Patent Publication Number: US-2022226064-A1

Title: Video glasses for use with a stereoscopic microscope for microsurgical procedures on patients

Description:
TECHNICAL FIELD 
     The present invention relates to video glasses for use with a stereoscopic microscope for microsurgical procedures on patients. 
     BACKGROUND OF THE INVENTION 
     Microscope-assisted surgery operation is known in the field of surgery of small structures, for example in neurosurgery or procedures on the ossicles in the middle ear, as well as in implant surgery. Thereby, the area to be treated, referred to in the following as the area of intervention, on the patient, at which the microsurgical procedure is to be performed, is represented, preferably by video glasses, in a magnified manner with the aid of a microscope. 
     From the pending patent application AT519845 by the inventors, video glasses for use with a stereoscopic microscope are known. It has turned out that the additional provision of the option to manually pivot the image display unit out and in the visual field of the surgeon wearing the video glasses without significant resistance and simultaneously the requirement to hold the image display unit stable in an upwardly pivoted state are not compatible or only implementable by an additional complex control circuit with sensors and drives, respectively. 
     Therefore, there is a demand to provide video glasses with an easy and without significant resistance at any time manually pivotable image display unit, while simultaneously keeping the image display unit in a stable position in at least one holding position even during fast movements of the surgeon wearing the video glasses and therefore high acceleration and centrifugal forces occurring thereby. 
     SUMMARY OF THE INVENTION 
     The objective is achieved by the video glasses according to the invention according to the features of claim  1 . Advantageous modifications are specified in the dependent claims  1  to  14 . Claim  15  specifies a stereoscopic microscope according to the invention. 
     Video glasses for use in microsurgical procedures according to the invention comprise a support device configured to fasten the video glasses to a head of a user, an image display unit for outputting images, a joint with a rotational axis, which connects the support device with the image display unit rotationally about the rotational axis between an operating position, in which the image display unit is arranged in front of the eyes of the user and images can be displayed to the user, and a rest position, in which the image display unit is arranged upwards out of the visual field of the user, and a locking device comprising a latching device and a catch arranged to let the latching device upon rotation in a rotational direction about the rotational axis engage the catch in a holding position and to release the latching device from the catch upon further rotation in the rotational direction, and wherein a rotation in the opposite rotational direction beyond the holding position is impeded as long as the latching device is engaged in the catch. 
     In an embodiment, the holding position corresponds to the rest position and/or the locking device comprises at least a further holding position between the rest position and the operating position. In an advantageous embodiment, the rotational angle from the holding position until release of the latching device from the catch is at least 10°. In a further advantageous embodiment, the rotational angle may be not more than 15° or is in a range from 10° to 15°. 
     The latching device may be configured as an elastically deformable tongue, and may be integrally made of plastic with the support device in a further advantageous embodiment. In an alternative embodiment, the latching device may comprise a pin biased by a spring and rotationally supported. 
     In a further preferred embodiment, the locking device is configured to only impede a rotation in the opposite rotational direction beyond the holding position in the rotational direction from the operating position in the rest position in the engaged state. In an embodiment, this may be achieved by the latching device comprising a pin rounded at one side and by the catch configured to let the rounded pin slide off the catch upon rotation in the opposite rotational direction. 
     The video glasses according to the invention may comprise a catch configured as notch. Said catch may be applied at a tip of a nose. In a preferred modification of the video glasses, the joint is a parallelogram joint. The video glasses according to the invention may further comprise an orientation sensor. The stereoscopic microscope according to the invention comprising video glasses according to the invention. 
    
    
     
       BRIEF DECRIPTION OF DRAWINGS 
         FIG. 1  shows a microsurgical stereoscopic microscope in an embodiment for use of the video glasses according to the invention. 
         FIG. 2  shows video glasses known from the prior art. 
         FIG. 3  shows video glasses in an embodiment preferred for the stereoscopic microscope according to the invention. 
         FIGS. 4A-D  show a preferred embodiment of the inventive locking device of the video glasses in different positions. 
         FIG. 5  shows a  3 D-view of the video glasses according to the invention in an embodiment. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS WITH REFERENCE TO THE FIGURES 
     Preferred embodiments of the video glasses  105  according to the invention for use with a stereoscopic microscope  100  in microsurgical procedures are described below with reference to the accompanying figures. 
       FIG. 1  shows schematically the design of a stereoscopic microscope  100  by the inventors in the pending patent application with the application no. PCT2019AT000005 in plan view for use in microsurgical procedures, with which the video glasses according to the invention may be preferably used. The stereoscopic microscope  100  comprises a stand  106  pivotally connectable with a robotic arm  111  via a joint  112 . The robotic arm  111  is affixable in a stable manner on the floor of the operating room via a holding device  106  to avoid vibrations to the greatest extent. Two optical image capturing units  113  are connectable to the stand  106  such that a stereoscopic image of the area of intervention  117  on the patient to be displayed during use can be captured and to define an image acquisition plane  110  by the two optical axis  107  of the image capturing units  113 . The image capturing units  113  are configured to enable an optical magnification up to  100  times. In an advantageous embodiment, the image capturing units  113  may be additionally configured to enable optical zoom-out. This is particularly advantageous for the user  103 , since he may get an overview of the area of intervention  117  and beyond. It also helps the user  103  to orient himself when approaching the area of intervention  117  with the surgical tools in hands. The images captured by both image capturing units  113  are transmitted and displayed by video glasses  105  comprising an optical image display unit  115  with a display to display an image to a user  103  wearing the video glasses  105 . For the stereoscopic correct and for the natural eye-hand-coordination required orientation of the images displayed to the user, the stereoscopic microscope comprises a detection device  104 , which detects the spatial orientation of the video glasses  105 . 
       FIG. 2  shows video glasses  300  with a support device  301  to hold the video glasses  300  on the head of the user  103  as known from the patent application of the inventors AT519845. The image display unit  115  is rotatably connected to a rotational axis  302  with respect to the support device  301  via joint  304 . The video glasses  300  additionally comprise a cable control  304 , which forms a manually operable loop with one end and which is affixed to the image display unit  115  with the other end such that the image display unit  115  is upwardly pivotable about the rotational axis  302  by the joint  304  to be guidable out of the visual filed of the user  103  wearing the video glasses  300  into the rest position. In the embodiment shown in  FIG. 2 , this is done by shortening the cable length by pulling on the cable control  304 . Thereby, the image display unit  115 , which is initially arranged in front of the eyes of the user  103  wearing the video glasses  300  and is in the operating position, is pivoted upwardly via the joint  304  about the rotational axis  302  above the eyes and therefore out of the visual field of the user  103  in the rest position against the weight force F. Conversely, if the cable length is lengthened, the image display unit  115  pivots back from the rest position in the operating position due to the weight force F. The video glasses  300  according to the invention are by no means limited to this embodiment, in particular other drives and also manual interventions are possible to guide the image display unit  115  out of the visual field of the user into the rest position (not shown) and vice versa from the rest position into the operating position. The image display unit  115  comprises image display devices  116  and a converging lens  303  for each eye of the user. The image display devices  116  of the image display unit  115  are arranged in a plane forming the image plane  109  and may be configured as either a single display, wherein the image output on the display is being divided for each image display unit  115 , or as two separate displays. 
       FIG. 3  shows an embodiment of the locking device  312  of the video glasses  300  according to the invention by way of example. Thereby, the joint  304  with the rotational axis  302  is affixed on one side via the lever arm  305  to the image display unit  115  via a mechanical connection  307 . The joint  304  is on the other side affixed to the support device  301  not shown such that a rotation of the joint  304  about the rotational axis  302  pivots the image display unit  115  relatively to the support device  301 . If, as shown in the Figure, the joint  304  is a rotational joint, the image display unit  115  is thereby pivoted about the joint axis  302 . If, in an embodiment, the joint  304  is configured as parallelogram joint (not shown), the image display unit  115  moves along a circular path without itself rotating about the rotational axis  302 . Therefore, the image display unit  115  may come to rest closer to the user&#39;s head in the rest position, forms a shorter lever, and advantageously allows a lower torque to be effective on the user&#39;s head. This increases the comfort of wear of the video glasses  300  in the rest position. 
     In a preferred embodiment, the video glasses  300  according to the invention comprise an electric drive  309 , which establishes a rotatable connection with the joint  304  via a sliding clutch  310 . The sliding clutch  310  has thereby the function not to stop the electric drive  309  when the image display unit  115  is in the rest position or in the operating position to avoid high currents by the electric drive  309 . Additionally, the sliding clutch  310  helps to reduce the force to be applied for the manual rotation of the image display unit  115 . For example, the force to be applied by the user  103  to move the image display unit  115  upwardly from the operating position into the rest position is only slightly greater than the weight force F. Further, the sliding clutch  310  improves safety, if the image display unit  115  is blocked in an intermediate position between the operating position and the drive position, to avoid, on one hand, too high currents by the electric drive  309  as before and, on the other hand, to prevent the user  103  from becoming trapped. The rotatable connection may either take place by direct connection of the joint  304  and the electric drive  309 , or by an intermediate reduction gear comprising intermeshing gears or belts or a combination of gears and belts. In an embodiment, the electric drive  309  may be configured as a servo motor. 
     In an advantageous embodiment according to the invention, the electric drive  309  is affixed to the support device  301  and drives the portion of the joint  304  affixed to the image display unit  115 . This embodiment provides the advantage that the weight of the image display unit  115  may be decreased and therefore contributes to the ability to pivot the image display unit  115  with less force effort by the electric drive  309  as well as manually. However, the electric drive  309  may just also be affixed to the image display unit  115 , wherein, in such event, the respective portion of the joint  304  which is connected to the support device  301  is driven. In order to control the position of the image display unit  115  with respect to the support device  301 , a sensor  311  may be mounted on the rotational axis of the electric drive  309  or the rotational axis  302  of the joint  304 . In an embodiment, the sensor  311  may be a rotation rate sensor or a rotatable resistor. 
     The locking device  312  comprises a latching device  306  and a catch  308  arranged to let the latching device  306  upon rotation in a rotational direction about the rotational axis  302  of the joint  304  engage the catch  308  in the holding position such that thereby a rotation in the opposite direction beyond the holding position is impeded, and to release the latching device  306  from the catch  308  upon further rotation in the rotational direction such that a rotation in the opposite rotational direction beyond the holding position is again possible. The latching device  306  may thereby be either affixed to the support device  301  and the catch  308  to the image display unit  115  or, vice versa, the latching device  306  to the image display unit  115  and the catch  308  to the support device  301 . The holding position is thereby either an intermediate position between the operating position and the rest position or, in an embodiment, the rest position itself. In a further embodiment, the locking device  312  may at least provides a further holding position between the rest position and the operating position. 
     In the following, the video glasses  300  according to the invention will be explained with reference to  FIGS. 4A-D .  FIGS. 4A-D  show the locking device  312  in different positions.  FIG. 4A  shows the locking device  312  in the holding position as it comes to rest after rotation from the operating position into the rest position, which in the Figure corresponds a rotation clockwise. The latching device  306 , here in an embodiment shown as biased and rotatable pin, is engaged in the catch  308 . In an embodiment, the latching device  306  may be an elastic tongue, preferably integrally formed with the support device  301 . The elasticity thereby applies the spring effect. In this embodiment, the catch  308  is formed as a nose projecting radially outward from the rotational axis  304  of the joint  302  and providing a notch at the tip. In the holding position, the latching device  306  is engaged in the notch as shown. The weight force F of the image display unit acts against this rotational direction. The catch  308  is supported against the latching device  306  (indicated by the arrow) and thus prevents a rotation of the image display unit  115  back in the direction of the operating position beyond the holding position. In the Figure, this corresponds to a rotation counterclockwise about the rotational axis  304 . 
       FIG. 4B  shows the locking device  312  upon further rotation in the rotational direction, corresponding in the Figure to a rotation clockwise. The latching device  306  initially remains in the catch  308 . Only after the rotation is further rotated beyond an angle α, the latching device  306  is released again from the catch  308 . In a preferred embodiment, the angle α is about 10°, 15° or in the range of 10° to 15°. If now rotated counterclockwise, as illustrated in  FIG. 4C , the latching device  306  will mesh the catch  308  from the opposite side and engage. Accordingly, the catch  308  is only again supported against the latching device  306  upon rotation in the opposite rotational direction. In the Figure, this is a rotation clockwise. Upon further rotation counterclockwise, the latching device  306  is again released from the catch  308  and a further rotation about the rotational axis  304  of the joint  302  may take place without restrictions until the image display unit  115  returns again to the operating position. This position is shown in  FIG. 4D . If the image display unit  115  is again rotated towards the rest position by rotation about the rotational axis  304 , the locking device  312  is returned to the holding position as shown in  FIG. 4A . 
       FIG. 5  shows an embodiment of the video glasses  300  according to the invention comprising a support device  301 , an image display unit  115 , a joint  304  with the rotational axis  302  and an optical marking  313  at a predetermined positions on the video glasses  300  for detection of the spatial orientation of the video glasses  300  by the detection device  104 . The marks may be, for example, colored or in the infrared range reflective dots, lines or other symbols recognizable by image recognition. The rotational axis  302  is in parallel to the forehead of the user  103  when the video glasses  300  are worn. The image display unit  115  is arranged in front of the eyes of the user  103  in the operating position. If the image display unit  115  with the joint  304  is upwardly rotated about the rotational axis  302 , the image display unit comes to rest in the rest position above the eyes and out of the visual field of the user  103 . Further, in this position, the video glasses  300  in this embodiment are in the holding position and the latching device  306  is engaged in the catch  308  of the locking device  312  and prevents a rotation towards the operating position beyond the holding position, which, in this case, is also the rest position. The image display unit  115  is thereby held stably in the rest position. In order to return the image display unit  115  again in the operating position, the image display unit  115  has first to be raised upwardly beyond the rest position either manually or with the electric drive  309  by rotating the joint  302  about the joint axis  304  until the latching device  306  is released from the catch  308 . Only then, the image display unit  115  may be returned in the opposite rotational direction of the joint  304  about the rotational axis  302  into the operating position.