建構無線傳輸與網際網路之居家看護系統

Development of Home-care System Using RF Transceiver and Internet

涂清源(Chin-Yuan Tu)

指導教授 ： 徐良育

中原大學/工學院/醫學工程研究所/碩士(2002年)

https://doi.org/10.6840/cycu200200505

摘要

鑑於台灣人口結構趨於高齡化之現象，老人居家安養成為社會即將面臨的一項難題。對於居家老人而言，定期往返醫療單位之例行檢查工作，不但造成舟車勞頓之苦，同時對於突發狀況，無法即時獲得諮詢與評估。因此若能發展一套活用於居家環境之看護系統，即可提供完善與便捷之醫療服務，充分運用現有之醫療資源。
本研究所研發之居家看護系統，主要包含生理訊號擷取、無線傳輸、訊號處理、資料庫建立與網路傳輸等方面。在生理訊號擷取方面，利用電極取得心電圖訊號，經由增益為570倍的放大與截止頻寬為0.5～100Hz之濾波處理，以獲得完整之訊號波形。另一方面，利用MSP430F148微控制器與TRF6900射頻收發器構成無線傳輸與數位轉換模組。將訊號作類比/數位轉換後，即可包裝為資料封包，由射頻收發器於高頻頻帶傳送；接收端亦用相同通訊協定收集傳送封包，並且透過RS232介面傳輸至個人電腦進行分析、處理與儲存之工作。在個人電腦中，除了繪製接收之生理訊號波形，並且針對訊號作特徵化處理，計算生理參數，以評估受測者生理狀況。受測過程之同時，亦可建立網路連結，利用winsock應用程式與遠端伺服器建立通道，進行訊號之傳送。待資料接收與處理完畢後，隨即儲存檔案於Access資料庫中，作為長期生理狀況之記錄與追蹤。
實驗結果方面，在無線傳輸效能評估上，於有效距離7公尺內可達100％之正確率，封包遺失率則為6.83%，傳輸率亦可達38400 bps，提供精確可信之即時傳輸。然而，實驗結果發現訓練序列長度與封包遺失率及採樣率成反比；若減短訓練序列長度則產生封包遺失率提高之情況，此現象可於後續發展的系統中利用外部A/D加以改善。評估網路傳輸方面，傳輸速率為0.5 Kbps，傳輸正確率亦可達98.99%，滿足網路可信度之要求。目前系統之網路傳輸率過低，對於即時性之目標仍有一段差距，為系統未來需探討與修訂之處。

關鍵字

微控制器 ； 射頻收發器 ； 居家看護 ； 網路傳輸

並列摘要

Due to the increase of aging population in Taiwan, taking care of elderly will become a social problem we will face in the coming century. The routine medical checkups not only cause weariness for elderly to make the trip but also cannot provide real-time consultation and medical assessment. Thus, a home-care system is proposed to provide monitoring service in order to take full advantage of existing medical resource.
In this study, the proposed system consists of signal acquisition, radio frequency (RF) transmission, signal processing, internet communication and database modules. The ECG signal is amplified and filtered in the signal acquisition module. The total gain of ECG amplifier is 570 and the filter bandwidth is from 0.5 to 100 Hz. The RF transmission module is consist of MSP430F148 micro-controller and TRF6900 RF transceiver. The bio-signal is digitized by the built-in analog-to-digital converter (ADC) in the micro-controller and organized into a data package. As soon as the package is established, it is sent by the transceiver using the high-frequency band. On the receiver side, it utilizes the same communication protocol to extract signals from the received package. Data is then passed to the personal computer (PC) through the RS232 interface, on the receiving side, for signal processing, analysis and storage. In addition to waveforms display, the PC processes the acquired signals and obtains biological parameters such as heart rate for evaluating user’s physical condition. At the same time, the application program on the PC can establish internet connection with the remote server in the hospital. After processing, data is saved in the Access database for long-term physical condition monitoring.
The results indicate that the effective range of the RF transmission module is 7 meters with accuracy of 100%. In this range, the package missing rate is 6.83% and the transmission rate is 38400bps. This demonstrates that the RF module can provide reliable real-time transmission. However, it is found that the length of training sequence during package transmission is inverse proportional to signal sampling rate and package missing rate. The shorter the training sequence is the higher the package missing rate is. The trade-off between package missing rate and sampling rate can be resolved by external ADC in the future. The results of internet transmission evaluation indicate that the transmission rate is 0.5 kbps with 98.99% accuracy which is satisfactory for a reliable internet transmission. However, the transmission rate is too low for real-time purpose. Thus, it is necessary to increase the transmission rate in the future.

並列關鍵字

home-care ； internet transmission ； micro-controller ； transceiver

參考文獻

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