JP2009078041A - Medical solution cartridge and medical solution injection device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a medical solution cartridge and a medical solution injection device capable of administering medicine of high concentration accurately at a micro flow rate (injection speed) of less than 1 mL/h. <P>SOLUTION: The medical solution cartridge is composed of a medical solution holding part for holding a medical solution administered to a patient; a solution feeding means communicating with the medical solution holding part; a buffer tank part communicating with the solution feeding means; a flow rate measuring means for measuring the flow rate of the medical solution delivered by the solution feeding means; and an electric contact for controlling the solution feeding means and the flow rate measuring means from the outside. The medical solution injection device comprises a mounting part for detachably mounting the medical solution cartridge; a pressure contact type connector part located facing the electric contact when the medical solution cartridge is mounted; and a setting means for carrying out various setting of a medical solution injection flow rate and the like. Medical solution flow rate information obtained from the medical solution cartridge through the connector part based on the set medical solution injection flow rate is fed back, and the medical solution is discharged from the medical solution cartridge and injected into the patient. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a device for injecting a small amount of a chemical solution or a nutrient into a patient, and relates to a chemical solution cartridge in which a chemical solution storage unit, a liquid feeding unit (pump), and a flow rate measurement unit are integrated, and a chemical solution injection device that controls the chemical solution cartridge. Is.

  In a device for injecting a medical solution or a nutrient to a patient, there are many types of liquid feeding methods. For example, a peristaltic finger type peristaltic infusion pump configured to perform peristaltic movement of an infusion tube, a rotating roller There are various medical pumps such as a roller-type infusion pump provided with a syringe pump and a syringe pump that linearly pushes a pusher of a syringe.

However, these liquid delivery methods are intended for flow rates (injection rate) of 1 mL / h or higher, and are extremely accurate to achieve sustained (continuous) minute flow rates (injection rate) of less than 1 mL / h. In addition, a drive unit structure that does not rattle is required, and much cost and management are required to realize it in practice.

In addition, a piezoelectric pump using a vibration of a piezoelectric element has been proposed for a minute flow rate.

  A piezoelectric element is formed by forming a material having a piezoelectric effect for converting ceramic-based or polymer-based electrical energy into mechanical energy into a plate shape, and providing electrodes on both sides thereof. The piezoelectric element can be vibrated by alternately applying a voltage to the electrode.

  A piezoelectric pump is a pump in which this piezoelectric element is provided so as to cover at least one wall surface of a pump chamber made of a flexible material, and a liquid is discharged by applying pressure to the pump chamber by vibration of the piezoelectric element.

  This piezoelectric pump is used in devices that require micro flow rate liquid feeding and downsizing of the apparatus, such as a printer head of an ink jet printer and a liquid feeding pump of a fuel cell.

As a patent related to a piezoelectric pump using a piezoelectric element, as described in Patent Document 1, the pump chamber has a wall surface made of a flexible material, a suction check valve and a discharge check valve. A technique called a fixed supply pump that can make the liquid supply amount precisely constant by driving a pump chamber with an element is disclosed (Patent Document 1).
Japanese Patent Laid-Open No. 08-193579

  In the conventional piezoelectric pump, an elastic body such as rubber or resin is used for the check valve, and the opening and closing are passively performed by changing the pump chamber pressure by the piezoelectric element.

  However, if a soft material is used to improve the sealing performance of the check valve, the check valve will be deformed due to a pressure change and the discharge performance will be deteriorated once. If a hard material is used, the check valve will Deformation does not occur, but the sealing performance is lowered.

  Further, when vibrating at a high frequency like a piezoelectric element, the response performance of the check valve is required, and in the case of a passive check valve, it is not possible to respond quickly and the discharge performance of one time is deteriorated.

  The present invention has a check valve that operates cooperatively and actively with respect to the vibration of the piezoelectric element that drives the pump chamber, thereby improving the sealing performance and responsiveness of the check valve. It is an object of the present invention to provide a chemical liquid cartridge and a chemical liquid injection device having a pump that can efficiently and accurately perform microinjection.

In order to achieve the above-mentioned object, a chemical liquid cartridge according to the present invention is configured to control a liquid supply means from the outside, a chemical liquid storage section that stores a chemical liquid to be administered to a patient, a liquid supply means that communicates with the chemical liquid storage section. And a liquid supply means comprising: a chemical liquid pressure chamber having a valve body that actively prevents backflow of the chemical liquid at each of the chemical liquid suction port and the chemical liquid discharge port; and a chemical pressure chamber The piezoelectric element is arranged so as to cover at least one wall surface of the liquid crystal element, and when the piezoelectric element pressurizes and feeds the chemical pressure chamber, the valve body cooperates with the piezoelectric element to prevent the back flow of the chemical liquid. To do.

The valve element is driven by a piezoelectric element.

  Moreover, the said chemical | medical solution storage part is equipped with the atmosphere communication part connected to air | atmosphere, and the chemical | medical solution filling port for filling a chemical | medical solution, The pressure in a chemical | medical solution storage part becomes constant, It is characterized by the above-mentioned.

  Moreover, the said chemical | medical solution storage part is a bag-shaped tank which consists of a flexible resin material, The pressure in a chemical | medical solution storage part becomes fixed because it can deform | transform freely according to the chemical | medical solution residual amount.

  Further, the chemical solution is smoothly supplied from the chemical solution storage unit to the liquid supply unit by forming a notch that generates a capillary force in a region where the chemical solution storage unit and the liquid supply unit communicate with each other. And

  Further, the chemical injection device of the present invention includes a mounting portion to which a chemical cartridge can be detachably mounted, a pressure contact type connector portion that is positioned opposite to an electrical contact when the chemical cartridge is mounted, and a chemical injection flow rate. And a control means for controlling the chemical liquid cartridge based on the set chemical liquid injection flow rate, and by controlling the piezoelectric element and the valve body via the connector portion and the electrical contacts, The liquid medicine is ejected from the liquid medicine cartridge, and the liquid medicine is injected into the patient.

  ADVANTAGE OF THE INVENTION According to this invention, the chemical | medical solution cartridge and chemical | medical solution injection apparatus which have a pump which can be efficiently and accurately inject | poured even in the continuous (continuous) micro flow rate (injection speed) of less than 1 mL / h (0.1-1.0 mL / h) Can be provided.

(Example)
Preferred embodiments of the present invention will be described below with reference to the accompanying drawings, but are not limited to the examples. FIG. 1 is a perspective view of a chemical liquid cartridge according to the present invention and a chemical liquid injection device using the same, FIG. 2 is a cross-sectional view and a perspective view of the chemical liquid cartridge according to the present invention, and FIG. FIG. 4 is a cross-sectional view schematically showing the structure, and FIG. 4 is a schematic view showing the structure of the piezoelectric pump used in the liquid feed pump of the present embodiment.

[Structure of chemical injection device]
In FIG. 1, a chemical solution injection device 1 is a micro continuous injection pump for the purpose of injecting chemical solutions such as nutritional supplements, blood transfusions, chemotherapeutic agents, and anesthetics in ICU, CCU, NICU, and a display unit that is a display means. As shown in the figure, 10 is provided side by side with the operation unit 11 so as to be almost concentrated on the upper surface, thereby improving operability. Further, at least one chemical liquid cartridge 20 to be described later can be attached and detached, and a pressure contact type external connection part (signal connector) is provided at a position corresponding to an external connection part (electrical contact) 27 provided on the lower surface of the chemical liquid cartridge 20. ) 13 is provided with a chemical cartridge mounting portion 12. Reference numeral 17 denotes a RAM which functions as a work area for a program processed by the CPU (control unit) 15 and also functions as a storage means for temporarily storing data and the like during program processing. Reference numeral 16 denotes a ROM, which stores a program processed by the CPU 15. The display unit 10 preferably includes an operation indicator 10a for displaying the operation state of the chemical liquid injector 1. In addition, the flow rate (mL / h), the injection amount (mL), and the like are also displayed. Preferably, drug information (drug name etc.) of the drug solution cartridge 20 is also displayed. The operation unit 11 includes a power ON / OFF switch, a flow rate (injection speed: mL / h), a liquid feed start / stop switch, a setting switch, an injection amount (mL) setting switch, and the like. Preferably, an IC tag reader 36 that reads information written in an IC tag 29 described later is included. Reference numeral 18 denotes an external communication unit which can communicate with a host computer in a hospital, a host computer in a nurse center, or the like via a LAN or the like, and can monitor an operation state.

[Structure of chemical cartridge]
Next, an embodiment of the above-described chemical cartridge 20 will be described. In FIG. 2, a drug solution cartridge 20 contains a drug solution such as a chemotherapeutic agent, anesthetic agent, nutritional supplementation or blood transfusion to be administered to a patient, and sends out the drug solution according to an instruction from the drug solution injection device 1. And having a function of feeding back the measurement result to the chemical injection device 1, a chemical solution storage unit 21 for storing the chemical solution, a liquid supply unit 22 for sending out the chemical solution, a buffer tank 23, a flow rate measurement unit 24, and The chemical solution discharge port 25 is configured to be included in the main body case 26. Preferably, information such as drug name, upper limit / lower limit value of flow rate (mL / h), upper limit / lower limit value of injection volume (mL) is stored in a nonvolatile and non-rewritable manner, and patient name, patient ID, etc. can be written IC tag 29 is included. Note that the identification means may be a barcode instead of the IC tag 29, and a barcode reader instead of the IC tag reader 36.
In addition, an EEPROM is provided and downloaded from the host computer from a plurality of drug data (drug library: drug name, flow rate (mL / h) upper limit / lower limit value, injection volume (mL) upper limit / lower limit information, etc.), You may enable it to select the chemical | medical solution accommodated in the chemical | medical solution cartridge 20 and actually inject | poured into a patient.

  On the lower surface of the main body case 26, an external connection is made at a position corresponding to an engaging portion (not shown) that can be attached to and detached from the chemical liquid injector 1 and an external connection portion (signal connector) 13 provided in the chemical liquid injector 1. A portion (electrical contact) 27 is provided.

  Next, the internal structure of the chemical cartridge 20 will be described with reference to the schematic diagram of FIG. The chemical solution storage unit 21 that stores the chemical solution is disposed at the most upstream portion of the chemical solution flow path, and the internal pressure can be maintained equal to the atmospheric pressure through the atmosphere communication portion 30 that is aseptically communicated with the atmosphere. In addition, a chemical solution is provided on the downstream side of the chemical solution storage unit 21 by communicating with the liquid supply unit 22 through a lower flow port 31 in which an incision (not shown) capable of causing capillary action is formed in the inner wall. It is supplied to the liquid feeding unit 22.

  The liquid feeding unit 22 has a function of feeding a chemical solution by pump means including at least three piezoelectric pumps 33 described later. These piezoelectric pumps 33 are buffers having a constant volume communicating with the downstream side of the liquid feeding unit 22. The tank 23 is arranged in parallel. A downstream side of the buffer tank 23 is a pipe 32 having an inner diameter of 0.5 to 3.0 mm, and a flow rate measuring unit 24 is disposed along the pipe 32. Further, on the downstream side of the flow rate measuring unit 24, a chemical solution discharge port 25 having a structure that can be engaged with a chemical solution administration catheter 14 or a three-way cock (not shown) placed in the patient is provided.

[Principle of liquid feeding and control method]
Next, the structure of the piezoelectric pump 33, the principle of liquid feeding, and the control method will be described with reference to FIG. The piezoelectric pump 33 uses a liquid-feeding piezoelectric element 41 in which a material having a piezoelectric effect for converting ceramic or polymer electric energy into mechanical energy is formed into a plate shape, and electrodes 41a and 41b are provided on both surfaces thereof. This is a pump that uses a feature that the liquid feeding piezoelectric element 41 is displaced by applying different positive and negative voltages to the electrodes 41a and 41b, and a feature that the displacement direction is reversed by reversing the polarity of the applied voltage. It is a pump.

In the present embodiment, a liquid feeding piezoelectric element 41 is provided on at least one surface (either the inner surface or the outer surface, but preferably the outer surface) of the pump chamber 40 formed of a flexible material, and the flow of the chemical solution In order to control the direction in one direction, check valves 44 and 45 are provided in the suction port 42 and the discharge port 43 of the pump chamber 40, respectively, and a voltage is continuously applied alternately to the electrodes 41a and 41b. Then, liquid feeding is performed by utilizing the volume change of the pump chamber 40 caused by vibrating the liquid feeding piezoelectric element 41. When a positive voltage is applied to the electrode 41a and a negative voltage is applied to the electrode 41b, the liquid feeding piezoelectric element 41 is deformed in the direction of the arrow 48a, the inside of the pump chamber 40 becomes negative pressure, and the chemical is supplied from the suction port 42 to the pump chamber 40. When a voltage opposite to positive and negative is applied, it is deformed into an arrow 48b, the pump chamber 40 is pressurized, and the chemical solution is sent out by repeating the delivery of the chemical solution from the discharge port 43.

The check valves 44 and 45 provided at the suction port 42 and the discharge port 43 of the pump chamber 40 for preventing the above-described back flow of the chemical solution use a soft material in order to improve the sealing performance. If the valve is deformed and the discharge performance is deteriorated once and a hard material is used, the check valve is less deformed but the sealing performance is lowered. Furthermore, when vibrating at a high frequency like a piezoelectric element, the response performance of the check valve is required, and in the case of a check valve that passively opens and closes the valve by the pressure change of the general pump chamber 40, it is quick. A response cannot be made and the discharge performance of one time is deteriorated.

Therefore, in this embodiment, the check valves 44 and 45 are provided so that the check valve piezoelectric elements 46 and 47 are cantilevered, and the check valve piezoelectric element 46 is sandwiched between them. When a positive voltage is applied to the electrode 46a and a negative voltage is applied to the electrode 46b, the check valve 44 is deformed in the direction of the arrow 49a, and when a voltage opposite to the positive and negative is applied, the check valve 44 is deformed in the direction of the arrow 49b. When a negative voltage is applied to the electrode 47a provided so as to be sandwiched and a positive voltage is applied to 47b, the check valve 45 is deformed in the direction of arrow 410a, and when a reverse voltage is applied, the check valve 45 is deformed in the direction of arrow 410b. The check valves 44 and 45 can actively open and close the suction port 42 and the discharge port 43.

Next, the control mechanism of these piezoelectric elements will be described. When a voltage is applied to the electrodes 41a and 41b of the liquid feeding piezoelectric element 41 to deform it in the direction of the arrow 48b to pressurize the pump chamber 40 and push out the chemical liquid, the check valve piezoelectric element 46 moves in the direction of the arrow 49b. A voltage is applied to the electrodes 46a, 46b, 47a, 47b so that the check valve piezoelectric element 47 is deformed in the direction of the arrow 410b. Conversely, when the chemical solution is inhaled from the suction port 42, the liquid feeding piezoelectric element 41 is in the direction of the arrow 48a, the check valve piezoelectric element 46 is in the direction of the arrow 49a, and the check valve piezoelectric element 47 is in the direction of the arrow 410a. The voltages are applied to the electrodes 41a, 41b, 46a, 46b, 47a, 47b so as to be deformed.

The basic control of the piezoelectric elements 41, 46, 47 is as described above. While the deformation direction of the liquid feeding piezoelectric element 41 changes from the arrows 48a to 48b (48b to 48a), the suction port 42, By controlling the check valve piezoelectric elements 46 and 47 so as to close both the discharge ports 43, a chemical solution backflow caused by a response delay of the check valve, which becomes a problem when using a passive check valve, is prevented, and a high frequency Thus, the piezoelectric pump 33 can be driven efficiently.

  Since the piezoelectric pump 33 performs liquid feeding with the above-described structure, pulsation is generated in the flow of the chemical liquid due to the influence of the vibration of the liquid feeding piezoelectric element 41. Therefore, in this embodiment, in addition to providing the buffer tank 23 for suppressing pulsation on the downstream side of the liquid feeding section 22, at least three piezoelectric pumps 33 are arranged in parallel and are fed by a control method described later. This minimizes the pulsation.

  In the present embodiment, only the piezoelectric pump using the piezoelectric element as the liquid feeding means has been described, but instead of the piezoelectric element, an electrostrictive polymer, a polymer material typified by a conductive polymer, a shape memory alloy, etc. It goes without saying that other materials that convert electrical energy into mechanical energy can also be used.

[Countermeasures against pulsation]
Next, a method of liquid feeding control that makes it possible to suppress pulsation will be described. Since the piezoelectric pump 33 described in this embodiment performs the suction and discharge of the chemical liquid by the volume change of the pump chamber 40 due to the vibration of the liquid feeding piezoelectric element 41, the discharged chemical liquid is shown in FIG. A flow similar to the upper half of the sine curve (sine curve) shown in FIG.

  Therefore, in this embodiment, at least three piezoelectric pumps 33 are arranged in parallel, and control is performed by shifting the phase so that the sum of the flow rates discharged from the piezoelectric pumps 33 is always constant. As shown in (2), it is possible to significantly reduce pulsation, and further, by providing a buffer tank 23 on the downstream side of the piezoelectric pump 33, it is possible to realize liquid feeding almost close to pulsation.

[Principle of flow measurement]
Next, an embodiment of the flow rate measuring unit 24 will be described. In the flow rate measuring unit 24, a heating element 34 and two temperature sensors 35 are arranged so as to be in close contact with the pipe 32, and the liquid inside the pipe 32 is heated by the heating element 34. At this time, when the liquid flow rate is present in the pipe 32, the symmetry of heat transfer is hindered, and the liquid mass flow rate (injection rate: mL / h) is measured by measuring the asymmetry with the temperature sensor 35. .

  In the present embodiment, only the principle of heat transfer has been described as the flow rate measuring means, but it is also possible to use physical force due to the flow of liquid, Doppler effect, Coriolis force and the like. Not too long.

It is the external appearance schematic and schematic block diagram of the Example of this invention. It is a figure which shows the chemical | medical solution cartridge of the Example of this invention. It is a schematic diagram of the chemical | medical solution cartridge of the Example of this invention. It is a schematic diagram of the pump part of this invention. It is the schematic of the chemical | medical solution discharge amount curve of this invention.

Explanation of symbols

1 chemical injection device, 20 chemical cartridge, 24 flow rate measuring unit, 33 piezoelectric pump

Claims (6)

A liquid medicine container for containing a liquid medicine to be administered to a patient;
A liquid feeding means communicated with the chemical liquid container;
An electrical contact for controlling the liquid feeding means from the outside, and a chemical cartridge,
The liquid feeding means includes a chemical liquid pressure chamber having a valve body that actively prevents back flow of the chemical liquid at each of the chemical liquid suction port and the chemical liquid discharge port, and a piezoelectric element disposed so as to cover at least one wall surface of the chemical liquid pressure chamber Consists of
When the piezoelectric element pressurizes and feeds the chemical pressure chamber, the valve body cooperates with the piezoelectric element to prevent the chemical liquid from flowing backward. 2. The chemical cartridge according to claim 1, wherein the valve body is driven by a piezoelectric element.   The chemical solution cartridge according to claim 1, wherein the chemical solution storage portion includes an atmosphere communication portion communicated with the atmosphere and a chemical solution filling port for filling the chemical solution.   2. The chemical liquid cartridge according to claim 1, wherein the chemical liquid container is a bag-shaped tank made of a flexible resin material, and can be freely deformed according to the remaining amount of the chemical liquid.   2. The chemical cartridge according to claim 1, wherein a notch for generating a capillary force is formed in a region where the chemical solution container and the liquid feeding means are communicated with each other. A mounting part capable of detachably mounting the chemical cartridge according to claim 1;
A connector portion in a position opposite to the electrical contact when the chemical cartridge is mounted;
Setting means for setting the chemical injection flow rate;
Control means for controlling the chemical cartridge based on a set chemical injection flow rate, and a chemical injection device comprising:
A chemical solution injection device for discharging a chemical solution from the chemical solution cartridge and injecting a chemical solution to a patient by controlling the piezoelectric element and the valve body via the connector portion and the electrical contact.

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