# US 2011/0240555 A1 · Apparatus for extracorporeal blood treatment and method for managing such an apparatus > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2011/0240555 A1 - Document ID: US20110240555A1 - Status: Published application - Kind: A1 - Application number: 13/122,878 - Filed: 2009-09-24 - Published: 2011-10-06 - Earliest claimed: 2008-10-06 - Assignees: RD Nephrologie - Inventors: Alain Ficheux; Angel Argiles Ciscart - Web page: https://patentgrep.com/patent/US20110240555A1 ## CPC - A61M 1/3413: {Diafiltration} - A61M 1/341: {by measuring the filtrate rate or volume} - 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 A method for controlling an apparatus for treating blood outside the human body, with a view to improving the operation of the apparatus, the apparatus including a semi-permeable membrane carrying out an exchange of solutes, referred to as dialysis, and of liquid, referred to as ultrafiltration, with the blood, the method including at least one iteration of the following steps: determination of a so-called instantaneous value, of an ultrafiltration coefficient corresponding to the ratio of an ultrafiltration flow rate to a difference in pressure, the so-called transmembrane pressure, on either side of the semi-permeable membrane, comparison of the instantaneous value with at least one previously determined characteristic value; and control of the treatment apparatus to reach a maximum value of the ultrafiltration coefficient, the control including a variation of the ultrafiltration flow rate up to a value corresponding to the maximum value of the ultrafiltration coefficient. ## Claims ### Claim 1 A method for controlling an apparatus for treating blood outside the human body, with a view to improving the operation of said apparatus, said apparatus comprising a semi-permeable membrane carrying out an exchange of solutes, referred to as dialysis, and of liquid, referred to as ultrafiltration, with the blood, said method comprising at least one iteration of the following steps: determination of a so-called instantaneous value, of an ultrafiltration coefficient corresponding to the ratio of an ultrafiltration flow rate to a difference in pressure, the so-called transmembrane pressure, on either side of said semi-permeable membrane, comparison of said instantaneous value with at least one previously determined characteristic value; and control of said treatment apparatus so as to reach a maximum value of said ultrafiltration coefficient, said control comprising a variation of the ultrafiltration flow rate up to a value corresponding to said maximum value of said ultrafiltration coefficient. ### Claim 2 (depends on 1) The method according to claim 1, characterized in that the step of determination of the ultrafiltration coefficient comprises at least one iteration of the following steps: measurement of the transmembrane pressure, calculation of the ultrafiltration flow rate achieved by the semi-permeable membrane, and calculation of the ultrafiltration coefficient value by dividing said ultrafiltration flow rate by said transmembrane pressure. ### Claim 3 (depends on 1) The method according to claim 1, characterized in that the maximum value of the ultrafiltration coefficient is a value predetermined: by the manufacturer of the treatment apparatus, or during one or more previous treatment sessions. ### Claim 4 (depends on 1) The method according to claim 1, characterized in that the maximum ultrafiltration coefficient value is measured during the treatment session in progress by determination of the variation of said ultrafiltration coefficient as a function of the ultrafiltration flow rate, said determination comprising several iterations of the following steps: variation of the ultrafiltration flow rate measurement of the transmembrane pressure obtained for this ultrafiltration flow rate, calculation of the ultrafiltration coefficient value by dividing said ultrafiltration flow rate by said transmembrane pressure, and storage of said ultrafiltration coefficient calculated in association with the ultrafiltration flow rate; ### Claim 5 (depends on 1) The method according to claim 1, characterized in that it also comprises a determination of a hydraulic permeability of the semi-permeable membrane as a function of the ultrafiltration coefficient. ### Claim 6 An apparatus for treating blood outside the human body comprising a dialysis chamber comprising a semi-permeable membrane carrying out an exchange of solutes, referred to as dialysis, and of liquid, referred to as ultrafiltration, with the blood, said apparatus comprising: means of determination of a so-called instantaneous value of an ultrafiltration coefficient corresponding to the ratio of an ultrafiltration flow rate to a difference in pressure, the so-called transmembrane pressure, on either side of said semi-permeable membrane, means of variation of the ultrafiltration flow rate, and means for controlling said means of variation of the ultrafiltration flow rate, as a function of a comparison of said instantaneous value to a so-called maximum value, so as to reach a maximum ultrafiltration coefficient. ### Claim 7 (depends on 6) The apparatus according to claim 6, characterized in that the means of determination of the instantaneous ultrafiltration coefficient value include: means of measurement of the transmembrane pressure, means of measurement of the ultrafiltration flow rate achieved by the semi-permeable membrane, and means of calculation of the ultrafiltration coefficient value from said ultrafiltration flow rate and said transmembrane pressure. ### Claim 8 (depends on 6) The apparatus according to claim 6, characterized in that it also comprises means for storing at least one ultrafiltration coefficient value for an ultrafiltration flow rate value. ### Claim 9 (depends on 6) The apparatus according to claim 6, characterized in that the means for controlling comprise means of execution of instructions stored in storage means, said instructions carrying out a calculation of the maximum ultrafiltration coefficient value during a treatment session in progress by determination of the variation of said ultrafiltration coefficient as a function of the ultrafiltration flow rate, said determination comprising at least one iteration of the following steps: variation of the ultrafiltration flow rate measurement of the transmembrane pressure obtained for this ultrafiltration flow rate, calculation of the ultrafiltration coefficient value by dividing said ultrafiltration flow rate by said transmembrane pressure, and storage of said ultrafiltration coefficient calculated in association with the ultrafiltration flow rate; ### Claim 10 (depends on 6) The apparatus according to claim 6, characterized in that it also comprises means for manual activation: of the determination of the instantaneous ultrafiltration coefficient value, and/or of the determination of the maximum ultrafiltration coefficient value during a treatment session in progress. ### Claim 11 (depends on 6) The apparatus according to claim 6, characterized in that the dialysis chamber is disposable.