# US 10,441,695 B2 · Drive device for a membrane fluid pump and operating method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,441,695 B2 - Document ID: US10441695B2 - Status: Granted - Kind: B2 - Application number: 16/293,888 - Filed: 2019-03-06 - Published: 2019-09-12 - Granted: 2019-10-15 - Earliest claimed: 2018-03-08 - Assignees: Berlin Heart GmbH - Applicants: Berlin Heart GmbH - Inventors: Robert Steingräber - Web page: https://patentgrep.com/patent/US10441695B2 ## CPC - F04B 43/0081: {systems, control, safety measures} - 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 60/268: the displacement member being flexible, e.g. membranes, diaphragms or bladders - A61M 60/274: the inlet and outlet being the same, e.g. para-aortic counter-pulsation blood pumps - A61M 60/427: the force acting on the blood contacting member being hydraulic or pneumatic - A61M 60/538: Regulation using real-time blood pump operational parameter data, e.g. motor current - A61M 60/857: Implantable blood tubes - A61M 60/892: Active valves, i.e. actuated by an external force - F04B 43/00: Machines, pumps, or pumping installations having flexible working members (pumps or pumping installations specially adapted for elastic fluids F04B45/00) - F04B 49/20: by changing the driving speed - A61M 2205/3337: Controlling, regulating pressure or flow by means of a valve by-passing a pump - F04B 2201/0202: Linear speed of the piston - F04B 2201/0203: Acceleration of the piston - F04B 2205/03: Pressure in the compression chamber - F04B: POSITIVE-DISPLACEMENT MACHINES FOR LIQUIDS; PUMPS (machines for liquids, or pumps, of rotary-piston or oscillating-piston type F04C; non-positive-displacement pumps F04D; pumping of fluid by direct contact of another fluid or by using inertia of fluid to be pumped F04F) - 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 drive device is provided comprising a working pump, the working pump connected to a membrane fluid pump, and the working pump having a working piston able to oscillate axially between two reversal points for contracting and expanding a working chamber, and a control unit for controlling a movement of the working piston between the two reversal points. The controlled movement of the working piston comprises three temporally successive phases, in a first phase the working piston is accelerated to a speed that is greater than a speed at the end of the first phase, in a second phase the working piston is moved such that a specified speed of the working piston, a specified relative pressure in the working chamber, or a specified force of the working piston is substantially kept constant, and in a third phase the working piston is moved at a negative acceleration. ## Claims ### Claim 1 A drive device for a membrane fluid pump, the drive device comprising: a working pump, the working pump connected to the membrane fluid pump via a pressure line in order to drive the membrane fluid pump, and the working pump having a hollow cylinder and a working piston configured to oscillate axially therein between two reversal points for contraction and expansion of a working chamber in the working pump, the working chamber being in a pressure exchanging connection with the pressure line; and a control unit configured to control a movement of the working piston between the two reversal points, the controlled movement of the working piston comprising three temporally successive phases, wherein in a first phase the working piston is accelerated to a speed that is greater than a speed at the end of the first phase, wherein in a second phase the working piston is moved such that a specified speed of the working piston, a specified relative pressure in the working chamber, or a specified force of the working piston is kept substantially constant, and wherein in a third phase the working piston is moved at a negative acceleration. ### Claim 2 (depends on 1) The drive device of claim 1, wherein the control unit is configured to control the movement of the working piston according to a temporal position specification for the working piston, the speed of the working piston kept substantially constant in the second phase, and/or the control unit is configured to control the movement of the working piston according to a temporal relative pressure specification for the working chamber, the relative pressure in the working chamber kept substantially constant in the second phase, and/or the control unit is configured to control the movement of the working piston according to a temporal force specification for the working piston, the force of the working piston kept substantially constant in the second phase. ### Claim 3 (depends on 2) The drive device of claim 2, wherein the force of the working piston includes a load and an inertia of the working piston. ### Claim 4 (depends on 2) The drive device of claim 2, wherein the control unit is configured to determine the temporal position specification based on the temporal relative pressure specification, and to control the movement of the working piston according to the position specification. ### Claim 5 (depends on 2) The drive device of claim 2, wherein the temporal position specification includes a temporal speed specification and/or a temporal acceleration specification. ### Claim 6 (depends on 1) The drive device of claim 1, wherein the working pump comprises an equalizing valve for changing an air mass and/or a relative pressure in the working chamber, and the control unit is configured to control the equalizing valve according to a specification for the air mass and/or a specification for the relative pressure. ### Claim 7 (depends on 2) The drive device of claim 2, wherein the control unit is configured to determine the temporal position specification based on a reference trajectory of the working piston, wherein the reference trajectory takes into consideration a specified duration of the first phase, a specified duration of the second phase, a specified change in the acceleration of the piston in the first phase, a specified piston stroke, a specified maximum relative pressure, a specified pump rate, a specified relative evacuation duration, a specified filling degree, a specified evacuation degree, specified characteristic values for a membrane fluid pump to be connected. ### Claim 8 (depends on 2) The drive device of claim 2, wherein the drive device has an electric spindle motor for driving the working piston, and the control unit, in order to control the movement of the working piston according to the temporal position specification, is configured to determine a drive current strength for the spindle motor based on an estimated required torque for the spindle motor, wherein a load of the working piston, inertia of the working piston, estimated friction of the working piston, and/or a torque correction for compensating a position deviation and/or a speed deviation of the working piston from the temporal position specification factor into the torque. ### Claim 9 (depends on 8) The drive device of claim 8, wherein a position sensor is configured to measure during operation an instantaneous position and/or an instantaneous speed of the working piston, and wherein the control unit is configured to determine a position deviation and/or a speed deviation from the temporal position specification, to determine the torque correction based on the position deviation and/or the speed deviation, and to adjust the drive current strength such that the position deviation and/or the speed deviation of the working piston is reduced. ### Claim 10 (depends on 1) The drive device of claim 1 comprising a user interface by which user-specific parameters are settable during operation, the user-specific parameters including a degree of filling, a degree of evacuation of the membrane fluid pump, a piston stroke, a mean relative pressure, a relative evacuation duration, an evacuation pressure, a filling pressure, and/or a pump rate. ### Claim 11 (depends on 10) The drive device of claim 10, wherein the control unit is configured to adjust a temporal position specification, a temporal relative pressure specification, and/or the temporal force specification, for controlling the movement of the working piston, and/or to adjust a specification for an air mass, the specification for the relative pressure, and/or the specification for one of the two or both reversal points for controlling an equalizing valve during operation in response to a change in the user-specific parameters. ### Claim 12 (depends on 6) The drive device of claim 6, wherein the control unit is configured to set a filling degree for the membrane fluid pump by a change of a piston stroke and control of the equalizing valve according to a specification for a mean evacuation pressure in the working chamber or by a change of a mean relative pressure using the equalizing valve, and/or wherein the control unit is configured to set an evacuation degree by a change of the piston stroke and control of the equalizing valve according to a specification for a mean filling pressure in the working chamber, and/or by a change of the mean relative pressure using the equalizing valve. ### Claim 13 (depends on 1) The drive device of claim 1, wherein an inlet cannula connected to the membrane fluid pump is configured to supply a fluid to the membrane fluid pump, and an outlet cannula connected to the membrane fluid pump is configured to conduct a fluid out of the membrane fluid pump. ### Claim 14 A cardiac support system comprising: a membrane blood pump; an inlet cannula connected to the membrane blood pump, the inlet cannula configured to supply blood from a ventricle and/or an atrium of a heart to the membrane blood pump; an outlet cannula connected to the membrane blood pump, the outlet cannula configured to conduct the blood out of the membrane blood pump into a blood vessel; a working pump, the working pump connected to the membrane blood pump via a pressure line in order to drive the membrane blood pump, and the working pump having a hollow cylinder and a working piston configured to oscillate axially therein between two reversal points for contraction and expansion of a working chamber in the working pump, the working chamber being in a pressure exchanging connection with the pressure line; and a control unit configured to control a movement of the working piston between the two reversal points, the controlled movement of the working piston comprising three temporally successive phases, wherein in a first phase the working piston is accelerated to a speed that is greater than a speed at the end of the first phase, wherein in a second phase the working piston is moved such that a specified speed of the working piston, a specified relative pressure in the working chamber, or a specified force of the working piston is kept substantially constant, and wherein in a third phase the working piston is moved at a negative acceleration. ### Claim 15 A method for operating a drive device for a membrane fluid pump, the drive device comprising a working pump, the working pump connected to the membrane fluid pump via a pressure line in order to drive the membrane fluid pump, and the working pump having a hollow cylinder and a working piston configured to oscillate axially therein between two reversal points for contraction and expansion of a working chamber in the working pump, the working chamber being in a pressure exchanging connection with the pressure line, the method comprising moving the working piston in three temporally successive phases by: accelerating, in a first phase, the working piston to a speed that is greater than a speed of the working piston at an end of the first phase, moving, in a second phase, the working piston such that a predefined speed of the working piston, a predefined relative pressure in the working chamber, or a predefined force of the working piston is kept substantially constant, and deaccelerating the working piston in a third phase. ### Claim 16 (depends on 15) The method of claim 15, wherein the moving the working piston in three temporally successive phases comprises controlling the movement of the working piston according to a temporal position specification for the working piston, keeping the speed of the working piston substantially constant in the second phase, and/or wherein the moving the working piston in three temporally successive phases comprises controlling the movement of the working piston according to a temporal relative pressure specification for the working chamber, keeping the relative pressure in the working chamber substantially constant in the second phase, and/or wherein the moving the working piston in three temporally successive phases comprises controlling the movement of the working piston according to a temporal force specification for the working piston, and keeping the force of the working piston substantially constant. ### Claim 17 (depends on 16) The method of claim 16 further comprising determining the temporal position specification based on the temporal relative pressure specification, and controlling the movement of the working piston according to the temporal position specification. ### Claim 18 (depends on 16) The method of claim 16, wherein the moving the working piston in three temporally successive phases comprises controlling movement of the working piston according to the temporal position specification in the first phase and in the third phase, and controlling according to the temporal relative pressure specification and/or the temporal force specification in the second phase. ### Claim 19 (depends on 16) The method of claim 16, wherein the working pump comprises an equalizing valve for changing an air mass and/or a relative pressure in the working chamber, and wherein the moving the working piston in three temporally successive phases comprises controlling the movement of the working piston according to the temporal position specification and controlling the equalizing valve according to a specification for a mean relative pressure, or controlling the movement of the working piston according to the temporal relative pressure specification or according to the temporal force specification and controlling the equalizing valve such that the air mass at the end of an evacuation phase is minimal. ### Claim 20 (depends on 16) The method of claim 16 further comprising determining the temporal position specification based on a reference trajectory for the working piston, the reference trajectory taking into consideration a specified duration of the first phase, a specified duration of the second phase, a specified change in the acceleration of the working piston in the first phase, a specified piston stroke, a specified maximum relative pressure, a specified pump rate, a specified relative evacuation duration, a specified filling degree, a specified evacuation degree, specified characteristic values for a membrane fluid pump to be connected, in particular a displacement volume of the membrane fluid pump, specified characteristic values for an inlet cannula that may be connected to the membrane fluid pump, and/or specified characteristic values for an outlet cannula that may be connected to the membrane fluid pump. ### Claim 21 (depends on 15) The method of claim 15, wherein for driving the working piston the drive device has an electric spindle motor, and, for controlling the movement of the working piston according to a temporal position specification, determining a drive current strength for the spindle motor based on an estimated required torque for the spindle motor, wherein a load of the working piston, inertia of the working piston, estimated friction of the working piston, and/or a torque correction for compensating a position deviation and/or a speed deviation of the working piston from the temporal position specification factor into the torque. ### Claim 22 (depends on 21) The method of claim 21 further comprising measuring, during operation, an instantaneous position and/or an instantaneous speed of the working piston by a position sensor; determining a position deviation and/or a speed deviation from the temporal position; determining the torque correction based on the position deviation and/or the speed deviation; and adjusting the drive current strength such that the position deviation and/or the speed deviation of the working piston from the temporal position specification is reduced. ### Claim 23 (depends on 15) The method of claim 15 further comprising setting user-specific parameters during operation, the user-specific parameters including a degree of filling and/or a degree of evacuation of the membrane fluid pump, a piston stroke, a mean relative pressure, a relative evacuation duration, an evacuation pressure, a filling pressure, and/or a pump rate; and adjusting, in response to a change in the user-specific parameters, a temporal position specification, a temporal relative pressure specification, and/or the temporal force specification for controlling the movement of the working piston, and/or a specification for an air mass, the specification for the relative pressure, and/or the specification for the air mass at one of the two or at both reversal points for controlling an equalizing valve for changing the air mass and/or the relative pressure in the working chamber. ### Claim 24 (depends on 19) The method of claim 19 further comprising setting a specified filling degree of the membrane fluid pump by changing a piston stroke and controlling the equalizing valve according to a specification for a mean evacuation pressure in the working chamber or by changing the mean relative pressure using the equalizing valve, and/or a specified evacuation degree is set by changing a piston stroke and controlling the equalizing valve according to a specification for a mean filling pressure in the working chamber and/or by changing the mean relative pressure via the equalizing valve.