Stretch valve balloon catheter and methods for producing and using same

A safety catheter includes a flexible, multi-lumen shaft having an outer diameter, a distal tip, a proximal catheter end with a drain end and a proximal inflation end. The multi-lumen shaft defines a drain lumen, a distal hollow balloon portion, at least one inflation lumen, and a drainage port. A hollow stretch valve is coaxially disposed in the inflation or drainage lumen, or both, has a fixed portion within the inflation or drainage lumen, or both, and prevents fluid from passing through the drainage port in a steady state and has a sliding portion slidably disposed within the inflation or drainage lumen, or both, such that, in a stretched state when the proximal catheter end is stretched, the sliding portion slides within the inflation or drainage lumen, or both to permit fluid to pass through the balloon drainage port and/or wall of the catheter.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a catheter, especially an automatically deflating balloon catheter with a stretch valve and methods for using and manufacturing such a catheter.

2. Description of Related Prior Art

A number of conventional balloon catheters exist in the prior art. Some catheters are used to drain the bladder of a patient during surgical procedure or to treat bladder and/or urethra or prostate conditions, for example. For example, a common balloon catheter made by RUSCH® and referred to as a Foley catheter is widely used today for treating and draining a patient's bladder. The Foley catheter is shown inFIG. 1and has a multi-lumen shaft1that is disposed in the urethra10, a balloon portion3disposed at the distal end of the shaft1, a fluid drain section4disposed at the distal end of the balloon3, and a curved or straight, distal guiding tip5at the distal-most end of the entire catheter. When placed properly, the proximal-most side of the inflated balloon3rests on the interior wall31of the bladder30, entirely blocking off the urethrovesical junction11connecting the bladder30and the urethra10. In such a position, the fluid drain section4allows continuous drainage of the bladder30and the balloon3virtually entirely prevents the catheter from slipping out of the bladder. This ideally inserted position is shown inFIG. 1. As used herein, a fluid can be either a liquid or a gas. Exemplary fluids for inflating a balloon3are saline, sterile water, air, or carbon dioxide gas. Exemplary fluids drained by the catheters mentioned herein include urine and blood.

Basically, the catheter has a tube-like body with two lumens passing therethrough. The larger lumen is open to the bladder (distally) and empties into a non-illustrated ex-corporeal bag (proximally) for eventual disposal. A smaller lumen is used to inflate (and deflate) the balloon3with sterile water (typically) using a syringe attached to the inflation lumen fitting260(see, e.g.,FIG. 3). When inflated in the bladder, for example, the catheter is substantially prevented from sliding out of the urethra in use.

In a conventional balloon3, the balloon3has a substantially constant balloon wall thickness. The balloon3is fixed to the outer surface of a fluid drainage line (not illustrated inFIG. 1) and is not intended to be removed therefrom or to burst thereon unless an extraordinary amount of inflation occurs. If such an event happens, the material of the balloon will open at a random location based upon the microscopic fractures or weaknesses in the material itself. Such a tearing event is not supposed to occur under any circumstances during use with a patient.

Prior art catheters are not constructed to prevent tearing of the urethra during a catheter implanting procedure and are not constructed to break in any predefined way. Prior art catheters are designed to deflate only when actively deflated, either by a syringe similar to the one that inflated it or by surgery after the physician diagnoses the balloon as not being able to deflate, in which circumstance, a procedure to pop the balloon surgically is required.

Over 96 million indwelling catheters are sold worldwide on an annual basis. Twenty four million catheters are sold to hospitals in the U.S. There are numerous complications associated with those catheters that need to be prevented. These complications are responsible for increases in hospital stays, excessive bleeding, mortality, as well as morbidity. They also cause an increased expense and burden on the already-stressed health care system.

The complications result from several different mechanisms. First, and probably most common, is improper placement of the catheter. Because of the unique anatomy of the male urethra, placing a urethral catheter for urinary drainage can be difficult. A problem arises when the physician, technician, or nurse thinks that the catheter is actually in a proper position when it is not. The proper position for the catheter is with the balloon located in the cavity of the bladder. In this position, the tip distal to the balloon is located in the bladder and is used to drain the bladder cavity.

For placement of this catheter in the bladder30in the ideal position, however, the physician or technician has no visual aid. As shown inFIG. 1, the wall40defining the urethrovesical junction11is very short in the longitudinal direction of the urethra10. If the physician inserts the catheter too far into the bladder30, no damage occurs from balloon inflation; however, there is a possibility of leakage around the balloon3, which, under normal conditions, actually helps to lubricate the urethra10. In such a case, gentle proximal movement of the shaft1will place the proximal side of the balloon3against the urethrovesical junction11. The bladder30can then easily expand and stretch to compensate for the balloon3. A normal bladder capacity is 400 cc to 500 cc. A normal balloon capacity is approximately 10 cc to 12 cc although larger balloons are sometimes used. A typical balloon is 5 cc, however, most clinicians put 10 cc of water in the balloon for inflation. With 5 cc of water in the balloon, the diameter is approximately 2 cm and with 10 cc the diameter is approximately 2.5 cm.

Complications occur when the technician and/or nurse inflates the balloon when the balloon is not in the bladder. If the technician does not insert the catheter in far enough, then the balloon3will be inflated within the urethra10—a condition that, while common, is to be avoided at all costs and is a frequent cause of bladder infections created during a hospital or clinic visit. Infections arise because inflation of the bladder3inside the urethra10causes the urethra10to stretch too far and tear. Even though the urethra10is a flexible tube, it has limits to which it can be safely stretched from within. Almost every balloon catheter has a balloon outer diameter/circumference that well-exceeds the safe stretching limit of the urethra10. Therefore, if the balloon catheter is not inserted far enough, inflation of the balloon3will cause serious injury to the urethra10. This is especially true with elderly patients who have urethras that are not as elastic as younger patients. Also, just as important is the change in anatomy of older males, in particular, the prostatic portion of the urethra. With age, the prostate becomes larger and, sometimes, the catheter cannot be advanced through the prostatic portion of the urethra. When this occurs, the technician does not insert the catheter all the way into the bladder and inflates the balloon within the urethra. Alternatively, strictures, i.e., scar tissue, cause the catheter to halt and further pressure tears the urethral wall to create a new, unintended passage. Both of these improper insertions cause severe bleeding and damage.

The elastomeric balloon of present-day catheter products requires relatively high pressures to initiate inflation and expand to an expected full-diameter shape upon over-inflation. As such, when incorrectly placed in the urethra, the rapid inflation, combined with the high-pressure, causes the balloon to tear the surrounding membrane, referred to as the mucosa. Tearing of the urethra10in this way causes bleeding and allows bacteria to enter into the bloodstream at the tear site, thus causing the subsequent bladder infection. Significant bleeding can become life threatening. The urethra can normally dilate several millimeters; however, when the balloon is inflated, this dilation is usually several centimeters. Also, without sufficient and immediate venting of the balloon inflation fluid after improper placement, an accidental or intentional pull on the catheter externally can and does cause extensive bodily harm to the patient.

Life threatening bleeds, especially in patients who are anticoagulated, can and do occur. Also when the urine is infected, as in immunocompromised patients and the elderly, the bacteria enter the blood stream and can cause serious infections (e.g., sepsis), which frequently can lead to death. If the patient survives the initial trauma, then long-term complications, such as strictures, can and usually do occur. Strictures cause narrowings within the urine channel and usually require additional procedures and surgeries to correct.

Other mechanisms of catheter-induced injuries are inadvertent manipulation of the tubing or dislodging of the balloon—caused when the catheter is pulled from outside the patient due to a sudden jerk or tension. This commonly happens when the patient is ambulating or traveling from the bed to the commode or bathroom. The tubing may inadvertently become fixed while the patient is still moving, at which time a sudden jerk is imparted upon the balloon and pulls the balloon into the urethra, which tears the urethra, causing severe pain and bleeding. Injury caused by the improper, inadvertent, and/or early removal of an inflated balloon catheter is referred to as iatrogenic injury (also referred to as an in-hospital injury). Hundreds of thousands of such iatrogenic injuries occur each year—all of which need to be prevented, not only for patient safety, but also because the cost imposed on the medical health industry for each injury is enormous.

Yet another scenario occurs when the patient deliberately pulls on the catheter, thereby causing self-induced pain and injury to the urethra. This commonly happens in confused patients, for example, patients in nursing homes who have a disease or cognitive dysfunction problem, such as Alzheimer's disease, or other diseases that make the patient unable to understand the necessity of having a catheter. Confusion occurs when the patient has a spasm causing pain and a strong urge to urinate. During the spasm, the confused patient often tugs and pulls on a catheter, which results in injury. Like iatrogenic injuries, these self-induced injuries must be prevented. In the particular case of injury caused by catheter withdrawal when the balloon is inflated (either iatrogenic or self-induced), hospitals have categorized such injuries as “never events”—occurrences that should never happen. Under such circumstances, insurance typically does not cover the resulting extensive medical expenses.

The injuries mentioned herein are not limited to males and also cause severe damage to the female bladder and urethra. The injuries can also occur post-surgically, which makes the damage even more severe. One common situation where injury is caused is when the patient is medicated with morphine or other analgesics that render the patient confused and unable to make rational decisions. Feeling the foreign body inside the urethra, the confused patient does not know to leave it alone and, instead, gives it the injury-causing tug. These injuries have been well-documented and are not limited to adults. Numerous injuries are documented in pediatric patients.

Usually, it takes time to make a diagnosis of patient-caused catheter injury. Immediately after diagnosing the injury, a technician needs to deflate the catheter. However, once the urethra is torn, replacing the damaged catheter with another catheter is quite difficult and, in fact, exacerbates the injury. Sometimes, the patient has to be taken to the operating room to replace a urinary drainage tube once the injury occurs. Because catheters and leg bags are now used routinely in certain situations during home health care, this scenario is not limited to hospitals and occurs at nursing homes and patients' homes as well.

Most of the recent catheter technology has been focused on reducing urinary tract infections that are caused by catheters, injuries that are usually the most common catheter-related complications. One example of such technology is impregnation of the catheter with antimicrobials or antibiotics. But, these advances do nothing to prevent the injuries explained herein.

Accordingly, it would be beneficial to provide a balloon catheter that does not inflate past the tearing limit of a urethra and deflates in a desired, predefined way under certain conditions.

SUMMARY OF THE INVENTION

It is accordingly a desire to provide an automatically deflating pressure balloon catheter with a stretch valve and methods for manufacturing and using the catheter that overcome the hereinafore-mentioned disadvantages of the heretofore-known devices and methods of this general type and quickly and rapidly deflates if pulled out prior to physician-scheduled deflation of the balloon.

With the foregoing and other objects in view, there is provided, in accordance with the invention, a flexible, multi-lumen shaft having an outer diameter, a distal tip, a proximal catheter end with a drain end, a proximal inflation end, and a hollow stretch valve. The multi-lumen shaft defines a drain lumen extending through the shaft and operable to drain fluid adjacent the distal tip therethrough and out the proximal drain end, a distal hollow balloon portion defining a balloon interior and having at least one inflation port fluidically connected to the balloon interior, the balloon portion operable to be inflated outwardly through the at least one inflation port to a diameter greater than the outer diameter of the shaft, at least one inflation lumen parallel to the drain lumen and fluidically connected to the at least one inflation port, the at least one inflation lumen operable to inflate the balloon interior with an inflation fluid, and a drainage port. The drainage port fluidically connects at least one of the balloon interior and the at least one inflation lumen to at least one of the drain lumen and the environment of the balloon portion. The hollow stretch valve is coaxially disposed in the at least one inflation lumen and operable to permit the inflation fluid to pass therethrough, is positioned in the at least one inflation lumen to prevent fluid from passing through the drainage port in a steady state, has a distal valve end and a proximal valve end, has a fixed portion fixedly connected within the at least one inflation lumen at one of the distal valve end and the proximal valve end, and has a sliding portion slidably disposed within the at least one inflation lumen at the other one of the distal valve end and the proximal valve end such that, in a stretched state when the proximal catheter end is stretched, the sliding portion slides within the at least one inflation lumen to permit the inflation fluid to pass through the drainage port.

With the objects of the invention in view, there is also provided a safety catheter, comprising a flexible, multi-lumen shaft having an outer diameter, a distal tip, a proximal catheter end with a drain end, a proximal inflation end, and a hollow stretch valve. The multi-lumen shaft defines a drain lumen extending through the shaft and operable to drain fluid adjacent the distal tip therethrough and out the proximal drain end, a distal hollow balloon portion defining a balloon interior and having at least one inflation port fluidically connected to the balloon interior, the balloon portion operable to be inflated outwardly through the at least one inflation port to a diameter greater than the outer diameter of the shaft, at least one inflation lumen parallel to the drain lumen and fluidically connected to the at least one inflation port, the at least one inflation lumen operable to inflate the balloon interior with an inflation fluid, and a drainage port fluidically connecting the balloon interior to the drain lumen. The hollow stretch valve is coaxially disposed in the drain lumen and operable to permit fluid to pass therethrough, is positioned in the drain lumen to prevent fluid from passing through the drainage port in a steady state, has a distal valve end and a proximal valve end, has a fixed portion fixedly connected within the drain lumen at one of the distal valve end and the proximal valve end, and has a sliding portion slidably disposed within the drain lumen at the other one of the distal valve end and the proximal valve end such that, in a stretched state when the proximal catheter end is stretched, the sliding portion slides within the drain lumen to permit the inflation fluid to pass through the drainage port.

In accordance with another feature of the invention, the stretch valve has the stretched state at a pull force of between approximately 1 pound and approximately 15 pounds applied to the proximal shaft portion.

In accordance with a further feature of the invention, the stretch valve has the stretched state at a pull force of between approximately 1 pound and approximately 5 pounds applied to the proximal shaft portion.

In accordance with an added feature of the invention, the stretch valve has the stretched state at a pull force of between approximately 1.5 pounds and approximately 2 pounds applied to the proximal shaft portion.

In accordance with an additional feature of the invention, when the balloon portion is inflated with a fluid and a pull force of greater than approximately 15 pounds is applied to the proximal shaft portion, the stretch valve meets the stretched state and thereby deflates the inflated hollow balloon.

In accordance with yet another feature of the invention, when the balloon portion is inflated with a fluid and a pull force of greater than approximately 5 pounds is applied to the proximal shaft portion, the stretch valve meets the stretched state and thereby deflates the inflated hollow balloon.

In accordance with yet a further feature of the invention, when the balloon portion is inflated with a fluid and a pull force of greater than approximately 2 pounds is applied to the proximal shaft portion, the stretch valve meets the stretched state and thereby deflates the inflated hollow balloon.

In accordance with yet an added feature of the invention, the drainage port fluidically connects at least one of the balloon interior and the at least one inflation lumen to at least one of the drain lumen, the environment proximal of the balloon portion, and the environment distal of the balloon portion.

In accordance with yet an additional feature of the invention, the drainage port is a plurality of drainage ports fluidically connecting at least one of the balloon interior and the at least one inflation lumen to at least one of the drain lumen and the environment of the balloon portion.

In accordance with again another feature of the invention, the drainage port fluidically connects the balloon interior and the inflation lumen to the drain lumen.

In accordance with a concomitant feature of the invention, the drainage port is a plurality of drainage ports each fluidically connecting the balloon interior to the drain lumen and the hollow stretch valve is positioned in the drain lumen to prevent fluid from passing through the plurality of drainage ports in a steady state and has the sliding portion slidably disposed within the drain lumen such that, in a stretched state when the proximal catheter end is stretched, the sliding portion slides within the drain lumen to permit the inflation fluid to pass through the plurality of drainage ports.

The low-pressure balloon catheter of the present invention prevents injury by having the balloon automatically deflate before an injury can occur, for example, when being forced to withdraw from the bladder or being forced to inflate within a urethra. The stretch valve balloon catheter of the present invention prevents injury by having the balloon automatically deflate before an injury can occur, for example, when being forced to withdraw from the bladder prior to physician-scheduled manual deflation. While the catheters of the present invention makes it a safer device for urinary drainage, the present invention can also be used for any procedures in which balloons are used to occlude cavities. Examples of these procedures include coronary artery vessels and peripheral vascular vessels, such as the aorta and extremity vessels. Balloon dilations of other lumens, such as ureters and the esophagus, are also candidates for use of the catheter of the present invention. Further, the mechanism of pressure release can be used for any fluid or air-filled device such as tissue expanders, percutaneous devices, and the like.

Some of the embodiments of the present invention utilize a valve (e.g., a slit valve or a stretch valve) that permits reuse when utilized. With embodiments having no such valves, the invention is a single use catheter after deflation occurs. Although deflation of such a single-use catheter renders it useless, the act of immediate deflation protects the patient from serious harm and the cost of replacing a catheter is minimal as compared to the significant cost of treating catheter-induced injury. Prevention of such injuries is becoming more and more important because the injuries are commonplace. The increase occurs for a number of reasons. First, a greater percentage of the population is aging. Second, there is a current trend to use less-skilled health care personnel to perform more procedures and to be responsible for treatment, both of which save the hospitals and doctors money. The shortage of nursing professionals (e.g., R.N.s) exacerbates this trend. The present tendency is to use nursing professionals for more functions, such as administration and delivery of medications. This leaves only the least-skilled technicians with the task of taking vital signs and inserting catheters. Under such circumstances, more injuries are likely and do, in fact, occur. Lastly, catheter-related complications are becoming more severe due to the increased use of anticoagulation medication, such as PLAVIX®, that is frequently prescribed in treating cardiovascular disease.

Yet another possible complication arising from the standard Foley catheter is that the balloon will not deflate even when the deflation mechanism is activated. This situation can occur, for example, because the wrong fluid is used to inflate the balloon or when a fluid, such as saline, crystallizes, which happens occasionally. Sometimes, the ability to deflate the catheter is interrupted because the drainage channel that is used to deflate the balloon becomes obstructed, which is common if the catheter is left in place too long. Remedy of such a scenario involves an invasive procedure, which includes threading a needle or other sharp object somewhere through the body cavity to puncture the balloon and, thus, dislodge the catheter. This procedure is not desirable and is to be avoided if possible. Yet another possible complication can occur when the patient has a stricture, i.e., scar tissue in the urethra that impedes the passage of the catheter. When a technician is faced with a stricture, it seems to the technician that the catheter is no longer moving towards the bladder. Consequently, the technician uses excessive force to push the catheter into the bladder, thereby causing a tear that creates its own lumen into the penile and prostatic tissue. As is self-evident, this situation is accompanied by significant bleeding and the need for additional corrective procedures and surgery.

With the low-pressure or valved, auto-deflating balloons of the present invention, the technician, nurse, or doctor merely needs to pull on the catheter to cause the catheter to automatically deflate, thus sparing the patient from any additional surgical procedures.

The added benefit of the present invention is not just for safety, significant financial benefits arise as well. It is believed that catheter-induced injuries are much more common than public documentation suggests. Catheter-related trauma occurs no less that once a week in a large metropolitan hospital. Usually, each incident not only increases the patient's hospital stay substantially, but also the expense of the stay. Each incident (which is usually not reimbursed by insurance) can increase the cost to the hospital by thousands of dollars, even tens or hundreds of thousands of dollars. This is especially true when the patient brings a personal injury action against the hospital, physician(s), and/or staff. And, when additional surgery is required to repair the catheter-induced injury, increased expense to the hospital is not only substantial, if litigation occurs as a result of the injury, damages awarded to the patient can run into the millions of dollars. The catheters and methods of the present invention, therefore, provide a safer catheter that has the possibility of saving the medical industry billions of dollars.

To prevent urethra tearing occurrences due to premature-improper inflation of the balloon and/or due to premature removal of an inflated balloon, an exemplary embodiment of the invention of the instant application provides various balloon safety valves. Such valves are configured to release the inflation liquid from the balloon before injury occurs.

The maximum stress that a typical urethra can take without tearing and/or breaking is known and is referred to as a maximum urethra pressure. It is also possible to calculate how much pressure is exerted upon the exterior of a balloon of a balloon catheter by measuring the pressure required to inflate the balloon. Knowing these two values, it is possible to construct a balloon that breaks rapidly and/or ceases inflation if the maximum urethra pressure is exceeded.

For example, in a first exemplary embodiment, the balloon, which is typically some kind of rubber, silicone, elastomer, or plastic, can be made with a breaking point that instantly deflates the balloon if the pressure in the balloon exceeds the maximum urethra pressure. It is acknowledged and accepted that, once the balloon breaks, this catheter is useless and must be discarded because the cost of patient injury far outweighs the cost of the disposable catheter. Also, such a balloon is limited to inflation with a bio-safe fluid to prevent unwanted air/gas from entering the patient. If, however, air or other gas will not injure the patient, the fluid can be air or another gas.

As an alternative to a one-use breaking safety valve, a multi-use pressure valve can be added to the balloon inflation lumen and can be set to open into the drainage lumen if the maximum urethra pressure is exceeded in the balloon or the balloon inflation lumen. Such a valve can be located near or at the balloon inflation port, for example. Any combination of the above embodiments is envisioned as well.

Another exemplary embodiment of the present invention provides the catheter with a balloon that inflates with virtually no pressure. As used herein, “virtually no pressure,” “zero-pressure” and “low-pressure” are used interchangeably and are defined as a range of pressure between approximately standard atmospheric pressure and 0.3 atmospheres (5 psig). This is in contrast to “high-pressure,” which is greater than approximately 1.5 atmospheres (22 psig). With such a configuration, the zero-pressure balloon can be deflated with virtually no force. As such, when the clinician attempts to inflate the zero-pressure balloon of the present invention within a urethra, the balloon simply does not inflate. Likewise, when the already inflated balloon within the bladder is forced into the urethra, such deflation needs virtually no pressure to collapse the balloon to fit into the urethra. In both circumstances, injury to the urethra is entirely prevented.

Further exemplary embodiments of the present invention that prevents urethra tearing occurrences due to premature removal of an inflated balloon provides a balloon catheter with a stretch valve and methods for manufacturing and using such a valved catheter. In these variations, the invention takes advantage of the fact that premature removal of the inflated balloon catheter requires stretching of the catheter at the proximal side of the balloon. The valved catheter can be configured with a release mechanism that is a function of elongation. With short elongations, the balloon remains inflated however, when pulled beyond a preset limit, the valve automatically opens and drains the fluid filling the balloon. Some variations allow the balloon to even be refilled if deflation occurs without any injury. In either case, injury is prevented. Description of one exemplary embodiment herein in a way that separate from other exemplary embodiments is not to be construed mean that the one embodiment mutually exclusive of the other exemplary embodiments. The various exemplary embodiments of the safety catheter mentioned herein can be used separately and individually or they can be used together in any combination.

Although some variations are illustrated and described herein as embodied in a stretch valve balloon catheter and methods for producing and using such a catheter, they are, nevertheless, not intended to be limited to the details shown because various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims. Additionally, well-known elements of exemplary embodiments of the invention will not be described in detail or will be omitted so as not to obscure the relevant details of the invention.

Before further disclosure and description, it is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting. The terms “a” or “an”, as used herein, are defined as one or more than one. The term “plurality,” as used herein, is defined as two or more than two. The term “another,” as used herein, is defined as at least a second or more. The terms “including” and/or “having,” as used herein, are defined as comprising (i.e., open language). The term “coupled,” as used herein, is defined as connected, although not necessarily directly, and not necessarily mechanically.

As used herein, the term “about” or “approximately” applies to all numeric values, whether or not explicitly indicated. These terms generally refer to a range of numbers that one of skill in the art would consider equivalent to the recited values (i.e., having the same function or result). In many instances these terms may include numbers that are rounded to the nearest significant figure. In this document, the term “longitudinal” should be understood to mean in a direction corresponding to an elongated direction of the catheter. Lastly, the term “proximal” refers to the end of the catheter closest to the person inserting the catheter and is usually that end of the catheter with a hub. The distal end of the catheter is the end furthest away from the person inserting the catheter.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Herein various embodiment of the present invention are described. In many of the different embodiments, features are similar. Therefore, to avoid redundancy, repetitive description of these similar features may not be made in some circumstances. It shall be understood, however, that description of a first-appearing feature applies to the later described similar feature and each respective description, therefore, is to be incorporated therein without such repetition.

Referring now to the figures of the drawings in detail and first, particularly toFIG. 2thereof, there is shown a first embodiment of a pressure-limiting balloon catheter100that does not inflate past the tearing limit of a lumen in which the catheter100is placed, for example, in the urethra.

To prevent occurrences of urethra tearing due to premature-improper inflation of the balloon and/or due to premature removal of an inflated balloon, the invention of the instant application provides the balloon110with a balloon safety valve112. As set forth above, in a balloon3of a conventional catheter (see reference numerals1to5inFIG. 1), the high-pressure balloon3is fixed to the outer surface of the fluid drainage lumen120(not shown inFIG. 1) and is not intended to be removed therefrom or to burst thereon unless an extraordinary amount of inflation occurs. Such a tearing event is not supposed to occur under any circumstances during use with a patient. If such an event happens, the material of the balloon3will open at a random location, based upon the microscopic fractures or weaknesses in the material itself, and risk serious damage to the patient associated with the bursting, as well as a risk of balloon fragmentation, which could leave one or more pieces of the balloon3inside the patient after removal of the catheter1.

In contrast to such conventional devices, the balloon110of the present invention is created specifically to tear when a predefined pressure exists in or is exerted on the balloon110. The controlled tear will occur because the balloon safety valve112is present. Conventional balloons have constant balloon wall thicknesses (before inflation). In contrast thereto, the balloon safety valve112in the first embodiment is a defined reduction in balloon wall thickness. This reduction creates a breaking point or selected breaking points at which the balloon110is intended specifically to break when a predefined force exists in or is imparted on the balloon110. Because the balloon110is made of a material having a known tearing constant—dependent upon the thickness thereof (which is determined experimentally for different thicknesses of a given material prior to use in a patient), the balloon safety valve112of the present invention for urethra applications is matched to break when the pressure inside or exerted on the balloon110approaches the maximum urethra pressure.

In the embodiment shown inFIG. 2, a decreased thickness is formed as a first semi-circumferential groove114near a proximal end of the balloon110and/or as a second semi-circumferential groove116near a distal end of the balloon110. The grooves114,116can have any cross-sectional shape, including, trapezoidal, triangular, square, or rectangle, for example. Because rubber, plastic, and silicone materials tear well with thinner cuts, a relatively triangular shape or one with a narrow bottom can be an exemplary configuration. To make sure that the entire balloon110of the illustrated embodiment does not completely tear away from the fluid drainage lumen120, both grooves114,116do not extend around the entire circumference of the balloon110. As shown to the left of the proximal groove116inFIG. 2, the groove116is not present on at least an arc portion118of the circumference of the balloon110. The arc portion is defined to be sufficiently large so that, when the catheter100is removed from the patient, the balloon110cannot tear away entirely from the catheter100(and create the disadvantageous fragmentation situation as set forth above). The illustrated balloon safety valve112is, therefore, fashioned to keep the balloon110in one piece after breaking and remain firmly connected to the catheter100to insure that no piece of the balloon110will be left inside the patient after actuation of the balloon safety valve112. Alternatively, the groove can be along the length of the balloon parallel to the axis of the catheter. This groove can be made by skiving the balloon after attaching to the catheter or by skiving the balloon as it is formed during extrusion or dip molding. In this embodiment, when the pressure exceeds a predetermined limit, the balloon splits along the groove without releasing fragments.

It is noted that the balloon110is inflated through an inflation lumen130having a proximal opening, typically formed by one end of a luer connector (see260inFIG. 3). The illustrated end is connected to a non-illustrated inflation device, for example, a distal end of a syringe for inflation of the balloon110.

In this first embodiment, the balloon can be of an elastomer, rubber, silicone, or plastic, for example. Once the balloon breaks, the catheter is useless and must be discarded. Because the balloon110in this embodiment will break inside the patient, it should be inflated with a bio-safe fluid to prevent unwanted air, gas, or bio-unsafe fluid from entering the patient. In certain circumstances where balloon catheters are used, air or gas will not injure the patient if let out into the patient's body cavity. In such circumstances, the inflating fluid can be air under pressure, for example.

Maximum urethra pressure can also be tailored to the individual patient. Based upon a urethral pressure-measuring device, the patient's maximum urethra pressure can be measured before the catheter100is placed therein. A set of catheters100having different safety valve breaking constants can be available to the physician and, after estimating or calculating or knowing the patient's maximum urethra pressure, the physician can select the catheter100having a safety valve breaking constant slightly or substantially smaller than the patient's maximum urethra pressure. Accordingly, if the pressure in the balloon110approaches the patient's maximum urethra pressure for any reason, whether it is due to over-inflation, improper placement, and/or premature removal, the balloon110is guaranteed to break prior to the patient's lumen (in particular, the patient's urethra) and, therefore, prior to causing injury.

A second embodiment of the one-use breaking safety valve of a pressure-limiting balloon catheter200is shown inFIG. 3. The catheter200has a fluid drainage lumen220, a balloon inflation lumen230, and a secondary lumen240.

The fluid drainage lumen220is connected fluidically to the body cavity (i.e., the bladder30) for draining fluid from the body cavity.

The secondary lumen240can be used for any purpose, for example, for housing the radiation line that will supply energy to the radiation coil2. It can also be used for injecting fluid into any distal part of the catheter200or even the body cavity itself.

The balloon inflation lumen230begins at a proximal end with an inflating connector260that, in an exemplary embodiment, is one part of a luer connector. The balloon inflation lumen230continues through the body of the catheter200all the way to the balloon110and is fluidically connected to the interior of the balloon110.

Alternatively or additionally, the balloon safety valve is fluidically connected to the balloon inflation lumen230. In a second embodiment of the safety valve212, the valve212is formed integrally with the balloon inflation lumen230and is set to open into the environment (instead of into the patient) if the maximum urethra pressure is exceeded in the balloon110or the balloon inflation lumen230. Alternatively and not illustrated, the valve212is formed integrally with the balloon inflation lumen230and is set to open into the drainage lumen220if the maximum urethra pressure is exceeded in the balloon110or the balloon inflation lumen230. A further alternative includes opening both into the environment and into the drainage lumen220. Because this safety valve212is located near or at the balloon inflation port260in this configuration, fluid used to inflate the balloon will not enter the patient when the valve212opens.

The safety valve212in the second embodiment can merely be a narrowing of the distance between the balloon inflation lumen230and the outer surface250of the catheter220. InFIG. 3, the valve212has a rectangular cross-section and extends away from the balloon inflation lumen230. As shown inFIGS. 4,5, and6, respectively, the cross-section can be triangular (peaked or pyramidical in three-dimensions), curved (circular or cylindrical in three-dimensions), or trapezoidal (frusto-conical or bar-shaped in three-dimensions). The cross-sections are shown inFIGS. 3 to 7with the narrowing emanating from the balloon inflation lumen230outward. As an alternative, the narrowing can begin on the outer surface of the catheter and extend inwards towards the balloon inflation lumen230. A further alternative can have the narrowing extend from both the inner lumen230and the outer surface of the catheter.

The cross-sections illustrated are merely exemplary. What is important is that the thickness t between the bottom213of the valve212and the outer surface250of the catheter220in comparison to the thickness T of the catheter body over the remainder of the balloon inflation lumen230. An enlarged view of this thickness comparison is illustrated inFIG. 7. As long as the thickness t is smaller than the thickness T (t<T), and as long as the force Fbrequired to break the balloon is greater than the force Fsvrequired to break the portion213of the safety valve212(Fb>Fsv), then the portion213of the safety valve212is virtually guaranteed to break every time pressure exerting a force F in the balloon inflation lumen230is greater than the force Fsvrequired to break the safety valve (Fsv>F).

Based upon this analysis, the force Fsvrequired to break the safety valve can be tuned to whatever a patient needs or a physician desires and different sized valves can be available for any procedure and provided in the form of a kit. Whether a standard maximum urethra pressure is used or a patient-specific maximum urethra pressure is measured and used, experiments can be conducted prior to use on a patient on various catheter thicknesses t to determine the pressure needed to break the portion213of the safety valve212. For example, ten different maximum urethra pressures can be known as desirable set points and the thicknesses t can be varied such that pressure required to break the ten thicknesses correspond to the ten set point pressures. If, then, ten catheters are placed in such a kit, each having one of the ten thicknesses, then the physician has a range of 10 maximum urethra pressure values to use with the patient.

AlthoughFIGS. 3 to 7show indentations into the wall of the catheter, the indentation can be in the form of a through-hole entirely through the wall of the catheter communicating with the outside of the catheter over which is placed a sleeve. Depending upon the pressure in the inflation lumen, fluid can leak through the hole and lift up the sleeve and leak to atmosphere therefrom. Pressure is controlled in this embodiment by the modulus of the sleeve material. A harder sleeve that fits snugly on the catheter will not allow leakage at low pressure. Alternatively, a softer rubbery sleeve would lift up easily to release high pressure fluid.

The safety valve212of the second embodiment need not be confined to the body of the catheter200. Instead, the inflating connector260can, itself, be equipped with the pressure relief valve212. Alternatively, a non-illustrated modular attachment containing the safety valve212can be attached to the inflating connector260. Such a modular valve attachment is removable and replaceable (such as through a conventional luer or even a screw-threaded connection). Accordingly, as long as the catheter200can still be used after the valve212actuates (breaks), the used modular valve attachment can be replaced with a new attachment. The converse is also true for reuse of the attachment if the catheter200breaks and the valve of the attachment remains unbroken. A downstream end of the modular valve attachment (e.g., shaped as part of a luer connector) is attached removably to an upstream end of the inflating connector260and the upstream end of the modular valve attachment is to be connected to the balloon inflation device, which is commonly a syringe. The upstream end of the modular valve attachment is, likewise, part of a luer connector for easy connection to standard medical devices. In such a configuration, the safety valve212,312of the present invention can be entirely separate from the catheter200,300and, therefore, form a retrofitting device for attachment to any luer connector part present on conventional catheters.

As an alternative to the one-use breaking safety valve of the second embodiment, a multi-use pressure valve can be used. This third embodiment of the pressure-limiting balloon catheter300is illustrated inFIG. 8. The catheter300can be the same as the catheter200inFIG. 3except for the portion illustrated inFIG. 8. Instead of having a narrowing thickness t of the lumen wall, the valve portion313extends entirely to the environment (and/or into the drainage lumen220). However, a one-way valve314(shown only diagrammatically inFIG. 8) is attached to the open end of the valve portion313and is secured to the outer surface250of the catheter300to close off the open end of the valve portion313. The one-way valve314can be secured directly to the outer surface250(e.g., with an adhesive), or a connector315(e.g., a threaded cap) can secure the one-way valve314to the open end of the valve portion313. Regardless of the configuration, the one-way valve314includes a device that does not permit fluid from exiting the lumen230until a given resistance R is overcome. This given resistance R can be selectable by the physician depending upon the one-way valve that is chosen for use if a set of one-way valves having different resistances R are available for use by the physician. Just like the second embodiment, the resistance R can be set to correspond to desired maximum urethra pressure values. Therefore, when used, the fluid exits the one-way valve314into the environment well before the patient's maximum urethra pressure is exceeded by the balloon.

The one-way valve314can be a mechanical one-way valve. Additionally, the one-way valve314can be a material having a tear strength corresponding to a desired set of resistances R. The material can be a fluid-tight fabric, a rubber, a plastic, or silicone different from the material making up the catheter. The material can even be a rubber, plastic, or silicone the same as the material making up the catheter but having a reduced thickness t than the thickness T of the catheter. Alternatively, the one-way valve314can be a slit valve. Various exemplary embodiments of such a valve can be found in U.S. Pat. No. 4,995,863 to Nichols et al., which is hereby incorporated herein by reference in its entirety.

It can also be appreciated that the pressure release (or relief) valve can be a conventional pressure release valve comprised of a housing with a lumen, a ball, and a spring within the lumen wherein the spring presses the ball against a defined opening. When pressure on the ball exceeds the force of the spring, the ball moves away from the defined opening and fluid moves around the ball and vents to atmosphere. By controlling tension on the spring, the pressure at which the valve releases pressure can be controlled. It can also be appreciated that the pressure release valve can be coupled to a Luer connector, which can be coupled to a one-way check valve that can be used to inflate the balloon as is often used in conventional urinary drainage catheters.

Because the safety valve212,312is located at the proximal end of the catheter200,300, the distal end of the catheter200,300can take the form of a distal end of a conventional balloon catheter2,3,4,5. Alternatively, the distal end shown inFIG. 2can also be used for redundant over-pressure protection.

In another exemplary embodiment of the present invention,FIGS. 9 to 18illustrate alternatives to the elastomeric balloon described above. In particular, the above elastomeric balloon is replaced by a thin walled, pre-formed, fixed diameter balloon1010that inflates with virtually no pressure and withstands pressures between approximately 0.2 atmospheres (2.9 psi) and 0.5 atmospheres (7.35 psi), the latter of which is approximately equal to the maximum urethra pressure, without an appreciable increase in diameter. Examples of such balloon materials and thicknesses are used in the medical field already, such as those used in angioplasty. Other exemplary materials can be those used in commercial (party) balloons, for example, MYLAR®, or similar materials such as nylon, PTA, PTFE, polyethylene and polyurethane, for example. InFIGS. 9 and 13, the balloon1010is shown in a spherical shape. However, the balloon1010can be, for example, cylindrical with flat or conically tapering ends.

The inflation balloon1010can be formed by heating a tubular material within a mold or by heat-sealing thin sheets to one another (e.g., party balloons have two sheets). One example of the relatively non-compliant, thin-walled balloon1010of the present invention is formed using a blow-molding process. In the blow-molding process, a thermoplastic material such as nylon, polyurethane, or polycarbonate is extruded or formed into a hollow, tube-like shape (parison) and is subsequently heated and pressurized, usually with air, inside a hollow mold having a shape to form the final outer dimensions of the balloon. An example of the blow molded product is the common plastic soda or water bottle containers.

One exemplary, but not limiting, process to form the zero-pressure balloon of the present invention is described with respect toFIG. 11and includes, in Step1110, cutting a relatively short piece of “parison” tubing that is formed using standard “air-mandrel” extrusion techniques. In Step1120, one end of the tubing is sealed. The center portion of the tubing is placed in a hollow mold, leaving both ends extending outside of the mold in Step1130. The center of the tubing is heated in Step1140with a hot stream of air through a small hole in the center of the mold for a few seconds to soften the tubing walls within the mold. The inside of the tubing is pressurized with a fluid, e.g., air, in Step1150to stretch the tubing walls to conform to the inside dimensions of the mold. After a short cooling period, an additional stretch of the formed balloon is done in Step1160by pulling on the (external) parison and, after a second “blowing” in the same mold in Step1170, is used to create a very thin-walled balloon (much less than 0.001 inches, typically, based upon the parison wall thickness and the final balloon diameter). The extra (unblown) parison tubing is then cut off from both ends in Step1180, leaving the thin walled, relatively supple balloon and its “legs” to be mounted to the catheter as described below.

This exemplary process can be used to create thin, non-compliant balloons for “angioplasty” of blood vessels at pressures exceeding 12 atmospheres of pressure, for example. Although these pressures are not necessary in the present application, it is witness to the fact that very strong thin-walled balloons can result from the above manufacturing process.

The present invention's thin, non-compliant zero-pressure balloon can be attached to the drainage catheter in a number of ways. In a first exemplary attachment embodiment, reference is made to the process ofFIG. 12, the slit valve ofFIG. 13, and the removable balloon ofFIG. 16.

In an exemplary embodiment, each of the distal and proximal legs of the balloon1010manufactured according to the process ofFIG. 12is attached to the distal end of the drainage catheter using standard (e.g., FDA-approved) cements or by heat fusing the two pieces together. The non-compliant, thin-walled balloon is dimensioned to envelop the “slit valves” shown, for example, inFIG. 13, as an exemplary configuration of the invention. The balloon's thin walls allow folding of the balloon without a significant increase in the catheter outer diameter for ease in catheter insertion.

Exemplary embodiments of the internal balloon valve1012according to the invention are illustrated inFIGS. 13,14, and15. This internal balloon valve1012is formed by cutting the wall of the drainage lumen1120at the portion of the catheter within the balloon1010. The slit can be a single cut or a plurality of cuts. Some exemplary slit valves other than those shown are described in U.S. Pat. No. 4,995,863 to Nichols et al., all of which can be utilized for the present invention. The slit-opening pressure, therefore, can be regulated by adjusting the number, length and spacing of the slit(s) and the thickness of the drainage lumen wall1122. For example, the length and orientation of the slit(s)1012determines the pressure at which it/they will open and drain the balloon inflation lumen1130. In one particular embodiment shown inFIG. 15, the slits1124are cut through the elastomeric walls in a way that results in a wedge-shaped cross-section. With this wedge shape, fluid within the balloon can drain under pressure easily. The wedge can be increasing or decreasing. With the former, the edges are chamfered towards one another from the central axis of the balloon toward the exterior thereof (e.g., illustrated inFIG. 15) and, with the latter, the edges are chamfered towards one another from the exterior of the balloon toward the central axis.

In another exemplary embodiment, a non-illustrated, thin-walled slitted sleeve can be disposed over the portion of the drainage catheter wall1122within the balloon1010and covering a throughbore fluidically connecting the interior of the balloon1010to the interior of the drainage lumen1120. As such, pressure within the balloon1010will open the slit(s) of the sleeve, thereby fluidically connecting the balloon1010interior with the drainage lumen1120to transfer fluid in the balloon1010to the drainage lumen1120. Each of these exemplary balloon configurations entirely prevents damage caused by improper inflation or premature removal.

Alternatively, the balloon wall itself could be modified to burst at a particular pressure to release the inflation media. This weakened section could be created by mechanical, chemical, or thermal treatment for example. Mechanical measures may be accomplished by scratching the surface and, thus, thinning the balloon wall in a particular section to cause it to burst at a pre-determined pressure or actually slicing or punching a hole in the wall and covering the area with a thinner, weaker film of material which will tear at a predetermined pressure lower than the rest of the balloon. Likewise, a chemical solvent could be applied to create the same effect as the mechanical device above by making chemical changes to the plastic molecular structure of the balloon wall and, thereby, weakening a desired section of the balloon wall. Weakening a section of the wall by heat to thereby re-orient its molecular structure (much like softening by annealing) is also possible. Therefore, the preferential tearing of the balloon wall at a predetermined internal pressure can be effected in a number of ways as exemplified by, but not limited to, the methods described above.

A second exemplary, but not limiting, process to attach the zero-pressure balloon of the present invention to the safety catheter1600of the present invention, which can be used with or without the slit valves, is described with respect toFIGS. 12 and 16and includes, in Step1210, assembling a first proximal leg1620of the balloon1610over the distal end of the drainage catheter shaft1630in an “inverted” direction (open end toward the balloon interior as shown inFIG. 16). This inverted connection is accomplished with a mechanical release that can be formed, for example, merely by using the shape of the proximal leg1620of the balloon1610or by using a separate compression device, such as an elastic band, or by using adhesives that removably connect the proximal leg1620to the drainage catheter shaft1630. In a compression only example, the proximal balloon seal is, thereby, formed by the force of the “inverted” relatively non-compliant proximal leg1620being extended over and around the distal end of the flexible drainage catheter shaft1630by, for example, stretching the material of the drainage catheter shaft1630(e.g., silicone) to reduce its outer diameter. The other, distal leg1640of the balloon1610can, then, be attached in Step1220using cements (as in the first example above) or by heat fusion. It is noted that, while attachment is shown and described in an inverted orientation for the proximal leg1620and in a non-inverted orientation for the distal leg1640, these are not the only possible orientations for each and can be assembled in any combination of inverted and non-inverted orientations. For example, the distal leg1640can, as the proximal leg1620, be attached in an inverted direction not illustrated inFIG. 16.

To further aid in balloon assembly and catheter deflation and insertion, the outer diameter of the catheter1600under the balloon1610, as well as the inner diameter of the distal balloon leg1640, can be reduced as compared with the outer diameter of the drainage catheter shaft1630, which configuration is shown inFIGS. 16 to 19. The reduced-diameter portion of the catheter1600is referred herein as the distal tip portion1650and extends from the distal end of the drainage catheter shaft1630at least to the distal end of the distal balloon leg1640. As shown, the distal tip5(distal of the balloon1610) also can have the same reduced diameter (or can be reduced further or increased larger as desired). Thus, if the outer diameter of the distal tip portion1650is reduced immediately distal of the proximal balloon seal1620, any predetermined pull force will stretch the catheter shaft1630, thereby reducing the outer diameter of the catheter shaft1630at the proximal balloon seal and allowing the proximal balloon leg1620to slide or peel distally and deflate the balloon quickly, at which time all fluid is released therefrom into the bladder or urethra, for example. It is envisioned that the proximal balloon leg1620can be mounted with the balloon leg1620in a non-inverted or “straight” position if desired with similar results. However, in such a configuration, sliding of the proximal leg1620over the distal end of the catheter shaft1630may be more resistant to a pulling force on the exposed proximal end of the catheter shaft1630but the slight incursion of the balloon-filling fluid can be used to lubricate this connection and, therefore, the resistance to pulling decreases.

With a zero-pressure configuration as described and referred to herein, the balloon1010,1610is under zero-pressure or low pressure. Thus, the inflation device (e.g., a syringe) need not be configured to deliver pressure much above the low pressure range described above. Mere presence of the filling liquid in the balloon, makes the balloon large enough to resist and prevent movement of the balloon into the urethra and out of the bladder without having an internal, high pressure. As such, when inserted improperly in the urethra, the balloon will simply not inflate because there is no physical space for the balloon to expand and because the inflation pressure remains beneath the urethral damaging pressure threshold. If the inflation device is configured for low pressure, even maximum delivered pressure to the balloon will be insufficient to inflate the balloon within the urethra, thereby preventing any possibility of balloon inflation inside the urethra.

In the other case where the balloon is inflated properly within the bladder but the catheter is improperly removed out from the patient without deflating the balloon, safety devices of the invention prevent tearing of the urethra upon exit. Any combination of the internal balloon valve1012(e.g., the slit valve ofFIG. 13formed through the wall of a portion of the drainage lumen1120located inside the balloon1010,1610) and the removable proximal balloon seal1620can be used; one or both can be employed to provide the safety features of the invention. In operation, when a predetermined inflation pressure is reached, the internal balloon valve1012opens and any fluid in the balloon1010,1610is emptied through the drainage lumen1120into the bladder (distal) and/or the external drain bag (proximal), the latter of which is not illustrated. As set forth above, the point at which pressure causes the internal balloon valve1012to open is defined to be less than the pressure needed to damage the urethra when a fully inflated prior-art balloon catheter is improperly removed as described herein. In a low-pressure state, in which the balloon1010,1610is filled with a fluid (either liquid or gas), there is not enough pressure to force open the internal balloon valve1012and permit exit of the fluid out from the balloon1010,1610. In a higher-pressure state (below urethra damage pressure), in contrast, pressure exerted on the fluid is sufficient to open the internal balloon valve1012, thus permitting the fluid to quickly drain out of the balloon1010,1610and into the drainage lumen1120.

In a situation where the balloon1010,1610is in the urethra and inflation is attempted, pressure exerted by the surrounding urethral wall on the inflating balloon1010,1610will cause the internal balloon valve1012to open up well before the balloon1010,1610could inflate. Thus, the balloon inflation fluid will, instead of filling the balloon1010,1610, exit directly into the drainage lumen1120. In an alternative embodiment, the fluid used can be colored to contrast with urine (or any other fluid that is envisioned to pass through the drainage lumen). Thus, if the balloon1010,1610is inserted only into the urethra and inflation is attempted, the inflating fluid will immediately exit into the drainage lumen and enter the exterior (non-illustrated) drain bag. Thus, within a few seconds, the technician will know if the balloon1010,1610did not enter the bladder and inflate therein properly by seeing the colored inflation fluid in the drain bag. In such a situation, the technician needs to only insert the catheter further into the urethra and attempt inflation again. The absence of further colored inflation fluid in the drain bag indicates that correct balloon inflation occurred.

In the other situation where the balloon1010,1610is inflated within the bladder and the catheter100is pulled out from the bladder without deflating the balloon1010,1610, pressure exerted by the urethrovesical junction11upon the inflated balloon1010,1610will cause the valve1012to open up quickly and cause fluid flow into the drainage lumen1120before injury occurs to the junction11or the urethra. If, in such a situation, the catheter is also equipped with the removable balloon end (e.g., proximal end1620), then, as the removable balloon end is peeling off, the slit valve opens up to relieve pressure either before or at the same time the peeling off occurs. This allows the inflation fluid to exit even faster than if just the valve1012is present.

FIGS. 16 to 18illustrate an exemplary embodiment of the inventive catheter1600with the everting removable balloon1610. These figures illustrate the situation where the balloon1610is inflated within the bladder and, as indicated by the pull arrow, the catheter1600is pulled out from the bladder without deflating the balloon1610. Here, the distal seal1640of the balloon1610is fixed to the distal tip portion1650of the catheter1600, which tip5has a reduced outer diameter as compared to the drainage catheter shaft1630, and the proximal seal1620is removably attached (e.g., with a compression seal) to the drainage catheter shaft1630. The pulling force causes the drainage catheter shaft1630to move in the proximal direction out of the urethra and, thereby, compress the proximal side of the inflated balloon1610against the urethrovesical junction11. As the catheter shaft1630moves proximally, the force on the proximal seal1620increases until the seal1620breaks free of the catheter shaft1630, referred to herein as the breakaway point.FIG. 17illustrates the now partially inflated balloon1610just after the breakaway point. Because the diameter of the distal tip portion1650is reduced in comparison to the distal end of the catheter shaft1630, a gap opens up between the inner diameter of the proximal seal portion of the balloon1610and the outer diameter of the distal tip portion1650. This gap allows the inflating fluid to exit the balloon1610quickly into one or both of the urethra and the bladder before injury occurs to the junction11or to the urethra. As the central portion of the balloon1610is still larger than the urethral opening of the junction11, the friction and force imparted on the balloon1610causes the balloon1610to roll over itself, i.e., evert, until it is entirely everted as shown inFIG. 18. At this time, all of the inflating fluid is either in the urethra and/or in the bladder.

In an exemplary embodiment of the removable proximal balloon seal1620, a pulling force in a range of 1 to 15 pounds will cause the proximal balloon seal1620to pull free and allow eversion of the balloon1610, i.e., the breakaway point. In another exemplary embodiment, the range of force required to meet the breakaway point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds.

With regard to additional exemplary embodiments of self-deflating or automatically deflating balloon catheters according to the invention,FIGS. 19 and 20are provided to illustrate the construction and processes for manufacturing prior art urinary catheters, also referred to as Foley catheters. Although prior art urinary catheters are used herein to assist in the understanding of the exemplary embodiments of urinary balloon catheters according to the invention, neither are used herein to imply that the invention is solely applicable to urinary-type catheters. Instead, the technology described herein can be applied to any balloon catheter.

FIG. 19shows the balloon portion of the prior art catheter1900with the balloon in its uninflated state. An annular inner lumen wall1910(red) defines therein a drainage lumen1912. At one circumferential longitudinal extent about the inner lumen wall1910, an inflation lumen wall1920(orange) defines an inflation lumen1922and a balloon inflation port1924fluidically connected to the inflation lumen1922; in standard urinary catheters, there is only one inflation lumen1922and one inflation port1924. The views ofFIGS. 19 and 20show a cross-section through the inflation lumen1922and inflation port1924. If the inflation lumen1922extended all of the way through the catheter1900to its distal end (to the left ofFIGS. 19 and 20), then the balloon could not inflate as all inflation liquid would exit the distal end. Therefore, in order to allow inflation of the balloon, a lumen plug1926(black) closes the inflation lumen1922distal of the inflation port1924. In this exemplary illustration, the lumen plug1926starts at a position distal of the inflation port1924at the inflation lumen1922.

About the inner lumen and inflation lumen walls1910,1920around the inflation port1924is a tube of material that forms the balloon interior wall1930(green). The tube forming the balloon interior wall1930is fluid-tightly sealed against the respective inner walls1910,1920only at the proximal and distal ends of the tube. Accordingly, a pocket is formed therebetween. An outer wall1940(yellow) covers all of the walls1910,1920,1926,1930and does so in what has referred to herein as a fluid-tight manner, meaning that any fluid used to blow up the balloon through the inflation lumen1922and the inflation port1924will not exit the catheter1900through the fluid-tight connection.FIG. 20illustrates the fluid inflating the balloon (indicated with dashed arrows). Because at least the balloon interior wall1930and the outer wall1940are elastomeric, pressure exerted by the inflating fluid2000against these walls will cause them to balloon outwards as, for example, shown inFIG. 20. When the non-illustrated proximal end of the catheter1900is sealed with the fluid2000therein (e.g., with at least a part of a luer connector as shown inFIG. 3), the catheter1900will remain in the shape shown inFIG. 20.

As set forth above, the balloon2010of a urinary catheter should be inflated only when in the bladder2020.FIG. 20shows the catheter1900correctly inflated in the bladder2020and then, if needed, pulled proximally so that the inflated balloon2010rests against and substantially seals off the urethra2030from the interior of the bladder2020. “Substantially,” as used in this regard means that most or all of the urine in the bladder2020will drain through the drain lumen1912and will not pass around the inflated balloon2010more than is typical and/or required for correctly implanted urinary catheters. It is known that an insubstantial amount of urine will pass the balloon2010and, advantageously, lubricate the urethra2030but will not leak out the end of the urethra as muscles in the various anatomy of males and females will seal the end with sufficient force to prevent significant leakage.

Even though each of the walls is shown in different colors herein, the different colors do not imply that the respective walls must be made of different materials. These colors are used merely for clarity purposes to show the individual parts of the prior art and inventive catheters described herein. As will be described in further detail below, most of the different colored walls actually are, in standard urinary catheters, made of the same material. Some of the biocompatible materials used for standard Foley catheters include latex (natural or synthetic), silicone rubber, and thermoplastic elastomers (TPEs) including styrenic block copolymers, polyolefin blends, elastomeric alloys (TPE-v or TPV), thermoplastic polyurethanes, thermoplastic copolyester, and thermoplastic polyamides.

One exemplary process for creating the prior art urinary catheters starts with a dual lumen extrusion of latex. The dual lumen, therefore, already includes both the drainage lumen1912and the inflation lumen1922. Both lumen1912,1922, however, are extruded without obstruction and without radial ports. Therefore, in order to have the inflation port1924, a radial hole is created from the outside surface inwards to the inflation lumen. Sealing off of the distal end of the inflation lumen1922is performed in a subsequent step. The tube making up the inner balloon wall1930is slid over the distal end of the multi-lumen extrusion1910,1920to cover the inflation port and is fluid-tightly sealed to the inner multi-lumen extrusion at both ends of the tube but not in the intermediate portion. This tube can be made of latex as well and, therefore, can be secured to the latex multi-lumen extrusion in any known way to bond latex in a fluid-tight manner. At this point, the entire sub-assembly is dipped into latex in its liquid form to create the outer wall1940. The latex is allowed to enter at least a portion of the distal end of the inflation lumen1922but not so far as to block the inflation port1924. When the latex cures, the balloon2010is fluid tight and can only be fluidically connected to the environment through the non-illustrated, proximal-most opening of the inflation port, which is fluidically connected to the inflation lumen1922. In this process, the inner wall1910, the inflation lumen wall1920, the plug1926, the balloon inner wall1930, and the outer wall1940are all made of the same latex material and, therefore, together, form a very securely water-tight balloon2010.

As set forth above, all prior art balloon catheters are designed to deflate only when actively deflated, either by a syringe similar to the one that inflated it or by surgery after the physician diagnoses the balloon as not being able to deflate, in which circumstance, a procedure to pop the balloon surgically is required.

Described above are various embodiments of self-deflating or automatically deflating catheters according to the invention.FIGS. 21 to 33illustrate automatically deflating, stretch-valve balloon catheters in still other exemplary embodiments of the present invention.FIGS. 21 to 23show a first exemplary embodiment of a stretch-valve balloon catheter2100according to the invention,FIG. 21illustrating the balloon portion of the inventive catheter2100with the balloon in its uninflated state. An annular inner lumen wall2110(red) defines therein a drainage lumen2112. At one or more circumferential longitudinal extents about the inner lumen wall2110, an inflation lumen wall2120(orange) defines an inflation lumen2122and a balloon inflation port2124fluidically connected to the inflation lumen2122; in the inventive catheter, there can be more than one inflation lumen2122and corresponding inflation port2124even though only one is shown herein. Accordingly, the views ofFIGS. 21 to 23show a cross-section through the single inflation lumen2122and single inflation port2124. A lumen plug2126(black) closes the inflation lumen2122distal of the inflation port2124. In this exemplary illustration, the lumen plug2126starts at a position distal of the inflation port2124at the inflation lumen2122. This configuration is only exemplary and can start at the inflation port2124or anywhere distal thereof.

About the inner lumen and inflation lumen walls2110,2120around the inflation port2124is a tube of material that forms the balloon interior wall2130(green). The tube of the balloon interior wall2130is fluid-tightly sealed against the respective inner walls2110,2120only at the proximal and distal ends of the tube. Accordingly, a pocket is formed therebetween. An outer wall2140(yellow) covers all of the walls2110,2120,2126,2130in a fluid-tight manner.FIG. 21illustrates the fluid about to inflate the balloon (indicated with dashed arrows). Because at least the balloon interior wall2130and the outer wall2140are elastomeric, pressure exerted by the inflating fluid2200against these walls will cause them to balloon outwards as, for example, shown inFIG. 22. When the non-illustrated proximal end of the catheter2100is sealed with the fluid2200therein (e.g., with at least a part of a luer connector as shown inFIG. 3), the catheter2100will remain in the shape shown inFIG. 22.

FIG. 22shows the catheter2100correctly inflated in the bladder2020and then, if needed, pulled proximally so that the inflated balloon2210rests against and substantially seals off the urethra2030from the interior of the bladder2020.

The stretch-valve of the exemplary embodiment ofFIGS. 21 to 23has three different aspects. The first is a hollow, stretch-valve tube2220that is disposed in the inflation lumen2122to not hinder inflation of the balloon2210with the fluid2200. While the diameter of the stretch-valve tube2220can be any size that accommodates unhindered fluid flow through the inflation lumen2122, one exemplary inner diameter of the stretch-valve tube2220is substantially equal to the diameter of the inflation lumen2122and the outer diameter of the stretch-valve tube2220is just slightly larger than the diameter of the inflation lumen2122(e.g., the wall thickness of the tube can be between 0.05 mm and 0.2 mm). The proximal end of the stretch-valve tube2220in this exemplary embodiment is proximal of a proximal end of the balloon inner wall2130. The distal end of the stretch-valve tube2220is somewhere near the proximal end of the balloon inner wall2130; the distal end can be proximal, at, or distal to the proximal end of the balloon inner wall2130and selection of this position is dependent upon the amount of stretch S required to actuate the stretch-valve of the inventive catheter2100as described below. InFIG. 22, the distal end of the stretch-valve tube2220is shown at the proximal end of the balloon inner wall2130. Two ports are formed proximal of the balloon2210. A proximal port (purple)2150is formed through the outer wall2140and through the inflation lumen wall2020overlapping at least a portion of the proximal end of the stretch-valve tube2220. In this manner, a portion of the outer surface of the proximal end of the stretch-valve tube2220at the proximal port2150is exposed to the environment but there is no fluid communication with the inflation lumen2122and the proximal port2150. A distal port (white)2160is formed through the outer wall2140and through the inflation lumen wall2020overlapping at least a portion of the distal end of the stretch-valve tube2220. In this manner, a portion of the outer surface of the distal end of the stretch-valve tube2220at the distal port2160is exposed to the environment but there is no fluid communication from the inflation lumen2122to the distal port2160. To secure the stretch-valve tube2220in the catheter2100, the proximal port2150is filled with a material that fixes the proximal end of the stretch-valve tube2220to at least one of the outer wall2140and the inflation lumen wall2020. In one exemplary embodiment, an adhesive bonds the proximal end of the stretch-valve tube2220to both the outer wall2140and the inflation lumen wall2120.

In such a configuration, therefore, any proximal movement of the catheter2100at or proximal of the proximal port2150will also move the stretch-valve tube2220proximally; in other words, the distal end of the stretch-valve tube2220can slide S within the inflation lumen2122in a proximal direction.FIG. 23illustrates how the slide-valve of the invention operates when the proximal end of the catheter2100is pulled with a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter2100was still inflated when the force was imparted. In an exemplary embodiment of the stretch valve ofFIGS. 21 to 23, a pulling force in a range of 1 to 15 pounds will cause the stretch-valve tube2220to slide proximally S to place the distal end of the stretch-valve tube2220just proximal of the distal port2160, i.e., the deflation point of the stretch-valve shown inFIG. 23. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds.

As can be seen inFIG. 23, when the deflation point of the stretch-valve is reached, the interior of the balloon2210becomes fluidically connected to the distal port2160. Because the distal port2160is open to the environment (e.g., the interior of the bladder2020) and due to the fact that the bladder is relatively unpressurized as compared to the balloon2210, all internal pressure is released from the balloon2210to eject the inflating fluid2200into the bladder2020(depicted by dashed arrows), thereby causing the balloon2210to deflate rapidly (depicted by solid opposing arrows). It is noted that the distance X (seeFIG. 22) between the inflation port2124and the distal port2160directly impacts the rate at which the balloon2120deflates. As such, reducing this distance X will increase the speed at which the balloon2210deflates. Also, the cross-sectional areas of the inflation port2124, the inflation lumen2122, and the distal port2160directly impact the rate at which the balloon2220deflates. Further, any changes in direction of the fluid can hinder the rate at which the balloon deflates. One way to speed up deflation can be to shape the distal port2160in the form of a non-illustrated funnel outwardly expanding from the inflation lumen2122. Another way to speed up deflation is to have two or more inflation lumens2122about the circumference of the inner lumen wall2110and to have corresponding sets of a stretch-valve tube2220, a proximal port2150, and a distal port2160for each inflation lumen2122.

Still another possibility for rapidly deflating an inflated balloon is to drain the fluid2200into the drain lumen2112instead of the bladder. This exemplary embodiment is illustrated inFIGS. 24 to 26.FIG. 24illustrates the balloon portion of the inventive catheter2400with the balloon in its uninflated state. An annular inner lumen wall2410(red) defines therein a drainage lumen2412. At one or more circumferential longitudinal extents about the inner lumen wall2410, an inflation lumen wall2420(orange) defines an inflation lumen2422and a balloon inflation port2424fluidically connected to the inflation lumen2422; in the inventive catheter, there can be more than one inflation lumen2422and corresponding inflation port2424even though only one is shown herein. Accordingly, the views ofFIGS. 24 to 26show a cross-section through the single inflation lumen2422and single inflation port2424. A lumen plug2426(black) closes the inflation lumen2422distal of the inflation port2424. In this exemplary illustration, the lumen plug2426starts at a position distal of the inflation port2424at the inflation lumen2422. This configuration is only exemplary and can start at the inflation port2424or anywhere distal thereof.

About the inner lumen and inflation lumen walls2410,2420around the inflation port2424is a tube of material that forms the balloon interior wall2430(green). The tube of the balloon interior wall2430is fluid-tightly sealed against the respective inner walls2410,2420only at the proximal and distal ends of the tube. Accordingly, a pocket is formed therebetween. An outer wall2440(yellow) covers all of the walls2410,2420,2426,2430in a fluid-tight manner.FIG. 24illustrates the fluid about to inflate the balloon (indicated with dashed arrows). Because at least the balloon interior wall2430and the outer wall2440are elastomeric, pressure exerted by the inflating fluid2200against these walls will cause them to balloon outwards as, for example, shown inFIG. 25. When the non-illustrated proximal end of the catheter2400is sealed with the fluid2200therein (e.g., with at least a part of a luer connector as shown inFIG. 3), the catheter2400will remain in the shape shown inFIG. 25.

FIG. 25shows the catheter2400correctly inflated in the bladder2020and then, if needed, pulled proximally so that the inflated balloon2510rests against and substantially seals off the urethra2030from the interior of the bladder2020.

The stretch-valve of the exemplary embodiment ofFIGS. 24 to 26has three different aspects. The first is a hollow, stretch-valve tube2520that is disposed in the inflation lumen2422to not hinder inflation of the balloon2510with the fluid2200. While the diameter of the stretch-valve tube2520can be any size that accommodates unhindered fluid flow through the inflation lumen2422, one exemplary inner diameter of the stretch-valve tube2520is substantially equal to the diameter of the inflation lumen2422and the outer diameter of the stretch-valve tube2520is just slightly larger than the diameter of the inflation lumen2122(e.g., the wall thickness of the tube can be between 0.05 mm and 0.2 mm). The proximal end of the stretch-valve tube2520in this exemplary embodiment is disposed proximal of a proximal end of the balloon inner wall2430. The distal end of the stretch-valve tube2520is somewhere near the proximal end of the balloon inner wall2430; the distal end can be proximal, at, or distal to the proximal end of the balloon inner wall2430and selection of this position is dependent upon the amount of stretch S required to actuate the stretch-valve of the inventive catheter2400as described below. In the exemplary embodiment ofFIG. 25, the distal end of the stretch-valve tube2520is shown at proximal end of the balloon inner wall2430. Two ports are formed, one proximal of the balloon2510and one proximal of the inflation port2424. A proximal port (purple)2450is formed through the outer wall2440and through the inflation lumen wall2420to overlap at least a portion of the proximal end of the stretch-valve tube2520. In this manner, a portion of the outer surface of the proximal end of the stretch-valve tube2520at the proximal port2450is exposed to the environment but there is no fluid communication between the inflation lumen2422and the proximal port2450. A distal port (white)2460is formed through the inner lumen wall2410anywhere proximal of the inflation port2424to overlap a least a portion of the distal end of the stretch-valve tube2520. In this manner, a portion of the outer surface of the distal end of the stretch-valve tube2520at the distal port2460is exposed to the drainage lumen2412but there is no fluid communication between the inflation lumen2422and the distal port2460. To secure the stretch-valve tube2520in the catheter2400, the proximal port2450is filled with a material that fixes the proximal end of the stretch-valve tube2520to at least one of the outer wall2440and the inflation lumen wall2420. In one exemplary embodiment, an adhesive bonds the proximal end of the stretch-valve tube2520to both the outer wall2440and the inflation lumen wall2420.

In such a configuration, therefore, any proximal movement of the catheter2400at or proximal to the proximal port2450will also move the stretch-valve tube2520proximally; in other words, the distal end of the stretch-valve tube2520can slide S within the inflation lumen2422in a proximal direction.FIG. 26illustrates how the slide-valve of the invention operates when the proximal end of the catheter2400is pulled to a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter2400was still inflated when the force was imparted. In an exemplary embodiment of the stretch valve ofFIGS. 24 to 26, a pulling force in a range of 1 to 15 pounds will cause the stretch-valve tube2520to slide proximally S to place the distal end of the stretch-valve tube2520just proximal of the distal port2460, i.e., the deflation point of the stretch-valve shown inFIG. 26. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds.

As can be seen inFIG. 26, when the deflation point of the stretch-valve is reached, the interior of the balloon2510becomes fluidically connected to the distal port2460. Because the distal port2460is open to the drainage lumen2412(which is open the interior of the bladder2020and the non-illustrated, proximal drainage bag) and due to the fact that the bladder is relatively unpressurized as compared to the balloon2510, all internal pressure is released from the balloon2510to eject the inflating fluid2200into the drainage lumen2412(depicted by dashed arrows), thereby causing the balloon2510to deflate rapidly (depicted by solid opposing arrows). Again, it is noted that the distance X between the inflation port2424and the distal port2460(seeFIG. 25) directly impacts the rate at which the balloon2510deflates. As such, having this distance X be smaller will increase the speed at which the balloon2510deflates. Also, the cross-sectional areas of the inflation port2424, the inflation lumen2422, and the distal port2460directly impact the rate at which the balloon2120deflates. Further, any changes in direction of the fluid can hinder the rate at which the balloon deflates. One way to speed up deflation can be to shape the distal port2460in the form of a funnel outwardly expanding from the inflation lumen2422. Another way to speed up deflation can be to have two or more inflation lumens2422about the circumference of the inner lumen wall2410and to have corresponding sets of a stretch-valve tube2520, a proximal port2450, and a distal port2460for each inflation lumen2422.

Yet another exemplary embodiment that is not illustrated herein is to combine both of the embodiments ofFIGS. 21 to 23and24to26to have the fluid2200drain out from both of the distal ports2160,2460into both the bladder2020and the drain lumen2112, respectively.

Still another possibility for rapidly deflating an inflated balloon is to drain the fluid2200directly into the drain lumen2712in a straight line without any longitudinal travel X. This exemplary embodiment is illustrated inFIGS. 27 to 29.FIG. 27illustrates the balloon portion of the inventive catheter2700with the balloon in its uninflated state. An annular inner lumen wall2710(red) defines therein a drainage lumen2712. At one or more circumferential longitudinal extents about the inner lumen wall2710, an inflation lumen wall2720(orange) defines an inflation lumen2722and a balloon inflation port2724fluidically connected to the inflation lumen2722; in the inventive catheter, there can be more than one inflation lumen2722and corresponding inflation port2724even though only one is shown herein. Accordingly, the views ofFIGS. 27 to 29show a cross-section through the single inflation lumen2722and single inflation port2724. A lumen plug2726(black) closes the inflation lumen2722distal of the inflation port2724. In this exemplary illustration, the lumen plug2726starts at a position distal of the inflation port2724at the inflation lumen2722. This configuration is only exemplary and can start at the inflation port2724or anywhere distal thereof.

About the inner lumen and inflation lumen walls2710,2720around the inflation port2724is a tube of material that forms the balloon interior wall2730(green). The tube of the balloon interior wall2730is fluid-tightly sealed against the respective inner walls2710,2720only at the proximal and distal ends of the tube. Accordingly, a pocket is formed therebetween. An outer wall2740(yellow) covers all of the walls2710,2720,2726,2730in a fluid-tight manner.FIG. 27illustrates the fluid about to inflate the balloon (indicated with dashed arrows). Because at least the balloon interior wall2730and the outer wall2740are elastomeric, pressure exerted by the inflating fluid2200against these walls will cause them to balloon outwards as, for example, shown inFIG. 28. When the non-illustrated proximal end of the catheter2700is sealed with the fluid2200therein (e.g., with at least a part of a luer connector as shown inFIG. 3), the catheter2700will remain in the shape shown inFIG. 28.

FIG. 28shows the catheter2700correctly inflated in the bladder2020and then, if needed, pulled proximally so that the inflated balloon2810rests against and substantially seals off the urethra2030from the interior of the bladder2020.

The stretch-valve of the exemplary embodiment ofFIGS. 27 to 29has three different aspects. The first is a hollow, stretch-valve tube2820that is disposed in the inflation lumen2722to not hinder inflation of the balloon2810with the fluid2200. While the diameter of the stretch-valve tube2820can be any size that accommodates unhindered fluid flow through the inflation lumen2722, one exemplary inner diameter of the stretch-valve tube2820is substantially equal to the diameter of the inflation lumen2722and the outer diameter of the stretch-valve tube2820is just slightly larger than the diameter of the inflation lumen2722(e.g., the wall thickness of the tube can be between 0.05 mm and 0.2 mm). The proximal end of the stretch-valve tube2820in this exemplary embodiment is proximal of a proximal end of the balloon inner wall2730. The distal end of the stretch-valve tube2820is somewhere near the proximal end of the balloon inner wall2730; the distal end can be proximal, at, or distal to the proximal end of the balloon inner wall2730and selection of this position is dependent upon the amount of stretch S required to actuate the stretch-valve of the inventive catheter2700as described below. In the exemplary embodiment ofFIG. 28, the distal end of the stretch-valve tube2820is shown between the inflation port2724and the proximal end of the balloon inner wall2730. Two ports are formed, one proximal of the balloon2810and one between the inflation port2724and the proximal end of the balloon inner wall2730. A proximal port2750is formed through the outer wall2740through the inflation lumen wall2720to overlap at least a portion of the proximal end of the stretch-valve tube2820. In this manner, a portion of the outer surface of the proximal end of the stretch-valve tube2820at the proximal port2750is exposed to the environment but there is no fluid communication between the inflation lumen2722and the proximal port2750. A distal port (white)2760is formed through both inflation lumen wall2720and the inner wall2710distal of the proximal connection of the balloon inner wall2730to overlap a least a portion of the distal end of the stretch-valve tube2820. In this manner, opposing portions of the outer surface of the distal end of the stretch-valve tube2820at the distal port2760are exposed, one exposed to the interior of the balloon2810and one exposed to the drainage lumen2712but there is no fluid communication between either the inflation lumen2722or the drainage lumen2712and the distal port2760. To secure the stretch-valve tube2820in the catheter2700, the proximal port2750is filled with a material that fixes the proximal end of the stretch-valve tube2820to at least one of the outer wall2740and the inflation lumen wall2720. In one exemplary embodiment, an adhesive bonds the proximal end of the stretch-valve tube2820to both the outer wall2740and the inflation lumen wall2720. In the exemplary embodiment, the adhesive can be the same material as any or all of the walls2710,2720,2730,2740or it can be a different material. If the outer wall2740is formed by a dipping of the interior parts into a liquid bath of the same material as, for example, a dual lumen extrusion including the inner wall2710and the inflation lumen wall2720, then, when set, the outer wall2740will be integral to both the inner wall2710and the inflation lumen wall2720and will be fixedly connected to the stretch-valve tube2820through the proximal port2750.

In such a configuration, therefore, any proximal movement of the catheter2700at or proximal to the proximal port2750will also move the stretch-valve tube2820proximally; in other words, the distal end of the stretch-valve tube2820can slide S within the inflation lumen2722in a proximal direction.FIG. 29illustrates how the slide-valve of the invention operates when the proximal end of the catheter2700is pulled to a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter2700was still inflated when the force was imparted. In an exemplary embodiment of the stretch valve ofFIGS. 27 to 29, a pulling force in a range of 1 to 15 pounds will cause the stretch-valve tube2820to slide proximally S to place the distal end of the stretch-valve tube2820just proximal of the distal port2760, i.e., the deflation point of the stretch-valve shown inFIG. 29. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds.

As can be seen inFIG. 29, when the deflation point of the stretch-valve is reached, the interior of the balloon2810becomes fluidically connected to both the upper and lower portions of the distal port2760in a direct and straight line. Because the distal port2760is open to the drainage lumen2712(which is open the interior of the bladder2020and to the non-illustrated, proximal drain bag) and due to the fact that the bladder is relatively unpressurized as compared to the balloon2810, all internal pressure is released from the balloon2810to eject the inflating fluid2200into the drainage lumen2712(depicted by dashed arrows), thereby causing the balloon2810to deflate rapidly (depicted by solid opposing arrows). Unlike the embodiments above, the distance X between the deflation port (the upper part of distal port2760) and the lower part of distal port2760is zero—therefore, the rate at which the balloon2510deflates cannot be made any faster (other than expanding the area of the distal port2760). It is further noted that the inflation port2724also becomes fluidically connected to the drain lumen2712and, therefore, drainage of the fluid2200occurs through the inflation port2724as well. The cross-sectional area of the inflation lumen2722, therefore, only slightly impacts the rate of balloon deflation, if at all. One way to speed up deflation can be to shape the distal port2760in the form of a funnel outwardly expanding in a direction from the outer circumference of the catheter2700inwards towards the drainage lumen2712. Another way to speed up deflation can be to have two or more inflation lumens2722about the circumference of the inner lumen wall2710and to have corresponding sets of a stretch-valve tube2820, a proximal port2750, and a distal port2760for each inflation lumen2722.

FIG. 30reproducesFIG. 27to assist in explainingFIGS. 31 and 32on the same page.FIGS. 31 and 32show, respectively, the closed and opened positions of the stretch-valve tube2820inFIGS. 28 and 29. These figures are viewed in an orientation turned ninety degrees counterclockwise with regard to a central, longitudinal axis of the catheter2700viewed along the axis towards the distal end from the proximal end so that the view looks down upon the distal port2760. As can be seen, without pulling on the proximal end of the catheter2700(FIG. 31), the stretch-valve tube2820blocks the distal port2760. With a proximal force on the proximal end of the catheter2700, as shown inFIG. 32, the stretch-valve tube2820slides and no longer blocks the distal port2760.

FIGS. 33 to 36show alternative exemplary embodiments for the automatically deflating, stretch-valve, safety balloon catheter according to the invention. Where various parts of the embodiments are not described with regard to these figures (e.g., the balloon interior wall), the above-mentioned parts are incorporated by reference herein into these embodiments and are not repeated for reasons of brevity.

FIG. 33illustrates the balloon portion of the inventive catheter3300with the balloon3302in a partially inflated state. An annular inner lumen wall3310defines therein a drainage lumen3312. At one or more circumferential longitudinal extents about the inner lumen wall3310, an inflation lumen wall3320defines an inflation lumen3322and a balloon inflation port3324fluidically connected to the inflation lumen3322; in the inventive catheter, there can be more than one inflation lumen3322and corresponding inflation port3324even though only one is shown herein. Accordingly, the views ofFIGS. 33 to 36show a cross-section through the single inflation lumen and single inflation port. No lumen plug closes the inflation lumen3322distal of the inflation port3324as set forth above in alternative embodiments. In this exemplary embodiment, a stretch-valve mechanism3330serves to plug the inflation lumen3322distal of the inflation port3324as described in further detail below. An outer wall3340covers all of the interior walls3310and3320in a fluid-tight manner and forms the exterior of the balloon3342but does not cover the distal end of the inflation lumen3322. The outer wall3340is formed in any way described herein and is not discussed in further detail here.

The stretch-valve mechanism3330is disposed in the inflation lumen3322to not hinder inflation of the balloon3302with inflating fluid. A proximal, hollow anchor portion3332is disposed in the inflation lumen3320proximal of the inflation port3324. While the diameter of the hollow anchor portion3332can be any size that accommodates unhindered fluid flow through the inflation lumen3322, one exemplary inner diameter of the hollow anchor portion3332is substantially equal to the diameter of the inflation lumen3322and the outer diameter of the hollow anchor portion3332is just slightly larger than the diameter of the inflation lumen3322(e.g., the wall thickness of the tube can be between 0.05 mm and 0.2 mm). The longitudinal length of the hollow anchor portion3332is as long as desired to be longitudinally fixedly secured within the inflation lumen3322when installed in place. The tube, from its shape alone, can provide the securing connection but, also, an adhesive can be used in any manner, one of which includes creating a proximal port as shown in the above embodiments and utilizing the dipped exterior to form the fixed connection. The distal end of the hollow anchor portion3332in this exemplary embodiment is proximal of a proximal end of the balloon3302. The distal end of the hollow anchor portion3332can be nearer to the inflation port3324, but not at or distal of the inflation port3324; both ends of the hollow anchor portion3332can be proximal, at, or distal to the proximal end of the balloon3302and selection of this position is dependent upon the amount of stretch that is desired to actuate the stretch-valve of the inventive catheter3300as described below. In the exemplary embodiment ofFIG. 33, the stretch-valve mechanism3330also includes an intermediate stopper wire3334connected at its proximal end to the hollow anchor portion3332and a stopper3336connected to the distal end of the stopper wire3334. The stopper3336is sized to be slidably disposed in the inflation lumen3322while, at the same time, to provide a fluid-tight seal so that liquid cannot pass from one side of the stopper3336to the other side within the inflation lumen3322. The stopper3336is located distal of the inflation port3324. The stopper wire3334, therefore, spans the inflation port3324. Because the stopper3336must traverse the inflation port3324, it must be just distal of the inflation port3324but the hollow anchor portion can be located anywhere proximal of the inflation port3324. While the length of the stopper wire3334needs to be sufficient to span the inflation port3324, it can be as long as desired, which will depend on where the hollow anchor portion3332resides as well as the amount of stretch desired. As the catheter3300stretches more at its proximal end and less at its distal end when pulled from the proximal end, the hollow anchor portion3322can be further proximal in the inflation lumen3322than shown, and can even be very close to or at the proximal end of the inflation lumen3322.

In such a configuration, therefore, any proximal movement of the catheter3300at or proximal to the inflation port3324will also move the stretch-valve mechanism3330proximally; in other words, the stopper3336slides proximally within the inflation lumen3322from distal of the inflation port3324to a proximal side of the inflation port3324. When the proximal end of the catheter3300is pulled to move the stopper3336across the inflation port3324with a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter3300was still inflated when the force was imparted, fluid in the balloon3342can exit distally out the inflation lumen3322. In an exemplary embodiment of the stretch valve ofFIG. 33, a pulling force in a range of 1 to 15 pounds will cause the stretch-valve mechanism3330to slide proximally to place the stopper3336just proximal of the inflation port3324, i.e., the deflation point of the stretch-valve shown inFIG. 33. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds. When the stopper3336traverses the inflation port3324, the balloon3342automatically deflates and the inflating fluid exits into the bladder out the distal end of the inflation lumen3332, which is open at the distal end of the catheter3300.

FIG. 34illustrates the balloon portion of the inventive catheter3400with the balloon3402in a partially inflated state. An annular inner lumen wall3410defines therein a drainage lumen3412. At one or more circumferential longitudinal extents about the inner lumen wall3410, an inflation lumen wall3420defines an inflation lumen3422and a balloon inflation port3424fluidically connected to the inflation lumen3422; in the inventive catheter, there can be more than one inflation lumen3422and corresponding inflation port3424even though only one is shown herein. No lumen plug closes the inflation lumen3422distal of the inflation port3424as set forth above in alternative embodiments. In this exemplary embodiment, a stretch-valve mechanism3430serves to plug the inflation lumen3422distal of the inflation port3424as described in further detail below. An outer wall3440covers all of the interior walls3410and3420in a fluid-tight manner and forms the exterior of the balloon3442but does not cover the distal end of the inflation lumen3422. The outer wall3440is formed in any way described herein and is not discussed in further detail here.

The stretch-valve mechanism3430is disposed in the inflation lumen3422and does not hinder inflation of the balloon3402with inflating fluid. A proximal, hollow anchor portion3432is disposed in the inflation lumen3420proximal of the inflation port3424. While the diameter of the hollow anchor portion3432can be any size that accommodates unhindered fluid flow through the inflation lumen3422, one exemplary inner diameter of the hollow anchor portion3432is substantially equal to the diameter of the inflation lumen3422and the outer diameter of the hollow anchor portion3432is just slightly larger than the diameter of the inflation lumen3422(e.g., the wall thickness of the tube can be between 0.05 mm and 0.2 mm). The longitudinal length of the hollow anchor portion3432is as long as desired to be longitudinally fixedly secured within the inflation lumen3422when installed in place. The tube, from its shape alone, can provide the securing connection but, also, an adhesive can be used in any manner, one of which includes creating a proximal port as shown in the above embodiments and utilizing the dipped exterior to form the fixed connection. The distal end of the hollow anchor portion3432in this exemplary embodiment is at a proximal side of the balloon3402. The distal end of the hollow anchor portion3432can be nearer to the inflation port3424, but not at or distal of the inflation port3424; both ends of the hollow anchor portion3432can be proximal, at, or distal to the proximal end of the balloon3402and selection of this position is dependent upon the amount of stretch that is desired to actuate the stretch-valve of the inventive catheter3400as described below. In the exemplary embodiment ofFIG. 34, the stretch-valve mechanism3430also includes an intermediate hollow stopper tube3434connected at its proximal end to the hollow anchor portion3432and a stopper3436connected to the distal end of the stopper tube3434. The stopper tube3434is only a circumferential portion of the hollow anchor portion3432and is located opposite the inflation port3424so that it does not obstruct fluid flow through the inflation port3424. The stopper, in contrast, is a solid cylinder having the same outer diameter as the hollow anchor portion3432. The entire mechanism3430is sized to be slidably disposed in the inflation lumen3422while, at the same time, to provide a fluid-tight seal at the stopper3436so that liquid cannot pass from one side of the stopper3436to the other side within the inflation lumen3422. The stopper3436is located distal of the inflation port3424. The stopper tube3434, therefore, spans the inflation port3424. Because the stopper3436must traverse the inflation port3424, it must be just distal of the inflation port3424but the hollow anchor portion3432can be located anywhere proximal of the inflation port3424. While the length of the stopper tube3434needs to be sufficient to span the inflation port3424, it can be as long as desired, which will depend on where the hollow anchor portion3432resides. As the catheter3400stretches more at its proximal end and less at its distal end when pulled from the proximal end, the hollow anchor portion3422can be further proximal in the inflation lumen3422than shown, and can even be very close to or at the proximal end of the inflation lumen3422.

In such a configuration, therefore, any proximal movement of the catheter3400at or proximal to the inflation port3424will also move the stretch-valve mechanism3430proximally; in other words, the stopper3436slides proximally within the inflation lumen3422from distal of the inflation port3424to a proximal side of the inflation port3424. When the proximal end of the catheter3400is pulled to move the stopper3436across the inflation port3424with a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter3400was still inflated when the force was imparted, fluid in the balloon3442can exit distally out the inflation lumen3422. In an exemplary embodiment of the stretch valve ofFIG. 34, a pulling force in a range of 1 to 15 pounds will cause the stretch-valve mechanism3430to slide proximally to place the stopper3436just proximal of the inflation port3424, i.e., the deflation point of the stretch-valve shown inFIG. 34. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds. When the stopper3436traverses the inflation port3424, the balloon3442automatically deflates and the inflating fluid exits into the bladder out the distal end of the inflation lumen3432, which is open at the distal end of the catheter3400.

FIG. 35illustrates the balloon portion of the inventive catheter3500with the balloon3502in a partially inflated state. An annular inner lumen wall3510defines therein a drainage lumen3512. At one or more circumferential longitudinal extents about the inner lumen wall3510, an inflation lumen wall3520defines an inflation lumen3522and a balloon inflation port3524fluidically connected to the inflation lumen3522; in the inventive catheter, there can be more than one inflation lumen3522and corresponding inflation port3524even though only one is shown herein. No lumen plug closes the inflation lumen3522distal of the inflation port3524as set forth above in alternative embodiments. In this exemplary embodiment, a stretch-valve mechanism3530serves to plug the inflation lumen3522distal of the inflation port3524as described in further detail below. An outer wall3540covers all of the interior walls3510and3520in a fluid-tight manner and forms the exterior of the balloon3542but does not cover the distal end of the inflation lumen3522. The outer wall3540is formed in any way described herein and is not discussed in further detail here.

The stretch-valve mechanism3530is disposed in the inflation lumen3522to not hinder inflation of the balloon3502with inflating fluid. A proximal, hollow anchor portion3532is disposed in the inflation lumen3520proximal of the inflation port3524. While the diameter of the hollow anchor portion3532can be any size that accommodates unhindered fluid flow through the inflation lumen3522, one exemplary inner diameter of the hollow anchor portion3532is substantially equal to the diameter of the inflation lumen3522and the outer diameter of the hollow anchor portion3532is just slightly larger than the diameter of the inflation lumen3522(e.g., the wall thickness of the tube can be between 0.05 mm and 0.2 mm). The longitudinal length of the hollow anchor portion3532is as long as desired to be longitudinally fixedly secured within the inflation lumen3522when installed in place. The tube, from its shape alone, can provide the securing connection but, also, an adhesive can be used in any manner, one of which includes creating a proximal port as shown in the above embodiments and utilizing the dipped exterior to form the fixed connection. The distal end of the hollow anchor portion3532in this exemplary embodiment is at a proximal side of the balloon3502. The distal end of the stretch-valve mechanism3530can be nearer to the inflation port3524, but not at or distal of the inflation port3524; both ends of the hollow anchor portion3532can be proximal, at, or distal to the proximal end of the balloon3502and selection of this position is dependent upon the amount of stretch that is desired to actuate the stretch-valve of the inventive catheter3500as described below. In the exemplary embodiment ofFIG. 35, the stretch-valve mechanism3530also includes an intermediate bias device3534, such as a spring, connected at its proximal end to the hollow anchor portion3532and a stopper3536connected to the distal end of the bias device3534. The bias device3534is located at the inflation port3524but not to obstruct fluid flow through the inflation port3524. The stopper3536, in contrast, is a solid cylinder having the same outer diameter as the hollow anchor portion3532. The entire mechanism3530is sized to be slidably disposed in the inflation lumen3522while, at the same time, to provide a fluid-tight seal at the stopper3536so that liquid cannot pass from one side of the stopper3536to the other side within the inflation lumen3522. The stopper3536is located distal of the inflation port3524. To prevent distal movement of the stopper3536, a restrictor3538is provided distal of the stopper3536. The bias device3534, therefore, spans the inflation port3524. Because the stopper3536must traverse the inflation port3524, it must be just distal of the inflation port3524but the hollow anchor portion3532can be located anywhere proximal of the inflation port3524. While the length of the bias device3534needs to be sufficient to span the inflation port3524, it can be as long as desired, which will depend on where the hollow anchor portion3532resides. As the catheter3500stretches more at its proximal end and less at its distal end when pulled from the proximal end, the hollow anchor portion3522can be further proximal in the inflation lumen3522than shown, and can even be very close to or at the proximal end of the inflation lumen3522.

In such a configuration, therefore, any proximal movement of the catheter3500at or proximal to the inflation port3524will also move the stretch-valve mechanism3530proximally; in other words, the stopper3536slides proximally within the inflation lumen3522from distal of the inflation port3524to a proximal side of the inflation port3524. When the proximal end of the catheter3500is pulled to move the stopper3536across the inflation port3524with a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter3500was still inflated when the force was imparted, fluid in the balloon3542can exit distally out the inflation lumen3522. In an exemplary embodiment of the stretch valve ofFIG. 35, a pulling force in a range of 1 to 15 pounds will cause the stretch-valve mechanism3530to slide proximally to place the stopper3536just proximal of the inflation port3524, i.e., the deflation point of the stretch-valve shown inFIG. 35. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds. When the stopper3536traverses the inflation port3524, the balloon3542automatically deflates and the inflating fluid exits into the bladder out the distal end of the inflation lumen3532, which is open at the distal end of the catheter3500.

FIG. 36illustrates the balloon portion of the inventive catheter3600with the balloon3602in a partially inflated state. An annular inner lumen wall3610defines therein a drainage lumen3612. At one or more circumferential longitudinal extents about the inner lumen wall3610, an inflation lumen wall3620defines an inflation lumen3622and a balloon inflation port3624fluidically connected to the inflation lumen3622; in the inventive catheter, there can be more than one inflation lumen3622and corresponding inflation port3624even though only one is shown herein. No lumen plug closes the inflation lumen3622distal of the inflation port3624as set forth above in alternative embodiments. In this exemplary embodiment, a stretch-valve mechanism3630serves to plug the inflation lumen3622distal of the inflation port3624as described in further detail below. An outer wall3640covers all of the interior walls3610and3620in a fluid-tight manner and forms the exterior of the balloon3642but does not cover the distal end of the inflation lumen3622. The outer wall3640is formed in any way described herein and is not discussed in further detail here.

The stretch-valve mechanism3630is disposed in the inflation lumen3622to not hinder inflation of the balloon3602with inflating fluid. A non-illustrated proximal anchor is disposed in the inflation lumen3620proximal of the inflation port3624. The proximal anchor can be any size or shape that accommodates unhindered fluid flow through the inflation lumen3622, one exemplary inner diameter of the hollow anchor portion is a tube substantially equal to the diameter of the inflation lumen3622with an outer diameter just slightly larger than the diameter of the inflation lumen3622(e.g., the thickness of the tube can be between 0.07 mm and 0.7 mm). The longitudinal length of this hollow anchor can be as long as desired to be longitudinally fixedly secured within the inflation lumen3622when installed in place. The anchor in this exemplary embodiment is at or near the non-illustrated proximal end of the inflation lumen3622. The distal end of the stretch-valve mechanism3630can be nearer to the inflation port3624, but not at or distal of the inflation port3624; selection of the anchor's position is dependent upon the amount of stretch that is desired to actuate the stretch-valve of the inventive catheter3600as described below. In the exemplary embodiment ofFIG. 36, the stretch-valve mechanism3630also includes an intermediate cord3634, either inelastic or elastic, connected at its proximal end to the anchor. A stopper3636is connected to the distal end of the cord3634. The cord3634is located at the inflation port3624but not to obstruct fluid flow through the inflation port3624. The stopper3636, in contrast, is a solid cylinder having the a diameter that allows it to slidably move within the inflation lumen3622when the cord3634pulls it but, at the same time, to provide a fluid-tight seal so that liquid cannot pass from one side of the stopper3636to the other side within the inflation lumen3622. The stopper3636is located distal of the inflation port3624. To prevent distal movement of the stopper3636, a restrictor3638is provided distal of the stopper3636. The cord3634, therefore, spans the inflation port3624. Because the stopper3636must traverse the inflation port3624, it must be just distal of the inflation port3624but the anchor can be located anywhere proximal of the inflation port3624. While the length of the cord3634needs to be sufficient to span the inflation port3624, it can be as long as desired, which will depend on where the anchor resides. As the catheter3600stretches more at its proximal end and less at its distal end when pulled from the proximal end, the anchor can be further proximal in the inflation lumen3622than shown, and can even be very close to or at the proximal end of the inflation lumen3622. It can even be attached to the luer connector half that prevents fluid from flowing out the proximal end of the inflation lumen3622.

In such a configuration, therefore, any proximal movement of the catheter3600at the proximal end where the anchor resides will also move the stretch-valve mechanism3630proximally; in other words, the stopper3636slides proximally within the inflation lumen3622from distal of the inflation port3624to a proximal side of the inflation port3624. When the proximal end of the catheter3600is pulled to move the stopper3636across the inflation port3624with a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter3600was still inflated when the force was imparted, fluid in the balloon3642can exit distally out the inflation lumen3622. In an exemplary embodiment of the stretch valve ofFIG. 36, a pulling force in a range of 1 to 15 pounds will cause the stretch-valve mechanism3630to slide proximally to place the stopper3636just proximal of the inflation port3624, i.e., the deflation point of the stretch-valve shown inFIG. 36. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds. When the stopper3636traverses the inflation port3624, the balloon3642automatically deflates and the inflating fluid exits into the bladder out the distal end of the inflation lumen3622, which is open at the distal end of the catheter3600.

An alternative exemplary embodiment combines the embodiments ofFIGS. 30 and 36to tether the tube2820at the proximal end of the catheter.

FIG. 37illustrates the balloon portion of the inventive catheter3700with the balloon3742in a partially inflated state. An annular inner lumen wall3710defines therein a drainage lumen3712. At one or more circumferential longitudinal extents about the inner lumen wall3710, an inflation lumen wall3720defines an inflation lumen3722and a balloon inflation port3724fluidically connected to the inflation lumen3722; in the inventive catheter, there can be more than one inflation lumen3722and corresponding inflation port3724even though only one is shown herein. A lumen plug3736fluidically closes the inflation lumen3722distal of the inflation port3724so that all inflation fluid3702is directed into the balloon3742. The lumen plug3736can plug any point or extent from the inflation port3724distally. An outer wall3740covers all of the interior walls3710and3720in a fluid-tight manner and forms the exterior of the balloon3742but does not cover the distal end of the drainage lumen3712. The outer wall3740is formed in any way described herein and is not discussed in further detail here.

In this exemplary embodiment, a hollow, stretch-valve tube3730is disposed in the drainage lumen3712to not hinder drainage of the fluid to be drained (e.g., urine). While the diameter of the stretch-valve tube3730can be any size that accommodates unhindered fluid flow through the drainage lumen3712, one exemplary inner diameter of the stretch-valve tube3730is substantially equal to the diameter of the drainage lumen3712and the outer diameter of the stretch-valve tube3730is just slightly larger than the diameter of the drainage lumen3712(e.g., the wall thickness of the tube can be between 0.07 mm and 0.7 mm). The proximal end of the stretch-valve tube3730in this exemplary embodiment is proximal of a proximal end of a deflation port3760. The distal end of the stretch-valve tube3730is not distal of the distal end of the balloon3742so that the balloon3742can be deflated; the distal end can be anywhere between the two ends of the balloon3742but is shown in an intermediate position inFIG. 37. The distal end of the stretch-valve tube3730is at a distance S distal of the deflation port3760and selection of this distance S is dependent upon the amount of stretch required to actuate the stretch-valve of the inventive catheter3700as described below. In the exemplary embodiment ofFIG. 37, the longitudinal length of the deflation port3760is shown as less than one half of the longitudinal length of the stretch-valve tube3730. The drainage port3760is formed through the inner lumen wall3710and the stretch-valve tube3730is positioned to overlap at least the drainage port3760. In this manner, a portion of the outer surface of the distal end of the stretch-valve tube3730closes off the drainage port3760to prevent fluid communication between the balloon3742and the drainage lumen3712through the drainage port3760.

To secure the stretch-valve tube3730in the catheter3700, a proximal anchor3732is disposed in the drainage lumen3710away from the deflation port3760, here proximally. The proximal anchor3732can be any size or shape that accommodates unhindered fluid flow through the drainage lumen3712, one exemplary inner diameter of the hollow anchor3732being a tube or ring substantially equal to the diameter of the drainage lumen3712with an outer diameter just slightly larger than the diameter of the drainage lumen3712(e.g., the thickness of the tube can be between 0.07 mm and 0.7 mm). The longitudinal length of this hollow anchor3732can be as long as desired but just enough to longitudinally fixedly secure the stretch-valve tube3730within the drainage lumen3712when installed in place. The anchor3732in this exemplary embodiment is at the proximal end of the balloon3742but can be further inside the balloon3742(distal) or entirely proximal of the balloon3742. In an exemplary embodiment, the anchor3732has a stepped distal orifice that permits the proximal end of the stretch-valve tube3730to be, for example, press-fit therein for permanent connection. In another exemplary embodiment, the anchor3732is an adhesive or glue that fixes the proximal end of the stretch-valve tube3730longitudinally in place within the drainage lumen3712. The adhesive can be the same material as any or all of the walls3710,3720,3740or it can be a different material. In an exemplary non-illustrated embodiment where a fixation port or set of fixation ports are formed through the inner wall3710proximal of the proximal-most end of the balloon3742and about the proximal end of the stretch-valve tube3730, if the outer wall3740is formed by a dipping of the interior parts into a liquid bath of the same material as, for example, a dual lumen extrusion including the inner wall3710and the inflation lumen wall3720, then, when set, the outer wall3740will be integral to both the inner wall3710and the inflation lumen wall3720and will be fixedly connected to the stretch-valve tube3730through the fixation port(s).

In such a configuration, therefore, any proximal movement of the catheter3700at or proximal to the drainage port3760will also move the stretch-valve tube3730proximally; in other words, the distal end of the stretch-valve tube3730can slide within the drainage lumen3712in a proximal direction. When the proximal end of the catheter3700is pulled to a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter3700was still inflated when the force was imparted, the force will cause the stretch-valve tube3730to slide proximally to place the distal end of the stretch-valve tube3730just proximal of the drainage port3760, e.g., with a pulling force in a range of 1 to 15 pounds. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds.

When the deflation point of the stretch-valve tube3730starts, the interior of the balloon3742becomes fluidically connected directly into the drainage lumen3712(which is open to the interior of the bladder2020and to the non-illustrated, proximal drain bag) and, due to the fact that the bladder is relatively unpressurized as compared to the balloon3742, all internal pressure is released from the balloon3742to eject the inflating fluid3702directly into the drainage lumen3712, thereby causing the balloon3742to deflate rapidly. Because there is no intermediate structure between the balloon inflating fluid3702and the drainage lumen3712, the rate at which the balloon3742deflates is fast. One way to speed up deflation can be to shape the drainage port3760in the form of a funnel outwardly expanding in a direction from the outer wall3740towards the interior of the catheter3700. Another way to speed up deflation can be to have two or more drainage ports3760about the circumference of the inner lumen wall3710and/or to enlarge the cross-sectional area of the drainage port3760.

FIG. 38illustrates a balloon portion of the inventive catheter3800with a balloon3842in a partially inflated state. An annular inner lumen wall3810defines therein a drainage lumen3812. At one or more circumferential longitudinal extents about the inner lumen wall3810, an inflation lumen wall3820defines an inflation lumen3822and a balloon inflation port3824fluidically connected to the inflation lumen3822; in the inventive catheter, there can be more than one inflation lumen3822and corresponding inflation port3824even though only one is shown herein. A lumen plug3836fluidically closes the inflation lumen3822distal of the inflation port3824so that all inflation fluid3802is directed into the balloon3842. The lumen plug3736can plug any point or extent from the inflation port3724distally. An outer wall3840covers all of the interior walls3810and3820in a fluid-tight manner and forms the exterior of the balloon3842but does not cover the distal end of the drainage lumen3812. The outer wall3840is formed in any way described herein and is not discussed in further detail here.

In this exemplary embodiment, a hollow, stretch-valve tube3830is disposed in the drainage lumen3812to not hinder drainage of the fluid to be drained (e.g., urine). While the diameter of the stretch-valve tube3830can be any size that accommodates unhindered fluid flow through the drainage lumen3812, one exemplary inner diameter of the stretch-valve tube3830is substantially equal to the diameter of the drainage lumen3812and the outer diameter of the stretch-valve tube3830is just slightly larger than the diameter of the drainage lumen3812(e.g., the wall thickness of the tube can be between 0.07 mm and 0.7 mm). The proximal end of the stretch-valve tube3830in this exemplary embodiment is proximal of a proximal end of a deflation port3860. The distal end of the stretch-valve tube3830is not distal of the distal end of the balloon3842so that the balloon3842can be deflated; the distal end can be anywhere between the two ends of the balloon3842but is shown in an intermediate position inFIG. 38. The distal end of the stretch-valve tube3830is at a distance S distal of the deflation port3860and selection of this distance S is dependent upon the amount of stretch required to actuate the stretch-valve of the inventive catheter3800as described below. In the exemplary embodiment ofFIG. 38, the longitudinal length of the deflation port3860is shown as less than one half of the longitudinal length of the stretch-valve tube3830. The drainage port3860is formed through the inner lumen wall3810and the stretch-valve tube3830is positioned to overlap at least the drainage port3860. In this manner, a portion of the outer surface of the proximal end of the stretch-valve tube3830closes off the drainage port3860to prevent fluid communication between the balloon3842and the drainage lumen3812through the drainage port3860.

In this exemplary embodiment, in comparison to the embodiment ofFIG. 37, a second drainage port3862is provided in the inner lumen wall3810aligned with the drainage port3860, and both drainage ports3860,3862are aligned with the inflation port3824. As such, when the stretch-valve tube3830moves proximally to uncover the drainage ports3860,3862, inflation fluid3802from inside the balloon3842exits from both the inflation port3824and the drainage port3860.

To secure the stretch-valve tube3830in the catheter3800, a proximal anchor3832is disposed in the drainage lumen3810away from the deflation ports3860,3862, here proximally. The proximal anchor3832can be any size or shape that accommodates unhindered fluid flow through the drainage lumen3812, one exemplary inner diameter of the hollow anchor3832being a tube or ring substantially equal to the diameter of the drainage lumen3812with an outer diameter just slightly larger than the diameter of the drainage lumen3812(e.g., the thickness of the tube can be between 0.07 mm and 0.7 mm). The longitudinal length of this hollow anchor3832can be as long as desired but just enough to longitudinally fixedly secure the stretch-valve tube3830within the drainage lumen3812when installed in place. The anchor3832in this exemplary embodiment is at the proximal end of the balloon3842but can be further inside the balloon3842(distal) or entirely proximal of the balloon3842. In an exemplary embodiment, the anchor3832has a stepped distal orifice that permits the proximal end of the stretch-valve tube3830to be, for example, press-fit therein for permanent connection. In another exemplary embodiment, the anchor3832is an adhesive or glue that fixes the proximal end of the stretch-valve tube3830longitudinally in place within the drainage lumen3812. The adhesive can be the same material as any or all of the walls3810,3820,3840or it can be a different material. In an exemplary non-illustrated embodiment where a fixation port or set of fixation ports are formed through the inner wall3810proximal of the proximal-most end of the balloon3842and about the proximal end of the stretch-valve tube3830, if the outer wall3840is formed by a dipping of the interior parts into a liquid bath of the same material as, for example, a dual lumen extrusion including the inner wall3810and the inflation lumen wall3820, then, when set, the outer wall3840will be integral to both the inner wall3810and the inflation lumen wall3820and will be fixedly connected to the stretch-valve tube3820through the fixation port(s).

In such a configuration, therefore, any proximal movement of the catheter3800at or proximal to the drainage ports3860,3862will also move the stretch-valve tube3830proximally; in other words, the distal end of the stretch-valve tube3830can slide within the drainage lumen3812in a proximal direction. When the proximal end of the catheter3800is pulled to a force that is no greater than just before injury would occur to the urethrovesical junction or the urethra if the catheter3800was still inflated when the force was imparted, the force will cause the stretch-valve tube3830to slide proximally to place the distal end of the stretch-valve tube3830just proximal of the drainage ports3860,3862, e.g., with a pulling force in a range of 1 to 15 pounds. In another exemplary embodiment, the range of force required to meet the deflation point is between 1 and 5 pounds, in particular, between 1.5 and 2 pounds.

When the deflation point of the stretch-valve tube3830starts, the interior of the balloon3842becomes fluidically connected directly into the drainage lumen3812(which is open to the interior of the bladder2020and to the non-illustrated, proximal drain bag) and, due to the fact that the bladder is relatively unpressurized as compared to the balloon3842, all internal pressure is released from the balloon3842to eject the inflating fluid3802directly into the drainage lumen3812, thereby causing the balloon3842to deflate rapidly. Because there is no intermediate structure between the balloon inflating fluid3802and the drainage lumen3812, the rate at which the balloon3842deflates is fast. One way to speed up deflation can be to shape the drainage ports3860,3862in the form of a funnel outwardly expanding in a direction from the outer wall3840towards the interior of the catheter3800. Another way to speed up deflation can be to have two or more drainage ports3860about the circumference of the inner lumen wall3810and/or to enlarge the cross-sectional area of the drainage ports3860,3862.

Reference is made to the flow chart ofFIG. 39to explain one exemplary embodiment of a process for making a catheter according to the embodiment ofFIGS. 21 to 23.

The catheter starts, in Step3910with a dual lumen extrusion of latex. This extrusion, therefore, defines the annular inner lumen wall2110with the drainage lumen2112and, at one or more circumferential longitudinal extents about the inner lumen wall2110, an inflation lumen wall2120with the inflation lumen2122. The dual lumen, therefore, already includes both the drainage lumen2112and the inflation lumen2122. Both lumen2112,2122, however, are extruded without obstruction and without radial ports. Therefore, in order to have the inflation port2124, a radial hole needs to be created between the outside surface of the extrusion and the inflation lumen.

In step3912, the balloon inflation port2124is made to fluidically connect the environment of the extrusion to the inflation lumen2122.

Sealing off of the distal end of the inflation lumen2122can be performed in Step3914by inserting or creating a plug2126therein or the sealing can occur simultaneously with the creation of the outer wall2140below.

In step3916, a balloon sleeve2130is placed about the inflation port2124and is fixed to the exterior of the inflation lumen wall2120at both ends to define a fluid-tight balloon interior2200therebetween. As such, inflation of the balloon2210can occur through the inflation lumen2122. For example, the tube2130making up the inner balloon wall is slid over the distal end of the dual-lumen extrusion to cover the inflation port2124and is fluid-tightly sealed to the inner multi-lumen extrusion at both ends of the tube but not in the intermediate portion. This tube can be made of latex as well and, therefore, can be secured to the latex multi-lumen extrusion in any known way to bond latex in a fluid-tight manner.

In step3918, the entire sub-assembly is covered with the outer wall2140. For example, the entire sub-assembly is dipped into latex in its liquid form to create the outer wall2140. In the alternative embodiment where a distal inflation lumen plug is not used, the latex can be allowed to enter at least a portion of the distal end of the inflation lumen2122but not so far as to block the inflation port2124. When the latex cures, the balloon2210is fluid tight and can only be fluidically connected to the environment through the proximal-most opening of the inflation port, which is fluidically connected to the inflation lumen2122. In this process, the inner wall2110, the inflation lumen wall2120, the plug2126, the balloon wall2130, and the outer wall2140are all made of the same latex material and, therefore, together, form a very securely water-tight balloon2210.

The sub-process described in Steps3910to3920can be skipped if desired and, instead, completed by utilizing a standard Foley catheter, on which the following steps are performed.

The stretch valve is now created. A proximal port2150is formed through the outer wall2140and through the inflation lumen wall2020in step3920. A distal port2160is formed through the outer wall2140and through the inflation lumen wall2020in step3922. Then, in step3924, the stretch-valve tube2220is inserted through either one of the proximal or distal ports2150,2160such that the proximal port2150overlaps at least a portion of the proximal end of the stretch-valve tube2220and the distal port2160overlaps at least a portion of the distal end of the stretch-valve tube2220. In this manner, two portions of the outer surface of the proximal end of the stretch-valve tube2220at the proximal and distal ports2150,2160are exposed to the environment but there is no fluid communication with the inflation lumen2122and the proximal or distal ports2150,2160.

In Step3926, the proximal port2150is used to secure the stretch-valve tube2220in the catheter2100. In one exemplary embodiment, the proximal port2150is filled with a material that fixes the proximal end of the stretch-valve tube2220to at least one of the outer wall2140and the inflation lumen wall2020. In an exemplary embodiment, an adhesive bonds the proximal end of the stretch-valve tube2220to both the outer wall2140and the inflation lumen wall2120. In another exemplary embodiment, a portion of the present sub-assembly is dipped into latex in its liquid form to plug the proximal port2150and fixedly secure the stretch-valve tube2220to both the outer wall2140and the inflation lumen wall2120. When the latex cures, the connection at the proximal port2150is fluid tight and no longer permits fluidic connection to the environment therethrough. In this process, therefore, the filled proximal port2150, the inflation lumen wall2120, and the outer wall2140are all made of the same latex material and, therefore, together, form a very securely water-tight connection.

In such a configuration, therefore, any proximal movement of the catheter2100at or proximal of the proximal port2150will also move the stretch-valve tube2220proximally; in other words, the distal end of the stretch-valve tube2220can slide within the inflation lumen2122in a proximal direction.

Reference is also made to the flow chart ofFIG. 39to explain one exemplary embodiment of a process for making a catheter according to the embodiment ofFIGS. 24 to 26.

The catheter starts, in Step3910with a dual lumen extrusion of latex. This extrusion, therefore, defines the annular inner lumen wall2410with the drainage lumen2412and, at one or more circumferential longitudinal extents about the inner lumen wall2410, an inflation lumen wall2420with the inflation lumen2422. The dual lumen, therefore, already includes both the drainage lumen2412and the inflation lumen2422. Both lumens2412,2422, however, are extruded without obstruction and without radial ports. Therefore, in order to have the inflation port2424, a radial hole needs to be created between the outside surface of the extrusion and the inflation lumen.

In Step3912, the balloon inflation port2424is made to fluidically connect the environment of the extrusion to the inflation lumen2422.

Sealing off of the distal end of the inflation lumen2422can be performed in Step3914by inserting or creating a plug2426therein or the sealing can occur simultaneously with the creation of the outer wall2440below.

In Step3916, a balloon sleeve2430is placed about the inflation port2424and is fixed to the exterior of the inflation lumen wall2420at both ends to define a fluid-tight balloon interior2200therebetween. As such, inflation of the balloon2240can occur through the inflation lumen2422. For example, the tube2430making up the inner balloon wall is slid over the distal end of the dual-lumen extrusion to cover the inflation port2424and is fluid-tightly sealed to the inner multi-lumen extrusion at both ends of the tube but not in the intermediate portion. This tube can be made of latex as well and, therefore, can be secured to the latex multi-lumen extrusion in any known way to bond latex in a fluid-tight manner.

In Step3918, the entire sub-assembly is covered with the outer wall2440. For example, the entire sub-assembly is dipped into latex in its liquid form to create the outer wall2440. In the alternative embodiment where a distal inflation lumen plug is not used, the latex can be allowed to enter at least a portion of the distal end of the inflation lumen2422but not so far as to block the inflation port2424. When the latex cures, the balloon2240is fluid tight and can only be fluidically connected to the environment through the proximal-most opening of the inflation port, which is fluidically connected to the inflation lumen2422. In this process, the inner wall2410, the inflation lumen wall2420, the plug2426, the balloon wall2430, and the outer wall2440are all made of the same latex material and, therefore, together, form a very securely water-tight balloon2240.

The sub-process described in Steps3910to3920can be skipped if desired and, instead, completed by utilizing a standard Foley catheter, on which the following Steps are performed.

The stretch valve is now created. A proximal port2450is formed through the outer wall2440and through the inflation lumen wall2020in Step3920. A distal port2460is formed through the inner wall2410into the inflation lumen2422in Step3922. Then, in Step3924, the stretch-valve tube2520is inserted through either one of the proximal or distal ports2450,2460such that the proximal port2450overlaps at least a portion of the proximal end of the stretch-valve tube2520and the distal port2460overlaps at least a portion of the distal end of the stretch-valve tube2520. In this manner, one portion of the outer surface of the proximal end of the stretch-valve tube2520at the proximal port2450is exposed to the drain lumen2412and another portion of the outer surface of the distal end of the stretch-valve tube2520at the distal port2460is exposed to the environment but there is no fluid communication with the inflation lumen2422to either of the proximal or distal ports2450,2460.

In Step3926, the proximal port2450is used to secure the stretch-valve tube2520in the catheter2400. In one exemplary embodiment, the proximal port2450is filled with a material that fixes the proximal end of the stretch-valve tube2520to at least one of the outer wall2440and the inflation lumen wall2020. In an exemplary embodiment, an adhesive bonds the proximal end of the stretch-valve tube2520to both the outer wall2440and the inflation lumen wall2420. In another exemplary embodiment, a portion of the present sub-assembly is dipped into latex in its liquid form to plug the proximal port2450and fixedly secure the stretch-valve tube2520to both the outer wall2440and the inflation lumen wall2420. When the latex cures, the connection at the proximal port2450is fluid tight and no longer permits fluidic connection to the environment therethrough. In this process, therefore, the filled proximal port2450, the inflation lumen wall2420, and the outer wall2440are all made of the same latex material and, therefore, together, form a very securely water-tight connection.

In such a configuration, therefore, any proximal movement of the catheter2400at or proximal of the proximal port2450will also move the stretch-valve tube2520proximally; in other words, the distal end of the stretch-valve tube2520can slide within the inflation lumen2422in a proximal direction.

Reference is made to the flow chart ofFIG. 40to explain one exemplary embodiment of a process for making a catheter according to the embodiment ofFIGS. 27 to 29.

The catheter starts, in Step4010with a dual lumen extrusion of latex. This extrusion, therefore, defines the annular inner lumen wall2710with the drainage lumen2712and, at one or more circumferential longitudinal extents about the inner lumen wall2710, an inflation lumen wall2720with the inflation lumen2722. The dual lumen, therefore, already includes both the drainage lumen2712and the inflation lumen2722. Both lumen2712,2722, however, are extruded without obstruction and without radial ports. Therefore, in order to have the inflation port2724, a radial hole needs to be created between the outside surface of the extrusion and the inflation lumen.

In Step4012, the balloon inflation port2724is made to fluidically connect the environment of the extrusion to the inflation lumen2722.

Different from the other exemplary embodiments described, a distal port2760is created in Step4014before, after, or at the same time as the balloon inflation port2724. The distal port2760connects the environment to the interior of the drain lumen2712. In an exemplary embodiment, the distal port2760is proximal of the balloon inflation port2724.

Sealing off of the distal end of the inflation lumen2722can be performed in Step4016by inserting or creating a plug2726therein or the sealing can occur simultaneously with the creation of the outer wall2740below.

In Step4018, a balloon sleeve2730is placed about the inflation port2724and the distal port2760and is fixed to the exterior of the inflation lumen wall2720at both ends to define a fluid-tight balloon interior2200therebetween. As such, inflation of the balloon2810can occur through the inflation lumen2722. For example, the tube2730making up the inner balloon wall is slid over the distal end of the dual-lumen extrusion to cover the inflation port2724and is fluid-tightly sealed to the inner multi-lumen extrusion at both ends of the tube but not in the intermediate portion. This tube can be made of latex as well and, therefore, can be secured to the latex multi-lumen extrusion in any known way to bond latex in a fluid-tight manner.

The stretch valve is now completed. A proximal port2750is formed through the inflation lumen wall2020in Step4020. Then, in Step4022, the stretch-valve tube2820is inserted through either one of the proximal or distal ports2750,2760such that the proximal port2750overlaps at least a portion of the proximal end of the stretch-valve tube2820and the distal port2760overlaps at least a portion of the distal end of the stretch-valve tube2820. In this manner, two portions of the outer surface of the proximal end of the stretch-valve tube2820at the proximal and distal ports2750,2760are exposed to the environment but there is no fluid communication with the inflation lumen2722and the proximal or distal ports2750,2760. Alternatively, Steps4022can occur before4018to insert the stretch-valve tube2820before the balloon sleeve2730is placed and fixed. In such a case, the creation of the proximal port2750can occur before, after, or at the same time as creating the distal port2760and the balloon inflation port2724, in which embodiment, all three ports2724,2750,2760can be created at the same time.

In Step4024, the entire sub-assembly is covered with the outer wall2740. For example, the entire sub-assembly is dipped into latex in its liquid form to create the outer wall2740. In the alternative embodiment where a distal inflation lumen plug is not used, the latex can be allowed to enter at least a portion of the distal end of the inflation lumen2722but not so far as to block the inflation port2724. When the latex cures, the balloon2810is fluid tight and can only be fluidically connected to the environment through the proximal-most opening of the inflation port, which is fluidically connected to the inflation lumen2722. In this process, the inner wall2710, the inflation lumen wall2720, the plug2726, the balloon wall2730, and the outer wall2740are all made of the same latex material and, therefore, together, form a very securely water-tight balloon2810.

In previous embodiments, the proximal port2750pierced the outer wall2740. In this exemplary embodiment, however, there is no need to do so. Here, the proximal port2750can be filled with material of the outer wall2740itself to fix the proximal end of the stretch-valve tube2820to at least one of the outer wall2740and the inflation lumen wall2020. When the latex cures, the connection at the proximal port2750is fluid tight and no longer permits fluidic connection to the environment therethrough. In this process, therefore, the filled proximal port2750, the inflation lumen wall2720, and the outer wall2740are all made of the same latex material and, therefore, together, form a very securely water-tight connection. In an alternative exemplary embodiment, an adhesive can be used to bond the proximal end of the stretch-valve tube2820to the inflation lumen wall2720.

In such a configuration, therefore, any proximal movement of the catheter2700at or proximal of the proximal port2750will also move the stretch-valve tube2820proximally; in other words, the distal end of the stretch-valve tube2820can slide within the inflation lumen2722in a proximal direction.

Reference is made to the flow chart ofFIG. 41to explain one exemplary embodiment of a process for making a catheter according to the embodiment ofFIGS. 37 and 38.

The catheter starts, in Step4110with a dual lumen extrusion of latex. This extrusion, therefore, defines the annular inner lumen wall3710,3810with the drainage lumen3712,3812and, at one or more circumferential longitudinal extents about the inner lumen wall3710,3810, an inflation lumen wall3720,3820with the inflation lumen3722,3822. The dual lumen, therefore, already includes both the drainage lumen2712,2812and the inflation lumen2722,2822. Both lumen2712,2722,2812,2822, however, are extruded without obstruction and without radial ports. Therefore, in order to have the inflation port3724,3824, a radial hole needs to be created between the outside surface of the extrusion and the inflation lumen.

In Step4112, the balloon inflation port3724,3824is made to fluidically connect the environment of the extrusion to the inflation lumen3722,3822.

Different from the other exemplary embodiments described, with regard to the embodiment ofFIG. 37, the deflation port3760is created in Step4114before, after, or at the same time as the balloon inflation port3724. The deflation port3760connects the interior of the balloon3742to the interior of the drain lumen3712. In an exemplary embodiment, the deflation port3760is proximal of the balloon inflation port3724but can be at or distal thereof.

Different from the other exemplary embodiments described, with regard to the embodiment ofFIG. 38, the drainage ports3860and3862are created in Step4114before, after, or at the same time as the balloon inflation port3824. The drainage port3860connects the interior of the balloon3842to the interior of the drain lumen2712and the drainage port3862connects the interior of the inflation lumen3822to the interior of the drain lumen2712. In an exemplary embodiment, the drainage ports3860,3862are aligned with the balloon inflation port3824but they can be distal or proximal thereof. When aligned, a single through-hole can be made through the entire catheter, penetrating both the inflation and drainage channels3712,3722,3812,3822and both walls3710,3720,3810,3820of the catheter. Alternatively, the drainage ports3860,3862can be spaced from one another with either one or neither aligned with the inflation port3824.

In Step4116, a fixation through-hole3732,3832is created through both sides of the outer wall3810but not through the inflation lumen wall3720,3820. This fixation through-hole3732,3832will create the measures for fixing the stretch-valve tube3730,3830inside the drainage lumen3712,3812. The fixation through-hole3732,3832can be placed anywhere proximal of the drainage ports3760,3860,3862. The fixation through-holes3732,3832need not be aligned circumferentially with the inflation port3724,3824if desired but the fixation through-holes3732,3832are shown inFIGS. 37 and 38as aligned therewith. In the exemplary embodiment shown, the fixation through-hole3732,3832is still within the proximal end of the balloon3842but it can equally be further proximal of the balloon3842to any length.

Sealing off of the distal end of the inflation lumen3722,3822can be performed in Step4118by inserting or creating a plug3736,3836therein or the sealing can occur before forming the fixation ports or just before or simultaneously with the creation of the outer wall3740,3840below in Step4124.

In Step4120, the stretch-valve tube3730,3830is inserted into the drainage lumen3712,3812and aligned so that the stretch-valve tube3730,3830covers all drainage ports3760,3860,3862and all of the fixation through-holes3732,3832. The distal end of the stretch-valve tube3730,3830is positioned at the distal distance S desired for operation of the stretch valve. For example, the distance can be up to 1 mm, up to 2 mm, up to 3 mm and up to even 1 or 2 cm. The distance S can also be dependent on the amount of stretch at the proximal end of the catheter as the displacement of the stretch-valve tube is proportional to the stretch of the catheter. For example, if the catheter is 500 mm long and is pulled 20%, then it will be 600 mm long (a 100 mm stretch). A 10 mm or longer stretch-valve tube made from a stiff material, such as metal (e.g., stainless steel, titanium, etc.) polycarbonate, polyimide, polyamide, polyurethane (Shore 55D-75D), and the like, located near the balloon of the catheter has its proximal end glued to the inside of the inflation or drainage lumen. When this catheter is stretched than 20%, then the distal tip of a 10 mm stretch valve will move 2 mm in the proximal direction. Accordingly, if the drainage port(s) is placed 2 mm proximal to the distal end of the stretch-valve tube (here, S=2 mm), it will remain sealed by the stretch-valve tube at a stretch of about 20%. But, when the catheter is pulled slightly more than 20% (or 2 mm), the drainage port will unseal and the inflation fluid within the balloon will discharge out the drainage port. As catheters vary among manufacturers, calibration of the percent stretch to the force required to stretch the catheter can be done for each different type of catheter. This force is defined in engineering terms as a modulus of the catheter and is a function of the modulus of the material and the effective wall thickness of the catheter. Low modulus materials and catheters will stretch more than high modulus materials and catheters when exposed to the same force. Exemplary catheters are those made from latex rubber or silicone rubber. Silicone rubber generally has a higher modulus than latex and, therefore, more force is required to stretch the catheter sufficiently to discharge the pressure within the balloon. Those of skill in the art, therefore, will understand that different stretch valves lengths can provided to dump the balloon pressure as a function of a tug-force on the different catheters made from the different materials and having different wall thicknesses. Accordingly, even though the stretch-valve tube distances are given, they are exemplary and can change for different catheters having different materials/thicknesses. As such, these exemplary distances for actuating the stretch-valve tube applies to all embodiments described herein but are not limited thereto.

If the fixation through-holes3732,3832are within the inflation expanse of the balloon sleeve (as shown), then an adhesive can be used within the fixation through-holes3732,3832to fix the proximal end of the stretch-valve tube3730,3830thereat before attachment of the balloon sleeve. If the fixation through-holes3732,3832are within the expanse of the balloon sleeve but only overlap at the fixed proximal end of the balloon sleeve (not illustrated), then the same adhesive that fixes the proximal end of the balloon sleeve can be used within the fixation through-holes3732,3832to fix the proximal end of the stretch-valve tube3730,3830thereat. Finally, if the fixation through-holes3732,3832are outside the expanse of the balloon sleeve proximally, then an adhesive or the same material that creates the outer wall3740,3840(see below) can be used within the fixation through-holes3732,3832to fix the proximal end of the stretch-valve tube3730,3830.

In Step4122, the balloon sleeve is placed about the inflation port3724,3824and the fixation through-holes3732,3832(if the fixation through-holes3732,3832are within the expanse of the balloon sleeve) and the balloon sleeve is fixed to the exterior of the inner and inflation lumen walls3710,3720,3810,3820at both ends to define a fluid-tight balloon interior therebetween. As such, inflation of the balloon3742,3842can occur through the inflation lumen3722,3822. For example, the balloon sleeve making up the inner wall of the balloon3742,3842is slid over the distal end of the dual-lumen extrusion to cover at least the inflation port3724,3824and is fluid-tightly sealed to the inner multi-lumen extrusion at both ends of the balloon sleeve but not in the intermediate portion. The balloon sleeve can be made of latex as well and, therefore, can be secured to the latex multi-lumen extrusion in any known way to bond latex in a fluid-tight manner.

In Step4124, the entire sub-assembly is covered with the outer wall3740,3840. For example, the entire sub-assembly is dipped into latex in its liquid form to create the outer wall3740,3840. In the alternative embodiment where a distal inflation lumen plug3736,3836is not used, the latex can be allowed to enter at least a portion of the distal end of the inflation lumen3722,3822but not so far as to block the inflation port3724,3824. When the latex cures, the balloon3742,3842is fluid tight and can only be fluidically connected to the environment through the proximal-most opening of the inflation port, which is fluidically connected to the inflation lumen3722,3822. In this process, the inner wall3710,3810, the inflation lumen wall3720,3820, the plug3736,3836, the balloon wall, and the outer wall3740,3840are all made of the same latex material and, therefore, together, form a very securely water-tight balloon3742,3842.

In such a configuration, therefore, any proximal movement of the catheter3700,3800at or proximal of the proximal anchor3732,3832will also move the stretch-valve tube3730,3830proximally; in other words, the distal end of the stretch-valve tube3730,3830can slide within the inflation lumen3722,3822in a proximal direction.

The steps outlined above in the exemplary embodiments need not be done in the order described or illustrated. Any of these steps can occur in any order to create the catheter according to the various exemplary embodiments.

The catheters200,300,1000,1600,2100,2400,2700,3300,3400,3500,3600,3700,3800according to the invention can be used in vascular applications. It is known that every vessel has a tearing pressure. Balloons are used in coronary arteries, for example. If a coronary artery balloon were to burst, there would be less damage if the burst was controlled according to the invention. The same is true for a renal or iliac blood vessel. In such situations, the breakaway catheter improves upon existing catheters by making them safer. From the urinary standpoint, the breakaway balloon will not only prevent injury, but will also be a signal to the technician that he/she needs to obtain the assistance of a physician or urologist with respect to inserting the catheter.