Battery-Less Smart Diaper Based on NFC Technology

Modern disposable diapers are carefully designed to transport fluid away from the skin to prevent irritation and dermatitis. These devices are used not only for babies. In fact, they are increasingly used for the elderly since both average life expectancy and the number of people who need special care are increasing. Diapers must be changed to prevent skin rash caused by the skin being exposed to wetness for a long time and to high the pH levels of urine. However, it is not easy to check the state of diapers (of babies or the elderly) without removing the baby’s or the elderly’s clothes. In this paper, we propose a smart diaper equipped with a battery-less near field communication (NFC) tag. Moisture is detected by changes in capacitance between two electrodes located on the back sheet of the diaper, while capacitance is determined from the charge time through a high-value resistor using a microcontroller. The change in capacitance as a function of the wet conditions is simulated and measured. The tag is based on an NFC IC with energy harvesting. The power required to feed the electronics and microcontroller is obtained from the magnetic field generated by a smartphone with NFC used as a reader. A simple model is proposed to estimate the volume of urine in the diaper. We compare this approach with others in the literature and study how the capacitance is affected by the body and the materials.

[1]  A. Palma,et al.  Flexible Passive near Field Communication Tag for Multigas Sensing. , 2017, Analytical chemistry.

[2]  Gaetano Marrocco,et al.  Pervasive electromagnetics: sensing paradigms by passive RFID technology , 2010, IEEE Wireless Communications.

[3]  Tao Dong,et al.  Microfluidic paper-based analytical devices for colorimetric detection of urinary tract infection biomarkers on adult diapers , 2015, 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC).

[4]  David Girbau,et al.  Chipless Dielectric Constant Sensor for Structural Health Testing , 2018, IEEE Sensors Journal.

[5]  David Girbau,et al.  Battery-Less Soil Moisture Measurement System Based on a NFC Device With Energy Harvesting Capability , 2018, IEEE Sensors Journal.

[6]  Frances Talaska Fischbach,et al.  A manual of laboratory diagnostic tests , 1980 .

[7]  Etienne Perret,et al.  Low cost low sampling noise UWB Chipless RFID reader , 2015, 2015 IEEE MTT-S International Microwave Symposium.

[8]  A. Koptioug,et al.  The "smart" diaper moisture detection system , 2004, 2004 IEEE MTT-S International Microwave Symposium Digest (IEEE Cat. No.04CH37535).

[9]  Hannah Kausche,et al.  Towards paper based diaper sensors , 2015, 2015 IEEE Biomedical Circuits and Systems Conference (BioCAS).

[10]  Manel Gasulla,et al.  Analysis of a Direct Interface Circuit for Capacitive Sensors , 2009, IEEE Transactions on Instrumentation and Measurement.

[11]  S. Tedjini,et al.  A Group-Delay-Based Chipless RFID Humidity Tag Sensor Using Silicon Nanowires , 2013, IEEE Antennas and Wireless Propagation Letters.

[12]  Chen Yuquan,et al.  Design of wireless SAW humidity sensor node based on radio wake-up technique , 2010, 2010 IEEE 12th International Conference on Communication Technology.

[13]  Benjamin D. Braaten,et al.  A low cost flexible passive UHF RFID tag for sensing moisture based on antenna polarization , 2014, IEEE International Conference on Electro/Information Technology.

[14]  John C Batchelor,et al.  Smart radio-frequency identification tag for diaper moisture detection. , 2015, Healthcare technology letters.

[15]  Chris D. Nugent,et al.  Towards developing effective Continence Management through wetness alert diaper: Experiences, lessons learned, challenges and future directions , 2010, 2010 4th International Conference on Pervasive Computing Technologies for Healthcare.

[16]  A. Stogryn,et al.  Equations for Calculating the Dielectric Constant of Saline Water (Correspondence) , 1971 .

[17]  R. W. Lau,et al.  The dielectric properties of biological tissues: II. Measurements in the frequency range 10 Hz to 20 GHz. , 1996, Physics in medicine and biology.

[18]  Saifur Rahman,et al.  A Low-Cost wet Diaper Detector Based on Smart Phone and BLE Sensor MD , 2017 .

[19]  Jun Zou,et al.  A New Wireless Sensor System for Smart Diapers , 2008, IEEE Sensors Journal.

[20]  Feng Chi,et al.  Automated Alarm System for Diaper Wet Using GSM , 2014, 2014 IEEE 17th International Conference on Computational Science and Engineering.

[21]  Antonio J. Jara,et al.  Secure use of NFC in medical environments , 2009 .

[22]  Hans-Erik Nilsson,et al.  An incontinence alarm solution utilizing RFID based sensor technology , 2011, 2011 IEEE International Conference on RFID-Technologies and Applications.

[23]  A. Lázaro,et al.  Semi-Passive Time-Domain UWB RFID System , 2013, IEEE Transactions on Microwave Theory and Techniques.

[24]  D. Girbau,et al.  Near-Field Soil Moisture Sensor with Energy Harvesting Capability , 2018, 2018 48th European Microwave Conference (EuMC).

[25]  J. V. van Gool,et al.  Urine output rate and maximum volume voided in school-age children with and without nocturnal enuresis. , 2007, The Journal of pediatrics.

[26]  G. Erasala,et al.  Safety evaluation of superabsorbent baby diapers. , 2009, Regulatory toxicology and pharmacology : RTP.

[27]  John A Kellum,et al.  Oliguria as predictive biomarker of acute kidney injury in critically ill patients , 2011, Critical care.

[28]  Tareq Khan,et al.  A Smart Wearable Gadget for Noninvasive Detection and Notification of Diaper Moister , 2018, 2018 IEEE International Conference on Electro/Information Technology (EIT).

[29]  R. W. Lau,et al.  The dielectric properties of biological tissues: III. Parametric models for the dielectric spectrum of tissues. , 1996, Physics in medicine and biology.

[30]  Rahul Bhattacharyya,et al.  UHF RFID tag IC power mode switching for wireless sensing of resistive and electrochemical transduction modalities , 2018, 2018 IEEE International Conference on RFID (RFID).

[31]  R. Adam.  Skin Care of the Diaper Area , 2008, Pediatric dermatology.

[32]  S. Gevorgian,et al.  Line Capacitance and Impedance of Coplanar-Strip Waveguides on Substrates with Multiple Dielectric Layers , 2001, 2001 31st European Microwave Conference.

[33]  Manos M. Tentzeris,et al.  Ambient RF Energy-Harvesting Technologies for Self-Sustainable Standalone Wireless Sensor Platforms , 2014, Proceedings of the IEEE.

[34]  C. Di Natale,et al.  Humidity Sensing by Polymer-Loaded UHF RFID Antennas , 2012, IEEE Sensors Journal.

[35]  Antonio Lázaro,et al.  A Survey of NFC Sensors Based on Energy Harvesting for IoT Applications , 2018, Sensors.

[36]  Dominique Paret.  Design Constraints for NFC Devices: Paret/Design Constraints for NFC Devices , 2016 .

[37]  Yi Zhao,et al.  NFC-WISP: A sensing and computationally enhanced near-field RFID platform , 2015, 2015 IEEE International Conference on RFID (RFID).

[38]  A. Lázaro,et al.  Passive Wireless Temperature Sensor Based on Time-Coded UWB Chipless RFID Tags , 2012, IEEE Transactions on Microwave Theory and Techniques.

[39]  Hans-Erik Nilsson,et al.  Home care with NFC sensors and a smart phone , 2011, ISABEL '11.

[40]  Marti Boada,et al.  Battery-Less NFC Sensor for pH Monitoring , 2019, IEEE Access.

[41]  Tao Dong,et al.  A smart phone-based robust correction algorithm for the colorimetric detection of Urinary Tract Infection , 2015, 2015 37th Annual International Conference of the IEEE Engineering in Medicine and Biology Society (EMBC).

[42]  Tao Dong,et al.  Dipsticks integrated on smart diapers for colorimetric analysis of urinary tract infections in the field , 2014, Proceedings of the 16th International Conference on Mechatronics - Mechatronika 2014.

[43]  Ferat Akkoç,et al.  Development and Experimental Comparison of Low-Cost, Reliable Capacitive Touch Sensing Boards , 2016, Sensors.

[44]  G. Drach,et al.  Male peak urinary flow rate: relationships to volume voided and age. , 1979, The Journal of urology.

[45]  Juha Virtanen,et al.  Inkjet-Printed Humidity Sensor for Passive UHF RFID Systems , 2011, IEEE Transactions on Instrumentation and Measurement.

[46]  Aung Aung Phyo Wai,et al.  Smart wireless continence management system for persons with dementia. , 2008, Telemedicine journal and e-health : the official journal of the American Telemedicine Association.

[47]  Antonio Lázaro,et al.  Color Measurement and Analysis of Fruit with a Battery-Less NFC Sensor , 2019, Sensors.

[48]  Klaus Finkenzeller,et al.  Rfid Handbook: Fundamentals and Applications in Contactless Smart Cards and Identification , 2003 .

[49]  R. Colella,et al.  Wearable UHF RFID Sensor Tag in 3D-Printing Technology for Body Temperature Monitoring , 2018, 2018 2nd URSI Atlantic Radio Science Meeting (AT-RASC).

[50]  Busra Ozdenizci,et al.  The Survey on Near Field Communication , 2015, Sensors.

[51]  Ramon Villarino,et al.  A Passive Harmonic Tag for Humidity Sensing , 2014 .

[52]  L.M. Ang,et al.  Wireless intelligent incontinence management system using smart diapers , 2008, 2008 5th International Conference on Electrical Engineering/Electronics, Computer, Telecommunications and Information Technology.

[53]  Huaji Zhang,et al.  The Influence on the Absorption Properties of Paper Diapers by the SAP Mass Ratio and Fluff Pulp , 2015 .

[54]  Sigurd Wagner,et al.  Capacitive sensing of droplets for microfluidic devices based on thermocapillary actuation. , 2004, Lab on a chip.

[55]  Bruce A. Brod.  Association of Skin Wetness and pH With Diaper Dermatitis , 1994 .