WO2012059082A2

WO2012059082A2 - Highly flexible endoscope made of silicone, and method for producing same

Info

Publication number: WO2012059082A2
Application number: PCT/DE2011/001911
Authority: WO
Inventors: Jörg Müller; Kristina Kaiser; André BORN; Thorsten Zehlicke
Original assignee: Mueller Joerg; Kristina Kaiser; Born Andre; Thorsten Zehlicke
Priority date: 2010-11-01
Filing date: 2011-11-01
Publication date: 2012-05-10
Also published as: WO2012059082A3; WO2012059082A9; DE102010049890A1

Abstract

The invention relates to a flexible endoscope or an endoscope attachment and to a method for producing same. Until now only glass fiber endoscopes have existed for examining very small channels that are highly sensitive to mechanical or sensory stimuli in particular in medicine, such as the tuba auditiva for example. Said glass fiber endoscopes are flexible but still too rigid to be painlessly inserted into the middle ear for example. Thus, said glass fiber endoscopes carry the risk of hemorrhages and mucous membrane injuries which can lead inter alia to the formation of scars with subsequent chronic middle ear inflammation. A soft, highly flexible endoscope made of silicone would solve said problems and render operations such as those that are currently carried out for diagnostic purposes unnecessary in many cases. The flexibility of the endoscope is achieved by using silicone as the imaging material. The light guides are produced from highly flexible soft silicone that is highly transparent in the light spectrum required for use by applying, pressing, and curing silicones that are initially liquid in layers. Each layer, which has a thickness of only a few micrometers, consists of rib waveguides which have a width and height of a few micrometers and which are made of a highly refractive silicone layer (core) surrounded by a weakly refractive silicone layer (casing), and each strip waveguide of the highly refractive structured layer generates an image pixel. A soft silicone lens (2) which can be produced by curing a drop of silicone on an anti-adhesive coated substrate focuses the image signal onto the waveguide matrix (1). The waveguide matrix (1) and the lens (2) are encased with an optically highly transparent, weakly refractive casing (3). An optically insulating soft material (4), for example silicone, is subsequently applied by spraying, brushing, or the like and cured. Further functions can be realized in said optically insulating layer (4), for example a mechanical control that is realized by thin metal bands, by means of which the distal end of the endoscope can be bent, or channels for feeding and suctioning liquids. Finally, the endoscope is coated with an optically conductive casing which is used to supply light for lighting the object to be observed and which consists of an optically transparent silicone layer or a layer system of optically transparent, weakly and highly refractive silicone layers, wherein a highly refractive shaft 6 can be found between two weakly refractive shafts (5) and (7) so that the light is guided in the highly refractive region (6). The silicone endoscope is suitable for examining very small channels that are highly sensitive to mechanical or sensory stimuli in particular in medicine on the basis of the material properties of the silicone endoscope.

Description

Highly flexible endoscope made of silicone and its manufacturing method Description

The present invention relates to a highly flexible endoscope made of silicone, the

- As image transmission unit has a waveguide matrix 1 made of silicone, the

highly transparent silicones is constructed with different refractive indices, wherein the high refractive index layers 8 serve as a strip waveguide for signal transmission and the low-refractive layers 9, the isolation between the individual

Strip waveguide layers form and each layer is only a few microns high, and

- As light supply has a three-layer system of low-5, high-6 and low-breaking 7 highly transparent silicones, wherein the light is guided in the high-refractive, located in the middle layer, wherein

there is an optically insulating silicon layer 4 between the image transfer unit and the light supply channel, which separates the two optical signals and which can be used to integrate further functions, such as a system for controlling the distal end of the endoscope or channels for introducing and aspirating liquids, in which

- The image signal is focused by a lens 2 made of high refractive index silicon on the waveguide matrix, wherein the lens is inserted to protect against the ingress of light through the light supply in a layer of low-breaking silicone 3.

For studies of the smallest mechanically or sensory high-sensitive channels, especially in medicine, such. As the tuba auditiva, so far only glass fiber endoscopes exist, as they are known for example from US000003010357A and DE000001901 84U. These are flexible but still too rigid, e.g. to be introduced into the middle ear without pain. Thus, they contain the risk of bleeding and mucosal injury, which i.a. to

Scarring with subsequent chronic otitis media may result. Although some endoscope models have been developed specifically for such applications, they are in practice because of the described possible complications and the high pain load during the investigation, not for middle ear examination used, but have their way into the

Neurosurgery and found in the industrial and security sectors. There

For this reason, ultrasonographic images of the middle ear do not allow a clear diagnosis. Therefore, surgical procedures (tympanoscopy) are performed for a long time

Recovery phase of the patient and with which high immediate and consequential costs are associated. A soft, highly flexible silicone endoscope would solve these problems and in many cases eliminate the operations that are currently performed for diagnostic purposes.

With the invention, such an endoscope and a method for its production is provided.

The waveguide matrix 1 described in [0001] is obtained by sequential pressing and

Curing optically high-refractive 8 and low-refractive 9, a few microns higher

Silicone layers produced, wherein for the impression of each individual silicone layer

| Confirmation copy | non-stick-coated and a non-stick-coated silicone impression die, between which the thin silicone layer to be cured is distributed homogeneously by means of a dosing unit in the required amount and preferably compressed under low vacuum or pressure and with the parameters required for the respective silicone (temperature and curing time ) is applied. After the curing process, the non-stick silicone stamp is peeled off the freshly pressed layer which remains on the non-anti-aft coated silicone layer. For optimal signal transmission to take place, all highly refractive strip conductor layers 8 must be arranged parallel to one another, ie before the pressing operation of a high refractive index layer, the structured and nonstick silicone stamp must be aligned parallel to the already pressed layers on the non-nonstick silicone substrate. Figure 5 shows a possible setup for pressing and curing thin

Silicone layers. The waveguide matrix 1 can after completion to the desired

Dimensions are cut by means of a sharp blade. The outer diameter of a tube endoscope for adults should not exceed 0.8 mm, for children 0.5 mm. Thus, the dimensions of the waveguide matrix 1 are limited to approximately 0.5x0.5 mm ² for an adult endoscope, and for a child endoscope to approximately 0.35x0.35 mm ² . With a cross section of about 4 μητι ² per strip conductor 10 - sufficient size to perform a sufficiently high performance within the strip - and an insulating jacket 9 with 2 μητι distance to the next strip conductor layer 8 is a resolution of about 15,600 pixels in the adult endoscope and 7,600 pixels to realize the child endoscope, each of the strip conductor realizes an image pixel. The distal end of the matrix can be cut to a desired viewing angle after completion, usually 0 °, 30 ° and 45 °, see Figure 6.

The preparation of a molding system described in [0004] stem made of silicone

preferably by means of a pressing operation between two non-stick-coated silicon wafers which have been previously patterned with photolithography and wet-chemical and in particular also dry-chemical isotropic and anisotropic etching processes,

The non-stick layer of all surfaces referenced in the invention with "anti-adhesion" may be e.g. be a monomolecular layer of a short or long chain halogen silane or a mixture of short and long chain halogen silanes, which in practice, the deposition of a mixture of the long-chain 1 H, 1 H, 2H, 2H-Perfluorooctyltrichlorsilane and the short-chain Dichlorodimethylsilan from Has proven gas phase (, wherein first the long-chain and then the short-chain gas and then a small proportion of water vapor are passed into the recipient).

The silicone lens 2 for focusing the image signal on the waveguide matrix 1 by placement and curing of a silicone drop of defined volume on a

non-stick coated substrate, for example made of silicone or silicon implemented. The radius and curve shape of the lens can be adjusted by the quality of the release layer, which can be characterized by the contact angle between the drop material and the substrate surface.

The silicone lens 2 can be fixed on the waveguide matrix 1 by curing a thin intermediate layer of the same high refractive index silicone material.

So that no coupling of the light from the light feed ring 5-7 takes place through the silicone lens 2 in the waveguide matrix 1, protrude the insulating layer 4 and the light supply ring on the

Silicone lens out. For production, the endoscope is preferably completely or only the endoscope head dipped in low-refractive silicon and cured head-on before the application of the insulating layer, so that the silicone lens 2 is completely covered by the material 3 and the entire unit forms a cylindrical shape. The cylinder 1-3 is immersed in the next step in an optically insulating silicone 4 and hung to cure, so that in turn forms a cylindrical shape. In the same way, a low-breaking 5, a high-refractive 6 and a low-refractive 7 are successively successively

Silicon layer applied, which realize the light supply to the object to be observed.

In the optical isolation layer 4 further functions can be integrated, for example, thin, highly flexible metal bands can be introduced to control the distal end of the endoscope in the layer, as are common in other endoscope models, as well as channels for introducing and aspirating liquids ,

In the last step, the distal end of the endoscope is cut to the desired angle to the right, wherein the cutting edge preferably extends slightly above the lens tip.

At the proximal end of the silicone endoscope, the same signal evaluation unit can be used as in commercially available endoscopes.

LIST OF REFERENCE NUMBERS

1 waveguide matrix

2 lens

3 Optically low-profile cladding of the lens and the waveguide matrix

4 Optically insulating layer

5 Optically low-breaking silicone mantle!

6 Optically high refractive silicone sheath

7 Optically low-profile Stiikon jacket

8 Optically high refractive stripline layer

9 Optically low-resistance insulating layer

10 single rib waveguides

11 Structured silicone stamp

12 U nstructured S il i stem pel

13 Liquid silicone to be cured

14 silicon wafers to stabilize the flexible silicone stamp

15 Lower part of the pressing device

16 Upper part of the pressing device

17 Screw for adjusting the pressure

18 Vacuum connection for fixing the silicon wafer and the upper silicone stamp Vacuum connection for pumping out the chamber before the pressing process to exclude air pockets during pressing

Claims

claims

1. Flexible endoscope or endoscope attachment and method for its preparation for

Investigation of the smallest, in particular mechanically or sensory sensitive, channels whose image transmission through optical fibers is made of highly flexible, soft, highly transparent silicone required for the application of high-transparency silicone and which forms an image transfer unit, which is produced by layered application, pressing and curing of initially liquid silicones, wherein each layer of only a few microns thick of a few microns wide and high rib waveguides of a high refractive index silicon (core) surrounded by a low refractive silicon layer (cladding) and each of the waveguides of the high refractive, structured layer generates an image pixel.

2. Endoscope and its method of manufacture according to claim 1, characterized in that the ribs of the waveguide matrix may have different cross-sectional shapes, for. B. semicircular, trapezoidal, rectangular, triangular, square, round or oval.

3. endoscope and its method of preparation according to claims 1 and 2, characterized

characterized in that the application of a liquid silicone layer is preferably realized by means of spraying or spin-coating or depositing a drop of defined volume.

4. endoscope and its method of preparation according to claims 1 to 3, characterized

characterized in that the pressing of the liquid silicone takes place under preferably low pressure or vacuum between a non-stick coated and a non-stick silicone stamp, the non-stick coating preferably being realized by the gas deposition of a mixture of long and short chain halosilanes.

5. endoscope and its method of preparation according to claims 1 to 4, characterized

characterized in that the curing of the silicone layers takes place under preferably low pressure or vacuum at the temperature and curing time required for the respective silicone.

6. endoscope and its method of preparation according to claims 1 to 5, characterized

characterized in that after curing, the non-stick coated silicone stamp is preferably taken on one side and peeled off so that the cured thin silicone layer on the non-stick-coated stamp and possibly the molded in the previous steps waveguide matrix layers.

7. endoscope and its method of preparation according to claims 1 to 6, characterized

characterized in that a soft silicone lens, which by the curing of a

Silicone drop on a non-stick-coated substrate can be produced, the image signal focused on the waveguide matrix.

8. endoscope and its method of preparation according to claims 1 to 7, characterized

characterized in that the waveguide matrix and the lens with an optical

be surrounded by a highly transparent, low-breaking mantle, which covers the lens just completely flat.

9. endoscope and its method of preparation according to claims 1 to 8, characterized

characterized in that the signal receiving unit described in 1 to 8 is coated with an optically insulating, soft material, for example. Silicone, which by spraying, brushing o.Ä. can be applied and cured and this can accommodate more functions, such as a realized by thin metal bands mechanical control, with the aid of the distal end of the endoscope can be bent, or channels for supplying and aspirating liquids.

10. endoscope and its method of preparation according to claims 1 to 9, characterized

characterized in that it is coated with an optically conductive sheath which serves to light supply for illuminating the object to be observed, which consists of an optically transparent silicone layer or of a layer system of optically transparent low- and high-refractive silicon layers, with a high-refractive between two niederbrechenden Layers is located so that the light is guided in the high-refractive area.

11. endoscope and its method of preparation according to claims 1 to 10, characterized

characterized in that it can have any viewing angles between 0 "and about 45 °, wherein the viewing angle through a section of the waveguide matrix to the desired viewing angle by means of a sharp cutting tool and after performing the steps described in claims 7 to 10 also the entire distal end of Endoscope can be realized, the latter section preferably parallel to the section of the

Waveguide matrix and slightly above the lens tip runs.

12. Endoscope and its method of preparation according to claims 1 to 11, characterized

in that the mold for the production of the waveguides is produced by the patterning of silicon substrates by means of photolithography and wet-chemical and in particular also dry-chemical isotropic and anisotropic etching processes.