Controller for manipulation of instruments within a catheter

An everting catheter system which includes an elongated outer catheter having an outer catheter lumen and an opening, an elongated inner catheter movable in the outer catheter lumen and having the inner catheter lumen adapted to receive an elongated instrument and an everting element coupled to the outer catheter and the inner catheter. With movement of the inner catheter in the outer catheter lumen, the everting element can be everted through the opening of the outer catheter. A controller is coupled to the inner catheter for moving the inner catheter in the outer catheter lumen and for moving the instrument in the inner catheter lumen.

BACKGROUND OF THE INVENTION 
An everting catheter typically includes an outer catheter having an outer 
catheter lumen and an inner catheter movable longitudinally in the outer 
catheter lumen and having an inner catheter lumen. An everting element is 
coupled to the outer catheter and the inner catheter so that, with 
movement of the inner catheter distally in the outer catheter lumen, the 
everting element can be everted through an opening in the outer catheter. 
An everting catheter of this type can be inserted through a passage in the 
human body with the everting element in an inverted position. An 
elongated, flexible instrument can then be introduced through the inner 
catheter lumen and the everting element to position the instrument into a 
desired body region and accomplish any of a variety of medical procedures 
and/or viewing of internal body regions. 
The use of an everting catheter requires the control and manipulation of 
several different components. For example, movement and control of the 
inner catheter is required in connection with the eversion and inversion 
of the everting element, and movement and control of the instrument 
relative to the inner catheter is necessary in order to properly position 
the instrument within the body of the patient. In addition, the outer 
catheter must be properly positioned. Because of these multiple 
controlling and positioning tasks, the use of an everting catheter system 
commonly requires two attendants. 
Non-everting catheters also may require multiple controlling and 
positioning functions during use. For example, a non-everting catheter may 
have an instrument extending through the lumen of the catheter and into 
the body of the patient. During use, it is commonly necessary to position 
the catheter and the instrument within the patient; however, unlike 
everting catheters, only a single catheter needs to be positioned. 
Various controllers for manipulating an instrument in a catheter lumen are 
known. For example, one prior art device, known as a guidewire torquer, 
includes a collet clamped onto a guidewire which extends through an access 
catheter or angioplasty catheter. The torquer allows the operator to 
operate the guidewire about a central axis and move the guidewire 
proximally and distally. However, the torquer does not control the 
position of the catheter. 
In the field of arthrectomy devices, it is known to use a hand-held 
controller attached to a guiding catheter. The controller rotates a drive 
cable or instrument shaft which manipulates cutting surfaces on the distal 
end of the instrument. The controller has a pull knob which can advance 
and withdraw the cutting surface of the instrument within the lumen of the 
catheter. Other controllers of this type rotate an instrument or drive 
cable which imparts rotational energy to the cutting surface. 
Another known controller imparts ultrasonic energy to an instrument shaft 
which extends through the lumen of a catheter. A controller of this type 
may also have a pistol-trigger grip which allows an ultrasonic ablative 
surface to be advanced and withdrawn. Other types of pistol-trigger grip 
devices which are attached to primary catheters can be used for grabbing 
forceps or scissors. 
SUMMARY OF THE INVENTION 
This invention provides a controller which greatly simplifies catheter and 
instrument positioning and control within the body of a patient. Although 
the invention is particularly adapted for use with an everting catheter 
where positioning and control functions are more complex, this invention 
is also adapted for use with a non-everting catheter. 
With respect to the everting catheter, this invention provides an everting 
catheter system which includes an everting catheter and a controller. The 
controller is coupled to the inner catheter for moving the inner catheter 
in the outer catheter lumen and for moving the instrument in the inner 
catheter lumen relative to the inner catheter. Because the controller is 
coupled to the inner catheter, it can move and position the inner 
catheter. In addition, the controller has the capability of moving and 
positioning the instrument in the inner catheter lumen. The controller 
enables one-handed control and positioning of both the inner catheter and 
the instrument leaving the other hand of the attendant free. This converts 
what has characteristically been a two-attendant operation to a 
one-attendant operation. 
The movement of the instrument in the inner catheter lumen may be 
longitudinal and/or rotational. In order to accomplish this movement, the 
controller preferably includes a driving device for moving the instrument. 
The driving device may take many different forms and, in a preferred 
construction, includes a movable, endless member for contacting and 
driving the instrument longitudinally in the inner catheter lumen. For 
example, the movable, endless member may be a drive wheel, drive belt, 
drive chain or other endless member. One advantage of an endless, movable 
member is that no shuttle or back and forth movement is necessary for it 
to move the instrument through substantial distances. In addition, it 
promotes compactness and simplicity of the controller. 
In a preferred construction, the driving device also includes a secondary 
wheel engageable with the instrument and cooperable with the drive wheel 
for moving the instrument. An important advantage of the secondary wheel 
is that it cooperates with the driving wheel to provide rolling, as 
opposed to sliding, contact with the instrument. The secondary wheel may 
also be a drive wheel or it may be an idler wheel which is driven solely 
by virtue of its contact with the instrument. 
The driving device may be driven manually or with a motor. A manual drive 
has the advantage of light weight, lower cost and retention of "feel" by 
the operator. Again, to avoid a shuttling or ratcheting type of operation, 
it is preferred to use an endless, movable member having a region 
engageable by a thumb of an operator to impart a manual driving force to 
the driving device for moving the instrument longitudinally. This latter 
endless, movable member may be the same endless movable member which 
contacts and drives the instrument or it may be a separate member 
contacted by the thumb which drives the endless, movable member directly 
or through intermediate drive wheels or the like. 
In a preferred construction, the controller is also able to rotate the 
instrument. At least a portion of the controller, and preferably the 
driving device, may be movable or rotatable to accomplish this function. 
The controller preferably includes a supporting structure which in turn may 
include a housing coupled to a proximal end portion of the inner catheter. 
The housing may be a separate member permanently or releasably coupled to 
the proximal end portion of the inner catheter. Alternatively, the housing 
and inner catheter may be of one-piece construction, in which event, the 
coupling of the housing to the catheter is an integral coupling. In any 
event, the housing has a passage which communicates with the inner 
catheter lumen and which is adapted to receive the instrument. 
Although the housing can be of various different constructions, it 
preferably forms a handle section or handle which is adapted to be 
manually grasped. In a preferred construction, the housing extends 
proximally of the region of the endless, movable member, which is 
engageable and drivable by the thumb of an operator, to form the handle. 
By placing the handle proximally of the thumb-driven region of the member, 
driving of such member by the thumb of an operator in a one-handed 
operation is facilitated. 
The housing can advantageously be used to provide for rotation of the 
instrument. With this construction, the housing includes a rotatable 
section or drive section rotatable generally about the axis of the 
passage, and the driving device is carried by the rotatable section ,and 
is capable of gripping the instrument. Accordingly, rotation of the 
rotatable section rotates the instrument. 
In one embodiment, the housing is a separate member which is coupled to the 
proximal end portion of the catheter. To accomplish this, the housing of 
the controller can advantageously include a mounting section adapted to be 
coupled to the catheter. In this event, the drive section of the housing 
is coupled to both the handle and the mounting section intermediate the 
handle and the mounting section. 
When the driving device includes both a drive wheel and a secondary wheel, 
the peripheral surfaces of these wheels are arranged in generally 
confronting relationship and adapted to receive the instrument 
therebetween. At least one of these peripheral surfaces of the wheels may 
have a groove for receiving the instrument. The groove is particularly 
advantageous for an instrument, such as certain endoscopes, having a 
relatively fragile lens and/or optical system near the distal end portion 
of the instrument and a cross section which reduces toward the distal end. 
Instruments of this type can be slid through this groove without damaging 
the optical system, and the thicker, more proximal regions of the 
instrument can still be gripped with sufficient firmness by the wheels to 
form a driving connection between the wheels and the instrument. 
In a preferred construction, at least a portion of the passage through the 
controller extends proximally of the drive wheel and the secondary wheel. 
In this event, the controller preferably includes means in the passage for 
guiding the instrument from the proximal portion of the passage to the 
driving device. Although this means may include any form of constraint on 
the instrument which will achieve the desired guiding purpose, in a 
preferred embodiment, the guiding means includes first and second spaced 
alignment tabs for guiding the instrument between the drive wheel and the 
secondary wheel. In order to permit the tabs to extend all the way to the 
region between the drive wheel and the secondary wheel, the wheels 
preferably define first and second annular spaces, and the tabs are 
received in the annular spaces, respectively. 
To enhance the driving connection between the driving device and the 
instrument, interlocking projections and recesses may be provided on the 
instrument and the driving device to provide a positive driving 
relationship between these components. Preferably, some of these 
projections and recesses are on the peripheral surface of the drive wheel 
of the driving device. The projections on the instrument are preferably 
located proximally of the distal end of the instrument, and at least some 
of the projections are along a region of the instrument which is at the 
driving device when the distal end of the instrument is adjacent the 
opening of the catheter. 
Many of the features of this invention are applicable to both everting and 
non-everting catheter systems. Thus, the controller may be coupled to the 
proximal end portion of a catheter which may be either everting or 
non-everting. 
The invention, together with additional features and advantages thereof, 
may best be understood by reference to the following description taken in 
connection with the accompanying illustrative drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows an everting catheter system 11 which is particularly adapted 
for accessing the fallopian tubes; however, it should be understood that 
the features of this invention are also applicable to catheter systems 
adapted for other purposes. The catheter system 11 generally comprises an 
outer catheter 13, and inner catheter 15, an everting element 17 (FIG. 1A) 
and an elongated instrument 19. The outer catheter 13 includes an 
elongated, flexible catheter body 21 and an outer catheter fitting 23 
coupled to the proximal end of the catheter body 21. The outer catheter 13 
has an outer catheter lumen 25 (FIG. 1A) which extends from a proximal 
opening 27, which is provided by the outer catheter fitting 23, to a 
distal opening 29 (FIG. 1A) which, in this embodiment, is at the distal 
end of the catheter body 21. Of course, the catheter body 21 may have 
multiple lumens, if desired, and the distal opening 29 need not be at the 
distal end of the catheter body. 
The catheter body 21 has a distal end portion 31 which, in its unstressed 
condition, may be straight or of any other shape designed to best gain 
access to a desired region of the body. As shown in FIG. 1, the distal end 
portion 31 is curved and forms a portion of a circular arc in the 
unstressed condition, and this facilitates access to the ostia of the 
fallopian tubes. However, the shape of the distal end portion 31 forms no 
part of this invention, and the distal end portion is shown for 
convenience in FIG. 1A as linear. 
The outer catheter 13 may be of conventional construction, and the catheter 
body 21 may be constructed of a flexible, biocompatible polymeric 
material. The outer catheter fitting 23 has an injection leg 33 through 
which an inflation media can be supplied to the outer catheter lumen 25 to 
control the inversion and eversion of the everting element 17 in a known 
manner. 
The inner catheter 15 is extendible through the proximal opening 27 of the 
outer catheter 13 and is movable longitudinally in the outer catheter 
lumen 25. The inner catheter 15 also includes a catheter body 35 and an 
inner catheter fitting 37 coupled to the proximal end of the catheter body 
35. The inner catheter 15 has an inner catheter lumen 39 (FIG. 1A) which 
extends between a proximal opening 41 (FIG. 3) provided by one leg of the 
inner catheter fitting 37 and a distal opening 43 (FIG. 1A) at the distal 
end 44 of the catheter body 35. 
The catheter body 35 may be flexible or rigid depending upon the nature and 
purpose of the catheter system 11. However, in this embodiment, a distal 
region of the catheter body 35 is flexible such that the portion of the 
catheter body 35 that is within the distal end portion 31 in all positions 
of the inner catheter 15 relative to the outer catheter 13 is flexible. 
The fitting 37 has an injection leg 45 which can be used, for example, for 
injecting irrigation fluid, a contrast dye or drugs into the inner 
catheter lumen 39. The leg 45 can also be used for aspiration, if desired. 
The everting element 17 (FIG. 1A) is a thin, flexible membrane which is 
constructed of a suitable polymeric material. The everting element 17 is 
bonded as by an adhesive to the catheter body 21 of the outer catheter 13 
closely adjacent the distal opening 29 and to a distal tip region of the 
catheter body 35 of the inner catheter 15 in accordance with known 
techniques. This forms a chamber 47 with the catheter body 21 of the outer 
catheter 13. Consequently, inflation media from the injection leg 33 
acting in the chamber 47 can bring about inversion and eversion of the 
everting element 17. The everting element 17 has a distal end 49 which, in 
the everted position of FIG. 1A, is located distally of the distal opening 
29. The everting element 17 forms an extension 50 of the inner catheter 
lumen 39. 
The instrument 19 is elongated and flexible. The instrument 19 is 
introduced to the inner catheter lumen 39 through the proximal opening 41 
and can be moved both proximally and distally relative to the inner 
catheter 15 independently of the inner catheter. The instrument 19 
terminates distally in a distal end 51 (FIG. 1A). In this embodiment, the 
instrument 19 is an endoscope for examination of the fallopian tubes. 
However, the instrument may be virtually any elongated, flexible 
instrument for medical purposes, such as a guidewire or other instrument 
for either visualizing or carrying out a procedure on an interior region 
of the body of a patient. 
The catheter system 11 as described to this point in the Description of the 
Preferred Embodiment may be conventional. However, the catheter system 11 
departs from conventional systems in providing a controller 53 (FIG. 1) 
coupled to the inner catheter 15 for moving the inner catheter in the 
outer catheter lumen 25 and instrument 19 in the inner catheter lumen 39 
relative to the inner catheter. 
The controller 53 includes a supporting structure which, in this 
embodiment, is in the form of a housing 55 (FIG. 2). Although the housing 
55 can be of different constructions, in this embodiment, it is 
constructed of a suitable hard polymeric material, and it has a passage 57 
extending therethrough which is adapted to receive the instrument 19 (FIG. 
3). As illustrated, the housing 55 includes a mounting section 59 adapted 
to be coupled to the inner catheter 15, a drive section or rotatable 
section 61 and an elongated handle or handle section 63 which is adapted 
to be manually grasped. The mounting section 59 includes a short, 
internally threaded tube having an inner conical projection 65, a head 67 
integral with the tube and an annular groove 69 between the head and the 
tube. 
The handle section 63 includes an elongated tube 71 and a tubular connector 
73 which receives and is affixed to the proximal end of the tube 71. The 
connector 73 has an annular groove 75. The grooves 75 and 69 are received 
within openings in the drive section 61 to mount the drive section 61 and 
the handle section 63 for rotational movement about the axis of the 
passage 57 relative to the mounting section 59 as described more 
specifically below. The drive section 61 is located between the mounting 
section 59 and the handle section 63 and has an opening 77. 
The controller 53 includes a driving device 79 for moving the instrument 19 
longitudinally in the inner catheter lumen 39 relative to the inner 
catheter 15. Although the driving device 79 can take different forms, 
including various ratchet or shuttle devices, it preferably includes a 
movable endless member, such as a drive wheel 81 for contacting and 
driving the instrument 19 longitudinally. The driving device 79 in this 
embodiment also includes a secondary wheel 83 which is cooperable with the 
drive wheel 81 for moving the instrument 19 longitudinally. 
The wheels 81 and 83 are rotatably mounted on the drive section 61, and for 
that purpose, the drive section has opposite side walls 85 (FIGS. 4-6) 
joined by end walls 87 (FIGS. 2 and 3) and a transverse wall 89 (FIGS. 
4-6). Thus, the drive section 61 forms a container with the opening 77 
being generally opposite the transverse wall 89. Although the drive 
section 61 can be a one-piece member, in this embodiment, it comprises two 
molded half sections 90 (FIGS. 5 and 6) suitably adhered together. 
Although the wheels 81 and 83 can be rotatably mounted on the drive section 
61 in different ways, in this embodiment, each of the wheels includes 
oppositely extending stub shafts 91 (FIG. 4) received in inwardly facing 
bearings 93 integrally formed on the side walls 85, respectively. This 
mounts the wheels 81 and 83 for rotation about parallel rotational axes 
which extend transverse to the axis of the passage 57. 
Although the wheels 81 and 83 can be configured in different ways, in this 
embodiment, they are identical, and each of them is of one-piece integral 
construction and includes a central drive disc 95 having a peripheral 
surface 97 and outer discs 99 having gear teeth 101 on their peripheral 
surfaces. With the wheels 81 and 83 rotatably mounted within the drive 
section 61 of the housing 55, the peripheral surfaces 97 are in generally 
confronting relationship and adapted to receive the instrument 19 
therebetween so that, upon rotation of the drive wheel 81, the instrument 
19 can be moved longitudinally in the passage 57 of the housing. In 
addition, the gear teeth 101 of the drive wheel 81 drivingly engage the 
gear teeth 101 of the secondary wheel 83 so that there is a positive drive 
connection between these two wheels, and slippage between these wheels is, 
therefore, prevented. This makes the secondary wheel 83 a drive wheel and 
improves the frictional characteristics of the wheels 81 and 83 on the 
instrument 19. If desired, the controller 53 may be constructed so that 
the secondary wheel 83 can be directly manually driven. 
The opening 77 exposes a region of a portion of the drive wheel 81, and 
such region is engageable by a thumb of an operator to impart manual 
driving force to the drive wheel 81. In the illustrated embodiment, the 
exposed portion includes a portion of the peripheral surface of the drive 
wheel 81, i.e., a portion of the peripheral surface 97 and a portion of 
the peripheral surface containing the gear teeth 101. The drive section 61 
completely encloses the wheels 81 and 83, except for this exposed portion 
of the drive wheel 81 so that the driving motion of the driving device 79 
is unlikely to be unintentionally impeded. The handle section 63 of the 
housing 55 extends proximally of the region of the drive wheel 81 which is 
exposed through the opening 77 to conveniently position the handle section 
for manual grasping of the controller 53 and the exposed region of the 
drive wheel for being manually driven by the thumb of the operator. 
The wheels 81 and 83 can be constructed of various different hard and soft 
materials, and it is not necessary that they both be constructed of the 
same material. Although the wheels 81 and 83 may be constructed of a 
metal, they may also be constructed of soft material, such as a soft 
rubber or a relatively hard polymeric material, such as hard polyurethane. 
If desired, one or both of the wheels 81 and 83 may have an outer, 
relatively softer, jacket. In the illustrated embodiment, each of the 
wheels 81 and 83 is of one-piece integral construction and is constructed 
of a relatively hard polymeric material to provide a strong positive 
driving connection between the interengaging teeth 101. 
To enable the wheels 81 and 83 to grip the instrument 19 with the desired 
degree of compressive force, the peripheral surfaces 97 of the wheels 81 
and 83 each have a groove 103 arranged to confront the corresponding 
groove of the other wheel as shown in FIG. 4. These grooves 103 are sized 
and adapted to receive the instrument 19 with the desired amount of 
compressive force for driving the instrument 19 without damaging the 
instrument. 
Although the controller 53 can be used with many different kinds of 
instruments, the instrument 19 is an endoscope of the type having a distal 
end portion 105 (FIG. 1) which contains relatively delicate optics and 
which is of smaller cross-sectional area than a region of the instrument 
located proximally of a location 107 (FIG. 1) on the instrument. The two 
grooves 103 are sized to slidably receive the distal end portion 105 
containing the delicate optics without compressively loading the distal 
end portion. It is not until the location 107 of the instrument 19 is 
located at the grooves 103 that the grooves begin to compressively load 
the instrument to form a driving connection therewith. In this manner, the 
instrument 19 can be more quickly advanced through the controller 53 up to 
the location 107 without turning of the wheels 81 and 83 and without 
risking damage to the optics in the distal end portion 105. 
In this embodiment, the housing 55 is constructed so that the drive section 
61 and the handle section 63 are rotatable as a unit about the axis of the 
passage 57 relative to the mounting section 59. Although this can be 
accomplished in different ways, in one preferred form, it is accomplished 
by adhesively attaching the drive section 61 to the handle section. In the 
illustrated embodiment, the connector 73 has a head 109 (FIGS. 3 and 5) 
within the drive section 61. The head 109 has lateral edges 111 (FIG. 5) 
which engage the opposite side walls 85, respectively, of the drive 
section 61 to prevent rotation of the connector 73 and the entire handle 
section 63 about the axis of the passage 57 relative to the drive section 
61. Thus, the drive section 61 and the handle section 63 are not 
relatively rotatable about the axis of the passage 57. However, the head 
67 (FIGS. 3 and 6) of the mounting section 59 is circular as viewed in 
FIG. 6 and is of small enough diameter so that the side walls 85 do not 
impede relative rotation between the mounting section 59 and the drive 
section 61 about the axis of the passage 57. Also, the fit between the 
opening in the end wall 87 and the mounting section 59 is sufficiently 
loose so as to permit this rotation. This structure which couples the 
drive section 61 to the mounting section 59 for relative rotation may be 
considered to be a coupling. 
Although the controller 53 can be coupled to the inner catheter 15 in 
various different ways, such as by constructing the housing 55 and the 
inner catheter fitting 37 of one-piece integral construction, in this 
embodiment, the housing 55 is a separate element, and the controller 53 is 
releasably coupled to the inner catheter 15. As shown in FIG. 3, the inner 
catheter fitting 37 has a leg 113 with external threads which is threaded 
into the mounting section 59. A seal 115 is compressively loaded between 
the distal end of the projection 65 and an adjacent region of the leg 113 
to provide a seal between the fitting 37 and the controller 53. The seal 
115 is compressed sufficiently to provide a seal around the instrument 19. 
As shown in FIG. 4, there is a portion of the passage 57 which extends 
proximally of the wheels 81 and 83. This invention provides means for 
guiding the instrument 19 to the wheels 81 and 83 and into the grooves 
103. Although this means may take different forms, in the illustrated 
embodiment, it includes a pair of tabs 117 (FIGS. 2-5) which extend 
distally into the drive section 61 and into annular spaces or recesses 119 
(FIGS. 2 and 4), respectively, between the discs 95 and 99. In this 
embodiment, the alignment tabs 117 extend at least to a location at which 
the wheels 81 and 83 are tangent to each other as shown in FIG. 3. 
Consequently, the tabs 117 serve to guide the instrument 19 into the 
grooves 103 when the instrument is being initially threaded into the 
controller 53. 
In use, the outer catheter 13 with the everting element 17 in the inverted 
position, i.e., entirely within the outer catheter lumen 25, is inserted 
into the body of the patient to the desired region. The instrument 19 is 
then inserted through the passage 57 and the grooves 103 of the controller 
and through the inner catheter fitting 37 into the inner catheter lumen 
39. If the instrument 19 is of the type described above having the distal 
end portion 105 of reduced diameter, it may be slid through the grooves 
103 without rotation of the wheels 81 and 83. However, when the location 
107 reaches the wheels 81 and 83, the instrument 19 can be advanced or 
moved distally only by rotating the drive wheel 81. In this position, the 
instrument 19 is frictionally gripped between the drive wheel 81 and the 
secondary wheel 83 so that rotation of the drive wheel 81 moves the 
instrument 19 longitudinally. 
When the everting element 17 is everted, it grips the instrument 19 and 
pulls it distally. However, when it is desired to move the instrument 19 
relative to the everting element 17, the controller 53 can be used. 
Movement of the instrument 19 longitudinally and longitudinal movement of 
the inner catheter 15 can be easily accomplished in a one-handed 
operation. Thus, the physician merely grasps the handle section 63 with 
his thumb contacting the drive wheel 81 and, by so doing, his thumb can 
drive the drive wheel and instrument, and his hand can move the inner 
catheter. These movements of the instrument 19 can be coordinated with the 
eversion and inversion of the everting element 17 as desired. 
The driving device 79, and in particular the wheels 81 and 83, grip the 
instrument 19. Accordingly, rotation of the handle section 63 and the 
drive section 61 of the housing 55 relative to the mounting section 59 as 
shown, for example, in phantom lines in FIG. 6 rotates the instrument 
relative to the inner catheter 15. This may be useful, for example, if the 
instrument 19 has an angled distal tip section. 
FIG. 7 shows a catheter system 11a which is identical to the catheter 
system 11 in all respects not shown or described herein. Portions of the 
catheter system 11a corresponding to portions of the catheter system 11 
are designated by corresponding reference numerals followed by the letter 
"a." 
The catheter system 11a is identical to the catheter system 11, except that 
the catheter is of the non-everting type. Thus, the catheter system 11a 
has no everting element and may be considered as comprising only the inner 
catheter 15a and the controller 53a. Of course, in the embodiment of FIG. 
7, the catheter 15a is not an inner catheter but rather the only catheter 
of the system. The controller 53a is identical to the controller 53 and 
controls the longitudinal and rotational position of the instrument 19a 
within the catheter 15a. 
FIG. 8 shows a catheter system 11b which is identical to the catheter 
system 11 in all respects not shown or described herein. Portions of the 
catheter system 11b corresponding to portions of the catheter system 11 
are designated by corresponding reference numerals followed by the letter 
"b." 
The only difference between the catheter systems 11 and 11b is that the 
latter provides interlocking projections or gear teeth 131 and recesses 
133 on the instrument 19b and the drive wheel 81b and the secondary wheel 
83b. This provides a positive driving relationship between the driving 
device 79b and, in particular, the wheels 81b and 83b, and the instrument 
19b. The teeth 131 and the recesses 133 of the wheels 81b and 83b are 
located on the peripheral surfaces 97b, and they cooperate with the teeth 
131 and recesses 133 of the instrument 19b to form a gear drive between 
these members. The teeth 131 and the recesses 133 can be provided on the 
instrument 19b in any suitable manner, such as by encasing the basic 
instrument in a jacket containing the teeth and recesses. The teeth 131 
and recesses 133 can also be incorporated into the catheter system 11a of 
FIG. 7. 
If the teeth 131 and recesses 133 are utilized, they need not extend for 
the full length of the instrument 19b. With reference to FIGS. 1 and 1A, 
the teeth 131 and recesses 133 may be located proximally of the distal end 
51 of the instrument 19b and along a length of the instrument which 
includes a region of the instrument which is at the driving device 79b 
when the distal end of the instrument is adjacent the distal opening 29. 
With this construction, the teeth 131 may be proximally of the location 
107 (FIG. 1) on the instrument 19b and will not hamper sliding movement of 
the instrument through the controller 53b up to the location 107. However, 
the positive drive connection between the instrument and the wheels 81b 
and 83b is obtained where that driving connection is desirable. By 
providing the positive drive connection, slippage between the drive wheel 
81b and the instrument 19b is eliminated, and the physician is assured of 
having precise control over the longitudinal movements of the instrument. 
Although exemplary embodiments of the invention have been shown and 
described, many changes, modifications and substitutions may be made by 
one having ordinary skill in the art without necessarily departing from 
the spirit and scope of this invention.