Abstract:
A floating connector adapted for use with microwave surgical instruments is presented. The disclosure provides for the use of cost-effective and readily available non-floating connectors in a floating housing which can compensate for dimensional variations and misalignments between the connectors. Multiple connectors of varying types can therefore be used within a single support housing without requiring the costly precision manufacturing processes normally associated with such multiple connector assemblies. The floating connector is suitable for use with electrical connections as well as fluidic connections.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application claims the benefit of priority to U.S. Provisional Application Ser. No. 60/990,341 entitled “FLOATING CONNECTOR FOR MICROWAVE SURGICAL DEVICES” filed Nov. 27, 2007 by Gene H. Arts et al which is incorporated by reference herein. 

   BACKGROUND 
   1. Technical Field 
   The present disclosure relates generally to microwave surgical devices used in tissue ablation procedures. More particularly, the present disclosure is directed to a floating connector assembly for coupling a microwave ablation antenna to a microwave generator. 
   2. Background of Related Art 
   Microwave ablation of biological tissue is a well-known surgical technique used routinely in the treatment of certain diseases which require destruction of malignant tumors or other necrotic lesions. Typically, microwave surgical apparatus used for ablation procedures includes a microwave generator which functions as a source of surgical radiofrequency energy, and a microwave surgical instrument having a microwave antenna for directing the radiofrequency energy to the operative site. Additionally, the instrument and generator are operatively coupled by a cable having a plurality of conductors for transmitting the microwave energy from the generator to the instrument, and for communicating control, feedback and identification signals between the instrument and the generator. The cable assembly may also include one or more conduits for transferring fluids. 
   Commonly, the microwave instrument and the cable are integrated into a single unit wherein the cable extends from the proximal end of the instrument and terminates at a multi-contact plug connector, which mates with a corresponding receptacle connector at the generator. Separate contact configurations are typically included within the multi-contact connector to accommodate the different electrical properties of microwave and non-microwave signals. Specifically, coaxial contacts are used to couple the microwave signal, while non-coaxial contacts in a circular or other arrangement are used to couple the remaining signals and/or fluids. Suitable coaxial and non-coaxial connectors are commercially available “off the shelf” that can be used side-by-side within a single housing in the construction of a cost-effective multi-contact connector for microwave ablation systems. 
   The use of two disparate connectors within a single housing may have drawbacks. Specifically, the coaxial and non-coaxial connectors assembled within the cable-end plug must be precisely aligned with their mating connectors on the microwave generator receptacle to avoid interference or binding when coupling or uncoupling the connectors. The need for such precise alignment dictates the connectors be manufactured to very high tolerances, which, in turn, increases manufacturing costs and reduces production yields. This is particularly undesirable with respect to the microwave surgical instrument, which is typically discarded after a single use and thus subject to price pressure. 
   SUMMARY 
   The present disclosure provides a floating connector apparatus having at least two connectors, such as a coaxial and a non-coaxial connector, within a single supporting housing. At least one of the connectors is floatably mounted to the housing. By using a floating rather than a rigid mounting, the floating connector is afforded a range of movement sufficient to compensate for spacing variations between and among the corresponding mating connectors. In this manner, commonly-available connectors can be used in a single supporting housing without requiring exacting manufacturing tolerances and the associated costs thereof. 
   In one embodiment, a plug (i.e., male) housing and a corresponding mating receptacle (i.e., female) housing are provided. The male housing includes a fixedly inputted male coaxial connector, such as a QN connector, that is mounted in spaced relation relative to a fixedly mounted male circular connector, such as an Odu™ Medi-Snap™ connector. The counterpart female housing includes a female coaxial connector that is fixedly mounted to the receptacle housing in spaced relation relative to a female circular connector that is floatably mounted to the receptacle housing. The floating female circular connector has at least one degree of freedom of movement, for example, the floatably mounted connector can move along the X-axis (i.e. left-right); the Y-axis (up-down); the Z-axis (in-out); or it can rotate, pitch, or yaw about the longitudinal axis of the circular connector, or any combination thereof. A positive stop can be included for limiting inward movement of the floating connector along its Z-axis to enable sufficient coupling force to be generated when mating the connectors. When the plug and receptacle are coupled, the floatably mounted connector is able to adjust to spacing and angular variations between it and the fixed connectors. This eliminates binding and interference among the connectors, establishes and maintains electrical continuity, provides tactile feedback to the user, and permits multiple connectors to be included within a single housing without the expense of precision manufacturing and high production tolerances. 
   According to another embodiment, the floating connector is mounted to a plate-like mounting assembly that includes a stationary rim concentrically disposed around a suspended inner member. The stationary rim is rigidly coupled to, or is integral to, the receptacle housing. The connector is rigidly coupled to the suspended inner member. The stationary rim and suspended inner member are resiliently coupled along the substantially annular interstice between the rim and the member. It is contemplated the interstitial edges of the stationary rim and suspended inner member can abut or overlap. The resilient coupling can include one or more elastomeric materials or springs as further described herein. In an embodiment, the resilient coupling can be a captured o-ring. The floating connector may include a floating member having a connector fixedly disposed therethrough, the connector including a mating end adapted to couple to a mating connector and a mounting end which mounts to the floating member. The floating connector may further include a support member having an opening defined therein, the opening including an internal dimension greater than the mounting end of the connector to define a clearance between the opening and the mounting end of the connector, the floating member and the connector being positioned in substantial concentric alignment with the opening. The floating connector also includes an elastomeric coupling fixedly disposed between the floating member and the support member. 
   According to a further embodiment of the present disclosure, the floating connector assembly may include a resilient spring mounting plate, which further includes an outer stationary rim and suspended inner member that are coupled by at least one thin resilient beam. The beam is attached at one end to the stationary rim and at the other end to the suspended inner member. The rim, the member and the resilient beams can be a single piece formed by, for example, stamping, injection molding, laser cutting, water jet machining, chemical machining, blanking, fine blanking, compression molding, or extrusion with secondary machining. The spring plate can include at least one slot defining a floating region concentrically disposed within a fixed region, the slots further defining the spring beam. The spring beam couples the floating region and the fixed region. The spring plate further includes a connector fixedly disposed therethrough. The connector includes a mating end adapted to couple to a mating connector and a mounting end which mounts to the floating region of the spring plate. 
   The mounting assembly may include a support member having an opening defined therein, the opening including an internal dimension greater than the mounting end of the connector to define a clearance between the opening and the mounting end of the connector, the spring plate and the connector being positioned in substantial concentric alignment with the opening. The floating connector includes a collar for securing the spring plate to the support member, the collar further including an aperture defined therein having an internal dimension greater than the mating end of the connector to define a second clearance between the aperture and the mating end of the connector, and at least one coupling device which attaches the collar and the spring plate to the support member. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other aspects, features, and advantages of the present disclosure will become more apparent in light of the following detailed description when taken in conjunction with the accompanying drawings in which: 
       FIG. 1  is an oblique view of an embodiment of a floating connector in accordance with the present disclosure; 
       FIG. 2  is an exploded view of an embodiment of the floating connector of  FIG. 1  having a resilient mounting plate, circular connector, and coaxial connector; 
       FIG. 3  is an enlarged view of the resilient spring mounting plate of  FIG. 2 ; 
       FIG. 4  is an enlarged view of a circular connector mounted atop the resilient spring mounting plate of  FIG. 3 ; 
       FIG. 5A  is a side cross sectional view of one embodiment of the floating connector in accordance with the present disclosure; 
       FIG. 5B  is a top view of one embodiment of the floating connector in accordance with the present disclosure; 
       FIG. 6A  is a side cross sectional view of another embodiment of the floating connector in accordance with the present disclosure showing a floating member resiliently coupled to a support member in a substantially overlapping configuration; 
       FIG. 6B  is a top view of the embodiment of the floating connector shown in  FIG. 6A  in accordance with the present disclosure; 
       FIG. 7A  is a side view of still another embodiment of the floating connector in accordance with the present disclosure showing a floating member resiliently coupled to a support member and configured to limit movement to a single axis of motion; 
       FIG. 7B  is a top view of the embodiment of the floating connector shown in  FIG. 7A  in accordance with the present disclosure; 
       FIG. 8A  is a side view of yet another embodiment of the floating connector in accordance with the present disclosure showing a floating member and support member in a substantially abutting configuration having a positive stop member; 
       FIG. 8B  is a top view of the embodiment of the floating connector shown in  FIG. 8A  in accordance with the present disclosure; 
       FIG. 8C  is a bottom view of the embodiment of the floating connector shown in  FIG. 8A  in accordance with the present disclosure; 
       FIG. 9  is a side view of still another embodiment of the floating connector in accordance with the present disclosure showing a floating member resiliently coupled to a support member by a captured o-ring, and having a positive stop member; and 
       FIGS. 10A-10C  are side views illustrating the coupling and uncoupling of the floating connector with a connector assembly. 
   

   DETAILED DESCRIPTION 
   Particular embodiments of the present disclosure will be described herein with reference to the accompanying drawings. In the following description, well-known functions or constructions are not described in detail to avoid obscuring the present disclosure with unnecessary detail. References to connector gender presented herein are for illustrative purposes only, and embodiments are envisioned wherein the various components described can be any of male, female, hermaphroditic, or sexless gender. Likewise, references to circular and coaxial connectors are illustrative in nature, and other connector types, shapes and configurations are contemplated within the present disclosure. 
   Referring to  FIG. 1 , there is disclosed a floating connector assembly  100  that includes support member  110  having an outer surface  111  and an inner surface  112 . Support member  110  further includes a coaxial connector  160  fixedly mounted thereto in spaced relation relative to floating connector  120 . Floating connector  120  is fixedly mounted to support member  110  by a coupling device  150 , as will be described in detail below. Coaxial connector  160  may be mounted to support member  110  by any suitable means such as by a nut or a clip (not shown) as is well-known in the art. The spaced relationship of floating connector  120  to coaxial connector  160  substantially mirrors the spaced relationship of a corresponding mating connector assembly  790 , shown by example in  FIGS. 10A-C , wherein male circular connector  780  is configured to matingly engage female circular connector  740  and coaxial connector  785  is configured to matingly engage coaxial connector  760 . 
   With reference to  FIG. 2 , floating connector  120  includes a collar  130  and a female circular connector  140  which is configured to floatably mount within floating connector  120  as will be further described herein. Female circular connector  140  can be of a keyed type such as an Odu™ or LEMO™ connector as will be familiar to the skilled artisan. Support member  110  and collar  130  further include openings  115  and  135 , defined therein respectively, dimensioned to permit floating movement of and accommodate electrical and/or fluidic connections to, female circular connector  140 . 
   Floating connector  120  further includes a spring plate  200  having an arrangement of slots  250 ,  250 ′,  270 ,  270 ′ defined thereon which, in turn, are arranged to define a fixed region  210  and a floating region  220  having spring beams  280  disposed therebetween (see  FIG. 3 ). Spring plate  200  can be constructed of any material having spring-like properties, such a spring steel or a resilient polymer, and can be formed by any suitable means, such as stamping, injection molding, laser machining, water jet machining, or chemical machining. A recess  114  is disposed upon outer surface  111  and located around the perimeter of opening  115 , and is dimensioned to provide floating movement of spring plate  200  sufficient to enable proper coupling of connector  140  with a mating connector. As can be readily appreciated, recess  114  also prevents excessive inward movement of spring plate  200  to enable sufficient mating forces to be generated during coupling, and also to prevent exceeding the elastic limits of spring plate  200 . 
   As best seen in  FIG. 3 , floating region  220  further includes a centrally disposed mounting hole  260  defined therein dimensioned to receive a mounting boss  142  of female circular connector  140 . In one embodiment, mounting hole  260  is substantially circular and includes opposing flat areas  265  dimensioned to accept mounting boss  142  having corresponding opposing flat areas (not shown) to inhibit unintended rotation of female circular connector  140  within mounting hole  260 , as is well-known in the art. Female circular connector  140  can be retained to spring plate  200  by a nut  145 , as shown in  FIGS. 5A and 5B , or may be retained by any suitable means such as integral clip, external clip, or adhesive. Slots  250 ,  250 ′ further describe stops  240 ,  240 ′ for limiting the range of motion of floating member  220  along the X-axis, the Y-axis, the Z-axis, and/or rotationally about the Z-axis (i.e. longitudinal axis) of female circular connector  140 . 
   With reference now to  FIGS. 4 ,  5 A, and  5 B, female circular connector  140  of spring plate  200  is sandwiched between collar  130  and support member  110  in substantial coaxial alignment with opening  115  and opening  135 . Collar  130  and spring plate  200  are affixed to support member  110  by a coupling devices  150  which can be threaded fasteners, rivets, adhesive, bonding, or other suitable coupling devices. By this configuration, spring beams  280  and/or the overall resilient properties of spring plate  200  afford circular connector  140  a range of movement within openings  115  and  135  and recess  114 , for example, along the X-axis (left-right), the Y-axis (up-down), the Z-axis (in-out), and/or rotationally about the Z-axis (roll). 
   By way of example,  FIGS. 10A-10C  show a schematic illustration of the coupling and uncoupling of the connector assembly with floating connector assembly  700 . In particular,  FIG. 10A  shows male circular connector  780  poised to mate with female circular connector  740 , wherein the longitudinal axis of male circular connector  780  is misaligned by an illustrative angle  750  with respect to longitudinal axis Z of circular connector  740 . In  FIG. 10B , as the connector assemblies are joined, coaxial connectors  785  and  760 , which are fixed to their respective support members, couple normally, while male circular connector  780 , which is imprecisely aligned with circular connector  740 , causes spring beams  720  (see  FIG. 3 ) and/or spring plate  710  to deflect in response to the coupling forces applied by male circular connector  780  to circular connector  740 . This permits female circular connector  740  to move into substantial alignment with male circular connector  780  as the connectors are brought into a fully-coupled state. In this manner, the desired coupling of two connectors  740  and  780 , which were originally misaligned, is achieved without the interference or binding which would normally be encountered with such initial misalignment and/or imprecise alignment. Turning now to  FIG. 10C , as the connector assemblies are decoupled, male circular connector  780  parts from circular connector  740 , enabling spring beams  720  and/or the overall resilient properties of spring plate  710  to bias circular connector  740  back to its original position, i.e., into substantially orthogonal alignment with support member  705 . 
   Other embodiments contemplated by the present disclosure are shown with reference to  FIG. 6A-FIG .  9 .  FIGS. 6A and 6B  show one embodiment of a floating connector having a floating assembly  305  which includes a female circular connector  340  that is fixedly mounted to a floating member  300  though an opening  302  provided therein. The opening  302  is dimensioned to accept a mounting boss  342  of circular connector  340  as previously described herein. Floating member  300  is concentrically aligned with an opening  315  defined in a support member  310 , and is further dimensioned to extend at the perimeter thereof beyond the edge of opening  315 . An elastomeric coupling  320  is adhesively disposed between floating member  300  and support member  310  along the perimetric interstice defined by the overlap therebetween. Elastomeric coupling  320  may be formed from any suitable resilient material, such as rubber, neoprene, nitrite, silicone, foam rubber, or polyurethane foam. Additionally or optionally, elastomeric coupling  320  can include bellows-like corrugations to alter the resilient properties thereof. 
     FIGS. 7A and 7B  show another embodiment of a floating connector in accordance with the present disclosure wherein the motion of a floating assembly  405  is substantially limited to a single axis of motion. A plurality of bar-shaped elastomeric couplings  420  are adhesively disposed between a floating member  400  and a support member  410 , and are arranged in mutually parallel configuration and generally orthogonal to the desired axis of motion. The range of motion of floating assembly  405  is dictated by the shape and arrangement of at least one bar-shaped coupling  420 . Other embodiments are envisioned which include, for example, elastomeric couplings of other shapes and arrangements, including without limitation square-shaped or dot-shaped elastomeric couplings in a lattice arrangement. 
   Turning now to  FIGS. 8A ,  8 B, and  8 C, another embodiment in accordance with the present disclosure is provided wherein a floating member  520  is concentrically disposed within an opening  525  defined in a support member  510 , the opening having a stationary rim  528  that is rigidly coupled to, or is integral to, support member  510 . A floating assembly  505  includes a connector  540  that is rigidly coupled to the floating member  520 . Stationary rim  528  and floating member  520  are resiliently coupled along their annular interstice by an elastomeric coupling  530  that is adhesively disposed between stationary rim  528  and floating member  520 . The overall resilient properties of elastomeric coupling  530  afford floating assembly  505 , and particularly, circular connector  540 , a range of movement to permit coupling with a misaligned mating connector, such as connector  780 , as previously described herein. Optionally, a positive stop  560  is included for limiting the inward excursion of floating assembly  505  along the Z-axis during coupling to allow sufficient mating force to be generated when coupling the connectors  540  with, for example, connector  780 . In one embodiment, positive stop  560  has an annular shape and is fixedly disposed in concentric relation to floating assembly  505  at an inner surface  512  of support member  510  along the perimeter of opening  525 . Positive stop  560  can also include a standoff  562  which can be formed integrally with positive stop  560  for dictating the maximum inward displacement of floating assembly  505 . 
   In another embodiment as illustrated in  FIG. 9 , a stationary rim  628  and a floating member  620  are joined along their annular interstice by a captured o-ring  650 . A floating assembly  605  includes a connector  640  that is rigidly coupled to the floating member  620 . The captured o-ring  650  may be formed from any suitable resilient material, such as rubber, neoprene, nitrile, or silicone, and is compressively retained within opposing semicircular saddles  624  and  626  formed in the circumferential edges of opening  625  and floating member  620 , respectively. Upon coupling, the captured o-ring  650  can deform and/or partially roll in response to the mating forces applied to connector  640 , and in this manner, permit connector  640  to move into substantial alignment a misaligned mating connector, for example, connector  780 , as the connectors are brought into a fully-coupled state. 
   The described embodiments of the present disclosure are intended to be illustrative rather than restrictive, and are not intended to represent every embodiment of the present disclosure. Further variations of the above-disclosed embodiments and other features and functions, or alternatives thereof, may be made or desirably combined into many other different systems or applications without departing from the spirit or scope of the disclosure as set forth in the following claims both literally and in equivalents recognized in law.