Patent Publication Number: US-2016227994-A1

Title: Intravaginal Imaging Device, System and Method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of European Patent Office Patent Application serial number 15154180.2, filed Feb. 6, 2015, entitled “Intravaginal Camera,” which is incorporated by reference herein in its entirety. 
     FIELD OF THE INVENTION 
     The present invention relates to medical imaging, and more particularly, is related to an intravaginal imaging device. 
     BACKGROUND OF THE INVENTION 
     Colposcopy is a medical diagnostic procedure to examine an illuminated, magnified view of the cervix and the tissues of the vagina and vulva. There are known methods and instrumentation used to observe changes of the cervix mucosa. Inspection of the cervix has generally been performed by insertion of medical devices inside in the vagina. The medical devices, such as a speculum  100 , as shown in  FIG. 1 , separate the soft tissue of the vaginal walls and provide a direct optical path to the cervix for an external optical device, such as a colposcope. The speculum  100  also provides a path for an external light source to illuminate the cervix. 
     However, use of a speculum  100  with an external light source has undesirable qualities, such as excessive expansion of the vagina wall throughout the entire length of the vagina, rather than just in the vicinity of the cervix. The result is unnecessary deformation of the vagina and cervix region, as well as unnecessary discomfort for the patient. In addition, the colposcope and additional standalone examination unit are expensive, and may not be practically used in combination with other diagnostic tools, such as ultrasound systems. 
     For some intravaginal cameras, focus adjustment is performed by manually adjusting the distance between the lens and sensor. But this method is not convenient for intravaginal applications. Some intravaginal cameras have a small numerical aperture (NA) that can provide a large depth of field (DOF) to replace focus adjustment. But small NA optical systems are generally unsuitable to provide high resolution and may increase the luminous flux. 
     A liquid lens camera, for example, an intraoral camera as disclosed in patent applications such as EP 2161607 A1, EP 1780757 A1, and PCT/CN2008/001900, generally includes a first liquid and a second liquid of equal density sandwiched between two transparent windows in a conical vessel. The first liquid is generally conductive, while the second liquid is generally insulating. A variable voltage can be selectively applied to electrodes in electrical communication with the conductive liquid. The interface between the first and second liquid changes its shape depending on the voltage applied across the conical structure. In this way, the liquid lens can attain the desired refraction power by means of changing the voltage applied on the electrodes. The variation of voltage leads to a change of curvature of the liquid-liquid interface, which in turn leads to a change of the focal length of the lens. However, several factors including the orientation of the camera in relation to the housing and potential buildup of mucus around the lenses make the intraoral camera unsuitable for intravaginal use. Therefore, there is a need in the industry to address some of the abovementioned shortcomings. 
     SUMMARY OF THE INVENTION 
     Embodiments of the present invention provide an intravaginal imaging device, system and method. Briefly described, an aspect of the present invention is directed to an intravaginal imaging device. The imaging device is housed within an elongated housing having a proximal end and a distal end. The distal end includes a sealing endcap window, an objective disposed behind the window having first lens group and a second lens group configured to focus on a target, an image detector disposed behind the objective configured to detect an image from the objective, and a LED light source disposed behind the window configured to illuminate the target. A connecting portion in communication with the image detector is disposed at the proximal end. The connecting portion is configured to convey an image from the image detector to an external device. The intravaginal imaging device is configured to be used in conjunction with a speculum where the intravaginal imaging device is inserted within jaws of the speculum and positioned within the spacers of the speculum. 
     Other systems, methods and features of the present invention will be or become apparent to one having ordinary skill in the art upon examining the following drawings and detailed description. It is intended that all such additional systems, methods, and features be included in this description, be within the scope of the present invention and protected by the accompanying claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The components in the drawings are not necessarily to scale, emphasis instead being placed upon clearly illustrating the principles of the present invention. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principals of the invention. 
         FIG. 1  is a schematic diagram of a prior art speculum. 
         FIG. 2  is a schematic cutaway diagram showing a first exemplary embodiment of an intravaginal imaging device. 
         FIG. 3  is a detail of the distal end of the intravaginal imaging device of  FIG. 2 . 
         FIG. 4  is a schematic diagram illustrating an example of a system for executing functionality of the present invention. 
         FIG. 5  is a schematic diagram of an exemplary embodiment of a gynecological imaging system. 
         FIG. 6  is a block diagram of an exemplary method for use of an intravaginal imaging device on a patient by a medical practitioner. 
     
    
    
     DETAILED DESCRIPTION 
     Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers are used in the drawings and the description to refer to the same or like parts. 
     Exemplary embodiments of an intravaginal imaging device are intended to perform intravaginal acquisition, cervix acquisition, and the like. It is therefore desirable for a lens module of the camera to have a large depth of field (DOF) and wide field of view (FOV) in a large range of working distances, for example, from under 1 mm to infinity. The camera may be used in a large working distance range with a big DOF. The intravaginal imaging device may focus at a far distance, for example, when positioned at the entrance of the vagina, or at a near distance, for example, when positioned adjacent to the cervix. Focus adjustment is used to provide appropriate image quality. 
     Generally, a first embodiment of an intravaginal imaging device includes a housing enclosing an illumination system, a lens system, attachment means for a vagina expander, and electrical components. The illumination system is used to provide enough light to illuminate the cervix and vagina interior. Polarized illumination may be used to limit reflections. For example, one or more white light emitting diodes (LEDs) may be used in the illumination system, which may be preferable due to small size, long lifetime and high luminous flux. Similarly, illumination in one or more specific wavelengths or bands of wavelengths may be used to directly or indirectly illuminate the target, for example via a fluorescence effect. For example, the illumination system may include LEDs with different colors, such as red/green/blue or other color combinations in order to produce a better tissue image, or to highlight or discern certain features in the image. 
     A first embodiment of the invention is explained in detail with reference to  FIG. 2 , which shows the intravaginal imaging device  200  in a schematic half-section. The elongated housing  206  houses optics and electronics. The optics may include a series of fixed lens groups  240 ,  241 ,  242  which map a target object (not shown), such as the cervix of a patient, on an image detector  207 . The fixed lens groups  240 ,  241 ,  242  may be formed of optical glass. In alternative embodiments, one or more of the fixed lens groups  240 ,  241 ,  242  may be formed of sapphire, or other appropriate materials. While three fixed lens groups are shown in the first embodiment, alternative embodiments may include one, two, four or more fixed lens groups. 
     Here, the fixed lens groups  240 ,  241 , and  242  are positioned between the target object (not shown) and the image detector  207 . The first fixed lens group  240  is located behind an ingress window  238  ( FIG. 3 ) at the distal end  205  of the elongated housing  206 . The first fixed lens group  240  conveys an image to a second fixed lens group  241 . Likewise, the second fixed lens group  241  and the third fixed lens group  242  transmit the image to the image detector  207 . 
     As shown in  FIG. 2 , each of the three fixed lens groups  240 ,  241 ,  242  has two fixed lenses. However, in alternative embodiments there may be more or fewer fixed lens groups, and each fixed lens group may include, one, two, three or more lenses. 
     A variable lens  208  is positioned between the second fixed lens  241  and the third fixed lens  242 . In alternative embodiments, the variable lens  208  may be positioned elsewhere with respect to the fixed lens groups, such as behind the third lens group  242 . The liquid lens is preferably located near the aperture  210 . The variable lens  208  under the first embodiment is a liquid lens. However, other variable lenses are possible in alternative embodiments. For example, rather than a liquid lens, one or more conventional solid lenses may be configured to be movable along an optical axis of the distal end  205  of the elongated housing  206 , behaving as a classical focusing system. The fixed lens groups  240 ,  241 ,  242 , the variable lens  208  and the ingress window  238  share a common optical axis. In general, the illumination provided by the illumination system is aligned with the common optical axis. 
     The imaging characteristics of the variable liquid lens  208  are controllable with electrical voltage as provided to electrodes (not shown) via an electrical lead  209  from an electrical controller  211 . The electrical controller  211  may be housed within the elongated housing  206 , as shown, or may be external to the elongated housing in alternative embodiments. 
     Further, the elongated housing  206  of the intravaginal imaging device  200  includes a variable aperture  210 , the diameter of which is adjustable in a specified ratio to the focal position. The variable aperture  210  may be implemented as a liquid crystal panel (LCD), which is controlled by a further electrical voltage via an additional electrical connection (not shown). In alternative embodiments a mechanical aperture may be used. 
     The image detector  207  may be trained with the controller  211  to control the image sharpness. The controller  211  may further control the voltage for the variable liquid lens  208  via the electrical lead  209 . The processor may be implemented as a computer, as described further below. An image at the image detector  207  may further include a scale configured to indicate a size of a region of interest. For example, a scale may be blended with the image at the image detector  207 , or the controller  211  may superimpose upon the image of the image detector. The scale may be faded into the image at a desired intensity. 
     A sheath  260  may surround the proximal end  204  of the elongated housing  206 . The center axis of the proximal end  204  of the elongated housing  206  may not be aligned with the center axis of the distal end  205  of the elongated housing  206 . As a result, merely rotating the proximal end  204  around its axis outside the vagina may reposition the distal end  205  near the cervix, for example, allowing the user to more easily locate the portio of the cervix. 
     A connecting portion  290  may be located at the proximal end  204  of the elongated housing. The connecting portion may provide physical connections, for example, electrical connections and or gas/fluid connections, for example, for expanding/deflating the vagina expander  310  ( FIG. 3 ). The connecting portion may further include means for wireless connection, for example, WiFi or BlueTooth wireless connections. 
     The elongated housing  206  may be formed of a biocompatible plastic, such as a medical grade biocompatible plastic. Alternatively, other materials may be used for the housing that are suitable for sterilization, such as, but not limited to silicone, latex, or metal such as medical grade titanium. 
     Under the first embodiment, the elongated housing  206  is approximately 293 mm in length, has a maximum diameter of approximately 25.7 mm, and a minimum diameter at the distal end  205  of approximately 12.7 mm (without the vagina expander  310 ). Of course, these dimensions are provided as a non-limiting example, and dimensions of alternative embodiments may vary significantly. 
       FIG. 3  shows a detail  300  of the distal end  205  of the elongated housing  206 . A transparent ingress window  238  may serve as an end cap to the distal end  205  of the elongated housing  206 , providing both an optical ingress into the camera  200 , as well as a fluid seal to the interior of the camera  200 . Illumination means  345 , such as one or more white LEDs may be disposed behind the ingress window  238  to provide illumination to the target of the camera  200 . The illumination levels of the illumination means  345  may be controlled by the electrical controller  211  located within the elongated housing  206  or a remote controller (not shown) located remotely to the elongated housing  206 . 
     A vagina expander  310  may be removably fastened to the distal end  205  of the elongated housing  206 . The vagina expander  310  may be configured as a generally ring shaped tube structure substantially surrounding the distal end  205  of the distal end  205  of the elongated housing  206 , such that the soft tissue is held apart to allow a clear field of view in front of the distal end  205  of the elongated housing  206 . The optical path of the intravaginal imaging device  200  passes through an aperture in the vagina expander  310 . 
     The vagina expander  310  may be removably attached to the distal end  205  of the elongated housing  206  by one or more of several attachment means  335 , for example, a threaded attachment, a tongue in groove attachment, a friction fit attachment where the vagina expander is attached by friction to an otherwise smooth external surface of the distal end  205  of the elongated housing  206 , or other means familiar to persons having ordinary skill in the art. The attachment means  335  are generally disposed at an inner diameter D 1  of the vagina expander, and mate with corresponding means at or near the distal end  205  of the elongated housing  206 , in particular, around an outer diameter at or near of the distal end  205  of the elongated housing  206 . 
     Under the first embodiment, the vagina expander  310  includes a mucus trap  330 , formed as a recessed region in a forward facing portion of the vagina expander. The mucus trap  330  may extend entirely around the distal end  205  of the elongated housing  206 , such that mucus collects within the recess rather than collecting in front of the ingress window  230 , thereby keeping the optical and/or illumination path of the intravaginal imaging device  200  unobstructed and unobscured. 
     While different embodiments of the vagina expander  310  may have different fixed sizes, the interior diameter DI is substantially the same, being configured to mate to the distal end  205  of the elongated housing  206 . However, in alternate embodiments the vagina expander  310  may have differently sized outer diameters, for example, but not limited to in the range of 10 mm up to 50 mm. 
     While the intravaginal imaging device  200  distal end  205  of the elongated housing  206  includes means for connecting to an optional vagina expander  310 , the intravaginal imaging device  200  may be operated without a vagina expander  310 . For example, the intravaginal imaging device  200  may be used in conjunction with a speculum  100  ( FIG. 1 ), where the intravaginal imaging device  200  is inserted within the jaws  150  ( FIG. 1 ) of the speculum  100  ( FIG. 1 ), and then positioned within the spacers  110 ,  120  ( FIG. 1 ) as needed to obtain access to the desired target, for example, the cervix. It should be noted that when used in this fashion, the intravaginal imaging device  200  is preferably not attached to the speculum  100  ( FIG. 1 ), but rather used concurrently, but independently. Therefore, the use of the term “vagina expander” within this disclosure and the claims should not be interpreted to mean the speculum. 
     Alternatively, the intravaginal imaging device  200  may be used in combination with a speculum  100  using a suitable holder provided by the speculum  100  or/and intravaginal imaging device  200  so as to affix the intravaginal imaging device  200  to the speculum  100 , or provide a movable connection so that the intravaginal imaging device  200  is moveable along the speculum, for example, along a rail or slot. 
     In a second embodiment the intravaginal imaging device  200  may include a variably sized vagina expander  310 . For example, the intravaginal imaging device  200  may include means for expanding or contracting the outer diameter DO of the vagina expander  310 . Such expansion/contraction means may include inflation/deflation of gasses and/or fluids in an expanding/contracting tube within the vagina expander  310 . Control of the amount of expansion/contraction may be controlled by the controller  211  located within the housing  206 , or external to the housing  206 . 
     In alternative embodiments, the vagina expander  310  may be implemented as a disposable or cleanable tube or cover pulled over the elongated housing  206 . 
     As previously mentioned, the controller  211  ( FIG. 2 ) for executing the functionality described in detail above may be a computer, an example of which is shown in the schematic diagram of  FIG. 5 . Such functionality may be related to the systems described above, for example, the illumination System, the focus or autofocus system, the auto-inflation system, and other such systems that may be electronically controlled. The system  500  contains a processor  502 , a storage device  504 , a memory  506  having software  508  stored therein that defines the abovementioned functionality, input and output (I/O) devices  510  (or peripherals), and a local bus, or local interface  512  allowing for communication within the system  500 . The local interface  512  can be, for example but not limited to, one or more buses or other wired or wireless connections, as is known in the art. The local interface  512  may have additional elements, which are omitted for simplicity, such as controllers, buffers (caches), drivers, repeaters, and receivers, to enable communications. Further, the local interface  512  may include address, control, and/or data connections to enable appropriate communications among the aforementioned components. 
     The processor  502  is a hardware device for executing software, particularly that stored in the memory  506 . The processor  502  can be any custom made or commercially available single core or multi-core processor, a central processing unit (CPU), an auxiliary processor among several processors associated with the present system  500 , a semiconductor based microprocessor (in the form of a microchip or chip set), a macroprocessor, or generally any device for executing software instructions. 
     The memory  506  can include any one or combination of volatile memory elements (e.g., random access memory (RAM, such as DRAM, SRAM, SDRAM, etc.)) and nonvolatile memory elements (e.g., ROM, hard drive, tape, CDROM, etc.). Moreover, the memory  506  may incorporate electronic, magnetic, optical, and/or other types of storage media. Note that the memory  506  can have a distributed architecture, where various components are situated remotely from one another, but can be accessed by the processor  502 . 
     The software  508  defines functionality performed by the system  500 , in accordance with the present invention. The software  508  in the memory  506  may include one or more separate programs, each of which contains an ordered listing of executable instructions for implementing logical functions of the system  500 , as described below. The memory  506  may contain an operating system (O/S)  520 . The operating system essentially controls the execution of programs within the system  500  and provides scheduling, input-output control, file and data management, memory management, and communication control and related services. 
     The I/O devices  510  may include input devices, for example but not limited to, a keyboard, mouse, scanner, microphone, etc. An input device may include a switch or actuator configured to start the autofocus procedure, for example, implemented as a switch on the housing, an external wired or wireless footswitch or by a keyboard, keypad, touchscreen, or other mechanism. Furthermore, the I/O devices  510  may also include output devices, for example but not limited to, a display, et cetera, which may be connected via a USB connector, or the illumination means  345  ( FIG. 3 ). Finally, the I/O devices  510  may further include devices that communicate via both inputs and outputs, for instance but not limited to, a wireless communication system, a radio frequency (RF) or other transceiver, a telephonic interface, a bridge, a router, or other device. 
     When the system  500  is in operation, the processor  502  is configured to execute the software  508  stored within the memory  506 , to communicate data to and from the memory  506 , and to generally control operations of the system  500  pursuant to the software  508 , as explained above. 
     When the functionality of the system  500  is in operation, the processor  502  is configured to execute the software  508  stored within the memory  506 , to communicate data to and from the memory  506 , and to generally control operations of the system  500  pursuant to the software  508 . The operating system  520  is read by the processor  502 , perhaps buffered within the processor  502 , and then executed. 
     When the system  500  is implemented in software  508 , it should be noted that instructions for implementing the system  500  can be stored on any computer-readable medium for use by or in connection with any computer-related device, system, or method. Such a computer-readable medium may, in some embodiments, correspond to either or both the memory  506  or the storage device  504 . In the context of this document, a computer-readable medium is an electronic, magnetic, optical, or other physical device or means that can contain or store a computer program for use by or in connection with a computer-related device, system, or method. Instructions for implementing the system can be embodied in any computer-readable medium for use by or in connection with the processor or other such instruction execution system, apparatus, or device. Although the processor  502  has been mentioned by way of example, such instruction execution system, apparatus, or device may, in some embodiments, be any computer-based system, processor-containing system, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions. In the context of this document, a “computer-readable medium” can be any means that can store, communicate, propagate, or transport the program for use by or in connection with the processor or other such instruction execution system, apparatus, or device. 
     Such a computer-readable medium can be, for example but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, device, or propagation medium. More specific examples (a nonexhaustive list) of the computer-readable medium would include the following: an electrical connection (electronic) having one or more wires, a portable computer diskette (magnetic), a random access memory (RAM) (electronic), a read-only memory (ROM) (electronic), an erasable programmable read-only memory (EPROM, EEPROM, or Flash memory) (electronic), an optical fiber (optical), and a portable compact disc read-only memory (CDROM) (optical). Note that the computer-readable medium could even be paper or another suitable medium upon which the program is printed, as the program can be electronically captured, via for instance optical scanning of the paper or other medium, then compiled, interpreted or otherwise processed in a suitable manner if necessary, and then stored in a computer memory. 
     In an alternative embodiment, where the system  500  is implemented in hardware, the system  500  can be implemented with any or a combination of the following technologies, which are each well known in the art: a discreet logic circuit(s) having logic gates for implementing logic functions upon data signals, an application specific integrated circuit (ASIC) having appropriate combinational logic gates, a programmable gate array(s) (PGA), a field programmable gate array (FPGA), etc. 
     The above described embodiments of an intravaginal imaging device may be used for cervix inspection inside in the vagina with or without a speculum, because of the ergonomic shape including the vagina expander or inflatable bellow. This assists in observing the cervix regarding changes of the cervix mucosa. Advantages include lower costs compared with traditional colposcopy equipment and procedures, and no mandatory usage of a speculum, which is more comfortable and convenient for the patient. The intravaginal imaging device may be used in combination with ultrasound systems, for example via USB interface, providing a direct view and LED illumination on the region of interest (ROI) based on intravaginal use. The intravaginal imaging device may provide a digital image for recording and data transfer. In addition the ergonomic shape provides easy handling and avoids contamination of the internal optics. 
     As shown in  FIG. 5 , the intravaginal imaging device  200  may be a component of a gynecological examination system  400 , including another imaging system  410 , an image processor  420 , and an image display  430 . The imaging system  410  may be, for example, an ultrasonic imaging unit, a magnetic resonance tomography (MRT) unit and/or a computed tomography (CT) scan unit. 
     The image processor  420  may be configured to enhance and/or refine the images produced by the intravaginal imaging device  200  and/or the imaging system  410 , either independently, or in concert. For example, the image processor  420  may be configured to overlay images from the intravaginal imaging device  200  and the imaging system  410 , for example, by using registration techniques, or by manipulating either or both images to match/overlay features displayed by the images. 
     The image display  430  may represent a single display device, which may be capable of displaying multiple images simultaneously, for example, side-by-side or overlaid, or may be separate displays, for example, for independently displaying the output of the intravaginal imaging device  200  and the imaging system  410 . The image display  430  may use cathode ray tubes, LED display screens, plasma display screens, and/or other display mechanisms, alone or in combination. 
     While  FIG. 5  depicts the imaging system  410 , the image processor  420 , and the image display  430  as individual blocks, the functionality of two or more of these blocks may be combined in a single device. 
     The software of the gynecological examination system  400  allows matching of the ultrasound, MRT or CT images with the visible image of the intravaginal imaging device  200 . By this the gynecologist may obtain more information for his diagnosis than with either image alone. The ergonomic shape of the intravaginal imaging device  200  and the adapted interface makes the intravaginal imaging device  200  part of the combined gynecological examination system  400 . The gynecological examination system  400  may be used, for example, to compare images produced during the examination by the intravaginal imaging device  200  with preoperative and/or intraoperative images from the imaging system  410 , or other preoperative and/or intraoperative images. 
       FIG. 6  is a block diagram of an exemplary method  600  for use of an intravaginal imaging device on a patient by a medical practitioner. It should be noted that any process descriptions or blocks in flowcharts should be understood as representing modules, segments, portions of code, or steps that include one or more instructions for implementing specific logical functions in the process, and alternative implementations are included within the scope of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention. 
     The method is described with reference to  FIGS. 1 and 2 . The intravaginal imaging device  200  is inserted within the jaws  150  of a speculum  100 , as shown by block  610 . The intravaginal imaging device  200  is positioned within spacers  110 ,  120  of the speculum  100 , as shown by block  620 . The speculum  100  and intravaginal imaging device  200  are positioned in proximity of the cervix of the patient, as shown by block  630 . While the intravaginal imaging device  200  is able to focus over a distance range from zero to infinity, Practically, the light transfer from the LED&#39;s is not sufficient to illuminate the cervix when the intravaginal imaging device  200  is be positioned outside of the vagina. Therefore, herein “proximity of the cervix of the patient” generally indicates a distance range from 0 to 200 mm. An image of the cervix is captured with the intravaginal imaging device  200 , as shown by block  640 . 
     In summary, it will be apparent to those skilled in the art that various modifications and variations can be made to the structure of the present invention without departing from the scope or spirit of the invention. In view of the foregoing, it is intended that the present invention cover modifications and variations of this invention provided they fall within the scope of the following claims and their equivalents.