爪先装着型センサによる階段昇降を含む歩行時消費エネルギー推定

抄録

An alternative method for the quantitative assessment of energy consumption during level walk and stair walk using body-mounted sensor is discussed since the calorie counters commercially available scarcely estimate the energy consumption during ascending.Energy consumption is calculated by the metabolic model developed using the oxygen consumption during various walk including stair walk. The metabolic model is formulated as the time lag element of first order and its input is the energy requirement defined as the polynomial of horizontal and ver-tical walking velocity (2D walking velocity). The 2D walking velocity is derived by the integration of horizontal and vertical accelerations measured by a 3D pedometer attached on subject's tiptoe. The 3D pedometer consists of three accelerometers and three ceramic gyroscopes and estimates three dimensional displacement of the tiptoe during walk. The relation between 2D walking velocity and oxygen uptake is investigated to develop the energy requirement model. The energy requirement model developed in this study agrees with the measured oxygen uptake during 2D walking with the correlation coefficient of 0.93. Moreover time constant of the metabolic model is determined from the time trajectory of the oxygen uptake during walking exercise with constant velocity. The experiments including level walk, ascending and descending are performed for ten subjects and show that the energy consumption during ascending estimated using the 3D pedometer increases exceedingly compared with that during the level walk. Furthermore the estimated energy consumption highly correlates with the oxygen uptake with the correlation coefficient of 0.91 on average. The quantitative assessment of energy consumption of 2D walk by proposed method is confirmed.