VISION CATHETER

Abstract

A catheter having a distal end for insertion into a patient and including: a catheter tube enclosing at least a first catheter lumen and a vision lumen separated from the first catheter lumen, the first catheter lumen having a first distal opening at the distal end of the catheter; a window closing off a distal end of the vision lumen and having a planar interior window surface facing the vision lumen and a planar exterior window surface; and a vision device positioned in the vision lumen and having a vision module, such as a camera with an image sensor or an optical fibre, having an optical axis extending through the window; wherein the interior window surface and/or the exterior window surface is/are non-orthogonal with respect to the optical axis of the vision module, and the window surfaces are non-parallel.

Claims

1. A catheter comprising: a distal end; a catheter tube having a first catheter lumen and a vision lumen separated from the first catheter lumen, the first catheter lumen having a first distal opening at the distal end of the catheter, and the vision lumen having a distal end; a window closing off the distal end of the vision lumen and having an interior window surface facing the vision lumen and an exterior window surface; and a vision device positioned in the vision lumen and comprising a vision module having an optical axis extending through the window, wherein the interior window surface and/or the exterior window surface is/are non-orthogonal with respect to the optical axis of the vision module, and wherein the interior window surface and the exterior window surface are non-parallel.

2. The catheter of claim 1, wherein the vision module comprises a lens stack and an image sensor.

3. The catheter of claim 1, wherein the interior window surface and/or the exterior window surface are sized and structured to generate an effective view direction of the vision module angled with respect to the optical axis by an angle in the range 1° to 15°.

4. The catheter of claim 3, wherein the angle in the range of 3° to 12°.

5. The catheter of claim 1, wherein the window is sized and structured to refract an effective view direction of the vision module away from the optical axis.

6. The catheter of claim 5, wherein the interior window surface and/or the exterior window surface is/are substantially planar.

7. The catheter of claim 1, wherein the interior window surface and/or the exterior window surface is/are substantially planar.

8. The catheter of claim 1, wherein the exterior window surface is non-orthogonal with respect to the optical axis.

9. The catheter of claim 8, wherein the interior window surface is orthogonal with respect to the optical axis.

10. The catheter of claim 8, wherein an angle between a surface normal of the exterior window surface and the optical axis is in the range 1° to 45°.

11. The catheter of claim 1, wherein the interior window surface is non-orthogonal with respect to the optical axis.

12. The catheter of claim 11, wherein the exterior window surface is orthogonal with respect to the optical axis.

13. The catheter of claim 11, wherein an angle between a surface normal of the interior window surface and the optical axis is in the range 1° to 45°.

14. The catheter of claim 1, wherein the vision lumen extends substantially in parallel to the first catheter lumen.

15. The catheter of claim 1, wherein the catheter tube comprises a flush inlet, a flush channel fluidly connected to the flush inlet, and one or more flush openings directed towards the exterior window surface and fluidly connected to the flush inlet via the flush channel.

16. The catheter of claim 1, wherein the catheter tube comprises one or more flush channels and a flush inlet, each of the one or more flush channels including a flush opening directed towards the exterior window surface, the flush inlet connected via the one or more flush channels to respective of the one or more flush openings, the one or more flush openings oriented so that pressurised flush fluid supplied to the flush inlet flows through the one or more flush channels and exits through the flush openings to flush the exterior window surface.

17. The catheter of claim 1, wherein the vision device comprises a housing which includes the window and forms a sealed compartment encompassing the vision module.

18. The catheter of claim 17, wherein the housing and the window are integrally formed in a one-piece part.

19. The catheter of claim 18, wherein the housing of the vision device is retained in the vision lumen by a friction fit.

20. The catheter of claim 1, wherein the catheter is an endotracheal tube.

21. The catheter of claim 21, wherein the endotracheal tube is a double-lumen endotracheal tube.

22. A catheter vision system comprising: a catheter according to claim 1; and a monitor, wherein the catheter is connectable to the monitor and the monitor is adapted to display an image captured by the vision device.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0046] Embodiments of this disclosure will be described in more detail in the following with regard to the accompanying figures. The figures show one way of implementing the present invention and are not to be construed as being limiting to other possible embodiments falling within the scope of the attached claim set.

[0047] FIG. 1 is a schematic perspective illustration of a catheter in the form of a single-lumen endotracheal tube,

[0048] FIG. 2 is a schematic perspective illustration of the distal end of the catheter of FIG. 1,

[0049] FIG. 3 is a schematic perspective illustration of a catheter in the form of a double-lumen endotracheal tube,

[0050] FIG. 4 is a schematic perspective illustration of the distal end of the catheter of FIG. 3,

[0051] FIG. 5 is a schematic cross-sectional illustration of a distal end of the catheter of FIG. 3,

[0052] FIG. 6 is a schematic perspective illustration of a vision device for implementation in the catheter of FIGS. 1-2 or in the catheter of FIGS. 3-5,

[0053] FIG. 7 is a schematic exploded illustration of the vision device of FIGS. 6-7,

[0054] FIG. 8 is a schematic cross-sectional illustration of a first embodiment of the vision device of FIGS. 6-7,

[0055] FIG. 9 is a schematic cross-sectional illustration of a distal end of the first embodiment of the vision device shown in FIG. 8,

[0056] FIG. 10 is a schematic cross-sectional illustration of a second embodiment of the vision device of FIGS. 6-7,

[0057] FIG. 11 is a schematic detail illustration of a distal end of the second embodiment of the vision device shown in FIG. 10, and

[0058] FIG. 12 is a schematic illustration of a monitor.

DETAILED DESCRIPTION OF THE INVENTION

[0059] FIGS. 1 and 2 illustrate a first catheter 1a in the form of a single-lumen endotracheal tube. As can best be seen in FIG. 1, the catheter 1a comprises an extruded catheter tube 4 extending from a proximal end 3 to a distal end 2. The catheter 1a further comprises a first cuff 5 inflatable via an inflation tube, which at an end comprises a first valve 61 and a first pilot balloon 6. The first valve 61 comprises an inlet for connection to a pressure source such as a syringe and the first pilot balloon 6 provides a tactile indication of the pressure inside the first cuff 5. As best seen in FIG. 2, the catheter tube 4 encloses a first catheter lumen 10 having a first distal opening 11 at the distal end 2 of the catheter tube 4 and a first proximal opening 12 at the proximal end 3 of the catheter tube 4 as seen in FIG. 1. The catheter tube 4 further comprises a vision lumen 30 extending in parallel to and separate from the first catheter lumen 10. A vision device 40 is positioned in the vision lumen 30 and comprises a camera having an image sensor and a lens stack, one or more light sources 48 (as seen in FIG. 7), and a window 31 (best seen in FIG. 7). The window 31 closes off a distal end of the vision lumen 30 from an external medium 70, typically air. The distal end of the vision lumen 30 is located adjacent to the first distal opening 11 of the first catheter lumen 10 as seen in FIG. 2. The vision device 40 comprises a plug 50 (as seen in FIG. 1.) connectable to a socket 52 of monitor 51, which is shown in FIG. 12, for displaying images captured by the vision device 40 on the monitor 51. Alternatively, the vision device 40 could be wirelessly connected to the monitor 51.

[0060] FIGS. 3-5 illustrate a second catheter 1b in the form of a double-lumen endotracheal tube. The second catheter 1b comprises an extruded catheter tube 4 similar to the catheter tube 4 of the first catheter 1a as shown in FIGS. 1 and 2 but differs therefrom by further comprising a second catheter lumen 20 extending between a second proximal opening 22 at the proximal end 3 of the catheter tube 4 and a second distal opening 21 at the distal end 2 of the catheter tube 4. The second catheter lumen 20 is adjacent to and separate from the first catheter lumen 10 and the vision lumen 30 as best seen in FIG. 5. As seen in FIG. 4 and similar to the first catheter 1a, the vision device 40 is located at a distal end of the dedicated vision lumen 30 adjacent to the first distal opening 11 of the first catheter lumen 10. The vision device 40 closes off the distal end of the vision lumen 30 and is tightly retained in the vision lumen 30 by a friction fit. The catheter 1 further comprises a second cuff 7 inflatable via an inflation tube, which at an end comprises a second valve 81 and a second pilot balloon 8. The second cuff 7 is positioned between the first distal opening 11 and the second distal opening 21. The second valve 81 comprises an inlet for connection to a pressure source such as a syringe and the second pilot balloon 8 provides a tactile indication of the pressure inside the second cuff 7. Furthermore, by means of a flush inlet 60, the window 31 of the vision device 40 may be flushed via flush openings 61 formed in the catheter tube 2, as best seen in FIG. 4. The flush inlet 60 is connected to the flush openings 61 via a number of dedicated flush channels 62 co-extruded in an outer wall of the catheter tube 4 as illustrated in FIG. 5. The catheter wall forming the first catheter lumen may cut at an angle to expose an interior surface of the tube distal of the vision device 40. Longitudinal channels may be drilled, e.g. laser drilled, from the exposed interior surface into the wall to establish fluid communication between the flush openings 61 and the flush channels 62. The longitudinal channels may be angled toward the vision device 40. As in the first catheter 1a, the vision device 40 comprises a plug 50 connectable to a socket 52 of monitor 51, which is shown in FIG. 12, for displaying images captured by the vision device 40 on the monitor 51. Alternatively, the vision device 40 could be wirelessly connected to the monitor 51.

[0061] The vision device 40 is illustrated in FIGS. 6-8 and 10 and comprises a housing including a housing wall 49 and an end cover 47. The housing wall 49 and end cover 47 are adhered together to form a sealed compartment which encompasses a vision module 41 held by a holder 46. The holder 46 is sized and structured to match an internal surface of the housing and to receive the vision module, thus can be used to facilitate insertion of the vision module into the housing and to secure the vision module within the housing in a desired orientation, as shown in FIG. 10. The housing wall 49 has a window 31 integrally moulded so the housing wall 49 and window 31 forms a single element. The window 31 comprises a planar exterior window surface 33 and a planar interior window surface 32, which is shown in FIGS. 8-11. The vision module 41 comprises a lens stack 43, e.g. of three lenses, two light sources 48, and an image sensor 42 with an optical axis 41a extending through the lens stack 43 and the window 31. The light sources 48 are supplied with power by the printed circuit board 44 and provide illumination for the image sensor 42. The image sensor 42 is electrically connected to a printed circuit board 44 for processing image signals from the image sensor 42 and transmitting these signals, e.g. through a cable 45, to a monitor 51 as shown in FIG. 12 for displaying the images to the operator. Alternatively, image signals could be transmitted unprocessed from the image sensor 42 to an external image processing unit (not shown), which could be positioned in the handle or in the monitor.

[0062] A first embodiment of the window 31 is schematically illustrated in FIGS. 8-9. As best seen in FIG. 9, the exterior window surface 33 of the window 31 is planar and has a surface normal 33a parallel to the optical axis 41a of the image sensor 42 of the vision module 41. A surface normal 32a of the interior window surface 32 forms an angle, β.sub.int, of about 8.5° with respect to the optical axis 41a of the vision device 40.

[0063] A second embodiment of the window 31 is schematically illustrated in FIGS. 10-11. As best seen in FIG. 11, the interior window surface 32 of the window 31 has a surface normal 32a parallel to the optical axis 41a. The exterior window surface 33 has a surface normal 33a forming an angle, β.sub.ext, of about 8.5° with respect to the optical axis 41a.

[0064] A third embodiment of the window is not illustrated but corresponds to a combination of the first and second embodiment. In the third embodiment, the interior window surface 32 and the exterior window surface 33 are planar and non-parallel. Further, the surface normal 32a of the interior window surface 32 forms an angle, β.sub.int, of up to about 4°-5° with respect to the optical axis 41a of the vision device 40, while the surface normal 33a of the exterior window surface 33 forms an angle, β.sub.ext, of up to about 4°-5° with respect to the optical axis 41a.

[0065] In all three embodiments, an external medium 70 of air surrounds the catheter, the vision lumen 30 encloses an internal medium 71 of air, and the window 31 consists essentially of polycarbonate with a refraction index of 1.58. The window 33 refracts the effective view direction 41b away from the catheter tube 4 by an angle α of about 5° with respect to the optical axis 41a. This leads to a larger fraction of the image captured by the vision device 40 to be occupied by the inspected anatomy. Each of the above described embodiments can be implemented in the first catheter 1a shown in FIGS. 1-2 or second catheter 1b shown in FIGS. 3-5. For illustrative purposes, the angles between surface normals, the optical axis, and the effective view angles are schematically exaggerated and may be smaller in practice.

[0066] An angle α between the optical axis 41a and the effective view direction 41b of about 5°-8° has been found to provide an adequate trade-off between decreasing the view occupied by the catheter tube 4 while retaining enough to allowing navigating the catheter to the desired location. The skilled person will appreciate that this angle is achieved by choosing the combination of the window refraction index and angles between the respective surface normals 32a, 33a and the optical axis 41a.

[0067] The following items are examples of various embodiments disclosed above:

[0068] Item 1. A catheter having a distal end for insertion into a patient, and comprising: a catheter tube enclosing at least a first catheter lumen and a vision lumen separated from the first catheter lumen, the first catheter lumen having a first distal opening at the distal end of the catheter; a window closing off a distal end of the vision lumen and having an interior window surface facing the vision lumen and an exterior window surface; and a vision device positioned in the vision lumen and comprising a vision module, such as a camera with an image sensor or an optical fibre, having an optical axis extending through the window; wherein the interior window surface and/or the exterior window surface is/are non-orthogonal with respect to the optical axis of the vision module, and wherein the interior window surface and the exterior window surface are non-parallel.

[0069] Item 2. A catheter according to any one of the previous items, wherein the window is adapted to refract an effective view direction of the vision module away from the catheter tube.

[0070] Item 3. A catheter according to any one of the previous items, wherein the interior and/or exterior window surface is/are substantially planar.

[0071] Item 4. A catheter according to any one of the previous items, wherein the exterior window surface is non-orthogonal with respect to the optical axis and optionally the interior window surface is orthogonal with respect to the optical axis.

[0072] Item 5. A catheter according to any one of the previous items, wherein an angle between a surface normal of the exterior window surface and the optical axis is in the range 1° to 45°.

[0073] Item 6. A catheter according to any one of the previous items, wherein the interior window surface is non-orthogonal with respect to the optical axis and optionally the exterior window surface is orthogonal with respect to the optical axis.

[0074] Item 7. A catheter according to any one of the previous items, wherein an angle between a surface normal of the interior window surface and the optical axis is in the range 1° to 45°.

[0075] Item 8. A catheter according to any one of the previous items, wherein the vision lumen extends substantially in parallel to the first catheter lumen.

[0076] Item 9. A catheter according to any one of the previous items, wherein the interior window surface and/or the exterior window surface are adapted so that an effective view direction of the vision module is angled with respect to the optical axis by an angle in the range 1° to 15°, preferably in the range 3° to 12°.

[0077] Item 10. A catheter according to any one of the previous items, wherein the catheter tube comprises a flush inlet connected via one or more flush channels to respective flush openings oriented so that pressurised flush fluid supplied to the flush inlet flows through the flush channel(s) exits through the flush openings directed towards the exterior surface of the window.

[0078] Item 11. A catheter according to any one of the previous items, wherein the vision device comprises a housing which includes the window and forms a sealed compartment encompassing the vision module.

[0079] Item 12. A catheter according to item 11, wherein the housing and the window are integrally formed.

[0080] Item 13. A catheter according to any one of items 11-12, wherein the housing of the vision device is retained in the vision lumen by a friction fit.

[0081] Item 14. A catheter according to any one of the previous items, wherein the catheter is an endotracheal tube, such as a double-lumen endotracheal tube or a single-lumen endotracheal tube.

[0082] Item 15. A catheter vision system comprising a catheter according any one of the previous items and a monitor, wherein the catheter is connectable to the monitor and the monitor is adapted to display an image captured by the vision device.

LIST OF REFERENCES

[0083] 1a first catheter [0084] 1b second catheter [0085] 2 distal end [0086] 3 proximal end [0087] 4 catheter tube [0088] 5 first inflatable cuff [0089] 6 first pilot balloon [0090] 61 first valve [0091] 7 second inflatable cuff [0092] 8 second pilot balloon [0093] 81 second valve [0094] 10 first catheter lumen [0095] 11 first distal opening [0096] 12 first proximal opening [0097] 20 second catheter lumen [0098] 21 second distal opening [0099] 22 second proximal opening [0100] 30 vision lumen [0101] 31 window [0102] 32 interior window surface [0103] 32a surface normal [0104] 33 exterior window surface [0105] 33a surface normal [0106] 40 vision device [0107] 41 vision module [0108] 41a optical axis [0109] 41b effective view direction [0110] 42 image sensor [0111] 43 lens stack [0112] 44 printed circuit board [0113] 45 cable [0114] 46 holder [0115] 47 end cover [0116] 48 light source [0117] 49 housing wall [0118] 50 plug [0119] 51 monitor [0120] 52 socket [0121] 60 flush connection [0122] 61 flush opening [0123] 62 flush channel [0124] 70 external medium [0125] 71 internal medium [0126] α angle of effective view direction with respect to the optical axis [0127] β.sub.int angle of the surface normal of the interior window surface with respect to the optical axis [0128] β.sub.ext angle of the surface normal of the exterior window surface with respect to the optical axis