A signal processing circuit for controlling operation of an implanted ventricular assist device comprising an input module for receiving one or more signals of a patient from one or more sensors. A processor for processing the received signals is included, the processor configured to compare a total blood output on a left side of the patient's heart with a total blood output on a right side of the patient's heart; determine at least one from the group consisting of the presence of fluid imbalance between the left and right sides of the patient's heart and the absence of fluid imbalance between the left and right sides of the patient's heart based on the comparison; and when the presence of fluid imbalance is determined, control the implanted ventricular device to restore fluid balance between the left and right sides of the patient's heart.

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.

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.

A disposable fluid pump is provided with a housing including first and second faces, with a sidewall extending between the first and second faces. The housing defines a chamber, with an inlet and an outlet in fluid communication with the chamber. An impeller is rotatably mounted within the chamber and includes a plurality of flexible vanes. Such a pump may be incorporated into a disposable fluid flow circuit that is adapted to be mounted on a durable hardware for processing a fluid. In such a fluid flow circuit, the fluid pump may be integrated into a cassette of the circuit or, alternatively, the inlet and outlet of the fluid pump may be directly connected to fluid flow conduits of the circuit.

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.

To provide a simple embodiment of a rotor for a fluid pump which is nevertheless very flexible in handling and compressible, in accordance with the invention a conveying blade is provided having at least two struts and a membrane spanned between them in the expanded state, wherein the struts each have at least one joint, in particular more than one joint, which enables an angling in a first direction in a first movement plane and bounds an overelongation beyond an elongation angle of in particular 180° in the opposite second direction. In particular when a plurality of joints are provided at the struts, they, and with them the conveying blades, are particularly flexible for simple compressibility.

To provide a simple embodiment of a rotor for a fluid pump which is nevertheless very flexible in handling and compressible, in accordance with the invention a conveying blade is provided having at least two struts and a membrane spanned between them in the expanded state, wherein the struts each have at least one joint, in particular more than one joint, which enables an angling in a first direction in a first movement plane and bounds an overelongation beyond an elongation angle of in particular 180° in the opposite second direction. In particular when a plurality of joints are provided at the struts, they, and with them the conveying blades, are particularly flexible for simple compressibility.

Apparatus and methods are described including a blood pump that includes a catheter, a first impeller disposed on the catheter, and a second impeller disposed on the catheter, proximally to the first impeller. A motor drives the first and second impellers to pump blood of a subject, by driving the first and second impellers to rotate. The blood pumps is configured such that (a) the first and second impellers are shaped differently from each other when the first and second impellers are in non-radially-constrained configurations, (b) the first and second impellers are sized differently from each other when the first and second impellers are in non-radially-constrained configurations, and/or (c) the first and second impellers are driven by the motor to rotate under respective rotation conditions that are different from each other. Other applications are also described.

Apparatus and methods are described including a blood pump that includes a catheter, a first impeller disposed on the catheter, and a second impeller disposed on the catheter, proximally to the first impeller. A motor drives the first and second impellers to pump blood of a subject, by driving the first and second impellers to rotate. The blood pumps is configured such that (a) the first and second impellers are shaped differently from each other when the first and second impellers are in non-radially-constrained configurations, (b) the first and second impellers are sized differently from each other when the first and second impellers are in non-radially-constrained configurations, and/or (c) the first and second impellers are driven by the motor to rotate under respective rotation conditions that are different from each other. Other applications are also described.

Apparatus and methods are described including a catheter, and first and second impellers configured to be inserted into a subject's body via the catheter, the first and second impellers being disposed in series with each other. A first impeller cage is disposed around the first impeller, and a second impeller cage is disposed around the second impeller. A sleeve extends longitudinally along more than 50 percent of a distance between the first and second impellers. Other applications are also described.