Blood pump controller and system

Abstract

A blood pump system includes a blood pump and a corresponding controller. The blood pump includes an impeller sealed within a pump housing and hydraulically suspended within the pump housing. The pump impeller includes a magnet and is a rotor of a brushless direct current (DC) motor that is driven by electrical signals through stator coils in the pump housing, creating a rotating magnetic field. The rotating magnetic field attracts the magnetized impeller and spins it with the rotating field. The controller provides field-oriented control for the brushless DC motor in the blood pump. The field-oriented control in the controller is provided in a programmable logic device separate from the control processor, so that software or hardware failures related to the control processor do not stop the blood pump. The field-oriented control allows sensing of blood flow through the pump without having a sensor in the blood flow.

Description

Technical Field

[0001] This disclosure generally relates to blood pumps, and more specifically to blood pump controllers and systems. Background Technology

[0002] Medical blood pumps increase blood flow to patients with insufficient blood flow to the heart. A ventricular assist device (VAD) is a specific type of implantable blood pump. A VAD is placed parallel to the left or right ventricle of a patient who cannot receive the required blood flow. Known blood pumps use several different pump types and motor configurations, as well as methods for driving these pump motors. Some blood pumps use a pump motor to drive a radial flow pump, while others have a motor shaft directly aligned with the impeller to drive an axial flow pump to deliver blood. Maintaining a reliable seal around the motor shaft in the pump can be problematic. Other pumps use an impeller that is completely sealed within the pump housing and hydrodynamically suspended within it. The impeller itself becomes the magnetized rotor portion of the motor. Receiving electrical signals creates a rotating magnetic field to rotate the rotor motor stator coils, which are directly integrated into the pump housing. The entire stator becomes part of the pump fluid itself. Some blood pumps include sensors in the blood flow to sense pressure and flow rate. Other blood pumps use various methods to estimate the pump's pressure and / or discharge flow rate to avoid placing sensors in the blood flow, as blood clots can form around the sensors.

[0003] Known devices and methods for blood pumps and controllers do not provide precise speed control of the pump, or allow direct blood flow sensing without sensors in the bloodstream, and have other drawbacks; for example, some mechanical pump designs significantly impair blood flow through the pump. Many controllers estimate specific parameters, such as pressure or flow rate. These estimates are a potential source of error in providing appropriate treatment to the patient (i.e., proper control of the blood pump). Some malfunctions within the pump controller can cause the blood pump to stop, potentially endangering the patient's life. An improved blood pump controller is needed to address these shortcomings in the prior art. Summary of the Invention

[0004] A blood pump system includes a blood pump and a corresponding controller. The blood pump includes an impeller sealed within a pump housing and hydrodynamically suspended within the housing. The pump impeller includes a magnet and is the rotor of a brushless direct current (DC) motor driven by an electrical signal through stator coils in the pump housing, which creates a rotating magnetic field. The rotating magnetic field attracts the magnetized impeller and causes it to spin with the rotating field. The controller provides field-oriented control for the brushless DC motor in the blood pump. This field-oriented control is provided in a programmable logic device separate from the control processor, so that software or hardware failures associated with the control processor will not stop the blood pump. Field-oriented control allows sensing of blood flow through the pump without the need for sensors within the blood flow itself.

[0005] As shown in the accompanying drawings, the foregoing and other features and advantages will become clear from the following more specific description. Attached Figure Description

[0006] This disclosure will be described in conjunction with the accompanying drawings, wherein similar reference numerals denote similar elements, and:

[0007] Figure 1 It is a block diagram of a system including a blood pump, cables, and a system controller;

[0008] Figure 2 This is a block diagram illustrating a system with additional details according to a preferred embodiment;

[0009] Figure 3 The components of the system controller in a preferred embodiment are shown;

[0010] Figure 4 This is a block diagram showing some parts of a system controller implemented on a system-on-a-chip (SOC);

[0011] Figure 5 This is a block diagram of a blood pump according to a preferred embodiment;

[0012] Figure 6 This is a block diagram illustrating how a system controller drives the stator coils, providing an estimate of the blood flow through the blood pump;

[0013] Figure 7 It is shown Figure 6 A block diagram of a suitable implementation of the digital current processing logic shown;

[0014] Figure 8 This is a flowchart of a suitable method for generating drive signals for a blood pump motor;

[0015] Figure 9 This is a flowchart of a method for determining the speed of a blood pump motor;

[0016] Figure 10 yes Figure 3 The diagram shows a block diagram of one specific implementation of FPGA motor control within a system controller, which provides field-oriented control for the blood pump motor.

[0017] Figure 11 This is a flowchart illustrating how the system controller monitors and processes alerts.

[0018] Figure 12 This is a table that displays warning conditions and corresponding notifications;

[0019] Figure 13 This is a flowchart illustrating the methods by which the system controller monitors and processes alarms.

[0020] Figure 14 This is a table that displays alarm conditions and corresponding notifications;

[0021] Figure 15 This is a flowchart of a method for displaying multiple alarms and / or alerts that are simultaneously active on a system controller display;

[0022] Figure 16 It is a flowchart illustrating the methods by which clinicians program system controllers for specific patients;

[0023] Figure 17 This is a flowchart of a method for monitoring the processor to trigger alarms when an error occurs in an FPGA motor controller or system controller;

[0024] Figure 18 It is a block diagram of the hierarchical structure used by the power controller within the system controller to determine which power source will supply power to the system controller;

[0025] Figure 19 It is the system controller based on Figure 18 A flowchart illustrating how the power supply hierarchy determines which power supply to use.

[0026] Figure 20 This is a flowchart illustrating various methods of patient use of the system controller;

[0027] Figure 21 This is a block diagram showing a backup power charger in a power manager that charges an internal backup battery when certain conditions are met; and

[0028] Figure 22 yes Figure 21 The flowchart shows the method by which the backup battery charger charges the backup battery. Detailed Implementation

[0029] The blood pump system comprises a blood pump and a corresponding controller. The blood pump includes an impeller sealed within a pump housing and hydrodynamically suspended within the housing. The pump impeller includes a magnet and is the rotor of a brushless direct current (DC) motor driven by an electrical signal passing through stator coils in the pump housing, creating a rotating magnetic field. This rotating magnetic field attracts and magnetizes the impeller, causing it to spin with the rotating field. The controller provides field-oriented control for the brushless DC motor in the blood pump. This field-oriented control is provided in a programmable logic device separate from the control processor, so software or hardware failures associated with the control processor will not stop the blood pump. Field-oriented control allows sensing of blood flow through the pump without the need for sensors within the blood flow itself.

[0030] refer to Figure 1The diagram illustrates a blood pump system 100 including a blood pump 110, a cable 124, and a system controller 130. The blood pump 110 may be an implantable blood pump. A ventricular assist device (VAD) is a suitable embodiment of the blood pump 110. The blood pump 110 preferably includes an impeller sealed within a pump housing and hydrodynamically suspended within the pump housing. The impeller includes multiple magnets, and the blood pump has multiple stator coils in a brushless DC motor that, when driven by multiple drive signals, causes the impeller to rotate within the pump housing.

[0031] The blood pump 110 includes a connector 120 that receives a mating connector 122 on a cable 124. The applicant has developed medical connectors suitable for use with implantable devices such as pacemakers and blood pumps, as shown and described in the following U.S. patents: 10,480,690; 10,741,968; 10,833,451; 10,855,026; 10,886,663; and 11,309,662. Connectors 120 and 122 may be connectors as shown in these listed patents, or may be any other suitable type of connector. In one particular embodiment, the cable 124 is a percutaneous cable connected to the blood pump 110 implanted in a patient, passing through the skin and connecting to an external controller (such as a system controller 130). The cable 124 includes a suitable connector 126 that mates with a corresponding connector 128 in the system controller, allowing the system controller 130 to provide drive signals to the stator coils in the brushless DC motor of the blood pump 110.

[0032] like Figure 1As shown, the system controller 130 preferably includes controller logic 140; a backup battery 150; a display 160; one or more input keys 170; one or more LEDs 180 for warnings and / or alarms; one or more audio devices 190 for warnings and alarms; and a warning / alarm vibrator motor 192 for providing tactile notification of warnings and alarms. The controller logic 140 monitors the function of the brushless DC motor in the blood pump 110 and provides appropriate drive signals to the stator coils in the brushless DC motor to cause the blood pump 110 to operate at a desired speed. The backup battery 150 is housed within the housing of the system controller 130 and provides power when an external power source (such as a primary battery or AC / DC adapter) is not plugged into the system controller 130 or is not supplying power to the system controller 130. The display 160 can be any suitable type of display. In the most preferred embodiment, the display 160 is a low-power liquid crystal display (LCD). Input keys 170 are provided to provide user input to the system controller. Input keys may include, for example, a mute key that silences an audio device when it indicates a warning, and a "next" key that allows navigation from the current screen to the next screen in a multi-screen message. LED 180 is used to provide visual indication of a warning or alarm detected by system controller 130. For example, one or more LEDs 180 may provide a slow yellow flashing signal in the event of a warning and a fast red flashing signal in the event of an alarm. One or more audio devices 190 are used to provide audio indication of a warning or alarm detected by system controller 130. For example, one or more audio devices 190 may provide a slow, gentle beep in the event of a warning and a fast, loud beep in the event of an alarm.

[0033] The blood pump system disclosed and claimed in this article may also include other components, such as Figure 2 The system 200 is shown in the figure. Figure 2 The system controller 210 in the middle is Figure 1 A suitable example is the system controller 130, while the blood pump 260 is... Figure 1A suitable example of a blood pump 110 is shown. The system controller 210 includes an internal backup battery 150 as discussed above. The system controller 210 also includes a clinician interface that allows a clinician interface computer 230 to be connected to the system controller 210. Medical clinicians can use the clinician interface computer 230 to set the speed of the blood pump in the system controller 210 and also define or select various warning and alarm conditions. The system controller 210 includes a blood pump interface for receiving a cable 266 connected to the blood pump 260. The system controller 210 is located externally to the body and can be connected to a suitable connector 264 that connects to a percutaneous cable 262 to connect to the implanted blood pump 260. Of course, the blood pump 260 can also be located externally to the body, with a percutaneous tube connecting to a blood vessel inside the body. Note that the connector 264 can be used to insert an extension cable that allows the system controller to be located further away from the patient. This would be helpful, for example, if the patient needs to undergo surgery.

[0034] The system controller 210 also includes an interface to the primary battery 250 and an AC / DC power adapter 240 that receives power from a regional alternating current (AC) power source. In a preferred embodiment, the system controller 210 preferably does not include circuitry for charging the primary battery 250. The primary battery 250 is removably coupled to the exterior of the system controller housing, such that when the primary battery 250 needs to be recharged, it can be removed from the system controller and connected to a desktop battery charger 270.

[0035] System controller 210 uses a power hierarchy to determine which power source to apply for its operation. When AC / DC power adapter 240 is plugged into a local AC power source and then into system controller 210, AC / DC power adapter 240 supplies power to system controller 210. When primary battery 250 is plugged into system controller 210 and AC / DC power adapter 240 is not plugged into system controller 210, or is plugged into system controller 210 but not providing power (such as during a power outage), primary battery 250 supplies power to system controller 210. When neither AC / DC power adapter 240 nor primary battery 250 supplies power to system controller 210, system controller 210 is powered by backup battery 150. This configuration provides safety and convenience. When a patient connected to a blood pump will be staying in one place for an extended period, the patient can use system controller 210 in tethered mode by plugging the AC / DC power adapter into a wall socket and then into system controller 210, thus preventing the primary battery 250 or backup battery 150 from being depleted. When the patient no longer wishes to be tethered to the AC / DC power adapter 240, they can unplug it, allowing the system controller 210 to be used in an untethered mode. In this mode, the relatively large primary battery 250 can provide several hours of power to the system controller 210 before needing recharging. When the primary battery 250 is nearly discharged and needs recharging, the patient can disconnect it from the system controller 210 and connect a different primary battery. When the primary battery 250 is disconnected, the system controller 210 is powered by the backup battery 150. Therefore, the backup battery 150 inside the housing of the system controller 210 provides power to ensure that the blood pump 260 continues to operate even when both the AC / DC power adapter 240 and the primary battery 250 are disconnected. During normal use, the system controller 210 is only powered by the backup battery for a short period required for the user to disconnect a discharged primary battery and replace it with a fully charged one. The backup battery 150 is preferably a lithium-ion rechargeable battery, and the system controller 210 includes a charging circuit that keeps the backup battery 150 charged when the system controller 210 is connected to the AC / DC power adapter 240 or the primary battery 250. The primary battery used with the system controller 210 (such as...) Figure 2 The primary batteries (250, 250A and 250B) are preferably rechargeable lithium-ion batteries.

[0036] The desktop battery charger 270 receives power from an AC / DC power adapter 290 coupled to regional AC power. The desktop battery charger 270 can charge multiple primary batteries simultaneously. For Figure 2In a specific example, the desktop battery charger 270 can charge two primary batteries 250A and 250B simultaneously. Of course, other configurations of the desktop battery charger can charge more or fewer primary batteries as needed. In the most preferred embodiment, the system controller 210 includes a latching system for mechanically and electrically attaching the primary battery 250 to the housing of the system controller 210, and the desktop battery charger 270 also provides the exact same or similar latching system, so the primary battery is attached to the desktop battery charger 270 in the same manner as it is attached to the system controller. This provides ease of use, allowing users to become accustomed to connecting and disconnecting primary batteries on the system controller and to using the same methods and procedures to connect and disconnect primary batteries to the desktop battery charger. The desktop battery charger 270 can charge the primary batteries using any suitable charging method. In a preferred embodiment, the desktop battery charger 270 can recharge the primary batteries in approximately three hours.

[0037] refer to Figure 3 The system controller 310 is Figure 1 The system controller 130 shown is Figure 2 A suitable embodiment of the system controller 210 shown is illustrated. The system controller 310 includes a backup battery 150 located inside the housing of the system controller, as referenced above. Figure 1 System controller 130 and Figure 2 The system controller 210 described therein. Figure 1 The controller logic 140 in the middle may include, for example, Figure 3 The monitoring processor 320, control processor 330, and programmable logic device shown are configured to provide motor control, such as an FPGA motor control 340. The functions of the system controller are divided into... Figure 3The three blocks 320, 330, and 340 shown offer significant advantages. First, the control processor 330 is a microcontroller that provides the necessary management functions to the system controller 310, including monitoring of alerts and alarms, outputting to a display, receiving user input via input keys 170, performing power switching between power supplies, etc. The FPGA motor controller 340 is a field-programmable gate array (FPGA) programmed to provide sensorless field-oriented control (SFOC) of the brushless DC motor in the blood pump. By dedicating the control of the blood pump to the FPGA motor controller 340, the blood pump will continue to operate and be controlled by the FPGA motor controller 340 even if the control processor 330 stops working. Therefore, even if the control processor 330 stops operating normally, the FPGA motor controller 340 will continue to operate and control the blood pump because the FPGA motor controller is implemented in hardware that does not depend on the functionality of the control processor 330 for normal operation. Furthermore, the FPGA motor controller 340 operates according to an electronic clock, rather than using software that can have variable timing. Therefore, the FPGA motor controller 340 can control very high-speed motors that are difficult to control via a processor running software. The FPGA motor controller 340 is also a dedicated single-function circuit, free from irrelevant or other features that could cause it to fail. Furthermore, the FPGA can have room for expansion to add other dedicated hardware functions to the system controller, such as: interfaces from the implanted controller to the implanted controller for external parameter programming, and interfaces for medical implantable communication services (MICS) or Bluetooth communication with the implanted controller; interfaces to microelectromechanical systems (MEMS) pressure sensor circuits for flow measurement; and interfaces for percutaneous battery charging systems.

[0038] While sensorless field-oriented control (SFOC) of brushless DC motors is well-known, this approach has not yet been used in blood pumps. SFOC offers numerous advantages over known blood pump technologies. Blood pumps require operation at relatively high speeds of thousands or tens of thousands of RPMs, varying by no more than 100 RPM. SFOC allows for more precise motor control because it provides the exact position (rotor angle) of the spinner (or impeller). In contrast to known drive systems used in blood pumps, SFOC is a closed-loop design. With precise rotor position, the spin rate or speed is known, and the field in the stator can be driven to produce maximum torque. This is the fundamental difference that SFOC offers in controlling brushless DC (BLDC) motors compared to other motor drive mechanisms. For induction motors or motors operating using other open-loop controls such as trapezoidal or sinusoidal drives, the rotor position and speed are unknown. For open-loop systems, the actual rotational speed of the rotor (impeller) is only estimated. For SFOC, the rotational speed can be measured.

[0039] SFOC also improves power efficiency, resulting in lower power consumption compared to trapezoidal or sinusoidal drive methods used for the same motor design. This is because the SFOC algorithm optimizes pump motor torque. The energy sent to the phase coils of the stator creates a magnetic field that is always in the precise position to maximize the rotor's spin. Since there is no misalignment of the magnetic field in the phase coils driving the rotor with respect to the rotor's permanent magnetic field, energy is minimized. Increased power efficiency leads to reduced power consumption, reduced heat generation, and a smaller system controller. Furthermore, increased power efficiency allows for the use of smaller backup batteries or allows for longer operation of larger backup batteries.

[0040] The SFOC method for driving pump motors also reduces torque ripple. Torque ripple is also a result of the rotor only spinning because the magnetic field in the stator is not optimally positioned. If the stator field lags behind or leads the rotor field relative to its optimal position, the rotor decelerates and / or deviates from its central axis. Without SFOC, the rotor wobbles more. SFOC significantly reduces this torque ripple (rotor speed jitter and wobble) because the SFOC algorithm attempts to drive the axial displacement parameter toward zero and smooth the torque value. The result of reduced torque ripple is longer motor bearing life and potentially better prevention of hemolysis.

[0041] SFOC also allows the motor itself to be used as a sensor, as rotor position provides precise speed, and measuring motor current is useful for flow measurement and obstruction detection. SFOC is "sensorless" because there are no separate sensors, such as Hall effect sensors for detecting rotor speed, mechanical load sensors, or separate governor circuits. The current sensor used in the SFOC algorithm to perform motor control can also sense load changes affecting the motor. Therefore, the measured variables, current sensing values, torque ripple, and programmed speed can be used to estimate the flow rate through the pump and detect obstructions in the flow.

[0042] SFOC uses a three-dimensional geometry to switch back and forth between a rotating reference and a fixed reference, and between the voltage of the induced current and the current of the indicated voltage. SFOC has been implemented in software in the past, but running SFOC in a software-controlled environment requires a very high-speed microcontroller. It is assumed that the program in the microcontroller simultaneously performs calculations for the SFOC cycle that spins the pump motor and also runs other software performing other functions, such as monitoring the battery, recording motor control events, displaying messages on the LCD, generating alarms, and communicating via USB. In that case, the timing of the SFOC algorithm is very likely to be interfered with by the operation of other software. SFOC requires precise timing. Software systems are inherently unable to be precisely timed in all situations. A malfunction in one part of the software system will affect other operating software parts. For this reason, implementing SFOC in an FPGA provides independence from the microcontroller performing other functions, ensuring that the blood pump continues to operate even if the microcontroller fails or malfunctions. Furthermore, the FPGA implementation of SFOC disclosed and claimed herein provides a very accurate hardware timer, thereby ensuring very high-speed control of the blood pump motor. Once the pump motor speed is set in the FPGA motor control 340, the pump motor spins precisely at that speed, regardless of what the monitoring processor 320 or the control processor 330 is doing, and regardless of whether one or both of these processors 320 and 330 malfunction. This allows the control processor to malfunction, lock up, or stop without warning, while the FPGA motor control 340 continues to spin the pump motor precisely at the programmed speed. Furthermore, the control processor can be intentionally stopped so that its software can be updated, while the FPGA motor control 340 continues to spin the pump motor precisely at the programmed speed. Once the pump motor speed setting is set in the FPGA motor control 340, all that is required for the FPGA motor control 340 to continue spinning the pump motor at the set speed is uninterrupted power.

[0043] Because system controller 310 controls critical life support equipment (i.e., a blood pump), a failure of system controller 310 can result in injury or death. For this reason, a monitoring processor 320 is provided to independently monitor control processor 330 and FPGA motor control 340. Even if control processor 330 fails, preventing it from alerting the user, monitoring processor 320 will detect the failure and provide necessary warnings and / or alarms. In a suitable embodiment, control processor 330 can send periodic heartbeat messages to monitoring processor 320, and monitoring processor 320 can assume control processor 330 is functioning correctly as long as it receives heartbeat messages within a defined time frame. For example, heartbeat messages can be sent via a Universal Asynchronous Receiver / Transmitter (UART) channel between control processor 330 and monitoring processor 320. However, it should be noted that monitoring processor 320 has other ways of determining when a problem occurs in system controller 310 besides monitoring heartbeats from control processor 330. For example, monitoring processor 320 can independently monitor the parameters of FPGA motor circuit 340 to determine whether the blood pump speed is normal. Regardless of the source of the fault, when monitoring processor 320 detects a fault in the system controller, whether in control processor 330 or FPGA motor control 340, monitoring processor 320 can provide alerts and / or alarms to the user, letting them know what needs to be done to resolve the problem. This could be replacing the faulty system controller with a properly functioning one.

[0044] The monitoring processor 320 can be a microcontroller, or it can be a simple state machine or other combination of hardware / software. The monitoring processor 320 can be any suitable entity capable of monitoring and controlling the processor 330 and the FPGA motor control 340.

[0045] In a preferred embodiment, both the control processor 330 and the FPGA motor control 340 can be implemented as a system-on-a-chip (SoC). Figure 4 A suitable example of this SoC implementation is shown in the figure. Figure 4 The system controller 410 in the middle is Figure 1 System controller 130 in Figure 2 210 and Figure 3 A suitable implementation of 310 in the above. System controller 410 includes a system-on-a-chip (SoC) 420. SoC 420 includes an FPGA architecture 430; a control processor 470; a clinician interface 480; a primary battery interface 484; and an AC / DC power interface 486. FPGA architecture 430 is... Figure 3This is a suitable embodiment of the FPGA motor control 340 shown. The FPGA architecture 430 implements sensorless field-oriented control (SFOC) logic 440 and a pulse-width modulation (PWM) signal generator 450, which provides drive signals to the stator coils of the brushless DC motor in the blood pump via a blood pump interface 460. The SFOC logic 440 includes a motor speed and position estimator 442 and a pump motor speed setting 444. The motor speed / angle estimator 442 preferably estimates both motor speed and angle. The pump motor speed setting 444 is most preferably written to the SFOC logic 440 by an SFOC device driver 472 in the control processor 470, as a result of receiving input from a clinician via a clinician interface 480 to set the pump motor speed. The clinician interface 480 preferably includes a graphical user interface (GUI) 482 that allows the clinician to interact with the system controller 410 when the clinician's computer system is coupled to the clinician interface 480. The control processor 470 additionally includes an alert manager 474, an alarm manager 476, and a power manager 478. The functions of the alert manager 474 and the alarm manager 476 can be combined. The functions of the alert manager 474, the alarm manager 476, and the power manager 478 are discussed in more detail below. The control processor 470 on the SOC 420 is also coupled to the backup battery 150, the display 160, one or more input keys 170, one or more LEDs 180, and one or more audio devices 190, as discussed above. Figure 4 The SOC implementation shown provides an efficient and low-cost method for controlling the function of a blood pump.

[0046] Figure 5 A block diagram of blood pump 510 is shown. Blood pump 510 is... Figure 1 A suitable embodiment of the blood pump 110 is shown. The blood pump 510 includes an inlet 520, a pump chamber 540, and an outlet 530. The inlet 520 is connected to a blood vessel from which blood needs to be pumped. The outlet 530 is connected to a blood vessel into which blood needs to be pumped. In other words, the inlet 520 is a low-pressure port and the outlet 530 is a high-pressure port. The pump chamber 540 is sealed, and an impeller 550 within the pump chamber 540 is hydrodynamically suspended within the pump chamber 540. This means that the impeller has no shaft or other mechanical connection to drive it. The impeller includes multiple magnets. Figure 5 In a specific embodiment, three magnets 560, 562, and 564 are shown. Within the scope of the preferred embodiment, there may be a ratio of... Figure 5 The three more magnets shown. Figure 5Multiple pump phase coils 570, 572, and 574 used to drive the impeller are also shown. Coils 570, 572, and 574 are stator coils and are part of the drive section of the brushless DC motor in the blood pump. In the most preferred embodiment, pump phase coils 570, 572, and 574 are wired in a star topology as a standard three-phase motor. The system controller provides a drive signal to pump phase coils 570, 572, and 574, which is a pulse width modulation (PWM) voltage. The PWM voltage creates a near-sinusoidal current that generates an electromagnetic field that acts on magnets on the impeller, causing the impeller to rotate and pump blood.

[0047] refer to Figure 6 SFOC Logic 610 is Figure 4 A suitable embodiment of the SFOC logic 440 shown is illustrated. The SFOC logic 610 includes... Figure 4 The pump motor speed setting 444 is shown and discussed above. The pump motor speed setting 444 is preferably set by a clinician via a clinician interface. The pump motor drive circuit 620 includes a digital motor current register 622 containing values ​​of the digital motor current, discussed in more detail below. The digital motor current values ​​in the digital motor current register 622 are processed by phase current processing logic 624. The result is a PWM for each phase of the blood pump motor. Therefore, for a three-phase blood pump motor, the digital current processing logic generates PWM1630, PWM2640, and PWM3650. These are pulse-width modulated signals that drive the motor driver integrated circuit 680. Each phase has a current sensor from which the current can be determined. Thus, phase 1 has a P1 current sensor 632; phase 2 has a P2 current sensor 642; and phase 3 has a P3 current sensor 652. In a preferred embodiment, the current sensors 632, 642, and 652 are series resistors such that the voltage across the current sensing resistors is proportional to the current supplied in each phase.

[0048] The digital motor current conversion circuit 660, under the control of the digital motor current measurement circuit 658, converts the sensed current into a motor current value. The voltage from each current sensing element needs to be amplified; therefore, three amplifiers 662, 664, and 666 amplify the voltages from their corresponding current sensing elements 632, 642, and 652. The amplified signals are input to an analog-to-digital converter (ADC), which, under the control of circuit 658, generates a digital motor current value 672. These digital motor current values ​​672 are written to the digital motor current register 622, thereby creating a closed-loop system for controlling the blood pump motor.

[0049] exist Figure 6In the specific embodiment shown, PWM signals 630, 640, and 650 do not have sufficient driving force to directly drive the pump phase coils. Therefore, they are input to the motor driver integrated circuit 680, which then generates a corresponding drive signal for the three-phase coils from each PWM signal. Thus, pump phase 1 drive circuit 682 drives pump phase 1 coil 570 in the blood pump 510; pump phase 2 drive circuit 684 drives pump phase 2 coil 572; and pump phase 3 drive circuit 686 drives pump phase 3 coil 574.

[0050] Figure 6 One specific implementation of the phase current processing logic 624 shown in Figure 7 The digital motor current value 672 is shown at 710. It undergoes a Park and Clarke transformation via Park and Clarke transformation logic 720, generating a magnetizing (DC) motor current 722 and a torque-generating (quadrature) motor current 724. A first proportional-integral (PI) controller 750 then compares the magnetizing (DC) motor current 722 with a reference DC current 732 to generate a DC error signal. In the most preferred embodiment, the reference DC current 732 has a zero value. Similarly, a second PI controller 752 compares the torque-generating (quadrature) motor current 724 with a reference quadrature current 734 to generate a quadrature error signal. The reference quadrature current 734 is preferably calculated based on a desired speed reference and the motor's physical parameters. These signals are then processed by inverse Park and Clarke transformation logic 770 and input to a space vector pulse width modulation (SVPWM) control block 780 to generate the magnetizing (DC) PWM duty cycle and the torque-generating (quadrature) PWM duty cycle. The SVPWM control block 780 calculates the average of the minimum and maximum values ​​of each phase voltage and calculates the resulting voltage offset, subtracting it from each instantaneous phase voltage. The output of the SVPWM control block 780 is three third harmonic injected phase voltages IPV1 782, IPV2 784, and IPV3 786. Phase voltages 782, 784, and 786 are input to a PWM signal generator 790, which inserts a dead time and supports either edge-aligned or center-aligned pulse width modulation. The PWM signal generator 790 generates three pulse width modulated signals PWM1 630, PWM2 640, and PWM3 650, which are then used to generate the drive signals for the blood pump motor phases, such as... Figure 6 As shown in the image.

[0051] Figure 8 It is shown that preferably it is made of Figure 7The phase current processing logic 710 shown in the figure executes method 800. The digital motor current value is read (step 810). Next, a Parker-Clark transform is performed on the digital motor current value to determine the magnetizing (DC) motor current and the torque-generating (quadrature) motor current (step 820). The magnetizing (DC) motor current is compared with a reference DC current using a proportional-integral controller PI1 to generate a DC error signal (step 830). The torque-generating (quadrature) motor current is compared with a reference quadrature current using a second PI controller PI2 to generate a quadrature error signal (step 840). The inverse Parker-Clark transform is used to generate the magnetizing (DC) PWM duty cycle and the torque-generating (quadrature) duty cycle (step 850). For each phase, the minimum and maximum values ​​of the phase voltage are averaged to generate a phase voltage offset (step 860). For each phase, the phase voltage offset is subtracted from the instantaneous phase voltage to generate the third harmonic injected phase voltage (step 870). For each phase, a PWM signal generator inserts a dead time and generates a PWM control signal from the injected phase voltage (step 880). Then, a PWM control signal is used to drive the blood pump motor (step 890). Then, method 800 is completed.

[0052] refer to Figure 9 Method 900 is preferably derived from Figure 4 The motor speed / angle estimator 442 in the system executes. The rotor position is calculated using the stator voltage vector and stator current vector (step 910). The stator voltage vector and stator current vector are then applied to the motor model to estimate the rotor position (step 920). The PI controller then uses the estimated rotor position to generate the speed output frequency (step 930). The speed output frequency is then displayed on the system controller display (step 940).

[0053] Figure 3 FPGA motor control 340 and Figure 4 One specific implementation of the FPGA architecture 430 in Figure 10 Figure 1000 shows the FPGA architecture 1000. The FPGA architecture 1000 includes a microcontroller interface 1010 that allows the control processor to write values ​​to registers in the FPGA architecture 1000. To understand the functionality of the circuit system in Figure 1000, some additional information about controlling the BLDC motor using field-oriented control (FOC) is described below.

[0054] A brushless direct current (BLDC) motor has a magnetized rotor and an energized stator to make the motor run. The rotor is the “rotating” part inside the motor core. In a preferred embodiment, the pump impeller itself is the actual physical rotor. Spinning the impeller pumps blood into the pump inlet and out through the axial flow outlet. The stator is the stationary “fixed” part of the BLDC motor. It consists of three (3) coils (phases), each coil wound in an orientation tangent to three points 120 degrees away from the outside of the motor. When the motor control system sends voltage signals (i.e., waveforms of varying voltages) through the stator coils, the varying currents generated in the phase coils by these varying voltages produce a varying magnetic field around the coils. Therefore, the magnetic field caused by the current flowing through the phase coils will have poles pointing along a line passing through the central axis of the motor.

[0055] Field-oriented control (FOC) algorithms measure phase currents and use these phase currents to measure and control phase voltages. FOC is a closed-loop system design.

[0056] The three phases of a BLDC motor are rotated 120 degrees relative to each other and evenly distributed around the circumference of the motor. Each individual coil generates a current and induces an associated magnetic field of a specific magnitude when energized by a varying voltage signal. This magnetic field is always perpendicularly aligned with the coil, with one pole (north or south) pointing towards the central axis of the motor core and the other pole directly away from that axis. This allows us to understand the three magnetic fields created in the three ABC phase coils from a geometric perspective.

[0057] The combined magnitude of the three magnetic forces (three magnetic field vectors) generated in each coil, along with their N-S directions (polarity), together form a magnetic field with a specific intensity (magnitude) and a specific north-south orientation (direction) within the motor core and interior. The magnetic field generated in the stator always traverses and passes through the motor's axis of rotation.

[0058] The rotor has at least one set of alternating NSNS… magnetic pole pairs on its circumference. The magnetic pole pairs on the rotor are oriented across the rotor's axis of rotation (north and south poles on opposite sides of the rotor). The rotor moves (rotates) because its magnetic pole pairs are attracted by the relative poles (N to S and S to N) of the rotating magnetic field generated by the coils in the stator.

[0059] The FOC control algorithm creates a magnetic field in the stator by sending rapidly changing voltage waveforms to the stator phase coils of the motor. The changing voltage waveforms cause alternating current to flow through the stator coil wires, generating a rapidly changing magnetic flux within the stator. Correct operation of the FOC algorithm involves energizing only two phases of the stator at any given time, with one phase coil having a positive voltage (and positive current) and the other, opposite phase, having a negative voltage (and negative current), thus always generating opposite north and south magnetic fluxes on opposite sides of the motor core. The rotor moves to align its pole pairs (NS) with the continuously rotating combination of magnetic fields generated in the energized stator coils. The FOC algorithm sends independent and precisely coordinated voltage waveforms through the stator coils, which generates a rotating magnetic field inside the motor, pointing across the motor core. This rotating magnetic field attracts the rotor poles and causes the rotor to spin with the rotating field.

[0060] The primary objective of the calculations performed by the FOC algorithm is always to align (and rotate) the combined magnetic fields of the stator to be perpendicular to the rotor's magnetic field. This alignment causes the stator (magnetic) field to pull one side of the rotor and push the other, thus rotating the rotor with maximum force. By design, the FOC algorithm sends energy into the stator coils to maximize the rotational force on the spinner. This rotational force is called torque. The FOC algorithm produces the maximum torque.

[0061] Field-oriented control is achieved by generating a series of very high-speed discrete control output voltages and simultaneously measuring discrete current samples at very high speed. Therefore, the waveform is a continuous signal generated and measured through a series of discrete control settings and measurements. FOC calculations involve back-and-forth conversions of current and voltage waveforms and transformations from a "fixed" reference frame to a "rotating" reference frame.

[0062] Proportional-integral (PI) closed-loop control uses feedback measurements of the PI controller output and the desired output value (called the PI controller reference) to match the PI controller output to the desired output value. The difference between the PI controller output and the PI controller reference is the PI controller error. A Field-Oriented Control (FOC) uses one or more closed-loop PI controllers in several parts of its operation.

[0063] refer to Figure 10 I d I q The PI control for the time scheduling of speed 1030 includes a speed PI controller 1032, which uses the estimated actual speed from the position and speed estimator 1026 and the reference speed from the rate limiter 1020 to output I. q Orthogonal current reference. Next, I q The PI controller 1034 uses this I q Reference, measured I q The output voltage is determined by the current and the physical parameters of the motor. qQuadrature voltage reference. Finally, I d DC PI controller 1034 uses I d Reference value zero and measured I d The output voltage is determined by the current and the physical parameters of the motor. d (DC voltage) reference.

[0064] v, as the voltage reference signal from the PI controller 1030 q and v d The signal is the input to FOC transform block 1040, specifically the input to the inverse Parker transform 1042, and the output of the inverse Parker transform 1042 is v. α and v β The phase voltages are rotated, and these voltages become the inputs of the Clarke inverse transformer 1044, which then outputs v. a v b and v c These are phase voltages in a fixed reference frame. Therefore, these transformations perform voltage waveform changes from the rotating reference frame v. q / v d To fixed system v a v b v c Geometric transformation.

[0065] exist Figure 7 In the middle, the proportional-integral controller 1 (PI1) 750 will convert the quadrature voltage v q The output is fed into the inverse Parker transform in logic 770. Also in... Figure 7 In the middle, the proportional-integral controller 2 (PI2) 752 will v d The (DC voltage) output is fed into the inverse Parker converter in logic 770.

[0066] The inverse Parker transformation in Logic 770 will rotate the phase vector voltage v α and v β The output is fed into the inverse Clarke transform in logic 770, which transforms the three phase voltage space vectors v a v b v c The output is directly fed to SVPWM block 780. The inverse Parker and inverse Clarke transform logic 770 essentially performs the mathematical operations involved to convert the desired quadrature voltage (speed) and DC voltage into the phase voltages required to generate the stator phase voltage waveform.

[0067] The Parker and Clark transform logic 720 first represents I in coordinates of a fixed reference frame and measures it from three physically positioned coils in the stator. a I b I c The phase current waveform is converted into two rotating phase currents I α and Iβ ,from Figure 10 The output of the Clarke transform block 1046.

[0068] Then in Parker transformation block 1048, the rotating phase current I... α and I β The measured (or actual) value I is converted into the coordinates seen in the rotated coordinate system. q (Actual orthogonal current) and I d (Actual DC current) waveform. I q (Orthogonal) and I d (DC) current is represented in a rotating coordinate system as the phase current I in a fixed reference system. a I b I c The same current.

[0069] As discussed, Figure 7 Logic 720 and Figure 10 The Clarke transform outputs the rotating phase current I in 1048. α and I β ,and Figure 7 Logic 770 and Figure 10 The inverse Parker transform outputs the rotating phase voltage v. α and v β The rotating phase voltage and rotating phase current are used by the position and speed estimator 2026 in a “closed loop” to generate a feedback value of the actual (estimated) speed, which is fed back to the speed Pi controller 1032 and the rotor position angle output, which is the input to the Parker 1048 and the inverse Parker 1042 transform.

[0070] Sensorless Field-Oriented Control (SFOC) is a processing loop that takes a single-sample current measurement from all motor stator phases, generates a single-sample output value that alters the voltage waveform in those same phases, and then loops back to operate on another sample. When rotor speeds reach thousands and tens of thousands of RPMs, the loop speed and sampling rate need to be extremely fast. Implementing the SFOC algorithm in an FPGA is the only way to achieve this, where the clock that times the loop operation is very fast and very stable. While a microprocessor may have the computational power to perform mathematical operations, the processor clock and interrupt structure cannot provide stable, uniformly timed operations for loop control, especially at very high speeds. Dedicated FPGA logic can also perform mathematical operations much faster than a microcontroller can.

[0071] The system controller identifies two different event classes that can be detected. The first is a warning, which is considered a medium-priority event requiring notification to the user. The second is an alert, which is considered a high-priority event requiring notification to the user and immediate remedial action. (See below for reference.) Figure 11 and 12 Discussion and warnings, for reference Figure 13 and 14 Discuss the alarm.

[0072] refer to Figure 11 Method 1100 is preferably executed by the alert manager 474 in the control processor 470, such as Figure 4 As shown in the diagram. Monitor the alert conditions (step 1110). As long as no alert condition triggers an alert (step 1120 = No), method 1100 loops back to step 1110 and continues. Once an alert condition triggers an alert (step 1120 = Yes), a slow audible alert sound is activated, one or more slowly flashing yellow LEDs are activated, a soft tactile indication such as a slight vibration is provided, and an alert is displayed on the monitor (step 1130). If the user presses a mute button (step 1140 = Yes), which is one of the input keys 170, then the audio alert sound is muted and the soft tactile indication is disabled for a first preset time period, such as 15 minutes (step 1150). If the alert continues for more than a second preset time period, such as 20 minutes (step 1160 = Yes), then a "Call for Help" message is displayed (step 1170). Method 1100 then returns to step 1110 and continues.

[0073] like Figure 4 As shown, the control processor 470 includes an alert manager 474 and an alarm manager 476. Note that the functions of these two can be combined. However, experience shows that alerts (medium-priority events) need to be treated differently than alarms, which are considered high-priority events. When all events are treated as high-priority alarms, this can lead to unnecessary or even life-threatening actions, which are unnecessary for medium-priority events. Therefore, the controllers disclosed and claimed herein distinguish between medium-priority events, referred to herein as "alerts," and high-priority events, referred to herein as "alarms."

[0074] Figure 12 Table 1200 shows a list of multiple alerts that can be detected and acted upon. Each row in Table 1200 defines an alert based on defined alert conditions, the entity for detection conditions, and a notification message provided on the display as a result of a detected alert. Figure 12In the "Detector" column, most alerts include the CP, as most alerts can be detected by the CP. For alerts that can be detected independently of the CP by the monitoring processor (SP), the SP is included. The following alerts are detected by the CP: Pump Low Flow Alert 1210, displaying a "Pump Low Flow" message; Pump Power Overcurrent Alert 1212, displaying a "Pump Power High" message; Pump Power High Alert 1214, displaying a "Pump Power High" message; Pump Low Alert 1216, displaying a "Pump Power Low" message; Pump Low Speed ​​Alert 1218, displaying a "Pump Speed ​​Low" message; Pump Speed ​​Error Alert 1220, displaying a "Pump Speed ​​Error" message; System Overtemperature Alert 1222, displaying a "System Failure" message; Backup Battery Failure Alert 1224, displaying a "System Failure" message. The following warnings are triggered: CP detects "Backup Battery Low" warning 1226 and displays "Backup Battery Low" message. CP detects "Backup Battery Discharge" warning 1228 and displays "Backup" message. CP detects "Primary Battery Low" warning 1230 and displays "Battery Low" message. CP detects "Primary Battery Very Low" warning 1232 and displays "Battery Very Low" message. CP detects "Primary Battery Critical" warning 1234 and displays "Battery Critical" message. SP detects "Control Processor or FPGA Fault" warning 1236 and displays "System Fault" message. CP detects "DC Input Difference" warning 1238 and displays "System Fault" message. SP detects "Software Fault" warning 1240 and displays "System Fault" message. CP detects "Mute Button Stuck" warning 1242 and displays "System Fault" message. CP detects "Next Button Stuck" warning 1246 and displays "System Fault" message. The CP detected "Alert Test" warning 1248 and displayed the "Alert Test" message. Figure 12 The warnings shown, as well as any other suitable warnings, are within the scope of the disclosure and claims herein.

[0075] By definition, alerts are less severe than alarms. Therefore, for alerts where clinicians need more immediate information, patients should only see / hear / feel medium-priority notifications. For all these alerts, patients can also be instructed to call the clinic for help. For example, the "Call for Help" instruction can be indicated by a glowing telephone icon on the front of the controller and a "Call for Help" message on the controller display. The alert message contains an alert number that the patient can read to clinicians when calling for help. Even alerts that do not require notification to a clinician are logged.

[0076] Figure 12The specific warnings shown are merely illustrative. Other warning conditions can be detected within the scope of this disclosure and the claims, resulting in corresponding notifications. Furthermore, although... Figure 12 Most alerts are shown as being detected only by the CP, but in alternative implementations, the Service Processor (SP) can also monitor many alert conditions detected by the CP and can provide alert notifications independently of the CP. This is particularly useful in the event of a CP failure.

[0077] See Figure 13 Method 1300 is preferably executed by the alarm manager 476 in the control processor 470, such as Figure 4 As shown in the diagram. Monitor alarm conditions (step 1310). As long as no alarm condition triggers the alarm (step 1320 = No), method 1300 loops back to step 1310 and continues. Once the alarm condition triggers the alarm (step 1320 = Yes), a loud and rapid audible alarm sound is activated, one or more rapidly flashing red LEDs are activated, a strong tactile indication (such as a violent vibration) is provided, and the alarm is displayed on the monitor (step 1330). If the user presses the mute button (step 1340 = Yes), this has no effect (step 1350), because the alert can be muted by the user for a predefined period of time, but the alarm cannot. If the alarm continues for more than a third preset period of time, such as five minutes (step 1360 = Yes), then a "Call for Help" message is displayed (step 1370). Method 1300 then loops back to step 1310 and continues.

[0078] Figure 14Table 1400 shows a list of alarms that can be detected and acted upon. Each row in Table 1400 defines an alarm based on defined alarm conditions, the entity that can detect the conditions, and a notification written to the display as a result of the detected alarm. The "Pump Stop" alarm 1410 is detected by the CP and SP, and a "Pump Stop" notification is displayed. The pump can stop for a variety of reasons, including: the pump drive system is disconnected, damaged, pulled out, or otherwise damaged; the FPGA motor control can no longer make the pump motor spin; the controller is powered off; the only power supply is a depleted internal backup battery, which can no longer provide sufficient current to operate the pump; the pump is blocked by a blood clot; or the pump motor itself is malfunctioning or otherwise damaged. The "Pump Disconnect" alarm 1412 is detected by the CP, and a "Pump Disconnect" message is displayed. The "Pump Restart Failure" alarm 1414 is detected by the CP, and a "Pump Restart Failure" message is displayed. The "No Battery" alarm 1416 is detected by the CP, and a "No Battery" message is displayed. The "Emergency Alarm Test" alarm 1418 is detected by the CP, and an "Alarm Test" message is displayed. The CP detects the "Alarm Test" alarm 1420 and displays the "Alarm Test" message. The SP detects the "Power Supply Failure" alarm 1422 and displays the "Emergency Alarm" message. In a suitable implementation, the SP monitors and controls the regulated power supply in the system, and if any regulated power supply fails to provide voltage within a specified range, the SP can detect this condition and provide an emergency alarm in response to detecting this power supply failure. Figure 14 The alarms shown, as well as any other suitable alarms, are within the scope of the disclosure and claims herein. Furthermore, in alternative embodiments, Figure 14 Many alerts detected by CP can also be detected by SP.

[0079] Alarm and warning messages output to the display have a simple format: an alarm or warning label with a numerical identifier, followed by simple instructions on how to correct the condition (if possible), and potentially one or two additional instructions such as "Call for help" or "Replace controller".

[0080] Sometimes multiple warnings and / or alarms may occur simultaneously. The control processor 470 preferably executes... Figure 15 Method 1500. If no multiple alerts and / or alarms occur simultaneously (step 1510 = No), method 1500 completes. If multiple alerts and / or alarms occur simultaneously (step 1510 = Yes), the alerts and alarms are scrolled continuously on the display from highest priority to lowest priority (step 1520). By scrolling multiple alerts / alarms on the display, the user can easily view all pending alerts and alarms as messages scroll across the display. Then method 1500 completes.

[0081] Although Figure 4 The alert manager 474 and alarm manager 476 shown are separate entities, but the functions of both can be provided by software in the control processor.

[0082] Figure 16 A method 1600 for a clinician to program a blood pump is illustrated. The clinician connects a clinician interface computer to a clinician interface on the controller (step 1610). The clinician interface computer can be any suitable computing device, including but not limited to a desktop computer, laptop computer, tablet computer, or smartphone. The clinician invokes the GUI in the clinician interface and uses the GUI to set the pump motor speed (step 1620). The clinician can also define or select warning and alarm conditions (step 1630), such as thresholds for one or more warning or alarm conditions. Method 1600 is then completed.

[0083] As referenced above Figure 3 As discussed, the presence of the monitoring processor 320 allows for monitoring the health status of the control processor 330 and the FPGA motor control 340. Figure 17 Method 1700 is preferably derived from Figure 3 The monitoring processor 320 shown executes the following steps: The monitoring processor monitors the control processor and the SFOC core in the FPGA (step 1710). When there is a difference between the pump motor speed setting and the reported pump speed (step 1720 = Yes), an alert or alarm is triggered (step 1730). When there is no difference in step 1720 (step 1720 = No) but there is a delayed report from the control processor (step 1740 = Yes), an alert or alarm is triggered (step 1730). Method 1700 then loops back to step 1710 and continues. From method 1700, we see that the monitoring processor has the ability to detect problems with the control processor and the SFOC core in the FPGA, thus providing an additional layer of protection if one or both of the control process and / or the SFOC core cease to function properly. In some cases, if the system controller does indeed fail to operate properly, the triggered alarm will be an immediate replacement of the system controller.

[0084] As referenced above Figure 2 The system controller 210 discussed operates according to the defined power hierarchy. Figure 4 The system controller 470 in the diagram shows a power manager 478 that manages power from three sources: the primary battery, the AC / DC power adapter, and the backup battery. Figure 18 Table 1800 shows Figure 4The power manager 478 can use a suitable power hierarchy, defined from highest to lowest priority. Therefore, the AC / DC power adapter 1810 has the highest priority, meaning that the power manager 478 will use the AC / DC power adapter's power when it is available. The primary battery 1820 has the next highest priority, meaning that the power manager 478 will use the primary battery's power when the AC / DC power adapter is unavailable (this could be due to the AC / DC power adapter being unplugged from the system controller or due to a power outage). The backup battery 1830 within the system controller housing has the lowest priority. Therefore, the power manager 478 will only use the backup battery's power when neither the AC / DC power adapter nor the primary battery is available. The backup battery is designed for use only during the very short period between switching to the primary battery, therefore it does not have sufficient capacity to operate the system controller and blood pump for any extended period. The backup battery is designed to operate the blood pump for 30 minutes under normal conditions, meaning it is sufficient for the typical one or two minutes required by the user to switch to the primary battery pack.

[0085] Figure 19 Method 1900 is preferably derived from Figure 4 The power manager 478 executes. When the AC / DC power adapter provides power, the power from the AC / DC power adapter is used (step 1910). When the AC power adapter does not provide power, the power from the primary battery is used (step 1920). When neither the AC / DC power adapter nor the primary battery provides power, the power from the backup battery is used (step 1930). Then, method 1900 loops back to step 1910 and continues.

[0086] Although Power Manager 478 is in Figure 4 The functions of the power manager 478 are shown as being provided by the control processor 470, but in a preferred embodiment, the functions of the power manager 478 are performed by a separate power management integrated circuit that transmits the power status to the control processor.

[0087] Figure 20Method 2000 illustrates different operating modes of the system controller and blood pump. For tethered operation, where the user will remain in a location near a power outlet for a period of time, the user can plug in the AC / DC power adapter (step 2010). For untethered operation, where the user is not in a location near a power outlet, the primary battery is attached, and then the AC / DC power adapter is unplugged (step 2020). Because the system controller can be used for untethered operation, the system controller is a wearable device, where size, weight, and temperature are considerations for wearability. To replace the primary battery in the untethered state, the attached primary battery is removed and replaced by attaching a different primary battery (step 2030). To charge the primary battery not attached to the system controller, the primary battery is connected to a desktop battery charger (step 2040). In a preferred embodiment, the mechanical and electrical connection between the primary battery and the desktop battery charger is exactly the same as the mechanical and electrical connection between the primary battery and the system controller. This allows the user to disconnect and connect the primary battery to the desktop battery charger using the same actions a user would use to disconnect and connect the primary battery to the system controller.

[0088] like Figure 21 As shown, Figure 4 The power manager 478 shown preferably includes a backup battery charger 2100 for charging the backup battery 150. The backup battery charger 2100 is preferably configured according to... Figure 22 Method 2200 operates as follows: When power is available from the AC / DC power adapter (step 2210 = Yes), the backup battery is charged (step 2220). When power is not available from the AC / DC power adapter (step 2210 = No), but the backup battery capacity is less than the backup battery minimum threshold RBMT and the primary battery capacity is greater than the primary battery minimum threshold PBMT (step 2230 = Yes), the backup battery is charged (step 2240). Otherwise (step 2230 = No), the backup battery is not charged, and method 2200 loops back to step 2210. Once the backup battery has been charged in steps 2220 or 2240, charging may stop if any of the following conditions listed in step 2250 are met: 1) the charging current of the backup battery reaches the minimum charging taper current allowed under the charger voltage; or 2) the backup battery temperature exceeds the limit; or 3) the multi-hour charging timer expires; or 4) other error conditions. Therefore, the backup battery charger attempts to keep the backup battery fully charged so that it can meet the power needs of the AC / DC power adapter and the primary battery during short-term power interruptions.

[0089] The blood pump system comprises a blood pump and a corresponding controller. The blood pump includes an impeller sealed within a pump housing and hydrodynamically suspended within the housing. The pump impeller includes a magnet and is the rotor of a brushless direct current (DC) motor driven by an electrical signal passing through stator coils in the pump housing, creating a rotating magnetic field. This rotating magnetic field attracts the magnetized impeller and causes it to spin with the rotating field. The controller provides field-oriented control for the brushless DC motor in the blood pump. This field-oriented control is provided in a programmable logic device separate from the control processor, so software or hardware failures associated with the control processor will not stop the blood pump. Field-oriented control allows sensing of blood flow through the pump without the need for sensors within the blood flow itself.

[0090] The disclosure and claims herein support a system controller for driving a blood pump, the blood pump including an impeller sealed within a pump housing and hydrodynamically suspended within the pump housing, wherein the impeller includes a plurality of magnets, and the blood pump includes a plurality of stator coils in a brushless direct current (DC) motor, the impeller rotating within the pump housing when the plurality of stator coils are driven by a plurality of drive signals, wherein the system controller includes: an electrical connector for electrically connecting the system controller to the blood pump to provide a plurality of drive signals from the system controller to the plurality of stator coils in the brushless DC motor in the blood pump; a display; a control processor for providing management functions to the system controller and displaying at least one message on the display; and a programmable logic device that provides field-oriented control of the brushless DC motor in the blood pump by providing a plurality of drive signals to the plurality of stator coils in the brushless DC motor in the blood pump via the electrical connector, wherein the programmable logic device operates independently of the operation of the control processor.

[0091] The disclosure and claims of this document also support a system controller for driving a blood pump, the blood pump including an impeller sealed within a pump housing and hydrodynamically suspended within the pump housing, wherein the impeller includes a plurality of magnets, and the blood pump includes a plurality of stator coils in a brushless DC motor, the impeller rotating within the pump housing when the plurality of stator coils are driven by a plurality of drive signals, wherein the system controller includes: an electrical connector for electrically connecting the system controller to the blood pump to provide the plurality of drive signals from the system controller to the plurality of stator coils in the brushless DC motor in the blood pump; a display; at least one input key for a user of the system controller; at least one visual indicator for a user; at least one audio device for signaling to the user warning or alarm conditions; and a backup battery inside the housing of the system controller, which provides power when the external primary battery fails to supply power to the system controller. The backup battery provides power when the system controller is powered and when the external AC / DC adapter does not provide power to the system controller; a clinician interface that provides a graphical user interface allowing medical clinicians to use a clinician computer coupled to the clinician interface to set the speed of the blood pump and define or select at least one warning or alarm condition in the system controller; a control processor that provides management functions for the system controller, displays at least one message on a display, and activates at least one of a visual indicator and at least one audio device to signal warning or alarm conditions; and a programmable logic device that provides field-oriented control of the brushless DC motor in the blood pump by providing multiple drive signals to multiple stator coils in the brushless DC motor in the blood pump via electrical connectors, wherein the programmable logic device operates independently of the operation of the control processor.

[0092] The disclosure and claims herein additionally support a blood pump system comprising: (A) a blood pump including: an impeller sealed within a pump housing and hydrodynamically suspended within the pump housing, wherein the impeller includes a plurality of magnets; a plurality of stator coils in a brushless DC motor that, when driven by a plurality of drive signals, causes the impeller to rotate within the pump housing; and (B) a system controller electrically coupled to the blood pump, providing a plurality of drive signals to the plurality of stator coils in the brushless DC motor of the blood pump, the system controller including: a display; a control processor that provides management functions for the system controller and displays at least one message on the display; and a programmable logic device that provides field-oriented control of the brushless DC motor in the blood pump by providing the plurality of drive signals to the plurality of stator coils in the brushless DC motor of the blood pump independently of the operation of the control processor.

[0093] Those skilled in the art will recognize that many variations are possible within the scope of the claims. Therefore, while this disclosure has been specifically shown and described above, those skilled in the art will understand that these and other changes in form and detail may be made therein without departing from the spirit and scope of the claims.

Claims

1. A system controller for driving a blood pump, the blood pump including an impeller sealed within a pump housing and hydrodynamically suspended within the pump housing, wherein the impeller includes a plurality of magnets, and the blood pump includes a plurality of stator coils in a brushless direct current (DC) motor, the plurality of stator coils causing the impeller to rotate within the pump housing when driven by a plurality of drive signals, wherein the system controller includes: An electrical connector for electrically connecting a system controller to a blood pump to provide the plurality of drive signals from the system controller to the plurality of stator coils in a brushless DC motor in the blood pump; monitor; A control processor that provides management functions to the system controller and displays at least one message on a display. as well as A programmable logic device that provides field orientation control of a brushless DC motor in a blood pump by providing the plurality of drive signals to the plurality of stator coils in the brushless DC motor in the blood pump via an electrical connector, wherein the programmable logic device is configured to continue providing the plurality of drive signals when a control processor ceases to operate.

2. The system controller as described in claim 1 further includes a backup battery inside the system controller.

3. The system controller of claim 2, further comprising a power manager that selects a power source for powering the system controller according to a defined power hierarchy, wherein the power source is selected from: power from an AC / DC adapter coupled to a first external connector on the system controller; power from a primary battery coupled to a second external connector on the system controller; and power from a backup battery inside the system controller.

4. The system controller of claim 1, wherein the programmable logic device includes a field-programmable gate array (FPGA).

5. The system controller of claim 1, wherein the control processor and programmable logic device are implemented in a system-on-a-chip (SoC).

6. The system controller as claimed in claim 1, further comprising: At least one input key for the user of the system controller; At least one visual indicator for the user; as well as At least one audio device used to signal a warning or alarm condition to a user.

7. The system controller of claim 1, further comprising a clinician interface that provides a graphical user interface allowing a medical clinician to use a clinician computer coupled to the clinician interface to set the speed of the blood pump and define or select at least one warning or alarm condition in the system controller.

8. The system controller of claim 1, further comprising a monitoring processor coupled to the control processor and the programmable logic device, wherein the monitoring processor monitors the functionality of the control processor and the programmable logic device according to at least one monitored parameter, and provides a warning or alarm signal when the at least one monitored parameter indicates a warning or alarm condition.

9. The system controller of claim 1 further includes an alert manager that allows defining or selecting a plurality of alerts and corresponding alert notifications, detecting when one of the plurality of alerts is triggered, and providing at least one notification corresponding to the triggered alert.

10. The system controller of claim 1, further comprising an alarm manager that allows defining or selecting a plurality of alarms and corresponding alarm notifications, detecting when one of the plurality of alarms is triggered, and providing at least one notification corresponding to the triggered alarm.

11. The system controller of claim 1, further comprising a motor driver integrated circuit that receives a pulse width modulation drive signal from a programmable logic device and generates the plurality of drive signals to the plurality of stator coils in the brushless DC motor of the blood pump.

12. The system controller of claim 1, further comprising a digital motor current conversion circuit that receives current sensed in each of the plurality of drive signals sent to the blood pump and generates a digital motor current value fed back to the programmable logic device therefrom.

13. The system controller of claim 12, wherein field-oriented control performs Park and Clark transformations on digital motor current values ​​to determine magnetized DC motor current and torque-generated quadrature motor current, compares the magnetized DC motor current with a reference DC current using a first proportional-integral controller to generate a DC voltage signal, compares the torque-generated quadrature motor current with a reference quadrature current proportional to a desired motor speed signal using a second proportional-integral controller to generate a quadrature voltage signal, performs an inverse Park transformation on the DC voltage signal and the quadrature voltage signal to generate two rotating phase voltage signals, then performs an inverse Clark transformation on the two rotating phase voltage signals to generate pulse width modulation duty cycle signals in phase space, and generates multiple pulse width modulation signals used to drive the plurality of stator coils using a space vector modulation control block.

14. A system controller for driving a blood pump, the blood pump including an impeller sealed within a pump housing and hydrodynamically suspended within the pump housing, wherein the impeller includes a plurality of magnets, and the blood pump includes a plurality of stator coils in a brushless DC motor, the plurality of stator coils causing the impeller to rotate within the pump housing when driven by a plurality of drive signals, wherein the system controller includes: An electrical connector for electrically connecting a system controller to a blood pump to provide the plurality of drive signals from the system controller to the plurality of stator coils in a brushless DC motor in the blood pump; monitor; At least one input key for the user of the system controller; At least one visual indicator for the user; At least one audio device used to signal a user to a warning or alarm condition; The backup battery inside the system controller housing provides power when the external primary battery does not supply power to the system controller and when the external AC / DC adapter does not supply power to the system controller. A clinician interface that provides a graphical user interface that allows medical clinicians to use a clinician computer coupled to the clinician interface to set the speed of the blood pump and define or select at least one warning or alarm condition in the system controller; A control processor that provides management functions to the system controller, displays at least one message on a display, and activates at least one of a visual indicator and the at least one audio device to signal a warning or alarm condition. as well as A programmable logic device that provides field orientation control of a brushless DC motor in a blood pump by providing the plurality of drive signals to the plurality of stator coils in the brushless DC motor in the blood pump via an electrical connector, wherein the programmable logic device is configured to continue providing the plurality of drive signals when a control processor ceases to operate.

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