1. A wire discharge-machining apparatus comprising:
a wire electrode set as cutting wires provided in parallel with a distance therebetween and facing a workpiece;
a machining power source that generates a machining voltage; and
a plurality of feeder units that are electrically connected to the cutting wires respectively of the wire electrode and supply the machining voltage between the cutting wires and the workpiece respectively, wherein
in the parallel cutting wires, the feeder units are arranged such that a direction of a current passed to at least a part of the cutting wires becomes a direction different from a direction of a current passed to other cutting wires.
2. The wire discharge-machining apparatus according to claim 1, wherein the feeder units are electrically connected to the wire electrode by having feeders connected to the cutting wires alternately arranged at a side where the cutting wires come close to the workpiece and at a side where the cutting wires move far from the workpiece such that directions of currents passing through the cutting wires become opposite between the cutting wires adjacent to each other.
3. The wire discharge-machining apparatus according to claim 1, wherein the feeder units are electrically connected to the wire electrode by having the feeders connected to the cutting wires alternately arranged at a side where cutting wires come close to the workpiece and at a side where cutting wires move far from the workpiece such that a plurality of adjacent cutting wires are set as groups, directions of currents passed to cutting wires in a same group become a same direction, and directions of currents passed to cutting wires in adjacent groups become opposite to each other.
4. The wire discharge-machining apparatus according to claim 1, wherein the feeder units are electrically connected to the wire electrode by having the feeders connected to the cutting wires alternately arranged at a side where cutting wires come close to the workpiece and at a side where cutting wires move far from the workpiece such that directions of currents passed to cutting wires arranged at both ends in a parallel direction of a plurality of parallel cutting wires become opposite to directions of currents passed to cutting wires arranged at other than the both ends.
5. The wire discharge-machining apparatus according to claim 1, wherein the feeder units are provided at both sides of cutting wires, any one of the cutting wires is selected, and the machining voltage from the machining power source is supplied between the cutting wires and the workpiece.
6. The wire discharge-machining apparatus according to claim 5, wherein the feeder units that include the feeder units not selected and provided at both sides of cutting wires function as supporting members of the wire electrode.
7. The wire discharge-machining apparatus according to claim 5, wherein the feeder units provided at both sides of the cutting wires are connected in such a manner that these feeder units are arranged in a line in a direction orthogonal to the cutting wires.
8. The wire discharge-machining apparatus according to claim 1, wherein a positional relationship among the feeder units, the workpiece or a stage on which the workpiece is mounted, and a guide roller that winds cutting wires is that the feeder units are arranged at both sides of the workpiece or the stage on which the workpiece is mounted and that at least one of guide rollers arranged at both sides of the workpiece or the stage on which the workpiece is mounted is arranged between the feeder units and the workpiece or the stage on which the workpiece is mounted.
9. The wire discharge-machining apparatus according to claim 1, wherein a positional relationship among the feeder units, the workpiece or a stage on which the workpiece is mounted, and a guide roller that winds cutting wires is that the feeder units are arranged at both sides of the workpiece or the stage on which the workpiece is mounted and that the guide roller is arranged at a side of the feeder units where the workpiece or the stage on which the workpiece is not mounted.
10-23. (canceled)
24. A wire discharge-machining method, wherein the workpiece is slice-machined by the wire discharge-machining apparatus according to claim 1.
25. A thin sheet manufacturing method using the wire discharge-machining apparatus according to claim 1.
26. A semiconductor wafer manufacturing method using the wire discharge-machining apparatus according to claim 1, wherein the workpiece is a semiconductor wafer material.
27. The semiconductor wafer manufacturing method according to claim 26, wherein the semiconductor wafer material is silicon or silicon carbide, or a material having silicon or silicon carbide as a main component.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A ventricular assist system comprising:
(a) a ventricular assist device including a pump and an inlet element defining an inlet opening communicating with the pump, the inlet element being adapted for positioning with the inlet opening disposed within a ventricle of a heart when the system is in an operative condition; and
(b) an expandable stent adapted for positioning within the ventricle when the system is in the operative condition.
2. The system of claim 1 further comprising a mounting securing a part of the stent in position relative to the inlet element when the stent is positioned within the ventricle.
3. The system of claim 1 wherein the mounting includes an anchor element configured for attachment to the heart and wherein the inlet element and the stent are secured to the anchor element with the system is in the operative condition.
4. The system of claim 3, wherein the anchor element includes a channel extending therethrough.
5. The system of claim 4, further comprising a one-way valve positioned at least partially within the channel.
6. The system of claim 5, further comprising a sealing element configured to be positioned within the channel proximal to the one-way valve to seal the channel.
7. The system of claim 4, wherein the channel has a diameter and the stent has a collapsed condition and an expanded condition, the diameter of the channel being adapted to allow the stent to pass through the channel when the stent is in the collapsed condition.
8. The system of claim 7, wherein the anchor element includes a ring.
9. The system of claim 7, wherein the anchor element includes a substantially cylindrical member configured to be mounted to the heart at various positions along a length of the substantially cylindrical member.
10. The system of claim 1 wherein the stent includes a plurality of struts, the struts having inner ends and outer ends, the inner ends being disposed adjacent one another and the outer ends extending away from one another when the stent is in an expanded condition.
11. The system of claim 1, wherein the stent has a collapsed condition and an expanded condition, the stent being substantially cylindrical when in the expanded condition.
12. The system of claim 1, wherein the stent is formed of a braided mesh.
13. A method of installing a ventricular assist device in a subject comprising:
mounting the ventricular assist device to the subject so that an inlet opening of an inlet element is disposed within a ventricle of the heart and the inlet opening communicates with a pump;
positioning an outflow cannula so that the outflow cannula communicates with the pump and with an artery;
positioning a stent in the ventricle at least partially upstream of the inlet of the pump.
14. The method as claimed in claim 13 further comprising operating the pump to draw blood from the ventricle and return the blood to the artery, and holding a wall of the ventricle away from the inlet opening with the stent.
15. The method of claim 13, further comprising passing the stent through a channel in the ventricular assist device while the stent is in a collapsed condition.
16. The method of claim 15, further wherein the step of passing the stent through the channel in the ventricular assist device includes passing the stent through a one-way valve positioned at least partially within the channel.
17. The method of claim 15, further comprising transitioning the stent from the collapsed condition to an expanded condition.
18. The method of claim 17, further comprising sealing the channel with a sealing element.