CATHETER WITH IMAGING CAPABILITY ACTS AS GUIDEWIRE FOR CANNULA TOOLS

• US 20080243031A1
• Filed: 04/02/2007
• Published: 10/02/2008
• Est. Priority Date: 04/02/2007
• Status: Active Grant

• Current Assignee: University of Washington
• Original Assignee: University of Washington
• Inventors: Seibel, Eric J., Johnston, Richard S., Melville, Charles David
• Granted Patent: US 8,840,566 B2
• Time in Patent Office: Days
• US Class Current: 600/566
• CPC Class Codes: A61B 1/0008 characterised by distal tip features
• CPC Class Codes: A61B 1/00172 with means for scanning
• CPC Class Codes: A61B 10/02 Instruments for taking cell samples or for biopsy A61B10/0038 and A61B10/0045 take precedence; needle locating or guiding means A61B17/3403; samplers for enzymology or microbiology C12M1/26; sampling or preparing biological specimens G01N33/48
• CPC Class Codes: A61B 10/0266 means for severing sample
• CPC Class Codes: A61B 10/0283 with vacuum aspiration, e.g. caused by retractable plunger or by connected syringe A61B10/025, A61B10/0266 take precedence
• CPC Class Codes: A61B 10/04 Endoscopic instruments
• CPC Class Codes: A61B 10/06 Biopsy forceps , e.g. with cup-shaped jaws
• CPC Class Codes: A61B 2017/320004 abrasive
• CPC Class Codes: A61B 2017/320008 Scrapers

Abstract

A catheter having an imaging device on its distal end serves as a guidewire for cannula tools, enabling the tools to be advanced to a desired site in a patient'"'"'s body. One exemplary embodiment of such a catheter is a scanning fiber endoscope. The images facilitate navigation through linked body lumens and also enable an operator to view a site where a biopsy sample is to be taken with a cannula tool. Exemplary cannula tools include bristles or sharp points that scrub cells from adjacent tissue, a biopsy needle that can be thrust into tissue, a loop that cuts away tissue, a cutting edge that slices tissue from a site, and forceps. The sample can be carried by a bodily or introduced fluid to a proximal end of the catheter through an annular gap between the catheter and the cannula tool, or the cannula tool can retain the sample.

Claims

1. A catheter system with an imaging capability, for guiding a tool to a desired location within a body of a patient, comprising:

(a) an elongate flexible catheter shaft having proximal end and a distal end, said elongate flexible catheter shaft being adapted to be advanced within a body of a patient, to a desired location;

(b) an imaging scanner for imaging within a body of a patient, the imaging scanner being disposed within and at the distal end of the elongate flexible shaft, to enable imaging at least during one of;

(i) while the elongate flexible catheter shaft is being advanced within the body of a patient;

(ii) while the distal end of the elongate flexible body is disposed at a desired location within a body of a patient; and

(iii) while the elongate flexible catheter shaft is being withdrawn from within the body of a patient; and

(c) a cannula that includes a lumen sized and shaped to readily slide over the elongate flexible catheter shaft toward the distal end of the elongate flexible shaft, the cannula being adapted to be slid over the elongate flexible shaft and toward the desired location, the elongate flexible shaft thus serving as a guidewire for positioning the cannula at a desired location within a body of a patient.

2. The catheter system of claim 1, wherein the cannula is sized sufficiently larger than the elongate flexible catheter shaft to provide a generally annular passage around an outer perimeter of the elongate flexible shaft, so that the annular passage is adapted to convey a lavage fluid for collecting cells from a desired location within a body of a patient.

3. The catheter system of claim 2, further comprising a pump in fluid communication with the annular passage, said pump being configured for extracting cells comprising a biopsy sample through the annular passage from a distal end of the cannula by drawing the biopsy sample with a fluid through the lumen, toward the proximal end of the elongate flexible catheter shaft.

4. The catheter system of claim 3, wherein when the cannula is disposed proximate to tissue, the pump applies a negative pressure that draws the tissue and the cannula toward each other.

5. The catheter system of claim 3, wherein the cannula includes a plurality of outwardly extending abrasive points disposed at spaced-apart positions on the exterior surface of the cannula, proximate to a distal end thereof, said abrasive points abrading cells from an internal site within a body of a patient for collection as a biopsy sample.

6. The catheter system of claim 5, further comprising a plurality of orifices formed in the cannula proximate to the spaced-apart positions where the plurality of outwardly extending abrasive points are disposed, so that the plurality of orifices provide fluid communication paths for cells conveyed with a fluid to pass into the annular passage and be drawn by the pump through the annular passage toward the proximal end of the cannula.

7. The catheter system of claim 3, further comprising a biopsy trap disposed between and in fluid communication with the pump and the proximal end of the cannula, the biopsy trap serving to trap cells and tissue comprising a biopsy sample after the biopsy sample exits from the cannula.

8. The catheter system of claim 3, wherein the cannula includes a balloon that is disposed around an exterior of the cannula adjacent to the distal end of the cannula, an outer surface of the balloon having an abrasive coating so that when the balloon is selectively inflated while the distal end of the cannula is disposed at an internal site with a body of a patient, and the cannula is moved while the abrasive coating is in contact with tissue at the internal site, cells are dislodged from the tissue by the abrasive coating on the balloon and are drawn with a fluid into and through the annular passage by the pump, toward the proximal end of the cannula.

9. The catheter system of claim 1, wherein the cannula includes a plurality of short bristles that extend outwardly of an outer surface of the cannula to provide a brush that dislodges cells and collects the cells dislodged from tissue at a desired location within a body of a patient.

10. The catheter system of claim 1, wherein the cannula has a sharpened distal end adapted to pierce tissue and collect cells dislodged from tissue at a desired location within a body of a patient.

11. The catheter system of claim 1, wherein the cannula comprises forceps that include jaw that can selectively be opened and closed, the jaws being configured so that when closed on tissue, the tissue can be withdrawn with the cannula as a biopsy sample, from an internal site within a body of a patient.

12. The catheter system of claim 1, wherein the cannula comprises a snare loop that extends generally distal of a distal end of the cannula, the snare loop being employed to cut away tissue comprising a biopsy sample from an internal site within a body of a patient.

13. The catheter system of claim 12, wherein the snare loop is coupled to a power supply that is selectively activated to heat the snare loop with an electrical current sufficiently to cut through tissue, thereby freeing the biopsy sample from adjacent tissue.

14. The catheter system of claim 12, wherein the snare loop is coupled to a line that extends proximally and is pulled to tighten the snare loop around tissue to cut the tissue from adjacent tissue.

15. The catheter system of claim 1, wherein the cannula tool includes a helical member having a cutting blade formed on its distal end and disposed in the cannula, within an annular gap defined between an interior surface of the cannula and an outer surface of the elongate flexible catheter shaft, rotation of the cannula causing the cutting blade to cut free a piece of tissue comprising a biopsy sample at an internal site within a body of a patient, the piece of tissue being then drawn into and through the annular gap toward a proximal end of the cannula.

16. The catheter system of claim 15, further comprising a prime mover, and a rotational driver that is configured to drivingly couple with the cannula where exposed outside a body of a patient, the prime mover causing the rotational driver to rotate the cannula about the elongate flexible catheter shaft so that the cutting blade is rotated into tissue to cut away the piece of tissue.

17. The catheter system of claim 1, further including a passage for conveying a pressurized fluid, wherein the passage is configured to direct the pressurized fluid at a velocity sufficient to dislodge cells from tissue at a desired location within a body of a patient, the cells that are dislodged being withdrawn through the passage when a suction at a sub-ambient pressure is applied in fluid communication with a proximal end of the passage.

18. The catheter system of claim 1, wherein the imaging scanner includes a scanning device selected from the group consisting of:

(a) a scanning optical fiber that is driven by actuators to move in a specific scanning pattern to optically scan an internal site with light to produce an image of the internal site; and

(b) a micro-mechanical electrical systems (MEMS) that has a scanning beam used to optically scan an internal site with light to produce an image of the internal site.

19. The catheter system of claim 1, wherein the cannula includes an outer elongate sheath that is movable between a first position that protects a tool portion of the cannula during insertion and retraction of the cannula within a body of a patient, and a second position that exposes the tool portion, when the tool portion is disposed at the desired internal site.

20. The catheter system of claim 1, wherein the cannula includes a guide collar disposed proximate to a distal end of the cannula, the guide collar being attached to one side of the cannula and having the lumen formed within the guide collar, the lumen being sized and configured to slide over the elongate flexible catheter shaft.

21. The catheter system of claim 3, wherein the annular passage serves to convey cells toward a proximal end of the cannula after the cells are released from tissue at a desired site as a result of an explosive thermal heating caused by a focused light beam transmitted from the imaging scanner toward the tissue.

22. A system for guiding a cannula that includes a tool, to a desired position within a body of a patient while imaging a path along which the system is being advanced or withdrawn, comprising:

(a) a flexible elongate catheter;

(b) an imaging device disposed at a distal end of the flexible elongate catheter, the imaging device being adapted to produce an image signal corresponding to an image of tissue along the path followed as the flexible elongate catheter is introduced through a passage within a body of a patient, the imaging device enabling details of the path to be observed to assist introduction of the flexible elongate catheter along the path, to a desired position within a body of a patient; and

(c) a cannula having a lumen that is sized to slide freely along the flexible elongate catheter toward a desired position within a body of a patient, enabling the cannula to be guided by the flexible elongate catheter when advanced to a desired position within a body of a patient or while the flexible elongate catheter is being withdrawn from a body of a patient.

23. The system of claim 22, wherein the tool comprising the cannula includes means for freeing a biopsy sample from tissue at a desired position within a body of a patient, the biopsy sample comprising cells or a piece of the tissue.

24. The system of claim 23, wherein the cannula includes a passage for carrying the biopsy sample toward a proximal end of the passage, for collection external to a body of a patient.

25. The system of claim 22, further comprising a prime mover that applies a rotational force to the cannula to rotate the tool so that it interacts with tissue adjacent to the tool to free a biopsy sample from the tissue.

26. The system of claim 22, wherein the imaging device comprises a scanning device selected from the group consisting of:

(a) a scanning optical fiber that is driven by actuators to move in a specific scanning pattern to optically scan an internal site with light to produce an image of the internal site; and

(b) a micro-mechanical electrical systems (MEMS) that has a scanning beam used to optically scan an internal site with light to produce an image of the internal site.

27. A system for guiding a tool to a desired location in a body of a patient, comprising:

(a) an elongate flexible catheter extending between a proximal end and a distal end;

(b) a scanning fiber device disposed at the distal end of the elongate flexible catheter, said scanning fiber device including an actuator that drives the scanning fiber in a desired pattern to scan a region, the scanning fiber device producing an output signal that is usable to produce an image of an internal site consisting of at least one of;

(i) tissue and anatomical structures while the elongate flexible catheter is being advanced along a path through a body of a patient, the image assisting in maneuvering the distal tip of the elongate flexible catheter to a desired location; and

(ii) tissue and anatomical structure after a distal tip of the elongate flexible catheter has been advanced to a desired location within a body of a patient; and

(c) a cannula having a lumen that is configured to be advanced over the elongate flexible catheter and guided thereby to a desired location within a body of a patient to which the distal tip of the elongate flexible catheter has been advanced.

28. The system of claim 27, wherein the tool is adapted to free cells or a piece of tissue from a desired location within a body of a patient, the cells or the piece of tissue comprising a biopsy sample.

29. The system of claim 28, wherein the cannula includes a passage through which the biopsy sample is drawn toward a proximal end of the cannula, for collection.

30. The system of claim 29, further comprising:

(a) a pump for drawing the biopsy sample toward the proximal end of the cannula; and

(b) a trap disposed adjacent to the proximal end of the cannula, for collecting the biopsy sample.

31. The system of claim 28, further comprising a rotational driver for rotating the cannula and the tool, so that the tool interacts with adjacent tissue to free the biopsy sample from the adjacent tissue.

32. The system of claim 27, wherein the cannula includes a balloon disposed around an exterior surface of the cannula, adjacent to a distal end of the cannula, and a fluid passage through which a pressurized fluid is selectively communicated to an interior volume of the balloon to selectively inflate the balloon so that the balloon provides stabilization for the elongate flexible catheter while imaging an internal site with the scanning fiber device.

33. The system of claim 27, wherein the tool includes a needle at a distal end of the cannula that is selectively thrust into tissue, said needle being used to carry out at least one function selected from the group consisting of:

(a) stabilizing the elongate flexible catheter while imaging with the scanning fiber device; and

(b) taking a biopsy sample from tissue at an internal site.

34. The system of claim 33, wherein the needle includes angled points disposed around a bevel edge of the needle that engage the tissue as the needle is thrust into the tissue.

35. The system of claim 28, wherein the tool comprises forceps having jaws that can be selectively closed to grasp tissue.

36. A system for guiding a tool to a desired location in a body of a patient, comprising:

(a) an elongate flexible catheter extending between a proximal end and a distal end;

(b) a resonant scanning beam device disposed at the distal end of the elongate flexible catheter, said resonant scanning beam device including an actuator that drives a scanning beam to move at about its resonant frequency, in a desired pattern, to optically scan a region, the scanning beam device producing an output signal that corresponds to an image of tissue; and

(c) a cannula that is configured to be advanced over the elongate flexible catheter and to be guided thereby to a desired location within a body of a patient to which the distal tip of the elongate flexible catheter has been advanced.

37. The system of claim 36, wherein the cannula includes a tool for taking a biopsy sample comprising either cells or a piece of tissue from the desired location.

38. A system for carrying out an image-guided biopsy at a desired location in a body of a patient, comprising:

(a) a flexible elongate catheter having a distal end and a proximal end, a cross-sectional diameter of the flexible elongate catheter being less than 2 millimeters;

(b) an imaging system disposed at the distal end of the flexible elongate catheter, the imaging system being configured to produce a high resolution image of a site proximate to the distal end of the flexible elongate catheter; and

(c) a cannula that is sized and shaped to slide freely over the flexible elongate catheter and to be guided by the flexible elongate catheter toward a desired location in a body of a patient, the imaging system producing an image of tissue at a desired location to provide visual guidance for taking a biopsy sample of tissue at the desired location.

39. The system of claim 38, wherein the cannula includes a tool for taking the biopsy sample.