Urinary flow control device

Abstract

A device (100) for controlling urinary flow, comprising: a urine inlet (102) and a urine outlet (104); a fluid-based actuator comprising an expandable chamber, adjustable between a contracted configuration and an expanded configuration; an actuation conduit (112) through which fluid may be forced into and / or removed from the chamber; wherein when the fluid-based actuator is in one of the contracted and the expanded configurations, urine is able to flow from the urine inlet to the urine outlet; and in the other configuration, urine is prevented from flowing from the urine inlet to the urine outlet. The device may be installed in a user's bladder with the urine inlet located in the bladder and the urine outlet located in the urethra. The device may be inserted and extracted from a user without requiring intrusive surgery, allowing the device to be readily replaced, when needed.

Description

[0001] Urinary flow control device

[0002] FIELD

[0003] The present invention relates to urinary flow control devices, particularly for people with urinary incontinence, but also for people with urinary retention.

[0004] BACKGROUND

[0005] One of the causes of urinary incontinence (Ul) - the involuntary leakage of urine - is the loss or weakening of the urethral sphincter which affects approximately 5% of people around the globe. In men, Ul is particularly common in people with prostate cancer who have undergone a prostatectomy, affecting approximately 10% of patients undergoing prostatectomy annually in the USA. Ul is also a common problem for patients with an enlarged prostate, affecting 30-40% of patients undergoing transurethral resection of the prostate (TURP) annually in the USA. In women, pregnancy and childbirth may lead to weak pelvic floor muscles or damage the surrounding nerves which can make the urethral sphincter incompetent. Ul severely affects the quality of life in patients of all ages.

[0006] Various methods exist for treating Ul, each with its own inherent problems. A common, cheap solution is the use of diapers, which simply absorb any leaked urine, before being disposed of by a user. Diapers do not offer a long-term solution, as they need to be replaced regularly. Additionally, the use of diapers generates excessive waste due to each diaper requiring disposal after one use.

[0007] Catheters offer a short-term solution. A catheter is a soft hollow tube which may be passed into the bladder in order to drain urine, among other uses. Catheters offer only a short-term solution, as with long-term use various issues may arise, including urinary tract infections (UTIs) and flow disruption due to mineral deposition within the catheter. A catheter also simply directs the urine flow to a receptacle (usually worn) outside the patient’s body without providing any control over the flow.

[0008] Surgically implanted devices are also known, for example that may be inserted into the body via surgery. One such procedure provides a user-controllable urethral constriction cuff in order to control the flow of urine out of the bladder. This provides a solution for some patients, but there are inherent risks with surgery, as well as costs.

[0009] Urinary retention is the inability to fully empty the bladder. This can lead to discomfort and other complications. Urinary retention can have various causes. These include obstructive causes in which the urine flow path from the bladder is blocked, e.g. benign prostatic hyperplasia, urethral strictures and tumours in the pelvic region. There are also neurological causes, e.g. spinal cord injury, multiple sclerosis, stroke and Parkinson’s disease, and there are muscle dysfunction causes, e.g. detrusor muscle underactivity (the bladder muscle fails to contract, hindering expulsion of urine) and pelvic floor dysfunction (weakness or coordination issues within pelvic floor muscles can prevent complete bladder emptying).

[0010] SUMMARY OF THE INVENTION

[0011] When viewed from a first aspect, the present invention provides a device for controlling urinary flow, comprising: a urine inlet; a urine outlet; a fluid-based actuator comprising an expandable chamber, the fluid-based actuator being adjustable between a contracted configuration in which the chamber contains a first volume of fluid and an expanded configuration in which the chamber contains a second volume of fluid, the second volume being greater that the first volume; an actuation conduit through which fluid may be forced into the chamber and / or through which fluid may be removed from the chamber; wherein: when the fluid-based actuator is in one of the contracted and the expanded configurations, urine is able to flow from the urine inlet to the urine outlet; and when the fluid-based actuator is in the other of the contracted and the expanded configurations, urine is prevented from flowing from the urine inlet to the urine outlet.

[0012] In a set of embodiments, the device is insertable into a urethra for installation in a user’s bladder and urethra and arranged such that, in use, the urine inlet is located in the bladder and the urine outlet is located in the urethra. This may advantageously enable the device to be inserted and extracted from a user without requiring intrusive surgery, allowing the device to be readily replaced, when needed, and reducing the risk to the user.

[0013] In a set of embodiments, the device comprises a urine conduit extending between the urine inlet and the urine outlet thereby forming a flow path between the urine inlet and the urine outlet. The urine conduit may extend through the whole of the urethra, i.e. providing a flow path from the bladder to outside the body. In other embodiments the urine conduit may extend only part way through the urethra, i.e. providing a flow path from the bladder part way through the urethra. The urine conduit may have a substantially circular cross-section. It may form a substantially tube-like shape. Such embodiments may advantageously ensure that the device has no sharp edges on an exterior surface thereof, thereby improving comfort and reducing risk of damage to the urethra during insertion and / or extraction of the device from a user.

[0014] In a set of embodiments, the device may have separate actuation conduits, e.g. one through which fluid may be forced into the chamber and another through which fluid may be removed from the chamber. In a set of other embodiments, these functions may be provided by the same actuation conduit - i.e. in such embodiments the device has one actuation conduit through which fluid may be forced into the chamber and through which fluid may be removed from the chamber. The actuation conduit is thus operably connected to the fluid-based actuator Such embodiments may advantageously reduce the number of parts required for the device.

[0015] In a set of embodiments, the actuation conduit may have a first opening operably coupled to a fluid inlet of the fluid-based actuator, and a second opening arranged to be located outside the body when the device is installed in a user. The first opening may be located at or near to a first end of the actuation conduit, and the second opening may be located at or near to a second end of the actuation conduit. This enables the actuation conduit to be accessed by the user when the device is installed in the body and thus allows control of the fluid-based actuator by a user from outside of the body. In other embodiments the second opening may be located inside the body, but close to the outside of the body when installed in a user, so that the second opening can still be easily accessed. In a set of embodiments, the actuation conduit extends through the urethra to a location outside the body when the device is installed in a user. Although it is normally desirable not to obstruct the flow path of urine (so as to allow near normal urination flow rate), a small enough conduit will not compromise flow too much and it conveniently makes use of the urethra for controlling the operation of the device.

[0016] In a set of embodiments, the actuation conduit extends through the urine conduit. The actuation conduit may be located in the flow path between the urine inlet and the urine outlet. This provides a relatively straightforward arrangement and thus reduces overall manufacturing complexity (and therefore cost).

[0017] In other embodiments the actuation conduit may be at least partially contained within a wall of the urine conduit - i.e. the actuation conduit may be formed within a wall of the urine conduit so as not to further obstruct the flow path between the urine inlet and the urine outlet. This may advantageously avoid decreasing the cross-sectional area of the flow path, thus maintaining a high urine flow rate.

[0018] In a set of embodiments, the device comprises a valve for preventing fluid from exiting the chamber of the fluid-based actuator. The valve may be a manually operable valve. The valve may be located at or towards the second end of the actuation conduit and may thus be arranged to be located outside of the body when the device is installed in a user. The actuation conduit may comprise the valve or the valve may be attached to the actuation conduit. The inclusion of a valve enables the fluid-based actuator to be maintained in the expanded configuration until it is desired to change it to the contracted configuration. The valve may be releasable by a user so as to allow the user to easily commence urination. In a set of embodiments, the valve can be operated between a first configuration and a second configuration. In the first configuration fluid is prevented from passing through the actuation conduit from the chamber of the fluid-based actuator to the second opening of the actuation conduit. In the second configuration fluid is able to pass through the actuation conduit from the chamber of the fluid-based actuator to the second opening of the actuation conduit. The fluid forced into the chamber may comprise any non-toxic fluid, e.g. suitable liquids or gases. In a set of embodiments, the fluid forced into the chamber comprises a non-toxic liquid e.g. water or saline solution. In other embodiments, the fluid forced into the chamber comprises a non-toxic gas, e.g. air. Such non-toxic fluids advantageously ensure that an undesired leakage from the fluid-based actuator into the body does not cause harm thereto, thereby improving safety.

[0019] The device may further comprise a pump arranged to force liquid through the actuation conduit into the fluid-based actuator. The pump may be arranged to be located outside the body when the device is in use. The pump may comprise the valve. In a set of embodiments, the pump is releasably attachable to the second end of the actuation conduit. Such embodiments may advantageously enable the pump to be detached from the actuation conduit when not in use. Detaching the pump may be convenient and it may reduce potential discomfort for the user. The pump may be stored remotely from the actuation conduit and not permanently attached to it. In other embodiments, the pump may be permanently attached to the second end of the actuation conduit. The pump may be integrally moulded with the actuation conduit. Such embodiments may advantageously improve sealing between the pump and the actuation conduit, thus preventing fluid from leaking out of the actuation conduit and / or the pump. In a set of embodiments, the pump is manually operable.

[0020] The pump may be a positive displacement pump. The pump may be a peristaltic pump. Such pumps can be operated manually without requiring a power source. They may also function as the valve by preventing movement of fluid in both directions unless such movement is caused by the pump.

[0021] The pump, the actuation conduit and the fluid-based actuator may form a sealed system. A sealed system does not require topping up of fluid and instead simply moves fluid from one location to another. For example, in a sealed system, the fluid may be moved between the expandable chamber and a storage reservoir. The pump may be located between the expandable chamber and the storage reservoir.

[0022] In a set of embodiments, the pump comprises a squeeze pump. The squeeze pump may be relatively small - e.g. operable using a single hand, operable using a thumb and a finger on the same hand, etc. The squeeze pump may be integrally moulded with the actuation conduit which simplifies manufacture and reduces cost.

[0023] In a set of embodiments, the pump is arranged to force enough fluid into the fluidbased actuator to change it from the contracted configuration to the expanded configuration with a single actuation thereof. Such embodiments may improve usability of the device, since a user can quickly and conveniently commence urination at a maximum flow rate with a single actuation. In some embodiments a single actuation of the pump in the opposite direction is also sufficient to change the expandable chamber to the fully contracted configuration. Such embodiments may provide a convenient feedback mechanism for the user, allowing them to determine the configuration of the fluid-based actuator based on the configuration of the pump, which they can see and / or feel.

[0024] It will be appreciated that in other embodiments the expandable chamber may collapse to the contracted configuration without actuation of the pump (e.g. by opening a valve).

[0025] In a set of embodiments, the pump comprises a syringe. The syringe may be attachable to (e.g. insertable into or onto) the second end of the actuation conduit. The valve may be operable through insertion and removal of the syringe. The valve may be arranged to allow fluid to pass therethrough when the syringe is inserted into the actuation conduit, and it may be arranged to prevent fluid from passing therethrough when the syringe is removed from the actuation conduit. Such embodiments may provide a convenient mechanism for forcing fluid into and removing fluid from the fluid-based actuator.

[0026] In a set of embodiments, the device comprises a casing extending from the urethral opening of the bladder (the urethral neck) into the bladder when the device is installed in a user. The urine inlet may be formed in a wall of the casing, which may be a side wall of the casing. The urine inlet may comprise one or more holes formed in the wall of the casing. The fluid-based actuator may be at least partly located within the casing. The fluid-based actuator may be wholly located within the casing. In a set of embodiments, the casing has a substantially cylindrical shape. The casing may have a rounded end. Such embodiments may advantageously ensure that the casing does not have any sharp edges, thus improving comfort and reducing risk of damage to the user while the device is installed in a user, and during insertion and extraction of the device through the urethra.

[0027] In a set of embodiments, the casing comprises a plurality of independently moulded portions attached to each other. The casing may comprise a cap portion having a rounded end attached to an inlet portion having the urine inlet formed in a side wall thereof. The different portions of the casing may be attached to each other and may form a seal therebetween, e.g. using a biocompatible adhesive. The casing may be formed from a biocompatible material e.g. silicone. The casing may be at least partially flexible and, as discussed further below, may have one or more openings for drainage and / or for insertion of tools such as a cystoscope into the bladder while the device is in place. This may further advantageously improve comfort and reduce risk of damage to the user while the device is installed in a user and during insertion and extraction of the device through the urethra.

[0028] In a set of embodiments, the expandable chamber may comprise a balloon. The balloon may be made of an elastic material, e.g. silicone, that can stretch when expanded. In other embodiments the balloon may be non-elastic such that it is expandable to a predetermined size and / or shape. In a set of embodiments, the balloon is located in the flow path between the urine inlet and the urine outlet.

[0029] In a set of embodiments, the balloon is arranged to abut the urine inlet when in the expanded configuration thereby blocking or closing off the urine inlet and preventing urine from entering the device therethrough. The balloon may be configured to contract away from the urine inlet when in the contracted configuration thereby allowing urine to enter the device through the urine inlet. Such embodiments may advantageously ensure that urine is not allowed to enter the device when the balloon is in the expanded configuration, thereby preventing urine from being held or stored within the device. Stored urine can crystallise and leave residue which can result in damage to the internals of the device and can present a health hazard to the user.

[0030] In a set of embodiments, the urine inlet comprises one or more holes formed in a wall of the casing, and the balloon is arranged to abut a peripheral wall of each hole when in the expanded configuration thereby preventing urine from entering the device therethrough. The balloon may be arranged to protrude into each hole when in the expanded configuration so as to form a seal with the peripheral wall of each hole. Such embodiments may advantageously improve sealing between the balloon and the urine inlet and thus prevent leakage of urine through the device.

[0031] The balloon may be arranged to abut an internal wall of the urine conduit between the urine inlet and the urine outlet when in the expanded configuration so as to prevent urine from flowing from the urine inlet to the urine outlet through the urine conduit. The urine conduit may comprise a constricted portion located between the urine inlet and the urine outlet. The balloon may be arranged to abut an inner surface of the constricted portion of the urine conduit when in the expanded configuration so as to prevent urine from flowing from the urine inlet to the urine outlet through the urine conduit. The balloon may be arranged to protrude into the constricted portion of the urine conduit when in the expanded configuration so as to form a seal with the inner surface of the constricted portion.

[0032] The balloon may have any appropriate shape depending on the shape of the device, particularly the casing. The balloon may have a substantially spherical shape when in the expanded configuration. It may have a substantially ovoid shape when in the expanded configuration. It may have a substantially elongate shape when in the expanded configuration. It may have a substantially cylindrical shape with rounded ends when in the expanded configuration. It may have a substantially tube-like shape when in the expanded configuration. It may have a substantially toroidal shape when in the expanded configuration. The substantially toroidal shape may have a circular cross-section. In other words, if the toroidal shape is described as a tubular ring, with the major radius being the distance from the centre of the tube to the centre of the torus and the minor radius being the radius of the tube, then the tube may have a circular cross-section in a plane that includes the centre of the torus. It may instead have a substantially oval shaped cross-section. It may have a substantially pill-shaped cross-section. The balloon may have an overall elongated donut-shape when in the expanded configuration.

[0033] In a set of embodiments, the actuation conduit extends at least partially through the balloon. The actuation conduit may extend fully through the balloon. The actuation conduit may be fixed to a surface (e.g. an upper surface) of the casing so as to provide an anchor for the actuation conduit and optionally also the balloon, so as to keep the balloon in place relative to the casing. A surface of the balloon may be fixed to a surface of the actuation conduit so as to seal the surface of the balloon to the actuation conduit. The second opening of the actuation conduit may be formed in a side wall thereof and communicate directly with the balloon.

[0034] In a set of embodiments, the balloon has a substantially toroidal shape having a central opening extending along a longitudinal axis of the device. The actuation conduit may at least partially extend through the central opening, and the first opening of the actuation conduit may communicate with the balloon at the central opening.

[0035] The central opening of the balloon may be sized so as to accommodate insertion of monitoring instruments therethrough (e.g. pH sensors, temperature sensors, etc.). This may advantageously provide a convenient mechanism for monitoring the user and / or the device without requiring the device to be removed from the user. Where the device has a casing, an instrument hole may be provided in the casing arranged such that instruments may be inserted into the bladder therethrough. The instrument hole may be ideally blocked or closed off by the expandable chamber, e.g. by the balloon, when it is in its expanded configuration so as to prevent urine entering the device through the instrument hole in normal use.

[0036] In a set of embodiments, the balloon may have a fluid inlet located in a side-wall of the central opening. The actuation conduit may comprise one or more fluid outlets located in the side wall thereof and operably coupled to the fluid inlet(s) of the balloon. The actuation conduit may extend through the central opening and be fixed to the interior surface of an end wall of the device. Such embodiments may advantageously provide a mechanism for holding the balloon in place relative to the casing.

[0037] In a set of embodiments, the balloon has a substantially toroidal shape and is positioned adjacent to a resilient portion of the urine conduit, the balloon being arranged to collapse the urine conduit when in the expanded configuration so as to prevent urine flow from the urine inlet to the urine outlet through the urine conduit. The substantially toroidal balloon may be fixed to an exterior surface of a wall of the urine conduit. The balloon may be restricted from expanding in an outwards direction by a restraining member. The toroidal balloon may be fixed to an interior surface of the wall of the urine conduit, and the wall of the urine conduit may be prevented from expanding in an outwards direction by a restraining member. The restraining member may comprise a stiff mesh.

[0038] The device may comprise a sealing member moveable from a first position in which urine flow is prevented from flowing from the urine inlet to a second position in which urine is able to flow from the urine inlet to the urine outlet. The fluid-based actuator may be arranged to move the sealing member between the first and second positions by changing between the expanded and contracted configurations.

[0039] The sealing member may be fixed to the casing at a first end thereof and arranged to abut a wall of the urine conduit so as to form a seal between the urine inlet and the urine outlet. At least a portion of the fluid-based actuator may be fixed to the sealing member. At least a portion of the fluid-based actuator may be fixed to the casing, e.g. to an internal wall of the casing. The fluid-based actuator may be arranged to abut the sealing member. The fluid-based actuator may be arranged to abut the internal wall of the casing. The fluid-based actuator may be located between the sealing member and an interior wall of the casing. The fluid-based actuator may be arranged to bias or force the sealing member into the first position when it is in the expanded configuration. It may be arranged to bias or force the sealing member into the second position when it is in the expanded configuration. The sealing member may comprise a portion of resilient material, and it may be arranged to maintain the first position or the second position when in an unstressed position.

[0040] In a set of embodiments, the device further comprises a resilient outlet tube extending between the urine inlet and the urine outlet. The outlet tube being resilient may enable it to deform as required in order to conform to the shape of the urethra as the user moves, thereby improving comfort for the user and decreasing risk of damage to the user. The resilient outlet tube may form a majority of the urine conduit between the urine inlet and the urine outlet. The urine conduit may further comprise a portion of the casing, e.g. a portion of the inlet portion of the casing. The actuation conduit may extend through the resilient outlet tube, e.g. through a urine flow path therein.

[0041] As noted above, the outlet tube may be long enough to extend through the whole urethra or it may have a length that terminates within the urethra.

[0042] In a set of embodiments, the device is arranged such that, in use, at least a majority of (or all of) the outlet tube is located in the urethra, with the outlet tube being arranged to inhibit movement of the device towards the bladder. The outlet tube may therefore provide a convenient positioning mechanism for preventing the device from entering into the bladder, advantageously ensuring that the device remains in place in use and does not e.g. fully enter into the bladder where it could prevent the device from being used to control urinary flow out of the bladder through the urethra.

[0043] In a set of embodiments, the resilient outlet tube is attached to the casing. In a set of embodiments, the resilient outlet tube is attached to the inlet portion of the casing. In a set of embodiments, the resilient outlet tube is releasably attached to the casing, e.g. to the inlet portion of the casing. This may enable a physician, doctor or nurse who inserts and installs the device in a user to exchange the resilient outlet tube with tubes of different sizes and / or shapes in order to more closely match the anatomy of the user in question. Alternatively, in another set of embodiments the resilient outlet tube is fixedly (or permanently) attached to the casing, e.g. to the inlet portion of the casing. In such embodiments the device may be manufactured in different sizes, and a physician, nurse or doctor may select a device having an outlet tube of the appropriate size for the anatomy of the user in question. Various forms of releasable attachment mechanism may be used. For example, a screw thread or a bayonet mechanism could be used to attach the casing to the outlet tube. However, for speed and security of attachment, a clip mechanism is used in some embodiments to releasably attach the resilient outlet tube to the casing. A clip mechanism may be a snap-on mechanism in which one part is pushed into or onto the other part until a clip engages to secure the two parts together. In some embodiments the casing is inserted inside the outlet tube as this reduces the risk of leakage. In some embodiments the clip mechanism comprises one or more tongues on one part, e.g. the outlet tube, the tongues being arranged to be biased away from their natural, i.e. , non-stressed, position during the engagement process, i.e. during the process of attaching to a structure present on the other part (e.g. the inlet portion of the casing). The tongues may be arranged to return towards their non-stressed position in the clipped state, in which the two parts (e.g. the outlet tube and the casing) are releasably attached. In the clipped state, the one or more tongues may be in a hooked engagement with a structure present on the other part so that release is hindered. The hook may be on the tongues so as to hook the other part, or the hook may be formed on the other part so as to hook the tongues. In the clipped state, a shoulder surface on one part may be in contact with a hook surface on the other part. The angle that these surfaces make to the engagement direction may determine the ease with which the two parts may be disengaged. For example, if the shoulder surface is substantially perpendicular to the engagement direction then separation of the two parts by pulling them apart may be very difficult or impossible. A lower angle may allow a pulling force to bias the tongues away from their non-stressed position to permit disengagement. The clip mechanism may comprise a cylindrical tube provided inside the outlet tube, the cylindrical tube having one or more tongues angled radially inwardly in their non-stressed position and being deformable radially outwardly by insertion of the casing through the cylindrical tube. The casing may have a flange at the end which engages and is attached to the outlet tube, the flange having a larger diameter than the rest of the casing part that inserts inside the outlet tube, the flange section pressing the tongues radially outwardly as it is inserted through the cylindrical tube and the flange section providing the hook surface that engages with the shoulder surface on the distal end of the tongues once it has been inserted beyond the tongues (and the tongues have sprung back radially inwardly towards their non-stressed position).

[0044] In a set of embodiments, at least a portion of the casing (e.g. at least a portion of the inlet portion of the casing) is positioned within a portion of the outlet tube when the outlet tube is attached to the casing. Such a connection may advantageously provide a sealed or water-tight connection between the casing and the outlet tube, thereby ensuring that urine passes from the urine inlet to the urine outlet without leaking out from the side of the device and e.g. becoming trapped in the urethra, thus helping avoid potential health risks. In a set of embodiments, the outlet tube, when in a non-stressed position, comprises a substantially straight portion extending from the urine inlet and a curved portion located between the substantially straight portion and the urine outlet. In other words, the outlet tube may be substantially J-shaped. Such a shape may align with the typical shape of the urethra exiting from the bladder in male users, and thus provide the above-mentioned functionality of inhibiting movement of the device towards the bladder through the interaction of the outlet tube with the natural shape of the urethra. Such embodiments may therefore be particularly suitable for male users of the device.

[0045] In a set of embodiments, the curved portion of the outlet tube permits bending around at least one axis. In a set of embodiments, the curved portion of the outlet tube may permit bending around at least one axis in order to straighten the outlet tube. Such embodiments may advantageously improve ease of insertion and extraction, since the outlet tube may straighten or bend as required to match the shape of the urethra during insertion and extraction, thus reducing the force exerted on the urethra by the outlet tube as it moves therethrough during insertion or extraction.

[0046] In a set of embodiments, the urine outlet is positioned at an end of the resilient outlet tube. The end of the resilient outlet tube may be laterally compressible so as to allow partial collapse of the urine outlet. This may ensure that the outlet tube can be laterally compressed as required in order to prevent it exerting too much force on the urethra during insertion, extraction, or when the device is installed in a user.

[0047] In a set of embodiments, the outlet tube comprises a tapering portion located towards the urine outlet, the tapering portion narrowing towards the urine outlet. This may advantageously reduce the pressure applied by the urine outlet at the end of the outlet tube to the urethral wall during removal of the device from a user, thus improving comfort and reducing risk of damage as well as improving ease of extraction.

[0048] In a set of embodiments, the outlet tube comprises a portion of reinforcing material located near to the urine outlet. The portion of reinforcing material may comprise a reinforcing ring. The reinforcing material may be embedded within a side wall of the outlet tube. The reinforcing material may enclose a portion of the flow path between the urine inlet and the urine outlet. The reinforcing material may be arranged to permit lateral compression and resist expansion. Thus, the reinforcing material may provide sufficient structural rigidity to the outlet tube to enable an extraction tool having an expanding member located at an end thereof to be inserted into the urine outlet at the end of the outlet tube and expanded in order to frictionally grip the device and enable extraction thereof. The use of such an extraction tool may be more difficult without the presence of such a reinforcing material since the material used for the majority of the outlet tube may be too flexible to provide enough friction between it and the expanding member of the tool to enable the device to be extracted through the urethra. In a set of embodiments, the portion of reinforcing material is made from ePTFE. In other embodiments, the portion of reinforcing material may be made from other materials, e.g. nylon, polyester, nitinol, steel, etc.

[0049] In a set of embodiments, the outlet tube comprises one or more holes in a side wall thereof located near to the urine outlet. These holes may provide a convenient mechanism for fastening a suture or thread or flexible line to the outlet tube for use in insertion and / or extraction of the device.

[0050] In a set of embodiments, the outlet tube may be sufficiently stiff (or may have at least a portion which is sufficiently stiff) that it can maintain its shape and / or form so as to maintain a flow path even in the presence of obstructions. For example, when used for treating urinary retention, the stiffness may be selected to ensure a flow path to bypass a physical obstruction such as a tumour or enlarged prostate or to counter the constriction of a sphincter muscle. If required, different outlet tubes with different physical characteristics (e.g. different stiffnesses) can be made available to the physician so that an appropriate or optimal outlet tube can be selected for the condition being treated and can be attached to the casing.

[0051] In a set of embodiments, the outlet tube comprises a constricted portion arranged such that, in use, it is located substantially adjacent to a urethral sphincter. This constricted portion may also aid in positioning the device (both in urinary incontinence treatments and urinary retention treatments), as the urethral sphincter may grip the constricted portion and thus inhibit the device from moving towards the bladder and / or towards the urethra in view of non-constricted portions adjacent thereto. This grip may also provide a seal between the bladder wall and the device, preventing urine from passing into the urethra around the exterior of the device. The outlet tube may comprise a tapering portion which widens from the constricted portion to the remainder of the outlet tube. This may avoid any sharp edges on the exterior surface of the outlet tube.

[0052] In a set of embodiments, the constricted portion of the outlet tube comprises reinforcing material arranged to inhibit kinking and / or constriction of the constricted portion. The reinforcing material may be integrated into a wall of the constricted portion, it may be located adjacent to an interior face of the wall of the constricted portion, or it may be located adjacent to an exterior face of the wall of the constricted portion. The reinforcing material may advantageously ensure that the constricted portion does not significantly bend or kink during insertion and / or removal of the device, thus improving comfort and reducing risk of damage during insertion / extraction. The reinforcing material may advantageously ensure that the constricted portion does not collapse under pressure from the urethral sphincter while the device is installed in a user, thus ensuring that the cross-sectional area of the constricted portion is maintained while the device is installed in a user and therefore does not inhibit the flow of urine. As noted above, this is particularly beneficial in the treatment of urinary retention, but is also advantageous in treatment of urinary incontinence to ensure optimal flow when the valve is open. By way of example, the reinforcing material may comprise a mesh or it may comprise a helical coil. A mesh may be formed from two helical coils wound with opposite senses (e.g. one clockwise and one anticlockwise). The reinforcing material may be formed integrally with the constricted portion. For example, the reinforcing material may be formed integrally with the wall of the constricted portion by overmoulding. For example, the reinforcing material may be placed into a mould and then the material of the wall (and optionally the rest of the outlet tube) may be moulded over and / or around the reinforcing material.

[0053] Alternatively, reinforcement may be provided by shaping of the outlet tube. For example, the outlet tube may comprise one or more ribs or other projections on its internal surface (i.e. projecting into the flow path). The added material of these projections provides resistance against kinking. The presence of one or more ribs or projections at distinct angular positions around the axis is better than a uniform increase in wall thickness as the ribs or projections take up less area in the flow path, thus allowing a large enough cross-sectional area for the desired flow rate. Ribs may be provided along the full length of the outlet tube (which may be easier for manufacturing) or they may be provided only the region (or regions) which require resistance to kinking, e.g. the constricted section adjacent to the skirt. In some embodiments two or more ribs or projections may be arranged to come into contact with each other under bending motion so as to resist further bending (i.e. resist kinking). It is preferred that any ribs or other projections formed in this way have rounded edges and corners (e.g. edges and corners with a radius to prevent sharp changes of direction in the surface). Rounding the edges and corners smooths the surface and hinders bacterial growth.

[0054] In a set of embodiments, the casing comprises a constricted portion which is attached to the outlet tube. The inlet portion of the casing may comprise the constricted portion. The constricted portion of the casing may be at least partly positioned within the constricted portion of the outlet tube when the device is assembled. In a set of embodiments, the constricted portion of the casing is releasably attached to the outlet tube, the constricted portion of the casing being at least partly positioned within the constricted portion of the outlet tube when the outlet tube is attached to the casing. Thus, the casing may be sized appropriately for a strong releasable attachment to the outlet tube.

[0055] In a set of embodiments, the outlet tube is substantially straight. Such a structure is more appropriate for female users as the female urethra is substantially straight. The outlet tube may comprise a flexible plate located near to the urine outlet. The flexible plate may be arranged to remain outside the body and to inhibit movement of the device towards the bladder. This arrangement corresponds to the female anatomy and is therefore particularly suitable for female users. The flexible plate may be integrally formed with the outlet tube or it may be a separate part that is attachable to the outlet tube. A separate part may be advantageous to allow for different lengths of outlet tube which can be selected according to the user’s particular anatomy. In a set of embodiments, the device comprises a resilient skirt arranged, in use, to inhibit movement of the device towards the urethra, the resilient skirt being positioned between the urine inlet and the urine outlet. The resilient skirt may therefore function as a positioning structure. The resilient skirt may extend laterally from the device and thus be arranged to contact the bladder wall if the device moves towards the urethra, thereby inhibiting the device from moving further into the urethra. The skirt being resilient may help ensure that it can conform to the shape of the urethral opening when the device is installed, and thus prevent it from digging into the bladder wall and causing damage or discomfort to the user.

[0056] In a set of embodiments, the resilient skirt is positioned substantially adjacent to the urine inlet. This may ensure that the urine inlet does not move into the urethra and thus prevent fluid communication between the urine inlet and urine contained in the bladder, ensuring the device remains functional while it is installed in a user.

[0057] In a set of embodiments, the resilient skirt and the outlet tube are integrally moulded. This may provide a convenient mechanism for manufacturing the device in a manner which ensures the resilient skirt remains attached to the device in the same position when it is installed. In embodiments where the outlet tube is releasably attachable to the casing and the resilient skirt and the outlet tube are integrally moulded, the skirt may similarly be releasably attachable to the casing by virtue of its integral moulding with the resilient outlet tube. In a set of embodiments, the resilient skirt is formed at an end of the outlet tube. The resilient skirt may be formed at the opposite end of the outlet tube to the urine outlet.

[0058] In a set of embodiments, the resilient skirt comprises one or more radially extending ridges. In a set of embodiments, the resilient skirt comprises a plurality of radially extending ridges having a portion of material extending therebetween, each of the radially extending ridges having a greater thickness than the material extending therebetween. The ridges and the material extending therebetween may be integrally moulded and formed from the same material - e.g. silicone. These ridges may provide resiliency to the skirt so as to cause it to return to a non-stressed position after deviating from the non-stressed position due to external forces applied thereto. In a set of embodiments, the radially outer ends of the radially extending ridges taper in thickness from their thickest points to the thickness of the material extending therebetween. The upper surfaces of the ridges may also have a rounded profile. Such embodiments may advantageously ensure that the surface of the skirt having the radially extending ridges protruding therefrom has an overall smooth surface without any sharp or angled edges.

[0059] In some embodiments, each of the radially extending ridges has a thickness at their thickest point that is at least 2 times greater than a thickness of the material extending therebetween. In some embodiments, each of the radially extending ridges has a thickness at its thickest point that is up to 10 times greater than a thickness of the material extending therebetween. In some embodiments, the radially extending ridges have a thickness at their thickest points of from 0.1 mm to 2 mm. In some embodiments, the portions of material extending between the radially extending ridges have a thickness of from 0.05 mm to 0.5 mm. Such thickness ratios and ranges may provide a good balance of flexibility and resiliency for the skirt.

[0060] In a set of embodiments, when in a non-stressed position, the resilient skirt comprises a first face which is substantially smooth and a second face comprising the radially extending ridges protruding therefrom, the first face facing away from the urine inlet and the second face facing towards the urine inlet. In other words, the radially extending ridges may only be present on one face of the resilient skirt. This may provide the skirt with the required levels of resiliency though inclusion of the ridges while also ensuring that the face which may contact the bladder wall (i.e. the first face facing away from the urine inlet) is smooth so as to minimise the risk of urine getting trapped underneath the skirt. It may also help improve comfort by ensuring that the ridges do not protrude into the bladder wall.

[0061] In a set of embodiments, the resilient skirt, when in a non-stressed position, is substantially planar. The resilient skirt may form a substantially disc-like shape when in a non-stressed position. Such embodiments may enable the skirt to function as a positioning structure as described above. In a set of embodiments, the resilient skirt permits folding so as to conform to the shape of the exterior surface of the outlet tube, and the resilient skirt permits folding so as to conform to the shape of the exterior surface of the casing - e.g. the inlet portion of the casing. In such embodiments, the resilient skirt may permit folding in two different directions - towards the casing, and towards the urine outlet. This may advantageously allow the skirt to collapse around the device when sufficient force is applied thereto so as to enable easy insertion and extraction of the device. In a set of embodiments, the resilient skirt permits folding so as to wrap around the exterior surface of the outlet tube, and the resilient skirt permits folding so as to wrap around the exterior surface of the casing e.g. the inlet portion of the casing. In a set of embodiments, the resilient skirt permits folding into a substantially tube-shaped configuration wrapping around the outlet tube, and the resilient skirt permits folding into a substantially tube-shaped configuration wrapping around the casing e.g. the inlet portion of the casing. The resilient skirt may be arranged to fold into the substantially tube-shaped configuration wrapping around the outlet tube during insertion of the device into a urethra, and to fold into the substantially tube-shaped configuration wrapping around the casing (e.g. the inlet portion of the casing) during removal of the device through the urethra.

[0062] In a set of embodiments, the resilient skirt is arranged, in use, to permit folding into a substantially truncated-cone-shaped configuration located at least partially in a urethral opening of a bladder, with the base of the truncated-cone shape facing towards the bladder. This may enable the skirt to conform to the shape of the urethral opening of the bladder and thus allow the device to sit comfortably within the urethral opening, with the urine inlet located as close to the urethral opening as possible without being obstructed by it, or by the skirt.

[0063] In a set of embodiments, the radially extending ridges have a notch at their radially inner ends. The radially inner ends of the radially extending ridges may taper in thickness from their thickest points to the thickness of the material extending therebetween. The angle of the taper may be selected so as to define the cone angle of the truncated-cone shape. The angle of the taper may be selected so as to match the cone shape of the urethral neck. In some embodiments the angle of the taper may be in a range having a lower end point of 20 degrees, 30 degrees or 40 degrees and having an upper end point of 40 degrees, 50 degrees or 60 degrees, such as 20 to 40 degrees, 20 to 50 degrees, 20 to 60 degrees, 30 to 40 degrees, 30 to 50 degrees, 30 to 60 degrees, 40 to 50 degrees or 40 to 60 degrees. Each of these angles is measured with respect to the axis of the device (i.e. such that an angle of 20 degrees is a narrow notch allowing a lower range of motion and an angle of 60 degrees is a larger notch allowing a greater range of motion).

[0064] The angle of the taper defines a first range of folding of the skirt between the nonstressed configuration of the skirt and the position in which the radially inner taper of the ridges contacts the outer wall of the casing. In this first range of folding, the skirt has a first, low stiffness. Folding up to this point requires only deformation of the thin material between the ridges and the thin material forming the hinge at the base of the radially inner taper. Folding beyond this point, i.e. into a second range of folding requires some deformation of the ridges and thus provides a second, higher stiffness (high relative to the first stiffness, but still being a low enough stiffness that the skirt can fold up completely to wrap around the casing during extraction). The first range of folding with the low stiffness allows the skirt to deform easily and settle in the urethral neck where it can closely conform to the shape of the urethral neck and provide a good seal. The higher stiffness in the second range of folding resists further folding of the skirt so that it does not readily collapse, but instead defines the optimal position of the device within the bladder with the urine inlet positioned to facilitate complete voiding of the bladder.

[0065] In a set of embodiments, the device may comprise an inlet protector extending outwardly from the device from a position between the urine inlet and the urine outlet. The resilient skirt may be or may act as the inlet protector. In other embodiments, the inlet protector may not be resilient but may be a skirt.

[0066] The inlet protector functions to protect the urine inlet by separating it from contact with the bladder wall and thus keeping it out of contact with tissue. Problems can arise when the process of evacuating the bladder causes tissue from the bladder wall to be sucked into the urine inlet. There are a number of issues with this. For example, the tissue can get stuck to the device which blocks the urine inlet. The tissue can also be damaged by this process, resulting in bleeding. Also, small pieces of tissue can lodge within the device causing blockage and biofouling. This reduces the available size of the urine inlet which reduces the flow rate. A high flow rate is better as it flushes any fouling or urine deposits (e.g. due to crystallisation over time of residual urine) out of the device. A lower flow rate is less effective at such flushing so that deposits build up quicker and present a greater infection risk, thus reducing the time that the device can remain in place. As the inlet protector extends outwardly from the device from a position between the urine inlet and the urine outlet (i.e. so that the urine inlet is held more towards the bladder, away from the urethra and the urethral neck) it keeps the urine inlet slightly separated from the bladder wall tissue and thus ensures a good flushing flow rate with reduced risk of fouling.

[0067] In a set of embodiments, the inlet protector is foldable such that it axially overlaps the urine inlet. Here, axially should be interpreted to mean in a direction parallel to a longitudinal axis of the device. In other words, the inlet protector is foldable such that at least one plane can be drawn perpendicular to the longitudinal axis of the device that intercepts both the urine inlet and the inlet protector. The inlet protector may be foldable such that it axially overlaps the entirety of the inlet, or it may axially overlap only a portion of the urine inlet. In some embodiments there may also be overlap in the circumferential direction (either full or partial circumferential overlap) between the inlet protector and the urine inlet. However, in other embodiments there could be axial overlap, but no circumferential overlap, e.g. where the inlet protector comprises flaps that fold up circumferentially adjacent to the urine inlet. Where the urine inlet comprises a plurality of holes in a side wall of the device, the inlet protector may axially overlap at least a hole located axially closest to the urine outlet.

[0068] In a set of embodiments, the skirt or inlet protector reduces in thickness between its radially inner edge and its radially outer edge. The reduction in thickness may be effected by a smooth taper or a stepped taper. In the case of a smooth taper, the thickness may taper between an inner radius and an outer radius. In some examples the inner radius may be the skirt’ s / inlet protector’s radially inner edge. In some embodiments the outer radius may be the skirt’ s / inlet protector’s radially outer edge. In other embodiments the smooth tapered section may extend across only a part (e.g. a middle part) of the skirt / inlet protector. In the case of a stepped taper, the skirt / inlet protector may include one or more step reductions in thickness.

[0069] These step reductions may each be at a given radius (although in other examples they need not necessarily be symmetrical). A stepped taper may be easier to manufacture. The taper (stepped or smooth) is arranged such that the skirt / inlet protector gets thinner towards its radially outer edge (i.e. it gets thinner as the radius increases). This reduces the volume of material in the outer parts of the skirt / inlet protector. The outer parts of the skirt / inlet protector experience more folding (e.g. overlapping) when it is folded up against the outlet tube or inlet section and therefore when the outer parts of the skirt / inlet protector are thinner, these folded sections have a reduced thickness. Thus, in the folded state, the device overall has a smaller diameter which is easier and more comfortable to insert and remove through the urethra. The thicker parts of the skirt / inlet protector at the radially inner side provide the required stiffness to ensure that it unfolds when the device is deployed and resists folding up in normal use (e.g. so that the device is located correctly in the urethral neck). Where the skirt / inlet protector has one or more radially extending ridges as discussed above, these may have a uniform thickness (i.e. be non-tapered) so as to provide greater resilience for deploying and maintaining the skirt / inlet protector in its non-stressed configuration. However, in other examples, the (or each) radially extending ridge may also reduce in thickness between its radially inner edge and its radially outward edge, e.g. it may be tapered (smooth or stepped). The tapering of the radially extending ridges may match the tapering of the thinner material between ridges, i.e. the ridges may maintain a consistent increase in thickness relative to the thinner material between ridges.

[0070] Although the skirt provides a degree of sealing in the urethral neck and the constricted portion of the outlet tube may be held tightly by the urethral sphincter muscle, there is still a possibility in some users of leakage past the skirt and bypassing the device. This may occur particularly for example in the case of users with some scar tissue in the region of the sphincter muscle, e.g. as a result of surgery. The scar tissue has a different hardness to the surrounding tissue and can reduce the sealing quality. Thus, in a set of embodiments, a compressible material is provided around at least a portion of the outlet tube. The compressible material may form a compressible tube or jacket around the outlet tube. If the outlet tube comprises a constricted portion, the compressible material may be provided around the constricted portion so that the overall diameter of the device can be kept low, and also as this is an area particularly prone to poor sealing. The compressible material may be provided in a region that overlaps with the skirt when the skirt is folded against the outlet tube (e.g. during insertion of the device). However, due to the compressibility of the compressible material, the skirt can compress the material such that the compressible material does not cause any increase in overall diameter of the device during insertion. The compressible material is ideally very soft so as to compress easily during insertion and not increase the overall resistance or discomfort to the user. The compressible material may be a foam, optionally a memory foam. The softness of the compressible material will allow it to adapt to the form of the particular user’s urethra, e.g. to deform and seal around any areas of scar tissue and thus provide a seal against bypass leakage. The compressible material may be arranged such that it can compress in the radial dimension by a factor of at least 2, at least 3, at least 4, or at least 5.

[0071] Features of any embodiment described herein may, wherever appropriate, be applied to any other embodiment described herein. Where reference is made to different embodiments or sets of embodiments, it should be understood that these are not necessarily distinct but may overlap.

[0072] BRIEF DESCRIPTION OF THE DRAWINGS

[0073] Certain embodiments of the invention will now be described, by way of example only, and with reference to the accompanying drawings in which:

[0074] Fig. 1 shows a perspective view of a device for controlling urinary flow in accordance with an embodiment of the invention;

[0075] Figs. 2a-f show schematic cross-sections of devices for controlling urinary flow illustrating mechanisms by which urine flow is controlled in accordance with various embodiments of the present invention;

[0076] Fig. 3 shows a side view of an outlet tube for a device for controlling urinary flow in accordance with an embodiment of the invention;

[0077] Figs. 4 & 4b show a distal end of an outlet tube for a device for controlling urinary flow in accordance with an embodiment of the invention;

[0078] Fig. 5 shows a resilient skirt of a device for controlling urinary flow in accordance with an embodiment of the invention;

[0079] Figs. 6a-e show a device for controlling urinary flow in accordance with embodiments of the invention in various positions; Figs. 7a & 7b show devices for controlling urinary flow in accordance with embodiments of the invention when installed in male users;

[0080] Fig. 8 shows a perspective view of a device for controlling urinary flow in accordance with an embodiment of the invention;

[0081] Fig. 9 shows a device for controlling urinary flow in accordance with an embodiment of the invention when installed in a female user;

[0082] Figs. 10a and 10b show a clip mechanism and reinforcement material in accordance with embodiments of the invention;

[0083] Fig. 10c shows two possible profiles for a reinforcement structure;

[0084] Figs. 11a-c show a resilient skirt of a device for controlling urinary flow in accordance with embodiments of the invention;

[0085] Figs. 12a and 12b show a compressible jacket of a device for controlling urinary flow in accordance with embodiments of the invention; and

[0086] Figs. 13a-d and 14a-d show further embodiments of a resilient skirt / inlet protector.

[0087] DETAILED DESCRIPTION OF THE DRAWINGS

[0088] Fig. 1 shows a device 100 for controlling urinary flow in accordance with an embodiment of the invention, in a non-stressed position (i.e. where no external forces are applied thereto). The device 100 comprises a urine inlet 102, a urine outlet 104, a casing 106, a resilient outlet tube 108, a resilient skirt 110, an actuation conduit 112 and a squeeze pump 114. The casing 106 comprises an inlet portion 116 rigidly connected to a cap portion 118 so as to form a water-tight seal e.g. using adhesive. In other embodiments, the casing 106 may instead be formed as a single integrally moulded piece. The inlet portion 116 comprises a plurality of holes 120 formed in the side wall thereof to form the urine inlet 102.

[0089] As will be described in more detail later with reference to Figs. 6a-e and Figs. 7a-b, the device 100 is insertable into a urethra to be positioned in the urethral opening of a bladder, with a majority of the outlet tube 108 extending away from the urethral opening of the bladder into the urethra, and the casing 106 extending away from the urethral opening of the bladder into the bladder.

[0090] The casing 106 and the outlet tube 108 have a substantially circular cross-section in this embodiment and therefore form an overall tube shape. This ensures that there are no sharp or angled edges present on the device 100, thereby improving comfort and reducing risk of damage during insertion, during removal, and while the device is installed in a user.

[0091] The casing 106, specifically the cap portion 118 thereof, is the portion of the device 100 which is first inserted through the urethral meatus when installed in a user. Accordingly, the proximal end of the casing 106 (the cap portion 118 in this embodiment) is rounded in order to reduce the pressure applied to the urethral meatus during insertion, thereby reducing the risk of damage and improving comfort. This also improves comfort while the device is installed in a user in case a user’s bladder comes into contact with the casing 100.

[0092] The inlet portion 116 of the casing 106 is releasably attachable, and partially encased by, the outlet tube 108 e.g. using clips located on the outer surface of the inlet portion 116 of the casing 106 and on the inner surface of the outlet tube 108, so as to allow the outlet tube 108 to be disconnected from the casing 106. A clip mechanism is illustrated in Figs. 10a and 10b which are described in more detail later. This allows the outlet tube 108 to be exchanged with outlet tubes of different sizes and shapes in order to align with the anatomy of the user of the device. When installed in a user, the outlet tube 108 inhibits movement of the device 100 towards the bladder, and the resilient skirt 110 inhibits movement of the device towards the urethra. An embodiment of the outlet tube 108 is described in more detail later with reference to Figs. 3-5.

[0093] A manually controllable valve mechanism is contained within the casing 106 which uses a fluid-based actuator (not shown in Fig. 1) comprising an expandable chamber to control the flow of urine from the urine inlet 102 to the urine outlet 104. This is described in more detail later with reference to Figs. 2a-f. The chamber of the fluid-based actuator is operably connected to the actuation conduit 112 which extends through the outlet tube 108 and terminates at the squeeze pump 114. The actuation conduit permits fluid (e.g. air, water, etc.) to be forced into the chamber of the fluid-based actuator located inside the casing 106, and similarly permits fluid to be removed from the chamber. The squeeze pump 114 can be manually squeezed e.g. using a thumb and a finger in order to force fluid into the chamber of the fluidbased actuator. A valve (not shown in Fig. 1) is also provided along the actuation conduit, e.g. at the point of connection to the squeeze pump 114, to allow fluid to be removed from the chamber of the fluid-based actuator when the valve is opened and prevent fluid from exiting the chamber when the valve is closed.

[0094] Figs. 2a-f show schematic cross-sections of devices 100a-f for controlling urinary flow. These figures illustrate mechanisms by which urine flow is controlled in accordance with various embodiments of the present invention. All of Figs. 2a-f show the casing 106 having holes 120 formed in a wall thereof to form the urine inlet 102, though this may be located in a different location e.g. at the end of the rounded end of the casing in other embodiments. The urine inlet 102 in the side wall, as shown, is preferred for a better (more complete) evacuation of the bladder.

[0095] In the embodiment of Fig. 2a, device 100a comprises a balloon 122a formed from resilient material e.g. silicone which functions as a manually operable valve mechanism, with the balloon 122a functioning as a fluid-based actuator. The balloon 122a is located in the flow path between the urine inlet 102a and the urine outlet (not shown in Fig. 2a). The balloon 122a provides an expandable chamber which, when filled with fluid (e.g. air, water, or any other non-toxic, biocompatible fluid), expands from a contracted configuration to an expanded configuration (the expanded configuration being illustrated in Fig. 2a). When in the expanded configuration, the balloon 122a has a substantially ovoid shape.

[0096] The actuation conduit 112a extends through the urine conduit and is operably coupled to the balloon 122a in order to allow fluid to be forced into and removed from the balloon 122a. The actuation conduit 112a also extends through the balloon 122a and is attached to the internal surface of the proximal end of the casing 106a (e.g. the cap portion 118 where present) in order to keep the balloon 122a in position relative to the inlet holes 120a. One or more holes are formed in the side wall of the actuation conduit 112a in order to allow fluid communication between the actuation conduit 112a and the balloon 122a. Since the cross-sectional area of the actuation conduit 112a is small relative to the cross-sectional area of the urine conduit between the urine inlet 102a and the urine outlet, its presence in the flow path does not significantly impact the overall flow rate of urine out of the bladder. When the balloon 122a is in the contracted configuration, the surface thereof contracts away from the urine inlet 120a, thereby allowing urine to enter the device 100a through the urine inlet 120a. Urine can then flow out of the bladder, past the balloon 122a, i.e. through the device 100a from the urine inlet 120a to the urine outlet (not shown in Fig. 2a), and out of the urethra. When fluid is forced into the balloon 122a, it expands into the expanded configuration shown in Fig. 2a and abuts the peripheral walls of the urine inlet holes 120a, thereby forming a seal which prevents urine from entering the device 100a and prevents further urination. When the balloon 122a is in the expanded configuration, it protrudes slightly into the urine inlet holes 120a in order to ensure that a tight seal is formed therewith. Fluid can then be removed from the balloon 122a in order to move it back to the contracted configuration and thus allow urine to flow through the device 100a.

[0097] Since the balloon 122a prevents urine from entering the device 100a through the urine inlet holes 120a when in the expanded configuration, urine is prevented from pooling within the device 100a for an extended period of time. This advantageously ensures that stored urine does not crystallise within the device 100a and leave residue which can result in damage to the internals of the device 100a (e.g. the balloon 122a) and present a health hazard to the user.

[0098] In the embodiment of Fig. 2b, the device 100b comprises a balloon 122b formed from resilient material which functions as a manually operable valve mechanism, with the balloon 122b functioning as a fluid-based actuator, in much the same manner as described above with reference to Fig. 2a. The device 100b differs from the device 100a shown in Fig. 2a in that the actuation conduit 112b is embedded in the wall of the casing 106b, rather than located in the urine conduit between the urine inlet 102b and the urine outlet (not shown in Fig. 2b). This maximises the cross-sectional area of the flow path between the urine inlet 102b and the urine outlet, thus increasing flow rate, while also protecting the actuation conduit from damage e.g. due to deposits thereon from urine passing through the device 100b. The actuation conduit 112b exits the walls of the casing 106b at a location corresponding to the location of the balloon, and extends partially into the balloon 122b so as to enable fluid communication therebetween. The balloon 122b also has a slightly different overall ovoid shape compared to the balloon 122a shown in Fig. 2a, but otherwise operates in a similar manner. In the embodiment of Fig. 2c, the device 100c comprises a balloon 122c formed from resilient material which functions as a manually operable valve mechanism, with the balloon 122c functioning as a fluid-based actuator, in much the same manner as described above with reference to Fig. 2a and 2b. The balloon 122c differs from the balloons 122a and 122b in that it has an overall toroidal shape having a central opening through which the actuation conduit 112c extends. One or more holes are formed in the side wall of the central opening of the toroidal balloon 122c, and in the side wall of the actuation conduit 112c, which enable fluid communication between the actuation conduit 112c and the balloon 122c.

[0099] In the embodiment of Fig. 2d, the device 100d comprises a balloon 122d formed from resilient material which functions as a manually operable valve mechanism, with the balloon 122d functioning as a fluid-based actuator. The device 100d functions in much the same manner as described above in relation to Fig. 2a. However, in addition to abutting the peripheral walls of the urine inlet holes 120d and forming a seal therewith when in the expanded configuration, the casing 106d further comprises a constricted portion 124d, formed as an annular rim protruding from the internal surface thereof, which the balloon 122d also abuts when in the expanded configuration. This provides additional sealing between the urine inlet holes 120d and the urine outlet (not shown in Fig. 2d), thereby reducing the risk of urine leakage particularly where the device is installed in a user for an extended period of time. This is also particularly useful in embodiments where additional holes are provided in the walls of the casing 106d - e.g. additional holes at the rounded proximal end of the device 100d for allowing instrument insertion therethrough (not shown in Fig. 2d) - since urine flow through such holes to the urine outlet is also prevented by the balloon 122d when in the expanded configuration. In other embodiments, the balloon 122d may not abut the inlet holes 120d in the expanded configuration, but rather only abut the constricted portion 124d of the casing 106d.

[0100] In the embodiment of Fig. 2e, the device 100e comprises a balloon 122e formed from resilient material functioning as a fluid-based actuator, and a resilient sealing member 126e extending from an interior wall of the casing 106e, which together function as a manually operable valve mechanism for controlling the flow of urine.

[0101] The resilient sealing member 126e is formed from a resilient material, e.g. silicone.

[0102] Fig. 2e shows the device 100e when the balloon 122e is in the expanded configuration. When in the expanded configuration, the balloon 122e abuts and pushes against the resilient sealing member 126e in order to force it against the peripheral wall of the urine inlet hole 120e, thereby forming a seal between the urine inlet 102e and the urine outlet (not shown in Fig. 2e). When the balloon 122e is in the contracted configuration, it no longer applies force to the resilient sealing member 126e. As a result of its resilience, the sealing member 126e moves towards the proximal end of the casing 106e, away from the peripheral wall of the urine inlet hole 120e which it abuts when the balloon 122e is in the expanded configuration. In other words the resilience of the sealing member 126e biases it towards the open position. This allows urine to flow through the device 100e from the urine inlet 102e to the urine outlet (not shown in Fig. 2e). Like the device 100b shown in Fig. 2b, the actuation conduit 112e is embedded in the side wall of the casing 106e.

[0103] It will be appreciated that the balloon 122e could equally be located below the resilient sealing member 126e, in which case the same functionality would apply overall except that the resiliency of the sealing member 126e would cause it to abut the peripheral wall of the urine inlet hole 120e when the balloon 122e is in the contracted configuration (thereby preventing urine flow), and the balloon 122e would force the sealing member 126e away from the peripheral wall of the urine inlet hole 120e when in the expanded configuration (thereby allowing urine to flow from the urine inlet 102e to the urine outlet). The resilience of the sealing member 126e would thus bias it towards the closed position rather than the open position.

[0104] In the embodiment of Fig. 2f, the device 10Of comprises a balloon 122f formed from resilient material functioning as a fluid-based actuator and a restraining member 128f formed from a stiff mesh. The balloon 122f has a substantially toroidal shape and surrounds the exterior surface of the casing 106f, adjacent to a resilient portion 130f of the casing 106f. Fig. 2f shows the balloon 122f in a partially expanded state - i.e. somewhere between the contracted configuration and the expanded configuration. When fluid is forced into the balloon 122f via the actuation conduit 112f, it expands. However, it is prevented from expanding outwardly by the restraining member 128f, and therefore expands inwardly towards the resilient portion 130f of the casing 106f. As a result, the resilient portion 130f of the casing 106f collapses inwards. When the balloon 128f is fully expanded (i.e. in the expanded configuration), the resilient portion 130f of the casing 106f collapses enough to prevent urine from flowing through the device 10Of from the urine inlet holes 120f to the urine outlet (not shown in Fig. 2f). Like the device 100b of Fig. 2b, the actuation conduit 112e is embedded in the wall of the casing 106e.

[0105] It will thus be seen that each of the devices 100a-f discussed above comprise a fluid-based actuator with an expandable chamber adjustable from a contracted configuration to an expanded configuration via insertion and removal of fluid through an actuation conduit, and that in one of the expanded or contracted configurations urine is prevented from flowing from the urine inlet to the urine outlet, and in the other configuration urine is able to flow from the urine inlet to the urine outlet. It will be appreciated by those skilled in the art that the various features discussed above in relation to the embodiments of Figs. 2a-f could be combined in any appropriate manner, e.g. by changing from an embedded actuation conduit 112 to an actuation conduit 112 located in the urine conduit or vice versa, etc.

[0106] Fig. 3 shows a resilient outlet tube 108’ for a device 100 for controlling urinary flow in accordance with an embodiment of the invention. This outlet tube 108’ is a different version of the outlet tube to the outlet tube 108 shown in Fig. 1. As described previously with reference to Fig. 1 , the resilient outlet tube 108’ is releasably (and optionally rigidly) connected to the inlet portion 116 of the casing 106 (not shown in Fig. 3 for the sake of simplicity), with the inlet portion 116 of the casing 106 being partially encased by the outlet tube 108’. This connection is also water tight.

[0107] The resilient outlet tube 108’ comprises the resilient skirt 110, a first portion 132 and a second portion 134. The skirt 110 is described in more detail later with reference to Fig. 5. When the resilient outlet tube 108’ is in a non-stressed position, as shown in Fig. 3, the first portion 132 is substantially straight and the second portion 134 is curved. The resilient outlet tube 108’ in this embodiment has a substantially circular cross-section. The first portion 132 comprises a constricted portion 136 having a smaller cross-sectional area than the curved second portion 134. The substantially straight first portion 132 also comprises a tapering portion 138 which has a crosssection which tapers from the cross-sectional area of the constricted portion 136 to the larger cross-section of the curved second portion 134 so as to form the shape of a truncated cone. Two holes 140 are provided in the side wall of the resilient outlet tube 108’ on opposing sides near to the urine outlet 104. These holes 140 are sized to allow a suture or thread or flexible line to be connected to the outlet tube 108’ for insertion and / or extraction of the device.

[0108] It will be appreciated that the inlet portion 116 of the casing 106 comprises a similarly constricted portion for insertion into the constricted portion 136 where the outlet tube 108’ shown in Fig. 3 is used.

[0109] In this embodiment, the resilient skirt 110 is integrally moulded with the outlet tube 108’. This ensures that the resilient skirt 110 stays in position relative to the outlet tube 108’ and the casing 106, and reduces manufacturing complexity (and therefore cost).

[0110] The curved second portion 134 of the outlet tube 108’ curves through an angle of approximately 90° when in a non-stressed position to form an overall J-shape. This shape advantageously aligns closely with the anatomy of the male urethra. As a result, the curved outlet tube 108’ functions as a positioning mechanism when the device 100 is installed in a patient, helping to prevent the device 100 from moving towards the bladder or towards the urethra away from the ideal position where the urine inlet 102 (not shown in Fig. 3) is located close to the urethral opening of the bladder. Since the anatomy of the urethra varies from patient to patient, the outlet tube 108’ is manufactured in a number of different sizes (e.g. three, or more), particularly though not exclusively with regard to the length of the substantially straight first portion 132. A tube of the correct size is selected to match the anatomy of the specific patient. Since the outlet tube 108’ is releasably attached to the inlet portion 116 of the casing 106 (not shown in Fig. 3), the same casing 106 can be used for patients irrespective of their individual anatomy, and only the outlet tube 108’ is selected for a particular patient. This advantageously keeps manufacturing costs down while still enabling the device 100 to be used for any male patient. In particular, an appropriate size of outlet tube 108 can be selected at the time of insertion (e.g. at an operation site) and thus can be selected for the specific patient. This allows inspection, measurement and / or analysis of the patient by a professional before selection of the optimal size of outlet tube 108. Once selected, the chosen outlet tube 108 can be attached quickly, e.g. clipped into place. However, in other embodiments the outlet tube 108’ may be permanently connected to the casing 106.

[0111] The constricted portion 136 also aids positioning. When the device 100 is installed in a user, the constricted portion 136 aligns with the sphincter at the urethral opening of the bladder. The sphincter effectively grips the device 100 at the constricted portion forming a seal therewith. This helps prevent leakage of urine around the device 100, and also helps prevent the device 100 from moving towards the bladder or urethra. The skirt 110 also aids in positioning the device 100, though this is described in more detail later with reference to Figs. 5 and 6a-e.

[0112] The constricted portion 136 in this embodiment comprises reinforcing material integrated into the walls thereof in order to inhibit the constricted portion from significantly bending or kinking during insertion and / or removal from a user, thus improving comfort and reducing risk of damage during insertion / extraction. The reinforcing material further prevents the constricted portion 136 from significantly collapsing under pressure from the urethral sphincter while the device 100 is installed in a user, thus ensuring that the flow path from the urine inlet 102 to the urine outlet 104 is not obstructed by such a collapse. The reinforcing material may take the form of a mesh or a helical coil. In some examples, a mesh may be formed from two helical coils; one with a clockwise spiral and the other with an anticlockwise spiral. The reinforcing material may be moulded integrally with the walls, e.g. by overmoulding.

[0113] Alternatively, reinforcement may be provided by shaping of the outlet tube. Two examples of internal shaping are shown in Fig. 8c. Each of these shows four ribs 169 (although any number may be used) on the internal surface of the outlet tube 108, projecting into the flow path. The added material of these projections provides resistance against kinking while not adversely reducing the area of the flow path and thus allowing a desired flow rate to be maintained. The ribs 169 may be provided along the full length of the outlet tube or they may be provided only in the constricted section 136. Although not illustrated in the figure, the ribs 169 will be preferably formed with a radius on each edge 169a and a radius at each corner 169b to prevent sharp changes of direction in the surface. Rounding the edges and corners smooths the surface and hinders bacterial growth.

[0114] The outlet tube 108’ may be exchanged for a different type of positioning mechanism in order to allow the device 100 to be used for female patients. Such outlet tubes may have a substantially different overall shape than the outlet tube 108’ used for male patients, e.g. being substantially shorter, being substantially straight (i.e. not forming an overall J-shape), and optionally having a radially extending, flexible plate located near to the urine outlet to prevent the device from slipping further into the bladder.

[0115] The outlet tube 108’ also comprises a tapering portion 142 at the end thereof closest to the urine outlet 104. This tapering portion 142 reduces pressure applied by the urine outlet 104 to the urethral wall during removal of the device 100 from a user, thus improving comfort and reducing risk of damage during extraction. The outlet tube 108’ further comprises a reinforcing ring (not shown in Figs. 3a and 3b).

[0116] The outlet tube 108 may be sufficiently stiff (or may have at least a portion which is sufficiently stiff) that it can maintain its shape and / or form so as to maintain a flow path even in the presence of obstructions. For example, when used for treating urinary retention, the stiffness may be selected to ensure a flow path to bypass a physical obstruction such as a tumour or enlarged prostate or to counter the constriction of a sphincter muscle. Different outlet tubes 108 with different physical characteristics (e.g. different stiffnesses) can be made available to the physician so that an appropriate or optimal outlet tube can be selected for the condition being treated and can be attached to the casing 106.

[0117] Fig. 4a shows a cut-through of the outlet tube 108’ in more detail. The outlet tube 108’ comprises a reinforcing ring 144 embedded in the wall of the outlet tube 108’, near to the urine outlet 104. The reinforcing ring 144 in this embodiment is located at the point along the outlet tube 108’ at which the tapering portion 142 is widest. The reinforcing ring 144 is formed from a material that permits lateral compression so as to compress the end of the outlet tube 108’, but resists expansion when force is applied outwardly from within the ring 144. In this embodiment the reinforcing ring 144 is formed from ePTFE. The reinforcing ring 144 provides a level of structural rigidity to the end of the outlet tube 108’ when an outward force is applied thereto from inside it, since the remaining material of the outlet tube 108’ is more flexible as set out in more detail below with reference to Figs. 6a-e. This means that an extraction tool having an expanding member located at an end thereof can be inserted into the outlet tube 108’ and expanded in order to remove the device 100 from the user through the urethra. The reinforcing ring 144 provides a sufficiently high reaction force to the expanding member of the extraction tool in order to ensure that the friction between the tool and the outlet tube 108’ is sufficient to allow removal of the device 100.

[0118] Fig. 4b shows a cross-section of the outlet tube 108’. It can be seen that in this embodiment the reinforcing ring 144 has a substantially circular cross section - i.e. having the shape of an o-ring. However, in other embodiments the reinforcing ring 144 may have any appropriate shape, e.g. having a substantially rectangular crosssection thereby forming a sheath. In other embodiments the reinforcing ring 144 may be formed from a thread with high tensile strength encircling the flow path within the outlet tube 108’ and embedded within the wall of the outlet tube 108’.

[0119] Fig. 5 shows the resilient skirt 110 in more detail, shown in its non-stressed position. The skirt 110, in its non-stressed position, is substantially planar, and forms an overall disc-like shape. It comprises four radially extending ridges 146 protruding from a first face 148 thereof (facing towards the urine inlet 102 of the device 100 when the outlet tube 108, 108’ is attached to the inlet portion 116 of the casing 106). The second, opposite face 150 is substantially smooth, and is designed for contact with the bladder wall when the device 100 is installed in a user. Extending between the four radially extending ridges 146 is a portion of comparatively thin material 152.

[0120] The four radially extending ridges 146 provide the skirt 110 with resiliency - i.e. they ensure that the skirt 110 returns to the non-stressed position shown in Fig. 5 after being deformed away therefrom through application of an external force. The portions of comparatively thin material 152, provide the skirt 110 with flexibility, and are able to fold in on themselves in certain circumstances. This is shown in more detail in Figs. 6a-e. The skirt 110 in this embodiment is formed as a single integrally moulded piece, which is also integrally moulded with the outlet tube 108, 108’, connected thereto at the end opposite the urine outlet 104 (e.g. at the constricted portion 136 in the embodiment of Fig. 3), and formed from silicone. The radially outer ends of the radially extending ridges 146 taper in thickness from their thickest points to the level of the thin material 152 extending therebetween so as to form an overall smooth surface without any sharp or angled edges. The upper surfaces of the ridges 148 (the surface furthest from the thin material 152) also has a rounded profile without sharp edges.

[0121] In this embodiment, the radially extending ridges 146 are about five times thicker (at their thickest points) than the portions of comparatively thin material 152 extending therebetween - with the ridges 146 being approximately 1 mm thick and the material 152 being approximately 0.2 mm thick. This is not limiting, however. Different thicknesses and / or ratios could be applied in other embodiments.

[0122] The resilient skirt 110 aids positioning of the device 100 within the bladder. In particular, the resilient skirt 110 extends laterally from the device 100 and thus contacts the bladder wall or the urethral neck if the device moves towards the urethra. This causes the skirt to bend and fold, but as the skirt 110 cannot exit through the urethra until it has folded up, its resilience provides resistance to this movement and thus inhibits the device from moving further into the urethra (in the absence of a strong enough force). As the skirt 110 folds and deforms in the urethral neck, it remains in good contact with the bladder wall, thereby continuing to guide urine towards the urine inlet 102. If the device 100 is pulled a small amount in the direction of exiting the bladder, the resilience of the skirt 110 will help to encourage the device back towards the bladder such that the skirt 110 is closer to its natural, non-stressed state. In this way, the skirt 110 helps to position the device 100 optimally within the bladder.

[0123] Figs. 6a-e show various perspective views of the device 100 illustrating how it can deform in various ways. Each of these figures shows many of the same parts of the device 100 as shown in Figs. 1-5, though the provision of reference signs for all features of the device 100 in the figures is omitted here for ease of understanding. Furthermore, part of the casing 106 is not shown in Figs. 6a-e for the sake of simplicity. While the outlet tube 108 shown in Figs. 6a-e is the same version as that shown in Fig. 1, and therefore does not have some features which are present in the version 108’ of Figs. 3 and 4a-b, it will be appreciated that the bending and straightening functionality of the outlet tubes 108’ is the same as that shown in Figs. 6a-e for this version of the outlet tube 108.

[0124] Fig. 6a shows the outlet tube 108 in a non-stressed position, forming an overall J- shape as discussed previously with reference to the outlet tube 108’ of Figs. 3 & 4a- b. Fig. 6a also shows the resilient skirt 110 in a non-stressed position, extending radially from the outlet tube 110 and forming a substantially planar shape as discussed previously with reference to Fig. 5.

[0125] Fig. 6b shows how the skirt 122 can fold towards the outlet tube 108, and towards the inlet portion 116 of the casing 106. Fig. 6b also shows how the curved section 134 of the resilient outlet tube 108 can bend in order to substantially straighten the outlet tube 108.

[0126] Fig. 6c shows the device 100 in a substantially straight configuration, where the curved portion 134 of the resilient outlet tube 108 has been substantially straightened. The device 100 substantially adopts this configuration whilst the device is being inserted into a urethra, although it will bend in order to pass around any bends in the urethra as will be appreciated by those skilled in the art.

[0127] Furthermore, Fig. 6c shows the skirt 110 in a folded configuration wrapping around the outlet tube 108. The skirt 110 adopts this configuration while the device is being inserted into a urethra. This allows the device 100 to have an overall small cross- sectional area, and avoids the skirt 110 from inhibiting insertion of the device 100 into a user.

[0128] Fig. 6d shows the device 100 where the outlet tube 108 is in a substantially nonstressed configuration, and the skirt 110 is folded into a substantially truncated- cone-shaped configuration. This is the natural state of the device 100 whilst it is installed in a male user, when held in the optimal position where the casing 106 is located within the bladder, the outlet tube 108 is located in the urethra, and the skirt 110 is located at least partially in the urethral opening and conforming to the shape thereof. In the embodiments shown in Figs. 6a-e, the outlet tube 108 does not include a constricted portion 136 since it shows a different version of the device 100. However, it will be appreciated that the outlet tube 108 can include the constructed portion 136 located adjacent to the skirt 110 and thus gripped by the urethral sphincter when the device 100 is installed, as described previously.

[0129] Fig. 6e shows the device 100 in a substantially straight configuration like Fig. 6c, except that it shows the configuration of the device 100 during extraction from a user. The overall configuration is the same as that shown in Fig. 6c, except that the skirt 110 is in a folded configuration wrapping around the inlet portion 116 of the casing 106, rather than around the outlet tube 108.

[0130] Fig. 7a shows the device 100 when installed in a male user with benign prostatic hyperplasia (BPH). It can be seen that the casing 106 is located inside the bladder 200, the outlet tube 108 is located inside the urethra 202, and the skirt 110 is partially located inside the urethral opening 204 of the bladder 200. The actuation conduit 112 extends through the urethra 202 out of the urethral meatus 208 to a location outside the body, and the pump 114 is located outside the body. Users with BPH have an enlarged prostate 206. The outlet tube 108 for such users therefore comprises a longer straight section 132 in order to accommodate this.

[0131] Fig. 7b shows the device 100 when installed in a male user post robotic-assisted laparoscopic prostatectomy (post-RALP). Post-RALP users do not have a prostate, since this is removed during the procedure. The device 100 sits in the same location relative to the bladder 200 and the urethra 202 as described above with reference to Fig. 7b. However, since the prostate is not present, the outlet tube for such users comprises a shorter straight section 132 in order to accommodate this.

[0132] Fig. 8 shows a device 100’ for controlling urinary flow in accordance with an embodiment of the invention. All components of the device 100’ are the same as described previously with reference to Figs. 1 , 2 and 5 for the device 100, except the outlet tube 108” is different. It comprises a substantially straight portion 154, and a flexible plate 156 located near to the urine outlet 104. This arrangement aligns with the female anatomy and is therefore particularly suitable for female users, since the female urethra is significantly shorter than a male’s and is substantially straight. The flexible plate 156 remains outside of the body and inhibits movement of the device towards the bladder. The substantially straight portion 154 and the flexible plate 156 are formed from resilient, flexible material e.g. silicone.

[0133] Fig. 9 shows the device 100’ when it is installed in a female user. It can be seen that the casing 106 is located inside the bladder 200’, the substantially straight portion 154 of the outlet tube 108” is located inside the urethra 202’, and the skirt 110 is partially located inside the urethral opening 204’ of the bladder 200’. The flexible plate 156 is located outside the body, near to the urethral meatus 208’. The actuation conduit 112 extends through the urethra 202’, out of the urethral meatus 208’ to a location outside the body, and the pump 114 is located outside the body.

[0134] Fig. 10a shows a cross-section of a J-shaped outlet tube 108’” which is similar to those already discussed above. However, the outlet tube 108’” illustrates two additional features (which may also be applied to the other outlet tubes 108, 108’, 108” discussed above, either both or only one of the additional features). Firstly, the outlet tube 108’” has reinforcing material 190 embedded therein in the region of the constricted portion 128. The reinforcing material 190 serves to resist kinking of the outlet tube 108’” in the region where its wall is thinnest (i.e. in the constricted portion 136) while also providing resistance against collapse from the surrounding sphincter muscle when the outlet tube 108’” is installed in a user. The reinforcing material 190 is formed as a mesh from two helical wires. One helical wire is wound in a clockwise sense and the other helical wire is wound in an anticlockwise sense.

[0135] Figs. 10a and 10b also show a female part 160 of a releasable attachment mechanism in the form of a clip mechanism which is mounted in the upper end of the outlet tube 108’” adjacent to the skirt 110 and is arranged to receive a portion of the casing 106. The male part 162 of the clip mechanism comprises a flange 164 formed on the end of the casing 106.

[0136] The female part 160 comprises a cylinder embedded within the outlet tube 108’” and having a plurality of resilient tongues 166 each of which bends radially inwardly when in its non-stressed position. However, each tongue 166 can be pressed radially outwardly, e.g. by the flange 164 passing through the cylinder of the female part 160. Once the flange 164 has passed the bottom of the tongues 166, they snap back into their non-stressed position (or close to it - they may be in contact with the outer wall of the casing 106) above the flange, thus holding the flange securely beneath the tongues 166. The upper end of the flange 164 (the proximal end) forms a hook surface 167 which engages with a shoulder surface 168 on the bottom (distal side) of the tongues 166. The engagement of these surfaces 167, 168 hinders separation of the casing 106 from the outlet tube 108”’, thus ensuring that the two parts are held securely together in use.

[0137] Figs. 11a-c show a resilient skirt 110’ similar to that shown in Fig. 5. Fig. 11a is a plan view, Fig. 11 b is a cross-section through the line A-A of Fig. 11a and Fig. 11c is a perspective view. As with the skirt 110 of Fig. 5, the skirt 110’ is shown in its non-stressed position and it has four radially extending ridges 146 protruding from a first face 148. The opposite face 150 is substantially smooth. Extending between the four radially extending ridges 146 is a portion of comparatively thin material 152. The difference between the skirt 110 of Fig. 5 and the skirt 110’ of Figs. 11a-c is that the radially extending ridges 146 of the skirt 110’ each have a notch 170 at their radially inner ends. The notch 170 is formed from a tapered surface 172 that tapers from the thickest part of the ridge 146 down to the thinnest part (which may be the same thickness as the portion 152, although this is not essential). The notch 170 acts like a hinge. The reduced thickness of the skirt 110’ in this area makes it more flexible and allows easier folding within a range of folding defined by the angle of the taper 172. The angle of the taper 172 is chosen such that when the tapered surface 172 abuts the outside of the casing of the device, the skirt 110’ forms a truncated cone shape as shown in Fig. 6d, but with a particular cone angle defined by the taper angle. This angle may be designed to match the taper that is typically found in the urethral neck. This allows the skirt 110’ to fold readily into this position inside the bladder, but the contact of the tapered surface 172 with the casing resists further folding such that it can hold this form and retain its position within the bladder. Further folding of the skirt 110’ is possible when sufficient force is applied, e.g. to remove the device back through the urethra. Under such force, the skirt 110’ folds into a second range of folding in which the ridges 146 are deformed and the skirt wraps around the outside of the casing of the device. It will be appreciated that the notches 170 of Figs. 11a-c may be applied to the skirt 110 of any other embodiment. Figs. 12a and 12b show another feature that may be included in any of the other embodiments described here. Fig. 12a is a side view and Fig. 12b is a crosssection of an outlet tube 108”” which features a jacket 180 of compressible material around the constricted portion 136. The jacket 180 is formed from a very soft material, such as foam, that is able to compress to a high degree (e.g. its thickness can be compressed by a factor of at least three. The jacket 180 can thus easily compress during installation and removal, but will also expand around the outlet tube 108”’ to conform to the shape of the urethra. As the jacket 180 in this embodiment is formed around the constricted portion 136 the jacket 180 will conform to the inside of the urethra in the region of the sphincter muscle. This area can be prone to scarring after surgery which is a common cause of leakage due to the different textures of the scar tissue and healthy tissue. In particular, scar tissue is harder and less compressible. The jacket 180 thus provides an additional seal that can avoid bypass leakage of any urine that manages to pass the skirt 110 and the urine inlet holes 102.

[0138] Figs. 13a-d show further embodiments of a resilient skirt 110. The skirt 110 also acts as an inlet protector that can fold over the urine inlet 102 during withdrawal of the device 100 through the urethra, protecting the tissue in the urethra from any sharper edges, e.g. of the urine inlet holes 120. Fig. 13a is a section view, Fig. 13b is a perspective view showing the section of Fig. 13a. Fig. 13c is a plan view and Fig. 13d is a perspective view of the whole skirt 110. The skirt 110 in this example has five radially extending ridges 146, with a comparatively thinner web of material 152 extending between the ridges 146. As can be seen in Fig. 13a, the skirt has a tapered section 220 which reduces in thickness between its radially inner edge 221 and its radially outer edge 222. The reduction in thickness is achieved via a smooth taper from the skirt’s radially inner edge 221 to the skirt’s radially outer edge. The taper reduces the volume of material in the outer parts of the skirt. The outer parts of the skirt experience more folding (e.g. overlapping) when the skirt is folded up against the outlet tube (as shown in Fig. 6c) or inlet section (as shown in Fig. 6e). For example, to reduce the outer circumference of the skirt down to the outer circumference of the outlet tube 108, the skirt 110 must become folded over itself. As the wider parts of the skirt 110 (with the greatest radius) are thinner, these folded sections have a reduced thickness and the overlaps (whether these are overlaps just of the thin webbing part 152 with itself or overlaps of the webbing 152 with ridges 146) are correspondingly thinner. Thus, in the folded state, the device 100 overall has a smaller diameter which is easier and more comfortable to insert and remove through the urethra. The thicker parts of the skirt 110 at the radially inner side provide the required stiffness to ensure that the skirt unfolds when the device is deployed and resists folding up in normal use (e.g. so that the device is located correctly in the urethral neck). As shown in Figs. 13a-d, the five radially extending ridges 146 are also tapered so that they reduce in thickness between the radially inner edge 221 and radially outward edge 222. The tapering of the radially extending ridges 146 matches the tapering of the thinner web 152 between ridges 146, i.e. the ridges 146 always have the same height above the thinner material 152.

[0139] Figs. 14a-d are similar to Figs. 13a-d, but instead of a smooth taper, the skirt 110, which again also acts as an inlet protector, has a stepped taper. The stepped tapered section 230 in this embodiment comprises three sections of different thicknesses 230a, 230b, 230c and thus the skirt 110 includes two step reductions in thickness between these three sections. Each step reduction takes place at a particular radius so that each of the three sections 230a, 230b, 230c is a ring of constant thickness. As can be seen in Fig. 14a, the five radially extending ridges 146 are also stepped down in thickness in the same manner (and with the step reductions taking place at the same radii as for the thinner material 152).

[0140] It will be appreciated that, although the tapering of Figs. 13 and 14 is shown in isolation, these features can be combined with the other features described elsewhere and in relation to the other figures.

[0141] It will be appreciated by those skilled in the art that the invention has been illustrated by describing one or more specific embodiments thereof, but is not limited to these embodiments; many variations and modifications are possible, within the scope of the accompanying claims.

[0142] Certain specific embodiments of the invention will now be set out by way of example:

[0143] Embodiment 1. A device for controlling urinary flow, comprising: a urine inlet; a urine outlet; a fluid-based actuator comprising an expandable chamber, the fluid-based actuator being adjustable between a contracted configuration in which the chamber contains a first volume of fluid and an expanded configuration in which the chamber contains a second volume of fluid, the second volume being greater that the first volume; an actuation conduit through which fluid may be forced into the chamber and / or through which fluid may be removed from the chamber; wherein: when the fluid-based actuator is in one of the contracted and the expanded configurations, urine is able to flow from the urine inlet to the urine outlet; and when the fluid-based actuator is in the other of the contracted and the expanded configurations, urine is prevented from flowing from the urine inlet to the urine outlet.

[0144] Embodiment 2. A device as set out in embodiment 1 , wherein the device is insertable into a urethra for installation in a user’s bladder and urethra and wherein the device is arranged such that, in use, the urine inlet is located in the bladder and the urine outlet is located in the urethra.

[0145] Embodiment 3. A device as set out in embodiment 1 or 2, wherein the actuation conduit is an actuation conduit through which fluid may be forced into the chamber and through which fluid may be removed from the chamber.

[0146] Embodiment 4. A device as set out in any preceding embodiment, wherein the actuation conduit has a first opening located at or near to a first end of the actuation conduit and operably coupled to a fluid inlet of the fluid-based actuator, and a second opening located at or near to a second end of the actuation conduit which is arranged to be located outside the body when the device is installed in a user.

[0147] Embodiment 5. A device as set out in any preceding embodiment, wherein the actuation conduit extends through the urethra to a location outside the body when the device is installed in a user. Embodiment 6. A device as set out in any preceding embodiment, wherein the device comprises a urine conduit extending between the urine inlet and the urine outlet thereby forming a flow path between the urine inlet and the urine outlet.

[0148] Embodiment 7. A device as set out in embodiment 6, wherein the actuation conduit is formed within a wall of the urine conduit.

[0149] Embodiment 8. A device as set out in any preceding embodiment, wherein the device comprises a valve for preventing fluid from exiting the chamber of the fluid-based actuator.

[0150] Embodiment 9. A device as set out in embodiment 8, wherein the valve is a manually operable valve.

[0151] Embodiment 10. A device as set out in embodiment 8 or 9, wherein the valve is arranged to be located outside of the body when the device is installed in a user.

[0152] Embodiment 11. A device as set out in embodiment 8, 9 or 10, wherein the valve is releasable by a user so as to allow the user to commence urination.

[0153] Embodiment 12. A device as set out in any of embodiments 8 to 11, wherein the valve can be operated between a first configuration and a second configuration, wherein in the first configuration fluid is prevented from passing through the actuation conduit from the chamber of the fluid-based actuator and in the second configuration fluid is able to pass through the actuation conduit from the chamber of the fluid-based actuator.

[0154] Embodiment 13. A device as set out in any preceding embodiment, wherein the fluid is a liquid and the device further comprises a pump arranged to force such liquid through the actuation conduit into the chamber of the fluid-based actuator.

[0155] Embodiment 14. A device as set out in embodiment 13, wherein the pump is arranged to be located outside the body when the device is in use. Embodiment 15. A device as set out in embodiment 13 or 14, wherein the pump is releasably attachable to a or the second end of the actuation conduit.

[0156] Embodiment 16. A device as set out in embodiment 13, 14 or 15, wherein the pump is manually operable.

[0157] Embodiment 17. A device as set out in any of embodiments 13 to 16, wherein the pump is located between the expandable chamber and a storage reservoir.

[0158] Embodiment 18. A device as set out in any of embodiments 13 to 17, wherein the pump comprises a squeeze pump.

[0159] Embodiment 19. A device as set out in any of embodiments 13 to 18, wherein the pump is arranged to force enough fluid into the fluid-based actuator to change it from the contracted configuration to the expanded configuration with a single actuation thereof.

[0160] Embodiment 20. A device as set out in any preceding embodiment, wherein the device comprises a casing extending from the urethral opening of the bladder into the bladder when the device is installed in a user.

[0161] Embodiment 21. A device as set out in embodiment 20, wherein the urine inlet is formed in a wall of the casing, optionally a side wall of the casing.

[0162] Embodiment 22. A device as set out in embodiment 20 or 21 , wherein the fluid-based actuator is at least partly located within the casing.

[0163] Embodiment 23. A device as set out in any preceding embodiment, wherein the expandable chamber comprises a balloon.

[0164] Embodiment 24. A device as set out in embodiment 23, wherein the balloon is made of an elastic material, optionally silicone.

[0165] Embodiment 25. A device as set out in embodiment 23 or 24, wherein the balloon is located in the flow path between the urine inlet and the urine outlet. Embodiment 26. A device as set out in embodiment 23, 24 or 25, wherein the balloon is arranged to abut the urine inlet when in the expanded configuration thereby blocking or closing off the urine inlet and preventing urine from entering the device therethrough.

[0166] Embodiment 27. A device as set out in any of embodiments 23 to 26, wherein the urine inlet comprises one or more holes formed in a wall of the casing, and wherein the balloon is arranged to abut a peripheral wall of each hole when in the expanded configuration thereby preventing urine from entering the device therethrough.

[0167] Embodiment 28. A device as set out in embodiment 27, wherein the balloon is arranged to protrude into each hole when in the expanded configuration so as to form a seal with the peripheral wall of each hole.

[0168] Embodiment 29. A device as set out in any of embodiments 23 to 28, wherein the urine conduit comprises a constricted portion located between the urine inlet and the urine outlet; and wherein the balloon is arranged to abut an inner surface of the constricted portion of the urine conduit when in the expanded configuration so as to prevent urine from flowing from the urine inlet to the urine outlet through the urine conduit.

[0169] Embodiment 30. A device as set out in any of embodiments 23 to 29, wherein the actuation conduit is fixed to a surface of the casing so as to provide an anchor for the actuation conduit and optionally also the balloon.

[0170] Embodiment 31. A device as set out in any of embodiments 23 to 30, wherein the balloon has a substantially toroidal shape having a central opening extending along a longitudinal axis of the device.

[0171] Embodiment 32. A device as set out in embodiment 31 , wherein the central opening of the balloon is sized so as to accommodate insertion of monitoring instruments therethrough. Embodiment 33. A device as set out in any preceding embodiment, wherein the device has a casing and wherein the casing comprises an instrument hole arranged such that instruments may be inserted into the bladder therethrough.

[0172] Embodiment 34. A device as set out in embodiment 33, wherein the instrument hole is blocked or closed off by the expandable chamber when it is in its expanded configuration so as to prevent urine entering the device through the instrument hole.

[0173] Embodiment 35. A device as set out in any of embodiments 23 to 34, wherein the balloon has a substantially toroidal shape and wherein the balloon is positioned adjacent to a resilient portion of the urine conduit, the balloon being arranged to collapse the urine conduit when in the expanded configuration so as to prevent urine flow from the urine inlet to the urine outlet through the urine conduit.

[0174] Embodiment 36. A device as set out in embodiment 35, wherein the balloon is fixed to an exterior surface of a wall of the urine conduit.

[0175] Embodiment 37. A device as set out in embodiment 35 or 36, wherein the balloon is restricted from expanding in an outwards direction by a restraining member.

[0176] Embodiment 38. A device as set out in embodiment 35, 36 or 37, wherein the balloon is fixed to an interior surface of the wall of the urine conduit, and wherein the wall of the urine conduit is prevented from expanding in an outwards direction by a restraining member.

[0177] Embodiment 39. A device as set out in embodiment 37 or 38, wherein the restraining member comprises a stiff mesh.

[0178] Embodiment 40. A device as set out in any preceding embodiment, wherein the device comprises a sealing member moveable from a first position in which urine flow is prevented from flowing from the urine inlet to a second position in which urine is able to flow from the urine inlet to the urine outlet. Embodiment 41. A device as set out in embodiment 40, wherein the fluidbased actuator is arranged to move the sealing member between the first and second positions by changing between the expanded and contracted configurations.

[0179] Embodiment 42. A device as set out in any preceding embodiment, wherein the device comprises a resilient outlet tube extending between the urine inlet and the urine outlet.

[0180] Embodiment 43. A device as set out in embodiment 42, wherein the device is arranged such that, in use, at least a majority of the outlet tube is located in the urethra.

[0181] Embodiment 44. The device as set out in embodiment 42 or 43, wherein the resilient outlet tube is releasably attachable to the valve section.

[0182] Embodiment 45. The device as set out in embodiment 44, wherein the device comprises a clip mechanism to releasably attach the resilient outlet tube to the valve section.

[0183] Embodiment 46. A device as set out in any of embodiments 42 to 45, wherein the outlet tube, when in a non-stressed position, comprises a substantially straight portion extending from the urine inlet and a curved portion located between the substantially straight portion and the urine outlet.

[0184] Embodiment 47. A device as set out in embodiment 46, wherein the curved portion of the outlet tube may permit bending around at least one axis in order to straighten the outlet tube.

[0185] Embodiment 48. A device as set out in any of embodiments 42 to 47, wherein the outlet tube comprises a portion of reinforcing material located near to the urine outlet, the reinforcing material arranged to permit lateral compression and resist expansion. Embodiment 49. A device as set out in any of embodiments 42 to 48, wherein the outlet tube comprises one or more holes in a side wall thereof located near to the urine outlet.

[0186] Embodiment 50. The device as set out in any of embodiments 42 to 49, wherein the outlet tube comprises a constricted portion arranged such that, in use, it is located substantially adjacent to a urethral sphincter.

[0187] Embodiment 51. The device as set out in embodiment 50, wherein the constricted portion of the outlet tube comprises reinforcing material.

[0188] Embodiment 52. The device as set out in embodiment 51 , wherein the reinforcing material comprises a mesh and / or one or more helical coils.

[0189] Embodiment 53. The device as set out in embodiment 52, wherein the reinforcing material is formed integrally with the constricted portion.

[0190] Embodiment 54. The device as set out in any of embodiments 42 to 53, further comprising a compressible material, such as a compressible tube or compressible jacket, provided around the outlet tube.

[0191] Embodiment 55. The device as set out in embodiment 54 and embodiment 50, wherein the compressible material is provided around the constricted portion.

[0192] Embodiment 56. The device as set out in embodiment 54 or 55, wherein the compressible material is foam.

[0193] Embodiment 57. The device as set out in any of embodiments 54 to 56, wherein the compressible material is arranged to compress in the radial dimension by a factor of at least 2.

[0194] Embodiment 58. A device as set out in any preceding embodiment, wherein the device comprises a resilient skirt arranged, in use, to inhibit movement of the device towards the urethra, the resilient skirt being positioned between the urine inlet and the urine outlet. Embodiment 59. A device as set out in embodiment 58, wherein the resilient skirt extends laterally from the device and thus is arranged to contact the bladder wall if the device moves towards the urethra, thereby inhibiting the device from moving further into the urethra.

[0195] Embodiment 60. The device as set out in embodiment 58 or 59, wherein the resilient skirt comprises one or more radially extending ridges.

[0196] Embodiment 61. A device as set out in embodiment 58, 59 or 60, wherein the resilient skirt comprises a plurality of radially extending ridges having a portion of material extending therebetween, each of the radially extending ridges having a greater thickness than the material extending therebetween.

[0197] Embodiment 62. The device as set out in embodiment 60 or 61 , wherein the or each radially extending ridge has a notch at its radially inner end.

[0198] Embodiment 63. The device as set out in embodiment 62, wherein the or each radially extending ridge tapers in thickness towards the radially inner edge.

[0199] Embodiment 64. The device as set out in embodiment 63, wherein the angle of the taper is in a range of 20 to 60 degrees to the axis of the device.

[0200] Embodiment 65. A device as set out in any of embodiments 58 to 64, wherein the resilient skirt, when in a non-stressed position, is substantially planar.

[0201] Embodiment 66. A device as set out in any of embodiments 58 to 65, wherein the resilient skirt permits folding so as to conform to the shape of the exterior surface of the outlet tube, and the resilient skirt permits folding so as to conform to the shape of the exterior surface of the casing.

[0202] Embodiment 67. A device as set out in any of embodiments 58 to 66, wherein the resilient skirt permits folding into a substantially tube-shaped configuration wrapping around the outlet tube, and the resilient skirt permits folding into a substantially tube-shaped configuration wrapping around the casing. Embodiment 68. A device as set out in embodiment 67, wherein the resilient skirt is arranged to fold into the substantially tube-shaped configuration wrapping around the outlet tube during insertion of the device into a urethra, and to fold into the substantially tube-shaped configuration wrapping around the during removal of the device through the urethra.

[0203] Embodiment 69. A device as set out in any of embodiments 58 to 68, wherein the resilient skirt is arranged, in use, to permit folding into a substantially truncated- cone-shaped configuration located at least partially in a urethral opening of a bladder, with the base of the truncated-cone shape facing towards the bladder.

[0204] Embodiment 70. The device as set out in any of embodiments 58 to 69, wherein the skirt reduces in thickness between its radially inner edge and its radially outer edge.

[0205] Embodiment 71. The device as set out in embodiment 70, wherein the reduction in thickness forms a smooth taper or a stepped taper.

[0206] Embodiment 72. The device as set out in embodiment 70 or 71 and as set out in any of embodiments 60 to 64, wherein each radially extending ridge reduces in thickness between its radially inner edge and its radially outer edge.

Claims

Claims1. A device for controlling urinary flow, comprising: a urine inlet; a urine outlet; a fluid-based actuator comprising an expandable chamber, the fluid-based actuator being adjustable between a contracted configuration in which the chamber contains a first volume of fluid and an expanded configuration in which the chamber contains a second volume of fluid, the second volume being greater that the first volume; an actuation conduit through which fluid may be forced into the chamber and / or through which fluid may be removed from the chamber; wherein: when the fluid-based actuator is in one of the contracted and the expanded configurations, urine is able to flow from the urine inlet to the urine outlet; and when the fluid-based actuator is in the other of the contracted and the expanded configurations, urine is prevented from flowing from the urine inlet to the urine outlet.

2. A device as claimed in claim 1 , wherein the actuation conduit has a first opening located at or near to a first end of the actuation conduit and operably coupled to a fluid inlet of the fluid-based actuator, and a second opening located at or near to a second end of the actuation conduit which is arranged to be located outside the body when the device is installed in a user.

3. A device as claimed in claim 1 or 2, wherein the device comprises a urine conduit extending between the urine inlet and the urine outlet thereby forming a flow path between the urine inlet and the urine outlet; and wherein the actuation conduit is formed within a wall of the urine conduit.

4. A device as claimed in claim 1, 2 or 3, wherein the device comprises a valve for preventing fluid from exiting the chamber of the fluid-based actuator.

5. A device as claimed in any preceding claim, wherein the device comprises a casing extending from the urethral opening of the bladder into the bladder when the device is installed in a user.

6. A device as claimed in any preceding claim, wherein the expandable chamber comprises a balloon.

7. A device as claimed in claim 6, wherein the balloon is located in the flow path between the urine inlet and the urine outlet.

8. A device as claimed in claim 6 or 7, wherein the balloon is arranged to abut the urine inlet when in the expanded configuration thereby blocking or closing off the urine inlet and preventing urine from entering the device therethrough.

9. A device as claimed in any of claims 6 to 8, wherein the urine conduit comprises a constricted portion located between the urine inlet and the urine outlet; and wherein the balloon is arranged to abut an inner surface of the constricted portion of the urine conduit when in the expanded configuration so as to prevent urine from flowing from the urine inlet to the urine outlet through the urine conduit.

10. A device as claimed in any of claims 6 to 9, wherein the actuation conduit is fixed to a surface of the casing so as to provide an anchor for the actuation conduit and optionally also the balloon.

11. A device as claimed in any of claims 6 to 10, wherein the balloon has a substantially toroidal shape having a central opening extending along a longitudinal axis of the device.

12. A device as claimed in any preceding claim, wherein the device has a casing and wherein the casing comprises an instrument hole arranged such that instruments may be inserted into the bladder therethrough.

13. A device as claimed in claim 12, wherein the instrument hole is blocked or closed off by the expandable chamber when it is in its expanded configuration so as to prevent urine entering the device through the instrument hole.

14. A device as claimed in any of claims 6 to 13, wherein the balloon has a substantially toroidal shape and wherein the balloon is positioned adjacent to a resilient portion of the urine conduit, the balloon being arranged to collapse the urine conduit when in the expanded configuration so as to prevent urine flow from the urine inlet to the urine outlet through the urine conduit.

15. A device as claimed in claim 14, wherein the balloon is fixed to an exterior surface of a wall of the urine conduit.

16. A device as claimed in claim 14 or 15, wherein the balloon is restricted from expanding in an outwards direction by a restraining member.

17. A device as claimed in any preceding claim, wherein the device comprises a sealing member moveable from a first position in which urine flow is prevented from flowing from the urine inlet to the urine outlet to a second position in which urine is able to flow from the urine inlet to the urine outlet; and wherein the fluid-based actuator is arranged to move the sealing member between the first and second positions by changing between the expanded and contracted configurations.

18. A device as claimed in any preceding claim, further comprising a resilient outlet tube extending between the urine inlet and the urine outlet; and optionally wherein the device is arranged such that, in use, the outlet tube is substantially located in a urethra, the outlet tube being arranged to inhibit movement of the device towards the bladder.

19. A device as claimed in claim 18, wherein the outlet tube comprises a constricted portion arranged such that, in use, it is located substantially adjacent to a urethral sphincter.

20. A device as claimed in claim 19, wherein the constricted portion of the outlet tube comprises reinforcing material.

21. A device as claimed in any of claims 18 to 20, further comprising a compressible material, such as compressible tube or compressible jacket, provided around the outlet tube.

22. A device as claimed in claim 21 , wherein the compressible material is provided around the constricted portion.

23. A device as claimed in claim 21 or 22, wherein the compressible material is arranged to compress in the radial dimension by a factor of at least 2.

24. A device as claimed in any preceding claim, wherein the device comprises a resilient skirt arranged, in use, to inhibit movement of the device towards the urethra, the resilient skirt being positioned between the urine inlet and the urine outlet.

25. A device as claimed in claim 24, wherein the resilient skirt permits folding so as to conform to the shape of the exterior surface of the outlet tube, and the resilient skirt permits folding so as to conform to the shape of the exterior surface of the casing.

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