WO2012028843A1

WO2012028843A1 - Visualisation apparatus

Info

Publication number: WO2012028843A1
Application number: PCT/GB2011/001270
Authority: WO
Inventors: Jeremy Colin Russel
Original assignee: Smiths Medical International Limited
Priority date: 2010-09-01
Filing date: 2011-08-26
Publication date: 2012-03-08
Also published as: GB201014545D0

Abstract

An endoscope (1) supports an expansible stent (2) towards its patient end (12) between two video chips (13B and 14B) directed towards one another at a small angle. The video chips (13 and 14) are arranged to view both the inside of the trachea (40) or other body passage and opposite ends of the stent (2). A cables (15, 18) extends from the video chips (13B and 14B) to a monitor display (3), signals from the chips being supplied via the cable to provide representations of the field of view of both chips on the monitor. When the display images indicate that the (endoscope 1) is in the correct position, the stent (2) is expanded off and the display images are checked to ensure that the stent extends over the desired region of the passage (40).

Description

VISUALISATION APPARATUS

This invention relates to visualisation apparatus of the kind including an elongate support structure.

The invention is more particularly, but not exclusively, concerned with visualisation apparatus for medical use.

Endoscopes or similar visualisation devices are used for providing an image of a body site to a clinician such as for use in diagnosis, monitoring or surgery. One application for such endoscopes is in the positioning of stents in a body cavity or passage, such as a blood vessel, oesophagus or the like. The endoscope is inserted into the body passage with the stent and the output of the endoscope is monitored to determine when the stent is in the correct position. The stent is then expanded within the body cavity to contact and support the inside of the passage following which the endoscope is removed, leaving the stent in position. This can enable the forward end of the stent to be positioned accurately within the passage. However, it is not possible to determine whether the rear end of the stent is positioned correctly until after the stent has been expanded, when it is very difficult to remove or replace. This is especially a problem because the nature of the stent is that it contracts axially as it expands radially so it is difficult to judge where the rear end of the stent will be located after expansion.

It is an object of the present invention to provide alternative visualisation apparatus.

According to one aspect of the present invention there is provided visualisation apparatus of the above-specified kind, characterised in that the apparatus includes first and second imaging means supported thereon at different locations spaced from one another along the length the support structure, and that the apparatus includes display means arranged to receive outputs from the imaging means such as to provide a display representation of images from the two different locations along the support structure. The imaging means are preferably directed towards one another at a small angle. The first and second imaging means may include a video chip arranged to provide an electrical image output to the display means. The electrical image output is preferably provided via an electrical cable. The apparatus may include a generally elongate device supported on an external surface of the support structure, the device extending along a region between the first and second imaging means. The generally elongate device is preferably be an expansible stent.

According to another aspect of the present invention there is provided endoscope apparatus including an elongate support body and an expansible stent supported on the body close to one end, characterised in that the apparatus includes first and second imaging means supported on the support body at spaced locations at opposite ends of the stent, that the imaging means are arranged to view both the inside of a body passage within which the stent is to be positioned and respective opposite ends of the stent, and that the apparatus includes a display monitor arranged to receive outputs from the two imaging means such as to provide a display representation at the two different locations along the support body.

According to a further aspect of the present invention there is provided a method of positioning a device within a passage including the steps of mounting the device between two spaced imaging means on visualisation apparatus, viewing on a display images from the imaging means of two different locations along the passage as the apparatus is extended along the passage, determining when the displayed locations indicate a suitable position for the device within the passage, causing the device to be released from the apparatus and locate within the passage between the displayed locations, and subsequently removing the visualisation apparatus to leave the device in position.

According to yet another aspect of the present invention there is provided a method of positioning a stent within a body passage including the steps of mounting the stent between two spaced imaging means on an endoscope, viewing on a display images from the imaging means of two different locations along the body passage as the endoscope is extended along the passage, determining when the displayed locations indicate a suitable position for the stent within the passage, causing the stent to expand off the endoscope so as to be released from the endoscope and locate within the passage between the displayed locations, and subsequently removing the endoscope to leave the stent in position.

Visualisation apparatus in the form of an endoscope for inserting a stent in the trachea and its method of operation, will now be described, by way of example, with reference to the accompanying drawings, in which:

Figure 1 is a cross-sectional side elevation of the endoscope and stent prior to insertion;

Figure 2 illustrates a first step in positioning the endoscope within the trachea;

Figure 3 illustrates a subsequent step where the stent is expanded within the

trachea; and

Figure 4 illustrates a further step where the endoscope is removed to leave the stent in position.

With reference first to Figure 1 , there is shown an endoscope 1 supporting an expansible stent 2 and providing an image output to a display 3.

The endoscope 1 comprises an elongate support body 10 of a bendable plastics material with a bore 1 1 extending along its length and closed at its forward end 12. The endoscope 1 may be steerable, such as by means of a pull cord (not shown) along one side that is operable to curve the endoscope to one side when pulled. Alternatively, the endoscope could be of a malleable construction (by incorporating a malleable metal element) such that it can be bent to a desired shape, which it retains during insertion. In another form, the body could be of a material that can be bent to a desired shape temporarily but will gradually relax to its initial shape over time. The endoscope includes two separate viewing means, one 13 being located close to the patient, forward end 12 and the other 14 being spaced rearwardly from it by a distance of about 20 - 100mm. The viewing means 13 and 14 each comprise a light source, such as an LED 13 A arid 14A, and a video chip and lens unit 13B and 14B. The viewing means 13 and 14 are mounted within the wall of the body 10 to view respective regions of the trachea 40 located radially outwardly of the endoscope 1. Preferably, the viewing means 13 and 14 are directed at a small angle towards one another, to improve viewing of the stent 2. It will be appreciated that the endoscope could include additional viewing means if desired, such as one mounted at the forward, patient end and directed to view axially forwardly of the endoscope. This may be useful for preliminary navigation of the endoscope during insertion. The viewing means 13 and 14 are connected by wires 15 extending along the bore 11 to an electrical connector 16 mounted at the rear end of the endoscope 1. A mating connector 17 at one end of a cable 18 is connected with the endoscope connector 16, the cable extending to the display 3.

The display 3 may be of any conventional kind and is arranged to represent two separate images 33 and 34 corresponding to the regions viewed by the video chip units 13 and 14 respectively. The display could be mounted directly on the endoscope 1 instead of via the cable 18. Alternatively, the display could be head-mounted, such as on a helmet, goggles or glasses. The display image could be presented in a head-up display manner by projection on a semi- transparent, reflective screen so that the image can be viewed by looking through the screen.

The stent 2 may be of any conventional kind, such as of a metal or plastics construction or a combination of both metal and plastics. The stent 2 is expansible in some way, such as by mechanical actuation, by internal pressure, such as exerted by an internal inflatable balloon, or by temperature change (incorporating a shape memory alloy or other phase-change material) caused by warming to body temperature. The stent 2 is a close fit on the body 10, so that it is not displaced axially when the endoscope 1 is inserted in the body, and its length is such that it extends along the region between the two viewing means 13 and 14 without covering them but preferably so that opposite ends of the stent are visible by the viewing means and in the display representations 33 and 34. Prior to insertion, the stent 2 is loaded on the endoscope 1 in its retracted state between the two viewing means 13 and 14, as shown in Figure 1.

With reference now to Figure 2, this shows the endoscope 1 inserted in the trachea 40 to a region 41 of restriction, trauma or the like, where it is desired to position the stent 2. The clinician views the display 3 until the images 33 and 34 show the desired trachea region 41 above and below the edges of the stent 2 so that he knows that the stent is correctly positioned.

The clinician now causes the stent 2 to expand radially off the body 10 into contact with the region 41. The stent expands this region 41 slightly to improve patency of the trachea 40 along the region. As the stent 2 expands it shrinks slightly in length. The clinician observes the image of the stent 2 occupying a greater part of the area of the display representations 33 and 34, as shown in Figure 3. The two images 33 and 34 of opposite ends of the stent 2 enable the clinician to confirm correct placement.

In the final step shown in Figure 4, the endoscope 1 is pulled rearwardly out of the trachea 40 leaving the stent 2 in position in the trachea.

By employing two viewing means in the above way, one can position a stent or similar device with greater accuracy and confidence. Incorrect placement is immediately apparent. The two viewing means enable the clinician to check that the stent or other device is of the appropriate length or enable the clinician to change the stent before expansion if the size is not correct.

It will be appreciated that the endoscope need not employ video chips but could instead include fibre optic viewing and illumination cables. Where a video chip is used, the signal need not be supplied via a cable but could be supplied instead by wireless means, such as by RF transmission. The invention is not confined to use with tracheal stents but could be used on support structures for various different applications, such as non-medical applications, for example pipe lining equipment.

Claims

1. Visualisation apparatus (1) including an elongate support structure (10), characterised in that the apparatus includes first and second imaging means (13, 14) supported thereon at different locations spaced from one another along the length the support structure (1 1), and that the apparatus includes display means (3) arranged to receive outputs from the imaging means (13, 14) such as to provide a display representation of images from the two different locations along the support structure (10).

2. Visualisation apparatus according to Claim 1 , characterised in that the imaging means (13, 14) are directed towards one another at a small angle.

3. Visualisation apparatus according to Claim 1 or 2, characterised in that the first and second imaging means (13, 14) include a video chip (13B, 14B) arranged to provide an electrical image output to the display means (3).

4. Visualisation apparatus according to Claim 3, characterised in that the electrical image output is provided via an electrical cable (15, 18).

5. Visualisation apparatus according to any one of the preceding claims, characterised in that the apparatus (1) includes a generally elongate device (2) supported on an external surface of the support structure (10), and that the device (2) extends along a region between the first and second imaging means (13 and 14).

6. Visualisation apparatus according to Claim 5, characterised in that the generally elongate device is an expansible stent (2).

7. Endoscope apparatus including an elongate support body (10) and an expansible stent (2) supported on the body close to one end, characterised in that the apparatus includes first and second imaging means (13 and 14) supported on the support body (10) at spaced locations at opposite ends of the stent (2), that the imaging means (13, 14) are arranged to view both the inside of a body passage (40) within which the stent. (2) is to be positioned and respective opposite ends of the stent (2), and that the apparatus includes a display monitor (3) arranged to receive outputs from the two imaging means (13, 14) such as to provide a display representation at the two different locations along the support body (10).

8. A method of positioning a device (2) within a passage (40) including the steps of

mounting the device (2) between two spaced imaging means (13 and 14) on visualisation apparatus (1), viewing on a display (3) images from the imaging means (13 and 14) of two different locations along the passage (40) as the apparatus is extended along the passage, determining when the displayed locations indicate a suitable position for the device (2) within the passage (40), causing the device (2) to be released from the apparatus (1) and locate within the passage (40) between the displayed locations, and subsequently removing the visualisation apparatus (1) to leave the device (2) in position.

9. A method of positioning a stent (2) within a body passage (40) including the steps of mounting the stent (2) between two spaced imaging means (13 and 14) on an endoscope ( 1), viewing on a display (3) images from the imaging means (13 and 14) of two different locations along the body passage (40) as the endoscope is extended along the passage, determining when the displayed locations indicate a suitable position for the stent (2) within the passage (40), causing the stent (2) to expand off the endoscope (1) so as to be released from the endoscope and locate within the passage (40) between the displayed locations, and subsequently removing the endoscope (1) to leave the stent (2) in position.