[[alternative]]Effects of Inhalation of Essential Oils on Heart Rate Variability

[[abstract]] 本實驗的目的在了解使用薰衣草、茉莉、洋甘菊、檀香或佛手柑精油吸入性芳香療法應用於162位健康大學生生理參數的影響。實驗前，受試者先進行心率變異度分析5分鐘，每種精油使用量為0.15mL，以超音波噴霧吸入的方式進行10分鐘的芳香療法，之後再做心率變異度分析後測5分鐘。藉由記錄芳香療法前後的心率變異數值來評估薰衣草、茉莉、洋甘菊、檀香或佛手柑對於自主神經系統的反應，同時亦以佛手柑精油的主要香味化合物乙酸沉香酯，檢驗吸入前後的心率變異度變化。心率變異的測量值包括心跳數、高頻功率、低頻功率與低頻/高頻功率比等。本研究採敘述性統計與配對樣本t檢定比較前後測測量值，並使用單因子共變數分析(One-way ANCOVA)及平均測量值(Δ, %)的〔（後測值－前測值）/前測值〕，再使用單因子變異數分析(ANOVA)比較五組精油間之組間差異。P<0.05表示具有統計上的意義。 結果顯示：受試者使用薰衣草精油在心率變異測量值中，低頻/高頻功率比(P＝0.048)顯著增加，顯示使用薰衣草精油吸入性芳香療法具活化交感神經活性。使用洋甘菊(P<0.01)、檀香(P＝0.02)與佛手柑精油(P＝0.037) 吸入性芳香療法後，在取對數後高頻功率測量值皆上升，且洋甘菊在低頻功率/高頻功率比(P<0.01)測量值下降，顯示使用洋甘菊、檀香與佛手柑三種精油吸入性芳香療法具有提升副交感神經活性，可達到舒緩放鬆的效果。使用茉莉精油雖然能使取對數後低頻功率提升些微提升，但不具顯著性，顯示使用茉莉精油吸入性芳香療法活化交感神經活性效果不明顯。受試者使用佛手柑精油的主要香味化合物乙酸沉香酯之吸入性芳香療法後，在取對數後高頻功率(P<0.01)測量值及常規化高頻功率(P<0.01)測量值顯著上升，常規化低頻功率(P<0.01)測量值顯著下降，顯示使用乙酸沉香酯成分吸入性芳香療法與佛手柑精油相同，具有提升副交感神經活性的效果。經單因子變異數分析後顯示，薰衣草及茉莉精油具有相同的上升交感神經活性特質；洋甘菊、檀香則具有相同的上升副交感神經活性特質。佛手柑精油雖具有上升交感神經活性特質，但不顯著。[[abstract]] This research aims to investigate the effects of inhalation of essential oils including lavender, jasmine, chamomile, sandalwood, bergamot, and linalyl acetate which is the main ingredient of bergamot, on the autonomic nervous system. Parameters of Heart Rate Variability (HRV) including heart rate, high frequency signal, low frequency signal, and low to high frequency ratio were measured on 162 university students before and after inhalation of the essential oils. Paired t-test was used to compare pre- and post-test data. One-way Analysis of Covariance (ANCOVA) using baseline data as the covariates and Analysis of Variance (ANOVA) on mean percentage pre-post changes were used to compare the differences between the five essential oil groups. P values less than 0.05 were considered statistically significant. Results showed that the low to high frequency ratio was significantly increased (P=0.048) after the inhalation of lavender essential oil, indicating an activation of sympathetic nervous system. Natural- logarithmic transformed high frequency signal was significantly increased after the inhalation of chamomile (P<0.01), sandalwood (P=0.02), and bergamot essential oils (P=0.037), indicating an activation of the parasympathetic nervous system.A significant increase in the low to high frequency ratio was observed after the inhalation of chamomile (P<0.01). Therefore, inhalation of chamomile, sandalwood, and bergamot essential oils could activate the parasympathetic nervous system leading to a relaxation effect. Inhalation of jasmine essential oil led to a slight increase in the natural-logarithm transformed low frequency signal but the change was not statistically significant. Therefore, the parasympathetic nervous system did not changed significantly with the using of jasmine essential oil. A significant increase in natural-logarithm transformed high frequency signals (P<0.01), normalized high frequency signals (P<0.01), and a decrease in normalized low frequency signals (P