Abstract:
The prism glasses include movable prism lenses and, optionally. detachable temples. The movable lenses permit the user to alter the viewing angle from substantially 90 degrees downward to substantially 90 degrees upward. The glasses include a planar frame plate, a bridge, a forward outboard face and view ports therethrough. Two prisms, one for each view port, transmit the image. Prism frames have mounting elements for attachment and detachment to complementary mount elements on the frame. The mounts permit either rotation or removal and re-insertion on the frame. In a first mode of operation, the prism transmits a 90 degrees image. The prism mounts cooperate with the complementary frame mounts and the prism lenses can be (a) removed and re-positioned at a 180 degrees position or (b) moved 180 degrees from the downward 90 degree viewpoint to an upward 90 degree viewpoint to the second operational mode.

Description:
[0001]    The present invention relates to prism glasses wherein the user can view images 90 degrees downward or 90 degrees upward by moving the prism lenses on the eyeglass frame. Also, the present invention relates to prism glasses with detachable temples. 
       BACKGROUND OF THE INVENTION  
       [0002]    Prism glasses, and particularly glasses made only of plastic or non metallic, non-ferrous (non-magnetic) material, are used in many situations including, but not limited to, reducing the claustrophobic feeling when a user is subjected to an MRI procedure. During this procedure, the user typically lies flat on his or her back and his or her body is inserted either feet first or head first into a large cylindrical MRI container which generally makes considerable noise during the MRI procedure. When the user wears prism glasses, the user can see either images downward at the user&#39;s feet or upward beyond the user&#39;s head. Technicians may converse with the users or the users may view a film or other visual distraction at the user&#39;s feet or beyond the user&#39;s head. Of course, if the user is lying on his or her back, the image is “down” in the direction of the user&#39;s feet or “up” above the user&#39;s head. Herein, the point of reference for up and down is the eyeglass frame resting on the user&#39;s nose. 
         [0003]    One prior art device employs an eyeglass frame where the prism lenses are permanently mounted in a fixed manner on the frames and the user&#39;s view is always 90 degrees downward. 
         [0004]    U.S. Pat. No. 4,804,261 to Kirschen shows Anti-Claustrophobic Glasses. The Kirschen patent uses angled mirrors that causes image reversal. Also, the mirror angle is not fixed in the Kirschen system so adjustment of the mirror angle to capture the correct image view is time consuming and problematic as angle could change due to vibrations, gravity, and patient movement. An incorrect mirror angle will prevent the patient from seeing intended image target. Further, the Kirschen mirror system may come out of adjustment, that is, change its angular view, during the MRI scan due to MRI system vibration, patient movement or a loose mirror unit. The term MRI as used herein refers to Magnetic Resonance Imaging (MRI), or nuclear magnetic resonance imaging. Kirschen has a back surface mirror mounted on spectacle frame which is attached to the patient&#39;s head with an adjustable elastic band. The elastic band requires adjustment for every patient, which takes time and, if not adjusted correctly, could be uncomfortably tight or too loose, causing misalignment of the angled mirror, changing the person&#39;s view of the intended target. It is not easy to clean the elastic band that comes in contact with patient hair, potentially enabling the spread of lice, viruses, bacteria and germs 
         [0005]    U.S. Pat. No. 5,173,720 to Lee is a Field of View Changer so patients can go in Head-First or Feet-First into the MRI cylinder and maintain visual contact outside the bore to see a projection screen, mural, technologist or friendly face. 
       OBJECTS OF THE INVENTION  
       [0006]    It is an object of the present invention to provide prism glasses with movable lenses such that the user, or an assistant to the user, can alter the viewing angle from substantially 90 degrees downward to substantially 90 degrees upward by removing the lenses or altering the position of the lenses with respect to the eyeglass frame and the viewing port. The user&#39;s eyes, when looking straight forward, view images through the frame view ports (left and right ports). Alternatively, the prism lenses may rotate on the frame in the plane of the eyeglass frame plate. 
         [0007]    It is a further object of the present invention to provide clip-on temples for prism glasses. 
         [0008]    It is another object of the present invention to provide prism glasses wherein and prism mounted in the prism frame can be rotated to alter the viewing angles from 90 degrees downward to substantially 90 degrees upward. 
         [0009]    Another object of the present invention is to utilize a wrap around strap rather than detachable temples. 
       SUMMARY OF THE INVENTION  
       [0010]    One embodiment of the prism glasses includes movable prism lenses and detachable temples wherein the movable lenses permit the user to alter the viewing angle from substantially 90 degrees downward to substantially 90 degrees upward. The detachable temples (an optional feature) permit the user to selectively attach temples on the eyeglass frame or to use a clip-on strap rather than the detachable temples. This feature enables the prism glasses to fit large or small adult heads or smaller child heads. The prism glasses with movable prism lenses and detachable temples includes an eyeglasses frame having a generally planar frame plate and a bridge centrally located in the frame plate. The bridge is adapted to rest the frame on an user&#39;s nose. Frame end pieces are disposal at terminal ends of the frame plate. The frame plate has a forward facing outboard face or surface and the plate defines view ports as through passages on opposite sides of the bridge. Two detachable temples each have a releasable lock end piece at one end. The frame plate end pieces have complementary end lock elements which are complementary to the releasable lock end piece on the temples. Two prisms, one for each view port, transmit an image 90 degrees from an image source into the view port and hence the user&#39;s eyes. Each prism has a prism frame with prism frame mount elements thereon to permit removable attachment and detachment to and from said eyeglasses frame. Alternatively, the prism frame mounts move or rotate with respect to the frame to re-position the prism lenses 180 degrees. The glasses frame has a pair of complementary mount elements disposed about the through passages on said forward facing outboard face of the frame plate. The complementary frame mounts are complementary to the prism frame mounts. In this manner, the prism glasses have at least first and second modes of operation. In a first mode, each said prism transmits a downwardly disposed image 90 degrees through the view ports. The prism frame mount elements cooperate with the complementary frame plate mount elements and permit the prism lenses to be (a) removed and re-positioned at a 180 degrees position or (b) moved 180 degrees from the downward 90 degree viewpoint to an upward 90 degree viewpoint. Therefore, in the second mode, each prism transmits an upwardly disposed image 90 degrees through the respective view port. The prism frame mounts and the eyeglasses frame mounts may be one of a lip interlock with a channel such that the lenses slide up or down with respect to the frame enabling the lenses to be removed and re-inserted into the lip-channel interlock; a circular prism frame with a lip-channel mount for 180 degree rotation; a tongue and groove mount system which operates similar to the lip and channel system; an interference fit between the prism frame mount elements and the complementary frame plate mount elements; tabs interlocking with tab lock capture channels such that the lenses clip onto the tab lock capture channels (and can be removed therefrom by a lateral force); snap in tabs interlocking with capture channels; detents and indent interlocks (operating like a ball and socket click-in system); and interfacing threads on the prism frame mount elements and the complementary frame plate mount elements (male and female threads) permitting the lens frames to be screwed into the eyeglasses frame. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0011]    Further objects and advantages of the present invention can be found in the detailed description of the preferred embodiments when taken in conjunction with the accompanying drawings in which: 
           [0012]      FIG. 1  diagrammatically illustrates a user or a patient viewing a downward image I 1  when the user is moved feet first into a large MRI unit or, in an alternative mode, the user views image I 2  which is above the user&#39;s head. The upward 90 degree viewpoint may be used when the user is put head first into an MRI unit; 
           [0013]      FIG. 2  diagrammatically illustrates the eyeglasses frame of the present invention and, more particularly, a view of an inboard or interior surface of the frame plate; 
           [0014]      FIG. 3  diagrammatically illustrates a top view of the eyeglasses frame in accordance with the principles of the present invention; 
           [0015]      FIG. 4  diagrammatically illustrates a partial view of the frame from section line A′-A″ in  FIG. 2 ; 
           [0016]      FIG. 5  diagrammatically illustrates the eyeglasses frame with a removable prism lens in a prism lens frame as well as the removable temples from the perspective of section line B′-B″ in  FIG. 2 . 
           [0017]      FIG. 6A  and  FIG. 6B  diagrammatically illustrate a side view and a top view of one of the temples for the eyeglasses; 
           [0018]      FIG. 7  diagrammatically illustrates optics of the prism in conjunction with image I 3  at a 90 degree view angle compared with the user&#39;s eye E; 
           [0019]      FIG. 8  diagrammatically illustrates the prism in the prism frame; 
           [0020]      FIG. 9  diagrammatically illustrates an alternate embodiment of the invention wherein the prism and prism frame is rotatably mounted with respect to the eyeglass frame (permitting 180 degree rotation in the eyeglass frame plane); 
           [0021]      FIG. 10  diagrammatically illustrates a prism frame lip and an eyeglass channel retaining the lip; 
           [0022]      FIG. 11  diagrammatically illustrates L-shaped clips which are rotatable with respect to the glasses frame permitting removal of the prism lens and the prism frame; 
           [0023]      FIG. 12  diagrammatically illustrates a plurality of tabs which hold the prism frame; 
           [0024]      FIG. 13  diagrammatically illustrates snap and snap channel mounts (which may be replaced by detents and indents); 
           [0025]      FIG. 14  diagrammatically illustrates a circular prism mount and prism lens; and 
           [0026]      FIG. 15  diagrammatically illustrates a screw-on or threaded connection feature of the prism frame in conjunction with the eyeglass frame. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0027]    The present invention relates to prism glasses with movable lenses such that the user can alter the viewing angle from substantially 90 degrees downward to substantially 90 degrees upward. Another feature of the present invention is a detachable temple. 
         [0028]      FIG. 1  diagrammatically illustrates a user or a patient viewing a downward image I 1  when the user is moved feet first into a large MRI unit or, in an alternative embodiment, the user views image I 2  which is above the user&#39;s head when the user is put head first into an MRI unit. User  10  is lying on movable bed  12 . User  10  is wearing eyeglasses  14 . With respect to MRI unit  16 , user  10  on bed  12  is moved inward into the opening or core of MRI  16 , feet first. In one instance, the user may see image I 1  which is downward and further beyond the feet of the user. In another instance, user  10  may see image I 2  which is outboard of MRI unit  16  and beyond the MRI cavity. Alternatively, user  10  may be inserted into alternate MRI unit  16   a  in a head first manner. Similarly, depending upon the configuration of the prism lenses in prism glasses  14 , the user may see image I 2  which is above the head of the user or may see image I 1  which is laterally disposed downward past the user&#39;s feet. 
         [0029]      FIGS. 2-8  diagrammatically illustrate several aspects of the present invention. These aspects include a removable prism lenses such that the user can alter his or her view from 90 degrees downward to 90 degrees upward (from I 1  to I 2  in  FIG. 1 ). Further,  FIGS. 2-8  diagrammatically illustrate removable temples. Similar numerals designate similar items throughout the drawings. Eyeglasses  14  include a generally planar frame plate  20 . Frame plate  20  includes a centrally located bridge  22  and opposing but facing nose pads  24 ,  26 . The left segment  27  of eyeglasses  14  is substantially similar to the right segment  29 , that is, one segment is a mirror of the other segment. Eyeglasses  14  include viewing ports  30  on opposite sides of bridge  22 . The terminal ends  32  of frame plate  20  have, in the illustrated embodiment, end lock elements  34  which are complementary to releasable lock end elements  36  ( FIG. 5 ) of temples  38 . 
         [0030]    In the illustrated embodiment of  FIG. 2 , eyeglass frame  20  includes a rear or inboard surface  41 . The frame  20  includes front facing or outboard surface  42 . Outboard surface  42  and inboard surface  41  are best shown in  FIG. 3 . 
         [0031]      FIG. 3  shows a plurality of mount elements  44   a,    44   b  which oppose each other and protrude from front face  42  of eyeglass frame  20 . 
         [0032]      FIG. 4  shows that frame mount  44   b  extends the vertical distance of view port  30 . This frame prism mount assures that once the prism is mounted by insertion into the frame, the viewing angle is always proper. 
         [0033]      FIG. 5  diagrammatically shows that prism lens  50 , which is mounted in prism frame  52 , is insertable in frame mount  44   a  as noted by directional arrow  53 . Further,  FIG. 5  shows that releasable lock end piece  36  of temple  38  is insertable as noted by arrow  55  into complementary end lock element  34  on glasses frame  20 .  FIG. 5  shows lip-channel mount system. 
         [0034]      FIG. 6A  shows that, in one embodiment, the releasable lock end piece  36  includes tab ends  60 ,  62  which permit flexible tab action in the direction of double headed arrow  63  such that releasable lock element  36  can be pushed together as noted by arrow  55  in  FIG. 5  and inserted and removed into complementary end lock element  24  of frame  20 . 
         [0035]      FIG. 6A  is a side view of temple  38  and  FIG. 6B  is a top view of temple  38 . Of course, the eyeglasses have two temples just as the eyeglasses have two prism lenses mounted in respective prism frames. To achieve an absolute correct viewing angle, the prisms must be positioned over view ports  30 . 
         [0036]      FIG. 7  shows that the user&#39;s eye E sees image I 3  at a substantially 90 degree angle due to reflection and refraction in prism  50 . Prism  50  is mounted in a prism frame  52 . Certain portions of the frame are shown in  FIG. 8 . Particularly, prism frame  52  includes protruding lip  70  which lip cooperates with the pair of capture channels  44 A,  44 B shown in  FIGS. 2 ,  3 . Alternately, a tongue and groove or interference fit may be provided. The attachment mechanism mounting the movable prism lenses to frames  20  can be altered.  FIG. 9  shows that prism lenses  50  can be rotated as shown in direction arrow  81  when the prism lenses  50  are mounted on a circular prism frame  80 . The prism lens  50  is rectangular but the lens frame is circular, or at least the prism frame mount lip is circular. Rotation of 180 degrees of the prism and lip in the frame plane changes a downward view angle to an upward view angle. 
         [0037]      FIG. 10  shows that prism frame  80  has an outwardly extending lip  82 . Lip  82  cooperates and travels within the C-shaped channel formed by eyeglass frame mount  84 . By rotating the lens  50  from the position shown by a solid line in  FIG. 9  to the position shown in dashed lines such that the upper and lower surfaces of prism lens  50 , that is, surfaces  51 A,  51 B are reversed from the solid line illustration to a broken-line reversed position (surface  51 B located closer to bridge  22 ), the user has altered the viewing angle from 90 degrees downward to 90 degrees upward. As used herein, the term “upward” and “downward” refer to angles of view either above the eyeglass frame (referencing an upward view in the eyeglass frame plane) as compared with the opposite view when the user sees items downward with respect to the eyeglass frame. 
         [0038]      FIG. 11  shows that prism frame  80  can be mounted to eyeglass frame  20  by L-shaped brackets. The brackets  86   b  may be rotatable as noted by movement arrow direction  87 . Some of the L-shaped brackets  86   a  may be fixed compared with others which may be movable L-shaped brackets  86   b.    
         [0039]      FIG. 12  diagrammatically illustrates fixed L-shaped tabs  90  attached to eyeglass frame  20 . In this manner, lip  70  of prism frame  52  can cooperate and slide into and out of the tabs  90  in  FIG. 12 . The L-shaped tabs form C-shaped channels with frame surface  42 . 
         [0040]      FIG. 13  shows a snap-in mount element  92  in the prism frame. The prism frame  92  may have outwardly protruding snaps configured as tabs  89  which snapping tabs cooperate with front protruding tabs  92  from frame  20 . Opposing tapered end surfaces assist attachment and detachment. A snap channel  94  is formed beneath protruding snap tab  92  of frame  20 . Snap channel  94  captures the protruding lip or tab  92  from prism frame  52 . 
         [0041]      FIG. 14  diagrammatically illustrates that prism lens  50  may be mounted on a round prism frame  96 . 
         [0042]      FIG. 15  is the view from section line C′-C″ in  FIG. 14  and shows that prism frame  96  includes threads  97 . A frame mount  98  from eyeglass frame  20 , protruding from the front face of the frame, includes a plurality of threads  99 . Alternatively, threads  99  may be placed on view port edge  83 . The male and female threads may be reversed in  FIG. 15 . Likewise, lips and channels and tabs and capture channels may be reversed. 
         [0043]    The present invention can be used by bed-ridden patients, by others who want to read in bed or view TV near the end of the bed, by industrial workers and others who view work 90 degrees disposed from a straight-on view angle, or as a military observation tool. The new prism glasses can be used with any MRI Coil and by all MRI System manufacturers. The inventive glasses are magnetically inert (containing no ferrous metal, made from magnetically inert plastic and nylon parts), and lightweight. 
         [0044]    Prior art devices with metallic hinges, or even hinges were made of a non-ferrous material, cause image artifacts and distortion of scans of the head or brain, thereby making the prior art glasses poor candidates for fMRI which typically studies the brain. 
         [0045]    As a military observation tool, the user could sit or lie down for long periods while wearing the prism glasses and maintain watch while scanning horizon (lying flat on back) or sitting up watching skyward. With one prism UP and the other DOWN, a field soldier or animal tracker could keep watch front and back while lying on their back, looking for any movement. An industrial use would permit a factory worker while working an assembly line, to see items upwardly disposed (at equipment) or downwardly disposed (PC Board Soldering) for long periods of time without causing neck strain. 
         [0046]    Other uses include any situation in which a patient is in an environment where the view to the front is blocked or occluded and the situation tends to cause anxiety. 
         [0047]    A mountain climbing instructor could use the prism glasses to view images upward without creating neck strain. A typist could look straight ahead and see manuscript on their desk as well as the keys being typed while looking straight ahead. Bicyclist could use the prism glasses to keep their head down while seeing straight ahead, maintaining minimal wind resistance, and the person could still be able to glance over the top of the spectacles to maintain a normal view when needed without fully raising head. Workers who must keep looking upward at a bridge, crane, elevator, windows, building, scaffolding, etc. could use the upward view of the prism glasses, and individuals who need to see downward (i.e. crane operator, factory workers) for long periods could rotate the prisms the opposite direction accordingly, thereby minimizing neck strain. Patient&#39;s and individuals who must lie flat on their back can use prism glasses to view TV screen that is wall mounted, whether the TV is at the foot of their bed or towards the head of their bed and the images would not be reversed 
         [0048]    The claims appended hereto are meant to cover modifications and changes within the scope and spirit of the present invention.