生理訊號監測用之具Web界面的ZigBee無線感測網路

Abstract

無線感測網路在居家健康照護上尚未被廣泛地使用，大多數在健康照護相關的研究都只著重於點對點的傳輸，而沒有採取網路的架構。為了實現無線感測網路，並使它有高的網路定址能力，我們採取最新的 ZigBee 無線技術，它也是無線個人區域網路的一種，建構在IEEE 802.15.4 的標準之上，有低功率消耗，高網路定址能力等優點。 在這篇論文中所實現的生理訊號監測系統是由許多無線感測裝置、路由器與個人區域網路仲裁器所組成的，它們都是採取 ZigBee Alliance的規格去設計，使用一個 ZigBee 的發展模組，它包含了一個微控制器 ( MSP430F1611, TI, USA ) 與ZigBee 射頻 ( UZ2400, UBEC, Taiwan ) 晶片。我們建構了一個樹狀三階層式的網路架構在上述的發展模組上。它會將受測者身上所量測到的生理訊號，如：心電圖、血氧濃度以及人體活動狀態訊號傳給網路中之路由器，而路由器會去負責分配每個無線感測裝置可擁有的傳送時間，並且使用階層式的路由方式去傳送封包給個人區域網路仲裁器。而個人區域網路仲裁器則會從路由器所送來的封包中，去取出我們所要的生理訊號資料，再透過RS232傳送給個人電腦。 這個無線感測裝置可以被應用在居家健康照護系統上，且它使用了 web 2.0 的技術，可以使量測到的生理訊號即時且流暢的顯示在網頁上。這個想法已經被成功地實現，並且有著web-based的管理與控制能力與許多的優點，包含了高定址能力、低功率消耗、快速的反應時間。 此論文讓醫護專業人員可以即時監看病人的健康情形與控制無線感測網路的動作，但是這點在病人隱私權上面卻是相當有道德爭議，未來居家健康照護系統必須去加強資料安全以保護病人的隱私權。

Wireless Sensor Network ( WSN ) is really underdeveloped in today's home-care systems. Most researches in the home-care systems focused on the peer-to-peer communication without network topologies. To implement the wireless sensor network with high addressing capability, we uses the ZigBee wireless technology, which is also a sort of wireless personal area network ( WPAN ). ZigBee was based on the standard of IEEE 802.15.4 and has the advantages of low power consumption and high addressing capability. In this study we implemented a physiological signal monitoring system which was composed of wireless devices, routers, and personal area network ( PAN ) coordinators, which stands to the standards of the ZigBee Alliance. We carried out the whole design using a ZigBee development tool kit, it contains a micro-controller ( MCU, MSP430F1611, TI, USA ) and ZigBee RF chip ( UZ2400, UBec, Taiwan ). Furthermore, ZigBee network ( NWK ) layer and application ( APP ) layer are built on MCU for the WSN with three-level topology. The physiological signals such as electrocardiogram ( ECG ), SpO2, and body action status are measured and transmitted wirelessly to the router, and the router uses hierarchical routing method to forward the package to the PAN coordinator. On the PAN coordinator side, data are extracted form received packages and then passed to the personal computer through RS232. This Wireless Sensor Network system can be used as a home health-care systems. Besides, it uses the Web 2.0 technology which can display the measured physiological signals on the web page in realtime. We had successfully implemented this idea. Furthermore, it has many advantages such as a web-based control-and-management ability, highly addressing capability, low power consumption, and fast response time. This study makes it possible for the professional medical personnel to monitor the patient's health status and control the wireless sensor network, but it is a very controversial issue to the patient's privacy. It is necessary to enhance the security of the home health-caring system in the future to protect the patient's privacy.