Abstract:
A catheter with an improved retaining, activation and locking features is provided which is a safe device with reduced irritation and discomfort for a patient. The retaining mechanism positioned at the proximal end of the catheter assumes a “closed” position for introduction and removal of the catheter into and from the body cavity of a patient, and is transitioned into the “open” position when the catheter is positioned within the body cavity by mechanically manipulating the retaining mechanism through an activation mechanism having a piston member slideably displaceable within a cylinder housing member. A locking mechanism is included for maintaining the catheter in the “open” position.

Description:
REFERENCE TO RELATED APPLICATIONS 
     This patent application is a Continuation in Part Application of U.S. patent application Ser. No. 12/490,669 filed 24 Jun. 2009, now pending and of U.S. patent application Ser. No. 13/369,372 filed on 9 Feb. 2012, now pending. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to surgical devices. In particular, this invention relates to surgical systems directed to infusion and draining of fluids to and from a patient&#39;s body. 
     More in particular, this invention is directed to a catheter system having a retaining mechanism for maintaining the catheter in a relatively stable position within a body cavity of a patient. 
     Still further this invention is directed to a catheter system which includes a retaining mechanism which is selectively displaced to an “open” position within a patient&#39;s body cavity during a procedure to maintain relative stability within the patient&#39;s body. Additionally, this invention is directed to a catheter system which is selectively displaceable to a “closed” position for insert and removal of the catheter prior to and subsequent to a procedure. 
     More in particular, this invention is directed to an activation system which uses a piston to activate the retaining mechanism into the “open” or “closed” positions. 
     Still further, this invention is directed to a catheter system which includes a releasable locking mechanism to maintain the retaining mechanism in an “open” position during drainage, irrigation and/or medicinal delivery. 
     BACKGROUND OF THE INVENTION 
     Surgical devices directed to infusion and draining of fluids to and from a patient&#39;s body has been known for many years. 
     Initially, a catheter was developed known as the Foley catheter which incorporated a balloon-tipped retention urinary catheter. In this system, a balloon was provided with a drainage port as well as an infusion port. A proximal end of the catheter was provided and a side port was incorporated for inflation of the balloon. The balloon was inflated through some type of syringe which allowed passage of liquid through the side port. In this manner, the catheter was retained within a body cavity during a procedure. Since the Foley catheter was introduced, numerous types of catheter systems have been developed which permit retention of the catheter within the body cavity of a patient. 
     One of the important problems associated with catheters which are inserted into body cavities and retained therein during a procedure is the complexity of maintaining the retaining mechanism within the body cavity in a releasably locked condition. 
     A need has been developed to reduce the overall diameter of a catheter tubular member while maintaining a continuous flow passageway for either draining or infusion of liquids to and from the body cavity. 
     Complex mechanisms have been tried for releasably locking the retaining mechanism within the body cavity, however, such mechanisms generally are complex to operate and further (most importantly) take a large amount of manipulation which results in an extended time interval for the locking/unlocking procedure of the retaining mechanism. Such extended times are important especially when a patient is undergoing a procedure. 
     Subsequent to a catheter being positioned within the body cavity of a patient, the activation mechanism remains external to the patient&#39;s own body. A caregiver or other medical personnel manipulates the activation mechanism to transition the device between open and closed positions which correspond to the wings being in an extended position and in a flush position with respect to a flexible tubular member portion of the catheter. 
     Patients often will displace this portion of the catheter and such contact may cause the catheter to be unintentionally transitioned from the open to the closed position. This condition is especially true in cases where patients are catheterized but remain mobile. 
     Therefore, it is important for catheters to be equipped with a locking mechanism to protect against unintended transitioning while providing a locking mechanism which is easily manipulatable and reduces the time required for the caregiver to extend the retaining mechanism into the open position or the closed position. 
     Such locking mechanisms are important since it is critical that they be designed for use with the type of improved retaining mechanism as is herein described so that if the catheter is locked into its open position and subsequently removed from the patient&#39;s body cavity, the flexibility of the retaining mechanism will minimize tearing, rupturing, bleeding, and/or scarring to the lining of the patient&#39;s body cavity. 
     PRIOR ART 
     Prior art catheter systems for insertion and maintenance of the catheter within a body cavity of a patient are known in the art. Catheters having a retaining mechanism have been known since at least as early as the well-known Foley catheter which is a balloon-tipped retention urinary catheter. Originally, the Foley catheter was specifically directed to a urinary catheter system and included a balloon at an end of the catheter with a drainage port and an infusion port. A side port provided for inflation of the balloon where the balloon was inflated through a syringe or some like opening to pass the liquid through the port and expand the balloon in a radial direction. However, such prior art relied upon a balloon tip at the end of the catheter which essentially filled up the body cavity and necessitated additional flow passages for drainage and/or infusion of liquids. 
     Such prior art systems were cumbersome in nature and resulted in a substantially large diameter catheter tubular member which was inserted through orifices in the patient&#39;s body. Additionally, operating mechanisms were somewhat complex in that the maintenance of the retention member (which was the balloon) was based upon use of external mechanisms which were complex and took time to operate. 
     Other prior art catheter systems such as that disclosed in the Termanini U.S. Pat. No. 4,154,242 were directed particularly to bladder catheter devices where retention mechanisms were provided in the form of spring elements being used as wings which were expanded into a mushroom-like open contour. The spring-like wings were opened within the body cavity to an “open” position to maintain the catheter within the body cavity. However, such prior art, although having the springs covered by thin walls of the catheter tubing, could be punctured and cause possible infection in the patient. 
     Additionally, such prior art systems necessitated the use of a threaded member to actuate the expandable wings (springs) which increases the time needed to open and close the wings. This time extension may be a critical parameter during a procedure and thus is a disadvantage of such prior art systems. 
     Other prior art systems which used wing-like members to maintain the catheter within body cavities of a patient are exemplified by the Wallace reference, U.S. Pat. No. 2,649,092. However, although such catheter systems provided for wings which could be radially extended from a tubular section, such did not provide for a simple and easily maneuverable locking mechanism to permit the wings to be maintained in the “open” position and/or “closed” position. 
     Other prior art systems as exemplified by the Kohl U.S. Pat. No. 3,397,699 were directed to retaining catheters which have resiliently biased wing flanges. However, although such prior art catheter systems did include radially extensible wings, the releasable locking procedure does not provide for an easily maneuverable and manipulatable actuation mechanism for the extension and retraction of the wings. Such results in a more complex and time consuming operation which may be a critical factor. 
     Other prior art catheter systems such as that disclosed in the Hakki U.S. Pat. No. 5,569,219 shows a hollow elastomeric tubular member with inflatable stiffening and/or reinforcing members capable of being inflated with some type of fluid. However, such prior art systems require multiple lumens and the inflatable function is made more cumbersome in manufacture and is disadvantageous in having a circular cross-sectional area even when deformed. 
     A further prior art system is disclosed in the Hakky U.S. Pat. No. 7,264,609 which does not include a Foley type balloon at a proximal end, but does not provide for a reliable, simple, and easily manipulatable locking mechanism for the wing members in either an open or closed position. 
     In other prior art catheter systems, such as that shown in the Santomieri U.S. Pat. No. 3,938,530 reference, there is disclosed a retention type catheter which expands wings in a radial direction to maintain the catheter within a body cavity. However, such prior art systems necessitate a cumbersome mechanism for actuating the retaining mechanisms to expand and/or retract the wings. Additionally, such prior art systems do not provide for a releasable locking system which is actuated in a time optimization procedure. 
     None of the prior art systems provide for an activation mechanism which is located at a distal end of a flexible tubular member with the activation mechanism having a piston member slidably displaceable within a cylinder housing member to selectively displace the retaining mechanism into an “open” position and a “closed” position. Additionally, such prior art systems do not provide for a piston member to be selectively displaceable in a linear direction for displacing the retaining mechanism into an “open” and “closed” position where the wing members are extended in a radial direction with respect to the axial direction. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an indwelling catheter with a retaining mechanism, the state of which is easily controlled by a person administering the urinary procedure and which is safe for the patient. 
     It is a further object of the present invention to provide an indwelling catheter with an improved retaining mechanism at the proximal end which is easily actuated by a person administering the procedure with no need of a sterile syringe or a sterile fluid and which is sufficiently stiff for introduction inside urinary bladder without the need for a stylet or a catheter introducer. 
     The catheter of the present invention includes a tubular member defining a longitudinal channel extending between the proximal and distal ends thereof. The longitudinal channel is adapted for passage of bodily fluids therethrough. A retaining mechanism is located at the proximal end of the tubular member for insertion into a body cavity of a patient. An activation mechanism is positioned at the distal end of the tubular member. An actuation linkage extends within the longitudinal channel of the tubular member of the catheter and is operatively coupled to the retaining and activation mechanisms. This coupling enables the actuation linkage to actuate the retaining mechanism to assume either an “open” position in which the catheter is retained within in the body cavity of a patient or a “closed” position used for insertion and removal of the catheter. 
     The actuation linkage is formed as a stainless steel wire, nylon wire, Dacron wire, or a plastic wire, etc., and reciprocates within the longitudinal channel of the tubular member of the catheter under the control of the activation mechanism. When the actuation linkage wire is retracted towards the distal end of the tubular member, the retaining mechanism is transformed into the “open” position, and when the actuation linkage wire is moved towards the proximal end of the tubular member, the retaining mechanism is transitioned in the “closed” position. 
     There are several modifications of the retaining mechanism contemplated in the present urinary catheter. For example, the retaining mechanism may include a pair of slits extending from a tip of the catheter along the wall of the tubular member, which are transformable into “wings” extending radially from the walls of the tubular member and spanning a distance corresponding to the length of the slits formed in the walls of the tubular member at the proximal end thereof. The retaining mechanism may be modified to include additional slits and wings so long as the retaining mechanism may remain easily controlled and compatible with the additional features herein described. 
     When inserted into the body cavity of a patient, the retaining mechanism of the catheter is in the “closed” position. Once the catheter is situated within the body cavity, the retaining mechanism is transformed into the “open” position and the wings press against the walls of the patient&#39;s body cavity to hold the catheter in place within the body cavity. The flexible material (silicone rubber or Latex) of the tubular member makes the thus created wings of the retaining mechanism “user friendly” causing minimal irritation to the walls of the body cavity by contact with the wings. Additionally, the openings formed between the wings are quite large to permit full drainage of the fluid from a patient&#39;s body cavity and effective delivery of medication or irrigation fluid thereto when needed. 
     The activation mechanism of the subject catheter is applicable to the above-described retaining mechanism. The activation mechanism is positioned at the distal end of the tubular member and includes a piston member which is slideably displaceable within a cylinder housing member. The actuation linkage extends throughout the longitudinal channel of the catheter through the piston member where it is secured to the piston member at a lower end portion. The piston member may transition within the cylinder housing member between a first position and a second position to actuate the “closed” or “open” positions of the retaining mechanism, respectively. 
     When the piston member is in a first position, the front end of the piston member is abutting the proximal end of the cylinder housing member. This positioning, corresponding to the “closed” position of the retaining mechanism will allow a user to easily insert the catheter into the body cavity of a patient or similarly, to remove the catheter therefrom at the end of a procedure. When the piston member is in a second position, the front end of the piston member has been pulled downward to displace the tip of the piston member from the proximal end of the cylinder housing member. 
     In a preferred embodiment, the cylinder housing member has two slots (a first slot and a second slot) extending in a longitudinal direction along the surface thereof defining a “U”-shaped configuration. The piston member includes a first protuberance extending from a surface thereof which is correspondingly shaped to fit within the slots of the cylinder housing member. The piston member is rotatable about an axis for positioning the first protuberance within the first and second slots of the cylinder housing member. 
     As the piston member is transitioned between first and second positions it is guided by the first protuberance which slides along the first slot of the cylinder housing member. As the piston member is slid to a second position to actuate the “open” position of the retaining mechanism, the first protuberance is stopped by a stop member on the distal end of the cylinder housing member. 
     The activation mechanism includes a locking mechanism to lock the retaining mechanism into the “open” position. The piston member is rotated in a predetermined direction to reposition the first protuberance from the first slot to the second slot of the cylinder housing member. As the first protuberance of the piston member is situated within the second slot, it is locked into position by a second protuberance on the front edge of the stop member of the cylinder housing member. 
     When it is desired that the catheter assume its “closed” state, personnel administering the procedure may unlock the activation mechanism by rotating the piston member in the opposite direction to overcome the second protuberance on the stop member of the cylinder housing member and reposition the first protuberance from the second slot back to the first slot of the cylinder housing member. At this point, the retaining mechanism will assume its “closed” position and the catheter may be safely removed from the body cavity of a patient. 
     These and other features and advantages of the present invention will become apparent in view of the further detailed description if taken in conjunction with the accompanying Patent Drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic representation of the catheter of the present invention showing the retaining mechanism in its “closed” position. 
         FIG. 2  is a schematic representation of the catheter of the present invention showing the retaining mechanism in its “open” position. 
         FIG. 3  shows the activation mechanism of the catheter of the present invention on a larger scale, illustrating direction of rotation as the first protuberance is moved from a first slot to a second slot of the cylinder housing member to “lock” the retaining mechanism into its “open” position. 
         FIG. 4  is an enlarged view of the retaining mechanism of the present invention in its “open” position. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to  FIGS. 1-4 , there is catheter  10  adapted for insertion into a body cavity of a patient to permit passage of fluids therethrough and permit infusion and/or draining of the liquids from the body of the patient. In overall concept, catheter  10  includes a retaining mechanism  20  which can be displaced from a “closed” position as shown in  FIG. 1  to an “open” position as shown in  FIGS. 2 and 4 . The “open” position is defined as the catheter prior to insertion of catheter  10  into the body of the patient as shown in  FIG. 1 . Once catheter  10  is inserted into the body cavity of the patient, catheter  10  can be operated to a position as shown in  FIGS. 2 and 4  where catheter  10  is maintained in a relatively stable position within the body cavity of the patient. 
     The “closed” position of catheter  10  is shown in  FIG. 1  where the tubular member  12  maintains a substantially constant diameter throughout its extended length between tubular member distal end  16  and tubular member proximal end  14 . The “open” position is illustrated in  FIGS. 2 and 4  where once catheter  10  has been inserted into the body cavity of the patient, wing members  78  may be expanded having an envelope diameter greater than the remaining outer diameter of tubular member  12 . The envelope diameter of wing  78  are greater than the diameter of the remaining portions of tubular member  12  in order to block the removal of catheter  10  from the body cavity of the patient. 
     Retaining mechanism  20  is specifically adapted and designed for mounting and securement of catheter  10  within the body cavity of the patient during a procedure or at other times when fluids within the body cavity are being drained or fluids are being infused into the body cavity. In the manner indicated, retaining mechanism  20  maintains a relatively positionally stable condition of catheter  10  when such is maintained within the body cavity of the patient. 
     As previously discussed, and further will be described in following paragraphs, catheter  10  is inserted through passages within the human body into the body cavity of the patient in the “closed” position ( FIG. 1 ) and then releasably locked into the “open” position shown in  FIGS. 2 and 4  where the wings  78  are expanded to an envelope diameter greater than the diameter of the remaining portion of the tubular member. In this manner, movement of the patient will not dislodge catheter  10  from the body cavity of the patient and such provides a stable platform for the maintenance of catheter  10  within the body cavity of the patient. 
     Catheter  10  as seen in  FIGS. 1-2 and 4  includes tubular member  12  which is flexible in composition and extends between tubular member proximal end  14  and tubular member distal end  16 . Tubular member  12  is formed of a flexible composition such as rubber, various plastic compositions and/or polymers which permit flexibility of tubular member  12 . The particular compositional nature of tubular member  12  is not important to the inventive concept as herein described with the exception that the composition permits sufficient flexibility to permit tortuous passage through passageways of the patient&#39;s body. 
     Tubular member  12  includes longitudinal channel  18  which extends from tubular member distal end  16  to a closed tubular member proximal end  14 . Longitudinal direction  44  with respect to longitudinal channel  18  is defined as a center axis of tubular member  12 . Thus, longitudinal direction  44  as depicted in  FIG. 1  is not necessarily a linear direction but rather as defined in Applicant&#39;s subject system, is an axis line extension of tubular member  12 . Thus, longitudinal direction  44  may be tortuous in contour and assume different linear type curvatures. Wire  32  extends through longitudinal channel  18  and the annular cross-section between wire  32  and the inner walls of the tubular member  12  form tubular member flow passageway  96  to permit infusion or draining of fluid therethrough. 
     Retaining mechanism  20  assumes two positions, either the “closed” position shown in  FIG. 1  or the “open” position shown in  FIGS. 2 and 4  dependent upon the activation of catheter  10 . Retaining mechanism  20  is formed of a plurality of slits  66  which extend in longitudinal direction  44  through a length L as shown in  FIG. 1 . A plurality of slits are passed through the wall of tubular member  12  throughout the slit length L. There may be two or more slits  66  formed through the wall of tubular member  12  dependent upon the usage of catheter  10 . 
     Once catheter  10  is actuated from the “closed” position in  FIG. 1  to the “open” position in  FIGS. 2 and 4 , the slits  66  are transformed into wings  78  which provides for relatively stable positioning of catheter  10  within the body cavity of the patient. Since wings  78  are formed by slits  66  extending through length L through tubular member  12  for a predetermined distance, wings  78  are preferably formed integral with the tubular member  12 . Wings  78  are formed of the same composition as tubular member  12 , not important to the inventive concept as herein described with the exception that wings  78  be operable between the “closed” position shown in  FIG. 1  to the “open” position shown in  FIGS. 2 and 4  and vice versa. 
     Initially, in overall concept and in operation sequence, catheter  10  is in the “closed” position as shown in  FIG. 1  and is inserted through an orifice in a patient&#39;s body and is passed or extended into the body cavity of interest within the patient. Wings  78  are radially displaced with respect to longitudinal direction  44  (radially displaced with respect to the axis line of tubular member  12 ) and through the operation of activation mechanism  26  and activation linkage  32  as will be described in following paragraphs. When wings  78  are displaced in the radial direction with respect to longitudinal direction  44 , the catheter is maintained in a relatively stable position and a relatively releasably locked position within the patient&#39;s body cavity. 
     In this manner, retaining mechanism  20  of catheter  10  is insertable into the body cavity of the patient positioned in itself at the proximal end  14  of tubular member  12  with the retaining mechanism  20  being generally integral and unitarily formed of a tubular flexible material composition as has previously been described. In the manner to be further detailed in following paragraphs, retaining mechanism  20  is controllably and selectively actuated for assuming either the “open” position or “closed” position. Piston member  28  includes piston flow passageway  98  which is in fluid communication with tubular member flow passageway  96  to permit fluid being infused or drained to be infused or egressed from catheter  10 . Piston flow passageway  98  extends throughout the length of piston member  28 . 
     Catheter  10  further includes activation mechanism  26  positioned at tubular member distal end  16  of tubular member  12 . Activation mechanism  26  includes piston member  28  which is slideably received and slideably displaceable within cylinder housing member  30  for selectively displacing retaining mechanism  20  into the “open” position and the “closed” position. 
     Activation mechanism  26  further includes a releasable locking mechanism  36  for selectively driving an actuation linkage  32  for selective displacement of retaining mechanism  20  to the “open” or “closed” position. As will be further detailed, locking mechanism  36  permits the releasable locking of retaining mechanism  20  in the “open” position when retaining mechanism  20  is positionally located within the body cavity of the patient and actuated for infusion or drainage of fluids. 
     Catheter  10  still further includes actuation linkage  32  which includes wire  34  extending from tubular member proximal end  14  of tubular member  12  through activation mechanism  26  to which it is secured. Wire  34  may be formed of a flexible composition such as plastic or other type composition compatible with the human body however the composition for wire  34  is not important to the inventive concept as herein described with the exception that it be sufficiently flexible to pass through tubular member longitudinal channel  18  in a tortuous manner. 
     Wire  34  is fixed to piston member  28  through a tie  80  formed on one end of piston member  28  and to an inner surface of tubular member  12  at the tubular member proximal end  14 . Thus, wire  34  is fixedly mounted to a tip or end portion of tubular member  12  at tubular member proximal end  14  and secured in a fixed manner to piston member  28  on the other end as is clearly seen in  FIGS. 1 and 2 . The particular mode of tying of wire  34  to piston member  28  may be through a number of different modes which are not important to the inventive concept with the exception that wire  34  is fixedly attached to piston member  28  on one end and to the tip of tubular member  12  at the tubular proximal end  14 . 
     In this manner when piston member  28  is displaced in axial direction  82 , there is a displacement of tubular member proximal end  14  which permits radial displacement of wings  78 . Since wire  34  extends through the longitudinal channel  18  and fixedly couples the retaining mechanism  20  and the activation mechanism  26  each to the other with the actuation linkage  32  reciprocally displaceable in the axial direction in a bi-directional manner relative to tubular member  12  and retaining mechanism  20  under control of the activation mechanism  26 . 
     Activation mechanism  26  further includes cylinder housing member  30  generally formed of a relatively inflexible composition such as a closed cell plastic composition or some other like inflexible composition. Cylinder housing  30  may be transparent in order to allow viewing of the activation mechanism  26  during operational considerations. 
     Slots  38  and  40  as shown in  FIGS. 1-3  are formed through a sidewall of cylinder housing member  30 . First and second slots  38  and  40  extend in axial direction  82  as is seen in  FIGS. 1-3 . Both first and second slots  38  and  40  pass through the sidewall of cylinder housing member  30  and are formed into a U-shaped configuration and are in “open” communication each with respect to the other through communication passage or opening  94 . Passageway  94  is the base of the overall U-shaped contour formed by slots  38  and  40  and passageway  94  provides for open communication between slots  38  and  40 . 
     As will be further described in following paragraphs, the axial lengths of first and second slots  38  and  40  are not of equal length. As will be described, first slot  38  has an extended length in axial direction  82  which is greater than the axial length of second slot  40  to permit maintenance of wings  78  in an operable position when catheter  10  is in the “open” position. 
     First protuberance  50  is fitted to be slideably received in both first and second slots  38  and  40 . First protuberance  50  extends in a radial direction from piston member  28  and is secured to a wall of piston member  28  that is generally formed integral therewith. First protuberance  50  extends above an outer wall surface of the cylinder housing member  30  to allow actuation and displacement of first protuberance  50  in axial direction  82  whether in first slot  38  or second slot  40 . Thus, displacement of first protuberance  50  in axial direction  82  within either of first or second slots  38  and  40  causes a responsive displacement of piston member  28  within cylinder housing member  30 . 
     As is seen in  FIGS. 1 and 2 , first protuberance  50  may be rotated from first slot  38  to second slot  40  in a reversible manner by rotation of piston member  28  about an axial line in axial direction  82  to provide a transference of first protuberance member  50  from one slot  38  to the second slot  40  or vice versa. Displacement of first protuberance  50  in axial direction  82  provides for operability of retaining mechanism  20  from a “closed” position to an “open” position or vice versa. 
     Stop member  42  is positionally located at a proximal end of cylinder housing member  30  and provides for a termination point in the displacement of first protuberance  50  when slideably operated within first and second slots  38  and  40 . Stop member  42  is generally formed in one piece formation with respect to cylinder housing member  30  or may be a separate element which is fixedly attached to cylinder housing member  30 . Stop member  42  is generally formed of an inflexible composition such as a closed cell plastic or some like composition. Stop member  42  includes front edge  58  which is a termination surface for the displacement of first protuberance  50  within either of first or second slots  38  and  40 . First protuberance  50  extends in a radial direction through the wall of cylinder housing member  30  and can be actuated by the thumb of a user to displace first protuberance  50  in either of slots  38  or  40 . 
     As has been stated, stop member  42  serves as a stopping or termination point for longitudinal or axial displacement of first protuberance  50  upon actuation by the user. First protuberance  50  is rotatable about axis line  82  of cylinder housing member  30  for positioning first protuberance  50  within first and/or second slots  38  and/or  40  of cylinder housing member  30 . First protuberance  50  is thus slideably displaceable within first or second slots  38  and  40  when displaced in the direction defined by longitudinal slot direction arrow  54  shown in  FIG. 2 . First protuberance  50  may be releasably locked into alignment with either first or second slots  38  or  40 . 
     Stop member  42  includes lug or second protuberance  56  which extends in axial direction  82  above stop member leading edge  58  and extends into communication passageway or channel  94  which provides open communication between first and second slots  38  and  40 . Second protuberance  56  is configured to permit a force sliding of first protuberance  50  from first slot  38  to second slot  40  in a reversible manner but provide an impediment to the rotation where first protuberance  50  must forcibly be moved through communication channel  94 . Thus, second protuberance or lug  56  provides for an impediment to the passage of first protuberance  50  from first to second slot  38  and  40  in a reversible manner. Second protuberance  56  is contoured to permit rotation of first protuberance  50  reversibly between slots  38  and  40  with a friction fitting which allows first protuberance  50  to be forced from one slot to the other slot  38  or  40 . 
     In this manner, when catheter  10  is in a “closed” position as shown in  FIG. 1 , first protuberance  50  is positioned at a distal end of first slot  38 . Subsequently, after insertion of catheter  10  and retaining mechanism  20  into the body cavity of the patient, first protuberance  50  may be displaced in axial direction  82  to the leading edge surface  58  of stop member  42 . In this position, catheter  10  provides for the “open” position as shown in  FIG. 2  where the wings  78  are extended in a radial direction with respect to tubular member  12 . First protuberance  50  may then be forced through communication passage or channel  94  into alignment with second slot  40 . Due to the fact that second slot  40  has a length less than the length of the first slot  38 , first protuberance  50  may be displaced in axial direction  80  within second slot  40  without transferring or repositioning wings  78  into a “closed” position. Thus, when first protuberance  50  is within second slot  40  as is shown in  FIG. 3 , any displacement of first protuberance  50  within second slot  40  will not affect the “open” position of catheter  10  and retaining mechanism  20 . Only by forcing first protuberance  50  through communication channel  94  into first slot  38  and a resultant displacement of first protuberance member  50  in axial direction  82  can the retaining mechanism  20  be collapsed to assume a “closed” position as shown in  FIG. 1 . 
     Piston member  28  may include retaining members in the form of O-rings  84  to permit a smooth displacement of piston member  28  within cylinder housing member  30 . O-rings  84  may be formed of a rubber type composition and maintain stability of piston member  28  as piston member  28  is displaced in axial direction  82 . 
     The subject concept is further directed to a method of operationally actuating catheter  10  within a patient&#39;s body cavity to permit catheter  10  to be operationally in an “open” position or a “closed” position as has previously been discussed. Initially, there is the establishment of a tubular member  12  having tubular member proximal end  14  and tubular member distal end  16 . Tubular member  12  defines longitudinal channel  18  extending therethrough from tubular member proximal end  14  to tubular member distal end  16  with the tubular member distal end  16  being of a closed configuration. Longitudinal channel  18  extending through tubular member  12  permits bi-directional passage of fluids through tubular member  12 . Retaining mechanism  20  is established and includes a plurality of slits  66  clearly shown in  FIG. 1  in the “closed” position wherein when catheter  10  is operationally actuated, slits  66  expand into wings  78  as seen in  FIG. 2 . In this manner, retaining mechanism  20  is controllably and selectively displaceable to assume the “open” position ( FIG. 2 ) and the “closed” position ( FIG. 1 ). Retaining mechanism  20  is selectively displaced into the “open” position or the “closed” position by slideably displacing piston member  20  within cylinder housing member  30 . 
     Activation of an actuation linkage  32  extending through the longitudinal channel  18  of the tubular member  12  permits displacement of the actuation linkage to operationally move the catheter  10  from the “open” position to the “closed” position and vice versa. The actuation linkage  32  couples retaining mechanism  20  and activation mechanism  26  each to the other. Retaining mechanism  20  is displaceable in a radial direction relative to longitudinal direction  44  defining an axis line of tubular member  12  in response to a displacement of piston member  28  in axial direction  82  as seen in  FIG. 1 . 
     Displacing of piston member  28  includes the step of displacing piston member  28  from a first position to a second position within cylinder housing member  30  to selectively displace retaining mechanism  20  to assume an “open” position. The displacement step of the piston member  28  further includes displacing piston member  28  from a second position to a first position within cylinder housing member  30  to selectively displace retaining mechanism  20  to assume the “closed” position. In this manner, first protuberance  50  being displaced in a bi-directional direction in accordance with direction line  54  creates a responsive displacement of piston member  28  in axial direction  82  which then causes wire  34  to be contracted or extended resulting in wings  78  being in the “open” position or the “closed” position. 
     The step of displacing piston member  28  further includes the step of sliding first protuberance  50  formed on a wall of the piston member  28  within first slot  38  formed through a wall of the cylinder housing member  30  in the bi-directional axial direction  82 . 
     First protuberance  50  when bearing against first slot  38  first end  86  provides for catheter  10  to be in the “closed” position. When first protuberance  50  is displaced to first slot second end  88 , retaining mechanism  20  is operatively displaced to the “open” position seen in  FIG. 2 . 
     Thus, the piston displacement step further includes the sliding of first protuberance  50  formed on a wall of piston member  28  within first slot  38  of cylinder housing member  30  in axial direction  82  to provide the “open” and “closed” conditions for catheter  10 . 
     The activating step includes the locking step of retaining mechanism  20  into an “open” position where there is provided elongated second slot  40  in “open” communication with first slot  30  through channel  94 . The locking step includes rotation of first protuberance  50  when it is adjacent second end  88  of first slot  38  into alignment with second slot  40  at second end  92  of second slot  40 . 
     As has been previously discussed, second slot  40  and first slot  38  are of different axial lengths with the second slot  40  having a shorter length in the axial direction  82  than that of first slot  38 . The length of second slot  40  is designed to permit displacement of first protuberance  50  throughout the length of second slot  40  without displacement of retaining mechanism  20  into a “closed” position. Thus, when first protuberance  50  is at any point in second slot  40  retaining mechanism  20  is maintained in the “open” position as seen in  FIG. 2 . Only by forceful displacement of first protuberance  50  through channel  94  into first slot  38  and then a further displacement of first protuberance  50  to upper end  86  of first slot  38  can catheter  10  be returned from the “open” position to the “closed” position as shown in  FIG. 1 . 
     Thus, the unequal lengths of first slot  38  and second slot  40  are designed such that a displacement of first protuberance  50  in second slot  40  does not provide for any displacement of wings  78  from the “open” position shown in  FIG. 2 . 
     Nub or second protuberance or lug  56  formed on a front edge of stop member  58  extends partially into open passageway  94  between first slot  38  and second slot  40  to provide an impediment to the rotational displacement of first protuberance  50  from first slot  38  to second slot  40  or vice versa. Nub or lug or second protuberance  56  provides for a type of frictional fit for first protuberance  50  when being rotated between first and second slots  38  and  40 . In this manner, the user of catheter  10  can force protuberance  50  between first and second slots  38  and  40 , however, once protuberance  50  is in one of the first or second slots  38  or  40 , protuberance  50  is essentially releasably locked within the slot  38  or  40  and can only be moved in the axial direction  82  in free flow. 
     Although this invention has been described in connection with specific forms and embodiments thereof, it will be appreciated that various modifications other than those discussed above may be resorted to without departing from the spirit or scope of the invention as defined in the appended claims. For example, functionally equivalent elements may be substituted for those specifically shown and described, certain features may be used independently of other features, and in certain cases, particular locations of the elements may be reversed or interposed, all without departing from the spirit or scope of the invention as defined in the appended claims.