Implementation of a Cyber-Physical System Using Wireless Sensor Networks for Monitoring Patients
Sensing, distributed computation and wireless communication are the essential building components of a Cyber-Physical System (CPS). Having many advantages such as mobility, low power, multi-hop routing, low latency, self-administration, utonomous data acquisition, and fault tolerance, Wireless Sensor Networks (WSNs) have gone beyond the scope of monitoring the environment and can be a way to support CPS. This paper presents the design, deployment, and empirical study of an eHealth system, which can remotely monitor vital signs from patients such as body temperature, blood pressure, SPO2, and heart rate. The primary contribution of this paper is the measurements of the proposed eHealth device that assesses the feasibility of WSNs for patient monitoring in hospitals in two aspects of communication and clinical sensing. Moreover, both simulation and experiment are used to investigate the performance of the design in many aspects such as networking reliability, sensing reliability, or end-to-end delay. The results show that the network achieved high reliability - nearly 97% while the sensing reliability of the vital signs can be obtained at approximately 98%. This indicates the feasibility and promise of using WSNs for continuous patient monitoring and clinical worsening detection in general hospital units.
 T. A. Brennan, L. L. Leape , N. M. Laird, L. Hebert, A. R. Localio, A. G. Lawthers, J. ‘P. Newhouse, P. C. Weiler, and H. H. Hiatt, Incidence of adverse events and negligence in hospitalized patients. Results of the Harvard medical practice study I. New England Journal of Medicine, Feb 1991, 324(6):3706.
 T. J. Commission, 2008 national patient safety goals.
 R. M. Wilson, W. B. Runciman, R. W. Gibberd, B. T. Harrison, L. Newby, and J. D. Hamilton, The quality in australian health care study. Medical Journal Australia, , 1995, 163(9):45871
 L. L. Leape, T. A. Brennan, N. Laird, A. G. Lawthers, A. R. Localio, B. A. Barnes, L. Hebert, J. P. Newhouse, P. C. Weiler, and H. Hiatt, The nature of adverse events in hospitalized patients. Results of the harvard medical practice study ii. New England Journal of Medicine, Feb 1991, 324(6):37784.
 M. D. Buist, E. Jarmolowski, P. R. Burton, S. A. Bernard, B. P. Waxman, and J. Anderson. Recognising clinical instability in hospital patients before cardiac arrest or unplanned admission to intensive care. A pilot study in a tertiary-care hospital. Medical Journal of Australia, Jul 1999, 171(1):225.
 M. Hravnak, L. Edwards, A. Clontz, C. Valenta, M. A. Devita, and M. R. Pinsky, Defining the incidence of cardiorespiratory instability in patients in step-down units using an electronic integrated monitoring system. Archives of Internal Medicine, Jun 2008, 168(12):13008.
 A. Kho, D., Rotz K. Alrahi, W. C. Ardenas, K. Ramsey, D. Liebovitz, G. Noskin, and C. Watts,. Utility of commonly
captured data from an ehr to identify hospitalized patients at risk for clinical deterioration. AMIA, 2007.
 K. Zeitz and H. McCutcheon. Policies that drive the nursing practice of postoperative observations. International journal of nursing studies, Oct 2002, 39(8):8319.
 V.Q. Son, B.L. Wenning, A. Timm-Giel, C. Grg, A Model of Wireless Sensor Networks using Opportunistic Routing in Logistic Harbor Scenarios. In Proceedings of the 2nd International Conference on Dynamics in Logistics (LDIC2009), Springer-Verlag Berlin Heidelberg 2011, ISBN: 978-3-642-11995-8, 489-499.
 O. Gnawali, R. Fonseca, K. Jamieson, Collection Tree Protocol, Technical Report SING-09-01.
 Cisco System, Drger Patient Monitoring Deployment in the Cisco UnifiedWireless Network Infrastructure , Deployment Guide, 2010.
 T. Gao, T. Massey, L. Selavo, D. Crawford, B. rong Chen, K. Lorincz, V. Shnayder, L. Hauenstein, F. Dabiri, J. Jeng, A. Chanmugam, D. White, M. Sarrafzadeh, and M. Welsh, The advanced health and disaster aid network: A light-weight wireless medical system for triage. IEEE Transactions on Biomedical Circuits and Systems, Aug 2007.
 Y.-H. Lin, I.-C. Jan, P.-I. Ko, Y.-Y. Chen, J.-M. Wong, and G.-J. Jan, A wireless PDA-based physiological monitoring system for patient transport. IEEE Transactions on Information Technology in Biomedicine, 2004,8(4):439447.
 Y. Chu, and A. Ganz, A mobile teletrauma system using 3G networks. IEEE Transactions on Information Technology in Biomedicine, Dec. 2004, 8(4):456462.
 P. Rubel, J. Fayn, G. Nollo, D. Assanelli, B. Li, L. Restier, S. Adami, S. Arod, H. Atoui, M. Ohlsson, L. Simon-
Chautemps, D. Telisson, C. Malossi, G.-L. Ziliani, A. Galassi, L. Edenbrandt, and P. Chevalier, Toward personal ehealth in cardiology. Results from the epi-medics telemedicine project. Journal of Electrocardioly, Oct 2005,38(4):100106.
 K. Lorincz, D. J. Malan, T. R. F. Fulford-Jones, A. Nawoj, A. Clavel, V. Shnayder, G. Mainland, and M. Welsh. Sensor networks for emergency response: Challenges and opportunities. IEEE Pervasive Computing, Sep 2004
 A. Wood, G. Virone, T. Doan, Q. Cao, L. Selavo, Y. Wu, L. Fang, Z. He, S. Lin, and J. Stankovic, Alarmnet,Wireless sensor networks for assisted-living and residential monitoring. Technical Report CS-2006-11, Dec 2006
 J. Ko, R. Mus aloiu-Elefteri, J. H. Lim, Y. Chen, A. Terzis, T. Gao,W. Destler, and L. Selavo, MEDiSN: medical emergency detection in sensor networks. In SenSys, 2008.
 M. Hravnak, L. Edwards, A. Clontz, C. Valenta, M. A. Devita, and M. R. Pinsky. Defining the incidence of cardiorespiratory instability in patients in step-down units using an electronic integrated monitoring system. Archives of Internal Medicine, Jun 2008, 168(12):13008.
 D. W. Curtis, E. J. Pino, J. M. Bailey, E. I. Shih, J. Waterman, S. A. Vinterbo, T. O. Stair, J. V. Guttag, R. A. Greenes, and L. Ohno-Machado, Smartan integrated wireless system for monitoring unattended patients. Journal of the American Medical Informatics Association, 2008.
 SANITAS Blood Pressure Measurement Device, available at http://www.sanitas-online.de/web/en/products/
bloodpressure/wrist/SBC27.php, last access 2014.
 Finger Pulse Oximeter, available at http://www.preissuchmaschine.de/trend/FING/Fingerpulsoximeter-CMS.html, last access 2014.
 DS18B20 Temperature sensor, available at https://www.sparkfun.com/products/245, last access 2014.
 J. P Killeen., T. C Chan., C. Buono,W. G. Griswold, and L. A. Lenert, A wireless first responder handheld device for rapid triage, patient assessment and documentation during mass casualty incidents. AMIA, 2006.
 J. Polastre, J. Hill, D. Culler, Versatile low power media access for wireless sensor networks. In Proceedings of the 2nd international conference on Embedded networked sensor systems Baltimore, MD, USA, 2004, 95107.
 V.Q. Son, B.L. Wenning, A. Timm-Giel, C. Grg, WiSeCo-MaSys: a Tool for Data Collection and Management of Wireless Sensor Networks. In the Proceedings of the International Conference on Advanced Technologies for Communication (ATC2010), Ho Chi Minh City, Vietnam, October 2010, 43-48.
 G. Werner-Allen, K Lorincz., M. Ruiz, O. Marcillo, J. Johnson, J. Lees, M.Welsh, Deploying aWireless Sensor Network on an Active Volcano. IEEE Internet Computing, Volume 10, Issue 2, March 2006, 18-25.
 T. Schmid, H. Dubois-Ferrire, M. Vetterli, SensorScope: Experiences with a wireless building monitoring sensor network. In Proceedings of the Workshop on Real-World Wireless Sensor Networks, Stockholm, Sweden, June 2005.
 P. Padhy, K. Martinez, A. Riddoch, H.L.R. Ong, J. K Hart., Glacial Environment Monitoring using Sensor Networks. In Proceedings of theWorkshop on Real-WorldWireless Sensor Networks, Stockholm, Sweden, June 2005.
 Crossbow TelosB Datasheet, http://www.willow.co.uk/TelosB Datasheet.pdf, last access in April 2013.
 J. E. Sinex, Pulse oximetry: principles and limitations. American Journal of Emergency Medicine, Jan 1999, 17(1): 5967.
 V.Q. Son, B.L. Wenning, A. Timm-Giel, C. Grg, A model of Wireless Sensor Networks using Context-awareness in Logistics Applications. In the Proceedings of the 9th Conference on Intelligence Transportations Systems Telecommunications (ITST), Lille, France, October 2009, 2-7.
 P. Levis, N. Lee, M. Welsh, D. Culler, TOSSIM: Accurate and Scalable Simulation of Entire TinyOS Applications. In Proceedings of the First ACM Conference on Embedded Networked Sensor Systems (SenSys 2003), California, USA, 2003, 126-137.