( )-7.fm

J. of the Korean Sensors Society Vol. 19, No. 4 (2010) pp. 297 305 y x f w p j q v mg sƒ Á *Á«kw**Á **, Design and evaluation of wireless sensor network routing protocol for home healthcare Seung-Chul Lee, Yong-Su Seo*, Tae-Ha Kwon**, and Wan-Young Chung**, Abstract A home healthcare system based wireless sensor network, which can continuously monitor and manage the elderly's electrocardiogram(ecg) signal at any space at home without space limit is proposed. The communication coverage of wireless network is expended by multi-hop wireless sensor network. In order to send the elderly s ECG data wirelessly, a small size ECG sensor node was designed to forward the ECG data over multi-hop relay network. The packet acquired by mobile ECG node is transmitted through wireless intermediate nodes to base station for analyzing the packet reception rate. Modified minimum cost forwarding(mmcf) protocol and flooding protocol are designed and implemented to check the transmission efficiency of a packet in a wireless sensor network. The developed MMCF protocol shows an advantage of high reception rate by reduced network traffic. Key Words : tele-healthcare, healthcare monitoring, routing protocol, wireless sensor network 1. d y l wš,» l,, š l š ƒ ù w l ƒ w il x f w k ƒ š.»» y w š y ƒš. ü y l w y d l d rw w w w m y»ƒ w ƒ š. 30 %~90 %¾ w. m» w y x m, x»» f w v š [1,2]. p m w k(dead m» w»» (elec- spot)ƒ w. y w trocardiogram), x (blood pressure), x (blood sugar), l w w w. sy (SpO2) y d l ƒ w w w» w w w œw (Department of Electronic Engineering, Graduate School, Pukyong National University) * w œw (Department of Electronic Engineering, Dongseo University) ** w œw (Department of Electronic Engineering, Pukyong National University) Corresponding author : wychung@pknu.ac.kr (Received : March 9, 2010, Revised : May 20, June 21, 2010 Accepted : July 5, 2010) s p e w,» j ƒw [3,4]. y š p j», m» y l [5-7] ¾ y š. w, p j w ³ v e g d w» š. 297

40 Á Á«kwÁ py q v mg w» š [8], x y w. w, il x f w» w x f q v mg wš [9,10] e š. w,» q v mg w k y ƒ û ƒ [11]. w, y l ¼» š, Fig. 1. Architecture of the proposed home healthcare system. y, y š v w w. š š v y y l artifact) yƒ y sw» x f w 100 v x l z qk ƒ w [12]. y y w» w y y y ƒ r š, ƒ (, p, y ) w y y. w. x f w v v mg p j y p j» v w w» w x w» w e, w š v w l p v y w ù l ƒ» [13]. w qk l w. x w x f l d l w ƒ š. w w l w l w» w ƒƒ l ful w s (MMCF) v mg l. w ful xw. v mg» ü y l y z y ƒƒ ew l PC l x w x py» qk (packet reception rate) s z fp w w ƒw. w y ƒ p j. w ful qk w q w» w w y e p x xw. qk w. 2.1. l 2. l» w. y» y lr l 2.2. l Fig. 2 y z w x (a), l w Fig. 1 l (b) l ful w w y x f l š l (c) w. d l w x w š. (mobile ecg node), l lr, v, m w (intermediate node), l w 3 V p l ƒ w w l (base station), y l, qk. Fig. 2(a) x, w ful y» w s. z w w, v ú w (motion - l f p» ƒ wz 19«4y, 2010 298

y x f w p j q v mg sƒ 41 Fig. 2. Block diagrams of mobile ECG node(a), intermediate node(b), base station(c). Fig. 3. Sketch of Burst transmission.. p(burst)» ƒ(ecg slice) l w j r wš wù qk l w qk ƒ. Fig. 3 2 p l» w 20 p w p w š. 2.3. y x f w q v mg ful x y y j» w wš, d y x f q v mg p j mw l š w. Fig. 4(a) l w v v mg p j š.» v ƒƒ ƒ l w». l w s š w. w» y(ad-hoc)». v» e pw w š. v (implosion) š w. w, qk w vƒ v lƒ p j ñ ƒ. v v mg qk w v w» w qk p i y wš w qk w [13]. w qk w y e p(hop count or TTL) w w lƒ s ú y 12 bit l y w. w, 10 s e Fig. 2(b) p j x z qk s» w w. Fig. 4(a) v wš l w mg 3 A qk q.» f k w.» v. (beacon message) w w, v v mg» F A qk 1 l s w. Fig. 2(c)» 1 p j l w w. ful x p, ù w x l œw. w, v v mg» w w, m (RS-232) w qk w ful l w w. p j p v»w x ƒ l ƒ. w, ƒƒ v l w qk x f w v v w, qk mg jš y š w» z k v s (minimum cost forwarding or MCF)» w MCF» MMCF v mg xw. MCF w IDù 299 J. Kor. Sensors Soc., Vol. 19, No. 4, 2010

42 Á Á«kwÁ Fig. 4. Home healthcare routing protocols: Flooding (a), MMCF (b). w ww q š [14].» MCF v mg (source node or mobile ECG node) l (base station) ¾ s w w» sƒ. w MMCF q v mg l l w w w» w MCF» w w m ƒ w. x f MMCF v mg xwš,» l p w x qk w w. w l PC l ƒ w w w. Fig. 4 (b) fulƒ w LQI(link quality indicator) F w š, l l w š. LQI d CC2420 m [15] l qk y» 50 110. Fig. 4(b), F 204 310 LQI w wš, w 204 w. MMCF» ql k w s z w ƒ. w F w» w w A, 5, 4, 3 l l w w. 3. x 3.1. q v mg x 2.3 w y x f q v mg w x» w. x ü e w w, w l z w» w x f q v mg xw. Fig. 5 x TinyOS xw v v mg x fp y y g l w l ƒ v p j z wš, w» š. fs p HealthcareM, Flooding answers router, Flooding questions router, ECGC, QueuedSend, GenericComm w. ƒƒ fs p ƒ š lr x fs p y œwš, w wz 19«4y, 2010 300

y x f w p j q v mg sƒ 43 Fig. 5. System architecture of flooding protocol. Fig. 6. System architecture of MMCF protocol.. "ECGC" fs p lr z w ú y 12 bit l y z w w, w Radio Power_ yw. w l l Control_Mobile or Intermediate node z w» w HealthcareM 2 p 100 ù x q»(radio fremsec» 10 v wš r w quence) 3~31¾ w w q» w. z 20 byte l w. Flooding answers router fs p Fig. 6 l z Fig. 5, fs p w v m w l x fp l l w q v mg w w. v v mg» x l PC l w w» w» ECGC, QueuedSend, GenericComm w ƒ w. Fig. 5 5ƒ { k(idle), y y k(active), v (sample rate), k (select channel), q (power control) k Idle Status_Mobile or Intermediate node w { k yw. w Active Status_Mobile or Intermediate node w { k y y k, y y x UPDATE_BEACON ù w v (50 Hz, 100 Hz, 200 Hz) y w w q x w w» w Sample Rate_Mobile_Node w. w w. ƒƒ v Fig. 7» v v mg v w p w k x f q v mg w x f ƒ w v q w. Select_Channel_Mobile_Node š. Fig. 6 fs p HealthcareM, MMCF answers router, MMCF questions router,. HealthcareM fs p x w. 6ƒ š, f (beacon control), { k(idle), y y k š, { k(idle), y (active), q (power control) k 4ƒ y k(active), q (power_control) k 3ƒ. MMCF answers. e router fs p f» w ù x w w ƒ w. w f»ƒ ¼ š x w x q ˆ ¼ w q x w ƒ. w. ful l l ¾ ü l ý l»y k. š r kw v w (origin_node sequence number)ƒ, y 301 J. Kor. Sensors Soc., Vol. 19, No. 4, 2010

44 Á Á«kwÁ Fig. 7. System architecture of flooding protocol. e p q z ù ( l ) origin_node sequence number w w. š idƒ l ww w. w idƒ l id q z ww s w w.»y jš,, y e p y wš, w z w w. Fig. 8 v v mg p j p v l wš, p j y w xw MMCF v mg š. ful l w š, IDƒ l q w l ww w, l l LQI ( l kw. š q w wwš s w w. ƒ š, j p. š q w w jš, s w w. 3.2. x Fig. 8. Flowchart of MMCF protocol. Fig. 9. Nodes deployment in indoor environment. x w (2y ) ewš v mg qk d w. Fig. 9 2y 4d š. ü l 50 Cm e ew. 7 )»y k s, ü 2 ew š, k. w 20 m, ¼ ƒ 60 m. 2418y f ƒ y z j ul l RS-232 f x j w ƒ w. l ü x fp w, l w. x l l 1.5 m e w š, 2 3» x 7 m, 14 m, 21 m 28 m, 35 m, 42 m, 50 m 7 m e xw. 3.3. x Table 1 2 v MMCF» x l l PC¾ qk wz 19«4y, 2010 302

y x f w p j q v mg sƒ 45 Table 1. The packet reception rate for mobile ECG node of flooding protocol Distance the deployed spaces Total packets received Total packet drops Total packets Packet reception rate(%) 1.5 m Room 501 0 501 100 1 7 m Hallway 201 299 500 40.2 1 14 m Hallway 194 306 500 38.8 1 21 m Hallway 204 296 500 40.8 3 28 m Hallway 204 296 500 40.8 4 35 m Hallway 185 315 500 37 4 42 m Hallway 222 278 500 44.4 4 Hops Table 2. The packet reception rate for mobile ECG node of MMCF protocol Distance the deployed spaces Total packets received Total packet drops Total packets Packet reception rate(%) 1.5 m Room 507 0 507 100 1 7 m Hallway 505 0 505 100 1 14 m Hallway 504 0 504 100 2 21 m Hallway 501 2 503 99.6 3 28 m Hallway 498 5 503 99 4 35 m Hallway 518 3 521 99.4 4 42 m Hallway 502 3 505 99.4 4 50 m Hallway 501 3 504 99.4 4 Hops w œ š. v» l ƒ¾ x d 100 % ù ü d w s³ qk 40 %. w, x ƒ 21 m e 14 m(28 m 31 m) qk. ü y y j»ƒ w». x f v v mg v l w w w 9 ƒ p j w p j p v. MMCF v mg (2418) 100 % š, s³ 99.5 %. Fig. 10. The packet Reception rate for hop count. v mg 7 y 48 % qk, MMCF v mg 7y x sƒ 96.5 % œ ƒ. Fig. 11 MMCF v mg» x ƒ ü qk p j w 50 m e l PC w qx š, p w l w v» x ƒ 35 m e qk p j p v k. l PC w qx š. Fig. 10 y e p qk œ y 100 v w 10 š. x w l w, l PC 10 l 1~7 ¾ 5 m e qx y w. MMCF 99 % w 1y l 7y p j x w w y qx w š, v y qk d w. v 37 % û qk w 10 303 J. Kor. Sensors Soc., Vol. 19, No. 4, 2010

46 Á Á«kwÁ w ƒ ƒ w w. x f ww q v mg sƒ w» w l ƒ wš qk ƒ w v f xw. w MMCF v p j p v k q v mg qk. w ful x w w» w f» w. Fig. 11. ECG waveform for comparing protocols. 2009 ( w» ) w w (2009-0075095). Fig. 12. ECG waveform for each sampling rates. š qx y w. Fig. 12 50 Hz, 100 Hz, 200 Hz x v ECG qx š. Fig. 12(a), 1 l 50 Hz 10 v w QRS ùkù, Pq Tq yƒ š y y w. Fig. 12(b), (c) 100 Hz 200 Hz qx š, 100 Hz 200 Hz P q, QRS, T qx w ùkù y w. p j y y l x f w 100 Hz v w. 4. y x f l w» w ü ew py x ym ƒ w w. w l PC l x š x [1] S. Koch, Home telehealth current state and future trends, International Journal of Medical Informatics, vol. 75, Issue 8, pp. 565-576, 2006. [2] M. Rigby, Applying emergent ubiquitous technologies in health: The need to respond to new challenges of opportunity, expectation, and responsibility, International Journal of Medical Informatics, vol. 76, Supplement 3, pp. S349-S352, 2007. [3] T. Bratan, M. Clarke, R. Jones, A. Larkworthy, and R. Paul, Evaluation of the practical feasibility and acceptability of home monitoring in residential homes, Journal of Telemedicine and Telecare, vol. 11, Supplement 1, pp. 29-31, 2005. [4] U. Varshney, Patient monitoring using infrastructure-oriented wireless LANs, International Journal of Electronic Healthcare, vol. 2, no. 2, pp. 149-163, 2006. [5] A. Milenkovic, C. Otto, and E. Jovanov, Wireless sensor networks for personal health monitoring: Issues and an implementation, Computer Communications, vol. 29, Issues 13-14, pp. 2521-2533, 2006. [6] K. Lorincz, D. J. Malan, R.F. Jones, A. Nawoj, A. Clavel, V. Shnayder, G. Mainland, and M. Welsh, Sensor networks for emergency response: Challenges and opportunities, IEEE Pervasive Computing, vol. 3, Issue 4, pp. 16-23, 2004. [7] S.-H. Toh, S.-C. Lee, H.-J. Lee, and K.-H. Do, Mobile u-healthcare system in IEEE 802.15.4 WSN and CDMA network environments, J. Kor. wz 19«4y, 2010 304

y x f w p j q v mg sƒ 47 Sensors Soc., vol. 18, No. 5, pp. 337-342, 2009. [8] L. Alazzawi and A. Elkateeb, Performance evaluation of the WSN routing protocols scalability, Journal of Computer Systems, Networks, and Communications, vol. 2008, no.14, 2008. [9] Available at: http://www.mobihealth.org. [10] Available at: http://fiji.eecs.harvard.edu. [11] W.R. Heinzelman, A. Chandrakasan, and H. Balakrishman, Energy-efficient communication protocol for wireless microsensor network, in Proceedings of the 33 rd International Conference on System Sciences, vol. 8, p. 8020, 2000. [12] J.-W. Lee and G.-K. Lee, Design of an adaptive filter with a dynamic structure for ECG signal processing, International Journal of Control, Automation, and Systems, vol. 3, No. 1, pp. 137-142, 2005. [13],,,, üy l l w p j v x, wz, 17 «, 3y, pp.168-176, 2008. [14] F. Ye, A. Chen, S. Lu, and L. Zhang, A scalable solution to minimum cost forwarding in large sensor networks, in Proc. IEEE 10th Int. Conf. Computer Communications and Networks, Arizona, pp. 304-309, 2001. [15] Available at: http://focus.ti.com/lit/ds/symlink/cc2420. pdf, 20, 2007. 1999 w fulœw (œw ) 2005 w ful p jw (œw ) 2006 ~x w w œ w : p j, q v mg, x f, œ 1975 w œw (œw ) 1982 w w œw (œw ) 1992 w w œw (œw ) 1990 ~1991 w œ w ( ) 1994 ~x w lœw : l, ql, Remote Sensing «k w 1975 w œw (œw ) 1990 w œw (œw ) 1993 w œw (œw ) 1982 ~x w ful m œw :, {, x, k, RF IC DESIGN 1987 w œw (œw ) 1989 w w œw (œw ) 2009 v w» œ w (œw ) 1999 ~2008 w ful œw 2008 ~x w ful m œw : il p j, p j, j, il x f 305 J. Kor. Sensors Soc., Vol. 19, No. 4, 2010