JP2008545476A - Fluid delivery device and fluid delivery method provided with an electrochemical pump having an ion exchange membrane - Google Patents

Abstract

  The present invention relates to an apparatus and method for controllably adjusting a fluid delivery apparatus. The fluid delivery device (10) has an electrochemical pump (18) capable of transferring fluid (22). A displaceable member (14) is disposed between the electrochemical pump product chamber (16) and the storage chamber (12), and the electrochemical pump product chamber (16) receives water generated from the electrochemical pump (18). Can be held. The displaceable member (14) is controllably displaced each time water is generated from the electrochemical pump (18), and the storage chamber (12) is delivered according to the displacement of the displaceable member (14). To accommodate.

Description

  The present invention is a CIP application filed on May 1, 2002, U.S. Patent Application No. 10/137661, which is incorporated herein by reference. The present invention relates to a fluid delivery device provided with an electrochemical pump for delivering a small amount of fluid in a highly accurate and controllable manner. The device of the present invention can change the fluid delivery rate during operation by simple means.

  In the medical field, it may be necessary to administer fluids and / or chemicals in small amounts over a relatively long period of time. Examples of such fluids include biologics, drugs, lubricants, aromatic fluids, chemical substances (chemical agents), and the like. A common example for such purposes is when a drug is gradually taken into the human body. And as an example of a general device for gradually injecting such fluid to the human body, an infusion device that administers fluid by intravenous administration from a bottle or bag suspended on the patient by gravity It is.

  Other methods of gradually administering fluid have also been devised that eliminate the need to suspend the fluid dispensing device over the patient and give the patient greater mobility. An example of such a method is to use a diffusion controlled delivery pump that allows fluid to diffuse through the membrane at a constant rate. The dose can be adjusted by changing the properties of the membrane, such as a transdermal drug administration patch, or the concentration of the solution in contact with the membrane. Other transdermal administration techniques include iontophoresis, in which charged drugs are transcutaneously utilizing low volt currents; electroporation, in which temporary aqueous pores are formed in the skin using short high-voltage electrical pulses. A sonophoresis method that uses low frequency ultrasonic energy to disrupt the stratum corneum; a heat energy method that uses heat to make the skin more permeable and increase the energy of drug molecules; Examples include a magnetic energy method that has been studied as a means for increasing the drug flux. Of these transdermal technologies, only iontophoresis (iontophoresis) can be developed as a product only for the purpose of partial pain relief. The transdermal system is not the preferred method for gradual administration of fluid in all cases, and it is necessary to consider various factors that may affect its usefulness, such as the following. That is, the adhesives used to secure such devices to individuals may not adhere well to everyone's skin, and certain formulations may cause excessive skin irritation or allergies. Or wake you up. Furthermore, the transdermal system is cumbersome to wear and very expensive. In addition, since a high blood concentration is required, a drug with low efficacy cannot be administered accurately.

  Another mechanism for gradually dispensing fluid to an individual person is a mechanical pump dispenser. The mechanical pump dispenser uses various types of mechanical pumps to drain fluid from the storage chamber. Examples of the process using such a mechanical pump include a continuous intravenous infusion pump system such as a system manufactured by Intevac, an epidural infusion system, a subcutaneous infusion system using a portable insulin infusion pump, and the like. Externally mounted pumps are also commonly used for percutaneous catheters, but external pumps are often bulky and can be strapped in a form typical to the wearer or carried on a belt or leather strap. Inconvenient. A common drawback of mechanical pumps is that the part inserted into the body can cause infection. Furthermore, most mechanical pumps are designed to deliver a relatively large amount of fluid and cannot effectively deliver a small amount of fluid or perform such a delivery over an extended period of time.

  Other fluid delivery methods include the use of pressure to administer fluid to individual persons. For example, the fluid is collected in a flexible storage chamber under pressure by a loaded storage chamber dispenser, and then the fluid is selectively discharged by the force of the storage chamber pressure. In this case, the discharge is usually regulated by a number of complex valve systems. The pressurized gas dispenser discharges fluid by the pressurized gas. In the case of an osmotic dispenser, a fluid is sent out using a solute showing a certain osmotic pressure gradient with respect to water. The “OROS system” manufactured by ALZA is an example of such an osmotic drive system, and uses the osmosis phenomenon as an energy source for drug delivery. In the “OROS system”, the drug solution flows out of the tablet at a constant zero flow rate, and the tablet is in the gastrointestinal (GI) tract until all the solid drug in the core is dissolved or the unit disappears. To proceed. In vivo and in vitro studies have shown that the delivery rate is independent of gastrointestinal motility, pH, and food in the gastrointestinal tract. Drug release is controlled by drug solubility in gastric juice, osmotic pressure of the core formulation and membrane size and permeability.

  Although fluid delivery devices of the types and techniques described above can be used, further improvements thereof are desired. For example, when a drug is gradually administered into the human body, it is often desirable to administer a fluid in small portions continuously over an extended period of time. In such applications, it is desirable that fluid dispensers be extremely accurate and reliable, have a small lightweight size that can be carried, and are convenient and simple to use. In general, implantable drug delivery pumps and systems are designed to deliver the drug directly to the desired site to maximize the effect of the drug while minimizing undesirable side effects in other parts of the body. Yes.

  A large number of implantable drug delivery pumps and systems are currently in use. An example of a widely used implant is an electrochemical SynchroMed pump capable of programming large volumes (18 mL). This SynchroMed pump can be used for many therapies, but its disadvantages are high cost, increase the overall cost of therapy, and surgery is required to install it for large pumps And so on.

  A delivery pump smaller than the above-mentioned SynchroMed pump is also known. For example, an osmotic pump of a DUROS system. In the operation, water is osmotically sucked into the salt chamber through the membrane, the piston is pressed and inserted into the drug chamber, and the drug is pushed out from the delivery hole. The driving force for the drug delivery of this pump is osmotic pressure, which reaches 200 atm, depending on the salt used. In addition, the pressure required to pump the drug out of the device is small, and the drug delivery rate is constant as long as some excess undissolved salt remains in the salt chamber. This infiltration system is small and simple compared to mechanically driven devices, and is reliable and low in manufacturing costs. Since this osmotic system is small, it can be implanted in a doctor's treatment room with a simple operation. On the other hand, the delivery rate of the osmotic pump is fixed and cannot be adjusted during its operation.

  Gas generators that are portable and can accurately dispense medication in small amounts are also used in medication delivery systems. For these gas generation systems, galva batteries (voltaic batteries) and electrolysis cells are used. In the gas generating voltaic battery, hydrogen and oxygen gas are generated at the cathode and the anode, respectively, by the reaction between the metal or metal oxide and the electrolytic solution. A voltaic cell is an electrochemical cell that does not require an external voltage to cause an electrochemical reaction. Typically, the anode and cathode of a voltaic cell regulate the current passing through the cell, and then through a resistor that directly regulates the generation of gas that exerts a force on the diaphragm or piston (thus causing the drug to drain). Connected. Delivery systems based on the use of hydrogen generating voltaic cells are disclosed in numerous patents (see, for example, Patent Documents 1 to 3).

  In the batteries disclosed in these patents, the zinc anode reacts with the alkaline electrolyte to produce zinc oxide, and water molecules are reduced on the porous carbon electrode to generate gaseous hydrogen. Further, oxygen generating voltaic cells configured as zinc / air button type cells in which reducing oxygen is reduced at the cathode to form hydroxide ions are also disclosed (for example, Patent Documents 4 to 5). reference). Hydroxide ions are oxidized at the anode to release oxygen.

  For a voltaic cell, the electrolysis cell requires an external DC power source to cause an electrochemical reaction. When a voltage is applied to the electrodes, the electrolyte dissipates the gas and pushes out the diaphragm or piston, thereby draining the fluid. Three types of electrolytic gas generation cells have been proposed for use in fluid delivery systems. The first type is based on water electrolysis that requires an operating voltage of 1.23V or higher. The second type, also known as oxygen and hydrogen gas pumps, requires a lower DC voltage than that used in water electrolysis systems. A polymer ion exchange membrane is used for both the first and second types. The third type uses chemical compounds that can be decomposed by electrolysis that produces reduced metal at the cathode and generates gaseous oxygen by oxidation of water at the anode.

  In addition, an electrochemically actuated fluid dispenser using electrolysis of water is also disclosed (see, for example, Patent Document 6). In this dispenser, water is held in an electrochemical battery, porous metal electrodes are connected to both sides of a solid polymer cation exchange membrane, and both electrodes are in contact with water together with conductivity, and are respectively anodes or cathodes. It is configured to use oxygen or hydrogen generated from. Thus, hydrogen, oxygen or a mixed gas thereof (which are generated by electrolysis of water when a DC current is passed between the electrodes) is used as a pressurizing source of the fluid dispenser.

  Electrochemical oxygen and hydrogen pumps are constructed similarly to the water electrolysis cell described above and are described in several US patents (see, for example, patent documents 7-10). In the electrochemically operated fluid dispenser disclosed in these patents, the porous gas diffusion electrodes respectively connected to the opposing surfaces of the ion exchange membrane holding water functioning as an electrolyte are connected. Having an electrochemical cell. Electrochemically driven fluid dispensers utilize the phenomenon that hydrogen is supplied to the anode of an electrochemical cell and hydrogen turns into hydrogen ions at the anode when a DC current is passed between the anode and cathode. . When the generated hydrogen ions reach the cathode through the ion exchange membrane, an electrochemical reaction occurs and gaseous hydrogen is generated. Since the basic effect of these processes is to transfer hydrogen from one side of the membrane to the other, this cell is also called a hydrogen pump. The pressurized hydrogen produced at the cathode is used as a power source for pushing pistons, diaphragms and the like.

  In this type of electrochemical battery, oxygen can be used as a reactant instead of hydrogen, in which case the cell acts as an oxygen pump. In this way, oxygen is reduced on one side of the electrolysis cell holding water and water is oxidized on the other side, and the molecular oxygen thus generated pushes the liquid out of the proximity storage chamber Used as power.

  A gas generating electrolysis cell is disclosed that uses a compound that generates reduced metal at the cathode, generates gaseous oxygen by oxidation of water at the anode, and can be decomposed by electrolysis (see, for example, Patent Document 11). This cell has a graphite anode, an electrolytic solution, and a cathode made of copper hydroxide as its entire configuration. When a current flows through the circuit to which the cell is connected, copper is released as ions from the cathode and oxygen is released at the anode. In order to ensure storage stability, the active cathode material is selected such that each cell requires an applied voltage to allow the electrochemical reaction to proceed. A battery is provided in the circuit in order to pass a current through the gas generating cell. The amount of oxygen generated at the anode is directly proportional to the current, and a pressurizing agent that plays the role of releasing fluid from a bladder or other fluid holding reservoir (with movable walls in conjunction with gas generation) Acts as

  The electrochemically-actuated fluid delivery device described above is useful for certain applications, but not best for other applications. In particular, pumps based on gas generating cells are sensitive to temperature and atmospheric pressure. Therefore, osmotic or electroosmotic pumps are often more suitable.

  Osmotic pumps use dip water or another hydraulic fluid. This pump consists of the following three chambers: a salt chamber, a water chamber and a fluid chamber. The salt chamber and the water chamber are separated by a semipermeable membrane. This configuration provides a high osmotic driving force for moving water through the membrane. This membrane allows water but not salt. The fluid chamber is separated from the other two chambers by a flexible diaphragm. Water permeates osmotically into the salt chamber, which creates a fairly high hydrostatic pressure, and this hydrostatic pressure pushes the diaphragm and drains the fluid. The use of osmotic pumps is limited to applications where constant fluid delivery is required. To change the fluid flow rate, it is necessary to provide a large number of osmotic pumps with different outputs. Osmotic pumps also require charging--a time during which the liquid diffuses through the semipermeable membrane and begins to dissolve the osmotic material in a steady state--which delays the delivery of fluid and is more immediate or Impairs suitability for urgent use. The fluid delivery amount of the osmotic device cannot be changed, and the fluid delivery cannot be interrupted after the delivery is started. Therefore, it is desirable to use a device that can be switched on quickly and that can change the feed amount by remote control.

  The electroosmotic pump is an electrolysis cell having an ion exchange permselective membrane, and therefore requires an external DC power source to cause an electrode reaction. An electrochemically actuated fluid dispenser based on electroosmotic fluid transfer is disclosed (see, for example, Patent Document 12). The pump has a plastic housing with a fluid inlet and outlet, a pair of spaced silver-silver chloride electrodes disposed in the housing and connected to a DC power source, a porous ceramic plug having a high zeta potential for the fluid, Between the ceramic plug and the electrode facing it, a cation exchange membrane arranged on each side of the ceramic plug and in the housing leading from the fluid inlet to one side of the plug and from the other side of the plug to the outlet It consists of the flow path provided in. When a potential difference is applied between the anode and the cathode, the liquid feeding fluid flows from the anode to the cathode through the porous plug. One of the unique disadvantages of electroosmotic pumps with this porous plug is that the fluid delivery pressure is very low (much lower than 0.5 atm). Furthermore, the zeta potential is affected by ions in the working fluid, reducing the electroosmotic flow rate. Another drawback of this electroosmotic pump is that it requires an external DC power source, which reduces the overall volumetric efficiency of the fluid delivery device.

  Accordingly, there is a need for an implantable high volumetric fluid dispenser having a high performance programmable delivery structure that can be rapidly adjusted to vary fluid delivery as desired. The delivery structure part occupies only a small part of the fluid dispenser, and it is desired that a small amount of fluid can be delivered accurately and is not affected by atmospheric pressure or temperature.

US Pat. No. 5,951,538 US Pat. No. 5,707,499 US Pat. No. 5,785,688 US Pat. No. 5,242,565 US Pat. No. 5,925,030 US Pat. No. 5,891,097 US Pat. No. 5,938,640 U.S. Pat. No. 4,902,278 US Pat. No. 4,886,514 U.S. Pat. No. 4,522,698 US Pat. No. 5,744,014 U.S. Pat. No. 3,923,426

  It is an object of the present invention to provide a fluid delivery device that includes a high volumetric efficiency fluid dispenser such that its fluid delivery mechanism occupies a small portion of the overall device.

  Another object of the present invention is to provide a fluid delivery device that is small, portable and implantable.

  Another object of the present invention is to provide a fluid delivery device capable of accurately delivering a small amount of fluid with high accuracy.

  It is another object of the present invention to provide an adjustable fluid delivery device that can be controlled to quickly change the liquid delivery rate.

  Another object of the present invention is to provide a fluid delivery device that has fewer moving parts, has a simple structure, and is less mechanically damaged.

  Another object of the present invention is to provide a fluid delivery device that does not use any parts that can be compressed, can be used at any altitude, and can be used under a wide range of atmospheric pressures. It is.

  The gist of the present invention consists of the following elements: (a) an electrochemical pump capable of transporting water; (b) an electrochemical pump production chamber capable of holding water generated from the electrochemical pump under high pressure; (C) a displaceable member that can be displaceably adjustable in response to the generation of water from the electrochemical pump; (d) a storage chamber that can contain fluid delivered in response to the displacement of the displaceable member; ) A fluid delivery device capable of adjustable water transfer comprising an electrochemical pump, an electrochemical pump product chamber, a displaceable member and a housing containing a storage chamber. The displaceable member is preferably selected from the group consisting of a piston, bladder, bellows, diaphragm, plunger, and combinations thereof. The fluid delivery device may further include a catheter for delivering fluid to a desired site.

  In a preferred embodiment of the invention, the pump structure consists of a protective porous separator, a first electrode, a second electrode, an ion exchange membrane and an electrical controller. In this embodiment, the pump further enables the fluid delivery to be started and stopped more quickly with an actuation switch, controller, such as a remotely controllable or impossible electrical resistance or circuit that initiates fluid delivery, and more Means that allow rapid adjustment and a support member that physically supports the membrane may be included.

  In a further embodiment of the invention, the storage chamber has one or more openings, for example outlets and supply / resupply ports, which are biologics, drugs, lubricants, fragrances, chemical agents and mixtures thereof. Contains one fluid selected from the group consisting of:

In yet another embodiment of the present invention, the following steps: (a) providing a fluid delivery device using an electrochemical water delivery pump; (b) delivering water from an electrochemical water delivery pump Expanding the volume of the pump output chamber; (c) generating sufficient pressure from the expanded output chamber; and (d) controlling from the fluid delivery device by displacing the displaceable member. A fluid delivery method comprising the steps of:
Exist.

  The fluid delivery device of the present invention is provided with an electrochemical pump for delivering a small amount of fluid in a highly accurate and controllable manner, and the fluid delivery rate can be changed during operation by simple means.

  Hereinafter, the present invention will be described in more detail. While the present invention may be embodied in a variety of different forms, several aspects thereof are described in detail herein and in the drawings. However, the embodiment shown here is merely an example of the principle of the present invention, and the present invention is not limited to the embodiment shown here.

  Similar or similar elements and / or components referred to herein are designated by the same reference numerals in all figures.

  FIG. 1 shows a first embodiment of the present invention, namely a fluid delivery device 10 comprising a storage chamber 12, a displaceable member 14, an electrochemical pump product chamber 16, an electrochemical pump 18 and a housing 20. FIG. 1 schematically illustrates the fluid delivery device of the present invention, so some of its components may differ from the actual scale for a clearer graphical understanding.

  The reservoir 12 can contain a fluid 22 that is delivered as the displaceable member 14 is displaced, for example, a fluid such as a biologic, a drug, a lubricant, a fragrance, a chemical, or a mixture thereof. The “fluid” referred to in the present invention means a liquid, gel, paste, or other semi-solid substance that can be delivered from a storage unit. The reservoir 12 is provided with one or more openings 24 for controlling the delivery of the fluid 22 from the fluid delivery device 10. The storage unit 12 can be made of various arbitrary materials such as metal, glass, natural or synthetic plastic, and composites thereof.

  The displaceable member 14 is disposed between the reservoir 12 and the electrochemical pump product chamber 16. In FIG. 1, the displaceable member 14 is shown to be composed of a piston, but other similar members known in the art, such as bladders, bellows, diaphragms, Examples include but are not limited to plungers and combinations thereof.

  The electrochemical pump product chamber 16 is disposed between the displaceable member 14 and the electrochemical pump 18 and provides water 26 that is controllably generated during operation of the electrochemical pump 18, as will be described in detail below. Can be held. As with the reservoir 12, the electrochemical pump product chamber 16 can be made of a variety of arbitrary materials such as metal, glass, natural and synthetic plastics, and composites thereof.

  The electrochemical pump 18 shown in FIG. 1 includes a porous protective separator 28, an auxiliary electrode chamber 30, an auxiliary electrode 32, an ion exchange membrane 34, an active electrode 36, an electric resistance 38, an operation switch 40, and a support member 42.

The perforated protective separator 28 is located at the end of the fluid delivery device, distal from the reservoir 12. This porous protective separator 28 normally allows H ₂ O molecules from the human body to pass through, but in cooperation with a saline solution from the auxiliary electrode chamber 30 —a metal halide such as NaCl—for example, an external source 46 —such as the interior of a living body. The water from − is diffused or transferred into the auxiliary electrode part 30. Separator 28 can be made of one of many materials, such as, but not limited to, metals, glass, natural or synthetic plastics, composites, and the like. A porous protective gel may be used as long as it fulfills the purpose of this separator. This porous protective separator or gel usually passes H ₂ O (water) molecules or saline. Furthermore, you may provide water or a salt solution storage part in this separator or gel.

  The porous protective separator 28 may not be provided, and the auxiliary electrode portion 30 may be self-contained without the separator. In such an embodiment, the auxiliary electrode is exposed directly to the fluid and the required amount of water is supplied to the auxiliary electrode portion 30 without the transfer of water from an external source.

  In the first embodiment of the present invention, the anion exchange membrane, the auxiliary electrode 32, the anion exchange membrane 34, and the active electrode 36 are each disposed adjacent to the porous protective separator 28. The auxiliary electrode 32 is composed of a porous cathode pellet that is easily reduced when connected to the active metal anode. The auxiliary electrode 32 is easily reduced when coupled with porous silver chloride, manganese dioxide, or other active metal anodes, or promotes a reduction reaction, such as acid reduction or generation of gaseous hydrogen from water. Can be composed of substances. The active metal anode 36 is a solid pellet, mesh, or metal powder type electrode manufactured from zinc, iron, magnesium, aluminum, other corrosion resistant metals or alloys, and the like. Although not shown, the auxiliary electrode 32 is provided with a conventional current collector made of silver, titanium, platinum, or other corrosion-resistant metal, for example, a screen-type, mesh-type or wire-type current collector. Also good. In addition, the active metal anode 36 may be provided with a conventional current collector such as a screen, mesh, or wire type made of the same metal as described above, and other metals such as an active anode metal and the like. You may comprise brass etc. which were coat | covered with the same metal. Although the above description has been presented for the purpose of illustrating specific examples of electrode materials and current collectors, the use of other electrode materials well known to those skilled in the art may be considered as well.

  The anion exchange membrane 34 is disposed between the first electrode 32 and the second electrode 36. Constituent substances of the anion exchange membrane 34 are well known in the art and need not be described in detail. In short, these substances are strong base type cross-linked polymer resins. A suitable example of such a resin is a copolymer of styrene and divinylbenzene having a quaternary ammonium ion as a charged group, which has high selectivity for chloride ions but is resistant to organic contamination. It shows high resistance to it. An example of such an anion membrane is a Neosepta type membrane commercially available from AMERIDA (www.america.com).

  In the second embodiment of the present invention in which a cation exchange membrane is provided, the auxiliary electrode 32, the cation exchange membrane 34, and the active electrode 36 are each disposed close to the porous protective separator 28. The auxiliary electrode 32 is a solid pellet type, mesh type or metal powder type electrode made of zinc, iron, magnesium, aluminum, or other corrosion-resistant metal or alloy. The active metal anode 36 is a porous cathode pellet that is easily reduced when connected to the anode 36. The auxiliary electrode 32 is easily reduced when connected to porous silver chloride, manganese dioxide, or other active metal anodes, or promotes a reduction reaction, such as acid reduction or generation of gaseous hydrogen from water. Can be composed of substances. Although not shown, the auxiliary metal electrode 32 may be provided with a conventional current collector made of the same metal as the anode 36, for example, a screen-type, mesh-type or wire-type current collector. Alternatively, it may be composed of other metals, such as brass coated with a metal similar to the active anode metal. The active electrode 36 may also comprise a conventional current collector made of silver, titanium, platinum, or other corrosion resistant metal, such as a screen type, mesh type or wire type current collector. While specific examples of electrode materials and current collectors have been shown in the above description for purposes of illustration, other electrode materials well known to those skilled in the art are possible.

  In FIG. 1, the cation exchange membrane 34 is disposed between the first electrode 32 and the second electrode 36. Constituent substances of the anion exchange membrane 34 are well known in the art and need not be described in detail. In short, these substances are strong base type cross-linked polymer resins. A suitable example of such a resin is a copolymer of styrene and divinylbenzene having a sulfonate ion as a charged group, and has high selectivity for sodium ion. Such commercially available cationic membranes, for example, Nafion type membranes, are sold by Dupont.

  An electrical control circuit 38 is connected to each electrode via a known wire conduit and directly controls the amount of water delivered from the external source 46 to the pump product chamber 16 as will be described in detail below. The support member 42 is a very porous solid disk material that imparts mechanical rigidity to the ion exchange membrane and acts to transport water therethrough. The support member 42 is made of a hard plastic, ceramic, glass, a corrosion-resistant metal such as titanium, or a combination thereof.

  When activated, fluid delivery device 10 delivers fluid 22 according to the following process. When the operating switch 40 is first pressed, the electric circuit is completed and an electrode reaction takes place at each of the electrodes 32 and 36, water is extracted from the external supply source 46, and finally the electric pump product through the ion exchange membrane 34. It is sent to the chamber 16. In this way, water from the external supply source 46, for example, the human body, is introduced into the first electrode chamber 30 through the porous protective separator 28.

  In the first embodiment of the present invention, when the first electrode 32 is made of silver chloride and the second electrode is made of zinc, the following reaction occurs. First, silver chloride constituting the first electrode becomes metallic silver, and chloride ions are released into the solution according to the following formula.

2AgCl + 2e ⁻¹ → 2Ag + 2Cl ⁻ (1)

  As a result, the generated chloride ions dissolve in water and move through the ion exchange membrane 34 toward the second electrode 36 in the electric pump product chamber 16 under the influence of an electric field. In the second electrode 36, zinc is dissolved according to the following formula.

Zn → Zn ²⁺ + 2e ⁻ (2)

  The zinc ions thus formed react with the introduced chloride ions to produce zinc chloride according to the following formula.

Zn ²⁺ + 2Cl ⁻ → ZnCl ₂ (3)

  In addition to the electrochemical formation of zinc chloride according to formula (3), water is entrained in the chloride ions as they pass through the membrane, and more water is produced at the other end of the membrane. This water delivery is known in the industry as an electroosmotic transport. Since this anion membrane is selective to anions, only anions can pass through this membrane. In this way, water is fed in only one direction through the membrane.

  The steadily increasing ion concentration in the electrochemical pump product chamber 16 due to the continuous production of zinc chloride further enhances the water delivery by the osmotic effect. However, this ion exchange membrane cannot prevent the back diffusion of zinc chloride molecules from the pump product chamber 16 to the electrode chamber 30. The degree of this reverse diffusion depends on the nature of the ion exchange membrane and the difference in concentration between the pump product chamber 16 and the auxiliary electrode chamber 30. Thus, an equilibrium concentration of zinc chloride is achieved in the electrochemical pump product chamber 16 and, as a result, water is pumped by the osmotic effect. In this way, a steady state flux of water feed into the pump product chamber 16 due to both electroosmotic and osmotic effects is achieved. The osmotic flux is due to the electro-osmotic flux that provides the desired concentration gradient. Thus, the osmotic flux can be modified by modifying the electroosmotic driving force. In the case of an osmotic system, such correction is impossible and the fluid delivery rate cannot be adjusted. Water molecules sent to the electrochemical pump product chamber 16 generate pressure in the chamber. The generation of this pressure causes some back-feeding of water from the pump product chamber 16 to the auxiliary electrode chamber 30.

  The steady state flux obtained for a given ion exchange membrane can be expressed by the following mathematical formula.

J _{Steady State flux} = J _eo + J _of -J _bd -J _hf (I)

In the above equation, J _eo = electroosmotic flux, J _of = osmotic flux, J _bd = back diffusion flux, J _hf = hydraulic flux is there.

  In the second embodiment of the present invention, when the first electrode 32 is made of zinc and the second electrode 36 is made of silver chloride, the following reaction occurs. First, the zinc of the electrode is dissolved according to the following formula.

Zn → Zn ²⁺ + 2e ⁻ (4)

  Sodium ions present in the saline solution pass through the ion exchange membrane 34 in the direction of the second electrode 36 of the pump product chamber 16 under the influence of the electric field. In the second electrode 36, silver chloride is converted into metallic silver according to the following formula, and chlorine ions are released into the solution.

2AgCl + 2e ⁻ → 2Ag + 2Cl ⁻ (5)

  The transferred sodium ions react with chlorine ions according to the following formula to produce sodium chloride.

Na ⁺ + Cl ⁻ → NaCl (6)
Besides the electrochemical production of sodium chloride according to equation (6), when sodium ions are passing through the membrane, water is electroosmotically pumped with the sodium ions and further water is produced on the other side of the membrane. The Since the cation membrane has selectivity for cations, only cations can pass through the membrane. Therefore, water is sent through the membrane in only one direction.

  Since sodium chloride is continuously produced, the ion concentration steadily rises in the electrochemical pump product chamber 16 and further feeds water by the osmotic effect. However, the ion exchange membrane causes back-feeding of sodium chloride ions from the pump product chamber 16 to the first electrode chamber 30. The degree of such reverse feeding depends on the nature of the ion exchange membrane and the difference in concentration between the pump product chamber 16 and the auxiliary electrode section 30. Thus, an equilibrium concentration of sodium chloride is achieved in the pump product chamber 16 and water is pumped by the osmotic effect. Steady state flux of water feed into the pump product chamber 16 is achieved by both electroosmotic and osmotic effects. The osmotic flux is due to the electroosmotic flux that provides the desired concentration gradient. Thus, the osmotic flux can be modified by modifying the electroosmotic driving force. Such a correction is impossible in an osmotic system, and therefore the amount of fluid delivery cannot be adjusted. The water molecules transported to the electrochemical pump product chamber 16 generate pressure in the chamber. This pressure generation causes some back-feeding of water from the pump product chamber 16 to the auxiliary electrode chamber 30. The steady state flux obtained for a given ion exchange membrane can be expressed by the same equation as given above.

  In both embodiments described above, high pressure can be generated in the electrochemical pump product chamber 16. High pressure is preferred for delivering viscous compositions and for allowing delivery operations that are less sensitive to ambient pressure changes.

FIG. 6 shows the pressure generated in the first embodiment. The maximum pressure that can be generated (P _max , the pressure at which the flux is zero) is 20 psi at 0.136 mA / cm ² . When operated at a current density of 3.8 times (0.525 mA / cm ² ), a P _{max of} 700 psi was obtained. FIG. 7 shows the pressure generated in the second embodiment of the present invention. P _max is 350 psi at 0.136 mA / cm ² .

  The generated pressure becomes a force that pushes the displaceable member 14 (the only movable member). The displaceable member 14 is displaced laterally from the electrochemical pump product chamber 16 to controllably discharge fluid from the storage chamber 12. The apparatus and process described above are related to the resistance value or the signal output from the electric controller 38, but as long as the amount of water to be pumped is proportional to the current, the apparatus and process can be performed at a relatively accurate rate for a long time. The fluid can be sent out under control. Therefore, the fluid delivery amount of the present apparatus is controlled not by the amount of water entering the housing by the convection action by the porous protective separator 28 but by the selection of the electric controller 38 or the signal output from the electric controller. In addition, the amount of fluid delivery or the delivery mode (profile, time mode of delivery), for example, regular delivery in a pulse manner, can be selected by other means, for example, resistances of different resistance values, Can be easily changed by changing (but not limited to) the signal output.

In the embodiment of the invention shown in the drawing, a proportional relationship between volume flux and current density was obtained in the volume flux in the high and low range. In a first embodiment, in Figure 2 for volume flux ranging from 2.0~10.0μLh ^-1 cm ^-2, 0.1~2.5μLh ^- the volume flux ranging from 1 cm ^-2 Are shown in FIG. The current density required to generate such a volume flux depends on the type of film used, but for example, as shown in FIG. 4, a volume flux of 0.5 μLh ⁻¹ cm ⁻² is generated. The required current density is only 20 μAcm ⁻² . In the embodiment shown in FIG. 1, it is also clear that high stability is maintained in operation over 1000 hours.

  The above description is merely illustrative of the present invention, and the present invention is not limited thereto but only by the appended claims, and those skilled in the art who have obtained the disclosure of the present invention will be within the scope of the present invention. Various changes and modifications can be made without departing from the above.

Schematic sectional view of a fluid delivery device having an anion exchange membrane manufactured according to the present invention In the fluid delivery apparatus having the anion exchange membrane manufactured by the present invention, the relationship between the volume flux and the current density in the volume flux range of 2.0-10.0 μLh ⁻¹ cm ⁻² is shown. Graph (cell parameters: Neosepta AMI 7001 ion exchange membrane, powdered zinc anode, nickel mesh cathode, 0.9% NaCl electrolyte) In the fluid delivery device having an anion exchange membrane manufactured according to the present invention, a graph showing the relationship between the volume flux and the current density in the volume flux range of ^{0 to} 2.5 μLh ⁻¹ cm ⁻² (cell parameter: AFN). (Ion exchange membrane, solid zinc anode, silver chloride cathode, 0.9% NaCl electrolyte) In the fluid delivery device having an anion exchange membrane manufactured according to the present invention, a graph showing the relationship between the volume flux and the current density in the volume flux range of 0.5 to 2.5 μLh ⁻¹ cm ⁻² (cell parameter) : Neosepta AMX ion exchange membrane, solid zinc anode, silver chloride cathode, 0.9% NaCl electrolyte) FIG. 3 is a graph showing the relationship between the volume flux and the current density in the volume flux range of 0.2-1.2 μLh ⁻¹ cm ⁻² in the fluid delivery device having a cation exchange membrane manufactured according to the present invention (cell parameter). : NAFION 177 cation exchange membrane, solid zinc anode, silver chloride cathode, 0.9% NaCl electrolyte) In a fluid delivery device having an anion exchange membrane manufactured according to the present invention, a graph showing the relationship of volume flux to pressure applied to an electrochemical product chamber at two different current densities (cell parameter: Neosepta AFN). (Ion exchange membrane, solid zinc anode, silver chloride cathode, 0.9% NaCl electrolyte) In a fluid delivery device having a cation exchange membrane produced according to the present invention, a graph showing the relationship of volume flux to pressure applied to an electrochemical product chamber at two different current densities (cell parameter: NAFION 117). Cation exchange membrane, solid zinc anode, silver chloride cathode, 0.9% NaCl electrolyte)

Claims (38)

  Electrochemical pump capable of delivering water; Electrochemical pump production chamber capable of holding water delivered from the electrochemical pump; Controllable according to the delivery of water from the electrochemical pump A displaceable member disposed between the electrochemical pump and the storage chamber; a storage chamber capable of accommodating a fluid pumped according to the displacement of the displaceable member; the electrochemical pump, the electrochemical pump A fluid delivery device comprising a product chamber, a displaceable member and a housing for housing a storage chamber.   The fluid delivery device according to claim 1, wherein the electrochemical pump comprises a first electrode, a second electrode, an ion exchange membrane, and an electric controller.   The fluid delivery device according to claim 2, wherein the electrochemical pump further includes an operation switch and a support member.   The fluid delivery device according to claim 3, wherein the electrochemical pump further comprises a porous protective separator or a porous protective gel through which water molecules or saline passes.   The fluid delivery device according to claim 4, wherein the porous protective separator or the porous protective gel has a water storage part or a saline storage part.   The fluid delivery device of claim 2, wherein the first and second electrodes form a voltaic electrode pair.   The fluid delivery device according to claim 2, wherein the ion exchange membrane is an anion or cation exchange type membrane.   The fluid delivery device of claim 1, wherein the displaceable member is selected from the group consisting of a piston, bladder, bellows, diaphragm, plunger, and combinations thereof.   The fluid delivery device of claim 1, wherein the reservoir contains a fluid selected from the group consisting of biologics, drugs, lubricants, perfumes, chemical agents and mixtures thereof.   The fluid delivery device of claim 1, wherein the storage chamber has one or more openings.   An electrochemical pump having a first electrode, a second electrode, an ion exchange membrane and an electric controller, capable of feeding water; and an electrochemical pump capable of holding water sent from the electrochemical pump A product chamber; a displaceable member disposed between the electrochemical pump and the storage chamber that controllably displaces in response to the flow of water from the electrochemical pump; delivered according to the displacement of the displaceable member A fluid delivery apparatus comprising: a storage chamber capable of containing a fluid; and an electrochemical pump, an electrochemical pump product chamber, a displaceable member, and a housing containing the storage chamber.   The fluid delivery device of claim 11, wherein the electrochemical pump further comprises an activation switch and a support member.   The fluid delivery device according to claim 11, wherein the electrochemical pump further comprises a porous protective separator or a porous protective gel through which water molecules or saline passes.   The fluid delivery device according to claim 4, wherein the porous protective separator or the porous protective gel has a water storage part or a saline storage part.   The fluid delivery device of claim 11, wherein the first and second electrodes form a voltaic electrode pair.   The fluid delivery device according to claim 11, wherein the ion exchange membrane is an anion or cation exchange type membrane.   12. A fluid delivery device according to claim 11, wherein the displaceable member is selected from the group consisting of a piston, bladder, bellows, diaphragm, plunger and combinations thereof.   12. A fluid delivery device according to claim 11, wherein the reservoir contains a fluid selected from the group consisting of biologics, drugs, lubricants, fragrances, chemical agents and mixtures thereof.   The fluid delivery device of claim 11, wherein the storage chamber has one or more openings.   Electrochemical pump capable of delivering water; Electrochemical pump production chamber capable of holding water delivered from the electrochemical pump; Controllable according to the delivery of water from the electrochemical pump A displaceable member that is disposed between the storage chamber capable of containing a fluid pumped in response to the displacement of the displaceable member and the electrochemical pump product chamber; an electrochemical pump; A fluid delivery device comprising an electrochemical pump product chamber, a displaceable member and a housing housing the storage chamber, wherein the electrochemical pump is operably mounted in proximity to one end of the fluid delivery device, A porous protective separator or a porous protective gel through which molecules or saline is passed, and a first electrode chamber disposed adjacent to the porous protective separator or the porous protective gel A first electrode disposed adjacent to the first electrode chamber; an ion exchange membrane disposed adjacent to the first electrode; a second electrode disposed adjacent to the ion exchange membrane; A fluid delivery device comprising an electrical controller in electrical communication with the second electrode.   21. The fluid delivery device of claim 20, wherein the electrochemical pump further comprises an operatively connected activation switch for starting and stopping fluid delivery.   21. The fluid delivery device of claim 20, wherein the electrochemical pump further comprises a support member that is operably attached to the ion exchange membrane and that can provide physical support to the ion exchange membrane.   The fluid delivery device according to claim 18, wherein the porous protective separator or the porous protective gel has a water storage part or a saline storage part.   21. The fluid delivery device of claim 20, wherein the first and second electrodes form a voltaic electrode pair.   21. The fluid delivery device according to claim 20, wherein the ion exchange membrane is an anion or cation exchange type membrane.   21. The fluid delivery device of claim 20, wherein the displaceable member is selected from the group consisting of a piston, bladder, bellows, diaphragm, plunger, and combinations thereof.   21. The fluid delivery device of claim 20, wherein the reservoir contains a fluid selected from the group consisting of biologics, drugs, lubricants, fragrances, chemical agents and mixtures thereof.   21. The fluid delivery device of claim 20, wherein the storage chamber has one or more openings.   21. The fluid delivery device of claim 20, wherein the electrical controller facilitates starting and stopping fluid delivery and adjusting the fluid delivery rate.   30. The fluid delivery device of claim 29, wherein the electrical controller is an electrical circuit.   32. The fluid delivery device of claim 30, wherein the electrical controller enables various delivery modes including pulse delivery.   30. The fluid delivery device of claim 29, wherein the electrical controller enables various delivery modes including pulse delivery.   21. The fluid delivery device of claim 20, wherein the electrical controller can be remotely controlled.   Providing a fluid delivery device using an electrochemical water feed pump; feeding water from the electrochemical water feed pump at a rate proportional to the signal output from the electrical controller; Enlarging the volume of the product chamber with a chemical water pump; generating sufficient pressure from the expanded output chamber; and being controllable from the fluid delivery device by displacing the displaceable member A fluid delivery method comprising the step of discharging the fluid.   The fluid delivery method according to claim 34, further comprising the step of controlling a fluid delivery mode.   The fluid delivery method according to claim 34, further comprising a step of adjusting a fluid delivery amount.   The fluid delivery method according to claim 36, wherein the adjustment of the fluid delivery amount is performed by changing a signal output of the electric controller.   35. The fluid delivery method according to claim 34, further comprising a step of providing a switch operably between the first electrode and the second electrode, and a step of controlling fluid delivery by operating the switch.

Images