患者自控式電動步行矯具之控制邏輯演算–比較按鈕控制和姿態引發控制

Abstract

半身癱瘓的患者像是腦傷、即隨損傷、脊柱裂等等的患者現在幾乎都是以輪椅代步。因為長期坐在輪椅上，站立步行將能夠提供這些患者很多生理上和心理上的好處。以往患者若要站立步行只能使用純機構式的交替式步行矯具，現在因為科技的進步，具有動力的醫療用外骨骼已經可以在臨床上使用。 研究目的： 台灣大學醫學工程學研究所復健工程學實驗室最近正在開發一款醫療用外骨骼叫做UPGO，患者自控式電動步行矯具來幫助半身癱瘓的使用者站立及步行。本篇論文的目的是要比較兩種不同的醫療用外骨骼UPGO的控制邏輯演算法，按鈕控制和姿態引發控制在日常生活中的表現有甚麼不同。 假說： 1. 兩種不同控制邏輯的步行速度會相同 2. 使用姿態引發控制會需要比較少的精神負擔 3. 按鈕控制提供使用者更精準地控制因此更容易應付障礙物 4. 按鈕控制可以讓使用者輕易地進出狹小的空間 受試者： 我們使用4位常人受試者 實驗方法： 本論文使用四個不同的測驗來模擬日常生活的患者使用外骨骼所會遇到的情況來驗證四個假說，分別是平地步行測試、精神負擔測試、障礙物測試、狹小空間測試。患者會穿著外骨骼並且使用兩種不同的控制邏輯來進行這四個不同的測試並且比較測試結果。 實驗結果： 平地步行測試中，使用姿態引發控制邏輯的使用者平均步行速度比按鈕控制的要高一點，約7%。姿態引發控制邏輯的三分鐘步行速度也明顯比7公尺步行速度要快；相反的按鈕控制邏輯的三分鐘步行速度明顯比7公尺步行速度要慢。另外姿態引發控制邏輯的三分鐘步行速度顯著的比按鈕控制還要快。在精神負擔測試中，按鈕控是邏輯的平均步行速度下降的較姿態引發控制邏輯多。在障礙物測試中姿態引發控制邏輯的通過時間稍微比按鈕控制短一點，但是姿態引發控制邏輯障礙物的次數比按鈕控制邏輯多很多。在狹窄空間測試中，按鈕控制邏輯可以更快的進出狹小空間。

Most persons with paraplegia, including spinal cord injury, spina bifida, brain injury etc., use a wheelchair for daily mobility. Walking provides many physiological benefits for persons with paraplegia. The ability to stand and walk also contributes to quality of life and convalescence. The Reciprocating Gait Orthosis (RGO) is the most frequently used brace for the ambulatory needs of a paralyzed child or adult. Recently, many scientists and engineers have been working to develop powered exoskeletons. Because of advancements in computers, motor efficiency, and battery capacity, it is now possible to develop powered exoskeletons that can be used in daily life. Purpose: National Taiwan University’s Rehabilitation Engineering Laboratory in the department of Biomedical Engineering and the Rehabilitation Engineering Research Center has recently been developing a User-controlled Powered Gait Orthosis (UPGO) to provide an affordable powered orthosis without sacrificing its performance in assisting persons with paraplegia with standing and walking. The objective of this research is to compare the efficacy of the UPGO’s push button control algorithm in daily walking activities with that of the postural control algorithm similar to the one used with the ReWalk. Hypotheses: 1. The walking speed with the push button control will not be different than that with the posture control. 2. The postural control requires lesser mental effort than the user control. 3. The push button control will allow the user to perform more precise control of each step so that the user can manage complex obstacle situation in the daily life compared to the postural control. 4. The push button control allows the user to perform different step length on each step. As a result, user can perform U-turn in narrow spaces such as elevator more easily compared to postural control. Subjects: We will use 4 nondisabled subjects as models for persons with paraplegia. Method: This experiment performed the Level Ground Walking Task, Mental Loading Task, Obstacle Task and Narrow Space Task on two different control algorithm to test the hypotheses and know the effect of control algorithm. Subjects will perform the above 4 tasks on two different days using a different control algorithms for each day to avoid interaction and user confusion. Results: In Level Ground Walking Task, average walking speed of postural control is slightly higher (7%) than push button control. The highest walking speed of Postural Control occur in 3 minute walking trial compared to 7-m walking trial. There was a significant speed drop in 3 minute walking trial of push button control. 3 minute Walking Speed of postural control is significantly higher than that of push button control. For the Mental Loading Task, average walking speed of push button control decrease more in mental loading task. For the Obstacle Task, push button control have fewer contact error compared to postural control but require more time to navigate through obstacles. In Narrow Space Task, push button control require less time to perform a U-turn in narrow space.