Systems, devices, and methods for improving wireless power transmission are disclosed herein. A method of powering an implantable ventricular assist device with an external charging device includes receiving a signal indicative of a change in a property of a deformable coil of the resonant circuit. A performance property of the deformable coil is determined based on the signal. An adjustment to a tuning of the resonant circuit is identified based on the performance property of the deformable coil. The resonant circuit is tuned according to the adjustment to the tuning of the resonant circuit. The resonant circuit is driven to transmit power to a secondary coil electrically coupled with the implantable ventricular assist device to power the ventricular assist device.

Apparatus comprising and methods are described including a blood pump that includes an axial shaft, and an impeller disposed on the axial shaft. The impeller is configured to pump blood of the subject by rotating. The impeller and the axial shaft are configured to undergo axial back-and-forth motion during operation of the impeller. A distal tip element is disposed at a distal end of the blood pump. The distal tip element defines an axial-shaft-receiving tube, configured to receive at least a portion of the axial shaft during forward motion of the axial shaft. The distal tip element additionally defines an atraumatic distal tip portion disposed distally of the axial-shaft-receiving tube. Other applications are also described.

Apparatus comprising and methods are described including a blood pump that includes an axial shaft, and an impeller disposed on the axial shaft. The impeller is configured to pump blood of the subject by rotating. The impeller and the axial shaft are configured to undergo axial back-and-forth motion during operation of the impeller. A distal tip element is disposed at a distal end of the blood pump. The distal tip element defines an axial-shaft-receiving tube, configured to receive at least a portion of the axial shaft during forward motion of the axial shaft. The distal tip element additionally defines an atraumatic distal tip portion disposed distally of the axial-shaft-receiving tube. Other applications are also described.

Disclosed herein is an implantable blood pump assembly that includes a housing defining an inlet, an outlet, a flow path extending from the inlet to the outlet, and an internal compartment separated from the flow path. The blood pump assembly further includes a rotor positioned within the flow path and operable to pump blood from the inlet to the outlet, a stator positioned within the internal compartment and operable to drive the rotor, and an inlet conduit connected to the housing inlet and having a downstream end that has a reduced cross-sectional area that produces a localized region of high velocity blood flow. The blood pump assembly further includes at least one pressure sensor positioned between the inlet and the outlet and configured to detect a pressure of blood flowing through the flow path. The pressure sensor is located adjacent the downstream end of the inlet conduit.

Disclosed herein is an implantable blood pump assembly that includes a housing defining an inlet, an outlet, a flow path extending from the inlet to the outlet, and an internal compartment separated from the flow path. The blood pump assembly further includes a rotor positioned within the flow path and operable to pump blood from the inlet to the outlet, a stator positioned within the internal compartment and operable to drive the rotor, and an inlet conduit connected to the housing inlet and having a downstream end that has a reduced cross-sectional area that produces a localized region of high velocity blood flow. The blood pump assembly further includes at least one pressure sensor positioned between the inlet and the outlet and configured to detect a pressure of blood flowing through the flow path. The pressure sensor is located adjacent the downstream end of the inlet conduit.

Extracorporeal circuit devices can be used for on-pump open-heart surgery to support surgical procedures such as coronary artery bypass grafting. In some cases, a centrifugal pump is used as part of an extracorporeal circuit. Centrifugal pump heads are described herein that induce flow on two sides of an impeller plate, and that can be conveniently mechanically assembled.

Extracorporeal circuit devices can be used for on-pump open-heart surgery to support surgical procedures such as coronary artery bypass grafting. In some cases, a centrifugal pump is used as part of an extracorporeal circuit. Centrifugal pump heads are described herein that induce flow on two sides of an impeller plate, and that can be conveniently mechanically assembled.

A catheter pump is disclosed herein. The catheter pump can include a catheter assembly that comprises a drive shaft and an impeller coupled to a distal end of the drive shaft. A driven assembly can be coupled to a proximal end of the drive shaft within a driven assembly housing. The catheter pump can also include a drive system that comprises a motor and a drive magnet coupled to an output shaft of the motor. The drive system can include a drive assembly housing having at least one magnet therein. Further, a securement device can be configured to prevent disengagement of the driven assembly housing from the drive assembly housing during operation of the pump.

A catheter pump is disclosed herein. The catheter pump can include a catheter assembly that comprises a drive shaft and an impeller coupled to a distal end of the drive shaft. A driven assembly can be coupled to a proximal end of the drive shaft within a driven assembly housing. The catheter pump can also include a drive system that comprises a motor and a drive magnet coupled to an output shaft of the motor. The drive system can include a drive assembly housing having at least one magnet therein. Further, a securement device can be configured to prevent disengagement of the driven assembly housing from the drive assembly housing during operation of the pump.

A temporary, removable mechanical circulatory support heart-assist device has at least two propellers or impellers. Each propeller or impeller has a number of blades arranged around an axis of rotation. The blades are configured to pump blood. The two propellers or impellers rotate in opposite directions from each other. The device can be configured to be implanted and removed with minimally invasive surgery.