Retrograde instrument
A minimally invasive surgical instrument includes a U-turn mechanism that transmits actuating forces around a U-turn. The U-turn mechanism is coupled between segments of the instrument and has a bend radius that is smaller than flexible arms having a similar cross section diameter. The actuating forces transmitted by the U-turn mechanism are used to move distal components of the instrument, such as an end effector and a wrist mechanism.
1. A surgical instrument assembly comprising:
a retrograde surgical instrument comprising:
a transmission mechanism;
a proximal body segment, wherein a proximal end of the proximal body segment is coupled to the transmission mechanism;
a distal body segment;
a component coupled to a distal end of the distal body segment; and
a U-turn mechanism coupled between the proximal and the distal body segments, the U-turn mechanism comprising a proximal face, a distal face, and cable guide tubes, each of the cable guide tubes having a first end and a second end, the first end being coupled to the proximal face, and the second end being coupled to the distal face,
wherein the U-turn mechanism has a constant fixed shape so that a distance between the proximal face and the distal face is unchangeable.
2. The instrument assembly of claim 1 :
wherein the cable guide tubes are substantially equal length.
3. The instrument assembly of claim 1 :
wherein the U-turn mechanism comprises a single part.
4. The instrument assembly of claim 1 further comprising:
a joint coupling the U-turn mechanism to the distal body segment.
5. The instrument assembly of claim 1 :
wherein the distal body segment is substantially rigid and straight, and
wherein the U-turn mechanism is fixedly attached to the distal body segment.
6. The instrument assembly of claim 1 further comprising:
a guide tube comprising an interior channel though which the proximal body segment, the distal body segment, the component, and at least a portion of the U-turn mechanism of the retrograde surgical instrument pass.
7. The instrument assembly of claim 1 :
wherein the component comprises a wrist assembly.
8. The instrument assembly of claim 1 :
wherein the component comprises an end effector.
9. A method comprising:
transmitting actuating forces from a transmission mechanism through a U-turn mechanism, the U-turn mechanism comprising a proximal face, a distal face, and cable guide tubes, each of the cable guide tubes having a first end and a second end, the first end being coupled to the proximal face, and the second end being coupled to the distal face, wherein the U-turn mechanism has a constant fixed shape so that a distance between the proximal face and the distal face is unchangeable.
10. The method of claim 9 :
wherein the transmitting actuating forces through the U-turn mechanism comprises moving tendons in the cable guide tubes of the U-turn mechanism.
11. The method of claim 10 :
wherein the moving tendons in the cable guide tubes further comprises moving the tendons in cable guide tubes of substantially equal length.
12. The method of claim 9 :
wherein U-turn mechanism comprises a single fixed shape part.
13. The method of claim 9 , further comprising:
transmitting the actuating forces through a joint that couples the U-turn mechanism to a distal body segment of a surgical instrument.
14. The method of claim 9 , wherein the transmitting actuating forces through the U-turn mechanism further comprises:
transmitting the actuating forces through a substantially rigid and straight distal body segment coupled between the U-turn mechanism and a distal component.
15. The method of claim 9 :
wherein the transmitting actuating forces through the U-turn mechanism comprises transmitting the actuating forces through the U-turn mechanism to a wrist assembly coupled between the U-turn mechanism and a distal component.
16. The method of claim 9 :
wherein the transmitting actuating forces through the U-turn mechanism comprises transmitting the actuating forces through the U-turn mechanism to an end effector.
17. A surgical instrument assembly comprising:
a transmission mechanism;
a distal component; and
a U-turn mechanism, the U-turn mechanism comprising a proximal face, a distal face, and cable guide tubes, each of the cable guide tubes having a first end and a second end, the first end being coupled to the proximal face, and the second end being coupled to the distal face;
wherein the U-turn mechanism is coupled between the transmission mechanism and the distal component; and
wherein the U-turn mechanism has a constant fixed shape so that a distance between the distal face and the proximal face is unchangeable.
18. The instrument assembly of claim 17 :
wherein the distal component is selected from a group consisting of a wrist mechanism and an end effector.