Modular artificial skeletal muscle actuators and exoskeletons powered thereby
Inventors
Behboodi, Ahad • Lee, Samuel C. K. • Binder-Macleod, Stuart A. • Wright, Henry
Assignees
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Publication Number
US-12083067-B2
Publication Date
2024-09-10
Expiration Date
Abstract
A modular artificial skeletal muscle (MASM) actuator having a plurality of dielectric elastomer units assembled in series or in parallel. A proximal anchoring member is connected to a proximal end of at least one proximal dielectric elastomer unit and is configured for attachment to a proximal anchor point relative to a user. A tension member has a proximal end attached to a distal end of at least one distal dielectric elastomer unit and a distal end configured for attachment to a distal anchor point relative to the user. A controller is configured to cause simultaneous contraction or expansion of plurality of dielectric elastomer units, which contraction or expansion causes displacement of the tension member. A plurality of MASM actuators may be attached to an exoskeleton attached about an ankle of a user and controlled for therapeutic purposes, such as for assisting pediatric patients with cerebral palsy.
Core Innovation
The invention provides a modular artificial skeletal muscle (MASM) actuator built from a plurality of dielectric elastomer units assembled in series or in parallel. A proximal anchoring member connects to a proximal end of at least one proximal dielectric elastomer unit and is configured for attachment to a proximal anchor point relative to a user. A tension member is connected at a proximal end to a distal end of at least one distal dielectric elastomer unit and has a distal end configured for attachment to a distal anchor point relative to the user.
A controller attached to a power source and to the plurality of dielectric elastomer units causes simultaneous contraction or expansion of the plurality of dielectric elastomer units. The contraction or expansion causes displacement of the tension member, and the displacement of the tension member provides corresponding displacement of a distal portion relative to a proximal portion when used in an exoskeleton frame. In the modular MASM actuator, the plurality of dielectric elastomer units is disposed in a pocket attached to a textile member.
The tension member is confined for some portion of its length within a conduit in the textile member. The disclosure further includes flexible, low-friction and electrically insulating coverings over external surfaces, and a self-sensing circuit that detects the relative longitudinal state of at least one dielectric elastomer unit and provides feedback for the controller to contract or expand based on the detected state. For powered exoskeleton and AFO use, the modular MASM actuator is arranged with ankle plantarflexion and dorsiflexion actuators and optionally inversion and eversion actuators, with walking gait phase detection and phase-based control logic.
Claims Coverage
The document includes multiple independent claims. Across these claims, the inventive coverage centers on modular dielectric elastomer unit stacks in a MASM actuator, their coupling to a tension member with proximal/distal anchoring, and controller-driven simultaneous contraction or expansion to displace the tension member or control stiffness.
Modular series/parallel dielectric elastomer MASM actuator with proximal anchoring and tension-member displacement
A modular artificial skeletal muscle (MASM) actuator comprising a plurality of dielectric elastomer units assembled in series or in parallel; a proximal anchoring member connected to a proximal end of at least one proximal dielectric elastomer unit and configured for attachment to a proximal anchor point relative to a user; a tension member having a proximal end attached to a distal end of at least one distal dielectric elastomer unit and a distal end configured for attachment to a distal anchor point relative to the user; and a controller attached to a power source and to the plurality of dielectric elastomer units, the controller configured to cause simultaneous contraction or expansion of plurality of dielectric elastomer units, which contraction or expansion causes displacement of the tension member.
Textile-pocket confinement of dielectric elastomer units and conduit confinement of tension members
The plurality of dielectric elastomer units is disposed in a pocket attached to a textile member, and each respective tension member is confined for some portion of its length within a conduit in the textile member.
Powered ankle exoskeleton using simultaneous contraction/expansion to displace a tension member
A powered exoskeleton comprising a frame configured for placement about an ankle joint with proximal and distal portions configured to move relative to one another with at least one degree of freedom; a plurality of modular MASM actuators including at least one plantarflexion MASM actuator and at least one dorsiflexion MASM actuator, the plurality of MASM actuators comprising a plurality of dielectric elastomer units assembled in series or in parallel, a proximal anchoring member attached to a proximal anchor point on the frame, a tension member with adjustable length between the proximal anchor point and the distal anchor point, and a controller configured to cause simultaneous contraction or expansion of plurality of dielectric elastomer units, which causes displacement of the tension member and corresponding displacement of the distal portion relative to the proximal portion.
Metatarsal-aligned footplate with MASM-driven tension-member displacement
A powered exoskeleton comprising a frame about an ankle joint including a distal portion comprising a footplate configured for positioning beneath a foot and comprising a joint positioned to align with a metatarsal joint; and one or more modular MASM actuators comprising a plurality of dielectric elastomer units assembled in series or in parallel, a proximal anchoring member attached to the proximal frame and proximal anchor point, a tension member with an adjustable length between the proximal anchor point and the distal anchor point, and a controller configured to cause simultaneous contraction or expansion of plurality of dielectric elastomer units to displace the tension member and move the distal portion relative to the proximal portion.
Stiffness control exoskeleton with dielectric elastomer units disposed in a textile pocket
An exoskeleton comprising a plurality of members configured to be attached to the user and one or more dielectric elastomer units anchored to at least one member and connected to a controller configured to modulate power to the one or more dielectric elastomer units to control stiffness of the at least one member, wherein the one or more dielectric elastomer units is disposed in a pocket that is attached to a textile member.
Ankle-foot orthotic with metatarsal-aligned dielectric elastomer joint and controller-modulated stiffness
An ankle-foot orthotic (AFO) comprising a frame having a proximal frame portion removably attached proximal to an ankle joint and connected to a footplate secured beneath a foot, the footplate having a joint positioned to align with a metatarsal joint, wherein the joint comprises one or more dielectric elastomer units proximally anchored to a proximal portion of the footplate and distally anchored to a distal portion of the footplate, and the joint connected to a controller configured to modulate stiffness of the one or more dielectric elastomer units by modulating power to the one or more integrated dielectric elastomer units.
Overall, the claims cover modular MASM actuators that use series/parallel dielectric elastomer unit stacks with proximal anchoring and a tension-member connection, coupling and packaging of those elements in textile pockets with conduit confinement for tension members, powered ankle exoskeleton configurations where controller-driven simultaneous contraction or expansion displaces the tension member to move frame portions, and stiffness-modulating wearable systems including a textile-pocketed stiffness-control exoskeleton and an AFO with a metatarsal-aligned dielectric elastomer joint whose stiffness is modulated by controller-controlled power.
Stated Advantages
Provides simultaneous contraction or expansion of a plurality of dielectric elastomer units to cause displacement of a tension member.
Enables corresponding displacement of a distal portion relative to a proximal portion in a powered exoskeleton frame.
Controls stiffness of at least one member by modulating power to one or more dielectric elastomer units.
Positions a footplate joint to align with a metatarsal joint in a powered exoskeleton/AFO configuration.
Documented Applications
Powered exoskeleton configured to augment ankle plantarflexor and dorsiflexor muscle function, with optional inversion and eversion actuators.
Walking-gait phase detection and phase-based control in a powered exoskeleton.
An ankle-foot orthotic (AFO) comprising a frame and a metatarsal-aligned dielectric elastomer joint with controller-modulated stiffness.
Exoskeleton including members attachable to a user where dielectric elastomer units disposed in a pocket attached to a textile member are used to control stiffness of the member.
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