Triaxial accelerometer for patient physiological monitoring and closed-loop control of implantable ventricular assist devices

Abstract

A blood circulation assist system includes a ventricular assist device (VAD), a remote accelerometer, and a controller that controls operation of the VAD based on an output of the remote accelerometer. The blood circulation assist system includes a VAD, a controller, and a remote accelerometer. The VAD includes an impeller. The remote accelerometer is configured to generate a remote accelerometer output indicative of an acceleration measured by the remote accelerometer. An implanted controller controls the rotational speed of the impeller based on the remote accelerometer output.

Description

Cross-references to related application data

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 346,007, filed on May 26, 2022; the entire disclosure of which is incorporated herein by reference for all purposes. Background Art

[0002] Ventricular assist devices, called VADs, are used for both short-term (i.e., days, months) and long-term blood circulation assistance (i.e., years or a lifetime) where the patient's heart is unable to provide adequate circulation, commonly referred to as heart failure or congestive heart failure. According to the American Heart Association, more than five million Americans suffer from heart failure, and approximately 670,000 new cases are diagnosed each year. People with heart failure often experience shortness of breath and fatigue. Years of living with blocked arteries and / or high blood pressure can weaken the heart and make it unable to pump enough blood to the body. As symptoms worsen, advanced heart failure occurs.

[0003] Patients with heart failure may use a VAD while they are waiting for a heart transplant or as a long-term replacement therapy (destination therapy). Patients may also use a VAD while they are recovering from heart surgery. Thus, a VAD can assist a weakened heart (i.e., partial support) or can effectively replace the function of the native heart. Summary of the invention

[0004] A simplified overview of some embodiments of the present invention is presented below to provide a basic understanding of the present invention. Summary of the present invention is not a broad overview of the present invention. It is not intended to identify the key / determining elements of the present invention or to describe the scope of the present invention. Its sole purpose is to present some embodiments of the present invention in a simplified form as a preface to the specific embodiments presented later.

[0005] The blood circulation assist system and related methods use a remote accelerometer that measures the acceleration of the patient's body away from the implanted ventricular assist device. In some embodiments, the implanted transcutaneous energy system (TETS) power receiver unit includes a remote accelerometer, and the remote accelerometer measures the acceleration induced by the TETS power receiver unit. In some embodiments, the implanted controller unit includes a remote accelerometer, and the remote accelerometer measures the acceleration induced by the implanted unit. In many embodiments, the measured acceleration is processed for controlling the operation of the VAD, generating patient monitoring data, and / or generating VAD monitoring data. In some embodiments, the measured acceleration is processed to measure the patient's activity level, which is used to control the output level of the VAD based on the patient's activity level. In such embodiments, the output level of the VAD can increase in response to an increase in the patient's activity level and decrease in response to a decrease in the patient's activity level. In some embodiments, the measured acceleration is processed to track the patient's cardiac cycle timing, which is used to control the output change of the VAD synchronously with the patient's cardiac cycle timing. In some embodiments, the measured acceleration is used to generate patient monitoring data and / or VAD monitoring data. By controlling the operation of the VAD based on the patient's activity level and / or in synchronization with the timing of the patient's cardiac cycle, the circulatory support provided is better tailored to the patient's needs. The availability of patient monitoring data and / or VAD tracking data can enable an improved ability to diagnose patient health issues and / or VAD operation issues. In some embodiments where the VAD includes a power transistor for controlling current flowing to a motor stator of the VAD, the remote accelerometer is located away from the power transistor and electrical noise generated by the power transistor. As a result of being located away from the electrical noise, the remote accelerometer can generate an output signal that more accurately reflects the acceleration induced by the remote accelerometer.

[0006] Therefore, in one aspect, a blood circulation assist system comprises a ventricular assist device (VAD), a transcutaneous energy transfer system (TETS) power receiver, a controller and a remote accelerometer. The VAD comprises an inlet, an outlet, an impeller and a motor stator, which is operable to rotate the impeller to pump blood flow. The inlet is configured to couple with the patient's ventricle to receive blood flow from the ventricle. The outlet is configured to couple with the patient's blood vessel to transmit blood flow to the blood vessel. The TETS power receiver is configured to be implanted and receive energy emitted by an external TETS transmitter. The controller is configured to be implanted, process a remote accelerometer output, and control the rotation speed of the impeller based on the remote accelerometer output. The remote accelerometer is configured to generate a remote accelerometer output. In some embodiments, the TETS power receiver comprises a remote accelerometer, and the remote accelerometer output indicates the acceleration of the TETS power receiver. In other embodiments, the controller comprises a remote accelerometer, and the remote accelerometer output indicates the acceleration of the controller. In many embodiments, the remote accelerometer output indicates acceleration in three orthogonal directions.

[0007] The remote accelerometer can be integrated into the TETS power receiver in any suitable manner. For example, the remote accelerometer can be mounted to the inner surface of the TETS power receiver housing that forms the outer surface of the TETS power receiver. The TETS power receiver may include a TETS power receiver coil that is enclosed within the TETS power receiver housing. The TETS power receiver housing may be made of any suitable material or combination of materials. For example, the TETS power receiver housing may include a titanium panel that includes the inner surface of the TETS power receiver housing and the outer surface of the TETS power receiver. In some embodiments, the TETS power receiver includes a TETS power receiver printed circuit board assembly (PCBA), and the remote accelerometer is mounted to the TETS power receiver PCBA.

[0008] In many embodiments, the TETS power receiver and controller are configured to be implanted at a suitable location spaced apart from the VAD. In many embodiments, the blood circulation assistance system includes a TETS power receiver connection cable that connects the TETS power receiver to the controller. In some embodiments, the TETS power receiver is configured for implantation in the chest area of ​​the patient. In many embodiments, the blood circulation assistance system includes a controller connection cable that connects the controller to the VAD. In some embodiments, the controller is configured for implantation in the abdominal wall area of ​​the patient.

[0009] In many embodiments, the controller is configured to process the remote accelerometer output to determine the range of the parameter. For example, the controller may be configured to process the remote accelerometer output to determine the patient's heart rate and control the speed of the impeller based on the heart rate. The controller may be configured to process the remote accelerometer output to determine the patient's ventricular contraction amplitude. The controller may be configured to process the remote accelerometer output to determine the patient's cardiac output size. The controller may be configured to process the remote accelerometer output to determine the patient's valve opening timing. The controller may be configured to process the remote accelerometer output to monitor the patient's valvular disease. The controller may be configured to process the remote accelerometer output to determine the patient's respiratory rate. The controller may be configured to process the remote accelerometer output to monitor the occurrence of pump thrombosis in the VAD. The controller may be configured to process the remote accelerometer output to monitor the occurrence of obstruction in the VAD. The controller may be configured to process the remote accelerometer output to monitor the occurrence of instability of the impeller. The controller may be configured to process the remote accelerometer output to monitor the patient's orientation. The controller may be configured to process the remote accelerometer output to determine when the patient is in a prone position. The controller may be configured to process the remote accelerometer output to determine when the patient is in a supine position. The controller may be configured to process the remote accelerometer output to determine the angle of recline when the patient is in a supine position. The controller may be configured to process the remote accelerometer output to determine when the patient is in a sitting position. The controller may be configured to process the remote accelerometer output to determine when the patient is in a standing position. The controller may be configured to process the remote accelerometer output to monitor the patient for falls. The controller may be configured to process the remote accelerometer output to monitor the patient for syncope. The controller may be configured to process the remote accelerometer output to determine whether the patient is active or at rest. The controller may be configured to process the remote accelerometer output to determine a health indicator of the patient.

[0010] In some embodiments, the controller is configured to process the remote accelerometer output to detect the cardiac cycle timing of the patient. The cardiac cycle timing may include the heart rate and / or occurrence time of each of one or more cardiac cycle events. The controller may be configured to change the speed of the impeller synchronously with the cardiac cycle timing. For example, the controller may be configured to increase the speed of the impeller during the ventricular systole period. The controller may be configured to process the remote accelerometer output to detect the occurrence time of at least one heart sound, and detect the timing of the ventricular systole period based on the occurrence time of the at least one heart rate. The at least one heart sound may include the sound of at least one atrioventricular valve closure of the patient and / or the sound of at least one semilunar valve closure of the patient. The controller may be configured to change the speed of the impeller on the target cardiac cycle based on the detected timing of one or more cardiac cycles occurring before the target cardiac cycle. The controller may be configured to change the speed of the impeller on the target cardiac cycle based on the detected timing of the target cardiac cycle.

[0011] In some embodiments, the controller is configured to process the remote accelerometer output to measure the patient's activity level, and control the speed of the impeller based on the activity level. For example, the controller may be configured to process the remote accelerometer output to measure the patient's respiratory rate and / or the patient's diaphragm contraction, and base the activity level on the respiratory rate and / or diaphragm contraction. The controller may be configured to process the remote accelerometer output to measure the patient's activity level, and control the speed of the impeller based on the activity level. The controller may be configured to process the remote accelerometer output to measure the respiratory rate and / or diaphragm contraction, and base the activity level on the respiratory rate and / or diaphragm contraction.

[0012] On the other hand, a blood circulation assist system includes a VAD, a TETS power receiver, a controller and a remote accelerometer. The VAD includes a housing defining a blood flow channel, an inlet, an outlet, an impeller disposed in the blood flow channel, a motor stator and a VAD accelerometer. The motor stator is operable to rotate the impeller to pump blood flow in the patient's body. The inlet is configured to couple with the ventricle of the heart to receive blood flow from the ventricle. The outlet is configured to couple with a blood vessel to transmit blood flow to the blood vessel. The VAD accelerometer is configured to generate a VAD accelerometer output indicating the acceleration of the VAD. The TETS power receiver is configured to be implanted and receive energy emitted by an external TETS transmitter. The controller is configured to be implanted, process the VAD accelerometer output and the remote accelerometer output, and control the rotation speed of the impeller based on at least one of the VAD accelerometer output and the remote accelerometer output. The remote accelerometer is configured to generate a remote accelerometer output. In some embodiments, the TETS power receiver includes a remote accelerometer, and the remote accelerometer output indicates the acceleration of the TETS power receiver. In other embodiments, the controller includes a remote accelerometer, and the remote accelerometer output is indicative of acceleration of the controller.

[0013] In many embodiments, the VAD is configured to be mounted to a heart wall of the heart. The controller can be configured to process the VAD accelerometer output to monitor the motion of the heart wall, thereby detecting the timing of the heart's cardiac cycle, and controlling the speed of the impeller based on the timing of the cardiac cycle.

[0014] In some embodiments, the TETS power receiver includes a remote accelerometer and is configured for implantation in the chest region of the patient. The controller may be configured to process the remote accelerometer output to determine the patient's breathing rate and further control the rotational speed of the impeller based on the breathing rate.

[0015] In some embodiments, the VAD includes control electronics configured to control a drive current supplied to the motor stator to rotate the impeller. In some embodiments, the drive current supplied to the motor stator is further used to magnetically levitate the impeller.

[0016] In some embodiments, the controller is configured to determine the patient's posture. For example, the controller can be configured to determine the patient's posture based on the remote accelerometer output and / or the VAD accelerometer output.

[0017] On the other hand, a blood circulation assist system includes a ventricular assist device (VAD), a controller and a remote accelerometer. The VAD includes an inlet, an outlet, an impeller and a motor stator, which is operable to rotate the impeller to pump blood flow. The inlet is configured to couple with the patient's ventricle to receive blood flow from the ventricle. The outlet is configured to couple with the patient's blood vessel to transmit blood flow to the blood vessel. The controller is configured to process a remote accelerometer output indicating the acceleration of the patient at the remote accelerometer position, and control the rotation speed of the impeller based on the remote accelerometer output. The remote accelerometer is configured to generate a remote accelerometer output. The remote accelerometer is configured to be implanted in the patient at the remote accelerometer position. The remote accelerometer position is separated from the VAD to isolate the remote accelerometer from the noise generated by the VAD. The remote accelerometer position can be any suitable position separated from the VAD to isolate the remote accelerometer from the noise generated by the VAD. For example, in some embodiments, the remote accelerometer position is in the chest area of ​​the patient. In some embodiments, the remote accelerometer position is in the abdominal wall area of ​​the patient.

[0018] For a more complete understanding of the nature and advantages of the present invention, reference should be made to the ensuing detailed description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 An implantable circulatory assist system according to an embodiment is shown, the implantable circulatory assist system including a ventricular assist device (VAD), an implantable controller, and a transcutaneous energy transfer system (TETS) power receiver.

[0020] Figure 2 The implanted Figure 1 Blood circulation support system.

[0021] Figure 3 shows the method for integrating a remote accelerometer into Figure 1 Some options for the TETS power receiver for the blood circulation assist system.

[0022] Figure 4 yes Figure 1 Schematic diagram of an embodiment of a TETS power receiver for a blood circulation assistance system.

[0023] Figure 5 shows the method for integrating a remote accelerometer into Figure 1 Some options for implantable controllers for blood circulation assistance systems.

[0024] Figure 6 yes Figure 1 A schematic diagram of an embodiment of an implant system controller for a blood circulation assist system.

[0025] Figure 7 According to many embodiments, the system operates using acceleration measured via a remote accelerometer. Figure 1 A simplified schematic diagram of a method of a blood circulation assist system.

[0026] Figure 8 It is shown that according to many embodiments, Figure 1 The speed of the VAD of the circulatory assist system varies in synchronization with ventricular contractions based on heart sounds, ventricular wall motion, and / or pump operating parameters.

[0027] Fig. 9 yes Figure 1 Exploded view of the implanted components of the circulatory support system.

[0028] Fig.10 yes Figure 1 Illustration of a VAD, a circulatory assist system, that is attached to a patient's heart to augment the blood pumping performed by the patient's left ventricle.

[0029] Fig.11 yes Figure 1 A cross-sectional view of a VAD, a blood circulation assist system.

[0030] Fig.12 is used for Figure 1 Illustration of an embodiment of a control unit of a VAD blood circulation assistance system.

[0031] Fig.13 yes Fig.12 A cardiopulmonary bypass view of a control unit illustrating a VAD accelerometer included in the control unit in accordance with many embodiments.

[0032] Fig.14 yes Figure 1 Schematic diagram of an embodiment of a VAD blood circulation assist system.

[0033] Fig.15 is through Figure 1 A graph of example raw acceleration of the VAD generated by the VAD accelerometer of a circulatory assist system.

[0034] Fig.16 Is Fig.15 A graph of the average normalized acceleration of the VAD generated from the raw acceleration.

[0035] Fig.17 Is Fig.15 The acceleration generates a graph of the velocity of the VAD.

[0036] Fig.18 Is Fig.17 A graph of the displacement of the VAD generated by the velocity.

[0037] Fig.19 yes Figure 1 Schematic diagram of the external components of the blood circulation assistance system. DETAILED DESCRIPTION

[0038] In the following description, various embodiments of the present invention will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the embodiments. However, it will also be apparent to those skilled in the art that the present invention can be practiced without these specific details. In addition, in order not to confuse the described embodiments, well-known features may be omitted or simplified.

[0039] Many existing ventricular assist devices operate essentially in a fixed speed mode. In such ventricular assist devices, the impeller of the ventricular assist device (VAD) rotates at a constant rotational speed set by the clinician. Many existing VADs use a centrifugal blood pump or an axial flow blood pump with a head / flow curve (HQ curve) that shows the inverse relationship between the blood flow rate through the VAD and the pressure change across the VAD at each rotation speed of the impeller. The inverse relationship between the blood flow rate through the VAD and the pressure change across the VAD provides a certain degree of physiological blood flow response, because the blood flow rate through the VAD will increase in response to a decrease in the pressure change across the VAD. However, compared to the ability of the native heart to regulate cardiac output between resting and exercise states (native ~4-25L / min, VAD ~3-6L / min), the level of physiological flow response provided by the VAD operating at a constant speed is small.

[0040] In many embodiments, a circulatory assist system includes a VAD and a remote accelerometer that is implanted to be spaced apart from the VAD. The remote accelerometer measures acceleration induced by the remote accelerometer that is processed by the circulatory assist system to monitor the physiological needs of the patient. The circulatory assist system automatically adjusts the VAD impeller speed in response to the physiological needs of the patient. In many embodiments, the circulatory assist system automatically reduces the VAD impeller speed during sleep / rest to prevent ventricular suction events. Automatically reducing the VAD impeller speed during sleep / rest provides room for using a higher average VAD impeller speed to provide enhanced perfusion / support when the patient is not sleeping or resting. In many embodiments, the circulatory assist system automatically increases the speed of the VAD impeller during more active patient states (e.g., during exercise) to provide above average perfusion / support.

[0041] In many embodiments, the blood circulation assist system periodically reduces the VAD impeller speed to produce cyclical opening of the ventricular valves (i.e., aortic valve, pulmonary valve) with the goal of inhibiting the development of ventricular valvular regurgitation. For example, aortic valve regurgitation may be caused by structural failure of the aortic valve caused by prolonged closure of the aortic valve produced via the use of a fixed-speed left ventricular assist device (LVAD). It has been suggested that prolonged closure of the aortic valve can lead to deterioration of the biomechanics of the aortic valve.

[0042] In many embodiments, a remote accelerometer is used in a blood circulation assistance system. The remote accelerometer is configured to generate an output signal indicating an acceleration induced by the remote accelerometer. The blood circulation assistance system processes the output signal to monitor the patient's physiological state, which can be used to enhance patient diagnosis and / or perform closed-loop control of the VAD impeller speed based on the patient's physiological state. In some embodiments, the VAD impeller speed increases or decreases within a preset value range according to the patient's physical activity. The modulation of the VAD impeller speed can be customized to the patient based on any suitable patient parameter or combination of patient parameters (such as, for example, patient size, range of motion and / or physical activity). In some embodiments, the blood circulation assistance system includes an implanted transcutaneous energy transfer system (TETS) power receiver, which includes a remote accelerometer. The TETS power receiver can be implanted in any suitable location in the patient's body, such as, for example, the patient's chest area. In some embodiments, the blood circulation assistance system includes an implanted controller, which includes a remote accelerometer. The controller can be implanted in any suitable location in the patient's body, such as, for example, the patient's abdominal area.

[0043] The blood circulation assist system can be configured to process the acceleration measured by the remote accelerometer to determine any suitable number of a series of possible physiological states of the patient and / or the condition of the VAD. For example, the patient's physiological state that can be determined includes patient position data, patient activity level, patient events, one or more health indicators and cardiac cycle timing. The condition of the VAD that can be determined includes detecting the occurrence of pump thrombosis and / or the blockage of the VAD inlet, VAD outlet and / or VAD impeller. The patient position data can indicate whether the patient is in a prone position, supine position, sitting position or standing position. If the patient is in a supine position, the patient's recline angle can be measured. The recline angle of the patient in the supine position can indicate the degree of heart failure, because the recline angle can indicate the number of pillows required to allow circulation while sleeping. The patient's activity level can indicate whether the patient is at rest or in an active state. If the patient is in an active state, the patient's activity level can be quantified using any suitable method. Patient events that can be detected can include, for example, patient falls and patient syncope. An example health indicator that can be determined is the distance traveled during a timed walk (e.g., a six-minute hallway walk). The patient's cardiac cycle timing can be monitored via processing of acceleration measured by a remote accelerometer to detect heart sounds (e.g., S1, S2, S3, S4). The detected heart sounds can be used to determine heart rate, ventricular contractility, cardiac output, and valve opening time. The acceleration measured by the remote accelerometer can be processed to detect valve disease (e.g., stenosis, regurgitation, etc.) and respiratory rate.

[0044] Referring now to the drawings, wherein like reference numerals represent like parts throughout the several views, Figure 1 Implantable components of a blood circulation assistance system 10 are shown according to an embodiment. Figure 2 A blood circulation assist system 10 is shown implanted in a patient 12. The system 10 includes a ventricular assist device (VAD) 14, a ventricular cuff 16, an outflow cannula 18, an implant controller 20, a transcutaneous energy transfer system (TETS) power receiver 22, a TETS power transmitter 24, a controller to VAD connection cable 26, a TETS power receiver to controller connection cable 28, and a remote accelerometer 30. Figure 2In the illustrated embodiment, the remote accelerometer 30 is implanted in the patient at a remote accelerometer location separate from the VAD 14 so as to isolate the remote accelerometer 30 from noise generated by the VAD, such as electrical switching noise generated by the VAD 14 through power transistors included within the VAD 14 for controlling the current supply to the windings of the stator of the VAD 14. The remote accelerometer 30 can be configured to be implanted in the patient at any suitable location so as to isolate the remote accelerometer 30 from noise generated by the VAD 14, including but not limited to in the abdomen of the patient, below the diaphragm of the patient, or in the chest region. The remote accelerometer 30 can be a suitable 3-axis accelerometer (e.g., with 10-bit or 12-bit resolution) that is located in the chest region and generates an output that is processed to discern heart sounds. The remote accelerometer 30 can be included in the controller 20 or the TETS power receiver 22, as described herein.

[0045] The VAD 14 may be attached to the tip of the left ventricle, as shown, or the right ventricle, or a separate VAD may be attached to each of the ventricles of the heart 32. The VAD 14 may be capable of pumping the entire blood flow delivered to the left ventricle from the pulmonary circulation (i.e., up to 10 liters per minute). Related blood pumps suitable for use with the present invention are described below and in U.S. Pat. Nos. 5,695,471, 6,071,093, 6,116,862, 6,186,665, 6,234,772, 6,264,635, 6,688,861, 7,699,586, 7,976,271, 7,997,854, 8,007,254, 8,152,49 3, 8,419,609, 8,652,024, 8,668,473, 8,852,072, 8,864,643, 8,882,744, 9,068,572, 9,091,271, 9,265,870, and 9,382,908, all of which are incorporated herein by reference in their entirety for all purposes. The VAD 14 may be attached to the heart 32 via a ventricular cuff 16, which may be sutured to the heart 32 and coupled to the VAD 14. In the illustrated embodiment, the output of the VAD 14 is connected to the ascending aorta via an outflow cannula 18, such that the VAD 14 effectively diverts blood from the left ventricle and pushes it to the aorta for circulation through the rest of the patient's vascular system.

[0046] A controller-to-VAD connection cable 26 connects the VAD 14 to an implanted controller 20 operated by the monitoring system 10. Related controller systems suitable for use with the present invention are described in more detail below and in U.S. Pat. Nos. 5,888,242, 6,991,595, 8,323,174, 8,449,444, 8,506,471, 8,597,350, and 8,657,733, European Patent No. 1812094, and U.S. Patent Publication Nos. 2005 / 0071001 and 2013 / 0314047, all of which are incorporated herein by reference in their entirety for all purposes.

[0047] The VAD 12 includes an inlet casing 112, a rotor / impeller 140, a motor stator 120, and an outlet opening 105 (eg, Fig.10 and Fig.11 14. When implanted, inlet cannula 112 extends into the ventricle and outlet opening 105 is placed in fluid communication with a blood vessel via outflow cannula 18. Rotor / impeller 140 is controllably rotated via a controlled drive current provided to motor stator 120. The rate of blood flow through VAD 14 can be controlled by controlling the rotation rate of rotor / impeller 140. In many embodiments, VAD 14 includes electronics 130 (in Figures 10 to 13 ), the electronic device 130 includes a power transistor that is controlled to control the drive current provided to the motor stator, thereby controlling the rotation rate of the rotor / impeller 140. In many embodiments, the power transistor of the electronic device 130 also controls the levitation current provided to the motor stator to control the magnetic levitation of the rotor / impeller 140.

[0048] Implant controller 20 is configured to supply power to VAD 14 and control the operation of VAD 14. Implant controller 20 is configured to be implanted in a suitable location in patient 12 spaced apart from VAD 14. Implant controller 20 is operatively coupled to VAD 14 via controller-to-VAD connection cable 26. Implant controller 20 is configured to receive and process signals from remote accelerometer 30 ( Figure 2 , Figure 3 and Figure 5 ) to control the rotation rate of the rotor / impeller 140, as described herein. Figure 5 and Figure 6 In the illustrated embodiment, implantable controller 20 includes a remote accelerometer 30 .

[0049] TETS power receiver 22 is configured to receive power transmitted by TETS power transmitter 24 for powering the operation of system 10. TETS power receiver 22 is configured to be implanted in a suitable location within patient 12 that is spaced apart from VAD 14 and controller 20. TETS power receiver 22 is operatively coupled to controller 20 via TETS power receiver-to-controller connection cable 28 and supplies power to controller 20. Figure 3 and Figure 4 In the illustrated embodiment, the TETS power receiver 22 includes a remote accelerometer 30 .

[0050] Figure 3 Some options for integrating a remote accelerometer 30 into a TETS power receiver 22 are shown. In the illustrated embodiment, the TETS power receiver 22 includes a cover / cap 34 and a printed circuit board assembly (PCBA) 36. The cover / cap 34 can be made of any suitable material (e.g., titanium). In some embodiments, the remote accelerometer 30 is mounted to the inner surface of the cover / cap 34. In some other embodiments, the remote accelerometer 30 is included in the PCBA 36. Mounting the remote accelerometer 30 to the inner surface of the cover / cap 34 can provide optimal tissue coupling. In embodiments where the remote accelerometer 30 is mounted to the inner surface of the cover / cap 34, the remote accelerometer 30 can be operatively connected to the PCBA 36 via suitable electrical interconnects for power and communication. In embodiments where the TETS power receiver 22 includes a remote accelerometer 30, the TETS power receiver 22 can include suitable shielding to suppress noise in the output of the remote accelerometer 30 caused by the TETS electromagnetic field generated by power transmission from the TETS power transmitter 24 to the TETS power receiver 22.

[0051] Figure 4 yes Figure 3Schematic diagram of an embodiment of a TETS power receiver 22. The TETS power receiver 22 includes a PCBA 36, a TETS power receiver coil 38, and a TETS power receiver battery unit 40. In the illustrated embodiment, the PCBA 36 includes a remote accelerometer 30, a memory 42, a processor 44, and a communication unit 46. However, the remote accelerometer 30 may alternatively be attached to the cover / cap 34 and operatively coupled to the PCBA 36 via suitable electrical interconnects for power and communication as described herein. The memory 42 may store appropriate instructions executable by the processor 44 for controlling the electrical characteristics of the TETS power receiver coil 38 to improve the efficiency of power transmission from the TETS power transmitter 24 to the TETS power receiver coil 38. The memory 42 may store appropriate instructions executable by the processor 44 for receiving an output from the remote accelerometer 30 and controlling the operation of the communication unit 46 to send the output from the remote accelerometer 30 to the controller 20 or acceleration data generated by the processor 44 via processing of the output from the remote accelerometer 30. TETS power receiver battery cell 40 may store energy for operating TETS power receiver 22, implant controller 20, and / or VAD 14 during time periods when TETS power receiver coil 38 is not receiving power.

[0052] Figure 5 Some options for integrating the remote accelerometer 30 into the implantable controller 20 are shown. In the illustrated embodiment, the implanted controller 20 includes a housing 48 and a printed circuit board assembly (PCBA) 50. The housing 48 can be made of any suitable material, such as titanium. In one embodiment, the remote accelerometer 30 is mounted to the inner surface of the housing 48. In another embodiment, the remote accelerometer 30 is included in the PCBA 50. Mounting the remote accelerometer 30 to the inner surface of the housing 48 can provide optimal tissue coupling. In embodiments where the remote accelerometer 30 is mounted to the inner surface of the housing 48, the remote accelerometer 30 can be operatively connected to the PCBA 50 via suitable electrical interconnects for power and communication.

[0053] Figure 6 yes Figure 514. A schematic diagram of an embodiment of an implanted controller 20 is shown. The controller 20 includes a PCBA 50, a controller battery unit 52, and a haptic unit 60. In the illustrated embodiment, the PCBA 50 includes a remote accelerometer 30, a memory 54, a processor 56, and a communication unit 58. In some embodiments, the PCBA 50 includes a motor control unit 62 configured to control a drive current supplied to the motor stator 120 of the VAD 14 to control the rotation rate of the rotor / impeller 140, thereby controlling the flow rate of blood flow through the VAD 14. The remote accelerometer 30 may alternatively be attached to an inner surface of the housing 48 and operatively coupled to the PCBA 36 via suitable electrical interconnects for power and communication as described herein. The memory 54 may store suitable instructions executable by the processor 56 for processing the output of the remote accelerometer 30 to monitor the physiological needs of the patient, automatically adjusting the VAD impeller speed in response to the physiological needs of the patient, determining any suitable number of a range of physiological states of the patient discernible from the output of the remote accelerometer 30, and / or monitoring the condition of the VAD 14 as described herein. The controller battery unit 52 may store energy for operating the VAD 14, the controller 20, and / or the TETS power receiver 22 during periods when the TETS power receiver coil 38 is not receiving power. The communication unit 58 may be configured to transmit control commands to the VAD 14 via the controller to VAD connection cable 26. The communication unit 58 may also include a suitable wireless communication unit for receiving programming updates and / or for sending alarms, VAD operating data, and / or patient physiological data to an external system monitor.

[0054] The controller 20 may be configured to cause the haptic unit 60 to operate to generate a haptic alarm to alert the patient that the power stored in the controller battery unit 52 and / or the TETS receiver battery unit 40 has dropped below a suitable minimum threshold so that the patient can take action to send power to the TETS power receiver 22 using the TETS power transmitter 24 to recharge the controller battery unit and / or the TETS power receiver battery unit 40. To prevent a long-term potential failure of the haptic unit 60, the controller 20 may periodically command the haptic unit 60 to operate and process the output of the remote accelerometer 30 to determine whether the haptic unit 60 is operating normally or in a faulty state. If the controller 20 determines that the haptic unit 60 is in a faulty state, the controller 20 may transmit an appropriate alarm indicating a failure of the haptic unit 60 via wireless communication of the communication unit 58.

[0055] Figure 7is a simplified schematic diagram of a method 70 for operating a blood circulation assistance system using acceleration measured by a remote accelerometer. Although the method 70 is described herein with respect to the blood circulation assistance system 10, the method 70 may be implemented by any suitable blood circulation assistance system. The actions of the method 70 may be practiced in any suitable combination, subcombination, and / or order.

[0056] In act 72, the remote accelerometer 30 generates an output indicative of the acceleration of the remote accelerometer 30. The acceleration of the remote accelerometer 30 may be induced via gravity and patient physiological activity (eg, cardiac activity, breathing).

[0057] In action 74, the controller 20 processes the output of the remote accelerometer 30 to monitor the orientation of the patient. In many embodiments, the output from the remote accelerometer 30 includes acceleration due to gravity and is therefore indicative of the orientation of the remote accelerometer 30 and, therefore, the orientation of the portion of the patient 12 where the remote accelerometer 30 is located relative to the vertical direction. The controller 20 may process the output from the remote accelerometer 30 using any suitable method 20 to determine the orientation of the remote accelerometer 30 relative to the vertical direction. In many embodiments, the remote accelerometer 30 is configured to measure acceleration in three orthogonal directions (e.g., X-axis acceleration, Y-axis acceleration, and Z-axis acceleration). Each of the X-axis acceleration, the Y-axis acceleration, and the Z-axis acceleration may be processed by the controller 20 to calculate a corresponding moving average having an appropriate time period (e.g., 10 to 15 seconds) corresponding to the X-axis gravity-induced acceleration, the Y-axis gravity-induced acceleration, and the Z-axis gravity-induced acceleration, respectively. The X-axis gravity-induced acceleration, the Y-axis gravity-induced acceleration, and the Z-axis gravity-induced acceleration define a gravity vector indicating the orientation of the remote accelerometer 30 relative to the vertical direction. The controller can process the gravity vector using any suitable method 20 to generate an indication of the orientation of the patient relative to a suitable reference axis or reference direction. For example, the gravity vector can be converted from the axis system of the remote accelerometer 30 to a suitable patient reference axis system, for example, the patient X-axis extends forward relative to the patient's chest, the patient Y-axis extends to the left relative to the patient's chest, and the patient Z-axis extends toward the top of the patient's chest. As another example, a reference gravity orientation vector corresponding to a known orientation of the patient 12 and / or the remote accelerometer 30 can be generated by placing the patient 12 and / or the remote accelerometer 30 in a known orientation relative to the vertical (e.g., standing upright, lying horizontally on the patient's left side, lying horizontally on the patient's right side, lying horizontally on the patient's back, and lying horizontally on the patient's abdomen). The gravity vector can be compared to each of the one or more reference gravity orientation vectors using known methods to determine the relative angle between the gravity vector and the corresponding reference gravity orientation vector. The resulting relative angle(s) indicate an orientation of the patient 12 and / or remote accelerometer 30 relative to a reference orientation of the patient 12 and / or remote accelerometer 30 .

[0058] In action 76, the controller 20 processes the output of the remote accelerometer 30 to track the patient's cardiac activity. In some embodiments, the output of the remote accelerometer 30 is processed by the controller 20 to detect and / or measure heart sounds. Heart sounds that can be detected and / or measured via the remote accelerometer 30 include a first sound (S1) generated by closing the atrioventricular valve during ventricular contraction and a second sound (S2) generated by closing the semilunar valve during ventricular diastole. In some patients, the occurrence of aortic regurgitation (also known as aortic regurgitation) generates a corresponding sound, which can be detected by removing the accelerometer 32. In some embodiments, the output of the remote accelerometer 30 is processed by the controller 20 using a suitable bandpass filter (e.g., 100 Hz to 400 Hz) to isolate the acceleration caused by heart sounds. The acceleration caused by heart sounds can be processed by the controller 20 to detect / measure heart sounds. Heart sounds can be used to monitor the cardiac cycle timing of the heart, and to monitor whether aortic regurgitation occurs in the patient. In some embodiments, the output of the remote accelerometer 30 is processed by the controller 20 to detect and / or measure the heart rate. In some embodiments, the output of the remote accelerometer 30 is processed by the controller 20 using a suitable bandpass filter (eg, 0.5 Hz to 4.0 Hz) to isolate the acceleration caused by the heart rate. The acceleration caused by the heart rate can be processed by the controller 20 to determine and track the heart rate.

[0059] The timing of the patient's cardiac cycle is detected by monitoring the drive current supplied to the VAD 14, the rotational speed of the rotor / impeller 140, the blood flow rate through the VAD 14, and / or the pressure difference across the rotor / impeller 140. For example, during ventricular contraction, for a given rotational speed of the rotor / impeller 140, changes in ventricular pressure cause corresponding changes in the drive current supplied to the VAD 14. In some embodiments, the rotational speed of the rotor / impeller 140 is kept constant over one or more cardiac cycles to avoid changes in the drive current due to changes in the rotational speed of the rotor / impeller 140. By monitoring the drive current provided to the VAD 14, the timing of the cardiac cycle can be detected by detecting the time period corresponding to ventricular contraction. For example, in many embodiments, the rotor drive current substantially follows a sinusoidal shape throughout the cardiac cycle. Peak flow (and drive current) occurs at the maximum left ventricular pressure, i.e., mid-systole. Minimum flow (minimum drive current) occurs at the lowest left ventricular pressure, i.e., the beginning of diastole. In summary, the beginning of diastole can be detected by detecting the minimum drive current. Peak systole can be detected by detecting the maximum drive current. The onset of systole can be detected by detecting the sudden change in the drive current slope (dI / dt) at the end of diastole.

[0060] In act 78, controller 20 processes the output of remote accelerometer 30 to track the patient's breathing. The patient's breathing rate and diaphragm contraction amplitude can be determined by controller 20 by processing the output of remote accelerometer 30 using a suitable bandpass filter (e.g., approximately 0.2 Hz to 1.0 Hz (12 to 60 breaths per minute)) to isolate the acceleration caused by breathing. The acceleration caused by breathing can then be processed by controller 20 to determine the corresponding breathing rate and diaphragm contraction amplitude. The frequency range and direction of movement can be used to isolate the respiratory motion. In addition, the acceleration caused by breathing will generally have a lower amplitude (1 mg to 10 mg) and a regular pattern.

[0061] In act 80, controller 20 monitors the activity level of patient 12. The activity level of patient 12 may be defined as a suitable function of one or more of patient 12's breathing rate, diaphragm contraction amplitude, ventricular contraction amplitude, heart rate, and / or orientation.

[0062] In act 82, controller 20 controls operation of VAD 14 based on the patient's activity level and / or cardiac cycle timing. In some embodiments, controller 20 controls the rotational speed of rotor / impeller 140 such that the output of VAD 14 varies based on the measured activity level to provide increased support in response to an increase in the measured activity level and to provide decreased support in response to a decrease in the activity level. In some embodiments, controller 20 increases the average rotational speed of rotor / impeller 140 to increase the output of VAD 14 and decreases the average rotational speed to decrease the output of VAD 14.

[0063] In some embodiments, controller 20 controls the operation of VAD 14 to synchronize the operation of VAD 14 with the cardiac cycle timing. In addition to determining the cardiac cycle timing via processing of the output of remote accelerometer 30, controller 20 may determine the cardiac cycle timing based on operating parameters of VAD 14 (e.g., current, pump speed, and / or flow rate).

[0064] Figure 8The synchronization of the change in velocity of the VAD 14 with the contraction of the ventricles based on heart sounds, ventricular wall motion, and / or pump operating parameters is shown according to many embodiments. As described herein, the VAD 14 may include a VAD accelerometer 210 that measures the acceleration of the VAD 14, which may be processed by the controller 20 to track ventricular wall motion. At the beginning of the cardiac cycle, both the atria and the ventricles are in relaxation (diastole). Blood flows into the atria and from the atria into the ventricles. The contraction of the atria (atrial systole) pumps additional blood from the atria into the ventricles. The atrial systole ends before the ventricular systole. During the ventricular systole, each of the ventricular pressures 270 (only one is shown for clarity) increases over the corresponding atrial pressure 272 (only one is shown for clarity), thereby causing the valve of the corresponding atrium to close. The closing of the valve of the atrium generates the first heart sound (S1). Further contraction of the corresponding ventricle increases the ventricular pressure 270 to above the corresponding output vessel pressure (e.g., aortic pressure 274), causing the corresponding semilunar valve to open and blood to flow out of the ventricle. After the ventricular systole, the ventricle relaxes (ventricular diastole). As the ventricle relaxes, each ventricular pressure 270 drops below the corresponding output vessel pressure, causing the corresponding semilunar valve to close. The closing of the semilunar valve generates a second heart sound (S2). Further relaxation of the ventricle reduces each of the ventricular pressures to below the corresponding atrial pressure (e.g., left atrial pressure 272), causing the valve of the atrium to open.

[0065] Heart wall motion 276 during contraction of the ventricles during ventricular systole causes acceleration of VAD 14 measured by accelerometer 210. In the illustrated embodiment, the heart wall motion-induced acceleration of VAD 14 is primarily reflected in Z-axis acceleration 240 ( Fig.16 Thus, the Z-axis displacement is 266 ( Fig.19 ) can be processed to monitor heart wall motion 276 to measure the time and intensity of each ventricular contraction period and thereby indicate cardiac cycle timing. Detection of heart sounds (S1 and S2) can also be used alone or in conjunction with the timing of ventricular contractions determined via evaluation of heart wall motion 276 to determine cardiac cycle timing.

[0066] Ventricular heart wall motion can be monitored by processing the output of the accelerometer 210 using an appropriate bandpass filter (e.g., the main left ventricular wall motion range should be 0.5 Hz to 3 Hz (30 BPM to 180 BPM)) to isolate the acceleration caused by ventricular heart wall motion. Heart wall motion can be processed to determine cardiac cycle timing, ventricular contraction strength, and ventricular contraction efficiency. Direction (z-axis, in line with the inflow cannula), frequency range, and timing regularity can be used to isolate left ventricular (LV) wall motion. The transition from a low acceleration cycle to a high acceleration cycle (or a change in acceleration, jerk) can be used to indicate the beginning of the cardiac cycle (beginning of systole). Maximum acceleration can be used to estimate contraction strength. Then, contraction strength combined with minimum / average / maximum flow through the pump can be used to estimate contraction efficiency. Ventricular contraction strength and ventricular contraction efficiency can be monitored to monitor the health of the patient's heart (e.g., to detect signs of recovery or weakness). Heart wall motion can also be monitored to detect arrhythmias. Irregular cardiac cycle timing periods (start of systole) can also be used to detect arrhythmias. In addition, heart rates above and below the normal range can be used to detect arrhythmias.

[0067] In act 82, VAD 14 may be operated to vary the output of VAD 14 in synchronization with the timing of the cardiac cycle. For example, VAD 14 may be operated to pump blood at a greater rate during ventricular systole than the rate at which VAD 14 pumps blood during the remainder of the cardiac cycle. The rotational speed of rotor / impeller 140 may be varied to vary the rate at which VAD 14 pumps blood. Any suitable variation of the output of VAD 14 may be used. For example, Figure 8 As shown in , the rotational speed of rotor / impeller 140 can be varied during ventricular systole to increase the output of VAD 14 during ventricular systole. In the example shown, the rotational speed of rotor / impeller 140 varies during ventricular systole (i.e., increases from a first rotational speed (r1) to a second rotational speed (r2), remains at the second rotational speed (r2) for a period of time, and then decreases back to the first rotational speed (r1)).

[0068] Any suitable method may be used to control the timing of output changes of VAD 14. For example, cardiac cycle timing observed during one or more previous cardiac cycles may be used to control the timing of output changes of VAD 14 during the current cardiac cycle. As another example, when sufficiently fast processing is utilized, cardiac cycle timing of a target cardiac cycle may be used to control the timing of output changes of VAD 14 during the target cardiac cycle.

[0069] In act 84, controller 20 processes the remote accelerations to monitor for the occurrence of operational problems with VAD 14. The accelerations measured by remote accelerometer 30 may include accelerations induced via operation of VAD 14. Induced accelerations may include accelerations induced via vibrations of rotor / impeller 140, speed of rotor / impeller 140, speed changes of rotor / impeller 140, and / or mass / balance of rotor / impeller 140. Accelerations measured by remote accelerometer 30 may also be induced as a result of ingestion of an object, such as a blood clot, by VAD 14. Accelerations measured by removal accelerometer 32 may also be induced by a suction event, which may occur when VAD 14 over-pumps blood from the ventricle. The output of remote accelerometer 30 may be processed using a suitable bandpass filter (e.g., 0.5 Hz to 3.0 Hz) to isolate accelerations induced via operation of VAD 14. Accelerations induced via operation of the VAD 14 can be processed to monitor for excessive rotor vibrations, ingestion of objects, and / or the occurrence of aspiration events. For example, a suitable bandpass filter can be applied around the operating rotor speed (50 Hz to 150 Hz) and potential subsequent harmonics. Changes (particularly increases) in the vibration amplitude of the resulting filtered acceleration can indicate rotor imbalance caused by ingested thrombus or thrombus formation on the rotor. Aspiration events can be detected via the combined occurrence of three events: (1) changes in LV wall motion (as measured by the VAD accelerometer 210), (2) low average flow through the pump (which can be detected via the rotor drive current), and (3) low minimum flow fluctuations (which can be detected via the occurrence of small changes in the drive current).

[0070] In act 86, controller 20 generates patient monitoring data. The generated patient monitoring data may be any suitable combination of the patient's orientation(s), the patient's cardiac activity, and the patient's respiration. Controller 20 outputs the patient monitoring data (act 88) and the VAD monitoring data (act 90) via communication unit 58.

[0071] In act 92, the controller 20 periodically operates the haptic unit 60 for a short period of time and processes the output of the remote accelerometer 30 to determine whether the haptic unit 60 actually generates accelerations of the remote accelerometer 30 that are consistent with proper operation of the haptic unit 60. If the controller 20 determines that the output of the remote accelerometer 30 is inconsistent with proper operation of the haptic unit 60, the controller 20 outputs a haptic unit fault alarm via the communication unit 58 to notify the patient and / or healthcare professional of the faulty state of the haptic unit 60.

[0072] Example VAD Configuration

[0073] refer to Fig.10 and Fig.11, VAD 14 has a circular housing 110 and is shown implanted in patient 12, with a first side 111 of housing 110 positioned against the patient's heart 32 and a second side 113 of housing 110 facing away from heart 32. First side 111 of housing 110 includes inlet cannula 112 that extends into the left ventricle LV of heart 32. Second side 113 of housing 110 has chamfered edges 114 to avoid irritation of other tissue that may come into contact with VAD 14, such as the patient's septum. In order to construct the shape of the disc-shaped housing 110 shown in a compact form, the stator 120 and electronics 130 of VAD 14 are positioned on the inflow side of the housing facing the first side 111, and the rotor / impeller 140 of VAD 14 is positioned along the second side 113. This positioning of stator 120, electronics 130, and rotor / impeller 140 allows edge 114 to be chamfered along the contour of rotor / impeller 140, for example, at least as Figure 3 and Fig.10 shown.

[0074] Reference Fig.11 , the VAD 14 includes a partition wall 115 within the housing 110, the partition wall 115 defining a blood flow conduit 103. The blood flow conduit 103 extends from an inlet opening 101 of the inlet cannula 112 through the stator 120 to an outlet opening 105 defined by the housing 110. A rotor / impeller 140 is positioned within the blood flow conduit 103. The stator 120 is disposed circumferentially around a first portion 140a of the rotor / impeller 140, such as around a permanent magnet 141. The stator 120 is also positioned relative to the rotor / impeller 140 so that, in use, blood flows within the blood flow conduit 103 through the stator 120 before reaching the rotor / impeller 140. The permanent magnet 141 has a permanent magnetic north pole N and a permanent magnetic south pole S for combined active and passive magnetic suspension of the rotor / impeller 140 and for rotation of the rotor / impeller 140. The rotor / impeller 140 also has a second portion 140b including impeller blades 143. The impeller blade 143 is located in the volute 107 of the blood flow conduit such that the impeller blade 143 is close to the second surface 113 of the housing 110 .

[0075] The disc-shaped housing 110 further includes a circumferential wall 116 extending between the first face 111 and the removable cover 118. As shown, the circumferential wall 116 is formed as a hollow circular cylinder with a width W between opposing portions of the circumferential wall 116. The housing 110 also has a thickness T between the first face 111 and the second face 113, the thickness T being less than the width W. The thickness T is from about 0.5 inches to about 1.5 inches, and the width W is from about 1 inch to about 4 inches. For example, the width W may be about 2 inches, and the thickness T may be about 1 inch.

[0076] The circumferential wall 116 encloses an interior compartment 117 surrounding the dividing wall 115 and the blood flow conduit 103, wherein the stator 120 and the electronics 130 are disposed in the interior compartment 117 around the dividing wall 115. The removable cover 118 includes a second face 113, a chamfered edge 114, and defines the outlet opening 105. The cover 118 can be threadedly engaged with the circumferential wall 116 to seal the cover 118 in engagement with the circumferential wall 116. The cover 118 includes an inner surface 118a of the cover 118 that defines a volute 107 in fluid communication with the outlet opening 105.

[0077] Within the internal compartment 117, the electronic device 130 is positioned adjacent to the first face 111, and the stator 120 is positioned adjacent to the electronic device 130 on a side of the electronic device 130 opposite to the first surface 111. The electronic device 130 includes a circuit board 131 and various components carried on the circuit board 131 to control the operation of the VAD 14 (e.g., magnetic levitation and / or driving of the rotor) by controlling the power supply to the stator 120. The housing 110 is configured to accommodate the circuit board 131 in the internal compartment 117 approximately parallel to the first face 111 to effectively utilize the space within the internal compartment 117. The circuit board also extends radially inward toward the partition wall 115 and extends radially outward toward the circumferential wall 116. For example, the size of the internal compartment 117 is generally designed to be no larger than the size required for accommodating the circuit board 131, as well as the space for heat dissipation, material expansion, potting materials, and / or other elements for mounting the circuit board 131. Therefore, the outer shape of the housing 110 proximate the first face 111 generally closely conforms to the shape of the circuit board 131 to provide an outer dimension that is not significantly larger than the dimensions of the circuit board 131 .

[0078] Continue to refer Fig.11 , the stator 120 includes a back iron 121 and pole pieces 123a-123f, which are arranged spaced apart around the partition wall 115. The back iron 121 extends around the partition wall 115 and is formed as a generally flat disk of ferromagnetic material (such as steel) to conduct magnetic flux. The back iron 121 is arranged next to the control electronics 130 and provides a base for the pole pieces 123a-123f.

[0079] Each of the pole pieces 123a-123f is L-shaped and has a drive coil 125 for generating an electromagnetic field to rotate the rotor / impeller 140. For example, the pole piece 123a has a first leg 124a that contacts the back iron 121 and extends from the back iron 121 toward the second face 113. The pole piece 123a may also have a second leg 124b that extends from the first leg 124a through an opening of the circuit board 131 toward the partition wall 115 near the location of the permanent magnet 141 of the rotor / impeller 140. In one aspect, each of the second legs 124b of the pole pieces 123a-123f is inserted through an opening of the circuit board 131. In one aspect, each of the first legs 124a of the pole pieces 123a-123f is inserted through an opening of the circuit board 131. In one aspect, the opening of the circuit board encloses the first legs 124a of the pole pieces 123a-123f.

[0080] In a general aspect, the VAD 14 may include one or more Hall sensors that may provide an output voltage that is proportional to the strength of the magnetic field between at least one of the pole pieces 123a-123f and the permanent magnet 141, and the output voltage may provide feedback to the control electronics 130 of the VAD 14 to determine if the rotor / impeller 140 and / or the permanent magnet 141 are not in their expected positions for operation of the VAD 14. For example, the position of the rotor / impeller 140 and / or the permanent magnet 141 may be adjusted, e.g., the rotor / impeller 140 or the permanent magnet 141 may be pushed or pulled toward the center of the blood flow conduit 103 or the center of the stator 120.

[0081] Each of the pole pieces 123a-123f also has a suspension coil 127 for generating an electromagnetic field to control the radial position of the rotor / impeller 140. Each of the drive coil 125 and the suspension coil 127 includes a plurality of windings of a conductor around the pole pieces 123a-123f. Specifically, each of the drive coils 125 is wound around two adjacent pole pieces (such as pole pieces 123d and 123e) in the pole piece 123, and each suspension coil 127 is wound around a single pole piece. The drive coil 125 and the suspension coil 127 are wound around the first leg of the pole piece 123, and the magnetic flux generated by passing current through the coils 125 and 127 during use is conducted through the first and second legs of the pole piece 123 and the back iron 121. The drive coils 125 and the suspension coils 127 of the stator 120 are arranged in opposing pairs and are controlled to drive the rotor and radially levitate the rotor / impeller 140 by generating an electromagnetic field that interacts with the permanent magnetic poles S and N of the permanent magnet 141. Since the stator 120 includes both the drive coils 125 and the suspension coils 127, only a single stator is required to levitate the rotor / impeller 140 using only passive and active magnetic forces. In this configuration, the permanent magnet 141 has only one magnetic moment and is formed by a single piece of permanent magnet 141. For example, the stator 120 can be controlled as discussed in U.S. Pat. No. 6,351,048, the entire contents of which are incorporated herein by reference for all purposes. Other related patents, namely, U.S. Patent Nos. 5,708,346, 6,053,705, 6,100,618, 6,222,290, 6,249,067, 6,278,251, 6,351,048, 6,355,998, 6,634,224, 6,879,074, and 7,112,903, all of which are incorporated herein by reference in their entirety for all purposes.

[0082] The rotor / impeller 140 is arranged in the housing 110 so that the permanent magnet 141 of the rotor 140 is located upstream of the impeller blades, closer to the inlet opening 101. The permanent magnet 141 is housed in the blood flow conduit 103 near the second leg 124b of the pole piece 123 to provide a passive axial centering force through the interaction of the permanent magnet 141 with the ferromagnetic material of the pole piece 123. When the rotor / impeller 140 is centered in the partition wall 115, the permanent magnet 141 of the rotor / impeller 140 and the partition wall 115 form a gap 108 between the permanent magnet 141 and the partition wall 151. The gap 108 can be from about 0.2 mm to about 2 mm. For example, the gap 108 can be about 1 mm. The permanent magnetic north pole N and the permanent magnetic south pole S of the permanent magnet 141 provide a permanent magnetic attraction between the rotor / impeller 140 and the stator 120, which acts as a passive axial centering force that tends to maintain the rotor / impeller 140 generally centered within the stator 120 and tends to resist the movement of the rotor / impeller 140 toward the first face 111 or toward the second face 113. When the gap 108 is small, the magnetic attraction between the permanent magnet 141 and the stator 120 is large, and the size of the gap 108 is designed to allow the permanent magnet 141 to provide a passive magnetic axial centering force with a magnitude sufficient to limit the rotor / impeller 140 from contacting the inner surface 118a of the partition wall 115 or the cover 118. The rotor / impeller 140 also includes a shroud 145 that covers the end of the impeller blade 143 facing the second face 113, and the shroud 145 helps to guide the blood flow into the volute 107. When the rotor / impeller 140 is suspended by the stator 120, the shroud 145 and the inner surface 118a of the cover 118 form a gap 109 between the shroud 145 and the inner surface 118a. The gap 109 is from about 0.2 mm to about 2 mm. For example, the gap 109 is about 1 mm.

[0083] As blood flows through the blood flow conduit 103, the blood flows through the central aperture 141a formed through the permanent magnet 141. The blood also flows through the gap 108 between the rotor / impeller 140 and the dividing wall 115, and through the gap 109 between the shield 145 and the inner surface 108a of the cover 118. The gaps 108 and 109 are large enough to allow sufficient blood flow to limit the formation of clots that may occur if the blood is allowed to become stagnant. The gaps 108 and 109 are also large enough to limit the pressure on the blood cells, thereby preventing the blood from being damaged when flowing through the VAD 14. Because the size of the gaps 108 and 109 limits the pressure on the blood cells, the gaps 108 and 109 are too large to provide a meaningful hydrodynamic suspension effect. That is, the blood does not act as a bearing within the gaps 108 and 109, and the rotor is only magnetically suspended. In various embodiments, the size and dimensions of the gaps 108 and 109 are designed so that the blood flowing through the gaps can form a film that provides a hydrodynamic suspension effect. In this way, the rotor can be suspended by magnetic forces, fluid dynamics, or both.

[0084] Because the rotor / impeller 140 is radially suspended by active control of the suspension coils 127 as previously described, and because the rotor / impeller 140 is axially suspended by passive interaction of the permanent magnets 141 and the stator 120, no magnetic field generating rotor suspension components are required near the second face 113. The integration of all components for rotor suspension (i.e., the suspension coils 127 and the pole pieces 123) in the stator 120 allows the profile of the cover 118 to match the shape of the impeller blades 143 and the volute 107. Additionally, the integration of the rotor suspension components in the stator 120 eliminates the need for electrical connectors extending from the compartment 117 to the cover 118, which allows the cover to be easily installed and / or removed and eliminates a potential source of pump failure.

[0085] In use, the drive coil 125 of the stator 120 generates an electromagnetic field through the pole piece 123, which selectively attracts and repels the magnetic north pole N and magnetic south pole S of the rotor / impeller 140 to cause the rotor / impeller 140 to rotate within the stator 120. For example, one or more Hall sensors can sense the current position of the rotor / impeller 140 and / or the permanent magnet 141, wherein the output voltage of the one or more Hall sensors can be used to selectively attract and repel the magnetic north pole N and magnetic south pole S of the rotor / impeller 140 to cause the rotor / impeller 140 to rotate within the stator 120. As the rotor / impeller 140 rotates, the impeller blades 143 force blood into the volute 107, so that the blood is forced to flow out of the outlet opening 105. Additionally, the rotor draws blood into the VAD 14 through the inlet opening 101. As blood is drawn into the blood pump by the rotation of the impeller blades 143 of the rotor / impeller 140, the blood flows through the inlet opening 101 and through the control electronics 130 and the stator 120 toward the rotor / impeller 140. The blood flows through the aperture 141a of the permanent magnet 141, flows between the impeller blades 143, the shroud 145 and the permanent magnet 141, and flows into the volute 107. The blood also flows around the rotor / impeller 140, flows through the gap 108 and flows through the gap 109 between the shroud 145 and the inner surface 118a of the cover 118. The blood leaves the volute 107 through the outlet opening 105, which can be coupled to an outflow cannula.

[0086] Fig.12A Hall sensor assembly 200 for a VAD 14 is shown in accordance with many embodiments. The Hall sensor assembly 200 includes a printed circuit board assembly (PCBA) 202 and six individual Hall effect sensors 208 supported by the printed circuit board 202. The Hall effect sensors 208 are configured to convert the position of the rotor / impeller 140 of the VAD 14. In the illustrated embodiment, the Hall effect sensors 208 are supported to stand upright orthogonally relative to the PCBA 202, and the longest edge of each of the Hall effect sensors 208 is aligned to have an orthogonal component relative to the surface of the PCBA 202. Each of the Hall effect sensors 208 generates an output voltage that is directly proportional to the strength of the magnetic field located between at least one of the pole pieces 123a-123f and the permanent magnet 141. The voltage output by each of the Hall effect sensors 208 is received by the control electronics 130, which processes the sensor output voltage to determine the position and orientation of the rotor / impeller 140. The determined position and orientation of the rotor / impeller 140 is used to determine if the rotor / impeller 140 is not in an expected position for operation of the VAD 14. For example, the position of the rotor / impeller 140 and / or the permanent magnet 141 may be adjusted, for example, the rotor / impeller 140 or the permanent magnet 141 may be pushed or pulled toward the center of the blood flow conduit 103 or the center of the stator 120. The determined position of the rotor / impeller 140 may also be used to determine a rotor eccentricity or a target rotor eccentricity, as described in U.S. Pat. No. 9,901,666 (the entire contents of which are incorporated herein by reference for all purposes), which may be used to estimate the flow rate of blood pumped by the VAD 14.

[0087] Fig.13 2 is a cardiolateral view of the control electronics 130, according to many embodiments, showing the accelerometer 210 included in the control electronics 130. In many embodiments, the accelerometer 210 is a three-axis accelerometer that measures the acceleration experienced by the control electronics 130 (and thus the VAD 14) on three orthogonal axes, namely, an X-axis 212, a Y-axis 214, and a Z-axis 216. In the illustrated embodiment, the X-axis 212 and the Y-axis 214 are respectively oriented to be orthogonal to the axis of rotation of the rotor / impeller 140, and the Z-axis 216 is parallel to the axis of rotation of the rotor / impeller 140.

[0088] Fig.141 is a schematic diagram of the VAD 14. The VAD 14 includes control electronics 130, a Hall effect sensor assembly 200, a motor stator 120, and a rotor / impeller 140. In the illustrated embodiment, the control electronics include a processor 218, a memory device 220 (which may include read-only memory and / or random access memory), an accelerometer 210, a motor control unit 222, and a communication unit 224. In some embodiments, the memory device 220 stores one or more software applications that can be executed by the processor 218 for various functions. For example, the one or more software applications can effectively control the motor control unit 222 to achieve radial levitation and rotational drive of the rotor / impeller 140 during operation. In some embodiments, one or more programs implement processing of the output from the accelerometer 210 and / or operating parameters of the VAD 14 (e.g., drive current, rotational speed, flow rate, pressure differential across the impeller), as described herein, to detect and / or measure patient physiological events and / or activity (e.g., patient orientation, patient activity level, heart wall motion, heart sounds, heart rate, respiratory rate, diaphragm contraction, cardiac cycle timing). One or more programs may implement control of the motor control unit 222 to synchronize changes in the output of the VAD 14 with the patient's cardiac cycle timing, as described herein. For example, during a period of ventricular contraction, the output of the VAD 14 may increase for a period of time in order to enhance the pumping of blood that occurs via the contraction of the ventricles, thereby reducing the associated load on the ventricles. One or more programs may implement control of the motor control unit 222 to change the output of the VAD 14 based on the patient's activity level. For example, in many embodiments, the output of the VAD 14 increases in response to an increase in patient activity and decreases in response to a decrease in patient activity. One or more programs may also be used to implement processing of output from accelerometer 210 and / or operating parameters of VAD 14 to generate patient monitoring data and / or VAD monitoring data, as described herein. Communication unit 224 provides wired and / or wireless communication between VAD 14 and controller 20. In some embodiments, motor control unit 222 is included in VAD 14. In other embodiments, motor control unit 222 is included in controller 20.

[0089] Example measured acceleration

[0090] Fig.15 is a graph of raw acceleration of VAD 14 measured by tri-axial accelerometer 210 during an animal study. The raw acceleration shown includes X-axis acceleration 236, Y-axis acceleration 238, Z-axis acceleration 240, and magnitude 242 of the raw acceleration. Fig.15 Also shown is the flow rate 244 of the VAD 14 during the measurement of the raw acceleration.

[0091] Fig.16 Is Fig.15 24. The graph of average normalized acceleration of the VAD generated from the raw acceleration of the VAD. The average normalized acceleration shown includes an X-axis average normalized acceleration 246, a Y-axis average normalized acceleration 248, a Z-axis average normalized acceleration 250, and a magnitude of the average normalized acceleration 252. Each average acceleration is generated by subtracting the corresponding average acceleration over the entire sampling period from the corresponding raw acceleration graph (so that the resulting average is zero). Fig.16 Also shown is the flow rate 244 of the VAD 14 during the measurement of the raw acceleration. Fig.16 For readability, a constant acceleration offset has been combined with each of the acceleration components (i.e., the X-axis average normalized acceleration 246 has 300 mg added to it, the Y-axis average normalized acceleration 248 has 100 mg added to it, the Z-axis average normalized acceleration 250 has 100 mg subtracted from it, and the total average normalized acceleration magnitude 252 has 300 mg subtracted from it) in order to separate the plotted components.

[0092] Fig.17 It is through Fig.16 A graph of the velocity of the VAD 14 generated by integrating the average normalized acceleration of the accelerometers. The outputs of at least three accelerometers (or one accelerometer and one gyroscope) can be integrated to determine the corresponding three-dimensional velocity. With fewer accelerometers, the large amount of rotational motion may cause significant errors in the resulting three-dimensional velocity. Although an accelerometer can provide a reasonable estimate of velocity when the rotational motion is not significant, the rotational motion of the VAD can be significant. For example, if the beating of the heart causes the accelerometer to swing back and forth in a motion that includes rotation, the error caused by the centripetal acceleration can accumulate. Although the error may be very small for a period of time, the magnitude of the error can grow over time. In many embodiments, the acceleration caused by gravity is filtered out before the acceleration is integrated to determine the three-dimensional velocity. The velocities shown include X-axis velocity 254, Y-axis velocity 256, Z-axis velocity 258, and total velocity 260. Fig.17 Also shown is the flow rate 244 of the VAD 14 during the measurement of the raw acceleration. Fig.17 For ease of readability, a constant velocity offset is combined with each velocity component (i.e., 30 mm / sec is added to the X-axis velocity 254, 10 mm / sec is added to the Y-axis velocity 256, 10 mm / sec is subtracted from the Z-axis velocity 258, and 30 mm / sec is subtracted from the total velocity 260) in order to separate the plotted components.

[0093] Fig.18 is through Fig.1726. The displacements shown include an X-axis displacement 262, a Y-axis displacement 264, a Z-axis displacement 266, and a total displacement 268. Fig.18 Also shown is the flow rate 244 of the VAD 14 during the measurement of the raw acceleration. Fig.18 For ease of readability, a constant displacement offset is combined with each displacement component (i.e., 1 mm is added to the X-axis displacement 262, 0.3 mm is added to the Y-axis displacement 264, 0.3 mm is subtracted from the Z-axis displacement 266, and 30 mm / sec is subtracted from the total displacement 268) in order to separate the plotted components.

[0094] External system components

[0095] Fig.19 is a schematic diagram of the external components of the blood circulation assist system 10. The external components of the system 10 include a TETS power transmitter 24 and a system monitor 300. The TETS power transmitter 24 includes a TETS power transmission coil 302, a memory 304, a processor 306, a power transmission coil control unit 308, and a communication unit 310. The power transmission coil control unit 308 is configured to control the operation of the TETS power transmission coil 302 under the control of the processor 306. The memory 304 stores instructions executable by the processor 306 to control the operation of the TETS power transmission coil control unit. The TETS power transmitter 24 may include a housing defining an internal volume in which the TETS power transmission coil 302 is disposed. In some embodiments, the TETS power transmitter 24 is deformable and / or flexible so as to conform at least partially to the patient's anatomy when placed on the patient's body for transmitting power to the TETS power receiver 22.

[0096] In many embodiments, the TETS power transmitter 24 is configured to be coupled to a power source 212, such as a wall outlet or other suitable external power source. The TETS power transmission coil 302 can have any suitable resonant frequency. For example, the resonant frequency of the TETS power transmission coil 302 can be in the range of 100 kHz to 10 MHz, or in the range of 100 kHz to 20 MHz.

[0097] In many embodiments, the external system monitor 300 is configured to monitor the operation of the implanted components of the system 10. The external system monitor 300 can receive patient monitoring data and VAD monitoring data from the controller 20. The external system monitor 300 can receive any alarms output by the implanted controller 20, including haptic unit fault status alarms and any alarms generated due to the occurrence of VAD operational problems (e.g., aspiration events, VAD thrombus exit, and instability of the rotor / impeller 140). In some embodiments, the external system monitor 300 is operable to download software updates to the controller 20, VAD 14, and / or TETS power receiver 22.

[0098] Example Embodiments

[0099] Example 1 is a blood circulation assist system, which includes a ventricular assist device (VAD), a transcutaneous energy transfer system (TETS) power receiver, a controller and a remote accelerometer. The VAD includes an inlet, an outlet, an impeller and a motor stator, which is operable to rotate the impeller to pump blood flow. The inlet is configured to couple with the patient's ventricle to receive blood flow from the ventricle. The outlet is configured to couple with the patient's blood vessels to transmit blood flow to the blood vessels. The TETS power receiver is configured to be implanted and receive energy emitted by an external TETS transmitter. The controller is configured to be implanted, process a remote accelerometer output, and control the rotation speed of the impeller based on the remote accelerometer output. The remote accelerometer is configured to generate a remote accelerometer output. In some embodiments, the TETS power receiver includes a remote accelerometer, and the remote accelerometer output indicates the acceleration of the TETS power receiver. In some embodiments, the controller includes a remote accelerometer, and the remote accelerometer output indicates the acceleration of the controller.

[0100] Example 2 is the blood circulation assistance system of claim 1, wherein the TETS power receiver comprises a remote accelerometer.

[0101] Example 3 is the blood circulation assistance system of claim 2, wherein the TETS power receiver includes a TETS power receiver coil and a TETS power receiver shell, the TETS power receiver shell enclosing the TETS power receiver coil and including the outer surface of the TETS power receiver, and the remote accelerometer is mounted to the inner surface of the TETS power receiver shell.

[0102] Example 4 is the blood circulation assistance system of claim 3, wherein the TETS power receiver housing comprises a titanium panel comprising an inner surface of the TETS power receiver housing and an outer surface of the TETS power receiver.

[0103] Example 5 is the blood circulation assistance system of claim 2, wherein the TETS power receiver comprises a TETS power receiver printed circuit board assembly (PCBA), and the remote accelerometer is mounted to the TETS power receiver PCBA.

[0104] Example 6 is the blood circulation assistance system of claim 2, further comprising a TETS power receiver connection cable connecting the TETS power receiver to the controller.

[0105] Example 7 is the blood circulation assistance system of claim 6, wherein the TETS power receiver is configured for implantation in the chest area of ​​the patient.

[0106] Example 8 is the blood circulation assistance system of claim 6, further comprising a controller connection cable connecting the controller to the VAD.

[0107] Example 9 is the blood circulation assistance system of claim 6, wherein the controller is configured for implantation in the abdominal wall region of the patient.

[0108] Example 10 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine the patient's heart rate and control the rotational speed of the impeller based on the heart rate.

[0109] Example 11 is the blood circulation assist system of any of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine the patient's ventricular contraction amplitude.

[0110] Example 12 is the circulatory assist system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine a magnitude of the patient's cardiac output.

[0111] Example 13 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine the patient's valve opening timing.

[0112] Example 14 is the blood circulation assist system of any of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to monitor valve disease in the patient.

[0113] Example 15 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine the patient's breathing rate.

[0114] Example 16 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to monitor the occurrence of pump thrombosis in the VAD.

[0115] Example 17 is the circulatory assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to monitor the occurrence of an obstruction in the VAD.

[0116] Example 18 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to monitor the occurrence of instability of the impeller.

[0117] Example 19 is the blood circulation assistance system of any of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to monitor the orientation of the patient.

[0118] Example 20 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a prone position.

[0119] Example 21 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a supine position.

[0120] Example 22 is the blood circulation assistance system of Example 21, wherein the controller is configured to process the remote accelerometer output to determine a recline angle when the patient is in a supine position.

[0121] Example 23 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a sitting position.

[0122] Example 24 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a standing position.

[0123] Example 25 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to monitor a fall of the patient.

[0124] Example 26 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to monitor the patient for syncope.

[0125] Example 27 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine whether the patient is in an active state or in a resting state.

[0126] Example 28 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to determine a health indicator of the patient.

[0127] Example 29 is a blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process a remote accelerometer output to detect a cardiac cycle timing of the patient, the cardiac cycle timing including the heart rate and occurrence time of each of one or more cardiac cycle events, and the controller is configured to change the rotational speed of the impeller synchronously with the cardiac cycle timing.

[0128] Example 30 is the blood circulation assistance system of Example 29, wherein the controller is configured to increase the rotational speed of the impeller during ventricular systole.

[0129] Example 31 is the blood circulation assistance system of Example 30, wherein the controller is configured to process the remote accelerometer output to detect the occurrence time of at least one heart sound, and detect the timing of the ventricular systole based on the occurrence time of the at least one heart sound.

[0130] Example 32 is the blood circulation assist system of Example 31, wherein the at least one heart sound includes the sound of at least one atrioventricular valve closing of the patient and / or the sound of at least one semilunar valve closing of the patient.

[0131] Example 33 is the blood circulation assistance system of Example 29, wherein the controller is configured to change the rotational speed of the impeller over a target cardiac cycle based on the detected timing of one or more cardiac cycles occurring prior to the target cardiac cycle.

[0132] Example 34 is the blood circulation assistance system of Example 29, wherein the controller is configured to change the rotational speed of the impeller over the target cardiac cycle based on the detected timing of the target cardiac cycle.

[0133] Example 35 is the blood circulation assistance system of Example 29, wherein the controller is configured to process the remote accelerometer output to measure the patient's activity level and control the rotational speed of the impeller based on the activity level.

[0134] Example 36 is the blood circulation assistance system of Example 35, wherein the controller is configured to process the remote accelerometer output to measure the patient's breathing rate and / or the patient's diaphragm contraction, and to base the activity level on the breathing rate and / or diaphragm contraction.

[0135] Example 37 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the controller is configured to process the remote accelerometer output to measure the patient's activity level, and control the rotational speed of the impeller based on the activity level.

[0136] Example 38 is the blood circulation assistance system of Example 37, wherein the controller is configured to process the remote accelerometer output to measure breathing rate and / or diaphragm contraction, and to base the activity level on the breathing rate and / or diaphragm contraction.

[0137] Example 39 is the blood circulation assistance system of any one of Examples 1 to 9, wherein the remote accelerometer output indicates acceleration in three orthogonal directions.

[0138] Example 40 is a blood circulation assist system, which includes a ventricular assist device (VAD), a transcutaneous energy transfer system (TETS) power receiver, a controller and a remote accelerometer. The VAD includes a housing defining a blood flow channel, an inlet, an outlet, an impeller disposed in the blood flow channel, a motor stator and a VAD accelerometer. The motor stator is operable to rotate the impeller to pump blood flow in the patient's body. The inlet is configured to couple with the ventricle of the heart to receive blood flow from the ventricle. The outlet is configured to couple with a blood vessel to transmit blood flow to the blood vessel. The VAD accelerometer is configured to generate a VAD accelerometer output indicating the acceleration of the VAD. The TETS power receiver is configured to be implanted and receive energy emitted by an external TETS transmitter. The controller is configured to be implanted, process the VAD accelerometer output and the remote accelerometer output, and control the rotation speed of the impeller based on at least one of the VAD accelerometer output and the remote accelerometer output. The remote accelerometer is configured to generate a remote accelerometer output. The TETS power receiver comprises a remote accelerometer and the remote accelerometer output is indicative of an acceleration of the TETS power receiver, or the controller comprises a remote accelerometer and the remote accelerometer output is indicative of an acceleration of the controller.

[0139] Example 41 is a blood circulation assist system of Example 40, wherein the VAD is configured to be mounted to the heart wall of the heart, the controller is configured to process the VAD accelerometer output to monitor the movement of the heart wall to detect the cardiac cycle timing of the heart, and the controller is configured to control the rotational speed of the impeller based on the cardiac cycle timing.

[0140] Example 42 is the blood circulation assistance system of Example 41, wherein the TETS power receiver is configured for implantation in the chest area of ​​the patient, the controller is configured to process the remote accelerometer output to determine the patient's breathing rate, and the controller is configured to further control the rotational speed of the impeller based on the breathing rate.

[0141] Example 43 is the blood circulation assistance system of any one of Examples 40 to 42, wherein the VAD further comprises control electronics configured to control a drive current supplied to the motor stator to rotate the impeller.

[0142] Example 44 is the blood circulation assistance system of Example 43, wherein the driving current supplied to the motor stator is further used to magnetically levitate the impeller.

[0143] Example 45 is the blood circulation assistance system of any one of Examples 40 to 42, wherein the controller is configured to determine the patient's posture based on the remote accelerometer output and the VAD accelerometer output.

[0144] Example 46 is a blood circulation assist system, which includes a ventricular assist device (VAD), a controller and a remote accelerometer. The VAD includes an inlet, an outlet, an impeller and a motor stator, which is operable to rotate the impeller to pump blood flow. The inlet is configured to couple with the patient's ventricle to receive blood flow from the ventricle. The outlet is configured to couple with the patient's blood vessel to transmit blood flow to the blood vessel. The controller is configured to process a remote accelerometer output indicating the acceleration of the patient at the remote accelerometer position, and control the rotation speed of the impeller based on the remote accelerometer output. The remote accelerometer is configured to generate a remote accelerometer output. The remote accelerometer is configured to be implanted in the patient at the remote accelerometer position. The remote accelerometer position is separated from the VAD to isolate the remote accelerometer from the noise generated by the VAD.

[0145] Example 47 is the blood circulation assist system of Example 46, wherein the remote accelerometer is configured for implantation in the chest region of the patient.

[0146] Example 48 is the blood circulation assist system of Example 46, wherein the remote accelerometer is configured for implantation in the abdominal wall region of the patient.

[0147] Example 49 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine the patient's heart rate and control the rotational speed of the impeller based on the heart rate.

[0148] Example 50 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine the patient's valve opening timing.

[0149] Example 51 is the blood circulation assist system of any of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to monitor valve disease in the patient.

[0150] Example 52 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine the patient's breathing rate.

[0151] Example 53 is the circulatory assist system of any of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to monitor the occurrence of pump thrombosis in the VAD.

[0152] Example 54 is the circulatory assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to monitor the occurrence of occlusion in the VAD.

[0153] Example 55 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to monitor the occurrence of instability of the impeller.

[0154] Example 56 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to monitor the patient's orientation.

[0155] Example 57 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a prone position.

[0156] Example 58 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a supine position.

[0157] Example 59 is the blood circulation assistance system of Example 58, wherein the controller is configured to process the remote accelerometer output to determine the recline angle when the patient is in the supine position.

[0158] Example 60 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a sitting position.

[0159] Example 61 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine when the patient is in a standing position.

[0160] Example 62 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to monitor a fall of the patient.

[0161] Example 63 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to monitor the patient for syncope.

[0162] Example 64 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine whether the patient is in an active state or in a resting state.

[0163] Example 65 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to determine a health indicator of the patient.

[0164] Example 66 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to detect the patient's cardiac cycle timing, which includes the heart rate and occurrence time of each of one or more cardiac cycle events, and the controller is configured to change the rotational speed of the impeller synchronously with the cardiac cycle timing.

[0165] Example 67 is the blood circulation assist system of Example 66, wherein the controller is configured to increase the rotational speed of the impeller during ventricular systole.

[0166] Example 68 is the blood circulation assistance system of Example 67, wherein the controller is configured to process the remote accelerometer output to detect the occurrence time of at least one heart sound, and detect the timing of the ventricular systole based on the occurrence time of at least one heart sound.

[0167] Example 69 is the blood circulation assist system of Example 68, wherein the at least one heart sound includes the sound of at least one atrioventricular valve closing of the patient and / or the sound of at least one semilunar valve closing of the patient.

[0168] Example 70 is the blood circulation assistance system of Example 66, wherein the controller is configured to change the rotational speed of the impeller over a target cardiac cycle based on the detected timing of one or more cardiac cycles occurring prior to the target cardiac cycle.

[0169] Example 71 is the blood circulation assistance system of Example 66, wherein the controller is configured to change the rotational speed of the impeller over the target cardiac cycle based on the detected timing of the target cardiac cycle.

[0170] Example 72 is the blood circulation assistance system of Example 66, wherein the controller is configured to process the remote accelerometer output to measure the patient's activity level and control the rotational speed of the impeller based on the activity level.

[0171] Example 73 is the blood circulation assistance system of Example 72, wherein the controller is configured to process the remote accelerometer output to measure the patient's breathing rate and / or the patient's diaphragm contraction, and to base the activity level on the breathing rate and / or diaphragm contraction.

[0172] Example 74 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the controller is configured to process the remote accelerometer output to measure the patient's activity level and control the rotational speed of the impeller based on the activity level.

[0173] Example 75 is the blood circulation assistance system of Example 74, wherein the controller is configured to process the remote accelerometer output to measure breathing rate and / or diaphragm contraction, and to base the activity level on the breathing rate and / or diaphragm contraction.

[0174] Example 76 is the blood circulation assistance system of any one of Examples 46 to 48, wherein the remote accelerometer output indicates acceleration in three orthogonal directions.

[0175] Other variations are within the spirit of the invention. Thus, while the invention is susceptible to various modifications and alternative constructions, certain illustrated embodiments thereof are shown in the drawings and described in detail above. However, it should be understood that this is not intended to limit the invention to the specific form or forms disclosed, but on the contrary, is intended to cover all modifications, alternative constructions and equivalents that fall within the spirit and scope of the invention, as defined by the appended claims.

[0176] The use of the terms "a", "an" and "the" and similar designations in the context of describing the present invention (especially in the context of the following claims) is intended to be interpreted as covering both the singular and the plural, unless otherwise specified herein or clearly contradicted by the context. The terms "include", "have", "include" and "cover" should be interpreted as open-ended terms (i.e., meaning "including, but not limited to"), unless otherwise noted. The term "connected" should be interpreted as being partially or completely included, attached, or combined together, even if there are some intermediaries. The recording of the value range herein is intended only to be used as a shorthand method for individually citing each individual value falling within the range, unless otherwise specified herein, and each individual value is incorporated into this specification as if it were recorded separately in this specification. All methods described herein can be performed in any suitable order, unless otherwise specified herein or clearly contradicted by the context. The use of any and all examples, or exemplary language (e.g., such as ") provided herein is intended only to better illustrate embodiments of the present invention, and does not constitute a limitation on the scope of the present invention, unless otherwise required. The language in this specification should not be interpreted as indicating that any unclaimed element is necessary for practicing the present invention.

[0177] Preferred embodiments of the present invention are described herein, including the best mode known to the inventor for implementing the present invention. Variations of these preferred embodiments become apparent to those of ordinary skill in the art after reading the foregoing description. The inventor expects that those skilled in the art will adopt these variations as appropriate, and the inventor intends that the present invention be practiced in other forms other than those specifically described herein. Correspondingly, the present invention includes all modifications and equivalents of the subject matter described in the claims attached hereto, as permitted by applicable laws and regulations. In addition, any combination of the above-mentioned elements in all possible variations thereof is encompassed by the present invention, unless otherwise stated herein or clearly contradictory to the context.

[0178] All references, including publications, patent applications, and patents, cited herein are hereby incorporated by reference as if each reference were individually and specifically indicated to be incorporated by reference and were set forth in its entirety herein.

Claims

1. A blood circulation auxiliary system, comprising: a ventricular assist device (VAD) comprising an inlet, an outlet, an impeller, and a motor stator operable to rotate the impeller to pump blood flow, wherein the inlet is configured to couple with a ventricle of a patient to receive the blood flow from the ventricle, wherein the outlet is configured to couple with a blood vessel of the patient to deliver the blood flow to the blood vessel; a transcutaneous energy transfer system (TETS) power receiver configured to be implanted and receive energy transmitted by an external TETS transmitter; a controller configured to be implanted, process a remote accelerometer output, and control a rotational speed of the impeller based on the remote accelerometer output; as well as a remote accelerometer configured to generate the remote accelerometer output, wherein: the TETS power receiver comprises the remote accelerometer and the remote accelerometer output is indicative of an acceleration of the TETS power receiver, or The controller includes the remote accelerometer, and the remote accelerometer output is indicative of an acceleration of the controller.

2. The system according to claim 1, characterized in that The TETS power receiver includes the remote accelerometer.

3. The system according to claim 2, characterized in that: The TETS power receiver comprises a TETS power receiver coil and a TETS power receiver housing, the TETS power receiver housing enclosing the TETS power receiver coil and comprising an outer surface of the TETS power receiver; and The remote accelerometer is mounted to an interior surface of the TETS power receiver housing.

4. The system according to claim 3, characterized in that The TETS power receiver housing includes a titanium panel that includes an inner surface of the TETS power receiver housing and an outer surface of the TETS power receiver.

5. The system according to claim 2, characterized in that: The TETS power receiver comprises a TETS power receiver printed circuit board assembly (PCBA); and The remote accelerometer is mounted on the TETS power receiver PCBA.

6. The system of claim 2, further comprising a TETS power receiver connection cable connecting the TETS power receiver to the controller.

7. The system according to claim 6, characterized in that The TETS power receiver is configured for implantation in a chest region of the patient.

8. The system of claim 6, further comprising a controller connection cable connecting the controller to the VAD.

9. The system according to claim 6, characterized in that The controller is configured for implantation in an abdominal wall region of the patient.

10. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to: processing the remote accelerometer output to determine the patient's heart rate; and The rotational speed of the impeller is controlled based on the heart rate.

11. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine an amplitude of ventricular contraction of the patient.

12. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine a magnitude of the patient's cardiac output.

13. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine a valve opening timing of the patient.

14. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to monitor valve disease in the patient.

15. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine a breathing rate of the patient.

16. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to monitor the VAD for the occurrence of pump thrombosis.

17. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to monitor the occurrence of an occlusion in the VAD.

18. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to monitor for the occurrence of instability of the impeller.

19. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to monitor the orientation of the patient.

20. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine when the patient is in a prone position.

21. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine when the patient is in a supine position.

22. The system according to claim 21, characterized in that The controller is configured to process the remote accelerometer output to determine a recline angle when the patient is in a supine position.

23. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine when the patient is in a sitting position.

24. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine when the patient is in a standing position.

25. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to monitor a fall of the patient.

26. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to monitor the patient for syncope.

27. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine whether the patient is in an active state or in a resting state.

28. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to determine a health indicator of the patient.

29. The system according to any one of claims 1 to 9, characterized in that: The controller is configured to process the remote accelerometer output to detect the timing of the patient's cardiac cycle; The cardiac cycle timing includes the heart rate and occurrence time of each of one or more cardiac cycle events; as well as The controller is configured to vary the rotational speed of the impeller in synchronization with the cardiac cycle timing.

30. The system according to claim 29, characterized in that The controller is configured to increase the rotational speed of the impeller during ventricular systole.

31. The system according to claim 30, characterized in that The controller is configured to: processing the remote accelerometer output to detect a time of occurrence of at least one heart sound; as well as The timing of the ventricular systole is detected based on the occurrence time of the at least one heart sound.

32. The system according to claim 31, characterized in that The at least one heart sound comprises: The sound of at least one atrioventricular valve closing of the patient; and / or Sound of closure of at least one semilunar valve of the patient.

33. The system according to claim 29, characterized in that The controller is configured to vary the rotational speed of the impeller over a target cardiac cycle based on a detected timing of one or more cardiac cycles occurring prior to the target cardiac cycle.

34. The system according to claim 29, characterized in that The controller is configured to vary the rotational speed of the impeller over a target cardiac cycle based on the detected timing of the target cardiac cycle.

35. The system according to claim 29, characterized in that The controller is configured to: processing the remote accelerometer output to measure the patient's activity level; and The rotational speed of the impeller is controlled based on the activity level.

36. The system according to claim 35, characterized in that The controller is configured to: processing the remote accelerometer output to measure the patient's breathing rate and / or the patient's diaphragm contraction; and The activity level is based on the breathing rate and / or the diaphragm contraction.

37. The system according to any one of claims 1 to 9, characterized in that The controller is configured to: processing the remote accelerometer output to measure the patient's activity level; and The rotational speed of the impeller is controlled based on the activity level.

38. The system according to claim 37, characterized in that The controller is configured to: processing the remote accelerometer output to measure breathing rate and / or diaphragm contraction; and The activity level is based on the breathing rate and / or the diaphragm contraction.

39. The system according to any one of claims 1 to 9, characterized in that The remote accelerometer output is indicative of acceleration in three orthogonal directions.

40. A blood circulation support system, comprising: A ventricular assist device (VAD), the ventricular assist device (VAD) comprising a housing defining a blood flow channel, an inlet, an outlet, an impeller disposed within the blood flow channel, a motor stator, and a VAD accelerometer, wherein the motor stator is operable to rotate the impeller to pump blood flow in a patient, wherein the inlet is configured to couple with a ventricle of a heart to receive the blood flow therefrom, wherein the outlet is configured to couple with a blood vessel to transmit the blood flow to the blood vessel, and wherein the VAD accelerometer is configured to generate a VAD accelerometer output indicative of an acceleration of the VAD; a transcutaneous energy transfer system (TETS) power receiver configured to be implanted and receive energy transmitted by an external TETS transmitter; as well as a controller configured to be implanted, process the VAD accelerometer output and a remote accelerometer output, and control a rotational speed of the impeller based on at least one of the VAD accelerometer output and the remote accelerometer output; as well as a remote accelerometer configured to generate the remote accelerometer output, wherein: the TETS power receiver comprises the remote accelerometer and the remote accelerometer output is indicative of an acceleration of the TETS power receiver, or The controller includes the remote accelerometer, and the remote accelerometer output is indicative of an acceleration of the controller.

41. The system according to claim 40, characterized in that: The VAD is configured to be mounted to a heart wall of the heart; The controller is configured to process the VAD accelerometer output to monitor the motion of the heart wall to detect the timing of the cardiac cycle of the heart; as well as The controller is configured to control the rotational speed of the impeller based on the cardiac cycle timing.

42. The system according to claim 41, characterized in that: The TETS power receiver is configured to be implanted in a chest region of the patient; The controller is configured to process the remote accelerometer output to determine a respiration rate of the patient; as well as The controller is configured to control the rotational speed of the impeller further based on the breathing rate.

43. A system according to any one of claims 40 to 42, characterized in that The VAD further includes control electronics configured to control a drive current supplied to the motor stator to rotate the impeller.

44. The system according to claim 43, characterized in that The driving current supplied to the motor stator is further used to magnetically levitate the impeller.

45. The system according to any one of claims 40 to 42, characterized in that The controller is configured to determine a posture of the patient based on the remote accelerometer output and the VAD accelerometer output.

46. ​​A blood circulation support system, comprising: a ventricular assist device (VAD) comprising an inlet, an outlet, an impeller, and a motor stator operable to rotate the impeller to pump blood flow, wherein the inlet is configured to couple with a ventricle of a patient to receive the blood flow from the ventricle, wherein the outlet is configured to couple with a blood vessel of the patient to deliver the blood flow to the blood vessel; as well as a controller configured to process a remote accelerometer output indicative of an acceleration of the patient at a remote accelerometer location and to control a rotational speed of the impeller based on the remote accelerometer output; as well as A remote accelerometer configured to generate the remote accelerometer output, wherein the remote accelerometer is configured to be implanted in the patient at the remote accelerometer location, and wherein the remote accelerometer location is spaced apart from the VAD to isolate the remote accelerometer from noise generated by the VAD.

47. The system according to claim 46, characterized in that The remote accelerometer is configured for implantation in a chest region of the patient.

48. The system according to claim 46, characterized in that The remote accelerometer is configured for implantation in an abdominal wall region of the patient.

49. A system according to any one of claims 46 to 48, characterized in that The controller is configured to: processing the remote accelerometer output to determine the patient's heart rate; and The rotational speed of the impeller is controlled based on the heart rate.

50. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine a valve opening timing of the patient.

51. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to monitor valve disease in the patient.

52. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine a breathing rate of the patient.

53. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to monitor the VAD for the occurrence of pump thrombosis.

54. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to monitor the occurrence of an occlusion in the VAD.

55. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to monitor for the occurrence of instability of the impeller.

56. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to monitor the orientation of the patient.

57. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine when the patient is in a prone position.

58. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine when the patient is in a supine position.

59. The system according to claim 58, characterized in that The controller is configured to process the remote accelerometer output to determine a recline angle when the patient is in a supine position.

60. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine when the patient is in a sitting position.

61. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine when the patient is in a standing position.

62. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to monitor a fall of the patient.

63. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to monitor the patient for syncope.

64. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine whether the patient is in an active state or in a resting state.

65. The system according to any one of claims 46 to 48, characterized in that The controller is configured to process the remote accelerometer output to determine a health indicator of the patient.

66. The system according to any one of claims 46 to 48, characterized in that: The controller is configured to process the remote accelerometer output to detect the timing of the patient's cardiac cycle; The cardiac cycle timing includes the heart rate and occurrence time of each of one or more cardiac cycle events; as well as The controller is configured to vary the rotational speed of the impeller in synchronization with the cardiac cycle timing.

67. The system according to claim 66, characterized in that The controller is configured to increase the rotational speed of the impeller during ventricular systole.

68. The system according to claim 67, characterized in that The controller is configured to: processing the remote accelerometer output to detect a time of occurrence of at least one heart sound; as well as The timing of the ventricular systole is detected based on the occurrence time of the at least one heart sound.

69. The system according to claim 68, characterized in that The at least one heart sound comprises: The sound of at least one atrioventricular valve closing of the patient; and / or Sound of closure of at least one semilunar valve of the patient.

70. The system of claim 66, wherein: The controller is configured to vary the rotational speed of the impeller over a target cardiac cycle based on a detected timing of one or more cardiac cycles occurring prior to the target cardiac cycle.

71. The system according to claim 66, characterized in that The controller is configured to vary the rotational speed of the impeller over a target cardiac cycle based on the detected timing of the target cardiac cycle.

72. The system of claim 66, wherein: The controller is configured to: processing the remote accelerometer output to measure the patient's activity level; and The rotational speed of the impeller is controlled based on the activity level.

73. The system according to claim 72, characterized in that The controller is configured to process the remote accelerometer output to measure a breathing rate of the patient and / or a contraction of a diaphragm of the patient and to base the activity level on the breathing rate and / or the contraction of the diaphragm.

74. The system according to any one of claims 46 to 48, characterized in that The controller is configured to: processing the remote accelerometer output to measure the patient's activity level; and The rotational speed of the impeller is controlled based on the activity level.

75. The system according to claim 74, characterized in that The controller is configured to: processing the remote accelerometer output to measure breathing rate and / or diaphragm contraction; and The activity level is based on the breathing rate and / or the diaphragm contraction.

76. The system according to any one of claims 46 to 48, characterized in that The remote accelerometer output is indicative of acceleration in three orthogonal directions.

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