Apparatus and methods are provided, including a left-ventricular assist device that includes an impeller configured for insertion into a subject's left ventricle. A delivery tube passes through the subject's aorta, from outside the subject into the left ventricle. The delivery tube includes an outer layer that varies along a length of the delivery tube such that a flexural rigidity of the delivery tube at a first portion of the delivery tube, which is configured to traverse the aortic valve, is less than the flexural rigidity at a second portion, which is configured to traverse at least a portion of the aortic arch, and the flexural rigidity at the second portion is less than the flexural rigidity at a third portion, which is configured to traverse the descending aorta. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion into, and rotation within, a left ventricle of a subject, and an impeller coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood from the left ventricle. A frame surrounds the impeller and a tip portion is coupled to a distal end of the frame. The tip portion includes a distal curved portion, which, when deployed within the left ventricle, lies in a plane, and a proximal curved portion, which, when deployed within the left ventricle, does not lie in the plane and is curved such that, following the insertion of the axial shaft into the left ventricle via an aorta of the subject, a distal end of the proximal curved portion points toward an apex of the left ventricle. Other applications are also described.

Apparatus and methods are described including a left-ventricular assist device, that includes a collapsible pump-outlet tube configured for insertion, through an aorta of a subject, into a left ventricle of a heart of the subject such that the pump-outlet tube traverses an aortic valve of the subject. The device includes one or more bands, each of which is bonded to an outer wall of the proximal portion of the pump-outlet tube, without extending around a full circumference of the pump-outlet tube, such that, while the proximal portion of the pump-outlet tube is maintained in the open state, the proximal portion of the pump-outlet tube curves at respective locations of the bands. Other applications are also described.

Apparatus and methods are described including an axial shaft configured for insertion into, and rotation within, a ventricle of a heart of a subject. An impeller is coupled to the axial shaft and a frame surrounds the impeller. A pump-outlet tube surrounds the frame such that, as the axial shaft rotates, the impeller pumps blood proximally, from the ventricle, through the pump-outlet tube. A flat inlet guard, which is shaped to define one or more holes, is disposed around, and perpendicular to, the axial shaft and within the frame distally to the impeller, such that the blood flows to the impeller via the holes. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion, over a guidewire, into a subject's body, and for rotation within the subject's body. The axial shaft is shaped to define a shaft lumen for passage of the guidewire therethrough. An impeller is coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood of the subject. A thrust bearing is disposed distally from the axial shaft so as to inhibit distal movement of the axial shaft beyond the thrust bearing. The thrust bearing is shaped to define a bearing lumen that is configured to be continuous with the shaft lumen. At least a portion of the bearing lumen is frustoconically-shaped, a wider end of the frustoconically-shaped portion of the bearing lumen facing distally. Other applications are also described.

Apparatus and methods are described including a blood pump that includes an axial shaft configured for insertion into, and rotation within, a subject's body, and an impeller coupled to the axial shaft such that, as the axial shaft rotates, the impeller pumps blood of the subject. A frame surrounds the impeller and includes a distal conical portion. A bearing adjacent to the axial shaft is configured to stabilize the axial shaft while the axial shaft rotates. A bearing housing houses the bearing. The bearing housing is disposed at least partly within the distal conical portion of the frame such that at least 50% of the length of the bearing housing is disposed within the frame. Other applications are also described.

Apparatus and methods are described including inserting a drive-cable end of a drive cable, which includes a plurality of coiled wires, and a hollow-shaft end of a hollow shaft, which hollow-shaft end is shaped to define multiple shaft pores, into opposing ends of a coupling tube, which is shaped to define multiple coupling-tube pores. While the drive-cable end and hollow-shaft end are inside the coupling tube, a molten material is flowed between the coiled wires at the drive-cable end via the coupling-tube pores, and into the hollow-shaft end via the coupling-tube pores and shaft pores, such that, upon solidifying, the material bonds the drive cable to the shaft. Other applications are also described.

A bearing assembly of a swash plate in a steering gear component of a surgical instrument is disclosed. The swash plate being rotatable about an axis of rotation in a receiving opening of the steering gear component. The swash plate has an outer peripheral surface which provides a peripheral inner bearing surface, and the steering gear component has an inner peripheral surface in the receiving opening, which inner peripheral surface provides a peripheral outer bearing surface. The bearing assembly also comprises a plurality of rolling elements which are peripherally distributed between the peripheral inner bearing surface of the swash plate and the peripheral outer bearing surface of the steering gear component such that an integrated rolling element of the bearing assembly is provided by the swash plate, the steering gear component, and the plurality of rolling elements.

A surgical instrument and a bearing arrangement includes a wobble plate having a main shaft. The wobble plate is rotatable about two axes and to the main axes of the main shaft. An intersection of the two axes defines a pivot center of the wobble plate and is located on the main axis. The main shaft has a spherical coupling portion. The wobble plate includes a hollow spherical outer bearing opening. A bearing arrangement includes rolling bearing balls and a ball cage movably arranged in the outer bearing opening and delimits a hollow spherical inner bearing opening. The ball cage includes window openings in which the rolling bearing balls are arranged. The coupling portion has first round grooves for the rolling bearing balls and the outer bearing opening has second round grooves for the rolling bearing balls.

Apparatus and methods are described including a device configured for insertion into a left ventricle of a heart of a subject. A delivery tube is coupled to the device and configured to traverse an aortic arch of the subject while the device is within the left ventricle. An elongation-resistant fiber runs axially along the delivery tube so as to bias an orientation of the delivery tube while the delivery tube traverses the aortic arch such that the elongation-resistant fiber is disposed inside a curve of the aortic arch, thereby biasing an orientation of the device. Other applications are also described.