motor 15 increases when a torque load is applied to the DC motor 15. An extension time for the DC motor 15 can be set. Therefore, the infusion tube 3b can be properly closed by the clamp mechanism 14 regardless of manufacturing variations of the components.

Further, the drive time setting unit 81 sets the first extension time Ta as the extension time when the current value of the DC motor 15 is less than the predetermined value Ia, and sets the first extension time Ta as the extension time when the current value of the DC motor 15 is greater than or equal to the predetermined value Ia. , a second extension time Tb longer than the first extension time Ta is set as the extension time. Accordingly, by setting the first extension time Ta to 0 or a very short time, when the pusher 141 (clamp mechanism 14) moves from the open position to the closed position without the infusion tube 3b, the first photo The movement of the pusher 141 can be stopped at the timing when the sensor 171 detects the blockage or in a very short time after detecting the blockage. Therefore, it is possible to prevent the tip of the pusher 141 from being directly pressed against the wall portion 142 and deformed. Further, by setting the second extension time Tb to a time equal to or longer than the time ΔT corresponding to the amount of variation in the timing of the change in the light reception output signal of the first photosensor 171, the pusher 141 (clamping mechanism) can be 14) moves from the open position to the closed position, after detecting the blockage by the first photosensor 171, the pusher 141 is moved for the second extension time Tb, and then the movement of the pusher 141 is stopped. Therefore, the infusion tube 3b can be properly closed by the clamp mechanism 14 regardless of manufacturing variations of the components.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments. Moreover, the effects described in the present embodiment are merely enumerations of the most suitable effects resulting from the present invention, and the effects of the present invention are not limited to those described in the present embodiment.

For example, in the present embodiment, the clamping device 1 is applied to the drip monitoring device 100 that monitors dripping of an infusion droplet in a drip tube, but the present invention is not limited to this. That is, the clamp device 1 may be applied to an extracorporeal circulation device such as a dialysis device having a blood circuit.

1 clamp device 2 infusion bag 3 drip tube 3b infusion tube (tube)
4 clamp 5 light emitting unit 6 light receiving unit 7 amplifier circuit 8 control unit 9 control circuit 10 LED driver 11 LED
12 LCD driver 13 LCD
14 clamping mechanism 15 DC motor (driving unit)
16 motor current detection circuit 17 photosensor (operation detection unit)
20 droplet detector 81 drive time setting unit 82 drive control unit 100 drip monitor

Claims (6)

a clamping mechanism for opening or closing the tube;
a driving unit that drives the clamping mechanism;
a drive current detection unit that detects the drive current of the drive unit;
an operation detection unit that detects opening or closing of the tube by the clamping mechanism;
a drive control unit that drives the drive unit by outputting a drive signal and stops driving the drive unit by stopping the output of the drive signal;
a driving time setting unit that sets an extension time from detecting blockage of the tube to stopping the output of the driving signal based on the current value detected by the driving current detecting unit;
The drive control unit stops driving the drive unit based on the extension time set by the drive time setting unit when the operation detection unit detects that the tube is blocked. 2. The clamping device according to claim 1, wherein said drive time setting section sets said extension time based on an amount of increase in said current value per time at a predetermined timing in a drive state of said drive section. The drive time setting unit obtains a slope of change in the current value from an amount of increase in the current value per time at a predetermined timing in the drive state of the drive unit,
setting a first extension time as the extension time when the slope of the change in the current value is less than a predetermined threshold;
3. The clamping device according to claim 2, wherein a second extension time longer than the first extension time is set as the extension time when the slope of the change in the current value is equal to or greater than the predetermined threshold. 2. The clamping device according to claim 1, wherein said driving time setting section sets said extension time based on said current value at a specific timing. The driving time setting unit
when the current value is less than a predetermined value, setting a first extension time as the extension time;
5. The clamping device according to claim 4, wherein a second extension time longer than the first extension time is set as the extension time when the current value is equal to or greater than the predetermined value. A drip monitoring device for monitoring dripping of infusion droplets in a drip tube,
a droplet detection unit that detects the dropping of droplets;
and a clamping device according to any one of claims 1 to 5,
The driving control unit drives the driving unit when the droplet detecting unit continues to fail to detect a droplet for a predetermined period of time.

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