United States Patent |
5,076,281
|
Gavish
|
December 31, 1991
|
Device and method for effecting rhythmic body activity
Abstract
A biorhythm modulator, consisting of a sensor for monitoring biorhythmic
activity of the body of a user, a circuit for continuously analyzing the
biorhythmic activity and producing parameter signals based upon a
biorhythmic activity, a circuit for generating selectable sound-code
pattern signals, a central processing unit (CPU) connected to receive
signals from both the activity characteristic parameters producing circuit
and the selected sound patterns generating circuit, and to feed the
signals of the parameters and patterns to a sound pattern synthesizer for
producing music-like sound pattern signals, transduceable into audible
music-like patterns, and having a rhythm which is non-identical to the
rhythm of the biorhythmic activity. A method for modulating biorhythmic
activity is also described.
Inventors:
|
Gavish; Benjamin (65 Yasmin Street, P.O. Box 1141, Mevasseret Zion, IL)
|
Appl. No.:
|
686300 |
Filed:
|
April 16, 1991 |
Foreign Application Priority Data
Current U.S. Class: |
600/534; 128/905; 600/28; 600/545 |
Intern'l Class: |
A61B 005/00 |
Field of Search: |
128/716,721,731-732,905
600/26-28
|
References Cited [Referenced By]
U.S. Patent Documents
Primary Examiner: Smith; Ruth S.
Attorney, Agent or Firm: Nixon & Vanderhye
Parent Case Text
This is a continuation of application Ser. No. 07/358,146, filed May 30,
1989, now abandoned.
Claims
What is claimed is:
1. A biorhythm modulator, comprising:
a sensor for monitoring biorhythmic activity of the body of a user;
circuit means for continuously analyzing said biorhythmic activity and for
producing parameter signals based upon said biorhythmic activity;
means for generating selectable sound-code pattern signals;
a central processing unit (CPU) means, responsive to signals from both said
circuit means and said generating means, for supplying said parameter
signals and pattern signals to a sound pattern synthesizer for producing
music-like sound pattern signals, having a selectable rhythm, which
signals are transduceable into audible music-like patterns and have a
rhythm which is non-identical to the rhythm of the biorhythmic activity.
2. The biorhythm modulator as claimed in claim 1, wherein said sensor is a
piezoelectric transducer attached to a flexible belt.
3. The biorhythm modulator as claimed in claim 1, wherein said circuit
means include:
an amplifier for amplifying the output signals of said sensor;
an analog-to-digital converter connected at the output of said amplifier;
and
a biosignal pattern analyzer for analyzing biorhythmic activity of the user
and for producing signals representative of the biorhythmic activity.
4. The biorhythm modulator as claimed in claim 3, wherein said signals
representative of the biorhythmic activity are selected from the group
consisting of the following measurable and calculable parameters: starting
time of individual body activity periods; body activity period; times
characterizing body activity changes within an activity period; body
activity amplitude; change of body activity period and activity amplitude;
the mean period of activity; the mean amplitude of activity; the mean rate
of activity; the times characterizing activity changes within an activity
period; standard deviation of period and amplitude changes; stability of
period, rate and amplitude of activity; logic variables defining
interruptions in biosignal in terms of predetermined changes in period and
amplitude.
5. The biorhythm modulator as claimed in claim 1, wherein said means for
generating selectable sound-code pattern signals include a pattern code
storage means and a pattern sequencer.
6. The biorhythm modulator as claimed in claim 5, wherein said biorhythmic
activity includes respiration rate, further including a respiration drive
wherein said sound pattern synthesizer is connected with said pattern
sequencer to receive signals representative of the code number of a
specific sound-code pattern as set by said respiration drive controlling
the rhythm of the selected sound-code pattern relative to said monitored
respiration rate and as set by a state selector determining the nature of
the selected sound-code from a defined state of lowest to highest
biorhythmic activity.
7. The biorhythm modulator as claimed in claim 1 wherein said CPU means is
connected with said circuit means for analyzing signals selected from the
group consisting of signals representative of: the starting time of
individual activity periods; the mean of activity period, rate, amplitude
and times of characterizing activity changes within an activity period,
and the stability of period, rate and amplitude.
8. The biorhythm modulator as claimed in claim 1, further comprising
control means for controlling the operation time of the modulator.
9. The biorhythm modulator as claimed in claim 1, further comprising a
display exhibiting sensed activity rate and its stability.
10. A method for modulating biorhythmic activity, comprising:
sensing the biorhythmic activity of a user and transducing same into
electrical signals;
continuously analyzing said signals representative of the biorhythmic
activity for producing parameter signals based upon said biorhythmic
activity;
generating selectable sound-code pattern signals;
feeding said parameter signals and said sound-code pattern signals to a
sound-code pattern synthesizer for producing music-like pattern signals
having a rhythm which is non-identical to the rhythm of the biorhythmic
activity, and
transducing the music-like pattern signals into audible music-like sound to
be heard by the user, thereby forming a closed-loop biorhythmic modulator.
11. The method as claimed in claim 10, further comprising the steps of
selecting said music-like sound-code pattern signals from a group of
pattern signals representing natures of biorhythmic states ranging from a
state of lowest biorhythmic activity to a state of highest biorhythmic
activity, relative to the sensed biorhythmic activity.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a device and method for modulating
naturally occurring rhythmic body activity and more particularly to a
closed-loop device and a method of utilizing musical pattern for inducing
rhythms.
2. Discussion of Prior Art
Man and the higher animals respond, both psychologically and
physiologically, to stimuli in the environment. Through its activating
effect upon subcortical neuronal systems of the brain, sound modifies the
brain's pacing of cardiovascular, endocrine, metabolic, reproductive and
neurological functions.
The interaction between sound and motor activity of the body has been an
acknowledged fact since the early days of human civilization. It was seen
especially in the relation between dancing and music. However, the
isolation of musical elements that most affect psychophysiological
responses is not an easy task. It has been the subject of intensive
research.
Regularly recurring sound is known to affect respiration rate and serves as
a positive reinforcement of rhythmic movements, provided that respiration
and movements are synchronized with the sound. An example of this is the
effect of fast rhythmic drumming on the central nervous system; it affects
brain wave frequencies, and leads to a state of trance.
Yet music is much more than rhythmic or non-rhythmic patterns of sound.
That is why there has been much controversy about the quality and
magnitude of the physical effects of music on motor responses. For
example, in a variety of cultures it was believed that there exists a
specific correspondence between heart rate and musical rhythm. However,
scientific studies failed to confirm this hypothesis.
It has now been found that rhythmic cardiovascular activity of the body,
including the pulse rate, the respiration rate and the periodic change in
the diameter of small blood vessels associated with the activity of the
symphathetic nervous system (the so-called "vasomotion"), as well as the
brain waves respond most strongly to external stimuli with almost
identical rhythm. A certain type of "resonance" phenomenon occurs when
controlled musical patterns are induced in a body, causing shifts or
changes in the natural body activity to a higher or lower activity or
causing stabilization of the activity.
The rhythmic activities of a body are known to occur in frequency bands,
which are usually non-overlapping. The electrical signal representing
these activities presents instantaneous or average values. Examples of the
frequency bands are as follows: Vasomotion frequency is smaller or equal
to 0.1 Hz; respiration 0.15-0.4 Hz; heart beating 0.8-2 Hz; alpha, beta
and theta brain wave frequencies are higher or comparable to 4 Hz. Some
rhythms modulate others, e.g., respiration and vasomotion are expressed in
the ECG signal by frequency modulation.
SUMMARY OF THE INVENTION
In accordance with the present invention there is therefore provided a
biorhythm modulator, comprising a sensor for monitoring rhythmic activity
of the body of a user, circuit means for continuously analyzing said
rhythmic activity and producing activity characteristic parameter signals,
means for generating selectable sound pattern signals, a central
processing unit (CPU) connected to receive signals from both, said
activity characteristic parameters producing circuit means and said
selected sound pattern generating means and to feed the signals of said
parameters and patterns to a sound pattern synthesizer for producing
music-like sound pattern signals, transduceable into audible music-like
patterns, and bearing selected relationship to said characteristic
parameters of the rhythmic activity.
The invention further provides a method for modulating biorhythmic
activity, comprising sensing the rhythmic activity of a user and
transducing same into electrical signals, continuously analyzing said
signals representative of the biorhythmic activity for producing activity
characteristic parameter signals, generating selectable sound pattern
signals, feeding said activity characteristic parameter signals and said
sound pattern signals to a sound pattern synthesizer for producing
music-like sound pattern signals of selected relationship to said
characteristic parameter signals of the monitored biorhythmic activity,
and transducing the synthesized signals into audible music-like sound to
be heard by the user, thereby forming a closed-loop biorhythmic modulator.
The term "musical pattern" as used herein is meant to include not only
acoustical patterns or effects, but also effects or patterns produced by
optical signals similarly sensed by the body. Moreover, in conjunction
with the present invention, this term may also refer to a combined effect
of sound and visual patterns or effects perceivable by man or animals.
The invention will now be described in connection with certain preferred
embodiments directed to a respiration modulator with reference to the
following illustrative figures so that it may be more fully understood.
BRIEF DESCRIPTION OF THE DRAWINGS
With specific reference now to the figures in detail, it is stressed that
the particulars shown are by way of example and for purposes of
illustrative discussion of the preferred embodiments of the present
invention only and are presented in the cause of providing what is
believed to be the most useful and readily understood description of the
principles and conceptual aspects of the invention. In this regard, no
attempt is made to show structural details of the invention in more detail
than is necessary for a fundamental understanding of the invention, the
description taken with the drawings making apparent to those skilled in
the art how the several forms of the invention may be embodied in
practice.
In the drawings:
FIG. 1A is a perspective view of the respiration modulator attached to a
user, according to the present invention;
FIG. 1B is an enlarged view of the front panel of the respiration modulator
of FIG. 1A illustrating selectable modulator's function adjustments;
FIG. 2 is a block diagram of the biorhythm modulator of the present
invention;
FIG. 3A is a graphic representation of a biosignal, proportional to
variations in the chest circumference, and some of the parameters
evaluated thereby, and
FIG. 3B is a graphic representation of an example of a synthesized sound
pattern corresponding to the biosignal shown in FIG. 3A.
DETAILED DISCUSSION OF PREFERRED EMBODIMENTS
In the context of the particular example of a respiration modulator, there
is seen in FIGS. 1A, 1B and 2 a respiration modulator 2 comprising a
sensor 4, or a combination of sensors, provided that the respiration
activity can be elucidated from its output. Preferably, the sensor 4 may
consist of a piezoelectric transducer attached to a flexible belt affixed
around a user's chest. Further seen are earphones 6 which may be replaced
by a loudspeaker, the sound intensity of which is adjustable by a gain
control 8. Signals from the sensor 4 are fed to a filter and amplifier 10,
converted into digital signals by the A/D coverter 12, and then passed to
a biosignal pattern analyzer 14 which recognizes and calculates certain
parameters of the biosignal pattern and applies the parameters to the
Central Processing Unit (CPU) 16. As further seen in the figures, the
modulator 2 comprises pattern code storage 18 which consists of a memory
containing patterns of codes which can be translated into "music" by
first, transforming the patterns of code into sequences of codes signals
by the pattern sequencer 20. These patterns of codes are eventually fed at
a certain rhythm, phase and specificity controlled by the CPU 16, to a
sound pattern synthesizer 22. The pattern sequencer 20 feeds in turn the
CPU 16 with signals from which the selected sound will be generated. The
synthesizer 22 converts, in real time the sound pattern codes into a "real
music" which becomes audible to the user by the earphones 6 as adjusted by
the gain control 8.
The operation of the CPU 16 is controlled by the user or by an operator, by
means of the following controls: state selector 24, which determines the
nature of the sound synthesized; respiration drive 26 which increases or
decreases the rhythm of the sound synthesized patterns relative to the
monitored respiration rate which can be visually displayed on the
modulator, together with a respiration rate stability indication at 28;
sound pattern selector 30 which selects the desired sound pattern, and the
time selector 32, which sets the overall time of the system's operation
and shuts it off after the termination of the set duration. In addition,
as illustrated in FIG. 1B, the modulator 2 may include an error indicator
34 which emits a warning signal when the sensor 4 has not been placed
properly for obtaining meaningful signals. Other parameters, such as pulse
rate, if monitored, can also be displayed just as well, if desired.
The operation of the system will now be explained with reference also to
FIGS. 3A and 3B.
The user (or operator) affixes the sensor around the chest, selects by the
state selector 24 the nature of sound to be synthesized from the options
of the states of: "Deeply relaxed", "Relaxed", "Alert", "Excited" or
"Highly Excited", which are associated with the degree of biorhythmic
activity. If it is desired to increase or decrease the rhythm of the sound
synthesized patterns relative to the monitored respiration rate, the
respiration drive 26 is turned in the clockwise or respectively,
counterclockwise direction from the "0" position indicative of no change.
As the biosignal pattern analyzer 14 receives in digitized form, signals
as sensed by the sensor 4, it processes the same in real time, in order to
calculate the following parameters from an RA curve (see FIG. 3A):
Breathing Start Times--t(i), where i=1,2,3. . . is the breathing number;
Respiration Period--T(i)=t(i+1)-t(i);
Inspiration and Expiration times--T.sub.in (i) and T.sub.ex
(i)=T(i)-T.sub.in (i);
Respiration Amplitude--A(i);
Period Change--dT(i+1)=T(i+1)-T(i);
Relative Period Change--dT(i)/T(i);
Logical Variable (TRUE or FALSE)--F(i)=0 if Relative Period Change is
larger than, for example, 0.2, which means an interruption in breathing;
otherwise F(i)=1;
From these parameters other parameters are calculated in real time;
Mean Period--T=Average of the last successive five T(i) values for which
F(i)=1;
Mean Respiration Rate--f=60/T (breathings per min) provided that T is
expressed in sec.;
The means of A, T.sub.in, T.sub.ex are defined similarly;
Stability of the RR--S=dT/T, where dT is the standard deviation of the last
five dT(i) values for which F(i)=1.
The parameters t(i), T, f, T.sub.in, T.sub.ex, A and S are applied to the
CPU 16.
Taking into account the state of the respiration drive 26, the CPU 16
transforms T, T.sub.in and T.sub.ex into T', T'.sub.in and T'.sub.ex which
can be somewhat smaller or larger (but proportional values), as determined
by the respiration drive 26, and feed these values to the sound pattern
sequencer 20, which matches the sound pattern with the rhythm 1/T' and the
respiration characteristics T'.sub.in and T'.sub.ex. The pattern sequencer
20 sends to the CPU signals concerning the "musical period" T', i.e. at
times T', 2T', 3T'. . . (FIG. 3B). By comparing the phase difference
between these signals and the events of breathing start time [t(i) in FIG.
3A], the CPU can evaluate the capability of the sound patterns to
correctly follow the breathing patterns. In case of a failure, the CPU
restarts the operation of the pattern sequencer with an adjusted phase.
These cases are typical to the use of the respiration drive with a
difference between T' and T, which is not too large.
The synthesized sound pattern, schematically shown in FIG. 3B, contains
"musical units" of a period T'. The generated sound resembles music played
by four "instruments" identified by sound numbers 1-4. Sounds numbers 1
and 2 display a periodic pattern that resembles a breathing if number 1 is
played during the inspiration time T.sub.in, e.g., 0.2T' and number 2
during the expiration time T'-T'.sub.in, e.g. 0.8T'. In order to avoid
playing a boring sound pattern, sound numbers 3 and 4 generate a
background sound, which is not monotonous, every quarter of a period i.e.,
T'/4, as shown. Suppose the sound pattern played contains three "musical
units", then in order to store this information it is required to specify
a sequence of "events" containing a sound number, ON time and duration.
Taking T'=1 (a unity), the first "events" concerning sound numbers 1 to 4
are [1,0,0.2], [2,0.2,0.8], [3,0.25,0.25], [4,0.5,0.25]. In order to be
meaningful to the sound pattern synthesizer, the notation sound numbers
require codes for tone, intensity and a number of "musical parameters"
concerning the specific musical instrument, to be simulated by the
synthesizer as onset and decay times of the sound. Thus, the parameters
concerning sound number together with sequences of "events" define musical
pattern for a specific T'.sub.in /T' value i.e. fraction of time spent in
inspiration, for a given T'. Such sequences of events are contained in the
pattern code storage 18. Each sequence can be identified by a specialized
code to be supplied by the CPU 16 to the pattern sequencer 20. In its
simplest form, to each option of a biorhythmic activity state selection
and sound pattern selection correspond a number of pattern code sequences
with different T'.sub.in /T' values, to be matched with that of the user.
Given the values of T' and T'.sub.in /T' and the option number, the
pattern sequencer identifies a sequence with T'.sub.in /T' value close to
that supplied by the CPU and then releases the code signals to the sound
pattern synthesizer 22 at "musical units" of period T'. However, a
substantial amount of memory space can be saved by an improved pattern
sequencer: for example, such a sequencer can compose a periodic pattern
made of sound numbers 1 and 2 at the durations T'.sub.in and T'-T'.sub.in
', respectively as shown in FIG. 3B, thus making a "prerecording" of such
patterns unnecessary. Furthermore, the selection of sound numbers 3 and 4
can be made randomly instead of a preselected choice.
Such musical patterns have the advantage that the same "music" can be
played at any desired rhythm which is not attainable with recorded music,
since slowing down or speeding up the rhythm of recorded music changes
tones and nature of the sounds.
Hence, by means of predetermined selectable synthesized music which is
produced by synthesizing sound pattern with real time rhythmic biosignals
of a user and feeding the sound of synthesized music to be heard by the
user, there is formed a closed loop system wherein a controlled variation
in the rhythm and other parameters of the synthesized music can influence
the respiration rate which, in turn, otherwise influences the state or
degree of relaxation or excitation of the user.
It should be noted that in practice heart beats are also notable in the
pattern shown in FIG. 3A and could be used to analyze pulse rate.
The sensor can monitor changes in the skin blood volume e.g., by means of
an infrared photoplethysmographic transducer. Blood volume changes are
translated into variations in light absorptions and then transduced into
electric current signals. Such signals contain both, rhythm and amplitude
of the body activity. Another example of sensors which can similarly be
used are, ECG electrodes for monitoring the body's pulse rate. The body's
respiration rate and neural activity appear as frequency modulations.
Alternatively, there may be used EEG or EMG electrodes which monitor brain
wave frequencies, and respectively, electrical activity of the muscles.
It will be evident to those skilled in the art that the invention is not
limited to the details of the foregoing illustrative embodiments and that
the present invention may be embodied in other specific forms without
departing from the spirit or essential attributes thereof. The present
embodiments are therefore to be considered in all respects as illustrative
and not restrictive, the scope of the invention being indicated by the
appended claims rather than by the foregoing description, and all changes
which come within the meaning and range of equivalency of the claims are
therefore intended to be embraced therein.
* * * * *