Guidewire advancement system

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.

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 along the guidewire, can be slidably 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 The guidewire is then withdrawn, and the catheter is ready 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 physicians hand 
and inserted through a needle extending into the patient'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 
inadvertant extension of the guidewire prior to insertion and the 
awkwardness of manipulation during insertion leads to contamination of the 
sterile field and the patient'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.

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 15 
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 11 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 an external monitor 46. 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.