WO2001054567A1

WO2001054567A1 - Endoscopic assembly with non-visual locating device

Info

Publication number: WO2001054567A1
Application number: PCT/US2000/033210
Authority: WO
Inventors: E. Paul Harhen; Katsumi Oneda
Original assignee: Vision Sciences, Inc.
Priority date: 2000-01-27
Filing date: 2000-12-07
Publication date: 2001-08-02
Also published as: AU2001220693A1

Abstract

An endoscopic assembly (40) adapted to be used with a detecting assembly (70) external to the patient to identify the location of an endoscopic accessory (55) within a patient, or to measure the distance between two points within the patient. In one particular embodiment, the endoscopic assembly (40) has an insertion tube (44), a visual imaging system (49), an endoscopic accessory (55) and a position locating device (66). The insertion tube is insertable into a patient's body, and has a working channel (57) extending along at least a portion thereof. The visual imaging system is coupled to the insertion tube and is operational to allow the user to view an internal portion of the patient's body. The endoscopic accessory is positionable within the working channel, and is movable through the working channel to a position in which a distal end of the endoscopic accessory is adjacent or external to the working channel's distal end (60). The position locating device is connected to the endoscopic accessory and is locatable by the detecting assembly when the endoscopic accessory is positioned in the patient's body. The position locating device can thereby non-visually identify the location of the endoscopic accessory within the patient's body.

Description

ENDOSCOPIC ASSEMBLY WITH NON- VISUAL LOCATING DEVICE

CLAIM FOR PRIORITY

This is a Continuation-in-Part of U.S. Patent Application 09/370,563 entitled ENDOSCOPIC LOCATION AND VACUUM ASSEMBLY AND METHOD, filed on August 9, 1999.

TECHNICAL FIELD

The present invention is directed toward endoscopy, and more particularly toward apparatus and methods used during endoscopic procedures.

BACKGROUND OF THE INVENTION The use of endoscopes for diagnostic and therapeutic indications is rapidly expanding. To improve performance, endoscopes have been optimized to best accomplish selected purposes. For example, there are upper endoscopes for examining the esophagus, stomach and duodenum, colonoscopes for examining the colon, angioscopes for examining blood vessels, bronchoscopes for examining bronchi, laparoscopes for examining the peritoneal cavity, arthroscopes for examining joint spaces, nasopharyngoscopes for examining nasal passages and pharynxes, and intubation scopes for examining airways.

A conventional sheathed endoscope 10, shown in Figure 1 and disclosed in U.S. Patent No. RE. 34,110 and U.S. Patent No. 4,646,722, has an insertion tube 12 connected at a proximal end 14 to a handle or control body 16. The insertion tube 12 contains and protects an imaging device 18 having optical fibers or the like extending along the length of the insertion tube and terminating at a viewing window 19 in the insertion tube's distal end 20. The imaging device 18 conveys an image from the viewing window 19 to an eyepiece 22 on the control body 16 or to a monitor (not shown) so the user can see into a selected body cavity during an endoscopic procedure. During the endoscopic procedure, the insertion tube 12 is inserted into the body cavity, which is a highly contaminated area. The insertion tube 12 is isolated from the contaminated environment by a sheath assembly, thereby alleviating the problem of cleaning and sterilizing the insertion tube between procedures. As illustrated in Figure 1, a conventional sheath assembly (shown partially cut away for illustrative purposes) includes a flexible, elastic sheath 26 that tightly surrounds the endoscope's insertion tube 12 to isolate the insertion tube from the contaminated environment. The sheath assembly may also contain a working channel 28 that extends along the insertion tube 12 and terminates in a working port 30 to allow for the use of a conventional endoscopic accessory 31 without contaminating the endoscope itself. Once the endoscopic procedure has been completed, the sheath 26, including the working channel 28, is removed from the sheathed endoscope 10 and replaced with a new and sterile sheath assembly for the next procedure.

As seen in Figure 1, the sheath's distal end 32 includes a transparent window 34 positioned immediately adjacent to the viewing window 19 of the insertion tube 12. When the sheath 26 is axially stretched over the insertion tube 12, the stretched sheath material helps to hold the sheath's transparent window 34 in position next to the insertion tube's viewing window 19. The sheath's transparent window 34 is retained in a selected position to avoid misalignment, glare, distortion, or ghost images that may compromise the view through the sheathed endoscope 10.

During the endoscopic procedure, the user looks through the eyepiece 22 and out the distal end 20 of the insertion tube 12 to see into the selected body cavity of the patient. The endoscopist or surgeon must rely on the visual imaging system 18 to provide a visual indication of where the distal end 20 of the insertion tube 12 is relative to the selected body cavity. However, endoscopists and other surgeons have experienced difficulty determining precisely where the distal end 20 of the endoscope's insertion tube 12 is located relative to the patient's body while the insertion tube is being inserted into the body.

Once the insertion tube 12 is properly positioned in the selected body cavity, the endoscopist extends the endoscopic accessory 31 out the working port 30 at the distal end of the working channel 28 and into the body cavity, and performs the portion of the endoscopic procedure with the selected accessory tool 38 on the endoscopic accessory 31. The user or endoscopist can often see the tool 38 via the imaging system 18 during the procedure. Accordingly, such direct visualization of the tool facilitates the effectiveness of the procedure.

In other endoscopic procedures, direct visualization of the accessory tool 38 or a target location in the body cavity is not possible or practical, such as when the target location is in an obscured location or where trauma to the patient would be increased in order to gain the direct visualization. As a result, the endoscopist must often rely on the touch or feel from the endoscopic accessory 31 when not directly visible during the portions of the endoscopic procedure. The endoscopic procedure consequently may require several iterations of trial and error to properly and completely perform the selected endoscopic procedure. Such iterations are often time consuming and inefficient.

Three-dimensional location technologies have been commercialized in the medical field that allow real-time location information to be layered over pre- acquired images or models generated by magnetic resonance imaging (MRI) or CT scan systems. These location technologies, however, require a sensor or sending unit at a proximal end of a rigid instrument. The location of the instrument's distal tip is overlaid with the pre-acquired 3-D image and the particular location is determined by triangulation. This type of indirect visualization, however, cannot be applied to flexible instrumentation.

Other location systems have been developed that use miniature sensors deployed at the distal end of, for example, a catheter or neuroprobe that is flexible. The instrumentation ^"with the miniature sensors are then combined with navigation software and compared to the reference points on the pre-acquired CT or MRI image to precisely locate the position of the miniature sensor without direct visualization. This new type of system is described in U.S. Patent Nos. 5,391,199; 5,480,422; 5,546,951; and 5,568,809, all incorporated into this Application in their entirety by reference. SUMMARY OF THE INVENTION

The present invention is directed to an endoscopic assembly and methods of using the endoscopic assembly that overcome deficiencies experienced in the prior art. Embodiments of the endoscopic assembly are adapted to be used with a detecting assembly external to the patient to identify the location of an endoscopic accessory within the patient, or to measure the distance between two points within the patient.

In one particular embodiment, the endoscopic assembly has an insertion tube, a visual imaging system, an endoscopic accessory and a position locating device. The insertion tube is insertable into a patient's body, and has a working channel extending along at least a portion thereof. The visual imaging system is coupled to the insertion tube and is operational to allow the user to view an internal portion of the patient's body. The endoscopic accessory is positionable within the working channel, and is movable through the working channel to a position in which a distal end of the endoscopic accessory is adjacent or external to the working channel's distal end. The position locating device is connected to the endoscopic accessory and is locatable by the detecting assembly when the endoscopic accessory is positioned in the patient's body. The position locating device can thereby non-visually identify the location of the endoscopic accessory within the patient's body.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a partially-segmented isometric view of a sheathed endoscopic assembly known in the prior art.

Figure 2 is a partially-segmented, partially schematic, isometric view of a sheathed endoscope, an endoscopic accessory and a detecting assembly according to an embodiment of the present invention.

Figure 3 is an enlarged cross-sectional view taken substantially along Section 3-3 of Figure 2 showing a distal end of the sheathed endoscope and endoscopic accessory of Figure 2 in a first configuration. Figure 4 is a cross-sectional view of the portion of the endoscopic assembly of Figure 3 in a second configuration.

Figure 5 is a cross-sectional view of the portion of the endoscopic assembly of Figure 3 in a first detected position within a patient's body. Figure 6 is a cross-sectional view of the portion of the endoscopic assembly of Figure 3 in a second detected position within the patient's body.

Figure 7 is a partially-segmented, partially schematic, isometric view of an unsheathed endoscopic assembly, an endoscopic accessory, and a detection assembly according to another embodiment of the present invention. Figure 8 is a cross-sectional view of a distal portion of another endoscopic assembly according to another embodiment of the present invention.

Figure 9 is a cross-sectional view of a distal portion of yet another endoscopic assembly according to yet another embodiment of the present invention.

Figure 10 is a cross-sectional view of a distal portion of another endoscopic assembly according to still another embodiment of the present invention.

Figure 11 is a cross-sectional view of a distal portion of another endoscopic assembly according to still another embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present detailed description is generally directed toward endoscopic medical devices used to identify the location of an endoscopic accessory within a patient's body or measure a distance between two points within the patient's body, and toward methods for doing the same. Many specific details of certain embodiments of the invention are set forth in the following description and in Figures 2-9 to provide a thorough understanding of such embodiments. One skilled in the art, however, will understand that the present invention may have additional embodiments, or that the invention may be practiced without several of the details described in the following description.

Figure 2 illustrates an endoscopic assembly 40 according to one particular embodiment of the present invention. The endoscopic assembly 40 has a headpiece 42 that remains external to the patient and is manipulable by an operator during an endoscopic procedure. The headpiece 42 is connected to an insertion tube 44 sized to be inserted into the patient during the endoscopic procedure. The insertion tube 44 can be rigid or flexible. In the illustrated embodiment, the insertion tube 44 is contained within a sheath 45 isolating the insertion tube 44 from the patient during the endoscopic procedure.

In the illustrated embodiment, the headpiece 42 has a first end 46 terminating in an eyepiece 48, and an opposing second end 50. The eyepiece 48 is connected to a visual imaging system 49 to allow the operator to view the area being operated upon during the procedure. The second end 50 of the headpiece 42 is attached to the insertion tube 44. In the illustrated embodiment, the insertion tube 44 is flexible and controllable by a number of bending control wheels 53 on the headpiece 42.

The sheath 45 fits closely over the insertion tube 44, and terminates at a proximal fitting 43 shaped to receive at least a portion of the second end 50 of the headpiece 42. The proximal fitting 43 can be fabricated from a resilient or elastomeric material sized to closely conform and captively receive the second end 50, or can be fabricated with one or more fasteners (not shown) to facilitate attachment thereto. The proximal fitting 43 on the sheath 45 has a working port 52 designed to receive a working tool, such as the illustrated endoscopic accessory 55. The working port 52 can be angled with respect to the headpiece 42 to direct the endoscopic accessory 55 toward a working channel 57 within the sheath 45. The working channel 57 extends between the working port 52 and an end cap 58 at a distal end 59 of the sheath 45.

The insertion tube 44 in the illustrated embodiment has a proximal end 54 and a distal end 56. The proximal end 54 of the insertion tube 44 is connected to the second end 50 of the headpiece 42. The distal end 56 of the insertion tube 44 terminates within the end cap 58. The end cap 58 has an opening 60 through which the endoscopic accessory 55 can project during the endoscopic procedure, and a viewing window 61 through which the visual imaging system 49 can transmit images to the eyepiece 48. The working channel 57 is sealed at the opening 60 and the working port 52 to isolate the insertion tube 44 from bodily fluids from the patient during the procedure. The endoscopic accessory 55 has a proximal end 62 that remains external to the patient during the endoscopic procedure, and a distal end 64 that is positionable by the user within the working channel 57. The endoscopic accessory 55 can be inserted into the working port 52 and extended along the working channel 57 until its distal end 64 is near the opening 60 in the working channel, or to a point external to the opening 60. A position locating device 66 is attached to the distal end 64 of the endoscopic accessory 55.

The proximal end 62 of the endoscopic accessory 55 is coupled to a number of controls 68 for manipulating the distal end 64 of the endoscopic accessory. The user can manipulate the controls 68 to bend the distal end 64 of the endoscopic accessory 55, and with it the position locating device 66.

The position locating device 66 communicates with a detecting assembly 70 external to the patient to provide information to the user concerning the location of the position locating device within the patient. The position locating device 66 can be a transmitter that transmits a signal to a receiver within the detecting assembly 70, or can be a receiver that receives a signal from a transmitter in the detecting assembly. The position locating device 66 accordingly can have either a signal-receiving antennae or a signal-transmitting antennae. The position locating device 66 can otherwise be an electromagnetic locating device, an acoustical device, or another suitable form of device. The detecting assembly 70 can be integrated with a multi-dimensional image of the patient's body, such as an MRI or CT scan image. The detecting assembly 70 can superimpose the information received from the position locating device 66 over the multi-dimensional image of the patient's body to accurately illustrate to the operator the location of the position locating device with respect to the patient's body. Figure 3 illustrates a distal portion of the endoscopic assembly 40 in a first configuration in which the position locating device 66 is near the distal end 59 of the sheath 45. The insertion tube 44 is inserted into the sheath 45 until the distal end 56 of the insertion tube is adjacent the distal end 59 of the sheath. The endoscopic accessory 55 is inserted into the working channel 57 in the sheath 45 until the position locating device 66 approaches the opening 60 in the working channel. The endoscopic assembly 40 is thus configured for insertion into the patient and can provide both visual and non-visual locating information to the user concerning the distal end 56 of the insertion tube 44.

Figure 4 illustrates the endoscopic assembly 40 in a second configuration in which the position locating device 66 projects beyond the opening 60 in the working channel 57. In this second configuration, the visual imaging system 49 can provide information concerning the location of the distal end 56 of the insertion tube 44 relative to the patient's body while the position locating device 66 further provides information concerning the location of areas or bodies beyond the insertion tube's distal end. This second configuration can be useful in situations where the insertion tube 44 and the sheath 45 are too large to access a particular location, or where the environment is not conducive to visual location detection.

Figure 5 illustrates the distal portion of the endoscopic assembly 40 inside a patient's body. In the illustrated embodiment, the endoscopic accessory 40 and position locating device 66 are in a first detected position in which the first locating device is located adjacent a first location 72, and communicates this location to the detecting assembly 70 (not shown) to inform the user of the location of the first location 72 with respect to the patient's body. The distal end 64 of the endoscopic accessory 55 can be manipulated by the controls 68 (Figure 2) to place the position locating device 66 in the desired position for detecting the first location 72.

Figure 6 illustrates the distal portion of the endoscopic assembly 40 from Figure 5, but in this instance configured in a second detected position to detect the location of a second location 74 within the patient's body. After detecting the location of the first location 72, the user can manipulate the controls 68 to position the position locating device 66 against the second location 74. The user can use the detecting assembly 70 to record the location of the second location 74 within the patient's body. The user can store the recorded locations of the first and second locations 72/74, or can manipulate the data to determine, as an example, the distance between the first location 72 and the second location 74. This distance is generally illustrated as distance "d" in Figure 6. In operation, the user first obtains a multi-dimensional image of a selected portion of the patient's body. This image is then communicated to the detecting ^" assembly 70 to provide the detecting assembly with a reference frame corresponding to the portion of the patient's body. The insertion tube 44 is then inserted into the portion of the patient's body and the visual imaging system 49 used to help guide the distal end 56 of the insertion tube near the desired location within the patient's body. The endoscopic accessory 55 is inserted through the working channel 57 to a point at which a position locating device 66 is near the opening 60 in the working channel 57. The endoscopic accessory can be inserted into the working channel 57 either before or after the insertion tube 44 is inserted into the patient. The user then extends the position locating device 66 external to the opening 60 in the working channel 57, and uses the position locating device and the detecting assembly 70 to guide the position locating device to a selected location within the patient. In guiding the position locating device 66, the signal from the position locating device is superimposed over the multi-dimensional image of the portion of the patient to allow the user to visually identify the location of the endoscope and the accessory relative to the patient's body.

The above embodiment of the present invention has a number of advantages over the prior art. In situations conducive to visual imaging, the present invention provides a backup locating device for providing additional information to the user, and provides a location device for the endoscopic accessory when the accessory is extended beyond the distal tip of the insertion tube. In such situations, the user can use visual imaging to position the distal end of the insertion tube near the location to be operated upon, then use non-visual imaging to move the working tool to the precise location for the procedure.

In situations where visual imaging is not possible, the above embodiment provides the user with a means for positioning the endoscopic accessory at the location to be operated upon. In this and the prior, situation, the present invention can both provide the user with location information as well as a tool for performing the procedure. The location device need not be removed and replaced with a tool, such as when the location device is positioned at the distal tip of a catheter.

Figure 7 illustrates an endoscopic assembly 140 according to another embodiment of the present invention. In the illustrated embodiment, the endoscopic assembly 140 has a headpiece 142 attached to an insertion tube 144. A number of control wheels 153 on the headpiece 142 can be used to manipulate a distal end 156 of the insertion tube 144. A working port 152 on the headpiece 142 is coupled to a working channel 157 within the insertion tube 144 and terminates at an opening 160 at the distal end 156 of the insertion tube. An endoscopic accessory 155 having controls 168 can be inserted into the working port 152 and extended along the working channel 157 until the endoscopic accessory approaches or projects beyond the opening 160 in the insertion tube 144. This particular embodiment of the endoscopic assembly 140 can be used to provide both visual and non-visual information to a user in situations where a sheath is not necessary or desirable. Figure 8 illustrates a distal portion of another endoscopic assembly 240 according to another embodiment of the present invention. In this particular embodiment, a position locating device 266 at a distal end 264 of an endoscopic accessory 255 is coupled to a biopsy needle 276 configured to take one or more specimens from the patient. The endoscopic assembly 240 can also have a suction channel 278 for providing suction to the biopsy needle 276. The endoscopic accessory 255 and the biopsy needle 276 are controllable from a point external to the patient to selectively take specimens from within the patient. In this particular embodiment, a visual imaging system 249 can first be used to position the distal portion of the endoscopic assembly 240 near a point within the patient from which the user desires a specimen, and then the position locating device 266 can be used to assist in guiding the biopsy needle 276 to the exact location from which the specimen will be taken. The position locating device 266 can be attached directly to the biopsy needle, or can be attached to the distal end 264 of the endoscopic accessory 255.

Figure 9 illustrates a distal portion of yet another endoscopic assembly 340 according to another embodiment of the present invention. In this particular embodiment, an endoscopic accessory 355 terminates at its distal end 364 in a position locating device 366 and a mechanism 380 for ablating polyps or other masses. A control coupling 382 and a number of controls (not shown) can be used to manipulate the endoscopic accessory 355 and/or the mechanism 380 to ablate an undesired mass. In this embodiment, the visual imaging system 349 can be used by the system's operator to guide the endoscopic assembly 340 to the desired location within the patient, and the position locating device 366 can then be used to guide the mechanism 380 to the exact location from which the operator desires to take the specimen. The working channel 357 in the illustrated embodiment is integral with a sheath 345 surrounding the endoscopic insertion tube 344. The working channel 357, however, can instead be integral with the insertion tube 344 for situations in which a sheath is not necessary.

Figure 10 illustrates a distal portion of an endoscopic assembly 440 according to another embodiment of the present invention. The endoscopic assembly 440 has an insertion tube 444 removably positioned within a sheath 445. A position locating device 482 is encased within the distal portion 459 of the sheath 445. The position locating device 482 can instead be attached to the distal end 459 of the sheath 445. A connector 484 connects the position locating device 482 to a detection assembly (Figure 2) to send or receive signals therebetween. The endoscopic assembly 440 can also include a visual locating device 449. The endoscopic assembly 440 can therefore provide both visual and non-visual location information to the user.

Figure 11 illustrates an endoscopic assembly 540 according to another embodiment of the present invention. The endoscopic assembly includes an insertion tube 544 contained within a protective sheath 545. A position locating device 582 is attached to a distal portion 559 of the sheath 545. The position locating device 582 communicates with a detection assembly (Figure 2) to provide the user with information concerning the distal end of the endoscopic assembly 540. The position locating device 582 can be a transmitting device or a receiving device, and accordingly can have either a signal transmitting or a signal receiving antennae thereon. The position locating device 582 can be an electromagnetic locating device, an acoustical device, or any other suitable device. The position locating device 582 works in combination with a visual locating device 549 to provide the user with both visual and non-visual locating information.

From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.

Claims

CLAIMS We claim:

1. An endoscopic assembly usable with a detecting assembly during an endoscopic procedure performed within a portion of a patient's body, the endoscopic assembly comprising: an endoscopic insertion tube insertable into the patient's body, the insertion tube having a working channel having a distal end and extending along a portion of the insertion tube; a visual imaging system coupled to the insertion tube, the visual imaging system being operational to allow a user to view the portion of the patient's body; an endoscopic accessory positionable in the working channel, the endoscopic accessory being movable through the working channel to a position in which a distal end of the endoscopic accessory is adjacent or external to the working channel's distal end when the insertion tube is in the portion of the patient's body; and a position locating device connected to the endoscopic accessory and being locatable by the detecting assembly when the endoscopic accessory is positioned in the portion of the patient's body, the position locating device non-visually identifying the location of the endoscopic accessory in the portion of the patient's body.

2. The endoscopic assembly of claim 1 wherein the position locating device is movable from a first detected position to a second detected position in the portion of the patient's body to measure a distance therebetween.

3. The endoscopic assembly of claim 1 wherein the position locating device is a transmitting device.

4. The endoscopic assembly of claim 1 wherein the position locating device is a receiving device.

5. The endoscopic assembly of claim 1 wherein the position locating device includes a signal-receiving antenna.

6. The endoscopic assembly of claim 1 wherein the position locating device includes a signal-transmitting antenna.

7. The endoscopic assembly of claim 1 wherein the position locating device is an electromagnetic locating device.

8. The endoscopic assembly of claim 1 wherein the position locating device is an acoustical device.

9. The endoscopic assembly of claim 1 wherein the endoscopic accessory is a biopsy accessory that is usable to take a biopsy.

10. The endoscopic assembly of claim 1 wherein the endoscopic accessory is an ablating instrument.

11. The endoscopic assembly of claim 1 wherein the endoscopic assembly includes a sheath removably covering a portion of the insertion tube.

12. The endoscopic assembly of claim 1 wherein the insertion tube has a flexible distal portion steerable within the selected portion of the patient's body to control movement of the flexible distal portion.

13. An endoscopic assembly usable for an endoscopic procedure performed within a portion of a patient's body, comprising: a detecting assembly external to the patient's body, the detecting assembly having a multi-dimensional image of the portion of the patient's body; an endoscopic assembly having an insertion tube insertable into the patient's body, the insertion tube having a distal end, and a visual imaging system coupled to the insertion tube, the visual imaging system being operational to allow a user to view the portion of the patient's body; an endoscopic accessory movably positionable in the endoscopic assembly to a position in which a distal end of the endoscopic accessory is adjacent or external to the insertion tube's distal end when the insertion tube is in the portion of the patient's body; and a position locating device connected to the endoscopic accessory and being locatable by the detecting assembly to identify the position of the position locating device relative to portion of the patient's body when the endoscopic accessory is positioned in the portion of the patient's body, the position locating device non-visually identifying the location of the endoscopic accessory in the portion of the patient's body, and the identified location of the endoscopic accessory being imposed on the multi-dimensional image of the portion of the patient's body to allow the user to identify where the endoscopic accessory is in the portion of the patient's body.

14. The endoscopic assembly of claim 13 wherein the position locating device is movable relative to the insertion tube from a first detected position to a second detected position in the portion of the patient's body to measure a distance therebetween.

15. The endoscopic assembly of claim 13 wherein the position locating device is a transmitting device that transmits a signal, and the detecting assembly includes a receiving member that receives the signal.

16. The endoscopic assembly of claim 13 wherein the detecting assembly includes a transmitter that sends a signal to the position locating device, and the position locating device includes a receiver that receives the signal.

17. The endoscopic assembly of claim 13 wherein the position locating device is an electromagnetic locating device.

18. The endoscopic assembly of claim 13 wherein the position locating device is an acoustical device.

19. The endoscopic assembly of claim 13 wherein the endoscopic accessory is a biopsy accessory that is usable to take a biopsy.

20. The endoscopic assembly of claim 13 wherein the endoscopic accessory is an ablating instrument.

21. The endoscopic assembly of claim 13 wherein the endoscopic assembly includes a sheath removably covering a portion of the insertion tube, and a working channel sized to receive the endoscopic accessory and extending through the sheath adjacent to the insertion tube.

22. A method of performing an endoscopic procedure, comprising: obtaining a multi-dimensional image of a portion of a patient's body; inserting an insertion tube of an endoscopic assembly into the portion of the patient's body, the endoscopic assembly including a working channel extending along a portion of the insertion tube and a visual imaging device coupled to the insertion tube; extending an endoscopic accessory with a position locating device thereon through the working channel with a distal end of the endoscopic accessory being adjacent or external to a distal end of the working channel; non-visually locating the position of the position locating device within the patient's body relative to selected reference points after the insertion tube is positioned in the portion of the patient's body, the locating device being located by a detecting assembly that is external to the patient's body; superimposing the determined location of the locating device on the multidimensional image of the portion of the patient's body; and visually identifying the location of the accessory relative to the multidimensional image to determine the position of the accessory within the portion of the patient's body.

23. The method of claim 22, further including the step of performing an endoscopic procedure with the endoscopic accessory within the portion of the patient's body at the identified location.

24. The method of claim 22, further including the steps of positioning the accessory in a first position in the portion of the patient's body, non-visually locating the position of the locating device when the accessory is in the first position, moving the accessory from the first position to a second position, non-visually locating the position of the locating device when the accessory is in the second position, and measuring the distance between the first and second positions.

25. The method of claim 22, further including the step of performing an endoscopic procedure with the endoscopic accessory.

26. The method of claim 25 wherein the step of performing the endoscopic procedure includes taking a biopsy from the portion of the patient's body.

27. The method of claim 22, further comprising the step of visually viewing the portion of the patient's body through the visual imaging device when the insertion tube in inserted into the portion of the patient's body.

28. The method of claim 22 further comprising performing an endoscopic procedure in an area not visible to the user through the visual imaging device of the insertion tube.

29. An endoscopic assembly usable with a detecting assembly during an endoscopic procedure performed within a portion of a patient's body, comprising: an endoscopic assembly having an insertion tube insertable into the patient's body, a sheath covering a portion of the insertion tube, and a visual imaging system coupled to the insertion tube, the visual imaging system being operational to allow a user to view the portion of the patient's body; and a position locating device connected to a portion of the sheath and being detectable by the detecting mechanism when the sheath and insertion tube are positioned in the portion of the patient's body, the position locating device non-visually identifying the location of the portion of the sheath within the patient's body.

30. The endoscopic assembly of claim 29 wherein the position locating device is connected to a distal portion of the sheath.

31. The endoscopic assembly of claim 29 wherein the position locating device is a transmitting device.

32. The endoscopic assembly of claim 29 wherein the position locating device is a receiving device.

33. The endoscopic assembly of claim 29 wherein the position locating device includes a signal-receiving antenna.

34. The endoscopic assembly of claim 29 wherein the position locating device includes a signal-transmitting antenna.

35. The endoscopic assembly of claim 29 wherein the position locating device is an electromagnetic locating device.

36. The endoscopic assembly of claim 29 wherein the position locating device is an acoustical device.

37. An endoscopic assembly usable with a detecting assembly external to a patient during an endoscopic procedure performed within a portion of the patient's body, the endoscopic assembly comprising: an endoscopic insertion tube insertable into the patient's body; a visual imaging system coupled to the insertion tube, the visual imaging system being operational to allow a user to view the portion of the patient's body; an endoscopic accessory movably coupled to the insertion tube, the endoscopic accessory being movable to a position in which a distal end of the endoscopic accessory is adjacent or external to the distal end of the insertion tube when the insertion tube is in the portion of the patient's body; and a position locating device being locatable by the detecting assembly when the endoscopic accessory is positioned in the portion of the patient's body, the position locating device non-visually identifying the location of the endoscopic accessory in the portion of the patient's body.