A blood flow assist system can include an impeller assembly including an impeller shaft and an impeller on the impeller shaft, a primary flow pathway disposed along an exterior surface of the impeller. The system can include a rotor assembly at a proximal portion of the impeller shaft. A secondary flow pathway can be disposed along a lumen of the impeller shaft. During operation of the blood flow assist system, blood can be pumped proximally along the primary flow pathway and the secondary flow pathway. The system can include a sleeve bearing distal the impeller. The system can include a drive unit having a distal end disposed distal a proximal end of the second impeller. The drive unit comprising a drive magnet and a drive bearing between the drive magnet and the impeller assembly.

A blood flow assist system can include an impeller assembly including an impeller shaft and an impeller on the impeller shaft, a primary flow pathway disposed along an exterior surface of the impeller. The system can include a rotor assembly at a proximal portion of the impeller shaft. A secondary flow pathway can be disposed along a lumen of the impeller shaft. During operation of the blood flow assist system, blood can be pumped proximally along the primary flow pathway and the secondary flow pathway. The system can include a sleeve bearing distal the impeller. The system can include a drive unit having a distal end disposed distal a proximal end of the second impeller. The drive unit comprising a drive magnet and a drive bearing between the drive magnet and the impeller assembly.

A multi-stage hydraulic rotating machine (MSHRM) maintains near-optimal efficiency over widely varying conditions of service (COS) when controlling a fluid having a gas volume fraction (GVF) greater than 50% and large changes in volumetric flow rate (VFR) between stages. The MSHRM includes separately controlled stages having at least two different designs with different VFR ranges. Stage impellor differences can include impellor diameter, blade pitch, blade width, blade number, inlet diameter, and outlet diameter. Diffusers can differ in similar ways between stages. VFR ranges can be progressively higher or lower in successive stages. The stages can share a common VFR range within which incompressible liquids can be controlled. The MSHRM can function as a pump or turbine, and can be applicable to energy storage and recovery in “green” energy systems.

A multi-stage hydraulic rotating machine (MSHRM) maintains near-optimal efficiency over widely varying conditions of service (COS) when controlling a fluid having a gas volume fraction (GVF) greater than 50% and large changes in volumetric flow rate (VFR) between stages. The MSHRM includes separately controlled stages having at least two different designs with different VFR ranges. Stage impellor differences can include impellor diameter, blade pitch, blade width, blade number, inlet diameter, and outlet diameter. Diffusers can differ in similar ways between stages. VFR ranges can be progressively higher or lower in successive stages. The stages can share a common VFR range within which incompressible liquids can be controlled. The MSHRM can function as a pump or turbine, and can be applicable to energy storage and recovery in “green” energy systems.

A system includes a vertical molten sulfur pump assembly that includes a top portion adjacent to a first end of the vertical molten sulfur pump assembly and a bottom portion adjacent to a second end of the vertical molten sulfur pump assembly. A pump motor is disposed in the top portion, an impeller is disposed in the bottom portion within an impeller casing, and a shaft is disposed within a central column and connecting the pump motor with the impeller. A pump inlet is disposed at the second end below the impeller casing. The pump inlet and the impeller casing are configured to be immersed in molten sulfur. The vertical molten sulfur pump assembly is configured to pump the molten sulfur into the inlet and upwards through a discharge passageway by rotation of the impeller. A vibration sensor and a temperature sensor are disposed on an external surface of the bottom portion, on or proximate to the impeller casing and the pump inlet. The temperature sensor is configured to measure a temperature of the molten sulfur proximate to the pump inlet. The vibration sensor includes a substrate comprising a polymer and a resonant layer disposed on a surface of the substrate. The resonant layer includes an electrically conductive nanomaterial and is configured to produce a resonant response in response to receiving a radio frequency signal.

A system includes a vertical molten sulfur pump assembly that includes a top portion adjacent to a first end of the vertical molten sulfur pump assembly and a bottom portion adjacent to a second end of the vertical molten sulfur pump assembly. A pump motor is disposed in the top portion, an impeller is disposed in the bottom portion within an impeller casing, and a shaft is disposed within a central column and connecting the pump motor with the impeller. A pump inlet is disposed at the second end below the impeller casing. The pump inlet and the impeller casing are configured to be immersed in molten sulfur. The vertical molten sulfur pump assembly is configured to pump the molten sulfur into the inlet and upwards through a discharge passageway by rotation of the impeller. A vibration sensor and a temperature sensor are disposed on an external surface of the bottom portion, on or proximate to the impeller casing and the pump inlet. The temperature sensor is configured to measure a temperature of the molten sulfur proximate to the pump inlet. The vibration sensor includes a substrate comprising a polymer and a resonant layer disposed on a surface of the substrate. The resonant layer includes an electrically conductive nanomaterial and is configured to produce a resonant response in response to receiving a radio frequency signal.

Apparatus and methods are described including a blood pump that includes an impeller, and a motor configured to drive the impeller to pump blood by rotating the impeller. The impeller is configured to undergo axial motion, in response to changes in a pressure against which the impeller is pumping. A sensor detects the axial motion of the impeller, and generates a sensor signal in response thereto. A computer processor receives the sensor signal and generates an output in response thereto. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an impeller, and a motor configured to drive the impeller to pump blood by rotating the impeller. The impeller is configured to undergo axial motion, in response to changes in a pressure against which the impeller is pumping. A sensor detects the axial motion of the impeller, and generates a sensor signal in response thereto. A computer processor receives the sensor signal and generates an output in response thereto. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft, an impeller disposed on the axial shaft, a frame disposed around the impeller, and a motor disposed outside a subject's body, and configured to drive the impeller to pump blood from a distal end of the impeller to a proximal end of the impeller. A drive cable extends from outside the subject's body to the axial shaft, and is configured to impart rotational motion from the motor to the impeller by rotating. The drive cable is held in a preloaded state with respect to the frame, such that initiation of pumping of blood by rotation of the impeller does not cause the drive cable to axially elongate. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft, an impeller disposed on the axial shaft, a frame disposed around the impeller, and a motor disposed outside a subject's body, and configured to drive the impeller to pump blood from a distal end of the impeller to a proximal end of the impeller. A drive cable extends from outside the subject's body to the axial shaft, and is configured to impart rotational motion from the motor to the impeller by rotating. The drive cable is held in a preloaded state with respect to the frame, such that initiation of pumping of blood by rotation of the impeller does not cause the drive cable to axially elongate. Other applications are also described.