METHOD AND APPARATUS FOR FIBERSCOPE EMPLOYING SINGLE FIBER BUNDLE FOR CO-PROPAGATION OF IMAGE AND ILLUMINATION
An exemplary embodiment providing one or more improvements includes an endoscope which utilizes a single coherent fiber bundle for simultaneously carrying imaging and illumination light.
The present application is a continuation of U.S. Patent Application Ser. No. 14/209,794, filed on Mar. 13, 2014 which itself claims priority from U.S. Provisional Application Ser. No. 61/786,510, filed on Mar. 15, 2013, each of which applications are hereby incorporated by reference in their entireties.
BACKGROUNDBecause of their utility and versatility, fiberscopes are employed in extremely diverse applications: from nuclear reactor inspection to medical diagnosis. The ability to image an object that would normally be impossible to access without extremely invasive methods is indispensable in many fields.
In general terms, a fiberscope employs a flexible bundle of glass fibers to transmit an image from the distal end of the fibers, which can be positioned adjacent to the object to be imaged, to the proximal end of the fibers which can be positioned in a more accessible location. The bundle of fibers used for imaging can be referred to as an imaging fiber bundle. Current technology makes it possible to construct a sub-mm diameter imaging fiber that incorporates thousands of individual fibers. For instance, an imaging fiber bundle having 10,000 individual fibers that each have a 5 um diameter can have an outer diameter of only 0.5 mm. During imaging, each fiber serves as a pixel for the image and transmits this pixel via internal reflection from the distal end of the fiber to the proximal end of the fiber. The individual fiber size determines the pixel size for the transmitted image, and the size and density of the fibers influence the bending flexibility of the imaging fiber bundle.
Since the distal ends of the fibers in the imaging fiber bundle cannot image the object, fiberscopes require a distal imaging lens to image the object onto the surfaces of the distal ends of the fibers. The surfaces of the distal ends of the fibers can also be referred to as the distal end face of the imaging fiber bundle. In addition, since the proximal end of the imaging fiber bundle is very small, a viewing device is used to magnify the image that has been transmitted along the image fiber to the proximal end of the imaging fiber bundle so that the image can be viewed. The viewing device can utilize a lens arrangement and/or electronic sensor to magnify the image for viewing.
Effective utilization of the fiberscope generally requires illumination because fiberscopes are commonly employed to interrogate cavities which have little or no light. In conventional fiberscopes, this illumination is commonly provided by a series of physically distinct fibers that are dispersed around the circumference of the image fiber and are connected to a light source. In contrast to the imaging fiber, these illumination fibers are generally fewer in number and much larger in diameter than the imaging fibers. These illumination fibers are physically distinct from one another and from the imaging fibers. Further, the illumination fibers are separated from the imaging fibers using an opaque material such as a plastic jacket and, typically, the illumination fibers can each include a cladding and/or jacket.
Some fiberscopes can also be used for performing tasks at the distal end of the scope. These fiberscopes can include an integral tool that is incorporated into the distal end of the scope for performing a specific task. Other types of such fiberscopes can include one or more working channels into which different types of tools can be inserted and guided to the distal end of the scope for performing a variety of different tasks. Fiberscopes having one or more working channels can provide more flexibility for performing tasks as compared to fiberscopes with integrated tools.
A common challenge in fiberscope construction and, in particular, medical endoscopes, is seen with respect to economical construction and utilization. For instance, a medical endoscope having features as described could cost thousands of dollars. Disposal of such a device after a single use is prohibitively expensive. Therefore, the used endoscope is typically returned to the manufacturer for sterilization. Such a service, particularly for what is considered a bio-hazard, can be expensive. Accordingly, it is desirable to decrease the cost of a fiberscope while maintaining the quality and versatility of the device.
The foregoing examples of the related art and limitations related therewith are intended to be illustrative and not exclusive. Other limitations of the related art will become apparent to those of skill in the art upon reading of the specification and a study of the drawings.
SUMMARYThe following embodiments and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, not limiting in scope. In various embodiments, one or more of the above-described problems have been reduced or eliminated, while other embodiments are directed to other improvements.
In general, a method and associated apparatus are described for a fiberscope employing a single fiber bundle for co-propagating image and illumination light. In an embodiment, an endoscope is disclosed having an elongated coherent fiber bundle that includes a distal end and a proximal end. The coherent fiber bundle includes a plurality of different fibers that are surrounded by a common cladding and the coherent fiber bundle is configured to transfer light between the distal and proximal ends through the fibers. A working assembly includes an elongated probe having a distal end for insertion into a viewing area and a proximal end for manipulating the distal end of the probe. The distal end of the elongated coherent fiber bundle is positioned at the distal end of the probe. An imaging assembly includes a viewing device for receiving and modifying image light for viewing. The proximal end of the coherent fiber bundle can be positioned at the imaging assembly and the imaging assembly can be configured to transfer image light from the proximal end of the coherent fiber bundle to the viewing device. An illumination light source, forming part of the imaging assembly, can generate illumination light and insert the illumination light into the proximal end of the coherent fiber bundle which transfers the illumination light to the distal end of the coherent fiber bundle. The illumination light source is arranged such that the illumination light is inserted into the proximal end of the coherent fiber bundle at least essentially without the illumination light interacting with the image light between the proximal end of the coherent fiber bundle and the viewing device. A lens arrangement can form part of the working assembly and can be positioned at the distal end of the elongated probe, the lens arrangement includes an illumination portion arranged to receive illumination light from the distal end of the coherent fiber bundle and to disperse the illumination light into the viewing area. The lens arrangement also includes an imaging portion that is different than the illumination portion and that is arranged to receive image light from the viewing area including illumination light reflected from the viewing area and to insert the image light into the distal end of the coherent fiber bundle for transfer to the proximal end of the coherent fiber bundle where the image light is then transferred to the imaging assembly.
In another embodiment, an endoscope working assembly is disclosed which includes an elongated coherent fiber bundle having a distal end and a proximal end. The coherent fiber bundle includes a plurality of different fibers that are surrounded by a common cladding and the coherent fiber bundle is configured to transfer light between the distal and proximal ends using the fibers. An elongated probe has a distal end for insertion into a viewing area and a proximal end for manipulating the distal end of the probe. The distal end of the elongated coherent fiber bundle is positioned at the distal end of the probe. A lens arrangement can be positioned at the distal end of the elongated probe, the lens arrangement can include an illumination portion arranged to receive illumination light emitted from the distal end of the coherent fiber bundle and to disperse the illumination light into the viewing area. The lens arrangement can also include an imaging portion that is different than the illumination portion and that is arranged to receive image light from the viewing area that includes illumination light reflected from the viewing area and to insert the image light into the distal end of the coherent fiber bundle for transfer of the image light to the proximal end of the coherent fiber bundle. The coherent fiber bundle simultaneously emits the illumination light and receives the image light. A working assembly connector portion of an optical connector can be included for selectively optically coupling the working assembly to an imaging assembly having an imaging assembly connector portion of the optical connector. The working assembly connector portion can be connected to the proximal end of the coherent fiber bundle and is arranged to simultaneously transfer image light to the imaging assembly through coherent fiber bundle and receive illumination light from the imaging assembly through the coherent fiber bundle.
In another embodiment, an endoscope is disclosed which includes an elongated coherent fiber bundle having a distal end and a proximal end. The coherent fiber bundle includes a plurality of different fibers that are surrounded by a common cladding and the coherent fiber bundle is configured to transfer light between the distal and proximal ends using the fibers. A working assembly is included having an elongated probe with a distal end for insertion into a viewing area and a proximal end for manipulating the distal end of the probe. The distal end of the elongated coherent fiber bundle is positioned at the distal end of the probe. The working assembly can also include a lens arrangement positioned at the distal end of the probe and configured for transferring image light from the viewing area into the distal end of the coherent fiber bundle which carries the image light to the proximal end of the coherent fiber bundle and for transferring illumination light from distal end of the coherent fiber bundle into the viewing area. An imaging assembly can be included having a viewing device for receiving and modifying the image light for viewing. The proximal end of the coherent fiber bundle can be positioned at the imaging assembly and the imaging assembly can include an objective lens that is configured to transfer the image light from the proximal end of the coherent fiber bundle to the viewing device. An illumination light source arrangement can be included, which can form part of the imaging assembly, for inserting illumination light into the proximal end of the coherent fiber bundle which transfers the illumination light to the distal end of coherent fiber bundle. The coherent fiber bundle simultaneously carries the illumination light and the image light using the same fibers in the fiber bundle. The illumination light source arrangement produces polarized illumination light in a first orientation. A polarizing beam splitter, forming part of the imaging assembly, can be included and can be arranged to receive the first orientation polarized illumination light from the illumination light source arrangement. The polarizing beam splitter can reflect the first orientation polarized illumination light into the proximal end of the coherent fiber bundle for transfer by the coherent fiber bundle to the distal end of the coherent fiber bundle to illuminate the viewing area. The coherent fiber bundle and the viewing area randomize the polarization of the first orientation polarized light and the coherent fiber bundle also randomizes the polarization of the image light, which includes illumination light that is reflected by the viewing area. The polarizing beam splitter can also be configured to reflect polarized light having the first orientation received from the proximal end of the coherent fiber bundle, toward the illumination light source arrangement. The polarizing beam splitter can be arranged in a path of the image light between the proximal end of the coherent fiber bundle and the imaging assembly objective lens. The polarizing beam splitter can be configured to pass image light, that includes a second polarized orientation that is different than the first polarized orientation, to the imaging assembly objective lens for transfer to the viewing device.
In another embodiment, a method and associated apparatus are described for endoscopically imaging a viewing area in a cavity. A distal end of an endoscope probe can be inserted into the cavity. The endoscope probe can include a coherent fiber bundle having a plurality of different fibers that are surrounded by a common cladding and the coherent fiber bundle is configured to transfer light between a distal end and a proximal end through the fibers. The coherent fiber bundle can be arranged with the distal end of the coherent fiber bundle at the distal end of the probe. And the illumination light can be inserted into the proximal end of the coherent fiber bundle which transfers the illumination light from the proximal end of the coherent fiber bundle to the distal end of the coherent fiber bundle. The illumination light can be dispersed from the distal end of the coherent fiber bundle into the viewing area of the cavity. The image light can be received from the viewing area and inserting the image light into the distal end of the coherent fiber bundle which transfers the image light from the distal end of the coherent fiber bundle to the proximal end of the coherent fiber bundle. The image light can include illumination light reflected from the viewing area. The coherent fiber bundle simultaneously transfers the illumination light and the image light. The image light can be guided from the proximal end of the coherent fiber bundle to a viewing device and the image light and the viewing device can be used to display an image of the viewing area.
In addition to the exemplary aspects and embodiments described above, further aspects and embodiments will become apparent by reference to the drawings and by study of the following descriptions.
The following description is presented to enable one of ordinary skill in the art to make and use the invention and is provided in the context of a patent application and its requirements. Various modifications to the described embodiments will be readily apparent to those skilled in the art and the generic principles taught herein may be applied to other embodiments. Thus, the present invention is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features described herein including modifications and equivalents, as defined within the scope of the appended claims. It is noted that the drawings are not to scale and are diagrammatic in nature in a way that is thought to best illustrate features of interest. Descriptive terminology may be adopted for purposes of enhancing the reader's understanding, with respect to the various views provided in the Figures, and is in no way intended as being limiting.
Attention is now directed to the Figures wherein like reference numbers may refer to like components throughout the various views.
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In order to illuminate the viewing area using illumination light carried by circumferentially arranged fiber cores 75 (
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The parabolic mirror can be supported in the illumination cavity via threads 130 which can be used to move the parabolic mirror closer or further from the light source can modify the location to which light is reflected relative to the proximal end face of the glass cylinder. The imaging assembly segment of the coherent fiber bundle arrangement extends through a bore 132 in the parabolic mirror to an imaging cavity 134 where a proximal end face 136 of the imaging assembly segment is positioned. A multi-pitch GRIN rod lens can be used in place of imaging assembly segment 34 to transmit image light from optical interface 36 to imaging cavity 134. The imaging assembly segment can be centered in bore 132 using an O-ring 138. The glass cylinder can terminate short of the end of the imaging fiber which it encases and can be slightly longer than the protective stainless steel sheath. Imaging assembly segment 34 can be coated on the outside with paint or metallization to effectively prevent illumination light from entering the imaging fiber. An O-ring (not shown) can be positioned around the imaging assembly segment of the coherent fiber bundle where the segment passes through the parabolic mirror. This O-ring can center the fiber in the parabolic mirror without allowing the fiber to contact the surface of the mirror and can block illumination light from escaping from the illumination cavity into imaging cavity 134 where the illumination light could interfere with the imaging light.
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Imaging assembly 172 includes a light source 184 that is arranged in a ring, or annular shape to produce an illumination light 186 in an annular shape. The imaging assembly can also include an illumination lens 188 that images the illumination light from the light source, as examples, onto annular areas 190a (
By utilizing appropriate optics, imaging assembly 172 can adapt to connect and operate with disposable working assemblies having coherent fiber bundles with various diameters. For instance, if a disposable working assembly employing a coherent bundle with 50,000 individual fibers and a diameter of 1.1 mm is connected to the imaging assembly, the optics (such as the illumination and imaging lenses) and/or the light source and viewing device, can be adjusted such that the outer circumference of the illumination light (annular area 190) is at the maximum radius of the end face and the image that is transmitted by the endoscope is maximized, as shown in
It should be appreciated that combining the image and the illumination/radiation into the same fiber allows a single fiber optic connector to be employed for coupling disposable working assemblies to the imaging assembly since a single connector can transfer both illumination and imaging light between the working assembly and the imaging assembly. Standard off-the-shelf components can be employed to make this connection. For example, a standard fiber optic connector can have an internal ceramic or metal ferrule with an I.D. of anywhere from 230 um to 1580 um. Standard imaging fiber diameters (with coating stripped away) vary from 210 um to 1500 um and can be inserted into and for connection to a corresponding fiber optic connector. The connector can include one or more ferrules, which can be ceramic or metal components that form part of many fiber optic connectors. Standard fiber optic connectors are extremely economical in quantity.
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Endoscope 310 can be an exploratory tool which provides the ability to manipulate or sample material adjacent to the distal end of the probe. Working assembly 316 incorporates a working channel 342 through which tools, fluids, microwave probes, and the like can be passed from a proximal end 344 (
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The cores of the fiber bundle, during propagation, will homogenize and randomize the linear polarization of the light originally introduced to the fiber bundle. This effect also takes place with respect to light collected for the camera. The illumination of the random geometry of an imaged object 424 by the imaging fiber and a lens 426 at the distal end of the fiber bundle further randomizes the polarization of collected image light 428. In addition, the (S) component in collected image light is caused mainly by high intensity specular highlights from the object. Such components maintain the original (S) state of polarization and are responsible for an extended intensity range of the collected light. The coaxial illumination and imaging system of endoscope 400 rejects the (S) component in the image light, making the image less dynamically challenging for the camera's automatic exposure settings. This can result in better exposure and higher image quality. It should be appreciated that, in another embodiment, the S and P polarizations can be interchanged.
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The micro LED ring can be electrically interfaced to connector 606 by a cable 624 to receive power. The micro LED ring can contain micro LEDs that are arranged around a printed circuit board to produce an annularly-shaped illumination light. The micro LED ring can include integrated focusing optics which provide a high coupling efficiency of around 60% to 80% of the illumination light from the LEDs into an annular area at the proximal end of the coherent fiber bundle. Because of the high efficiency of the coupling, the micro LED ring can consume less power than light sources with lower coupling efficiencies. Lower power consumption can result in low operating temperatures and longer LED life. The light source is shown in a spaced apart relationship from the proximal end of the coherent fiber bundle for clarity, because the outer diameter of the micro LED ring is similar in size to the outer diameter of the coherent fiber bundle. In actual practice, the micro LED ring can be placed directly against the fiber bundle. The LEDs of the micro LED ring can produce narrowband illumination such as, for example, blue illumination. Therefore, the distal end of the coherent fiber bundle can include a light guide cylinder 620 (
The distal end of the coherent fiber bundle (
The image detector can be a CCD array and can include multiple individual pixel sensors for each of the fiber cores in the fiber bundle. Stated in another way, the CCD array can include a higher pixel resolution than a pixel resolution that would be represented by the area density of the fiber cores. Image detector 612 can be electrically connected to connector 606 using a cable 628 which can be used to provide power to the image detector and to carry data signals between the image detector and the connector. Separate electrical connectors can be provided for the micro LED light source and the electronic image detector or all connections can be integrated into one electrical connector as shown.
In one embodiment, imaging assembly 604 can be integrated with the working assembly. The imaging assembly can receive imaging data from the electronic image detector and can convert that data into an image that can be viewed. In another embodiment, power can be provided by a power source integrated into the working assembly. In another embodiment, the electronic image detector can be replaced by one or more lenses, such as would be found in an eyepiece. In yet another embodiment, endoscope arrangement 600 can be integrated into an imaging assembly and an optical arrangement can transfer the image and illumination light between the imaging assembly and the working assembly.
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Many advantages can be gained by the various embodiments described herein. The co-propagation of the illumination and the image in the same imaging fiber bundle decreases the number of endoscope components which reduces the cost of the endoscope. Moreover, the manner of construction allows the glass cylinder and GRIN lens assembly to be passively placed. Employing a single imaging fiber bundle arrangement enables t feasibility with respect to employing a common fiber optic SC/PC connector as an interface between the expensive optics/illumination imaging assembly and the disposable endoscope working assembly (tip). Decreasing the cost of the working assembly and producing the working assembly as a separate component from the imaging assembly allows the working assembly to be disposable to enhance economic feasibility. A properly constructed optics/illumination imaging assembly can have internal optics that allows the use of a variety of sizes of imaging fibers on the disposable endoscope working assembly. Incorporating the fiber ferrule into a common medical y-tube allows for the construction of an economical endoscope working assembly with a built-in working channel.
While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations thereof. It is therefore intended that the following appended claims and claims hereafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations as are within their true spirit and scope.
Claims
1. An endoscope working assembly, comprising:
- an elongated coherent fiber bundle including a distal end and a proximal end, wherein the coherent fiber bundle includes a plurality of different fibers that are surrounded by a common cladding and the coherent fiber bundle is configured to transfer light between the distal and proximal ends using the fibers;
- an elongated probe having a distal end for insertion into a viewing area and a proximal end for manipulating the distal end of the probe, and wherein the distal end of the elongated coherent fiber bundle is positioned at the distal end of the probe;
- a lens arrangement positioned at the distal end of the elongated probe, the lens arrangement including an illumination portion arranged to receive illumination light emitted from the distal end of the coherent fiber bundle and to disperse the illumination light into the viewing area, the lens arrangement also including an imaging portion that is different than the illumination portion and that is arranged to receive image light from the viewing area that includes illumination light reflected from the viewing area and to insert the image light into the distal end of the coherent fiber bundle for transfer of the image light to the proximal end of the coherent fiber bundle, wherein the coherent fiber bundle simultaneously emits the illumination light and receives the image light; and
- a working assembly connector portion of an optical connector for selectively optically coupling the working assembly to an imaging assembly having an imaging assembly connector portion of the optical connector, the working assembly connector portion connected to the proximal end of the coherent fiber bundle and arranged to simultaneously transfer image light to the imaging assembly through coherent fiber bundle and receive illumination light from the imaging assembly through the coherent fiber bundle.
2. The endoscope working assembly as defined in claim 1, wherein the illumination portion of the lens arrangement includes a light guide cylinder and the imaging portion of the lens arrangement includes a GRIN lens.
3. The endoscope working assembly as defined in claim 1, further comprising:
- a Y-tube handle that is configured to support the proximal end of the probe, and wherein the probe includes a working channel that extends through the probe from the distal end of the probe to the handle and which is configured to receive and guide endoscopic tools between the handle and the distal end of the probe.
4. An endoscope, comprising:
- an elongated coherent fiber bundle including a distal end and a proximal end, wherein the coherent fiber bundle includes a plurality of different fibers that are surrounded by a common cladding and the coherent fiber bundle is configured to transfer light between the distal and proximal ends using the fibers;
- a working assembly including an elongated probe having a distal end for insertion into a viewing area and a proximal end for manipulating the distal end of the probe, and wherein the distal end of the elongated coherent fiber bundle is positioned at the distal end of the probe, the working assembly including a lens arrangement positioned at the distal end of the probe and configured for transferring image light from the viewing area into the distal end of the coherent fiber bundle which carries the image light to the proximal end of the coherent fiber bundle and for transferring illumination light from distal end of the coherent fiber bundle into the viewing area;
- an imaging assembly including a viewing device for receiving and modifying the image light for viewing, and wherein the proximal end of the coherent fiber bundle is positioned at the imaging assembly and the imaging assembly includes an objective lens that is configured to transfer the image light from the proximal end of the coherent fiber bundle to the viewing device;
- an illumination light source arrangement, forming part of the imaging assembly, for inserting illumination light into the proximal end of the coherent fiber bundle which transfers the illumination light to the distal end of coherent fiber bundle, the coherent fiber bundle simultaneously carrying the illumination light and the image light using the same fibers in the fiber bundle, the illumination light source arrangement producing polarized illumination light in a first orientation; and
- a polarizing beam splitter, forming part of the imaging assembly, and arranged to receive the first orientation polarized illumination light from the illumination light source arrangement and for reflecting the first orientation polarized illumination light into the proximal end of the coherent fiber bundle for transfer by the coherent fiber bundle to the distal end of the coherent fiber bundle to illuminate the viewing area, wherein the coherent fiber bundle and the viewing area randomize the polarization of the first orientation polarized light and the coherent fiber bundle also randomizes the polarization of the image light, which includes illumination light that is reflected by the viewing area; the polarizing beam splitter is also configured to reflect polarized light having the first orientation received from the proximal end of the coherent fiber bundle, toward the illumination light source arrangement, the polarizing beam splitter arranged in a path of the image light between the proximal end of the coherent fiber bundle and the imaging assembly objective lens, and the polarizing beam splitter is configured to pass image light, that includes a second polarized orientation that is different than the first polarized orientation, to the imaging assembly objective lens for transfer to the viewing device.
5. A method for endoscopically imaging a viewing area in a cavity, comprising:
- inserting a distal end of an endoscope probe into the cavity, the endoscope probe including a coherent fiber bundle having a plurality of different fibers that are surrounded by a common cladding and the coherent fiber bundle is configured to transfer light between a distal end and a proximal end through the fibers, the coherent fiber bundle arranged with the distal end of the coherent fiber bundle at the distal end of the probe;
- inserting an illumination light into the proximal end of the coherent fiber bundle which transfers the illumination light from the proximal end of the coherent fiber bundle to the distal end of the coherent fiber bundle;
- dispersing the illumination light from the distal end of the coherent fiber bundle into the viewing area of the cavity;
- receiving image light from the viewing area and inserting the image light into the distal end of the coherent fiber bundle which transfers the image light from the distal end of the coherent fiber bundle to the proximal end of the coherent fiber bundle, the image light including illumination light reflected from the viewing area, wherein the coherent fiber bundle simultaneously transfers the illumination light and the image light; and
- guiding the image light from the proximal end of the coherent fiber bundle to a viewing device and using the image light and the viewing device to display an image of the viewing area.
6. The method as defined in claim 5, wherein the illumination light is inserted into a first portion of the coherent fiber bundle fibers and the image light is inserted into a second, different portion of the coherent fiber bundle fibers.
7. The method as defined in claim 5, further comprising:
- polarizing the illumination light with a certain polarized orientation before inserting the illumination light into the proximal end of the coherent fiber bundle; and
- blocking polarized light having only the certain polarized orientation from passing from the proximal end of the coherent fiber bundle to the viewing device.
Type: Application
Filed: Dec 20, 2017
Publication Date: May 10, 2018
Inventors: Joseph R. Demers (Pasadena, CA), Marek Sekowski (Pacific Palisades, CA)
Application Number: 15/848,449