Abstract:
A contact connection adapter for producing an intermittent electrical contact between two plugs has a main body and two socket-like receptacles placed thereon for the plugs. The cross-sections of the receptacle receiving the plugs to be connected intersect peripherally in this case in such a way that the plugs press against one another at their lateral contact faces and produce an electrical contact.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention  
         [0002]     The present invention relates to a contact connection adapter for producing an intermittent electrical contact between a first plug, particularly a standard terminal plug of a cardiac pacemaker electrode, and at least one second plug, particularly a typical laboratory plug for intermittent connection of the electrode to a stimulus threshold analyzer.  
         [0003]     2. Background Art  
         [0004]     The background of the present invention is the procedure during implantation of a cardiac pacemaker, defibrillator, or similar cardiological device, whose electrophysiological stimulation pulses are delivered by appropriate electrodes positioned in or on the heart. During the implantation procedure, the electrodes are typically advanced in a controlled way via the vascular system of the patient with the aid of a mandrel inserted into the electrode. This mandrel runs coaxially through the proximal terminal plug of the electrode. This plug is typically a plug standardized for medical application, designated IS-1/IS-4/DF-1, etc., for example, which may be implemented as unipolar or bipolar.  
         [0005]     After an electrode is seated, its seat and stimulation pulse delivery behavior must be analyzed, for which a stimulus threshold analyzer is responsible. This device simulates the cardiac pacemaker otherwise coupled via the electrode terminal plug and must be electrically connected to the electrode plug for this purpose. However, this may not be performed by simply plugging the plug into the device, since the electrode plug must be kept sterile, and, in addition, the mandrel is not to be pulled out of the electrode yet for the present test, since repositioning of the electrode with the aid of the control mandrel may possibly be necessary. Since the mandrel end is guided through the plug, the plug may not be inserted into a device socket in any case.  
         [0006]     DE 198 10 262 A1 (=U.S. Pat. No. 6,708,067 B1) discloses a test cable assembly, in which, on a cardboard-like support, a terminal pole of the electrode plug may be fixed on a clamp terminal attached to the support. The second pole, typically an electrode terminal ring, is contacted via an alligator clip, which simultaneously produces a further mechanical connection between the paperboard-like support and the electrode plug. Clamp terminal and alligator clip are electrically connected via thin litz wires, which may be plugged into a fitting socket of the test unit via a corresponding plug device.  
         [0007]     This previously known achievement of the object has a provisional character, and, in addition, multiple steps are necessary for the production of the adapter, namely cutting the paperboard support to length and wiring and attaching the terminal clamp and alligator clip. Handling this test adapter is cumbersome and the contact provided, particularly to the alligator clip, is in need of improvement in its reliability.  
       SUMMARY OF THE INVENTION  
       [0008]     The present invention is based on the object of specifying a contact connection adapter of the type cited at the beginning, which may be manufactured with significantly less production complexity, is extremely simple to handle, and offers high contact reliability between the electrical parts to be connected at the same time.  
         [0009]     This object is achieved by a contact connection adapter comprising a main body, in which socket-like receptacles for the two plugs to be connected, in the concrete example the terminal plug of a cardiac pacemaker electrode and a typical laboratory plug on a laboratory cable leading to the stimulus threshold analyzer, are placed. The cross-sections of these receptacles intersect peripherally in such a way that the plugs plugged into the receptacles press against one another at their lateral contact faces and produce an electrical contact.  
         [0010]     It may be seen that the main body itself does not require any contact elements to produce an electrical contact. This is produced solely via the plugged-in plugs directly with one another. Therefore, the contact connection adapter may be produced from a uniform material, such as plastic which may be injection molded. The adapter is thus also distinguished by especially good ability to be sterilized.  
         [0011]     Preferred embodiments of the contact connection adapter and features, details, and advantages thereof will become clear from the following description of the present invention on the basis of the attached drawing. 
     
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0012]      FIG. 1  shows a horizontal section of a contact connection adapter along section line I-I in  FIG. 2  having plugs to be connected before they are inserted into the adapter,  
         [0013]      FIG. 2  shows a side view of the adapter from arrow direction II in  FIG. 1 , and  
         [0014]      FIG. 3  shows a section of the adapter along section line III-III in  FIG. 2 . 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0015]     The contact connection adapter  1  shown in the drawing is used for producing an intermittent electrical contact between a standardized IS-1/IS-4/DF-1 terminal plug  2  of a cardiac electrode  3  shown cut away in  FIG. 1  and, in addition, two typical laboratory plugs  4 ,  5 —colloquially referred to as “banana plugs”—which are to be electrically connected via appropriate cables to the terminal sockets of a stimulus threshold analyzer (not shown in greater detail).  
         [0016]     The adapter  1  has an essentially cuboid main body  6 , which is injection molded from a transparent, sterilizable plastic material in one piece. A socket-like receptacle  7  is placed in the main body approximately centrally, but shifted toward the top and running parallel thereto, whose cross-sectional area pointing to the outside is housed in a projection  8 , which is triangular in profile. This extends beyond the top  9  of the adapter  1 .  
         [0017]     As may be seen from  FIG. 1 , the receptacle  7  is stepped twice starting from a plug area at the mouth having a diameter d 10 , namely to a somewhat narrower plug area  11  having the diameter d 11  and a deepest plug area  12  having an even smaller diameter d 12 . The plug areas  10 ,  11 , and  12  have their diameters d 10 , d 11 , and d 12  tailored to the corresponding external diameters D 13 , D 14 , D 15  of the plug shaft  13 , the annular contact  14 , and the tip contact  15  placed at the tip of the plug  2 . The shaft  13  is separated from annular contact  14  by a double peripheral annular seal  16  in this case. Likewise, a further pair of annular seals  17  are provided on the shaft area following the annular contact  14  before the step to the tip contact  15 .  
         [0018]     To receive the two laboratory plugs  4 ,  5 , the adapter has an essentially cylindrical receptacle  18 ,  19  in each of two planes P 18  and P 19 , which lie one behind another in the insertion direction E and are perpendicular thereto. As may be seen from  FIG. 1 , the depth of these receptacles  18 ,  19  approximately corresponds to the length l of the laboratory plugs  4 ,  5  and the receptacles end shortly before the narrow side  22  of the adapter  1  facing away from the mouth  20 ,  21 . They are each permeable to sterilization liquid there via an opening  23 ,  24 .  
         [0019]     As may be seen from  FIG. 3  in particular, the cross-sections of the receptacle  7  for the IS-1/IS-4/DF-1 plug  2  and the two receptacles for the laboratory plugs  4 ,  5  intersect slightly peripherally, so that the two cross-sectional volumes pass into one another via contact windows  25 ,  26  ( FIG. 1 ). If the IS-1 plug  2  is plugged into the receptacle  7  and a laboratory plug  4 ,  5  is plugged into each of the receptacles  18 ,  19 , the spring lamellae  27  of the laboratory plugs  4 ,  5  provide an optimum electrical connection to the annular contact  14  or tip contact  15  of the plug  2  via the contact windows  25 ,  26 .  
         [0020]     As may be seen from  FIG. 3  in particular, the two receptacles  18 ,  19  have an offset V to one another for adaptation to the stepped diameter reduction of the receptacle  7 .  
         [0021]     For the above-mentioned mandrel seated in the electrode, which is merely partially indicated in  FIG. 1  at reference number  28 , the receptacle  7  for the plug  2  is open laterally over its complete length through a passage slot  29  provided in the projection  8 . Furthermore, its innermost plug area  12  continues in the coaxial direction in a passage hole  30 , which expands into a funnel-shaped mouth  31 . Via the passage slot  29  and a passage hole  30 , the section of the mandrel  28  running in front of the tip contact  15  may be inserted into the receptacle  7  from the side. Direct threading is not possible, since the mandrel ends in a voluminous control handle. After the insertion of the mandrel into the receptacle  7 , the plug  2  may be plugged in. To make inserting the mandrel easier, the passage slot  29  is provided with insertion bevels  32 .