MICRO-ENDOSCOPE AND METHOD OF MAKING SAME
A micro-endoscope and method of making the same includes a mounting housing, a camera module received within the mounting housing, and an encapsulation material interposed between the camera module and the mounting housing for fixedly mounting the camera module within the mounting housing and/or inhibiting the passage of light between the camera module and the mounting housing. The micro-endoscope further includes a light guide having the mounting housing received therein.
The present application claims priority to U.S. Prov. App. Ser. No. 62/039,518, filed Aug. 20, 2014, the entity of which is expressly incorporated herein by reference.
BACKGROUNDThe present disclosure generally relates to medical devices, and more particularly relates to a micro-endoscope and a method of making the same. Micro-endoscopes are a type of endoscope having a very small cross-sectional dimension. This can present unique manufacturing challenges for the micro-endoscope. By way of example, a micro-endoscope can have an outside diameter that is less than about 4.0 mm. This small size inhibits easy manufacture of the micro-endoscope and makes it difficult to position an image capturing device, such as a camera, near the distal end of the micro-endoscope.
In one known micro-endoscope, a camera module is painted with a black paint and installed within an optical light guide near the distal end of the micro-endoscope. In particular, lateral sides of the camera module are painted with a thin coat of black paint and the camera module is fit via an interference fit within the light guide. Then, both the camera module and the light guide are received with in a steel outer sheath.
There are a number of potential drawbacks with this arrangement. For example, the dimensions of the camera module alone and/or the camera module with the black paint thereon can be too inconsistent resulting in problems when inserting the camera in the light guide tube. Also, the attachment of a ribbon cable to the back of the camera module can be susceptible to failure due to the connection being maintained by only relatively weak solder connections. Additionally, the micro-endoscope can suffer from decreased optical output due to stray light passing by the camera module. Further, the black paint can sometimes interfere with the optics of the camera module and it is possible for parasitic paint particles to develop due to local detachment of the black paint.
SUMMARYAccording to one aspect, a micro-endoscope device for insertion into a body includes a camera module received within a mounting tube and an encapsulation material interposed between the camera module and the mounting tube. The micro-endoscope device further includes a light guide tube annularly disposed around the mounting tube for transmitting light axially past the camera module and the mounting tube.
According to another aspect, a micro-endoscope with an encapsulated camera includes a mounting housing, a camera module received within the mounting housing, and an encapsulation material interposed between the camera module and the mounting housing for fixedly mounting the camera module within the mounting housing and/or inhibiting the passage of light between the camera module and the mounting housing. The micro-endoscope further includes a light guide having the mounting housing received therein.
According to a further aspect, a method of making a micro-endoscope includes inserting a camera module into a mounting housing and at least partially encapsulating the camera module with an encapsulation material interposed between the camera module and the mounting housing for fixedly mounting the camera module within the mounting housing and/or inhibiting the passage of light between the camera module and the mounting housing. The method further includes inserting the mounting housing into a light guide tube.
Referring now to the drawings wherein the showings are for purposes of illustrating one or more exemplary embodiments and not for purposes of limiting the same,
With additional reference to
The micro-endoscope 10 further includes an encapsulation material 20 and a light guide 22. The encapsulation material 20 is interposed between the camera module 14 and the mounting tube 12 for fixedly mounting the camera module 14 within the mounting tube 12 and/or inhibiting the passage of light between the camera module 14 and the mounting housing 12. The light guide 22 has the mounting housing 12 received or accommodated therein with the camera module 14 received within the mounting tube 12. In the illustrated embodiment, the light guide 22 is in the form of, and alternately referred to herein as, a light guide tube. The light guide tube 22 is annularly disposed around the mounting tube 12 for transmitting light axially past the camera module 14 and the mounting tube 12. In particular, glue or some other adhesive (not shown) can fixedly secure the mounting tube 12 and the light guide 22 together. In one embodiment, the light guide 22 can be formed of a light transmissive plastic.
Advantageously, the encapsulation material 20 and the inclusion of the mounting tube 12 overcome many of the drawbacks of known micro-endoscopes. In particular, providing the camera module 14 in an encapsulated state within the mounting tube 12 allows for good installation of the mounting tube 12 into the light guide 22. More specifically, the outer dimensions of the mounting tube 12 can be more precisely controlled than those of the camera module and/or the camera module with black paint added thereon. This enables a repeatable interference fit between the mounting tube 12 and the guide tube 22 that often failed in the known arrangement. Additionally, the use of the encapsulation material 20 instead of paint enables filling of any gaps between the camera module 14 and the surrounding mounting tube 12 and light guide 22. In contrast with the known arrangement that used paint, the use of the encapsulation material 20 better inhibits or reduces stray light from passing between the light and the camera (i.e., instead, light can only pass physically through the light guide). Further, adherence of the encapsulation material 20 is much greater than paint so the problem with parasitic paint particles is greatly reduced or eliminated.
The camera module 14 of the illustrated embodiment includes the forward facing imaging surface 14a and lateral walls 14c orthogonally extending rearwardly from the forward facing imaging surface 14a. The encapsulation material 20 is interposed between the lateral walls 14c and an inner radial surface 12a of the mounting tube 12. More particularly, the camera module 14 of the illustrated embodiment is generally cuboid shaped, though this is not required, and includes the rearward facing surface 14b opposite and spaced apart from the forward facing imaging surface 14a with the lateral walls 14c extending therebetween. The camera module 14 is arranged so as to form, at least in part, the distal end 10a of the micro-endoscope 10.
As shown, the encapsulation material 20 fully surrounds the camera module 14 and fills any gap between the camera module 14 and an interior (i.e., the inner radial surface 12a) of the mounting tube 12. The rearward facing surface 14b is axially spaced apart from a rear axial end 12b of the mounting tube 12 to define a first rearward area RA1 axially rearwardly of the rearward facing surface 14b. The encapsulation material 20 also fills the area RA2 so the encapsulation material 20 is disposed axially between the rearward facing surface 14b of the camera module 14 and the rear axial end 12b of the mounting tube 12 to fully encapsulate the rearward facing surface 14b of the camera module 14. Additionally, the encapsulation material 20 in this area secures the connection of the ribbon cable 18 to the camera module 14.
More specifically, the ribbon cable 18 is electrically connected to the camera module 14 (e.g., via soldered connections, not shown). In an known micro-endoscope, the soldered connections between a ribbon cable and the associated camera module are susceptible to failure. In the exemplary embodiment described and illustrated herein, encapsulation via the encapsulation material 20 enhances the connection of the ribbon cable 18 to the camera module 14 to inhibit inadvertent breakage or failure of the soldered connection between the ribbon cable 18 and the camera module 14. In an exemplary embodiment, the encapsulation material both fixedly mounts the camera module 14 within the mounting tube 12 and inhibits light transmission between the camera module 14 and the mounting tube 12. This arrangement also provides extra rigidity to the ribbon cable 18 by causing any force transmitted at that location to be imparted into the encapsulation material 20 instead of being handled by soldered connections between the ribbon cable 18 and the camera module 14. This provides increased mechanical robustness for the micro-endoscope 10 because strain relief for the ribbon cable 18 is provided.
In one exemplary embodiment, the encapsulation material 20 can be an adhesive that is optically black. Additionally, the encapsulation material 20 can be bio-compatible. For example, the encapsulation material 20 can be formulated to meet USP Class VI and ISO 10993 standards for use in the body. Additionally, or in the alternative, the encapsulation material 20 can be formulated such that it is stable against a wide variety of chemicals normally found in medical settings. In one specific exemplary embodiment, the encapsulation material 20 can be formed as a mixture of a two component epoxy adhesive and a colorant. One such exemplary two component epoxy has a specific gravity of about 1.16, a viscosity of about 30 Pas at 25 degrees Celsius, a cure time of about 5 hours to reach more than 10 Mpa of lap shear strength and about 23 hours to reach more than 1 MPa of lap shear strength. The epoxy can be transparent/color free and solvent free. A specific exemplary two component epoxy is sold under the trade name ARALDITE® CRYSTAL by Huntsman Advanced Materials (of Switzerland). The colorant can be a concentrated black colorant or pigment. A specific exemplary colorant is sold under the trade name EPO-TEK #11 by Epoxy Technology, Inc. (of Billerica, Mass.). An exemplary mixture ratio is 5-7% by weight of the colorant is added to the two-part epoxy. Alternately, another exemplary encapsulation material is an optically black adhesive (no colorant needed). a specific exemplary such adhesive is sold under the trade name EPO-TEK 320-3M by Epoxy Technology, Inc. (of Billerica, Mass.).
In the same or another exemplary embodiment, the mounting tube 12 can be selected from a thin material (e.g., a metallic material) that is not light transmissive and/or has a high reflectivity across the visible spectrum. For example, the mounting tube 12 can be formed from a material that has a light reflectivity greater than about 80%. Additionally, or in the alternative, the mounting tube can be selected from a material that has high ductility. By way of a specific example, the mounting tube 12 can be formed of a very thin (e.g., about 59 μm) aluminum or an aluminum alloy for preventing light transmission therethrough and providing high reflectivity across the visible spectrum (e.g., greater than 80%) to increase light transmission through the light guide tube 22.
As best shown in
As also shown and mentioned above, the forward facing imaging surface 14a of the camera module 14 and a forward axial end 12c of the mounting tube form the distal end 10a of the micro-endoscope 10. Additionally, the light guide tube 22 has a forward axial end 22b axially aligned with the forward facing imaging surface 14a of the camera module 14 and the forward axial end 12c of the mounting tube 12. Thus, the light guide tube 22, and particularly the forward axial end 22b thereof, also forms the distal end 10a of the micro-endoscope. As shown in the illustrated embodiment, the forward axial end 22b of the light guide 22 can include a chamfered edge 30 (see
The micro-endoscope 10 can additionally include a tubular scope shaft 32 annularly disposed around the light guide 22. In particular, a forward axial end 32a of the tubular scope shaft 32 can be axially spaced apart rearwardly from the forward facing imaging surface 14a of the camera module 14 and from the forward axial end 12c of the mounting tube 12. By way of example, the tubular scope shaft 32 can be formed of a metal, such as stainless steel. Still further, the micro-endoscope 10 can include an optical fiber 34 abutting the rearward axial end 22a of the light guide tube 22 and housed within the tubular scope shaft 32. The adhesive 38 can optionally fixedly secure the optical fiber 34 to the light guide 22.
With additional reference to
With reference to
With reference to
With additional reference to
Instead of the cone 42, a high thermal conductivity material (e.g., a thermal gel) could be used in the light guide 22′ or, instead of the disc or puck shaped member 44, a high thermal conductivity material could be used in the light guide 22 in
With reference now to
In one embodiment, the encapsulation material 20 is inserted inside the mounting housing 12, such as via an applicator with a fine tip. Optionally, heat can be applied, such as by a heat gun, to decrease the viscosity of the encapsulation material 20 and ensure that the encapsulation material 20 fills in all gaps around the camera module 14. With the camera module 14 fully installed or inserted into the mounting housing 12, further encapsulation material 20 can be injected into or added to the mounting housing 12 so that the rear facing surface 14b of the camera module 14 is fully encapsulated and the ribbon cable 18 is fully encapsulated particularly where the ribbon cable 18 connects to the camera module 14. As already mentioned herein, the encapsulation material 20 can be selected so that the material functions to both fix the camera module 14 within the mounting housing 12 and blocks the transmission of light thereby so that no light can pass between the camera module 14 and the inner radial surface 12a of the mounting housing 12.
Next, at S104, the mounting housing 12, with the camera module 14 already inserted therein, can be itself inserted into the light guide 22 (or into the light guide 22′). This can include the application of a glue or other adhesive to fix the mounting housing to the light guide 22 or 22′. The method could end after S104 such as in the case where the sub-assembly including the mounting housing 12, the camera module 14 and the light guide 22 is to be shipped remotely before being fully assembled into the micro-endoscope 10.
In the alternative, with additional reference to
Before or after steps S106, S108 and S110, the light guide 22 (or light guide 22′), and particularly the forward axial end 22b thereof, can be chamfered, as is known and understood by those skilled in the art, so as to provide chamfered edge 30 (
Optionally, a light reflecting and/or heat absorbing member, such as cone 42 or member 44 can be installed in the appropriate light guide 22′ or 22 prior to the adhesive 38 being added. Alternatively, a high thermal conductivity material could be used instead of the cone or member 44.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives or varieties thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
Claims
1. An endoscope, comprising:
- a camera module, with a camera that receives an image;
- a scope shaft, having a front portion, where the camera is mounted to receive the image from the front portion of the scope shaft;
- a light guide, having a light receiving end receiving light, and the light guide guiding the light along the light guide, the light guide emitting the light at a light transmitting end at the front portion of the scope shaft, the light emitted at the light transmitting end illuminating an area of the image at the front portion,
- the light guide having a first part adjacent the light receiving end, that has a hollow and tapered interior section, where the hollow part of the tapered interior section narrows in size in a direction away from the camera to define a conical chamber inside the light guide,
- and the light guide terminating at the front portion emitting the light.
2. The endoscope as in claim 1, wherein the light guide at the front portion forms a hollow cylindrical area which emits the light in a cylindrical shape, completely around the camera.
3. The endoscope as in claim 2, wherein the light guide at the light transmitting end surrounds the camera which is inside the hollow inside section of the light guide.
4. The endoscope as in claim 2, further comprising a cylindrical mounting tube, wherein the camera is within the cylindrical mounting tube, and the cylindrical mounting tube is located within the hollow inside section of the light guide.
5. The endoscope as in claim 4, wherein the light guide has a second part that has a constant inner diameter, and the camera is within the second part and is not within the first part.
6. The endoscope as in claim 1, wherein the light receiving end of the light guide is solid and does not have a hollow portion therein, and the hollow portion starts at a location spaced from the light receiving end.
7. The endoscope as in claim 1, wherein the light guide has a second part that has a constant inner diameter, that leads from the first part that has a tapered interior section to the light emitting end, and where the constant inner diameter part forms a constant diameter hollow cylindrical area.
8. The endoscope as in claim 7, wherein an outer diameter of the light guide has a tapered exterior diameter in an area of the first part.
9. The endoscope as in claim 8, wherein the outer diameter of the light guide has a constant exterior diameter in areas other than the first part.
10. An endoscope comprising:
- an endoscope tube;
- a camera, located in the endoscope tube and having an optical portion extending to image an imaging area at a first end of the endoscope tube;
- a light guide, having a first end which receives light, and having a second end which is exposed to illuminate the imaging area at the first end of the endoscope tube, lighting an area on the first end of the endoscope tube, where the second end of the light guide surrounds the camera and forms a hollow cylindrical area surrounding the camera;
- the first end of the light guide which receives the light being a filled, non-hollow, cylindrical area,
- the light guide having a conical section adjacent the first end, wherein the conical section of the light guide is hollow, and a diameter of the hollow section of the light guide increases towards the second end, to form the conical section, where the conical section leads to a constant diameter section, which forms the hollow cylindrical area that has a constant diameter,
- wherein the camera is located within the hollow cylindrical area which has the constant diameter.
11. The endoscope as in claim 10, further comprising a cylindrical mounting tube, and wherein the camera is mounted within the cylindrical mounting tube, and wherein the cylindrical mounting tube is located within the hollow interior section of the light guide.
12. The endoscope as in claim 10, wherein an outer diameter of the light guide tapers in exterior diameter in an area of the first part, getting larger in exterior diameter as the hollow conical section also increases in diameter.
13. The endoscope as in claim 11, further comprising encapsulation material inside the cylindrical mounting tube, preventing light from receiving reaching the camera.
14. A method of imaging using an endoscope, comprising:
- receiving an image into a camera portion of a scope shaft of an endoscope, the scope shaft, having a front portion, where the camera receives the image from the front portion of the scope shaft;
- guiding illuminating light for the camera on a light guide, having a light receiving end receiving light, and the light guide guiding the light along the light guide, the light guide emitting the light at a light transmitting end at the front portion of the scope shaft, the light emitted at the light transmitting end illuminating an area of the image at the front portion,
- guiding the light through the light guide through a first part adjacent the light receiving end, that has a hollow and tapered interior section, where the hollow part of the tapered interior section narrows in size in a direction away from the camera to define a conical chamber inside the light guide,
- the light exiting the light guide at the front portion emitting the light.
15. The method as in claim 14, wherein the emitting from the light guide at the front portion is in a hollow cylindrical area which emits the light in a cylindrical shape, completely around the camera.
16. The method as in claim 15, wherein the light guide at the light transmitting end surrounds the camera which is inside the hollow inside section of the light guide.
17. The method as in claim 15, further comprising mounting parts in a cylindrical mounting tube, wherein the camera is within the cylindrical mounting tube, and the cylindrical mounting tube is located within the hollow inside section of the light guide.
18. The method as in claim 17, wherein the light guide has a second part that has a constant inner diameter, and the mounting the camera is within the second part and is not within the first part.
19. The method as in claim 14, wherein the light receiving end of the light guide is solid and does not have a hollow portion therein and the solid portion receives the light, and the hollow portion starts at a location spaced from the light receiving end and the light is transmitted through the hollow portion.
Type: Application
Filed: Feb 1, 2019
Publication Date: Jun 6, 2019
Inventors: Stefan Troller (Sissach), Urban Schnell (Munchenbuchsee), Matthias Pfister (Bern), Michel Saint-Ghislain (Dudingen)
Application Number: 16/265,764