Portable level sensor

1. A portable level sensor for a flexible bag that is a stoma bag or a urine collection bag for collecting a fluid and/or a solid, wherein the portable level sensor comprises:

a flexible resistor element, having an electrical resistance that changes in dependence upon its degree of flexing;

means for attaching the flexible resistor element to an outside surface of the flexible bag; and

means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance; and

comprising an accelerometer programmed and arranged to generate a digital signal corresponding to an orientation of the flexible bag and transmit to a receiver a signal which varies in dependence on the orientation of the flexible bag.

2. The portable level sensor as claimed in claim 1 , wherein said means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance comprises:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver.

3. The portable level sensor as claimed in claim 1 , wherein said means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance comprises:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver;

and wherein the communication module is switchable between an active mode and an idle mode, wherein power consumption of the communication module in the idle mode is lower than in the active mode, and wherein the microprocessor is programmed to switch the communication module between the idle mode and the active mode by communicating the digital signal to the communication module.

4. A system for sensing a content level of the flexible bag that is a stoma bag or a urine collection bag comprising:

the portable level sensor according to claim 1 , wherein said means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance comprises:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver; and

a wireless receiver adapted to receive the wireless signal transmitted by the communication module and communicate the content level of the flexible bag to a user.

5. A system for sensing a content level of the flexible bag that is a stoma bag or a urine collection bag comprising:

the portable level sensor according to claim 1 , wherein said means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance comprises:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver; and

a wireless receiver adapted to receive the wireless signal transmitted by the communication module and communicate the content level of the flexible bag to a user, wherein the wireless receiver includes an alarm for alerting the user when the content level of the flexible bag exceeds a predetermined threshold.

6. A system for sensing a content level of the flexible bag that is a stoma bag or a urine collection bag comprising:

the portable level sensor according to claim 1 , wherein said means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance comprises:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver; and

a wireless receiver adapted to receive the wireless signal transmitted by the communication module and communicate the content level of the flexible bag to a user, wherein said wireless receiver includes means for alerting the user when the wireless signal received from the communication module indicates a decrease in the content level of the flexible bag and means for determining whether the wireless signal indicating a decrease in the content level of the flexible bag is associated with a mechanical failure of the attachment of the flexible resistor element to the flexible bag or with movement of the flexible bag.

7. A system for sensing a content level of the flexible bag that is a stoma bag or a urine collection bag comprising:

the portable level sensor according to claim 1 , wherein said means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance comprises:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver; and

a wireless receiver adapted to receive the wireless signal transmitted by the communication module and communicate the content level of the flexible bag to a user, wherein the flexible bag is a stoma bag and the wireless receiver includes means for detecting patterns of signals associated with a stoma bag user adopting a sitting or prone position.

8. A method for sensing a content level of a flexible bag comprising:

(a) providing a flexible resistor element having an electrical resistance that changes in dependence upon its degree of flexing attached to an outside surface of the flexible bag, such that the flexible resistor element flexes upon filling of the flexible bag; and

(b) periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance;

wherein the flexible bag is a stoma bag or a urine collection bag.

9. The method as claimed in claim 8 , in which the periodical polling of step (b) is carried out by a means comprising:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver.

10. The method as claimed in claim 8 , in which the periodical polling of step (b) is carried out by a means comprising:

(a) a communication module for transmitting a wireless signal to a receiver; and

(b) a microprocessor programmed and arranged to generate a digital signal corresponding to the electrical resistance of the flexible resistor element and to communicate said digital signal to the communication module for wireless transmission to the receiver; and

the method further comprising switching the communication module from an idle mode to an active mode by communicating the digital signal from the microprocessor to the communication module.

11. The method as claimed in claim 8 , further comprising receiving the transmitted signal, wherein the signal is wireless, to a wireless receiver and communicating the content level of the flexible bag to a user.

12. The method as claimed in claim 8 , further comprising alerting a user when the content level of the flexible bag exceeds a predetermined threshold.

13. The method as claimed in claim 9 , further comprising alerting a user when the wireless signal received from the communication module indicates a decrease in the content level of the flexible bag and determining whether the wireless signal indicating a decrease in the content level of the flexible bag is associated with a mechanical failure of the attachment of the flexible resistor element to the flexible bag or with movement of the flexible bag.

14. The method as claimed in claim 8 , wherein the flexible bag is a stoma bag and the method further comprises a step of detecting patterns of signals associated with a stoma bag user adopting a sitting or prone position.

15. A system for simultaneously sensing a content level of a plurality of flexible bags comprising:

(a) a plurality of portable level sensors according to claim 1 ; and

(b) a wireless receiver adapted to receive the signal transmitted by the communication module of each said portable level sensor and to communicate the content level of each flexible bag to a monitoring station.

16. A method for simultaneously sensing a content level of a plurality of flexible bags, said method comprising:

(a) attaching a plurality of portable level sensors according to claim 1 to an outside surface of each of the plurality of flexible bags, such that the flexible resistor element flexes upon filling of the flexible bag;

(b) periodically polling the electrical resistance of each flexible resistor element and transmitting to a receiver a separate signal corresponding to the electrical resistance of each flexible resistor element which varies in dependence on the said electrical resistance; and

(c) receiving the transmitted signal, wherein the signal is wireless, to a wireless receiver and communicating the content level of the flexible bag to a monitoring station.

17. A portable level sensor for a flexible bag for collecting a fluid and/or a solid, wherein the portable level sensor comprises:

a flexible resistor element, having an electrical resistance that changes in dependence upon its degree of flexing;

means for attaching the flexible resistor element to an outside surface of the flexible bag;

means for periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance; and

an accelerometer programmed and arranged to generate a digital signal corresponding to an orientation of the flexible bag and transmit to a receiver a signal which varies in dependence on the orientation of the flexible bag.

18. A system for sensing the content level of a flexible bag comprising the portable level sensor according to claim 17 and a receiver adapted to receive the digital signal transmitted by the accelerometer, wherein the receiver comprises means for calculating the actual content level of the flexible bag when the flexible bag is orientated at one or more degrees of deviation from an upright position and means for communicating the actual content level of the flexible bag to a user.

19. A method for sensing the content level of a flexible bag comprising

(a) providing the portable level sensor according to claim 17 attached to an outside surface of the flexible bag, such that the flexible resistor element flexes upon filling of the flexible bag;

(b) periodically polling the electrical resistance of the flexible resistor element and transmitting to a receiver a signal which varies in dependence on the said electrical resistance; and

(c) transmitting to the receiver a signal from the accelerometer which varies in dependence on the orientation of the flexible bag.