KR20170083398A - Apparatus and method for infusing medical liquid - Google Patents

Abstract

The chemical liquid injecting apparatus includes a micro pump, a power supply unit, a current sensor unit, and a control unit. The micro pump pumps the chemical liquid by alternately repeating a first stroke in which the chemical liquid is sucked and a second stroke in which the chemical liquid is discharged. The power supply unit outputs a driving voltage for driving the micro pump to the micro pump. The current sensor unit senses a current supplied from the power supply unit to the micropump. The control unit controls the power supply unit and switches the first and second strokes based on the current value sensed by the current sensor unit.

Description

[0001] Apparatus and method for infusing medical liquid [

The present invention relates to an apparatus and a method for injecting a chemical liquid, and more particularly to an apparatus and a method for injecting a chemical liquid such as insulin minutely.

Diabetes mellitus is a disease based on metabolic abnormalities caused by a lack of insulin, one of the hormones secreted by the body. Diabetic patients can use injectable insulin as one of the active methods. An insulin infusion device can be used so that insulin can be injected into the body in a manner suited to the blood sugar change of the patient.

The insulin injector uses a micropump to inject insulin into the body. When the micropump performs a pumping operation using a chemical reaction, the chemical reaction rate varies depending on the temperature, so that the fluidity of the insulin may vary. In order to compensate for this, if the pumping cycle is set based on a low temperature, the pumping cycle becomes too long at room temperature, so that the micropump is idle and the amount of pumping per unit time may decrease. When the pumping cycle is set based on the room temperature, the amount of insulin injected in one pumping cycle may be reduced at a low temperature, so that it is impossible to supply an accurate amount of insulin.

SUMMARY OF THE INVENTION An object of the present invention is to provide an apparatus and a method for injecting a drug solution such as insulin,

According to an aspect of the present invention, there is provided a chemical liquid injecting apparatus including a micro pump for pumping a chemical liquid by alternately repeating a first stroke in which a chemical liquid is sucked and a second stroke in which the chemical liquid is discharged, A current sensor unit for sensing a current supplied to the micro pump from the power supply unit, and a controller for controlling the power supply unit, and based on the current value sensed by the current sensor unit, And a control unit for switching between the first stroke and the second stroke.

According to an example of the chemical liquid injecting apparatus, when the absolute value of the current sensed by the current sensor unit during any one of the first stroke and the second stroke becomes smaller than the current set value, It is possible to control the power supply unit to switch to another stroke.

According to another example of the chemical liquid injecting apparatus, the chemical liquid injecting apparatus may further include a temperature sensor unit for sensing the temperature. The controller may set the current set value based on the temperature sensed by the temperature sensor unit.

According to another example of the chemical liquid injector, the controller may set the current set value higher as the temperature is higher.

According to another example of the chemical liquid injecting apparatus, the controller may set the current set value based on the maximum current value sensed by the current sensor unit at the start time of each of the first and second strokes.

According to another example of the chemical liquid injecting apparatus, the micropump is provided with an electric osmotic pump (hereinafter, referred to as " pump ") that receives a positive drive voltage from the power supply during the first stroke, and receives a negative drive voltage from the power supply during the second stroke electro-osmotic pump).

According to another example of the above-described chemical liquid injecting apparatus, the micropump includes a fluid path portion providing a flow path to the working fluid, a membrane disposed in the fluid path portion, the membrane allowing flow of the working fluid, And a first diaphragm disposed in the first diaphragm and a second diaphragm disposed in the second diaphragm, the first diaphragm and the second diaphragm being separated from each other by the flow of the working fluid, the diaphragm being disposed between the membrane and the first and second diaphragms, And an electrode unit including first and second electrodes to which the driving voltage is applied.

According to another example of the above-described chemical liquid injecting apparatus, the micropump is disposed on both sides of at least one of the first and second diaphragms, respectively, and the first and second diaphragms, And may further include a deformation restricting portion.

According to another example of the above-described chemical liquid injecting apparatus, the control unit may determine the magnitude of the current supplied from the power supply unit to the micropump when the at least one diaphragm is strained by the first and second strain restricting units, Current setting value can be set.

According to another example of the chemical liquid injecting apparatus, when the driving voltage is applied to the first and second electrodes, one of the first and second electrodes may generate ions and the other may consume ions. The working fluid may deform the first and second diaphragms as they flow through the membrane to achieve ion balance.

According to another example of the chemical liquid injecting apparatus, the power supply unit may include: a power source for outputting the driving voltage through a first terminal and a second terminal; and a control unit for controlling the first and second terminals and the first And a switch unit for switching connection between the first electrode and the second electrode. Wherein the switch portion connects the first and second terminals to the first and second electrodes respectively during the first stroke and connects the first and second terminals to the second and first electrodes respectively during the second stroke .

According to another example of the chemical liquid injecting apparatus, the control unit may control the switch unit so that the switch unit switches the connection when the absolute value of the current sensed by the current sensor unit becomes smaller than the current set value.

According to another example of the above-described liquid injecting apparatus, the liquid injecting apparatus may further include: a chemical liquid storing section for storing the chemical liquid; a first flow path connected between the liquid chemical storing section and the micropump; A second check valve for allowing the chemical liquid to flow only in a direction toward the micro pump, a second flow path connected to the injection needle and the micropump, and a second flow path for the chemical liquid to flow from the micropump to the injection needle And a second check valve for allowing the fluid to flow only in the direction of the first check valve.

According to an aspect of the present invention, a positive driving voltage is applied to a micropump to suck a chemical liquid. When the magnitude of the current applied to the micropump becomes smaller than the first current setting value, the step of applying a positive driving voltage to the micropump ends. A negative driving voltage is applied to the micropump to eject the chemical liquid. When the magnitude of the current applied to the micropump becomes smaller than the second current set value, the step of applying the negative driving voltage to the micropump ends.

According to an example of the chemical liquid injecting method, the first and second current setting values may be set based on the sensed temperature.

According to another example of the chemical solution injection method, the micropump may be an electro-osmotic pump.

According to another example of the above chemical solution injection method, the micropump further includes a fluid path portion providing a flow path to the working fluid, a membrane disposed in the fluid path portion, the membrane allowing flow of the working fluid, And a diaphragm disposed on both sides of the diaphragm and including a first diaphragm and a second diaphragm that isolate the working fluid and are deformed by the flow of the working fluid, and a diaphragm disposed between the membrane and the first and second diaphragms, And an electrode unit including first and second electrodes to which the driving voltage is applied.

According to another example of the chemical liquid injecting method, the micropump may be disposed on both sides of at least one of the first and second diaphragms, and may include first and second diaphragms, Two strain restricting portions may be further included.

Other aspects, features, and advantages will become apparent from the following drawings, claims, and detailed description of the invention.

The chemical liquid injector according to various embodiments of the present invention can rapidly inject an accurate amount of chemical liquid such as insulin.

1 is a block diagram conceptually showing a chemical liquid injecting apparatus according to an embodiment of the present invention.
2 is a block diagram conceptually showing a chemical liquid injecting apparatus according to another embodiment of the present invention.
3 is a block diagram schematically illustrating a power supply unit of a chemical liquid injector according to an embodiment of the present invention.
4 is a cross-sectional view schematically showing a micropump according to an embodiment of the present invention.
5 is a cross-sectional view schematically showing a micropump according to another embodiment of the present invention.
6 is a flowchart illustrating a method of injecting a chemical solution during one pumping cycle according to one embodiment of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. The effects and features of the present invention and methods of achieving them will be apparent with reference to the embodiments described in detail below with reference to the drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings, wherein like reference numerals refer to like or corresponding components throughout the drawings, and a duplicate description thereof will be omitted .

In the following embodiments, the terms first, second, etc. are used for the purpose of distinguishing one element from another element, rather than limiting. The singular expressions include plural expressions unless the context clearly dictates otherwise. Or " comprising " or " comprises ", or " comprises ", means that there is a feature, or element, recited in the specification and does not preclude the possibility that one or more other features or elements may be added.

1 is a block diagram conceptually showing a chemical liquid injecting apparatus according to an embodiment of the present invention.

1, the chemical liquid injector 100 includes a micro pump 110, a power source 120, a current sensor 130, and a controller 140.

The micro pump 110 is configured to pump the chemical liquid by alternately repeating the suction stroke in which the chemical liquid is sucked and the discharge stroke in which the chemical liquid is discharged. The power supply unit 120 is configured to output a driving voltage for driving the micropump 110 to the micropump 110. The current sensor unit 130 is configured to sense a current supplied from the power supply unit 120 to the micro pump 110. The control unit 140 controls the power supply unit 120 and is configured to switch the suction stroke and the discharge stroke based on the current value sensed by the current sensor unit 130. [

The chemical liquid injector 100 includes a first liquid passage 170 connected between the liquid storage unit 150 storing the chemical liquid, the injection needle 160 discharging the chemical liquid, the chemical liquid storage unit 150, and the micropump 110, And a second flow path 180 connected between the injection needle 160 and the micropump 110.

The micropump 110 is configured to pump the chemical liquid in accordance with the pumping cycle. The drug solution may be a liquid containing a drug such as insulin. The micropump 110 may pump a certain amount of the chemical liquid per pumping cycle. For example, the constant amount may be from a few tens of nanoliters to several microliters. The micropump 110 can generate a flow rate of several micro liters to several tens of micro liters per minute.

One pumping cycle includes a suction stroke and a discharge stroke. In the suction stroke, the micropump 110 generates a suction force, and the generated suction force causes the chemical liquid to flow into the micropump 110 from the chemical liquid reservoir 150 and is sucked into the micropump 110. In the discharge stroke, the micropump 110 generates a discharge power, and the chemical fluid is discharged from the micropump 110 and discharged to the outside through the injection needle 160 by the generated discharge power. The suction stroke may be referred to as a first stroke, and the discharge stroke may be referred to as a second stroke. Since the micro pump 110 repeats the pumping cycle, the suction stroke starts again after the discharge stroke.

According to another embodiment, there may be an idle stroke between the inhalation and ejection strokes and between the ejection stroke and the inhalation stroke. For example, when it is necessary to discharge a smaller amount of the chemical liquid than the maximum pumping amount of the micro pump 110, the amount of the chemical liquid injecting apparatus 100 per unit time can be adjusted by idling the micro pump 110 between the suction stroke and the discharge stroke have. According to yet another embodiment, there may be an idle time between pumping cycles to adjust the dose per unit time of the chemical liquid injector 100. [ For example, although the discharge stroke starts immediately after the suction stroke, another pumping cycle may be started after the idle time for adjusting the injection amount per unit time after the pumping cycle after the discharge stroke ends.

According to one example, the micropump 110 is a pump configured to pump a chemical liquid using a driving voltage supplied from the power supply unit 120. All kinds of pumps capable of generating a suction power capable of sucking the chemical liquid and a discharge power capable of discharging the chemical liquid using the driving voltage supplied from the power supply unit 120 can be used as the micro pump 110. [ For example, any type of pump, such as a mechanical displacement type micro pump and an electromagnetic motion type micro pump, can be used as the micro pump 110. A mechanical displacement type micropump is a pump that uses a solid or fluid motion such as a gear or a diagram to cause a pressure difference to induce a fluid flow. The pump is a diaphragm displacement pump, a fluid displacement pump , A rotary pump, and the like. Electromagnetic exercise type micro pump is a pump which uses electric or magnetic type energy to directly transfer fluid. It is used as an electro hydrodynamic pump (EHD), an electro osmotic pump, a hydrodynamic pump A magneto hydrodynamic pump, and an electro wetting pump.

The micropump 110 according to various embodiments of the present invention may be a pump that consumes current having a positive correlation with the rate at which fluid flows within the micropump 110 during the suction stroke and the discharge stroke. For example, the micropump 110 may be an electroosmotic pump or a piezo pump. For example, the micropump 110 may be a pump that moves fluids together with ions by moving ions in the fluid through an electric field. At this time, in the micropump 110, electrons are moved by the movement of ions, and the micropump 110 consumes current from the power supply unit 120. In this case, if the micro pump 110 can no longer generate a suction force or a fold output by the internal structure, the micro pump 110 is consumed because the ions in the fluid can not be moved or the moving speed of the ions is lowered The magnitude of the current to be applied is reduced. On the contrary, when the moving speed of the fluid in the micropump 110 is high, the amount of current consumed by the micropump 110 due to the ions moved with the fluid, that is, electrons, increases.

The power supply unit 120 outputs a driving voltage for driving the micropump 110 to the micropump 110. The power supply unit 120 may supply a positive driving voltage, for example, and a negative driving voltage, for example, during the ejection stroke of the micro pump 110 during the suction stroke of the micro pump 110 under the control of the control unit 140. [ When a positive driving voltage is applied to the micropump 110, the fluid in the micropump 110 may flow in the first direction to generate a suction force. When a negative drive voltage is applied to the micropump 110, the micropump 110 can flow in a second direction, which is the opposite direction of the first direction, . However, this is exemplary, and the power supply unit 120 may supply a negative driving voltage during the intake stroke and supply a positive driving voltage during the ejection stroke.

The driving voltage may be a DC voltage, for example. The power supply unit 120 may include a voltage regulator circuit to supply a stable DC voltage although not shown. Also, the power supply unit 120 may adjust the voltage level of the driving voltage under the control of the controller 140. For example, in order to increase the pumping amount of the micropump 110, the power supply unit 120 may supply a larger level of the driving voltage.

The current sensor unit 130 senses a current supplied from the power supply unit 120 to the micro pump 110. The current sensor unit 130 may provide the control unit 140 with current information I corresponding to the sensed current. The current information I may be an analog signal having a voltage or current level corresponding to the sensed current or a digital signal corresponding to the sensed current. When the power supply unit 120 supplies a positive drive voltage to the micropump 110, the current sensor unit 130 senses a positive current and the power supply unit 120 supplies a negative drive voltage to the micropump 110 The current sensor unit 130 can sense a negative current. As described above, the current supplied to the micropump 110 may have a positive correlation with the flow rate of the fluid in the micropump 110. When the fluid in the micro pump 110 moves in the first direction, the current sensor unit 130 senses the positive current and when the fluid in the micro pump 110 moves in the second direction, Can sense negative current. In addition, when the flow rate of the fluid in the micro pump 110 decreases, the magnitude of the current sensed by the current sensor unit 130 may also be reduced.

The control unit 140 is configured to control the power supply unit 120. The control unit 140 can control the timing of the suction stroke and the discharge stroke by controlling the polarity of the drive voltage output from the power supply unit 120. [ The control unit 140 is configured to switch the suction stroke and the discharge stroke based on the current value sensed by the current sensor unit 130. [ The control unit 140 outputs a control signal CS for controlling the power supply unit 120 and the power supply unit 120 can switch the suction stroke and the discharge stroke in response to the control signal CS.

According to an example, the control unit 140 may control the power supply unit 120 to terminate the suction stroke when the absolute value of the current sensed by the current sensor unit 130 during the intake stroke becomes smaller than the first current setting value . The control unit 140 can control the power supply unit 120 to end the suction stroke and start the discharge stroke. The control unit 140 may control the power supply unit 120 to terminate the discharge stroke when the absolute value of the current sensed by the current sensor unit 130 during the discharge stroke becomes smaller than the second current setting value. The control unit 140 can control the power supply unit 120 to finish the discharge stroke and start the suction stroke. Here, the first current setting value and the second current setting value may be equal to each other.

The controller 140 may further include a memory for storing the first current setting value and the second current setting value, and the first current setting value and the second current setting value may be stored in the memory 140, And the like. For example, the control unit 140 may set the first current setting value based on the maximum current value sensed by the current sensor unit 130 at the start of the intake stroke. The control unit 140 may set the second current setting value based on the maximum current value sensed by the current sensor unit 130 at the start time of the discharge stroke.

At the start of each of the suction stroke and the discharge stroke, that is, at the start of each stroke, the micropump 110 has a high flow rate while reversing the flow direction of the fluid inside. The micropump 110 may have a restoring force, and the fluid inside the micropump 110 may have a high flow rate at the start of each stroke due to the restoring force. As a result, a current having the largest magnitude flows at the start point of each stroke in the micropump 110.

The magnitude of the current flowing at the beginning of each stroke may vary depending on the ambient temperature of the micropump 110. The control unit 140 may set the first and second current setting values based on the maximum current value flowing to the micropump 110 at the start time of each stroke. The maximum current value flowing to the micropump 110 at the start of each stroke can be sensed by the current sensor unit 130. [ The current set values may correspond to the current value flowing to the micropump 110 at the end of each stroke. The control unit 140 may include a memory for storing first and second current setting values corresponding to the maximum current value flowing to the micropump 110 at the start time of each stroke. In this memory, the first and second current setting values corresponding to the maximum current value flowing at the start of each stroke can be stored in the form of a lookup table. According to an example, the user of the chemical liquid injecting apparatus 100 may vary the first current setting value and the second current setting value.

The chemical solution storage part 150 stores the chemical solution. The chemical solution storage part 150 may be included in the chemical liquid injecting apparatus 100 or may be disposed outside the chemical liquid injecting apparatus 100 and connected through the first flow path 170. The first flow path 170 is connected between the liquid reservoir 150 and the micropump 110 to provide a path through which the liquid flows from the liquid reservoir 150 to the micropump 110. The first check valve 172 may be provided in the first flow path 170 to allow the chemical liquid to flow only in the direction from the chemical solution storage part 150 to the micro pump 110, Therefore, even if the chemical liquid is discharged from the micro pump 110, the chemical liquid does not flow to the chemical liquid storage part 150 by the first check valve 172. The first check valve 172 is substantially closed so that the chemical liquid in the first flow path 170 can not flow in the direction opposite to the suction direction during the discharge stroke of the micropump 110. [ The first check valve 172 is connected to the first flow path 170 and the micropump 110 and the second check valve 172 is connected to the first flow path 170. [ Or may be installed in the micro-pump 110. The micro-

The injection needle 160 is a portion to be inserted into the body, and is a portion where the chemical liquid is discharged. The injection needle 160 may be mounted on the outside of the chemical liquid injecting apparatus 100 or may be disposed outside the chemical liquid injecting apparatus 100 and connected through the second flow path 180. The second flow path 180 is connected between the micropump 110 and the injection needle 160 to provide a path through which the chemical liquid discharged from the micropump 110 can flow into the injection needle 160. The second check valve 182 may be provided in the second flow path 180 to allow the chemical liquid to flow only in the direction from the micropump 110 to the injection needle 160, that is, in the discharge direction. Therefore, even when the drug solution is sucked into the micro pump 110, the drug solution does not flow from the injection needle 160 to the micro pump 110. The second check valve 182 is substantially blocked so that the chemical liquid in the second flow path 180 can not flow in the direction opposite to the discharge direction during the suction stroke of the micropump 110. [ The second check valve 182 is connected to the second flow path 180 and the micropump 110. The second check valve 182 is connected to the second flow path 180, Or may be installed in the micro-pump 110. The micro-

2 is a block diagram conceptually showing a chemical liquid injecting apparatus according to another embodiment of the present invention.

2, the chemical liquid injector 100a includes a micropump 110, a power supply 120, a current sensor 130, a temperature sensor 135, and a controller 140. The micropump 110, the power source unit 120, the current sensor unit 130 and the control unit 140 of the chemical liquid injector 100a shown in FIG. 2 include the micropump 110, the power source unit 120 ), The current sensor unit 130, and the control unit 140, which are not repeatedly described.

The temperature sensor unit 135 senses the temperature and may provide the controller 140 with temperature information T corresponding to the sensed temperature. The temperature information T may be an analog signal having a voltage or current level corresponding to the sensed temperature or a digital signal corresponding to the sensed temperature. The temperature sensor unit 135 may be disposed adjacent to the micropump 110 to sense the temperature of the micropump 110. In this case, the temperature sensor unit 135 may include a thermistor element proportional to or inversely proportional to the temperature. According to another example, the controller 140 can sense the temperature by mounting the temperature sensor unit 135 therein.

As described above, when the absolute value of the current sensed by the current sensor unit 130 during the current ongoing stroke becomes smaller than the current set value, the control unit 140 controls the power supply unit 120 to switch to another stroke have. For example, the control unit 140 may control the power supply unit 120 to terminate the suction stroke when the absolute value of the current sensed by the current sensor unit 130 during the suction stroke becomes smaller than the first current setting value. The control unit 140 can control the power supply unit 120 to end the suction stroke and start the discharge stroke. The control unit 140 may control the power supply unit 120 to terminate the discharge stroke when the absolute value of the current sensed by the current sensor unit 130 during the discharge stroke becomes smaller than the second current setting value. The control unit 140 can control the power supply unit 120 to finish the discharge stroke and start the suction stroke. Here, the first current setting value and the second current setting value may be equal to each other.

The control unit 140 may set the first and second current setting values based on the temperature sensed by the temperature sensor unit 135. [ For example, the control unit 1400 may set the first and second current set values higher as the temperature sensed by the temperature sensor unit 135 is higher. [0052] The controller 140 controls the first current setting value and the second current setting The controller 140 may further include a memory for storing the first and second current setting values corresponding to the sensed temperature in the memory. The first and second current setting values may be set to correspond to the temperatures sensed by the temperature sensor unit 135 by referring to the lookup table.

3 is a block diagram schematically illustrating a power supply unit of a chemical liquid injector according to an embodiment of the present invention.

Referring to FIG. 3, the power supply unit 120 may include a power supply 122 and a switch unit 124. The power supply unit 120 may supply a driving voltage to the first electrode 114 and the second electrode 115 of the micropump 110. [

The power source 122 includes a first terminal 122a and a second terminal 122b and the first terminal 122a is the anode of the power source 122 and the second terminal 122b is connected to the power source 122 ). ≪ / RTI >

The switch unit 124 may be configured to switch the connection between the first and second terminals 122a and 122b and the first and second electrodes 114 and 115 according to the control signal CS of the controller 140 .

The power supply unit 120 supplies a positive drive voltage, for example, a negative drive voltage during the ejection stroke of the micropump 110 under the control of the control unit 140 as described above . To this end, the switch unit 124 connects the first terminal 122a to the first electrode 114 and the second terminal 112b to the second electrode 115b in response to, for example, the control signal CS of the first level, ). The switch unit 124 connects the first terminal 122a to the second electrode 115 and the second terminal 112b to the first electrode 114 in response to a control signal CS of a second level, Lt; / RTI > For example, the first level may be a high level and the second level may be a low level.

The control unit 140 may output the control signal CS of the first level to the switch unit 124 during the intake stroke and output the control signal CS of the second level to the switch unit 124 during the ejection stroke .

When the absolute value of the current sensed by the current sensor unit 130 in FIG. 1 becomes smaller than the current setting value, the control unit 140 controls the switch unit 124 to switch between the first and second terminals 122a and 122b and the first The level of the control signal CS may be inverted to switch the connection between the first and second electrodes 114 and 115. [ For example, if the absolute value of the current sensed during the intake stroke becomes smaller than the current set value, the control unit 140 can output the level of the control signal CS to the second level and output it. The switch unit 124 connects the first and second terminals 122a and 122b to the second and first electrodes 115 and 114 in response to the second level control signal CS, ), A negative driving voltage is applied, and the ejection stroke can be started.

If the absolute value of the current sensed during the ejection stroke becomes smaller than the current set value, the control unit 140 can output the level of the control signal CS to the first level and output it. The switch unit 124 connects the first and second terminals 122a and 122b to the first and second electrodes 114 and 115 in response to the first level control signal CS, ), A positive driving voltage is applied, and the suction stroke can be started.

4 is a cross-sectional view schematically showing a micropump according to an embodiment of the present invention.

Referring to FIG. 4, a first check valve 172 and a second check valve 182 are connected to the micropump 110. However, this is exemplary, and the first check valve 172 and the second check valve 182 may be provided in the micropump 110, or may be installed in the first flow path 170 and the second flow path 180, respectively have.

The micropump 110 may be any pump as long as it consumes current having a positive correlation with the flow rate of the fluid in the micropump 110 during the suction stroke and the discharge stroke, as described above. According to one embodiment, a micropump 110 operating in an electroosmotic mode is illustrated by way of example in FIG. However, the present invention is not limited to electroosmotic micropumps.

The micropump 110 includes a membrane 111, a working fluid 112, a fluid path portion 113, first and second electrodes 114 and 115, and first and second diaphragms 116 and 117 can do. The fluid path portion 113 provides a path through which the working fluid 112 can flow. The membrane 111 is disposed in the fluid path portion 113 and the working fluid 112 can flow through the membrane 111. [ The first and second diaphragms 116 and 117 are disposed on both sides of the membrane 111 to isolate the working fluid 112 and deformed by the flow of the working fluid 112. The first and second diaphragms 116 and 117 may constitute a diaphragm portion. The first and second electrodes 114 and 115 are respectively disposed between the membrane 111 and the first and second diaphragms 116 and 117 and a driving voltage output from the power supply unit 120 is applied. The first and second electrodes 114 and 115 may constitute an electrode portion.

The membrane 111 is installed in a fluid path portion 113 that provides a path through which the working fluid 112 flows and may be formed of a porous material or structure so that the working fluid 112 can flow.

The first and second electrodes 114 and 115 are disposed on both sides of the membrane 111 in the fluid path portion 113, respectively. 4, the first and second electrodes 114 and 115 may be disposed in contact with both sides of the membrane 111, and the gap between the first and second electrodes 114 and 115 may be And can be held by the membrane 111. However, this is illustrative, and the first and second electrodes 114 and 115 may be disposed apart from both sides of the membrane 111. The first and second electrodes 114 and 115 may be formed of a porous material or a structure so that the working fluid 112 may flow as in the case of the membrane 111. [ For example, the first and second electrodes 114 and 115 may be made of porous carbon.

The first and second electrodes 114 and 115 are electrically connected to the power supply unit 120 to receive a driving voltage and can electrochemically react with the working fluid 112. The ions in the working fluid 112 move due to the electrochemical reaction of the first and second electrodes 114 and 115.

The power supply unit 120 may alternate the polarities of the driving voltages supplied to the first and second electrodes 114 and 115 under the control of the control unit 140 as described above. Thereby, the working fluid 112 in the micropump 110 alternately flows in the first direction and the second direction, and a suction force and a discharge power are generated.

When a driving voltage is applied to the first and second electrodes 114 and 115, one of the first and second electrodes 114 and 115 (e.g., 114) generates ions and the other (e.g., 115) . ≪ / RTI > The working fluid 112 flows through the membrane 111 to achieve ion balance. As the working fluid 112 flows, the first and second diaphragms 116, 117 are deformed.

For example, when a positive driving voltage is applied to the first and second electrodes 114 and 115, the working fluid 112 flows in a first direction, and the first and second diaphragms 116 and 117 And is deformed convexly in the first direction. Accordingly, a suction force is generated as the space on the left side of the first diaphragm 116 is widened. By this suction force, the chemical liquid flows into the micro pump 111 through the first check valve 172. Conversely, when a negative driving voltage is applied to the first and second electrodes 114 and 115, the working fluid 112 flows in the second direction, and the first and second diaphragms 116 and 117 are in the second Direction. As a result, the space on the left side of the first diaphragm 116 is narrowed and a folded output is generated. By this discharge, the chemical liquid passes through the second check valve 182 and is discharged from the micro pump 111.

The first and second diaphragms 116 and 117 may be made of a synthetic resin film on which aluminum is deposited or an ethylene vinyl alcohol copolymer (EVOH). The first diaphragm 116 and the second diaphragm 117 may be formed of a flexible material such as polyurethane or rubber.

The fluid path portion 113 has first and second openings 113a and 113b for delivery of a suction force and a discharge power. Illustratively, although the first and second check valves 172 and 182, which move the chemical liquid by the suction force and the discharge power, are shown connected to the first opening 113a of the fluid path portion 113, And the second check valves 172 and 182 may be connected to the second opening 113b of the fluid path portion 113. [ A check valve may also be connected to both the first and second openings 113a and 113b of the fluid path portion 113. [

The driving fluid 112 includes ions that move by the driving voltage applied to the first and second electrodes 114 and 115. The driving fluid 112 may be referred to as an electrolyte solution or an electrolyte solution. The driving fluid 112 may be electrolyzed by a driving voltage applied to the first and second electrodes 114 and 115, whereby ions may be generated. The efficiency of electrolysis may vary depending on the composition of the driving fluid 112, the temperature, the hydrogen ion concentration, the presence or absence of impurities, and the like. For example, the driving fluid 112 may be ammonium chloride solution or diluted sulfuric acid.

The driving fluid 112 is separated into two spaces by the membrane 111. When a driving voltage is applied to the first and second electrodes 114 and 115, ions are generated in one electrode (for example, 114), ions are reduced in another electrode (for example, 115) A gradient is created. The solvent in the driving fluid 112 moves through the membrane 111 due to the gradient of the ion concentration. As a result, the driving fluid 112 is caused to flow in one direction, and the micropump 110 generates a suction force or a folding output. The micro pump 110 uses the principle of electroosmosis phenomenon.

The electroosmosis phenomenon is a phenomenon in which the driving fluid 112 is divided into the membrane 111 and the like and the driving voltage is applied to the first and second electrodes 114 and 115 on both sides of the membrane 111, The electric charge of the electric double layer moves by the electric field, and the driving fluid 112 moves thereby causing the osmosis phenomenon. The direction of movement is determined by the sign of the excess charge, and the electroosmotic rate depends on the strength of the electric field, the amount of excess charge, the electrolyte concentration, the temperature, and the viscosity.

When the driving voltage is applied to the first and second electrodes 114 and 115, the driving fluid 112 moves through the membrane 111 in one direction due to the electroosmosis phenomenon. Since the driving fluid 112 is isolated by the first and second diaphragms 116 and 117, the first and second diaphragms 116 and 117 are moved by the movement of the driving fluid 112, It is deformed in the moving direction. As the first and second diaphragms 116 and 117 are deformed, the restoring force in the direction opposite to the moving direction of the driving fluid 112 also increases. When the force to move the driving fluid 112 by the electroosmosis phenomenon becomes equal to the restoring force, the driving fluid 112 can no longer move. Whereby the gradient of the ion concentration is strengthened, and the ion generation rate and the ion reduction rate are reduced. As a result, the magnitude of the current of the micropump 110 is reduced.

The control unit 140 can sense that the driving fluid 112 in the micropump 110 is no longer moved when the current of the micropump 110 becomes smaller than the current setting value, In order to switch, the power supply unit 120 may be controlled.

Conventionally, it has not been known when the driving fluid 112 is no longer able to move. In other words, at which point the micropump 110 could not generate a suction force any longer during the suction stroke, nor could it be determined that it could no longer generate a double output during the discharge stroke. Therefore, the micro pump 110 switches the stroke according to the preset time. However, as the micropump 110 utilizes the electroosmosis phenomenon, the electroosmotic rate may vary depending on the temperature, the strength of the electric field, the electrolyte concentration, and the like. Accordingly, the predetermined time may be after a considerable time has elapsed since the driving fluid 112 no longer moves. In this case, although the micropump 110 can inject a larger amount of the drug solution, it may cause a problem that only a small amount of the drug solution is injected. Further, even if the predetermined time has passed, the driving fluid 112 may be in a state in which it can move further. In this case, the chemical liquid injector 100 injects a certain amount of the chemical liquid by injecting a predetermined amount of chemical liquid in each pumping cycle, but the micropump 110 is switched to another line Accordingly, there is a problem that a certain amount of the chemical solution can not be injected.

According to various embodiments of the present invention, the controller 140 may sense when the drive fluid 112 is no longer moving through the magnitude of the current in the micropump 110. Thus, it is possible to know exactly when each stroke ended, and to start another stroke after each stroke has ended. Therefore, it is possible to ensure that the amount of the chemical liquid injected in one pumping cycle is constant, and also the chemical liquid can be injected at the maximum injection speed of the micro pump 110. Therefore, according to various embodiments of the present invention, the chemical liquid injecting apparatus 100 has an advantage that it can inject precisely the required amount quickly.

The first check valve 172 includes a first nozzle 178 formed in a second direction, a first fluid opening / closing means 174 located inside the first check valve 172 for opening and closing the first nozzle 178, And a first spring 176 that allows the first fluid opening and closing means 174 to open and close the first nozzle 178 by a pressure difference within the first nozzle 178 and the first check valve 172 . A first flow path 170 may be connected to an end of the first nozzle 178.

When the first diaphragm 116 expands in the first direction, a hydraulic pressure difference occurs between the chemical liquid passing through the first nozzle 178 and the chemical liquid inside the first check valve 172. At this time, the chemical liquid passing through the first nozzle 178 applies a force to the first fluid opening / closing means 174 in the direction in which the first spring 176 contracts, and accordingly, the first nozzle 178 is opened The chemical liquid in the one flow path 170 flows into the micropump 110 through the first check valve 172. When the first diaphragm 116 expands in the second direction, since the hydraulic pressure of the chemical liquid located in the first direction of the first fluid opening / closing means 174 is higher, the first fluid opening / closing means 174 moves in the first direction You will receive strength. The first fluid opening / closing means 174 is brought into close contact with the first nozzle 178, and the chemical liquid can not pass through the first check valve 172.

The first nozzle 178 may have a shape in which the cross-sectional area of the chemical liquid flows along the first direction. When the chemical liquid in the first flow path 170 is introduced by the suction force generated as the first diaphragm 116 is deformed in the first direction, the flow rate of the chemical liquid due to the first nozzle 178, The speed and flow pressure gradually increase. Accordingly, the force applied to the first fluid opening / closing means 174 by the chemical liquid that has passed through the first nozzle 178 can be increased.

The first fluid opening / closing means 174 may be in the form of a ball, and may be formed of silicone rubber or Viton rubber material. The first fluid opening / closing means 174 may have various shapes, but may be in the form of a ball in order to maximize the adhesion force for opening and shielding the first check valve 172. The first fluid opening / closing means 174 is not particularly limited in terms of material, but a rubber material can be used so that the first fluid opening / closing means 174 can be kept in tight contact with the inner surface of the first check valve 172. The first fluid opening / closing means 174 may be made of a silicone rubber or a vatone rubber material having chemical resistance and corrosion resistance.

The second check valve 182 includes a second nozzle 188 formed in a first direction, a second fluid opening and closing means 184 located inside the second check valve 182 and opening and closing the second nozzle 188, And a second spring 186 that allows the second fluid opening and closing means 184 to open and close the second nozzle 188 by a pressure difference within the second nozzle 188 and the second check valve 182 . And the second flow path 180 may be connected to the end of the second check valve 182 in the second direction.

When the first diaphragm 116 expands in the second direction, a hydraulic pressure difference occurs between the chemical liquid passing through the second nozzle 188 and the chemical liquid inside the second check valve 182. At this time, the chemical liquid passing through the second nozzle 188 applies a force to the second fluid opening / closing means 184 in the direction in which the second spring 186 contracts, and accordingly, the second nozzle 188 is opened, The chemical solution in the pump 110 flows into the second flow path 180 through the second check valve 182. When the first diaphragm 116 expands in the second direction, since the hydraulic pressure of the chemical solution located in the first direction of the second fluid opening / closing means 174 is lower, the second fluid opening / closing means 184 moves in the first direction You will receive strength. The second fluid opening / closing means 184 is brought into close contact with the second nozzle 188, and the chemical liquid can not pass through the second check valve 182.

The second nozzle 188 may have a shape in which the cross-sectional area of the fluid flowing along the second direction is reduced. When the chemical liquid in the micro pump 110 is discharged by the discharge power generated as the first diaphragm 116 is deformed in the second direction, the flow of the chemical liquid due to the second nozzle 188, The speed and flow pressure gradually increase. Accordingly, the force applied to the second fluid opening / closing means 184 by the chemical liquid passing through the second nozzle 188 can be increased.

The second fluid opening / closing means 184 may be in the form of a ball, and may be formed of silicone rubber or Viton rubber material. The shape and material of the second fluid opening / closing means 184 may be the same as the shape and material of the first fluid opening / closing means 174.

5 is a cross-sectional view schematically showing a micropump according to another embodiment of the present invention.

5, the micropump 110a is substantially the same as the micropump 110 shown in FIG. 4, except that it further includes first and second deformation restricting portions 118 and 119. As shown in FIG. Descriptions of overlapping components are omitted. The micro pump 110a may be used as the micro pump 110 of the chemical liquid injecting apparatus 100, 100a shown in FIGS.

The first and second deformation restricting portions 118 and 119 are disposed on both sides of the first diaphragm 116 so as to limit a range in which the first diaphragm 116 is deformed. When the first diaphragm 116 is deformed in the first direction, the deformation range is limited by the second deformation restricting portion 119. Further, when the first diaphragm 116 is deformed in the second direction, the deformation range is limited by the first deformation restricting portion 118. [

The control unit 140 controls the current set value so that the current value supplied from the power supply unit 120 to the micropump 110a when the deformation of the first diaphragm 116 is limited by the first and second deformation restricting units 118 and 119, As shown in FIG. Accordingly, when the magnitude of the current sensed by the current sensor unit 130 becomes equal to the current set value, when the first diaphragm 116 is limited in its deformation by the first and second deformation restricting units 118 and 119 That is, when it is no longer possible to generate a suction force and a fold output. The control unit 140 can switch the current operation to the other operation when the detected current is equal to or smaller than the current setting value.

Although the first and second deformation restricting portions 118 and 119 are shown as being disposed on both sides of the first diaphragm 116 in FIG. 5, this is exemplary and the first and second deformation restricting portions 118 and 119 119 may be disposed on both sides of the second diaphragm 117. According to another example, two pairs of deformation restricting portions may be disposed on both sides of both the first diaphragm 116 and the second diaphragm 117 have.

In the absence of the first and second deformation restricting portions 118 and 119, when the chemical liquid injector 100 is used for a long time, the elastic force of the first and second diaphragms 116 and 117 weakens, The range in which the diaphragms 116 and 117 are deformed can be gradually increased. Thereby, the amount of the chemical liquid injected into one pumping cycle can be gradually increased. However, according to the present embodiment, the micropump 110a includes the first and second deformation restricting portions 118 and 119 that limit the range in which the first diaphragm 116 is deformed, And the range in which the first and second electrodes 116 and 117 are deformed can be kept constant. Therefore, even if time passes, the amount of the chemical liquid injected into one pumping cycle can be constant, and the chemical liquid injector 100 can inject the correct amount of the chemical liquid.

6 is a flowchart illustrating a method of injecting a chemical solution during one pumping cycle according to one embodiment of the present invention.

One pumping cycle includes a suction stroke for sucking the chemical liquid and a discharge stroke for discharging the chemical liquid. According to the chemical solution injecting method of this embodiment, a positive driving voltage is applied to the micropump (110 in FIG. 1) to suck the chemical liquid (S10). The positive driving voltage is supplied by the power supply unit 120 controlled by the control unit 140.

When the magnitude of the current applied to the micropump 110 becomes smaller than the first current setting value, the step of applying a positive driving voltage to the micropump is terminated (S20). The current sensor unit 130 senses a current applied to the micro pump 110 from the power source unit 120. [ The controller 140 may control the power supply unit 120 to prevent the power supply unit 120 from applying a positive driving voltage when the detected current becomes smaller than the first current setting value.

A negative driving voltage is applied to the micropump 110 to discharge the chemical liquid (S30). The negative driving voltage is supplied by the power supply unit 120 controlled by the control unit 140. The control unit 140 may control the power supply unit 120 to apply the negative driving voltage immediately when the positive driving voltage is not applied. According to another example, the control unit 140 may control the power supply unit 120 to apply a negative driving voltage after waiting for a predetermined time to inject an intended amount of the chemical liquid.

If the magnitude of the current applied to the micropump 110 becomes smaller than the second current setting value, the step of applying the negative driving voltage to the micropump is terminated (S40). If the magnitude of the sensed current becomes smaller than the second current setting value, the controller 140 may control the power supply unit 120 so that the power supply unit 120 no longer applies the negative driving voltage. The second current setting may be equal to the first current setting.

According to another embodiment of the present invention, the controller 140 may set the first and second current setting values based on the sensed temperature. The temperature can be sensed by the temperature sensor unit (135 in FIG. 2). The first and second current setpoints may vary depending on the temperature. For example, the higher the temperature, the higher the first and second current settings.

Although the present invention has been described with reference to the limited embodiments, various embodiments are possible within the scope of the present invention. It will also be understood that, although not described, equivalent means are also incorporated into the present invention. Therefore, the true scope of protection of the present invention should be defined by the following claims.

100, 100a: chemical liquid injection device
110, 110a: Micro pump 120: Power source
130: current sensor 140:
150: chemical liquid storage part 160: injection needle
170: first flow path 172: first check valve
180: second flow path 182: second check valve

Claims (18)

A micro pump for pumping the chemical liquid by alternately repeating a first stroke in which the chemical liquid is sucked and a second stroke in which the chemical liquid is discharged;
A power supply for outputting a driving voltage for driving the micropump to the micropump;
A current sensor unit for sensing a current supplied from the power supply unit to the micropump; And
And a control unit for controlling the power supply unit and switching the first stroke and the second stroke based on a current value sensed by the current sensor unit. The method according to claim 1,
The control unit controls the power supply unit to switch from one of the strokes to another strokes when the absolute value of the current sensed by the current sensor unit during any one of the first stroke and the second stroke becomes smaller than the current set value Wherein the chemical liquid injecting apparatus comprises: 3. The method of claim 2,
And a temperature sensor unit for sensing the temperature,
Wherein the control unit sets the current setting value based on the temperature sensed by the temperature sensor unit. The method of claim 3,
Wherein the control unit sets the current set value higher as the temperature is higher. 3. The method of claim 2,
Wherein the control unit sets the current setting value based on a maximum current value sensed by the current sensor unit at the start time of each of the first and second strokes. The method according to claim 1,
Wherein the micropump is an electro-osmotic pump that is supplied with a positive driving voltage from the power supply during the first stroke and is supplied with a negative driving voltage from the power supply during the second stroke. Injection device. The method according to claim 1,
The micro-
A fluid path portion providing a flow path to the working fluid;
A membrane disposed within the fluid path portion and allowing flow of the working fluid;
A diaphragm disposed on both sides of the membrane, the diaphragm including first and second diaphragms separated from the working fluid and deformed by the flow of the working fluid; And
And an electrode unit disposed between the membrane and the first and second diaphragms and including first and second electrodes to which the driving voltage output from the power supply unit is applied. 8. The method of claim 7,
Wherein the micropump further comprises first and second deformation restricting portions disposed on both sides of at least one of the first and second diaphragms to limit a range in which the at least one diaphragm is deformed. Injection device. 9. The method of claim 8,
Wherein the control unit sets the magnitude of the current supplied from the power supply unit to the micro pump when the deformation of the at least one diaphragm is restricted by the first and second deformation restricting units to the current setting value. Injection device. 8. The method of claim 7,
When the driving voltage is applied to the first and second electrodes, one of the first and second electrodes generates ions and the other consumes ions,
Wherein the working fluid deforms the first and second diaphragms as they flow through the membrane to achieve ion balance. 8. The method of claim 7,
The power supply unit,
A power source for outputting the driving voltage through a first terminal and a second terminal; And
And a switch unit for switching a connection between the first and second terminals and the first and second electrodes under the control of the control unit,
Wherein the switch portion connects the first and second terminals to the first and second electrodes respectively during the first stroke and connects the first and second terminals to the second and first electrodes respectively during the second stroke Wherein the chemical liquid injecting apparatus comprises: 12. The method of claim 11,
Wherein the control unit controls the switch unit so that the switch unit switches the connection when the absolute value of the current sensed by the current sensor unit becomes smaller than the current set value. The method according to claim 1,
A chemical solution storage portion in which the chemical solution is stored;
A first flow path connected between the liquid reservoir and the micropump;
A first check valve for causing the chemical liquid to flow only in a direction from the chemical liquid storage portion to the micro pump;
An injection needle through which the chemical liquid is discharged;
A second flow path connected to the injection needle and the micro pump; And
Further comprising: a second check valve for allowing the chemical liquid to flow only in a direction from the micropump to the injection needle. Applying a positive drive voltage to the micropump to inhale the drug solution;
Terminating the step of applying a positive driving voltage to the micropump if the magnitude of the current applied to the micropump is less than the first current setting value;
Applying a negative driving voltage to the micropump to eject the chemical liquid; And
And terminating the step of applying a negative driving voltage to the micropump if the magnitude of the current applied to the micropump becomes smaller than the second current set value. 15. The method of claim 14,
And setting the first and second current setting values based on the sensed temperature. 15. The method of claim 14,
Wherein the micro-pump is an electro-osmotic pump. 15. The method of claim 14,
The micro-
A fluid path portion providing a flow path to the working fluid;
A membrane disposed within the fluid path portion and allowing flow of the working fluid;
A diaphragm disposed on both sides of the membrane, the diaphragm including first and second diaphragms separated from the working fluid and deformed by the flow of the working fluid; And
And an electrode unit disposed between the membrane and the first and second diaphragms and including first and second electrodes to which the driving voltage output from the power supply unit is applied. 18. The method of claim 17,
Wherein the micropump further comprises first and second deformation restricting portions disposed on both sides of at least one of the first and second diaphragms to limit a range in which the at least one diaphragm is deformed. Injection method.

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