GB2272093A

GB2272093A - Enuresis alarm

Info

Publication number: GB2272093A
Application number: GB9321851A
Authority: GB
Inventors: David Edward Cross
Original assignee: Smiths Group PLC
Current assignee: Smiths Group PLC
Priority date: 1992-11-03
Filing date: 1993-10-22
Publication date: 1994-05-04
Anticipated expiration: 2013-10-22
Also published as: GB9321851D0; GB2272093B

Abstract

The alarm has a housing 1 with a resistance monitoring circuit 13 driving a motor 15. A moisture-sensing strip 2 has two spaced conductive tracks 21 and 22 extending along it and is connected to the housing by press studs 12 and 20. The strip 2 is perforated with holes 24 to allow urine to pass through it. The strip extends within an outer sleeve (3, Fig. 1, not shown) one face (31) of which is presented to the wearer is permeable and non-absorbent, the opposite face (30) being non-permeable and absorbent. When urine reduces the resistance between the tracks 21 and 22, the monitoring circuit 13 drives the motor 15 to rotate an eccentric weight 17, to produce vibration, and a striker 18, to produce an audible alarm to wake the user. <IMAGE>

Description

ENURESIS ALARM APPARATUS This invention relates to enuresis alarm apparatus.

Enuresis alarms are used to detect inadvertent urination at night usually in young children, and, by sounding an alarm, alert the wearer so that he stops urination and thereby prevents bed-wetting. Existing alarms suffer from various problems one of which is that they often do not respond sufficiently quickly to prevent bed-wetting occurring. Also, different forms of alarm often have to be used for boys and girls. This makes it more expensive for enuresis clinics to maintain sufficient stocks of alarms.

It is an object of the present invention to provide improved enuresis alarm apparatus.

According to one aspect of the present invention there is provided enuresis alarm apparatus comprising a housing and a moisture sensing element, the housing including a resistance monitoring circuit connected to the moisture sensing element and an alarm unit connected to the circuit such that the alarm unit is triggered by a fall in resistance of the moisture sensing element, the moisture sensing element comprising an elongate strip of a flexible electrically-insulative material having spaced conductive tracks extending along its length and electrically connected at one end to the resistance monitoring circuit, the strip being permeable to moisture such that urine can flow through the strip, and the length of the strip being sufficient that the strip can extend in the region of the crotch of the wearer when the housing is supported in the region of a waistband.

Preferably, the strip is of a moisture-impermeable material, such as a non-woven plastics, formed with a plurality of holes therethrough. The strip may be secured to the housing by means of cooperating press studs, which also make connection of the conductive strips with the resistance monitoring circuit. The strip preferably extends within an outer sleeve having one face presented towards the wearer that is relatively permeable and non absorbent, such as of a synthetic plastics material, and an opposite face presented away from the wearer that is relatively non-permeable and absorbent, such as of a quilted cotton fabric.

The alarm unit may include a vibrating member that provides a vibrating tactile signal to the wearer. The alarm unit may include a motor and the vibrating member may be a weight mounted eccentrically on the motor. The motor may have a striker member arranged to contact a sounding member when the motor rotates so that an audible signal is produced for the wearer. The housing preferably has a clip arranged to engage the wearer's clothing.

An enuresis alarm according to the present invention, will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side elevation view of the alarm; Figure 2 is partly cut-away rear view of the alarm in the direction of arrow II of Figure 1; and Figure 3 is a more detailed view of a part of the alarm.

The alarm apparatus comprises an upper housing 1, a moisture-sensing strip 2 hanging from the housing, and an outer fabric sleeve 3 enclosing the housing and sensing strip. On the front face of the housing 1 there is a plastic clip 4, which fits over the upper, open end of the sleeve 3 and the waistband of pants (not shown). In use, the housing 1 is held inside the waistband at the front of the pants and the sleeve 3 extends down within the pants to the region of the wearer's crotch.

The housing 1 includes a two-part plastics casing 10 sealed against moisture ingress by an O-ring seal 11. At the lower end of the housing 1, on its exterior surface, two metal press studs 12 extend through the wall of the casing and are connected internally to a resistance monitoring circuit 13 of conventional construction (Figure 3). The circuit 13 is powered by a battery 14 within the housing 1 and provides a power output to a motor 15 when the resistance between the two press studs 12 drops below a predetermined level. The motor 15 has a shaft 16 on which an eccentric weight 17 is secured at one end. At the other end of the shaft 16 there is a striker arm 18, which contacts a fixed metal sounding plate 19 when the shaft rotates.

The moisture-sensing strip 2 is made of a moisture-impermeable, flexible, non-woven plastics such as polyester, PVC or polyolefine and is about 3cm wide by 15cm long. At its upper end, the strip 2 has two metal press studs 20 spaced from one another to fit with the studs 12 on the housing 1. The studs 20 make electrical connection with two electricallyconductive tracks 21 and 22 extending down opposite edges of the strip on its rear surface, that is, the surface presented towards the wearer. The tracks 21 and 22 are each about lom wide so that they are spaced from one another by a central region 23 also about lom wide.

The tracks 21 and 22 may be of a conductive carbon ink. The strip 2 is formed with a number of holes 24 through its thickness, which may each be about 2mm in diameter, the holes being equally distributed over the surface of the strip.

The strip 2 extends to the lower end of the outer sleeve 3, which is about 5cm wide by 20cm long and is made from a front panel 30 and a rear panel 31 of synthetic fabric material sewn about their edges but leaving an opening at the top. The rear panel 31 is presented to the wearer and is of a material that is relatively non-absorbent but relatively moisture-permeable compared with that of the front panel 30. By contrast, the front panel 30 is absorbent and is less permeable to moisture although it is not completely impermeable. The rear panel 31 may be of a woven polyester and the front panel 30 of a quilted cotton fabric.

The sleeve 3 can be easily slipped off the housing 1 for washing. The press studs 12 and 20 enable the sensing strip 2 to be removed easily from the housing and wiped down.

In use, when the wearer urinates, the urine passes relatively easily through the rear panel 31 of the sleeve 3 to contact the rear surface of the moisture-sensing strip 2. Contact with the urine causes the resistance between the two tracks 21 and 22 to fall. This drop in resistance appears across the press studs 20 and 12 and hence causes the circuit 13 to produce an alarm signal in the form of energization of the motor 15. Rotation of the motor shaft 16 causes vibration to be produced in the housing 1, because of the eccentric weight 17, and a sound to be generated by contact of the striker arm 18 on the sounding plate 19. This causes the wearer to be alerted by two different forms of signals, namely a tactile and an audible signal; this has been found to be particularly effective in waking the wearer and stopping urination quickly.

Because the sensing strip 2 extends to the region of the crotch, it is exposed rapidly to any urine produced, whether the apparatus is worn by a male or a female. The permeable nature of the panel 31 of the sleeve 3 enables urine to flow readily to the sensing strip 2. The holes 24 in the strip 2 allow urine to flow through the strip and into contact with the absorbent front panel 30 of the sleeve where further passage of urine is delayed. This is a considerable advantage in that it reduces the amount of urine that flows sideways over the rear surface of the sensing strip and hence reduces the leakage of urine out of the edges of the sleeve.

Although the sensing strip could be formed of a porous material, such as a woven fabric, it has been found easier to form conductive tracks on a smooth, continuous, non-woven material.

In normal use, the sensing strip 2 is oriented so that the conductive tracks 21 and 22 are presented to the wearer, to give the apparatus maximum sensitivity. For wearers who perspire freely, this might make the apparatus too sensitive and give false alarms caused by contact with perspiration. The sensitivity of the apparatus can, therefore, be reduced by connecting the strip 2 (or turning both the housing and the strip) so that the sensitive tracks 21 and 22 face away from the user. Thus, they will only come into contact with moisture originating from the body after it has passed through the holes 24 in the strip, and after it has thereby been reduced in quantity.

Claims

1. Enuresis alarm apparatus comprising a housing and a moisture-sensing element, wherein the housing includes a resistance monitoring circuit connected to the moisture sensing element and an alarm unit connected to the circuit such that the alarm unit is triggered by a fall in resistance of the moisture sensing element, wherein the moisture sensing element comprises an elongate strip of a flexible electrically-insulative material having spaced conductive tracks extending along its length and electrically connected at one end to the resistance monitoring circuit, wherein the strip is permeable to moisture such that urine can flow through the strip, and wherein the length of the strip is sufficient that the strip can extend in the region of the crotch of the wearer when the housing is supported in the region of a waistband.

2. Enuresis alarm apparatus according to Claim 1, wherein the strip is of a moisture impermeable material formed with a plurality of holes therethrough.

3. Enuresis alarm apparatus according to Claim 2, wherein the strip is of a non-woven plastics material.

4. Enuresis alarm apparatus according to any one of the preceding claims, wherein the strip is secured to the housing by means of cooperating press studs, which also make electrical connection of the conductive strips with the resistance monitoring circuit.

5. Enuresis alarm apparatus according to any one of the preceding claims, wherein the strip extends within an outer sleeve.

6. Enuresis alarm apparatus according to Claim 5, wherein the outer sleeve has one face presented towards the wearer that is relatively permeable and non-absorbent.

7. Enuresis alarm apparatus according to Claim 6, wherein the one face is of a synthetic fabric.

8. Enuresis alarm apparatus according to Claim 6 or 7, wherein the sleeve has an opposite face presented away from the wearer that is relatively non-permeable and absorbent.

9. Enuresis alarm apparatus according to Claim 8, wherein the opposite face is of a quilted cotton fabric.

10. Enuresis alarm apparatus according to any one of the preceding claims, wherein the alarm unit includes a vibrating member that provides a vibrating tactile signal to the wearer.

11. Enuresis alarm apparatus according Claim 10, wherein the alarm unit includes a motor, and wherein the vibrating member is a weight mounted eccentrically on the motor.

12. Enuresis alarm apparatus according to Claim 11, wherein the motor has a striker member arranged to contact a sounding member when the motor rotates so that an audible signal is produced for the wearer.

13. Enuresis alarm apparatus according to any one of the preceding claims, wherein the housing has a clip arranged to engage the wearer's clothing.

14. Enuresis alarm apparatus substantially as hereinbefore described with reference to the accompanying drawings.

15. Any novel feature or combination of features as hereinbefore described.