Abstract:
An inflatable uterine device to control uterine bleeding, comprising an inflatable balloon ( 10 ) and a hose ( 11 ) connecting the balloon to a fluid source. The fluid source comprises an open container ( 12 ). A first end of the hose can be integrally connected to the inflatable balloon and a second end of the hose can be integrally connected to the container, and a suspension means ( 14; 15 ) is provided at the second end of the hose. A method for producing an inflatable uterine device includes the following steps. Feeding an upper film ( 18 ) of plastic material from a first roll ( 17 ), feeding a lower film ( 20 ) of plastic material from a second roll ( 19 ), joining said upper film ( 18 ) and said lower film ( 20 ) along contour lines forming an inflatable balloon ( 10 ), a container ( 12 ) and a hose ( 11 ) connecting the balloon to the container in an open fluid path, said container ( 12 ) having an open end formed by the absence of a joint between said upper film ( 18 ) and said lower film ( 20 ), and cutting the films outside said contour lines.

Description:
[0001]     The present invention relates to an inflatable uterine device to control uterine bleeding. Uterine bleeding can be caused by post-partum hemorrhages following childbirth. Severe uterine bleedings can be a serious problem due to the large loss of blood. Hemorrhage is one of the major causes of maternal mortality. The invention relates also to a method for producing the uterine device.  
       PRIOR ART  
       [0002]     A device used for stanching uterine bleeding comprising an expandable balloon and a tubular handle connected therewith for the insertion of the balloon into the uterine cavity is disclosed in U.S. Pat. No. 6,024,753. The device further includes a hose for connecting the balloon to a fluid source. The hose is connected to a pump, which is controlled by a control unit. Both the pump and the control unit will require well-trained personnel and will involve high costs for producing and for operating the device, which is a drawback in several instances.  
         [0003]     A similar device is disclosed in U.S. Pat. No. 4,552,557. The pressure of an inflatable portion is measured by a pressure gauge. The device in one embodiment will allow accumulated blood or mucosal debris present in the uterus to be drained.  
         [0004]     In the devices disclosed in U.S. Pat. No. 6,024,753 and U.S. Pat. No. 4,552,557 an inflatable balloon is used. The balloon is formed by a material that will allow the balloon to expand and to fill the uterine cavity completely when inflated. The requirements on the material result in a high cost for producing the device. The pump and pressure measuring means will involve further costs and possible problems handling the equipment.  
         [0005]     A further drawback is that the devices may include air. Such embedded air has to be removed, so as not to risk that air embolism will occur if the balloon ruptures. The removal of air involves further costs.  
       SUMMARY OF THE INVENTION  
       [0006]     It is an object of the present invention to provide a device for controlling or stanching uterine bleedings that is without the drawbacks mentioned above. The device according to the invention can be produced at a very low cost and can be used under very primitive conditions. No pump or similar device is necessary to provide the required pressure for inflating the balloon and for exerting sufficient pressure on uterine blood vessels to curtail bleeding.  
         [0007]     According to the invention the fluid source comprises a container with an opening that will allow filling of a fluid, preferably water, into the container and through the hose into the balloon. Preferably, the opening is formed as a funnel, so as to facilitate the filling of fluid.  
         [0008]     The hose close to the container or the container itself is provided with suspension means. The suspension means can be used to suspend the device at such a height in relation to the balloon that the pressure in the balloon will reach a sufficient level. Normally, the surface of fluid in the container will be kept at least 1 m above the balloon. A 1 m long hose corresponds to a pressure in the balloon of about 70 mm Hg, which in most circumstances will be sufficient.  
         [0009]     The length of the hose will normally be no more than 3 meters, thus restricting the maximum pressure that can be obtained from the water pressure to about 220 mm Hg (29.3 kPa). At this pressure neither the tissue in the uterine cavity nor the uterus itself can be damaged. A working pressure of approximately 70 mm Hg would be a normal pressure. The hose may be provided with markings over a section or the complete length. The markings indicate the pressure in the balloon when the container is lifted. The hose may also be provided with a more detailed scale that can be used if a pressure clamp is used to raise the pressure in the system.  
         [0010]     The device, comprising the container, the hose and the balloon, according to the present invention can all be in an integral form and no connectors or similar devices are required to be present. When inflated the balloon will fill the uterine cavity and exert a sufficient pressure on the surrounding tissue to curtail bleeding.  
         [0011]     Different methods can be used for producing the device according to the invention. In one embodiment two sheets that are welded together in the appropriate shape form the device. The sheets are fed from two rolls to a welding and cutting device. Preferably, side edges of the device are welded and cut in one step. The cut out device is then either folded to an appropriate shape and size or rolled into a roll. The device is sterilised and wrapped in a package. If folded the device preferably is disposed on a sheet or plate that will function as a base plate when the device is unpacked. As a result of this producing method no air will be present within the device. As no cavities with air will be present in the device it is ensured that no air embolism occurs during use of the device.  
         [0012]     The package may include a clamp or similar device that can be used to close the container and/or to raise the pressure in the balloon. In the latter case the clamp can be moved over the hose from the container towards the balloon and may include rolls or other rotating means.  
         [0013]     The balloon has a size when inflated that is sufficient to fill the uterus of most women. Preferably a non-resilient material is used. A major advantage of using a non-resilient material is that the pressure in the area of filling the device, a filling pressure, will equal to a working pressure of the device. Thus, there will be no need for measuring the pressure of the balloon when it is located in the uterus.  
         [0014]     The term non-resilient should be understood to include materials that are completely without resilience and materials that will have a low degree of resilience and a substantially linear relation between expansion and pressure increase. When a non-resilient material is used the volume of the inflated balloon is at least 0.3 litre. In prior art devices the resilient material will cause a resistance when the pressure is increased. Therefore, the pressure normally has to be measured within the uterus.  
         [0015]     It is possible to produce the device at very low costs. Biocompatible but low-cost materials can be used, because it is not required that the material is resilient. Large amounts of the device can be distributed in developing countries to save many lives. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0016]      FIG. 1  is a schematic plan view of the device according to the invention.  
         [0017]      FIG. 2  is a schematic side elevation view of a production line for producing the device according to the invention.  
         [0018]      FIG. 3  is a schematic plan view of the production line in  FIG. 2 .  
         [0019]      FIG. 4  is a cross sectional view from line IV-IV in  FIG. 1 .  
         [0020]      FIG. 5  is a schematic plan view of the device in  FIG. 1  on a base plate with folding lines indicated with dashed lines.  
         [0021]      FIG. 6  is a schematic plan view of the device in  FIG. 5  in a folded condition.  
         [0022]      FIG. 7  is a schematic side elevation view of the folded device.  
         [0023]      FIG. 8  is a schematic side elevation view of the device rolled into a product roll.  
         [0024]      FIG. 9  is a schematic side elevation view of the device in  FIG. 1  extended and filled with liquid and an enlarged section showing a clamping element.  
         [0025]      FIG. 10  shows schematically a first embodiment of an introducing member.  
         [0026]      FIG. 11  shows schematically a second embodiment of an introducing member. 
     
    
     DETAILED DESCRIPTION  
       [0027]     Referring to  FIG. 1 , it can be seen that a device according to the invention comprises three main sections. It should also be noted that the device is shown in a configuration when delivered and ready for use. A balloon  10  constitutes the part of the device that is designed to fit in the human uterus. The balloon  10  is circular or approximately circular and completely flat in a non-inflated condition. In an inflated condition (not shown) it will assume a somewhat flattened but spherical shape. The volume of the balloon  10  in the inflated condition is between 0.3 litre and 2.5 litres, corresponding to a diameter of about 0.13 m to about 0.20 m. An appropriate size is achieved with a diameter of 0.155 m resulting in a maximum volume of about 1.5 litre. A balloon of that size will for most women exert a sufficient pressure, even if the balloon is not fully inflated. As an alternative two sizes of the balloon are provided. A smaller sized balloon will hold from about 0.3 l to about 1.5 l, and a larger sized balloon will hold from about 1 l to about 2.5 l.  
         [0028]     A balloon that is not fully inflated will adapt to the form of the uterus more closely and the shape of the balloon is of less importance. By using thin films the balloon can fill small and irregularly shaped cavities. Other sizes of the balloon may be provided for specific conditions such as when a differently sized uterus is to be treated. The design of the device and the thin material used will allow the use of more than one balloon if necessary.  
         [0029]     An annular flap  35  can be provided on the edge of the balloon opposite to the connection between the hose and the balloon. The flap  35  can receive a tip of an introducing member, for instance as the one shown in  FIG. 10 .  
         [0030]     The balloon is integral with a hose  11  extending from the balloon to a container  12 . The length of the hose  11  from a first end connected to the balloon to a second end connected to the container  12  will be sufficient to give the required pressure when the container  12  is filled with water and raised. The container is designed to be filled with a liquid, such as water, and has one open end where water can be filled and an opposite end, which is integrally connected to the hose. In the embodiment shown in  FIG. 1  the open end is shaped as a funnel  13 , so as to facilitate the filling of water. The funnel shaped opening  13  will allow water to be poured into the container.  
         [0031]     The container  12  is provided with a suspension means to facilitate the suspension thereof in a raised position. In the embodiment shown in  FIG. 1 a  longitudinal pocket  14  extending from a lower part of the container  12  to the funnel shaped opening  13  is used. The pocket is formed to receive a vertical rod or pin and is open in one end and closed in the other end. The open end is located at the lower part of the container  12 .  FIG. 9  shows an example of the use of the suspension means. Also a recess  15  formed between the pocket  14  and the funnel shaped opening  13  can be used as a suspension means.  
         [0032]     At an appropriate distance from the balloon  10  the hose  11  is provided with a scale  16  that can be used when an increased pressure is required. The use of the scale is further described with reference to  FIG. 9  and the enlarged section.  
         [0033]     In a preferred embodiment two sheets that are welded together form the device. A space between the sheets formed by welding seams can be filled with a liquid such as water as disclosed above. The complete device is mounted on a plate or sheet  23  that will hold the device and facilitate the handling thereof when the device is to be used. The plate  23  can be made from paper only or from a plastic film coated paper sheet.  
         [0034]     An example of a production line for the manufacturing thereof is shown in  FIG. 2 . A plastic film is rolled on a first roll  17  and forms an upper film  18 . A corresponding plastic film is rolled on a second roll  19  and forms a lower film  20 . The plastic film can be made from different plastic materials with appropriate properties. The material should allow a combined cutting and welding process and should also be biocompatible. Suitable materials are polypropylene, polymers such as ethylene methacrylic acid copolymer (EMA) and Ethylene Vinyl Acetate (EVA). At least the balloon is formed by thin films of a rigid or non-flexible material that are welded together.  
         [0035]     The upper film  18  and the lower film  20  are conveyed over a working table  21  to a welding and cutting device  22 . The films are welded together along the contour lines forming the device as shown in  FIG. 1 . There are no welded seams in the funnel shaped opening  13  and in the opening of the pocket  14 . In a preferred embodiment the seams are welded and the device is cut out at the same time.  
         [0036]     The welding and cutting device  22  can include a press form or a similar device that moves up and down as shown at arrow A, or a laser that welds and cuts in one step. Also other welding techniques, such as RF-heat-welding can be used.  
         [0037]     As can be seen in  FIG. 3  the films  18 ,  20  are so wide that two devices fit beside each other. The films can be even wider, so as to allow three or more devices to be welded and cut at the same time.  
         [0038]     In connection with or after the welding and cutting steps the device is mounted on the plate or sheet  23 , which can be formed by paper or a plastic material. The sheet  23  is fed from a third roll  31  below the working table  21 . In a preferred embodiment the device is attached to the plate  23  in the welding seams along the contour of the device. It is then a simple measure to release the device section by section from the plate  23  when the device is used.  
         [0039]     In an alternative embodiment the sheet  23  engages the two films before the welding and cutting device  22 . Thereby the films will adhere to the sheet  23  during the cutting and welding step. The complete device including the plate  23  is then wrapped into a package. A cutting device  30  moving up and down as shown at arrow B in  FIG. 2  cuts the plates into suitable sizes. The cutting device can also be a rotating device or a laser device or any other appropriate device.  
         [0040]     The device is sterilised with an appropriate method. Among the sterilization technologies currently available, ethylene oxide (EtO) gas can be mentioned. It is also possible to use other methods, such as gamma radiation and electron-beam radiation. Normally, the device is sterilised in the package.  
         [0041]      FIG. 4  is a cross sectional view of the complete device including the plate  23  wrapped in a package. It should be noted that the extension of the device in the vertical direction is exaggerated to facilitate the understanding of the invention. A plastic covering film  24  is wrapped over the device and attached to the plate  23  to form a sealed and sterile package. Three sections of the hose  11  and the balloon  10  are discernible as separate hollow spaces. These hollow spaces will be inflated when a liquid is poured into the container  12 . Welded seams  24  are formed where the device is attached to the plate  23 .  
         [0042]     Dashed lines in  FIG. 5  indicate folding lines where the device can be folded to assume the shape shown in  FIG. 6  and  FIG. 7 . The device is folded twice towards the centre of the device and the plate  23  will form a protective cover. By folding the device as shown an extremely compact package will be achieved. The size can be as small as a few millimetres thick, 350 mm long and 185 mm wide. A package of that size can be stored and distributed at very low costs, which in most cases, such as for use in developing countries, is advantageous.  
         [0043]     It is also possible to roll the device to form a product roll.  FIG. 8  shows a product roll  34  where the sheet  23  forms a protective exterior of the roll.  
         [0044]      FIG. 9  illustrates schematically the device in use. It should be assumed that the balloon is located within the uterus. The container  12  is suspended on a vertical rod  26  extending from a base plate  27 . The longitudinal pocket  14  is used for suspending the device. A liquid such as water has been poured into the container through the funnel shaped opening. An assumed water level is indicated at  28  and is located at a height of h above the balloon. As discussed above h should be in the interval of 1-3 m. The length of the hose is from about 1.0 m to about 3.0 m and preferably from about 1.5 m to 2.5 m. A suitable lower distance h=1.0 m corresponds to a pressure of about 70 mm Hg. If air may enter the space between the films during or after the manufacturing of the device a priming step is taken before the device is used.  
         [0045]     If it is desirable to increase the pressure in the balloon further a clamping element  29  can be mounted on the hose  11 , preferably in the area of the scale  16 . The clamping element  29  comprises in the shown embodiment two cylinders or wheels  32  bearing against each other. The cylinders  32  can be moved apart, so as to allow the hose to be inserted there between. The cylinders  32  are then pressed against each other as shown in the enlarged detail view in  FIG. 9 . In another embodiment (not shown) one cylinder rotates against an abutment.  
         [0046]     By moving the clamping element  29  in the direction of arrow C liquid within the hose will be forced toward the balloon where the pressure will rise. The increased pressure within the balloon will contribute to provide a sufficient pressure on uterine blood vessels to curtail bleeding. The position of the clamp  29  in relation to the scale will indicate the pressure in lower part of the hose and in the balloon.  
         [0047]     The clamping element  29  can also be used to close the container. It is then possible to increase the working pressure by enclosing the container  12  in a cuff or similar device. The pressure of the cuff is increased in a conventional manner and will lead to a corresponding increase of the working pressure. An advantage of using a non-resilient material is that the pressure that can be observed in the cuff will be equal to the working pressure of the balloon and the complete device.  
         [0048]      FIG. 10  shows an introducing member  36  that can be used to introduce the balloon into the uterus. In the embodiment shown the introducing member comprises an elongated handle  37 . The handle is in one end provided with a head having two extending rounded sections  38  and between said sections a rounded tip  39 . The rounded tip has a size that will allow it to be inserted in the annular flap  35 , when the balloon is to be introduced into the uterus. The two side sections  38  extend beyond the rounded tip and will ensure that no damage is caused to the uterus.  
         [0049]     The introducing member can be rigid and be made from a plastic material. It is also possible to form it in paper from the sheet  23 . In that case the introducing member is punched. In another embodiment the introducing member is formed by a gel that will dissolve in contact with blood and other body fluids.  
         [0050]     In the alternative embodiment shown in  FIG. 11  the introducing member  36  comprises a handle  37  with two sticks  40  extending in parallel from the handle. One of the sticks is arranged on one side of the flat balloon and then inserted through the annular flap  35  while the other stick extends on the opposite side of the balloon. With this arrangement it is possible to wind the empty flattened balloon around the introducing member and then to introduce it in the uterus.  
         [0051]     Normally, the balloon is introduced into the uterus empty and then a smaller amount of liquid is filled into the balloon. When the balloon is inflated by the liquid the introducing member can be withdrawn leaving the balloon in the uterus. Then a suitable amount of liquid is filled into the container  12  and the container is raised to an appropriate height over the balloon.  
         [0052]     In one embodiment the material and the thickness of the hose are chosen so as to withstand a pressure lower than a pressure where any tissue is damaged. When the clamping element is used and the pressure is increased over what can be obtained by positioning the container at a maximum distance from the balloon the limited strength of the material will ensure that the pressure is not increased to an injurious level. At higher pressures the hose, or any other part of the device exposed to the pressure, will rupture. It may be appropriate to provide the hose with a specific rupture section  33  that will be an indication of fracture. The section can be formed with a weakened material or as a thinner part.  
         [0053]     In an embodiment where all elements of the device are integrally connected to each other the device can be produced, stored and transported very efficiently. The storage and transport will be simplified also as a result of the thin and compact design. No separate parts or connectors have to be used, unless a clamping device is included. This design will facilitate in maintaining the device under sterile condition also during troublesome circumstances.