Active Ankle Foot Orthosis
First Claim
1. A variable-impedance active ankle foot orthosis comprising an actuator for modulating an impedance of an orthotic joint throughout a walking cycle for treating an ankle foot gait pathology.
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Accused Products
Abstract
An Active Ankle Foot Orthosis (AAFO) is provided where the impedance of an orthotic joint is modulated throughout the walking cycle to treat ankle foot gait pathology, such as drop foot gait. During controlled plantar flexion, a biomimetic torsional spring control is applied where orthotic joint stiffness is actively adjusted to minimize forefoot collisions with the ground. Throughout late stance, joint impedance is minimized so as not to impede powered plantar flexion movements, and during the swing phase, a torsional spring-damper (PD) control lifts the foot to provide toe clearance. To assess the clinical effects of variable-impedance control, kinetic and kinematic gait data were collected on two drop foot participants wearing the AAFO. It has been found that actively adjusting joint impedance reduces the occurrence of slap foot, allows greater powered plantar flexion, and provides for less kinematic difference during swing when compared to normals.
182 Citations
24 Claims
- 1. A variable-impedance active ankle foot orthosis comprising an actuator for modulating an impedance of an orthotic joint throughout a walking cycle for treating an ankle foot gait pathology.
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12. A device for treating an ankle foot gait pathology comprising:
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an orthosis including a leg portion attachable to a leg of a person and a foot portion attachable to a foot of the person; and
an actuator attachable to the leg portion for acting on a spring disposed between the actuator and the foot portion. - View Dependent Claims (13, 14, 15, 16, 17, 18)
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- 19. A method comprising modulating an impedance of an orthotic joint of an orthosis throughout a walking cycle.
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24. A method of treating an ankle foot gait pathology using functional electrical stimulation, comprising applying electrical pulses to elicit muscle contractions to actively modulate ankle impedance to achieve a torsional spring control during controlled plantar flexion so as to minimize forefoot collisions with the ground, minimizing impedance during late stance, and achieving a spring-damper positional control during a swing phase.
Specification