CN1698535A - Method for measuring blood pressure change rate - Google Patents

Abstract

The invention discloses a method for measuring blood pressure change rate which comprises the steps of, (1) collecting a series of signals related to human body pulses wave production and transmission characteristics, (2) obtaining characteristic parameter sequence of the collected signal, (3) determining blood pressure parameter according to the obtained signal characteristic parameter sequence.

Description

Measure the method for blood pressure rate

Technical field

The present invention relates to a kind of method of measuring blood pressure, relate in particular to a kind of measurement with each time or the method for the corresponding blood pressure rate of continuous several times heartbeat.

Background technology

Measuring blood pressure is the basic skills of understanding health condition and observing the state of an illness, especially necessary to the middle-aged and elderly people of suffering from cardiovascular disease.Blood pressure is in one day even all often have bigger fluctuation in a certain amount of time, so single or a spot of measurement be difficult to provide data and enough useful informations accurately and reliably, more can't calculate the various rates of change with the corresponding blood pressure of heartbeat.Specifically, heartbeat all can produce a corresponding pressure value each time, that is to say that pressure value is as the continuous variation of heart rate and with it one to one in fact, therefore the continuous like this pressure value that records can be referred to as and the corresponding pressure value sequence of heartbeat, and promptly can obtain and the rate of change of the corresponding blood pressure of heartbeat each time the calculating that this sequence is carried out rate of change.

Blood pressure is carried out the continuous measurement of long period and calculates for example changing with the corresponding blood pressure of heartbeat continuous rate of change in a certain amount of time each time for some physiological statuss of monitoring human that the state of an illness, pathology, emotional state etc. are very necessary, particularly to the vicissitudinous often people of some physiological statuss, for example athlete and the crowd that moils etc.

Measuring blood pressure mainly is divided into the intrusive mood measurement and can't harm formula measurement two big classes.The intrusive mood measurement method is a kind of method of direct measurement, a conduit will be inserted in the tremulous pulse during measurement, measures arterial pressure by the transducer that is connected with fluid column.This method need be by the professional health care personnel operation, and expense is high and cause bacterial infection easily and lose blood and wait medical-risk, is not suitable for daily measurement and health care, more impossiblely carries out successive blood pressure measurement and carries out the calculating of the continuous rate of change of blood pressure.

Harmless formula measurement method is a kind of indirect measuring method, mainly adopts three types equipment: pulse sphygomanometer, tone are measured sphygomanometer and based on the sphygomanometer in pulse wave transmission time.

The measuring method of pulse sphygomanometer has two kinds: auscultation and succusion.The auscultation ratio juris is to collect the Ke Shi sound, and whole device comprises cuff, mercury gauge (the employing electronic pressure transmitter is also arranged in recent years) and the stethoscope that can charge and discharge gas.When measuring the upper limb blood pressure, drain the gas in the cuff earlier, then with the smooth aptychus of cuff twine in upper arm, find out beating of brachial artery, put stethoscopic chest piece and locate in this.Open the mercury column switch, when the balloon by possessing valve alive when cuff is inflated, mercury column or indicator move immediately, when mercury column rises to default value, promptly stop inflation.Then, open the balloon valve of living slightly and slowly exit, mercury column then slowly descends (indicator revolution), should observe the scale that mercury column or indicator move this moment, ring if hear first sound of brachial artery, shown in scale be systolic blood pressure, the abbreviation systolic pressure; Sound equipment dies down suddenly or when can't hear, scale is designated as diastolic blood pressure when mercury column drops to, and is called for short diastolic pressure.But this method can only be determined systolic pressure and diastolic pressure, and is not suitable for some the 5th Ke Shi sound than the extremely unheard patient of overly soft pulse.

Succusion can remedy the above-mentioned deficiency of auscultation to a certain extent, and the patient more weak for the Ke Shi sound also can measure blood pressure.During use with the smooth aptychus of cuff twine in upper arm, cuff is charged and discharged gas.Determine that by measurement oscillation amplitude of pressure in expansible cuff pressure value, the vibration of pressure are by arterial vascular contraction and expand caused.The numerical value of systolic pressure, mean pressure and diastolic pressure can be monitored the pressure this cuff and be obtained when this cuff is slowly exitted.Mean pressure is engraved in the pressure in the attenuating device of this cuff during corresponding to this envelope peak.Pressure when systolic pressure is estimated as moment of a certain ratio that equals this peak amplitude before this envelope peak, corresponding to this envelope amplitude usually in the attenuating device of this cuff.Diastolic pressure is estimated as usually after the peak value of this envelope, the pressure when equaling moment of a certain ratio of this peak amplitude corresponding to the amplitude of this envelope in the attenuating device of this cuff.Use different ratio values can have influence on the accuracy of blood pressure measurement.

Most products in the market all are to adopt auscultation or succusion.But, therefore be difficult to realize frequent measurement, more impossible realization continuous measurement because these two kinds of methods all need cuff is charged and discharged gas.And, the frequency of using cuff to measure also be subjected to this cuff inflate the needed time and when measuring to the restriction of this needed time of cuff deflation.Usually, once complete blood pressure measurement needs about 1 minute.In addition, the size of cuff size also can impact the measurement result of blood pressure.Comprehensive above Several Factors, use traditional auscultation or succusion can't record a plurality of pressure values continuously, more can't record and the corresponding pressure value sequence of heartbeat each time, thereby also can't calculate and the corresponding blood pressure of heartbeat continuous rate of change in a certain amount of time each time.

The ultimate principle that tone is measured sphygomanometer is: when blood vessel was subjected to the external object compressing, the circumferential stress of blood vessel wall had been eliminated, and at this moment intrinsic pressure the and external pressure of blood vessel wall equates.By to the tremulous pulse pressurization, tremulous pulse is flattened.Record makes tremulous pulse keep flat pressure.Utilize one group to place surperficial eparterial pressure transducer array to measure this pressure, and therefrom calculate patient's blood pressure.But the shortcoming of this method is that the cost of the pick off of its use is higher, and its certainty of measurement is subjected to the influence of measuring position easily, so unpopular on market.Obviously, make in this way and also can't record a plurality of pressure values continuously, thereby also can't calculate blood pressure continuous variation tendency in a certain amount of time.

Sphygomanometer based on the pulse wave transmission time is to determine blood pressure according to the relation between arteriotony and the pulse wave transmission speed.When increased blood pressure, vasodilation, the pulse wave transmission speed is accelerated, on the contrary the pulse wave transmission speed slows down, and particular content can be referring to following document:

What 1) Messers.J.C.Bramwell and A.V.Hill showed, " The Velocity of thePulse Wave in Man (pulse wave velocity in the human body) ", be published in Royal Society of London's journal (Proceedings of the Royal Society, London), the 298-306 page or leaf, nineteen twenty-two;

2) B.Gribbin, A.Steptoe, shown with P.Sleight, " Pulse Wave Velocity asa Measure of Blood Pressure Change (as pulse wave to the measurement means of blood pressure ", " psychophysiology " the 13rd volume first phase, 86-90 page or leaf (Psychophysiology, vol.13, no.1), 1976.

Such sphygomanometer is in use by gathering photoelectricity plethysmographic signal and electrocardiosignal from the photoelectric sensor that is arranged on finger tip or other tip tissue location.This method can provide the blood pressure measuring device that is simple and easy to usefulness, and for traditional cuff formula sphygomanometer, have development cost lower (cost can reduce over half), volume little (approximately can reduce hundreds of times), power consumption few (approximately can reduce hundred times) and can realize advantages such as long-time continuous measurement arteriotony.Before adopting the blood pressure measuring of this method to take blood pressure, to calibrate it with standard-sphygmomanometer earlier, promptly find upper arm blood pressure and the relation of pulse wave between the transmission time.Just can record a plurality of pressure values continuously according to blood pressure and the relational expression of pulse wave between the transmission time determined then.Therefore, can realize successive blood pressure measurement in the certain hour based on the sphygmomanometry in pulse wave transmission time.But owing to utilize the method for electrocardiosignal to go up acquired signal simultaneously at two fingers (or other position).This has still brought certain inconvenience to measurement, is difficult to also to realize that long-time continuous truly measures.

The method of carrying out blood pressure measurement based on the characteristic parameter of photoelectricity plethysmographic signal only need go up acquired signal from a finger (or other position), therefore can be for measurement provide great facility, thus the harmless for a long time continuous measurement of real realization.But so far, still do not have and adopt this measuring method specifically to determine and once or the several times corresponding blood pressure of heartbeat or the technology of the continuous rate of change of blood pressure.Need explanation, said and the corresponding blood pressure of heartbeat several times are meant and the meansigma methods of the corresponding blood pressure several times of heartbeat several times in this description.Therefore, continuous measurement is with each time or several times corresponding blood pressure of heartbeat and rate of change thereof are still a blank.

Summary of the invention

The purpose of this invention is to provide and a kind ofly obtain in arbitrary period with each time or the method for the continuous rate of change (comprising absolute change rate and relative change rate) of the corresponding blood pressure of every several times heartbeat, thereby provide new useful information for medical treatment and health care by successive blood pressure measurement.

For achieving the above object, the invention provides the method for a kind of measurement and the corresponding blood pressure parameter of one or many heartbeat, may further comprise the steps: a) from the human body collection signal relevant with pulse wave; B) from the signal of being gathered, obtain characteristic parameter, obtain corresponding characteristic parameter sequence; C), determine and the corresponding blood pressure parameter of heartbeat at every turn or repeatedly according to the characteristic parameter sequence of determined signal.

In said method, described blood pressure parameter can comprise: pressure value, the continuous rate of change of blood pressure, instantaneous blood pressure rate, and with the rate of change of each (or several times) corresponding a plurality of pressure values of heartbeat.

Wherein, the continuous rate of change of blood pressure is meant the rate of change of measured continuous blood pressure value.The continuous blood pressure value be meant continuous measurement gained within a certain period of time with the corresponding pressure value sequence of heartbeat each time or several times.Survey the pressure value that sequence that a pressure value obtains then is called discontinuous measurement at set intervals.What mainly solve in the present invention is determining of the continuous rate of change of blood pressure.

Wherein the algorithm of the continuous rate of change of blood pressure can comprise blood pressure absolute change rate and/or blood pressure relative change rate.The computational methods of blood pressure absolute change rate can comprise time domain and frequency domain method.

When adopting time domain approach, can adopt one of following method to determine the blood pressure rate:

Suppose T={t ₁, t ₂, t ₃... t _n} ^TExpression pressure value sequence, t represents the meansigma methods of sequence T, T ₁={ t ₁', t ₂', t ₃' ... t _N-1' ^T={ t ₂-t ₁, t ₃-t ₂, t ₄-t ₃... t _n-t _N-1, t ' expression sequence T ₁Meansigma methods.)

(standard variance of sequence T)

(sequence T ₁Standard variance)

Described frequency domain method obtains the frequency spectrum of sequence T for sequence T being carried out Fourier transform (or other time domain is to conversion of frequency domain).

Blood pressure relative change rate's computational methods can be expressed as: (± blood pressure absolute change rate ÷ mediodespidine average) * 100%.

Instantaneous blood pressure rate is the slope of any arbitrarily on the reflection blood pressure time dependent continuous wave, i.e. dP/dt, and wherein P represents instantaneous pressure value.The time dependent continuous wave of blood pressure can obtain by extracting characteristic parameter and estimate from the signal relevant with transmission characteristic with the generation of pulse wave.The algorithm of instantaneous blood pressure rate can comprise instantaneous blood pressure relative change rate (dP/dt/P) and instantaneous blood pressure absolute change rate (| dP/dt|).

And the rate of change of each (or several times) corresponding pressure value of heartbeat be meant continuous two with the situation of change between the corresponding pressure value of (or several times) heartbeat at every turn.It can be the blood pressure relative change rate, also can be blood pressure absolute change rate, depends on the computational methods that adopted.For example, if adopt the difference of this twice pressure value is multiplied by 100% method again divided by the meansigma methods of this twice pressure value, then this instantaneous rate of change is the relative change rate; If adopt the absolute difference of this twice pressure value method divided by twice pressure value interlude, then this instantaneous rate of change is the absolute change rate.

Therefore, in the present invention, the continuous rate of change of blood pressure, the blood pressure instantaneous rate of change and with each corresponding blood pressure rate of (or several times) heartbeat be three notions arranged side by side.And blood pressure relative change rate and blood pressure absolute change rate are meant concrete rate of change computational methods.

In addition, described pulse wave is the contraction of heart and the fluctuation signal that expansion is produced, or by the caused signal relevant with blood flow of heartbeat.

In a kind of preferred embodiment of the present invention, the photoelectricity volumetric method is adopted in the measurement of pulse wave, promptly utilizes tip tissue sampling photoelectricity plethysmographic signal and the electrocardiosignal of photoelectric sensor from human body.According to the photoelectricity plethysmographic signal that is collected, determine the starting point and the respective vertices of each waveform, and between intercepting starting point and the summit a certain section as one of characteristic parameter of photoelectricity plethysmographic signal, can be described as the FY spacing.FY spacing section can be got from starting point and be begun to the limit whole period, perhaps gets the segment section time wherein.For example from starting point this section period of 90% to the limit, from starting point this section period of 80% to the limit, or the like, the rest may be inferred.

In such scheme, can come to determine the relation between FY spacing and the blood pressure: blood pressure=mFY like this ⁿ+ c, n ≠ 0, FY represents the FY spacing in the formula, m represents to adopt standard-sphygmomanometer that it is calibrated resulting calibration factor to each different measured with c, promptly represents the coefficient of relationship between upper arm blood pressure and the FY spacing.Contact pressure during calibration between appropriate change pick off and the health measured position, and be chosen under the different contact pressure values and finish calibration.

In addition, when needs further improve the precision of blood pressure measurement, can be according to determined FY pitch sequence, in conjunction with the pulse wave transmission time, and another feature parameter YG spacing of photoelectricity plethysmographic signal is come the calculating blood pressure value.Calculating formula is: blood pressure=mFY ⁿ+ a/PTT ²+ bYG+d, n ≠ 0, a ∈ [0, m/2] wherein, b ∈ [0, m/5].

Described step a) can comprise: that determines to be collected produces with pulse wave and the corresponding wave character point position of a series of signal that the transmission time is relevant; With wave character point, determine and corresponding one or several pulse wave transmission time of heartbeat once or several times according to determined signal.

In said method, for the photoelectricity plethysmographic signal, described wave character point is the summit and/or the end point of waveform; For electrocardiosignal, described wave character point is R wave crest point and/or R ripple starting point and/or R ripple end of a period point, and the arbitrary characteristics point on Q ripple, S ripple and the T ripple.In this case, can utilize the time difference between the point at the bottom of electrocardiosignal summit time or the photoelectricity plethysmographic signal utilize the electrocardiosignal summit time or photoelectricity plethysmographic signal summit between time difference obtain pulse wave transmission time sequence.

The present invention also can further comprise according to the corresponding pressure value sequence of heartbeat each time or several times, by certain method that embodies the sequence of values variation tendency, obtain the continuous rate of change of blood pressure.Concrete method can be one of the time domain of the top definite rate of change that has illustrated or frequency domain method.

In another kind of preferred version of the present invention, described definite blood pressure step of rate of change relatively continuously can be the relation of utilizing between FY spacing, YG spacing, blood volume and the blood pressure, is reflected and the relative variation tendency of the corresponding pressure value sequence of heartbeat once or several times by the relative variation tendency with the relative variation tendency of the corresponding FY pitch sequence of heartbeat once or several times and YG spacing.Can be in order to the relative percentage and the YG spacing and the volumetrical relative variation percentage ratio of blood that are used in one or several FY spacing fluctuation in certain period, the relative percentage that reflects corresponding with it pressure value fluctuation is to be reflected in the relative variation tendency of blood pressure in certain period.

Can utilize waveform area (comprising the area of waveform rising edge, the area of waveform trailing edge and the area of whole waveform) to obtain the blood cubical content to the photoelectricity plethysmographic signal.

Pass between described FY spacing, YG spacing, blood volume and the blood pressure is: blood pressure=mFY ⁿ+ aYG+bSV+c, n ≠ 0, wherein m represents to adopt standard-sphygmomanometer that it is calibrated resulting calibration factor to each different measured with c, promptly represents the coefficient of relationship between upper arm blood pressure and FY spacing, YG spacing and the blood volume, FY tabular form FY spacing, YG represents the YG spacing, SV represents the blood cubical content, and a, b, m are constant and a ∈ [0, m/2], b ∈ [0, m/5].

When the heart rate rate of change was less than a certain threshold value in set period, the calculating of blood pressure can also be ignored the influence of heart rate.Can establish a=0 this moment.

According to another embodiment of the present invention, determine that directly the method for the continuous rate of change of described blood pressure can comprise: determine FY spacing rate of change, YG spacing rate of change and blood rate of volumetric change; According to determined FY spacing rate of change, YG spacing rate of change and blood rate of volumetric change, and, determine continuous rate of change with the corresponding blood pressure of one or many heartbeat based on the relational expression between blood pressure and these parameters.

Utilize time domain approach or frequency domain method to determine FY spacing rate of change FYV, pulse wave transmission time rate of change PTTV, YG spacing rate of change YGV, or blood rate of volumetric change VR, wherein

Described time domain approach is determined FYV for adopting in the following equation each:

If T={t ₁, t ₂, t ₃... t _n} ^TExpression FY pitch sequence, pulse wave transmission time sequence, YG pitch sequence or blood volume sequence, t represents the meansigma methods of sequence T, T ₁={ t ₁', t ₂', t ₃' ... t _N-1' ^T={ t ₂-t ₁, t ₃-t ₂, t ₄-t ₃... t _n-t _N-1, t ' expression sequence T ₁Meansigma methods.

1) FYV, PTTV, YGV or $\mathrm{VR}=\sqrt{\frac{1}{n-1}\underset{i=1}{\overset{n}{\∑}}{(t_i-\stackrel{\‾}{t})}^2},$

2) FYV, PTTV, YGV or $\mathrm{VR}=\sqrt{\frac{1}{n-2}\underset{i=1}{\overset{n-2}{\∑}}{(t_{i+1}^{\′}-t_i^{\′})}^2}$

3) FYV, PTTV, YGV or $\mathrm{VR}=\sqrt{\frac{1}{n-2}\underset{i=1}{\overset{n-1}{\∑}}{(t_i^{\′}-\stackrel{\‾}{t^{\′}})}^2}$

Described frequency domain method is: described sequence T is carried out the conversion to frequency domain of Fourier transform or other time domain, obtain the frequency spectrum of sequence T.

In said method of the present invention, described frequency domain method can further comprise: in resulting sequence T (pressure value sequence for example, its corresponding frequency spectrum then is called the blood pressure frequency spectrum) the continually varying frequency spectrum in find out extremely low frequency rate of change, low frequency variations rate and high frequency rate of change, and determine to distinguish corresponding physiological situation with extremely low frequency rate of change, low frequency variations rate and the high frequency rate of change of described blood pressure frequency spectrum.

The extremely low frequency rate of change, low frequency variations rate and the high frequency rate of change that wherein define the blood pressure frequency spectrum adopt area-method, the area that is about to each frequency content is determined the variation of each frequency content than the gross area of last frequency spectrum, thereby reflects the variation of associated physiological status.

In addition, the method for intrasonic rate of change, extremely low frequency rate of change, low frequency variations rate and the high frequency rate of change of definition blood pressure frequency spectrum is:

Intrasonic rate of change: the gross area of the area/blood pressure frequency spectrum of blood pressure frequency spectrum in 0～0.003Hz scope;

Extremely low frequency rate of change: the gross area of blood pressure frequency spectrum area in 0.003～0.04Hz scope/blood pressure frequency spectrum;

Low frequency variations rate: the gross area of the area/blood pressure frequency spectrum of blood pressure frequency spectrum in 0.04～0.15Hz scope;

High frequency rate of change: the gross area of the area/blood pressure frequency spectrum of blood pressure frequency spectrum in 0.15～0.4Hz scope.

In addition, in above-mentioned all correlation techniques, the available pulse wave transmission time (PTT) substitutes the FY spacing and carries out the estimation of blood pressure or blood pressure rate.

The present invention can be used for suffering from the middle-aged and elderly people of cardiovascular disease, and the vicissitudinous often people of some physiological statuss, for example athlete and the crowd that moils etc., carrying out long continuous blood pressure measures, and then obtain in this time period and the continuous rate of change of the corresponding blood pressure of heartbeat each time, with the reflection physiological situation of human body or the variation of emotional state etc., even disclose some and be difficult to the change of state discovered, thereby provide enough useful informations for medical treatment and health care.

Brief Description Of Drawings

Below specific description of embodiments of the present invention in conjunction with the drawings, and by these explanations, it is clearer that above-mentioned purpose of the present invention, advantage and feature will become.Accompanying drawing comprises:

Fig. 1 is used to illustrate the flow chart of the measuring method of the continuous rate of change of blood pressure;

Fig. 2 is used to illustrate the flow chart of determining the blood pressure rate;

Fig. 3 is used for explanation and how utilizes electrocardiosignal and photoelectricity plethysmographic signal definition FY spacing, pulse wave transmission time, and each characteristic point on the photoelectricity plethysmographic signal;

Fig. 4 is used to illustrate the fluctuation situation of pulse wave transmission time in shorter a period of time;

Fig. 5 is used for illustrating that blood pressure was one day fluctuation situation;

Fig. 6 be used to illustrate with the corresponding pressure value of heartbeat each time in the fluctuation situation of shorter a period of time;

Fig. 7 is used to illustrate and the fluctuation situation of per five corresponding pressure values of heartbeat in shorter a period of time;

Fig. 8 be used to illustrate with the corresponding pressure value of heartbeat each time at the frequency spectrum of shorter a period of time;

Fig. 9 (a) be used for illustrating the photoelectricity plethysmographic signal with the corresponding FY spacing of heartbeat is in the fluctuation situation of shorter a period of time each time, Fig. 9 (b) is its corresponding frequency spectrum;

Figure 10 shows each feature pitch on the photoelectricity plethysmographic signal and the concrete definition of amplitude;

Figure 11 is used to illustrate with the pressure value of FY spacing estimation and the comparison (n=2) of actual value.

The specific embodiment

Fig. 1 is the flow chart according to the method for the continuous rate of change of measurement blood pressure of one embodiment of the present of invention.As shown in Figure 1, in this embodiment of the present invention, mainly comprise from the step 101 of human body acquired signal, Signal Pretreatment step 102, determine the step 103 of corresponding wave character point in the signal, determine the FY spacing, pulse wave transmission time and YG pitch sequence step 104, determine FY spacing rate of change (FYV), pulse wave transmission time rate of change (PTTV), changes in heart rate rate (HRV), and the step 105 of blood rate of volumetric change (VR), based on determined FYV, PTTV, the step 106 of the direct calculating blood pressure rate of change of parameter such as HRV and VR (BPV), calculating blood pressure relative change rate's step 107, with the step 108 of FY spacing (or in conjunction with other parameter) calculating blood pressure, and from the step 109 of pressure value sequence calculating blood pressure rate of change.

Below each step is elaborated.

● step 101: signals collecting

This step 101 comprises tip position (for example positions such as finger, ear-lobe and toe) or other non-tip position (comprise positions such as wrist, thigh) collection with the pulse wave relevant signal of the certain pick off of employing from human body, for example electrocardiosignal or photoelectricity plethysmographic signal, thereby determine the characteristic parameter relevant, for example pulse wave transmission time with pulse wave.The time of signals collecting can decide as required.About the technology contents of sort signal acquisition method can referring to:

1) Allen, J. and Murray, A. shown " Variability of photoplethysmographyperipheral pulse measurements at the ears; thumbs and toes (in the transmutability of the light plethysmogram pulses measure at ear, finger, toe place ", publish ofScience, Measurement and Technology (IEEE science, measurement and technology transactions), the 147th volume in IEEE Proceedings, the 403-407 page or leaf, 2000;

2) Allen, J. and Murray, A. shown " Comparison of regional variability inmulti-site photoplethysmographic pulse wave characteristics (regional variable comparison in multiple spot light plethysmogram impulse wave characteristic ", publish (first international medical signals and the meeting of information processing progress in First International Conferenceon Advances in Medical Signal and Information Processing, the 26-31 page or leaf, 2000;

3) Chan, K.W., Hung, K., Zhang, Y.T. " the Noninvasive and cufflessmeasurements of blood pressure for telemedicine (being used for the non-intruding of Telemedicine and the blood pressure measurement of sleeveless belt) " that is shown, publish in Proceedings of the 23rd Annual InternationalConference of the IEEE Engineering in Medicine and Biology Society (the 23rd International Year meeting transactions of IEEE medical science and biology society's engineering), the 4th volume, the 3592-3593 page or leaf, calendar year 2001.Or the like

● step 102: Signal Pretreatment

This step 102 comprises that a series of signal relevant with the pulse wave transmission time that step 101 is collected carries out noise remove and smoothly wait pretreatment.Certainly, whether carry out pretreatment and depend on the quality of signals that collected and the function of related hardware.Wherein noise remove mainly adopts methods such as signal being carried out filtering, smoothing processing then can adopt for example with signal subdivision to be some segments and the value of each point in the every segment meansigma methods with this section is replaced.These Signal Pre-Processing Method all can adopt existing technology, repeat no more herein.

● step 103: determine corresponding wave character point in the signal

This step 103 is used for determining the FY spacing intercept method of photoelectricity plethysmographic signal, and corresponding wave character point position between a series of signal relevant with the pulse wave transmission time.Specifically, some is put pairing physiological significance and determines whether adopting this to put calculating the pulse wave transmission time can to utilize signal, can be with reference to shown in Figure 3.Can define parameters such as corresponding FY spacing, YG spacing and pulse wave transmission time.For example, the intercept method of FY spacing section comprises: begin to the limit whole period from starting point, from starting point this section period of 90% to the limit, from starting point this section period of 80% to the limit, or the like the rest may be inferred.The computational methods in pulse wave transmission time: for the photoelectricity plethysmographic signal, this wave character point can comprise summit, end point and the arbitrfary point between these 2 of waveform.For electrocardiosignal, this wave character point can comprise other arbitrary characteristics points on R wave crest point, R ripple starting point, R ripple end of a period point and the R ripple, and the arbitrary characteristics point on Q ripple, S ripple and the T ripple.

● step 104: determine FY spacing, pulse wave transmission time and YG pitch sequence

In this step 104,, calculate each FY spacing, YG spacing and pulse wave transmission time by predetermined method according to the wave character point separately of the determined signal of step 103.

Fig. 3 has illustrated the characteristic point F, the Y that how to determine the photoelectricity plethysmographic signal in the signal, G etc. and corresponding pulse waveform characteristic point, and utilizes determined wave character point calculating FY spacing, YG spacing and pulse wave transmission time.It utilizes electrocardiosignal and photoelectricity plethysmographic signal definition pulse wave transmission time.Shown in Fig. 3 (a), the time 301 is represented the position of R wave crest point on time shaft on the electrocardiosignal, and time 302 and time 303 are represented point and the position of a summit on time shaft at the bottom of on the photoelectricity plethysmographic signal one respectively.These time values can be used for determining in a different manner the pulse wave transmission time.A kind of definite method is that the time difference between computation time 301 and time 302 obtains pulse wave transmission time Ts 304.Another kind of definite method is the time difference between computation time 301 and time 303, to obtain pulse wave transmission time Td 305.

Because Td 304 or Td 305 calculate by the characteristic point of different photoelectricity plethysmographic signal, the information that they transmit all is different from physiology and on the numerical value.Each characteristic point of photoelectricity plethysmographic signal is defined as follows: 1) F309: the zooming starting point of waveforms amplitude (or waveforms amplitude is from dropping to zooming turning point); 2) Y310: the peak of waveforms amplitude; 3) W311: first turning point of waveform trailing edge (for the signal that does not have this turning point, the W point is defined as and reaches waveform 50% point of high amplitude on the waveform trailing edge); 4) G312: first lowest amplitude point on the waveform trailing edge, shown in G313 among Fig. 3 (b); Or reach 1% point of high amplitude of waveform on the waveform trailing edge, shown in G312 among Fig. 3 (b); Or and the point that overlaps of F point, shown in the middle G (F) 314 of Fig. 3 (b) (different signals is depended in different definition).Wherein utilize photoelectricity plethysmographic signal definition FY spacing, shown in Fig. 3 (a), the intercept method of FY spacing section comprises: begin to the limit whole section time FY307 from starting point, can comprise that also the rest may be inferred from starting point this section period FY308 of 50% to the limit or the like.

By repeatedly calculating the pulse wave transmission time sequence just can obtain with Td 305 or Td 306 descriptions, and F309, Y310 and determined FY spacing of G312 and YG spacing.

If do not carry out blood pressure relative change rate's calculating this moment, then enter step 105 determine FYV, PTTV, HRV and VR and and then definite BPV; Otherwise calculating blood pressure relative change rate (step 107).

● step 105: determine FYV, PTTV, YGV and VR

This step 105 is used to utilize the rate of change analytic process of domain and frequency domain to calculate the rate of change (PTTV) in FY spacing rate of change (FYV), pulse wave transmission time, YG spacing rate of change (YGV), and the rate of change (VR) relevant with the blood volume.For example, concrete grammar can be:

When adopting frequency domain method, establish T={t ₁, t ₂, t ₃... t _n} ^TExpression FY pitch sequence or pulse wave transmission time or YG spacing, t represents the meansigma methods of sequence T, then can adopt following any equation to calculate corresponding rate of change FYV, PTTV or YGV.

1) FYV, PTTV or $\mathrm{YGV}=\sqrt{\frac{1}{n-1}\underset{i=1}{\overset{n}{\∑}}{(t_i-\stackrel{\‾}{t})}^2}$ (standard variance of sequence T)

In addition, suppose T ₁={ t ₁', t ₂', t ₃' ... t _N-1' ^T={ t ₂-t ₁, t ₃-t ₂, t ₄-t ₃... t _n-t _N-1, t ' expression sequence T ₁Meansigma methods.Then above-mentioned rate of change also can be obtained by following calculating formula:

2) FYV, PTTV or $\mathrm{YGV}=\sqrt{\frac{1}{n-2}\underset{i=1}{\overset{n-2}{\∑}}{(t_{i+1}^{\′}-t_i^{\′})}^2}$

3) FYV, PTTV or $\mathrm{YGV}=\sqrt{\frac{1}{n-2}\underset{i=1}{\overset{n-1}{\∑}}{(t_i^{\′}-\stackrel{\‾}{t^{\′}})}^2}$ (sequence T ₁Standard variance)

In addition, also can adopt frequency domain algorithm, to above-mentioned sequence T or T ₁Carry out Fourier transform (or other time domain is to conversion of frequency domain), obtain the frequency spectrum of sequence T.

Wherein frequency-domain analysis relates generally to several frequency components: extremely low frequency component (having comprised the intrasonic component), greatly between 0～0.04Hz; Low-frequency component is greatly between 0.04～0.15Hz; And radio-frequency component, greatly between 0.15～0.4Hz.Can calculate the amplitude on the frequency spectrum, area etc., to obtain corresponding rate of change.

Fig. 4 exemplarily illustrates the situation with one or many heartbeat corresponding pulse wave transmission time sequence pairing pulse wave transmission time rate of change PTTV.As shown in Figure 4, the continuous recording length of signal is about 5 minutes, thus can obtain with sequence of corresponding pulse wave transmission time of heartbeat each time and with per five the corresponding pulse wave of heartbeat transmission time sequences.

Though the present invention does not have strict restriction for the number of times of heartbeat, number of times is obtained too greatly just can not reflect some blood pressure fast, and promptly the radio-frequency component of blood pressure rate can not be reflected, thus number of times had better get the smaller the better.The continuous recording time span of signal depends on the time of the required monitoring of measured, thereby can be reflected at the changing conditions such as the state of an illness in this period.Continuous recording time span is hard-core.

Rate of change 401 among Fig. 4 and rate of change 402 are respectively the standard variance of corresponding pulse wave transmission time sequence.Fig. 4 (a) shows and corresponding pulse wave transmission time of heartbeat each time, and Fig. 4 (b) shows and per five the corresponding pulse wave of heartbeat transmission times, and promptly each value of this sequence is the meansigma methods of the value shown in per five Fig. 4 (a).As shown in the figure, the pulse wave transmission time sequence by the example shown in Fig. 4 (a) and 4 (b) all had bigger fluctuation between 0.3 second and 0.34 second.If T={t ₁, t ₂, t ₃... t _n} ^TExpression pulse wave transmission time sequence, t represents the meansigma methods of sequence T, rate of change PTTV 401 and rate of change PTTV 402 all can be by above-mentioned calculating formulas 1)-3) any acquisition, or adopt frequency domain analysis to calculate PTTV, promptly sequence T is carried out Fourier transform (or other time domain is to conversion of frequency domain), obtain the frequency spectrum of sequence T.By frequency component is analyzed, find out the physiological situation of corresponding with it physiological parameter and representative.

Wherein, analysis to frequency component mainly comprises: observing this signal by frequency spectrum has significant composition in which frequency band, and then can calculate area or the area of frequency band and the ratio of the frequency spectrum gross area of frequency band, thereby can reflect the physiological situation with corresponding physiological parameter of this frequency band and representative.For example, sympathetic nerve and parasympathetic activity situation etc. both can have been reflected by the area of the frequency band of 0.04-0.15Hz or the ratio of area in the frequency spectrum that calculates heart rate; And the frequency component of 0.15-0.4Hz can reflect breathing and parasympathetic activity.

Equally, can calculate YG spacing rate of change YGV (can with reference to said method) and blood rate of volumetric change (VR) by the method that embodies the sequence of values variation tendency.Its computational methods still can adopt the above 1)-3) and equation, or adopt frequency domain analysis to realize.

In addition, in the present invention, heart rate signal can obtain by electrocardiosignal or photoelectricity volume signals; Blood volume sequence then can be extracted from the waveform area of photoelectricity plethysmographic signal, comprises the area of waveform rising edge, the area of waveform trailing edge and the area of whole waveform.Obtain after heart rate sequence and the blood volume sequence, its rate of change computational methods also can adopt the above-mentioned time domain and the computational methods of frequency domain.

In addition, the calculating to blood rate of volumetric change (VR) also can obtain by the waveform area sequence of photoelectricity plethysmographic signal is carried out differentiate.

For example, under the situation of calculating whole area sequence, because the photoelectricity plethysmographic signal has the comparatively waveform of rule, therefore each independent waveform both can obtain an area value, promptly just can obtain the area value of this waveform until the starting point of next waveform since the starting point integration of a waveform, thereby can obtain the sequence of waveform area, can calculate rate of change, also can carry out the differential differentiate and can obtain the blood rate of volumetric change this area sequence with above-mentioned method.

● step 106: determine blood pressure rate BPV.The continuous rate of change of BPV general reference blood pressure can comprise blood pressure relative change rate and blood pressure absolute change rate.

This step 106 utilize FY spacing rate of change (FYV) that step 105 obtains, YG spacing rate of change (YGV) and and blood rate of volumetric change (VR) and BPV between relational expression, come direct calculating blood pressure absolute change rate BPV.Fig. 2 is used to illustrate the flow chart of above-mentioned calculating blood pressure rate of change.In step 201, promptly calculate FY spacing rate of change (FYV), YG spacing rate of change (YGV) and blood rate of volumetric change (VR) according to the described method of step 105.

The relational expression of calculating BPV can be expressed as BPV=f (FYV, YGV, VR, c) or BPV=f (PTTV, YGV, VR, c), the concrete form of f () depends on the concrete grammar of determining rate of change, based on the relation between blood pressure and FY or PTT, HR and the SV: blood pressure=mFY ⁿ+ aYG+bSV+c or blood pressure=m/PTT ²+ aYG+bSV+c, n ≠ 0.Wherein m represents to adopt standard-sphygmomanometer that it is calibrated resulting calibration factor to each different measured with c, promptly represent the coefficient of relationship between upper arm blood pressure and FY spacing, YG spacing and the blood volume, FY tabular form FY spacing, PTT represents the pulse wave transmission time, and YG represents the YG spacing, and SV represents the blood cubical content, a, b, m are constant and a ∈ [0, m/2], b ∈ [0, m/5].And can derive according to concrete rate of change method.Can adopt Calibration Method, promptly carry out once or several times measuring and determine these constants as standard with traditional reference instrument.

For example, if BP=mFY ²+ c (wherein m represents to adopt standard-sphygmomanometer that it is calibrated resulting calibration factor to each different measured with c), then can derive by simple mathematical obtains $\mathrm{BPV}=\sqrt{\frac{m}{n-1}\underset{i=1}{\overset{n}{\&Sum;}}{({F{Y}_i}^2-\stackrel{\&OverBar;}{{\mathrm{<figure-callout\; id="2"\; label="FY"\; filenames="A20041004241000301.png,A20041004241000311.png"\; state="\{\{state\}\}">FY</figure-callout>}}^2})}^2}=\sqrt{m}\&CenterDot;F{Y}^{2}V.$ By that analogy, when comprising a plurality of parameters: FY, YG and SV in the calculating formula of blood pressure, also can obtain corresponding BPV=f (FYV, YGV, VR, c).

Further, can judge that at the appointed time whether section interior changes in heart rate rate HRV (standard variance) is greater than a certain threshold value Th.This threshold value can be determined with the ratio of heart rate meansigma methods by the standard variance that calculates the changes in heart rate in the section at the appointed time, less than 3%, then can ignore the influence of changes in heart rate rate HRV as if this ratio.In this way, then calculate BPV (step 203) with top formula; Otherwise the calculating of blood pressure rate can be ignored the influence of changes in heart rate rate HRV, and this moment, (PTTV, VR c) calculated BPV (step 204) with formula BPV=f.

Can be by relative percentage and the YG spacing and the isoparametric relative variation percentage ratio of blood volume of one or several FY spacing fluctuation in certain period, the relative percentage that reflects corresponding with it pressure value fluctuation, therefore can be reflected in the relative variation tendency of blood pressure in certain period, rather than the absolute change rate of reflection blood pressure values.This is because because the fluctuation tendency of pressure value is the linear superposition of parameter fluctuation trend such as FY spacing, YG spacing and blood volume, so has known the fluctuation tendency of pulse wave transmission time and heart rate, promptly can generally determine the fluctuation tendency of blood pressure.

● step 107: calculating blood pressure relative change rate

This step 107 comprises utilizing and concerns the calculating blood pressure relative change rate between pulse wave transmission time and the blood pressure (systolic pressure and diastolic pressure) that its relational expression can be expressed as:

Blood pressure=mFY ⁿ+ aYG+bSV+c or blood pressure=m/PTT ²+ aYG+bSV+c,

N ≠ 0 wherein, m represents to adopt standard-sphygmomanometer that it is calibrated resulting calibration factor to each different measured with c, promptly represent the coefficient of relationship between upper arm blood pressure and FY spacing, YG spacing and the blood volume, FY tabular form FY spacing, YG represents the YG spacing, SV represents the blood cubical content, a, b, m are constant and a ∈ [0, m/2], b ∈ [0, m/5].

Based on this relational expression, just do not need to calibrate and to reflect and the relative change rate of the corresponding pressure value sequence of (or several times) heartbeat each time by FY spacing, YG spacing and the isoparametric relative change rate of blood volume.Promptly, reflect the relative percentage of corresponding with it pressure value fluctuation by relative percentage and the YG spacing and the isoparametric relative variation percentage ratio of blood volume of each (or several) FY spacing fluctuation in certain period.

Fig. 6 and Fig. 7 are used to illustrate the situation of the relative fluctuation of pressure value.Fig. 6 (a) shows and the corresponding systolic pressure value sequence of heartbeat situation of change within five minutes each time.Can see that by Fig. 6 (a) even in short 5 minutes, and the corresponding systolic pressure of heartbeat also has bigger fluctuation between 110mmHg and 118mmHg each time.

Need explanation, shown among Fig. 6 and Fig. 7 only is the fluctuation situation of blood pressure, is about to former sequence and deducts meansigma methods resulting sequence of values afterwards.Rate of change 601 is the standard variance of this systolic pressure value sequence.Fig. 6 (b) shows and the corresponding diastolic blood pressure values sequence of heartbeat situation of change within five minutes each time.Can be seen that by Fig. 6 (b) in 5 minutes, and the corresponding diastolic pressure of heartbeat also has bigger fluctuation between 68mmHg and 73mmHg each time, rate of change 602 is the standard variance of this diastolic blood pressure values sequence.Suppose BP={P ₁, P ₂, P ₃... P _n} ^TExpression and the corresponding pressure value sequence of heartbeat each time, P represents the meansigma methods of sequence B P, rate of change 601 and rate of change 602 all can be obtained by following calculating formula:

Formula 4:

Fig. 7 has illustrated and the fluctuation situation of per five corresponding pressure values of heartbeat in shorter a period of time.

Fig. 7 (a) shows and the corresponding systolic pressure value sequence of per five heartbeats situation of change within five minutes.Can be seen by Fig. 7 (a), and the corresponding systolic pressure of heartbeat also has bigger fluctuation between 110mmHg and 117mmHg each time, rate of change 701 is the standard variance of this systolic pressure value sequence.Fig. 7 (b) shows situation about changing with the corresponding diastolic blood pressure values sequence of per five heartbeats within five minutes.Can be seen that by Fig. 7 (b) in 5 minutes, and the corresponding diastolic pressure of heartbeat also has bigger fluctuation between 68mmHg and 73mmHg each time, rate of change 702 is the standard variance of this diastolic blood pressure values sequence.The method of calculating rate of change 701 and rate of change 702 is as described in the following formula 4.

● step 108: with FY spacing (or in conjunction with other parameter) calculating blood pressure

Blood pressure=mFY ⁿ+ c, n ≠ 0, wherein m represents to adopt standard-sphygmomanometer that it is calibrated resulting calibration factor to each different measured with c, promptly represents the coefficient of relationship between upper arm blood pressure and the FY spacing, and FY represents the FY spacing.Contact pressure during calibration between appropriate change pick off and the health measured position, and be chosen under the different contact pressure values and finish calibration.

In addition, when needs further improve the precision of blood pressure measurement, can be according to determined FY pitch sequence, in conjunction with the pulse wave transmission time, and another feature parameter YG spacing (it defines as shown in figure 10) of photoelectricity plethysmographic signal, adopt following method to determine: blood pressure=mFY ⁿ+ a/PTT ²+ bYG+d, a ∈ [0, m/2] wherein, b ∈ [0, m/5].

● step 109: from pressure value sequence calculating blood pressure rate of change

By the corresponding pressure value sequence of (or several times) each time heartbeat that records with FY spacing (or in conjunction with other parameter), and this pressure value sequence calculated and analyze by the rate of change analytic process of domain and frequency domain.Can adopt previously described method to obtain blood pressure variation tendency in a certain amount of time, to reflect the variation of corresponding physiological status.

Fig. 5 be used for illustrating blood pressure one day (from about 8 of mornings to about 4 of afternoons) the absolute change situation.As shown in Figure 5, systolic pressure and diastolic pressure all had obvious variation under different period or the different states in one day.Blood pressure 501 when driveing to work is corresponding to about 9 of mornings, relatively low value among systolic pressure and diastolic pressure all are in a day under this period and this kind state.Blood pressure 502 when preparing lessons is corresponding to about 11 of mornings, systolic pressure and relative higher value among diastolic pressure all is in a day under this period and this kind state.Blood pressure 503 when eating out is corresponding to about 12 noon, at systolic pressure under this period and this kind state with fall back to relatively low value among a day again; Though diastolic pressure also falls after rise to some extent, the amplitude that falls after rise is big less than systolic pressure.Blood pressure 504 when office moils is corresponding to about 2 pm, relative higher value among systolic pressure rises to a day again under this period and this kind state; Diastolic pressure then relatively steadily, does not have significant change.The blood pressure 505 of last class hour is corresponding to mid-afternoon, though the systolic pressure when systolic pressure moils than office under this period and this kind state falls after rise to some extent, but still is in value higher relatively in a day; And the diastolic pressure of diastolic pressure when moiling than office rise to some extent, also is in value higher relatively in a day.

Further, the present invention can observe intrasonic, extremely low frequency, low frequency and radio-frequency component from the frequency spectrum of blood pressure, thereby can the rate of change of each frequency content be defined, thereby can reflect the variation of associated physiological status better.The define method of frequency change rate mainly comprises area-method etc., and the area that is about to each frequency content is determined the variation of each frequency content than the gross area of last frequency spectrum.

Fig. 8 be used to illustrate the method according to this invention measured with the frequency spectrum of the corresponding pressure value of heartbeat in shorter a period of time each time.Fig. 8 (a) is depicted as and the frequency spectrum of the corresponding systolic pressure of heartbeat each time, and 3 comparatively significant frequency contents 801,802 and 803 are wherein arranged.801 are extremely low frequency component (having comprised the intrasonic component), greatly between 0～0.04Hz; 802 is low-frequency component, greatly between 0.04～0.15Hz; 803 is radio-frequency component, greatly between 0.15～0.4Hz.Fig. 8 (b) is depicted as and the frequency spectrum of the corresponding diastolic pressure of heartbeat each time, wherein also have 3 with (a) the corresponding to frequency component 804,805 and 806 of medium frequency composition.These frequency components have the important physical meaning, can be associated with sympathetic nerve, parasympathetic activity and respiratory movement etc. respectively.

Fig. 9 is used to illustrate the FY spacing of photoelectricity plethysmographic signal in the fluctuation situation of shorter a period of time, and corresponding frequency spectrum.Fig. 9 (a) is depicted as the fluctuation of FY spacing in 1 minute, and its fluctuation range is greatly within ± 0.03 second.Fig. 9 (b) is the frequency spectrum corresponding to the FY pitch sequence shown in Fig. 9 (a).By being clear that two frequency components among Fig. 9 (b): greatly about about 0.05Hz and about 0.3Hz.These two frequency components can be associated with sympathetic nerve, parasympathetic activity and respiratory movement respectively.Therefore, the FY spacing has also comprised and heart rate and the similar frequency component of blood pressure, can embody the important physical meaning.

Figure 10 is used to illustrate each feature pitch on the photoelectricity plethysmographic signal and the concrete definition of amplitude, comprises FY spacing 1001, YW spacing 1002, WG spacing 1003, GF spacing 1004, FG spacing 1007, FY amplitude 1005 and YW amplitude 1006.Wherein the definition of F, Y, W and G as described in Figure 3.The method for expressing of FY spacing can also comprise any section in the FY spacing 1001.

Figure 11 is used to illustrate according to of the present invention with the pressure value of FY spacing estimation and the comparison (n=2) of actual value.The estimation formula can adopt: blood pressure=mFY ²+ c, wherein m represents to adopt standard-sphygmomanometer to calibrate resulting calibration factor to each different measured with c, promptly represents the coefficient of relationship between upper arm blood pressure and the FY spacing, and FY represents the FY spacing.Pressure during calibration between appropriate change pick off and the Body contact end, and be chosen under the different force value and calibrate.Figure 11 (a) is depicted as the comparison of the systolic pressure and the actual value of estimation, and 7 times of representing to carry out under 7 different pressures values respectively of abscissa are measured, and vertical coordinate is represented the numerical value of systolic pressure; The mean error of measuring only is-1.8mmHg, and standard variance is 2.4mmHg.Figure 11 (b) is depicted as the diastolic pressure of same measured estimation and the comparison of actual value, and represented 7 the different pressures values of its abscissa are corresponding with each force value among Figure 11 (a) respectively; The mean error of measuring only is-2.2mmHg, and standard variance is 3.3mmHg.

More than the preferred embodiments of the present invention are described in detail for illustrative purposes; but those skilled in the art is to be appreciated that; under the situation of scope and spirit of the present invention; various improvement, interpolation and replacement all are possible, and all in the protection domain that claim of the present invention limited.

Claims (21)

1. the method for measurement and the corresponding blood pressure parameter of one or many heartbeat may further comprise the steps:

A. from the human body collection signal relevant with pulse wave;

B. from the signal of being gathered, obtain characteristic parameter, obtain corresponding characteristic parameter sequence;

C. according to the characteristic parameter sequence of determined signal, determine and the corresponding blood pressure parameter of heartbeat at every turn or repeatedly.

2. method according to claim 1 is characterized in that, described blood pressure parameter comprises: pressure value, the continuous rate of change of blood pressure relative change rate and/or blood pressure, instantaneous blood pressure rate, and with the corresponding blood pressure rate of each heartbeat.

3. method according to claim 2, it is characterized in that, the described signal relevant with pulse wave be and the generation of pulse wave and the relevant signal of transmission characteristic, the fluctuation signal that the contraction that comprises heart and expansion are produced, or by the caused signal relevant with blood flow of heartbeat.

4. method according to claim 3 is characterized in that described pulse wave is measured by optical sensor, pressure transducer, sonic transducer, photoelectric sensor, acceleration transducer, displacement transducer or electrode.

5. method according to claim 1 is characterized in that, described step a adopts the photoelectricity volumetric method to gather the photoelectricity plethysmographic signal relevant with the transmission time of pulse wave, and described step b further comprises:

According to the photoelectricity plethysmographic signal that is collected, to determine the wherein starting point and the respective vertices of each waveform, and intercept between described starting point and the summit one section as the FY spacing, this FY spacing is as one of characteristic parameter of described photoelectricity plethysmographic signal,

Wherein said FY spacing comprises: begin to the limit whole period from described starting point, or segment section time wherein.

6. method according to claim 5 is characterized in that, described step c further comprises: according to determined FY spacing, and the relation between described FY spacing and the blood pressure: blood pressure=mFY ⁿ+ c obtains the pressure value sequence, n ≠ 0 wherein, and FY represents the FY spacing, m represents to adopt standard-sphygmomanometer to calibrate resulting calibration factor to each different measured with c.

7. method according to claim 6 is characterized in that described step c further comprises calibration steps, wherein when calibration, changes the contact pressure between pick off and the health measured position, and calibrates under different contact pressure values.

8. method according to claim 5, it is characterized in that described step c further comprises: according to determined FY pitch sequence, the described pulse wave transmission time, and another feature parameter YG spacing of photoelectricity plethysmographic signal, adopt following calculating formula to come the calculating blood pressure value:

Blood pressure=mFY ⁿ+ a/PTT ²+ bYG+d, n ≠ 0 wherein, a ∈ [0, m/2], b ∈ [0, m/5]

Wherein said YG spacing is Y point on the photoelectricity plethysmographic signal waveform and the spacing between the G point, and wherein, the Y point is the summit of photoelectricity plethysmographic signal waveform; The G point is first lowest amplitude point on the waveform trailing edge; Or reach waveform 1% point of high amplitude on the waveform trailing edge; Or and the point that coincides of next starting point.

9. method according to claim 3 is characterized in that, according to determined and the corresponding pressure value sequence of heartbeat each time or several times, determines the continuous rate of change BPV of blood pressure by time domain or frequency domain method, wherein

Described time domain approach is:

If T={t ₁, t ₂, t ₃... t _n} ^TExpression pressure value sequence, t represents the meansigma methods of sequence T, T ₁={ t ₁', t ₂', t ₃' ... t _N-1' T={t ₂-t ₁, t ₃-t ₂, t ₄-t ₃... t _n-t _N-1, t ' expression sequence T ₁Meansigma methods

Method one: $\mathrm{BPV}=\sqrt{\frac{1}{n-1}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{(t_i-\stackrel{\&OverBar;}{t})}^2}$

Method two: $\mathrm{BPV}=\sqrt{\frac{1}{n-2}\underset{i=1}{\overset{n-2}{\mathrm{\&Sigma;}}}{(t_{i+1}^{\&prime;}-t_i^{\&prime;})}^2}$

Method three: $\mathrm{BPV}=\sqrt{{\frac{1}{n-2}\underset{i=1}{\overset{n-1}{\mathrm{\&Sigma;}}}(t_i^{\&prime;}-\stackrel{\&OverBar;}{t^{\&prime;}})}^2}$

Described frequency domain method obtains the frequency spectrum of sequence T for sequence T being carried out the conversion to frequency domain of Fourier transform or other time domain.

10. method according to claim 8, it is characterized in that, further comprise: from the waveform area of described photoelectricity plethysmographic signal, extract relevant information, described relevant information comprises the area of waveform rising edge, the area of waveform trailing edge and the area of whole waveform, determines the blood cubical content.

11. method according to claim 10, it is characterized in that, utilize FY spacing or pulse wave transmission time, relation between YG spacing, blood volume and the blood pressure, according to the relative change rate of the corresponding FY pitch sequence of one or many heartbeat, and YG spacing and the volumetrical relative change rate of blood, determine and the relative change rate of the corresponding pressure value sequence of heartbeat once or several times.

12. method according to claim 11, it is characterized in that, further comprise: utilize the relative percentage of one or more FY spacing fluctuations in certain period, and described YG spacing and the volumetrical relative change rate of blood, determine the relative percentage that corresponding pressure value fluctuates.

13. method according to claim 10 is characterized in that, determines the relation between described FY spacing, YG spacing and the blood pressure: blood pressure=mFY in the following manner ⁿ+ aYG+bSV+c, n ≠ 0, wherein m represents to adopt standard-sphygmomanometer to calibrate resulting calibration factor to each different measured with c, the relation between expression upper arm blood pressure and FY spacing, YG spacing and the blood volume, and FY represents the FY spacing, YG represents the YG spacing, SV represents the blood cubical content, and a, b are constant and a ∈ [0, m/2], b ∈ [0, m/5].

14. method according to claim 13 is characterized in that, when the heart rate rate of change is less than a certain threshold value in set period, ignores the influence of heart rate when determining blood pressure, at this moment a=0.

15. method according to claim 8 is characterized in that, further comprises: utilize time domain approach or frequency domain method to determine FY spacing rate of change FYV, pulse wave transmission time rate of change PTTV, YG spacing rate of change YGV, or blood rate of volumetric change VR, wherein

Described time domain approach is determined FYV for adopting in the following equation each:

If T={t ₁, t ₂, t ₃... t _n} ^TExpression FY pitch sequence, pulse wave transmission time sequence, YG pitch sequence or blood volume sequence, t represents the meansigma methods of sequence T, T ₁={ t ₁', t ₂', t ₃' ... t _N-1' ^T={ t ₂-t ₁, t ₃-t ₂, t ₄-t ₃... t _n-t _N-1, t ' expression sequence T ₁Meansigma methods.

1) FYV, PTTV, YGV or $\mathrm{VR}=\sqrt{\frac{1}{n-1}\underset{i=1}{\overset{n}{\mathrm{\&Sigma;}}}{(t_i-\stackrel{\&OverBar;}{t})}^2},$

2) FYV, PTTV, YGV or $\mathrm{VR}=\sqrt{\frac{1}{n-2}{\underset{i=1}{\overset{n-2}{\mathrm{\&Sigma;}}}(t_{i+1}^{\&prime;}-t_i^{\&prime;})}^2}$

3) FYV, PTTV, YGV or $\mathrm{VR}=\sqrt{\frac{1}{n-2}\underset{i=1}{\overset{n-1}{\mathrm{\&Sigma;}}}{(t_i^{\&prime;}-\stackrel{\&OverBar;}{t^{\&prime;}})}^2}$

Described frequency domain method is: described sequence T is carried out the conversion to frequency domain of Fourier transform or other time domain, obtain the frequency spectrum of sequence T.

16. method according to claim 15, it is characterized in that, further comprise and utilize following relational expression BPV=f (FYV, YGV, VR c) directly determines blood pressure rate BPV, wherein the concrete form of f () depends on described each parameter rate of change FYV, YGV, the concrete account form of VR, c represents to adopt standard-sphygmomanometer that it is calibrated resulting calibration factor to each different measured.

17. method according to claim 9, it is characterized in that, further comprise the extremely low frequency rate of change, low frequency variations rate and the high frequency rate of change that adopt area-method to determine the blood pressure frequency spectrum, wherein said area-method is the area of each frequency content to be determined the variation of each frequency content with respect to the gross area of described blood pressure frequency spectrum.

18. method according to claim 17, the frequency component of wherein said blood pressure frequency spectrum comprises: the intrasonic component, and its frequency range is between 0～0.003Hz; The extremely low frequency component, its frequency range is between 0.003～0.04Hz; Low-frequency component, its frequency range is between 0.04～0.15Hz; And radio-frequency component, its frequency range is between 0.15～0.4Hz, and the method for the intrasonic rate of change of described definite blood pressure frequency spectrum, extremely low frequency rate of change, low frequency variations rate and high frequency rate of change is:

Intrasonic rate of change: the gross area of the area/blood pressure frequency spectrum of blood pressure frequency spectrum in 0～0.003Hz scope;

Extremely low frequency rate of change: the gross area of blood pressure frequency spectrum area in 0.003～0.04Hz scope/blood pressure frequency spectrum;

Low frequency variations rate: the gross area of the area/blood pressure frequency spectrum of blood pressure frequency spectrum in 0.04～0.15Hz scope;

High frequency rate of change: the gross area of the area/blood pressure frequency spectrum of blood pressure frequency spectrum in 0.15～0.4Hz scope.

19. according to claim 5, each described method in 6,8,13,14 is characterized in that, further comprises: in the estimation of carrying out blood pressure or blood pressure rate, substitute described FY spacing with the pulse wave transmission time.

20. method according to claim 19, it is characterized in that, further comprise: definite corresponding wave character point position that produces the signal relevant with pulse wave that collected with the transmission time, with utilize determined wave character point position calculation and one or many heartbeat corresponding pulse wave transmission time sequence

Wherein, for the photoelectricity plethysmographic signal, described wave character point is the summit and/or the end point of waveform;

For electrocardiosignal, described wave character point is R wave crest point and/or R ripple starting point and/or R ripple end of a period point, and the arbitrary characteristics point on Q ripple, S ripple and the T ripple.

21. method according to claim 20, it is characterized in that, utilize the time difference between the point at the bottom of electrocardiosignal summit time or the photoelectricity plethysmographic signal, or the time difference between electrocardiosignal summit time or the photoelectricity plethysmographic signal summit, determine described pulse wave transmission time sequence.

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