Blood circulation support system including a controller and a plurality of sensors

Abstract

A blood circulation support system includes an implantable blood pump, the blood pump including a housing, a rotor operable to pump blood from an inlet to an outlet, a stator, and at least two of the following: a current sensor, a rotor position sensor, an accelerometer, and a pressure sensor. A controller is connected to the sensors and includes a signal processing module, the signal processing module is configured to receive a data stream from each sensor. The signal processing module can also be configured to filter the data streams received from the multiple sensors, determine at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump based on at least two filtered data streams, and output at least one of the operating parameter of the pump, the cardiac characterization, and the control parameter of the pump to at least one of an operator interface module and the pump control module.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 926,141, filed on October 25, 2019, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates generally to mechanical circulatory support systems and, more particularly, to an implantable blood pump assembly including a plurality of sensors and a controller that combines data streams received from the sensors. Background Art

[0004] A ventricular assist device (referred to as a VAD) is an implantable blood pump that can be used for both short-term applications (e.g., days, months) and long-term applications (e.g., years or an entire lifetime) in which the patient's heart is unable to provide adequate blood circulation, commonly referred to as a heart rhythm disorder or heart failure. Patients with heart rhythm disorders can use a VAD while they are waiting for a heart transplant or long-term purposeful treatment. In another example, a patient can use a VAD while recovering from heart surgery. Thus, a VAD can rescue a weakened heart (e.g., partial support) or can effectively replace the function of a natural heart, and the VAD can be implanted in a patient and powered by a power source located inside or outside the patient.

[0005] A controller may be used to control the operation of an implanted ventricular assist device. The controller may be operably connected to the ventricular assist device via a wired, wireless, and / or mechanical connection, which may be used to provide operating power (e.g., electrical and / or mechanical energy) to the ventricular assist device and control signals to control the operation of the ventricular assist device (VAD).

[0006] At least some ventricular assist devices utilize feedback from one or more sensors to control the operation of the ventricular assist device. Some ventricular assist devices, for example, use pressure sensors to measure pressure and monitor the patient's cardiac cycle to control the ventricular assist device. Although at least some sensors of ventricular assist devices provide valuable information, the quality and range of the information provided by the sensors are flawed. For example, sometimes the sensors cannot provide accurate information, which is attributed to failures and limitations in the sensor's operating performance. For example, some sensors such as current sensors may not provide usable information during all cardiac phases or pumping cycles. In addition, it may be difficult to determine whether each sensor is providing accurate information. In addition, certain values ​​(such as cardiac characteristics or pump operating parameters) cannot be determined solely from the data provided by each sensor, and therefore, each sensor may provide less than optimal diagnostic and therapeutic information for operating the ventricular assist device.

[0007] Accordingly, there is a need for improved ventricular assist systems that combine information from multiple sensors to monitor a patient's cardiac cycle and / or control the operation of a ventricular assist device. Summary of the invention

[0008] The present invention relates to a blood circulation support system, which includes an implantable blood pump and a controller. The implantable blood pump includes a housing, the housing defining an inlet, an outlet, a flow channel extending from the inlet to the outlet, and an internal compartment separated from the flow channel. The implantable blood pump also includes a rotor, the rotor is positioned in the flow channel and can be operated to pump blood from the inlet to the outlet, and a stator, the stator is positioned in the internal compartment and can be operated to drive the rotor. The implantable blood pump also includes a plurality of sensors, the sensors including at least two of the following: a current sensor configured to detect a current provided to the stator, a rotor position sensor configured to detect a position of the rotor relative to the housing, an accelerometer configured to detect an acceleration of the blood pump in at least one direction, and a pressure sensor positioned between the inlet and the outlet and configured to detect the pressure of blood flowing through the flow channel. The controller is connected to a plurality of the sensors and includes a signal processing module and at least one of an operator interface module and a pump control module. The signal processing module is configured to receive a data stream from each of the plurality of the sensors. The signal processing module is also configured to filter the data streams received from the multiple sensors, determine at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump based on at least two of the filtered data streams, and output at least one of the operating parameter of the pump, the cardiac characterization, and the control parameter of the pump to at least one of the operator interface module and the pump control module.

[0009] The present invention also relates to a method of operating an implantable blood pump. The blood pump includes a housing defining an inlet, an outlet, a flow channel extending from the inlet to the outlet, and an internal compartment separated from the flow channel. The blood pump also includes a rotor positioned in the flow channel and operable to pump blood from the inlet to the outlet, and a stator positioned in the internal compartment and operable to drive the rotor. The method includes using a plurality of sensors to detect at least two of the following: a current provided to the stator, a position of the rotor relative to the housing, an acceleration of the blood pump in at least one direction, and a pressure of blood flowing through the flow channel. The method also includes receiving a data stream from each of the plurality of sensors at a signal processing module of a controller connected to the plurality of sensors, and filtering the data streams received from the plurality of sensors by the controller. The method also includes determining, by the controller, at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump based on at least two filtered data streams, and outputting at least one of the operating parameter of the pump, the cardiac characterization, and the control parameter of the pump from the signal processing module to at least one of an operator interface module and a pump control module.

[0010] The present invention relates to an implantable blood pump, which includes a housing, the housing defining an inlet, an outlet, a flow channel extending from the inlet to the outlet, and an internal compartment separated from the flow channel. The implantable blood pump also includes a rotor positioned in the flow channel and operable to pump blood from the inlet to the outlet, a stator positioned in the internal compartment and operable to drive the rotor, and a plurality of sensors. The plurality of sensors include a current sensor configured to detect a current provided to the stator, a rotor position sensor configured to detect a position of the rotor relative to the housing, an accelerometer configured to detect an acceleration of the blood pump in at least one direction, and a pressure sensor positioned between the inlet and the outlet and configured to detect the pressure of blood flowing through the flow channel. The plurality of sensors are connected to a controller, which is configured to receive a data stream from each of the plurality of sensors, filter the data streams received from the plurality of sensors, and determine at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump based on the filtered data stream. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a schematic diagram of a mechanical blood circulation support system implanted into a patient's body.

[0012] Figure 2 is suitable for Figure 1 Schematic diagram of a blood pump assembly used in a mechanical blood circulation support system, wherein the blood pump assembly is in an operable position implanted in a patient's body.

[0013] Figure 3yes Figure 2 Schematic cross-sectional view of a blood pump assembly.

[0014] Figure 4 yes Figure 2 A cutaway perspective view of a blood pump assembly.

[0015] Figure 5 yes Figure 4 Magnified view of the blood pump assembly.

[0016] Figure 6 yes Figures 2 to 5 A partial schematic diagram of a blood pump assembly including a controller connected to a plurality of sensors.

[0017] Figure 7 can be included in Figure 6 An example diagram of data collected and output by a pressure sensor among the multiple sensors shown.

[0018] Figure 8 It can be Figure 6 An example diagram of data collected and output by multiple sensors is shown.

[0019] Fig. 9 It can be Figure 6 Another example diagram of data collected and output by multiple sensors is shown.

[0020] Fig. 10A and Fig. 10B is a flow chart illustrating one embodiment of a method of operating an implantable blood pump within a patient.

[0021] Fig.11 is a flow chart illustrating example data flow and processing of data acquired by sensors during operation of an implantable blood pump in a patient. DETAILED DESCRIPTION

[0022] The present invention relates to an implantable blood pump assembly. Embodiments of the implantable blood pump assembly disclosed herein include a plurality of sensors connected to a controller. For example, in some embodiments, the plurality of sensors include a current sensor, a rotor position sensor, an accelerometer, and a pressure sensor. A signal processing module of the controller receives a data stream from each of the plurality of sensors and filters the data stream. In some embodiments, at least one supplementary data stream is generated based on the data streams of the plurality of sensors. For example, the supplementary data stream may include the pressure of the blood flowing out of the blood pump assembly through an outlet. The controller may determine at least one of the operating parameters, cardiac characterization, and control parameters of the pump based on the filtered data stream. The operating parameters, cardiac characterization, or control parameters of the pump may be output to an operator interface module to be presented to an operator and / or output to a pump control module configured to control the blood pump assembly.

[0023] Further, the data streams can be compared and combined to provide clinical and surgical information that is more reliable and more accurate than information based on a single data stream alone. In some embodiments, the accuracy of each data stream can be determined based on a comparison of the data streams, and a quality rating can be assigned to each data stream based on the determined accuracy of the data streams. Thus, the implantable blood pump assembly described herein can provide more accurate and more complete information for clinical assessment of a patient than existing blood pump assemblies. In addition, the implantable blood pump assembly can be operated at least partially independently based on multiple data streams.

[0024] Now referring to the accompanying drawings, Figure 1 is a schematic diagram of a mechanical circulatory support system 10 implanted in a patient's body 12. The mechanical circulatory support system 10 includes an implantable blood pump assembly 14, which includes a blood pump 16, a ventricular cuff 18, and an outflow cannula 20. The mechanical circulatory support system 10 also includes an external system controller 22 and one or more power sources 24 (e.g., batteries).

[0025] The blood pump assembly 14 can be implanted as or can include a ventricular assist device (VAD) that is attached to the highest point of the left ventricle (as shown) or the right ventricle or both ventricles of the heart 26. The blood pump assembly 14 can be attached to the heart 26 by a ventricular cuff 18 that is sutured to the heart 26 and coupled to the blood pump assembly 14. The other end of the blood pump assembly 14 is connected to the ascending or descending aorta by an outflow cannula 20 so that the blood pump assembly 14 effectively diverts blood from the weakened ventricle and propels it to the aorta to circulate to the rest of the patient's vascular system. The ventricular assist device can include a centrifugal pump (shown) or an axial flow pump as further described herein that is capable of pumping the entire blood output delivered from the pulmonary circulation to the left ventricle (i.e., up to 10 liters / minute).

[0026] Figure 1 The mechanical circulatory support system 10 is shown during battery powered operation. A communication line 28 connects the implanted blood pump assembly 14 to an external system controller 22 for monitoring the operation of the system 10. In the illustrated embodiment, the communication line 28 is shown as a transmission line that exits through the patient's abdomen 30, although it should be understood that the blood pump assembly 14 can be connected to the external system controller 22 by any suitable communication line (including wired or wireless communication). The system can also be powered by one, two or more power sources 24. It should be understood that although the system controller 22 and the power sources 24 are shown to be located outside / external to the patient's body, the communication line 28, the system controller 22 and / or the power sources 24 can also be implanted in the patient's body as a separate component or integrated with the blood pump assembly 14, partially or completely.

[0027] Figure 2 is suitable for Figure 1 Schematic diagram of an implantable blood pump assembly 100 used in a mechanical blood circulation support system 10 of the present invention, wherein the blood pump assembly 100 is shown in an operational position implanted in a patient's body. In the embodiment shown, the blood pump assembly 100 is a left ventricular assist blood pump assembly connected to the left ventricle LV of the heart H.

[0028] The blood pump assembly 100 includes a blood pump 102 having an annular housing 104 having a first outer surface or first outer wall 106 and a second outer surface or second outer wall 108. The blood pump assembly 100 also includes an inlet cannula 110 (generally, an inlet conduit) extending from the first outer wall 106 of the pump housing 104 in the illustrated embodiment. Figure 2 When implanted in a patient as shown, the first outer wall 106 of the housing 104 is positioned against the patient's heart H, and the second outer wall 108 of the housing 104 faces away from the heart H. An inflow cannula 110 extends into the left ventricle LV of the heart H to connect the blood pump assembly 100 to the heart H. The second outer wall 108 of the housing 104 has a chamfered edge 109 to avoid irritation of other tissues that may contact the blood pump assembly 100, such as the patient's diaphragm.

[0029] Figure 3 yes Figure 2 Schematic cross-sectional view of blood pump assembly 100. Figure 4 is a cut-away perspective view of blood pump assembly 100 . Figure 5 1 is an enlarged view of the blood pump assembly 100. The blood pump assembly 100 also includes a stator 112, a rotor 114, an onboard controller 116, and a plurality of sensors 118 ( Figure 6 In the illustrated embodiment, at least some of the stator 112, rotor 114, onboard controller 116, and plurality of sensors 118 are enclosed within the pump housing 104. In the illustrated embodiment, the stator 112 and onboard controller 116 are positioned on the inflow side of the pump housing 104, toward the first outer wall 106, while the rotor 114 is positioned along the second outer wall 108. In other embodiments, the stator 112, rotor 114, and onboard controller 116 may be positioned at any suitable location within the pump housing 104 that enables the blood pump assembly 100 to function as described herein. The stator 112, rotor 114, and onboard controller 116 may be positioned at any suitable location within the pump housing 104 that enables the blood pump assembly 100 to function as described herein. Figure 2 110 ) provides power to the operable components of the blood pump assembly 100 (eg, the stator 112 and the onboard controller 116) from a remote power source.

[0030] The pump housing 104 defines a housing for pumping the pump from the ventricle (e.g., Figure 21 and 2. The pump housing 104 includes an inlet 122 for receiving blood, an outlet 124 for returning blood to the blood circulation system, and a flow channel 126 extending from the inlet 122 to the outlet 124. The pump housing 104 also defines an internal compartment 128 separated from the flow channel 126 by one or more partition walls 130, for example.

[0031] The pump housing 104 also includes an intermediate wall 132 between the first outer wall 106 and the second outer wall 108, and a peripheral wall 134 extending between the first outer wall 106 and the intermediate wall 132. The first outer wall 106, the partition wall 130, the intermediate wall 132, and the peripheral wall 134 collectively define an interior compartment 128 in which the stator 112 and the onboard controller 116 are enclosed.

[0032] In the illustrated embodiment, the pump housing 104 further includes a cap 136 removably attached to the pump housing 104 along the intermediate wall 132. In the illustrated embodiment, the cap 136 may be threadedly connected to the pump housing 104, although in other embodiments, the cap 136 may be connected to the pump housing 104 using any suitable connection means that enables the blood pump assembly 100 to function as described herein. For example, in some embodiments, the cap 136 is non-removably connected to the pump housing 104, such as by welding. The removable cap 136 includes the second outer wall 108, the chamfered edge 109, and defines the outlet 124. The cap 136 also defines a vortex chamber 138 in fluid communication with the outlet 124 and a rotor chamber 140 in which the rotor 114 is positioned. Any suitable connection structure may be used to attach the cap 136 to the pump housing 104. For example, the cap 136 may be threadedly engaged with the peripheral wall 134 to seal the engagement of the cap 136 with the peripheral wall 134.

[0033] The rotor 114 is positioned within the blood flow channel 126, specifically within the rotor cavity 140, and is operable to rotate in response to the electromagnetic field generated by the stator 112 to pump blood from the inlet 122 to the outlet 124. The rotor defines a central hole 142 through which blood flows during operation of the blood pump 102. The rotor 114 includes an impeller blade 144 positioned within the vortex cavity 138 of the blood flow channel 126, and a cover portion 146 covering an end of the impeller blade 144 facing the second outer wall 108 to help guide blood flow into the vortex cavity 138.

[0034] In the illustrated embodiment, the rotor 114 includes a permanent magnet 148 defining a central bore 142. The permanent magnet 148 has a permanent magnetic north pole N and a permanent magnetic south pole S for combined active and passive magnetic suspension of the rotor 114 and for rotating the rotor 114. In operation, the stator 112 is controlled to drive (i.e., rotate) the rotor by generating an electromagnetic field that interacts with the permanent magnetic poles S and N of the permanent magnet 148 and levitates the rotor 114 radially.

[0035] Any suitable stator 112 may be used to rotate the rotor 114. The stator 112 generally includes a plurality of winding structures that generate a suitable electromagnetic field that interacts with the rotor 114 to cause the rotor 114 to rotate and levitate. In the illustrated embodiment, the stator 112 includes a plurality of pole pieces 150 spaced circumferentially around the partition wall 130. The example blood pump assembly 100 includes six pole pieces 150, two of which are located at Figure 3 1. In other embodiments, the blood pump assembly 100 may include more than six or less than six pole pieces, such as four pole pieces, eight pole pieces, or any other suitable number of pole pieces that enable the blood pump assembly 100 to function as described herein. In the illustrated embodiment, each pole piece 150 includes a drive coil 152 for generating an electromagnetic field to rotate the rotor 114 and a suspension coil 154 for generating an electromagnetic field to control the radial position of the rotor 114.

[0036] Each of the drive coil 152 and the suspension coil 154 includes a plurality of conductor windings wound around the pole piece 150. The drive coil 152 and the suspension coil 154 of the stator 112 are arranged opposite each other in pairs, and are controlled to drive the rotor and radially levitate the rotor 114 by generating an electromagnetic field that interacts with the permanent magnetic poles S and N of the permanent magnet 148. For example, an applicable method for generating an electromagnetic field to rotate and radially levitate the rotor 114 is described in U.S. Patent 9,849,224, the entire contents of which are incorporated herein by reference for all purposes. Although the drive coil 152 and the suspension coil 154 are shown as separate coils in the illustrated embodiment, it should be understood that the drive coil 152 and the suspension coil 154 can be implemented as a single coil configured to generate an electromagnetic field for both rotating the rotor 114 and levitating the rotor 114.

[0037] The inlet cannula 110 is attached to the pump housing 104 at the inlet 122. Figure 4 As shown, the pump housing 104 includes an inlet sleeve receiving portion 156 including suitable connection structure for connecting the inlet sleeve 110 to the pump housing 104. In the illustrated embodiment, the pump housing 104 includes an internal threaded sleeve 158 that threadably engages an external thread 160 located on a downstream end 162 of the inlet sleeve 110 to connect the inlet sleeve 110 to the pump housing 104.

[0038] The inlet cannula 110 defines an inlet flow passage 164 that provides blood to the inlet 122 of the pump housing 104. Figure 4 As shown, in the illustrated embodiment, the inflow cannula 110 extends into the blood flow path 126 defined by the pump housing 104 such that the inlet channel 164 partially overlaps the blood flow path 126 .

[0039] The downstream end 162 of the inflow cannula 110 has a reduced cross-sectional area (e.g., relative to the upstream end of the inflow cannula 110), which forms a local high-speed blood flow region flowing through the inlet flow channel 164 and the blood flow channel 126. Specifically, the cross-sectional area of ​​the inlet flow channel 164 gradually and continuously decreases toward the downstream end 162 of the inflow cannula 110, so that the blood flowing through the inflow cannula 110 at a constant flow rate increases in velocity as it flows through the downstream end 162 of the inflow cannula 110. As a result, during operation of the blood pump assembly 100, the reduced cross-sectional area of ​​the downstream end 162 forms a local high-speed blood flow region flowing through the inlet 122 and through the blood flow channel 126.

[0040] In some embodiments, portion 172 of interior compartment 128 (at Figure 4 104 to hermetically seal the interior compartment 128 (shown in FIG. 104 ) from some portion of the interior compartment that may be in communication with a fluid (e.g., blood) to inhibit fluid from entering the portion of the interior compartment 128 that encloses the electronics (e.g., rotor 112 and onboard controller 116). For example, in the illustrated embodiment, the sensor assembly housing 174 forms a seal against the pump housing 104 to hermetically seal the interior compartment 128 ( Figure 4 A portion 172 in which the electronic components are encapsulated outside the internal cavity defined by the sensor assembly housing 174 is shown.

[0041] Additional references Figure 6 , the plurality of sensors 118 include at least one pressure sensor 178, a first current sensor 180, a second current sensor 182, an accelerometer 184, and a rotor position sensor 186. The first current sensor 180 and the second current sensor 182 are configured to detect current provided to the stator 112. For example, the first sensor 180 is connected to the drive coil 152 and is configured to measure the current provided to the drive coil 152 from the power supply to the stator 112. The second current sensor 182 is connected to the suspension coil 154 and is configured to measure the current provided to the suspension coil 154 from the power supply to the stator 112. In other embodiments, the blood pump assembly 100 may include any suitable current sensor that enables the blood pump assembly 100 to operate as described herein. For example, in some embodiments, the blood pump assembly 100 includes a single current sensor that is configured to measure both the current provided to the drive coil 152 and the current provided to the suspension coil 154. In some embodiments, the first current sensor 180 and / or the second current sensor 182 are located outside the housing 104. For example, in some embodiments, the first current sensor 180 and / or the second current sensor 182 may be connected to the controller 22 ( Figure 1 shown) and / or power supply 24 ( Figure 1 shown).

[0042] The rotor position sensor 186 is configured to detect the position of the rotor 114 relative to the stator 112. For example, in the illustrated embodiment, the rotor position sensor 186 is a Hall effect sensor that provides an output voltage that is proportional to the strength of the magnetic field between the pole piece 150 and the permanent magnet 148. The rotor position sensor 186 can provide the output voltage as a continuous data stream to the onboard controller 116. The onboard controller 116 can continuously track the position of the rotor 114 by correlating the data stream with the position of the rotor 114 relative to the stator 112. The data stream from the rotor position sensor 186 can be used to selectively attract and repel the permanent magnetic poles S and N of the permanent magnet 148 to adjust the position of the rotor 114 within the stator 112 and / or cause the rotor 114 to rotate during operation of the blood pump assembly 100.

[0043] In the illustrated embodiment, the blood pump assembly 100 includes two pressure sensors configured to detect the pressure of blood flowing through the blood flow path 126. For example, Figure 5 and Figure 6 As shown, in the illustrated embodiment, each pressure sensor 178 includes a sensing element 188 and a deflectable diaphragm 190 positioned between the sensing element 188 and the blood flow path 126. In other embodiments, the blood pump assembly 100 may include more than two or less than two pressure sensors 178.

[0044] The pressure sensors 178 are positioned so that each pressure sensor is capable of detecting the pressure of the fluid flowing through the blood flow path 126. For example, in the illustrated embodiment, the pressure sensors 178 are located near the downstream end 162 of the inflow cannula 110, at the interface between the inflow cannula 110 and the pump housing 104. More specifically, the pressure sensors 178 are located between the outlet 166 of the inflow cannula 110 and the inlet 168 leading to the rotor cavity 140.

[0045] The accelerometer 184 of the exemplary embodiment is mounted to the circuit board 170 of the onboard controller 116 and is configured to measure acceleration in at least one direction of the blood pump assembly 100. For example, the accelerometer 184 may be a three-axis linear accelerometer configured to measure acceleration in three directions.

[0046] In the illustrated embodiment, the blood pump assembly 100 has an axis 192 about which the rotor 114 rotates. In the illustrated embodiment, the blood flow channel 126 extends along the axis 192. The accelerometer is configured to detect acceleration of the blood pump assembly 100 in a first direction parallel to the axis 192, in a second direction perpendicular to the axis 192, and in a third direction perpendicular to the axis 192 and perpendicular to the second direction. The accelerometer is configured to provide a data stream indicating the detected acceleration to the controller 116. In some embodiments, the onboard controller 116 is configured to determine the patient's activity level, the orientation of the blood pump 102, and / or the displacement of the blood pump 102 or the heart wall based on the acceleration in at least one of the first direction, the second direction, and the third direction. In other embodiments, the blood pump assembly 100 may include multiple accelerometers 184, and each accelerometer 184 may provide information about the acceleration in at least one direction.

[0047] The onboard controller 116 may include one or more modules or devices enclosed within the pump housing 104. The onboard controller 116 may generally include any suitable computer and / or other processing unit, including any suitable combination of computers, processing units, and / or similar devices that can be communicatively coupled to each other (e.g., the onboard controller 116 can form all or part of a controller network). Thus, the onboard controller 116 may include one or more processors and associated storage devices that are configured to perform various computer-implemented functions (e.g., perform the methods, steps, calculations, and / or similar functions disclosed herein). As used herein, the term "processor" refers not only to integrated circuits included in computers as referred to in the art, but also to controllers, microcontrollers, microcomputers, programmable controllers (PLCs), application specific integrated circuits (ASICs), digital signal processors (DSPs), field programmable gate arrays (FPGAs), and other programmable circuits. In addition, the memory device of the onboard controller 116 may generally include memory elements, which include but are not limited to non-temporary computer-readable media (e.g., random access memory (RAM)), read-only memory (ROM)), computer-readable non-volatile media (e.g., flash memory), floppy disks, compact disc read-only memory (CD-ROM), magnetic optical disks (MOD), digital versatile discs (DVD), and / or other suitable memory elements. Such a memory device may generally be configured to store suitable computer-readable instructions that, when executed by a processor, configure the onboard controller 116 to perform various functions, including, but not limited to, controlling the supply of current to the stator 112, determining waveforms related to operating parameters of the pump, cardiac characteristics, or control parameters of the pump, determining or calculating cardiac conditions or cardiac characteristics based on information provided by the plurality of sensors 118, such as heart rate, contractility, end-systolic pressure, end-diastolic pressure, atrial recoil pressure, left ventricular contractility, left ventricular maximum pressure, and left ventricular relaxation, adjusting the speed of the rotor 114 based on information provided by the plurality of sensors 118 and / or one or more determined cardiac conditions or characteristics, outputting measurement data to an external controller (e.g., external system controller 22), and performing various other suitable computer-implemented functions. In addition, the memory may be used to store patient-specific parameters that the onboard controller 116 utilizes to control patient-specific operating aspects of the blood pump assembly 100 and associated software modules.

[0048] In the illustrated embodiment, the onboard controller 116 is implemented as one or more circuit boards 170 (in Figure 4 ) and a plurality of components (eg, a processor and a memory device) carried on a circuit board to control the operation of the pump 102 by controlling the electrical supply to the stator 112.

[0049] Communication lines (e.g. Figure 1 Communication lines 28 shown connect the blood pump assembly 100 and the onboard controller 116 to an external controller 22 ( Figure 1 As described above, the blood pump assembly 100 itself also includes a number of software applications that can perform various functions through the onboard controller 116, such as to control the radial suspension and / or drive of the rotor 114 of the pump assembly 100 during operation. The external system controller 22, in turn, can be connected to the battery 24 or a power module (not shown) connected to an alternating current (AC) electrical outlet. The external system controller 22 can also include an emergency backup battery (EBB) to power the system (e.g., when the battery 24 is exhausted) and a membrane coating with Bluetooth capabilities for wireless data communication. An external computer that can be configured by an operator such as a clinician or patient can be further connected to the circulatory support system 10, which is used to configure the external system controller 22, the implanted blood pump assembly 100 and / or patient-specific parameters, update the software on the external system controller 22 and / or the implanted blood pump assembly 100, monitor the operation of the system and / or serve as a line for system input or output.

[0050] Figure 6 is suitable for Figure 1 A schematic diagram of a sensing and control system 200 used in a mechanical blood circulation support system 10 is shown. The sensing and control system 200 includes a controller 202, which in some embodiments may include a controller 22 ( Figure 1 shown) and / or onboard controller 116 ( Figure 3 Controller 202 includes an operator interface module 204, a pump control module 206, and a sensor processing module 208. In some embodiments, one or more of the operator interface module 204, the pump control module 206, and the sensor processing module 208 are located at a computing unit separate from the controller 22 and the onboard controller 116.

[0051] The sensing and control system 200 also includes a plurality of sensors 118, including a pressure sensor 178, a first current sensor 180, a second current sensor 182, an accelerometer 184, and a rotor position sensor 186. The plurality of sensors 118 are connected to the controller 202 by suitable circuits to receive power from the controller and send signals to the controller. For example, a signal processing module 208 of the controller 202 is configured to receive data streams from the pressure sensor 178, the first current sensor 180, the second current sensor 182, the accelerometer 184, and the rotor position sensor 186. In addition, the controller 202 can generate supplementary data streams based on the data streams received from the plurality of sensors 118. For example, the controller 202 can determine a supplementary data stream characterizing the pressure of blood flowing out of the blood pump 102 through the outlet 124 based on the measurements from the first current sensor 180 and the at least one pressure sensor 178.

[0052] The signal processing module 208 is configured to filter the data streams received from the plurality of sensors 118. For example, some of the data streams may include waveform signals, and the data processing module 208 may perform waveform feature extraction on the data streams. During the waveform feature extraction process, the signal processing module 208 identifies waveform signal features that represent measured values, such as carrying current, rotor position, blood flow through the blood pump assembly 100, blood pressure leaving the blood pump assembly 100 (e.g., aortic pressure), and blood pressure entering the blood pump assembly 100 (e.g., left ventricle LV pressure). In addition, the signal processing module 208 may identify the patient's activity level, pumping direction, and movement of the left ventricle LV based on the data streams from the accelerometer and / or other sensors in the plurality of sensors.

[0053] In some embodiments, the signal processing module 208 can perform spectral analysis on the data stream based on the frequency spectrum. For example, in some embodiments, the spectral analysis includes applying a fast Fourier transform (FFT) to the data stream to identify features of the data stream, such as the frequency and amplitude of any periodic signals within the data stream. In some embodiments, a fast Fourier transform FFT can be applied to the accelerometer data stream, and the converted data stream can indicate frequencies associated with the rotor spin rate (rotor speed and its harmonics) and other vibration signals such as vibrations of valve closure. The vibration signal provides "heart sounds" (commonly known as "thump" sounds) that can be interpreted according to known diagnostic practices. For example, changes in the amplitude of the heart sound frequency can be used to detect the degree of valve opening, and even to diagnose valvular pathology, such as aortic valve regurgitation or stenosis.

[0054] Likewise, the signal processing module 208 can be configured to remove noise or artifacts from the signal, and / or adjust waveform parameters based on pre-set thresholds and ranges. In other words, the signal processing module 208 "cleans" the raw data stream to provide a filtered data stream, making it simpler for the controller 202 to use for calculations and / or output.

[0055] The controller 202 is also configured to compare the data streams and / or compare the values ​​determined based on the data streams, and determine the signal quality parameters of each data stream received from the sensor 118 at the signal processing module. For example, the controller 202 can determine the operating parameters of the pump, the cardiac characterization, or the control parameters of the pump based on each data stream, and compare the determined values ​​to determine the signal accuracy and reliability. In some embodiments, the controller 202 determines the values ​​derived separately from each data stream, such as heart rate. Based on the comparison, the controller 202 can associate the quality rating with each data stream or sensor 118. For example, if one of the determined values ​​is different from at least another determined value, the controller 202 can identify which value is more likely to be correct and associate a higher quality rating with the data stream used to determine the value. The controller 202 can associate lower quality ratings with other data streams. In some embodiments, data streams with lower quality ratings (e.g., quality ratings below a preset threshold) are omitted from further calculations.

[0056] In addition, the controller 202 may be configured to determine at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump based on the filtered data stream. For example, the controller 202 may determine any one of the following based on the filtered data stream: heart rate, cycle time, current carrying amplitude, displacement amplitude of the rotor 114, maximum flow through the blood pump assembly 100, minimum flow through the blood pump assembly 100, average flow through the blood pump assembly 100, flow amplitude through the blood pump assembly 100, maximum flow rate change through the blood pump assembly 100, minimum flow rate change through the blood pump assembly 100, maximum aortic pressure, minimum aortic pressure, average aortic pressure, maximum rate of change of aortic pressure, minimum rate of change of aortic pressure, maximum left ventricular pressure, minimum left ventricular pressure, average left ventricular pressure, maximum rate of change of left ventricular pressure, minimum rate of change of left ventricular pressure, maximum left ventricular acceleration, helix angle of the blood pump assembly 100, yaw angle of the blood pump assembly 100, activity level of the patient, and degree of opening of the aortic valve.

[0057] For example, the controller 202 may be programmed to determine the patient's heart rate by applying a fast Fourier transform to the pressure data collected by the pressure sensor 178, and / or by calculating the time intervals between cardiac cycle detection moments (e.g., systolic start, systolic end, diastolic start, and / or diastolic end) apparent from the pressure waveform. The controller 202 may also be programmed to determine ventricular filling pressure or minimum pressure, maximum pressure or maximum systolic pressure, pressure amplitude (i.e., the difference between maximum and minimum pressures), mean pressure, contractility (i.e., maximum systolic dP / dt), relaxation (i.e., minimum systolic dP / dt), end-systolic pressure, end-diastolic pressure, atrial recoil pressure, and any other cardiac characterization by applying mathematical operations to the data collected by the sensor 118.

[0058] In addition, the controller 202 can combine two or more data streams to determine operating parameters of the pump, cardiac characterization, and / or control parameters of the pump. In some embodiments, the controller 202 combines the data streams and provides a statistical weighted value. In other words, the controller 202 determines a statistical weight for each data stream based on a quality rating, a pre-set standard, and / or any other suitable factor, and calculates a value with the determined weight applied to each data stream.

[0059] For example, in some embodiments, the controller 202 can determine the heart rate value based on the accelerometer data stream, the flow waveform data stream, and the left ventricular pressure waveform data stream by applying a fast Fourier transform to each data stream. Applying a fast Fourier transform (FFT) to the data stream can highlight the peaks in the low frequency region (e.g., the low frequency region can be in the range of about 0.5 Hz to 3.0 Hz) in each data stream, and the heart rate value can be determined based on each data stream. In some embodiments, the heart rate value determined based on the flow waveform data stream can be used as a derived value, because the flow waveform data stream can have the highest quality rating and the highest accuracy level in the received data stream. For example, the flow waveform data stream can have a higher signal-to-noise ratio and sampling rate than the accelerometer and left ventricular pressure waveform data streams. However, the derived value can be compared with the heart rate value determined based on the accelerometer and left ventricular pressure waveform data streams to provide confidence for the derived value. For example, if one or both of the accelerometer and left ventricular pressure waveform data streams provide heart rate values ​​that match or are within a predetermined tolerance range for the derived value, the derived value may have a higher or stronger confidence level. If one or both of the accelerometer and left ventricular pressure waveform data streams provide heart rate values ​​that are outside the predetermined tolerance range for the derived value, the derived value may have a lower or weaker confidence level.

[0060] Furthermore, in some embodiments, the controller 202 is configured to determine the operating parameters of the blood pump assembly based on a multivariate algorithm or function that takes into account one or more of the measured values ​​and the determined cardiac characterization or condition. In some embodiments, for example, the controller 202 is configured to determine the target rotor speed based on a weighted function having one or more of the following variables: heart rate, minimum ventricular pressure, ventricular pressure amplitude, and maximum dP / dt.

[0061] Signal processing module 208 may output the determined (multiple) values ​​to pump control module 206 and / or operator interface module 204. Operator interface module 204 presents the values ​​to an operator using an input / output device 210 connected to controller 202. Input / output device 210 may include, for example, but not limited to, an input device including a keyboard, a mouse, a touch screen, (multiple) joysticks, (multiple) valve ports, buttons, switches, and / or other input devices. For example, but not limited to, the input / output device may include an output device including a display (e.g., a liquid crystal display (LCD) or an organic light emitting diode (OLED) display), a speaker, an indicator light, instructions for use, and / or other output devices. In some embodiments, operator interface module 204 is configured to receive at least one operator input such as a patient's clinical status and provide the operator input to pump control module 206 for controlling the operation of blood pump assembly 100. The patient's clinical status may be a clinical measurement or clinical observation such as a cardiac characterization or a medical diagnosis made by a medical professional.

[0062] The pump control module 206 may use the determined value(s) to control the operation of the blood pump assembly 100. Thus, the controller 202 may provide at least partially autonomous or closed-loop control for the blood pump assembly 100 by using information received from the sensor to modify the operation of the blood pump assembly 100. In some embodiments, the controller 202 provides operational control using any of the following based on the determined value(s): rotational speed of the rotor 114, heart assist device average flow control, heart assist device flow amplitude control, minimum left ventricular LV control, left ventricular LV pressure amplitude control, and combinations thereof. For example, in some embodiments, the pump control module 206 is included on the onboard controller 116 and is configured to control the rotational speed of the rotor 114 based on the determined value(s) received from the signal processing module 208. For example, the onboard controller 116 is operably connected to the stator 112 and is configured to control the operation of the blood pump 102 by controlling the current supply to the stator 112, and thereby controlling the rotation of the rotor 114. The pump control module 206 may be configured to control the rotor 114 in continuous flow operation and / or pulsating flow operation.

[0063] In some embodiments, for example, controller 202 is configured to control the operation of blood pump 102 to obtain a desired or preset cardiac characterization. Controller 202 may periodically or continuously interrogate sensor 118 and compare the detected or determined value to one or more set points (e.g., pressure set point, flow set point). If the detected or determined value is different from the set point, controller 202 may adjust the operation of blood pump assembly 100 to achieve the set point. In some embodiments, controller 202 is configured to determine whether the difference between the characterization and the set point exceeds a critical difference before adjusting the operation of blood pump assembly 100.

[0064] The set value may be established by operator input, such as from a patient or clinician, and may be stored in a storage device of the controller 202. The set value may be a fixed (i.e., time-invariable) set value, or the set value may be a time-variable set value. For example, the pressure set value may vary according to different phases of the cardiac cycle. That is, the pressure set value may be defined by a pressure curve that defines a desired pressure set value or a target pressure set value at different times or different phases of the cardiac cycle. In addition, the operator input may include a plurality of set values, and the controller 202 may select the set value based on the determined operating parameters and / or cardiac characterization. In some embodiments, the set value(s) may include a rated flow set value, a rated rotor speed set value, a rotor amplitude set value, and / or a set value for any other applicable operating parameter.

[0065] In addition, in some embodiments, the set point can be adjusted in real time based on the measured values ​​received from the sensor 118 and / or the determined heart condition or heart characterization. For example, in some embodiments, the controller 202 is configured to increase or decrease the pressure set point based on the maximum slope (dP / dt) of the measured ventricular pressure waveform. The maximum slope dP / dt is related to the contractility of the left ventricle and can be used to adjust the pressure set point and the resulting rotor speed to achieve the desired left ventricular unloading. For example, the controller 202 can be configured to increase the pressure set point and / or the rotor speed based on the determined maximum dP / dt to increase the left ventricular unloading. In addition, in some embodiments, the controller 202 is configured to increase or decrease the pressure set point based on the determined patient's heart rate. For example, an increased heart rate indicates an increase in demand for cardiac output (e.g., from exercise), and the controller 202 can be configured to increase the pressure set point by a corresponding amount. Additionally or alternatively, the controller 202 can be configured to increase or decrease the pressure set point based on feedback received from the accelerometer 184 included in the blood pump assembly 100. For example, based on feedback from accelerometer 184, controller 202 may determine that the user of blood pump assembly 100 is exercising or engaging in strenuous activity and increase the pressure setting or speed of the rotor accordingly.

[0066] In various embodiments, the controller 202 can determine certain pump operations and / or patient states based on the measurements received from the sensor 118, and control the blood pump 102 accordingly. For example, Table 1 below is an exemplary correlation table that shows how measured and / or determined parameters from the sensor 118 are linked and / or associated with pump operating conditions and patient states. In particular, for a particular parameter listed in the leftmost column, Table 1 shows how a positive (+) or negative (-) deviation from a mean or expected value of the parameter is associated with a particular pump condition ("inhalation") and / or one of a plurality of patient states ("arrhythmia", "hypertension", "exercise", "sleep", and "recovery").

[0067] Table 1

[0068]

[0069]

[0070]

[0071]

[0072] In Table 1, the rotor excursion amplitude refers to the average peak-to-peak radial rotor excursion amplitude over a period of time, in micrometers (μm). The rotor excursion amplitude can be determined based on the data stream from the rotor position sensor 186. The carrying current amplitude refers to the average peak-to-peak carrying current amplitude over a period of time, in milliamperes (mA). The carrying current amplitude can be determined based on the data stream from the current sensor 182. The minimum, average, and maximum flow values ​​refer to the average minimum, average, and maximum flow rates over a period of time, in liters per minute. The flow amplitude refers to the average peak-to-peak flow amplitude rate over the period of time, in liters per minute. The flow value can be determined based on the data stream from the current sensor 180. The minimum, average, and maximum left ventricular pressure values ​​refer to the average minimum, average, and maximum left ventricular pressure values ​​over a period of time, in millimeters of mercury (mmHg). The left ventricular pressure amplitude refers to the average peak-to-peak left ventricular pressure amplitude over a period of time, in millimeters of mercury (mmHg). The left ventricular pressure value can be determined based on the data stream from the inflow pressure sensor 178. Maximum left ventricular wall velocity refers to the average peak left ventricular wall velocity during systole over a period of time, in millimeters per second. Maximum left ventricular wall velocity can be determined based on the data stream from accelerometer 184. Patient activity level refers to the overall patient activity level provided as a percentage of the maximum level indicating the patient's "exercise" state. Patient activity level can be determined based on the data stream from accelerometer 184. Minimum, average, and maximum aortic pressures refer to the average minimum, average, and maximum aortic pressures, respectively, over the period of time, in millimeters of mercury (mmHg). Minimum, average, and maximum aortic pressures can be determined based on the data streams from current sensor 180 and pressure sensor 178. Aortic pressure amplitude refers to the average peak-to-peak aortic pressure amplitude over the period of time, in millimeters of mercury (mmHg). Aortic pressure amplitude is determined based on the data streams from current sensor 180 and pressure sensor 178. Heart rate refers to the average heart rate over a period of time, in beats per minute. Heart rate variability refers to the variability of the average heart rate over a period of time, provided as a percentage. Percent contraction refers to the average percentage of the cardiac cycle spent contracting. Heart rate, heart rate variability, and percent contraction can be determined based on data streams from the rotor position sensor 186, current sensor 182, pressure sensor 178, and accelerometer 184. Left ventricular systolic elastance (contractility) refers to the slope of the left ventricular elastance curve during systole (from the pressure-volume (PV) loop), which measures the contractility of the left ventricle in millimeters of mercury per milliliter (mmHg / mL). Left ventricular diastolic elastance refers to the slope of the left ventricular elastance curve during diastole (PV loop), which measures the diastolic stiffness of the left ventricle in millimeters of mercury per milliliter (mmHg / mL). The left ventricular filling state is a derived value that combines the minimum left ventricular pressure and flow amplitude and is provided as a percentage.Aortic Valve Flow is the estimated total flow across the aortic valve, provided in liters per minute. Total Cardiac Output is the estimated total cardiac output, provided in liters per minute. Ventricular Assist Device (VAD) Work Share is the percentage of total hydraulic work (systemic) performed by the VAD compared to the left ventricle. Systemic Vascular Resistance is the average systemic resistance over time, provided in mmHg / L per minute. Global Work Status is a derived value that combines the patient's activity level, left ventricular filling state, and heart rate, and is provided as a percentage. Inlet Occlusion is the percentage of the inlet that is occluded or blocked (where 100% means the inlet is completely blocked and 0% means the inlet is completely open). Outlet Occlusion is the percentage of the outlet that is blocked.

[0073] The parameters in Table 1 are derived from two or more measured or determined data streams. For example, based on the left ventricular pressure waveform and flow waveform, the hemodynamic state parameters (left ventricular contraction elastance, left ventricular diastolic elastance, left ventricular filling state, aortic valve flow, overall cardiac output, and ventricular assist device work share) can be determined. Similarly, based on the left ventricular pressure waveform and flow waveform, the systemic vascular resistance, overall use state, inlet occlusion, and outlet occlusion can be determined.

[0074] As shown in Table 1, the parameters can be used to indicate the operating state of the pump and the patient state. For example, the controller 202 can identify positive and negative changes (+ / -) from an average or expected value for each parameter and associate the change with one or more states listed along the top row of Table 1. States represented by "+" are associated with positive changes from an average or expected value for the corresponding parameter. States represented by "-" are associated with negative changes from an average or expected value for the corresponding parameter.

[0075] In some embodiments, when multiple parameters are associated with a single state, importance values ​​can be assigned to the parameters. The parameters can be weighted based on the importance values ​​to provide a more accurate indication of the state. The importance values ​​can be based on the quality level of the data fed from the sensor, the reliability of the determined parameters, and / or any other suitable factors. In such embodiments, the controller 202 can weight the parameters based on the importance values ​​to determine the operating state of the pump or the patient state represented by the positive deviation and the negative deviation. For example, Table 2 below shows an exemplary importance level list for the parameters listed in Table 1, where 5 represents the most important and 1 represents the least important.

[0076] Table 2:

[0077]

[0078]

[0079]

[0080] As described above, the controller 202 may control the blood pump 102 based on the operating state of the pump and / or the patient state as determined by the data feeds received from the plurality of sensors 118. For example, Table 3 below illustrates an exemplary control scheme that may be implemented by the controller 202 to control the blood pump 102. Specifically, Table 3 illustrates under what conditions the controller 202 will increase the pump speed ("+") relative to the rotor speed setpoint, and under what conditions the controller 202 will decrease the pump speed ("-") relative to the rotor speed setpoint.

[0081] Table 3:

[0082]

[0083] In addition, in some embodiments, the controller 202 is configured to control the speed of the rotor 114 according to a speed curve that defines a time-variable speed set point for the rotor 114. In these embodiments, the controller 202 may be configured to adjust the speed of the rotor 114 to different speed set points within a single cardiac cycle of the patient's heart. Such rotor speed control (also referred to as "synchronization pulsing") may be implemented by the controller 202 in any suitable manner that enables the blood pump assembly 100 to function as described herein. For example, in some embodiments, the controller 202 may be configured to increase the speed of the rotor 114 during systole (referred to as "co-pulsation"), or to decrease the speed of the rotor 114 during systole (referred to as "counter-pulsation"). In some other embodiments, the controller 202 may be configured to increase the speed of the rotor 114 during a first time period during systole, and to decrease the speed of the rotor 114 during a second time period during systole. In addition, the synchronization pulsing of the rotor may be implemented by the controller 202 at different time intervals. For example, controller 202 may be configured to adjust the speed of rotor 114 to different speed settings within a single cardiac cycle of the patient's heart or within more than one cardiac cycle of the patient's heart (eg, across two cardiac cycles).

[0084] In other embodiments, the controller 202 is configured to control the speed of the rotor 114 according to a fixed (i.e., time-invariable) speed setpoint. In such embodiments, the controller 202 may be configured to control the speed of the rotor 114 to obtain an average speed equal to the speed setpoint. The rotor speed profile and / or setpoint may be established by operator input (e.g., by a patient or clinician) and may be stored in a memory device of the controller 202.

[0085] Suitably, control and sensing system 200 is configured to combine information from different sensors 118 to provide operating parameters for different operating states of blood pump assembly 100. For example, when blood pump assembly 100 is in pulse mode, controller 202 relies primarily on sensors 118 rather than current sensors 180, 182 because current sensors 180, 182 may not provide a continuous stream of data when blood pump assembly 100 is operating in pulse mode.

[0086] In addition, based on the information received from the sensors 118, the controller 202 can switch between operating states. For example, if the filtered data stream from the accelerometer 184 indicates that the patient is active, the controller 202 can adjust the pulse synchronization process based on the information from the accelerometer 184. In some embodiments, based on the information from the multiple sensors 118, the controller 202 can select a pulse mode for the blood pump assembly 100 (e.g., a co-pulse mode in which the pump speed is increased during systole, a reverse pulse mode in which the pump speed is decreased during diastole, a combination of co-pulse and reverse pulse, or an asynchronous pulse mode). In addition, based on the information from the multiple sensors 118, the controller 202 can select one or more pulse parameters (e.g., amplitude, frequency, duration).

[0087] As described above, the controller 202 may employ one or more determined cardiac conditions or cardiac characterizations to perform closed-loop speed control of the pump rotor 114. For example, an increase in heart rate, minimum ventricular pressure, or ventricular pressure amplitude generally indicates an increased demand for cardiac output. Thus, in some embodiments, when data from at least one sensor 118 indicates an increase in heart rate, minimum ventricular pressure, and / or ventricular pressure amplitude, the controller 202 is configured to adjust the speed of the rotor 114 by a corresponding amount.

[0088] In addition, in some embodiments, one or more determined cardiac conditions or characterizations can be used to detect and / or evaluate the physiological function of the heart. For example, the left ventricular pressure amplitude (i.e., the difference between the maximum pressure and the minimum pressure) is a combined indicator of both filling pressure and cardiac contractility. The minimum dP / dt can be used to evaluate the relaxation rate of the ventricle and to identify possible fibrosis or conductivity problems. The maximum dP / dt can be used to evaluate the contractile elastance curve of the ventricle, which directly measures the left ventricular functional performance. For example, this can be used to detect left ventricular rehabilitation and thereby to adjust the target pressure and / or rotor speed setpoints stored in the controller 202.

[0089] Figure 7is an example graph of data that may be collected and output by pressure sensor 178 during operation of blood pump assembly 100. The example graph illustrates a left ventricular pressure waveform 700 (i.e., pressure versus time) over a period of approximately 3 seconds. Signal processing module 208 may receive waveform 700 and perform filtering operations such as waveform extraction, and then determine one or more numerical values ​​based on the filtered data stream. For example, controller 202 may be configured to determine ventricular filling pressure or minimum pressure by identifying a local minimum pressure value on the pressure waveform within a single cardiac cycle phase. Figure 7 An exemplary ventricular filling pressure value is shown at point 702 in FIG. Controller 202 may be further configured to determine the maximum systolic pressure by identifying a local maximum pressure value on the pressure waveform during a single cardiac cycle phase. Figure 7 An exemplary maximum systolic pressure value is shown at point 704 in FIG. The controller 202 is further configured to determine a pressure amplitude 706 within a single cardiac phase of the pressure waveform by determining the difference between the maximum pressure 704 and the minimum pressure 702. The controller 202 may also be configured to determine contractility by determining a maximum slope 708 of the pressure waveform within the systolic phase of a single cardiac cycle. The controller 202 may also be configured to determine relaxation by determining a minimum slope 710 of the pressure waveform within the systolic phase of a single cardiac cycle. The controller 202 may also be configured to determine end-systolic pressure and end-diastolic pressure by identifying pressure values ​​along the pressure waveform at the end of the systolic phase and the diastolic phase of the cardiac cycle, respectively. The controller 202 may also be configured to identify atrial recoil pressure by identifying a pressure value at a local maximum of the pressure waveform within the diastolic phase of a single cardiac cycle (i.e., between the end of systole of a first cardiac cycle and the beginning of systole of a second cardiac cycle). The controller 202 may be configured to determine or identify various phases of the cardiac cycle (e.g., systole and diastole) for the pressure waveform based on, for example, the minimum pressure value, the maximum pressure value, the maximum slope value, and the minimum slope value. For example, the controller 202 may be configured to determine that a particular portion of the pressure waveform corresponds to the systole phase of the cardiac cycle by determining or identifying an area between a maximum slope and a minimum slope on the pressure waveform.

[0090] Figure 880 is an example diagram of data that can be collected and output by multiple sensors. The example diagram shows an acceleration waveform 802, a rotor position waveform 804, a rotor speed waveform 806, a flow waveform 808, and an estimated flow waveform 810. For example, the acceleration waveform 802 is based on data collected by the accelerometer 184. The rotor position waveform 804 is based on data collected by the rotor position sensor 186. The flow waveform 808 is based on a value determined using a data stream from one or more sensors 118 (e.g., the first current sensor 180 and the pressure sensor 178). The data shown in the example diagram is collected while operating the controller 202 to synchronize the pulse of the blood pump assembly 100 with the heart pulse using the measurement results of the current sensors 180 and 182. For example, the controller 202 identifies when the instantaneous current / flow reading switches between low and high values ​​and changes the operation of the blood pump assembly to adapt to the change. When the instantaneous current / flow reading is higher than the average flow value, the instantaneous current / flow reading is considered to be a high value, and when the instantaneous current / flow reading is lower than the average flow value, the instantaneous current / flow reading is considered to be a low value. When the instantaneous current / flow reading transitions from a low value to a high value and indicates a change from diastolic flow to systolic flow, controller 202 identifies the onset of systole. Controller 202 then operates blood pump assembly 100 to account for the onset of systole.

[0091] Fig. 9 906, a rotor position waveform 904, a rotor speed waveform 906, a flow waveform 908, and an estimated flow waveform 910. For example, acceleration waveform 902 is based on data collected by accelerometer 184. Rotor position waveform 904 is based on data collected by rotor position sensor 186. Flow waveform 908 is based on values ​​determined using data streams from one or more sensors 118. The data shown in the example figure is collected while operating controller 202 to synchronize the pulses of blood pump assembly 100 with cardiac pulses using measurements from an outflow flow sensor located external to blood pump assembly 100.

[0092] Fig. 10A and Fig. 10B1 is a flow chart illustrating one embodiment of a method 1000 for operating an implantable blood pump (e.g., blood pump 102) in a patient. In the illustrated embodiment, method 1000 includes detecting 1004 a current provided to a stator (e.g., stator 112) using a current sensor (e.g., current sensors 180, 182), detecting 1006 a position of a rotor (e.g., rotor 114) relative to a housing (e.g., housing 104) using a rotor position sensor (e.g., rotor position sensor 186), detecting 1008 an acceleration of the blood pump in at least one direction using an accelerometer (e.g., accelerometer 184), and detecting 1010 a pressure of blood flowing through a flow channel using a pressure sensor (e.g., pressure sensor 178). Method 1000 also includes receiving 1012 a data stream from a current sensor at a signal processing module (e.g., signal processing module 208) of a controller connected to the plurality of sensors, receiving 1014 a data stream from a rotor position sensor at the signal processing module, receiving 1016 a data stream from an accelerometer at the signal processing module, and receiving 1018 a data stream from a pressure sensor at the signal processing module.

[0093] The method 1000 also includes filtering 1020, by the controller, each of the data streams received at the signal processing module, and determining 1022, by the controller, at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump based on at least two of the filtered data streams. For example, in some embodiments, filtering the data streams includes performing waveform feature extraction on the data streams. The waveform features (e.g., amplitude, frequency, wavelength) can indirectly correspond to an operating state of the pump and / or a cardiac characterization. Thus, the controller can utilize one or more waveform features extracted from one or more of the data streams to determine an operating parameter of the pump, a cardiac characterization, or a control parameter of the pump.

[0094] The method 1000 also includes outputting 1024 at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump from the signal processing module to at least one of an operator interface module (e.g., operator interface module 204) and a pump control module (e.g., pump control module 206). The pump control module can control the operation of the pump based on the values ​​received from the signal processing module. For example, in some embodiments, the pump control module controls the rotational speed of the rotor based on the values ​​received from the signal processing module. Additionally, in some embodiments, the operator interface module can provide the values ​​received from the signal processing module to an operator using a display.

[0095] In some embodiments, method 1000 also includes generating a supplemental data stream based on at least two of the data streams received by the signal processing module. For example, the signal processing module can determine a blood pressure waveform flowing through the outlet of the blood pump based on the current provided to the stator and the pressure of the blood flowing through the flow channel. Therefore, the supplemental data stream can represent the pressure of the patient's blood flow (e.g., aortic pressure). The supplemental data stream can be filtered and combined or compared with other filtered data streams. In addition, the controller can determine at least one of the operating parameters of the pump, the cardiac characterization, and the control parameters of the pump based on the supplemental filtered data stream.

[0096] Likewise, in some embodiments, method 1000 includes comparing the data streams received from each sensor. The data streams can be compared by determining a cardiac characterization based on each data stream and comparing the determined cardiac characterizations. For example, the determined values ​​can be evaluated to identify abnormal values, i.e., determined values ​​that are significantly different from at least two other values. In addition, the determined values ​​can be compared with directly measured or estimated values ​​to identify values ​​that are significantly different from the expected and / or measured cardiac characterizations. For example, in some embodiments, the patient's heart rate is determined based on each data stream. Each determined heart rate can be compared with the actual measured value of the patient's heart rate and / or the patient's expected heart rate range to check whether the data stream is within a preset accuracy range. Additionally or alternatively, the determined heart rates are compared to each other to check whether any data stream is significantly more accurate / less accurate than other data streams.

[0097] In addition, in some embodiments, method 1000 includes associating a quality rating with each data stream. For example, the signal processing module can assign a digital value or other numerical value to each data stream based on a point grading system or a predetermined level (e.g., levels 1-5, 1 is the lowest quality level, and 5 is the highest quality level). The quality rating can allow the controller to weight the data streams and rely more on data streams with higher quality ratings. In addition, in some embodiments, the controller can ignore data streams with quality ratings that do not meet a threshold. In addition, the controller can provide quality ratings for one or more data streams to be presented to the operator using an operator interface. In other embodiments, the data streams can be compared and rated in any suitable manner. For example, in some embodiments, the signal processing module can compare and evaluate the data streams based on data stream characterizations such as signal strength.

[0098] Fig.11 The present invention is to describe the information collected by the sensor and controlled by the controller (eg, Figure 62002) and a flowchart of the data processing. In the illustrated embodiment, data feeds are provided by current sensor 2002, rotor drive current sensor 2004, left ventricular pressure sensor 2006, and accelerometer 2008. Accelerometer 2008 includes Z-acceleration element 2010, Y-acceleration element 2012, and X-acceleration element 2014.

[0099] The data feeds from the sensors 2002, 2004, 2006, 2008 are transformed and / or filtered in order to extract a plurality of parameters. For example, the data feed from the current sensor 2002 undergoes a carried current transformation 2016 and a rotor radial position calculation 2018 to provide carried current data and rotor radial position data, respectively. The obtained carried current data and rotor radial position data undergo respective waveform feature extractions 2028 and 2030. The carried current waveform feature extraction 2028 can be used to determine or extract various parameters 2044, including heart rate and cycle time and carried current amplitude. Similarly, the rotor position waveform feature extraction 2030 can be used to determine various parameters 2046, including heart rate and cycle time (e.g., as redundant values) and carried displacement amplitude.

[0100] In addition, the rotor speed 2020 is calculated based on data feeds from the current sensor 2002 and / or the rotor drive current sensor 2004. For example, the controller receives one or more data streams of the displacement and angular position of the rotor and determines how much drive current and carrying current to provide to the rotor based on the data streams. The carrying current and drive current provided are measured by one or more current sensors 2002. The measured drive current is directly related to the rotor speed 2020. Therefore, the calculated rotor speed 2020 can be determined based on the data feed from the rotor drive current sensor 2004. The calculated rotor speed 2020 is used to calculate 2022 a flow value for the ventricular assist device. The resulting ventricular assist device flow value undergoes a ventricular assist device flow waveform extraction 2032 for determining or extracting various parameters 2048, including heart rate and cycle time (e.g., as redundant values), maximum, minimum and average flow (Q) (e.g., in liters / minute), flow amplitude (e.g., in liters / minute), and minimum and maximum slopes (dQ / dt) of the flow waveform.

[0101] Additionally, the calculated rotor speed 2020 is used in conjunction with the data feed from the left ventricular pressure sensor 2006 to calculate 2024 an aortic pressure value. The resulting aortic pressure value undergoes an aortic pressure (AOP) waveform extraction 2034 that can be used to determine or extract various parameters 2050, including heart rate and cycle time (e.g., as redundant values), maximum, minimum, and mean aortic pressure values ​​(e.g., in mmHg), aortic pressure amplitude (e.g., in mmHg), and minimum and maximum slopes of the aortic pressure waveform (dAOP / dt).

[0102] Additionally, the calculated ventricular assist device flow value 2022 is used in conjunction with the data feed from the left ventricular pressure sensor 2006 to calculate 2026 a left ventricular (LV) pressure value. The resulting left ventricular pressure value undergoes a left ventricular pressure (LVP) waveform extraction 2036 that can be used to determine or extract various parameters 2052, including heart rate and cycle time (e.g., as redundant values), maximum, minimum, and mean left ventricular pressure values ​​(e.g., in mmHg), left ventricular pressure amplitude (e.g., in mmHg), and minimum and maximum slopes of the left ventricular pressure waveform (dLVP / dt).

[0103] In the illustrated embodiment, data feeds from the Z-acceleration component 2010, the Y-acceleration component 2012, and the X-acceleration component 2014 undergo a feature extraction process to determine additional parameters. For example, the data feed from the Z-acceleration component 2010 undergoes a wall motion feature extraction 2038 process to determine or extract various parameters 2054, including heart rate and cycle time (e.g., as redundant values) and maximum left ventricular acceleration (e.g., in units of millimeters per second per second (mm / s / s)).

[0104] Additionally, in the illustrated embodiment, data feeds from the Z-acceleration component 2010, the Y-acceleration component 2012, and the X-acceleration component 2012 are combined in a pump direction determination function 2040 to determine the direction of the blood pump 102. The pump direction determination function 2040 may be used to determine or extract various parameters 2056, including the helix angle of the blood pump 102 and the yaw angle of the blood pump 102.

[0105] Furthermore, in the illustrated embodiment, data feeds from the Y-acceleration component 2012 and the X-acceleration component 2012 are combined in the patient activity level determination function 2042 to determine the patient activity level 2058 .

[0106] Likewise, two or more extracted parameters may be combined to provide a combined parameter 2060 and / or signal quality indicator. The combined parameter 2060 may include, for example but not limited to, heart rate, cardiac cycle variability, cardiac cycle contraction percentage, minimum flow through the blood pump assembly 100, maximum flow through the blood pump assembly 100, average flow through the blood pump assembly 100, flow amplitude through the blood pump assembly 100, maximum flow rate of change through the blood pump assembly 100, minimum flow rate of change through the blood pump assembly 100, maximum aortic pressure, minimum aortic pressure, average aortic pressure, aortic pressure amplitude, maximum rate of change of aortic pressure, minimum rate of change of aortic pressure, maximum left ventricular pressure, minimum left ventricular pressure, average left ventricular pressure, left ventricular pressure amplitude, maximum rate of change of left ventricular pressure, minimum rate of change of left ventricular pressure, maximum left ventricular acceleration, helix angle of the blood pump assembly 100, yaw angle of the blood pump assembly 100, and activity level of the patient.

[0107] Additionally, one or more patient clinical states 2062 may be determined based on the combined parameters 2060. The clinical states 2062 include, for example, but are not limited to, left ventricular systolic elastance (contractility), left ventricular diastolic elastance, left ventricular relaxation constant, left ventricular filling state, aortic valve flow, total cardiac output, ventricular assist device work fraction, systemic vascular resistance, aortic compliance, the patient's overall operational state, inlet occlusion, and outlet occlusion.

[0108] Although certain steps of the example methods are numbered, such numbering does not indicate that the steps must be performed in the order listed. Therefore, unless the description thereof specifically requires such order, the specific steps need not be performed in the exact order in which they are presented. The steps may be performed in the order listed, or in any other suitable order.

[0109] As described herein, the implantable blood pump assembly of the present invention provides several advantages over existing ventricular assist device designs. For example, embodiments of the implantable blood pump assembly disclosed herein include multiple sensors connected to a controller. By combining and / or comparing data streams from multiple sensors, the blood pump assembly provides a wider range of information and more reliable information than existing systems. Similarly, the controller is able to determine and provide information related to the accuracy of the signals from multiple sensors, which can make the operator more confident in the accuracy and reliability of the system. In addition, based on comparing the information from multiple sensors, the controller can determine a statistically weighted value to ensure that accurate information is used to operate the blood pump assembly. In addition, the implantable blood pump assembly can be at least partially autonomously operated using information provided by multiple sensors and closed-loop control of a controller connected to the multiple sensors.

[0110] Although the embodiments and examples disclosed in the present invention have been described with reference to specific embodiments, it should be understood that these embodiments and examples are only used to illustrate the principles and applications of the present invention. It should therefore be understood that the illustrative embodiments and examples may be modified multiple times, and other arrangements may be designed without departing from the spirit and scope of the present invention as defined by the claims. Therefore, the present application is intended to cover modifications and variations of these embodiments and their equivalents.

[0111] This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any device or system and performing any incorporated method. The patentable scope of the invention is defined by the claims and may include other examples that occur to those skilled in the art. If such other examples have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements that do not differ substantially from the literal language of the claims, then these other examples are within the scope of the claims.

Claims

1. A blood circulation support system, comprising: Implantable blood pump, including: a housing defining an inlet, an outlet, a flow passage extending from the inlet to the outlet, and an internal compartment separate from the flow passage; a rotor positioned within the flow channel and operable to pump blood from the inlet to the outlet; a stator positioned within the interior compartment and operable to drive the rotor; A plurality of sensors including at least two of the following: a current sensor configured to detect a current provided to the stator; a rotor position sensor configured to detect a position of the rotor relative to the housing; an accelerometer configured to detect acceleration of the blood pump in at least one direction; and a pressure sensor positioned between the inlet and the outlet and configured to detect a pressure of blood flowing through the flow channel; a controller connected to the plurality of sensors and comprising a signal processing module and at least one of an operator interface module and a pump control module, wherein the signal processing module is configured to: receiving a data stream from each of the plurality of sensors; filtering data streams received from the plurality of sensors; determining at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump based on at least two of the filtered data streams; and At least one of an operating parameter of the pump, the cardiac characterization, and a control parameter of the pump is output to at least one of the operator interface module and the pump control module.

2. The circulatory support system of claim 1, wherein the controller is configured to determine a signal quality parameter for each data stream received at the signal processing module. 3 . The circulatory support system of claim 1 , wherein for each data stream received from the plurality of sensors, the controller is configured to determine a cardiac representation based on the data stream and compare the determined cardiac representations with each other.

4. The circulatory support system of claim 3, wherein the controller is configured to associate each data stream with a quality rating based on a comparison of the determined cardiac characterizations.

5. The blood circulation support system according to claim 1, wherein the controller comprises a pump control module, and the pump control module is configured to: receiving from the signal processing module at least one of an operating parameter of the pump, the cardiac characterization, and a control parameter of the pump; and Operation of the implantable blood pump is controlled based on at least one of an operating parameter of the pump, the cardiac characterization, and a control parameter of the pump.

6. The circulatory support system of claim 1 , wherein the accelerometer is configured to detect acceleration of the pump in a first direction, a second direction, and a third direction, and wherein the controller is configured to determine an activity level of the patient based on the acceleration in at least one of the first direction, the second direction, and the third direction.

7. The circulatory support system of claim 1 , wherein the controller is configured to generate a supplemental data stream based on the data streams received from the current sensor and the pressure sensor, wherein the supplemental data stream includes the pressure of blood flowing from the implantable blood pump through the outlet.

8. The blood circulation support system according to claim 1, wherein the controller is configured as follows: assigning a statistical weight to each filtered data stream; and A statistical weight value is output for at least one of an operating parameter of the pump, the cardiac characterization, and a control parameter of the pump.

9. The circulatory support system of claim 8, wherein for each data stream received from the plurality of sensors, the controller is configured to: determining a cardiac characterization based on the data stream; comparing the determined cardiac representations to each other; and Each data stream is associated with a quality rating based on the comparison of the determined cardiac representations.

10. The circulatory support system of claim 9, wherein the controller is configured to determine a statistical weight for each filtered data stream based on a quality rating associated with the respective filtered data stream.

11. The circulatory support system of claim 1 , wherein the controller comprises the operator interface module, and wherein the operator interface module is configured to display at least one of an operating parameter of the pump, the cardiac representation, and a control parameter of the pump.

12. The circulatory support system of claim 1 , wherein the controller comprises the operator interface module and the pump control module, wherein the operator interface is configured to receive at least one operator input related to a clinical state of a patient and provide the operator input to the pump control module, and wherein the pump control module is configured to control operation of the pump based on the operator input and based on at least one of an operating parameter of the pump, the cardiac characterization, and a control parameter of the pump.

13. The circulatory support system of claim 1 , wherein the controller is configured to transmit a control signal to a pump control module to adjust operation of the pump when at least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump determined based on at least two filtered data streams exceeds a critical difference from a set value.

14. An implantable blood pump comprising: a housing defining an inlet, an outlet, a flow passage extending from the inlet to the outlet, and an internal compartment separate from the flow passage; a rotor positioned within the flow channel and operable to pump blood from the inlet to the outlet; a stator positioned within the interior compartment and operable to drive the rotor; Multiple sensors, including: a current sensor configured to detect a current provided to the stator; a rotor position sensor configured to detect a position of the rotor relative to the housing; an accelerometer configured to detect acceleration of the blood pump in at least one direction; and a pressure sensor positioned between the inlet and the outlet and configured to detect the pressure of blood flowing through the flow channel, Wherein a plurality of the sensors are connected to a controller, and the controller is configured as follows: receiving a data stream from each of the plurality of sensors; filtering data streams received from said plurality of said sensors; and At least one of an operating parameter of the pump, a cardiac characterization, and a control parameter of the pump is determined based on the filtered data stream.

15. The implantable blood pump of claim 14, wherein the plurality of sensors comprises a first current sensor connected to a drive coil of the stator, and a second current sensor connected to a suspension coil of the stator.

16. The implantable blood pump of claim 14, wherein the accelerometer is configured to detect acceleration of the blood pump in a first direction parallel to the rotation axis of the rotor, in a second direction perpendicular to the rotation axis, and in a third direction perpendicular to the rotation axis and perpendicular to the second direction.

17. The implantable blood pump of claim 14, wherein the controller is configured to combine the filtered data streams according to a statistical weighted value system based on an operational state of the implantable blood pump.

18. The implantable blood pump of claim 14, further comprising an onboard controller configured to control current supply to the stator and rotation of the rotor based on control signals received from the controller.

19. The implantable blood pump of claim 18, wherein the control signal is based on at least one of a determined operating parameter of the pump, a cardiac characterization, and a control parameter of the pump.

20. The implantable blood pump of claim 18, wherein the control signal comprises a selected pulse pattern.

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