A urinary catheter comprising an elongated hollow tube having a proximal end, a distal end, a drainage opening in the distal end and a liquid drainage lumen extending from the opening to the proximal end. A valve is located in the lumen near the distal end. Under normal conditions, the valve is open so as to permit urine to pass from the distal end to the proximal end. However, in response to fluid pressure applied to the valve by a cleansing solution on its side nearest the proximal end, the valve will close off the lumen and prevent access to the distal end. An opening for introducing the cleansing solution into the lumen on the side of the valve nearest the proximal end in an amount sufficient to cause the valve to close and to flush contaminants contained in the lumen out the proximal end is provided.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a urinary catheter in which the lumen may be 
periodically flushed outward to prevent bacterial contamination of the 
bladder. 
2. Description of the Prior Art 
The construction and use of catheters for the purpose of periodic or 
continuous drainage of the urinary bladder is well known in the art. Such 
devices are useful, for instance, when the urethra is blocked for any 
reason, causing retention of urine; when voluntary voiding is inadequate; 
when voluntary control of the sphinchter has been lost due to trauma, 
neurological damage or surgery; when involuntary emptying of the bladder 
is desired to facilitate diagnostic or surgical procedures; or for a 
variety of other reasons. 
A large variety of urinary catheters is known. These include simple tubes, 
tubes with expandable tips, and the Foley catheter which combines the 
advantages of the first two and is therefore the most popular for 
continuous catheterization beyond about 24 hours. In its simplest form, 
the Foley catheter consists of a flexible (rubber or plastic) tube of 
about 4-7 mm. diameter which is fabricated with a small diameter tube 
integral with the wall and leading to an expandable "balloon" chamber 
which is just below the tip which will drain the bladder. The chamber is 
collapsed for ease of insertion and once in place it is expanded with 
sterile medium such as air or saline solution to prevent the catheter from 
slipping out through the urethra. 
The most common and troublesome complication of urinary catheterization is 
colonization of the bladder and eventually the entire urinary tract with 
pathogenic bacteria, yeast and/or fungi. It has been reported that even 
with the best of available equipment and sterile technique, more than 25% 
of patients with indwelling urinary catheters can be expected to develop 
urinary tract infections after 30 days of continuous catheter drainage. 
Many attempts have been made to overcome this problem. Prophylactic use of 
systemic antibiotics which are excreted in the urine has not been 
successful since colonization is only slightly delayed and occurs with 
organisms resistant to the antibiotics used. Bladder irrigation with a 
solution of 0.25% acetic acid or a solution of neomycin-polymyxin is 
moderately successful, but requires a large amount of extra nursing 
attention. When this method is used, it is usually done with a 
triple-lumen Foley catheter as shown in FIG. 44 in a text by Calvin M. 
Kunin entitled "Detection, Prevention and Management of Urinary Tract 
Infections", Lea & Febiger, Philadelphia, Pa., 1974, 2d edition, Section 
IV, entitled "Care of the Urinary Catheter". 
The most common route of infection, once the closed drainage catheter has 
been placed using sterile technique, is colonization of the receiving bag, 
followed by retrograde ascent of the pathogens up the lumen of the 
catheter. In view of the non-motile nature of the pathogens, this 
occurrence was somewhat of a mystery until the early 1960's when careful 
observations revealed that small bubbles form along the walls of the 
catheter tubing and that over a period of hours, these bubbles grow and 
eventually separate from the wall and rise. The associated turbulent flow 
in the opposite direction of a slowly descending stream of urine 
eventually carries the organisms all the way to the bladder. The 
emplacement of a bubble trap in the line merely delays the process by a 
day or two, as the trap becomes infected and the process is repeated above 
it. 
SUMMARY OF THE INVENTION 
The present invention provides a urinary catheter comprising an elongated 
hollow tube having a proximal end, a distal end, a drainage opening in the 
distal end and a liquid drainage lumen extending from the opening to the 
proximal end. A blocking means, e.g., a valve, is located in the lumen 
near the distal end. Under normal conditions, the valve is open so as to 
permit urine to pass from the distal end to the proximal end. However, in 
response to fluid pressure applied to the valve by a cleansing solution on 
its side nearest the proximal end, the valve will close off the lumen and 
prevent access to the distal end. A means for introducing the cleansing 
solution into the lumen on the side of the valve nearest the proximal end 
in an amount sufficient to cause the valve to close and to flush 
contaminants contained in the lumen out the proximal end is provided.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The particular device set forth in the following description is a catheter 
for collecting urine from bladders which includes an automatic 
non-mechanical valve which operates during the flushing mode to prevent 
any re-entry of any voided urine or the flushing solution into the 
bladder. Thus, if desired, a strong chemical bacteriacide may be 
incorporated into the flushing solution. 
Although the flushable urinary catheter of this invention can be used with 
the human body in any position, i.e., standing up or lying down, the 
drawings show the device as it would be used with the human body standing 
up. Reference to upper and lower surfaces therefore refer to surfaces as 
viewed in the drawings with the flushable urinary catheter in the upright 
or vertical position. 
Referring now to FIG. 1, there is shown a catheter 10 comprising an 
elongated hollow tube having a proximal end 12 and a distal end 14. A 
liquid drainage lumen 16 extends from the distal end 14 to the proximal 
end 12. There is an opening or inlet port 18 in the distal end 14 which in 
the normal mode delivers urine from the bladder into the lumen 16 of the 
catheter 10. 
Located at the distal end of the catheter 10 adjacent to the downstream 
side of the inlet port 18 is a valve shown generally as 20. The valve is 
comprised of a retaining member or valve body 22, a funnel shaped, or 
first portion, 24 including a sleeve, or second portion, 26 and 
incorporates the sidewall 28 of the catheter tube 11. The outer periphery 
of the large end of the cone shaped portion 25 of the funnel 24 is 
attached at 30 to the inner surface of the walls of the catheter tube 11 
to assure a fluid-tight joint between the two surfaces. The funnel 24 
includes a flexible sleeve 26 attached at 34 to the small end of cone 25. 
In the preferred embodiment, the funnel 24 is fabricated as a single 
component, but it may be fabricated from a cone 25 and a flexible sleeve 
26 secured at a fluid-tight joint 34. The wall thickness of the cone 25 
tapers from a thick portion at the point of attachment 30 to a relatively 
thin portion at the point of attachment 34 to the sleeve 26. In between 
the two points of attachment of the cone 25, the upper and lower surfaces 
36 and 38, respectively, are gracefully shaped into gentle curves. The 
length and flexibility of the sleeve 26 will be discussed hereinafter. 
The retaining member 22 is a right circular cylinder with a coaxial bore 40 
(see FIG. 2) having the circular sidewall of the bore parallel with the 
longitudinal axis of the inner sidewalls of the catheter tube 11. The 
retaining member 22 is located at the distal end of the catheter and on 
the downstream side of the funnel member 24 and is secured to the inner 
wall 28 of the catheter 11 by fluid-tight attaching means. The exact 
location of the retaining member 22 is not critical but it is positioned 
so that a chamber 42 is formed between the upper surface 43 of the 
retaining member 22 and the lower surface 38 of the funnel 24. In 
addition, the position of the retaining member 22 and the length of the 
flexible tube 26 must be such that the flexible tube extends through the 
bore 40 of the retaining member 22. 
All of the components of the valve 20 shown in this embodiment are 
symmetrical about the longitudinal axis of the catheter. 
A side port opening 46 in the side wall of the catheter tube 11 is located 
approximately midway between the funnel member 24 and the retaining means 
22. Attached to the outer side wall of the catheter tube 11 and running in 
a longitudinal direction parallel to the catheter tube 11 is a flushing 
tube 44 for carrying flushing solution from the proximal end of the 
catheter to the valve chamber 42. The tube 44 has a passageway 48 running 
the full length of the catheter and has a right angle bend at the port 46 
so that the center passageway of the tube is in axial alignment with the 
center of port 46. The tube 44 is secured to the outer sidewall of the 
catheter tube 11 to provide a fluid-tight joint around the port 46 and is 
also secured either continuously along its length or at selected fastening 
points as at 50 and 52 to the sidewall of the catheter tube 11. 
Alternatively, a passageway may be formed into the sidewall of the 
catheter tube 11. In either case, the fabrication must assure a flowpath 
from the proximate end of the catheter to the chamber 42 of the valve 20. 
The operation of the flushable urinary catheter is described starting with 
the valve in the open position enabling urine to flow into one or more 
ports 18 in a direction shown by arrows 54 of FIG. 1 through the 
passageway at the distal end of the catheter tube 11 and into the mouth of 
the funnel 24 of the valve 20 as shown by the arrow 56. From the funnel 
mouth, the urine passes through the funnel 24 into and through the sleeve 
26. The gentle pressure of the urine on the inner sidewalls of the 
flexible sleeve 26 keeps the sleeve cylindrical in shape, thus permitting 
the urine to flow through the sleeve into the open portion of the lumen 16 
through which it flows to the proximate end. 
As the flexible sleeve 26 expands, it may or may not come in contact with 
the inner sidewalls 58 which form the bore or passageway 40 in the 
retaining means 22. When contact is made between the outer walls of the 
sleeve 26 and the inner walls 58 of the retaining means 22, the passageway 
between the lumen 16 and the chamber 42 is closed, thus preventing urine 
from entering the chamber or flushing tube 48 through port 46. If contact 
is not made between the outer walls of the sleeve 26 and the inner walls 
58 of the retracting means 22, retrograde flow of urine through the 
chamber 42 back down the tube 48 may be prevented by one or more check 
valves and/or by the resting piston in the pump used to deliver flushing 
solution. Such piston and associated valves do not form a part of this 
invention and are not shown. 
When it is desired to flush the lumen 16 of the catheter tube 11, the 
flushing solution is applied at the proximate end of the flushing tube 48 
from where it flows through the passageway 48 of the tube, through the 
port 46 and into the chamber 42 of the catheter 10. The direction of flow 
is shown by the arrows 60 in FIG. 2. The pressure of the flushing solution 
on the flexible sidewalls of the sleeve 26 causes the sleeve to collapse 
as at 62 of FIG. 2, closing the valve, and thus sealing the passageway 64. 
This prevents flow of the flushing solution from chamber 24 through the 
sleeve 26 and into the bladder. When the flow of the flushing solution is 
discontinued at the source, the pressure from the solution on the sides of 
the flexible sleeve ends. The sleeve 26 then either expands to its 
cylindrical shape by its own elastic nature or returns to its cylindrical 
shape as soon as the flow of urine exerts an internal pressure on the 
sidewalls to produce the same effect. In either case, the valve opens 
automatically when the flow of flushing solution is discontinued at the 
source. 
The tube 48 may be in communication with a syringe pump or the like, not 
shown, which would operate intermittently, as for instance controlled by 
an automatic timing device, to deliver a fixed amount of solution on a 
pre-determined schedule. The amount of flush solution and the time of its 
delivery would depend upon the observed rate of bubble formation, but with 
experience it will be possible to define reasonable limits, e.g., 10 ml. 
of flush solution in 1 minute every 20 minutes, 30 minutes, hour, etc. 
FIG. 3 shows the passageway 64 through the funnel 24 with the valve 20 open 
as it appears looking down from the distal end of the catheter in 
cross-section. The arrow 66 represents the downward flow of urine through 
the passageway. 
FIG. 4 shows the inner structure of the valve in the open position with the 
sleeve 26 in contact with the inner walls of the retaining means 22. 
FIG. 3 also shows the inner structure of the valve and catheter in 
cross-section with the valve as it appears in the closed position. The 
sleeve 26 is collapsed and the flushing solution flows through the bore 40 
of the valve body 22 into the drainage lumen 60. 
FIGS. 6-10 show a second embodiment of the urinary catheter of this 
invention. As described in relation to the first embodiment, the valve 69 
of the second embodiment is comprised of a retaining member 70 and a 
funnel member 72 which in cooperation with the inner sidewalls 28 of the 
catheter hollow tube 11 forms a valve chamber 76. In this second 
embodiment, the passageway 78 through retaining member 70, as it appears 
in transverse section, is oval shaped as best seen in FIGS. 9 and 10. The 
passageway 78, as seen in cross-section in FIG. 7, for example, is formed 
with the sidewalls 80 gently curved from the large opening 82 at the inlet 
side of the retaining member 70 to the small opening 84 at the discharge 
side. 
The funnel member 72 has an oval shaped transverse cross-section as best 
seen in FIG. 9. The funnel member 72 has oval shaped upper and lower 
openings and is formed with the sidewalls, as viewed in longitudinal 
cross-section as seen in FIGS. 6-8, for example, tapered from the upper 
opening to the lower opening. That is, the sidewalls are generally thick 
and inflexible as at 86 at the upper opening and relatively thin as at 88 
of the lower opening. 
As with the first embodiment, the longitudinal position of the retaining 
member 70 and the funnel member 72 are not critical. However, the funnel 
member must be located adjacent to the inlet port 18 and on the distal end 
side of the flushing solution side port 46. The longitudinal position of 
the retaining member 70 must be on the proximate side of the side port 46 
and its longitudinal position must be such that the end of the thin 
flexible funnel as at 88 is located substantially at the center of the 
passageway through the retaining member 70 as seen in FIG. 8. 
The interaction of the funnel member 72 with the retaining member 70 during 
the two modes of operation of the valve is described together with the 
operation of the catheter hereinafter. 
Urine flows through the inlet port 18 into the inner tubular portion of the 
catheter to the large opening 90 of funnel member 72 from where it flows 
through the smaller opening downwardly through the center passageway of 
the retaining member 70 into the lower tubular portion of the catheter and 
outwardly through the proximate end of the catheter. The flow of urine is 
shown by the direction of arrow 92 in FIG. 8. During the time the urine is 
flowing through the open valve 69, the thin tapered flexible ends of the 
funnel as shown at 88 have come in contact with the sidewalls of the oval 
shaped opening in the retaining member 70. This contact of the portion 88 
of the funnel with the sidewalls of the retaining member 70 prevents urine 
from flowing into the valve chamber 76 and through side port 46 into the 
flushing solution tube 48. When it is desired to flush the lumen of the 
flushable urinary catheter, a flushing solution is applied to the 
proximate end of the flushing solution tube 48 causing it to flow through 
side port 46 into valve chamber 76. The pressure of the flushing solution 
in chamber 76 upon the sidewalls of the funnel member 72 causes the 
sidewalls of the funnel to pull away from the sidewalls of the retaining 
member 70, thus leaving a passageway 74 for the flushing solution to enter 
and decontaminate the inner sidewalls of the flushable urinary catheter 
16. The valve is shown in this closed position in FIGS. 6 and 7. 
Typical materials which may be used in making the valve include synthetic 
rubbers, silicone rubber, soft polyethylene, polyvinylchloride, 
Silastic.RTM. and the like. 
The catheter of this invention, especially with the addition of the 
automatic pump, has several advantages, including the following: 
1. Retrograde movement of bubbles and microorganisms is effectively 
suppressed. 
2. There are no mechanical moving parts within the catheter itself, 
reducing the probability of failure in use. 
3. The flushing solution may contain a powerful antiseptic if desired, 
without exposing the patient to such agent. 
4. Convenience in emplacement and the need for minimal surveillance by the 
nursing staff will make this device highly acceptable in the profession. 
5. The expected remarkable decrease in catheter-borne urinary tract 
infections in patients requiring long-term catheterization will render 
this a very attractive device. 
Although the operation of the invention has been described in relation to 
two specific embodiments, it is apparent that variations may be made in 
the specific embodiments without departing from the invention as claimed. 
For example, it will be recognized that the catheter of this invention may 
be constructed with the addition of the standard Foley "balloon", either 
above, coincident with, or below the level of the flush valve mechanism.