歩行中に膝を摂動するための外骨格の設計と特性評価

目的：ヒト関節における機械的インピーダンス変調の理解の向上は、機能運動の根底にある神経力学についての洞察を提供します。インピーダンスの実験的推定には、再現性の高い摂動ダイナミクスと信頼性の高い測定機能を備えた特殊なツールが必要です。このホワイトペーパーでは、ETH膝の摂動器の設計と機械的特性評価を紹介します。歩行中に膝を摂動するための作動化された外骨格です。 METHODS: A novel wearable perturbation device was developed based on specific experimental objectives. Bench-top tests validated the device's torque limiting capability and characterized the time delays of the on-board clutch. Further tests demonstrated the device's ability to perform system identification on passive loads with static initial conditions. Finally, the ability of the device to consistently perturb human gait was evaluated through a pilot study on three unimpaired subjects. 結果：ETH膝摂動は、15％の精度以内に質量スプリングシステムを識別でき、16症例のうち10症例で観察されたトルクの分散の95％以上を占めています。スイング位相期間の2.52％の発症タイミング精度と36.5ミリ秒の上昇時間で、ヒト被験者に対して5度の拡張と屈曲摂動が実行されました。 結論：ETH膝摂動器は、歩行中の膝関節インピーダンスの推定の前提条件である安全で、正確にタイミングされた制御された摂動を提供できます。 重要性：このようなツールは、神経筋制御のモデルを強化することができ、歩行に影響を与え、支援デバイスの設計と制御を進めた障害に続くリハビリテーションの結果を改善する可能性があります。

OBJECTIVE: An improved understanding of mechanical impedance modulation in human joints would provide insights about the neuromechanics underlying functional movements. Experimental estimation of impedance requires specialized tools with highly reproducible perturbation dynamics and reliable measurement capabilities. This paper presents the design and mechanical characterization of the ETH Knee Perturbator: an actuated exoskeleton for perturbing the knee during gait. METHODS: A novel wearable perturbation device was developed based on specific experimental objectives. Bench-top tests validated the device's torque limiting capability and characterized the time delays of the on-board clutch. Further tests demonstrated the device's ability to perform system identification on passive loads with static initial conditions. Finally, the ability of the device to consistently perturb human gait was evaluated through a pilot study on three unimpaired subjects. RESULTS: The ETH Knee Perturbator is capable of identifying mass-spring systems within 15% accuracy, accounting for over 95% of the variance in the observed torque in 10 out of 16 cases. Five-degree extension and flexion perturbations were executed on human subjects with an onset timing precision of 2.52% of swing phase duration and a rise time of 36.5 ms. CONCLUSION: The ETH Knee Perturbator can deliver safe, precisely timed, and controlled perturbations, which is a prerequisite for the estimation of knee joint impedance during gait. SIGNIFICANCE: Tools such as this can enhance models of neuromuscular control, which may improve rehabilitative outcomes following impairments affecting gait and advance the design and control of assistive devices.