Evaluation of a Wearable Sensor System Monitoring Posture Changes and Activities for Use in Rehabilitation
Kosuke Motoi*, Shinobu Tanaka**, Yutaka Kuwae***,
Tadahiko Yuji***, Yuji Higashi***, Toshiro Fujimoto***,
and Ken-ichi Yamakoshi**
*Venture Business Laboratory, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan
**Graduate School of Natural Science and Technology, Kanazawa University
***Fujimoto Hayasuzu Hospital, 17-1 Hayasuzu-cho, Miyakonojyou-city, Miyazaki 885-0055, Japan
To evaluate the effectiveness of rehabilitation, physical therapists must assess the posture changes in patients standing-up, walking, etc. Conventional subjective assessment of using direct observation or interviews at rehabilitation centers and of the actual physical condition is difficult, calling for the development of objective measurement of the posture change and activity both at rehabilitation centers, and in the home. One way to do so is to record these using a video camera, but the measurement range is usually limited and not useful in rehabilitation. A wearable system for monitoring angle changes in the trunk, thigh, and calf on the sagittal plane together with walking speed we developed earlier, required that the user carry three sensors for the trunk, thigh, and calf and a data logger, and wear cumbersome cables. To eliminate this practical drawback, we designed a new sensor for rehabilitation and quantitatively assessed posture change during rehabilitation and activity in daily living using the new system. We combined the previous four units into two – a jacket-typed trunk unit holding a data logger and a sensor for measuring trunk angle change and a knee-supporter-typed lower limb sensors containing two angular sensors – greatly simplifying the cumbersome cable assembly. We measured activity in eight rehabilitation subjects and four subjects during daily living using the wearable device. Results demonstrated that our device could measured detailed motion characteristics as angle changes between body segments during rehabilitation, and the rate of four activities – standing, walking, sitting, and lying – during daily living, making it useful in rehabilitation.
-  A. Hendry, W. Gilchrist, G. Duncan, A. L. Evans, and D. C. Smith, “Measurement of walking speed in elderly inpatients,” Med. Biol. Eng. Comput., 28-6, pp. 602-604, 1990.
-  H. Zhu, G. F. Harris, J. J. Wertsch, W. J. Tompkins, and J. G. Webster, “A microprocessor-based data-acquisition system for measuring plantar pressures from ambulatory subjects,” IEEE Trans. Biomed. Eng., Vol.38, pp. 710-714, 1991.
-  J. O. Brooks, L. Friedman, D. L. Bliwise, and J. A. Yesavage, “Use of the wrist actigraph to study insomnia in older adults,” Sleep, Vol.16(2), pp. 151-155, 1993.
-  B. D. Evans and A. E. Rogers, “24-hour sleep/wake patterns in healthy elderly persons,” Applied Nursing Research, Vol.7(2), pp. 75-83, 1994.
-  R. Moe-Nilssen, “Test-retest reliability of trunk accelerometry during standing and walking,” Arch. Phys. Med. Rehab., Vol.79, pp. 1377-1385, 1998.
-  R. E. Mayagoitia, J. C. Lotters, P. H. Veltink, and H. Hermens, “Standing balance evaluation using a triaxial accelerometer,” Gait and Posture, Vol.16, pp. 55-59, 2002.
-  T. Tamura, M. Sekine, M. Ogawa, T. Togawa, and Y. Fukui, “Classification of acceleration waveforms during walking by wavelet transform,” Meth. Inform. Med., Vol.36, pp. 356-359, 1997.
-  M. Sekine, T. Tamura, M. Akay, T. Fujimoto, T. Togawa, and Y. Fukui, “Discrimination of walking patterns using wavelet-based fractal analysis,” IEEE Trans. Rehab. Eng., Vol.10(3), pp. 188-196, 2002.
-  M. Makikawa and H. Izumi, “Development of an ambulatory physical activity memory device and its application for the categorization of actions in daily life,” in Proc. Medinfo. ’95, pp. 747-750, 1995.
-  P. H. Veltink, B. J. Bussmann, D. Vries, L. J. Martens, and R. C. V. Lummel, “Detection of static and dynamic activities using uniaxial accelerometers,” IEEE Trans. Rehab. Eng., Vol.4, pp. 375-385, 1996.
-  J. Fahrenberg, F. Foerster, M. Smeja, and W. Muller, “Assessment of posture and motion by multichannel piezoresistive accelerometer recordings,” Psychophysiology, Vol.34, pp. 607-612, 1997.
-  B. Najafi, K. Aminian, A. Paraschiv-Ionescu, F. Loew, C. J. Bula, and P. Robert, “Ambulatory system for human motion analysis using a kinematic sensor: Monitoring of daily physical activity in the elderly,” IEEE Trans. Biomed. Eng., Vol.50(6), pp. 711-723, 2003.
-  S. Miyazaki, “Long-term unrestrained measurement of stride length and walking velocity utilizing a piezoelectric gyroscope,” IEEE Trans. Biomed. Eng., Vol.44(8), pp. 753-759, 1997.
-  K. Tong and M. H. Granat, “A practical gait analysis system using gyroscopes,” Medical Engineering & Physics, Vol.21, pp. 87-94, 1999.
-  K. Aminian, B. Najafi, C. Bula, P. F. Leyvraz, and Ph. Robert, “Spatio-temporal parameters of gait measured by an ambulatory system using miniature gyroscopes,” Journal of Biomechanics, Vol.35, pp. 689-699, 2002.
-  R. Williamson and B. J. Andrews, “Detecting absolute human knee angle and angular velocity using accelerometers and rate gyroscopes,” Med. Biol. Eng. Comput., Vol.39, pp. 1-9, 2001.
-  H. J. Luinge and P. H. Veltin, “Measuring orientation of human body segments using miniature gyroscopes and accelerometers,” Med. & Biol. Eng. & Comput., Vol.43, pp. 273-282, 2005.
-  H. Dejnabadi, B. M. Jolles, E. Casanova, P. Fua, and K. Aminian, “Estimation and visualization of sagittal kinematics of lower limbs orientation using body-fixed sensors,” IEEE Trans. Biomed. Eng., Vol.53(7), pp. 1385-1393, 2006.
-  S. Tanaka, K. Yamakoshi, and P. Rolfe, “New portable instrument for long-term ambulatory monitoring of posture change using miniature electro-magnetic inclinometers,” Med. & Biol. Eng. & Comput., Vol.32, pp. 357-360, 1994.
-  K. Motoi, S. Tanaka, M. Nogawa, and K. Yamakoshi, “Evaluation of a new sensor system for ambulatory monitoring of human posture and walking speed using accelerometers and gyroscope,” SICE Annual Conference 2003 Proceedings, pp. 563-566, 2003.
-  K. Motoi, S. Tanaka, M. Nogawa, and K. Yamakoshi, “Evaluation of a new sensor system for ambulatory monitoring of human posture together with walking speed,” Transaction of the Japanese Society for Medical and Biological Engineering, Vol.41(4), pp. 35-41, 2003.
Copyright© 2007 by Fuji Technology Press Ltd. and Japan Society of Mechanical Engineers. All right reserved.