A Lightweight Powered Hip Exoskeleton With Parallel Actuation for Frontal and Sagittal Plane Assistance

Area of Science:

• Robotics
• Biomechanics
• Assistive Technology

Background:

• Wearable robots and powered exoskeletons offer potential for improving ambulation in individuals with mobility impairments.
• Current hip exoskeletons primarily assist in the sagittal plane, neglecting the crucial frontal plane for mediolateral balance.
• Existing dual-plane hip exoskeletons are often too heavy and bulky for practical, real-world application.

Purpose of the Study:

• To present the kinematic model, mechatronic design, and testing of a novel powered hip exoskeleton.
• To develop a lightweight and slim-profile hip exoskeleton capable of providing both sagittal and frontal plane assistance during gait.
• To evaluate the torque generation capabilities and effects of the exoskeleton on gait parameters.

Main Methods:

• Development of a powered hip exoskeleton utilizing a unique parallel kinematic actuator.
• Design focused on achieving a lightweight (5.3 kg) and slim profile.
• Benchtop and human testing with five healthy subjects to assess torque generation and gait alterations.

Main Results:

• The developed exoskeleton is lightweight (5.3 kg) and slim, generating 30 N·m (sagittal) and 20 N·m (frontal) torque during gait.
• Achieved a torque density of 5.7 N·m/kg, representing a 53% increase over previous series kinematic designs.
• Human testing demonstrated that frontal plane torques can modify step width, while sagittal plane torques assist hip flexion/extension.

Conclusions:

• The novel parallel kinematic hip exoskeleton offers significant advancements in torque density and portability compared to existing designs.
• The device's ability to provide both sagittal and frontal plane assistance shows potential for improving gait economy and balance.
• This lightweight and effective exoskeleton may offer a viable solution for real-world ambulation assistance in individuals with mobility impairments.