area.Two main components oflavender oil comprised spectrum of the respective frequency bands derived linalyl acetate (32.46%)and linalool (31.91%). by Fast Fourier Transformation(FFT)were expressed A one-milliliter mixture of either undiluted as follows:Delta(0-3.99 Hz).Theta(4-7.99 Hz).Alphal sweet almond oil or 10%(v/v)of lavender in base oil (8-9.99Hz).Alpha2(10-12.99Hz)and Beta(13-30Hz) was delivered using an oxygen pump system through a plastic tube via respiratory masks in an inhalation Procedure set for adults that permitted selective routine air An A-B design was used,so that each flow(2 L/min).Before the experiment,they were individual session consisted of two trails.This design asked to inhale base oil and lavender oil to rate the was chosen because,with olfactory stimulation,the pleasantness of the smell on a five-point Likert scale.times court of stimulatory effects is unknown.which The participants.who indicated oil pleasantness might make results obtained from other designs,such within the target level range of 2-4 were chosen to as A-B-A,difficult to interpret(19).All experiments were participate in the present study conducted in a quiet room with ambient temperature (24+1C)and 40 to 50%humidity.The experiments Autonomic nervous system (ANS)and mood measure- were performed between 8.00 and 12.00 a.m.to minimize ment circadian variation.All participants attended to Mood state and ANS parameters.blood this research for two times,firstly,to measure the pressure,heart rate,skin temperature,and respiratory autonomic nervous system and mood change, rate.were recorded at the same time.The ANS secondly,to measure brain wave.Before ANS parameters were measured using life scope 8 bedside measurement beginning,the researcher clearly monitors (Nihon Kohden.Japan).The assessment of informed the procedure,then participants signed an mood state was based on the conceptual model Informed Consent Form describing the present study proposed by the Geneva Emotion and Odor Scale and their rights.In addition to ANS measurement, (GEOS)(17.This scale described their subjective the ANS electrodes were attached to the appropriate affective feelings by al00 mm visual analog scale positions;the ANS parameters,i.e.heart rate,skin based on the following five factors,pleasant feeling temperature,and respiratory rate,were recorded at (feel good),unpleasant feeling (feel bad,uncomfortable, one-minute intervals.Systolic and diastolic blood disgusted,frustrated,and/or stressed),sensuality pressure was recorded every five minutes.The tests (romantic),relaxation(relax,serene,and drowsy),and consisted of three trials:first session served as a refreshing(refresh,energetic). base line (resting period)and took ten minutes.After completion of the first session,subjects were asked to Electroencephalogram(EEG)recording rate their mood state scales.The second and third The set of 31 electrodes with 1 additional session took 20 minutes each.In the second.the sweet ground which was placed according to the international almond oil was inhaled to the subjects,then mood state 10-20 system at FP1,FP2.FZ,F3,F4,F7,F8,FT7,FC3, was measured after sweet almond oil inhalation.In the FCZ.FC4.FT8.T3.T4.T5.T6.TP7.TP8.C3.CP3. third trial.10%(v/v)lavender oil in sweet almond oil C4.CZ.CPZ.CP4.P3.P4.PZ.Ol.02 and OZ.Both was applied and mood state was measured after its mastoids would be used as the recording reference inhalation.Participants were required to measure their (average of both mastoids,Al +A2/2).The electro- brainwave again after the experiment no less than oculogram(EOG)was monitored with four electrodes seven days.The EEG experimental conditions were placed in both external acanthi(HEOL and HEOR). the same as autonomic nervous system experiment. left supraorbital (VEOU)and infraorbital (VEOL) The experimental procedure was divided into four regions.Electro-Caps are made of an elastic spandex- sessions of seven minutes each.Baseline EEG type fabric with recessed,silver/silverchloride recording was done with both eyes opened and eyes (Ag/AgCl)electrodes attached to the fabric.Electrode closed respectively.After that participants would be impedances were set below five kOhms(18).The inhaled undiluted sweet almond oil.Finally,10% recording system is Acquire Neuroscan version 4.3 Lavender in sweet almond oil was inhaled. (Neurosoft,INC).The online filter was set to a band pass with low pass is equal 70 Hz and high pass is Data and statistical analysis equal DC.A/D rate was 500 Hz.Gain was set at 19. The SPSS statistical package 17 was used Notch filter was open at 50 Hz.The relative power for data analysis on the effects of lavender oil on 600 J MedAssoc Thai Vol 95 No.4 2012600 J Med Assoc Thai Vol. 95 No. 4 2012 area. Two main components of lavender oil comprised linalyl acetate (32.46%) and linalool (31.91%). A one-milliliter mixture of either undiluted sweet almond oil or 10% (v/v) of lavender in base oil was delivered using an oxygen pump system through a plastic tube via respiratory masks in an inhalation set for adults that permitted selective routine air flow (2 L/min). Before the experiment, they were asked to inhale base oil and lavender oil to rate the pleasantness of the smell on a five-point Likert scale. The participants, who indicated oil pleasantness within the target level range of 2-4 were chosen to participate in the present study. Autonomic nervous system (ANS) and mood measure￾ment Mood state and ANS parameters, blood pressure, heart rate, skin temperature, and respiratory rate, were recorded at the same time. The ANS parameters were measured using life scope 8 bedside monitors (Nihon Kohden, Japan). The assessment of mood state was based on the conceptual model proposed by the Geneva Emotion and Odor Scale (GEOS)(17). This scale described their subjective affective feelings by a100 mm visual analog scale based on the following five factors, pleasant feeling (feel good), unpleasant feeling (feel bad, uncomfortable, disgusted, frustrated, and/or stressed), sensuality (romantic), relaxation (relax, serene, and drowsy), and refreshing (refresh, energetic). Electroencephalogram (EEG) recording The set of 31 electrodes with 1 additional ground which was placed according to the international 10-20 system at FP1, FP2,FZ, F3, F4, F7, F8, FT7, FC3, FCZ, FC4, FT8, T3, T4, T5, T6, TP7, TP8, C3, CP3, C4, CZ, CPZ, CP4, P3, P4, PZ, Ol, O2 and OZ. Both mastoids would be used as the recording reference (average of both mastoids, Al + A2/2). The electro￾oculogram (EOG) was monitored with four electrodes placed in both external acanthi (HEOL and HEOR), left supraorbital (VEOU) and infraorbital (VEOL) regions. Electro-Caps are made of an elastic spandex￾type fabric with recessed, silver/silverchloride (Ag/AgCl) electrodes attached to the fabric. Electrode impedances were set below five kOhms(18). The recording system is Acquire Neuroscan version 4.3 (Neurosoft, INC). The online filter was set to a band pass with low pass is equal 70 Hz and high pass is equal DC. A/D rate was 500 Hz. Gain was set at 19. Notch filter was open at 50 Hz. The relative power spectrum of the respective frequency bands derived by Fast Fourier Transformation (FFT) were expressed as follows: Delta (0-3.99 Hz), Theta (4-7.99 Hz), Alpha1 (8-9.99 Hz), Alpha2 (10-12.99 Hz) and Beta (13-30 Hz). Procedure An A-B design was used, so that each individual session consisted of two trails. This design was chosen because, with olfactory stimulation, the times court of stimulatory effects is unknown, which might make results obtained from other designs, such as A-B-A, difficult to interpret(19). All experiments were conducted in a quiet room with ambient temperature (24 + 1°C) and 40 to 50% humidity. The experiments were performed between 8.00 and 12.00 a.m. to minimize circadian variation. All participants attended to this research for two times, firstly, to measure the autonomic nervous system and mood change, secondly, to measure brain wave. Before ANS measurement beginning, the researcher clearly informed the procedure, then participants signed an Informed Consent Form describing the present study and their rights. In addition to ANS measurement, the ANS electrodes were attached to the appropriate positions; the ANS parameters, i.e. heart rate, skin temperature, and respiratory rate, were recorded at one-minute intervals. Systolic and diastolic blood pressure was recorded every five minutes. The tests consisted of three trials: first session served as a base line (resting period) and took ten minutes. After completion of the first session, subjects were asked to rate their mood state scales. The second and third session took 20 minutes each. In the second, the sweet almond oil was inhaled to the subjects, then mood state was measured after sweet almond oil inhalation. In the third trial, 10% (v/v) lavender oil in sweet almond oil was applied and mood state was measured after its inhalation. Participants were required to measure their brainwave again after the experiment no less than seven days. The EEG experimental conditions were the same as autonomic nervous system experiment. The experimental procedure was divided into four sessions of seven minutes each. Baseline EEG recording was done with both eyes opened and eyes closed respectively. After that participants would be inhaled undiluted sweet almond oil. Finally, 10% Lavender in sweet almond oil was inhaled. Data and statistical analysis The SPSS statistical package 17 was used for data analysis on the effects of lavender oil on