APPARATUS FOR GUIDING A MEDICAL TOOL

• US 20090234369A1
• Filed: 06/19/2007
• Published: 09/17/2009
• Est. Priority Date: 06/19/2006
• Status: Abandoned Application

• Current Assignee: University of Western Ontario
• Original Assignee: Robarts Research Institute
• Inventors: Cool, Derek, Fenster, Aaron, Gardi, Lori, Bax, Jeffrey
• Application Number:
  US12/303,415
• Publication Number:
  US 20090234369A1
• Time in Patent Office: Days
• US Class Current: 606/130
• CPC Class Codes: A61B 10/0233 Pointed or sharp biopsy instruments
• CPC Class Codes: A61B 17/3403 Needle locating or guiding means guides for suture needles A61B17/0482; guiding or tracking by nuclear magnetic resonance G01R33/285
• CPC Class Codes: A61B 2017/3405 using mechanical guide means
• CPC Class Codes: A61B 2017/3409 including needle or instrument drives
• CPC Class Codes: A61B 2017/3413 guided by ultrasound
• CPC Class Codes: A61B 2034/302 specifically adapted for manipulations within body cavities, e.g. within abdominal or thoracic cavities
• CPC Class Codes: A61B 2090/378 using ultrasound
• CPC Class Codes: A61B 2090/504 with a counterweight
• CPC Class Codes: A61B 2090/508 with releasable brake mechanisms
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 8/4245 involving determining the position of the probe, e.g. with respect to an external reference frame or to the patient
• CPC Class Codes: A61B 90/11 with guides for needles or instruments, e.g. arcuate slides or ball joints
• CPC Class Codes: A61B 90/50 Supports for surgical instruments, e.g. articulated arms

Abstract

There is provided a guide apparatus for orienting a medical tool relative to and through a remote fulcrum or remote center of motion. The guide apparatus may comprise: at least one crank arm comprising at least a portion of a first hinged coupling for hinged coupling to a stabilizer; at least one link arm comprising at least a portion of a second hinged coupling for hinged coupling to the crank arm at a location spaced from the first hinged coupling; a tool holder for supporting a medical tool on the link arm at a location spaced from the first hinged coupling; wherein the rotational axes of the first and second hinged couplings intersect to define a remote fulcrum. The guide apparatus may be configured to be an open-loop spherical chain or a closed-loop spherical chain.

Claims

1. An apparatus for guiding a medical tool, comprising:

at least one crank arm comprising at least a portion of a first hinged coupling for hinged coupling to a stabilizer;

at least one link arm comprising at least a portion of a second hinged coupling for hinged coupling to the crank arm at a location spaced from the first hinged coupling;

a tool holder for supporting a medical tool on the link arm at a location spaced from the first hinged coupling;

wherein the rotational axes of the first and second hinged couplings intersect to define a remote fulcrum.

2. The guide apparatus of claim 1, further comprising a brake for inhibiting rotational motion of the first hinged coupling.

3. The guide apparatus of claim 1, further comprising a brake for inhibiting rotational motion of the second hinged coupling.

4. The guide apparatus of claim 1, further comprising a first brake carried by the crank arm and actuable to inhibit rotational motion of the first hinged coupling;

and

a second brake carried by the link arm and actuable to inhibit rotational motion of the second hinged coupling.

5. The guide apparatus of claim 1, further comprising a rotational encoder for sensing rotational motion of the first hinged coupling.

6. The guide apparatus of claim 1, further comprising a rotational encoder for sensing rotational motion of the second hinged coupling.

7. The guide apparatus of claim 1, further comprising a first rotational encoder carried by the crank arm for sensing rotational motion of the first hinged coupling;

and a second rotational encoder carried by the link arm for sensing rotational motion of the second hinged coupling.

8. The guide apparatus of claim 1, further comprising a motor for controlling rotational motion of the first hinged coupling.

9. The guide apparatus of claim 1, further comprising a motor for controlling rotational motion of the second hinged coupling.

10. The guide apparatus of claim 1, further comprising a first motor carried by the crank arm actuable to control rotational motion of the first hinged coupling;

and a second motor carried by the link arm actuable to control rotational motion of the second hinged coupling.

11. The guide apparatus of claim 1, further comprising a counterweight or a spring balance for offsetting mass of the crank arm and the link arm.

12. The guide apparatus of claim 1, further comprising a counterweight or a spring balance carried by the link arm adjacent to the second hinged coupling.

13. The guide apparatus of claim 1, further comprising a counterweight or a spring balance carried by the crank arm adjacent to the first hinged coupling;

and a counterweight or a spring balance carried by the link arm adjacent to the second hinged coupling.

14. The guide apparatus of claim 1, wherein the tool holder axis passes through the remote fulcrum thereby forming an open-loop spherical chain.

15. The guide apparatus of claim 1, further comprising a shaft, for actuating a medical tool, coupled to a cylindrical joint of the tool holder.

16. The guide apparatus of claim 15, wherein the shaft axis passes through the remote fulcrum thereby forming an open-loop spherical chain.

17. The guide apparatus of claim 1, further comprising:

a second crank arm coupled to the first hinged coupling; and

a second link arm coupled to the tool holder; and

a third hinged coupling for hinged coupling of the second crank arm and the second link arm at a location spaced from the first hinged coupling and the tool holder.

18. The guide apparatus of claim 17, wherein the tool holder comprises two rings each independently coupled to the link arms.

19. The guide apparatus of claim 1, further comprising a medical tool.

20. The guide apparatus of claim 19, further comprising a counterweight for offsetting the mass of the medical tool.

21. The guide apparatus of claim 19, wherein the axis of the medical tool passes through the remote fulcrum.

22. The guide apparatus of claim 19, wherein the medical tool is an ultrasound transducer.

23. The guide apparatus of claim 1, further comprising a shaft, for actuating a medical tool, coupled to a cylindrical joint of the tool holder and coupled to a differential gear train housed within the tool holder.

24. The guide apparatus of claim 23, further comprising first and second rotational encoders housed within the tool holder, for measuring angular displacement of a base drum and outer ring, respectively, of the differential gear train.

25. The guide apparatus of claim 1, wherein the crank arm and the link arm are each of an arcuate shape having a central angle of less than 90 degrees.

26. The guide apparatus of claim 1, further comprising:

a second crank arm coupled to the first hinged coupling; and

a link arm assembly acting between each crank arm and the tool holder, each link arm assembly comprising at least two hingedly coupled link arms.