Abstract:
An electrical connector for multi-contact medical electrodes with plural-contact tails, including a tail-receiving member having a tail-receiving void defining an internal surface and an array of electrical conductors, preferably spring-loaded ball plungers, positioned along the internal surface. A locking mechanism is positioned within the tail-receiving member and can be moved from an open position in which a tail received within the void can be removed from the void, to a locked position in which the locking mechanism prevents removal of the tail. Some preferred embodiments include the locking mechanism being positioned adjacent the void opposite the conductors and extending into the void when in the locked position; the locking mechanism being a cam shaft and cam arrangement which allows for locking by rotation of the cam shaft; and the plural contacts being sleeves with necked-in ends to allow non-destructive withdrawal of the tail in the unlocked position.

Description:
RELATED APPLICATIONS 
     This is a continuation-in-part of patent application Ser. No. 09/552,260, filed on Apr. 19, 2000 by the inventor named herein, now U.S. Pat. No. 6,415,168. 
    
    
     FIELD OF THE INVENTION 
     This invention is related generally to electrical connectors for medical use and, more particularly, to medical connectors for multi-contact medical electrodes for use in facilitating surgical procedures. 
     BACKGROUND OF THE INVENTION 
     A variety of multi-contact medical electrodes, including depth electrodes, subdural strip electrodes and grid electrodes, are placed in the human body for various purposes, such as brain-mapping in epilepsy treatment. The plurality of wires necessarily extending from such electrodes typically lead to a plural-contact tail, which is a linear dielectric member with a linear array of sleeve-like contacts spaced therealong. Such plural-contact tails of multi-contact medical electrodes have been electrically joined to other equipment, such as monitoring equipment, by means of connectors designed specifically to accommodate such tails. 
     Many different connectors have been developed to facilitate such plural-contact connection. Examples of such prior plural-contact medical connectors are those disclosed in the following United States patents: U.S. Pat. No. 4,850,359 (Putz), U.S. Pat. No. 4,869,255 (Putz), U.S. Pat. No. 4,744,371 (Harris), U.S. Pat. No. 5,560,358 (Arnold et al.), U.S. Pat. No. 5,902,236 (Iversen), U.S. Pat. No. 4,516,820 (Kuzma), U.S. Pat. No. 4,712,557 (Harris), U.S. Pat. No. 4,461,304 (Kuperstein), U.S. Pat. No. 4,379,462 (Borkan et al.), U.S. Pat. No. 4,633,889 (Talalla et al.) and U.S. Pat. No. 4,676,258 (Inokuchi et al.). 
     Certain medical connectors of the prior art have a number of shortcomings and problems. Some prior connectors generally require a number of manual steps to operate, even for the final step of causing simultaneous electrical connection of the plural contacts. One-handed connection and disconnection may not be readily possible. Some prior devices require multiple parts which add to their complexity of operation. 
     Simplicity in structure and operation is particularly important considering that connection and disconnection typically occurs in a surgical setting, in which a surgeon or other doctor must be giving great attention to many other factors. Complexity in parts and operational procedures is a significant shortcoming, one which is important by medical personnel involved. 
     Maintaining reliable and constant connection throughout the period of use is another important consideration. Connectors which tend to provide electrical contact which is variable, depending on factors such as the degree of tightening, can be problematic. Still another shortcoming of certain prior art connectors is the lack of a definitive indication that electrical connection has been accomplished and put into effect. 
     Another concern with certain medical connectors for multi-contact electrodes, particularly in situations involving seizure disorders, is that devices essential to proper electrical connections can too easily be destroyed by inadvertent motions. More specifically, the plural-contact tails of multi-contact electrodes can break, or their plural contacts become dislodged, when forceful inadvertent yanking or pulling motions occur, as can occur during seizures. This is not a simple problem, because destruction of a plural-contact tail may make it difficult or impossible for a physician or technician to ascertain the proper association of contact leads with in-body contacts, and this makes further reliable use difficult or impossible for the in-body electrode associated with the destroyed plural-contact tail. 
     In summary, there remains a number of problems and shortcomings in prior connectors for use with multi-contact medical electrodes. 
     OBJECTS OF THE INVENTION 
     It is an object of this invention to provide an improved connector for multi-contact medical electrodes overcoming some of the problems and shortcomings of the prior art. 
     Another object of this invention is to provide an improved multi-contact medical connector which is simple in structure and operation in order to facilitate operations, including during surgery. 
     Another object is to provide an improved multi-contact medical connector requiring fewer manual steps to accomplish and secure electrical connection. 
     Another object is to provide an improved multi-contact medical connector which provides for locking the components in position after connection. 
     Another object is to provide an improved multi-contact medical connector which gives highly reliable electrical connections with minimal effort. 
     Another object is to provide an improved multi-contact medical connector which gives a definitive indication of the completion of electrical connection. 
     Still another object of the invention is to provide an improved multi-contact medical connection which is less susceptible to destruction of key connection parts due to inadvertent yanking, as can occur by virtue of seizure disorders. 
     These and other objects of the invention will be apparent from the following descriptions and from the drawings. 
     SUMMARY OF THE INVENTION 
     This invention is an improved electrical connector for in-body multi-contact medical electrodes having linear-array plural-contact tails. The electrical connector is of the type having a tail-receiving member and means for connection of all contacts. The improved multi-contact medical connector of this invention includes a tail-receiving member having an elongate tail-receiving void which receives the tail. The void defines an internal surface along which an array of electrical conductors are positioned. The conductors are biased toward the void to facilitate electrical engagement with the plural contacts of the tail when the tail is inserted into the void. The connector further includes a lock positioned within the tail-receiving member and moveable between an unlocked position and a locked position wherein the lock engages the tail and prevents the tail from being removed from the tail-receiving member. In preferred embodiments, the lock is positioned adjacent to the void and opposite from the array of conductors and engages the tail within the void. The lock preferably forces the tail against the internal surface when the lock is in the locked position. At the same time, the lock forces the contacts into the conductors. When in the unlocked position the electrical conductors are just beyond center with respect to the plural contacts of the tail, thereby providing reliable electrical contact. 
     The lock preferably comprises a rod and cams, the cams preferably being positioned in alignment with the conductors. The rod is movable in the tail-receiving member between unlocked and locked positions so that in the unlocked position the cams do not extend into the void and in the locked position the plunger forces the cams to extend into the void and force the contacts against the conductors. It is most preferable that the cam shaft is rotatable between the unlocked and locked positions so that in the unlocked position the cams do not extend into the void and in the locked position the cams extend into the void and force the contacts against the conductors. 
     A highly preferred embodiment of the invention includes a knob connected to the cam shaft to facilitate one-handed rotation of the cam shaft. 
     It is also preferred that the plural contacts of the tail are annular sleeves having necked-in ends, thereby allowing quick withdrawal of the plural-contact tail from the connector when in the unlocked position. 
     The tail-receiving member preferably has proximal and distal ends and the void extends from an opening at the proximal end to a stop near the distal end. 
     In a highly preferred embodiment, the electrical conductors are spring-loaded ball plungers. In such an embodiment the tail-receiving member defines wells along the internal surface holding the spring-loaded ball plungers and the ball plungers protrude beyond the internal surface into the internal space in the unlocked position. 
     The preferred method of securing connection between the medical electrode plural-contact tail and the tail-receiving member comprises: providing an array of electrical conductors positioned along the internal surface of the void in the tail-receiving member; providing a lock positioned adjacent to the void; inserting the tail into the void so that the contacts on the tail are aligned with the conductors; and moving the lock from an unlocked position to a locked position wherein the lock forces the tail against the internal surface to ensure that the tail cannot be withdrawn from the tail-receiving member. It is preferred that the conductors are biased toward the void to facilitate electrical engagement with the plural contacts of the tail. 
     In a highly preferred method, the lock comprises a rod and cams, and the cams are positioned in alignment with the conductors. To lock the tail inside the tail-receiving member, the rod is rotated so that the cams extend into the void and force the contacts against the conductors. 
     In alternate embodiment the improved multi-contact medical connector of this invention includes first and second elongate members which are pivotable with respect to one another about a pivot axis extending along their lengths. The first elongate member has a first face and an array of electrical conductors positioned therealong in an array which matches the spacing of the plural contacts of the plural-contact tail of the medical electrode with which the connector is used. The second elongate member extends along the first elongate member and has a tail-receiving void, a second face which is parallel to the void, and access openings along the second face to expose the plural tail contacts at the second face. The second elongate member is pivotable between open and closed positions with respect to the first elongate member. The pivoting is about an axis which extends along the common lengths of the elongate members. The closed position serves to place the plural contacts of a plural-contact medical electrode tail into engagement with the electrical conductors. 
     In a preferred embodiment of the alternate embodiment, a lock is positioned in one of the elongate members, most preferably the second elongate member, and is moveable between an unlocked position and a locked position wherein the lock engages the tail and prevents the tail from being removed from the tail-receiving void. In preferred embodiments, the lock is positioned adjacent to the void and opposite from the array of conductors when in the closed position and engages the tail within the void. The lock forces the contacts against the conductors. When in the closed and unlocked position the electrical conductors are just beyond center with respect to the plural contacts of the tail, thereby providing reliable electrical contact. 
     In highly preferred alternate embodiments, the second face is movable upon pivoting between the open position at which the second face is away from the first face and the closed position at which the second face is juxtaposed to the first face, and the electrical conductors are spring-loaded ball plungers along the first face which are biased toward the second face to facilitate electrical engagement with the plural contacts of the tail. The first elongate member preferably defines cylindrical wells (or “channels”) along the first face which receive and hold the spring-loaded ball plungers. Such channels are preferably perpendicular to the first face. The distal ends of the ball plungers are held near the first face in positions for biased engagement against the contacts of the multi-contact tail when the first and second faces are in juxtaposition to one another. 
     In certain preferred alternate embodiments, the second elongate member has proximal and distal ends and the void extends from an opening at the proximal end to a stop near the distal end, and the first elongate member includes a pair of opposed inwardly-facing endwalls between which the second elongate member extends in nested fashion with its ends adjacent to the endwalls. The proximal end of the second elongate member is that end into which the multi-contact medical electrode tail is inserted, and the distal end is the opposite end. 
     In certain of such preferred alternate embodiments, one of the endwalls forms a cutaway portion through which the electrode tail passes, thereby allowing pivoting movement of the second elongate member without interference with the electrode tail. Preferably, the pivot axis extends through both endwalls and both ends and at least one pivot pin extends along a portion of the pivot axis between at least one of the endwalls and the end adjacent thereto. Two pivot pins along such axis are preferably used—one spanning between combination of endwall and end. 
     In preferred alternate embodiments, the first and second elongate members have first and second stop surfaces, respectively, which abut one another to define the closed position, and at the closed position the second elongate member positions the electrode tail such that the spring-loaded ball plungers are just beyond center (overcenter) with respect to the plural contacts of the tail. This configuration serves to provide reliable electrical contact and also helps to keep the connector in the closed position. 
     In certain preferred alternate embodiments, the second elongate member includes a grip flange which serves to facilitate pivoting of the second elongate member from the closed to the open position. Such grip flange extends away from the pivot axis and provides a thumb-grip surface. 
     In certain highly preferred alternate embodiments, the ball plungers protrude beyond the first face toward the second elongate member, and the access openings on the second face are designed to facilitate the closing action during which the plural contacts of the medical electrode tail are brought into engagement with the ball plungers. More specifically, the second face has a lead edge which is adjacent to the second stop surface when the second elongate member is in the closed position, and the access openings on the second face extend laterally to the lead edge such that the second elongate member has lateral openings receiving the ball plungers as the second elongate member is pivoted to the closed position. 
     The alternate medical connector of this invention has significant advantages over connectors of the prior art. The connector is compact, at least in part from the fact that the orientation of the pivot axis, which is along the length of the first and second elongate members, minimizes the space in which opening and closing movement occurs. The medical connector of this invention is also very easy to use in that it can be opened and closed with one hand. The connector also provides excellent electrical connections and provides definite open and closed positions to facilitate operation and understanding. 
     The invention includes the medical connectors as described above, and also includes the combination of such connectors with the linear-array plural-contact tails of a multi-contact medical electrode. In highly preferred embodiments, the plural contacts of the plural-contact tail are annular sleeves having necked-in (e.g., crimped) ends. This configuration of plural-contact tail with the medical connectors of this invention with spring-loaded ball plungers allows quick withdrawal of the plural-contact tail without destruction of the plural-contact tail. A sudden pull allows the plural-contact tail to pull out from the connector while the connector is in its closed, but not locked, position. This is brought about by the combination of spring-loaded ball plungers and the necked-in annular-sleeve contacts. The contacts will ride right over the line of ball plungers without causing destruction of the plural-contact tail. 
     This advantage is significant in that it minimizes or prevents the problems which can occur if a patient&#39;s seizure causes violent jerking and yanking movements during e.g., a brain-mapping session. Such activity can result in the need for an expensive and time-consuming reorganization and reassembly of electrical components in order to allow resumption of the intended medical activity. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The drawings illustrate a preferred embodiment including the above-noted characteristics and features of the invention. The invention will be readily understood from the descriptions and drawings. In the drawings: 
     FIG. 1 is a perspective view of the alternate connector in an open condition, with the plural-contact tail of an in-body medical electrode in position for insertion into the connector. 
     FIG. 2 is a perspective view as in FIG. 1, but with the connector in closed condition. 
     FIG. 3 is a front elevation of FIG.  1 . 
     FIG. 4 is a front elevation of FIG. 2, but with cutaway portions to illustrate certain internal details. 
     FIG. 5 is a left side elevation of the alternate connector, with the tail in section, showing the connector just before it is closed. 
     FIG. 6 is a left side elevation as in FIG. 5, but with the connector fully closed. 
     FIG. 7 is an enlarged fragmentary cutaway view of a portion of FIG. 4, as indicated in FIG.  4 . 
     FIG. 8 is a perspective view of a cross section of the preferred electrical connector and tail. 
     FIG. 9 is a perspective view of the preferred electrical connector receiving a tail, but with cutaway portions to illustrate internal details. 
     FIG. 10 is a perspective view of a cross section of the preferred electrical connector and tail 
     FIG. 11 is a cross section view taken along the direction of tail insertion showing the connection of the preferred contact and conductor in the unlocked position. 
     FIG. 12 is a cross section view taken along the direction of tail insertion showing the connection of the preferred contact and conductor in the locked position 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     FIGS. 1-6 illustrate an improved electrical connector  10  for use with an in-body multi-contact medical electrode (the in-body portion of which is not shown) having a linear-array plural-contact tail  12 , having a linear array of electrical contacts  14  spaced therealong, each electrically linked by a tiny conductive wire running up and beyond tail  12  to a particular in-body contact on the in-body portion of the electrode. Connector  10  includes first and second elongate members  16  and  18  which are pivotable with respect to one another about a pivot axis A which extends along their lengths. 
     First elongate member  16  has a first face and an array of spring-loaded ball plungers  22  positioned therealong in a linear array which matches in its spacing the linear array of electrical contacts  14  of plural-contact tail  12 . Second elongate member  18  extends along first elongate member  16  and has a linear tail-receiving void  24 , a second face  26  which is parallel with and closely adjacent to void  24 , and access openings  28  along second face  26  and intersecting void  24  to expose contacts  14  at second face  26  in positions of alignment with, and intersecting, the round distal ends  22   a  of spring-loaded ball plungers  22 . 
     Second elongate member  18  pivots with respect to first elongate member  16  between open positions illustrated by FIGS. 1,  3  and  5  and a closed position illustrated by FIGS. 2,  4  and  6 . Pivot pins  31  (see cutaway portion of FIG. 4) extend along axis A and pivotably connect second elongate member  18  with first elongate member  16 . In the closed position, second face  26  is closely adjacent juxtaposed) to first face  18 , such that contacts  14  are placed into engagement with spring-loaded ball plungers  22 , each of which is electrically connected to one of the wires  30  which extend from connector  10  for easy connection by means not shown with other equipment. 
     First elongate member  16  preferably defines wells (or “channels”)  32  along first face  20  which receive and hold spring-loaded ball plungers  22 . Channels  32  are perpendicular to first face  20  and extend through first elongate member  16  to allow electrical connection with wires  30 . Spring-loaded ball plungers  22  are potted in their positions in channels  32  and protruding just beyond first face  20  by an epoxy  34  applied in a recess  36  (see cutaway portion of FIG. 4) which is formed in the outer surface  38  of first elongate member  16 . Distal ends  22   a  of spring-loaded ball plungers  22  are biased toward second face  26  to facilitate electrical engagement with contacts  14  of tail  12 . 
     Second elongate member  18  has proximal and distal ends  40  and  42 , and linear void  24  extends from an opening at proximal end  40  to a stop  44  near distal end  42 . The position of stop  44  is fixed such that full insertion of tail  12  into void  24  causes contacts  14  to be in alignment with access openings  28  along second face  26  of second elongate member  18 . First elongate member  16  includes a pair of opposed inwardly-facing endwalls  46  and  48  between which second elongate member  18  extends in nested fashion, with ends  40  and  42  adjacent to endwalls  46  and  48 , respectively. As shown best in FIGS. 5 and 6, endwall  46 , which is adjacent to proximal end  40  of second elongate member  18 , is formed with a cutaway portion  50  to accommodate the presence of electrode tail  12  during pivoting movement of second elongate member  18 . 
     As shown best in FIGS. 5 and 6, first and second elongate members  16  and  18  have first and second stop surfaces  52  and  54 , respectively, which abut one another to define the closed position. As seen best in FIG. 6, at the closed position second elongate member  18  positions tail  12  such that spring-loaded ball plungers  22  are just beyond-center with respect to contacts  14  of tail  12 . 
     Second elongate member  18  includes an integrally-formed grip flange  56  (see FIGS.  5  and  6 ), which extends away from pivot axis A. To open connector  10 , downward thumb pressure is applied on grip flange  56  to pivot second elongate member  18  away from the closed position shown in FIG.  6 . 
     As shown best in FIG. 3, second face  26  has a lead edge  58  which is adjacent to second stop surface  54  (and to first stop surface  52 ) when second elongate member  18  is in the closed position. Access openings  28  on second face  26  extend laterally on second face  26  to lead edge  58 . This provides a lateral opening to each access openings  28  to receive spring-loaded ball plungers  22  as second elongate member  18  is pivoted to the closed position. 
     FIG. 7 illustrates details of contacts  12  and their relationship to distal ends  22   a  of spring-loaded ball plungers  22 . Each contact  14  of plural-contact tail  12  is an annular sleeve which includes necked-in ends  14   a , formed by crimping. As can be seen, the outer diameter of contact sleeves  14  are slightly greater than the outer diameter of the adjacent dielectric support tube  60  along which contacts  14  are mounted. As earlier noted, this allows quick removal of plural-contact tail  12  from medical connector  10 , inadvertent or otherwise, without causing destruction of plural-contact tail  12 . 
     First and second elongate members  16  and  18  of medical connector  10  may be made of hard plastic materials, a wide choice of which is available and will be apparent to those receiving this disclosure. Second elongate member  18  is preferably made of translucent or transparent material so that the positions of contacts  14  can be seen even without looking at access openings  28 . A wide variety of materials is available for the various parts discussed and illustrated herein. 
     FIG. 8 shows a cross-section view of the preferred connector and plural-contact tail. Connector or tail-receiving member  816  includes tail-receiving void  818  into which tail  812  may be inserted. Void  818  defines internal surface  820 . Positioned along internal surface  820  are conductors  822 . Conductors  822  are preferably spring-loaded ball plungers which extend and are biased into void  818 . Void  818  extends from proximal opening  843  to distal stop  844 . 
     Connector  816  further includes lock  825  which is comprised of cams  826  and cam shaft or rod  824 . Lock  825  is positioned parallel to and adjacent void  818 , opposite conductors  822 . As shown, lock  825  is in the unlocked position in which cams  826  do not extend into void  818 . Upon rotation of shaft  824 , preferably via knob  827 , cams  826  extend into void  818 . 
     Tail  812  includes electrical contacts  814  which are preferably sleeves with necked in ends to allow non-destructive withdrawal of tail  812  when tail-receiving member  816  is in the unlocked position. Contacts  814  are spaced along tail  812  in a corresponding manner to the orientation of conductors  822  spaced along internal surface  820 . 
     FIG. 9 shows the preferred electrical connector and tail in connection but unlocked. Tail  812  is inserted into void  818  until its distal end reaches stop  844 . At this point contacts  814  are aligned with conductors  822 . Conductors  822  extend into void  818  and ensure reliable connection with contacts  814 . [Tial] Tail  812  is typically forced away from the portion of internal surface  820  on which conductors  822  are positioned. 
     FIG. 10, the connector is locked to prevent removal of tail  812  from void  818 . As can be seen, in the locked position cams  826  extend into void  818  from the side of internal surface  820  opposite conductors  822 . Cams  826  are extended into void  818  by the rotation of cam shaft  824 , preferably by a rotation of  45  degrees. Cams  826  force contacts  818  against conductors  822 . [Conductors  822 . Conductors] such that conductors  822  are pushed into wells  832  which creates an increasing spring force against contacts  814 . Cams  826  force tail  812  against the portion of internal surface  820  along which conductors  822  are positioned. In this manner the counteracting forces of cams  826  and conductors  822  ensure reliable connection and prevent removal of tail  812  from void  818 . 
     FIGS. 11-12 show the cross section view of the connection of a conductor and contact in unlocked and locked configurations respectively. Contact  814  is shown as a sleeve circling tail  812 . Contact  814  is aligned and in contact with conductor  822  which extends into tail-receiving void  818 . Cam shaft  824  is positioned adjacent void  818  opposite from conductor  822 . Cam  822  is connected to cam shaft  824  so that rotation of cam shaft  824  caused cam  822  to enter void  818 . In FIG. 12 cam shaft  824  has been rotated 45 degrees from its position in FIG. 11 so that cam  824  enters void  818  and contacts tail  812  or contact  814 . Recess  828  surrounds cam  826  so that cam may be rotated within tail-receiving member. 
     When cam  826  extends into void  818  it causes tail  812  to be forced toward internal surface  820  adjacent conductor  222 . Tail  812  may contact internal surface  820  while conductor  822  is forced from well  832  into contact with contact  814  by spring force. In this manner tail  812  is locked into position within void  818 . 
     Tail-receiving member  816  may be made of hard plastic materials, a wide choice of which is available and will be apparent to those receiving this disclosure. One face of tail-receiving member may be made of translucent or transparent material so that the positions of contacts  814  can be seen within member  816 . A wide variety of materials is available for the various parts discussed and illustrated herein. 
     While the principles of this invention have been described in connection with specific embodiments, it should be understood clearly that these descriptions are made only by way of example and are not intended to limit the scope of the invention.