# US 10,765,792 B2 · System and method for dialyzer evaluation > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,765,792 B2 - Document ID: US10765792B2 - Status: Granted - Kind: B2 - Application number: 16/801,666 - Filed: 2020-02-26 - Published: 2020-06-18 - Granted: 2020-09-08 - Earliest claimed: 2017-09-29 - Assignees: Fresenius Medical Care Holdings, Inc. - Applicants: Fresenius Medical Care Holdings, Inc. - Inventors: Louis LeeGrande Barrett; Chih-Hu Ho; Eric Stroup - Web page: https://patentgrep.com/patent/US10765792B2 ## CPC - A61M 1/1692: {Detection of blood traces in dialysate} - B01D 61/22: Controlling or regulating - A61M 1/267: {used for pumping} - A61M 1/361: {before treatment} - A61M 1/3612: {after treatment} - B01D 65/109: {Testing of membrane fouling or clogging, e.g. amount or affinity} - A61M 1/3663: {Flow rate transducers; Flow integrators} - A61M 2205/3306: Optical measuring means - A61M 2205/3334: Measuring or controlling the flow rate - A61M 2205/3386: Low level detectors - A61M 2205/50: with microprocessors or computers - A61M 2205/702: automatically during use - A61M 2205/707: Testing of filters for clogging - A61M 2209/02: Equipment for testing the apparatus - A61M 2230/207: hematocrit - B01D 2311/16: Flow or flux control - B01D 2311/246: Concentration control - 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 Embodiments of the disclosure provide a method for evaluating dialyzers used in different medical applications (e.g., hemodialysis). Red blood cell volume lost in a dialyzer is monitored by obtaining blood flowrate measurements and hematocrit measurements at input ports and output ports of the dialyzer. The flowrate and hematocrit measurements are used to determine an accumulation of red cell blood volume in the dialyzer. The measurements may be obtained in a lab environment with an in-vitro blood source or may be obtained in a clinical setting with an in-vivo blood source from a patient. ## Claims ### Claim 1 A dialyzer analysis system, comprising: a first sensor connected to a first portion of a blood flow path disposed on an input side of a dialyzer, wherein the first sensor is configured to obtain a measurement corresponding to hematocrit of blood in the first portion of the blood flow path; a second sensor connected to a second portion of the blood flow path disposed on an output side of the dialyzer, wherein the second sensor is configured to obtain a measurement corresponding to hematocrit of blood in the second portion of the blood flow path; and a controller configured to determine a red blood cell volume loss corresponding to an amount of red blood cells remaining in the dialyzer based on the measurements from the first and second sensors. ### Claim 2 (depends on 1) The system according to claim 1, wherein the controller is further configured to: determine a flowrate of the blood in the first portion of the blood flow path; and determine a flowrate of the blood in the second portion of the blood flow path; wherein determining the red blood cell volume loss is further based on the determined flowrate of the blood in the first portion of the blood flow path and the determined flowrate of the blood in the second portion of the blood flow path. ### Claim 3 (depends on 2) The system according to claim 2, wherein the controller is further configured to: determine an input red blood cell volume flow corresponding to blood flowing into the dialyzer based on the measurement from the first sensor and the flowrate of the blood in the first portion of the blood flow path; determine an output red blood cell volume flow corresponding to blood flowing out of the dialyzer based on the measurement from the second sensor and the flowrate of the blood in the second portion of the blood flow path; and determine a difference ΔR between the input red blood cell volume flow and the output red blood cell volume flow; wherein determining the red blood cell volume loss is further based on the difference ΔR. ### Claim 4 (depends on 3) The system according to claim 3, wherein determining the red blood cell volume loss is further based on using one or more ΔR values over a period of time to determine an accumulated red blood cell volume loss value. ### Claim 5 (depends on 4) The system according to claim 4, wherein using one or more ΔR values over a period of time to determine an accumulated red blood cell volume loss value comprises: multiplying each ΔR value by a respective time slice and summing respective red blood cell volume losses corresponding to each respective time slice. ### Claim 6 (depends on 4) The system according to claim 4, wherein using one or more ΔR values over a period of time to determine an accumulated red blood cell volume loss value comprises: determining a function for ΔR and integrating the function over the period of time. ### Claim 7 (depends on 2) The system according to claim 2, wherein determining the flowrate of the blood in the first portion of the blood flow path is based on a pumping rate of a pump configured to pump the blood in the first portion of the blood flow path into the dialyzer. ### Claim 8 (depends on 2) The system according to claim 2, further comprising: a flowmeter coupled to the first portion of the blood flow path; wherein the controller is configured to determine the flowrate of the blood in the first portion of the blood flow path using the flowmeter. ### Claim 9 (depends on 2) The system according to claim 2, further comprising: a flowmeter coupled to the second portion of the blood flow path; wherein the controller is configured to determine the flowrate of the blood in the second portion of the blood flow path using the flowmeter. ### Claim 10 (depends on 2) The system according to claim 2, wherein the controller is further configured to: determine the flowrate of the blood in the first portion of the blood flow path based on an ultrafiltration rate and the flowrate of the blood in the second portion of the blood flow path; or determine the flowrate of the blood in the second portion of the blood flow path based on the ultrafiltration rate and the flowrate of the blood in the first portion of the blood flow path. ### Claim 11 (depends on 1) The system according to claim 1, wherein the controller is further configured to output a rating for the dialyzer based on the red blood cell volume loss. ### Claim 12 (depends on 1) The system according to claim 1, wherein the controller is further configured to output a comparison of the dialyzer to one or more other dialyzers based on respective red blood cell volume losses determined for each dialyzer. ### Claim 13 A method for dialyzer analysis, comprising: obtaining, by a first sensor of a dialyzer analysis system connected to a first portion of a blood flow path disposed on an input side of a dialyzer, a measurement corresponding to hematocrit of blood in the first portion of the blood flow path; obtaining, by a second sensor of the dialyzer analysis system connected to a second portion of the blood flow path disposed on an output side of the dialyzer, a measurement corresponding to hematocrit of blood in the second portion of the blood flow path; and determining, by a controller of the dialyzer analysis system, a red blood cell volume loss corresponding to an amount of red blood cells remaining in the dialyzer based on the measurements from the first and second sensors. ### Claim 14 (depends on 13) The method according to claim 13, further comprising: determining a flowrate of the blood in the first portion of the blood flow path; and determining a flowrate of the blood in the second portion of the blood flow path; wherein determining the red blood cell volume loss is further based on the determined flowrate of the blood in the first portion of the blood flow path and the determined flowrate of the blood in the second portion of the blood flow path. ### Claim 15 (depends on 14) The method according to claim 14, further comprising: determining an input red blood cell volume flow corresponding to blood flowing into the dialyzer based on the measurement from the first sensor and the flowrate of the blood in the first portion of the blood flow path; determining an output red blood cell volume flow corresponding to blood flowing out of the dialyzer based on the measurement from the second sensor and the flowrate of the blood in the second portion of the blood flow path; and determining a difference ΔR between the input red blood cell volume flow and the output red blood cell volume flow; wherein determining the red blood cell volume loss is further based on the difference ΔR. ### Claim 16 (depends on 15) The method according to claim 15, wherein determining the red blood cell volume loss is further based on using one or more ΔR values over a period of time to determine an accumulated red blood cell volume loss value. ### Claim 17 A non-transitory computer-readable medium having processor-executable instructions stored thereon for dialyzer analysis, the processor-executable instructions, when executed, facilitating: obtaining, by a first sensor of a dialyzer analysis system connected to a first portion of a blood flow path disposed on an input side of a dialyzer, a measurement corresponding to hematocrit of blood in the first portion of the blood flow path; obtaining, by a second sensor of the dialyzer analysis system connected to a second portion of the blood flow path disposed on an output side of the dialyzer, a measurement corresponding to hematocrit of blood in the second portion of the blood flow path; and determining, by a controller of the dialyzer analysis system, a red blood cell volume loss corresponding to an amount of red blood cells remaining in the dialyzer based on the measurements from the first and second sensors. ### Claim 18 (depends on 17) The non-transitory computer-readable medium according to claim 17, wherein the processor-executable instructions, when executed, further facilitate: determining a flowrate of the blood in the first portion of the blood flow path; and determining a flowrate of the blood in the second portion of the blood flow path; wherein determining the red blood cell volume loss is further based on the determined flowrate of the blood in the first portion of the blood flow path and the determined flowrate of the blood in the second portion of the blood flow path. ### Claim 19 (depends on 18) The non-transitory computer-readable medium according to claim 18, wherein the processor-executable instructions, when executed, further facilitate: determining an input red blood cell volume flow corresponding to blood flowing into the dialyzer based on the measurement from the first sensor and the flowrate of the blood in the first portion of the blood flow path; determining an output red blood cell volume flow corresponding to blood flowing out of the dialyzer based on the measurement from the second sensor and the flowrate of the blood in the second portion of the blood flow path; and determining a difference ΔR between the input red blood cell volume flow and the output red blood cell volume flow; wherein determining the red blood cell volume loss is further based on the difference ΔR. ### Claim 20 (depends on 19) The non-transitory computer-readable medium according to claim 19, wherein determining the red blood cell volume loss is further based on using one or more ΔR values over a period of time to determine an accumulated red blood cell volume loss value.