Method and devices for performing minimally invasive surgery

1. A device for use in performing minimally invasive surgery, the device comprising a user interface comprising:

a proximal portion, an intermediate portion and a distal portion, where the intermediate portion connects the proximal portion to the distal portion; and

a pushrod, a shaft and a spring;

where the distal portion is configured to reversibly mate with a working end;

where the proximal portion is configured to allow a user to hold and direct the user interface, and to operate the working end attached to the distal portion of the user interface;

where the proximal portion of the user interface comprises a proximal handle and a distal handle joined together by and rotatable around a pivot;

where the pushrod comprises a proximal portion of the pushrod and a distal portion of the pushrod;

where the proximal portion of the pushrod comprises a proximal end of the proximal portion of the pushrod, and comprises a distal end of the proximal portion of the pushrod;

where the proximal end of the proximal portion of the pushrod is linked to the proximal handle, such that movement of the proximal handle around the pivot translates into axial movement of the pushrod;

where the distal portion of the pushrod comprises a proximal end of the distal portion of the pushrod, and comprises a distal end of the distal portion of the pushrod;

where the distal end of the proximal portion of the pushrod is joined to the proximal end of the distal portion of the pushrod at a junction;

where the distal end of the distal portion of the pushrod comprises an expansion for mating with the working end, the working end comprising a head piece having a proximal portion of the head piece connected to a distal portion of the head piece;

where the proximal portion of the head piece defines a recess for laterally receiving the expansion such that the proximal portion of the head piece mates with the distal portion of the shaft of the user interface and with the distal end of the working end pushrod;

where the shaft comprises a hollow tubular structure comprising a longitudinal axis and further comprises a proximal portion of the shaft and a distal portion of the shaft;

where the shaft surrounds at least part of the distal portion of the pushrod; where the distal portion of the pushrod is axially slidable within the shaft; and

where the spring surrounds the proximal end of the distal portion of the pushrod, and the spring is between and abuts the distal end of the proximal portion of the pushrod and the proximal portion of the shaft.

2. The device of claim 1 , where the user interface further comprises a shaft securing pin configured to insert within a recess in the distal handle, thereby securing the shaft from moving relative to the distal handle.

3. The device of claim 1 , where the shaft comprises an outer transverse diameter and the outer transverse diameter is between 1 mm and 3 mm.

4. The device of claim 1 , where the shaft comprises an outer transverse diameter and the outer transverse diameter is between 2 mm and 2.2 mm.

5. The device of claim 1 , further comprising the working end for performing a function during minimally invasive surgery, where the working end is configured to reversibly mate with the distal end of the distal portion of the user interface.

6. The device of claim 5 , where the function is selected from the group consisting of canulating, clip application, cutting, grasping, lighting, recording images, retracting, sealing, suctioning, and viewing images.

7. The device of claim 1 , wherein the working end has a grasping function, the working end further comprising:

a working end pushrod comprising a proximal portion of the working end pushrod and a distal end of the working end pushrod;

a first jaw and a second jaw connected to the distal end of the working end pushrod by a jaw pivot; and

a shaft clamp and one or more than one shaft clamp pins for aligning the shaft clamp with the proximal portion of the head piece;

where the distal portion of the head piece is connected to the proximal portion of the working end pushrod by a jaw pin;

where the first jaw and the second jaw approximate and separate from each other in response to axial movement of the working end pushrod; and

where the distal portion of the shaft and the distal end of the working end pushrod are secured to the head piece by placing the shaft clamp onto the proximal portion of the head piece and securing the shaft clamp onto the proximal portion of the head piece by threading a threaded fastener over both the shaft clamp and the proximal portion of the head piece.

8. The device of claim 1 , wherein the working end has a cutting function, the working end further comprising:

a working end pushrod comprising a proximal portion of the working end pushrod and a distal end of the working end pushrod;

a first blade and a second blade connected to the distal end of the working end pushrod by a blade pivot; and

a shaft clamp and one or more than one shaft clamp pins for aligning the shaft clamp with the proximal portion of the head piece;

where the distal portion of the head piece is connected to the proximal portion of the working end pushrod by a blade pin;

where the first blade and the second blade approximate and separate from each other in response to axial movement of the working end pushrod; and

where the distal portion of the shaft and the distal end of the working end pushrod are secured to the head piece by placing the shaft clamp onto the proximal portion of the head piece and securing the shaft clamp onto the proximal portion of the head piece by threading a threaded fastener over both the shaft clamp and the proximal portion of the head piece.

9. A device for use in performing minimally invasive surgery, the device comprising a working end for mating with a user interface, the working end having a grasping function, and the working end further comprising:

a head piece comprising a proximal portion of the head piece connected to a distal portion of the head piece;

a working end pushrod comprising a proximal portion of the working end pushrod and a distal end of the working end pushrod;

a first jaw and a second jaw connected to the distal end of the working end pushrod by a jaw pivot; and

a shaft clamp and one or more than one shaft clamp pins for aligning the shaft clamp with the proximal portion of the head piece;

where the distal portion of the head piece is connected to the proximal portion of the working end pushrod by a jaw pin;

where the first jaw and the second jaw approximate and separate from each other in response to axial movement of the working end pushrod;

where the proximal portion of the head piece comprises a recess for mating with the distal portion of a shaft of the user interface and the distal end of the working end pushrod; and

where the distal portion of the shaft and the distal end of the working end pushrod are secured to the head piece by placing the shaft clamp onto the proximal portion of the head piece and securing the shaft clamp onto the proximal portion of the head piece by threading a threaded fastener over both the shaft clamp and the proximal portion of the head piece.

10. A device for use in performing minimally invasive surgery, the device comprising a working end for mating with a user interface, the working end having a cutting function, and the working end further comprising:

a head piece comprising a proximal portion of the head piece connected to a distal portion of the head piece;

a working end pushrod comprising a proximal portion of the working end pushrod and a distal end of the working end pushrod;

a first blade and a second blade connected to the distal end of the working end pushrod by a blade pivot; and

a shaft clamp and one or more than one shaft clamp pins for aligning the shaft clamp with the proximal portion of the head piece;

where the distal portion of the head piece is connected to the proximal portion of the working end pushrod by a blade pin;

where the first blade and the second blade approximate and separate from each other in response to axial movement of the working end pushrod;

where the proximal portion of the head piece comprises a recess for mating with the distal portion of a shaft of the user interface and the distal end of the working end pushrod; and

where the distal portion of the shaft and the distal end of the working end pushrod are secured to the head piece by placing the shaft clamp onto the proximal portion of the head piece and securing the shaft clamp onto the proximal portion of the head piece by threading a threaded fastener over both the shaft clamp and the proximal portion of the head piece.