Guidewire migration controller

Disclosed herein is a guidewire migration controller for use with catheter devices such as atherectomy catheters. The guidewire migration controller includes a housing, a gripper insertable in the housing and a locking member. The locking member holds the gripper within the housing. The gripper has an opening for receiving a guidewire. The gripper permits the guidewire to rotate and holds the guidewire to control guidewire migration.

BACKGROUND OF THE INVENTION 
1. Field of Invention 
This invention relates to catheter devices which rely on guidewires to 
direct the catheter to a desired location within a body. More 
particularly, this invention relates to guidewire controllers. 
2. Previous Art 
As described in U.S. Pat. Nos. 5,250,059; 5,084,010 and 4,479,952 which are 
specifically incorporated herein by reference, there exists a plethora of 
different catheter designs. Where directional atherectomy catheters are 
used, it is desirable to employ a guidewire to guide the catheter to the 
desired position within a body. 
Typically, the catheter has a drive unit attached to a torque cable for 
rotating (or rotationally oscillating) a work element. The torque cable 
(cable) has a hollow interior. One end of the cable connects to the drive 
unit and the other end connects to the work element. Work elements 
include, for example, cutting devices, ablation elements and telemetry 
devices. 
A guidewire slides within the hollow interior of the torque cable in order 
to guide the catheter into a desired location within the body. The 
guidewire, for example, can guide an atherectomy catheter to an occluded 
region in the vasculature of a human body. 
The guidewire is manipulated to the desired location by rotating and 
feeding the guidewire from the drive unit through the torque cable. This 
feeding may be accomplished by hand, or otherwise. 
The drive unit rotates the torque cable. A drive unit is disclosed in U.S. 
Pat. No. 4,771,774 which is incorporated herein by reference. A torque 
cable is disclosed in commonly assigned U.S. patent application Ser. No. 
08/606,678 filed Feb. 2, 1996, Attorney Docket No. DEVI1434CON, the file 
wrapper continuation of U.S. patent application Ser. No. 08/165,058 filed 
Dec. 9, 1993, which is incorporated herein by reference. Rotation of the 
torque cable causes sympathetic rotation of the guidewire. Sympathetic 
rotation is the result of frictional forces developed between the rotating 
interior of the torque cable and the surface of the guidewire. 
The torque cable can also be translated along the longitudinal axis of 
catheter independently of cutter rotation. Torque cable translation causes 
sympathetic translation of the guidewire, also known as migration. 
Migration of the guidewire during operation of the work element is 
undesirable because the guidewire may interfere with operation of the 
catheter and the work element. What is desired is a way of controlling the 
axial migration of the guidewire. 
The guidewire must be able to rotate as the sympathetic action between the 
torque cable and guidewire may varyingly dictate. If the guidewire is kept 
from rotating at the proximal end, the spinning action of the torque cable 
against the guidewire may cause one end of the guidewire to twist and wind 
up with respect to the other end. This can cause the guidewire to deform 
and fail. 
What is needed is a device for controlling guidewire migration along the 
torque cable. The device should allow the guidewire to spin during 
rotation and longitudinal motion of the torque cable. The device for 
controlling the guidewire migration should be adapted for use with various 
guidewire types, torque cables and drive systems. 
SUMMARY OF THE INVENTION 
It is a general object of this invention to provide a guidewire migration 
controller which prevents substantial migration of the guidewire through a 
torque cable during catheter operation. 
It is another object of this invention to provide a device for controlling 
migration of a guidewire which adapts easily with a conventional drive 
unit. 
It is another object of this invention to provide a guidewire migration 
controller which inhibits substantial migration of the guidewire without 
interfering with rotation of the torque cable. 
In accordance with the above objects and those that will become apparent 
below, a device for controlling guidewire migration comprises: 
a housing; 
a guidewire gripper having an opening for gripping the guidewire, the 
guidewire gripper being insertable within the housing; and 
a locking member for locking the guidewire gripper within the housing, 
whereby, when the locking member locks the guidewire gripper within the 
housing, the guidewire gripper holds the guidewire to control guidewire 
migration. 
In a preferred embodiment of the present invention the locking member and 
the housing each define an opening for receiving a guidewire. 
In another preferred embodiment, the locking member rotatably attaches to 
the housing. 
In another preferred embodiment, the gripper rotates with the locking 
member. 
In another preferred embodiment, the locking member has a rotation adjuster 
for aligning the openings in the gripper and the locking member with the 
opening in the housing. 
In another preferred embodiment, the housing slidably attaches with a drive 
unit of an atherectomy catheter. The housing normally occupies a first 
position with respect to the drive unit to hold a guidewire. The housing 
slides to a second position to release the guidewire. 
In another preferred embodiment, the housing includes a body which defines 
an inner race. The locking member includes an annulus. The inner race 
rotatably connects with the annulus. 
It is an advantage of the present invention to provide a guidewire 
migration controller which controls migration of a guidewire through a 
torque cable of a catheter. 
It is another advantage of the present invention to provide a device for 
controlling guidewire migration which can be adapted for use with a 
conventional drive unit. 
It is another advantage of the present invention to provide a guidewire 
migration controller which does not significantly interfere with rotation 
of the torque cable.

DETAILED DESCRIPTION OF THE INVENTION 
The invention will now be described with specific reference to FIG. 1 which 
illustrates the guidewire controller generally designated by the reference 
numeral 100. The guidewire controller 100 is shown in operable attachment 
with an atherectomy catheter 101. 
The atherectomy catheter 101 has a drive unit 103, a catheter body 102, a 
work element housing 104, a work element 106, a torque cable 108, and a 
guidewire 110. The catheter body 102 has a proximal end 112, a distal end 
114 and a catheter lumen 115 extending therebetween. The torque cable 108 
extends through the catheter body 102 through the catheter lumen 115, 
between the proximal end 112 and the distal end 114. The work element 
housing 104 attaches to the distal end 114 of the catheter body 102. The 
work element 106 attaches to the torque cable 108. The work element 
housing 104 houses the work element 106. 
The drive unit 103 has a proximal end 117 and a distal end 118. The distal 
end 118 of the drive unit 103 connects with the proximal end 112 of the 
catheter body 102. The guidewire controller 100 attaches to the proximal 
end 117 of the drive unit 103. The torque cable 108 attaches within the 
drive unit 103. The drive unit 103 rotates the torque cable 108 and 
thereby actuates the work element 106. 
The torque cable 108 is a hollow tube having a central lumen 119 through 
which the guidewire 110 is fed. Rotation of the torque cable 108 may cause 
sympathetic rotation of the guidewire 110 within the torque cable 108. 
The guidewire 110 facilitates positioning of the atherectomy catheter 101 
(e.g. to within the coronary artery). Preferably, the work element 106 is 
a cutter which rotates (or rotationally oscillates) to remove tissue 
invaginated by the work element housing 104 (e.g. atheroma). An example of 
a catheter device and the use thereof is described in U.S. Pat. No. 
5,312,425 which is incorporated herein by reference. 
The guidewire 110 is made from material such as spring steel or Nitinol. 
The guidewire 110 has a diameter of between 0.009" and 0.018". 
A switch 116 is provided with the drive unit 103 to actuate the drive unit 
103. The drive unit has an electronically powered motor. Accordingly, the 
drive unit 103 includes a power source e.g. batteries, or an A/C plug. The 
switch 116 toggles the operation of the drive unit 103 in an on/off 
condition. It can be appreciated that various switches 116 can be employed 
which selectively regulate the rotational speed of the torque cable 108. 
An example of a drive unit which can be adapted for use with the present 
invention is disclosed in U.S. Pat. No. 4,771,774 which is incorporated 
herein by reference. 
With particular reference to FIG. 2, the guidewire migration controller 100 
is shown in an exploded perspective view. The guidewire migration 
controller 100 includes a housing 120, a gripper 122 and a locking member 
124. The guidewire 110 passes through the drive unit 103 and the guidewire 
migration controller 100. The gripper 122 permits rotation of the 
guidewire 110 and holds the guidewire 110 to selectively prevent guidewire 
migration. 
The housing 120 has a body 130 which is resilient. The body 130 has edges 
134 and 136 which define an opening 132 therebetween. The opening 132 
extends longitudinally along the body 130 for receiving the guidewire 110. 
The edges 134 and 136 normally remain separated from each other by the 
opening 132. 
The housing 120 includes a pair of ears 140 which extend from the body 130. 
Each ear 140 has a rail member 150. The drive unit 103 presses the ears 
140 together when the housing 120 connects with the drive unit 103. When 
the ears 140 are pressed together the housing 120 flexes and the ends 134 
and 136 move toward each other to hold the gripper 122 and the locking 
member 124 within the housing 120. 
The drive unit 103 has a proximal end 142. The proximal end 142 has a track 
member 146 which defines a track axis 144. The ears 140 slidably connect 
with the track member 146. The rail members 150 lock the ears 140 with the 
track member 146. The track member 146 contacts the ears 140 to press the 
edges 134 and 136 together and slidably hold the housing 120 with the 
drive unit 103. 
The gripper 122 has a gripper body 160 with a center slot 168 and edges 164 
and 166. The edges 164, 166 and the center slot 168 define an opening 162 
therebetween. The gripper body 160 is resilient and compressible so that 
the ends 164 and 166 are adjustably spaced apart to receive the guidewire 
110. Preferably, the opening is normally between several thousandths of an 
inch to one hundredth of an inch thick. The opening 162 is reduced in 
thickness when the gripper body 160 is compressed by the housing 120. 
The gripper 122 is made from a resilient material suitable for gripping a 
thin metal wire. The resilient material is preferably polymeric, such as 
for example, a polyurethane, RTV silicone, silicone rubber and varied 
elastomeric materials. It will be appreciated that when the gripper is 
inserted within the housing 120 and held by the locking member 124, the 
ends 164 and 166 are moved together, the gripper 122 (including the center 
slot 168) grips the guidewire 110. 
The locking member 124 has a body 170. The body 170 has edges 176 and 178. 
The edges 176 and 178 define a portion of an opening 172 therebetween. The 
body 170 defines a center opening 174. The edges 176 and 178 oppose each 
other and are normally apart. The opening 172 and the center opening 174 
receive the guidewire 110. 
The body 170 of the locking member 124 has an annulus 180 which 
circumscribes a portion of the body 170. The housing body 130 includes an 
inner race 182. The inner race 182 is annular in shape and configured for 
receiving the annulus 180 of the locking member. The inner race 182 and 
the annulus 180 rotatably connect. 
Although an annulus 180 and an inner race 182 are shown, alternate 
rotatable connections can be employed in accordance with the present 
invention. For example, a bearing structure can be added to rotatably 
attach the locking member 124 the housing 120. Alternatively, the locking 
member 124 can have an inner race and the housing 120 can have an annulus 
to provide a rotatable connection therebetween. 
When the guidewire gripper 122 grips the guidewire 110 and the locking 
member 124 locks with the housing 120, and the guidewire 110 
sympathetically rotates with the torque cable 108 (FIG. 1), the locking 
member 124 and the guidewire gripper 122 rotate with the guidewire 110. 
The drive unit 103 includes protuberances 153 and 155 attached to the track 
member 146. The rail member 140 of the housing 130 defines a portion of a 
detent 151. The ear 150 of the rail member 140 defines a portion of the 
detent 151. The detent 151 cooperates with the protuberance 153 to lock 
the housing 120 in a first position with the motor drive unit (FIG. 1). 
The housing 120 slides within the track member 146. The detent 151 
cooperates with the protuberance 155 to lock the housing 120 in a second 
position (shown in phantom in FIG. 3). When the housing 120 attaches to 
the drive unit 103, the track member 146 urges the rail members 140 
together to compress the housing 120. The housing is resilient and holds 
the rail members 140 against the track member 146 to hold the housing 120 
and the drive unit 103 together. 
The locking member 124 is provided with a rotation adjuster 190. The 
rotation adjuster 190 aligns the openings 162 and 172 of the gripper 122 
and locking member 124, respectively, with the opening 132 of the housing 
120. The rotation adjuster 190 is an extended pin grip. In an alternate 
embodiment (shown in phantom) the rotation adjuster 190 includes a recess 
192. 
With particular reference to FIG. 3 the guidewire 110 extends through the 
drive unit 103 and the guidewire migration controller 100. The housing 120 
of the guidewire migration controller 100 is in the first position with 
respect to the drive unit 103 to receive the guidewire 110. The housing 
120 slides along the track member 146 in the direction of the arrow 191 
and moves to the second position, generally shown in phantom (see also 
FIG. 1). In the second position, the guidewire migration controller 100 
releases the guidewire 110. 
The openings 132, 162 and 172 of the housing 120, the gripper 122 and the 
locking member 124 respectively align for reciprocally receiving and 
releasing the guidewire 110. 
The locking member 124 holds the gripper 122 so that the opening 162 of the 
gripper maintains alignment with the opening 172 of the locking member 
124. The rotation adjuster 190 adjusts the alignment of the openings 172 
and 162 in the locking member 124 and the gripper 122 respectively to 
align the openings 172 and 162. With the openings 172, 162, and 132 
aligned, the housing is moveable between the first and second positions to 
reciprocally receive and release the guidewire 110. 
With particular reference to FIG. 4, the guidewire migration controller 100 
is shown connected with the drive unit 103. The rail members 150 attach 
within the track member 146 of the drive unit 103. The gripper 122 holds 
the guidewire 110. 
It can be appreciated that when the guidewire 100 rotates sympathetically 
in response to rotation of the torque cable 108 (FIG. 1), the guidewire 
110 rotates the gripper 122. The gripper 122 and the locking member 124 
rotate together. The annulus 180 of the locking member 124 rotates within 
the race 182 of the housing 120. 
With particular reference to FIG. 5, the guidewire migration controller 100 
is shown attached to the track member 146 of the drive unit 103. The 
housing 120 occupies the first position as shown in FIG. 3. In the first 
position, the guidewire migration controller 100 holds the guidewire 110 
to control guidewire migration. The housing 120 is reciprocally slideable 
along the track member 146 in the direction of the arrow 190 to 
reciprocally receive and release the guidewire 110. 
While the foregoing detailed description has described the guidewire 
migration controller in terms of a preferred embodiment, it is to be 
understood that the above description is illustrative only and not 
limiting of the disclosed invention. Particularly, the shape of the 
gripper can vary to accommodate various types of guidewires. Additionally, 
the housing can be adapted for use with a variety of catheter devices. 
This invention is to be limited only by the claims as set forth below.