Actuator-equipped knee ankle foot orthosis

An actuator-equipped knee ankle foot orthosis comprising:

• a thigh-side brace to be attached to a user's thigh;
• a lower leg-side brace to be attached to the user's lower leg, the lower leg-side brace being connected to the thigh-side brace so as to be rotatable around the user's knee joint;
• an actuator unit attached to the thigh-side brace and capable of imparting assisting force around the user's knee joint to the lower leg-side brace;
• a thigh orientation detecting means capable of detecting an angle-related signal concerning a hip joint angle that is a forward and backward swing angle of the user's thigh, wherein the angle-related signal is not a direct measurement of the hip joint angle;
• and a control device configured to manage operational control for the actuator unit, wherein for each gait cycle, the control device calculates a thigh phase angle based on the angle-related signal and a drift elimination process, obtains an assisting force to be imparted to the lower leg-side brace by applying the thigh phase angle to an assisting force control data, which is stored in the control device in advance and indicates a relationship between the thigh phase angle and a size of the assisting force to be imparted to the lower leg-side brace, and controls the actuator unit to output the assisting force, wherein the gait cycle includes a heel contact phase including a heel contact time point when the user's heel contacts a surface in front of the user's body axis, a stance phase when the heel-contacted leg, after heel contact, is relatively moved backward while being in contact with the surface, and a swing phase when the leg contacting the surface since the end of the stance phase is raised and relatively moved forward, and wherein the assisting force control data is configured so that the actuator unit outputs no assisting force in a period after an initial stage of the swinging phase in which the actuator unit outputs the assisting force for rotating the lower leg-side brace in a knee bending direction around the user's knee joint to raise the user's leg, and wherein the control device inhibits an operation of the actuator unit in a case where a length of a vector defined by the hip joint angle and the hip joint angular velocity that has been used when calculating the thigh phase angle is between zero and the predetermined threshold value.

An actuator-equipped knee ankle foot orthosis comprising:

• a thigh-side brace to be attached to a user's thigh;
• a lower leg-side brace to be attached to the user's lower leg, the lower leg-side brace being connected to the thigh-side brace so as to be rotatable around the user's knee joint;
• an actuator unit attached to the thigh-side brace and capable of imparting assisting force around the user's knee joint to the lower leg-side brace;
• a thigh orientation detecting means capable of detecting an angle-related signal concerning a hip joint angle that is a forward and backward swing angle of the user's thigh, wherein the angle-related signal is not a direct measurement of the hip joint angle;
• and a control device configured to manage operational control for the actuator unit, wherein for each gait cycle, the control device calculates a thigh phase angle based on the angle-related signal and a drift elimination process, obtains an assisting force to be imparted to the lower leg-side brace by applying the thigh phase angle to an assisting force control data, which is stored in the control device in advance and indicates a relationship between the thigh phase angle and the size of the assisting force to be imparted to the lower leg-side brace, and controls the actuator unit to output the assisting force, wherein the gait cycle includes a heel contact phase including a heel contact time point when the user's heel contacts a surface in front of the user's body axis, a stance phase when the heel-contacted leg, after heel contact, is relatively moved backward while being in contact with the surface, and a swing phase when the leg contacting the surface since the end of the stance phase is raised and relatively moved forward, and wherein the assisting force control data is configured so that the actuator unit outputs the assisting force for rotating the lower leg-side brace in a knee extending direction around the user's knee joint in a later stage of the swing phase that is after an initial stage of the swinging swing phase in which the actuator unit outputs the assisting force for rotating the lower leg-side brace in a knee bending direction around the user's knee joint to raise the user's leg before the heel contact time point, and wherein the control device inhibits an operation of the actuator unit in a case where a length of a vector defined by the hip joint angle and the hip joint angular velocity that has been used when calculating the thigh phase angle is between zero and the predetermined threshold value.