遠距居家照護資訊系統用戶端設計與製作

The Design and Implementation of a Tele-Home Health Care System-Signal Acquisition Sub-System

蘇彥杰(Yen-Chieh Su)

指導教授 ： 婁世亮

中原大學/工學院/醫學工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500806

摘要

先進國家平均國民壽命增長，使人口結構老化的趨勢顯現而出，所因應衍生的問題有許多，醫療資源短缺為其一。一般認為結合電腦、通訊和醫療檢測科技將是解決此問題的主要方針。
醫療檢測如各式影像（CT、MR、CR、US…）都有預設的檢測項目和程序。為求資訊化，影像檢測在DICOM（Digital Imaging Communications on Medicine）標準裡對這些檢測項目、程序和參數有對應的層次定義；其所產生的資料訊息流通，有網路協定的訂定。藉這些層次定義和協定規範發展完成的醫學影像歸檔及傳輸系統（Picture Archiving and Communication System, PACS）也都經歷多年嚴苛的測試，才逐漸為臨床醫學界所接受。如同醫學影像，生理波形訊號如心電圖（Electrocardiograph, ECG）等的醫療檢測也規範有臨床檢測項目、程序和參數，但是它們所對應的層次並無明確地定義；近年來，以生理波形訊號資訊系統發表的文獻，鮮有對其系統運轉效率相關的測試報告。本研究課題依據DICOM標準的形式，對數項生理波形訊號之檢測做出層次的定義和網路協定的設計，並建置一套類似PACS的遠距居家照護資訊系統的使用者子系統，以之做為測試與評估的平台。
所建置的子系統在硬體部分包含一掌上型生理擷取系統和一部個人用電腦。該生理擷取系統具有四通道，可同時量取心電圖、體溫和血氧濃度。個人電腦則含有本課題設計製做的五套程式模組，分別是（1）訊號擷取模組，其功能以獲取掌上型生理訊號擷取系統之生理訊號為主；（2）檔案格式化模組，它藉由DICOM標準的規範將所接收得的生理訊號作檔案格式化；（3）佇列模組，其功能為提供系統處理多個程式工作的排程依據，此處所謂的工作即是程式對於一檔案的處理稱之；（4）資料庫模組，此模組不但做為受照護者基本資料的儲存處，提供檔案格式化的病人資料來源;還做為提供生理訊號檔案層次的紀錄處；（5）網路通訊模組，在這程式模組中含有吾人模擬DICOM傳輸協定的設計，其功能是將已格式化的生理訊號檔案傳送至醫院或診斷中心端。
系統完成後進行相關測試與評估，測試項目包含網路傳輸、各程式執行時間、及系統可靠度測試。在網路傳輸測試部分，吾人以目前台灣家庭中最為常見的兩種電腦網路環境進行測試，分別是ADSL(1Mbps/64Kbps)與Cable Modem（1.5Mbps /384Kbps）。測試結果發現，以ADSL而言傳送一生理訊號檔以100Kbytes較為合適，約需耗時16秒，Cable Modem為3秒。而以掌上型生理訊號擷取系統而言，擷取100KBytes之生理訊號約需耗時3分鐘；因此用戶端從擷取訊號到傳送一組四通道之生理訊號（心電圖：1通道、體溫：1通道、血氧濃度：2通道）至醫院或診斷中心端最長並不超過4分鐘，其中耗費在傳輸的時間約49秒。而在系統穩定度評估方面，以網路的穩定度最受質疑，其包含上傳頻寬的不足與網路壅塞時之網路穩定能力，均考驗系統是否能穩定執行之因素。
本研究已初步建立一遠距居家照護用戶端資訊系統之雛形，並可與醫院或診斷中心端之醫療資料管理子系統進行相關測試。希望本系統未來經過改進後能架設於一般家庭中，與架設於醫院或診斷中心之醫療資料管理子系統進行臨床測試，並能與醫院現有的PACS系統結合，以期能發現系統在實際使用上之改善空間，使系統性能更加完善。對於遠距居家照護資訊系統品質的提升有相當之助益。

關鍵字

生理波形訊號 ； 醫療資訊系統 ； 遠距居家照護

並列摘要

Shortage of medical resource has been a major issue to many developed countries. This issue is largely worsened due to the huge increase in the aging population. To alleviate such a problem, a thought of integrating computer, communication, and medical examination technologies is often suggested as the solution. The theme of the thought is to monitor vital physiology signals such as electrocardiograph (ECG), blood pressure (BP), saturated pulse oxygen (SPO2), and body temperature (BT) from distance by medical experts. A term for this thought is tele-home health care.
There are regulated examining procedures in performing medical imaging modalities such as CT, MR, CR and US. The images recorded from the examinations must be well managed to assure uncompromised medical practices. Computerization and interoperatability are the trend of managing medical records. To assure that these records can be classified and identified; objects in terms of natures and attributes must be defined. The examples of the objects are types of imaging modality, body parts being studied, techniques used in studies, etc. They can be organized in a layer fashion to facilitate the implementation of systematic management. DICOM (Digital Imaging Communications on Medicine) is a comprehensive standard regulating not only lots of layered objects but also many modules as building blocks of communication protocols. DICOM based PACS (Picture Archiving and Communication System) had been rigorously tested and accepted as daily clinical practices for years. Vital signals such as ECG are in waveform. They are analogous to medical images having clinical protocols regulated. Unfortunately, there is no clear definition to structure the physiological waveform signal examinations in layers which significantly hampers the development of tele-home health care (THHC) systems. This is probably the reason why recent papers report no quantitative evaluation of operation efficiency of THHC systems. This work designed a layer scheme to structure the physiological waveform signal examinations based on the DICOM standard. The layer scheme was then used to implement a THHC system which serves as the platform to be quantitatively evaluated in terms of operating efficiency and system reliability. It must be noted that the focus of this work is on the design and implementation of the signal acquisition (SA) subsystem of the THHC system.
The SA subsystem mainly includes a hand-held physiology signal detector and a personal computer (PC). The signal detector having four channels can acquire waveform signals at the same time including one channel of ECG, one channel of BT, and two channels of SPO2. The PC is used to run five software programs developed in this work. The first software module is designed to acquire physiology signals from the hand-held physiology signal detector. The second one is a module of file formatting which is used to regulate the acquired signals in a DICOM file fashion. The third one is a database management module. It does not record the patients’ demographic information but also serves as file book-keeping that logs files in the pre-defined layer structure. The fourth one is a file transmission module serving as a DICOM storage service. Finally, a job queuing module is developed to relay jobs among the processes above.
There were 61 patients tested in this study totally which generated 1,413 ECG files, 1,414 BT files, and 355 SPO2 files. The developed SA system was assessed by processing those generated files. In a period of 3 minutes, one ECG and two SPO2 files with each 100-Kbyte and one 2-Kbyte BT file are produced from the hand-held signal detectors. The internet applied in this study includes ADSL (1Mbps/64Kbps) and Cable Modem（1.5Mbps /384Kbps）technologies. The study results show that transferring a file (100 Kbytes) through ADSL and cable modem requires 16 and 3 seconds, respectively. This implies the elapsed time of delivering a set of files (1 ECG, 2 SPO2, and 1 BT) from the SA subsystem to a distance hospital is about 4 minutes. In terms of the system reliability, the internet is the major concern. Our experience indicates the heavy traffic of the internet can cause interrupts of file transmission.
A layer scheme structuring the physiological waveform signal examinations was designed and was used to accomplish the development of the signal acquisition subsystem of a THHC system. A laboratory evaluation shows the potential of the developed system and a comprehensive assessment in a clinic setting is ongoing. The experience gained from this study is that to assure the success of applying THHC systems in Taiwan, a dedicated high bandwidth internet must be built. This is because the data traffic jam issue will collapse the whole THHC infrastructure by the time THHC becomes popular.

並列關鍵字

Tele-home health care ； Physiological Waveform Signal ； Medical Information System

參考文獻

[3] 行政院衛生署 NII 遠距醫療，

[2] J. H. Hu; C. P. Wei; T. H. Cheng, “Investigating Telemedicine Developments in Taiwan Implications For Telemedicine Program Management Paul,” IEEE, 2002.

[13] F. Magrabi; N. H. Lovell; K. Huynh; B. G. Celler, “Home Telecare System Architecture to Support Chronic Disease Management,” IEEE, p3559-3562, 2001.

[14] S. L. Lou; D. R. Hoogstrate; H. K. Huang, “An Automated PACS Image Acquisition and Recovery Scheme for Image Integrity Based on The DICOM Standard,” Computerized Medical Imaging and Graphics, Vol. 21, pp.209-218, 1997.

[15] M. Tsiknakis; D. G. Katehakis, “Intelligent Image Management in a Distributed PACS and Telemedicine Environment,” 1996.