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 hydrodynamically 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 an electrical signal through a stator coil in the pump housing, thereby creating a rotating magnetic field. The rotating magnetic field attracts the magnetized impeller and causes it to spin with the rotating field. A controller provides field-oriented control for the brushless DC motor in the blood pump. Field-oriented control in the controller is provided in a programmable logic device separate from the control processor, so software or hardware failure associated with the control processor does not stop the blood pump. The field-oriented control allows for sensing blood flow through the pump without having a sensor in the blood flow.

Description

Technical Field

[0001] The present disclosure relates generally to blood pumps, and more particularly to blood pump controllers and systems. Background Art

[0002] Medical blood pumps increase blood flow for patients who have insufficient blood flow to their hearts. A ventricular assist device (VAD) is a specific type of implantable blood pump. The VAD is placed in parallel with the left or right ventricle of a patient who is unable to provide the required blood flow. Known blood pumps use several different pump types and motor configurations and 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 that is directly in line with the impeller to drive an axial flow pump to pump 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 suspended in a hydrodynamic manner within the pump housing. The impeller itself becomes the magnetized rotor portion of the motor. The motor stator coils that receive electrical signals to create a rotating magnetic field to rotate the rotor are built directly into the pump housing. The entire stator becomes part of the pump fluid body itself. Some blood pumps include sensors in the blood stream to sense pressure and flow. Other blood pumps use various methods to estimate the pressure and / or discharge flow of the pump to avoid placing the sensor in the blood stream because blood clots may form around the sensor.

[0003] Known devices and methods for blood pumps and controllers do not provide accurate speed control of the pump, or do not allow direct blood flow sensing without sensors in the blood flow, and have other disadvantages, for example, some mechanical pump designs more significantly impair blood flow through the pump. Many controllers estimate specific parameters, such as pressure or flow rate. These estimates are a source of potential errors in providing appropriate treatment to the patient (i.e., appropriate control of the blood pump). Some faults in the pump controller can stop the blood pump, 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 that is sealed within a pump housing and suspended in a hydrodynamic manner within the pump housing. The pump impeller includes a magnet and is the rotor of a brushless direct current (DC) motor that is driven by an electrical signal through a stator coil 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. 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 associated with 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.

[0005] The foregoing and other features and advantages will be apparent from the following more particular description, as illustrated in the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0006] The present disclosure will be described in conjunction with the accompanying drawings, wherein like numerals represent like elements, and:

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

[0008] Figure 2 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 the preferred embodiment are shown;

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

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

[0012] Figure 6 is a block diagram showing how the stator coils are driven by a system controller that provides an estimate of blood flow through a blood pump;

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

[0014] Figure 8 is a flow chart of one suitable method for generating a drive signal for a blood pump motor;

[0015] Fig. 9 is a flow chart of a method for determining the speed of a blood pump motor;

[0016] Fig.10 yes Figure 3 A block diagram of one specific implementation of FPGA motor control within a system controller shown in , which provides field-oriented control for a blood pump motor;

[0017] Fig.11 is a flow chart of a method for a system controller to monitor and process an alert;

[0018] Fig.12 is a table showing alert conditions and corresponding notifications;

[0019] Fig.13 is a flow chart of a method for a system controller to monitor and process an alarm;

[0020] Fig.14 is a table showing alarm conditions and corresponding notifications;

[0021] Fig.15 is a flow chart of a method for displaying multiple alarms and / or alerts that are simultaneously active on a system controller display;

[0022] Fig.16 is a flow chart of a method by which a clinician programs a system controller for a specific patient;

[0023] Fig.17 is a flow chart of a method for monitoring a processor to trigger an alarm when an error occurs in an FPGA motor controller or a system controller;

[0024] Fig.18 is a block diagram of a hierarchy used by a power controller within a system controller to determine which power supply will power the system controller;

[0025] Fig.19 The system controller is based on Fig.18 A flowchart of a method for determining which power source to use in a power hierarchy;

[0026] Fig. 20 is a flow chart illustrating various methods of using a system controller by a patient;

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

[0028] Fig. 22 yes Fig.21 A flowchart of a method for charging a backup battery by a backup battery charger in FIG. DETAILED DESCRIPTION

[0029] A blood pump system includes a blood pump and a corresponding controller. The blood pump includes an impeller that is sealed within a pump housing and suspended in a fluid-dynamic manner within the pump housing. The pump impeller includes a magnet and is the rotor of a brushless direct current (DC) motor that is driven by an electrical signal through a stator coil 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. 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 associated with the control processor will 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.

[0030] refer to Figure 1, a blood pump system 100 including a blood pump 110, a cable 124, and a system controller 130 is shown. The blood pump 110 can 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 suspended in a fluid-dynamic manner within the pump housing. The impeller includes a plurality of magnets, and the blood pump has a plurality of stator coils in a brushless DC motor that rotates the impeller within the pump housing when driven by a plurality of drive signals.

[0031] The blood pump 110 includes a connector 120 that receives a mating connector 122 on a cable 124. Applicants have developed medical connectors suitable for use with implanted 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 a particular embodiment, the cable 124 is a percutaneous cable connected to the blood pump 110 implanted in the patient, the percutaneous cable passes through the skin, and is connected 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 so that the system controller 130 can provide drive signals to the stator coils in the brushless DC motor in the blood pump 110.

[0032] like Figure 1As shown in , 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 operate the blood pump 110 at a desired speed. The backup battery 150 is inside the housing for the system controller 130 and provides power when an external power source (such as a primary battery or an AC / DC adapter) is not plugged into the system controller 130 or does not provide 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. The input keys may include, for example, a mute key that mutes an audio device when the audio device indicates an alert, and a "next" key that allows advancement from the current screen to the next screen in a multi-screen message. The LED 180 is used to provide a visual indication of an alert or alarm detected by the system controller 130. For example, the LED(s) 180 may provide a slow yellow flashing signal in the case of an alert and may provide a fast red flashing signal in the case of an alarm. The audio device(s) 190 are used to provide an audio indication of an alert or alarm detected by the system controller 130. For example, the audio device(s) 190 may provide a slow, soft beeping sound in the case of an alert and may provide a fast, loud beeping sound in the case of an alarm.

[0033] The blood pump system disclosed and claimed herein may also include other components, such as Figure 2 As shown in system 200. Figure 2 The system controller 210 is Figure 1 A suitable example of a system controller 130 in FIG. 1 , and a blood pump 260 is Figure 110. 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. The medical clinician 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 a blood pump 260. The system controller 210 is located outside the human body and can be connected to a suitable connector 264, which is connected to a percutaneous cable 262 to connect to the implantable blood pump 260. Of course, the blood pump 260 can also be located outside the human body, with a percutaneous tube connected to a blood vessel inside the human body. Note that the connector 264 can be used to insert an extension cable that allows the system controller to be farther away from the patient. For example, this will be helpful if the patient needs to undergo surgery.

[0034] The system controller 210 also includes an interface with a 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 housing of the system controller so that when the primary battery 250 needs to be recharged, the primary battery 250 can be removed from the system controller and connected to a desktop battery charger 270.

[0035] The system controller 210 uses the power hierarchy to determine which power source to apply to run the system controller 210. When the AC / DC power adapter 240 is plugged into a regional AC power source and plugged into the system controller 210, the AC / DC power adapter 240 provides power to the system controller 210. When the primary battery 250 is plugged into the system controller 210 and the AC / DC power adapter 240 is not plugged into the system controller 210, or is plugged into the system controller 210 but does not provide power (such as during a power outage), the primary battery 250 provides power to the system controller 210. When neither the AC / DC power adapter 240 nor the primary battery 250 provides power to the system controller 210, the system controller is powered by the backup battery 150. This configuration provides safety and convenience. When a patient connected to a blood pump will stay in one place for a period of time, the patient can use the system controller 210 in a tethered mode and plug the AC / DC power adapter into a wall outlet and plug into the system controller 210, so as not to drain the primary battery 250 or the backup battery 150. When the patient no longer wishes to be tethered to the AC / DC power adapter 240, the patient can unplug the AC / DC power adapter 240 so that the patient can use the system controller 210 in an untethered mode, wherein the relatively large primary battery 250 can provide power to the system controller 210 for several hours before needing to be recharged. When the primary battery 250 is nearly discharged and needs to be recharged, the patient can disconnect the primary battery 250 from the system controller 210 and connect a different primary battery to the system controller 210. When the primary battery 250 is disconnected, the system controller 210 is powered by the backup battery 150. Thus, 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. In normal use, the system controller 210 is powered by the backup battery only for the short time required for the user to disconnect the discharged primary battery and replace it with a charged primary battery. 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. Primary batteries (such as Figure 2 The primary cells 250, 250A and 250B) in the embodiment are preferably rechargeable lithium-ion cells.

[0036] Desktop battery charger 270 receives power from AC / DC power adapter 290 that is coupled to regional AC power. Desktop battery charger 270 can charge multiple primary batteries at a time. Figure 2In the specific example in FIG. 2 , the desktop battery charger 270 can charge two primary batteries 250A and 250B at the same time. 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 latch 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 an identical or similar latch 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, and the user can be accustomed to connecting and disconnecting the primary battery on the system controller, and the same method and process can be used to connect and disconnect the primary battery to the desktop battery charger. The desktop battery charger 270 can charge the primary battery using any suitable charging method. In a preferred embodiment, the desktop battery charger 270 can recharge the primary battery in approximately three hours.

[0037] refer to Figure 3 , the system controller 310 is Figure 1 The system controller 130 and Figure 2 A suitable embodiment of the system controller 210 is shown in FIG. 310. The system controller 310 includes a backup battery 150 located inside the housing of the system controller, as described above with reference to FIG. Figure 1 The system controller 130 and Figure 2 As described in the system controller 210 in FIG. Figure 1 The controller logic 140 in may include the following: Figure 3 The monitoring processor 320, control processor 330 and programmable logic device shown in FIG. 3 provide motor control, such as FPGA motor control 340. The functions of the system controller are divided into Figure 3The three blocks 320, 330, and 340 shown in FIG. 3 provide significant advantages. First, the control processor 330 is a microcontroller that provides the required management functions for the system controller 310, including monitoring of alerts and alarms, output to a display, receiving input from a user via input keys 170, performing power switching between power supplies, etc. The FPGA motor control 340 is a field programmable gate array (FPGA) that has been programmed to provide sensorless field oriented control (SFOC) of a brushless DC motor in a blood pump. By dedicating control of the blood pump to the FPGA motor control 340, the blood pump will continue to operate and be controlled by the FPGA motor control 340 even if the control processor 330 stops working. Therefore, even if the control processor 330 stops normal operation, the FPGA motor control 340 will continue to operate and control the blood pump because the FPGA motor controller is implemented in hardware that does not rely on the function of the control processor 330 to operate normally. In addition, the FPGA motor control 340 operates according to an electronic clock, rather than using software that can have variable timing. Thus, the FPGA motor control 340 can control very high speed motors that are difficult to control via a processor running software. The FPGA motor control 340 is also a dedicated single function circuit with no extraneous or other features that could cause it to fail. In addition, the FPGA can have room for expansion to add other dedicated hardware functions to the system controller, such as: a Medical Implant Communication Service (MICS) interface or a Bluetooth communication interface from and with the implanted controller for external parameter programming; an interface to a micro-electromechanical system (MEMS) pressure sensor circuit for flow measurement; and an interface for a transcutaneous battery charging system.

[0038] While sensorless field oriented control (SFOC) of brushless DC motors is well known, this approach has not been used for blood pumps. SFOC offers a number of advantages over known blood pump technologies. Blood pumps need to run at relatively high speeds of thousands or tens of thousands of RPM, with variations of no more than 100 RPM. SFOC allows for more precise motor control because it provides the exact position (rotor angle) for the spinning rotor (or impeller). In contrast to known drive systems for 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 essential difference that SFOC provides in controlling brushless DC (BLDC) motors versus other motor drive mechanisms. For induction motors or motors that run with other open-loop controls such as trapezoidal or sinusoidal drives, the rotor position and speed are unknown. For an open-loop system, the actual speed of the rotor (impeller) is only an estimate. For SFOC, the speed can be measured.

[0039] SFOC also improves power usage efficiency, resulting in reduced power consumption compared to trapezoidal drive or sinusoidal drive methods for the same motor design. This is because the SFOC algorithm optimizes the pump motor torque. The energy sent to the phase coils of the stator creates a magnetic field that is always in the exact position to spin the rotor with maximum force. Since the magnetic field in the phase coils driving the rotor is not in a precise position relative to the permanent magnetic field of the rotor, minimal energy is wasted. Increased power usage efficiency results in reduced power consumption, reduced heat generation, and a reduced size of the system controller. In addition, increased power usage efficiency allows the use of smaller backup batteries, or allows larger backup batteries to be used for longer periods of time.

[0040] The SFOC method of driving the pump motor also reduces torque ripple. Torque ripple is also the result of the magnetic field in the stator not being in the optimal position and allowing the rotor to simply spin. If the stator field lags or leads the optimal position relative to the rotor field, then the rotor slows down and / or deviates from its center axis. The rotor wobbles more without SFOC. 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 out the torque value. The result of reduced torque fluctuations is longer motor bearing life and potentially better protection against hemolysis.

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

[0042] SFOC uses three-dimensional geometry to convert back and forth between a rotating reference and a fixed reference and between a voltage that senses a current and a current that indicates a voltage. SFOC has been implemented in software in the past, but running SFOC in a software-controlled environment requires a very high-speed microcontroller. Assume that the program in the microcontroller simultaneously performs the calculations for the SFOC cycle that spins the pump motor and also runs other software that performs other functions, such as monitoring the battery, recording motor control events, displaying messages on an LCD, generating alarms, communicating via USB, etc. In that case, the timing of the SFOC algorithm is very likely to be interfered with by the operation of other software. SFOC requires exact timing. Software systems are inherently unable to accurately time in all situations. The failure of a part of a software system to operate correctly will affect other operating software parts. For this reason, implementing SFOC in an FPGA provides independence from a microcontroller that performs other functions, which ensures that the blood pump will continue to operate even if the microcontroller fails or the microcontroller fails. In addition, the FPGA implementation for SFOC disclosed and claimed herein provides a very accurate hardware timer, thereby ensuring very high-speed control of the blood pump motor. Once the speed of the pump motor is set in the FPGA motor control 340, the pump motor spins at exactly that speed, regardless of what the monitoring processor 320 or the control processor 330 is doing, and regardless of whether one or both of the two processors 320 and 330 fails. This allows the control processor to fail, lock up, or stop for no reason, while the FPGA motor control 340 continues to spin the pump motor at exactly the programmed speed. In addition, 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 at exactly 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 the system controller 310 controls important life support equipment (i.e., blood pumps), a failure of the system controller 310 can cause injury or death. For this reason, a monitoring processor 320 is provided to independently monitor the functions of the control processor 330 and the FPGA motor control 340. Even if the control processor 330 fails, which would result in the control processor 330 being unable to issue a fault alert to the user, the monitoring processor 320 will detect the failure of the control processor 330 and can provide the required alerts and / or alarms. In a suitable embodiment, the control processor 330 can send periodic heartbeat messages to the monitoring processor 320, and as long as the monitoring processor 320 receives the heartbeat message within a defined time range, the monitoring processor can assume that the control processor 330 is functioning normally. For example, the heartbeat message can be sent via a universal asynchronous receiver / transmitter (UART) channel between the control processor 330 and the monitoring processor 320. However, it is noted that in addition to monitoring the heartbeat from the control processor 330, the monitoring processor 320 has other ways to determine when a problem occurs in the system controller 310. For example, the monitoring processor 320 can independently monitor the parameters of the FPGA motor circuit 340 to determine whether the speed of the blood pump is normal. Regardless of the source of the fault, when the monitoring processor 320 detects a fault in the system controller, whether in the control processor 330 or in the FPGA motor control 340, the monitoring processor 320 can provide an alert and / or alarm that lets the user know what the user needs to do to resolve the problem, which may be replacing the defective system controller with a different system controller that is functioning properly.

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

[0045] In a preferred embodiment, both the control processor 330 and the FPGA motor control 340 may be implemented as a system on a chip (SoC). Figure 4 A suitable example of such a SoC implementation is shown in . Figure 4 The system controller 410 is Figure 1 The system controller 130 in Figure 2 210 and Figure 3 A suitable implementation of 310 in FIG. 4 is a system controller 410 including 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 34. The FPGA architecture 430 implements a sensorless field oriented control (SFOC) logic 440 and a pulse width modulation (PWM) signal generator 450 that provides drive signals to the stator coils of the brushless DC motor in the blood pump via the 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 the motor speed and angle. The pump motor speed setting 444 is most preferably written to the SFOC logic 440 by a SFOC device driver 472 in the control processor 470 as a result of receiving input from a clinician to set the pump motor speed via the clinician interface 480. 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 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 may 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, the one or more input keys 170, the one or more LEDs 180, and the one or more audio devices 190, as discussed above. Figure 4 The SOC implementation shown in provides an efficient and low-cost implementation for controlling the functions of a blood pump.

[0046] Figure 5 A block diagram of a blood pump 510 is shown in FIG. Figure 1 A suitable embodiment of the blood pump 110 in 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 the impeller 550 within the pump chamber 540 is suspended in a fluid-dynamic manner within the pump chamber 540. This means that the impeller has no shaft or other mechanical connection to drive the impeller. The impeller includes multiple magnets. In Figure 5 In the specific embodiment of FIG. 5 , three magnets 560, 562 and 564 are shown. Within the scope of the preferred embodiment, there may be more than Figure 5 Three more magnets are shown in FIG. Figure 5Also shown are a plurality of pump phase coils 570, 572, and 574 that are used to drive the impeller. Coils 570, 572, and 574 are stator coils that are part of the drive portion of the brushless DC motor in the blood pump. In the most preferred embodiment, the 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 the pump phase coils 570, 572, and 574, which is a pulse width modulated (PWM) voltage. The PWM voltage creates a near-sinusoidal current that generates an electromagnetic field that acts on the 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 SFOC logic 440 is shown in FIG. SFOC logic 610 includes Figure 4 640 and 650. These are pulse width modulated signals that drive the motor driver integrated circuit 680. Each phase has a current sense from which the current can be determined. Thus, phase 1 has a P1 current sense 632; phase 2 has a P2 current sense 642; and phase 3 has a P3 current sense 652. In a preferred embodiment, the current senses 632, 642, and 652 are series resistors such that the voltage across the current sense resistors is proportional to the current provided in each phase.

[0048] The digital motor current conversion circuit 660 converts the sensed current into motor current values ​​under the control of the digital motor current measurement circuit 658. The voltage from each current sensing element needs to be amplified, so there are three amplifiers 662, 664 and 666 that amplify the voltage from its corresponding current sensing element 632, 642 and 652. The amplified signals are input to an analog-to-digital converter (ADC), which generates digital motor current values ​​672 therefrom under the control of the circuit 658. 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 in , PWM signals 630, 640, and 650 do not have sufficient drive force to directly drive the pump phase coils, so they are input into a motor driver integrated circuit 680, which then generates corresponding drive signals for the three phase coils from each PWM signal. Thus, pump phase 1 drive circuit 682 drives pump phase 1 coil 570 in 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 A specific implementation of the phase current processing logic 624 shown in FIG. Figure 7 710 in FIG. The digital motor current value 672 is Park and Clarke transformed by Park and Clarke transformation logic 720, which generates a magnetizing (DC) motor current 722 and a torque generating (quadrature) motor current 724. Then, a first proportional integral (PI) controller 750 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. In a similar manner, 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 physical parameters of the motor. Then, these signals are processed by the inverse Park and Clarke transformation logic 770 and input to a space vector pulse width modulation (SVPWM) control block 780 to generate a magnetizing (DC) PWM duty cycle and a 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, which is subtracted 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. The phase voltages 782, 784, and 786 are input to a PWM signal generator 790, which inserts 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 drive signals for the blood pump motor phases, such as Figure 6 as shown in .

[0051] Figure 8 It is shown that preferably Figure 7Method 800 performed by the phase current processing logic 710 shown in . The digital motor current value is read (step 810). Next, the Park and Clarke 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 the 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 the reference quadrature current using a second PI controller PI2 to generate a quadrature error signal (step 840). The magnetizing (DC) PWM duty cycle and the torque generating (quadrature) duty cycle are generated using an inverse Park and Clarke transform (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 a third harmonic injected phase voltage (step 870). For each phase, the PWM signal generator inserts a dead time and generates a PWM control signal from the injected phase voltage (step 880). The PWM control signal is then used to drive the blood pump motor (step 890). The method 800 is then complete.

[0052] refer to Fig. 9 , method 900 is preferably performed by Figure 4 The motor speed / angle estimator 442 in FIG. 1 is executed. The rotor position is calculated using the stator voltage vector and the stator current vector (step 910). The stator voltage vector and the 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 a 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 A specific implementation of the FPGA architecture 430 in Fig.10 1000 in the FPGA architecture 1000. The FPGA architecture 1000 includes a microcontroller interface 1010 that allows a control processor to write values ​​to registers in the FPGA architecture 1000. To understand the functionality of the circuit system in diagram 1000, some additional information about controlling a BLDC motor using field oriented control (FOC) is described below.

[0054] A brushless DC (BLDC) motor has a magnetized rotor and a stator that is energized to make the motor run. The rotor is the "spinning" 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 wound in an orientation tangential to three points 120 degrees apart 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 create varying magnetic fields around the coils. Therefore, the magnetic field caused by the current flowing through the phase coils will have poles pointing along lines through the central axis of the motor.

[0055] The Field Oriented Control (FOC) algorithm measures the phase currents and uses these phase current measurements to control the phase voltages. FOC is a closed loop system design.

[0056] The three phases of a BLDC motor are oriented 120 degrees rotated from each other and are evenly distributed around the circumference of the motor. Each individual coil, when energized by a varying voltage signal, generates a current and induces an associated magnetic field of a specific magnitude that is always aligned perpendicular to the coil, with one pole (north or south) toward the central axis of the motor core and the other directly away from the central 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 and NS direction (polarity) of the three magnetic forces (three magnetic field vectors) generated in each coil together form a magnetic field with a specific strength (magnitude) and a specific north-south orientation (direction) within and inside the motor core. The magnetic field generated in the stator is always oriented across and through the motor's axis of rotation.

[0058] The rotor has at least one set of alternating NSNS… pole pairs around its circumference. The 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 pole pairs are attracted to opposite poles (N to S and S to N) of the rotating combined magnetic field produced by the coils in the stator.

[0059] The FOC control algorithm creates a magnetic field in the stator by sending rapidly changing voltage waveform signals to the stator phase coils of the motor. The changing voltage waveform causes an AC current to flow in the stator coil wires and creates a rapidly changing magnetic flux within the stator. Proper operation of the FOC algorithm energizes only two phases of the stator at any one time, with positive voltage (and positive current) in one phase coil and negative voltage (and negative current) in the other opposite phase, thereby always creating opposing North and South magnetic flux on opposite sides of the motor core. The rotor moves to relatively align its pole pairs (NS) with the continuously rotating combined 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 that points across the motor core. The rotating magnetic field attracts the rotor poles and causes the rotor to spin with the rotating field.

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

[0061] Field oriented control operates by generating a series of very high speed discrete control output voltages and simultaneously making very high speed measurements of discrete current samples. Thus, the waveform is a continuous signal generated and measured from a series of discrete control settings and measured values. FOC calculations involve conversions of current and voltage waveforms back and forth 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 a 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. FOC uses (one or more) closed-loop PI controllers in several parts of its operation.

[0063] refer to Fig.10 , I d ,I q The time-scheduled PI control of the position and 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 Quadrature current reference. Next, I q PI controller 1034 uses this I q Reference, measured I q The current and the physical parameters of the motor are used to output v qquadrature voltage reference. Finally, I d DC PI Controller 1034 Using I d The reference value zero and the measured I d The current and the physical parameters of the motor are used to output v d (DC voltage) Ref.

[0064] As the voltage reference signal v from the PI controller 1030 q and v d The signal is the input of the FOC transformation block 1040, specifically the input of the inverse Park transformation 1042, which outputs v α and v β The phase voltages are rotated and these voltages become the inputs of the inverse Clarke transform 1044, which then outputs v a 、v b and v c , which are the fixed reference frame phase voltages. Therefore, these transformations perform voltage waveforms from the rotating frame v q / v d To fixed system a 、v b 、v c The geometric transformation of .

[0065] exist Figure 7 In the process, the proportional integral controller 1 (PI1) 750 converts the quadrature voltage v q The inverse Park transform is output to logic 770. Also in Figure 7 In the proportional integral controller 2 (PI2) 752, v d (DC voltage) output to the inverse Park transform in logic 770.

[0066] The inverse Park transform in logic 770 rotates the phase vector voltage v α and v β The inverse Clarke transform is output to logic 770, which transforms the three phase voltage space vectors v a 、v b 、v c Output directly to SVPWM block 780. The Inverse Park and Inverse Clarke transformation logic 770 essentially performs the mathematical operations involved to convert the desired quadrature voltage (speed) and DC voltage into the phase voltages required to produce the stator phase voltage waveforms.

[0067] The Park and Clarke transformation logic 720 first converts the I measured from three fixed physically located coils in the stator into coordinates expressed in a fixed reference frame. a ,I b ,I c The phase current waveform is converted into two rotating phase currents I α and Iβ ,from Fig.10 The Clarke transform block 1046 outputs .

[0068] Then in the Park transformation block 1048, the rotating phase current I α and I β is converted into the measured (or actual) value I seen in the rotating coordinate system coordinates q (actual quadrature current) and I d (actual DC current) waveform. I q (orthogonal) and I d The (DC) current is expressed in a "rotating" coordinate system and the phase current I expressed in a fixed reference system a ,I b ,I c Same current.

[0069] As discussed, Figure 7 The logic 720 and Fig.10 The Clarke transform output of the 1048 rotating phase current I α and I β ,and Figure 7 The logic 770 and Fig.10 The inverse Park transform outputs the rotating phase voltage v α and v β Both the rotating phase voltages and rotating phase currents are used in a “closed loop” by the position and speed estimator 2026 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 Park 1048 and Inverse Park 1042 transformations.

[0070] The sensorless field oriented control (SFOC) algorithm is a processing loop that takes single-sample current measurements from all motor stator phases and then generates a single-sample output value that changes the voltage waveform in those same phases. It then loops back and operates again on another sample. When rotor speeds reach thousands and tens of thousands of RPM, the loop speed and sampling rate need to be very fast. Implementing the SFOC algorithm in an FPGA is the only way to achieve this goal, where the clock that times the loop operation is very fast and very stable. A microprocessor may have the computational power to perform the math, but the processor clock and interrupt structure cannot provide stable, evenly timed operation for loop control, especially at very high speeds. Dedicated FPGA logic will actually perform math operations faster than a microcontroller can.

[0071] The system controller recognizes two different event classes that can be detected. The first is a warning, which is considered a medium priority event that requires notification to the user. The second is an alarm, which is considered a high priority event that requires notification to the user and requires the user to take immediate remedial action. Fig.11 and 12 Discussion warning, reference Fig.13 and 14 Discuss the alert.

[0072] refer to Fig.11 , method 1100 is preferably performed by the alert manager 474 in the control processor 470, such as Figure 4 . Alert conditions are monitored (step 1110). As long as no alert condition triggers an alert (step 1120=no), the 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 shown on the display (step 1130). If the user presses a mute button (step 1140=yes), which is one of the input keys 170, 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 persists for more than a second preset time period, such as 20 minutes (step 1160=yes), a "Call for Help" message is displayed (step 1170). The method 1100 then returns to step 1110 and continues.

[0073] like Figure 4 As shown in , the control processor 470 includes an alert manager 474 and an alarm manager 476. Note that the functionality of these two can be combined. However, experience has shown that alerts (medium priority events) need to be treated differently from alarms, which are high priority events. When all events are treated as high priority alarms, this can lead to unnecessary and even life-threatening actions being taken, which are not required for medium priority events. Therefore, the controller disclosed and claimed herein distinguishes between medium priority events, which are referred to herein as "alerts", and high priority events, which are referred to herein as "alarms".

[0074] Fig.12 A table 1200 is shown that defines a plurality of alerts that can be detected and acted upon. Each row in the table 1200 defines an alert in terms of a defined alert condition, an entity that detects the condition, and a notification message that is provided on a display as a result of the detected alert. Fig.12In the "Detected By" column of the , most alerts include CP because most alerts can be detected by the control processor (CP). For those alerts that can be detected by the monitoring processor (SP) independently of the CP, include the SP. Pump Low Flow alert 1210 is detected by the CP and a "Pump Low Flow" message is displayed. Pump Power Over Current alert 1212 is detected by the CP and a "Pump Power High" message is displayed. Pump Power High alert 1214 is detected by the CP and a "Pump Power High" message is displayed. Pump Power Low alert 1216 is detected by the CP and a "Pump Power Low" message is displayed. Pump Speed ​​Low alert 1218 is detected by the CP and a "Pump Speed ​​Low" message is displayed. Pump Speed ​​Error alert 1220 is detected by the CP and a "Pump Speed ​​Error" message is displayed. System Over Temperature alert 1222 is detected by the CP and a "System Fault" message is displayed. Backup Battery Fault alert 1224 is detected by the CP and a "System Fault" message is displayed. A "Backup Battery Low" alert 1226 is detected by the CP, and a "Backup Battery Low" message is displayed. A "Backup Battery Discharging" alert 1228 is detected by the CP, and a "Backup" message is displayed. A "Primary Battery Low" alert 1230 is detected by the CP, and a "Battery Low" message is displayed. A "Primary Battery Very Low" alert 1232 is detected by the CP, and a "Battery Very Low" message is displayed. A "Primary Battery Critical" alert 1234 is detected by the CP, and a "Battery Critical" message is displayed. A "Control Processor or FPGA Failure" alert 1236 is detected by the SP, and a "System Failure" message is displayed. A "DC Input Poor" alert 1238 is detected by the CP, and a "System Failure" message is displayed. A "Software Failure" alert 1240 is detected by the SP, and a "System Failure" message is displayed. A "Mute Button Stuck" alert 1242 is detected by the CP, and a "System Failure" message is displayed. A "Next Button Stuck" alert 1246 is detected by the CP, and a "System Failure" message is displayed. The "Alert Test" alert 1248 is detected by the CP and an "Alert Test" message is displayed. Fig.12 The warnings shown in and any other appropriate warnings are within the scope of this disclosure and claims.

[0075] By definition, alerts are less severe than alarms. Therefore, the patient should only see / hear / feel medium priority notifications for alert conditions that the clinician needs to know about more immediately. For all of these alerts, the patient can also be instructed to call the clinic for help. For example, a "Call Help" instruction can be indicated by an illuminated phone icon on the front of the controller and a "Call Help" message on the controller display. The alert message has the alert number, which the patient can read to clinical staff when calling for help. Even those alerts that do not require notification of the clinician are recorded.

[0076] Fig.12The specific alerts shown in are shown only as examples. Other alert conditions may be detected, resulting in corresponding notifications, within the scope of the disclosure and claims herein. Fig.12 Most of the alerts in FIG. 1 are shown as being detected only by the CP, but in alternative embodiments, the service processor (SP) can also monitor many of the alert conditions detected by the CP and can provide alert notifications independently of the CP. This is very beneficial in the event of a CP failure.

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

[0078] Fig.14A table 1400 is shown defining a number of alarms that can be detected and acted upon. Each row in the table 1400 defines an alarm in terms of a defined alarm condition, an entity that can detect the condition, and a notification that is written to the display as a result of the detected alarm. A "Pump Stopped" alarm 1410 is detected by the CP and SP, and a "Pump Stopped" notification is displayed. The pump can stop for a number of reasons, including: the pump drive system is disconnected, damaged, unplugged, or otherwise damaged; the FPGA motor control can no longer spin the pump motor; the controller loses power; the only power supply is a depleted internal backup battery that can no longer provide enough current to run the pump; the pump is blocked by a blood clot; or the pump motor itself malfunctions or is otherwise damaged. A "Pump Disconnected" alarm 1412 is detected by the CP, and a "Pump Disconnected" message is displayed. A "Pump Restart Failed" alarm 1414 is detected by the CP, and a "Pump Restart Failed" message is displayed. A "No Primary Battery" alarm 1416 is detected by the CP, and a "No Battery" message is displayed. An "Emergency Alarm Test" alarm 1418 is detected by the CP, and an "Alarm Test" message is displayed. An "Alarm Test" alarm 1420 is detected by the CP and an "Alarm Test" message is displayed. A "Power Supply Failure" alarm 1422 is detected by the SP and an "Emergency Alarm" message is displayed. In one suitable embodiment, the SP monitors the regulated power supplies in the control system, and if any of the regulated power supplies does not provide a voltage within a specified range, the SP may detect this condition and provide an emergency alarm in response to detecting this power supply failure. Fig.14 The alarms shown in and any other suitable alarms are within the scope of the disclosure and claims herein. In addition, in alternative embodiments, Fig.14 Many alarms detected by the CP can also be detected by the 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 "Call for Help" and "Replace Controller."

[0080] Sometimes multiple alerts and / or alarms may occur simultaneously. The control processor 470 preferably executes Fig.15 15. When there are no multiple alerts and / or alarms occurring simultaneously (step 1510=no), the method 1500 is completed. When there are multiple alerts and / or alarms occurring simultaneously (step 1510=yes), the alerts and alarms are continuously scrolled on the display from the highest priority to the lowest priority (step 1520). By scrolling multiple alerts / alarms on the display, the user can easily view all pending alerts and alarms as the messages scroll on the display. The method 1500 is then completed.

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

[0082] Fig.16 A method 1600 for a clinician to program a blood pump is shown. The clinician connects a clinician interface computer to a clinician interface on a controller (step 1610). The clinician interface computer can be any suitable computing device, including but not limited to a desktop computer, a laptop computer, a tablet computer, or a smart phone. The clinician invokes a 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. The method 1600 is then completed.

[0083] As referenced above Figure 3 As discussed, the presence of the supervisory processor 320 allows the health of the control processor 330 and the FPGA motor control 340 to be monitored. Fig.17 The method 1700 is preferably performed by Figure 3 1700 is executed by the monitoring processor 320 shown in . 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 alarm or alert 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 alarm or alert is triggered (step 1730). The method 1700 then loops back to step 1710 and continues. We can see from method 1700 that the monitoring processor has the ability to detect problems with the control processor and the SFOC core in the FPGA, thereby providing another layer of protection when one or both of the control process and / or the SFOC core stops functioning properly. In some cases, if the system controller is indeed not functioning properly, the alarm triggered will be to immediately replace the system controller.

[0084] As referenced above Figure 2 As discussed, the system controller 210 operates according to a defined power hierarchy. Figure 4 The system controller 470 in FIG. 4 shows a power manager 478 that manages power from three sources (ie, primary battery, AC / DC power adapter, and backup battery). Fig.18 Table 1800 shows Figure 4A suitable hierarchy of power sources that can be used by the power manager 478 in the system controller is shown, wherein the hierarchy is defined from highest priority to lowest priority. Thus, the AC / DC power adapter 1810 is the highest priority, which means that when the AC / DC power adapter has power, the power manager 478 will use the power of the AC / DC power adapter. The primary battery 1820 has the next highest priority, which means that when the AC / DC power adapter has no power (which may be caused by the AC / DC power adapter being unplugged from the system controller or due to a power outage), the power manager 478 will use the power of the primary battery. The backup battery 1830 within the system controller housing has the lowest priority. Thus, the power manager 478 will use the power of the backup battery only when neither the AC / DC power adapter or the primary battery is available. The backup battery is designed to be used only in very short periods of time between switching between primary batteries, so the backup battery does not have sufficient capacity to operate the system controller and the blood pump for any extended period of time. The backup battery is designed to operate the blood pump for 30 minutes under normal conditions, which means that the backup battery is sufficient to meet the typical one or two minutes required for the user to switch between primary battery packs.

[0085] Fig.19 The method 1900 is preferably performed by Figure 4 The power manager 478 in the method 1900 is executed. 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, the method 1900 loops back to step 1910 and continues.

[0086] Although the power manager 478 Figure 4 4 is 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 communicates the power status to the control processor.

[0087] Fig. 202000 is a method showing different modes of operation of a system controller and a blood pump. For tethered operation, where the user will be in one place near an electrical 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 one place near an electrical outlet, attach the primary battery and then unplug the AC / DC power adapter (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 the wearability of the system controller. 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 a primary battery that is 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 that the user uses to disconnect and connect the primary battery to the system controller.

[0088] like Fig.21 As shown in Figure 4 The power manager 478 shown in FIG. 1 preferably includes a backup battery charger 2100 for charging the backup battery 150. The backup battery charger 2100 preferably operates according to Fig. 22 The method 2200 in the embodiment operates. 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 the method 2200 loops back to step 2210. Once the backup battery is charged in step 2220 or 2240, charging may be stopped when any of the following conditions listed in step 2250 are met, namely: 1) the charging current of the backup battery reaches the minimum charge taper current allowed at 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 short interruptions in power from the AC / DC power adapter and the primary battery.

[0089] A blood pump system includes a blood pump and a corresponding controller. The blood pump includes an impeller that is sealed within a pump housing and suspended in a hydrodynamic manner within the pump housing. The pump impeller includes a magnet and is the rotor of a brushless direct current (DC) motor that is driven by an electrical signal through a stator coil 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. 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 associated with the control processor do not stop the blood pump. Field-oriented control allows sensing of blood flow through the pump without having a sensor in the blood flow.

[0090] The disclosure and claims herein support a system controller for driving a blood pump, the blood pump comprising an impeller sealed within a pump housing and suspended in a fluid-dynamic manner within the pump housing, wherein the impeller comprises a plurality of magnets, the blood pump comprising a plurality of stator coils in a brushless direct current (DC) motor, the impeller being caused to rotate within the pump housing when the plurality of stator coils are driven by a plurality of drive signals, wherein the system controller comprises: 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 providing management functions for the system controller and displaying at least one message on the display; and a programmable logic device providing 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 or non-operation of the control processor.

[0091] The disclosure and claims herein also support a system controller for driving a blood pump, the blood pump including an impeller sealed within a pump housing and suspended in a fluid-dynamic manner within the pump housing, wherein the impeller includes a plurality of magnets, the blood pump including a plurality of stator coils in a brushless DC motor, which rotate the impeller 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 the user; at least one audio device for signaling a warning or alarm condition to the user; a backup battery internal to the housing of the system controller that is activated when an external primary battery is not providing power to the system controller The backup battery provides power when power is supplied and when the external AC / DC adapter is not providing power to the system controller; a clinician interface that provides a graphical user interface that allows 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; 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 a warning or alarm condition; and a programmable logic device that provides field-oriented control of a 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 an electrical connector, 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 comprising: an impeller sealed within a pump housing and suspended in a fluid-dynamic manner within the pump housing, wherein the impeller comprises 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; (B) a system controller electrically coupled to the blood pump and providing a plurality of drive signals to the plurality of stator coils in the brushless DC motor in the blood pump, the system controller comprising: 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 a plurality of drive signals to the plurality of stator coils in the brushless DC motor in the blood pump independently of the operation of the control processor.

[0093] Those skilled in the art will recognize that many changes may be made within the scope of the claims. Therefore, although the present disclosure has been particularly shown and described above, those skilled in the art will appreciate 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 comprising an impeller sealed within a pump housing and suspended in a fluid-dynamic manner within the pump housing, wherein the impeller comprises a plurality of magnets, the blood pump comprising 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 comprises: 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; monitor; a control processor that provides management functions for the system controller and displays at least one message on the display; as well as A programmable logic device that provides field-oriented 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 operates independently of the operation of a control processor.

2. The system controller of claim 1, further comprising a backup battery inside the system controller.

3. The system controller as described in claim 2 also includes a power manager that selects a power source for powering the system controller based on 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 comprises a field programmable gate array (FPGA).

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

6. The system controller of claim 1, further comprising: at least one input key for a user of the system controller; at least one visual indicator for a user; as well as At least one audio device for signaling an alert or alarm condition to a user.

7. The system controller of claim 1 further comprising a clinician interface providing a graphical user interface that allows 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 alert 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 functions of the control processor and the programmable logic device based on at least one monitored parameter and provides an alert or alarm signal when the at least one monitored parameter indicates an alert or alarm condition.

9. The system controller of claim 1 further comprising an alert manager that allows definition or selection of a plurality of alerts and corresponding alert notifications, detects when one of the plurality of alerts is triggered, and provides at least one notification corresponding to the triggered one of the alerts.

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

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

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

13. The system controller of claim 12 wherein the field oriented control performs Park and Clarke transforms on the digital motor current values ​​to determine a magnetizing (DC) motor current and a torque producing (quadrature) motor current, compares the magnetizing (DC) motor current to a reference DC current using a first proportional-integral controller to generate a DC voltage signal, compares the torque producing (quadrature) motor current to 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 transform on the DC and quadrature voltage signals to generate two rotating phase voltage signals, then performs an inverse Clarke transform on the two rotating phase voltage signals to generate a pulse width modulated duty cycle signal in phase space, and generates a plurality of pulse width modulated 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 comprising an impeller sealed within a pump housing and suspended in a hydrodynamic manner within the pump housing, wherein the impeller comprises a plurality of magnets, the blood pump comprising 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 comprises: 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; monitor; 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 a warning or alarm condition to a user; a backup battery inside the housing of the system controller that provides power when the external primary battery is not providing power to the system controller and when the external AC / DC adapter is not providing power to the system controller; a clinician interface providing a graphical user interface that allows a medical clinician to set a speed of the blood pump and define or select at least one alert or alarm condition in the system controller using a clinician computer coupled to the clinician interface; a control processor that provides management functions for the system controller, displays at least one message on the display, and activates at least one of the visual indicator and the at least one audio device to signal an alert or alarm condition; as well as A programmable logic device that provides field-oriented 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 operates independently of the operation of a control processor.

15. A blood pump system comprising: (A) Blood pump, including: an impeller sealed within and hydrodynamically suspended within the pump housing, wherein the impeller includes a plurality of magnets; a plurality of stator coils in the brushless DC motor that, when driven by a plurality of drive signals, cause the impeller to rotate within the pump housing; (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 in the blood pump, the system controller comprising: monitor; 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 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 with or without functionality independent of a control processor.

16. The blood pump system of claim 15, further comprising a backup battery located inside the housing of the system controller and a primary battery coupled to a connector external to the system controller.

17. The blood pump system of claim 16, further comprising a desktop battery charger for charging the primary battery when the primary battery is disconnected from the system controller.

18. The blood pump system of claim 17, further comprising a first AC / DC power adapter for powering the desktop battery charger.

19. The blood pump system of claim 18, further comprising a second AC / DC power adapter for powering the system controller.

20. The blood pump system of claim 15, wherein the control processor and the programmable logic device are implemented in a system on a chip (SOC).

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