脳卒中歩行強化のための適応股関節外骨格

実験的：Hip Exoskeleton for Stroke Gait Assistance

This study will be conducted on a sample population of stroke subjects (single arm). Subjects will be tested with the hip exoskeleton and baseline.

デバイス：Hip exoskeleton

The intervention is an experimental robotic hip exoskeleton in a powered state providing assistance to the user that has been previously developed by the team. It is used to improve walking gait performance.

他の：Baseline

The intervention will serve as a baseline where participants will be asked to perform the tasks without wearing a hip exoskeleton.

Temporal Convolutional Network (TCN) Model Performance (Joint Moment Accuracy)

This outcome represents the error with which the deep learning model embedded into our hip exoskeleton's microprocessor predicts hip joint moments in stroke patients. Specifically, the coefficient of determination (R²) is computed between the predicted hip joint moments and the ground truth measurements. Ground truth measurements are obtained from a laboratory-grade force plate system and inverse dynamics calculations. For these measures, higher R² values (closer to 1.0) indicate better correlation between predicted and actual hip joint moments. This metric provides a comprehensive assessment of the exoskeleton's ability to accurately estimate hip joint moments in stroke patients during tasks, with improved outcomes representing better assistive capabilities for the user.

Metabolic Cost for Level Ground Walking

Metabolic energy expenditure will be quantified using an indirect calorimetry system (Parvo Medics, UT) that measures oxygen consumption (VO₂) and carbon dioxide production (VCO₂) during experimental tasks. Measurements will be collected from each participant during a 5-minute baseline standing period followed by level ground walking trials under three conditions: without the exoskeleton, with the exoskeleton in a powered state, and with the exoskeleton in an unpowered state. Metabolic cost will be calculated from respiratory gas exchange data using standard equations for energy expenditure.

Biological Joint Work - Level Walking

Mechanical work performed by the lower limb joints during level walking will be quantified through biomechanical analysis of motion capture data. Joint moments and angular velocities will be derived through inverse dynamics and kinematics, respectively. Joint power, calculated as the product of joint moment and angular velocity, will be integrated with respect to time using trapezoidal integration to determine mechanical work. Positive work will be calculated by integrating positive joint powers, providing comprehensive quantification of joint energy generation at each joint during level walking.

Biological Joint Work - Incline Walking

Mechanical work performed by the lower limb joints will be quantified during incline walking through biomechanical analysis of motion capture data. Joint moments and angular velocities will be derived through inverse dynamics and kinematics, respectively. Joint power, calculated as the product of joint moment and angular velocity, will be integrated with respect to time using trapezoidal integration to determine mechanical work. Positive work will be calculated by integrating positive joint powers, providing comprehensive quantification of joint energy generation at each joint during the incline walking.

Biological Joint Work - Stair Ascent

Mechanical work performed by the lower limb joints will be quantified during stair ascent through biomechanical analysis of motion capture data. Joint moments and angular velocities will be derived through inverse dynamics and kinematics, respectively. Joint power, calculated as the product of joint moment and angular velocity, will be integrated with respect to time using trapezoidal integration to determine mechanical work. Positive work will be calculated by integrating positive joint powers, providing comprehensive quantification of joint energy generation at each joint during the stair ascent task.

Biological Joint Work - Sit to Stand

Mechanical work performed by the lower limb joints will be quantified during sit to stand through biomechanical analysis of motion capture data. Joint moments and angular velocities will be derived through inverse dynamics and kinematics, respectively. Joint power, calculated as the product of joint moment and angular velocity, will be integrated with respect to time using trapezoidal integration to determine mechanical work. Positive work will be calculated by integrating positive joint powers, providing comprehensive quantification of joint energy generation at each joint during the sit to stand task.

Biological Joint Work - go and Grab

Mechanical work performed by the lower limb joints will be quantified during a go and grab task through biomechanical analysis of motion capture data. In the go and grab task, participants take several steps, lean forward, and pick up a weighted object from a low surface just above ground level. Joint moments and angular velocities will be derived through inverse dynamics and kinematics, respectively. Joint power, calculated as the product of joint moment and angular velocity, will be integrated with respect to time using trapezoidal integration to determine mechanical work. Positive work will be calculated by integrating positive joint powers, providing comprehensive quantification of joint energy generation at each joint during the go and grab task.

10 Meter Walk Test (Self-selected)

This will be measured as the participant walks a distance of 10 meters across a gait mat at their self-selected (or comfortable) walking speed. This measure will be recorded in seconds with lower values indicating faster speed and higher values indicating slower speeds. Self-selected walking speed is highly correlated with functional ability and dependence.

The Timed up and go (TUG)

This will be measured as the time it takes a participant to rise from a chair, walk three meters at a self-selected pace, turn, walk back to the chair and sit down. The total time taken will be measured in seconds with longer times indicating poorer physical performance. This test assesses functional mobility and dynamic balance.

6 Minute Walk Test

This is a measurement of endurance and functional ability that assesses the participants ability to walk a distance over a time period of 6 minutes. It is measured in distance with greater distances indicating improved levels of endurance and functional ability.

Modified Stroke Impact Scale

The Modified Stroke Impact Scale (SIS) is a self-report questionnaire that evaluates disability and health-related quality of life after stroke. Each item is rated in a 5-point Likert scale in terms of the difficulty the patient has experienced in completing each item. Scores are transformed to a 0-100 scale, with 0 indicating the poorest perceived health status and 100 indicating the best, across domains of disability and health-related quality of life. Higher scores are indicative of improved quality of life.

Modified Activities-specific Balance Confidence

The modified activities specific balance confidence is a self-report measure of balance confidence in performing various activities without losing balance or experiencing a sense of unsteadiness. Confidence is rated for various activities on a scale from 0% to 100% for each activity, with 0% indicative of no confidence and 100% indicative of complete confidence. Scores reflect balance confidence with higher scores indicative of improved balance confidence.

Fast Self-selected Walking Speed

This will be measured as the participant walks on a treadmill at their fastest and safest walking speed. This measure will be recorded in meters/seconds with higher values indicating faster speed and lower values indicating slower speeds.