DEVELOPMENT OF PULSE-RESPIRATION RATIO
MEASUREMENT SYSTEM
*W. Huh, *M.K. Byeon, *S.H. Lim ,**Y.B. Park, ***H.K. Min,***Y.S. Woo
*Department of Electronic Engineering, Myongji University, S. Korea
**Dept. of Biofunctional Medicine and Diagnosis, College of Oriental Medicine,
Kyung-Hee University,
*** Department of Information Communication Engineering, Incheon University,
Email:[email protected], [email protected]
ABSTRACT
Pulse-respiration ratio has been used for estimating
the Han-Yeol (hot-cold nature) state of a subject since
the ratio is mentioned in Suwen (ancient oriental
medicine literature). In terms of pulse-respiration
ratio (Mac-Yule), if Mac Yule is over 5, it is in Yeol
(hot nature) state. If below 3, it is in Han (cold
nature) state. If 4, it is in normal state. We performed
this study to examine the optimum standard for
measuring pulse-respiration ratio based on
repeatability and reproducibility.
We developed the detection and processing system of
respiration, pulse wave, and EEG signal for pulserespiration ratio, measuring in psychologically stable
state. After the subject took a rest for 5 minutes on a
chair, we measured the subject's PPG, respiration,
and EEG, simultaneously. We calculated pulserespiration ratio by dividing the respiration cycle
average by the pulse cycle average according to each
standard including time section, and EEG frequency
domain analysis for searching alpha wave is
dominant period.
We could see more stabled pulse-respiration ratio in
relatively alpha dominant region of EEG than any
other regions.
I. Introduction
In oriental medicine, the doctor grasps the mutual
relation between patient's symptom and disease progress
and the inherent rules, identifies the properties of the
disease, and gives medical treatment by using four kinds
of diagnoses, watch, hearing, questionnaire, and touch.
In particular, pulse diagnostic (Mac-Jin), which
belongs to the touch diagnosis category, diagnoses the
disease area of viscera and bowels by watching pulsation
state of radial pulse. As unique diagnostic method in
oriental medicine, Mac-Jin has considered as an
important diagnostic method and frequently used in
clinics.
The Mac-Yule method, which classifies whether pulse
rate is high or low and belongs to the pulse diagnostic, is
used as major index for classifying cold and hot natures.
This method is used to analyze various pulse-phases. Jimac (slow pulse rate), Sue-Mac (fast pulse rate) and
Wan-Mac (normal pulse rate) are classified by quantity
of pulse rate, strongly. Ji-Mac, an independent pulsephase with a single concept, generally manages coldnature. The pulse rate is slow. Sue-Mac generally
manages hot-nature. The pulse rate is fast.
The Mac-Yule measurement method is divided into
measuring pulse rate per unit time and that per unit
respiration. According to literature, pulse rate is based on
stomach Gi and maintained by respiration Gi[1]. In
addition, pulse circulation is maintained by respiration
[2]. Thus, Mac-Yule through the measurement of pulse
rate per unit respiration is more suitable for the genuine
meaning of oriental medicine. If Mac-Yule is below 3, it
is Ji-Mac and has cold-nature. If 4, it is wan-Mac and
normal state. If over 5, it is Sue-Mac and has hot-nature.
Existing researches on Mac-Yule include the research
on hardware and software for detecting Mac-Yule[3,4],
on database for Mac-Yule diagnosis[5], on normalization
of Ji-Mac and Sue-Mac through Mac-Yule, and on the
pulse-phase of Ji-Mac through Mac-Yule and its
characteristic comparison[6].
In general diagnosis, a doctor lets a patient sit down or
lie down, and spread his/her arm for the physical and
psychological stability of the patient, and measures
his/her Mac-Jin for over 50 pulse counts[7].
However, in the existing researches, the stability of
Mac-Yule detection creates a problem because
psychological and emotional state and respiration
stability of a subject are not considered for the heart rate
and respiration rate controlled by human body's
consciousness and unconsciousness. Thus, a problem
arises for the stability of detecting Mac-Yule.
Through this research, I design a device to test the
brain waves of a subject by identifying his/her
psychological and emotional stability and measure MacYule when the subject is comfortable. The device is
composed of the hardware that detects and stores brain
waves, respiration waves, and pulse waves, the signal
processing block that identifies the stability status of a
subject, and the software that detects the cycle of each
signal.
II. System Configuration
Fig. 1 is the diagram of the devised system that can
detect Mac-Yule. This system consists of the transducer
part that converts biomedical signals into electric signals,
the preamp part that stabilizes micro biomedical signals,
the signal processing part that processes analogue signals,
and the software part that processes biological signals for
detecting Mac-Yul.
Fig. 1 Diagram of the pulse-respiration ratio detection
system
1. Hardware Configuration
1-1. Transducer part
The transducer part is composed of 3 kinds of biomedical
signals that we can achieve easily by using the prop of
glasses form. Fig. 2 is the diagram of the transducer part
to achieve biomedical signals.
The thermistor to detect RSP signals was placed right
under the nasal cavity to detect the change of breath to
identify the temperature gap between inhalation and
exhalation when the subject breathed, and composed
freely for the subject to easily control the location.
PPG signals was detected by wearing the system at the
lobule of auricle of the subject by using photos to electric
converter of Pico-Med Corp. product with the form of
forceps. This converter is composed of IR-LED light
source and photo-diode receptor.
We composed the EEG detection system while
attaching the Ag-AgCl instant electrode on the scalp of
the subject.
We devised the preamplifier part with the small size to
place it at the prop of glasses form with the transducer
part, and it played the role of stabilizing the signal at the
preamplifier part to achieve signal enlargement and
current buffering.
We composed the RSP signal part by zero pointcontrolling devices that controlled the zero point of the
bridge circuit and the bridge circuit using 4 thermistors
including the thermistor located at the transducer part.
According to the breathing, the resistance value of the
thermistor changed, and the voltage signal at the both
ends of the bridge circuit changed. Thus, we could detect
RSP signals.
We composed the PPG signal part by the current to
voltage amplifier to amplify the micro signal of photo
diode. The EEG was especially smaller than other signals,
so we stabilized the signal composing the amplifier that
amplified the signal first time to the preamp part.
1-3. Analog signal processing part
In the analog signal processing part, it amplifies the
biomedical signals into the appropriate size which is the
needed information at the output signal of the
preamplifier part and eliminates the unnecessary noise.
The signal processing part of the respiration (RSP)
signals is composed with an amplifier whose gain is 10,
and filters which eliminate the noise of power line of
60Hz. We composed it of low pass filter that the cut-off
frequency is 20Hz.
For the PPG signal processing, we composed low pass
filter and high pass filter to eliminate the high frequency
signal elements and DC components.
Fig. 3 shows the signal processing part of EEG. As the
EEG signal was derived from head so we composed it to
be divided into 2 parts. As the frequency components
existed from 1Hz~200Hz, so we composed notch filter to
eliminate power noise of 60Hz, and high and low pass
filters. In addition, as the gaining method of EEG was
derived by attaching Ag-AgCl electrodes directly to the
skin of the head, it could be dangerous due to the
excessive power line surge voltage. Thus, we separated
the power and the signal by using an isolation amplifier
to protect it.
Fig. 3 EEG signal processing part
Fig. 2 Transducer Part
1-2. Preamp part
2. Software System Composition
Fig. 4 shows the software flow of mac-yule detection.
We composed the software system by EEG power
spectrum analysis parts for deciding psychologically
stable state and signals period detection parts for
calculating Mac-Yule.
The EEG analysis system calculates power ratios of
alpha to beta spectrum components. The psychologically
stable state decision algorithm uses the power ratio of
alpha to beta spectrum of EEG. The Mac-Yule
calculation system calculates the ratio of mean pulse
signals period to mean respiration signals of it. The each
signal period is detected by using the zero-crossing
method. When the power ratio of alpha to beta spectrum
of EEG is bigger than a specific value, we select mean
value of the Mac-Yule of that period.
Fig. 8 shows that the subject wears the devised system.
We could measure 3 biomedical signals with ease and
convenience, simultaneously as the figure. Fig. 9 shows
the main screen of the signal capture program. As Fig. 8,
it shows RSP, PPG, and EEG signals while they are
measured simultaneously by wearing the system. They
are shown on the PC monitor.
Fig. 4 Software Flow of Mac Yule Detection System
Figure 8 System Wear
III. Experiment and Results
To check the capacity of the embodied system, we
measured the output signal of each module by using an
oscilloscope. Through this experiment, we confirmed
that the noise signal was eliminated, and stable RSP,
PPG, and EEG signals were measured. Fig. 5, 6, and 7
show the RSP, PPG, and EEG signals (of the closed
(a)/opened (b) eyes of the subject) measured by using the
oscilloscope.
Fig. 9 Main Screen of Biological Signal Acquisition
System
Fig. 10, 11, and 12 shows the alpha to beta power
spectrum ratio of EEG signals greater than 4, and the
Mac-Yule of each case of Wan-Mac (normal), Sue-Mac
(yeol-hot) and Ji-Mac (han-cold). The each case shows
small variation in Mac-Yule values.
Fig. 5 Measured RSP signal
Fig. 6 Measured PPG signal
Fig. 10 Spectrum Ratio of Stable State and Mac Yule in Wan-Mac (Normal)
(a) Closed
(b) Opened
Fig. 7 Measured EEG Signal when Closing/Opening
Subject's Eyes
Fig. 11 Spectrum Ratio of Stable State and Mac -Yule in
Sue-Mac (Yeol-hot)
Fig. 12 Spectrum Ratio of Stable State and Mac- Yule in
Ji-Mac (Han-cold)
IV. Conclusion
In this paper, we confirmed the performance of the
devised pulse-respiration rate detection hardware system
and its signal processing algorithm through the
experiments. The devised system can measure the pulserespiration ratio in psychologically stable state by using
RSP, PPG, and EEG signals. As the results of the
experiment, we can see that the variation of pulserespiration rate in the period of more than 4 alpha to beta
spectrum ratio of EEG signal is stable.
In the future, the system will expand to have real time
Mac Yule diagnosis function by adopting the real-time
frequency analysis system in spectrum analysis of EEG
signal.
Acknowledgments
This study was supported by a grant of the Korea Health
21 R&D Project, Ministry of Health & Welfare, Republic
of Korea (B050011)
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