Using a Triaxial Accelerometer for Movement Monitoring Presenter: Chang-Yu Tsai Adviser: Cheng- Jui Hung 2009/11/23

2 Outline  Introduction  Papers review  Future works  References

2009/11/23 3 Introduction  Triaxial accelerometer applications for a Behavior Monitoring Systems.  Advantages of MEMS Triaxial accelerometer ：  Low cost.  High precision.  Small volume.  Low power. MEMS: Microelectromechanical Systems ( 微機電系統 )

2009/11/23 4 Papers review  [1] Dean M. Karantonis, Michael R. Narayanan, Merryn Mathie, Nigel H. Lovell, Branko G. Celler,“Implementation of a Real-Time Human Movement Classifier Using a Triaxial Accelerometer for Ambulatory Monitoring,” IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006  [2] Koichi Sagawa,Hikaru Inooka, Yutaka Satoh,“Non-restricted measurement of walking distance,” IEEE Trans. January 30, 2009.

2009/11/23 5 Paper review(1) Abstract  In this way, the system distinguishes between periods of activity and rest.  Recognizes the postural orientation of the wearer, detects events such as walking and falls.

2009/11/23 6 Paper review(1) Abstract  12 tasks (283 tests)  Overall accuracy ： 90.8 %  Postural orientation ： 94.1 %  Walking ： 83.3 %  Fall ： 95.6 %

2009/11/23 7 Paper review(1) Methods Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 8 Paper review(1) TA Unit Triaxial Accelerometer (TA) ：  Dimension ： 22 X 50 X 50 mm  Weight ： 51 g  Range ： ±10 g  Noise ： 5.06 mg  Bandwidth ： 100 Hz  RAM ： 2 KB  A/D ： 45 Hz

2009/11/23 9 Paper review(1) Flow Chart TA signal Median Filter LPF Computer SMA SMA > th Abnormal Acc. peak Upright Sitting Lying Possible Fall Upright Active Lying Active Sitting Standing Inverted Determine Lying Position FrontBack Right Left n=3 LPF=0.25 HZ RestActivity YES NO YES NO YES

2009/11/23 10 Paper review(1) Flow Chart TA signal Median Filter LPF Computer SMA SMA > th Abnormal Acc. peak Upright Sitting Lying Possible Fall Upright Active Lying Active Sitting Standing Inverted Determine Lying Position FrontBack Right Left n=3 LPF=0.25 HZ RestActivity YES NO YES NO YES

2009/11/23 11 Paper review(1) Flow Chart TA signal Median Filter LPF Computer SMA SMA > th Abnormal Acc. peak Upright Sitting Lying Possible Fall Upright Active Lying Active Sitting Standing Inverted Determine Lying Position FrontBack Right Left n=3 LPF=0.25 HZ RestActivity YES NO YES NO YES

2009/11/23 12 Paper review(1) Flow Chart TA signal Median Filter LPF Computer SMA SMA > th Abnormal Acc. peak Upright Sitting Lying Possible Fall Upright Active Lying Active Sitting Standing Inverted Determine Lying Position FrontBack Right Left n=3 LPF=0.25 HZ RestActivity YES NO YES NO YES

2009/11/23 13 Paper review(1) Methods  The first step is median filtering:  n = 3  The second step is low pass filtering (LPF) ：  Cut-off frequency at 0.25 Hz  Signal Magnitude Area (SMA) ： SMA ：每秒所產生三軸運動量總和

2009/11/23 14 Paper review(1) Methods  The z-axis and the gravitational vector g by the relation:  θ = cos -1 (z). Z-axis Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 15 Paper review(1) Methods  Classification of lying postures X-axis Y-axis Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 16 Paper review(1) Methods  signal magnitude vector (SVM) ：  SVM at a threshold of 1.8 g. SVM: 信號向量強度 ( 向量合 )

2009/11/23 17 Paper review(1) Trial Experiment Protocol Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 18 Paper review(1) Trial Experiment Protocol Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 19 Paper review(1) Trial Experiment Protocol Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 20 Paper review(1) Trial Experiment Protocol Time (s) Walking (slow) Walking (fast) Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 21 Paper review(1) Trial Experiment Protocol Walking (slow) Walking (fast) Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 22 Paper review(1) Trial Experiment Protocol Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 23 Paper review(1) Trial Experiment Protocol Form Michael R. Narayanan, Merry, Nigel H. Lovell, IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006

2009/11/23 24 Paper review(2) Abstract  Walking distance is discussed.  A piezoelectric gyro.  The horizontal distance is obtained by integrating the horizontal acceleration twice every step.  Distance estimated ： 5.3 %  Average ： 0.0 %  Vertical distance ： 11.1 %. Authorized licensed use limited to: Southern Taiwan University of Technology. Downloaded on January 30, 2009 at 02:45 from IEEE Xplore. Restrictions apply.

2009/11/23 25 Paper review(2) Horizontal distance deg/s ：每秒角動量變化 Authorized licensed use limited to: Southern Taiwan University of Technology. Downloaded on January 30, 2009 at 02:45 from IEEE Xplore. Restrictions apply.

2009/11/23 26 Paper review(2) Calculation method Authorized licensed use limited to: Southern Taiwan University of Technology. Downloaded on January 30, 2009 at 02:45 from IEEE Xplore. Restrictions apply.

2009/11/23 27 Paper review(2) Experiment Authorized licensed use limited to: Southern Taiwan University of Technology. Downloaded on January 30, 2009 at 02:45 from IEEE Xplore. Restrictions apply.

2009/11/23 28 Future Works  Use the Triaxial accelerometer to do it.  Find a good method to distinguishes the slow walking and lying.  To count of metabolic energy expenditure.

2009/11/23 29 References  [1] Dean M. Karantonis, Michael R. Narayanan, Merryn Mathie, Nigel H. Lovell, Branko G. Celler,“Implementation of a Real-Time Human Movement Classifier Using a Triaxial Accelerometer for Ambulatory Monitoring,” IEEE TRANSACTIONS ON INFORMATION TECHNOLOGY IN BIOMEDICINE, VOL. 10, NO. 1, JANUARY 2006  [2] Koichi Sagawa,Hikaru Inooka, Yutaka Satoh“Non-restricted measurement of walking distance,” IEEE Trans. January 30, 2009.