Control system for a stent delivery system

1. A control system for controlling movement of a stent delivery system having a first shaft and a second shaft, the second shaft movable relative to the first shaft, the control system comprising:

a housing having a chamber formed therein;

a first drive at least partially positioned and movable within the housing and operably connected to the first shaft, the first drive being movable in response to a change in pressure within the chamber, the first drive contacting a first portion of an interior wall of the housing and forming a first seal;

a second drive at least partially positioned and movable within the housing and operably connected to the second shaft, the second drive being movable in response to the change in pressure within the chamber, the second drive contacting a second portion of the interior wall of the housing and forming a second seal;

a pressure controller operably connected to the housing the pressure controller changing the pressure within the chamber to move the second drive relative to the first drive;

a first spring biasing the first drive; and

a second spring biasing the second drive;

wherein movement of the second drive relative to the first drive in a first direction causes the second shaft to move relative to the first shaft to expand a stent operably connected thereto and movement of the second drive relative to the first drive in a second direction causes the second shaft to move relative to the first shaft to reconstrain the stent from an expanded configuration to a constrained configuration.

2. The control system of claim 1 , wherein in the second direction is in an opposite direction to the first direction.

3. The control system of claim 1 , wherein the pressure controller comprises a syringe.

4. The control system of claim 1 , wherein the pressure controller comprises a flexible membrane.

5. The control system of claim 1 , wherein the pressure controller comprises a balloon device.

6. The control system of claim 1 , further comprising a belt operably connected to the first drive and the second drive.

7. The control system of claim 1 , wherein the first shaft extends through the second drive and coaxially with the second shaft.

8. The control system of claim 1 , wherein the housing is provided within a handle.

9. The control system of claim 1 , wherein the first drive and the second drive move relative to each other in substantially equal and opposite directions in response to the pressure controller changing the pressure.

10. The control system of claim 1 , wherein the first drive and the second drive are at least partially positioned and movable within the chamber formed in the housing.

11. The control system of claim 1 , wherein the housing further comprises a stop adapted to limit the movement of the first drive or the second drive.

12. A stent delivery system comprising:

a first shaft;

a second shaft, the second shaft movable relative to the first shaft and coaxially extending within the first shaft;

a stent having a first end portion operably connected to the first shaft by a first constraining member and a second end portion operably connected to the second shaft by a second constraining member so that the first and second constraining members, in response to movement of the second shaft to the first shaft, apply a longitudinal tension to or release the longitudinal tension from the first end portion of the stent and the second end portion of the stent; and

a control system comprising:

a housing having a chamber formed therein;

a first drive at least partially positioned and movable within the housing and operably connected to the first shaft;

a second drive at least partially positioned and movable within the housing and operably connected to the second shaft;

a biasing member, the biasing member comprising a spring: and

a pressure controller operably connected to the housing, the pressure controller changing the pressure within the chamber and to move the second drive relative to the first drive so that movement of the second drive relative to the first drive in a first direction causes the second shaft to move relative to the first shaft to expand the stent operably connected thereto and movement of the second drive relative to the first drive in a second direction causes the second shaft to move relative to the first shaft to reconstrain the stent from an expanded configuration to a constrained configuration so that the longitudinal tension is applied to the first end portion and the second end portion of the stent in the constrained configuration by movement of the second drive relative to the first drive in the second direction.

13. The delivery system of claim 12 , wherein the first drive is movable in a first direction and the second drive is movable in an opposite direction to the first direction to change the longitudinal tension on the stent.

14. The control system of claim 12 , wherein the first drive and the second drive are at least partially positioned and movable within the chamber formed in the housing.

15. The control system of claim 12 , wherein the housing further comprises a stop adapted to limit the movement of the first drive or the second drive.