Control device for intravascular blood pump and blood pump system

Abstract

A control device for a blood pump, particularly a catheter-based intravascular blood pump, configured to utilize sensed or determined aortic and left ventricular pressures to calculate a coupling coefficient, which is used to determine how to adjust the rotational speed of the blood pump, such as when the blood pump is used in conjunction with an ECMO device.

Description

[Technical field]

[0001] (Citation of Related Application) This application claims priority to U.S. Provisional Patent Application No. 63 / 242,828, filed September 10, 2021, and U.S. Provisional Patent Application No. 63 / 257,715, filed October 20, 2021, which are incorporated by reference in their entireties.

[0002] SUMMARY OF THE DISCLOSURE The embodiments disclosed herein relate to a control system for an extracorporeal membrane oxygenation device. [Background technology]

[0003] Cardiogenic shock is the leading cause of death in patients with acute myocardial infarction (AMI) who arrive at the hospital alive. Cardiogenic shock is caused by a malfunction or problem in the heart that leads to the heart being unable to pump enough blood to the body. Cardiogenic shock is sometimes called vaso-occlusive shock.

[0004] Extracorporeal membrane oxygenation (ECMO) and extracorporeal life support (ECLS) allow blood gas exchange when the lungs are not functioning normally. For example, veno-arterial extracorporeal membrane oxygenation (VA-ECMO) and veno-venous-arterial extracorporeal membrane oxygenation (VVA-ECMO) may involve the use of mechanical circulatory devices (e.g., lung assist machines) for patients with oxygenation problems. In some cases, ECMO may be used for patients with oxygenation problems due to cardiogenic shock or other forms of hemodynamic compromise. The use of such devices in such situations may increase left ventricular afterload. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] U.S. Patent No. 5,911,685 Summary of the Invention [Problem to be solved by the invention]

[0006] Ventricular assist devices (VADs) and catheter-based ventricular assist devices (e.g., intravascular blood pumps) may be used to mechanically unload the left ventricle (e.g., to reduce pressure by reducing left ventricular volume) and / or decompress the left ventricle (e.g., to reduce left ventricular preload by reducing left ventricular volume that may result from a hole in the wall between the left and right atria). In some cases, such independent auxiliary flow may be insufficient to treat cardiogenic shock alone. [Means for solving the problem]

[0007] According to a first aspect of the disclosure, a controller for a blood pump, such as an intravascular blood pump, includes a processor configured to control a rotational speed of a motor of a catheter-based intravascular blood pump using a first selectable operating mode, the first selectable operating mode including determining a coupling coefficient k using a detected or determined aortic pressure value and a detected or determined left ventricular pressure value, and adjusting the rotational speed of the motor based on the determined value of the coupling coefficient k. In general, the first selectable operating mode may perform at least one adjustment to the rotational speed of the motor based on the determined value of the coupling coefficient k, the at least one adjustment being: increasing the rotational speed of the motor by a first amount when the coupling coefficient k is greater than a first threshold, or increasing the rotational speed of the motor by a second amount less than the first amount when the coupling coefficient k is less than or equal to the first threshold and greater than a third threshold, or decreasing the rotational speed of the motor by a third amount when the coupling coefficient k is greater than or equal to a fourth threshold and less than a second threshold, or decreasing the rotational speed of the motor by a fourth amount greater than the third amount when the coupling coefficient k is greater than or equal to a fifth threshold and less than a fourth threshold, or decreasing the rotational speed of the motor by a fifth amount greater than the fourth amount when the coupling coefficient k is less than the fifth threshold, or combinations thereof. Optionally, the first selectable operating mode may be further configured to keep the rotational speed of the motor constant when the coupling coefficient is equal to the second threshold.

[0008] In some embodiments, in the first selectable operating mode, the controller is configured to attempt to bring the coupling coefficient back to the target value if the coupling coefficient is outside the target range, and thereafter not perform further adjustments until the coupling coefficient is outside the target range. The controller initiates the speed adjustment process only if the coupling coefficient k is greater than a first threshold or less than a second threshold. Specifically, the speed is adjusted as follows:

[0009] If it is determined that the coupling coefficient k is greater than the first threshold, the controller initiates a subroutine that increases the motor rotation speed in steps until the coupling coefficient k is less than a predetermined value. Specifically, in the subroutine, the motor rotation speed is increased by a first amount if the coupling coefficient k is greater than the first threshold, and by a second amount if the coupling coefficient k is less than or equal to the first threshold but greater than a third threshold, after which each pressure value is measured and the coupling coefficient is determined. This cycle is repeated until it is determined that the coupling coefficient k is less than or equal to the third threshold, at which point the controller terminates the subroutine and returns to monitoring the coupling coefficient, making an adjustment only if the coupling coefficient is above the first threshold or below the second threshold.

[0010] If it is determined that the coupling coefficient k is less than the second threshold, the control device starts a subroutine to reduce the rotational speed of the motor in steps until the coupling coefficient k exceeds a predetermined value. Specifically, in the subroutine, the rotational speed of the motor is reduced by a third amount if the coupling coefficient k is equal to or greater than the second threshold and less than the fourth threshold, or by a fourth amount greater than the third amount if the coupling coefficient k is equal to or greater than the fifth threshold and less than the second threshold, or by a fifth amount if the coupling coefficient k is less than the fifth threshold, or a combination thereof. Each pressure value is then measured and the coupling coefficient is determined. This cycle is repeated until it is determined that the coupling coefficient k is equal to or less than the third threshold, at which point the control device ends the subroutine and returns to monitoring the coupling coefficient, making adjustments only if the coupling coefficient is above the first threshold or below the second threshold.

[0011] The processor may be configured to adjust the rotational speed of the motor at a first predetermined time interval t (eg, every 5-20 seconds, such as every 10 seconds) in the first selectable operational mode.

[0012] In some embodiments, the coupling coefficient k is determined at a second predetermined time interval (eg, may be every 1-5 seconds, such as every 2 seconds).

[0013] In some embodiments, the coupling coefficient k is the quotient of the average value of the detected or determined left ventricular pressure values ​​and the average value of the detected or determined aortic pressure values.

[0014] In some embodiments, the average value of the detected or determined left ventricular pressure values ​​and the average value of the detected or determined aortic pressure values ​​are determined over a third predetermined time interval (e.g., 10 seconds, which may be 8 to 12 seconds).

[0015] In some embodiments, the first threshold is 0.75, the second threshold is 0.55, the third threshold is 0.65, the fourth threshold is 0.65, and the fifth threshold is 0.15.

[0016] In some embodiments, the first threshold is a value obtained by adding a specified value to the target value of the coupling coefficient k, the second threshold is a value obtained by subtracting the specified value from the target value of the coupling coefficient k, the third target coupling coefficient k and the fourth target coupling coefficient k are target values ​​of the coupling coefficient k, and the fifth threshold is a value that is 15% to 35% of the target value of the coupling coefficient k.

[0017] In some embodiments, when the motor speed is adjusted by separate amounts, the second and third amounts are 0.8-1.9% of an operating range of motor rotational speeds over which the processor is configured to execute the first selectable operating mode (e.g., 12,000 rpm-22,000 rpm, a range identified as the difference between a maximum and minimum operating speed over which the processor is configured to implement control), the first and fourth amounts are 2-4.5% of that operating range, and the fifth amount is 8-19% of that operating range.

[0018] In some embodiments, the processor can be further configured to detect suction events and respond to those suction events by decreasing the motor rotational speed by a fifth amount when a first suction event is detected, decreasing the motor rotational speed by a sixth amount when a second suction event is detected, and lowering the upper limit of the motor rotational speed by the sixth amount for a first period of time (e.g., 10 minutes to 30 minutes, or 20 minutes, etc.) after detecting a second suction event within a predetermined time frame (e.g., 30 seconds to 5 minutes, or 2 minutes, etc.).

[0019] The processor may also be configured to detect whether an ECMO device (e.g., VVA-ECMO or VA-ECMO) is operably connected to the controller and prevent selection or execution of the first selectable mode of operation if a VA-ECMO device is not detected, or receive a selection that the processor should operate the blood pump using the first selectable mode of operation, or a combination thereof. In some embodiments, the processor may be configured to receive an input that a user confirms that an ECMO device is connected.

[0020] In some embodiments, a start-up process is used to operate the pump to quickly and safely reach a suitable operating speed. To achieve such operation, the processor may be configured to perform the following before executing the first selectable operating mode: increasing the rotational speed of the motor from zero to a minimum rotational speed that the processor is configured to use when executing the first selectable operating mode (e.g., a rotational speed of 5,000 rpm to 50,000 rpm, or 20,000 rpm to 40,000 rpm, and / or 25,000 rpm to 31,000 rpm); and determining a coupling coefficient k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value; and adjusting the rotational speed of the motor based on the value of the coupling coefficient k. Specifically, the speed is adjusted as follows: if k≧1, increase the rotational speed by a sixth amount, and repeat the determining and adjusting steps after a period of time (e.g., 5 to 30 seconds, or 10 seconds, etc.). If k<1, the rotation speed of the motor is adjusted according to a first selectable operating mode, and after the certain period of time has elapsed, the rotation speed of the motor is controlled according to the first selectable operating mode.

[0021] In some embodiments, the sixth amount is between 5% and 30% of the range of rotational speeds of the motor at which the processor is configured to execute the first selectable mode of operation.

[0022] The controller may also be configured to allow the motor to operate in other modes, such as when the blood pump is not operating in parallel with the ECMO device. In some embodiments, the processor may be configured to operate in a second selectable operating mode that receives a selection of one of a plurality of predetermined operating rotational speeds and adjusts the speed of the motor to the selected predetermined operating rotational speed, and a third selectable operating mode that is configured to increase the rotational speed of the motor at a predetermined rate up to a maximum operating rotational speed.

[0023] In some embodiments, the controller is configured to exit the first selectable mode of operation if the pressure values ​​used to control the motor are determined to be unreliable. In some embodiments, the processor is further configured during operation with the first selectable mode of operation to: determine whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both, are unreliable, and switch from the first selectable mode of operation to the second selectable mode of operation if the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both, are determined to be unreliable for a second period of time (e.g., 30 seconds to 5 minutes, or 1 minute to 3 minutes, or 2 minutes, etc.).

[0024] The processor may also be configured to activate an alarm notification when the coupling coefficient k is determined to be less than the fifth threshold, until the coupling coefficient k is determined to be greater than or equal to a sixth threshold, where the sixth threshold is greater than the fifth threshold and less than the fourth threshold. In some embodiments, the sixth threshold is 20% to 15% of a target value of the coupling coefficient k.

[0025] In some embodiments, the control device further comprises a display controlled by the processor, a first port configured to operably connect the processor to a catheter-based intravascular blood pump, an additional port configured to operably connect the processor to an extracorporeal membrane oxygenation (ECMO) system, and a housing configured to accommodate at least the processor.

[0026] According to a second aspect of the present disclosure, a blood pump system includes the blood pump controller described above and a catheter-based intravascular blood pump operably connected to the blood pump controller.

[0027] According to a third aspect of the present disclosure, a system for extracorporeal membrane oxygenation (ECMO) with a ventricular assist device includes an extracorporeal membrane oxygenation (ECMO) system and a blood pump system suitable for operating in parallel with the ECMO system, the blood pump system including the controller as described above and a catheter-based intravascular blood pump operably connected to the controller.

[0028] According to a fourth aspect of the present disclosure, there is provided a method of starting a blood pump, such as a catheter-based intravascular blood pump, for use in conjunction with an ECMO system. The method generally includes increasing a rotational speed of a motor of the catheter-based intravascular blood pump from zero to a predetermined minimum rotational speed (e.g., 5,000 rpm to 50,000 rpm, or 20,000 rpm to 40,000 rpm, or 31,000 rpm, etc.), determining a coupling factor k using a detected or determined aortic pressure value and a detected or determined left ventricular pressure value, and if k≧1, increasing the speed by a constant amount (e.g., 5% to 30% of the operating range, etc.), and repeating the steps of measuring pressure values ​​after a constant period of time and determining the coupling factor k until k<1.

[0029] In some embodiments, after the coupling coefficient k is determined to be less than 1, the system automatically switches to an automatic rate control mode suitable for use in conjunction with an extracorporeal membrane oxygenation (ECMO) system.

[0030] A fifth aspect of the present disclosure is a method of operating a blood pump, such as a catheter-based intravascular blood pump, for use in conjunction with an extracorporeal membrane oxygenation (ECMO) system. The method generally includes determining a coupling coefficient k using a detected or determined aortic disposition value and a detected or determined left ventricular disposition value, and adjusting a rotational speed of a motor of the catheter-based intravascular blood pump based on the determined value of the coupling coefficient k.

[0031] The method includes performing at least one adjustment to the rotation speed of the motor based on the determined value of the coupling coefficient k, the at least one adjustment being: increasing the rotation speed of the motor by a first amount when the coupling coefficient k is greater than a first threshold, or increasing the rotation speed of the motor by a second amount less than the first amount when the coupling coefficient k is less than or equal to the first threshold and greater than a third threshold, or decreasing the rotation speed of the motor by a third amount when the coupling coefficient k is greater than or equal to a fourth threshold and less than a second threshold, or decreasing the rotation speed of the motor by a fourth amount greater than the third amount when the coupling coefficient k is greater than or equal to a fifth threshold and less than a fourth threshold, or decreasing the rotation speed of the motor by a fifth amount greater than the fourth amount when the coupling coefficient k is less than the fifth threshold, or a combination thereof. Optionally, the method may be further configured to keep the rotation speed of the motor constant when the coupling coefficient is equal to the second threshold.

[0032] In some embodiments, the rotation speed adjustment process is initiated only if the coupling coefficient k is greater than a first threshold or less than a second threshold. Specifically, the speed is adjusted as follows:

[0033] If it is determined that the coupling coefficient k is greater than the first threshold, the controller initiates a subroutine that increases the motor rotation speed in steps until the coupling coefficient k is less than a predetermined value. Specifically, in the subroutine, the motor rotation speed is increased by a first amount if the coupling coefficient k is greater than the first threshold, and by a second amount if the coupling coefficient k is less than or equal to the first threshold but greater than a third threshold, after which each pressure value is measured and the coupling coefficient is determined. This cycle is repeated until it is determined that the coupling coefficient k is less than or equal to the third threshold, at which point the controller terminates the subroutine and returns to monitoring the coupling coefficient, making an adjustment only if the coupling coefficient is above the first threshold or below the second threshold.

[0034] If it is determined that the coupling coefficient k is less than the second threshold, the control device starts a subroutine to reduce the rotational speed of the motor in steps until the coupling coefficient k exceeds a predetermined value. Specifically, in the subroutine, the rotational speed of the motor is reduced by a third amount if the coupling coefficient k is equal to or greater than the second threshold and less than the fourth threshold, or by a fourth amount greater than the third amount if the coupling coefficient k is equal to or greater than the fifth threshold and less than the second threshold, or by a fifth amount if the coupling coefficient k is less than the fifth threshold, or a combination thereof. Each pressure value is then measured and the coupling coefficient is determined. This cycle is repeated until it is determined that the coupling coefficient k is equal to or less than the third threshold, at which point the control device ends the subroutine and returns to monitoring the coupling coefficient, making adjustments only if the coupling coefficient is above the first threshold or below the second threshold.

[0035] In some embodiments, the rate is adjusted repeatedly at predetermined time intervals t (eg, every 5-20 seconds, or every 10 seconds, etc.).

[0036] In some embodiments, the coupling coefficient k is determined at a second predetermined time interval (eg, may be every 1-5 seconds, such as every 2 seconds).

[0037] As described herein, the coupling coefficient k is the quotient of the average of the detected or determined left ventricular pressure values ​​and the average of the detected or determined aortic pressure values. In some embodiments, the average of the detected or determined left ventricular pressure values ​​and the average of the detected or determined aortic pressure values ​​are determined over a third predetermined time interval (e.g., 10 seconds, which may be 8-12 seconds).

[0038] In some embodiments, the first threshold is 0.75, the second threshold is 0.55, the third and fourth thresholds are 0.65, and the fifth threshold is 0.15.

[0039] In some embodiments, the first threshold is a value obtained by adding a specified value to the target value of the coupling coefficient k, the second threshold is a value obtained by subtracting the specified value from the target value of the coupling coefficient k, the third target coupling coefficient k and the fourth target coupling coefficient k are target values ​​of the coupling coefficient k, and the fifth threshold is a value that is 15% to 35% of the target value of the coupling coefficient k.

[0040] In some embodiments, when the motor speed is adjusted by separate amounts, the second and third amounts are 0.8-1.9% of an operating range of motor rotational speeds over which the processor is configured to execute the first selectable operating mode (e.g., 12,000 rpm-22,000 rpm, a range identified as the difference between a maximum and minimum operating speed over which the processor is configured to implement control), the first and fourth amounts are 2-4.5% of that operating range, and the fifth amount is 8-19% of that operating range.

[0041] According to one embodiment, the method includes detecting suction events and responding to the suction events by decreasing the motor speed by a fifth amount if a first suction event is detected, decreasing by a sixth amount if a second suction event is detected, and lowering the upper limit of the motor speed by the sixth amount for a first period of time (e.g., 10 minutes to 30 minutes, e.g., 20 minutes) after detecting the second suction event within a predefined time frame, which may be 30 seconds to 5 minutes, and in one embodiment is 2 minutes.

[0042] The method may further include detecting whether an ECMO device is operably connected to the controller and preventing selection or execution of the first selectable operating mode if an ECMO device is not detected, or receiving a selection from a user interface that the processor should operate the blood pump using the first selectable operating mode, or a combination thereof.

[0043] In some embodiments, the method also provides for control of the blood pump only if the pressure values ​​are reliable. Specifically, the method further includes determining whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable, and ceasing performance of the method if the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are determined to be unreliable for a period of time longer than a second period of time (e.g., 30 seconds to 5 minutes, and in some embodiments, 1 minute to 3 minutes, such as 2 minutes).

[0044] In some embodiments, the method also accommodates a situation where the coupling coefficient k is very low. Specifically, the method may further include activating an alarm notification when the coupling coefficient k falls below a fifth threshold until it is determined that the coupling coefficient k is equal to or greater than a sixth threshold (e.g., a value between 20% and 50% of a target value of the coupling coefficient k), where the sixth threshold is greater than the fifth threshold and less than the fourth threshold. [Brief description of the drawings]

[0045] [Figure 1] FIG. 1 is a schematic diagram illustrating one embodiment of the control device disclosed herein used as part of a system for providing ventricular assist device support for extracorporeal membrane oxygenation. [Diagram 2] FIG. 1 illustrates a distal portion of one embodiment of a catheter-based intravascular blood pump. [Diagram 3] FIG. 2 is a block diagram illustrating a control device disclosed herein. [Figure 4] 11 is a flow chart illustrating one embodiment of a first selectable mode of operation. [Diagram 5] FIG. 13 is a representative diagram showing a display of detected or determined pressure values ​​used to calculate a coupling coefficient k. [Figure 6]1 is a graphical representation showing the value of the rotational speed of the motor of a catheter-based intravascular blood pump (Nset, lower chart) varying in relation to the value of the coupling coefficient (kAIC, upper chart). [Figure 7] 1 is a flow chart illustrating one embodiment of various safety features incorporated into a first selectable mode of operation. [Figure 8] 1 is a graphical representation showing an example of a control state of the rotational speed of a motor of a catheter-based intravascular blood pump when a suction event is detected. [Figure 9] 11 is a flow chart illustrating one embodiment of a start-up routine used prior to utilization of the first selectable mode of operation. [Figure 10] 1 is a graphical representation illustrating a start-up routine for a catheter-based intravascular blood pump. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0046] VA-ECMO with VAD support is being tested for the treatment of cardiogenic shock or other forms of hemodynamic compromise, in which the ECMO device maintains systemic circulation and the VAD unloads the left ventricle (sometimes called LV decompression). However, this configuration can potentially increase cardiac afterload because ECMO returns blood to the descending aorta, i.e., counter to general blood flow. Increased afterload can require the heart to work harder to overcome the pressure gradient between the left ventricle and the aorta.

[0047] VAD performance may be challenged by new conditions such as aortic and left ventricular pressure decoupling and increased afterload. These two changes may affect the operation of device safety features such as suction detection based on differential pressure, aortic pressure, and pulsatility. Even with left ventricular unloading, suction detection may trigger suction alarms due to decoupling, some of which may be false positives. This may result in automatic rate reductions during automatic rate control, reduced LV unloading effect due to manual rate reductions, or continuous suction alarms (leading to noise / alarm fatigue). Furthermore, due to high afterload, manually finding the optimal pump speed (e.g. to avoid suction) may be difficult, resulting in similar problems.

[0048] Thus, the present inventors have recognized that a controller for a blood pump, such as a catheter-based intravascular blood pump, that can be used with an ECMO device would be advantageous, as described herein, with specific start-up and operating modes that control the speed of the blood pump motor based on a coupling coefficient k.

[0049] As can be seen with reference to FIG. 1, a system 1 for such treatment according to the present disclosure may include a controller 100, a blood pump 50, an ECMO device 90, and an optional separate oxygenator 98. Both the ECMO device 90 and the blood pump 50 may affect blood flow within the heart 3 of the patient 2. As shown, the ECMO device may include a blood flow inlet 91 and an outlet 92, the outlet 92 for supplying blood to the heart 3. The blood pump 50 is shown here with a distal-most portion located within the left ventricle of the heart 3 and a more proximal portion located within the aorta, and configured to move blood from the left ventricle to the aorta through a flow cannula. The blood pump 50 is a catheter-based intravascular blood pump. The ECMO device 90 may be in communication with the controller 100, for example, via one or more communication cables 115.

[0050] Although the controller 100 and the ECMO device 90 are shown in FIG. 1 as two separate devices, in some embodiments, the functions of the ECMO device and the functions of the controller may be integrated into a single unit (e.g., the controller 100) capable of executing the ECMO process and controlling the blood pump 50.

[0051] Although FIG. 1 shows an ECMO device and tubing configured for VA-ECMO, it is understood that the ECMO device can be readily substituted or reconfigured for other ECMO means, including, for example, VVA-ECMO.

[0052] One example of a blood pump 50 can be understood with reference to Figure 2. In particular, Figure 2 illustrates a catheter-based intravascular blood pump (sometimes referred to as a "blood pump"), which is described herein as one exemplary embodiment of a VAD.

[0053] The blood pump 50 includes a catheter 10 by means of which the blood pump 50 is temporarily introduced through the aorta and the aortic valve into the left ventricle of the heart. As shown in more detail in FIG. 2, the blood pump further includes a rotary pump device 70 fixed to the end of the catheter tube 20. The rotary pump device 70 may include a motor section 51 and a pump section 52 located axially spaced therefrom. A flow cannula 53 may have a first end connected to and extending from the pump section 52 and an inflow cage 54 at an opposite second end. The inflow cage 54 may have a soft, flexible, atraumatic tip 55 attached thereto. The pump section 52 may include a pump housing having an outlet opening 56. The pump device 70 may further include a drive shaft 57 protruding from the motor section 51 into the pump housing of the pump section 52. The electric motor of the motor section 51 may drive an impeller 58 as a thrust element via the drive shaft 57. This thrust element allows blood to be drawn through the inflow cage 54 and expelled through the outlet opening 56 during operation of the rotary pump device 70 .

[0054] Rotary pumping device 70 may also pump in the reverse direction, if appropriate, as desired, for example, if blood pump 50 is located in the right heart. In this regard, and for completeness, blood pump 50 is shown in FIG. 1 as one embodiment of a VAD for placement in the left heart to assist the left heart.

[0055] In FIG. 2, three lines, two signal lines 28A, 28B and a power line 29 for supplying current to the motor section 51, may run through the catheter tube 20 of the catheter 10 to the pump device 70. The two signal lines 28A, 28B and the power line 29 may be attached at their proximal ends to the control device 100. It is understood that in other embodiments, there may be additional lines for further functions. For example, a line for a purge fluid (not shown) may also run through the catheter tube 20 of the catheter 10 to the pump device 70. Additional lines may be added based on various sensing technologies.

[0056] As shown in FIG. 2, the signal lines 28A, 28B can be part of blood pressure sensors with corresponding sensor heads 30 and 60, respectively, which are located outside the housing of the pump section 52. The sensor head 60 of the first blood pressure sensor can be associated with the signal line 28B. The signal line 28A can be associated with and connected to the sensor head 30 of the second blood pressure sensor. The blood pressure sensor can be, for example, an optical pressure sensor that works according to the Fabry-Perot principle as described in US Pat. No. 5,911,685, in which case the two signal lines 28A, 28B are optical fibers. However, other pressure sensors can be used instead. Essentially, the signals of the pressure sensors each convey information about the pressure at the sensor's location, which can be of any suitable physical origin, for example optical, hydraulic or electrical, and are transmitted through the respective signal lines 28A, 28B to corresponding inputs of the data processing section 110 of the control device 100. In the example shown in FIG. 1, the pressure sensors may be positioned such that the aortic pressure AOP is measured by sensor head 60 and the left ventricular pressure LVP is measured by sensor head 30 .

[0057] The control device is connected via an input port to each of the signal lines 28A, 28B and receives the corresponding measurement signal, i.e., the measurement signal AOP meas and a measurement signal LVP relating to the left ventricular pressure LVP meas and can be received.

[0058] An example of the control device can be understood with reference to FIG. 3. Specifically, the control device 100 may include several components. A first component may include one or more processors 110 (including associated non-transitory computer-readable media containing instructions for controlling the processors). The control device 100 may include various ports 111, 112, 113, 114 operably connected to the processor 110 for receiving signals from and / or transmitting signals to various other components of the system. Not shown are various filters, converters, and the like that allow signals to be appropriately encoded, decoded, formatted, or otherwise modified to be read or transmitted by the control device. The control device 100 may include at least one port 111, 112, 113 that operably connects the processor to the blood pump 50. In some embodiments, the controller 100 may include one or more input ports 111, 112 for receiving pressure signals from two or more pressure sensors, such as pressure sensors measuring pressure in separate chambers of the heart, connected to the controller via, for example, optical fibers 28A, 28B, and a port 113 for a power line 29 or the like that provides current to the motor portion 51 of the blood pump 50. In some embodiments, the controller 100 may include an additional port 114 configured to operably connect the processor 110 to an extracorporeal membrane oxygenation (ECMO) system, such as a VA-ECMO system, via, for example, a communication cable 115 or other suitable additional lines.

[0059] The one or more processors 110 can be configured to acquire the external and internal signals for signal processing, such as calculating the difference between the two pressure signals as a basis for estimating the pump flow rate, and for signal analysis, such as deriving a real value of at least one characteristic parameter a, such as the left ventricular end-diastolic pressure EDLVP or the cardiac filling gradient FG, which characteristic parameter a can be used to control the blood pump motor speed, i.e. the rotational speed of the motor of the motor unit 51 of the blood pump 50.

[0060] The control device 100 may also include other components. In some embodiments, the one or more processors 110 may be configured to control a display 130, such as a touch-sensitive display. In some embodiments, the one or more processors 110 may be configured to control an audio speaker 140 (e.g., to generate an audible alarm). In some embodiments, the one or more processors 110 may be configured to receive input from one or more buttons or switches 150.

[0061] In some embodiments, the control device may include a housing 160 configured to house at least the processor 110 (within an interior volume of space defined by an exterior wall of the housing). In some embodiments, the wall of the housing may have a number of openings formed therethrough. In some embodiments, at least a portion of the display 120 may be located within at least one of the openings of the housing 160. In some embodiments, the display may be operably connected to the processor 110 but not located within or attached to the housing 160.

[0062] In some embodiments, the control device 100 may include a processor 110 configured to control the rotational speed of the motor of the blood pump 50 using a first selectable operating mode. One embodiment of the first selectable operating mode is illustrated in Figure 4, where the method 200 includes a first step 210 of detecting or determining a pressure value.

[0063] In one embodiment, the first step involves detecting or identifying two pressure values: a left ventricular pressure value and an aortic pressure value. For purposes of this disclosure, the detected or identified left ventricular pressure value is referred to as the peak value of the detected or identified left ventricular pressure value (LVP maxFor purposes of this disclosure, the detected or determined aortic pressure value is also referred to as the peak aortic pressure value (AOP max ).

[0064] These values ​​may be measured, for example, based on signals obtained from pressure sensors provided in blood pump 50. In some embodiments, the signals received by processor 110 from the pressure sensors may be utilized as variables in a calculation to determine the left ventricular pressure value or the aortic pressure value.

[0065] The values ​​may be detected or determined at a frequency of, for example, 0.2 Hz or greater, or 0.5 Hz or greater.

[0066] In some embodiments, the second step 220 of the first selectable operating mode is to determine a coupling coefficient k using the detected or determined left ventricular pressure values ​​and the aortic pressure values. The coupling coefficient k specifically comprises a quotient of an average value of at least some of the detected or determined left ventricular pressure values ​​and an average value of at least some of the detected or determined aortic pressure values ​​obtained over a predetermined time interval. In some embodiments, the predetermined time interval may be between 1 second and 5 seconds, for example 2 seconds. That is, in some embodiments, k is determined every 2 seconds.

[0067] In some embodiments, the LVP max and AOP max is identified every 1 to 5 seconds, for example every 2 seconds. Then, 2 to 10 LVPs identified in succession immediately before max and AOP max By calculating the average of the values ​​of max,mean and AOP max,mean In some embodiments, the LVP max,mean and AOP max,mean Each of the five LVPs identified in succession max and AOP maxThe coupling coefficient k may then be determined by averaging the values ​​of LVP max,mean / AOP max,mean It can be calculated as:

[0068] In one embodiment, the average detected or determined left ventricular pressure values ​​and the average detected or determined aortic pressure values ​​used to determine the coupling coefficients are themselves determined over a predetermined time interval that is different from the period used in determining k, in some embodiments this different time interval may be between 8 seconds and 12 seconds, for example 10 seconds.

[0069] Figure 5 shows a schematic diagram of a graphical representation 300 of left ventricular and aortic pressures as may appear on a display screen of a control device. The left ventricular pressure 310 and the aortic pressure 320 are shown as measured over time. In addition to the peak value of the left ventricular pressure 311, the peak value of the aortic pressure 321 is also shown. These two values ​​(311, 321) can be used to calculate a coupling coefficient k. With the graph shown in Figure 5, the value of the coupling coefficient k will be less than 1.

[0070] Referring again to FIG. 4, the method 200 used by the one or more processors 110 may include, after determining the coupling coefficient k, adjusting the rotational speed of the motor based on the determined value of the coupling coefficient k. As understood in the art, this "adjustment" may include indirect adjustment, in which the processor 110 is configured to send a signal to one or more other components or modules that perform some action based on the signal to adjust the speed of the motor.

[0071] The processor 110 may be configured to adjust the rotational speed of the motor at a predetermined interval in the first selectable operating mode, which in some embodiments may be every 5 seconds to every 20 seconds.

[0072] In some embodiments, the controller 100 may be configured to adjust the motor speed based on the value of the coupling coefficient k every 10 seconds. For example, in one embodiment, the coupling coefficient k is determined every 2 seconds based on pressure values ​​detected / determined over the previous 2 seconds, and after every 5th determination of the coupling coefficient k, the speed is adjusted based on that 5th value of the coupling coefficient.

[0073] In some embodiments, the processor 110 may be configured to adjust the rotational speed of the motor in the first selectable operating mode only after a predetermined time interval has elapsed since the last speed adjustment. In some embodiments, the coupling coefficient k is calculated every 1-5 seconds, e.g., every 2 seconds, but the coupling coefficient k is only used every 5-20 seconds, e.g., every 10 seconds, after the speed was last adjusted.

[0074] As shown in FIG. 4, after the coupling coefficient k is determined, the speed can be adjusted based on the value of the coupling coefficient k (221). This means that in one embodiment, the coupling coefficient k can be adjusted based on various thresholds (T1, T2, ..., T n ) In some embodiments, the threshold defines a range of coupling coefficients k that correspond to a particular type of motor speed regulation.

[0075] In some embodiments, the control system is designed around a target value of the coupling coefficient or a range of target values ​​of the coupling coefficient, and may automatically increase the rotational speed of the motor when the value of the coupling coefficient k is less than the target k value, and automatically decrease the rotational speed of the motor when the value of the coupling coefficient k is greater than the target k value.

[0076] In some embodiments, at least one speed adjustment is performed based on the determined value of the coupling coefficient k. The at least one adjustment consists of increasing the rotation speed of the motor by a first amount when the coupling coefficient k is greater than a first threshold, or increasing the rotation speed of the motor by a second amount less than the first amount when the coupling coefficient k is less than or equal to the first threshold and greater than a third threshold, or decreasing the rotation speed of the motor by a third amount when the coupling coefficient k is greater than or equal to a fourth threshold and less than a second threshold, or decreasing the rotation speed of the motor by a fourth amount greater than the third amount when the coupling coefficient k is greater than or equal to a fifth threshold and less than a fourth threshold, or decreasing the rotation speed of the motor by a fifth amount greater than the fourth amount when the coupling coefficient k is less than the fifth threshold, or combinations thereof. Optionally, the first selectable operating mode may be further configured to keep the rotation speed of the motor constant when the coupling coefficient is equal to the third threshold. A simplified description of such an approach is shown in Table 1 below.

[0077] Table 1 (Examples of possible values ​​of k and associated rotation speed adjustments) [Table 1]

[0078] In some embodiments, if the coupling coefficient is between a first threshold (or upper limit) and a second threshold (or lower limit) (T1, T2), no speed adjustment is performed. That is, if after the second step 220, the value of the coupling coefficient k is between T1 and T2 (where "between" is intended to include the upper and lower limits), no action is taken. These upper and lower limits may be centered around a target range of the coupling coefficient k defined by two thresholds (T3, T4) or may be centered around a common target value of the coupling coefficient k defined by a common threshold (i.e., T3=T4).

[0079] The amount of speed increase or decrease can depend on how close the determined coupling coefficient k is to the target value of the coupling coefficient k, and whether the coupling coefficient k is greater than or less than the target value of the coupling coefficient k. A simplified description of such an approach is shown below in Tables 2 and 3.

[0080] Table 2 (Adjustments made when the coupling coefficient is determined to be greater than the first threshold) [Table 2]

[0081] Table 3 (Adjustments made when the coupling coefficient is determined to be less than the second threshold) [Table 3]

[0082] The above description and approach are not intended to be limiting. As shown in Tables 1 and 2, if the determined value of the coupling coefficient k is greater than a first threshold, the controller attempts to reduce the coupling coefficient k by increasing the rotation speed in a stepwise manner until it is equal to or less than the target value or range of the target value. If the value is less than a second threshold, the controller does not attempt to reduce the coupling coefficient k. The control device attempts to increase the coupling coefficient k by decreasing the rotation speed in a stepwise manner until it reaches a target value or a range of target values ​​or higher.

[0083] In some embodiments, the first threshold T1 is a target value of the coupling coefficient k plus a predefined value (e.g., 0.1, 0.15, or 0.2, etc.), the second threshold T2 is a target value of the coupling coefficient k minus the predefined value, the third threshold T3 and the fourth threshold T4 are the target values ​​of the coupling coefficient k, and the fifth threshold T5 is a value between 15% and 35% of the target value of the coupling coefficient k. As a simple example, if the coupling coefficient k is 0.7, the predefined value is 0.15, and the fifth threshold is 20% of the target coupling coefficient k, the control device 110 can be configured to start a speed increase when the coupling coefficient k>0.85. In that configuration, the speed is increased by a medium speed increase when k>0.85, a small speed increase is used when the coupling coefficient k is between 0.7 and 0.85, and the speed increase is stopped when the coupling coefficient k reaches 0.7 or less. The controller may also be configured to initiate speed reduction when the coupling coefficient k is less than 0.55, whereby speed is reduced by large speed reductions when k<0.14, medium speed reductions are used when the coupling coefficient k is between 0.14 and 0.55, and speed reductions are stopped when the coupling coefficient k reaches 0.7 or greater.

[0084] In one embodiment, the first threshold is 0.75, the second and fifth thresholds are 0.65, the third threshold is 0.15, and the fourth threshold is 0.55.

[0085] In some embodiments, the speed adjustment amount can be based on the operating speed range of the motor (e.g., the difference between the maximum and minimum speeds at which the motor is designed to operate in the first selectable operating mode). That is, if the motor is designed to be controlled in this operating mode when rotating at, for example, 31,000 rpm to 46,000 rpm, the operating speed range can be 15,000 rpm. In some embodiments, the range can be 12,000 rpm to 22,000 rpm. In some embodiments, the small speed increase amount (second amount) and / or decrease amount (third amount) can be an amount between 0.8% and 1.9% of the operating range, the medium speed increase amount and / or decrease amount (first and fourth amount) can be an amount between 2% and 4.5% of the operating range, and the large speed decrease amount (fifth amount) can be an amount between 8% and 19% of the operating speed.

[0086] In some embodiments, the first speed adjustment amount (i.e., absolute amount) is equal to the fourth amount (i.e., absolute amount), and in some embodiments, the second speed adjustment amount (i.e., absolute amount) is equal to the third amount (i.e., absolute amount).

[0087] In one embodiment, the second and third amounts are 200 rpm, the first and fourth amounts are 500 rpm, and the fifth amount is 2000 rpm.

[0088] 4 illustrates a rate adjustment process 221 configured for use by the processor 110 in some embodiments. In the rate adjustment process 221, the rate is adjusted only if the coupling coefficient k is determined to be greater than a first threshold (T1) (230) or if the coupling coefficient k is determined to be less than a second threshold (T2) (231). If the coupling coefficient k is between the first threshold (T1) and the second threshold (T2), the rate adjustment process is effectively ignored and steps 210 and 220 are repeated.

[0089] If it is determined (230) that the coupling coefficient k is greater than the first threshold, a first sub-process 232 is initiated, whereby the speed is increased (as described above) until the coupling coefficient is less than the third threshold (T3). Specifically, in the first sub-routine 232, if the coupling coefficient k is greater than the first threshold (T1) (234), the motor rotation speed may be increased by a first amount (235), and if the coupling coefficient k is less than or equal to the first threshold (T1) and greater than the third threshold (T3) (236), the motor rotation speed may be increased by a second amount (237). The second increase in motor speed (i.e., the absolute value of the change in motor speed caused by the second amount) may be less than the first amount (i.e., the absolute value of the change in motor speed caused by the first amount). After the speed adjustments (235, 237) are performed, the pressure value is measured, and the coupling coefficient k is again determined (238) as described above for steps 220 and 221. This sub-process 232 is repeated until the coupling coefficient k is less than or equal to a third threshold (T3), at which point the sub-process 232 ends and the process returns to step 210 to measure the pressure value.

[0090] If it is determined that the coupling coefficient k is less than the second threshold 231, a second sub-process 233 is initiated, which reduces the speed (as disclosed herein) until the coupling coefficient exceeds a fourth threshold (T4). In some embodiments, the fourth threshold may be the same as the third threshold (T3). Specifically, in the second sub-routine 233, if the coupling coefficient k is less than the fourth threshold (T4) and greater than or equal to the second threshold (T2) (244), the motor rotation speed may be reduced by a third amount (245), if the coupling coefficient k is greater than or equal to the fifth threshold (T5) and less than the second threshold (T2) (242), the motor rotation speed may be reduced by a fourth amount (243), and if the coupling coefficient k is less than the fifth threshold (T5) (239), the motor rotation speed may be reduced by a fifth amount (240). The fourth reduction in motor speed (i.e., the absolute value of the change in motor speed caused by the fourth amount) can be less than the fifth reduction (i.e., the absolute value of the change in motor speed caused by the fifth amount). The third reduction in motor speed (i.e., the absolute value of the change in motor speed caused by the third amount) can be less than the fourth reduction in motor speed (i.e., the absolute value of the change in motor speed caused by the fourth amount). After the speed adjustments (240, 243, 245) are performed, the pressure value is measured and the coupling coefficient k is again determined (241) as described above for steps 220 and 221. This sub-process 233 is repeated until the coupling coefficient k is greater than or equal to the fourth threshold (T4), at which point sub-process 233 ends and the process returns to the pressure value measurement in step 210.

[0091] This can be seen graphically with reference to Figure 6. As shown in Figure 6, near the start 601 where the coupling coefficient k is between 1 and 0.75, the motor speed is increased in steps, with each step (e.g., each time the coupling coefficient k is recalculated based on updated pressure values) being a moderate speed increase until the coupling coefficient k is determined to be between 0.75 and 0.65 (602), after which each step is a smaller speed increase. Once the coupling coefficient k reaches 0.65 (603), no further speed changes are implemented until the coupling coefficient k is outside the range of 0.55 to 0.75. In a situation where the coupling coefficient k is rapidly decreasing toward 0, first, when it is determined that the coupling coefficient k is less than 0.55 but greater than 0.15 (604), the speed is decreased by a moderate amount each step, but when it is determined that the coupling coefficient k continues to decrease and is less than 0.15 (605), the speed is then decreased by a large amount each step until it is determined that the coupling coefficient k is greater than 0.15 but less than 0.55 (606). While the coupling coefficient k is greater than 0.15 but less than 0.55, the speed decrease continues, but by a moderate amount each step. When it is determined that the coupling coefficient k is between 0.55 and 0.65 (607), the speed decrease continues, but by a small amount each step, until it is again determined that the coupling coefficient k is greater than or equal to 0.65 (608). Again, no further speed changes are made until the coupling coefficient k exceeds 0.75 (609), then the speed is increased by a moderate amount in each step until the coupling coefficient k is between 0.75 and 0.66 (610), then the speed continues to be increased by smaller amounts in each step until the coupling coefficient k finally drops back to below 0.65 (611).

[0092] As shown in FIG. 7, the processor 110 may be configured to make other determinations and take corrective actions as necessary when certain events occur. The processor may be configured to execute a method 400 in which certain safety features may take precedence over the coupling factor determination 220 and speed adjustment 221 described above. For example, the processor 110 may be configured to determine (410) whether the pump position is incorrect (e.g., whether the blood pump is in the ventricle or whether the blood pump is in the aorta), which determination may be based on the detected or determined pressure value. In that case, an automatic corrective action may be taken (411). The corrective action 411 may include, for example, pausing the above-mentioned speed adjustments until the pump position is no longer determined to be incorrect, and may optionally automatically resume the above-mentioned speed adjustments at which point it is no longer determined to be incorrect. If the blood pump is correctly positioned but a suction event is detected (420), an alternative corrective action may be automatically taken (421).

[0093] In some embodiments, the processor 110 may be further configured to detect 420 one or more suction events and then automatically respond to the suction events 421 by decreasing the motor speed by a fifth amount upon detection of a first suction event, decreasing the motor speed by a sixth amount upon detection of a second suction event, and lowering the upper limit of the motor speed by the sixth amount (sometimes referred to as a "pause") for a period of time (e.g., 10 minutes to 30 minutes, or 20 minutes, etc.) after detecting the second suction event within a predetermined time frame (e.g., 30 seconds to 5 minutes, or 2 minutes, etc.).

[0094] The above process is represented diagrammatically in FIG. 8, which is a graph of the rotational speed of the motor over time. As shown, the rotational speed of the motor can be increased from 0 and go beyond P-2 (preset speed option #2, approximately 31,000 rpm) towards an initial maximum allowable speed P-9 (preset speed option #9, approximately 46,000 rpm) (801). Once the rotational speed exceeds P-2, the device is within the normal operating range of the device. During normal operation, there is a risk of suction occurring (802). Indeed, a first suction event 810 may be detected, and the rotational speed can be immediately reduced (803) while the suction event is cleared. Once the suction event is cleared (811), the rotational speed can be increased again. However, within a period of less than two minutes 804, a second event 812 may be detected, at which point the rotational speed can be automatically reduced again (805) until the second suction event is cleared (813). From that point on, a new maximum rotational speed 807 lower than P-9 (the previous maximum allowable speed) may be set for a period of 20 minutes (806). After the 20 minutes have elapsed, the maximum rotational speed may be increased again to P-9 (808) and the motor will begin to ramp up without a third suction event occurring.

[0095] In some embodiments, if the maximum speed is reduced, an alarm is generated indicating that a reduced rotation speed has been implemented.

[0096] In some embodiments, if suction is detected within the above period (e.g., within the 10-30 minute time window during which the maximum rotation speed is reduced), the rotation speed may be further reduced until the suction is eliminated, and the pause counter may be reset to begin a new 10-30 minute pause.

[0097] In some embodiments, when the pump motor speed reaches a lower limit speed (e.g., 31,000 rpm) configured for operation in the first selectable mode of operation, the rotational speed is not further reduced but an alarm is triggered, which in one embodiment is different from the alarm indicating that the maximum speed has been reduced.

[0098] Given the coordination required between ECMO and a VAD to provide the therapy that would benefit from the above-described techniques, the processor 110 can be configured to: (i) detect whether an ECMO device (e.g., a VA-ECMO or VVA-ECMO device) is operably connected to the controller and / or is operational, and prevent selection or execution of the first selectable mode of operation if the ECMO device is not detected and / or is not operational, (ii) receive a selection that the processor should operate the blood pump using the first selectable mode of operation, or (iii) both (i) and (ii). In some embodiments, the processor 110 can be configured to only perform (i). That is, a user cannot select the controller 100 to operate in the first selectable mode of operation unless the ECMO device 90 is detected as connected and / or operational.

[0099] In some embodiments, the controller 100 may be configured to receive a signal from a flow controller 99 associated with the ECMO device 90 indicating that ECMO is in operation, instead of or in addition to receiving a signal from the ECMO device 90. For example, in one embodiment, the controller 100 may not be permitted to operate in the first selectable mode of operation unless, in addition to receiving a signal from the ECMO device 90 indicating that the ECMO device 90 is connected, the controller 100 also receives a signal from the flow controller indicating that blood is flowing through the ECMO device 90 and that the ECMO device 90 is in operation.

[0100] Given the target coupling coefficient k, a start-up process may be performed by the processor to quickly and safely increase the speed of the blood pump 50 to an appropriate operating speed. This may be described with reference to FIG. 9. To accomplish start-up, the processor 110 may be further configured to perform a start-up method 500 prior to executing the first selectable operating mode 200. In some embodiments, the start-up method first entails increasing (510) the rotational speed of the motor from zero to a minimum rotational speed. This minimum rotational speed should be the minimum rotational speed that the processor 110 is configured to use when executing the first selectable operating mode. In some embodiments, this minimum speed is between 5,000 rpm and 50,000 rpm, e.g., between 20,000 rpm and 40,000 rpm, or 31,000 rpm.

[0101] Once the minimum rotational speed is reached, the processor 110 may determine (520) a coupling coefficient k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value in exactly the same manner as described above, where the coupling coefficient k is the quotient of the average detected or determined left ventricular pressure value and the average detected or determined aortic pressure value. Also, the detected or determined left ventricular pressure value may be a quotient of the peak detected or determined left ventricular pressure value (LVP max ), and the detected or determined aortic pressure value is the peak aortic pressure value (AOP max ).

[0102] Once the coupling coefficient k is specified, the speed can be adjusted.

[0103] As shown in FIG. 9, if the coupling coefficient k≧1 (530), the rotation speed may be adjusted by a sixth amount and then the coupling coefficient k may be determined again after a period of time and the speed may be adjusted again. In some embodiments, the period of time may be between 5 and 30 seconds, for example 10 seconds. In one embodiment, the sixth amount may be between 5% and 30% of the rotation speed range of the motor for which the processor is configured to execute the first selectable mode of operation. As mentioned above, in some embodiments, this range may be between 12,000 rpm and 20,000 rpm. For example, if the motor is designed to be controlled in this mode of operation when rotating at, for example, 31,000 rpm to 46,000 rpm, the operating speed range is 15,000 rpm, and therefore the sixth amount is between 750 rpm and 4,500 rpm. In one embodiment, the sixth amount is between 2,000 rpm and 3,000 rpm.

[0104] However, when the coupling coefficient k<1, a different path may be followed. Specifically, if it is determined that the coupling coefficient k is less than 1, the rotational speed of the motor may be adjusted (221) as described above according to the first selectable operating mode. Referring to FIG. 2, in one embodiment, the speed is adjusted only if it is determined that the coupling coefficient k is greater than a first threshold (T1) (230) or if it is determined that the coupling coefficient k is less than a second threshold (T2) (231). If the coupling coefficient k is between the first threshold (T1) and the second threshold (T2), the speed adjustment process is essentially ignored and steps 210 and 220 are repeated.

[0105] If it is determined (230) that the coupling coefficient k is greater than the first threshold, a first sub-process 232 is initiated, whereby the speed is increased (as described above) until the coupling coefficient is less than the third threshold (T3). Specifically, in the first sub-routine 232, if the coupling coefficient k is greater than the first threshold (T1) (234), the motor rotation speed may be increased by a first amount (235), and if the coupling coefficient k is less than or equal to the first threshold (T1) and greater than the third threshold (T3) (236), the motor rotation speed may be increased by a second amount (237). The second increase in motor speed (i.e., the absolute value of the change in motor speed caused by the second amount) may be less than the first amount (i.e., the absolute value of the change in motor speed caused by the first amount). After the speed adjustments (235, 237) are performed, the pressure value is measured, and the coupling coefficient k is again determined (238) as described above for steps 220 and 221. This sub-process 232 may be repeated until the coupling coefficient k is less than or equal to a third threshold (T3), at which point sub-process 232 ends and the process returns to step 210 to measure the pressure value.

[0106] If it is determined that the coupling coefficient k is less than the second threshold 231, a second sub-process 233 may be initiated, which reduces the speed (as disclosed herein) until the coupling coefficient exceeds a fourth threshold (T4). In some embodiments, the fourth threshold may be the same as the third threshold (T3). Specifically, in the second sub-routine 233, if the coupling coefficient k is less than the fourth threshold (T4) and greater than or equal to the second threshold (T2) (244), the motor rotation speed may be reduced by a third amount (245), if the coupling coefficient k is greater than or equal to the fifth threshold (T5) and less than the second threshold (T2) (242), the motor rotation speed may be reduced by a fourth amount (243), and if the coupling coefficient k is less than the fifth threshold (T5) (239), the motor rotation speed may be reduced by a fifth amount (240). The fourth reduction in motor speed (i.e., the absolute value of the change in motor speed caused by the fourth amount) can be less than the fifth reduction (i.e., the absolute value of the change in motor speed caused by the fifth amount). The third reduction in motor speed (i.e., the absolute value of the change in motor speed caused by the third amount) can be less than the fourth reduction in motor speed (i.e., the absolute value of the change in motor speed caused by the fourth amount). After the speed adjustments (240, 243, 245) are performed, the pressure value is measured and the coupling coefficient k is again determined (241) as described above for steps 220 and 221. This sub-process 233 is repeated until the coupling coefficient k is greater than or equal to the fourth threshold (T4), at which point sub-process 233 ends and the process returns to the pressure value measurement in step 210.

[0107] Because the fifth threshold is often very low and indicates a potential concern, the processor 110 may be further configured to activate an alarm notification if the coupling coefficient k is determined to be less than the fifth threshold. The alarm notification may remain until the coupling coefficient k is determined to be equal to or greater than another threshold that is greater than the fifth threshold and less than the fourth threshold. In some embodiments, the other threshold may be 20% to 50% of a target value of the coupling coefficient k.

[0108] After a period of time (eg, the same period of time as described above following step 531 ), the processor may automatically begin to operate according to the first selectable method 200 .

[0109] The above start-up process is illustrated in FIG. 10. In FIG. 10, it can be seen that the rotation speed can first be increased from 0 to a minimum operating speed (here P-2). After a period of time (here 10 seconds), it is determined that the coupling factor k is equal to or greater than 1, so that the speed is increased by a sixth amount to P-3. This process is repeated several times until the speed reaches P-6, after which it is determined that the coupling factor k is less than 1. During the period 850 when the coupling factor k is less than 1, adjustments can be made according to a first selectable operating mode, where the speed is slowly adjusted until the coupling factor k=0.65, as illustrated in FIG. 10.

[0110] The controller 100 may also be configured to operate the motor in other modes besides the first selectable operating mode. That is, the controller 100 may be configured for use even when, for example, the blood pump 50 is not operating in parallel with the ECMO device 90. In one embodiment, the controller 100 may be configured to operate in at least one other operating mode. For example, the controller 100 may be configured to operate in at least two other operating modes.

[0111] In one embodiment, the processor 110 can be further configured to operate in (i) a second selectable operating mode in which the processor 110 receives a selection of one of a plurality of predetermined operating rotational speeds and adjusts the rotational speed of the motor to the selected predetermined operating rotational speed, and (ii) a third selectable operating mode in which the processor 110 is configured to increase the rotational speed of the motor at a predetermined rate up to a maximum operating rotational speed.

[0112] In some embodiments, the controller 100 may be configured to exit the first selectable operating mode 200 if the pressure values ​​used to control the motor are determined to be unreliable. As will be apparent, the determination of unreliability may be performed in any manner known to those skilled in the art, including, for example, determining whether the identified pressure values ​​are within a predetermined range of expected pressure values ​​or whether the standard deviation of the measured pressure values ​​exceeds a threshold value.

[0113] In some embodiments, the processor may be further configured to determine whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable during operation with the first selectable operating mode 200, and to switch from the first selectable operating mode to the second selectable operating mode if the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are determined to be unreliable for a period of time. In some embodiments, the period of time may be between 30 seconds and 5 minutes, such as 2 minutes. In some embodiments, the switching operation from the first mode to the second mode may include automatically identifying a speed among a plurality of preset speeds that is closest to but does not exceed the current motor speed, and adjusting the speed to the identified preset speed. In some embodiments, an alarm or warning may be issued if the signal is determined to be unreliable.

[0114] The blood pump system disclosed herein may generally include the controller 100 described above and a catheter-based intravascular blood pump 50 operably connected to the controller.

[0115] The systems disclosed herein (e.g., a combined ECMO and VAD) may generally comprise two main groups of components: the first group is an extracorporeal membrane oxygenation (ECMO) system, e.g., a VA-ECMO system (e.g., an ECMO device 90, a flow controller 99, and various associated tubing and fittings, etc.); the second group is a blood pump system suitable for operating in parallel with the ECMO system, comprising the controller 100 described above and a catheter-based intravascular blood pump 50 operably connected thereto.

[0116] Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein which equivalents are intended to be encompassed by the following claims.

[0117] The embodiments of the present disclosure are described in detail with reference to the drawings, in which like reference numerals indicate similar or identical elements. It should be understood that the embodiments disclosed herein are merely examples of the present disclosure, which may be embodied in various forms. Well-known functions or structures are not described in detail to avoid obscuring the present disclosure with unnecessary details. Therefore, the details of the specific structures and functions disclosed herein should not be construed as imposing limitations, but merely as a basis for the claims, and further as a representative basis for teaching those skilled in the art that the present disclosure can be variously used in substantially any suitable specific structure.

Claims

1. 1. A control device for a blood pump, particularly a catheter-based intravascular blood pump, comprising: a processor configured to control a rotational speed of a motor of a catheter-based intravascular blood pump using a first selectable mode of operation; The first selectable operating mode is: determining a coupling coefficient k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value; and making at least one adjustment to the rotational speed of the motor based on the determined value of the coupling coefficient k; The at least one adjustment may include: increasing the rotational speed of the motor by a first amount if the coupling coefficient k is greater than a first threshold; or increasing the rotational speed of the motor by a second amount less than the first amount when the coupling coefficient k is less than or equal to the first threshold and greater than a third threshold; or decreasing the rotational speed of the motor by a third amount when the coupling coefficient k is greater than or equal to a second threshold and less than a fourth threshold; or decreasing the rotational speed of the motor by a fourth amount greater than the third amount when the coupling coefficient k is greater than or equal to a fifth threshold and less than the second threshold; or If the coupling coefficient k is less than the fifth threshold, decreasing the rotational speed of the motor by a fifth amount greater than the fourth amount; or The combination of these is the control device.

2. The control device of claim 1 , wherein the processor is further configured to maintain a constant rotational speed of the motor when the coupling coefficient is equal to the second threshold value.

3. 2. The control device according to claim 1, wherein the processor is configured to adjust the rotational speed of the motor when the determined value of the coupling coefficient k is greater than the first threshold or less than the second threshold; The adjustment is While the coupling coefficient k is greater than the third threshold, increasing the rotation speed of the motor by the first amount when the coupling coefficient k is greater than the first threshold, and increasing the rotation speed of the motor by the second amount when the coupling coefficient k is equal to or less than the first threshold and greater than the third threshold; and determining a coupling coefficient k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value; While the coupling coefficient k is greater than the third threshold, reducing the rotation speed of the motor by the third amount when the coupling coefficient k is equal to or greater than the fourth threshold and less than the second threshold, reducing the rotation speed of the motor by the fourth amount greater than the third amount when the coupling coefficient k is equal to or greater than the fifth threshold and less than the fourth threshold, and reducing the rotation speed of the motor by the fifth amount greater than the fourth amount when the coupling coefficient k is less than the fifth threshold; and determining a coupling coefficient k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value.

4. 4. A control device according to any one of claims 1 to 3, wherein the processor is configured to adjust the rotational speed of the motor at a first predetermined time interval in the first selectable operating mode, the first predetermined time interval being preferably between 5 and 20 seconds, and optionally the first predetermined time interval being preferably 10 seconds.

5. 4. A control device according to claim 1, wherein the coupling coefficient k is determined at a second predetermined time interval, the second predetermined time interval being preferably 1 to 5 seconds, and optionally the time interval being preferably 2 seconds.

6. A control device as claimed in any one of claims 1 to 3, wherein the coupling coefficient k is the quotient of the average value of the detected or determined left ventricular pressure values ​​and the average value of the detected or determined aortic pressure values, and the average value of the detected or determined left ventricular pressure values ​​and the average value of the detected or determined aortic pressure values ​​are preferably determined over a third predetermined time interval, the third predetermined time interval being preferably 8 to 12 seconds, and optionally the time interval being preferably 10 seconds.

7. 4. A control device according to claim 1, wherein the first threshold is 0.75, the second threshold is 0.55, the third threshold and the fourth threshold are 0.65, and the fifth threshold is 0.

15.

8. 4. The control device according to claim 1, wherein the first threshold value is a value obtained by adding a specified value to a target value of the coupling coefficient k, the second threshold value is a value obtained by subtracting the specified value from the target value of the coupling coefficient k, the third threshold value and the fourth threshold value are the target value of the coupling coefficient k, and the fifth threshold value is a value that is 15% to 35% of the target value of the coupling coefficient k, and / or the second amount is 0.8-1.9% of an operating range of the rotational speed of the motor over which the processor is configured to execute the first selectable operating mode, the first amount and the fourth amount are 2-4.5% of said operating range, and the third amount is 8-19% of said operating range, and the operating range of the rotational speed of the motor is preferably 12,000 rpm to 22,000 rpm.

9. 4. The control device of claim 1, wherein the processor is further configured to detect and respond to suction events; The response is, decreasing the rotational speed of the motor by a fifth amount upon detecting a first suction event; decreasing the rotational speed of the motor by a sixth amount upon detecting a second suction event; After detecting the second suction event within a predetermined time frame, reducing the upper limit of the rotational speed of the motor by the sixth amount for a first period of time. This is carried out by The control device, wherein the first period is preferably between 10 minutes and 30 minutes, and the predetermined time frame is preferably between 30 seconds and 5 minutes.

10. 4. The control device according to claim 1, wherein the processor further comprises: Detecting whether an extracorporeal membrane oxygenation (ECMO) device is operably connected to the controller, and preventing selection or execution of the first selectable operating mode if an ECMO device is not detected; or receiving a selection that the processor should operate the blood pump using the first selectable operating mode; or configured to implement any combination thereof; and / or The processor further comprises, before executing the first selectable mode of operation: increasing the rotational speed of the motor from zero to a minimum rotational speed that the processor is configured to use when executing the first selectable mode of operation; determining a coupling coefficient k using the detected or determined aortic pressure value and the detected or determined left ventricular pressure value; configured to adjust the rotational speed of the motor based on the value of a coupling coefficient k; The adjustment is if k≧1, increasing the rotational speed by a sixth amount and repeating steps bc after a period of time; adjusting the rotational speed of the motor in accordance with the first selectable mode of operation when k<1, and controlling the rotational speed of the motor in accordance with the first selectable mode of operation after the period of time has elapsed; The sixth amount is preferably between 5% and 30% of the range of rotational speeds of the motor at which the processor is configured to implement the first selectable mode of operation.

11. The control device according to any one of claims 1 to 3, the processor is further configured to receive a selection of one of a plurality of predetermined rotational operating speeds and operate in a second selectable operating mode to adjust the speed of the motor to the selected predetermined rotational operating speed; the processor is further configured to operate in a third selectable operating mode configured to increase the rotational speed of the motor at a predetermined rate up to a maximum operating rotational speed; The processor preferably further comprises: determining whether the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are unreliable during operation using the first selectable mode of operation; and switching from the first selectable mode of operation to the second selectable mode of operation when the detected or determined aortic pressure value, the detected or determined left ventricular pressure value, or both are determined to be unreliable for a second period of time; The second period of time is preferably between 30 seconds and 5 minutes.

12. 4. The control device according to claim 1, wherein the processor is further configured to: activate an alarm notification when it is determined that the coupling coefficient k is less than the fifth threshold, until it is determined that the coupling coefficient k is equal to or greater than a sixth threshold, the sixth threshold being greater than the fifth threshold and less than the fourth threshold, and the sixth threshold being preferably 20% to 50% of a target value of the coupling coefficient k.

13. The control device according to any one of claims 1 to 3, further comprising: a display controlled by said processor; a first port configured to operably connect the processor to the catheter-based intravascular blood pump; a second port configured to operably connect the processor to an extracorporeal membrane oxygenation (ECMO) system; and a housing configured to house at least the processor; A control device comprising:

14. 1. A blood pump system comprising: The control device according to any one of claims 1 to 3, a catheter-based intravascular blood pump operably connected to the controller.

15. 1. A system comprising: an extracorporeal membrane oxygenation (ECMO) system; a blood pump system adapted to operate in parallel with the ECMO system; The blood pump system includes a control device according to any one of claims 1 to 3, and a catheter-based intravascular blood pump operably connected to the control device.

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