Abstract:
The disclosure describes a system that is used to lock an accessory within a housing. For example, the accessory is a cystoscope that is locked to a hand held device that provides prostate ablation therapy. The system includes a sliding lock device (SLD) which receives and surrounds at least a portion of the cystoscope in an opening. Once the cystoscope is positioned within the SLD, the user may slide a cover to engage a tab of the cystoscope and secure the cystoscope within the SLD and the housing. The SLD also includes a mechanism for prohibiting cystoscope rotation. After the cystoscope is locked, the SLD allows for a defined amount of axial movement to facilitate prostate viewing and the deployment of prostate ablation therapy. Alternatively, the cover may slide in a rotational manner to secure the cystoscope.

Description:
TECHNICAL FIELD  
       [0001]     The invention relates to connectors and, more particularly, to devices for securely attaching accessories.  
       BACKGROUND  
       [0002]     Medical devices commonly include a wide variety of accessories to support patient needs and physician preferences. These accessories must be removable or replaceable to ensure sterile conditions between patients and procedures. In addition, disposable devices may interface with non-disposable equipment. Connectors are integral to the function of medical devices and the use of appropriate attachments.  
         [0003]     For example, cystoscopes are commonly used to examine the urethra and bladder for treating benign prostate hyperplasia (BPH) in men. BPH is a condition caused by the second period of continued prostate gland growth. This growth begins after a man is approximately 25 years old and may begin to cause health problems after 40 years of age. The prostate growth eventually begins to constrict the urethra and may cause problems with urination and bladder functionality. Minimally invasive techniques include inserting a needle through the urethra to place the needle at the prostate site. Once positioned correctly, the needle is heated to ablate the prostate tissue to reduce the tissue volume and treat BPH.  
         [0004]     A physician performs this procedure with a hand held device for inserting the needle and providing the therapeutic energy. The physician also uses a cystoscope to view inside of the urethra to correctly place the needle for proper therapy. In this example, a connector is used which allows the cystoscope to interface with the hand held device and reduce procedure time and increase treatment efficacy.  
       SUMMARY  
       [0005]     The disclosure describes a system that is used to lock an accessory within a device. For example, the accessory is a cystoscope that is locked to a hand held device that provides prostate ablation therapy. The system includes a sliding lock which receives and surrounds at least a portion of the cystoscope in an opening. Once the cystoscope is positioned within the sliding lock device (SLD), the user may slide a cover in one direction to engage a tab of the cystoscope and secure the cystoscope within the SLD. The SLD also includes a mechanism for prohibiting cystoscope rotation. After the cystoscope is locked, the SLD allows for a defined amount of axial movement to facilitate prostate viewing and the deployment of prostate ablation therapy. Alternatively, the cover may slide in a rotational manner to secure the cystoscope.  
         [0006]     Physicians prefer devices that are easy to use while providing safe and effective treatment for their patients. A simple device that is capable of locking an accessory such as a cystoscope may decrease treatment time and allow the physician to focus on the treatment.  
         [0007]     In one embodiment, the disclosure is directed to a system for releasably attaching a device to a housing comprising an elongate collar comprising a longitudinal bore, wherein a first end of the collar engages an opening in the housing, and wherein the collar is slideable within the opening in the housing and along a longitudinal axis of the bore of the collar, a collar flange on a second end of the collar comprising a substantially planar first mating surface, wherein the collar flange and first mating surface is substantially normal to the longitudinal axis of the bore of the collar, and a cover comprising a substantially planar second mating surface and a pair of sidewalls substantially parallel to the second mating surface in which the sidewalls form channels for engaging the collar flange, and wherein the second mating surface slides in a place over the first mating surface.  
         [0008]     In another embodiment, the disclosure is directed to system for releasably attaching a device comprising an elongate collar comprising a longitudinal bore, wherein a first end of the collar comprises at least one retaining structure that extends in a direction normal to a longitudinal axis of the bore of the collar, a collar flange on a second end of the collar comprising a substantially planar first mating surface, wherein the collar flange and first mating surface is substantially normal to the longitudinal axis of the bore of the collar, and a cover comprising a substantially planar second mating surface and a pair of sidewalls substantially parallel to the second mating surface in which the sidewalls form channels for engaging the collar flange, wherein the second mating surface comprises an opening, and wherein the second mating surface slides in a plane over the first mating surface.  
         [0009]     In an alternative embodiment, the disclosure is directed to a system for releasably attaching a device comprising an elongate collar comprising a longitudinal bore, wherein a first end of the collar comprises at least one retaining structure that extends in a direction normal to a longitudinal axis of the bore of the collar, a collar flange on a second end of the collar comprising a substantially planar first mating surface, wherein the collar flange and first mating surface is substantially normal to the longitudinal axis of the bore of the collar, and wherein a first portion of the collar flange is attached to the second end of the collar, and a cover comprising a substantially planar second mating surface coupled to the first portion of the collar flange, wherein the second mating surface comprises an opening.  
         [0010]     In various embodiments, the SLD may provide one or more advantages. For example, the SLD can be operated with only one hand as force is applied in just one direction to lock or unlock the device. The SLD prohibits cystoscope rotation while allowing for a defined amount of axial movement useful when providing therapy. The SLD also may accept any Storz compatible cystoscope that a physician prefers to use. In addition, the SLD is easily manufactured and assembled from a wide variety of injection moldable plastics and is inexpensive to produce.  
         [0011]     The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0012]      FIG. 1  is a conceptual diagram illustrating an exemplary cystoscope locked into a hand held device.  
         [0013]      FIGS. 2A and 2B  are side views of an exemplary sliding lock in two different positions with respect to a hand held device.  
         [0014]      FIGS. 3A and 3B  are front views of an exemplary sliding lock in open and locked configurations.  
         [0015]      FIG. 4  is a top view of an exemplary sliding lock removed from a hand held device.  
         [0016]      FIG. 5  is side view of two components of an exemplary sliding lock.  
         [0017]      FIG. 6A and 6B  are front views of an alternative sliding lock device.  
         [0018]      FIG. 7A and 7B  are front views of a snapping lock device.  
     
    
     DETAILED DESCRIPTION  
       [0019]      FIG. 1  is a conceptual diagram illustrating exemplary cystoscope  18  locked into a hand held device. As shown in  FIG. 1 , system  10  includes housing  12  which is attached to handle  14  and trigger  16 . Cystoscope  18  includes probe  20  and is locked within housing  12  by sliding lock device (SLD)  22 . In this exemplary embodiment, system  10  is utilized for the treatment of benign prostatic hyperplasia (BPH). A physician holds handle  14  and trigger  16  to guide probe  20  through a urethra. The physician uses the cystoscope to view the urethra through probe  20  and locate a prostate for positioning a needle (not shown) into the prostate from a catheter (not shown) adjacent to probe  20 . Once the physician identifies correct placement for the needle, trigger  16  is squeezed toward handle  14  to extend the needle into the prostate.  
         [0020]     With the exception of cystoscope  18 , system  10  is coupled to a radio frequency (RF) generator (not shown) that provides the energy used to ablate the prostate tissue. System  10  may also be coupled to a fluid delivery device (not shown) which may irrigate the treatment site with the fluid. Cystoscope  18  is an accessory and is not permanently disposed within housing  12 . The cystoscope  18  is typically an expensive, non-disposable instrument with many different designs. Physician preferences vary widely, so a removable cystoscope may be necessary for treatment efficacy.  
         [0021]     Probe  20  of cystoscope  18  may be inserted into an opening running the length of housing  12 . SLD  22  also resides within the opening to surround a portion of cystoscope  18 . Once cystoscope  18  is inserted into housing  12 , the physician may push SLD  22  into the locked conformation of the SLD which prevents cystoscope  182  from moving with respect to SLD  22 . SLD  22  does permit a defined amount of axial movement along the longitudinal axis of the opening in housing  12  between SLD  22  and the housing. This axial movement allows the physician to view the urethra when cystoscope  18  is pushed close to housing  12  and view needle placement in front of probe  20  when cystoscope is moved away from housing  12 .  
         [0022]     SLD  22  may provide certain advantages to the physician in operating system  10 . The physician may lock SLD  22  with only one hand, instead of using two hands to secure cystoscope  18  within housing  12 . SLD  22  also uses male locking structures, detents, and female locking structures, indents, to lock the SLD in either open or closed positions. While cystoscope  18  is secured within housing  12 , a defined amount of axial movement allows a small degree of flexibility to facilitate the treatment.  
         [0023]     Housing  12 , handle  14  and trigger  16  are constructed of a lightweight molded plastic such as polystyrene. In other embodiments, other injection molded plastics may be used such as polyurethane, polypropylene, high molecular weight polyurethane, polycarbonate or nylon. Alternatively, construction materials may be aluminum, stainless steel, a metal alloy or composite material. In addition, housing  12 , handle  14  and trigger  16  may be constructed of different materials instead of being constructed out of the same material. In some embodiments, housing  12 , handle  14  and trigger  16  may be assembled through snap fit connections, adhesives or mechanical fixation devices such as pins or screws.  
         [0024]     Cystoscope  18  may be any type of cystoscope or similar internal viewing device. The length of probe  20  may vary with respect to the intended procedure. In some embodiments, any scope with a Storz (Karl Storz, Germany) compatible locking design may be used. In other embodiments, SLD  22  may be located at the opposite end of housing  12  to be compatible with a certain type of cystoscope or facilitate ease of operation for the physician.  
         [0025]     While the exemplary system  10  illustrates SLD  22  within housing  12  to secure cystoscope  18 , SLD  22  may be used in any type of system to secure an accessory. For example, SLD  22  may be used to secure any type of scope or catheter to be inserted within a patient. In other embodiments, SLD  22  may be used to lock electrical cables, fluid lines, or any other system where simple and quick locking is beneficial to the system function. System  10  as described in  FIG. 1  will be used as an example of SLD  22  herein.  
         [0026]      FIGS. 2A and 2B  are side views of exemplary SLD  22  in two different positions with respect to housing  12 . As shown in  FIG. 2A , SLD  22  is located within housing  12  in the retracted position. The retracted position is used by the physician to navigate through the urethra. SLD  22  includes cover  24  coupled to collar flange  28 . Cover  24  includes limit flanges  35  and  36  and sidewall  34 . Collar flange  28  is attached to collar  26  which contacts the opening of housing  12 . Collar  26  includes retaining tabs  30  and  31  and o-ring  32 . Retaining tab  30  contacts bumper  38  to prohibit collar  26  from sliding out of housing  12 .  
         [0027]     Cover  24  is in the locked conformation to hold cystoscope  18  securely. Limit flange  35  prevents cover  24  from sliding off of collar flange  28 . Limit flange  36  also prevents cover  24  from sliding off of collar flange  28  at the opposing end of the cover. Limit flanges  35  and  36  are curved to match the ends of cover  24  and collar flange  28 . In some embodiments, limit flanges  35  and  36  may be any shape or size necessary to prevent cover  24  from becoming unattached from collar flange  28 .  
         [0028]     Sidewall  34  is opposite of and parallel to another sidewall (not shown) which couples cover  24  to collar flange  28 . Sidewall  34  allows cover  24  to move with respect to collar flange  28  in one dimension. This movement allows cover  24  to open or lock cystoscope  18  within SLD  22 . In some embodiments, collar flange  28  includes a guide structure for engaging sidewall  34 . The guide structure may comprise one or more guide tabs which contact sidewall  34 , where the guide tabs are thinner than the thickness of collar flange  28 .  
         [0029]     As the physician uses system  10 , cystoscope  18  may be handled separately from housing  12  or handle  14 . SLD  22  may prevent rotation of cystoscope  18  with respect to housing  12 . In some embodiments, retaining tabs  30  and  31  prevent collar  26  from rotating within housing  12 . Retaining tabs  30  and  31  may glide along rails within housing  12  to provide torque resistance along the entire sliding length of collar  26 . In other embodiments, more of less retaining tabs may be used to control torque induces rotation of SLD  22 .  
         [0030]      0 -ring  32  is attached to collar  26  and resides within housing  12 .  0 -ring  32  contacts a least a portion of the opening within housing  12  to provide some resistance to moving collar  26  within the opening of housing  12 .  0 -ring  32  may be constructed out of a soft plastic or rubber compound. In some embodiments, the material or thickness of o-ring  32  may vary to change the force required to move collar  26  within the opening of housing  12 .  
         [0031]      FIG. 2B  shows SLD  22  in the similar locked conformation as shown in  FIG. 2A . However,  FIG. 2B  displays the movement capable of SLD  22  within the opening of housing  12  as SLD  22  is shown in the extended position. After the physician has located the intended prostate site, cystoscope  18  may be pulled back a distance D to enable the physician to watch the needle enter the prostate tissue.  
         [0032]     Since cystoscope  18  is locked within SLD  22 , a pulling force on cystoscope  18  overcomes the static friction of o-ring  32  and causes collar  26  to slide within the opening. Retaining tabs  30  and  31  contact bumpers  38  and  39 , respectively, to prohibit SLD  22  from being removed from housing  12 . In some embodiments, bumpers  38  and  39  may be positioned at different locations within housing  12 . For example, housing  12  may position bumpers  38  and  39  further from the edge of housing  12  to allow SLD  22  to move a shorter distance D. Alternatively, bumpers  38  and  39  may be located closer to the edge of housing  12  to allow movement greater than distance D.  
         [0033]     SLD  22  allows cystoscope  18  to be removed from the SLD at any location of the SLD with respect to housing  12 . Collar  26  may be in the retracted, extended, or any other position when cystoscope  18  is added to or removed from SLD  22 . In some embodiments, cover  24  may not move up and down to lock or unlock cystoscope  18 . Cover  24  may slide in any direction within a plane, such as horizontally or diagonally, to lock and unlock cystoscope  18 .  
         [0034]     SLD  22  may be constructed of an injection moldable material with some degree of flexibility. The preferred material of SLD  22  is acrylonitrile butadiene styrene (ABS) due to its flexibility, strength and shape holding properties. Other possible materials which may be used to construct at least part of SLD  22  may include polyurethane, polypropylene, polycarbonate, nylon or other polystyrene polymers. Composites or flexible metal alloys including titanium or nitinol may be used to construct SLD  22  in some embodiments.  
         [0035]      FIGS. 3A and 3B  are front views of SLD  22  in unlocked and locked configurations. As shown in  FIG. 3A , SLD  22  includes cover  24  in the unlocked conformation covering collar flange  28 . Receiving channel  41  funnels down to bore  43  to facilitate insertion of cystoscope  18  into housing  12  through SLD  22 . Collar flange  28  includes detent  44 , detent  50  (shown in  FIG. 3B ), slot  47  and slot  49 , where a detent is a male locking structure. Cover  24  includes indents  40  and  42 , where an indent is a female locking structure. Cover also defines unlock edge  46  and lock edge  48 . The arrow indicates the direction cover  24  moves to lock cystoscope  18  in place within SLD  22 .  
         [0036]     Collar flange  28  is attached to collar  26  which forms receiving channel  41  and bore  43 . Collar flange  28  forms slots  47  and  49  which accept corresponding tabs from cystoscope  18 . Slots  47  and  49  include an outside curved edge and parallel sides to prevent cystoscope  18  from rotating within SLD  22 . In some embodiments, more or less slots may be formed by collar flange  28  which correspond to tabs of the accessory to be inserted into SLD  22 . In other embodiments, slots  47  and  49  may be formed into another shape such as a rectangle, triangle, or other shape to accept tabs from an accessory.  
         [0037]     Collar flange  28  also includes substantially similar detents  44  and  50  (shown in  FIG. 3B ). Detent  44  is round in shape and extends spherically outward from the first mating surface towards cover  24  which includes the second mating surface. Detent  44  provides the locking force to lock sliding cover  24  in place within respect to collar flange  28 . Indent  40  is mated with detent  50  in the unlocked conformation shown. As cover  24  slides in the direction of the arrow, the cover flexes slightly to move over detent  44  until indent  42  mates over detent  44 . Once detent  44  and indent  42  mate, cover  24  is locked in place until the physician provides enough force to the cover in the direction of sliding to overcome the bending modulus of the cover and separate the detent from the indent.  
         [0038]     In some embodiments, detents  44  and  50  and indents  40  and  44  may be formed into a non-spherical shape. Some shapes of detents and indents may include cubes, trapezoids, cylinders, pyramids, or any other three-dimensional shape. In other embodiments, the sizes of mating detents and indents may not be the same size while still performing the function of the detent and indent relationship. Additionally, the size of detents  44  and  50  and indents  40  and  42  may differ. SLD  22  may include more or less than two sets of indents and detents.  
         [0039]     The force required to lock or unlock SLD  22  is generally between 0.1 lbf and 16.5 lbf. Preferably, the force required to lock or unlock SLD  22  is between 0.3 lbf and 1.0 lbf. Ideally, the force required to lock or unlock SLD  22  is between 0.5 lbf and 0.8 lbf. These forces may be applied to overcome the mating of an indent and detent or overcome any other locking mechanism of SLD  22  as described herein.  
         [0040]     Cover  24  is the component responsible for unlocking and locking cystoscope  18  from SLD  22 . Cover  24  defines unlock edge  46  and lock edge  48  which partially form the main opening of the cover. Unlock edge  46  permits the tabs of cystoscope  18  to pass through cover  24  and into slots  47  and  49 . Curved unlock edge  46  has a radius of R 2 . In some embodiments, unlock edge  46  may be larger than necessary to accept the tabs of cystoscope  18 . Since unlock edge  46  does not need to contact any area of cystoscope  18 , the shape and size of unlock edge  46  may not conform to the size and shape of tabs on cystoscope  18 .  
         [0041]     Lock edge  48  of cover  24  has a radius of R 1 , where R 1  is less than R 2 . Lock edge  48  slides over the tabs of cystoscope  18  to lock the cystoscope within SLD  22 . The inner side of lock edge  48  may or may not contact the side of cystoscope  18  to generate a secure lock. As described above, detent  44  mates with indent  42  to hold lock edge  48  of cover  24  in place. In other embodiments, detents and indents may not be used to lock cover  24  in place. Lock edge  48  may contact a side of an accessory with enough force to provide a secure friction fit.  
         [0042]     In other embodiments, lock edge  48  could be slightly curved or include a different locking structure that contacts the accessory to lock cover  24  in place and secure the accessory within SLD  22 .  
         [0043]      FIG. 3B  shows cover  24  in the locked confirmation, wherein an accessory would be secured within SLD  22 . Indent  42  is mated with detent  44  (shown in  FIG. 3A ) and detent  50  on the first mating surface of collar flange  28  is visable. In the examples of  FIG. 3A  and  FIG. 3B , cover  24  moves up to lock an accessory and down to unlock the accessory. Alternatively, cover  24  may be inverted and mated to collar  28  so that cover  24  is moved down to lock the accessory within SLD  22 .  
         [0044]     In some embodiments, cover  24  may be a different length so that the cover moves less or move in order to change the conformation of SLD  22  from unlocked to locked. Cover  24  size may be related to the specific accessory to be locked in SLD  22 . Alternatively, SLD  22  may be shaped to allow cover  24  to slide from left to right or right to left to change the locked conformation of the SLD.  
         [0045]     In other embodiments, detent  50  may instead be a small hole in collar flange  28  that accepts a post of an accessory. In the case of an accessory which includes a post for alignment or connectivity with a connector such as SLD  22 , the small hole in collar flange  28  may receive the post to allow SLD  22  to be compatible with such an accessory. The post and small hole relationship may or may not function to assist securing the accessory within SLD  22 .  
         [0046]      FIG. 4  is a top view of SLD  22  removed from housing  12 . As shown in  FIG. 4 , collar  26  includes retaining tab  30  and o-ring  32 . Collar  26  is attached to collar flange  28  in which the first mating surface is in contact with the second mating surface of cover  24 . Collar flange  28  comprises guide tabs  52  and  53  which are engaged by sidewalls  34  and  51 . Sidewalls  34  and  51  also include retaining flanges which extend normal to each sidewall to encompass each respective guide tab. Limit flange  36  is also shown attached to cover  24 .  
         [0047]     Sidewalls  34  and  51  use a retaining flange to clamp on the guide tabs  52  and  53 . In this manner, bending of cover  24  as detents and indents mated or separated does not cause separation of cover  24  from collar flange  28 . In some embodiments, collar flange  28  may not comprise guide tabs  52  and  53  for sidewalls  34  and  51  to engage. Sidewalls  34  and  51  may extend to a greater length and engage the edges of collar flange  28 . In other embodiments, sidewalls  34  and  51  may not comprise retaining flanges. Sidewalls  34  and  51  may form acute angles with cover  24  to engage acute parallel surfaces of the edge of collar flange  28 . Angled sidewalls  34  and  51 , or other shapes, may perform the functional relationship between cover  24  and collar flange  28 .  
         [0048]      FIG. 5  is side view of the components of SLD  22 . As shown in  FIG. 5 , collar  26  and collar flange  28  are separated from cover  24 . Separating the first mating surface of collar flange  28  from the second mating surface of cover  24  illustrates the male and female locking structures for locking cover  24  in place with respect to collar flange  28 .  
         [0049]     Detents  44  and  50  are attached to collar flange  28  while indents  40  and  42  are formed into cover  24 . Detents  44  and  50  are raised a height above the first mating surface of collar flange  28 . Indents  40  and  42  are set a depth D into the second mating surface of cover  24 . In the preferred embodiment, height H and depth D are equal to provide optimal mating between each detent and indent pair. However, height H and depth D may be different from one another depending on the application of SLD  22 . Alternatively, dimensions may vary between detents  44  and  50  or indents  40  and  42 .  
         [0050]     In general, height H and depth D may be between 0.005 inches and 0.050 inches. Preferably, height H and depth D may be between 0.010 inches and 0.035 inches. Ideally, height H and depth D may be approximately 0.020 inches. Modifying height H and depth D changes the force required to lock or unlock cover  24  from collar flange  28 . For example, a greater height H and depth D may require a greater force to lock or unlock cover  24  while a smaller height H and depth D may require less force to operate the lock. Preferred forces to operate SLD  22  are further described in  FIG. 3A .  
         [0051]      FIGS. 6A and 6B  are front views of alternative rotating lock device (RLD)  54 . As shown in  FIG. 6A , RLD  54  includes collar  62  which is substantially similar to collar  26  and collar flange  28  of SLD  22 . Collar  62  includes a substantially circular flange, slot  64  and longitudinal bore  66 ; however, a partially circular flange similar to collar flange  28  may be used as well. Cover  56  includes unlock edge  60  and lock edge  58 . Cover  56  also includes a plurality of sidewalls (not shown) extending normal to cover  56  surface for engaging the circular flange of collar  62  (not shown). RLD  54  is in the unlocked conformation.  
         [0052]     Cover  56  is mated to the collar flange similar to SLD  22 , except that cover  56  slides circumferentially, or rotates, with respect to the collar flange to lock an accessory within RLD  54 . An accessory, such as cystoscope  18 , is inserted into bore  66  and tabs or the cystoscope fit into slot  64  within unlock edge  60 . The physician rotates cover  56  in the direction of the arrow to slide lock edge  58  of the cover to lock the tabs of cystoscope  18  within RLD  54 . In the preferred embodiment, cover  56  may rotate in either direction indefinitely. In other embodiments, one or more limit flanges of cover  56  only allow cover  56  to move in one direction to lock and in another direction to unlock.  
         [0053]      FIG. 6B  illustrates RLD  54  in the locked configuration. Lock edge  60  of cover  56  traps the tabs of cystoscope  18  to secure the cystoscope in place. Cover  56  may continue to rotate clockwise to fully trap the tab of cystoscope  18  in slot  64 . Cover  56  may be rotated in the direction of the arrow to unlock cystoscope  18  from RLD  54 .  
         [0054]     In some embodiments, RLD  54  may utilize male and female locking structures such as the detents and indents of SLD  22 . These locking structures may be located at positions between cover  56  and the collar flange of collar  62 . The positions may be in the plane of cover  56  rotation or along the circumferential edge normal to the plane of rotation along cover  65 . Locking RLD  54  into certain confirmations may be beneficial to unwanted unlocking of cystoscope  18  during a procedure.  
         [0055]      FIGS. 7A and 7B  are front views of alternative snapping lock device (SLD)  70 .  
         [0056]     As shown in  FIG. 7A , SLD  72  includes collar  72 , receiving channel  74  and bore  76  which are substantially similar to collar  26 , receiving channel  41  and bore  43  of SLD  22 . Collar flanges  78  and  80  are attached to collar  72 . Collar flange  78  includes ramped tab  90 , limit tab  94 , and mounting holes  82  and  84 . Similarly, collar flange  80  includes ramped tab  92 , limit tab  96 , and mounting holes  86  and  88 .  
         [0057]     Collar flanges  78  and  80  are only attached to collar  72  by the first portion of each collar flange comprising respective mounting holes  82 ,  84 ,  86  and  88  and limit tabs  94  and  96 . The second portion of each collar flange comprises ramped tabs  90  and  92 . The second portion of each collar flange is attached to any other structure, so each collar flange is capable of flexing radially outward when force is applied to each collar flange.  
         [0058]     For example, cystoscope  18  includes two opposite tabs which each fit between the ramped tab of one collar flange and the limit tab of the other collar flange. As cystoscope  18  is rotated clockwise, force is applied to ramped tabs  90  and  92  which cause collar flanges  78  and  80  to flex radially outward until the each ramped tab  90  and  92  snaps back into place indicating that each tab fits between the ramped tab and limit tab of one collar flange. In this locked position, cystoscope  18  cannot rotate within SLD  70 . A cover ( FIG. 7B ) is also used to lock cystoscope  18 .  
         [0059]     Thickness of collar flanges  78  and  80  and the shape of ramped tabs  90  and  92  change the force required to rotate and lock cystoscope  18 , or another accessory, into place. Counterclockwise rotation of cystoscope  18  forces collar flanges  78  and  80  to flex outward again in order to remove the cystoscope from SLD  70 .  
         [0060]      FIG. 7B  illustrates cover  100  which is part of SLD  70 . Cover  100  includes opening  110  which is partially outlined by lock edge  112  and unlock edge  114 . Mounting holes  102 ,  104 ,  106  and  108  align with mounting holes  82 ,  84 ,  86  and  88  of collar flanges  78  and  80 . Pins, screws or other fastening devices are used to attach cover  100  to collar flanges  78  and  80 . Cover  100  is mounted to collar flanges  78  and  80  before cystoscope  18  is locked into place.  
         [0061]     In the provided embodiment, cystoscope  18  rotated clockwise to lock and counterclockwise to unlock. In other embodiments, cystoscope may be rotated counterclockwise to lock and clockwise to unlock. In either case, cover  100  prevents cystoscope  18  from being removed from SLD  70 .  
         [0062]     The preceding specific embodiments are illustrative of the practice of the invention. It is to be understood, therefore, that other expedients known to those skilled in the art or disclosed herein may be employed without departing from the invention or the scope of the claims.  
         [0063]     Many embodiments of the invention have been described. Various modifications may be made without departing from the scope of the claims. These and other embodiments are within the scope of the following claims.