# US 11,998,730 B2 · Adaptive speed control algorithms and controllers for optimizing flow in ventricular assist devices > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,998,730 B2 - Document ID: US11998730B2 - Status: Granted - Kind: B2 - Application number: 17/585,295 - Filed: 2022-01-26 - Published: 2022-05-12 - Granted: 2024-06-04 - Earliest claimed: 2018-09-25 - Assignees: Tc1 LLC - Applicants: Tc1 LLC - Inventors: Charles Dague; Dan Harjes - Web page: https://patentgrep.com/patent/US11998730B2 ## CPC - A61M 60/562: for making blood flow pulsatile in blood pumps that do not intrinsically create pulsatile flow - 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 60/237: the blood flow through the rotating member having mainly axial components, e.g. axial flow pumps - A61M 60/422: the force acting on the blood contacting member being electromagnetic, e.g. using canned motor pumps - A61M 60/515: Regulation using real-time patient data - A61M 60/523: using blood flow data, e.g. from blood flow transducers - A61M 60/538: Regulation using real-time blood pump operational parameter data, e.g. motor current - A61M 60/816: Sensors arranged on or in the housing, e.g. ultrasonic flow sensors - A61M 2205/3334: Measuring or controlling the flow rate - A61M 2205/3365: Rotational speed - A61M 2230/06: Heartbeat rate only - 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 Method and systems control a rotational speed of a blood pump during ventricular diastole. A method includes controlling a blood pump in accordance with a first segment operational mode. A controller monitors the blood flow rate through the blood pump. The controller determines, based on the blood flow rate, whether continued controlling of the blood pump per the first segment operational mode would result in the blood flow rate through the blood pump being less than a target minimum blood flow rate. In response to a determination that continued controlling of the blood pump per the first segment operational mode would result in the blood flow rate through the blood pump being less than the target minimum blood flow rate, the controller controls the rotational speed of the blood pump so that the blood flow rate through the blood pump is approximate to the target minimum blood flow rate. ## Claims ### Claim 1 A method of controlling a rotation rate of a blood pump of a ventricular assist device, the method comprising: controlling, by a controller, a rotation rate of the blood pump in accordance with a first operational mode to pump blood from a ventricle of a patient to an artery of the patient; monitoring, by the controller, a blood flow rate through the blood pump; based on the blood flow rate through the blood pump, projecting, by the controller, that the blood flow rate through the blood pump would decrease below a target minimum blood flow rate during a first cardiac cycle ventricular diastole if the rotation rate of the blood pump is controlled in accordance with the first operational mode during the first cardiac cycle ventricular diastole; in response to the projection that the blood flow rate through the blood pump would decrease below the target minimum blood flow rate during the first cardiac cycle ventricular diastole, increasing, by the controller, the rotation rate of the blood pump relative to the rotation rate of the blood pump in accordance with the first operational mode to prevent the blood flow rate through the blood pump from dropping below the target minimum blood flow rate; based on the blood flow rate through the blood pump, projecting, by the controller, that the blood flow rate through the blood pump would not decrease below a target minimum blood flow rate during a second cardiac cycle ventricular diastole if the rotation rate of the blood pump is controlled in accordance with the first operational mode during the second cardiac cycle ventricular diastole; and in response to the projection that the blood flow rate through the blood pump would not decrease below the target minimum blood flow rate during the second cardiac cycle ventricular diastole, continue controlling, by the controller, the rotation rate of the blood pump in accordance with the first operational mode during the second cardiac cycle ventricular diastole. ### Claim 2 (depends on 1) The method of claim 1, wherein the target minimum blood flow rate is within a range from about 0 liters/minute to 2.0 liters/minute. ### Claim 3 (depends on 1) The method of claim 1, wherein the target minimum blood flow rate is within a range from 0.5 liters/minute to 1.5 liters/minute. ### Claim 4 (depends on 1) The method of claim 1, wherein projecting that the blood flow rate through the blood pump would decrease below the target minimum blood flow rate during the first cardiac cycle ventricular diastole comprises determining a relative difference between a current blood flow rate through the blood pump and the target minimum blood flow rate. ### Claim 5 (depends on 4) The method of claim 4, wherein projecting that the blood flow rate through the blood pump would decrease below the target minimum blood flow rate during the first cardiac cycle ventricular diastole comprises determining a current rate of change in the blood flow rate through the blood pump. ### Claim 6 (depends on 1) The method of claim 1, wherein the rotation rate of the blood pump in the first operational mode is constant. ### Claim 7 (depends on 1) The method of claim 1, wherein the rotation rate of the blood pump in the first operational mode is varied to generate a periodic pulsatile blood flow. ### Claim 8 (depends on 7) The method of claim 7, wherein the periodic pulsatile blood flow is synchronized with cardiac cycle timing of the patient. ### Claim 9 (depends on 8) The method of claim 8, wherein the periodic pulsatile blood flow is synchronized with cardiac cycle timing of the patient based on the blood flow rate through the blood pump. ### Claim 10 (depends on 8) The method of claim 8, wherein the rotation rate of the blood pump in accordance with the first operational mode is controlled, by the controller, to generate a blood pressure pulse during ventricular systole. ### Claim 11 (depends on 1) The method of claim 1, further comprising: detecting, by the controller, when the rotation rate of the blood pump for pumping blood at the target minimum blood flow rate decreases to or below the rotation rate of the blood pump in accordance with the first operational mode of the blood pump; and in response to detecting when the rotation rate of the blood pump for pumping blood at the target minimum blood flow rate decreases to or below the rotation rate of the blood pump in accordance with the first operational mode of the blood pump, reverting back to controlling the rotation rate of the blood pump in accordance with the first operational mode. ### Claim 12 (depends on 1) The method of claim 1, wherein the rotation rate of the blood pump in the first operational mode results in an opening and a closing of a semilunar valve of the patient during ventricular systole. ### Claim 13 (depends on 12) The method of claim 12, wherein the target minimum blood flow rate is within a range from about 0.0 liters/minute to 0.5 liters/minute. ### Claim 14 (depends on 13) The method of claim 13, wherein the target minimum blood flow rate is 0.0 liters/minute. ### Claim 15 (depends on 1) The method of claim 1, wherein the monitoring of the blood flow rate through the blood pump by the controller comprises estimating the blood flow rate based on the rotation rate of the blood pump and an operational parameter indicative of power consumption by the blood pump. ### Claim 16 (depends on 1) The method of claim 1, wherein the monitoring of the blood flow rate through the blood pump by the controller comprises estimating the blood flow rate based on the rotation rate of the blood pump and an operational parameter indicative of a pressure differential across the blood pump. ### Claim 17 (depends on 1) The method of claim 1, further comprising: measuring, via a sensor, a patient physiological parameter indicative of an activity level of the patient; and updating, by the controller, the target minimum blood flow rate based on the patient physiological parameter. ### Claim 18 (depends on 17) The method of claim 17, wherein: the sensor comprises an accelerometer; and the patient physiological parameter comprises accelerations of the patient measured by the accelerometer. ### Claim 19 (depends on 1) The method of claim 1, further comprising: processing one or more operational parameters of the blood pump to measure an activity level of the patient; and updating, by the controller, the target minimum blood flow rate based on the activity level of the patient. ### Claim 20 (depends on 19) The method of claim 19, wherein the one or more operational parameters of the blood pump comprise a pressure differential across the blood pump.