WO2013115640A1

WO2013115640A1 - Tracking of an endoscopic device

Info

Publication number: WO2013115640A1
Application number: PCT/NL2013/050042
Authority: WO
Inventors: Herke Jan NOORDMANS; Froukje Ellen EUWE; Lucas Alphonsus Maria Evers; Wilhelmus Josephus Maria KOOMEN; Arjen Jacobus van RHIJN; Stefan Leon BEEN; Michelle AGENANT
Original assignee: UMC Utrecht Holding BV
Current assignee: UMC Utrecht Holding BV
Priority date: 2012-01-31
Filing date: 2013-01-25
Publication date: 2013-08-08
Anticipated expiration: 2014-07-31
Also published as: NL2008205C2

Description

Title: Tracking of an endoscopic device.

The present invention relates to a marker device comprising a carrier with an array of tracking markers, which marker device is adapted to be mounted on an endoscopic device, such as an endoscope for an endoscopic camera or an endoscopic instrument, the endoscopic device having a longitudinal axis, wherein the tracking markers are trackable by (medical) tracking equipment so as to allow generation of optical guidance information for the endoscopic device by said equipment.

The document US 2010/0210902 discloses an endoscopic camera on which a marker device is mounted. The markers are arranged on rod-like elements. The known marker device has the markers distributed in an area at an upper side of the endoscopic camera. If the camera would be rotated over a large angle with respect to the longitudinal axis of the camera, the tracking equipment could at some point be unable to capture the position of sufficient markers and thus would not be able to provide univocal navigation information to the surgeon.

The invention has for an object to provide an improved marker device.

This object is achieved by a marker device comprising a carrier with an array of tracking markers, which marker device is adapted to be mounted on an endoscopic device, such as an endoscope for an endoscopic camera or an endoscopic instrument, the endoscopic device having a longitudinal axis, wherein the tracking markers are trackable by tracking equipment so as to allow generation of optical guidance information for the endoscopic device by said equipment, wherein the array of tracking markers comprises a set of more than four tracking markers which are arranged in such a configuration on the carrier that every subset of four tracking markers forms a unique configuration and such that in every angular position with respect to the longitudinal axis of the endoscopic device a reflection of at least four tracking markers can be captured by the tracking system.

In a possible embodiment the carrier has an application surface on which the array of tracking markers is applied, which application surface is situated in a convex three- dimensionally curved virtual surface.

In a further embodiment the array of tracking markers is formed by a pattern of reflective dots provided on or in the convex application surface of the carrier.

The reflective dots may be formed by reflective stickers adhered to the application surface. Alternatively, the reflective dots may be integrated within the application surface. It is also conceivable to paint the markers on the application surface. In an alternative embodiment the reflective markers could have a spherical, semi- spherical or another suitable 3D shape.

In a possible embodiment the carrier comprises a three-dimensionally curved shell, with an outer side that forms the application surface. The application surface is preferably convex and the shell preferably also has an inner surface that is concave.

The carrier shell possibly is a spheric cap shell.

In a preferred embodiment the shell has an opening in it. The opening allows that - during mounting - the end of the endoscope, which is for example to be coupled to the endoscopic camera, can be passed through the shell from the convex side in order to mount the shell on the endoscope.

The location of the hole in the shell is preferably such that the tracking equipment, in particular camera's of such equipment, have an optimal view on the carrier shell, while at the same time the carrier shell is not in the way during handling of the endoscope by a surgeon. The carrier shell is possibly made of a plastics material. The carrier shell is preferably manufactured by injection moulding. However, also other manufacturing methods are conceivable, such as thermoplastic moulding or vacuum forming. Also 3D printing of the carrier is possible.

It is also conceivable to manufacture the carrier form a metal, possibly by a forming process, e.g. metal injection moulding.

Important is that the same pattern of markers on the carriers is reproduced readily and univocally. This is advantageously done by providing the markers either directly during forming of the carrier, or by providing a preparatory feature during forming of the carrier on the locations where the markers should be provided in a subsequent step. As an example of a preparatory feature on the carrier one could think of a slightly recessed area in the convex surface in which a dot-like reflective sticker with a similar outer contour as said recess is applied to afterwards. Another example of a preparatory feature could be a hole in the carrier through which an attachment means of the marker could be inserted to attach the marker to the carrier. Such holes or recessed areas can be formed in plastic material e.g. during injection- or vacuum moulding or thermoforming the carrier.

In light of the above it is also conceivable to provide a template which is

advantageously used to aid in arranging the markers on the carrier. The template could be a removable template which is associated to the carrier surface during manufacturing of the carrier as a preparatory measure. After the markers have been provided to the surface of the carrier, e.g. by painting, the template can be removed an be disposed of. It is also possible to have a template that is reused for a whole batch of carriers or more batches of carriers. Preferably the marker device is a disposable product intended for single use. This is advantageous because the marker device can be produced sterile in a cost effective way and can be thrown away after use. Preferably, a relatively cheap plastic material suitable for a single sterile use is selected, which can be processed in a mass-production method, such as injection moulding.

In a possible embodiment the carrier comprises a coupling means to couple the carrier to the endoscopic device in such a way that the trackers provided on the carrier are positioned with regard to the endoscopic device in a univocal way. Possibly the coupling means is made of a plastics material, preferably by injection moulding. It is also possible that the coupling means is made partly from a plastics material and partly from another material, e.g. metal.

It is preferable that the carrier including the coupling means - or at least the plastic portion thereof - is formed in one piece, preferably by means of injection moulding. However, the coupling means may also be made as a separate part, e.g. from metal and/or plastics material, which is assembled with the rest of the carrier. Also it is possible to have a part of the coupling means being manufactured integrally with the shell, and another part being made separately, e.g. from a different material.

The invention furthermore relates to a combination of an endoscopic device and a marker device as described in the above, wherein the endoscopic device comprises an elongated rigid tube with a proximal end and a distal end, wherein the endoscopic device has at the proximal end a first coupling means and the carrier of the marker device has a second coupling means mating with the first coupling means of the endoscopic device, which assures a univocal mutual positioning and fastening of the marker device and the endoscopic device, wherein the convex outer surface of the shell faces in the distal direction.

The invention also relates to a system comprising tracking and navigation equipment and a marker device as described in the above, wherein the tracking and navigation equipment comprises at least one tracking camera to capture at least a part of the markers of the marker device and a computer to process the captured tracker data into optical guidance information for a surgeon.

The invention also relates to a method for manufacturing a marker device described in the above, in which the carrier is made of plastic by a forming process, e.g. injection moulding, thermoforming or vacuum-forming. The invention will be further elucidated in the following description with reference to the drawing, in which:

Fig. 1 shows a view in perspective of an assembly of an endoscopic camera and an endoscope with a possible embodiment of a marker device according to the invention, Fig. 2 shows another view in perspective of the assembly with the marker device of

Fig. 1 ,

Fig. 3 shows an exploded view of the assembly of Fig. 1 ,

Fig. 4 shows another exploded view of the assembly of Fig. 1

Fig. 5 shows a view in perspective of an endoscopic assembly, with another possible embodiment of a marker device according to the invention,

Fig. 6 shows a side view of the endoscopic assembly with the marker device of Fig.

5, and

Fig. 7 shows schematically a system comprising tracking equipment and a marker device according to the invention.

In Figs 1 and 2 is shown an assembly of an endoscopic camera 4 and an endoscope 1 which comprises an elongate rigid tube 1 1 with a proximal end 1 1 ' and a distal end 1 1 ". The rigid tube 1 1 houses an illumination and optical viewing system (not shown). The rigid tube 1 1 is at its proximal end 1 1 ' connected to a hub 12. The endoscope 1 has a longitudinal axis which is defined by the longitudinal axis of the tube 1 1 indicated by reference numeral 3.

The endoscope 1 is equipped with a marker device 2. The marker device 2 comprises a carrier which is formed as a shell 21 which has a convex outer surface 22 and a concave inner surface 24. The outer surface 22 is in this specific embodiment a substantially spherical outer surface 22.

On the outer surface 22 of the shell 21 a plurality of markers 23 are arranged. The markers 23 in this example are formed as light reflective dots on the outer surface 22. The markers 23 form an array of markers which may be detected by a (medical) tracking and navigation system used during surgery to provide a surgeon with optical information on the location of the endoscope 1 in the body of the patient.

Although the carrier 21 may be made of any material suitable for a surgical environment, it is preferably made of plastics material by means of injection moulding, or alternatively by another forming process to shape a plastic product such as thermoforming or vacuum forming.

The markers 23 may be stickers that are applied to the convex surface 22 of the carrier.

However, it is also possible to apply the markers 23 on the surface 22 by applying a reflective paint.

Another possibility is to provide the markers 23 during an injection moulding process of the carrier, by an in-mould labelling technique. In the latter case the markers 22 are integrated in the convex surface 22 of the carrier. Alternatively, it is also possible that the marker locations are provided on the application surface of the carrier 21 during forming of the carrier 21 , and that the markers are applied to the application surface subsequently. One could think of markings on the application that indicate where the markers should be applied. In this case the markers could be stickers or paint or have a 3D shape.

Although not shown, the markers could also have a 3D shape such as a spherical or semi-spherical shape. The carrier could for example be provided with attachment holes which indicate where the markers can be attached to the shell 21. The markers could be provided with a coupling means, e.g. a locking pin or a click means which is inserted through the attachment holes to attach the markers to the carrier.

The marker device 2 furthermore comprises a coupling means 25 for coupling the marker device 2 with the endoscopic device, in this case the endoscope 1. The coupling means 25 in this case comprises a bushing 25'. The bushing 25' is placed over a coupling pin 13 fixed to the hub 12 of the endoscope 1. The coupling means furthermore comprises a lateral engagement portion 25". On the opposite side of the hub 12 is arranged a clamping ring segment 30, which may be made of metal and which is fixedly attached to the plastic portion of the coupling means 25, e.g. by means of a screw. The ring segment 30 engages a portion of the circumference of the hub 12 and retains the marker device 2 coupled on the endoscope 1. The lateral engagement portions 25" engage the opposite lateral sides of the hub 12. Thereby the coupling means 25 is univocally coupled to the endoscope 1.

It is noted here that the coupling pin 13 in case of an endoscope 1 could be a light guiding pin which is used to guide light into the endoscope 1 , which is used to illuminate the inside of the patient's body where the endoscope 1 is used. However, the pin could also be a dedicated coupling pin on the endoscope or on another endoscopic instrument.

The coupling device 25 is rigidly attached to the shell 21. Preferably the coupling device 25 and the shell 21 are formed monolithically, preferably by injection moulding. In this way a univocal mutual positioning of the coupling device 25 and the shell 21 can be guaranteed. If also the markers 23 are integrated in the convex surface 22 of the shell, a univocal positioning of the array of markers with regard to the camera 1 can be guaranteed.

The shell 21 has an opening 27 in it. The opening 27 is located just under the coupling means 25. The opening 27 allows the end 14 of the endoscope 1 which is to be coupled to the endoscopic camera 4 to be passed through the shell 21 from the convex side after which the shell 21 can be moved downwards such that the bushing 25' slides over the coupling pin 13 and the lateral engagement portions 25" slide along the lateral sides of the hub 12.

The carrier 2, including the shell 21 and the coupling device 25, is preferably a disposable product, which is only for one-time use. The moulded carrier 2 can be produced with relatively low costs in a sterile way. The guaranteed univocal positioning of the carrier 2 with respect to the endoscope 1 , which is a result of the production method, has as an advantage that no calibration is necessary before it can be used with the camera 4 and the endoscope 1 and the tracking and navigation system in surgery.

As is shown in Fig. 7 the tracking and navigation equipment 50 comprises in this example two tracking cameras 51 to capture at least a part of the markers 23 of the marker device 2 and a computer 52 to process the captured tracker data into optical guidance information for a surgeon. The array of tracking markers 23 comprises a plurality of tracking markers 23, including more than four markers 23, which are arranged in such a configuration on the carrier 2 that every subset of four tracking markers 23 forms a unique configuration and such that in every angular position with respect to the longitudinal axis 3 of the endoscopic device 1 a reflection of at least four tracking markers 23 can be captured by the cameras 51 of the tracking and navigation system 50.

In Figs 5 and 6 is shown an endoscopic assembly including an endoscopic camera 4 and an endoscope 1 with alternative embodiment of the marker device. In this embodiment which is indicated by reference numeral 102, the carrier is formed as a cross with four arms 121'. The arms 121 ' have a radially inner portion 127 and a radially outer portion 128 which each extend in a surface substantially perpendicular to the longitudinal axis 3 of the endoscope 1. Furthermore there is an intermediate portion 129 which connects the outer and the inner portion 127 and 128 of the arm 121 '. The radially inner portion 127 is situated in front of the radially outer portion 128 of each arm 121 ', which means that the inner portion 127 is located closer to the distal end 1 1 " of the endoscope 1 than the outer portion 128. The intermediate portion 129 extends obliquely the two portions 127 and 128. In this configuration, the arms 121 ' all together form an outer surface which is essentially a three- dimensionally curved convex application surface in the sense of the present invention. On this convex outer surface the markers 123 are arranged.

The marker device 102 may also be made in one piece by injection moulding like the one shown in Figs 1 and 2. However, it is also possible that it is an assembled part from separately manufactured components. In the example of Figs 3 and 4 the marker device 102 has integral coupling means 125 that form one piece with the arms 121 ' of the carrier. This coupling means 125 is similar to the one described with reference to Figs 1 -4lt has one lateral engagement portion 125" similar to the lateral engagement portion 25" in Figs 1 and 2. On the opposite side of the hub 12 is arranged a clamping ring segment 130, which may be made of metal and which is fixedly attached to the plastic portion of the coupling means 125, e.g. by means of a screw. The ring segment 130 engages a portion of the

circumference of the hub 12 and retains the marker device 102 coupled on the endoscope 1. It must be understood that the two different embodiments shown in the Figs 1 , 2 and 5, 6 respectively are examples. Other suitable forms of the carrier are possible. It is for example possible to have a shell like the one shown in Fig. 1 , 2 which is not spherical, but has another three dimensionally curved surface, for example elliptical. Also segmented surfaces like the embodiment in Fig. 5, 6 has, are possible in other shapes than are shown in the figures.

In the examples of Figs 1-6 an endoscope for an endoscopic camera is equipped with the marker device. It must be understood however, that the marker device is also suitable for use with other endoscopic devices such as instruments for minimally invasive surgery.

Claims

1. Marker device comprising a carrier with an array of tracking markers, which marker device is adapted to be mounted on an endoscopic device, such as an endoscope for an endoscopic camera or an endoscopic instrument, the endoscopic device having a longitudinal axis, wherein the tracking markers are trackable by tracking equipment so as to allow generation of optical guidance information for the endoscopic device by said equipment, characterised in that the array of tracking markers comprises a set of more than four tracking markers which are arranged in such a configuration on the carrier that every subset of four tracking markers forms a unique configuration and such that in every angular position with respect to the longitudinal axis of the endoscopic device a reflection of at least four tracking markers can be captured by the tracking and navigation system.

2. Marker device according to claim 1 , wherein the carrier has an application surface on which the array of tracking markers is applied, which application surface is situated in a convex three-dimensionally curved virtual surface.

3. Marker device according to claim 2, wherein the array of tracking markers is formed by a pattern of reflective dots provided on the convex application surface of the carrier.

4. Marker device according to claim 3, wherein the reflective dots are formed by reflective stickers adhered to the application surface.

5. Marker device according to claim 3, wherein the reflective dots are integrated within the application surface.

6. Marker device according to claim 3, wherein the reflective markers have a spherical, semi-spherical or another suitable 3D shape.

7. Marker device according to any one of the claims 2 - 6, wherein the carrier is formed as a three-dimensionally curved shell, which has a convex outer surface defining the application surface and a concave inner surface.

8. Marker device according to claim 7, wherein the carrier shell is a spheric cap shell.

9. Marker device according to claim 7 or 8, wherein the carrier shell is made of a plastics material.

10. Marker device according to any one of the preceding claims, wherein the marker device is a disposable.

1 1. Marker device according to any one of the preceding claims, wherein the carrier comprises a coupling means to couple the carrier to the endoscopic device in such a way that the trackers provided on the carrier are positioned with regard to the endoscopic device in a univocal way.

12. Marker device according to claim 1 1 , wherein the coupling means is entirely or partly made of a plastics material.

13. Marker device according to claim 1 1 or 12, wherein the carrier including the plastic part of the coupling means is formed in one piece, preferably by means of injection moulding.

14. Marker device according to claim 1 1 , wherein the coupling means is made as a separate part, e.g. from metal and/or plastics material, which is assembled with the rest of the carrier.

15. A combination of an endoscopic device and a marker device according to any one of the claims 7-9, wherein the endoscopic device comprises an elongated rigid tube with a proximal end and a distal end, wherein the endoscopic device has, at the proximal end a first coupling means and the carrier of the marker device has a second coupling means mating with the first coupling means of the endoscopic device, which assures a univocal mutual positioning and fastening of the marker device and the endoscopic device, wherein the convex outer surface of the shell faces in the distal direction.

16. A system comprising tracking equipment and a marker device according to any one of the claims 1-14, wherein the tracking equipment comprises at least one tracking camera to capture at least a part of the markers of the marker device and a computer to process the captured tracker data into optical guidance information for a surgeon.

17. A method for manufacturing a marker device according to any one of the claims 1- 14, wherein the carrier is made of plastic by a forming process, e.g. injection moulding, thermoforming or vacuum-forming.

18. A method for manufacturing a marker device according to any one of the claims 1 - 14, wherein the carrier is made of plastic by a 3D printing process.

19. A method for manufacturing a marker device according to any one of the claims 1 - 14, wherein the carrier is made of metal by a forming process, e.g. metal injection moulding.