Abstract:
A bipolar endoscopic device is provided having a detachable power cord with a plug capable of forming a sealed connection with the endoscopic device. The plug is connected at a back face of a movable guide member of the endoscopic device and can be oriented in different orientations to accommodate different operators. The detachable plug forms a sealed connection with the endoscopic device so that the electrosurgical connection cannot be short-circuited by the outside environment such as a saline irrigation fluid.

Description:
This invention claims the benefit of co-pending U.S. Provisional Application No. 60/372,097, entitled “Medical Device With Improved Power Plug Connection”, filed Apr. 12, 2002, the entire disclosure of which is hereby incorporated by reference as if set forth in its entirety for all purposes. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to electrosurgical instruments and, more particularly, to endoscopes with an improved power plug connection for associated bi-polar electrode assemblies. 
     BACKGROUND OF THE INVENTION 
     While the inventive principles of the present invention are applicable to a variety of electrosurgical instruments, as a person skilled in the art will readily appreciate, for purposes of illustration and not limitation, the present invention will be described in reference to one possible embodiment, namely a resectoscope. 
     Generally, resectoscopes comprise a hollow sheath, a working element, a telescope and an electrode. The working element generally has a guide block that can slide or move, such as by a rack and pinion mechanism or spring, to move the electrode relative to the telescope. The guide block generally has a hole or connector for receiving a portion of the electrode and another hole for receiving an electric plug. The electric plug supplies electricity to the electrode for resection or the like. U.S. Pat. No. 4,538,610 to Kubota shows one type of resectoscope having a guide block or movable member and an extending connecting part. U.S. Pat. No. 4,149,538 to Mrava et al shows a resectoscope having a slide portion with a receptacle or channel for receiving the plug of an electrical lead (not shown). However, problems exist with these and other prior art devices. 
     There are generally two types of instruments used in electrosurgery. Monopolar devices employ a single electrode at the operative end of the instrument and an electrode return plate generally located under and in contact with the patient. The electrode plate constitutes a second dispersive electrode so that electrical current used to ablate or alter tissue passes through the patient. 
     Bipolar devices employ two electrodes spaced closely together at the operative end of the instrument so that the flow of current is confined to the tissue in close proximity to the electrodes. Bipolar devices require a saline or other electrolytic environment in order to provide a conductive path between the electrodes. One problem with bipolar devices is that the electrical connections must be electrically isolated from the saline environment in order to prevent electrical short-circuiting. Short-circuiting will reduce the effectiveness of the resectoscope for its intended function. In particular, the electric plug or bipolar cord must be sealingly engaged with the device. In order to provide a sealed connection prior art bipolar devices have integrated the bipolar cord into the device as a single unit. However, such an integrated design presents difficulties in maintaining a seal between the electrode and working element that is both leak proof and of low frictional drag on the electrode when it is mechanically moved in and out of the sheath by the user. 
     During an operation on a patient, the doctor or operator must feel confident and secure with his instrument. In the past, various different manufacturers of medical instruments produced different designs of instruments having electric cords connected at various different locations on their individual instruments. Doctors who have developed a preference for a certain type of instrument may feel uncomfortable in changing to other types or makes of the same instrument merely because of the change in orientation of the electrical wire such as in a resectoscope. Thus, a user who is comfortable with a resectoscope having a connector located on the top of the resectoscope such as that shown, for example, in Kubota (&#39;610), might feel uncomfortable using a resectoscope in which the electric power cord extends downward rather than upward such as shown, for example, in Mrava et al (&#39;538). In addition, the resectoscope shown and described in Mrava et al (&#39;538) would probably be uncomfortable for a left handed user. 
     U.S. Pat. No. 4,917,621 to Grossi et al, the subject matter of which is herein incorporated by reference, discloses a resectoscope having a disconnectable electrical plug that can be connected to the device on either a first or a second side. However, the electrical plug does not sealingly mate with the device. Accordingly, there is a need for a medical instrument having a power cord system that is adaptable to accommodate different user preferences. 
     In addition, there is a need for improved disposable active cords that are convenient to use and that provide more optimal sealing to protect against short-circuiting. 
     SUMMARY OF THE INVENTION 
     The foregoing problems are overcome and other advantages are provided by a medical endoscope with an improved electrical plug receptacle and electrical plug connector and power cord assembly. 
     It is therefore an object of the present invention to provide a detachable active power cord for a bipolar endoscopic device having a plug connector capable of forming a sealed connection with the electrode device. 
     It is another object of the present invention to provide a detachable power cord for use with a bipolar endoscopic device that can be connected to the device in different orientations to accommodate different operators. 
     It is a further object of the present invention to provide a detachable power cord or a bipolar device for use in a saline environment. 
     Still another object of the present invention is to provide a power cord for a bipolar endoscopic device that is interchangeable with various bipolar electrode models. 
     In one of many possible embodiments, the present invention contemplates an endoscope including a frame and a guide block, the guide block having an electrical plug recess located on a back face of the guide block. The recess extends through the guide block and intersects an opening for an electrode such that an electrical connector can be directly connected to the electrode assembly. The electrical connector can be inserted into the guide block so that the power cord extends from either side of the guide block to accommodate either a left or right handed operator. 
     The electrical connector is made of non-conductive material such as, for example, natural or synthetic rubber and preferably has a tapered shape to allow the user to more easily matingly engage the electrical connector into the opening in the guide block. 
     The foregoing aspects and other features of the invention are explained in the following description, taken in connection with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective rear view of the handle section of an electrosurgical instrument with a detachable power cord incorporating features of the invention shown attached to the electrosurgical instrument. 
         FIG. 2  is a perspective front view of the handle section shown in  FIG. 1  with the power cord shown attached in an alternative position. 
         FIG. 3  is a partial side view of the handle section shown in  FIG. 1 . 
         FIG. 4  is a sectional view of the electrosurgical instrument guide block with an electrode shown in place. 
         FIG. 5  is a partial sectional top view of the electrical connector positioned in the guide block shown connected to a proximal end of the electrode. 
         FIG. 6  is side view of the electrical connector. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIGS. 1 and 2  show partial perspective views of the handle section of a resectoscope working element  10 . Although the present invention will be described with reference to the working element  10  of  FIGS. 1–6 , it should be understood that the present invention may be used with various different types of resectoscope working elements, including Iglesias type working elements and McCarthy type working elements. The present invention may also be employed in any type of medical endoscope using an electrode but is particularly suited to bipolar devices used with an electrolytic irrigating fluid such as normal saline. In addition, it should be understood that the elements of the present invention may have any suitable size, shape or type of material. 
     The handle section of the working element  10  shown in  FIGS. 1–3  generally comprises a frame  12 , a handle  14 , a thumb guide  16 , a guide block  18 , and an electrical connector  20  with an integral bipolar power cord  22 . Working element  10  also comprises a telescope guide tube  24  and an electrode assembly  26  received in a guide tube  28 . Guide tubes  24  and  28  are received in a cooperating sheath (not shown) and extend forward along axis  30  to a working end as is well known in the art. A spring  32  biases guide block  18  in a rearward direction. Guide block  18  includes a telescope guide tube aperture  34  ( FIG. 4 ) through which guide tube  24  extends so that guide block  18  is slidable along guide tube  24  as guide block  18  is moved in a forward direction against spring  32 . An anti-rotation guide groove  36  cooperates with frame guide surfaces  38  to prevent rotation of guide block  18 . 
     Thus, guide block  18  is slidably mounted on guide tube  24  and rotationally constrained by frame guide surfaces  38 . An electrode reception aperture  40  at a front face  42  of guide block  18  receives a proximal end of electrode assembly  26 . An electrode locking mechanism (not shown) cooperates with electrode groove  44  ( FIG. 5 ) to retain the proximal end of electrode assembly  26 . A telescope  46  may be inserted into frame  12  that communicates with telescope guide tube  24  whereby telescope  46  can be inserted and retained in working element  10 . In operation, an operator grasps handle  14  with fingers and inserts thumb into thumb guide  16  to move guide block  18  in a forward direction compressing spring  32  and axially moving an electrode assembly  26  connected to guide block  18 . 
     Electrical connector  20  is removably inserted into guide block  18  to connect to the proximal end of electrode assembly  26 . Once electrical connector  20  is connected to guide block  18  electrosurgical current from an electrosurgical generator (not shown) can be transmitted via power cord  22  and electrical connector  20  directly to electrode assembly  26  to perform a desired operation. 
     As seen most clearly in  FIGS. 1 and 2 , electrical connector  20  is connected to guide block  18  through a back face  48 . Electrical plug  20  can be connected in alternate first and second positions so that power cord  22  extends from either the left or right side of working element  10  to accommodate right or left-handed users.  FIG. 1  shows a view of the handle portion of working element  10  from a position of a user with electrical plug  20  connected to guide block  18  with power cord  22  extending from a user&#39;s left side. Alternately, electrical plug  20  can be connected to guide block  18  so that power cord  22  extends from a user&#39;s right side as shown in phantom.  FIG. 2  shows a front view of the handle portion of working element  10  with electrical plug  20  connected to guide block  18  so that power cord  22  extends from a user&#39;s right side.  FIG. 2  also shows an alternate position with power cord  22  shown in phantom extending from a user&#39;s left side. 
     By providing a connection at back face  48  of guide block  18  the present invention allows for power cord  22  to be oriented to accommodate different users. For example, a right handed user would generally prefer to have power cord  22  on the left side of guide block  18  so that it would not interfere with the user&#39;s movement of guide block  18  or unnecessarily hinder the user&#39;s quick and unencumbered access to working element  10  with his or her left hand. Alternatively, a left handed user would prefer to have power cord  22  on the right side of guide block  18  such that the user could operate working element  10  without being annoyed or hindered by the protruding power cord  22 . 
     As best seen in  FIG. 5 , electrical connector  20  includes a body  50  that is substantially continuous with power cord  22  and an integral plug portion  52  extending substantially perpendicular to body  50 . Preferably, body  50  and plug portion  52  are molded as a single unit and made of a nonconductive material which has high lubricity, low moisture absorption, and a good dielectric strength, such as, for example, natural or synthetic rubber or Teflon, a trademark of E.I. Dupont Co. Preferably, plug portion  52  includes a tapered end  53  that mates with and provides a secure connection with guide block  18 . Electrical connector  20  is formed integrally with power cord  22  and includes an insulating sheath  54 . Plug portion  52  further has a central opening  55  that receives the proximal end of electrode assembly  26  when electrical connector  20  is attached to guide block  18 . 
     Power cord  22  generally includes electrically conductive bipolar wires  56  and  58  that are insulated within power cord  22  which is preferably made of nonconductive elastomeric material such as, for example, silicon rubber. Power cord  22  ends in a standard dual prong plug (not shown) for insertion into an electrical socket located on the electrosurgical power generator. Wire  56  is bonded to a first electrode contact  60  and wire  58  is bonded to outer electrode contact  62 . First and second contacts  60  and  62  are made of a conductive material such as, for example, beryllium copper and wires  60  and  62  are bonded to first and second contacts  60  and  62 , respectively, preferably by a solder bond. First and second O-rings  64  and  66  are located in central opening  55  to assist holding the proximal end of electrode assembly  26  in plug portion  52  and to seal first and second contacts  60  and  62  from the outside environment. Alternatively, the sealing means can be molded as part of the plug portion  52 . 
     Guide block  18  includes a central opening  68  that is coaxial with electrode reception aperture  40  and, thus, electrode assembly  26 . Central opening  68  has a shape that matingly corresponds to plug portion  52  and is in communication with a laterally extending recess  70 . Thus, when electrical connector  20  is connected to guide block  18  plug portion  52  is received in opening  68 . Body  50  is located within recess  70 . A finger-engaging portion  72  ( FIG. 5 ) may be integrally formed on electrical connector  20  to assist in removal of electrical connector  20  from guide block  18 . 
     The present invention generally provides that electrical connector  20  can be connected to guide block  18  at various orientations and positions, but which allows for electrical contact with the electrode assembly  26  which is sealed from the outside environment. 
     It is important to note that no matter which position or orientation an operator may choose to connect electrical connector  20  to guide block  18 , electrical connector  20  will always make electrical contact with the electrode assembly  26 . 
     It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention. Accordingly, the present invention is intended to embrace all such alternatives, modifications and variances which fall within the scope of the appended claims.