Classifications

• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F04—POSITIVE - DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS FOR LIQUIDS OR ELASTIC FLUIDS
  • F04B—POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS
  • F04B43/00—Machines, pumps, or pumping installations having flexible working members
  • F04B43/02—Machines, pumps, or pumping installations having flexible working members having plate-like flexible members, e.g. diaphragms
  • F04B43/04—Pumps having electric drive
  • F04B43/043—Micropumps
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
  • A61M5/142—Pressure infusion, e.g. using pumps
  • A61M5/14212—Pumping with an aspiration and an expulsion action
  • A61M5/14224—Diaphragm type
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M5/00—Devices for bringing media into the body in a subcutaneous, intra-vascular or intramuscular way; Accessories therefor, e.g. filling or cleaning devices, arm-rests
  • A61M5/14—Infusion devices, e.g. infusing by gravity; Blood infusion; Accessories therefor
  • A61M5/142—Pressure infusion, e.g. using pumps
  • A61M5/14244—Pressure infusion, e.g. using pumps adapted to be carried by the patient, e.g. portable on the body
  • A61M5/14276—Pressure infusion, e.g. using pumps adapted to be carried by the patient, e.g. portable on the body specially adapted for implantation

Definitions

• the present invention relates to a mesopump. More particularly the invention relates to a mesopump having reduced pump volume and weight for a given fluid pumping rate due to its compact design.
• the Government may have rights in this invention pursuant to Contract No. DABT63-97-C-0071, awarded by the Department of the Army.
• mesopumps could be developed with inlet and outlet ports in the center of the chamber to eliminate lateral channels.
• the present invention provides an electrostatically actuated diaphragm pump.
• the pump consists of a single molded plastic chamber with two thin diaphragms staked directly on top of each other.
• the diaphragms may be actuated with electrostatic, electromagnetic, or piezoelectric methods.
• the electrostatic actuation approach may be implemented in a similar manner to previous designs such as those in the above-referenced patent applications and patents.
• the unique feature of the present invention is the use of a single chamber for pumping, as distinguished from the prior art where three chambers are required.
• Each diaphragm has its own set of valving holes, wherein the holes in the upper and lower diaphragm are offset so that the surfaces form a sealed surface when they are electrostatically pulled together, yet allow flow through the diaphragm when separated.
• At least one inlet port and at least one outlet port are provided in the pump body for communication with the pump chamber.
• the ports are positioned to be sealed by the diaphragm by insuring contact with the diaphragms at a point nonaligned with the holes in the diaphragm.
• the inlet port may be located on the top of the pump chamber for engagement with the first diaphragm to open and close the inlet port.
• the outlet port may be positioned on the bottom of the pump chamber for engagement with the second diaphragm to open and close the outlet port. Since the pump of this invention is reversible, of course, the bottom and top are mere nomenclature and reverse terminology could be used to refer to the inlet/outlet positions.
• the pumps of the present invention may be formed into an array formed from a plurality of electrostatically actuated diaphragm pumps according to the present invention. These plurality of pumps may be connected through the inlet and outlet ports in parallel to form a sheet-like array, and, even to form multiple layers of sheets of the pumps. Alternatively, the plurality of pumps may be connected through the inlet and outlet ports in series. Both forms are contemplated by the present invention.
• FIGURE 1 is an enlarged, cross section view of a pump according to this invention
• FIGURE. 2 is a top or plan view of the device of FIGURE 1;
• FIGURES 3a-3f are schematic illustration of the operation of the pump shown in FIGURE 1;
• FIGURE 4 is a schematic diagram illustrating one sequence of control voltages for operation of the pump shown in FIGURE 1;
• FIGURE 5 is a schematic illustration of a four layer parallel array of pump cells of the type shown in FIGURE 1;
• FIGURES 6a and 6b illustrate two alternative shapes for pump bodies for pumps similar to the pump shown in FIGURE 1;
• FIGURE 7 is a schematic cross section illustration of a four layer pump array;
• FIGURE 8 is a schematic cross section illustration of two four layer pump arrays of FIGURE 7, stacked in series;
• FIGURE 9 is a schematic cross section illustration of a second configuration for massively parallel arrays of the pump of FIGURE 1.
• Fig. 1 shows the present invention, 10 generally, in cross section, with a body 11 defining a chamber having an upper region 13 a middle region 14 and a lower region 15.
• the chamber is separated into three regions by the upper and lower diaphragms 17 and 19, respectively, and the volume of each region is determined by the position of the diaphragms.
• Control electronics 21 provides voltage potentials VI, V2 and V3.
• each diaphragm has a separate electrode, as do the upper and lower surfaces of the chamber.
• the upper and lower surfaces of each diaphragm and the upper and lower surfaces of the bump chamber may be shorted to the same potential, so that only three control voltages are required. It is known to move diaphragms in chambers electrostatically by application of a voltage to one or more electrodes, and it is contemplated that the present invention will employ those techniques to accomplish the movements of diaphragm into and out of contact with each other and with the chamber itself.
• Each electrode consists of a conductive metal layer coated with a dielectric to prevent shorting between electrodes, as is known in the art.
• Diaphragms 17 and 19 have a plurality of holes 27 and 29, respectively, which permit passage of fluid through the diaphragm Holes 27 and 29 are nonaligned or positioned so that no hole in diaphragm 17 overlays any hole in diaphragm 19.
• Fig. 2 illustrates this arrangement, with the upper holes 27 in solid on diaphragm 17, and lower holes 29 in dotted line to illustrate they are located on lower diaphragm 29.
• the two diaphragms 17 and 19 are electrostatically pulled together, they form a sealed surface, yet allow flow through the diaphragm if actuated individually.
• upper port 33 communicates with upper chamber 13 and lower port 35 communicates with lower chamber 15.
• the upper chamber region 13 communicates with the middle region 14 via the upper holes 27, and the lower chamber region 15 communicates with the middle region 14 via the lower holes 29. Since fluid flow can be either in or out of port 33 and 35, both ports 33 and 35 will serve as an inlet or an outlet, depending on the configuration of the pump and attendant equipment during use of the pump.
• Figs. 3a-3f illustrate a pumping sequence where the inlet is on the bottom. An opposite configuration is equally appropriate since the pump is completely reversible.
• Figs. 3a illustrates the orientation where both diaphragms 17 and 19 have been pulled down, thus sealing lower port 35. Fluid is assumed to be contained in upper chamber 13, while middle chamber 14 and the lower chamber 15 are essentially eliminated by the position of the two diaphragms 17 and 19.
• FIG. 3b illustrates the initiation of the pump stroke by simultaneously moving diaphragms 17 and 19 together upward toward the top.
• Fig. 3c shows completion of the pump stroke, with both diaphragms 17 and 19 pushed up, thus sealing upper port 33. All of the fluid in chamber 13 of Fig. 3a has been expelled in Fig. 3c through upper port 33 and lower port 35 is open, so that the fluid is drawn into the lower chamber 15 through lower port 35.
• Fig. 3b illustrates the initiation of the pump stroke by simultaneously moving diaphragms 17 and 19 together upward toward the top.
• Fig. 3c shows completion of the pump stroke, with both diaphragms 17 and 19 pushed up, thus sealing upper port 33. All of the fluid in chamber 13 of Fig. 3a has been expelled in Fig. 3c through upper port 33 and lower port 35 is open, so that the fluid is drawn into the lower chamber 15 through lower port 35.
• Fig. 3b illustrates the initiation of the pump stroke by simultaneously moving
• Fig. 3d the upper diaphragm 17 remains in sealing relationship with upper port 33 while lower diaphragm 19 is pulled down, causing the fluid in lower chamber 15 to transfer to middle chamber 14 via holes 29.
• Fig. 3e illustrates the orientation of the lower diaphragm 19 completely pulled down to seal the lower port 35 while upper diaphragm 17 remains sealing upper port 33.
• Fig. 3f illustrates the midpoint of movement of upper diaphragm 17 down toward lower diaphragm 19, wherein fluid may be pulled from the middle chamber 14 into the upper chamber 13 to result in the orientation shown initially in Fig. 3a.
• Fig. 4 illustrates schematically a possible sequence of control voltages for the pump operation described above, where VI remains at a +V value, V2 remains at a -V value, and V3 alternates between +V and -V as illustrated, causing the electrostatic activation of diaphragms 17 and 19 as described with respect to Figs. 3a-3f.
• each pump channel has only one chamber, nominally divided into an upper region 13, middle region 14 and lower region 15, depending on the location of the diaphragms 17 and 19.
• the three stages of prior art pumping action is, in effect, contained in the single chamber of block 11.
• the design of the present invention is much more compact, with only one molded chamber for each pumping channel.
• the inlet and outlet ports are both in the center of the chamber, eliminating the use of lateral channels. This will permit an increase of pumping rate because of the elimination of lateral channels.
• Fig. 1 and others show how dead space has been eliminated, particularly since lateral channels are absent. Additionally, since both sides of the diaphragms are used in the pumping process, there is no need to mold in extra ports to provide pressure relief for unused diaphragm surfaces. Finally, the pump is reversible.
• FIGs. 5, 7 and 8 illustrates a pump stacking arrangement in which up to four layers of pumps operate in parallel.
• flow through channels 61 may be placed in individual bodies 63, with inlet/outlet 65 in the center of body 63, or pump body 67 can be hexagonal in shape, for example, with a central inlet/outlet 65 and flow through channels 69 at each corner of hexagon body 67.
• each layer is offset appropriately. This doubles the linear density of inlet/outlet ports over a single layer of pumps.
• Fig. 7 shows four layers 71, 73, 75, and 77.
• Fig. 8 illustrates a pair of four layer pump arrays stacked in series.
• Fig. 9 illustrates a second configuration for massively parallel arrays of the type shown in Fig. 1.
• Use of lateral channels 93 for inlet porting and lateral channels 95 for outlet porting permits the number of pump layers stacked on top of each other to be much greater, so a cube shaped array could be formed.

Landscapes

• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Reciprocating Pumps (AREA)

Priority Applications (5)

Applications Claiming Priority (2)

Publications (1)

Family

ID=23617153

Family Applications (1)

Country Status (8)

Families Citing this family (148)

Citations (8)

Family Cites Families (12)

• 1999
  • 1999-09-15 US US09/408,651 patent/US6179586B1/en not_active Expired - Lifetime
• 2000
  • 2000-09-15 AT AT00965096T patent/ATE354025T1/de not_active IP Right Cessation
  • 2000-09-15 CA CA002384993A patent/CA2384993A1/en not_active Abandoned
  • 2000-09-15 AU AU75872/00A patent/AU7587200A/en not_active Abandoned
  • 2000-09-15 WO PCT/US2000/025488 patent/WO2001020166A1/en not_active Ceased
  • 2000-09-15 DE DE60033410T patent/DE60033410T2/de not_active Expired - Lifetime
  • 2000-09-15 JP JP2001523518A patent/JP2003509624A/ja active Pending
  • 2000-09-15 EP EP00965096A patent/EP1212532B1/en not_active Expired - Lifetime

Patent Citations (9)

Non-Patent Citations (1)

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