| 研究生: |
黃健峻 Huang, Chien-Chun |
|---|---|
| 論文名稱: |
應用S轉換於去除生物訊號電源雜訊與震顫訊號量測分析之研究 Application of S-transform in Removing Powerline Interference from Biosignals and Design of a Tremor Measurement and Analysis System |
| 指導教授: |
楊明興
Young, Ming-Shing |
| 學位類別: |
博士 Doctor |
| 系所名稱: |
電機資訊學院 - 電機工程學系 Department of Electrical Engineering |
| 論文出版年: | 2009 |
| 畢業學年度: | 97 |
| 語文別: | 英文 |
| 論文頁數: | 75 |
| 中文關鍵詞: | 電源雜訊 、S轉換 、去雜訊 、肌肉疲勞 、加速度計 、震顫 |
| 外文關鍵詞: | S-transform, powerline interference, denoising, tremor, muscle fatigue, accelerometer |
| 相關次數: | 點閱:99 下載:7 |
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微弱的生物電訊號非常容易受到交流電源雜訊的干擾,特別是缺乏良好接地或屏蔽設施的場合。雖然許多去除電源雜訊的方法已經被開發出來,但是這些技術往往在去除電源雜訊干擾的同時,也衰減原本生物電訊號在60 Hz頻帶(電源雜訊)附近的能量。我們採用了S轉換,藉由它可在特定頻率成份解析出絕對相位的特性,以及多重時頻解析度的優點,來進行去除60 Hz電源雜訊干擾的計算。我們以心電圖(ECG)加上模擬60 Hz干擾的訊號測試結果,證實利用S轉換離線式去除雜訊的方法不但可以保留原始心電圖訊號的功率頻譜,更可以顯著降低60 Hz干擾的能量強度。此外,以S轉換去除60 Hz電源雜訊的能力,並不因為雜訊成份的強度大小有所改變。我們也從MIT心電圖資料庫中取出標準心電訊號、以生理訊號放大器(Model P511, Grass)記錄的肌電圖(EMG)與自發性癲癇大鼠受電源雜訊污染的腦波(EEG)測試,分別與陷波濾波器在去除60 Hz雜訊與保留原訊號能力的結果比較,證實了以S轉換去除電源雜訊此方法的卓越之處。參照以上的測試結果,我們成功建立了這個以S轉換去除電源雜訊干擾的新穎方法。
本研究另外建立一套多肢段生理性震顫量測與分析系統,並且於人體實驗中驗證系統的可用性,除了應用S轉換去除量測訊號中的電源雜訊,也以S轉換的時頻分析功能來探討震顫訊號的時頻能量分佈。本系統主要以黏貼於人體的微機械電容式加速度計,來量測肢體震顫(Tremor)。實驗包含有: (1)研究年齡效應在疲勞引發的肢體施力性震顫(Force Tremor)造成的影響,結果顯示:相較於肌電圖(Electromyography)、力量波動(Force Fluctuation),震顫訊號最適合用來描述不同年齡族群肌肉疲勞的特徵變化。(2)探討射擊選手瞄射過程中多肢段姿勢性震顫的特徵,證實較佳震顫控制是決定選手成績表現的因素之一。
Powerline interference always disturbs recordings of biomedical signals, especially when good grounding or shielding facilities are absence. Numerous methods have been developed to reduce powerline interference. However, most of these techniques not only reduce the interference but also attenuate the 60-Hz power of the biomedical signals themselves. We applied the S-transform, which provides an absolute phase of each frequency in a multi-resolution time-frequency analysis, to reduce 60-Hz interference offline. According to results from an electrocardiogram (ECG) to which a simulated 60-Hz noise was added, the S-transform de-noising process restored an identical power spectrum to that of the original ECG coincident with a significant reduction in the 60-Hz interference. Moreover, the S-transform de-noised the signal in an intensity-independent manner when reducing the 60-Hz interference. In the real ECG signal derived from the MIT database, electromyography (EMG) recorded by commercial biosignal amplifier (Model P511, Grass) and natural brain activity contaminated with 60-Hz interference, the S-transform also displayed superior merit to a notch filter in terms of noise removal and signal preservation. Based on these data, a novel application of the S-transform for removing powerline interference is established.
In this study, a multi-segment physiological tremor measurement and analysis system was built and its usability was verified in human experiments. MEMs type capacitive accelerometers were attached on human body for sensing tremor. The S-transform denoising method was applied to eliminate powerline interference from physiological signals. Besides, time-frequency presentation of tremor signal was performed based on S-transform. Conducted experiments included: (1) Investigation of age effect on fatigue-induced force tremor. Compared with EMG and force fluctuation (FF), muscle fatigue was most characterized with tremor in different age population. (2) Examining the organization of postural tremor of pistol shooters while they were aiming. The results implied that optimizing control in tremor leads to successful shooting.
1. Huhta J C and Webster J G 1973 60-Hz interference in electrocardiography IEEE Trans. Biomed. Eng. 20 91-101
2. Task Force of the European Society of Cardiology and the North Society of Pacing and Electrophysiology 1996 Heart rate variability: standards of measurement, physiological interpretation, and clinical use Circulation 93 1043-65
3. Ohashi J 1993 Changes in relations between surface electromyogram and fatigue level by repeating fatiguing static contractions Ann. Physiol. Anthropol. 12 285-96
4. Baratta R V, Solomonow M, Zhou B H and Zhu M 1998 Methods to reduce the variability of EMG power spectrum estimates J. Electromyogr. Kinesiol. 8 279-85
5. Ott H W 1976 Noise reduction techniques in electronic systems Wiley: New York
6. Thakor N V and Webster J G 1980 Ground-free ECG recording with two electrodes IEEE Trans. Biomed. Eng. 27 699-704
7. Shaw F Z, Yen C T and Chen R F 2003 A simple and effective process for noise reduction of multichannel cortical field potential recordings in freely moving rats J. Neurosci. Methods 124 167-74
8. Barr RE and Chan E K Y 1986 Design and implementation of digital filters for biomedical signal processing J. Electrophysiol. Technol. 13 73-93
9. Pottala E W, Horton M R and Bailey J J 1990 Suppression of powerline interference in the ECG signal using a bilinearly transformed null phase notch filter J. Electrocardiol. 23 Suppl 213-4
10. Ferdjallah M and Barr R E 1994 Adaptive digital notch filter design on the unit circle for the removal of powerline noise from biomedical signals IEEE Trans. Biomed. Eng. 41 529-36
11. Stockwell R G, Mansinha L and Lowe R P 1996 Localization of the complex spectrum: The S transform IEEE Trans. Signal Process. 44 998-1001
12. Pinnegar C R and Mansinha L 2003 The S-transform with windows of arbitrary and varying shape Geophysics 68 381-5
13. Assous S, Humeau A, Tartas M, Abraham P and L'Huiller J P 2005 Physiological effects of indomethacin and celecobix: an S-transform laser Doppler flowmetry signal analysis Phys. Med. Biol. 50 1951-9
14. Dash P K, Panigrahi B K and Panda G 2003 Power quality analysis using S-transform IEEE Trans. Power Deliv. 18 406-11
15. McAuley J H and Marsden C D 2000 Physiological and pathological tremors and rhythmic central motor control Brain 123 (Pt 8) 1545-67
16. Deuschl G, Krack P, Lauk M and Timmer J 1996 Clinical neurophysiology of tremor J. Clin. Neurophysiol. 13 110-21
17. Bain P 1995 Are neurophysiological techniques useful in differentiating tremor? In Handbook of Tremor Disorders Findley L J and Koller W C eds Marcel Dekker: New York pp 79-93
18. Cathers I, O'Dwyer N and Neilson P 2006 Entrainment to extinction of physiological tremor by spindle afferent input Exp. Brain Res. 171 194-203
19. Hallett M 1998 Overview of human tremor physiology Mov. Disord. 13 Suppl 3 43-8
20. Takanokura M and Sakamoto K 2001 Physiological tremor of the upper limb segments Eur. J. Appl. Physiol. 85 214-25
21. McAuley J H, Rothwell J C and Marsden C D 1997 Frequency peaks of tremor, muscle vibration and electromyographic activity at 10 Hz, 20 Hz and 40 Hz during human finger muscle contraction may reflect rhythmicities of central neural firing Exp. Brain Res. 114 525-41
22. Christou E A, Shinohara M and Enoka R M 2003 Fluctuations in acceleration during voluntary contractions lead to greater impairment of movement accuracy in old adults J. Appl. Physiol. 95 373-84
23. Oda S and Kida N 2001 Neuromuscular fatigue during maximal concurrent hand grip and elbow flexion or extension J. Electromyogr. Kinesiol. 11 281-9
24. Taylor A M, Christou E A and Enoka R M 2003 Multiple features of motor-unit activity influence force fluctuations during isometric contractions J. Neurophysiol. 90 1350-61
25. Hagbarth K E, Bongiovanni L G and Nordin M 1995 Reduced servo-control of fatigued human finger extensor and flexor muscles J. Physiol. 485 ( Pt 3) 865-72
26. Gandevia S C 2001 Spinal and supraspinal factors in human muscle fatigue Physiol. Rev. 81 1725-89
27. Lanza I R, Russ D W and Kent-Braun J A 2004 Age-related enhancement of fatigue resistance is evident in men during both isometric and dynamic tasks J. Appl. Physiol. 97 967-75
28. Morrison S and Newell K M 2000 Postural and resting tremor in the upper limb Clin. Neurophysiol. 111 651-63
29. Elble R J 2005 Gravitational artifact in accelerometric measurements of tremor Clin. Neurophysiol. 116 1638-43
30. Pellegrini B and Schena F 2005 Characterization of arm-gun movement during air pistol aiming phase J. Sports Med. Phys. Fitness 45 467-75
31. Morrison S and Newell K M 1996 Inter- and intra-limb coordination in arm tremor Exp. Brain Res. 110 455-64
32. Hwang I S, Huang C T, Cherng R J and Huang C C 2006 Postural fluctuations during pointing from a unilateral or bilateral stance Hum. Mov. Sci. 25 275-91
33. Morrison S and Keogh J 2001 Changes in the dynamics of tremor during goal-directed pointing Hum. Mov. Sci. 20 675-93
34. Keogh J, Morrison S and Barrett R 2004 Augmented visual feedback increases finger tremor during postural pointing Exp. Brain Res. 159 467-77
35. Wong W Y, Wong M S and Lo K H 2007 Clinical applications of sensors for human posture and movement analysis: a review Prosthet. Orthot. Int. 31 62-75
36. ADXL203 datasheet, Analog Device
http://www.analog.com/static/imported-files/data_sheets/ADXL103_203.pdf
37. Shaw F Z, Chen R F, Tsao H W and Yen C T 1999 A multichannel system for recording and analysis of cortical field potentials in freely moving rats J. Neurosci. Methods 88 33-43
38. Shaw F Z, Lai C J and Chiu T H 2002 A low-noise flexible integrated system for recording and analysis of multiple electrical signals during sleep-wake states in rats J. Neurosci. Methods 118 77-87
39. Shaw F Z 2004 Is spontaneous high-voltage rhythmic spike discharge in Long Evans rats an absence-like seizure activity? J. Neurophysiol. 91 63-77
40. Shaw F Z 2007 7-12 Hz high-voltage rhythmic spike discharges in rats evaluated by antiepileptic drugs and flicker stimulation J. Neurophysiol. 97 238-47
41. Chilukuri M V and Dash P K 2004 Multiresolution S-transform-based fuzzy recognition system for power quality events IEEE Trans. Power Deliv. 19 323-30
42. Ma W K, Zhang Y T and Yang F S 1999 A fast recursive-least-squares adaptive notch filter and its applications to biomedical signals Med. Biol. Eng. Comput. 37 99-103
43. Cresswell A G and Loscher W N 2000 Significance of peripheral afferent input to the alpha-motoneurone pool for enhancement of tremor during an isometric fatiguing contraction Eur. J. Appl. Physiol. 82 129-36
44. Taguchi K 1977 Spectral analysis of body sway ORL. J. Otorhinolaryngol. Relat. Spec. 39 330-7
45. Breithardt G, Cain M E, El-Sherif N, Flowers N C, Hombach V, Janse M, Simson M B and Steinbeck G 1991 Standards for analysis of ventricular late potentials using high-resolution or signal-averaged electrocardiography. A statement by a Task Force Committee of the European Society of Cardiology, the American Heart Association, and the American College of Cardiology Circulation 83 1481-8
46. Lakshmikanth A and Morcos M M 2001 A power quality monitoring system: a case study in DSP-based solutions for power electronics IEEE Trans. Instrum. Meas. 50 724-31
47. Salem M E, Mohamed A and Samad S A 2007 Fast detection and classification of power quality disturbances based on DSP implementation Int. Rev. Electr. Eng. 2 163-70