Abstract:
A portable intra-oral capture and display system includes: (a) a handpiece elongated for insertion into an oral cavity, said handpiece including a light emitter on a distal end thereof for illuminating an object in the cavity and an image sensor for capturing an image of the object and generating an image signal therefrom; (b) a portable, hand-cradled base containing in a single integral enclosure a light source for generating light, electronics for processing the image for display, a display monitor for displaying the image, a storage for storing the image, thereby providing a stored image for subsequent review and access, and an interface for transferring the stored image to a peripheral device; and (c) an optical connection for transmitting the light from the base to the light emitter in the camera, and an electrical connection for communicating the image signal from the image sensor in the camera to the processor in the base.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to intra-oral imaging systems for dental applications, and particularly to an intra-oral camera system that is used by a dental practitioner to display images of objects in the mouth.  
         BACKGROUND OF THE INVENTION  
         [0002]    Electronic handheld cameras configured with intra-oral imaging optics are used for capturing images of the inside of a patient&#39;s mouth. The camera typically has an elongated body that contains an image sensor and optics. The optics and sensor are designed for capturing images of the inside of the mouth when the distal or viewing end of the camera is inserted into the patient&#39;s mouth. Wires carrying electronic signals typically connect the image sensor to the proximal end of the camera where a communication interface is provided to an image processing system or display monitor that allows manipulation and display of the images. By viewing the displayed images, a diagnosis can be made and appropriate treatment prescribed.  
           [0003]    For illuminating the inside of the mouth, a fiber optic cable typically is used to transmit light to the viewing end of the camera. The light is generated by a high intensity light source such as a lamp or bulb typically held in a light box. In a typical embodiment, such as shown in U.S. Pat. No. 6,132,211, the fiber optic cable terminates in a connector that plugs into a power source housing that also includes the light source. Preferably, the housing for the power supply and the light source is supported on a countertop or on a post in the dental operatory room. In other words, the housing is basically immovable and portability is provided by having the portable handpiece removable from the housing. According to the &#39;211 patent, this design is chosen so that any number of operatories having a power source base and display may be serviced by a single handpiece system.  
           [0004]    In a typical installation, the housing containing the power supply and the light box includes a communications interface to an external image processing system or display monitor. This leads to various placements of the processor and monitor. For instance, in the Reveal® Imaging Platform sold by Welch Allyn® the monitor is mounted on top of the housing, which makes the whole assembly virtually unmovable. Consequently, similar to what was described above in connection with the &#39;211 patent, in the Reveal® Imaging Platform the handpiece is plugged into a receptacle on the housing.  
           [0005]    The use of intra-oral cameras among dental practitioners is well known. Besides their use in the diagnosis of dental and oral disease, they are used as well in providing a visual record of the condition of the patient. It is frequently the case that a dentist, orthodontist, or the like, may have multiple operatories where the use of such a camera is desirable. Current camera systems require either the use of an attached computer system and video monitor, or a separate monitor for the display of images. Thus the practitioner is required to either purchase multiple camera systems or display capabilities for each operatory, as such display systems are rather large and bulky.  
           [0006]    In many cases, a dentist desires to produce images of the interior of a patient&#39;s mouth in order to provide both a diagnosis of dental and oral disease as well as to provide a visual record of the condition of the patient. This process becomes cumbersome, costly, and inconvenient, as current camera systems are not designed for portability. What is needed is a truly portable camera system that would incorporate an integral display and provide advantages over the current state-of-the-art. Such a camera could incorporate wireless or other means to transmit the image data to a centrally located data storage and printing system.  
         SUMMARY OF THE INVENTION  
         [0007]    It is an object of the present invention to provide an intra-oral camera system with improved portability.  
           [0008]    It is a further object of the invention to provide an improved ability of the camera system to communicate with peripherals while preserving its portability.  
           [0009]    The present invention is directed to overcoming one or more of the problems set forth above. Briefly summarized, according to one aspect of the present invention, the invention resides in a portable intra-oral capture and display system comprising: (a) a handpiece elongated for insertion into an oral cavity, wherein the handpiece includes a light emitter on a distal end thereof for illuminating an object in the cavity and an image sensor for capturing an image of the object and generating an image signal therefrom; (b) a portable, hand-cradled base tethered to the handpiece, wherein the base contains in a single integral enclosure a light source for generating light, electronics for processing the image for display, a display monitor for displaying the image, a storage for storing the image, thereby providing a stored image for subsequent review and access, and an interface for transferring the stored image to a peripheral device; and (c) an optical connection for transmitting the light from the base to the light emitter in the camera, and an electrical connection for communicating the image signal from the image sensor in the camera to the processor in the base.  
           [0010]    In a further aspect of the invention, the capture and display system includes both a high quality image display along with means to transfer image data to a physically separate and distinct data storage in a peripheral device, such as a larger monitor, a printer or a computer. The means to transfer image data may comprise, for example: (a) wireless RF or microwave transceiver technology, (b) wireless IR technology, or (c) a physically small memory device, such as a flash RAM card, that is easily removed from the camera part of the system and subsequently plugged into the peripheral device.  
           [0011]    The advantage of the present invention lies in the integration of the display into the camera system. This integration enables the practitioner to view the results of image recording in close proximity to the capture location, and conveniently display the captured image(s) either for the practitioner&#39;s or patient&#39;s benefit. Such viewing occurs without the requirement of producing a physical print of the image. Integration of the display removes the requirement on the dentist to move a large bulky system (a video monitor and/or attached computer) from one operating room to the next. Alternatively, the requirement that the dentist purchase multiple such systems is eliminated.  
           [0012]    These and other aspects, objects, features and advantages of the present invention will be more clearly understood and appreciated from a review of the following detailed description of the preferred embodiments and appended claims, and by reference to the accompanying drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 shows an intra-oral camera and display system according to the invention.  
         [0014]    [0014]FIG. 2 shows a block diagram of the electronics in the integral base.  
         [0015]    [0015]FIG. 3 shows the integral base for the light source and hand held monitor of the system shown in FIG. 1, particularly as it would be used for wireless communication to a group of peripherals.  
         [0016]    [0016]FIG. 4 shows a flow chart for a process for correcting the color of the system shown in FIG. 1.  
         [0017]    [0017]FIG. 5 shows a second embodiment of an intra-oral camera and display system according to the invention.  
         [0018]    [0018]FIG. 6 shows a third embodiment of an intra-oral camera and display system according to the invention. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0019]    Because intra-oral cameras employing electronic sensors are well known, the present description will be directed in particular to elements forming part of, or cooperating more directly with, apparatus in accordance with the present invention. Elements not specifically shown or described herein may be selected from those known in the art. Certain aspects of the embodiments to be described may be provided in software. Given the system as shown and described according to the invention in the following materials, software not specifically shown, described or suggested herein that is useful for implementation of the invention is conventional and within the ordinary skill in such arts.  
         [0020]    Referring first to FIG. 1, an intra-oral dental camera system  10  includes a portable dental camera  12  and a power source, illumination source and a display unit integrally located in a portable enclosure (hereinafter referred to as the integral base  14 ) tethered to the camera  12 . The camera  12  and the integral base  14  thus constitute, in the terms of this invention, an intra-oral camera with integral display. The dental camera  12  includes a handpiece  16  and a cable  18  connecting the dental camera  12  to the integral base  14 . As shown for illustrative purposes in FIG. 1, the integral base  14  can be easily cradled in a hand, and includes a display monitor  20  that can be easily hand positioned relative to the dentist&#39;s and/or patient&#39;s line of sight. A set of user controls  22  are provided on the integral base  14  that can be easily hand-navigated for controlling the illumination and the images displayed on the monitor, as well as communicating with peripheral devices. The handpiece  16  supports a removable lens unit  24  that includes a lens  26  and light emitting apertures  28 . The handpiece  16  is generally elongated and cylindrical with a central axis. The lens  26  is positioned to receive light impinging on the handpiece in a direction substantially perpendicular and normal to the central axis of the handpiece.  
         [0021]    Referring to FIG. 2, the integral base  14  further includes a central processing unit (CPU)  30 , a CPU memory  31 , a power supply  32 , a wireless transceiver  34 , and flash memory (RAM)  36 . The user controls  22  interface with a video control unit  38  and an illuminator control unit  40 . The illuminator control unit  40  connects with an illumination source  42 , which provides illumination to the handpiece  16  through a fiber optic  44  that is part of the cable  18 . The illumination source may take a variety of forms known to those of skill in this art, such as a halogen arc lamp lighting system or a tungsten/halogen lamp. The power supply  32  is connected by a power cable (not shown) to a power source, such as a wall socket. The image signal communication between the handpiece  16  and the CPU  30  is maintained through an electrical connection  46 , which is also in the cable  18 . While not shown in detail, the handpiece  16  also supports a connection of the fiber optic  44  with the light emitting apertures  28  and a connection of the electrical conductor  46  to an image sensor  50 , such as a conventional charge coupled device (CCD). The image sensor  50  is arranged in a conventional optical path, with mirrors and other optical components as might be necessary, such that the lens  26  can form an image of an intra-oral object on the image sensor  50 .  
         [0022]    It should be noted that portability is facilitated by incorporating into the dental camera system  10  both a high quality image display  20  along with means to transfer image data to a physically separate and distinct data storage associated with an image printing capability. The high quality image display may be provided by a number of well-known technologies; for example, it is well-known in the art of hand-held televisions (e.g., the Casio EV660 Color Active Matrix Handheld TV) to use a small (e.g., 3 inch) screen with thin-film transistor active matrix (TFT) technology. The means to accommodate a transfer of image data may include (a) wireless RF or microwave transceiver technology, (b) wireless infra-red transmission technology, and/or (c) removable memory technology embodied in physically small elements, such as flash RAM cards or small hard drives, that are easily removed from the camera part of the system and subsequently plugged into either the image data storage or printer parts of the system.  
         [0023]    Accordingly, the dental camera system  10  can, through the transceiver  34  in its integral base  14 , initiate communication via wireless links  58  with a variety of peripheral units as shown in FIG. 3. Each of these units would have its own data storage for receiving the transmitted images. Without intending to be exhaustive as to type of peripheral unit that may be accessed, such peripheral units include a larger monitor or television receiver  60 , a printer  62 , and a computer system  64 , such as any conventional desktop PC, where the images may be stored. With this arrangement, a dental practitioner may view an image on the integral base  14  and immediately initiate its transfer to any one of the peripheral units  60 ,  62  or  64  by means of the user controls  22 . The incorporation of the transceiver  34  and the display monitor  20  into the dental camera system  10  further enables the practitioner to view the results of an image recording, and conveniently display the captured image(s) either for the practitioner&#39;s or patient&#39;s benefit. For this purpose, the transceiver  34  would receive images from a storage peripheral, such as the computer system  64 , and display the stored images on the display monitor  20 . Importantly, such viewing occurs without the requirement of producing a physical print of the image.  
         [0024]    Just as importantly, with this arrangement the practitioner can separate the movable, but clumsy and sometimes bulky, printing and processing operation from the dental operatory, and devote a particular room to these peripherals. Moreover, incorporation of the display as a tethered adjunct to the camera system removes the requirement on the dentist to move a large bulky system (a video monitor and/or attached computer) from one operating room to the next. Alternatively, the requirement that the dentist purchase multiple such systems for multiple operatories is eliminated.  
         [0025]    In a preferred embodiment, the image sensor  50  provides an image signal that the CPU  30  processes (as a video signal) for display on the display monitor  20 . The video control unit  38  interacts through the CPU  30  and the user controls  22  to provide functionality for several modes, including a video/still mode, a mode for initiating a recording of a still or video sequence, a mode for stopping the imagery at any point (freeze-frame), a mode for initiating transmission to any of the peripherals shown in FIG. 3 and a mode for initiating retrieval of a stored image from an external memory, e.g., from the computer system  64 . In the latter two modes, the images are transmitted and/or received via an antenna or light beam emitter (not shown) to/from any of the peripherals  60 ,  62  or  64 . Alternatively, the images may be stored in a removable memory and the removable memory is then transported to the peripheral units. For instance, the integral base  14  may also include a receptacle  66  for a physically small RAM card  68 , which may be easily removed from the integral base  14  and subsequently plugged into a corresponding receptacle (not shown) in any one of the peripheral units  60 ,  62  and  64 .  
         [0026]    In order to adjust the colorimetry of the dental camera system  10  to match the color of intra-oral objects, e.g., to match a natural tooth color, it is desirable to provide an optimum color calibration for an intra-oral camera application. FIG. 4 shows the process for correcting the color of a system designed for the collection of intra-oral images. It is desirable to have a broadband match (broadband spectrum) because of the need to match teeth under a variety of illumination conditions. The camera is first initialized in a stage  70  to clear previous color correction factors from the CPU memory  31 . These can be in the form of look up table elements, matrix elements, and the like. As is well-known in the color management arts, these digital data are used in a mathematical transformation process to modify the color characteristics of components of the system to allow for a true color rendition to occur throughout the system. The illuminator is allowed to stabilize for a period of time so that the spectral output of the illumination source  42  remains the same for a period of time that allows multiple images to be captured, without the need for adjustment of the illuminator color temperature (or spectral output characteristics). The display monitor  20  may also require a period of stabilization before use.  
         [0027]    In stage  72 , target materials are illuminated with the illumination source  42  so as to characterize the image recording response. Such target materials can include, but are not limited to, color matching charts for the fabrication of color-matched prostheses. For example, the target materials would include the white(s) that dental practitioners use to match teeth for prosthetic purposes, such as the fabrication of a crown. (Note that calibration would ordinarily not be done with the intra-oral camera in a patient&#39;s mouth; the camera would typically be hooked up to the computer  64  for this calibration process.) Calibration of the system includes measurements of such targets to establish the characteristic input color response for the intra-oral camera system. The characteristic is stored digitally in stage  74  in the CPU memory  31  and used to transform the unknown color of the teeth (which are imaged in a separate image recording event or events resulting from stage  76 ) to a color representation within the system that can be used to produce a “true-color” output. The calibration of each output device is also performed and stored in stage  78  in the respective memories (not shown) of each output device. Then, the dental image is output to a selected output device(s) in stage  80 , e.g., to the display monitor  20  or any of the output devices  60 ,  62  and  64  shown in FIG. 3. In this manner, the system can correct for color imbalance in any of the components in the system and render color corrected output regardless of the output channel.  
         [0028]    In a second embodiment of the invention shown in FIG. 5, the intra-oral camera and display system includes a docking unit  100  with a recessed area  102  for mating with the integral base  14 . The power supply  32  in the integral base  14  includes rechargeable batteries  104  connected to externally accessible charging electrodes  106 . The docking unit  100  is provided with a battery charger  108  connected to externally accessible charging electrodes  110 . When the integral base  14  is inserted into the recessed area  102  on the docking unit  100 , the electrodes  106  and  110  are electrically connected and the batteries  104  are recharged.  
         [0029]    In a third embodiment of the invention shown in FIG. 6, the handpiece  16  of the intra-oral camera and display system includes electronics and an interface for communicating with the integral base  14  across a wireless transmission linkage  116  or by means of a removable memory  118 . More specifically, the handpiece  16  includes its own light source  120 , processor  122 , transceiver  124  and power supply  126 . In addition, the power supply  126  may include rechargeable batteries  128 , and the intra-oral camera and display system can further include a docking unit  130  with a battery charger  132 . Both the handpiece  16  and the docking unit include mating electrodes  134  and  136  such that when the handpiece  16  is inserted into the docking unit  130 , the electrodes  134  and  136  are electrically connected and the batteries  128  are recharged. In addition, as shown in FIG. 5, the integral base may have its own docking unit; moreover, the two docking units could be combined in one component.  
         [0030]    The invention has been described with reference to a preferred embodiment. However, it will be appreciated that variations and modifications can be effected by a person of ordinary skill in the art without departing from the scope of the invention.  
       Parts List  
       [0031]    [0031] 10  dental camera system  
         [0032]    [0032] 12  portable dental camera  
         [0033]    [0033] 14  integral base  
         [0034]    [0034] 16  handpiece  
         [0035]    [0035] 18  cable  
         [0036]    [0036] 20  display monitor  
         [0037]    [0037] 22  user controls  
         [0038]    [0038] 24  removable lens unit  
         [0039]    [0039] 26  lens  
         [0040]    [0040] 28  light emitting apertures  
         [0041]    [0041] 30  CPU  
         [0042]    [0042] 31  CPU memory  
         [0043]    [0043] 32  power supply  
         [0044]    [0044] 34  wireless transceiver  
         [0045]    [0045] 36  flash memory  
         [0046]    [0046] 38  video control unit  
         [0047]    [0047] 40  illuminator control unit  
         [0048]    [0048] 42  illumination source  
         [0049]    [0049] 44  fiber optic  
         [0050]    [0050] 46  electrical conductor  
         [0051]    [0051] 50  image sensor  
         [0052]    [0052] 58  wireless link  
         [0053]    [0053] 60  larger monitor or television receiver  
         [0054]    [0054] 62  printer  
         [0055]    [0055] 64  computer system  
         [0056]    [0056] 66  receptacle  
         [0057]    [0057] 68  RAM card  
         [0058]    [0058] 70  initialize stage  
         [0059]    [0059] 72  illuminate target stage  
         [0060]    [0060] 74  compute stage  
         [0061]    [0061] 76  record stage  
         [0062]    [0062] 78  output compute stage  
         [0063]    [0063] 80  output select stage  
         [0064]    [0064] 100  docking unit  
         [0065]    [0065] 102  recessed area  
         [0066]    [0066] 104  rechargeable batteries  
         [0067]    [0067] 106  charging electrodes  
         [0068]    [0068] 108  battery charger  
         [0069]    [0069] 110  charging electrodes  
         [0070]    [0070] 116  wireless link  
         [0071]    [0071] 118  removable memory card  
         [0072]    [0072] 120  light source  
         [0073]    [0073] 122  processor  
         [0074]    [0074] 124  transceiver  
         [0075]    [0075] 126  power supply  
         [0076]    [0076] 128  rechargeable batteries  
         [0077]    [0077] 130  docking unit  
         [0078]    [0078] 132  battery charger  
         [0079]    [0079] 134  electrodes  
         [0080]    [0080] 136  electrodes