WO2004098401A1

WO2004098401A1 - A diaper-based monitoring and informing system, a monitoring module and an electronic diaper

Info

Publication number: WO2004098401A1
Application number: PCT/IB2004/001457
Authority: WO
Inventors: Olaf Such; Josef Lauter; Harald Reiter; Ralf Schmidt; Andras Montvay; Jens MÜHLSTEFF
Original assignee: Philips Intellectual Property & Standards Gmbh; Koninklijke Philips Electronics N. V.
Priority date: 2003-05-08
Filing date: 2004-04-30
Publication date: 2004-11-18

Abstract

A diaper-based monitoring and informing system (1) comprising a diaper (10) and a monitoring module (15) carried by the diaper, said system being arranged to monitor a vital sign of an individual wearing the diaper (10). The monitoring and informing system (1) comprises sensing means (20) arranged to measure an electrical signal (43) propagating in the body of the individual. The monitoring module comprises front-end electronics (40) with an analysis means arranged to determine a health-related parameter and to actuate an informing means (50) upon an event the health-related parameter exceeds a predetermined value in order to warn a remotely arranged caregiver upon an abnormal health condition of the individual. The informing means (50) comprise a user interface (52) with a plurality of means (52a, 52b, 52c) arranged to enable a suitable feedback to the caregiver.

Description

A diaper-based monitoring and informing system, a monitoring module and an electronic diaper

The invention relates to a diaper-based monitoring and informing system arranged to monitor a vital sign of an individual wearing the diaper and to inform a remotely arranged caregiver upon an abnormal health condition of the individual, said monitoring and informing system comprising a diaper and a monitoring module carried by said diaper.

The invention further relates to a monitoring module conceived to be carried by a diaper arranged to be worn by an individual, said monitoring module being arranged to monitor a vital sign of the individual.

The invention still further relates to an electronic diaper arranged to monitor a vital sign of an individual wearing the diaper.

An embodiment of a diaper-based monitoring and informing system as is set forth in the opening paragraph is known from US 2002/0057202. The known monitoring and informing system is arranged to monitor a respiration rate, a body temperature and a crying condition of an infant wearing the diaper. For this purpose the known monitoring and informing system comprises a sensing means located on a waist portion of the diaper worn by the infant, said sensing means comprising a plurality of meters, namely a pressure sensor, a thermometer and a microphone. The corresponding inputs of the meters are converted into suitable electrical signals, which are transmitted to a remotely arranged unit for purposes of signal analysis. In case it is found that any of the meters has detected an abnormal infant condition, a specific alarm to a remotely arranged caregiver is generated.

It is a disadvantage of the known monitoring and informing system that an indirect measurement is undertaken for determining a possible life-threatening condition. A pressure sensor actuatable by in- and out- movements of the infant's belly cannot discriminate between events of different severity, thus limiting a reliability of the monitoring system as a whole. It is a further disadvantage of the known system that the signal analysis is carried out by a remotely arranged unit, thus necessitating a full data transmission thereto. This feature implies high power consumption of the system, reducing its durability. It is an object of the invention to provide a reliable and a durable diaper-based monitoring and informing system.

For this purpose the monitoring and informing system according to the invention comprises: sensing means arranged to make a contact with an individual's body, said sensing means being further arranged to measure an electrical signal propagating in said body, said electrical signal being representative of said sign; analysis means arranged to analyze said electrical signal in order to determine a health-related parameter, said analysis means being further arranged to actuate an informing means upon an event the health-related parameter reaches a predetermined value. The technical measure of the invention is based on the insight that main vital signs of an individual, like a cardiac activity and a respiration rate can successfully be assessed by measuring a corresponding electrical signal. For measuring the cardiac activity the suitable electrical signal is an electrocardiogram. The respiration rate is obtainable from a body impedance measurement. The method of obtaining the respiration rate from the body impedance measurement is known for people skilled in the art of ECG.

In the monitoring and informing system according to the invention the measured electrical signal is made available to the analysis means. Preferably, the analysis means comprises a processor arranged to determine a health-related parameter from the measured electrical signal. For example, for the cardiac activity a suitable health-related parameter is a heart rate. For a body impedance measurement a suitable health-related parameter is a respiration rate. In order to assess the health condition of the individual, the analysis means further comprises suitable means arranged to compare an actual health-related parameter with a pre-stored predetermined value. Preferably, the pre-stored predetermined value is stored in a look-up table of a memory unit of the processor. In case it is established that the health-related parameter has reached a predetermined value, the analysis means actuate the informing means in order to warn a remotely arranged caregiver about an abnormal condition of the individual. Preferably, the informing means are remotely arranged from the monitoring and informing system, a communication between the informing means and the monitoring and informing system being enabled by means of a wireless communication. In an alternative embodiment, the informing means can comprise a stationary unit, which is connected to the monitoring and informing system by means of a suitable cabling. In an embodiment of the system according to the invention said system further comprises informing means actuatable by the analysis means, said informing means being arranged to warn the remotely arranged caregiver about the event the health-related parameter of the individual reached the predetermined value. Preferably, the informing means are arranged to sound an alarm, for example a siren or the like, or to actuate a suitable optical warning, like an emergency light. In order to enable this feature the informing means are preferably arranged with a suitable user interface, like a loud speaker, or a light source. In a more sophisticated embodiment, the user interface can comprise a screen where next to a perceptive signaling to the caregiver a textual back-up on the individual's health condition is given. In this case, also measures to be undertaken by the caregiver are preferably shown on the screen.

In a further embodiment of the system according to the invention the user interface comprises an RF-receiver. It is found to be particular advantageous to use a radio frequency range to enable a wireless communication between the analysis means and the informing means. Preferably, the RF-receiver comprises a mobile phone. It is found to be particular advantageous to use the functional possibilities of contemporary mobile telephone units for purposes of warning the remotely located caregivers about the abnormal health condition of the individual. It is also possible to send a textual message in form of an SMS- message to the corresponding mobile telephony unit of the caregiver, said message comprising the necessary steps to be undertaken by the caregiver in order to cope with the abnormal condition of the individual.

In a still further embodiment of the system according to the invention the sensing means are integrated into a material of the diaper in a waist portion of the diaper. This technical measure is based on the insight that for purposes of a heart-rate monitoring it is sufficient to use a limited number of electrodes, for example two, the electrodes being located in a waist area of the individual. By integrating the electrodes into the waist portion of the diaper, also a good mechanical contact between the active surface of the electrode and the individual's body is enabled. Preferably, the electrodes are manufactured of conductive foils, which are printed, laminated, glued, spray coated or are integrated with the diaper's material in any other suitable way. Alternatively, the electrodes can be made of conductive textile a paint. Also conductive rubber or plastic are suitable for usage as electrode materials. By integrating the electrodes with the material of the diaper a convenient disposable monitoring means is provided. It is also possible to locate the sensing means in a leg portion of the diaper. In this embodiment an improved contact with the individual's skin is achieved, thus improving a signal to noise ratio of the measured electrical signal. Preferably , a contact surface of the sensing means comprises projections which still further improve the contact between the electrodes and the individual's skin. It is advantageous to provide the sensing means with an integrated pre-amplifier to ensure a good quality of the measured electrical signal.

The monitoring module according to the invention comprises: sensing means arranged to make a contact with an individual's body, said sensing means being further arranged to measure an electrical signal propagating in said body, said electrical signal being representative of said sign; - analysis means arranged to analyze said electrical signal in order to determine a health-related parameter, said analysis means being further arranged to actuate an informing means upon an event the health-related parameter exceeds a predetermined threshold.

It is found to be advantageous to provide a separate monitoring module so that it can be fit to practically any diaper of any design and material, the module being reused after the full diaper is disposed of. Preferably, the monitoring module comprises informing means actuatable by the analysis means in order to warn the remotely arranged caregiver about the event the health-related parameter of the individual reaches the predetermined value. A suitable informing means is a mobile phone, a baby-phone or the like, said units being suitably arranged to communicate with the analysis means of the monitoring module. It is advantageous to provide the informing means with a user interface arranged to generate a perceptible signal to the caregiver in case the individual has an abnormal health condition. Still preferably, the user interface is arranged to present a textual message to the caregiver, preferably comprising steps to be undertalcen in order to reduce potentially harmful effects of said abnormal condition.

The electronic diaper according to the invention comprises sensing means arranged to make a contact with an individual's body, said sensing means being further arranged to measure an electrical signal propagating in said body, said electrical signal being representative of said sign. It is found to be particular advantageous to provide a diaper with integrated sensing means which improves a signal quality in comparison to systems where the sensing means are mechanically attached to the diaper. By providing the sensing means arranged for measuring an electrical signal propagating in the individual's body, a reliable monitoring system is enabled. The sensing means is preferably arranged on a waist portion or on a leg portion of the diaper as in these body areas the electrical signal propagating in the individual's body is measurable. In order to improve a quality of the measured electrical signal the sensing means is preferably provided with a preamplifier. In order to improve a signal to noise ratio of the measured electrical signal, a contact surface of the sensing means is preferably arranged with projections which reduce a movement artifact improving the signal quality.

These and other aspects of the invention will be discussed in more detail with reference to figures.

Fig. 1 presents in a schematic way an overview of an embodiment of the monitoring and informing system according to the invention.

Fig. 2 presents in a schematic way an embodiment of the electrodes with projections suitable for use in the monitoring and informing system according to the invention.

Fig. 3 presents in a schematic view an embodiment of the monitoring module according to the invention comprising front-end electronics.

Fig. 1 presents in a schematic way an overview of an embodiment of the monitoring and informing system according to the invention. The monitoring and informing system 1 comprises a diaper 10 and a monitoring module 15 arranged to monitor a vital sign of the individual wearing the diaper 10. For sake of clarity the diaper 10 is shown in an unfolded way, depicting an inner side of the diaper. The inner side of the diaper has a front area 11, a back area 12 separated from the front area 11 by an imaginary line 13. The front area has a waist portion 14. A diaper fastening mechanism 16a, 16b is preferably located on the back area 12. Preferably, the diaper fastening mechanism 16a, 16b uses a Velcro band. When the diaper is put on the individual and is fastened around his waist area, the electrodes 20 make contact with the individual's body. Preferably, the electrodes are manufactured of conductive foils, which are printed, laminated, glued, spray coated or are integrated with the diaper's material in any other suitable way. Alternatively, the electrodes can be made of conductive textile, paint, rubber, plastic or any other suitable conductive material. By integrating the electrodes with the material of the diaper a convenient disposable monitoring means is provided. It is also possible to locate the sensing means in a leg portion 14a of the diaper. In this embodiment an improved contact with the individual's skin is achieved, thus improving a signal to noise ratio of the measured electrical signal. The electrodes 20 are preferably powered by a battery unit (not shown). Preferably, a surface of the electrodes 20 conceived to make contact with the individual's skin comprises projections in order to reduce a movement artifact in the measured electrical signal. An example of a suitable projection is discussed with reference to Fig. 2. The measured signals from the electrodes 20 are forwarded to the front-end electronics 40 by means of wiring 30. The front-end electronics 40 comprises an input amplifier 41, a band-pass filter 42 at output of which a good quality electrical signal 43 representing a monitored physiological condition is produced. In an example of Fig. 1 a characteristic ECG-spectrum is shown. In order to perform a suitable signal analysis, for example to deduce a heart-rate, the front-end electronics further comprises a micro-processor 45, the input signal 43 thereto being pre-digitized by an analogue-to-digital converter 44. The functioning of the font-end electronics will be discussed in more detail with reference to Fig. 3. In case it is determined that an abnormal health condition of the individual has occurred, an alarm is forwarded by a transmission unit 46 to the informing means 50. Preferably, the informing means 50 is an RF-unit comprising a user-interface 52. The user-interface can have a light source 52a, for example a light emitting diode or any other suitable light source, or a loud speaker 52b arranged for sounding a warning alarm. In a more sophisticated embodiment of the informing means, the informing means are arranged with a screen to load textual information, comprising for example necessary steps to be undertalcen by the caregiver. In this case a suitable textual messages are generated by the microprocessor 45. Preferably, a list of messages corresponding to a plurality of alarm situations is stored in a memory unit of the microprocessor 45. For example, in case the health-related parameter has reached a value corresponding to an anxiety of the individual, for example a crying baby, a message 'Please check on your baby' in highlighted on a screen 52c of the user-interface 52. In case a severe health condition has occurred, a message 'call an ambulance' is generated on the screen 52c. It is also possible that a set of instructions, for example how to perform a CPR is generated on the screen 52c. Fig. 2 presents in a schematic way an embodiment of the electrodes with projections suitable for use in the monitoring and informing system according to the invention. Fig. 2 shows an isomeric view of a section of a diaper 10 with an electrode 20 integrated on a inner side of a front area 11 of the diaper. The front area 11 has a waist portion 14 and an imaginative 13 separating it from a back area (not shown). The electrode body 20 comprises a contact surface 20a conceived to enable a contact with the individual's skin which is provided with a number of projections 22 to engage to the skin. Due to such an arrangement of the contact surface 20a, the actual surface area of the electrode is reduced, while being spatially distributed over a substantial total area. It is found that in such an arrangement a very low pressure is sufficient to keep the electrode in a constant contact with the skin. Preferably, the electrode body 20 is manufactured from an elastic material, for example a conductive rubber, the projections 22 thus exhibiting a certain degree of resiliency in two orthogonal directions in a horizontal plane. This ensures that even in cases when the electrode body 20 is subjected to minor translations with respect to the patient's skin due to individual's movements, the tips of the projections 22 stay substantially at the same place, thus reducing the movement artifacts. In order to improve the electrical contact of the projections and the patient's skin, the projections can be provided with metal particles of can be fully coated with a metal layer. In this case the use of Ag is preferable as it is found that Ag enables a good s in contact. Alternatively, a rubber material can be loaded with carbon particles to make it conductive. Preferably a voluminous conductivity is achieved. In this case the resulting electrode is wear proof. Still alternatively, a usage of wealdy conductive or capacitively coupled electrodes is possible. It is also possible to provide holes 23 in the electrode body 20 in the areas between the projections 22 in order to remove accumulated sweat from beneath the electrodes in order to minimize a possible skin irritation. The electrode 20 is provided with a suitable wiring 30 to provide an electrical contact with a battery unit (not shown) and the analysis means (not shown) of the monitoring module.

Fig. 3 presents in a schematic view an embodiment of the front-end electronics of the monitoring and informing system according to the invention. The front-end electronics 40 is suitable to be used in a diaper (not shown) and is arranged to receive electrical signals measured by suitable sensing means 21, attached to the diaper or integrated thereon. The sensing means 21 comprise electrodes 20 which are arranged to monitor a vital sign of the individual by means of measuring an electrical signal representative to said sign. The sensing means 21 can additionally comprise a further sensor 22 arranged to measure a body temperature, a pressure or a movement or any other suitable vital sign. The readings of the pressure sensor can be used to validate the reading of the sensor 20. For example for the sensor 20 being an ECG sensor, which has lost a contact to the individual's body and thus reports a zero heart-rate, the pressure sensor detecting that the individual breathes can send a signal to the micro-processor of the front-end electronics to discard the readings of the ECG sensor. The sensing means 21 are preferably arranged to perform a continuous monitoring of the vital sign of the individual and is further arranged to provide a corresponding signal, for example by means of a wire-less communication or by means of a suitable wiring, to the front-end electronics 40 of the system. The front-end electronics 40 is arranged to analyze the signal from the sensing means 21. For that purpose the front-end electronics 40 comprises a data processing means 47 arranged to process the measured signal and to forward the processed signal to the analysis means 48. The data processing means 47 comprises a preamplifier 41, an analogue processing circuit 42a and an ADC unit 44. The data processing means 47 forwards the corresponding data to the analysis means 48, arranged to analyze said data in order to yield a health-related parameter. For example, in case the sensor 20 is arranged to monitor a cardiac activity of the individual, the resulting data comprises an electrocardiogram. In this case the analysis means 48 is arranged to determine a corresponding heart-rate of the individual. In case the sensor 20 is arranged to monitor a respiration rate of the individual, the resulting data comprises an inhalation-exhalation curve. In this case the analysis means 48 is arranged to determine the respiration rate of the individual. The determination of the corresponding rates can be done using a per se known computation algorithms (not shown). The determined health-related parameter is then written into a first look-up table 48a. The analysis means 48 is further arranged to compare said health-related parameter to a predetermined value, which is preferably stored in a second look-up table 48b. Preferably, the second look-up table 48b comprises a plurality of predetermined values. For example, a first predetermined value can be set to a condition of an anxiety of the individual, a second predetermined value can be set to a condition of a minor medical abnormality and a further predetermined value can be set to a condition of a medical emergency. It is also possible that the look-up table 48b comprises a gradual conditioning of the health-related parameter, given, for example by an analytical expression. In case the analysis means 48 detects that the health-related parameter reaches the predetermined value, it generates a trigger signal to actuate the transmission means 46. The transmission means 46 receive the trigger signal and generate a suitable feedback to a remote caregiver by actuating an informing means 50 located at a remote location of the caregiver. An example of a suitable feedback is a textual message 46a transmitted to a user-interface 52. Alternatively, the user-interface can comprise a loud speaker (not shown) arranged to replay a prerecorded message or a musical tone. Still alternatively, the user interface can comprise an actuatable light source.

Claims

CLAIMS:

1. A diaper-based monitoring and informing system (1) arranged to monitor a vital sign of an individual wearing a diaper (10) and to inform a remotely arranged caregiver upon an abnormal health condition of the individual, said monitoring and informing system comprising the diaper (10) and a monitoring module (15) carried by said diaper, said monitoring module comprising: sensing means (21) arranged to make a contact with an individual's body, said sensing means being further arranged to measure an electrical signal (43) propagating in said body, said electrical signal being representative of said sign; analysis means (48) arranged to analyze said electrical signal in order to determine a health-related parameter (48a), said analysis means being further arranged to actuate an informing means (50) upon an event the health-related parameter reaches a predetermined value (48b).

2. A system (1) according to claim 1, wherein said system further comprises informing means (50) actuatable by said analysis means (48), said informing means being arranged to warn the remotely arranged caregiver about the event the health-related parameter (48a) of the individual reaches the predetermined value (48b).

3. A system (1) according to claim 2, wherein the informing means (50) comprises a remotely arranged user interface (52) arranged to generate a perceptible signal to the caregiver.

4. A system according to claim 3, wherein the analysis means (48) are further arranged to forward a predefined textual message (46a) to the user interface (52), the user interface comprising means (52c) to present said message to the caregiver.

5. A system according to claim 4, wherein the user interface (52) comprises an RF-unit.

6. A system according to claim 5, wherein the RF-unit comprises a mobile telephony unit.

7. A system according to any one of the preceding claims, wherein the sensing means (21) comprises an ECG sensor.

8. A system according to claim 7, wherein the ECG sensor is further arranged to enable an impedance measurement on the individual's body.

9. A system according to claim 8, wherein the sensing means (21) is integrated into a material of the diaper (10) in a waist portion (14) of the diaper.

10. A system according to claim 8, wherein the sensing means is integrated into a material of the diaper (10) in a leg portion (14a) of the diaper.

11. A system according to any one of the preceding claims 9 or 10, wherein a surface (20a) of the sensing means (20) conceived to enable a contact with the individual's skin comprises projections (22).

12. A system according to claim 1, wherein the sensing means comprises a preamplifier.

13. A monitoring module (15) conceived to be carried by a diaper (10) arranged to be worn by an individual, said monitoring module being arranged to monitor a vital sign of the individual, said monitoring module comprising: sensing means (21) arranged to make a contact with an individual's body, said sensing means being further arranged to measure an electrical signal propagating in said body, said electrical signal being representative of said sign; analysis means (48) arranged to analyze said electrical signal in order to determine a health-related parameter (48a), said analysis means being further arranged to actuate an informing means (50) upon an event the health-related parameter reaches a predetermined value (48b).

14. A monitoring module (15) according to claim 13, wherein said module further comprises informing means (50) actuatable by said analysis means, said informing means being arranged to warn the remotely arranged caregiver about the event the health-related parameter (48a) of the individual reaches the predetermined value (48b).

15. A monitoring module (15) according to claim 14, wherein the informing means (50) comprises a remotely arranged user interface (52) arranged to generate a perceptible signal to the caregiver.

16. A monitoring module (15) according to claim 15, wherein the analysis means

(48) are further arranged to forward a predefined textual message (46a) to the user interface (52), the user interface comprising means (52c) to present said message to the caregiver.

17. A monitoring module (15) according to claim 16, wherein the user interface (52) comprises an RF-unit.

18. A monitoring module according to claim 17, wherein the RF-unit comprises a mobile telephony unit.

19. An electronic diaper (10) arranged to monitor a vital sign of an individual wearing the diaper, said diaper comprising sensing means (21) arranged to make a contact with an individual's body, said sensing means being further arranged to measure an electrical signal propagating in said body, said electrical signal being representative of said sign.

20. An electronic diaper (10) according to claim 19, wherein the sensing means

(20) is integrated into a material of the diaper in a waist portion (14) of the diaper.

21. An electronic diaper (10) according to claim 19, wherein the sensing means is integrated into a material of the diaper (10) in a leg portion (14a) of the diaper.

22. An electronic diaper (10) according to any one of the preceding claims 19 to

21, wherein a surface (20a) of the sensing means (20) conceived to enable a contact with the individual's skin comprises projections (22).

23. An electronic diaper (10) according to Claim 19, wherein the sensing means

(21) comprises a preamplifier.