Abstract:
The present invention is directed to systems and methods that couple together optical devices in a manner that prevents damaging light from escaping the coupling except through the devices. In order to prevent damaging light from coming into contact with the user, the present invention obscures the source optical device by using at least one moveable gate to prevent damaging light from being transmitted outside of the coupling until such time as the target optical device is fully inserted into the coupling, thereby preventing light that could potentially damage a person from escaping the system except through the optical device.

Description:
TECHNICAL FIELD 
     The present invention relates generally to an optical transmission coupling and more particularly to an optical transmission coupling that substantially prevents harmful light from the optical source from prematurely escaping the coupling before the target optical transmission connector is inserted into the coupling. 
     BACKGROUND OF THE INVENTION 
     The use of optical devices in various applications has brought about a need for the capability of coupling optical devices together in situations where the applicable light source from the incoming optical device is already energized, creating a risk that damaging light will endanger those exposed to it. For example, various systems and devices used for medical purposes incorporate the use of an optical source (for example, a laser) for a variety of applications, including utilizing light to visually determine the location of certain medical devices as they travel through a patient&#39;s body. The optical source can be something in the visible spectrum (i.e., can be seen with the naked eye) or something in the non-visable spectrum that may require the use of additional apparatus to view the light source at issue. 
     An example of one application of this technology incorporates a catheter stylet with an optical fiber that allows the medical provider to correctly position the catheter within the patient. Other applications include the use of fiber optic technology to facilitate the medical use of laser catheters to ablate lesions or perform angioplasty. As the technology develops, it is expected that the use of optical devices in conjunction with various light sources will greatly increase in the medical industry. 
     However, various light sources used in such applications (e.g., light emitting diodes, lasers, etc.) can be harmful to those who may be exposed to the light eminating from the source. Damaging light can be produced from a variety of sources and can injure a person, such as causing damage to eyesight (e.g., retina, lens). For example, the coherence and low divergence of laser light means that it can be focused by the eye into an extremely small spot on the retina, quickly (sometimes in less than one second) resulting in localized burning and permanent damage. 
     Various standards apply to the safety of laser products emitting laser radiation and have led to the adoption of safety designations. Lasers have been classified according to the degree of optical radiation hazard in order to aid hazard evaluation and to adequately develop user safety control measures. Lasers are usually labeled with a safety class number that identifies how dangerous the laser is. Class I lasers are inherently safe as the light is either low power or very diffuse. Class II lasers are considered safe during normal use as the blink reflex of the eye will generally prevent damage. Lasers of Class III and above present increasing levels of risk for significant damage of both eyes and skin. 
     People working with Class III and above can protect their eyes with safety goggles that are designed to absorb light of a particular wavelength. Such precautions and perhaps other protective gear would normally be required in systems where optical connectors are coupled to other connectors outside of an enclosure. In certain medical applications, for example, one optical device provides the light source of the system, while the second optical device connector is a disposable component of the system that is changed out and discarded after each use cycle of the system (e.g., catheter stylets with optical fibers). 
     Regulations or product guidelines may explicitly require that the light source transmitted from the source optical device be turned off when the disposable component of the system is changed out for lasers classified as Class III or above. Alternatively, protective gear may be required for any system operator or other person whose eyesight could potentially be exposed to the damaging light. However, the danger that system operators will not power down the light source when appropriate or fail to use suitable protective gear (or fail to use it properly) in the operation of the system is high. Also, problems could exist where the coupling between the light source and the target connector fails (sometimes because of a failure to properly interlock the connectors, and sometimes because of mechanical failure). Such a failure could result in damage to operators and patients. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention is directed to systems and methods that couple together optical devices in a manner that prevents damaging light from escaping the coupling except through the devices. In order to prevent damaging light from coming into contact with the user, the present invention obscures the source optical device by using at least one moveable gate to prevent damaging light from being transmitted outside of the coupling until such time as the target optical device is fully inserted into the coupling, thereby preventing light that could potentially damage a person from escaping the system except through the optical device. 
     In order to prevent light from being inappropriately transmitted from the source device, the coupling may utilize any number of embodiments to insure that damaging light is only transmitted beyond the coupling through a proper optical device. Such embodiments incorporate one or more gate shutters that effectively close the light canal of the coupling when the coupling is in its natural condition (i.e., when no optical device is attached to the source optical device. Various embodiments of the invention utilize complimentary redundant components that each act to prevent damaging light from being transmitted outside of the coupling. This redundancy ensures that there is no single point of failure that could result in a complete failure of the coupling. 
     The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
         FIG. 1  is a side view of an embodiment of the present invention that utilizes a split shutter design to prevent damaging light from being transmitted outside of the coupling body; 
         FIG. 2  is an exploded view of the embodiment shown in  FIG. 1 ; 
         FIG. 3  is a cross-sectional view of the embodiment shown in  FIG. 1 ; 
         FIG. 4  is a perspective view of an embodiment that utilizes tabbed coupling inserts that flex out of the light path to prevent damaging light from being transmitted outside of the coupling body; 
         FIG. 5  is an exploded view of the embodiment shown in  FIG. 4 ; 
         FIGS. 6 and 6A  show exploded and sectional views of the embodiment that utilizes tabbed post coupling inserts that rotate out of the light path to prevent damaging light from being transmitted outside of the coupling body; 
         FIGS. 7 and 7A  show embodiments that utilizes torsion spring gated pins that rotate out of the light path to prevent damaging light from being transmitted outside of the coupling body; 
         FIG. 8  shows one embodiment of an optical coupling having longitudinal springs controlling the gates that prevents damaging light from being transmitted outside of the coupling body; and 
         FIGS. 9 and 9A  show views of an embodiment that utilizes a elastomeric housing for supplying the force for controlling the flexing of gates that prevent damaging light from being transmitted outside of the coupling body. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to the embodiment of the invention shown in  FIG. 1 , optimal transmission arrives from an optical source, not shown. The optical source, which can be any type of optical source, such as laser, LED, laser diode, bulb, arclights, etc., is connected to optical device  100 , which can be any type of connector, such as a SMA905 fiber optic connector (Amphenol Subminiature version A) or an FC/APC (with or without threads). Various types of light sources may be used depending on the application. A laser (light amplified stimulated emission of radiation) is a device that emits electromagnetic radiation of any frequency (e.g., infrared, ultraviolet, X-ray, radio, microwave, etc.) and is often used as the light source. Optical device  100 , in this embodiment, connects to coupling  30  via threads  102  of coupling  30  and internal threads (not shown) at the end of optical device  100 . Any coupling type can be used to connect optical device  100  to coupling  30 . 
     Upstream flange  103  and downstream flange  108  function as the external barriers that provide the seat for shutter  107 . Shutter (or gate)  107  is split into twin sections, each held in place on coupling  30  by garter springs  105 . Garters  105  are themselves seated between outside shutter flange  104  and inside shutter flange  106 . Adjacent to flange  108  is slot  210  into which retention clip  109  is positioned to lock ferrule  208  into place once it is properly positioned into coupling  30 . Clip  109 , as will be seen, provides a positive latch mechanism so that the user will have a positive tactile sense when downstream connector  20  is inserted into distal end  121  of coupling  30 . This positive latch will prevent inadvertent improper positioning of optical device connector  20  with respect to optical device  100 . Threads  112  are used in one embodiment to mount coupling  30  to a device panel, such as to panel  120 , with the coupling being contained within an enclosure with only end  121  visible to the user. A threaded nut (not shown) can be used to secure coupling  30  to panel  120 . Note that while two gates are shown in the embodiment, any number and configuration of gates can be used to achieve positive closure of the transmission path within coupling  30  prior to the full withdrawal of connector  20  from coupling  30 . 
       FIG. 2  shows an exploded view of the embodiment of the invention as shown in  FIG. 1 .  FIG. 2  illustrates how downstream (often disposable and attached only semi-permanently for easy connection and removability) connector  20  mates with optical device  100  via coupling  30 . Connector  20  has optical transmission path  209 , flange  207 , ridge  206  and ferrule  208 . Transmission path  209  can be, for example, either single mode fibers or multi-mode fibers or any other transmission medium. In this embodiment, the end of ferrule  208  is positioned essentially flush with tip  201  of optical device  100  when connectors  20  and  100  are both properly positioned within coupling  30 . Optical device  100  is threaded onto coupling  30  via threads  102 . Note that the present invention is applicable for connecting any types of optical devices together safely. 
     In the embodiment shown in  FIGS. 1 and 2 , coupling  30  is generally comprised of coupling body  202 , split shutter  107 , garter springs  105 , and retention clip  109 . Elastic garter springs  105  are seated over split shutter  107  to hold them in place around coupling body  202 . Split shutter  107  is mounted to coupling body  202  so that shutter gates  204  fit through slot  205  in body  202  and block any light emanating from end  201  from transmission through coupling  30  even though optical transmission is occurring into coupling  30  via optical device  100  from the optical source. It is noted that while some embodiments of the invention utilize slots (e.g., slots  205 ) that are located on the sides of the coupling, which may allow at least some light to escape from the coupling, the primary danger to eyesight is the direct beam transmitted from the source that would beam directly out of the device panel, for example, until such time as the ferrule is inserted into the coupling. The present invention obviates this danger to eyesight. Also, in the embodiment shown, the body of coupling  30  is within a housing such that the only optical transmission that is of concern is optical transmission from coupling end  121 . 
     When it is desired to connect optical device  20  to optical device  100 , ferrule  208  of connector  20  is inserted into end  121  of coupling body  202  of coupling  30  to a point where ferrule flange  207  is properly seated within coupling body  202  such that ridge  206  is inward (toward proximal end) of slot  210  and retention clip  109 . Retention clip  109  serves to provide tactile sensing and, if desired, sound sensing, for the user indicating that connector  20  is properly seated within coupling  30 . Clip  109  provides a pull-out force of approximately one pound to prevent connector  20  from being inadvertently withdrawn. Chip  109  makes a simple temporary connection and any suitable mechanism can be substituted therefor. 
     The operation of this embodiment is described with reference to the cross-sectional view  FIG. 3  of coupling  30 . In  FIG. 3 , optical device  100 , which is the source of the light in this embodiment, is attached to coupling  30 . The two sections of split shutter  107  are identical in design and are reversed in their orientation around coupling body  202  so that shutter gates  204  and  301  make physical contact with each other when split shutter  107  is properly seated around coupling body  202 , thereby preventing damaging light from device  100  from traveling through light canal  302  formed within coupling body  202 . When ferrule  208  is inserted into distal end  121  of coupling  30 , it travels through mouth  305  of ferrule seat  304 , passes through canal  303 , and through light canal  302  until it makes contact (or near contact) with end  201  of optical device  100 . The diameter of ridge  206  prevents ridge  206  from moving into light canal  302  because of the reduced diameter of canal  302  over the diameter of canal  303 . 
     When ferrule  208  first comes into contact with shutter gate  301  it gradually forces gate  301  and split shutter  107  radially outward (perpendicular) from the centerline of coupling body  202 . This is made possible due to the elasticity of garter springs  105 . This operation moves gate  301  out of light canal  302  and begins to open the light canal to optic transmission. However, until both gates  204  and  301  are open, such transmission is blocked. Note that while the second gate is mostly open prior to full engagement (when the device is substantially engaged) of device  20 , the body of device  20  will block damaging light from escaping. Garter springs  105  must be capable of radially expanding to increase their diameter so that ferrule  208  can be inserted further into coupling body  202  to eventually force shutter gate  204  to open. Garter springs  105  may be metallic or non-metallic. It should be noted that flexible bands can be used to perform the same function instead of, or in addition to, the garter springs. Such bands can be polymeric in nature (e.g., rubber, silicone, etc.), but any material with elastomeric properties may be used. 
     As discussed, ferrule  208  gradually forces gate  301  to translate outward and eventually the ferrule comes into contact with gate  204  and gradually forces shutter gate  204  of split shutter  107  out of canal  302  allowing ferrule  208  to become positioned near end  201  of device  100 . This allows the optical path from device  100  to be complete to device  20 , thereby completing the coupling process. 
     Once ferrule  208  is properly seated within coupling  30 , retention clip  109  (as discussed above) provides a tactile sense to a user of proper seating and also requires an extraction force to be applied to remove device  20 . 
     Retention clip  109  may be of any configuration that acts to provide a positive quick-disconnect for mating ferrule  208  to coupling  30 . Embodiments of the present invention also use alternate methods for securing ferrule  208  to coupling  30 , such as spring connector designs in which ferrule  208  snaps or locks into place once it is seated properly. As ferrule  208  is being withdrawn from light canal  302 , shutter gate  204  gradually descends back into light canal  302  as split shutter  107  is pushed back toward coupling body  202  by virtue of garter springs  105  which provide sufficient force to cause the shutters (gates) to close as device  20  is being withdrawn. This operation is a result of the fact that ferrule  208  is no longer pushing gate  204  out of light canal  302 . As ferrule  208  continues to be withdrawn from light canal  302 , gate  301  also gradually descends back into light canal  302  as split shutter  107  is pushed back toward coupling body  202  by virtue of garter springs  105 . Prior to the point where the ferrule is completely removed from light canal  302  and even though device  20  is still at least partially inserted into coupling  30 , gates  204  and  301  are both back in the closed state in which they prevent damaging light from being transmitted through light canal  302 . The fact that the gates are split means that one of the gates (in this case, the gate closest to the light source) will fully close before the second gate is closed. Note also that the gates will both be closed before ferrule  208  is removed from light canal  302 . This insures that at least one gate is closed before connector  20  is fully disengaged. 
     Because the invention prevents exposure of system users to what could be otherwise be damaging light, the invention in effect eliminates the need to power down the light source or use protective gear when coupling optical devices together since the level of light escaping the claimed coupling is reduced to non-damaging levels (e.g., levels that are inherently safe, levels that do not require the use of protective gear, levels that do not require the implementation of protective measures to prevent light from damaging eyesight, etc.). Note that the fiber optic cable can be used directly in the connector but in practice a ferrule connector can be used as discussed herein. 
       FIG. 4  is a perspective view of an embodiment of the present invention that utilizes tabbed coupling inserts that flex out of the light path to prevent damaging light from being transmitted outside of the coupling body. As with other embodiments,  FIG. 4  shows incoming optical device  100  as a fiber optic connector, which provides the light source to the system. Also utilized in this embodiment are the components of retention clip  109  used to provide tactile sense by the user to ferrule  208 . In this embodiment of the present invention, gates  401  and  402  prevent damaging light from being transmitted outside coupling  40 . 
       FIG. 5  is an exploded view of the embodiment of  FIG. 4  that uses gated inserts to prevent light from being transmitted outside coupling  40  when device  20  is not connected. Coupling  40  is comprised of coupling body  500 , gates  401  and  402 , and retention clip  109 . Gates  401  and  402  are positioned in this embodiment linearly along the length of coupling body  500 , which provides for complimentary and incremental redundancy of the system. Ferrule  208  of device  20  is inserted into coupling body  500  and snapped into place when ferrule flange  207  is properly seated within coupling body  500 . 
     In the embodiment shown in  FIG. 5 , gate  402  is positioned in coupling body  500  and supports gate  502 , which when closed prevents damaging light (defined herein as light that can cause damage to a human) from traveling through the light canal of coupling body  500 . Similarly, gates  401  is also positioned in coupling body  500  supporting gate  501  which when closed also prevents damaging light from traveling through the light canal of coupling body  500 . Gates  501  and  502  are flexible and may be made of any material with elastomeric qualities that allow them to move out of the optic transmission path when device  20  is inserted in coupling  40  and to spring back into their formed configurations when device  20  is withdrawn from coupling  40 . 
     When ferrule  208  is inserted into the light canal, gates  501  and  502  are sequentially rotated outward from the light canal and toward the sides of coupling body  500 . As ferrule  208  is being withdrawn from the light canal within coupling body  500 , gates  502  and  501  return sequentially to their original positions within the light canal where they prevent damaging light from being transmitted outside coupling  40 . Note that both gates are in the closed (perpendicular to body  500 ) position before device  20  is fully removed from coupling  40 . 
       FIG. 6  shows an embodiment of the present invention that utilizes tabbed post coupling inserts that rotate out of the light path to prevent damaging light from being transmitted outside of the coupling body. The system shown in  FIG. 6  again shows incoming optical device  100  as a fiber optic connector connected to coupling  60 , which is generally comprised of coupling body  600 , gate posts  601  and  604 , garter spring  65 , and retention clip  109 . Optical device  20  is inserted into coupling body  600  and snapped into a quick-disconnect relationship with the connector, as discussed above. 
       FIG. 6A  shows a cross-section view of the embodiment shown in  FIG. 6 , in which identical gate posts  601  and  604  are mounted into the coupling body in a staggered arrangement in which gate post  604  is mounted in hole  605  and gate post  601  is mounted in hole  607  in a staggered and inverted configuration compared to the mounting of gate post  604 . This configuration, as do all of the embodiments discussed herein, provides for a complimentary and redundant system in which no single point of failure results in damaging light escaping from the coupling. Gates  603  on posts  601  and  604  prevent damaging light from traveling through light canal  61  of coupling body  600 . Prior to an optical device being inserted into coupling body  600 , gates  603  prevent light from being transmitted outside of coupling body  600  by blocking the light canal of coupling  60 , i.e. being positioned perpendicular to body  600  within the light canal. Gates  603  extend into the light canal under control of garter spring(s)  65  mounted around coupling body  600  so that it engages groove  602  of tabbed post coupling inserts  601  and  604 . This operation causes gates to be positioned inside of the light canal to provide a system for preventing damaging light from being transmitted outside of coupling  60 , except when an optical device is fully engaged within coupling  60 . 
     When the optical device is inserted into the light canal, gates  603  are rotated outward out of the light canal and move toward the sides of coupling body  600  by the ferrule of the optical device. As the optical device ferrule is being withdrawn from the light canal, the spring action of garter spring  65  acting on grooves  602  rotate gates  603  back into position within the light canal where they prevent damaging light from being transmitted outside coupling  60 . 
       FIG. 7  is perspective view of an embodiment  700  of the present invention that utilizes torsion spring gated pins  702 - 1  and  702 - 2  that rotate out of the light path to prevent damaging light from being transmitted outside of the coupling body. In one version of this embodiment as seen in  FIG. 7A , spring-wound gated pins  701  are inserted into staggered holes through the body of the coupling. The pins are linearly positioned along coupling body  700 , and wound with a tension spring (not shown) that acts to allow the rotation of spring-wound pin  701  to a position in which gate tabs  720 - 1  and  720 - 2  extend into light canal  730  when the ferrule is not inserted. When the ferrule is inserted into the coupling, the ferrule pushes gate tabs  720 - 1  and  720 - 2  outward toward the sides of coupling body  700  causing the spring-wound pins to rotate against force exerted by the torsion springs  703 . When the ferrule is removed, the torsion spring forces the pins to return to their natural position in which the gated tabs block the light canal thereby preventing damaging light from being transmitted out of coupling  700 . 
       FIG. 8  shows embodiment  800  of the present invention that utilizes linear springs  802  to rotate gate  805  into light path  806  to prevent damaging light from being transmitted outside of the coupling body when an output optic device is not connected. Gate  805  rotates with pin  804  (which in turn rotates within slots (not shown) in housing  801 . Gate  805  is shown in the open position, as though a downstream connector (not shown) were connected to coupling  800 . Any configuration of rotation is possible and a plurality of such gates would advantageously be used in a coupling. When an output optic device is inserted into coupling  800 , its ferrule pushes against gates  804  to cause the gate to rotate outward toward the sides of coupling body  800  causing the spring-based gates to rotate. When the ferrule is removed, the springs force the gates to return to their resting (closed) positions in which the gates block the light canal of coupling body  800 , thereby preventing damaging light from being transmitted out of coupling  800 . 
       FIGS. 9 and 9A  show views of an embodiment  90  that utilizes elastomeric housing  901  for supplying the force for controlling the flexing of gates that prevent damaging light from being transmitted outside of the coupling body. Window  902  is used to allow the housing to be molded and to form gates within the housing body for selectively blocking light from being transmitted through the light canal of the coupling at the wrong time. 
       FIG. 9A  shows light canal  91  having gates  903  positioned therein. Gates  903  are elastomeric and, if desired, can be formed as part of housing  901  as above-discussed. Gates  903  function in the same manner as do the gates in the other embodiments in that when a downstream optical connector is inserted in the distal end of the coupling the ferrule on the inserted optical device pushes open the optic canal by causing the gates to flex outward. Note that the ends of the gates do not necessarily have to touch the sides of the optic canal since the damaging light from many types of sources is concentrated in the center of the canal. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.