# US 4,395,260 A · Drip chamber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,395,260 A - Document ID: US4395260A - Status: Granted - Kind: A - Application number: 06/269,937 - Filed: 1981-06-01 - Granted: 1983-07-26 - Earliest claimed: 1981-06-01 - Assignees: Sorenson Research Co., Inc. - Inventors: Robert J. Todd; Gordon S. Reynolds - Web page: https://patentgrep.com/patent/US4395260A ## CPC - A61M 5/1411: {Drip chambers (A61M5/1689, A61M5/40 take precedence)} - A61M 5/162: Needle sets, i.e. connections by puncture between reservoir and tube - 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)} ## Abstract An apparatus and method for effectively eliminating the risk of introducing air bubbles into a fluid delivery system such as to administer parenteral fluids to a patient. The apparatus comprises a baffle positioned within a drip chamber for deflecting fluid expelled from a fluid resistor in order to eliminate turbulence and the formation of micro-bubbles during rapid filling or flushing of the fluid delivery system. The drip chamber also comprises a filter membrane positioned across the outlet of the drip chamber. The filter membrane is attached to a filter carrier assembly which enables the filter membrane to be momentarily displaced so that air bubbles trapped beneath the filter membrane may escape. ## Claims ### Claim 1 An improved drip chamber comprising: a housing having a fluid inlet, a fluid outlet, and walls defining a chamber; means for deflecting incoming fluid from said outlet so as to reduce turbulence of the incoming fluid; a filter membrane carrier assembly positioned over said fluid outlet, said filter membrane carrier assembly having a means for filtering said fluid; and means for displacing at least a portion of said filter membrane carrier assembly to release entrapped air bubbles from beneath said means for filtering said fluid. ### Claim 2 (depends on 1) An apparatus as defined in claim 1 wherein said entire housing is constructed of flexible plastic material. ### Claim 3 (depends on 1) An apparatus as defined in claim 1 wherein said means for deflecting said fluid comprises a conically-shaped baffle which presents a convex surface positioned beneath said fluid inlet. ### Claim 4 (depends on 1) An apparatus as defined in claim 1 wherein said means for deflecting said fluid comprises a flat baffle oriented at an angle beneath said fluid inlet. ### Claim 5 (depends on 3, 4) An apparatus as defined in claim 3 or 4 wherein said baffle comprises a plurality of radially spaced flanges which extend outward to engage the interior wall of said housing. ### Claim 6 (depends on 1) An apparatus as defined in claim 1 wherein the lower portion of said housing is interiorily shaped to provide a seat for a portion of said filter membrane carrier assembly. ### Claim 7 (depends on 6) An apparatus as defined in claim 6 wherein the lower portion of said housing further comrises a deformable, resilient portion connected to said filter membrane carrier assembly so as to bias said filter membrane carrier assembly against said seat. ### Claim 8 (depends on 1) An apparatus as defined in claim 1 wherein said filter membrane carrier assembly comprises a framework configurated as a truncated cone having a seat in the upper portion thereof and a filter membrane supported on said framework, and wherein said means for displacing said filter membrane carrier assembly to release said entrapped air bubbles comprises a stem attached to said means for deflecting said fluid from said inlet, said stem having a flared portion configurated to engage said seat, and said stem being displaceable through the upper portion of said framework in order to release air bubbles entrapped within said filter membrane when said stem is displaced upwardly. ### Claim 9 (depends on 8) An apparatus as defined in claim 8 wherein the lower portion of said housing further comprises a deformable, resilient portion connected to said stem so as to bias said stem against said seat. ### Claim 10 An improved drip chamber for use in a fluid delivery system for administering parenteral fluids to a patient, said drip chamber comprising: a housing; an inlet in fluid communication with said housing; a baffle positioned within said housing adjacent said fluid inlet; an outlet in fluid communication with said housing; a filter membrane carrier assembly positioned over said fluid outlet and said filter membrane carrier assembly having a means for filtering said fluid; and means for displacing said filter membrane carrier assembly to release entrapped air bubbles from beneath said means for filtering said fluid. ### Claim 11 (depends on 10) An apparatus as defined in claim 10 wherein said baffle presents an essentially convex surface positioned beneath said fluid inlet. ### Claim 12 (depends on 10) An apparatus as defined in claim 10 wherein said baffle presents an angularly oriented, essentially planar surface positioned beneath said fluid inlet. ### Claim 13 (depends on 10) An apparatus as defined in claim 10 wherein said housing is interiorily shaped to provide a seat for said filter member carrier assembly, and wherein said means for displacing said filter membrane carrier assembly to release entrapped air bubbles further comprises means for momentarily displacing said filter membrane carrier assembly so that said filter membrane carrier assembly is unseated from said seat. ### Claim 14 (depends on 13) An apparatus as defined in claim 13 wherein the lower portion of said housing further comprises a resilient portion connected to said filter membrane carrier assembly so as to bias said filter membrane carrier assembly against said seat. ### Claim 15 (depends on 10) An apparatus as defined in claim 10 wherein said filter membrane carrier assembly comprises a framework configurated as a truncated cone having a seat in the upper portion thereof and a filter membrane supported on said framework, and wherein said means for displacing said filter membrane carrier assembly to release said entrapped air bubbles comprises a stem attached to said baffle, a portion of said stem being configurated to engage said seat, said stem being displaceable through said framework so as to momentarily unseat said stem from said seat. ### Claim 16 (depends on 15) An apparatus as described in claim 15 wherein the lower portion of said housing further comprises a resilient portion connected to said stem so as to bias said stem against said seat. ### Claim 17 An improved drip chamber for use in a fluid delivery system for administering parenteral fluids to a patient, said drip chamber comprising: a housing having a fluid inlet, a fluid outlet and walls defining a chamber wherein at least the lower portion of said walls are made of a resilient plastic, said housing being interiorily shaped to provide an annular seat in the lower portion thereof; a baffle positioned beneath said fluid inlet having a plurality of radially spaced flanges which extend outward to engage said walls; a filter positioned across said fluid outlet and configurated to engage said seat; and a filter carrier connected to said filter, said carrier comprising an outlet tube connected to said resilient wall portion so that said filter carrier is biased by said resilient wall portion such that said filter engages said seat, and wherein said filter and filter carrier are displaceable so as to momentarily unseat said filter from said seat. ### Claim 18 An improved drip chamber for use in a fluid delivery system for administering parenteral fluids to a patient, said drip chamber comprising: a housing having a fluid inlet, a fluid outlet and walls defining a chamber wherein at least the lower portion of said walls are made of a resilient plastic, said housing being interiorly shaped to provide an annular seat in the lower portion thereof; a baffle positioned beneath said fluid inlet; a filter positioned across said fluid outlet, said filter comprising a framework configurated as a truncated cone having a seat in the upper portion thereof and a filter membrane supported on said framework; and a stem attached to said baffle, said stem having a portion configurated to engage said seat, and wherein said stem is biased by said resilient wall portion such that said stem engages said seat, and wherein said stem and said baffle are displaceable so as to momentarily unseat said stem from said seat.