# US 2014/0190885 A1 · Fluid circuits for sorbent cartridge with sensors > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0190885 A1 - Document ID: US20140190885A1 - Status: Published application - Kind: A1 - Application number: 13/835,735 - Filed: 2013-03-15 - Published: 2014-07-10 - Earliest claimed: 2013-01-09 - Assignees: Medtronic, Inc. - Inventors: Thomas E. Meyer; David B. Lura; Bryant J. Pudil; Martin T. Gerber - Web page: https://patentgrep.com/patent/US20140190885A1 ## CPC - A61M 1/1696: {with dialysate regeneration} - A61M 1/284: {Continuous flow peritoneal dialysis [CFPD]} - A61M 1/287: {Dialysates therefor} - A61M 1/288: {Priming (priming in extracorporeal blood circuits A61M1/3643)} - A61M 1/3472: {with treatment of the filtrate} - A61M 1/3486: {Biological, chemical treatment, e.g. chemical precipitation; treatment by absorbents} - B01D 15/08: Selective adsorption, e.g. chromatography - B01D 15/361: {Ion-exchange} - 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 system for measuring at least one fluid characteristic at various stages within a sorbent system that has a sorbent cartridge that has at least one material layer and at least one fluid passageway in at least one location in the sorbent system to provide a diverted sample stream from the various stages. At least one fluid characteristic of the diverted sample stream is measured. ## Claims ### Claim 1 A system for measuring at least one fluid characteristic at various stages within a sorbent regeneration system, comprising: a sorbent cartridge having at least one material layer; at least one fluid passageway in at least one location in the sorbent regeneration system to provide a diverted sample stream from the various stages; wherein the at least one fluid characteristic of the diverted sample stream is measured. ### Claim 2 (depends on 1) The system of claim 1, wherein the fluid is the dialysate from a dialyzer. ### Claim 3 (depends on 1) The system of claim 1, wherein the system has various positions along a sorbent regeneration flow path for additionally measuring at least one or more fluid characteristic. ### Claim 4 (depends on 1) The system of claim 1, wherein the at least one material layer comprises one or more selected from a urease-containing material, alumina, zirconium phosphate, zirconium oxide, a divalent ion exchanger, activated carbon, and combinations thereof. ### Claim 5 (depends on 4) The system of claim 4, wherein all material layers of the sorbent system are contained within a single container or cartridge. ### Claim 6 (depends on 4) The system of claim 4, wherein at least one material layer of the sorbent system is contained in a separate container or cartridge from at least one of the other material layers of the sorbent system. ### Claim 7 (depends on 1) The system of claim 1, wherein a measured characteristic is the conductivity of the diverted sample stream. ### Claim 8 (depends on 7) The system of claim 7, wherein the conductivity of the diverted sample stream is measured by electrodes. ### Claim 9 (depends on 1) The system of claim 1 wherein the measured characteristic is the pH of the diverted sample stream measured by a pH selective electrode. ### Claim 10 (depends on 1) The system of claim 1, wherein the measured characteristic is an ammonium ion concentration of the diverted sample stream measured by an ion selective electrode. ### Claim 11 (depends on 1) The system of claim 1, wherein the at least one fluid characteristic is measured from separate locations within one of the material layers. ### Claim 12 (depends on 1) The system of claim 1, wherein the at least one fluid characteristic is measured from separate locations of different material layers. ### Claim 13 (depends on 1) The system of claim 1, wherein the at least one fluid characteristic is measured at a central location within the sorbent cartridge. ### Claim 14 (depends on 1) The system of claim 1, wherein the fluid characteristic is measured from multiple locations within the sorbent cartridge. ### Claim 15 (depends on 1) The system of claim 1, further comprising at least two sensors. ### Claim 16 (depends on 15) The system of claim 15, wherein the sorbent regeneration system comprises at least one sensor that measures at least one characteristic of a plurality of separate sample streams. ### Claim 17 (depends on 1) The system of claim 1, wherein each sample stream contacts a defined sequence of material layers. ### Claim 18 (depends on 3) The system of claim 3, wherein a first sample stream has not contacted any of the material layers and a second sample stream has contacted at least one material layer. ### Claim 19 (depends on 1) The system of claim 1, further comprising a first sampling valve for selectively directing a first sample stream and a second sample stream to a sensor. ### Claim 20 (depends on 19) The system of claim 19, further comprising a second sampling valve, operable in combination with the first sampling valve for selectively directing the first sample stream, the second sample stream and a third sample stream to the sensor. ### Claim 21 (depends on 20) The system of claim 20, further comprising a third sampling valve, operable in combination with the first and second sampling valves for selectively directing the first sample stream, the second sample stream, the third sample stream and a fourth sample stream to the sensor. ### Claim 22 (depends on 18, 19) The system of any one of claim 18, 19, or 20, wherein at least one sample stream is a fluid that has contacted at least one material layer within the sorbent system. ### Claim 23 (depends on 18, 19) The system of any one of claim 18, 19, or 20, wherein at least one of the sample streams has not contacted a material layer within the sorbent system. ### Claim 24 (depends on 18, 19) The system of any one of claim 18, 19, or 20, wherein at least one of the sample streams has contacted all material layers within the sorbent system. ### Claim 25 (depends on 1) The system of claim 1, wherein two or more material layers are present in a single housing, and a selected sample stream is directed through an internal conduit within the single housing. ### Claim 26 (depends on 25) The system of claim 25, with the proviso that an internal conduit is not an outlet of the single housing from which effluent fluid has contacted all of the material layers within the single housing. ### Claim 27 (depends on 18) The system of claim 18, wherein a second sample stream has only contacted a urease-containing material layer and no other of the plural material layers. ### Claim 28 (depends on 14) The system of claim 14 wherein the one or more sample streams are selected from the group consisting of a first sample stream that has not contacted any material layer, a second sample stream that has contacted the urease-containing material layer and has not contacted any downstream material layers, a third sample stream that has contacted a material layer downstream from the urease-containing material layer and a fourth sample stream that is spent dialysate eluted from an outlet of the dialyzer. ### Claim 29 (depends on 1) The system of claim 1, further comprising a dialysate flow path for circulating fluid to the sorbent regeneration system wherein the monitoring system monitors at least one the fluid characteristic of a hemodialysis, hemodiafiltration, hemofiltration, or peritoneal dialysis system. ### Claim 30 (depends on 29) The system of claim 29, further comprising at least one of: an infusate supplied to the dialysate flow path at a position between an outlet of the sorbent regeneration system and an inlet of a dialyzer; and a buffer and water supplied to the dialysate flow path. ### Claim 31 (depends on 29) The system of claim 29, wherein the dialysate flow path is a controlled compliant flow path. ### Claim 32 (depends on 29) The system of claim 29, wherein the dialysate flow path has a small volume and a control valve for selectively metering fluid in and out of the dialysate flow path. ### Claim 33 (depends on 29) The system of claim 29, wherein the sorbent regeneration system selectively meters fluid into and out of the dialysate flow path using any one of a control pump, a water pump, an acid concentrate pump, a replacement fluid pump, and combinations thereof. ### Claim 34 (depends on 29) The system of claim 29, wherein the system is capable of moving fluid bi-directionally in the dialysate flow path. ### Claim 35 (depends on 1) The system of claim 1, further comprising a conductivity sensor for monitoring a number of feeds selected from the group consisting of: a first sample stream sampled from a point upstream of an acid feed; a second sample stream sampled from a point downstream of the acid feed; a third sample stream sampled from a point downstream of the dialyzer; a fourth sample stream sampled from a point downstream of a bicarbonate feed; a fifth sample stream sampled from a point upstream of a water feed; and a sixth sample stream sampled from a point downstream from the water feed. ### Claim 36 (depends on 1) The system of claim 1 further comprising a dialysate flow path for circulating a dialysate between a dialyzer and the sorbent cartridge. ### Claim 37 A method for determining a solute concentration of a fluid, comprising the steps of: circulating the fluid through a sorbent regeneration system having at least one material layer; and intermittently operating at least one sampling valve between at least a first sample configuration to direct a first sample stream to a first sensor and a second sample configuration to direct a second sample stream to a second sensor. ### Claim 38 (depends on 37) The method of claim 37, further comprising a dialysate flow path for circulating fluid to a sorbent cartridge wherein the monitoring system monitors at least one the fluid characteristic of a hemodialysis, hemodiafiltration, hemofiltration, or peritoneal dialysis system. ### Claim 39 (depends on 37) The method of claim 37, further comprising the step of determining a urea content of the fluid based at least in part on the difference in conductivity between the first sample stream and the second sample stream. ### Claim 40 (depends on 37) The method of claim 37, further comprising the step of determining a urea content of the fluid based at least in part on the difference in pH between the first sample stream and the second sample stream. ### Claim 41 (depends on 37) The method of claim 37, further comprising the step of determining a urea content of the fluid based at least in part on the difference in ammonium ion concentration between the first sample stream and the second sample stream. ### Claim 42 (depends on 37) The method of claim 37, further comprising the step of determining a urea clearance of a dialyzer based at least in part on the difference in conductivity between the first sample stream and the second sample stream. ### Claim 43 (depends on 37) The method of claim 37, further comprising intermittently providing an electrolyte bolus or diluent to a dialysate flow path and measuring the conductivity of the first and second sample streams, the first sample stream being sampled at an inlet of a dialyzer and the second sample stream being sampled at an outlet of the dialyzer. ### Claim 44 (depends on 33) The methods of claim 33, wherein the sorbent cartridge has plural materials including urease comingled or intermixed within the sorbent cartridge, wherein the dialysate contacts a plurality of materials in a sequential order. ### Claim 45 (depends on 37) The method of claim 37, wherein the at least one material layer includes an ion exchange resin selective for calcium ions and magnesium ions and releasing hydrogen ions in exchange for calcium or magnesium ions. ### Claim 46 (depends on 33, 39) The method of claim 33 or 39, wherein the first sample stream contains fluid that has not contacted a urease-containing material and the second sample stream is fluid that has contacted a urease-containing material of the sorbent system but has not contacted any downstream materials of the sorbent system. ### Claim 47 (depends on 33) The method of claim 33, further comprising intermittently directing a third sample stream to the conductivity sensor where the third sample stream has contacted a sorbent material of the sorbent cartridge downstream from the urease-containing material. ### Claim 48 (depends on 42) The method of claim 42, wherein a first sample stream has not contacted either a urease containing layer or the material layer removing calcium and magnesium ions and releasing hydrogen ions in exchange, and a second sample stream has contacted the material layer removing calcium and magnesium ions and releasing hydrogen ions in exchange but has not contacted the urease containing layer. ### Claim 49 (depends on 44) The method of claim 44, wherein a difference in conductivity or pH between the first sample stream and the second sample stream is used to determine the calcium and magnesium concentration of the fluid entering the sorbent system. ### Claim 50 (depends on 44) The method of claim 44, wherein a third sample stream has contacted a layer containing urease and also the material layer removing calcium and magnesium ions and releasing hydrogen ions in exchange and the difference in conductivity, pH or ammonium ion concentration between the second sample stream and the third sample stream is used to determine the urea concentration of the fluid entering the sorbent system. ### Claim 51 (depends on 1) The system of claim 1, wherein the at least one fluid passageway includes a fluid inlet positioned upstream of the sorbent cartridge. ### Claim 52 (depends on 1) The system of claim 1, wherein the at least one fluid passageway includes a fluid inlet positioned within the sorbent cartridge. ### Claim 53 (depends on 1) The system of claim 1, wherein the at least one fluid passageway includes a fluid inlet positioned downstream of the sorbent cartridge. ### Claim 54 (depends on 1) The system of claim 1, wherein the at least one fluid passageway includes at least two fluid inlets selected from the group of a first fluid inlet positioned upstream of the sorbent cartridge, a second fluid inlet positioned within the sorbent cartridge, and a third fluid inlet positioned downstream of the sorbent cartridge. ### Claim 55 (depends on 52) The system of claim 52, wherein the fluid inlet includes two or more fluid inlets positioned spaced apart within the sorbent cartridge. ### Claim 56 (depends on 1) The system of claim 1, further comprising a sorbent bypass flow path to provide a bypass fluid flow external to the sorbent cartridge. ### Claim 57 (depends on 1) The system of claim 1, further comprising a dialyzer bypass flow path to provide a bypass fluid flow external to a dialyzer and downstream of the sorbent cartridge.