A blood pump system is implantable in a patient for ventricular support. A pumping chamber has an inlet for receiving blood from a ventricle of the patient. An impeller is received in the pumping chamber. A motor is coupled to the impeller for driving rotation of the impeller. A motor controller is provided for tracking systolic and diastolic phases of a cardiac cycle of the patient and supplying a variable voltage signal to the motor in a variable speed mode to produce a variable impeller speed linked to the cardiac cycle. The impeller speed comprises a ramping up to an elevated speed during the diastolic phase in order to reduce a load on the ventricle at the beginning of the systolic phase.

A control circuit for a sensorless implantable blood pump configured to determine mitral valve regurgitation includes processing circuitry configured to generate an estimated blood flow waveform from the sensorless implanted blood pump and generate an alert if between an end period of diastole and a beginning period of systole a measured amplitude of the estimated blood flow waveform does not include an inflection point.

Multi-cell battery packs can be made safer with certain features that mitigate the consequences of cell failure. Parameters of a cell are monitored to determine when the cell should be disconnected from the pack in case of a fault. The battery is reconfigured to continue operating in a safer mode. An over-charging prevention system reduces the maximum voltage that remaining battery pack can be charged to, so that the cells do not overcharge. Additional circuitry allows the disconnected cell to be periodically reconnected to the battery pack to determine if its conditions have sufficiently improved. The cells also include components for self-powering these cell functions while it is disconnected from the rest of the circuit.

An implantable pump system is provided, suitable for use as a left ventricular assist device (LVAD) system, having an implantable pump, a battery, a controller, and a programmer. The implantable pump includes a flexible membrane coupled to an actuator assembly via a skirt that extends toward the inlet of the pump and curves to guide blood toward the outlet. The actuator assembly is magnetically engageable with electromagnetic coils, so that when the electromagnetic coils are energized, the actuator assembly causes wavelike undulations to propagate along the flexible membrane to propel blood from the inlet, across the skirt, and through the outlet of the implantable pump. The controller may be programmed by a programmer to operate at frequencies and duty cycles that mimic physiologic flow rates and pulsatility while operating in an efficient manner that avoids thrombus formation, hemolysis and/or platelet activation.

An implantable pump system is provided, suitable for use as a left ventricular assist device (LVAD) system, having an implantable pump, a battery, a controller, and a programmer. The implantable pump includes a flexible membrane coupled to an actuator assembly via a skirt that extends toward the inlet of the pump and curves to guide blood toward the outlet. The actuator assembly is magnetically engageable with electromagnetic coils, so that when the electromagnetic coils are energized, the actuator assembly causes wavelike undulations to propagate along the flexible membrane to propel blood from the inlet, across the skirt, and through the outlet of the implantable pump. The controller may be programmed by a programmer to operate at frequencies and duty cycles that mimic physiologic flow rates and pulsatility while operating in an efficient manner that avoids thrombus formation, hemolysis and/or platelet activation.

Apparatus and methods are described for manufacturing a housing for an impeller of a blood pump. A frame is treated in order to enhance bonding between an inner surface of the frame and an inner lining. Subsequently, the inner lining is coupled to the inner surface of the frame along at least a portion of a central cylindrical portion of the frame. Subsequent to coupling the inner lining to the inner surface of the frame along at least a portion of the central cylindrical portion of the frame, a portion of an elongate tube is placed around at least a portion of the frame. While heating the inner lining, the frame, and the portion of the elongate tube, pressure is applied such as to cause the portion of the elongate tube to become coupled to the frame. Other applications are also described.

Shape memory alloys are used in aerospace structures, orthodontics, cardiovascular prosthetic devices, sensors and controllers, and many other engineering, technology, science, and other fields. The methods are described in the case of a temporary heart assist pump to illustrate the concepts, but the method applies to many other fields. The properties of shape memory alloys are used to fold or collapse and implant in the human body a device without breaking the device as it reaches body temperature or without reaching permanent plastic deformation. The properties of nitinol are also used to describe intended explantation of the device, at body temperature, from the body without breaking it. Such planned explantation may be needed in cases where the device is designed for temporary use, such as mechanical circulatory support devices intended for temporary use and then removal of all components of the device from the body. The same method can be used for devices that have not been initially designed for removal, such as stents or valves, that must later be explanted for reasons unanticipated when they were installed. The methods ensure that the devices stay within stress-strain-temperature conditions so they remain elastic, or under the upper stress plateau, or remain plastic, but always under the breaking strain, of shape memory alloys at: room or environmental conditions; cooler than environmental conditions; and at a higher temperature, or body temperature. The methods described may also be applied to other industrial applications, where shape memory alloys may be installed and removed at different temperatures. Applications in other industries, include aerospace, civil structures, mechanical structures are contemplated.

Shape memory alloys are used in aerospace structures, orthodontics, cardiovascular prosthetic devices, sensors and controllers, and many other engineering, technology, science, and other fields. The methods are described in the case of a temporary heart assist pump to illustrate the concepts, but the method applies to many other fields. The properties of shape memory alloys are used to fold or collapse and implant in the human body a device without breaking the device as it reaches body temperature or without reaching permanent plastic deformation. The properties of nitinol are also used to describe intended explantation of the device, at body temperature, from the body without breaking it. Such planned explantation may be needed in cases where the device is designed for temporary use, such as mechanical circulatory support devices intended for temporary use and then removal of all components of the device from the body. The same method can be used for devices that have not been initially designed for removal, such as stents or valves, that must later be explanted for reasons unanticipated when they were installed. The methods ensure that the devices stay within stress-strain-temperature conditions so they remain elastic, or under the upper stress plateau, or remain plastic, but always under the breaking strain, of shape memory alloys at: room or environmental conditions; cooler than environmental conditions; and at a higher temperature, or body temperature. The methods described may also be applied to other industrial applications, where shape memory alloys may be installed and removed at different temperatures. Applications in other industries, include aerospace, civil structures, mechanical structures are contemplated.

A method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle includes obtaining a signal from a motor of a heart assist pump device and filtering the signal to remove noise. The method also includes determining a speed synchronization start point at which time the motor of the heart assist pump device will begin a change in speed of operation based on the filtered signal. The method further includes modulating a speed of the motor of the heart assist pump device to a target speed at the speed synchronization start point, thereby synchronizing the change in speed of operation with a patient's cardiac cycle.

A method for synchronizing operation of a heart assist pump device to a patient's cardiac cycle includes obtaining a signal from a motor of a heart assist pump device and filtering the signal to remove noise. The method also includes determining a speed synchronization start point at which time the motor of the heart assist pump device will begin a change in speed of operation based on the filtered signal. The method further includes modulating a speed of the motor of the heart assist pump device to a target speed at the speed synchronization start point, thereby synchronizing the change in speed of operation with a patient's cardiac cycle.