Abstract: 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.

Abstract: 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 motor is configured to generate rotational motion. A rotation shaft extends from the motor to the first impeller and imparts the rotational motion from the motor to the first impeller. A gear mechanism disposed between the first and second impeller is configured to effect a change in rotational motion that is imparted from the first impeller to the second impeller, such that the second impeller rotates in a different manner from the first impeller. Other applications are also described.

Abstract: 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 motor is configured to generate rotational motion. A rotation shaft extends from the motor to the first impeller and imparts the rotational motion from the motor to the first impeller. A gear mechanism disposed between the first and second impeller is configured to effect a change in rotational motion that is imparted from the first impeller to the second impeller, such that the second impeller rotates in a different manner from the first impeller. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump (24) configured to be placed inside a blood vessel of a in subject, the blood pump including an impeller (28) configured to pump blood by rotating. A support cage (254) is shaped to define a narrow portion (256) that is configured to be disposed around the impeller, and to maintain a separation between a wall of the blood vessel and the impeller, and a radial extension (258) from the narrow portion of the support cage that extends radially outward with respect to the narrow portion of the support cage, the radial extension being configured to substantially maintain a longitudinal axis of the impeller in alignment with a local longitudinal axis of the blood vessel by contacting the wall of the blood vessel. Other applications are also described.

Abstract: Apparatus and methods are described including a blood pump (24) configured to be placed inside a blood vessel of a in subject, the blood pump including an impeller (28) configured to pump blood by rotating. A support cage (254) is shaped to define a narrow portion (256) that is configured to be disposed around the impeller, and to maintain a separation between a wall of the blood vessel and the impeller, and a radial extension (258) from the narrow portion of the support cage that extends radially outward with respect to the narrow portion of the support cage, the radial extension being configured to substantially maintain a longitudinal axis of the impeller in alignment with a local longitudinal axis of the blood vessel by contacting the wall of the blood vessel. Other applications are also described.