Medical imaging probe with rotary encoder

• US 20080177139A1
• Filed: 01/22/2008
• Published: 07/24/2008
• Est. Priority Date: 01/19/2007
• Status: Active Grant

• Current Assignee: Sunnybrook Health Sciences Centre
• Original Assignee: Sunnybrook Health Sciences Centre
• Inventors: Munce, Nigel Robert, Yang, Victor Xiao Dong, Thind, Amandeep Singh, Courtney, Brian, Foster, Francis Stuart
• Granted Patent: US 8,712,506 B2
• Time in Patent Office: Days
• US Class Current: 600/109
• CPC Class Codes: A61B 1/00112 Connection or coupling means
• CPC Class Codes: A61B 1/00172 with means for scanning
• CPC Class Codes: A61B 1/00183 for variable viewing angles
• CPC Class Codes: A61B 5/0035 adapted for acquisition of images from more than one imaging mode, e.g. combining MRI and optical tomography
• CPC Class Codes: A61B 5/0062 Arrangements for scanning
• CPC Class Codes: A61B 5/0066 Optical coherence imaging
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence
• CPC Class Codes: A61B 5/0095 by applying light and detecting acoustic waves, i.e. photoacoustic measurements
• CPC Class Codes: A61B 5/6852 Catheters
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 8/12 in body cavities or body tracts, e.g. by using catheters catheters per se A61M25/00
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 8/445 Details of catheter construction
• CPC Class Codes: A61B 8/4461 Features of the scanning mechanism, e.g. for moving the transducer within the housing of the probe
• CPC Class Codes: A61B 8/483 involving the acquisition of a 3D volume of data
• CPC Class Codes: A61B 8/5238 for combining image data of patient, e.g. merging several images from different acquisition modes into one image for image registration algorithms G06T7/30
• CPC Class Codes: A61B 8/5292 using additional data, e.g. patient information, image labeling, acquisition parameters
• CPC Class Codes: A61B 8/543 involving acquisition triggered by a physiological signal
• CPC Class Codes: G02B 23/2423 of the distal end
• CPC Class Codes: G02B 6/3604 : Rotary joints allowing relative rotational movement between opposing fibre or fibre bundle ends
• CPC Class Codes: G10K 11/002 : Devices for damping, suppressing, obstructing or conducting sound in acoustic devices G10K1/06 - G10K1/10 take precedence; for electro-mechanical transducers for communication H04R3/002

Abstract

The present invention provides minimally invasive imaging probe having an optical encoder integrated therewith for accurately measuring or estimating the rotational velocity near the distal end of the medical device, such as an imaging probe which undergoes rotational movement during scanning of surrounding tissue in bodily lumens and cavities.

Claims

1. An imaging probe for insertion into bodily lumens or cavities for imaging a vicinity of said bodily lumens or cavities, comprising:

a) an elongate hollow shaft having a longitudinal axis having distal and proximal end sections and an elongate midsection, an imaging assembly being located in said elongate hollow shaft remote from said proximal end section for emitting an energy beam and receiving reflected energy signals reflected back from vicinity of bodily lumens or cavities, said imaging assembly being connected to a first end of an imaging conduit, said imaging conduit extending through the elongate hollow shaft and having a second end, extending through the said proximal end section of said hollow shaft, said imaging conduit being configured to deliver energy to said imaging assembly;

b) rotational drive mechanism for imparting rotational motion to said imaging conduit and said imaging assembly about said longitudinal axis;

c) a scanning mechanism configured to deliver said energy beam along a path out of said elongate hollow shaft to give forward or side viewing capability of said imaging assembly;

e) a rotary encoder mechanism including a light source and an encoder member, said encoder member having an encoder interface located within or upon said encoder member, said encoder interface including features that interact with light, said rotary encoder mechanism including a first encoder fiber optic having a distal end wherein the first encoder fiber optic extends along a portion of said elongate hollow shaft, through which light is emitted towards said encoder member having said encoder interface which interacts with said emitted light, light collection means for collecting light, where said collected light results from the interaction of said emitted light with said encoder interface, detection means for detecting said collected light, said rotary encoder mechanism connectable to an image processing and display system, and wherein as said encoder member experiences rotary motion relative to said distal end of said first encoder fiber optic, light emitted from said distal end of said first encoder fiber optic interacts with said encoder interface and is detected by said detection means, an output of said detection means being used by said image processing and display system to estimate or measure the rotational motion of said imaging mechanism; and

e) said rotary encoder mechanism including at least one distal optical element optically coupled to said distal end of said first encoder fiber optic.

2. The imaging probe of claim 1 wherein said distal optical element is a focusing element.

3. The imaging probe of claim 1 wherein said distal optical element is a collimating element.

4. The imaging probe of claim 1 wherein said distal optical element is a polarization filter.

5. The imaging probe of claim 2 wherein said light collection means is said first encoder fiber optic.

6. The imaging probe of claim 2 wherein said light collection means is a second encoder fiber optic.

7. The imaging probe of claim 6 wherein said encoder interface is a transmissive encoder interface, and wherein said second encoder fiber optic collects said collected light from said transmissive encoder interface.

8. The imaging probe of claim 6 wherein said encoder interface is a reflective encoder interface, and wherein said second encoder fiber optic collects said collected light from said reflective encoder interface.

9. The imaging probe of claim 2 wherein said detection means is an optical coherence tomography detection system.

10. The imaging probe of claim 9 wherein said encoder interface is a variable thickness encoder interface and said variable thickness is detected by said optical coherence tomography detection system.

11. The imaging probe of claim 10 wherein said variable thickness encoder interface is a wall of said imaging probe.

12. The imaging probe according to claim 11 wherein the optical coherence tomography detection system is an optical coherence tomography imaging system.

13. The imaging probe of claim 2 wherein said encoder interface is a reflective encoder interface.

14. The imaging probe of claim 2 wherein said encoder interlace is a transmissive encoder interface.

15. The imaging probe of claim 3 wherein said encoder interface is a transmissive encoder interface.

16. The imaging probe of claim 3 wherein said encoder interface is a reflective encoder interface.

17. The imaging probe of claim 2 wherein said encoder interface is an interferometric encoder interface.

18. The imaging probe of claim 2 wherein said encoder interface is a variable interference encoder interface.

19. The imaging probe of claim 6 wherein said encoder interface is a variable interference encoder interface.

20. The imaging probe of claim 4 wherein said encoder interface is a polarization dependent interface.

21. The imaging probe of claim 20 wherein said light collection means is said first encoder fiber optic.

22. The imaging probe of claim 20 wherein said light collection means is a second encoder fiber optic.

23. The imaging probe of claim 2 wherein said encoder interface is a polarization dependent interface and said first encoder is a polarization maintaining fiber optic.

24. The imaging probe of claim 1 wherein said encoder interface contains at least one index portion, wherein light interacting with said index portion causes said output of said detection means to identify a known index angle of rotation.

25. The imaging probe of claim 1 wherein said encoder interface member is a hollow cylindrically shaped component.

26. The imaging probe of claim 25 wherein said first encoder fiber optic emits light onto an encoder interface on an inner surface of said hollow cylindrically shaped component.

27. The imaging probe of claim 25 wherein said first encoder fiber optic emits light onto an encoder interface on an outer surface of said hollow cylindrically shaped component.

28. The imaging probe of claim 1 wherein said encoder interface member is an annular shaped component.

29. The imaging probe of claim 1 wherein said first encoder fiber optic rotates in conjunction with said imaging conduit when said imaging conduit undergoes rotational motion.

30. The imaging probe of claim 1 wherein said first encoder fiber optic is relatively static with respect to said imaging conduit when said imaging conduit undergoes rotational motion.

31. The imaging probe of claim 29 wherein said external sheath includes an eccentrically shaped channel and said encoder interface member has a similarly shaped outer contour such that said similarly shaped encoder interface member is restricted from undergoing free rotation within said eccentrically shaped channel.

32. The imaging probe of claim 31 wherein said first encoder fiber optic is translatable along said longitudinal axis of said imaging probe.

33. The imaging probe of claim 30 wherein said first encoder fiber optic is translatable along said longitudinal axis of said imaging probe.

34. The imaging probe of claim 30 wherein said distal end of said first encoder fiber optic translates such that it remains optically aligned along longitudinal axis with said encoder interface when imaging assembly undergoes translation.

35. A medical device for insertion into bodily lumens or cavities for imaging a vicinity of said bodily lumens or cavities, comprising:

a) an elongate hollow shaft having a longitudinal axis having distal and proximal end sections and an elongate midsection, a functional, component being located remote from said proximal end section wherein said function component undergoes rotary motion, said functional component being connected to a first end of a torque transmission shaft, said torque transmission shaft extending through said elongate hollow shaft and having a second end, extending through said proximal end section of said hollow shaft, said torque transmission shaft being configured to impart rotational motion onto said functional component;

b) rotational drive mechanism for imparting rotational motion to said torque transmission shaft and said functional component about said longitudinal axis;

c) a rotary encoder mechanism including a light source and an encoder member, said encoder member having an encoder interface located within or upon said encoder member, said encoder interface including features that interact with light, said rotary encoder mechanism including a first encoder fiber optic having a distal end wherein said first encoder fiber optic extends along a portion of said elongate hollow shaft, through which light is emitted towards said encoder member having said encoder interface which interacts with said emitted light, light collection means for collecting light, where said collected light results from an interaction of said emitted light with said encoder interface, detection means for detecting said collected light, said rotary encoder mechanism connectable to a rotary control interface, and wherein as said encoder member experiences rotary motion relative to said distal end of said first encoder fiber optic, light emitted from said distal end of said first encoder fiber optic interacts with said encoder interface and is detected by said detection means, an output of said detection means being used by rotary control interface to estimate or measure said rotational motion of said functional component; and

e) said rotary encoder mechanism including at least one distal optical element optically coupled to said distal end of said first encoder fiber optic.

36. The medical device of claim 35 wherein said functional component is an atherectomy head, wherein said atherectomy head enables atherectomy to occur.

37. The medical device of claim 35 wherein said functional component is an abrasive head, wherein such abrasive head enables pulverizing of material.