Abstract:
An otoscope provides a disposable speculum sleeve that conducts light to a narrow tip holding an electronic camera. By removing the light source from the tip, the diameter of the tip may be further reduced to allow the space of the ear canal to be shared between the otoscope and a tool such as a curette for removing foreign objects or to permit the tip to navigate around ear obstructions. The sleeve may provide for multidirectional illumination of the ear structure for improved visualization. The tip and sleeve may be flexible for increased patient comfort when using a compact tip design.

Description:
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
     CROSS REFERENCE TO RELATED APPLICATION 
     BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to an otoscope for inspection of the ear and in particular to an otoscope employing an electronic camera insertable into the ear canal. 
         [0002]    An otoscope is a medical device allowing a healthcare professional to inspect the ear canal and tympanic membrane (eardrum). A simple otoscope provides for a hollow funnel-shaped speculum whose small end is inserted into the ear canal. The funnel shape of the speculum stabilizes the otoscope against the ear canal wall and may limit the depth of insertion of the speculum. Modern otoscopes include an internal source of illumination directed down the speculum axis from a contained battery-operated lamp and may provide a magnifying lens supported outside the ear and aligned with the axis of the speculum to provide an enlarged image of the ear structure being viewed. 
         [0003]    Recently otoscopes have been developed that include a digital camera fitting within the speculum to permit the documentation of a diagnosis by image capture. U.S. patent application Ser. No. 4/461,103 filed Aug. 15, 2014, assigned to the assignee of the present invention and hereby incorporated by reference, discloses an otoscope having the camera mounted on a distal end of a flexible stalk of narrow diameter. The small size of the stalk permits improved access to the ear canal possibly in conjunction with other instruments. The flexibility of the stalk moderates the pressure that may be applied to the ear canal by contact with the small diameter of the stalk. Light emitting diodes surround the camera at the end of the speculum to direct axial light toward the field of view of the camera. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention provides an otoscope employing a light pipe in the speculum, surrounding a stalk that holds a camera, to deliver light to the inner ear. The light pipe moves the light source away from the tip of the speculum permitting an even narrower outside diameter of the speculum. In addition, the light pipe may have an exposed diffuser surface before its tip to disperse the light into the ear canal and ear tissue providing multidirectional illumination for improved viewing of ear structure. 
         [0005]    Specifically, in one embodiment, the invention provides an otoscope having a housing that may be held and supported adjacent to an outer ear of a patient and which includes an elongate probe element having a proximal end supported by the housing so that a distal end of the elongate probe element may extend along an axis into the ear canal of the outer ear in the inspection position. An electronic camera is supported at the distal end of the elongate probe element for viewing into the ear canal when the distal end of the elongate probe element is in the inspection position in the ear canal. A coaxial sheath, positioned around the probe element, conducts light from a proximal end of the sheath to a distal end of the sheath proximate to the electronic camera. 
         [0006]    It is thus a feature of at least one embodiment of the invention to provide an improved light delivery system for an otoscope that can reduce the probe size and provide improved illumination. 
         [0007]    The coaxial sheath may be a tubular light pipe. 
         [0008]    It is thus a feature of at least one embodiment of the invention to provide a light that is easily fabricated, fir example, in the shape of the speculum. 
         [0009]    The outer diameter of the coaxial sheath at a distal 0.5 or one centimeter length of the coaxial sheath may be less than 5 millimeters or less than three millimeters. 
         [0010]    It is thus a feature of at least one embodiment of the invention to provide an extremely narrow otoscope probe that is easier to maneuver (for example, around obstructions) and which can share the ear canal with other instruments. 
         [0011]    The coaxial sheath, when surrounding the elongate probe, may be coated with an elastomer to reduce pressure against the patient&#39;s ear canal. 
         [0012]    It is thus a feature of at least one embodiment of the invention to provide a small diameter otoscope probe that is nevertheless comfortable to the patient with the flexing reducing contact force between the otoscope probe and ear canal. 
         [0013]    The coaxial sheath may be constructed at least in part of a transparent elastomeric material. 
         [0014]    It is thus a feature of at least one embodiment of the invention to impart flexibility by using a resilient material. 
         [0015]    A distal portion of the coaxial sheath, before the distal end of the coaxial sheath, may emit light in a direction having a lateral component perpendicular to the axis. For example, the distal portion may be a substantially light conducting tube emitting light radially with respect to the tube axis. 
         [0016]    It is thus a feature of at least one embodiment of the invention to provide a more diffuse illumination of ear structure such as reduces brightness variation and hotspot reflection. 
         [0017]    The distal portion may include a light diffusing outer surface. 
         [0018]    It is thus a feature of at least one embodiment of the invention to provide moldable feature that couples conductive light and disperses it at multiple radial angles for multidirectional illumination. 
         [0019]    The distal portion may provide an outer surface presenting radially extending ridges or bristles for removal of material from the ear canal. 
         [0020]    It is thus a feature of at least one embodiment of the invention to incorporate tool surfaces into the otoscope in proximity to the end of the probe. 
         [0021]    The coaxial sheath may include mechanical retention elements cooperating with corresponding elements on the housing for releasably attaching the coaxial sheath to the housing through an applied force to the coaxial sheath. 
         [0022]    It is thus a feature of at least one embodiment of the invention to provide a light pipe that can do double duty as a disposable speculum. 
         [0023]    The applied force may be a torsional force about the axis. 
         [0024]    It is thus a feature of at least one embodiment of the invention to provide an attachment method familiar to users of conventional otoscope speculums. 
         [0025]    The elongate probe may be supported on the housing by a retraction mechanism allowing extension and retraction of the elongate probe along the axis with respect to the housing. 
         [0026]    It is thus a feature of at least one embodiment of the invention to permit retraction of the probe to protect the probe when the speculum is removed. 
         [0027]    The sheath may cooperate with the retraction mechanism to retract the elongate probe when the sheath is removed from around the elongate probe and to extend the elongate probe when the sheath is installed around the elongate probe. 
         [0028]    It is thus a feature of at least one embodiment of the invention to provide automatic retraction of the probe when the protective sheath is removed and extension of the probe when the protective sheath is installed reducing the chance of damage to the camera. 
         [0029]    The cooperation between the sheath and the retraction mechanism may include a helical internal thread on the sheath. 
         [0030]    It is thus a feature of at least one embodiment of the invention to permit a familiar attachment method for the sheath to trigger the extension and retraction of the probe. 
         [0031]    The sheath may include an optically transparent portion covering the camera so that the camera field of view extends through the optically transparent portion. 
         [0032]    It is thus a feature of at least one embodiment of the invention to make use of the transparent light conducting material of the sheath to provide a protective and sterile field preserving window over the camera lens. 
         [0033]    The housing may include a detachable grip portion extending in a direction having a component perpendicular to the axis for supporting the otoscope with a single hand gripping the grip portion. 
         [0034]    It is thus a feature of at least one embodiment of the invention to permit the otoscope to work with standard otoscope charging stations and stands and the associated grips received by those charging stations and stands. 
         [0035]    The otoscope may further include a barcode decoder for receiving signals from the camera imaging a barcode to decode the barcode. 
         [0036]    It is thus a feature of at least one embodiment of the invention to permit the otoscope to capture barcodes that may be used to link acquired images to patient files. 
         [0037]    These particular objects and advantages may apply to only sonic embodiments falling within the claims and thus do not define the scope of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0038]      FIG. 1  is a perspective view of an otoscope constructed according to the present invention providing a housing presenting on a front side an electronic display and on a rear side having a camera on a probe element extending away from the electronic display for insertion into the ear canal and covered by a disposable speculum; 
           [0039]      FIG. 2  is an elevational cross-section through the probe element and the disposable speculum showing a mechanism for retracting the probe element and camera when the speculum is removed and extending the probe element and camera when the speculum is in place; 
           [0040]      FIG. 3  is a detailed fragmentary view of  FIG. 2  with the camera element fully extended showing radial and axial illumination of the ear canal such as creates a diffuse lighting for better resolving ear structure; 
           [0041]      FIG. 4  is a side elevational view of the speculum installed on the probe element showing flexibility of the combined assembly; 
           [0042]    Fig,  5  is a detailed cross-section of the distal end of  FIG. 4  showing radial teeth on the speculum for assisting in the removal of foreign material from the ear canal and showing a lens protector incorporated into the disposable speculum; and 
           [0043]      FIG. 6  is a simplified block diagram of the electronics of the otoscope of  FIG. 1 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
       [0044]    Referring now to  FIG. 1 , an otoscope  10  of the present invention may provide a housing  12  having a head portion  14  and a detachable grip portion  16 . The grip portion  16  is sized to be grasped by the hand of a healthcare professional in the manner of a conventional otoscope with the grip portion  16  extending generally upward from the healthcare professional&#39;s hand to the head portion  14 . 
         [0045]    A front surface of the head portion  14  may provide for an electronic display  18 , for example, being a backlit three-color liquid crystal display (LCD) of a type known in the art. An elongate probe assembly  20  may extend from a rear face of the head portion  14  in a direction away from the display  18  along an axis  22  normal to the surface of the display  18 . The probe assembly  20  may include a generally conical sheath  24  constructed at least in part of the transparent thermoplastic material to provide for light conducting properties as will be described below. 
         [0046]    As is generally understood, the outer ear  33  of a human patient includes the pinna  37  providing a sound collecting structure. The pinna  37  surrounds an ear canal  36  leading to and terminating at the tympanic membrane or eardrum  38 . A length of the ear canal  36  in an average adult human is approximately 2.5 centimeters and the ear canal  36  has an average diameter of approximately 0.7 centimeters. 
         [0047]    Referring now also to  FIG. 2 , the sheath  24  may taper inward as one moves away from the head portion  14  to a distally located sheath tip  26 . The sheath  24  provides a central bore which holds an extendable cylindrical probe  28  having on its distal tip a front facing electronic camera  30  for acquiring multi-pixel, three-color images in a field of view directed along the axis  22 . Electronic camera  30  may, for example, be a self-contained charge coupled device (CCD) camera such as is commercially available providing, for example, a measurement area of 1.4 mm diagonal and 62,500 pixels. 
         [0048]    A proximal end of the cylindrical probe  28  is supported by a spring-loaded slider  32  that may move along the axis  22  with respect to structure of the housing  12  generally constrained for translational motion only. A helical compression spring  34  may extend between an inwardly extending flange  39  of the housing  12  and a rearward radially outwardly extending flange  41  on the slider  32  to bias the slider  32  in a retraction direction withdrawing the camera  30  within a protective sleeve  35 . The sleeve  35  is fixed with respect to the housing  12  and surrounds the camera  30  for protection when the camera  30  is fully retracted. 
         [0049]    A proximal end of the conical sheath  24  may provide for a collar  40  having internal threads that can engage outwardly extending pins  42  of the slider  32 . Clockwise rotation of the collar  40  (looking toward the proximal end) pulls the pins  42  forward toward the sheath tip  26  of the sheath  24  while pulling the sheath  24  onto the housing  12 . Forward motion of the pins  42  moves the slider  32  forward against the force of the spring  34  extending the camera  30  to a position proximate to the sheath tip  26 . Thus, the fragile camera  30  is exposed only when the protective sheath  24  is in place. A detent feature on the housing  12  (not shown) may lock the collar  40  against dislodgment or, alternatively, friction provided by the force between the internal threads and the pins  42  may serve the same purpose. 
         [0050]    Referring now also to  FIG. 3 , all or part of the sheath  24  may be constructed of a transparent material so that light emitting diodes  44  mounted on the structure of the housing  12  may project light  52  into a proximal portion of the conical sheath  24 . From there, the light  52  may be conducted by internal reflection in the manner of a light pipe to the distal sheath tip  26  of the conical sheath  24 . The light emitting diodes  44 , as attached to structure of the housing  12 , will be retained when the conical sheath  24  is removed and may be oriented to face a feature on the conical sheath  24  that promotes coupling of light  52  from the LEDs  44  into the conical sheath  24 , for example, an optical flat perpendicular to the direction of light propagation. 
         [0051]    In one embodiment, the LEDs  44  may provide for a combination of red, green, and blue elements so that the hue of the project light  52  from the LED  44  may be controlled, for example, to accentuate certain ear structure. At the sheath tip  26  a portion of light  52   a  exits in a direction parallel to the axis  22 ; however, some light  52   b  in a distal region  46  of the sheath  24 , before sheath tip  26 , may be coupled by a diffusing roughness  48  on the outer surface of the sheath  24  out of the sheath  24  to provide light  52   b  emanating along a radial direction from the sheath  24  to strike the walls of the ear canal  36 . This light  52   b,  through reflection and scattering between the outer surface of the sheath  24  and the walls of the ear canal  36  and through internal conductance to the tissue of the ear canal  36 , provides diffuse multi-angle illumination of the ear structure in the ear canal providing improved viewing of that structure through more uniform illumination and illumination arriving at multiple angles. The region  46  may be, in one embodiment, five millimeters in length along the axis  22  and as much as one and a half centimeters in some embodiments. 
         [0052]    Referring now to  FIG. 4 , the diameter  31  of the sheath tip  26 , measured in a plane perpendicular to the axis  22 , may be less than two millimeters and the diameter  41  of the sheath  24  in the distal region  46 , extending from the sheath tip  26  along the axis  22  by at least five millimeters and in one embodiment one centimeter, may be less than five millimeters and in some embodiments less than three millimeters to be substantially smaller than the ear canal  36 . It is intended that the sheath  24  that surrounds the camera  30  be sized to allow imaging of the eardrum  38  past minor obstructions, such as normally present earwax, and to allow passage within the ear canal  36  by medical instruments such as a curette for removing obstructing bodies such as earwax while probe assembly  20  is in place for imaging, that is, to permit instruments to extend to the side and pass the end of the sheath tip  26 . 
         [0053]    Referring still to  FIG. 4 , as noted above, the present invention provides a sheath tip  26  that is more flexible than a typical otoscope speculum. Generally the flexibility of the sheath tip  26  is intended to improve the comfort to the patient and reduce risk of damage to structure of the outer ear  33  caused by a small diameter probe. When the head portion  14  is stabilized, a perpendicular force  68  applied to the distal end of the sheath tip  26  of 100 grams will cause a deflection  69  of no less than one millimeter. In contrast, a similar force applied to the end of the atypical speculum will provide a corresponding deflection at the end of the speculum of much less than one millimeter. It will be appreciated that this flexibility may be provided by constructing the cylindrical probe  28  and conical sheath  24  from a flexible material or by mounting the cylindrical probe  28  and conical sheath  24  to the housing  12  through a flexible or compliant mount that allows a tipping of these elements in response to applied lateral force, or by a coating of the cylindrical conical sheath by elastomeric material, or by a combination of these approaches. 
         [0054]    Referring now to  FIG. 5 , the sheath tip  26  of the sheath  24  may be closed by an optically transparent, low distortion window  50  allowing images to be detected therethrough while protecting the camera  30  from contamination while also providing a sterile shield between the camera  30  and patient. An outer surface of the sheath  24  proximate to the sheath tip  26  may include rearwardly canted bristles or teeth  53  that may serve the purpose of assisting in the removal of debris and material from the ear canal  36  using the sheath  24  itself. These teeth  53  may be formed simultaneously with the material of the sheath  24  to be optically clear and therefore to pass illumination. Alternatively, the teeth  53  may be overmolded of a flexible elastomeric material such as silicone rubber thereby serving also to reduce the pressure between the sheath tip  26  and the ear canal  36  by a cushioning operation. 
         [0055]    The cylindrical probe  28  may be constructed of a relatively flexible material such as a silicone or polyvinyl chloride material and may be tubular to provide a passage for electrical conductors  54  communicating pixel image data from the camera  30 . 
         [0056]    Referring now to  FIG. 6 , the otoscope  10  may incorporate an electronic controller  102  such as a microcontroller being in essence an electronic computer and I/O circuitry. The controller  102  will provide a processor  104  communicating with a memory  106  permitting non-transient storage of a program  108 . Generally the program  108  will provide for the receipt of signals from the camera  27  and the display on display  18  of images from the camera and will provide for transmission of such images to affiliated equipment, for example, a PACS device. Program  108  may perform normal image processing, for example, exposure control, contrast adjustment, color balance and the like. The program  108  through the controller  102  may also control the illumination of the LEDs  66  as part of the exposure control process. In addition the memory  106  may hold a barcode decoder program  111  allowing the otoscope  10  to also be used for reading data from barcodes  117 , for example, to identify a particular image to a particular patient&#39;s file and transmit that barcode data with images in a protocol for linking the two. 
         [0057]    The controller  102  may also communicate either through a wireless transceiver  112  or an electrical connector  114  with other devices, for example, to permit the transmission of image data and barcode data to a remote electronic medical record server. 
         [0058]    A power button  113  may communicate with the controller  102  to put electronic circuitry into a low power sleep state, disabling the display  18 , camera  27 , and LEDs  66 . 
         [0059]    The program  108  in a standby mode may cycle through different colors on the LEDs  44  or display particular colors (e.g., pink) to improve the attractiveness of the otoscope  10  for pediatric patients who may be fearful of medical equipment The otoscope circuitry described above may be powered by a battery  109  contained in a grip that may be removably connected to the housing  12  by electrical and mechanical connector  115 . 
         [0060]    A sleeve detector switch  120  may also be provided to detect whether sheath  24  is in place before activating the otoscope  10  to prevent use of the otoscope  10  without a protective sheath  24 . 
         [0061]    It will be appreciated that the sheaths  24  are constructed to be relatively low-cost and therefore disposable, for example, such as may be manufactured by injection molding, and in this regard a variety of different sleeve types may be provided, for example, having different teeth designs for different purposes including other medical inspection of the nose or the like. 
         [0062]    Certain terminology is used herein for purposes of reference only, and thus is not intended to be limiting. For example, terms such as “upper”, “lower”, “above”, and “below” refer to directions in the drawings to which reference is made. Terms such as “front”, “back”, “rear”, “bottom” and “side”, describe the orientation of portions of the component within a consistent but arbitrary frame of reference which is made clear by reference to the text and the associated drawings describing the component under discussion. Such terminology may include the words specifically mentioned above, derivatives thereof, and words of similar import. Similarly, the terms “first”, “second” and other such numerical terms referring to structures do not imply a sequence or order unless clearly indicated by the context. 
         [0063]    When introducing elements or features of the present disclosure and the exemplary embodiments, the articles “a”, “an”, “the” and “said” are intended to mean that there are one or more of such elements or features. The terms “comprising”, “including” and “having” are intended to be inclusive and mean that there may be additional elements or features other than those specifically noted. It is further to be understood that the method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed. 
         [0064]    References to “a controller” and “a processor” can be understood to include one or more microprocessors that can communicate in a stand-alone and/or a distributed environment(s), and can thus be configured to communicate via wired or wireless communications with other processors, where such one or more processor can be configured to operate on one or more processor-controlled devices that can be similar or different devices. Furthermore, references to memory, unless otherwise specified, can include one or more processor-readable and accessible memory elements and/or components that can be internal to the processor-controlled device, external to the processor-controlled device, and can be accessed via a wired or wireless network. 
         [0065]    “Diameter” as used herein should not be understood to require a cylindrical or circular element but to simply describe a diameter of a circumscribing cylinder closely conforming to the element. 
         [0066]    It is specifically intended that the present invention not be limited to the embodiments and illustrations contained herein and the claims should be understood to include modified forms of those embodiments including portions of the embodiments and combinations of elements of different embodiments as come within the scope of the following claims. All of the publications described herein, including patents and non-patent publications are hereby incorporated herein by reference in their entireties.