Device for Preventing Involuntary Micturition

The present invention relates to a device for preventing involuntary micturition, preferably in human females.

Numerous devices for preventing involuntary micturition in human females are known. Such devices include for instance a device inserted in the urethra by means of a special instrument, said device expanding in the urethra when the instrument is removed. Such devices are usually difficult to manipulate and irritate a patient during use.

The object of the present invention is to provide a device easy to insert and causing no irritation to a patient carrying the device.

The object of the invention is accomplished by a device comprising an oblong, substantially form-stable, flexible body with varying cross-sectional area depending on the distance from an end of the body and providing at least one knob forming a thickening arranged at a distance from a first end of the body, and that the first end of the oblong body is provided with a comparatively thin, transverse flap, extending substantially perpendicular to the axis of the body.

As a result the inventive device is easily inserted in the urethra and has shown itself to be unproblematic during use. Moreover the device is easily removable, since it can be pressed out by the user during voluntary micturition. Optionally it can also be withdrawn by holding on to the flap. The flap acts also as a safeguard against the device being too deeply inserted in the urethra. Further the inventive device is of special advantage with respect to prevention of involuntary micturition due to its tendency to position itself in such a way that the knobs are located within the strongest sections of the urethral muscles, thus increasing the sphincteral pressure of the urethra.

In an especially preferred embodiment the oblong body is a shaft comprising three mutually spaced knobs.

In accordance with the invention the knob or knobs can be of ellipsoid shape thus achieving an especially gentle and well-functioning co-operation with the surrounding urethral tissue and muscles.

Further in accordance with the invention, the thin, transverse flap can have the form of an annular disc. Thus the inventive device is easy to manipulate during the insertion and the optional withdrawal.

FIG. 1 is a side view of an especially suitable embodiment of an inventive device, and

FIG. 2 is a graphic representation of the pressure in the urethra of a person with a normally functioning urethra, and of a patient suffering from urinary incontinence.

The device of FIG. 1 comprises an oblong body in form of a comparatively thin shaft 1 with three mutually spaced ellipsoid knobs 2, 3 and 4, the knob 4 being at the distal end of the shaft, said end being placed furthest inside the urethra during use. The proximal end of the shaft 1 is provided with a thin disc 5.

In a preferred embodiment the device is of a length of approx. 5 cm, and the shaft 1 is of annular cross-section with a diameter of approx. 2 mm. The knobs 2, 3 and 4 have a mutual distance of approx. 4 mm and their largest diameter measured perpendicular to the shaft is approx. 7 mm. The length of the knobs 2, 3 and 4 is approx. 8 mm, measured in the longitudinal direction of the shaft. The annular disc 5 is of a diameter of approx. 14 mm and of a thickness of less than 0.5 mm. The entire device is suitably integrally made of a comparatively soft plastic material having such a rigidity that it is easily inserted in the urethra. The shaft is optionally hollow to receive an insertion means in form of a long, thin pin. The plastic material is preferably tissue-compatible and desinfecting.

The urethra of an adult human female is usually of a length of 3-5 cm and surrounded by muscles over its entire length from the bladder to the external urethral ostium. The strongest muscles of this muscle group are situated adjacent the bladder as well as in the middle of the urethra. These muscles usually seal off the urethra. A graphic representation of the pressure maintaining a sealed urethra in a human female usually follows a curve depicted at I in FIG. 2. The abscissa indicates the length of the urethra measured from the bladder to the external urethral ostium (M), and the ordinate indicates the pressure measured in Pa. Usually the pressure in the urethra is approx. 600-700 Pa. The intravesical pressure of a person standing upright is normally between 300 and 400 Pa, as indicated by means of curve II in FIG. 2. Thus the normal safety margin is approx. 400 Pa over the entire length of the urethra. Curve III of FIG. 2 shows a pressure distribution for the urethra of a patient suffering from incontinence. As is apparent, only a short part of the urethra, i.e. approx. 5 mm, is subjected to a sphincteral pressure higher than the intravesical pressure.

The device of FIG. 1 was tested with the patient on which the pressure distribution of curve III, FIG. 2, was measured. Prior to insertion of the device the ability of the urethra to retain liquids was tested. The bladder was filled with 300 ml water (75% filled), whereupon the person was asked to take the elevator up to the next floor and return via the staircase. This trip was repeated twice. During the experiment the person lost the 300 ml water and additionally approx. 50-100 ml liquid produced during the experiment.

The experiment was then repeated with the device of FIG. 1 inserted in the urethra. During this experiment the person lost only approx. 15 ml.

An examination of the position of the device in the urethra revealed that the knob 2 closest to the disc 5 was about in the middle of the urethra, i.e. within the area where the sphincteral pressure is highest, while the two following knobs were positioned in the vesical ostium and inside the bladder, respectively. It cannot be excluded that the two latter knobs had some effect with respect to retaining liquid, but the presence of three knobs 2, 3 and 4 allows the device to obtain a better position with respect to the muscles of the urinary tract compared to a device with only one knob. By measuring the pressure in the urethra of a patient suffering from incontinence it is apparent where the muscles are strongest, thus permitting the selection of the device best corresponding to the needs of the patient in question. In such a case the distances between the knobs and the annular disc 5 may differ from the ones above.

The above experiment was repeated with other patients, i.a. also with men, and had the same promising results.

A special characteristic of the inventive device is that it turned out to act as a stimulant to the urethral muscles. Experiments have shown that these muscles displayed a temporary increase in strength after use of the inventive device.

The invention is described with respect to a preferred embodiment. Many alterations can, however, be made without thereby deviating from the scope of the invention. The knobs can be of a shape other than ellipsoid. The annular disc can be replaced by a small strip projecting to one side with respect to the shaft. The device can, if so desired, be provided with a cavity (6) as to increase its flexibility. This cavity can for instance open outwardly at the end where the annular disc is located. In such a case the inventive device can be inserted by means of a stiff, oblong means 7 inserted in the cavity (6) and removed after the inventive device has been positioned in the urethra. The number of knobs can, if desired, also differ from the one shown. Instead of a thin shaft with knobs the oblong body can be of larger diameter and provided with a number of recesses.