| 摘要: | 以往的照明著重在製造成本、發光效率、色彩表現等等，沒有特別注意光源對於人體的危害或影響，直到照明影響生理回饋的研究被提出後，人們才開始注重光譜的色溫、照度和演色性，因此探討不同照明因子對於使用者的生理表現以及身體狀況，成為人因工程中相當重要的課題。
本研究以模擬辦公室內環境為實驗空間，評估光譜可調式光源箱所設計不同色溫或不同晝夜節律刺激值的照明情境，對使用者的生心理影響和提升精神狀況之成效。實驗招募受試者於模擬辦公室內進行靜態文書作業，同時延續先前團隊既有的照明人因評估技術，並加以改進實驗流程、測驗內容與問卷評估。本研究使用腦波儀進行腦波量測作為生理回饋的客觀評估工具，受試者問卷作為主觀評估工具，並利用Matlab撰寫程式進行後續的主客觀數據分析，整合上述所有內容，以此來建立新的照明人因評估。
實驗中使用光源照明分析控制軟體、腦波儀、光譜可調式光源箱以及問卷評估等多項工具。使用光源照明分析控制軟體搭配光譜可調式光源箱，在固定工作面照度為500 lx的條件下，設計出九種不同色溫不同晝夜節律刺激值(Circadian stimulus, CS)的光源光譜，並選擇其中五種進行了兩個實驗，實驗一研究目的為比較不同晝夜節律刺激值的影響，使用相同色溫5000 K，不同CS值0.25、0.35、0.45；實驗二研究目的為比較不同色溫的影響，相同CS值0.45，不同色溫3000、4000、5000 K。
腦波儀負責量測受試者於LED燈箱調控情境下的腦波訊號，並且匯入MATLAB軟體進行數據分析，其中包含快速傅立葉轉換(Fast Fourier transform, FFT)、經驗模態分解法(Empirical mode decomposition, EMD)、希爾伯特轉換(Hilbert transform, HT)、機率密度函數(Probability density function, PDF)以及接收者操作特徵曲線(Receiver operating characteristic curve, ROC curve)等運算，最後將接收者操作特徵曲線的曲線下面積(Area under the curve, AUC)依情境排列作為客觀指標；以問卷評估所得之評分，亦依情境排列後成為主觀指標。主客觀指標分別匯入SPSS統計軟體進行變異數分析，檢視指標於三種情境之間是否具顯著差異，以進一步探討主客觀指標的情境狀況。
研究結果顯示在主客觀指標方面，實驗一於相同色溫不同晝夜節律刺激值的光譜下，兩者具有相近之處，且情境一(色溫為5000 K，晝夜節律刺激值為0.25)有較好的覺醒程度；然而實驗二於相同晝夜節律刺激值不同色溫的光譜下，受試者評估問卷上的光源亮暗程度於情境之間具有顯著差異，但受試者腦波的不同頻段於情境之間都沒有顯著差異。期許基於現階段的實驗結果，在未來的其它照明情境中，主客觀的實驗結果能夠取得更出色的成果。;In the past, people mainly focused on the manufacturing cost, luminous efficiency and color performance of lighting and did not pay special attention to the harm or impact of light sources on the human body. It was not until the research on the effect of lighting on physiological feedback was proposed that people began to pay attention to the color temperature, illuminance and color rendering of the lighting spectrum. Therefore, the manipulation of different lighting factors for the user’s physiological performance and physical condition has become a very important topic in human factors engineering.
This study uses a simulated office environment as an experimental space to evaluate the effects of different lighting spectra on user’s attention level. Lightingscenarios with different correlated color temperature (CCT) or different circadianstimulus (CS) were designed by using the spectrum adjustable light sources. Participants were recruited to perform the static paperwork in the office, while their brainwaves were measured as an objective evaluation. A questionnaire was used as a subjective evaluation tool, and codes written in the MATLAB environment were used for subsequent subjective and objective data analysis.
Nine lighting spectra were designed with 3 levels of CCT and 3 levels of CS, while the task illuminance was fixed at 500 lx. Then, we chose five spectra to conduct two experiments. The first experiment is to investigate the influence of circadian stimulus, and tested three lighting scenarios with a fixed CCT at 5000 K and different CS values at 0.25, 0.35, and 0.45. The second experiment is to compare the effects of different color temperatures, and tested three lighting scenarios with the same CS at 0.45 and different CCT at 3000, 4000, and 5000 K.The collected brainwave signals underwent several processes, including Fast Fourier transform (FFT), empirical mode decomposition, Hilbert transform, probability density function and receiver operating characteristic curve (ROC curve). Finally, the areas under the curves (AUCs) were calculated to be the objective indicators of binary classifications. On the other hand, the scores of the questionnaires were arranged in the order of the lighting environments, and then became the subjective indicators. Both of them were collected into SPSS for the analysis of variance (ANOVA) to check if there was any significance among the three lighting environments, so as to further explore if there were any correlationsbetween the subjective and objective indicators.
The results show that the first experiment (with the same CCT and different CS values) has similarities between the subjective and objective indicators, and scenario one (CCT at 5000 K and CS at 0.25) relates to better alertness level. In the second experiment (with the same CS and different CCTs), the light-source brightness in the questionnaire assessment has significant differences between thelighting environments, though the analysis of brainwaves in several frequency bands shows no significance. The current experimental design and data analysis method shall be applicable to test other lighting scenarios in the future. |
