URINE COLLECTION DEVICE

Abstract: A device for collecting urine includes a container (1) kept at vacuum, an interface (27) locatable at the urethral opening of a person and a pump (4) operable to create a vacuum within the container (1). A sensor senses the presence of urine at the interface (27) and opens a valve (8) to allow the pumping of urine from the interface (27) to the container (1).

Description: URINE COLLECTION DEVICE The present invention relates to a urine collection device, the preferred embodiment using a stored vacuum to allow immediate rapid removal of urine at the rate it is produced. Millions of people world wide are afflicted with the problem of urinary incontinence, the economic costs of this distressing condition are extremely high but the cost in terms of human suffering is incalculable. Both men and women are afflicted by the condition although many more women are affected and incidence increases with age. For many younger men external catheter systems provide an adequate solution to the problem of severe urinary incontinence, but these systems are far less satisfactory for older men who are more likely to experience continence problems. For women incontinence management solutions are extremely limited. Internal catheters are associated with a host of medical problems, particularly urinary tract infections and urethral erosions. Large disposable pads to absorb urine are a safer option but are far from an ideal solution. Pads are bulky and require frequent changing if the wearer is to remain comfortable and free from odour problems. For immobile patients and those with sensory loss, wet pads can exacerbate the risk of pressure injury. One of the major problems in designing a device to cope with incontinence is the very high flow rate which is a characteristic of urine flow. During a void the urine flow rate increases rapidly to a peak rate of 25-30 millilitres per second. To pump urine directly requires a powerful pump able to reach a high flow rate as soon as it is activated. This is extremely difficult to achieve and would require a much larger pump and power source than can be easily transported. The present invention seeks to provide a urine collection device. According to an aspect of the present invention, there is provided a urine collection device as specified in claim 1. According to another aspect of the present invention there is provided a method of collecting urine as specified in claim 9. The preferred embodiment provides a device for use by individuals who are unable to control the flow of urine or who are not technically incontinent but whose limited mobility makes transfer to the toilet extremely difficult. The preferred embodiment is designed to remove urine at the rate at which it is produced either from an interface positioned in the patient's underwear or from a portable urinal. The device uses a vacuum reservoir, maintained in a rigid storage container, to produce a strong suction at the moment the device is activated. Various embodiments of the present invention is described below, by way of example only, with reference to the accompanying drawings, in which: Figure la shows an embodiment of large capacity device system with flat disc filter; Figure lb is a cross-sectional view of the large capacity device with flat disc filter; Figure lc is an enlarged cross-sectional view of top of the large capacity device with flat disc filter; Figure 2a is a cross-sectional view of an alternative embodiment of large capacity device with cartridge filter. Figure 2b is a enlarged cross-sectional view of the top of the large capacity device of Figure 2a; Figure 3a shows an embodiment of complete small capacity device; Figure 3b is a cross-sectional view of the small capacity device of Figure 3a; Figure 3c is an enlarged cross-sectional view of the top of the small capacity device of Figure 3a; Figure 4 shows another embodiment of small capacity device system with ovoid storage container to fit in waist worn bag; Figure 5a shows an example of layered female interface; and Figure 5b is a cross-sectional view of the layered female interface of Figure 5a. Two basic versions of the device are described below, which can be triggered by two different methods. The first described version is designed for individuals who are in wheelchairs and incorporates a very large capacity storage container which could contain as much urine as would be produced in a twelve hour period. The second described version is designed for individuals who are mobile and self-sufficient and has a small container which would need to be emptied after each operation. The basic operation of the preferred device. The device described comprises four main parts :- 1. A rigid container which is connected by a tube to a small pump and pressure switch or vacuum transducer and switch. The pump evacuates air from the container until it reaches a set vacuum at which the pressure switch or vacuum transducer and switch, turns off the pump. The pressure switch or vacuum and transducer and switch, is set so that every time the vacuum falls slightly below the set vacuum, the pump will activate again. By this means a vacuum is maintained in the container. There is a hydrophobic filter between the pump and the urine storage container to prevent liquid from being pumped out of the container. The pump may, for example, be a diaphragm or piston pump or any other suitable pump. 2. The interface, tube from the interface to the container and valve. The interface is connected to the container by a long flexible tube. The valve acts on the tube close to the container. The valve is normally closed, and holds the stored vacuum in the container. The interface with the patient can either be in the form of a pad positioned in the patient's underwear or a portable urinal. The valve may, for example, be a solenoid valve or any other suitable valve. 3. The lid of the container, which incorporates a high bubble-point filter. The tube from the interface is connected into the top of the lid. The high bubble-point filter, when wetted, will only allow liquid to pass through it. The filter also has a bypass to allow the air in the tube to be evacuated before the oncoming urine. 4. The trigger, pressure transducer and control electronics. The trigger, for the valve to open, can either be a remote manual operation or via an electronic sensor which is positioned in the interface. The electronic sensor, detects the presence of urine and triggers the device to operate without any other intervention. This trigger sends a signal to the control electronics to open the valve. When urine production stops, either the pressure transducer senses that the pressure has fallen significantly in the container and it sends a signal to the control electronics to close the valve, or the valve is closed by the a signal from the sensor in the pad because the presence of urine is no longer being sensed. The valve can be triggered to close in several different ways, for example: 1) when the sensor in the interface no longer detects the presence of urine; 2) when the fall in vacuum within the storage container at the end of urine production is sensed by the pressure transducer which can trigger the valve to close; 3) the valve could be set to close in response to a time switch. To prepare the device for use the pump evacuates the container to about 0.5 to ON bar absolute. When the desired vacuum is reached the pressure switch deactivates the pump and the vacuum is maintained within the container. When the device is triggered, the valve opens releasing the vacuum from the container. The vacuum sucks urine along the tube from the interface. As the vacuum falls in the container, the pump is switched on to maintain the vacuum. If there is a mixed stream of air and urine passing into the device, the vacuum is maintained because the high bubble-point filter only allows urine to pass through it. When urine production stops, there is a short delay before the valve closes so that any residual urine is sucked out of the pad and tube. The pump remains active until the vacuum is restored so that the device is ready for the next occurrence. The large capacity devices of Figures la, lb, lc, and 2a, 2b The embodiments of large capacity device preferably have a 1.5 - 2.5 litre capacity rigid storage container 1. The lid to the container has a bag 2 attached to it which lines the inside of the container. The liner and lid are disposable to avoid contaminating the storage container with urine. In the wall of this liner there are one or more hydrophobic filters 3 with pore size small enough to prevent the passage of bacteria. The surface area of the filter is sufficient to allow an air flow through it to keep pace with the maximum urine influx, but will not allow any urine to pass through. The purpose of the filter is to allow the volume inside the liner to be evacuated, and to remove any air sucked into the container with the urine. The filter also prevents any bacteria escaping from the urine storage liner into the pump or the surrounding atmosphere. The volume within the container is connected to the small diaphragm pump 4, via an outlet 20. The pump should have a flow rate of at least 2 litres of air per minute at atmospheric pressure. The pump outlet can have a silencer 41 fitted to reduce noise. The diaphragm pump is controlled by a pressure switch or pressure transducer and switch 5. The pressure switch or pressure transducer and switch, activates the pump whenever the vacuum is less than a predetermined pressure, for example, less than ON bar, and disconnects the pump from the power source when the vacuum is greater than a predetermined pressure, for example greater than 0.6 bar. Urine is drawn into the container through a tube 6 which goes into the top of the lid 11. The tube has a bore of 4-6 mm in this example. To minimise the tube's resistance to flow the bore needs to be large. However, an over-large bore causes the liquid column to break up when flowing up hill. The tubing needs to be crush resistant but in this version of the device, the valve 8 is a pinch valve and requires a flexible tube to act upon. Therefore the tube has a moulded pliable insert 7 to be acted on by the pinch valve. This means that the tube can be disposed of without contaminating the valve with urine. The electronic trigger can be any sort of device which is capable of rapidly detecting the presence of urine, e.g. A heat transducer, an optical, a resistance or conductivity device. The manual trigger can be an electrical switch. Both the large and small container systems can use any of the triggers. In Figures la, lb, lc and 3a, 3b, 3c the tubing will take urine from the interface to the inlet at the top of the lid of the container. The urine then passes through a filter material, in the lid of the container. In Fig. 2a the tubing will conduct the urine directly into the top of the filter cartridge housing 12 through inlet 13. This material has the effect of preserving the stored vacuum in the container by preferentially allowing aqueous liquid to pass through while resisting the passage of air/gas. The filter material could be a cellulose ester membrane filter with a defined pore size between 0.8 and 8 micrometers in this example. The filter may be a flat disc 10 incorporated in the lid of the storage container 11 or a filter cartridge 36 within a filter housing 12, incorporating 0.1 -0.5m 2 effective filtration area. The flat disc filter, 10 shown in Figs, lc and 3c is supported by a rigid disc of material 14 integral with the lid which is perforated. This section might also be made from a rigid wire or plastic mesh. Once the filter has been wetted it is impervious to air at the maximum pressure which the suction source can exert. It is necessary therefore, both to remove the airlock and to allow the vacuum to reach the solenoid valve and ultimately the interface, to include a by-pass. For the flat disc filter a hole 17 O. lmm-lmm in diameter, allows the removal of the air block at the beginning of second and subsequent urine flows. The filter will still allow liquid rather than air to pass when a mixed stream is drawn through the apparatus. For the filter cartridge, a capillary tube 18 by-pass from the base of the filter cartridge into the top of the storage container performs the same function as the hole 17 in the flat disc. These by-pass devices are positioned so that any liquid in the system will obstruct air flow through them. Alternatively the by-pass hole could be in the filter support with a larger, non-critical size hole in the filter material. In one embodiment, at the end of urination, when the system is empty, air will begin to flow through the filter by-pass causing the vacuum in the system to be lost, until the pressure transducer senses that the vacuum has fallen to 0.9 bar and causes and electronic control to switch the solenoid valve shut. Alternatively, the valve may be triggered to close and the pump operated to re-evacuate the storage container. The large storage container system (Figs, la, lb, 2a, and 2b) preferably has sufficient capacity to store twelve hours urine production. When the bag is full, it can be emptied via the tap 19 in this diagram situated on one side of the lid. These systems will be most useful to wheelchair-bound individuals who can have the storage and pumping system behind or under the wheelchair. The preferred system would be the flat disc filter system because it is smaller and less expensive to produce. However, for elderly or ill people with a high level of urinary inclusions, the filter cartridge, with large effective filtration area, will be necessary to prevent blocking the filter prematurely. The small capacity device, of Figures 3a, 3b, 3c In this embodiment, the small capacity device has a 300-600 ml capacity rigid storage container 21. In one embodiment there is no lining to the container. The container is evacuated through a tube in the lid 22 which is protected by a hydrophobic filter 23. The hydrophobic filter is to the same specifications as the filters in the wall of the liner in the large version of the device. In another embodiment, the small capacity device uses a liner with hydrophobic filters inset similar to the large capacity devices. This system is emptied after each void by removing the lid completely and pouring the contents away. The solenoid valve 24 in this example is plugged in line to the tubing rather than acting on a moulded section of the tube. The reason for this is that the plugged in solenoid valve is considerably lighter than the solenoid pinch valve. This system is suitable for ambulant persons who could carry the device in a bag around the waist. It could also be useful to those wheelchair bound individuals who have good upper body mobility, but may not wish to be burdened with the more cumbersome large container system. This small container system would also be ideal, used in conjunction with a urinal. The urinal and device could easily be stored in a small shoulder bag. The device and urinal could be flushed by pouring some mild disinfectant solution into the urinal after each use. Figure 4 shows the small capacity system fitted into a waist worn bag. In this illustration the cylindrical container has been replaced by an ovoid container 25 to give the whole system a neater and more comfortable fit. A lighter pump 26 may be used for this system and could be powered by six 1.5 volt AA size batteries 42. Any suitable battery pack or energy storage device could be used to power the pump 26. The pumping and storage systems can be used with any of the different patient/device interfaces described below. A reasonable space is preferably provided between the filter and the lid to prevent fluid from becoming trapped between the two surfaces, which could dramatically reduce flow rates. A double lumen tube is preferably used to protect the sensor cable. There may also be provided sound-proofing for the system. Either a male urinal or a female urinal can be attached to the pumping and storage systems. The valve could be controlled by an electronic sensing device or more simply switched manually by the user as required. An embodiment of layered female interface 27 is shown in Fig. 5a and in detailed cross-section in Fig. 5b. The layered interface is generally curved rectangular in shape, having a lower edge 28, an upper edge 29 and side edges 30 and 31. The upper and lower edges may be straight as shown or rounded. The lower edge 28 is positioned towards the back of the person when worn and hence the upper edge 29 is towards the front. The rectangle is preferably only 5-9 cm wide, so that no bunching occurs in use, and 15-25 cm in length. The layered interface is curved in longitudinal cross-section to ensure a close fit to the body. There is a rounded rectangular hole 32 between 2-5 cm wide and 5-12 cm long, in the outer layer 33 of the interface. The hole is positioned towards the upper edge of the layered interface to correspond approximately with the urethral opening. This hole allows urine to penetrate rapidly into the layered interface and the covered section at the lower end of the layered interface provides a small reservoir 34 from which urine is sucked away. The suction tube is attached to the under surface of the layered interface at the lower end. The connector 35 penetrates the outer impervious layer 35 of the interface to communicate with the layer above 37. The outer layer 33 of the layered interface is impervious to air and liquids. It may be made of any suitable material, for example polyethylene or polypropylene sheets or non- woven materials coated with latex or silicone. Immediately above the impervious layer there is a spacing layer 37 composed of open-surfaced material that allows aqueous liquid to flow between layer 33 and 38 without restricting the flow. Polyester wadding, fibrous material, open celled foam or similar materials could be used to form this layer. Layer 38 is a nylon mesh, with 3-10μm pore size which is bonded in the pad so that the urine has to pass through it before passing through the suction tube. This mesh preferentially allows liquid to flow through while slowing the passage of air and is used to avoid the loud sucking noise which otherwise occurs at rapid rates of air/urine uptake. Above the nylon mesh there is a layer of open-structured shape-retaining material 39. This layer provides structural stability and allows urine to flow down the length of the interface into the reservoir section 34 at the lower end. The layer above is a receiving layer 40 which rapidly takes up urine and allows it to flow through to the lower layers. This could be a polyester fleece, needle-felt or any suitable soft comfortable material. An additional cover-stock layer may be added to cover the patient contact surface which would help to reduce wet-back and increase patient comfort. The entire layered interface will need to be positioned within specially designed underwear.

Claims: CLAIMS 1. A urine collection device for collecting urine produced by a person, including a container for storing collected urine, interface means for coupling the device to the urethral opening of a user, sensing means operable to sense the presence of urine at the interface means; and pumping means operable on the sensing of presence of urine to pump urine into the container. 2. A device according to claim 1 , wherein the pumping means is operable to produce a vacuum within the container: said vacuum drawing urine from the interface means to the container. 3. A device according to claim 1 or 2, wherein pumping means is operable substantially continuously. 4. A device according to any preceding claim, wherein the sensing means includes a heat transducer, an optical sensor, a resistivity sensor or a conductivity sensor. 5. A device according to claim 4, wherein the pumping means includes a valve coupled to the sensing means, the valve opening a connection to the container when the presence of urine at the interface means is sensed. 6. A device according to claim 5, wherein the valve is manually operable. 7. A device according to any one of claim 1 including a manually operable valve for opening a connection between the interface means and the container. 8. A device according to any preceding claim, including a filter between the interface means and the container which allows the passage of liquid but which resists the passage of air/gas. 9. A method of collecting urine in a device including a container for storing collected urine and a urethral track opening interface, including the steps of sensing the presence of urine at the interface and pumping urine from the interface to the container. 10. A method according to claim 9, wherein urine is pumped at the rate at which it is produced. 11. A method according to claim 10, including the step of sensing the rate of production of urine and pumping substantially at said rate. 12. A method according to claim 10, wherein urine is pumped at a predetermined rate equivalent to the expected rate of production of urine.

Inventors: JOWITT FELICITY ANN, TINNION ELEANOR ANN, WOLFF HEINZ SIEGFRIED, JOWITT, FELICITY, ANN, TINNION, ELEANOR, ANN, WOLFF, HEINZ, SIEGFRIED
Applicants: JOWITT FELICITY ANN, TINNION ELEANOR ANN, UNIV BRUNEL, WOLFF HEINZ SIEGFRIED, BRUNEL UNIVERSITY, JOWITT, FELICITY, ANN, TINNION, ELEANOR, ANN, WOLFF, HEINZ, SIEGFRIED
Application year: 2000
Main classification: A61B5
IPC codes: A61B5, A61F5, A61G5