# US 10,117,983 B2 · Pressure/flow characteristic modification of a centrifugal pump in a ventricular assist device > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,117,983 B2 - Document ID: US10117983B2 - Status: Granted - Kind: B2 - Application number: 15/352,141 - Filed: 2016-11-15 - Published: 2017-05-18 - Granted: 2018-11-06 - Earliest claimed: 2015-11-16 - Assignees: Tc1 LLC - Applicants: Tc1 LLC - Inventors: Alexander Medvedev; Muhammad Sami - Web page: https://patentgrep.com/patent/US10117983B2 ## CPC - F04D 15/0066: {by changing the speed, e.g. of the driving engine} - A61M 60/148: in line with a blood vessel using resection or like techniques, e.g. permanent endovascular heart assist devices - A61M 60/178: drawing blood from a ventricle and returning the blood to the arterial system via a cannula external to the ventricle, e.g. left or right ventricular assist devices - A61M 60/232: Centrifugal pumps - A61M 60/411: generated by an electromotor - A61M 60/546: of blood flow, e.g. by adapting rotor speed - A61M 60/585: User interfaces - F04D 13/06: the pump being electrically driven - F04D 15/0088: {Testing machines} - F04D 29/22: specially for centrifugal pumps - A61M 2205/3334: Measuring or controlling the flow rate - F05D 2270/3061: of the working fluid - F04D: NON-POSITIVE-DISPLACEMENT PUMPS (engine fuel-injection pumps F02M; ion pumps H01J41/12; electrodynamic pumps H02K44/02) - 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)} - F05D: INDEXING SCHEME FOR ASPECTS RELATING TO NON-POSITIVE-DISPLACEMENT MACHINES OR ENGINES, GAS-TURBINES OR JET-PROPULSION PLANTS ## Abstract A ventricular assist device is disclosed. The ventricular assist device may include a centrifugal pump and a controller. The controller may be configured to cause the centrifugal pump to operate at a first speed above a predetermined flow rate. The controller may also be configured to cause the centrifugal pump to operate at a second speed below the predetermined flow rate, wherein the predetermined flowrate is indicative of a crossover point between systole and diastole phases of a person's cardiac cycle. ## Claims ### Claim 1 A ventricular assist device comprising: a centrifugal pump having a motor; and a controller, wherein the controller is configured to at least: measure a current of the motor; determine an estimated flow rate through the centrifugal pump based on the current; cause the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and cause the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle. ### Claim 2 A method of controlling a centrifugal pump in a ventricular assist device of a person, wherein the method comprises: measuring a current of a motor of a centrifugal pump in a ventricular assist device: determining an estimated flow rate through the centrifugal pump based on the current: causing the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and causing the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle. ### Claim 3 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein the first speed comprises a minimum operating speed as set by a clinician. ### Claim 4 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein the second speed is greater than the first speed. ### Claim 5 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein the second speed comprises a set speed as set by a clinician. ### Claim 6 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein when the motor of the centrifugal pump is operating at the second speed, the motor of the centrifugal pump is operating at a constant current. ### Claim 7 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein causing the motor of the centrifugal pump to operate at the second speed comprises controlling the motor of the centrifugal pump to maintain a parameter at a substantially constant value, wherein the parameter is selected from a group consisting of: motor current, motor voltage, motor power, back electromotive force, and a combination of the same. ### Claim 8 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein the method further comprises: determining a current flow rate with a flow measurement sensor. ### Claim 9 (depends on 8) The method of controlling a centrifugal pump of claim 8, wherein the method further comprises: comparing the current flow rate to the predetermined flow rate. ### Claim 10 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein the predetermined flow rate is set by a clinician. ### Claim 11 (depends on 2) The method of controlling a centrifugal pump of claim 2, wherein the method further comprises: identifying a suction event in the centrifugal pump and reducing a speed of the motor of the centrifugal pump to alleviate the suction event. ### Claim 12 A controller for operating a centrifugal pump in a ventricular assist device of a person, wherein the controller comprises: one or more processors configured to execute instructions stored on a non-transitory medium, the instructions executable by the one or more processors to at least: measure a current of a motor of a centrifugal pump in a ventricular assist device; determine an estimated flow rate through the centrifugal pump based on the current; cause the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and cause the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle. ### Claim 13 (depends on 12) The controller for operating a centrifugal pump of claim 12, wherein the second speed is greater than the first speed. ### Claim 14 A non-transitory machine readable medium having instructions stored thereon for operating a centrifugal pump in a ventricular assist device of a person, the instructions executable by one or more processors to at least: measure a current of a motor of a centrifugal pump in a ventricular assist device; determine an estimated flow rate through the centrifugal pump based on the current: cause the motor of the centrifugal pump to operate at a first speed when the estimated flow rate is greater than a predetermined flow rate; and cause the motor of the centrifugal pump to operate at a second speed when the estimated flow rate is less than the predetermined flow rate, wherein the predetermined flowrate is indicative of an actual flow rate through the pump at a crossover point between systole and diastole phases of a person's cardiac cycle. ### Claim 15 (depends on 14) The non-transitory machine readable medium of claim 14, wherein the second speed is greater than the first speed.