Abstract:
A safety device for use with a catheter to which a discharge conduit is connected includes a flexible, pleated segment that permits the discharge conduit to be temporarily axially elongated if sudden or excessive force is applied thereto. The pleated segment also permits limited torsional movement of the conduit. The safety device preferably includes a rotatable, fluid-tight connector that permits relative rotation between those elements to which it is connected.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     1. Field of the Invention.  
         [0002]     The invention relates to catheters and, more particularly, to a safety device that can be used with a catheter, such as a urinary catheter, that will result in a reduced tendency to cause pain to the user upon the application of sudden or forceful movements.  
         [0003]     2. Description of the Prior Art.  
         [0004]     A typical internal, or indwelling, urinary catheter is known as a Foley catheter. Such catheters consist of a hollow tube having a tip at one end which is inserted into the body. The tip has one or more openings that communicate with the interior of the hollow tube. The other end of the tube is disposed externally of the body and is connected to a waste receptacle by means of a flexible discharge conduit. An annular inflatable portion, or balloon, is spaced inwardly from the tip. The balloon is deflated during placement of the catheter into the body and thereafter is inflated after the tip is properly positioned within the body in the urinary bladder.  
         [0005]     In order to inflate the balloon, the external portion of the catheter is provided with a branch arm having a one-way valve structure through which fluid such as water or air under pressure may be admitted. The valve communicates with the inflatable balloon through a narrow passageway lying substantially parallel to the hollow tube. By insertion of either water or air under pressure in this manner, the balloon, when inflated, assumes a generally toroidal shape. In the example where the catheter is inserted into the urinary bladder, the inflated toroid serves to retain the tip of the catheter at the entrance of the urinary bladder. Such placement of the tip assures proper drainage of the bladder through the openings provided at the tip of the hollow tube.  
         [0006]     The waste receptacle typically is a small, flexible bag made of a plastics material that is secured to the patient&#39;s leg by straps or tape to permit ambulatory movement of the patient. Alternatively, the waste receptacle may be mounted to a structure that supports the patient, such as a bed or a wheelchair. Regardless of the manner in which the waste receptacle is positioned and secured in place, the connection between the waste receptacle and the external portion of the catheter is maintained by the flexible discharge conduit which usually takes the form of tubing made of a plastics material.  
         [0007]     A problem arises if unintended force, either axial or torsional, is applied to the discharge conduit. Such applications of force can occur, for example, if the patient accidentally catches the conduit on a stationary object while walking, or if the conduit becomes kinked while the patient turns over during sleep. With the balloon fully inflated, the pulling or dislodging of the catheter from its location in the urinary bladder and through the urethra (urinary canal) can cause severe lacerations, bleeding, and the possibility of damage to the external urinary sphincter with permanent urinary incontinence. Any displacement of the balloon also will cause severe pain to the patient. Even if the inflated balloon is not pulled into or through the urinary canal, the mere rotation of the hollow tube within the urinary canal will cause severe pain to the patient.  
         [0008]     The problem of pain caused by urinary catheters has been addressed by the prior art. U.S. Pat. No. 4,710,169, the disclosure of which is incorporated herein by reference, discloses an indwelling urinary catheter intended for use by male patients that deals with this problem in several ways. First, the catheter itself includes a collapsible segment that extends substantially the entire length of the urethra. This feature of the invention is stated to provide no longitudinal rigidity so that body movements cannot be translated along the entire length of the catheter. The &#39;169 patent also discloses an external seal that is fitted over the end of the penis. The catheter tube extends through the end of the seal which is defined by a series of accordion folds. The purpose of these folds is to dampen external forces applied to the catheter tube. The &#39;169 patent also addresses the problem of kinking of the discharge tube. Semi-rigid discharge tubes provide “torsional resistance.” The device disclosed in the &#39;169 patent is not usable with female patients, nor is it useful if strong torsional force is applied to the discharge tube.  
         [0009]     Another approach is exemplified by U.S. Pat. No. 3,951,153, the disclosure of which is incorporated herein by reference. The &#39;153 patent discloses a safety device in the form of a coupling that connects severed sections of a catheter. Upon the application of sudden force to the catheter, typically by pulling on the conduit connected to the waste receptacle, the coupling separates and thereby prevents the application of further force to the catheter. While the device disclosed in the &#39;153 patent may prevent catastrophic harm to the patient, the separation of the coupling results in the loss of fluid communication with the waste receptacle. Moreover, even if the coupling separates at a relatively low level of force, it is likely that the patient will experience substantial pain. It is doubted that the coupling would prevent the application of torsional forces to the catheter.  
         [0010]     It also is known to use external catheters, rather than indwelling catheters. See, for example, U.S. Pat. Nos. 4,378,018, 4,713,066, and 4,846,816, the disclosures of which are incorporated herein by reference. Although such catheters presumably would avoid harm and pain associated with pulling a tube and an attached balloon into or through the urethra, such catheters would not be suitable for use by females. External catheters also have other drawbacks, such as possible leakage, that limit their use even with male patients.  
         [0011]     Despite the approaches of the prior art, there remains a need for a device that is usable with a catheter that will prevent or minimize harm and pain to the patient upon the application of axial or torsional forces to the catheter. Any such device hopefully would be inexpensive and would remain usable after axial or torsional forces have been applied thereto. Also, any such device desirably would be usable with catheters of all types, including urinary catheters suitable for use with patients of either sex.  
       SUMMARY OF THE INVENTION  
       [0012]     In response to the foregoing concerns, the present invention provides a new and improved safety device that is usable with catheters, particularly urinary catheters of the indwelling type. The device according to the invention is usable with a catheter that includes an elongate, flexible tube having a first, internal fluid passageway. The tube has a tip end that in use is inserted into and retained within a body cavity, a central portion that is inserted into and retained within a duct that is in fluid communication with the body cavity, and an exit end that in use is disposed externally of the duct. The tip end includes one or more openings that permit fluid communication between the body cavity and the first fluid passageway. In a typical urinary catheter, an annular inflatable section is spaced inwardly from the tip end, and an input valve is disposed adjacent the discharge end. A second fluid passageway establishes fluid communication between the annular inflatable section and the input valve. The second fluid passageway is separate from the first fluid passageway.  
         [0013]     It is expected that the catheter will be connected to a waste receptacle by a discharge conduit. The discharge conduit has a first end connected to the exit end of the catheter and a second end intended to be connected to the waste receptacle. The discharge conduit thus establishes fluid communication between the exit end and the waste receptacle.  
         [0014]     The safety device according to the invention comprises a flexible, pleated segment that preferably is included as part of the discharge conduit or the exit end. The pleated segment permits the discharge conduit to be temporarily axially elongated such that the catheter tube will not be moved. Preferably, the pleated segment will be able to stretch at least about 50 percent more than its unstretched length. The pleated segment also permits limited torsional movement of the conduit or the exit end.  
         [0015]     The safety device also desirably includes a rotatable, fluid-tight connector that is included as part of the discharge conduit or the exit end. The rotatable connector permits relative rotational movement between the elements to which it is connected, thereby preventing or minimizing the transmission of twisting forces to the catheter tube.  
         [0016]     By using the safety device according to the invention, harm and pain caused to the patient that might result from pulling or twisting the discharge conduit can be minimized or eliminated. The device according to the invention will be inexpensive to manufacture and will remain usable after axial or torsional forces have been applied thereto. Also, the device will be usable with catheters of all types, including urinary catheters suitable for use with patients of either sex.  
         [0017]     The foregoing and other features and advantages of the invention will be apparent from an examination of the accompanying specification, claims, and drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0018]      FIG. 1  is a perspective view of a Foley catheter;  
         [0019]      FIG. 2  is a cross-sectional view of the catheter of  FIG. 1  taken along a plane indicated by line  2 - 2  in  FIG. 1 ;  
         [0020]      FIG. 3  is a side elevation view of the catheter of  FIG. 1  showing a balloon portion thereof in an inflated condition;  
         [0021]      FIG. 4  is a schematic representation of a Foley catheter connected to an exit conduit and a waste receptacle, and showing a flexible segment and a rotatable connection included as part of the exit conduit;  
         [0022]      FIG. 5  is an enlarged view of the flexible segment included as part of the exit conduit; and  
         [0023]      FIG. 6  is an enlarged, exploded view of the rotatable connector included as part of the exit conduit.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]     Referring generally to the drawings, and particularly to  FIG. 4 , a safety device according to the invention is indicated by the reference numeral  10 . The safety device  10  includes a pleated segment  20  and a rotatable connector  30 . The safety device  10  is intended to be used with an indwelling urinary catheter, commonly referred to as a Foley catheter. While the safety device  10  is disclosed in the environment of an indwelling Foley catheter, it can be used in connection with other types of catheters, including external urinary catheters. Indeed, the safety device  10  could be used in any application where it is desired to reduce or eliminate the effects of axial or torsional force that are applied to connected segments of tubing. Accordingly, while the most likely beneficial use of the safety device  10  will be with indwelling urinary catheters, the use of the safety device  10  is not intended to be so limited.  
         [0025]     Referring now to  FIGS. 1-3 , a typical Foley urinary catheter for use with male patients is indicated by the reference numeral  40 . Catheters identical or similar to the catheter  40  are commercially available from a number of companies, including Bard Medical Division,  8195  Industrial Boulevard, Covington, Ga. 30014. The catheter  40  includes an elongate, slender tube  42  made of latex, vinyl, silicone, or similar material that defines a first, hollow passageway  44 . The tube  42  has a tip end  46 , a central portion  48 , and an exit end  50 . The tube  42  is adapted for insertion into the patient&#39;s bladder through his urethra in order to permit urine to be drained from the bladder.  
         [0026]     The tip end  46  is provided with a pair of elongated openings  52  that are disposed on opposite sides of the end  46  and which establish fluid communication with the passageway  44 . The exit end  50  provides a cylindrical opening for the passageway  44  so that the passageway can be connected to a suitable waste receptacle, as will be described.  
         [0027]     A thin, expansible balloon  54  is disposed adjacent to the openings  52  on the side of the openings  52  closest to the central portion  48 . The balloon  54  is connected to the tube  42  by means of a second, hollow passageway  56  ( FIG. 2 ). The second passageway  56  extends through a branch tube  58 . A check valve  59  is disposed in the branch tube  58  near the exposed end thereof. The valve  59  is adapted to permit water or air to be introduced into the balloon  54  through the passageway  56 . As shown in  FIG. 3 , the introduction of such water or air into the balloon  54  will cause it to expand into a substantially toroidal shape. The expanded balloon  54  prevents the tip end  46  from being withdrawn unintentionally from the bladder, which is indicated schematically by the dashed lines in  FIG. 3 .  
         [0028]     Referring now to  FIG. 4 , a discharge conduit  60  includes a first end  62  and a second end  64 . The first end  62  is connected to the exit end  50  by means of the rotatable connector  30 . The second end  64  is connected to a waste receptacle  66  in the form of a small, flexible bag. The discharge conduit  60  and the waste receptacle  66  are made of a plastics material such as polyurethane or vinyl. The bag  66  includes wings  68  with slots  70 , and an outlet  72  having a stopcock  74 . The bag can be attached to the patient&#39;s leg by the use of suitable straps or tape passed through the slots  70 . When necessary, the bag  66  can be drained by opening the stopcock  74 . The conduit  60  and the bag  66  are commercially available from Bard Medical Division,  8195  Industrial Boulevard, Covington, Ga. 30014.  
         [0029]     The pleated segment  20  that constitutes part of the safety device  10  is included as part of the conduit  60 . Preferably, the segment  20  is located in the first end  62 , relatively close to the exit end  50 . The segment  20  also could be included as part of the exit end  50 , if desired. Alternatively, and less desirably, the segment  20  could be located in another portion of the conduit  60  remote from the first end  62 . The rotatable connector  30  preferably defines the end of the first end  62 , although it, too, could be located elsewhere, such as part of the exit end  50  or in another portion of the conduit  60 . If desired, the safety device  10  could include only the pleated segment  20  or only the rotatable connector  30 , although the use of both is preferred.  
         [0030]     The pleated segment  20  includes a plurality of angled sidewalls  76  that are joined by sharp-edged peaks  78  and valleys  80 . The number, thicknesses and length of the sidewalls  76 , the peaks  78 , and the valleys  80  are chosen to provide a desired percentage of elongation under a sudden, but temporary, axial load. Desirably, the pleated segment will elongate at least approximately 50 percent under load. That is, if the pleated segment in unstressed condition is four inches long, under load it will elongate to at least about six inches. Such a load might be encountered if the patient were to catch the conduit  60  on an unnoticed object while climbing into or out of bed. It is expected that the conduit  60  will remain in a compressed configuration as shown in  FIG. 4  under normal operating conditions, i.e., the conduit  60  will support its own weight. However, if the conduit  60  is suddenly pulled or twisted, the segment  20  will elongate and thereby prevent or minimize force from being applied to the exit end  50 .  
         [0031]     The rotatable connector  30  includes male luer connectors  82  at each end that are joined by a centrally located, rotatable, fluid-tight fitting  84 . Female luer connectors  86 , each having a barbed end  88 , join the male luer connectors  82  to the open ends of the exit end  50  and the conduit  60 , respectively. Desirably, the fitting  84  will be sufficiently loose that it will rotate under virtually any torsional load while remaining fluid-tight. The male luer connectors  82  and the fitting  84  are commercially available from Scientific Commodities, Inc., P.O. Box 2458, Lake Havasu City, Ariz. 86406, model no. BB821. Female luer connectors  86  having barbed ends  88  are available from the same company, model no. BB330.  
         [0032]     Although the invention has been described in its preferred form with a certain degree of particularity, it will be understood that the present disclosure of the preferred embodiment has been made only by way of example and that various changes may be resorted to without departing from the true spirit and scope of the invention as hereinafter claimed. For example, and not by way of limitation, multiple pleated segments  20  and multiple rotatable connectors  30  could be used. It is intended that the patent shall cover, by suitable expression in the appended claims, whatever features of patentable novelty exist in the invention disclosed.