End effector coupler for surgical arm

1. An end effector coupler for a surgical arm, the end effector coupler comprising:

a body comprising a proximal portion and an opposite distal portion, the distal portion including a distal end;

a proximal coupler connected to the proximal portion and releasably couplable to the surgical arm;

a tool lock for releasably retaining a tool stem to the end effector coupler, the tool lock comprising:

a keyed opening extending through the distal end proximally into the distal portion, the keyed opening configured to receive the tool stem therein;

a pin bore extending through the distal end proximate to the keyed opening;

a pin disposed in the pin bore and extendable from the pin bore to engage and retain the tool stem when the tool stem is inserted into the keyed opening; and

a biasing element located in the pin bore and engaging the pin to bias the pin to extend from the distal end; and

a pin release comprising an actuator extending beyond an external surface of the body and engaging the pin, the pin release operable to retract the pin into to the body to disengage the pin from the tool stem allowing release of the tool stem from the keyed opening.

2. The end effector coupler of claim 1 , wherein the pin limits rotation of the tool stem relative to the keyed opening to prevent release of the tool stem from the keyed opening when the pin engages the stem.

3. The end effector coupler of claim 1 , wherein the body includes a tapered bore aligned along a central axis running through the keyed opening and configured to receive the tool stem therein.

4. The end effector coupler of claim 3 ; wherein the tapered bore is configured to receive a complimentary tapered section of the tool stem to form a taper-to-taper interface to limit relative motion between the end effector coupler and the tool stem.

5. The end effector coupler of claim 1 , wherein the proximal coupler further includes a tapered protrusion coaxial with the proximal coupler and extending and engageable with a complimentary tapered bore of a distal portion of the surgical arm to form a taper-to-taper interface to limit relative motion between the surgical arm and the end effector coupler.

6. The end effector coupler of claim 5 , wherein the tapered protrusion includes a flat outer surface engageable with a flat surface of the complimentary tapered bore to align the end effector coupler relative to the surgical arm.

7. The end effector coupler of claim 1 , wherein the keyed opening further comprises a keyway extending radially from a tapered bore of the keyed opening and sized to receive a key bit of the tool stem therethrough, the key bit including an angled face engageable with a proximal portion of the keyway to limit axial movement of the tool stem relative to the keyed opening, and wherein the tapered bore is configured to receive a complimentary tapered section of the tool stem to form a taper-to-taper interface to limit relative motion between the end effector coupler and the tool stem, wherein a distal portion of the pin is configured to engage a notch of the tool stem to limit rotation of the tool stem relative to the end effector coupler, and wherein the angled face is configured to engage the proximal portion of the keyway substantially simultaneously with the tapered bore in receipt of the complimentary tapered section of the tool stem and substantially simultaneously with the distal portion of the pin in engagement with the notch of the tool stem.

8. An assisted surgical system comprising:

a surgical arm moveable and lockable in a position selected by a user;

a tool movable with the surgical arm, the tool including a stem for coupling thy: tool to the surgical arm;

an end effector coupler comprising:

a body including a proximal portion and an opposite distal portion, the distal portion including a distal end;

a proximal coupler connected to the proximal portion and releasably couplable to the surgical arm;

a tool lock for releasably retaining the tool stem to the end effector coupler, the tool lock comprising:

a keyed opening extending through the distal end into the distal portion, the keyed opening configured to receive the tool stem therein;

a pin disposed in a pin bore adjacent the keyed opening, the pin extendable from the pin bore to engage and retain the tool stem when the tool stem is inserted into the keyed opening;

a biasing element in the pin bore and engaging the pin to bias the pin to extend from the distal end; and

a pin release comprising an actuator extending beyond an external surface of the body and engaging the pin, the pin release operable to retract the pin into to the body to disengage the pin from the tool stem allowing release of the tool stem from the keyed opening.

9. The system of claim 8 , wherein the pin limits rotation of the tool stem relative to the keyed opening to prevent release of the tool stem from the keyed opening when the pin engages the stem.

10. The system of claim 8 , wherein the end effector coupler further includes a tapered bore aligned along a central axis running through the keyed opening and configured to receive the tool stem therein.

11. The system of claim 10 , wherein the tapered bore is configured to receive a complimentary tapered section of the tool stem to form a taper-to-taper interface to limit relative motion between the end effector coupler and the tool stem.

12. The system of claim 8 , wherein the proximal coupler further includes a tapered cylindrical protrusion coaxial with the proximal coupler and extending and engageable with a complimentary tapered bore of a distal end of the surgical arm to form a taper-to-taper interface to limit relative motion between the surgical arm and the end effector coupler.

13. The system of claim 12 , wherein the tapered cylindrical protrusion includes a flat outer surface engageable with a flat surface of the complimentary tapered bore to align the effector relative to the arm.

14. The system of claim 8 , further comprising:

a control device in communication with the surgical arm and operable to transmit a signal to unlock the surgical arm.

15. The system of claim 8 , the tool stem comprising:

a key bit extending radially from the tool stem, wherein the keyed opening includes a stem opening and a keyway, the stem opening configured to receive the tool stem therein, and the keyway extending radially from less than a full circumference of the stem opening, the keyway sized to receive the key bit therethrough to allow the end effector coupler to receive the tool stem.

16. The system of claim 15 , the key bit further comprising:

an angled face on a proximal side of the key bit.

17. The system of claim 16 , the keyed opening further comprising:

a counterbore extending radially from the stem opening, the counterbore sized to receive the key bit therein to limit axial movement of the stem relative to the keyed opening.

18. The system of claim 17 , wherein the angled face of the key bit is configured to engage a distal portion of the keyed opening to draw the tool stem into the keyed opening when the stem is rotated within the keyed opening.

19. The system of claim 8 , the tool further comprising:

a flange extending radially outward from the stem and engageable with the pin to translate the pin proximally.

20. The system of claim 19 , the flange of the tool further comprising:

a notch sized to receive a distal tip of the pin to limit rotation of the tool relative to the end effector coupler when the pin is received within the notch.

21. The system of claim 20 , wherein the notch extends through a radially outer portion of the flange and includes an axis not parallel to an axis of the flange to promote contact between the flange and the pin to limit rotation of the tool relative to the end effector coupler when the pin engages the notch.