NCT04038151

Intuitive Control of a Hybrid Prosthetic Leg During Ambulation

• Status: Recruiting
• Phase: N/A
• Study type: Interventional
• Enrollment: 20 (estimated)
• Sponsor: Shirley Ryan AbilityLab · Academic / Other
• Sex: All
• Age: 18 Years – 95 Years
• Healthy volunteers: Not accepted

Summary

The objective of this research is to determine the clinical benefits of an innovative and lightweight powered leg controlled using our intent recognition framework in laboratory and community environments.

Detailed description

The hypothesis of this study is that using the Hybrid Leg with seamless, automatic transitions will result in participants choosing to become more active and improve their community participation compared to when using their own passive prosthetic leg. The Hybrid Leg is an an innovative and lightweight powered leg that has 2 operating modes: active and passive. When in active mode, the Hybrid Leg is capable of supplying 120 NM of knee torque and actively repositioning the ankle during non-weight bearing phases of gait. When in passive mode, the motor and transmission are decoupled from the knee, which then behaves like an Ottobock 3R95 passive prosthetic knee, and the non-backdriveable mechanism of the ankle allows it to behave as an energy return foot. Allowing the device to behave passively if the battery becomes depleted or the actuators become damaged is an important enabling safety factor that will allow us to complete our study. Phase 1: We will enroll 20 subjects a clinical trial of the leg and control system who will be fit with the Hybrid Leg and receive in-lab therapy to learn how to ambulate with the device. Phase 2: Subjects will be randomized into a clinical trial of the leg and control system with an AB-BA design; condition A - subjects own device; condition B - Hybrid Leg. Subjects will complete an extensive ambulation and community mobility training to learn optimal use of their own passive device or the Hybrid Leg. After training the subjects will complete a full biomechanical analysis for each device as they complete ambulation circuits that include standing, level-ground walking, walking on slopes and on stairs, sit-stand transitions and transitions between these activities. Phase 3: After completing phase 2 subjects will complete 4-week trials using their assigned prosthesis (Condition A or B) at home and within their community. During the trials subjects will be monitored using mobile phone based sensors and socket mounted activity monitor to determine how often the user performs the ambulation activities.

Conditions

• Amputation

Interventions

Type	Name	Description
DEVICE	Hybrid Leg	The Hybrid Knee uses an actively variable transmission in combination of a passive spring/damper system. This allows the motor torque output to be adapted to the requirements of active dynamic tasks - changing the effective transmission ration from zero (fully passive) for level ground walking to a maximum value (fully active) for sit-to-stand transfers. This provides physiological knee torque and speed with a small motor and primary transmission system while also maximizing electrical efficiency, which minimized battery weight. The knee prototype weights 1.7kg. The Semi-active ankle can actively reposition during non-weight bearing phases of gait and uses a non back driveable transmission to maintain its set point during weight bearing activities.
DEVICE	Prescribed Passive Prosthesis	Participants will participate in training sessions of community skills and advanced ambulation training for their home, prescribed passive prosthesis.

Timeline

• Start date: 2018-12-01
• Primary completion: 2024-06-30
• Completion: 2025-06-30
• First posted: 2019-07-30
• Last updated: 2024-05-17

Locations

1 site across 1 country: United States