# US 2011/0031268 A1 · Electrokinetic pump designs and drug delivery systems > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2011/0031268 A1 - Document ID: US20110031268A1 - Status: Published application - Kind: A1 - Application number: 12/728,844 - Filed: 2010-03-22 - Published: 2011-02-10 - Earliest claimed: 2005-11-23 - Inventors: Deon Stafford Anex; Charles Martin Schwimmer; David Laurence Black; Richard Dean Rush; Michael James Gearhart - Web page: https://patentgrep.com/patent/US20110031268A1 ## CPC - F04B 19/04: Pumps for special use - A61M 5/14526: {the piston being actuated by fluid pressure} - F04B 17/00: Pumps characterised by combination with, or adaptation to, specific driving engines or motors - F04B 19/006: {Micropumps (F04B43/043 and F04B43/095 take precedence)} - A61M 2005/14513: {with secondary fluid driving or regulating the infusion} - A61M 2209/045: for filling, e.g. for filling reservoirs - Y10T 137/0391: Affecting flow by the addition of material or energy - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract One embodiment of the present invention provides a piston assembly having a piston housing filled with an electrolyte; a housing within the piston housing that divides the piston housing into a first portion and a second portion, the housing having apertures, a shaft connecting the housing to a piston head outside of the piston housing; and a porous material inside of the housing in contact with the electrolyte. Additionally, there are provided a method for filling the delivery chamber with a delivery fluid by withdrawing the piston head from within the delivery chamber. Yet another embodiment provides a method for filling a fluid delivery assembly by withdrawing a shaft from within the fluid delivery assembly to simultaneously displace a moving pump element within the delivery chamber and bypass fluid around a housing in the pump chamber. ## Claims ### Claim at position 1 -28. (canceled) ### Claim 29 A method for operating a fluid delivery system comprising: providing a delivery chamber having a piston assembly therein, wherein the piston assembly includes a pump housing having a pair of electrodes therein, a piston head outside of the pump housing and attached to a shaft extending through a wall in the pump housing, and a material housing attached to the shaft and between the electrodes; and filling the delivery chamber with a delivery fluid by drawing the piston assembly at least partially out of the delivery chamber. ### Claim 30 (canceled) ### Claim 31 (depends on 29) A method for operating a fluid delivery system according to claim 29 further comprising: advancing the piston head in the delivery chamber to expel the delivery fluid from the delivery chamber. ### Claim 32 (depends on 31) A method according to claim 31 wherein advancing the piston head comprises electrokinetically moving pump fluid in the pump housing through the material housing. ### Claim 33 (depends on 32) A method according to claim 32 wherein electrokinetically moving pump fluid within the pump chamber comprises providing an electric field between the pair of electrodes. ### Claim 34 (canceled) ### Claim 35 A method for operating a fluid delivery assembly having a pump housing including a pump chamber and a delivery chamber, the method comprising: withdrawing a shaft from the pump housing to simultaneously displace a moving pump element within the delivery chamber and bypass fluid around a material housing in the pump chamber. ### Claim 36 (depends on 35) A method for operating a fluid delivery assembly according to claim 35 wherein withdrawing the shaft introduces a delivery fluid into the delivery chamber and into contact with the moving pump element. ### Claim 37 (depends on 35) A method of operating fluid delivery assembly according to claim 35 further comprising: advancing the moving pump element in the delivery chamber to expel the delivery fluid from the delivery chamber. ### Claim 38 (depends on 37) A method of operating a fluid delivery assembly according to claim 37, wherein advancing the moving pump element comprises electrokinetically moving fluid in the pump chamber. ### Claim 39 (depends on 35) The method of claim 35 further comprising: actuating a bypass in the shaft during the withdrawing step. ### Claim 40 (depends on 31) A method for operating a fluid delivery system according to claim 31, further comprising: fixing the position of the pump housing relative to the delivery chamber after filling the delivery chamber and before advancing the piston head. ### Claim 41 (depends on 29) A method for operating a fluid delivery system according to claim 29, further comprising: removably attaching a container including the delivery fluid to an outlet in the delivery chamber prior to filling the delivery chamber, wherein filling the delivery chamber comprises drawing delivery fluid from the container into the delivery chamber. ### Claim 42 A method for operating a fluid delivery system according to 31, further comprising: attaching a delivery device to an outlet in the delivery chamber prior to advancing the piston head, wherein the delivery fluid is expelled into the delivery device during the advancing step. ### Claim 43 (depends on 35) A method for operating a fluid delivery system according to claim 35, further comprising: removably attaching a container including the delivery fluid to an outlet in the delivery chamber prior to withdrawing the shaft, wherein withdrawing the shaft comprises drawing delivery fluid from the container into the delivery chamber. ### Claim 44 (depends on 37) A method for operating a fluid delivery system according to claim 37, further comprising: attaching a delivery device to an outlet in the delivery chamber prior to advancing the moving pump element, wherein the delivery fluid is expelled into the delivery device during the advancing step. ### Claim 45 A method for operating a fluid delivery system comprising: filling a delivery chamber with a delivery fluid by drawing a piston assembly at least partially out of the delivery chamber, the piston assembly including a piston head and a pump housing having a pair of electrodes therein; providing an electric field between the pair of electrodes; and advancing the piston head within the delivery chamber using electrokinetic energy created by the pair of electrodes such that the delivery fluid is expelled from the delivery chamber. ### Claim 46 (depends on 45) The method of claim 45, wherein providing an electric field causes a pump fluid to move in the pump housing to create electrokinetic energy. ### Claim 47 (depends on 46) The method of claim 46, wherein the fluid moves through a porous material in the material housing. ### Claim 48 (depends on 45) The method of claim 45, wherein the piston system further includes a shaft extending through a wall in the pump housing, and wherein drawing the piston assembly at least partially out of the delivery chamber comprises moving the shaft. ### Claim 49 (depends on 45) A method for operating a fluid delivery system according to claim 45, further comprising: removably attaching a container including the delivery fluid to an outlet in the delivery chamber prior to filling the delivery chamber, wherein filling the delivery chamber comprises drawing delivery fluid from the container into the delivery chamber. ### Claim 50 (depends on 45) A method for operating a fluid delivery system according to claim 45, further comprising: attaching a delivery device to an outlet in the delivery chamber prior to advancing the piston head, wherein the delivery fluid is expelled into the delivery device during the advancing step.