足底壓力感測元件數量對於平衡參數準確度之影響

目的：本研究欲探討不同數量的足底壓力感測元件對平衡參數準確度之影響。方法：招募12名6個月內無下肢骨骼神經傷害的參與者，使用Pedar-X system收集參與者左右兩腳單腳站立時，30 秒內之足壓數據。統計分析用皮爾森相關係數（PCC）分析不同數量（3、5、7、9、11、13、15、17個）感測元件的CoP軌跡與效標Pedar-X system 99個感測元件之相關；並將少量感測元件和效標所求得的移動面積誤差值進行百分比計算，觀察少量感測元件與效標間的誤差。結果：不論是前後（AP）或左右（ML）軸向，當感測元件達9個時，其CoP軌跡準確性已與效標相當（ML：r = 0.952；AP：r = 0.913，p ＜ .05），並在11個時趨於平穩（ML：r = 0.971；AP：r = 0.931，p ＜.05），且前後（ML）與內外（AP）軸向相關性皆＞ 0.9，呈高度相關（p ＜ .05）；CoP移動面積的誤差值在11個感測元件已達平穩，再增加數量則無法明顯降低移動面積誤差的能力。結論：隨著感測元件的數量增加，與效標測得相關性與移動面積誤差值也隨之提高與降低，此結果證明少量壓力感測元件與效標的偵測數值有高度相關，也提供開發者在未來可以依據準確度需要選取感測器的數量，減少材料與傳輸時間上的成本。

關鍵字

鞋內足壓系統；壓力中心；單腳站立

並列摘要

Purposes: This study was conducted to investigate the influence of different numbers of plantar pressure sensors on the accuracy of balance parameters. Method: Twelve participants without neoromuscular injury in the lower extremities within 6 months were recruited. The Pedar-X system was used to collect the plantar pressure data from the participants within 30 seconds of period while they were performing single-leg-stance on both left and right limbs. Statistical analysis was performed to analyze the correlation between the CoP trajectories of different numbers of sensors (3, 5, 7, 9, 11, 13, 15, 17, arbitrary unit) and the criterion of validity (99 sensors) using Pearson correlation coefficients (PCC). The percentage of the error in the moving area obtained from a small number of sensors and the 99 sensors systemwas calculated to observe the error between two parties. Results: Regardless of the Anterior-Postrior (AP) or Medial-Lateral (ML) axis, with 9 sensing elements, the accuracy of the CoP trajectory was equivalent to the 99 sensors system (ML: r = 0.952; AP: r = 0.913, p ＜ .05); in addition, the AP and the ML axial correlations were ＞ 0.9, showing a high correlation (p ＜ .05).The error value of the CoP moving area reached convergence when the numbers of sensing elements were equal or more than 11, and increasing the number of the sensors not further reduce the the moving area error. Conclusions: With the increase of the number of sensors, the correlation of the detected validity enhanced while the moving area error decreased accordingly. This result demonstrated that a fwer l number of pressure sensors can reveal a high correlation with thecriterion of validity; additionally, it also provides useful information for developers to determine the number of sensors based on accuracy requirement, thus reducing the cost of materials and transmission time while designing the product.