Abstract:
An accessory is adapted to removably couple to a laser source connector separate from a fiber connector. The accessory includes a first contact element configured to form an electrical connection to a first portion of the laser source connector. The accessory further includes a second contact element configured to form an electrical connection to a second portion of the laser source connector. The second portion of the laser source connector is electrically insulated from the first portion of the laser source connector. The accessory also includes a network connected to the first contact element and the second contact element. The network establishes a defined electrical characteristic between the first and second contact element when a fiber connector is connected to laser source connector.

Description:
FIELD OF THE INVENTION 
     This invention relates surgical probes for laser surgery and more particularly to a fiber connector accessory with defined electrical characteristics. 
     BACKGROUND OF THE INVENTION 
     Laser surgical probes deliver laser energy from a laser source to a treatment site for tissue. Typically, a laser surgical probe includes a handpiece and an optical fiber that is connected to the laser source by a fiber connector for the probe, so that the optical fiber carries laser energy from the source to the handpiece. For safety reasons, laser sources are configured so that the laser source does not produce laser energy unless a probe is connected to the laser source. Early laser sources used well-known internal circuitry for electrical detection of the probe. Such circuits included, for example, a voltage source coupled to a fixed resistance that would produce a current when a probe connector was connected to the laser source to complete an electrical circuit. When a probe was not connected, the circuit would be open (infinite resistance), and the laser source would be disabled. 
     U.S. Pat. No. 5,085,492 to Kelsoe et al. (hereinafter “the &#39;492 patent”) discloses an alternative to the internal circuitry for detecting connection of the probe. In the configuration described in the &#39;492 patent, the laser source includes a cantilevered, U-shaped ground wire and a contact that serve as a complementary connector for the fiber connector. The fiber connector in turn includes a network of electrical components establishing a fixed electrical characteristic between a contact element mechanically supported by a fiber holding means and another part of the fiber connector that electrically and mechanically engages with the U-shaped ground wire. This provides a defined electrical characteristic for the fiber connector itself, which is in turned used by the laser source to detect the presence of a connected fiber. 
     One significant drawback of the system described in the &#39;492 patent is that the laser source can only be used with fiber connectors that include a network of electrical components to define an electrical characteristic for the fiber connector. Modifying the fiber connectors of other laser surgical probes to include such a network of electrical components would introduce additional complications in manufacturing the probe as well as additional cost. There is a need, therefore, for a system that would allow these other laser surgical probes to be used with laser sources like the one described in the &#39;492 patent. 
     BRIEF SUMMARY OF THE INVENTION 
     In particular embodiments of the present invention, an accessory is adapted to removably couple to a laser source connector separate from a fiber connector. The accessory includes a first contact element configured to form an electrical connection to a first portion of the laser source connector. The accessory further includes a second contact element configured to form an electrical connection to a second portion of the laser source connector. The second portion of the laser source connector is electrically insulated from the first portion of the laser source connector. The accessory also includes a network connected to the first contact element and the second contact element. The network establishes a defined electrical characteristic between the first and second contact element when a fiber connector is connected to laser source connector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a laser connector accessory mounted to a laser source according to a particular embodiment of the present invention; 
         FIGS. 2A and 2B  show a side view of the laser connector accessory of  FIG. 1  relative to a laser source connector; 
         FIG. 3  shows in more detail particular features of the laser connector accessory depicted in  FIG. 1 ; and 
         FIG. 4  illustrates an installation tool that can be used to install the laser connector accessory of  FIG. 1  according to a particular embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  illustrates a laser connector accessory  100  according to a particular embodiment of the present invention. In the depicted embodiment, the laser connector accessory  100  is mounted to a console of a laser source  200 . The laser source  200  includes a laser source connector  202  having a first portion  204  that receives a fiber connector coupled to a laser surgical handpiece. The laser source connector  202  also includes a second portion  206  that is electrically insulated from the first portion  204 , which allows the two portions  204  and  206  to be maintained at different voltages. In the depicted embodiment, the second portion  206  is a U-shaped ground wire, but other forms of conductive material and/or electrical components that are electrically isolated from the first portion  204  may be used as well. 
     The laser connector accessory  100  includes a network  102  connecting a first contact element  104  and a second contact element  106 . The network  102  represents any network of electrical components connected between the first contact element  104  and the second contact element  106  to establish a defined electrical characteristic between the first contact element  104  and the second contact element  106 . An insulator  108 , which may be any insulating material that can be reliably formed on the laser connector accessory  100  including but not limited to polyimide, is formed around the first and second contact elements  104  and  106  so that the first and second contact elements  104  and  106  are only electrically connected through the network  102  and so that the second contact element  106  is insulated from a fiber connector contacting the laser connector accessory  100 . In the depicted embodiment, the insulator  108  is formed as a single piece, but multiple pieces of insulative material could also be used to perform various functions described for the insulator  108 . Although the illustrated embodiment shows the network  102  as a resistor, it should be understood by one skilled in the art that other electrical components that useful for establishing an electrical characteristic such as resistance, capacitance, or inductance, including but not limited to resistors, capacitors, inductors, transistors, or diodes, may be employed alone or in combination with one another in the network  102 . 
     The laser connector accessory  100  is mounted to the second portion  206  of the laser source connector  202  so that the second contact element  106  and the second portion  206  are electrically connected to one another. In the depicted embodiment, the second contact element  106  is a conductive metal frame that includes clips  110  for holding the laser connector accessory  100  to the second portion  206  of the laser source connector  202 . The conductive metal frame of the second contact element  106  may also include holes  112  that allow the metal frame to be facilitate engagement of an installation tool with the conductive metal frame as described in greater detail with reference to  FIG. 4  below. 
     When the laser connector accessory  100  is placed in contact with the laser source connector  202 , as shown in  FIG. 1 , the first contact element  104  makes electrical contact with the first portion  204  of the laser source connector  202 . This in turn forms an electrical connection between the first portion  204  and the second portion  206  across the network  102 , thereby establishing a defined electrical characteristic between the first portion  204  and the second portion  206 . The electrical characteristic is in turn detected by the laser source  200  to verify the connection of a laser surgical handpiece to the laser source  200 . 
       FIGS. 2A and 2B  show a side view of the laser connector accessory  100  relative to the laser source connector  202 .  FIG. 2A  depicts the laser connector accessory  100  when no fiber connector is connected to the laser source  200 , while  FIG. 2B  depicts the laser connector accessory  100  when a fiber connector  212  is connected to the laser source  200 . As visible in  FIG. 2A , the second portion  206  of the laser source connector  202  is cantilevered away from the console of the laser source  200  when the fiber connector  212  (shown with fiber-holding portion  214 ) is not connected to the laser source connector  202 . As shown in  FIG. 2B , when a fiber-holding portion  214  of the fiber connector  212  is pushed into the first portion  204  of the laser source connector  202 , an outer portion  216  of the fiber connector pushes the laser connector accessory  100  into contact with the laser source connector  202 , thus establishing a defined electrical characteristic across the network  102  between the first portion  204  and the second portion  206  of the laser source connector  202 . 
     Because probes may be connected and disconnected from the laser source  200  hundreds or thousands of times, it is preferable that the laser connector accessory  100  be capable of reliably making electrical contact after multiple instances of probe connection and removal. For this reason, it is advantageous to mechanically bias the first contact element  104 , which is brought into and out of contact with the first portion  204  of the laser source connector  202 , toward the first contact portion  204  so as to facilitate good electrical contact with the first contact portion  204 . This can be done, for example, by one or more spring-like joints between the first contact element  104  and the other parts of the laser connector accessory  100 . One difficulty that can arise, however, is that repeatedly pushing the first contact element  104  against the first contact portion  204  can permanently deform the spring joints to the point that they are unable to provide a reliable contact force, possibly even to the point that the first contact element  104  breaks off of the laser connector accessory  100 . Consequently, it is advantageous to adapt the first contact element  104  by careful selection of materials and shape of the spring joints so that they can be repeatedly deformed without suffering any permanent damage. An example of a suitable material is high-strength Cu—Ni—Sn alloy, which is flexible with good spring properties. 
     Because the insulator  108  is disposed between the second contact element  106  and the outer portion  216  of the fiber connector, no electrical connection is made between the laser connector accessory  100  and the outer portion  216  of the fiber connector  212  when the fiber connector  212  is connected to the laser source connector  202 . If this were not the case, then the network in the fiber connector  212  could be connected in parallel with the network  102  of the laser connector accessory  100 , which could at least in principle alter the defined electrical characteristic sufficiently that the laser source  200  would not recognize that the fiber connector  212  had been connected. Because the outer portion  216  is electrically insulated from the laser connector accessory  100  and therefore also insulated from the second portion  206  of the laser source connector  202 , no connection across the network in the fiber connector is established. Consequently, the laser connector accessory  100  as described can be used with laser surgical handpieces that include a network within the fiber connector as well as laser surgical handpieces that do not. 
       FIG. 3  shows in more detail particular features of the laser connector accessory  100  depicted in  FIG. 1 . As shown in  FIG. 3 , the first contact element  104  and the insulator  108  can be formed as a flexible circuit with the insulator  108 , such as a polyimide sheath, surrounding a conductive trace. One end of the conductive trace is connected to the first contact element  104  and the other end is connected to the network  102 , shown in  FIG. 3  as a chip resistor. Opposite the conductive trace, the network  102  has another end for electrical connection to the second contact element  106 . When the flexible circuit is bonded to the second contact element  106 , the network  102  is electrically connected to the second contact element  106 . For example, if the second contact element  106  includes a metal frame, the end can be electrically connected to the metal frame by conductive epoxy. The insulator  108  prevents shorting between the second contact element  106  and the first contact element  104  and/or the conductive trace. 
       FIG. 4  illustrates an installation tool  300  that can be used to install the laser connector accessory  100 . The installation tool  300  includes arms  302  sized to fit within the holes  110  of the metal frame of the second contact element  106 . The arms  302  may then be used to deform the metal frame so that the clips  112  on the sides of the metal frame are pulled inwardly. The clip  112  on the top of the frame can be hooked on top of the second portion  206  of the laser source connector  202 , and the remaining clips  112  may then be positioned within the second portion  206 . When the arms  302  are released, the metal frame returns to its previous shape, and the clips  112  move outwardly to clip onto the second portion  206  of the laser connector  202 . The arms  302  are then disengaged from the holes  110 , leaving the installed laser connector accessory  100  mounted on the second portion  206 . 
     The laser connector accessory  100  can be removed by engaging the arms  302  into the holes  110  and deforming the metal frame to move the clips  112  inwardly, allowing the laser connector accessory  100  to be removed. The metal frame can be formed from a electrically conductive material that can survive a large number of deformations for installation while still fitting securely onto the second portion  206 . An example of a suitable material is high-strength Cu—Ni—Sn alloy, which is flexible with good spring properties. As a safety feature, the installation tool  300  can be attached to an activation key for the laser source  200  such that the laser connector accessory  100  cannot be installed or removed while the activation key is in place. The laser connector accessory  100  can also be attached to the console of the laser source  202  to prevent the laser connector accessory  100  from being lost when it is removed or is inadverently detached from the console, such as when the laser connector accessory  100  was not securely clipped to the second portion  206 . 
     While certain embodiments of the present invention have been described above, these descriptions are given for purposes of illustration and explanation. However, numerous variations, changes, modifications and departures from the devices and methods disclosed above may be adopted without departure from the scope of the present invention as claimed. In particular, there are numerous mechanical configurations for removably coupling the laser connector accessory to a laser source connector separately from the fiber connector such that the contact elements of the laser connector accessory are held in contact with the corresponding portions of the laser source connector. For example, one skilled in the art of the present invention would readily conceive of other structures for supporting the contact elements, including molded plastic parts, metal pieces, rigid or flexible structures, or any other suitable structure using materials and manufacturing methods known in the art. These, and all other such variations, changes, modifications and departures from the devices and methods known to one skilled in the art of the present invention, should be understood to be encompassed in the claims with a scope that would include them.