Research Journal of Applied Sciences, Engineering and Technology 4(21): 4463-4468, 2012
ISSN: 2040-7467
© Maxwell Scientific Organization, 2012
Submitted: May 01, 2012
Accepted: June 08, 2012
Published: November 01, 2012
Testing and Analysis of Pulse Detection Circuits Based on the Concept of
Chinese Medicine
Xinsheng Che, Xiaoxue Gu, Dongxue Fan and Hui Xu
Shenyang University of Technology, Shenyang 110870, P.R. China
Abstract: In order to get real pulse information and research pulse instrument by using Chinese medicine,
a method about testing pulse detection circuits is proposed by use of the definition of Chinese medicine
pulse in this study and detection circuits from three different pulse instruments are analyzed using this
method. The existence of distortion in circuits is proved by using electronic circuit simulation and hardware
circuit experiments. At the same time, the quantified distortion errors of three pulse detection circuits are
given according to describing the pulse parameters of Chinese medicine. These pulse parameters and data
can be used to optimize the pulse detection circuits.
Keywords: Chinese medicine pulse, electronic circuit simulation, pulse detection circuit, pulse instrument,
pulse parameter
Principles and compositions of pulse instrument:
Pulse instrument is a kind of Chinese medicine pulse
diagnosis instrument which can collect, analyze,
process and obtain human pulse diagrams automatically
(Zhao et al., 2006) and it consists of sensor unit, signal
conditioning unit, data acquisition unit and computer
unit in general (Fan, 2007). The corresponding system
diagram is shown in Fig. 1.
Human pulse signal is transformed to electronic
signal through pulse sensor and signal conditioning unit
amplify the weak signal and filter off noise. Then
analog quantity is transformed to digital quantity
through A/D converter. Finally, the pulse diagrams are
shown by computer.
INTRODUCTION
Traditional Chinese Medical Pulse instrument
should be objective (Lu et al., 2010). There are many
methods of pulse detection and pulse instruments, but
there is no pulse instrument or method of pulse
detection which can be proofed to get real human pulse
diagrams. Pulse instrument is a testing instrument and
represents a kind of testing technology. A method of
verifying pulse instrument should be put forward to
build the instrument with no distortion. This is also
clinical objective demand of pulse application.
Many kinds of pulse instruments exist on different
research directions. According to the definition of
pulse, all the structures, detection circuits and
processing data of pulse instruments are similar. The
distortion focuses on the filter circuits of signal
conditioning. According to the filter circuits which are
used in pulse instruments, a method is brought up to
test the pulse detection circuits by using circuit
simulation and experiments. The research of this study
is the basis of optimizing pulse detection circuit and
evaluating the distortions by pulse parameters.
Extension-rule based TP method has commended.
Recovering pulse signal: According to Chinese
medicine, pulse is defined as the form which doctors
feel by their fingers. It is the function of changing force
by time in description of curve.
Pulse signal meets the Dirichlet condition in a short
time and can be described by Fourier series which gives
the pulse characteristic from the aspect of signal and
provides basis for the design of pulse collection system
(Zhu, 1995), extraction of pulse feature and access of
pulse signal:
DETECTION OF PULSE SIGNAL
Pulse instrument is a medical instrument which can
reflect pulse signal objectively. The system
composition depends on the description and research
direction of pulse signal (CUI INC., 2010). According
to the definition of Chinese medicine, description and
detection about pulse are more directive and objective
based on Fourier series.

f t   d 0   d n sinn1   n 
(1)
n 1
where, d0 is static stress from doctors’ fingers (stress for
getting pulse) which is a direct current value in pulse
Corresponding Author: Xinsheng Che, Shenyang University of Technology, Shenyang 110870, P.R. China
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Res. J. Appl. Sci. Eng. Technol., 4(21): 4463-4468, 2012
Fig. 1: System diagram of pulse detection instrument
instrument based on pulse original definition. The
second part is the doctor fingers’ feeling about the pulse
(pulse waveform) which is described as harmonic
waves where dn is the magnitude. In general d0 is much
larger than dn.
Except for the direct current, i.e., the stress for
getting pulse, there are much noises mixed in pulse
signal, like power frequency interference (50 Hz) and
high frequency interference, which should be filtered
off. To separate static stress and pulse waveform, highpass filter circuits with low cut-off frequency are used.
Some pulse instrument can be seen in literatures in
recent years. The first one we want to analyze is the one
designed by Shenyang University of Technology in
2003. There uses a two voltage-controlled active
Butterworth high-pass filter circuit to filter out the
direct signal and its cut-off frequency is 0.143 Hz4. This
filter circuit is named as Example 1 for short in this
study.
The second model is a pulse instrument designed
by Tianjin University in 2007 in which high-pass filter
circuit is combined with low-pass filter circuit (Che
et al., 2005). The high-pass filter circuit is named as
Example 2 for short. Its cut-off frequency is 0.08 Hz.
The cut-off frequency of the low-pass filter circuit is 40
Hz. High frequency component of pulse can be
preserved and most high frequency noise can be
filtered.
The pulse instrument designed by Guangdong
University of Technology in 2008 also uses high-pass
filter circuit combined with low-pass filter circuit (Gen,
2007). The cut-off frequency of the high-pass and the
low-pass filter circuits are 0.025 and 45 Hz,
respectively. The high-pass filter circuit is named as
Example 3 for short.
The filter circuit of the pulse instrument designed
by Northeast Normal University in 2008 adopts lowpass filter and notch circuit taking into account the
influence of the industrial power frequency (Li, 2008).
The pulse system designed by Nanjing Information
Engineering University filters out high frequency noise
by using a second order low-pass filter circuit whose
cut-off frequency is 40 Hz (Wang, 2008).
Filter circuits which mentioned above can be
divided into four categories:




High-pass filter circuit
High-pass filter circuit combined with low-pass
filter circuit
Low-pass filter circuit combined with notch circuit
Low-pass filter circuit
ANALYSIS ABOUT FILTERS OF PULSE
INSTRUMENTS
The detection precision of useful signal can be
improved on the condition that the lager DC component
is filtered off because of the limited digits of AD
converter. The requirements of high-pass filters are the
smooth amplitude in pass band, low cut-off frequency
point and narrow transitional band.
Analysis about high-pass filter circuit: The
simulation software AD09 (Altium Designer Summer
09) can be used to calculate and test the performance of
filter circuit. It can do three types of simulation directly,
i.e., analog, digital and mixed-signal circuit diagrams.
AC small signal analysis in AD09 can be used to
analyze amplitude frequency characteristic about three
high-pass filter circuits in examples mentioned in
section 2. The starting frequency is set at 0.01 Hz, the
stop frequency is 40 Hz and the step of frequency is
0.01 Hz.
The filter circuit of Example 1 is shown in Fig. 2a4.
Its amplitude and phase frequency characteristic are
shown in Fig. 3a by analysis of AD9 and its cut-off
frequency of this high-pass filter is 0.143 Hz.
The filter circuit of Example 2 and 3 are shown in
Fig. 2b7 and 2c8, respectively. Their amplitude and
phase frequency characteristics are shown in Fig. 3b
and 3c. For Example 2, the low end cut-off frequency
of high-pass filter circuit is 0.08 Hz and the upper cutoff frequency of the low-pass filter circuit is 40 Hz.
And for Example 3, the pass band of the filter circuit is
from 0.025 to 45 Hz, respectively.
Analysis about transmission characteristics of pulse
signal: According to the above analysis, the reasons
which affect pulse signal have been found that highpass filter circuit affects the transmission of pulse
4464 Res. J. Apppl. Sci. Eng. Technol.,
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4(21)): 4463-4468, 2012
2
mple 1
(a) Exam
(bb) Example 2
(c) Example 3
Fig. 2: Filter circuits of threee examples
75.0
50.0
25.0
-00.00
-25.00
-50.00
-75.00
-100
10.00
20.00
30.000
Frequency (Hz)
F
40.00
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.00
Voltage
phase
10.00
(a)
( Example 1
( Example 2
(b)
4.500
40.00
Voltage (V)
4.000
3.500
3.000
20.00
30.000
Frequency (Hz)
F
Volltage
phase
20.00
0.00
2.500
-20.00
2.000
-30.00
1.500
0..00
10.00
20.00
30.00
Frequency (H
Hz)
( Example 3
(c)
Fig. 3: Diaggrams of amplitu
ude and phase freequency characteeristics of three examples
4465 4
40.00
Phase (o)
Voltagee
phase
100
75.0
50.0
25.0
-00.0
-25.0
-50.0
-75.0
-100
40.00
Phase (o)
1.100
1.000
Voltage (V)
0.900
0.800
0.700
0.600
0.500
0.400
0.300
0.200
0.100
0.000
0.00
Phase ( )
Voltage (V)
1.000
Res. J. Apppl. Sci. Eng. Technol.,
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4(21)): 4463-4468, 2012
2
1.00
Vin
Vin ,Vout (V)
0.25
122
13
14
Time (s)
0.25
Vouut
Vout
-0.50
Vin
-0.50
15
166
13
12
14
Time (s)
(a) Example 1
16
(bb) Example 2
1.00
Vin (V)
15
4..00
Vin
1.000
0.25
Vout (V)
Vin ,Vout (V)
1.00
Vout
-22.00
-0.50
12
13
14
Time (s)
1
15
16
(c) Example 3
Fig. 4: Input and output sign
nals of filter circcuits of three exaamples
(b) Example 3
(a) Exaample 1
nals of exampless
Fig. 5: Input and output sign
signal. Wee should have a look at the pulse
p
input signnal
and outputt signals throug
gh high-pass fillter circuits.
The pulse
p
instrumen
nt referred in Example 1 has
h
been used in clinical praactice for 2 yeears. During thhis
5 patients’ pulsse signals. In thhis
time, it hass collected 285
study, som
me of the pulse signals have been
b
standardizzed
by Matlab to signal sourcce which can be
b used in circcuit
simulation software. Thee difficulty aboout signal sourrce
in this studdy has been sollved. Filter circuit should be drawn a ciircuit diagram in
the AD09.. Piecewise lin
near source VPWL
V
is used to
o circuit. In the Part Field TAB of VPWL
V
input of
componnents, the File Name should be filled in a File
F of
import data. Discrette data of pulse
p
signal can
c be
importeed to the circuit. Using this method,
m
compllicated
data caan be simulatedd. Human pulsse signal is irrregular
signal in one cycle, so this is an effective methhod to
simulatte.
Traansient analysiis of AD09 cann be used to sim
mulate
the circcuit. Its output signal is a funnction of time.. Input
and outtput signals of filter circuits can
c be obtainedd.
Inpput and outpuut data of thrree high-pass filters
circuitss are shown in Fig. 4.
4466 Res. J. Appl. Sci. Eng. Technol., 4(21): 4463-4468, 2012
Table 1: Parameters of input and output pulse signals and relative errors
h2
High-pass filter circuit
h1
Parameters of input signal
1
0.4536
0.9723
0.3006
Values of output
Relative error (%)
2.7700
33.730
Values of output
1.0043
0.4319
Relative error (%)
0.4300
4.7800
Values of output (h1~h4/4.157)
1.0087
0.4474
Relative error (%)
0.8700
1.3670
h3
0.2176
0.2520
15.8100
0.2041
6.2000
0.2132
2.0200
h4
0.0300
0.1234
311.33
0.0340
13.3300
0. 0291
3.0000
t1 (s)
0.4922
0.4022
18.2900
0.4945
0.4800
0.4937
0.3000
t2 (s)
0.9022
0.9198
1.9500
0.9079
0.6300
0.9051
0.3200
t3 (s)
0.0978
0.0802
18.0000
0.0921
5.8300
0.0849
13.1900
The parameters of input and output pulse signal are
compared in Table 1. The input pulse signal has been
normalized as t = 1s and h1 = 1. Input and output pulse
data are from AD09.
The filter circuit in Example 3 can amplify input
signal with a ratio about 4.157, so the output signal of
Example 3 should be divided by that ratio.
Relative error = (Output values - Input values)
/Input values100% in Table 1.
Fig. 6: Pulse diagram in an ideal situation CONCLUSION
Analysis about actual circuits: Actual high-pass filter
circuit of Example 1 is tested and the pulse signal
comes from magnetoelectric pulse generator by which
many kinds of pulse signals can be reappeared (Xu,
2008; Che, 2005). The magnetoelectric pulse generator
is as an actual pulse to be input into the high-pass filter
circuit and then input and output signals can be
observed by a dual channel oscilloscope as shown in
Fig. 5a where channel 1 is input signal and channel 2 is
output signal of the high-pass filter circuit.
The high-pass filter circuit of Example 3 is made.
The pulse condition signal is input into the circuit by
reference to the above. The results are shown in Fig. 5b
where channel 1 is input signal of high-pass filter
circuit and channel 2 is output signal. This filter circuit
can amplify input signal with a ratio about 4.157.
In the process of pulse detection, the filter circuit
of processing pulse signal can filter out the press for
getting pulse. At the same time, it also brings the
distortion of pulse signal. The filter circuits have been
simulated by using VPWL building signal source in
AD09. Using the pulse data obtained by the simulation,
the real circuits have been tested. The results of above
two methods are similar. This research has solved the
problems of test and analysis of pulse instruments in
method and the need of reused pulse signal source.
Pulse parameters: Pulse diagram can only be
understood by sense organs. The parameterization is
more useful for the classification of pulses by analyzing
the pulse diagrams. In an ideal situation, pulse diagram
tested by pulse instrument is shown in Fig. 6.
In Fig. 6, h1 is main pulse amplitude, h2 is the
amplitude before dicrotic pulse, h3 is the amplitude of
dicrotic notch pulse and h4 is the amplitude of dicrotic
pulse according to the description of pulse
characteristic parameters. Where t1 is the time period of
acute ejection period, t2 is the time period of systolic
period and t3 is that of diastolic period. These
parameters reflect the characteristics of pulse diagram.
REFERENCES
ACKNOWLEDGMENT
This study is supported by the Shenyang Science &
Technology Planning Item No. F10-213-1-00.
Che, X.S., 2005. Magnetoelectric Pulse Generator.
Practical New-type Patent, Patent Number:
ZL200520089617.1.
Che, X.S., Z.X. Zhang and Y.J. He, 2005. The
acquisition and direct description of pulse in
Chinese medicine. ICEMI’ 2005 Conf. Proc., 1(6):
49-52.
Fan, W.F., 2007. Research on multi-dimensional
collection of Chinese medicine pulse. MA. Thesis,
Shenyang University of Technology, Shenyang.
4467 Res. J. Appl. Sci. Eng. Technol., 4(21): 4463-4468, 2012
Gen, J.J., 2007. Advanced development of acquisition
system on pulse tracings of traditional Chinese
medicine. MA. Thesis, Tianjin University, Tianjin.
Lu, X.Z., G.Q. Hu and H.M. Cao, 2010. Research
progress and prospect of pulse condition
instrument. The 11th National Academic
Conference on TCM Diagnosis, Beijing, China, pp:
74-78.
Li, Z.L., 2008. Research on pulse diagnosis instrument
based on extension detecting. MA. Thesis,
Guangdong University of Technology, Guangzhou.
Wang, Y.B., 2008. The portable instrument of multiple
pulse. MA. Thesis, Northeast Normal University,
Changchun.
Xu, R.Q., 2008. Design of pulse detection system and
research of pulse signal processing algorithm. MA.
Thesis,
Nanjing
Information
Engineering
University, Nanjing.
Zhao, C.M., X.Z. Yang and Y.L. Song, 2006. The
development of TCM pulse pattern diagnostic
system. China J. Tradit. Chin. Med. Pharm.,
(supplement), pp: 260-262.
Zhu, W.F., 1995. Diagnostics of Traditional Chinese
Medicine. Shanghai Science and Technology Press,
Shanghai.
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