# US 5,700,372 A · Dialyzer with a constricted part made of a material capable of swelled by dializing liquid > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,700,372 A - Document ID: US5700372A - Status: Granted - Kind: A - Application number: 08/523,526 - Filed: 1995-09-01 - Granted: 1997-12-23 - Earliest claimed: 1994-09-02 - Assignees: Terumo Kabushiki Kaisha - Inventors: Shingo Takesawa; Noriyuki Hosoya; Masatomi Sasaki - Web page: https://patentgrep.com/patent/US5700372A ## CPC - A61M 1/342: {Adding solutions to the blood, e.g. substitution solutions (for preventing coagulation A61M1/3672)} - A61M 1/1627: {Dialyser of the inside perfusion type, i.e. blood flow inside hollow membrane fibres or tubes} - A61M 1/3427: {back through the membrane, e.g. by inverted trans-membrane pressure [TMP]} - B01D 61/28: Apparatus therefor - B01D 61/30: Accessories; Auxiliary operation - B01D 63/02: Hollow fibre modules - A61M 1/3413: {Diafiltration} - B01D 2313/24: Specific pressurizing or depressurizing means - 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)} - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) ## Abstract A dialyzer provided in a cylindrical housing with a bundle of hollow fiber membranes and first flow paths and second flow paths separated from each other by said hollow fiber membranes and allowed to effect dialysis and ultrafiltration through the medium of said hollow fiber membranes between a body liquid flowing through said first flow paths and a dialyzing liquid flowing through said second flow paths, characterized in that a constricted part is formed halfway in the length of said second flow paths with a material capable of being swelled by said dialyzing liquid so as to confer a difference of pressure on said dialyzing liquid on the upstream side and the downstream side of said dialyzing liquid relative to said constricted part. ## Claims ### Claim 1 A dialyzer comprising a cylindrical housing in which is positioned a bundle of hollow fiber membranes, first flow paths and second flow paths separated from each other by said hollow fiber membranes for effecting dialysis and ultrafiltration through the medium of said hollow fiber membranes between a body liquid flowing through said first flow paths and a dialyzing liquid flowing through said second flow paths, a body liquid inlet and body liquid outlet in fluid communication with the first flow paths, a dialyzing liquid inlet and a dialyzing liquid outlet in fluid communication with the second flow paths, and a constricted part formed halfway along the length of said second flow paths with a material capable of being swelled by said dialyzing liquid so as to confer a difference of pressure on said dialyzing liquid on an upstream side and a downstream side of said dialyzing liquid relative to said constricted part. ### Claim 2 (depends on 1) A dialyzer according to claim 1, wherein the pressure of said dialyzing liquid flowing through said second flow paths is so set as to be higher than that of said body liquid flowing through said first flow paths on the upstream side of said dialyzing liquid relative to said constricted part and the pressure of said dialyzing liquid flowing through said second flow paths is so set as to be lower than that of said body liquid flowing through said first flow paths on the downstream side of said dialyzing liquid relative to said constricted part. ### Claim 3 (depends on 1) A dialyzer according to claim 1, wherein said bundle of hollow fiber membranes possesses a periphery and the housing possesses an inner wall, said constricted part being formed by a constricted part-forming member intervening between the periphery of the bundle of said hollow fiber membranes and the inner wall surface of said housing. ### Claim 4 (depends on 1) A dialyzer according to claim 1, wherein said constricted part is formed by a constricted part-forming member that fills a gap between adjacent hollow fiber membranes. ### Claim 5 (depends on 1) A dialyzer according to claim 1, wherein said material capable of being swelled by said dialyzing liquid has a dialyzing liquid absorption capacity of not less than 10%. ### Claim 6 (depends on 2, 3, 4, 5) A dialyzer according to any of claims 2 through 5, including an ultrafiltration rate control means connected to the dialyzing liquid inlet and the dialyzing liquid outlet for adjusting the amount of water to be removed from the body liquid flowing through said first flow path. ### Claim 7 (depends on 3) A dialyzer according to claim 3, wherein said constricted part-forming member is formed of dialyzing liquid-swellable fibers. ### Claim 8 (depends on 1) A dialyzer according to claim 1, wherein said hollow fiber membranes possess a packing ratio in said constricted part in a range of from 105 to 200% based on the packing ratio in parts other than said constricted part.