EP0839019A1 - Moisture detection systems - Google Patents

Abstract

A moisture detection garment comprising a garment, at least part of which is formed into pants, and a detector; the detector comprising a moisture detector sensor in circuit with an alarm characterised in that the alarm includes a signal transmitter for transmitting an alarm signal to a separate receiver to provide a remote indication of an alarm condition.

Description

"Moisture Detection Systems"

This invention relates to a moisture detection systems, particularly for use in the detection of the emission of urine or wet faeces.

An indication of a person passing urine or wet faeces can be extremely useful in toilet training young children or retraining adults who have suffered from an accident resulting in incontinence. Such an indication is also of value to a person who is physically disabled and has no control of bowel or bladder movement. Such an indication would allow that person or the nursing staff caring for him to change dressings which would then result in less likelihood of sores developing.

The introduction of a garment which is easily applied and which provides either a visual or audio signal to indicate the passing of urine or wet faeces would represent a considerable improvement.

The invention also provides a separate detector which can be selectively removed from the garment and transferred to another garment which obviates the need for each garment to be provided with its own detector.

In those situations where the audible signal emitted by the detector is likely to go unnoticed, a transmitter/receiver arrangement is provided so that the audible signal is emitted at the receiver which may be located within the audible range of the supervising personnel.

According to the present invention there is provided a moisture detection garment comprising a garment, at least part of which is formed into pants, and a detector; the detector comprising a moisture detector sensor in circuit with an alarm.

Preferably, the detector further includes an integrated circuit timer adapted to be triggered by said sensor and to activate said alarm.

Preferably, said alarm operates for a first predetermined period after being activated by said timer. Preferably, said alarm can only be reactivated after said timer has entered a stand-by mode at the end of a second predetermined period following the triggering of the timer. Preferably also, said second predetermined period commences only after said sensor ceases to detect an alarm condition.

Preferably, power is constantly applied to the circuit, and may be provided by a battery.

Preferably, the sensor comprises a dual interleaved sensor. Most preferably, the integrated circuit timer is triggered by conductivity of the sensor rising above a pre-determined level.

Preferably, no external controls are provided for the user. The moisture detection garment may be laundered and re-used without losing its moisture detection properties.

Further according to the present invention there is provided a moisture detection garment comprising a garment, at least part of which is formed into pants, and a detector; the detector comprising a moisture detector sensor in circuit with an alarm and manually operable switching means.

Preferably, the switching means are covered by a membrane and include a light emitting diode (LED) which indicates when the detector is activated.

Preferably, the sensor is in the form of two separate metallic members provided as copper strips.

Preferably, the copper strips are not coated with a protective coating or lacquer.

Preferably, two end tabs protrude from the detector, each carrying one connection to one of the two copper strips to enable connection to the detector's internal printed circuit board (PCB) . The end tabs may be between 13mm and 3mm in length and tin coated to allow either solder or pressure connection. Separation between the strips may be in the range of 1.5mm to 0.75mm.

Preferably, the circuit and the copper strips are located on a flexible PCB made, of for example, a polyester of approximately 25mm square.

Most preferably, the detector is located in the crotch of the pants, and the circuit may be an integral part of the garment. The circuit may be removable.

The detector may be approximately 24mm long x 24mm wide x 12mm deep, excluding the sensor.

Still further according to the present invention there is provided a moisture detector for use with a garment comprising a moisture detector sensor in circuit with an alarm and manually operable switching means, the moisture detector being provided as a single integral unit suitable for attachment to a garment.

The moisture detector unit may for example be configured to correspond to a pocket or pouch provided on the garment or provided with fixing means for attachment to a conventional garment.

Preferably, the moisture detector may include a transmitter as an addition or alternative to the alarm, a separate receiver being provided for remote indication of an alarm condition.

Embodiments of the present invention will now be described, by way of example, with reference to the accompanying drawings in which:-

Fig 1 is a schematic view of a moisture detection garment in accordance with a first embodiment of the present invention;

Fig 2 is a schematic diagram of a detector circuit of the embodiment of Fig 1;

Fig 3 is a circuit diagram of the sensing and alarm circuity of Fig 2; Fig 4 is a circuit diagram of the sensing and alarm circuitry of a preferred embodiment of the invention. Fig 5 is a circuit diagram of a suitable transmitter for use with the detector of the present invention; and Fig 6 illustrates a suitable arrangement of printed circuit for use with the detector of the present invention.

Fig 1 shows a moisture detection garment in the form of a pair of pants 1; the pants 1 having a moisture detector 2, and a switching means 3. The activation of the switching means 3 activates the detector 2. The garment 1 further includes an audio alarm which is activated when moisture is detected.

The switching means 3 also includes a light emitting diode 4 which indicates when the detector 2 is activated.

The sensor is in the form of two separate copper strips 5a and 5b which are separated by a gap of 1.5mm to 0.75mm.

The copper strips 5a and 5b are positioned on a flexible polyester PCB 6. The detector 2 includes two end tabs of between 13mm and 3mm in length which protrudes from the detector 2 enabling connection of the detector 2 to the copper strips 5a and 5b either by solder or pressure connection.

The copper strips 5a and 5b are not coated with any protective coating or lacquer, as this would hinder their ability to detect moisture. The detector 2 containing the sensor element 5a and 5b and the electronics is approximately 65 millimetres by 50 millimetres by 13.5 millimetres in dimension with a 1.5 millimetre wall. Also the detector 2 has a front panel consisting of a membrane covered switching means 3. The rear of the detector is fitted with an adhesive-backed flexible PCB 6 for moisture detection which feeds the connectors through a fine slot on the back of the case which is sealed with an epoxy resin, the detector 2 being fixed to the garment 1 with a strong adhesive.

The detector 2 will withstand vigorous hand or machine washing due to its construction and is not required to be removed for this function.

When in use, the garment is worn by a person and the press stud 4 is closed to activate the sensor 2. When moisture is detected an audio alarm may be activated.

Fig. 2 shows a schematic diagram of the detector and alarm circuit. When the circuit 8 is completed by moisture at the wires 5a and 5b a signal is produced which is amplified in the amplifier 7. The signal is passed through a timer circuit and oscillator circuit 9 to the piezo-electric element 10 of a loudspeaker which produces a signal.

Fig. 3 shows a more detailed embodiment of the circuit of Fig. 2.

Fig. 4 is a circuit diagram of the sensing and alarm circuitry of a particularly preferred embodiment of the invention. Power is applied to the circuit constantly (i.e. it has no on/off switch as in the first embodiment), the quiescent power requirement of the circuit being very small, such that a battery life of several months may be expected.

The circuit of Fig. 4 comprises a dual interleaved sensor 12 similar to that of the previous embodiment connected to an integrated circuit timer 14 (suitably ICM 7555 CMOS timer) , which controls the operation of a mask-programmable melody generator 16, which in turn drives a piezo-electric sounder 18. The circuit is powered by a battery (not shown, suitably a lithium CR2340 button cell).

The timer 12 is triggered and activates the melody generator 16 whenever the conductivity of the sensor rises above a threshold determined by resistors Rl and R2 (suitably 1 and lOMohm respectively). The melody generator 16 operates for a period determined by its programming and then stops and returns to its quiescent mode. Once the conductivity of the sensor 14 falls back below the threshold level, the timer 12 enters a stand-by mode for a period determined by capacitor Cl (suitably 33uF) , during which it cannot re-trigger the melody generator 16. Once the alarm has been triggered, it cannot be re-triggered until the conductivity of the sensor 12 drops and the stand-by period has elapsed. Accordingly, the battery will not be drained by the alarm sounding periodically if the garment remains wet for an extended period (e.g. while being laundered) .

No controls are provided for the user as none are necessary. The alarm and stand-by periods are predetermined, and the device does not have to be switched on and off. The battery may be replaceable, or rechargeable or the device can simply be discarded once its battery dies .

DIMENSIONS. Dimensions may vary to suit application specifications, but in general would approximate the dimensions below:

Length - 24mm ± 0.5mm Breadth - 24mm + 0.5mm Height - 12mm ± 1.0mm

All dimensions are dependent on components used, the main component effecting the dimensions being:

(a) Battery (b) Piezo Sounder

The sensor has not been included in these dimensions as it is assumed that the sensor will take the form of a strip or pad manufactured in a flexible material approximately 1mm thick to the end users requirements.

The detector is slipped between the gusset bi-layer in underwear and sewn in during manufacture of the garment. The sensor is provided on the surface of the garment to directly contact the body.

Alternatively, the sensor may be manufactured to form part of the gusset, or lie just below the upper layer of the gusset. Thus the shape and positioning of the sensor part of the detector is variable to suit requirements . The invention thus provides a re-usable garment incorporating a moisture detector which can be laundered along with the garment and the battery selected to give a few months life or long-term wear over a year or more.

For example alternative preferred embodiments will now be described.

The already described preferred embodiments have wide applicability but some further features and additions provide for a wider range of uses.

In one such alternative the sensing and alarm device are combined in a single, integral stand-alone unit which can either be used with pants garments provided with a suitable pocket for receiving the unit or, with the addition of appropriate fastening means, the unit can be used with a wide range of conventional garments. In either case, the arrangement has the advantage that a single sensor and alarm unit can be easily transferred from garment to garment as each garment is in turn soiled and sent for laundering.

Such a unit can therefore be in continuous use and it is thus advantageous that it be provided with replaceable batteries which are preferably of a rechargeable type.

A further advantage of such a stand-alone unit is that, as the user only requires a single unit, additional features can be readily incorporated. For example, the audio sounder audio 'device already described can be supplemented or replaced by a simple pager device which in combination with an appropriate receiver allows for remote indication of moisture detection. In such embodiments (as partly illustrated in Figs 5 and 6) there is included an aerial for the transmitter which can be a simple loop arrangement or be incorporated as part of the circuit board.

Embodiments incorporating transmitter means can be such as to transmit signals to a receiver which may receive alarm signals from a plurality of detector units .

The incontinence alarm comprises two units, a broad band wireless frequency modulation transmitter, and a pocket-sized receiver.

In a particular embodiment the transmitter is of surface mount construction on a PCI 200 substrate, to BS 43548. Using broad-band UHF transmission FM modulated by a Wien bridge, the transmitter is stable over a wide range of temperature and humidity. The FM modulation is 2.1 KHz having a rise time of 3 milliseconds, which satisfies the requirements of MPT 1340. The moisture sensor is a flexible printed circuit attached to the transmitter.

The transmitter section only is totally enclosed in a soft latex encapsulant. This material is acceptable close to the body being non-irritant, it also waterproofs the electronics.

The receiver incorporates a frequency locked loop, with automatic gain control which improves reception in difficult areas. This unit is enclosed in a pocket-sized enclosure with retaining clip. Modifications and improvements may be incorporated without departing from the scope of the invention.

Claims

1. A moisture detection garment comprising a garment, at least part of which is formed into pants, and a detector; the detector comprising a moisture detector sensor in circuit with an alarm characterised in that the alarm includes a signal transmitter for transmitting an alarm signal to a separate receiver to provide a remote indication of an alarm condition.

2. A garment as claimed in Claim 1, wherein the detector further includes an integrated circuit timer adapted to be triggered by said sensor and to activate said control circuit.

3. A garment as claimed in any preceding Claim, wherein said control circuit operates for a first predetermined period after being activated by said timer.

4. A garment as claimed in Claim 3, wherein said control circuit can only be reactivated after said timer has entered a stand-by mode at the end of a second predetermined period following the triggering of the timer.

5. A garment as claimed in Claim 4, wherein said second predetermined period commences only after said sensor ceases to detect an alarm condition.

6. A garment as claimed in any preceding Claim, wherein the sensor comprises a dual interleaved sensor.

7. A garment as claimed in Claim 2, wherein the integrated circuit timer is triggered by conductivity of the sensor rising above a pre-determined level.

8. A garment as claimed in any preceding Claim, wherein said control circuit includes a light emitting diode (LED) which indicates when the detector is activated.

9. A garment as claimed in any preceding Claim, wherein the detector is located in the crotch of the pants, and the circuit is an integral part of the garment.

10. A garment as claimed in any preceding Claim, wherein the transmitter is encapsulated.