CN101862201A - Method for representing cardiophonogram in intelligent cardiophone of mobile phone - Google Patents

Abstract

The invention relates to a method for representing the cardiophonogram in an intelligent cardiophone of a mobile phone, comprising the following steps: measuring cardiac sound signals by using a piezoelectric vibrating cardiac sound sensor, amplifying and filtering the cardiac sound signals by using a voltage preamplifier, transmitting the cardiac sound signals to the mobile phone by using a microphone input end for a USB interface of the mobile phone, storing the cardiac sound signals by using the recording function of the mobile phone, displaying a period-power-frequency graph for the cardiac sound signals in one period on the display screen of the mobile phone, drawing a 540Hz frequency coordinate for the cardiac sound signals in one period by using the improved polar coordinate drawing method, calculating the characteristic of the power spectrum for the cardiac sound signals in one period, normalizing the energy of the cardiac sound signals, compressing the indexes, drawing a change rule for the power and frequency of the cardiac sound signals in one period on an improved polar coordinate diagram, and signifying a peak point with an arrow to obtain a new period-power-frequency graph for the cardiac sound signals, which can vividly represent the change rule of the power and the frequency of the cardiac sound signals in one period and can effectively disclose the individual physiological characteristic of each cardiac sound signal.

Description

Phonocardiographic method for expressing in the intelligent mobile phone heart sound inspection device

Technical field

The present invention proposes a kind of phonocardiogram method for expressing that is used for the human body cardiechema signals is carried out visual description that is attached on the mobile phone.

Background technology

Hear sounds detects and analyzes is a kind of important and economic means of understanding heart and blood vessel state, because the heartfelt wishes signal is to follow life a kind of physiological signal all the time.From 1843, George P.Cammann has invented ears (double track) stethoscope (binaural stethoscope), Dr.Littmann light stethoscope design, that possess dual-purpose chest piece (bell and membranous type) to eighties of last century Harvard University's sixties medical college, the history in existing more than 100 year of traditional stethoscope has very high practical value to patient disease's diagnosis.And current advanced electronic stethoscope can amplify 18 times to sound, can connect PC and carry out software analysis.The Littmann stethoscope of for example foremost 3M company, comparatively well-known brand also have the bell of WelchAll-yn, Sprague-Rappaport, Thinklabs, ADC, DRG, Japan modest etc.Hear sounds has the clinical value that electrocardio is not replaced, the variation that the variation by research heartfelt wishes signal can researching human body itself, and be the clinical diagnosis service.

At present, the common method that electronic stethoscope detects hear sounds is to use the heart sound transducer pickoff signals, and through the oversampling circuit processing and amplifying, demonstrates waveform at liquid crystal display at last.For example use the heart sound transducer of electromagnetism conversion regime, the sound press that the vibration of thoracic wall is produced in air chamber converts the signal of telecommunication to, after utilizing the amplification of voltage or electric charge, A/D conversion, single-chip microcomputer signal processing then, waveshape signal is transferred to display shows shocking waveshape in body.Certainly the hear sounds waveform information also can deposit independent disk in, and by computer sound card successor computer, or storage or be sent to other computer by the Internet.

These class methods, the device that needs comparatively speaking is many, the cost height, it is not too convenient to use, and is unfavorable for detecting use whenever and wherever possible, and the electron medical treatment of the analysis of PCG Signal diagnosis aspect on the still rare Practical significance is popularized product at present.Along with the raising of people's living standard and the prolongation of average life, the sickness rate of cardiovascular disease is also in rising trend.Most of patients is known nothing the health of heart situation of oneself at ordinary times, more have no way of prevention and treatment, and just arrive hospital emergency when serious symptoms occurring.During the outbreak of many cardiovascular disease, typical pathology electrocardiosignal is written in water, when waiting to go to a doctor difficulty capture typical pathology electrocardiogram, this has brought difficulty to diagnosis and treatment to a certain extent.So exploitation a kind of being used for carried out the visual device of examining of seeing to the human body cardiechema signals on the cell phone platform of quite popularizing, and to provide a kind of phonocardiogram method for expressing that the human body cardiechema signals is carried out visual description according to the ardware feature of mobile phone be highly significant.Mobile phone develops into multimedia information lib from single conversation instrument at present.But still there is not product as medical science self health care instrument, thus the invention of intelligent mobile phone heart sound inspection device, to the new function of developing mobile phone, promote the Development of New Generation smart mobile phone and all have active operation significance.

Summary of the invention

Technical problem: the present invention is based on electronic technology and stethoscopic correlation technique, proposed a kind ofly to be attached to being used on the mobile phone human body cardiechema signals is carried out the visual phonocardiogram method for expressing of examining of seeing.Because mobile phone is the Communication Equipment that people are accustomed to carrying, and utilizes the intelligent hear sounds inspection device of mobile phone as platform development, can sees user's oneself heart anywhere or anytime on the one hand and examine; On the other hand, can also write down personalized physiologic information, problematic waveform is stored, form dynamic, can alternative electronic health record.The function of mobile phone is the restriction that is subjected to hardware, how to realize the human body cardiechema signals is carried out simple and effective visual description? therefore need study this problem, thereby widen the range of application of mobile phone.

Technical scheme: a kind of phonocardiogram method for expressing that is used for the intelligent mobile phone heart sound inspection device, its cardiechema signals is to obtain by following method: utilize piezoelectric shock heartfelt wishes pick off to measure cardiechema signals earlier, after forward voltage amplifier amplification filtering, mike input by mobile phone USB interface is transferred to mobile phone to this signal again, by the sound-recording function in the mobile phone cardiechema signals is stored, on the display screen of mobile phone, demonstrate cycle-power that the cardiechema signals constituted-frequency diagram of one-period then.

Because hear sounds is a kind of periodic mechanical vibration, be cardiac muscle and a kind of reflection of cardiac valve and trunk wall characteristics, the mechanism of production of oneself is arranged, corresponding just should have the criteria for classifying of oneself and a specific form of expression.The physiological feature of hear sounds is more important than the rhythm of the heart, thus we need carry out when unique, frequency-domain analysis.Utilize improved polar coordinate method to draw the frequency coordinate of one-period cardiechema signals, above being drawn in after then cardiechema signals being handled with logarithm, and represent with arrow, can obtain a kind of new cycle-power-frequency phonocardiogram, this new cycle-power-frequency phonocardiogram, power and the frequency change rule of statement cardiechema signals in one-period of image is to disclose the inherent individual physiological feature of cardiechema signals.Concrete grammar is:

1) for single channel cardiechema signals s (the n) (n=1,2,3 of one-period ... N), N is its length, utilizes Fourier transformation to ask the power spectrum characteristic of s (n), promptly

Then its energy is carried out normalized, carries out the index compression again, thereby have:

$P\left(n\right)=e^{\frac{\left|W\left(n\right)\right|}{{\left|\right|\left|W\left(n\right)\right|\left|\right|}_{\∞}}}$

F(n)＝2πn/Nf _h n＝0，…，N (1)

F wherein _hBe the upper limiting frequency of cardiechema signals, though the hear sounds frequency spectrum mainly concentrates on 0-200Hz, complete representation requires more information, so get f _h〉=540Hz;

2) 360 ° of polar coordinate with routine are divided into 540 parts, and each part represented 1Hz, and a labelling is carried out for 45 ° in every interval, and concentrically ringed maximum amplitude still is restricted to 1, can obtain an improved polar diagram;

3) power-frequency change rule of picture one-period cardiechema signals on this improved polar diagram, order:

x＝Pcos(F)

y＝Psin(F)

With x, y is drawn on this improved polar diagram, and represents peak point with arrow, can obtain one-period-power-frequency phonocardiogram.Shown in accompanying drawing 1, accompanying drawing 2.

Corresponding Huang among a in the accompanying drawing 1, b, c oscillogram and the e, green, red color line segment are the T-P-F characteristic descriptions of getting one-period with the hear sounds that the individual extracts at different time, varying environment, distinct device, and blue line segment corresponding among d oscillogram in the accompanying drawing 1 and the e is the T-P-F characteristic description that another person's hear sounds is got one-period.

From accompanying drawing 1 as seen, (1) cycle-power-frequency (T-P-F) figure has reacted the power of cardiechema signals of one-period and the relation of frequency, go round and begin again and on same circle, describe its change procedure, the comparison of visual pattern, very clearly presented the details difference in its change procedure, realized effectively the periodicity of cardiechema signals is described, the feature description of utilization to cardiechema signals arranged.When (2) analyzing the power spectrum of cardiechema signals, promptly signal is carried out normalized, again it is carried out index and handle, its objective is to amplify to level off to zero details, maximum is compressed in 1.(3) cardiechema signals is a kind of nonlinear time-varying signal, be that same individual is differentiated at the cardiechema signals of different time sections, though this difference is very faint, the cardiechema signals difference between the different people is apparent in view, and hear sounds cycle-power-frequency diagram can effectively reflect this point.(4) cardiechema signals of only getting one-period is analyzed, and can effectively reduce amount of calculation, improves pictorial display speed and efficient on mobile phone.

Beneficial effect: cardiophony is the important method of the non-invasive detection of heart disease, has the advantage that electrocardiogram, ultrasound cardiogram are not replaced, utilize the cycle-power-frequency diagram of intelligent mobile phone heart sound inspection device, user can be monitored the heart of oneself anywhere or anytime, visual pattern presented details difference in the hear sounds change procedure, realized effectively the periodicity of cardiechema signals is described, the feature extraction of utilization to cardiechema signals arranged.Simultaneously can write down personalized heart physiological information, problematic waveform is stored, the later analysis comparison is provided, form electronic health record dynamic, that can transmit.Particularly this health care checkout gear of exploitation on widely used cell phone platform has outstanding more advantage, can open up the new function of mobile phone, the development of promotion Development of New Generation smart mobile phone.

Description of drawings

Fig. 1 is the cycle-power-frequency diagram of a plurality of cardiechema signals of the present invention;

Fig. 2 is the cycle-power-frequency diagram of single cardiechema signals of the present invention.

The specific embodiment

The cardiechema signals of intelligent mobile phone heart sound inspection device of the present invention is to obtain by following method: utilize piezoelectric shock heartfelt wishes pick off to measure cardiechema signals earlier, after forward voltage amplifier amplification filtering, mike input by mobile phone USB interface is transferred to mobile phone to this signal again, by the sound-recording function in the mobile phone cardiechema signals is stored, on the display screen of mobile phone, demonstrate cycle-power that the cardiechema signals constituted-frequency diagram of one-period then.

Because hear sounds is a kind of periodic mechanical vibration, the physiological feature of hear sounds is more important than the rhythm of the heart, thus we need carry out when unique, frequency-domain analysis.Utilize improved polar coordinate method to draw the frequency coordinate of one-period cardiechema signals, above being drawn in after then cardiechema signals being handled with logarithm, and represent, can obtain a kind of new cycle-power-frequency phonocardiogram with arrow.This new cycle-power-frequency phonocardiogram, power and the frequency change rule of statement cardiechema signals in one-period of image is to disclose the inherent individual physiological feature of cardiechema signals.

For single channel cardiechema signals s (t) (t=1 ..., n), can utilize Fourier transformation to ask its power spectrum characteristic, thereby have:

$P\left(n\right)=e^{\frac{\left|W\left(n\right)\right|}{{\left|\right|\left|W\left(n\right)\right|\left|\right|}_{\∞}}}$

F(n)＝2πn/Nf _h?n＝0，…，N (1)

Wherein

f _hIt is the upper limiting frequency of cardiechema signals.Though the hear sounds spectrum concentration at 10-200Hz, is described fully and is required more information, so get f usually _h〉=540Hz.Order:

x＝Pcos(F)

y＝Psin(F) (2)

In 0～2 π scope, with f _h/ 2 π are the Hz/ degree, draw the frequency coordinate of one-period with improved polar coordinate method, then with x, above y is drawn in, and represent with arrow, can get the cycle-power shown in the accompanying drawing 1-frequency phonocardiogram.

Corresponding Huang among a in the accompanying drawing 1, b, c oscillogram and the e, green, red color line segment are the descriptions that cardiechema signals that same man extracts at different time, varying environment, distinct device is got the cycle-power-frequency hear sounds characteristic of one-period, and corresponding blue line segment is the description of another man's cardiechema signals cycle-power-frequency hear sounds characteristic of getting one-period among d oscillogram and the e.

" cycle-power-frequency phonocardiogram " program of using the matlab programming to realize is:

Y=s (t); The cardiechema signals of % input one-period

Y=fft (y, 58); % Fourier power analysis

Y(1)＝[]；

n＝length(Y)；

Power0=abs (Y (1:n/2)) .^2/n^2; % power

Freq=1080* (1:n/2) ./n; % the fs{ frequency

Power=power0/norm (power0); The % energy normalized

am0＝power；

N＝length(am0)；

nn＝540；

figure

t＝0:20:2*pi；

Polarcxf (t, sin (t), '-w '); % draws improved circle coordinates

for?i＝1:N

hold?on；

Rx (i)=exp (am0 (i)) * 0.4; The % index is handled

R＝Rx(i)；

if?R＞0.005

A (i+1)=(freq (i) * 2*pi)/nn; % angle [0,2*pi]

x(i)＝R*cos(a(i+1))；

y(i)＝R*sin(a(i+1))；

yy＝0；

xx＝0；

K=floor (am0 (i)+1.8); The % round numbers

for?j＝1:10*k

plot(xx，yy，’B-’)；％---

yy＝(y(i)/(10*k))+yy；

xx＝(x(i)/(10*k))+xx；

hold?on；

end

ho]d?on；

compass(x(i)，y(i))；

else

R＝am0(i)；

end

end

Title (' normalized power/w ');

Xlabel (' frequency/(0-540Hz) '); Ylabel (' time/one-period T ');

axis?equal

" cycle-power-frequency phonocardiogram " of resulting single cardiechema signals as shown in Figure 2.

Claims (1)

1. phonocardiogram method for expressing that is used for the intelligent mobile phone heart sound inspection device is characterized in that:

1) for the single channel cardiechema signals s (n) of one-period, n=1,2,3 wherein ... N, N is its length, utilizes Fourier transformation to ask the power spectrum characteristic of s (n), promptly

Then its energy is carried out normalized, carries out the index compression again, thereby have:

$P\left(n\right)=e^{\frac{\left|W\left(n\right)\right|}{{\left|\right|\left|W\left(n\right)\right|\left|\right|}_{\∞}}}$

F(n)＝2πn/Nf _h n＝0，…，N

F wherein _hBe the upper limiting frequency of cardiechema signals, though the hear sounds frequency spectrum mainly concentrates on 0-200Hz, complete representation requires more information, so get f _h〉=540Hz;

2) 360 ° of polar coordinate with routine are divided into 540 parts, and each part represented 1Hz, and a labelling is carried out for 45 ° in every interval, and concentrically ringed maximum amplitude still is restricted to 1, can obtain an improved polar diagram;

3) power-frequency change rule of picture one-period cardiechema signals on this improved polar diagram, order:

x＝Pcos(F)

y＝Psin(F)

With x, y is drawn on this improved polar diagram, and represents peak point with arrow, can obtain one-period-power-frequency phonocardiogram.

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