Relaxation refreshment apparatus

A relaxation refreshment apparatus includes a relaxation refreshment chair provided for giving to the user a vibratory stimulus variable in accordance with a detected relaxing degree of the user, an optical stimulus with exterior light shielded at the top part of the chair, a pneumatic stimulus operatively connected to an aromatizer nearby, for giving to the user an aromatic stimulus and an acoustic stimulus with a sound output unit, the apparatus being thus capable of intensively providing to the user various stimuli with an arrangement simplified and effectively realizing a compactness with dimensional minimization.

BACKGROUND OF THE INVENTION 
This invention relates to relaxation refreshment apparatuses and, more 
particularly, to an apparatus which provides to the user vibratory, 
optical, pneumatic and acoustic stimuli in a desired combination to have 
the user recover from a state of mental fatigue and for realizing mental 
relaxation and refreshment. 
The relaxation refreshment apparatus of the kind referred to finds its 
utility when used in, for example, highly technological business offices 
requiring consecutive VDT operation, highly intellectual operation and the 
like. The invention is useful for quick elimination of mental stress to 
avoid accumulation thereof. 
DESCRIPTION OF RELATED ART 
In recent years, growing automation of office facilities has increased VDT 
(video display terminal) operators attending to document preparation or 
composition by means of word processors, computer programming and the 
like. Mental stress caused by the VDT operation for long hours has become 
an important issue. Not only in the case of VDT operation, but also in the 
case of other causes such as generally increased commuting distance, 
mental stresses due to anxiety, displeasure, anger, irritation and so on, 
the issue of the mental stress has been growing. When mental stress 
increases, there arises a deterioration in contemplative faculty or 
attentiveness so that the reaction of an operator will slow so as to 
render a deterioration of operation efficiency and an increasing frequency 
of operational mistake or trouble. In eliminating such stress occurring in 
the operation as in the above, it is encouraged to rest for about ten 
minutes after every one or two hour of operation, but it has been 
ascertained that the feeling of fatigue cannot be sufficiently removed by 
rest alone. 
In Japanese Patent Laid-Open Publications Nos. 61-220653 and 62-38162 of 
Hiroshi Hagiwara et al, there have been disclosed stress dissolving 
apparatuses in which a chair or bed having portions engageable with the 
user's back and waist is provided with a plurality of vibrators disposed 
as mutually separated in height and crosswise directions of the user so 
that the mental stress can be dissolved by means of an optimum vibration 
given to the user's body. In another Japanese Patent Laid-Open Publication 
No. 62-87168 of I. Mihara et al, there has been suggested a brain wave 
induction system which detects fundamental wave of .alpha.-wave in human 
brain waves and generates an output signal of a frequency slightly lower 
or higher than the detected fundamental wave. The user's sense of sight is 
stimulated by the output signal in an attempt to reduce the user's mental 
stress or to provide mental relaxation. 
According to these known devices, a result satisfiable to some extent is 
achievable in respect of stress reduction. In taking a rest during a 
certain operation and thereafter returning to continue the same operation, 
however, it is desirable that, after the relaxation achieved by the 
reduction of stress, the level of the user's consciousness be elevated 
gradually so as to attain effectively a mental refreshment. In this 
respect, the known devices still fail to suggest a measure for gradually 
elevating the level of consciousness after the relaxation achieved. In the 
prior art the consciousness level is suddenly enhanced after the use of 
the device or a rather long time is required for reaching an adequate 
consciousness level for resuming normal operation. 
In U.S. Pat. No. 5,024,650 to H. Hagiwara et al, on the other hand, there 
is disclosed a stress dissolving refreshment system, in which, after an 
actuation of a relaxed-state induction means for a relaxing period, a 
refresh stimulus means is actuated to generate a weak stimulus during a 
disillusion period for gradually elevating the user's consciousness level. 
A refresh stimulus means is then actuated to generate a strong stimulus 
during a refreshing period for elevating the user's consciousness level to 
a level adequate for returning to the normal operation. That system uses 
properly selective stimuli of various known types in which such optimum 
vibration of a so-called l/f fluctuation for the relaxation of the, user, 
an illumination of 10,000 1.times. for the purpose of elevating the 
consciousness level and an air-stream stimulus. 
With such known refreshment system, however, required stimulus generating 
arrangement for complex use of the various stimuli causes a rise in 
complicacy and dimensional enlargement. That is, the generation of 
illumination of 10,000 1.times. requires so many lighting devices, and the 
air-stream stimulus in combination with other stimuli requires a 
complicated air supply system. 
SUMMARY OF THE INVENTION 
A primary object of the present invention is, therefore, to provide an 
intense relaxation refreshment apparatus provided with respective means 
for providing various stimuli, while effectively simplifying the 
arrangement, and capable of allowing the entire apparatus to be compact 
for promotion of practical use. 
According to the present invention, the object is made attainable by means 
of a relaxation refreshment apparatus in which a relaxed degree of the 
user is detected by a detecting means, a vibratory stimulus is given to 
the user by a vibrating means of a relaxation refreshment chair in 
accordance with the relaxed degree detected, an optical stimulus is given 
to the head of the user sitting in the chair by an optical stimulus means 
including lighting equipment and means for scattering incident light from 
the lighting equipment towards the head of the user while providing a 
pneumatic stimulus by a pneumatic stimulus means over an area from the 
head part to neck part, an aromatic stimulus is given to the user with an 
aroma carried by a blow of air of the pneumatic stimulus, and an acoustic 
stimulus is provided to the user's auditory sense from an acoustic 
stimulus means, characterized in that an exterior-light interceptive means 
or exterior-light shield carrying the optical stimulus means is mounted to 
a top part of the chair, the pneumatic stimulus means comprises a blower 
having a blow-off port and disposed adjacent to the top part of the chair, 
an aromatizer providing the aromatic stimulus is operatively associated 
with the optical stimulus means and preferably is disposed in linkage to 
the blower, the acoustic stimulus means comprises a sound output unit 
which is disposed adjacent to the top part of the chair, and the 
vibratory, optical, pneumatic, aromatic and acoustic stimuli are provided 
through a control means in a predetermined time schedule. 
All other objects and advantages of the present invention shall become 
clear from the following description of the invention and with reference 
to preferred embodiments shown in accompanying drawings.

While the present invention shall now be described with reference to the 
respective embodiments shown in the .drawings, it will be readily 
appreciated that the intention is not to limit the present invention only 
to these embodiments shown but rather to include all alterations, 
modifications and equivalent arrangements possible within the scope of 
appended claims. 
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
Referring to FIG. 1 showing a first embodiment of the relaxation 
refreshment apparatus according to the present invention, the apparatus 10 
comprises a relaxation refreshment chair 11 which is provided at lower 
portion of the back 12 and extended end portion of the seat 13 with 
vibration sources 14 and 15 as vibratory stimulus means, for giving to the 
user's waist and legs an optimum vibratory stimulus as required. With 
respect to the seat 13 of the chair 11, a sensor 16 as means for detecting 
relaxed degree or degree of relaxation of the user as well as an operator 
17 for starting the apparatus 10 and placing it in actuating state are 
provided. 
The seat 13 is preferably provided for accommodating therein a blower 18 
and a controller 19, so that the blower 18 will communicate through a 
conduit 21 with a blow-off port 20 provided at top part of the back 12 for 
providing a blow of air to an area from the head part to neck part of the 
user sitting and leaning on the chair 11, and thus the blower 18 will act 
as a pneumatic stimulus means optimumly providing a pneumatic stimulus to 
the user. An aromatizer 22 acting as an aromatic stimulus means is mounted 
to a part of the conduit 21, so that an aroma will be carried by the air 
blow passing through the conduit 21 and blown off from the port 20 for 
giving to the user an aromatic stimulus together with the foregoing 
pneumatic stimulus. At the top part of the back 12, such sound output unit 
23 as a loudspeaker is provided as an acoustic stimulus means adjacent to 
the blow-off port 20. Further to the top part of the back 13, a hood 24 is 
mounted as an exterior light intercepting means in a manner movable 
between a using position and a non-using position, and lighting equipment 
25 and a reflector plate 26 for scattering incident light from the 
equipment 25 are disposed inside the hood 24 as an optical stimulus means, 
substantially as opposed to each other. 
To the controller 19, an output of the sensor 16 or an operating input from 
the operator 17 is provided, so that the vibration sources 14 and 15, 
blower 18, aromatizer 22, sound output unit 23 and lighting equipment 25 
will be properly actuated, so as to provide to the user sitting in the 
chair 11 relaxing and refreshing treatments. Preferably, the vibratory 
stimulus is varied in a range of 20 to 40 Hz in initial state and in a 
pattern of l/f fluctuation and, as the relaxed degree is elevated, the 
varying range is made narrower to be closer to 30 Hz. From the sound 
output unit 23 such as a loudspeaker, a music or such masking sound as 
white noise is reproduced. With the sensor 16, on the other hand, the 
relaxed degree is measured at regular intervals, for example, at intervals 
of 3 seconds, the results of the measurement being provided as inputs to 
the controller 19, the user is then induced to a relaxed state by the 
vibratory stimulus given for several minutes, this relaxed state is 
maintained for about seven minutes, thereafter the illuminance of the 
lighting equipment 25 is elevated and, then, the equipment 25 is made to 
flash repeatedly for 10 seconds so as to naturally elevate disillusion or 
awakening level of the user. Thereafter, the illuminance of the lighting 
equipment 25 should preferably be raised abruptly to be at about 10,000 
1.times. while, at the same time, a cool pneumatic stimulus is provided 
from the blow-off port 20 for about three minutes with respect to an area 
from the head part to the neck part of the user, with simultaneous 
provision of the aromatic stimulus from the aromatizer 22 and the acoustic 
stimulus from the sound output unit 23, and the awakening level of the 
user is raised to be good enough for promptly returning to the operation, 
whereby the mental stress of the user is dissolved preferably within about 
ten minutes in total. 
In the present instance, the relaxation refreshment chair 11 capable of 
providing the vibratory stimulus is equipped further with the blow-off 
port 20 of the blower 18 for giving the pneumatic stimulus, aromatizer 22 
giving the aromatic stimulus, sound output unit 23 giving the acoustic 
stimulus and lighting equipment 25 giving the optical stimulus as 
intensively arranged inside the movable hood 24, so that the entire 
structure can be simplified to effectively realize the compactness and 
dimensional minimization. 
Referring next to FIGS. 2 to 4, there is shown schematically a second and 
more practical embodiment of the relaxation refreshment apparatus 
according to the present invention, in which substantially the same 
constituent elements as those in the first embodiment of FIG. 1 are 
denoted by the same reference numerals as those in FIG. 1 but as added by 
30. In this case, the relaxation refreshment chair 41 is provided to be in 
a reclining type with the back 42 made rotatable when operated by the 
user, while the chair 41 and hood 54 movably mounted to the chair are 
provided in the intensive manner similar to the foregoing embodiment with 
the vibration sources 44 and 45, the blower's blow-off port 50 for the 
pneumatic stimulus, aromatizer 52 for the aromatic stimulus, sound output 
unit 53 for the acoustic stimulus and lighting equipment 55 for the 
optical stimulus. While in the present instance the blow-off port 50 and 
aromatizer 52 are mounted on the side of the hood 54 and the sound output 
unit 53 is installed in the back 42 of the chair 41, they may be properly 
modified in the disposition in accordance with the shape and so on of the 
chair 41 and hood 54. 
Further, the hood 54 is provided to be rotatable between both states shown 
in FIGS. 2 and 3, that is, between the using state of FIG. 2 and non-using 
state of FIG. 3, and a pair of the blow-off ports 50 and 50' are provided 
inside the hood 54 to oppose each other for applying an air flow to the 
area from the head part to the neck part of the user. As this time, it is 
preferable to provide the blower and blow-off ports 50 and 50' integrally 
and for rendering blowing direction to be variable. More specifically, as 
shown in FIGS. 5 and 6, a main body 50a of the blower is mounted into a 
square-shaped mounting frame 50b with upward and downward projections of 
the main body 50a engaged in corresponding holes made in upper and lower 
sides of the frame 50b, so that the main body 50a will be pivotable about 
vertical axis of both projections with respect to the mounting frame 50b, 
whereas the mounting frame 50b itself is mounted between a pair of 
mounting plates 50c and 50d which are fixed as mutually opposed to proper 
portion of the hood 54, with sideward projections of these plates engaged 
in corresponding holes made in both lateral sides of the frame 50b, so 
that the main body 50a and mounting frame 50b will be pivotable about 
horizontal axis of both sideward projections with respect to the mounting 
plates 50c and 50d. Consequently, the main body 50a of the blower is held 
freely rotatable vertically and horizontally so as to be variable in the 
direction of air blown out of the blow-off ports 50 and 50'. 
Further, as shown in FIG. 7, at least one of the blow-off ports is provided 
at its inner frame 50e held inside the mounting frame 50b with an aroma 
ejection port 57a fixed through the inner frame 50e, while the ejection 
port 57a itself is coupled to a conduit 57 passing a compressed air flow 
carrying an aroma sent from the aromatizer 52, whereby the pneumatic 
stimulus and aromatic stimulus are simultaneously provided from the 
blow-off ports 50 and 50' to the user. As shown in FIG. 8, on the other 
hand, a further simplified arrangement may be attained such that a 
blow-off port 50Aa is assembled with an integral blower body 50Ab 
incorporating therein a blower fan 50Ac so as to form a pneumatic stimulus 
means 50A. 
For generating the aromatic stimulus, it is preferable to employ such 
arrangement as shown in FIG. 9. That is, as the user first operates the 
operator 47 to actuate the controller 49 (FIG. 3) and after a 
predetermined time lapsed, a control signal generator 61 of the controller 
49 sends an actuating signal to a miniature pump 62 for generating a 
pressurized air, an actuation of which pump a pressurized air is applied 
to a cartridge 63 of a fragrance effective for soothing the user's mental 
condition as well as to another cartridge 64 of a fragrance effective for 
activating the user's mental condition. Both cartridges 63 and 64 are 
commonly coupled to a pressurized air path switching means 65, so that two 
flows of the pressurized air which are passed through the fragrance 
cartridges 63 and 64 to carry respectively the mental condition soothing 
fragrance and the mental condition activating fragrance are made to reach 
the path switching means 65. Switching signals are provided to the 
switching means 65 in accordance with a predetermined relaxation 
refreshment program so that, in the relaxing period, the switching means 
65 opens the air flow path of the mental condition soothing fragrance and, 
in the refreshing period, the means 65 opens the other path of the mental 
condition activating fragrance. Thus, the pressurized air passed through 
the air path switching means 65 carries either one of the two different 
fragrances through fragrance ejecting nozzle 57 to the blower 50. 
Referring to FIG. 10, there is shown a time chart in an aspect of the 
program incorporated in the controller 49. In the drawing, a symbol RL 
denotes the relaxing period, a symbol RL/RF denotes a transitional period 
from the relaxing period to the refreshing period, and a symbol RF denotes 
the refreshing period. In respective waveforms a through k of the drawing, 
a is a starting signal for driving the controller 49 with the operator 47 
actuated by the user. b denotes operating state of the relaxation 
refreshment chair 41, showing that, in response to the starting signal, 
the hood 54 is rotated to the using position, the back 42 is gradually 
inclined to shift to its horizontal position, which position being 
maintained for the relaxing period RL and transitional period RL/RF, then, 
as the refreshing period is reached, the back 42 is gradually raised and, 
as the refreshing period terminates, a state prior to the starting signal 
is restored. c denotes ON/OFF state of a fluorescent lamp forming part of 
the lighting equipment 55, showing that the lamp is not lighted ON for the 
relaxing period RL and transitional period RL/RF, but is lighted ON in the 
refreshing period RF to emit light of 10,000 1.times. d denotes ON/OFF 
state of a incandescent lamp employed preferably for an indirect 
illumination of the lighting equipment 55, showing that, prior to the 
generation of starting signal, the incandescent lamp is kept at lighted ON 
state of an illuminance of about 500 1.times., a reception of the 
starting signal causes the illuminance inside the hood 54 to be gradually 
decreased to fully lighted OFF state, and this state is maintained for the 
relaxing period. As the transition period RL/RF is reached, the 
illuminance of the incandescent lamp is gradually raised to a fully 
lighted ON state but is repeatedly lighted OFF and ON in the transitional 
period, thereafter the fully lighted ON state is maintained during the 
refreshing period RF and, upon termination of this period, the initial 
state prior to the starting signal is restored. 
Further in FIG. 10, e is of a state of images given by a TV set employed as 
desired, showing that, when the hood 54 is out of the using position, the 
TV set is in ON state to provide the image but, when the hood 54 is 
pivoted to the using position, the TV set is turned OFF to put out the 
image, and, as the refreshing period is reached, the TV set is turned ON 
again to provide the image. f represents acoustic state of sound 
reproduced by such sound output unit 53 as a loudspeaker, showing that the 
sound is radiated without interruption from the relaxing period RL to the 
refreshing period RF. g denotes a state in which the pump 62 generating 
the pressurized air blow for carrying the fragrance of the aromatic 
stimulus, showing that the pump 62 is actuated once at initial stage of 
the relaxing period RL to have the fragrance for soothing the mental 
condition provided shortly, and is kept actuated during the refreshing 
period RF for providing the fragrance for activating the mental condition 
of the user. In h and i, the operation of the blower 50 or 50A for the 
pneumatic stimulus is shown, in which the blower is driven once at initial 
stage of the relaxing period RL for providing shortly the pneumatic 
stimulus together with the aromatic stimulus of the mental soothing 
fragrance, and is kept driven in the refreshing period RF for providing 
continuously the pneumatic stimulus together with the aromatic stimulus of 
the mental activating fragrance, while the opposed blow-off ports 50 and 
50' are preferably provided for being driven mutually independently with 
differently varied intensity. 
Further, j denotes the operating state of the hood 54, showing that, in 
response to the starting signal for the apparatus 40, the hood 54 is 
rotated to the using position so that, throughout the respective periods 
RL, RL/RF and RF the hood can function to restrain any external influence 
on the user's consciousness while particularly in the refreshing period RF 
the optical stimulus is effectively given. In the non-using state of the 
apparatus 40, the hood 54 is rotated to the non-using state at the last 
stage of the refreshing period, for the sake of a next user. k denotes the 
operation of the pressurized air path switching means 65, showing that the 
means is actuated at both of the relaxing and refreshing periods RL and RF 
for providing the aromatic stimulus with the different fragrances. 
In FIGS. 11 to 13, there are shown more practical models capable of being 
put in commerce, in which the same constituent members as those in the 
embodiment of FIG. 1 are denoted by the same reference numerals as those 
used in FIG. 1 but with an addition of 60. 
Referring to a use aspect of the relaxation refreshment apparatus of the 
present invention in the practical models, including those which have been 
already described with reference to the second embodiment of FIG. 2, the 
illuminance inside the hood by means of a part of the lighting equipment 
55 for the optical stimulus in the initial stage is set to be about 500 
1.times., the user mounts the sensor 46 acting as the relaxed degree 
detecting means to own finger tips and, after sitting in the reclining 
relaxation refreshment chair 41, the operator 47 is operated by the user. 
At this time, an initial value of intensity of the vibratory stimulus is 
set through the operator 47, the controller 49 is actuated with a start 
button of the operator 47 depressed, the illuminance by means of the 
lighting equipment 55 is first gradually reduced and the fully lighted OFF 
state is attained. The reclining back 42 of the chair 41 is rotated by 
about 180 degrees, that is, substantially to its horizontal position, and 
the vibratory stimulus is given to the user's body parts including 
substantially the waist and legs by means of the vibration sources 44 and 
45. In the initial stage, the vibratory frequency is varied in the range 
of 20 to 40 Hx and in the pattern of l/f fluctuation, similar to the 
embodiment of FIG. 1, and this frequency varying range is made narrower as 
the relaxed degree of the user increases with the time lapsed. The 
vibratory amplitude, that is, the intensity of the vibratory stimulus is 
simultaneously weakened. 
The relaxed degree of the user is measured by the sensor 46 at regular time 
intervals of, for example, 3 seconds, and the detection is made on the 
basis of, for example, the skin electric resistance. At the same time, a 
music sound or such masking sound as the white noise and the like is 
produced by the sound output unit 53 as the acoustic stimulus, in order to 
intercept any external noise. 
In this case, the respective stimulus means are controlled by the 
controller 49 so as to induce the user into a relaxed state within several 
minutes, and this state is maintained, for example, for about seven 
minutes. During this relaxing period RL, the user may happen to be put 
into a slight hypnotic state. As this seven minutes relaxing period RL 
lapses, the illuminance of the part of the lighting equipment 55 is 
gradually increased so that the initial illuminance of about 500 1.times. 
will be restored after, for example, one minute, the lighting is flashed 
for ten seconds and the awakening level of the user is gradually elevated. 
Thereafter, the back 42 of the chair 41 is raised by about 90 degrees, and 
the illuminance of the lighting equipment 55 is abruptly raised to be 
about 10,000 1.times.. Further, the pneumatic stimulus, by means of cool 
air blown on the head and neck parts of the user for about three minutes 
through the blow-off ports 50 and 50', together with the aromatic 
stimulus, by means of the mental activating fragrance carried by the air 
blown and a user is brought into the refreshed state sufficient to return 
immediately to the operation. It will be appreciated that the mental 
stress of the user can be thus eliminated within about ten minutes in 
total, and the user is put into the state good for prompt returning to the 
operation. 
Referring to FIGS. 14 and 15, there is shown a third embodiment of the 
relaxation refreshment apparatus according to the present invention, in 
which substantially the same or similar constituent elements as or to 
those in the embodiment of FIG. 1 are denoted by the same reference 
numerals as those used in FIG. 1 but with an addition by 90. In the 
present instance, instead of the hood used in the foregoing embodiments, 
there is provided a capsule 100a which encloses therein the whole of the 
reclining relaxation refreshment chair 101, so that the user sitting in 
this chair can be substantially completely isolated from the exterior. In 
the present embodiment, the blow-off ports 110 and 110a, conduits 111 and 
111a, aromatizers 112 and 112a and sound output units 113 and 113a are 
disposed in inside walls of the capsule so as to oppose each other on both 
sides of the chair 101, and the lighting equipment 115 is provided on the 
inside wall at the top part of the capsule 100a. Other arrangements in 
this embodiment are the same as those in the foregoing embodiments FIG. 1 
and of FIGS. 2 to 4, so that the same functions and effect can be also 
attained by the present embodiment. 
According to another feature of the present invention, the apparatus 
control by the controller is executed on the basis of the 
electrocardiogram or respiration of the user, instead of the detection of 
the skin electric resistance. Referring here to FIGS. 16 and 17, the 
detecting means 130 measures with an electrocardiograph the R--R intervals 
of the electrocardiogram, detection outputs of the detecting means 130 are 
provided to a control means 131 for discrimination therein of the relaxed 
degree and awakening degree of the user. In the present instance, the 
control means 131 comprises means for storing the R--R intervals of the 
electrocardiogram in time series, a fast Fourier transformation (FFT) 
means for frequency-analyzing fluctuation spectrum of the R--R intervals 
of the electrocardiogram, means for numerically presenting activities of 
the sympathetic nerves and parasympathetic nerves by measuring the power 
around 0.1 Hz and the power around 0.3 Hz from results of the 
frequency-analysis, and means for numerically presenting the degree of 
physical awakening or mental state on the basis of equilibrium 
relationship in the activities of the sympathetic and parasympathetic 
nerves. By this control means, a means of inducing a relaxed state 132 
providing mainly the vibratory stimulus or a refreshing stimulus means 133 
providing mainly optical, pneumatic and aromatic stimuli for the 
refreshing by elevating the activity of the parasympathetic nerves higher 
than that of the sympathetic nerves, is driven. In practice, in the 
present instance, a relaxation refreshment room 140a is provided for the 
relaxation refreshment apparatus 140 for isolating the interior thereof 
from the exterior, the relaxation refreshment chair 141 is disposed in 
this room 140a, the vibration sources 144 and 145 are disposed 
respectively at a lower portion of the back 142 and adjacent to the lower 
end of the seat 143, and the lighting equipment 155 is disposed on an 
interior surface of the ceiling wall of the room 140. While not shown in 
FIG. 17, the respective stimulus means are also provided to the relaxation 
refreshment chair 141 as has been disclosed with reference to FIG. 1 and 
FIGS. 2 to 4, and substantially the same arrangements as those in the 
foregoing embodiments, except for the above aspect of the detecting means 
and related arrangement, attain the same functions and effect. 
In FIG. 18, there is shown a time series of the R--R intervals in the 
electrocardiogram by the detecting means, while in FIG. 19 there is shown 
a power spectrum as a result of the frequency analysis of the R--R 
intervals, in which a respiratory sinus arrhythmia (RSA) around 0.3 Hz 
reflects the activity of the parasympathetic nerves while a Myer wave 
(blood pressure) arrhythmia (MWSA) around 0.1 Hz reflects the activities 
of both of the sympathetic nerves and parasympathetic nerves. Accordingly, 
it is possible to assume the activities of the sympathetic nerves by 
dividing MWSA with RSA, or to discriminate the awakening degree by 
operating the difference in the activity between the sympathetic nerves 
and the parasympathetic nerves. 
Further, in FIG. 20, there is shown a conceptual explanatory diagram for 
RSA and MWSA. As will be clear from this diagram, a heart beat pacemaker 
determining the heart beat cycle is receiving double control of mutually 
reverse sympathetic nerves (cardiac sympathetic nerves) and 
parasympathetic nerves (cardiac vagus nerves), and the control is achieved 
in their equilibrium state. At this time, the sympathetic nerves are 
effective to attain a promotional action, while the parasympathetic nerves 
attain a checking or stopping action, with respect to the heart. With 
respect to bronchial muscles, on the other hand, the sympathetic nerves 
attain an atony action while the parasympathetic nerves achieve a 
contractile action. With respect to blood paths, the sympathetic nerves 
attain the contractile action to raise the blood pressure, while the 
parasympathetic nerves achieve an expansion action to lower the blood 
pressure. Accordingly, it will be appreciated that any fluctuation in the 
heart beat number has a fixed relation to RSA or MWSA, tension degree of 
the sympathetic and parasympathetic nerves can be discriminated by 
analyzing the power spectrum of the fluctuation in the R--R intervals of 
the heartbeat, and the user's awakening degree can be discriminated by 
determining the activities of the sympathetic and parasympathetic nerves 
as has been partly described.