Abstract:
A guidewire advancement system for inserting catheter guidewires into blood vessels, and more particularly a guidewire dispensing system for the controlled sterile insertion of a coiled spring guidewire to avoid infection of the patient. The system provides for the transmission of an electrical signal by the guidewire to determine its location within the body.

Description:
RELATED APPLICATION(S) 
     This application is a continuation of application Ser. No. 09/069,431 filed Apr. 29, 1998, now U.S. Pat. No. 6,011,988 a continuation of application Ser. No. 08/455,698 filed May 31, 1995, now U.S. Pat. No. 5,810,012, which is a continuation of application Ser. No. 08/221,083 filed Mar. 31, 1994, now U.S. Pat. No. 5,448,993, which is a continuation of application Ser. No. 07/993,414 filed Dec. 21, 1992, now abandoned, which is a continuation of application Ser. No. 07/788,049 filed Nov. 5, 1991, now U.S. Pat. No. 5,273,042 which is a continuation of U.S. application Ser. No. 07/509,500 filed on Apr. 13, 1990, now abandoned, which is a continuation-in-part of U.S. application Ser. No. 07/372,047 filed on Jun. 27, 1989, now U.S. Pat. No. 4,917,094, which was a divisional application of U.S. application Ser. No. 07/114,451 filed on Oct. 28, 1987, now U.S. Pat. No. 4,860,757, the entire contents of the above applications are incorporated herein by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     The invention relates to devices for the insertion of catheter guidewires into blood vessels. A guidewire is inserted so that a catheter, which is coaxially engaged with the guidewire, may be inserted into the. blood vessel. The guidewire is then withdrawn, and the catheter is ready for further positioning and use. It is imperative that guidewires be inserted without contamination of the sterile field to avoid unnecessary infection of the patient. 
     Guidewires are generally comprised of a coiled spring guide with a distal tip and one or more wires running longitudinally within the spring. Such guidewire constructions are disclosed in U.S. Pat. Nos. 4,003,369 and 4,676,249. Catheters are generally hollow, flexible tubes used to convey liquids or other instruments to a desired location in the body. 
     Existing systems for guidewire insertion suffer from continued problems arising from the lack of ease in manipulation and the exposure during insertion to a non-sterile environment. Normally, a guidewire is removed completely from its package prior to use, is wound in the physician&#39;s hand and inserted through a needle extending into the patient&#39;s artery, or through a cannula into some other body cavity. Three or more hands are required to hold the needle stationary while the “J” guidewire is pulled through a straightener, then pushed through the port in the needle. The inadvertent extension of the guidewire prior to insertion and the awkwardness of manipulation during insertion leads to contamination of the sterile field and the patient&#39;s blood stream. It is also desirable that the physician or operator be able to tactilely sense the progress of the guidewire tip during insertion to insure better control. 
     SUMMARY OF THE INVENTION 
     A catheter guidewire is packaged for use in a hollow tube or casing which maintains a sterile environment for the guidewire prior to use. The guidewire is displaceable through an outlet at one or both ends of the tube for insertion into the desired artery or body cavity. 
     An aperture in the casing is located adjacent to the outlet so as to provide access to the guidewire surface. By applying a lateral frictional force to the surface of the guidewire in the direction of the outlet, the guidewire can be displaced through the narrow tube and the outlet. 
     A second tube attached to the outlet and disposed to receive the guidewire as it exits the casing can be used to straighten a “J” guidewire prior to entering a canal through a needle or cannula. In a preferred embodiment of the invention, the aperture for frictionally displacing the guidewire can be located in the straightening tube. The invention thus provides a means for maintaining a sterile environment during storage and insertion of the guidewire. Only one hand is necessary to operate the dispensing mechanism while the desired sensitivity to guidewire placement in maintained. 
     In another preferred embodiment, a moveable member is positioned over the aperture to maintain a sterile environment for the guidewire while at the same time providing the frictional force to displace the guidewire. This moveable member can be hand actuated rollers or a slidable bar or any other suitable mechanical device that maintains the tactile sense of the operator with regard to directing the guidewire through the system. The member which can be manually depressed to frictionally engage the guidewire surface. The moveable member can also be placed in a housing used to hold the two ends of the casing. 
     One embodiment of the system provides for the transmission of an electrocardiographic signal through the guidewire to determine the position of the distal end of the guidewire that has been inserted into a body canal. The housing that holds the frictionally engaging member referenced above is positioned about the aperture and used to transmit an internally generated electrical signal onto the conductive guidewire element. 
     The above, and other features of the invention, including various novel details of construction and combination of parts, will now be more particularly described with reference to the accompanying drawings and pointed out in the claims. It will be understood that the particular guidewire advancement system embodying the invention is shown by way of illustration only and not as a limitation of the invention. The principle features of this invention may be employed in varied embodiments without departing from the scope of the invention. For example, the device can be utilized in the catheterization of any body cavity or artery, or alternatively in any veterinary applications involving catheterization procedures. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, features and advantages of the invention will be apparent from the following more particular description of preferred embodiments of the invention, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. 
     FIG. 1 illustrates a plan view of the guidewire system generally; 
     FIG. 2 schematically illustrates a close up view of the guidewire aperture operated by hand; 
     FIG. 3 illustrates a plan view of an alternative embodiment where the aperture is located in the guidewire straightener; 
     FIG. 4 illustrates a perspective view of a guidewire advancement system using a slidable bar; 
     FIG. 5 illustrates a perspective view of a guidewire advancement system using rollers; and 
     FIG. 6 is a magnified cross-sectional view illustrating the use of an external monitor that displays an internally generated electrical signal transmitted along the guidewire that is employed in determining the position of the guidewire. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the guidewire advancement system  10  is illustrated in FIG. 1. A flexible hollow tube  11  can be disposed in the shape of a curve or loop(s) as depicted to facilitate ease of operation. A guidewire  12  of standard coiled spring design is slidably inserted into tube  11 . The guidewire  12  can enter or exit tube  11  through either of the two open ends  17  and  18 . The guidewire  12  is inserted into a vein or artery through a needle, or canal or cavity by a cannula  19 . 
     One end of the guidewire  12  can be formed in the shape of a flexible “J”  13 . The “J”  13  may be straightened by pulling the end of the guidewire bearing the “J” back into the straightening element  14 . The straightener  14  has a narrow hollow tube to which the “J” must conform upon entry therein. The straightener  14  is attached to tube  11  by inserting a small diameter portion  20  of straightener  14  into the port  17 . The outer diameter of portion  20  is chosen so that it fits snugly into the hollow tube  11  at  17 . The purpose of the “J”  13  is to permit the guidewire operator to more precisely direct the insertion of the guidewire to the precise arterial location desired. As the guidewire proceeds along the inside of an artery there are commonly two or more paths for it to follow. The operator, using the tension in the straightened “J” to return to its preferred shape, can direct the guidewire down the desired artery path. Simply by rotating the guidewire within the cannula  19 , the “J”  13  will be. redirected as desired. 
     Existing guidewire packages typically involve the complete removal of the guidewire from the tubing in which they are stored before use. This often exposes the guidewire to non-sterile environments thereby risking the infection of the patient when the exposed guidewire is inserted into the bloodstream. 
     The present invention claims. the use of apertures  15  and  16  located adjacent the two end ports  17  and  18 . These apertures provide access to the guidewires  12  so that it may be inserted into the bloodstream without being first removed from its storage tube  11  or jacket. The apertures and  16  permit the use of the guidewire to be confined within the sterile field thereby substantially reducing the risk of unnecessary infection. 
     FIG. 2 illustrates how the apertured guidewire system may be operated by hand. By inserting his or her thumb into the aperture  16 , the operator frictionally engages the guidewire  12 , and can either advance or retract it as shown. This design permits one handed operation that is sensitive to guidewire placement. Aperture  16  may be used, as opposed to aperture  15  in FIG. 1, where the operator prefers to use the straight end  21  of the guidewire through port  18 , instead of the “J” shaped end  13 . 
     FIG. 3 illustrates another preferred embodiment of the invention where the straightener  14  is provided with aperture  25 . The guidewire  12  can be manipulated through aperture  25  directly adjacent the guidewire exit point  22 , instead of further back along the tube  11  at aperture  15  in FIG.  1 . 
     To further isolate the guidewire from exposure to non-sterile environments the apertures  15  and  16  can be enclosed with an element  30  as illustrated in FIGS. 4 and 5. The element  30  is used to hold the two ends of the tube  11  in the shape of a loop as shown in FIG.  1 . The two ends of tube  11  are both snapped into the two parallel partially open tubes  33  extending through element  30  such that the apertures  15  and  16  (not shown) are completely enclosed. 
     A rectangular opening  31  can be made in the element  30  opposite the apertures (not shown) in tube  11 . A slidable cam or bar  32  may be fitted into opening  31  that can be manually depressed to frictionally engage the guidewire. By positioning the cam  32  at one end of the opening  31 , the guidewire  12  may be advanced through the tube  11  in one direction. By depressing the cam  32  to engage the guidewire, the operator slides the cam  32  to the other end of the opening  31 , releasing the cam  32  from its depressed position, moving the cam  32  back to its position at the opposite end of the opening  31 , and then repeating this sequence of steps until the guidewire is in the desired location. 
     FIG. 5 illustrates a further embodiment of the invention in which a number of rollers  35  may be depressed to engage the guidewire  12  through an enclosed aperture in tube  11 . These rollers frictionally engage the guidewire  12  such that their manually actuated rotation causes the guidewire to be pushed through tube  31  for insertion into the artery. 
     Both the cam  32  of FIG.  4  and the rollers  35  of FIG. 5 may be held within member  30  by resilient means which lift the cam  32  or rollers  35  off of the guidewire  12  when not manually depressed against it by the operator. This resilient means renders the cam  32  or rollers  35  easier to cycle a number of times to fully extend the guidewire. 
     Another preferred embodiment is illustrated in the magnified cross sectional view of FIG.  6 . As in FIG. 4, a conductive guidewire  12  is displaceable through tubing  11 , that is held by a housing  30 . A slideable bar  32  is configured to move back and forth within an opening  31 . The bar  32  is supported by a track  43 . A lower portion of the track  43  incorporates a conductive lining  44  in conductive contact with a conductive pad  40  mounted on the underside of bar  32 . The track  43  and attached lining  44  are flexible thereby permitting the bar  32  to be depressed manually by the operator such that the pad  40  comes in contact with the guidewire through aperture  15  of tube  11 . The lining  44  is in conductive contact with an outlet  42  by wire  41 . The outlet  42  is mated with an external plug  45  connected to a monitoring circuit  38  including a diode  39  and an external monitor  46 . The diode  39  prevents any back current from being transmitted from circuit  38  into the guidewire which can be harmful to the patent. The electrical signal generated by an internal organ such as the human heart transmits a signal through the guidewire  12  to pad  40  when the bar  32  is depressed. This signal is transmitted through the distal tip of the guidewire that has been inserted into a bodily canal or artery to determine the location of the distal tip within the body being catheterized. As the tip approaches the heart muscle, it transmits the electrical current generated about the heart along the guidewire through the engaging means of the housing to be displayed by the monitor  46 . This system provides for a more precise positioning of the guidewire as well as the catheter while at the same time providing for the sterile insertion of the guidewire. 
     EQUIVALENTS 
     While this invention has been particularly shown and described with references to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described specifically herein. Such equivalents are intended to be encompassed in the scope of the claims.