一個整合心電圖壓縮與錯誤保護之機制及其在居家照護系統中藍芽傳輸之應用

An Integrated ECG Compression and Error Protection Scheme and Its Application to Bluetooth Transmission in Home Tele-Care Systems

林宗翰(Zong-Hang Lin)

指導教授 ： 繆紹綱

中原大學/工學院/電子工程研究所/碩士(2004年)

https://doi.org/10.6840/cycu200400400

摘要

近年來，無線技術的發展吸引了許多研究者利用無線傳輸機制來傳送如心電圖(Electrocardiogram, ECG)的生理訊號，以提供居家照護(Home Tele-care)系統中病患在行動上的便利性。對於居家照護，藍芽(Bluetooth)是頗具吸引力的無線技術，因為它有低功率、低花費且容易使用的優點，但它必須解決在頻寬限制與來自無線區域網路(Wireless Local Area Network, WLAN)干擾的潛在問題。
本論文針對ECG訊號提出一個SPIHT (Set Partitioning in Hierarchical Trees)壓縮演算法與UEP (Unequal Error Protection) 機制的整合設計，接著以藍芽封包格式來傳送ECG訊號，並在遭受高斯雜訊、Rayleigh衰減的通道以及受WLAN干擾的情況下，評估在不同的藍芽訊號功率與雜訊比時，接收端的ECG重建訊號品質。本論文的研究與模擬主要分成兩大部份，第一部份為純軟體模擬；第二部份為實際利用藍芽產品來架設一個居家照護系統。
根據第一部份的結果，在各種不同的模擬狀況下，有使用所提出之整合機制的效能，都優於無加任何壓縮與錯誤保護措施者。甚至在較強烈的WLAN干擾(0 dBm)下，也可以將心電圖訊號的重要資訊部份，包括P波、QRS波以及T波等，在接收端重建出在臨床上可接受的波形品質。第二部份的結果顯示出，在真實的室內環境中，藍芽的有效資料流量的確會受到Fading或WLAN干擾的影響。因此我們預期在藍芽系統關掉重傳機制以滿足系統即時需求的情況下，我們所提出的設計是可以發揮效用的。

關鍵字

干擾 ； 居家照護 ； 無線區域網路 ； 壓縮 ； 藍芽 ； 錯誤保護

並列摘要

Recently, the development of wireless technology attracts many researchers to transmit physiological signals such as electrocardiogram (ECG) wirelessly, for a home tele-care system in order to provide the mobility advantage. For the home tele-care, Bluetooth (BT) is an attractive wireless technology because it has the advantages of low power, low cost, and wide accessibility. But it has to cope with the potential problems in limited bandwidth and induced interference from WLAN (Wireless Local Area Network).
In this thesis, we propose an integration design, including a compression algorithm called SPIHT (Set Partitioning in Hierarchical Trees) and an UEP (Unequal Error Protection) scheme for ECG signals. Then, we transmit the ECG signals in BT packet formats and evaluate the reconstruction quality of received ECG signals at different S/N ratios of BT under the AWGN and Rayleigh fading channels and WLAN interference. The research and simulation in this thesis are divided into two main parts. The first part is the pure software simulation. In the second part, we use BT products to set up a home tele-care system.
According to the results of the first part, the performance with the proposed integration scheme is usually much better than without the scheme under various simulation conditions. Even under the stronger interference from WLAN (power = 0 dBm), the important features of an ECG waveform, including P wave, QRS complex, and T wave, could be well reserved at a receiver site with clinically acceptable reconstruction quality. The results of the second part show that the effective data throughput of BT is indeed degraded by Fading effects and WLAN interference in a real indoor environment. Therefore, we expect that the proposed design could be effective when BT turns the re-transmission function off to satisfy real-time requirement of the system.

並列關鍵字

Error Protection ； Interference ； Home Tele-Care ； Compression ； WLAN ； BT

參考文獻

[9] 涂清源，建構無線傳輸與網際網路之居家看護系統，私立中原大學醫學工程學系碩士論文，民國91年。

[2] J. Schepps and A. Ronsen, "Microwave Industry Outlook—Wireless Communications in Healthcare," IEEE Trans. Microwave Theory and Techniques, Vol. 50, pp. 1044-1045, March 2002.

[3] J. Millan, S.-E. Park, S. Kiefer, and J-U. Meyer, "TOPCARE – Implementation of a Telematic Homecare Platform in Cooperative Health Care Provider Networks," Proc. of the IEEE Second Joint EMBS/BMES Conf., pp. 1869-1870, Oct. 2002.

[7] Y. H. Nam, Z. Halm, Y. J. Chee, and K. S. Park, "Development of Remote Diagnosis System Integrating Digital Telemetery For Medicine, " IEEE Engineering in Medicine and Biology, vol. 20, pp. 1170-1173, Nov. 1998.

[11] S. Jalaeddine, C. Hutchens, R. Strattan, and W. Coberly, "ECG data Compression Techniques - a Unified Approach," IEEE Trans. Biomed. Eng., vol. 37, pp. 329-343, April 1990.