萬芳醫院建構 Sensor Network 的規劃 短中長期目標規劃

1. 萬芳醫院建構Sensor Network的規劃短中長期目標規劃

2. 萬芳醫院建構Sensor Network的規劃短期目標規劃 使用者登入 醫生 帳號密碼輸入 護士 帳號密碼輸入 個人使用紀錄 首頁-病患名單 RFID tag 病人基本資料 高風險值報告 檢驗報告 放射報告 用藥 生化報告 線上藥典 血液報告 鏡檢報告 血清免疫報告

3. 應用無線技術於生理檢驗模組範例( 短期目標 ) * 書寫錯誤 * 輸入錯誤 1.量測生理資料 2. 記錄生理資料於紙本上 3. 至護理站輸入生理資料 預估作業所需時間 : 10 min 應用地點 : 院內 預估作業所需時間 : 1 min 2.確認生理資料 1.量測生理資料 應用地點 : 院內、居家、救護車

4. 整合性的跨功能系統設計範例 流程:開藥(醫生) 包藥(藥劑師) 給藥(護士) * RFID • 醫生開立醫囑 • 系統依用藥頻率及用藥期間展開用藥明細檔 • 藥局根據包藥及送藥 • 護士查詢安排照護行程 • 護士根據時給藥及記錄 • * 應用RFID 提高病人用藥安全 * RFID 病人病歷+用藥明細  為具生醫研究價值之資料庫

5. The System Architecture Physician requests information using a PDA. The request is transmitted to Web Server The Patient Web Portal sends a request/response message to retrieve the “Patient Safety Data” Patient Safety Portal/ Web Service Server Patient Safety Portal sends a request/response to retrieve “HIS” data Patient Safety Data is transmitted to requestor and formatted to “XML” XML Lab Med Ris HRR Basic Data IDS

6. System Deployment in the Ward Area Room 1 Identity Verification (With Bedside Card) Admission, Registry & Identity Verification Room N Web Service Server Identity Verification (with Medical Order, Application Form and HR Clinical Decision Engine Dept. Of Radiology Injection Room Endoscopy Room Discharge Hospital Information Center

7. Some Problems in the Ward Area Complains from personnel • Wi-Fi remote transmission delay Data pre-load might run out of the limited memory of handheld Data loaded by reading RFID pasted to different regions might not work when emergent condition Data pre-load by the indoor positioning is one way to go (Context-awareness) • Handheld device management When? Who? Where? Which?

8. Handheld RFID Medical Assistant System with Location-based Service Web Services Platform Clinical Decision Engine RFID Mobile Assistance RFID Wi-Fi RFID Control Patient Medical DataBase Front-end Medical Assistance Report Medication Wi-Fi Signal Collector RadioMap &Feature DataBase HRR Local Data Collector Location-aware Position Engine

9. Location-aware Data Access and Location-aware Mobile Database Local Data Collector Position Engine Radio Map and Feature Database Medical Database Personnel Handheld Location-aware Service send(Samples) Collect WiFi Signal Samples send(Samples) Analyze Samples request(Sample Feature) Search and Match response(Candidates) Rank Position Change? return(Position) send(New Position) request(New Position) Package Up Local Data response(New Local Data) return(New Local Data) request(Local Data) update(Packaged Local Data) show(Local Data)

10. Real-time Status Management for Mobile Devices Position Engine Radio Map and Feature Database Personnel Handheld Location-aware Service Collect WiFi Signal Samples send(Samples) send(Samples) request(Signal Feature) Analyze Samples Search and Match Rank Candidates response(Candidates) update(Device Status) Check Device Status RequestDevice Status request() response(Device Status) return(Device Status) Show Device Status

11. 802.11 Base Indoor Position System Signals for Radio Map Radio Map DataBase Radio Map DataBase Feature DataBase AP Signal for Positioning Estimated Location Query and Response Phase 2 : Feature Extracting Phase 3 : Position Algo. Designing Phase 4 : On-line Positioning Phase 1 : Radio Map Calibration Position Algorithm

12. 802.11 Base Indoor Position System RSSI2 MAC2 RSSI1 MAC1 AP1 Phase 1 : Radio Map Calibration (1/2) AP2 • Received Signal Strength Indicator (RSSI) and MAC address would be recorded • Ref. point density and sampling time should be decided first by system requirements • Meter-level position systems usually have square-meter-level ref. point density • Divides the radio map into individual regions by layout Ref. Point

13. 802.11 Base Indoor Position System Phase 1 : Directional Effect (2/2) U N W E S D

14. 802.11 Base Indoor Position System Phase 2 : Feature 1 - Received APs (1/2) AP Matching Table Num. of APs List of APs U u MAC1,MAC2,…MACu N E W w MAC1,MAC2,…MACw S s MAC1,MAC2,…MACs D

15. 802.11 Base Indoor Position System Phase 2 : Feature 2 – Distribution (2/2) • It’s difficult to evaluate what kind of the bell-shaped distribution is • We can characterize the RSSI of an AP by sample mean μ and stand deviation σ U MAC1 σ1 μ1 N MAC2 σ2 μ2 W E MAC3 σ3 μ3 MAC4 σ4 μ4 S D

16. 802.11 Base Indoor Position System Phase 3 : Position Algorithm - AP Matching (1/6) Given A = {AP1, AP2, AP3}, use A to find the solution point set S AP1 AP2 Candidate Set S :Members in S can receive {AP1, AP2, AP3} in the radio map AP3 shift AP5 AP4

17. 802.11 Base Indoor Position System Phase 3 : Position Algorithm - AP filter (2/6) • Filter out the newly adding AP by building a AP table to prevent empty S • Ignore the rushing AP which is collected on positioning with detecting probabilities lower than a threshold

18. 802.11 Base Indoor Position System Phase 3 : Position Algorithm – Scoring (3/6) • In order to choose one of the candidate member in S from step one, we need to give each of them a score • Choose the point with best-matched score as the result • To score the member of S instead of all ref. points in the radio map • Find the way to measure the error of strength of each candidate member

19. 802.11 Base Indoor Position System Phase 3 : Scoring Methods – Scoring (4/6) Avgk : Avg. power of APk on positioning μk : Avg. power of APk in the radio map R : total number of detected APs Si : (Region, Ref. ID, Direction), member of S Ideal 1: • Ignore standard deviation • Larger variance means that the sample value shifts significantly • One way to compare two random variables is to standardize them

20. 802.11 Base Indoor Position System Phase 3 : Scoring Methods – Scoring (5/6) σk : the s.t.d. of signal strength of APk in the radio map Ideal 2 : • How do we value each AP? - Amplify the error(>1) of avg. power of each AP - Lessen the error(>1) of avg. power of each AP Ideal 3 :

21. 802.11 Base Indoor Position System Phase 3 : Scoring Methods – Scoring (6/6) • Similarly, How do we value the candidate member, Si ? A : set of detected APs on positioning ASi : set of collected APs on Si in the radio map A is contained in ASi by the definition of Si AP matching degree : Final Scoring Formula :

22. 802.11 Base Indoor Position System Position System Block Diagram Power Signatures of {AP1,…APR} AP Filter Radio Map DataBase AP Matching Candidate Set S Feature DataBase Scoring Connection Method 1 Method 2 Method n Web Service Position Platform Estimating Result

23. Experiments and Evaluations • 實驗地點 • 台大資訊系五樓東側 • 在既有的無線基地台中，選擇其中三個測試

24. Parameters and Scoring Functions • 1 reference point / 9 m2 • 100 samples per direction in each reference point in constructing the radio map • 4 scoring functions in the experiments

25. 位置誤差的實驗 (1/2)

26. 位置誤差的實驗 (2/2) • 定位誤差（單位：公尺） • 3公尺內可達90%可信度，6公尺內可達95%的可信度 • 在同樣的條件與環境下，Ekahau 系統的定位平均誤差為2.67公尺

27. 區域辨識率的實驗

28. 位置感知服務的效能提升

29. 結論與討論 “Valley of Death” The Darwinian Sea Basic Research Invention Innovation & New Business 創新創業價值鏈斷層 • 有沒有更簡單有效的室內定位方法？ • 學界：藉由研發更好的設備，更好的演算法，更好的Scoring Function等策略，來改善室內定位效能 • 各位同學可以繼續研究 • 業界：利用既有成熟的技術，改善作業流程與程序，來改善室內定位效能 • 僅利用Passive RFID就可以達到非常接近100%區域定位能力的方法 • 研發太空船上的原子筆 • 用鉛筆 市場考驗

30. Q & A & D