JPH0392134A - Electronic sphygmomanometer - Google Patents

Abstract

PURPOSE:To measure blood pressure values accurately through avoiding influences due to individual variations and pulse wave noises by determining a maximum and minimum blood pressure values based on wave form areas of te pulse wave within ranges set by range setting devices. CONSTITUTION:In an electronic sphygmomanometer measuring blood pressure based on variations of cuff pressure, range setting devices 34, 36 set ranges of maximum and minimum blood pressure values on the basis of a maximum value of wave form area of pulse wave. A blood pressure value determination device 1 determines the maximum and minimum blood pressure values based on the wave form areas of pulse wave within the ranges set by the range setting devices 34, 36. It is possible, as a result, to measure a correct blood pressure values through avoiding influences due to individual variations and pulse wave noises, and to reduce a ratio of immeasurableness.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic sphygmomanometer, and particularly to an electronic sphygmomanometer that measures blood pressure based on cuff pressure fluctuations.

[Prior art] In conventional electronic blood pressure monitors that use the waveform area of the pulse wave due to cuff pressure fluctuations, the systolic blood pressure and diastolic blood pressure values are determined by determining the maximum value or by setting a predetermined reference value (threshold level). Based on this reference value, for example, if the reference value was exceeded for two consecutive beats, the cuff pressure corresponding to the previous beat was used as the systolic blood pressure value. [Problems to be Solved by the Invention] However, the waveform area of the pulse wave reflects changes in the intravascular volume under the cuff more than the method of determining the amplitude, and when the amount of information is large and the pulse wave is small, Although it is advantageous for
On the other hand, it is sensitive to noise, so it is subject to many fluctuations due to breathing, and it is also affected by pulse wave noise caused by body movements, resulting in inaccurate blood pressure values and a high rate of unmeasurable blood pressure values. There were some problems. The present invention provides an electronic sphygmomanometer that eliminates the above-mentioned drawbacks of the conventional art, eliminates the effects of individual fluctuations and pulse wave noise, allows accurate blood pressure measurements, and reduces the rate of unmeasurable blood pressure. [Means for Solving the Problem] In order to solve this problem, the electronic blood pressure monitor of the present invention is an electronic blood pressure monitor that measures blood pressure based on cuff pressure fluctuations, and has the following features: A range setting means for setting a range based on the maximum value of the waveform area of the pulse wave, and a systolic blood pressure value and a diastolic blood pressure value based on the waveform area of the pulse wave within the range set by the range setting means. and blood pressure value determining means for determining the blood pressure value.

Further, the blood pressure value determining means uses the difference in waveform area of adjacent pulse waves as a reference. [Function] In this configuration, since the blood pressure value is determined after setting a rough range in advance, the influence of individual fluctuations and pulse wave noise is eliminated, accurate blood pressure values can be measured, and the rate of failure to measure is reduced. let

[Example] Hereinafter, an example of the present invention will be described in detail with reference to the accompanying drawings. Configuration of electronic blood pressure monitor> Figure 1 shows the configuration of the electronic blood pressure monitor of this embodiment. This is a lock diagram. 1 is a CPU for arithmetic control that controls this electronic blood pressure monitor; 2 is a ROM that stores programs showing the execution procedure of the CPUI, initial values, etc.; and 3 is a RAM for auxiliary storage. An L-DL value storage unit 31 stores the wave height value L measured and calculated by the wave height value and the difference DL between the wave height values, and the maximum waveform area L. ．． L to remember 8. (2) a storage unit 32; an S-DI value storage unit 33 that stores the waveform area S and the difference Ds between the waveform areas;
Maximum waveform area S. ■Memorize S. . Storage unit 34, systolic blood pressure value determined from the peak value. Beat SYSL corresponding to the diastolic blood pressure value. The SYS1DIAL section 35 stores the DIAL, and the systolic blood pressure value determined from the waveform area. SYS1D that stores the beats SYSs and DIAs corresponding to the diastolic blood pressure value
IA. It includes part 36. 4 is a cuff pressure detection unit consisting of a pressure sensor 41, an amplifier 42, and an A/D converter 43; 5 is a cuff pressure control unit consisting of an exhaust valve that controls the pressure of a cuff 6; Blood pressure is measured based on the cuff pressure detected by the cuff pressure detection unit 4 when the pressure in the cuff 6 is reduced after being increased by the control unit 5.

Note that the pressurization or depressurization by the cuff pressure control unit 5 may be performed automatically, or even if it is performed manually, this does not affect the present invention. 7 is the detected systolic blood pressure value. This is a display unit for notifying the diastolic blood pressure value, insufficient pressurization, measurement inability, etc. C.P.
U.I. The ROM 2, RAM 3, cuff pressure detection section 4, cuff pressure control section 5, and display section 7 are interconnected by a bus 8 to exchange data.

Blood pressure measurement using cuff wave height> Figure 2A is a diagram showing the pulse wave height L of cuff pressure fluctuations. This figure is an enlarged view of a part of the cuff pressure reduction process.
It is expressed as p.

FIG. 2B shows the wave height values shown in FIG. 2A in order of maximum wave height L. ．． This is a diagram normalized by 8. In this embodiment, the first beat in which the peak value exceeds, for example, 30% of the maximum peak value L was is defined as the systolic blood pressure beat S Y S L.

Next, the maximum wave height value L. ．． After passing 8, the wave height is 8.
Difference DL between two adjacent peak values that falls below 0%
If the difference DL is, for example, 20% or more of the maximum wave height value Lsaw, then the subsequent beat is set as the diastolic blood pressure beat DIAL, and if the difference DL never becomes, for example, 20% or more, the first beat when the difference DL becomes 80% or less? Let the diastolic blood pressure be DIAL. If the measurement is completed without reaching 80% or less, the measurement is deemed impossible. Blood pressure determination based on waveform area> Figure 3A is a diagram showing the waveform area S of the pulse wave due to cuff pressure fluctuations. This figure is an enlarged view of a part of the cuff decompression process, and the area of the current pulse wave is represented by S, and the area of the pulse wave one beat before is represented by SP. FIG. 3B shows the waveform areas shown in FIG. 3A in order of maximum waveform area S. It is a figure standardized and shown by Saw.

In this embodiment, within the range from when the waveform area reaches, for example, 20% or more of the maximum waveform area S8 to before it exceeds 50% when 50% or more is two consecutive beats, the The beat after the waveform area difference Ds becomes maximum is the systolic blood pressure beat SYSs, or if the above range does not exist, the first beat when the waveform area S exceeds, for example, 50% (30%) of the maximum waveform area. Let the systolic blood pressure be S Y S s. Next, after passing the maximum waveform area S sag, the maximum waveform area S
50% (3
0%) or less within the range of two consecutive beats, the beat after the maximum waveform area difference DL between adjacent beats is the diastolic blood pressure beat DIAs, or if the above range does not exist,
When the waveform area S is 50% or less of the maximum waveform area for two consecutive beats, the first beat when the waveform area S becomes 50% or less is called the diastolic blood pressure beat DIAs, and the measurement ends before it becomes 70% or less of the maximum waveform area. In this case, diastolic blood pressure cannot be measured by waveform area. Selection of blood pressure value> First, as the systolic blood pressure value, if the systolic blood pressure beat SYSL determined from the above-mentioned wave height value and the systolic blood pressure pulse SYSL determined from the waveform area are not more than 4 beats apart, S
Let Y S L be the systolic blood pressure beat and the cuff pressure at that point as the systolic blood pressure value. If S Y S L and S Y S s
or more than 4 beats apart, SYS. If Ds of one beat before is checked and it is negative, the determination of S Y S s is judged to be inaccurate and SYSL is taken. Otherwise, S Y S is less susceptible to fluctuations due to pulse wave noise, etc.
Take s.

On the other hand, as for the diastolic blood pressure value, if the systolic blood pressure pulse DIAL determined from the above-mentioned wave height value and the systolic blood pressure pulse DIAI determined from the waveform area are not more than 4 beats apart, D
I A L is taken as the diastolic blood pressure beat, and the cuff pressure at that point is taken as the diastolic blood pressure value. If DIAL and DI A s are 4 or more beats apart, compare the DL of DI A s and the DL of DIAg one beat before, and if the DL of DIAg is larger, the judgment of DIAs is made. is judged to be inaccurate and DIAL
I take the. Otherwise, use DIAs that is less susceptible to fluctuations due to pulse wave noise, etc. Note that the above selection method is just one example, and if higher accuracy is desired, the error criteria for the determination based on the wave height value and the determination based on the waveform area can be made smaller to make a more precise determination. However, in general, the selection criteria described in this example are considered to be sufficient. Flowchart> Figures 4A and 4B are flowcharts showing the main control procedure of the electronic blood pressure monitor of this embodiment, and Figures 5 to 7 show systolic blood pressure values corresponding to steps S10, 520, and S30 in Figure 4B. Flowchart showing the procedure of the measurement routine, Fig. 8~
What about figure 10? Steps S40, S50 in Figure 4B. S60
2 is a flowchart showing the procedure of a routine for measuring the diastolic blood pressure value corresponding to . First, in the main control procedure, in step Sl, the initial value (pressure value is O) after power-on is set, and the cuff pressure is made zero. Pressurization is started in step S2, and steps S2 and S3 are repeated until the predetermined pressure value is reached. When the predetermined pressure is reached, step S
Proceed from step 3 to step 84 to start decompression and observe the pulse wave of cuff pressure fluctuations. As shown in FIGS. 2A and 3A, L and S at each beat are determined in step S5, and (L-Lp) is determined as Dt. in step S6.
Then, (S-Sp) is stored as D3. In step S7, the maximum value of L and S is L■. and S. Find ■. In step S8, S is 8■8 2 as the end point of observation.
0%? s<s. ■xo. 2) is determined, and when this condition - is reached, observation is stopped and exhaust is performed in step S9. The electronic blood pressure monitor then determines the systolic blood pressure value and the diastolic blood pressure value based on the data collected in steps S5 to S7. First, in step SIO, the systolic blood pressure is recognized by L, and in step S20, the systolic blood pressure is recognized by S. Step S
In step 30, it is determined which of the above recognition methods has recognized the more appropriate systolic blood pressure, and the more accurate value is selected. Next, in step S40, the diastolic blood pressure is recognized by L, and in step S50, the diastolic blood pressure is recognized by S. Step S
In step 60, it is determined which of the above recognitions is the more appropriate k value, and a more accurate diastolic blood pressure value is selected. In step S70, the determined systolic blood pressure and diastolic blood pressure are displayed, and if pressurization is insufficient or cannot be determined, a notification thereof is displayed. Figure 5 shows the step SIO routine. First, in step Sll, L is the maximum wave height L mill! For example, 3
It is determined whether the value is 0% or more (L≧LIIIXX0.3), and if it is, the beat at this time is set as the systolic blood pressure beat S Y S t. shall be.

FIG. 6 shows the routine of step S20.

First, in step S21, S is 2 of the maximum waveform area S may
Search for a range where the value exceeds 0% and then falls below 50% for two consecutive beats. If this range exists, the process proceeds to step S22, and within this range, the maximum beat of D3 is determined as the systolic blood pressure beat S Y S s
Suppose that On the other hand, if the above range does not exist, the process proceeds to step 323 and the maximum waveform area S. ．． 50% of 8 (
30%) is the systolic blood pressure beat S Y S s
Suppose that FIG. 7 shows the routine of step S30.

? In step S31, S Y S L and S Y S s
It is determined whether or not they are separated by 4 beats or more, and if they are not separated, the process proceeds to step S35 and the cuff pressure of SYS L is set as the systolic blood pressure value (hereinafter referred to as SYS value). If the distance is 4 or more beats, the process proceeds to step S32, where it is determined whether Di at the beat before S Y S m is negative or not. If it is negative, the cuff pressure of S Y S L is changed at step S33. , if not negative, the cuff pressure of SYSs is set as the systolic blood pressure in step S34. FIG. 8 shows the routine of step S40. First, in step S41, L, . ! Check that you have reached the next beat,
In step S42, L is the maximum wave height value L. ．． Determine whether it is 80% or less of 8 (L≦LmazX0.8), and
If it is below, the process proceeds to step S43, and it is checked whether there is a beat where D5 is 20% or more of the maximum L8. If so, that beat is set to DIAL in step S44, and if not, the first beat of which the percentage has fallen below 80% is set to DIAL in step S45. FIG. 9 shows the routine of step S50. First, in step S51, it is determined whether the beat after S wax has been reached, and then in step S52, S has reached the beat after S wax. ．． 7 of 8
After falling below 0% (80%), 50% for 2 consecutive beats
(30%) or less. If this range exists, the process advances to step S53, and the maximum D beat within the range is set as DIAs. If not, the process advances to step S54 and 2
S < S east x 0 for consecutive beats. Find the beat that is 5. If there is a beat, the process proceeds to step S55; if not, the process proceeds to step S65 shown below, where the DIAL cuff pressure is set as the diastolic blood pressure value (hereinafter referred to as DIA value). FIG. 10 shows the routine of step S60.

First, in step S61, D I A L and D I A s
Check to see if they are four beats or more apart, and if they are not, proceed to step S65 and change the cuff pressure of DIAL to DI.
Let it be the A value. On the other hand, if the distance is 4 beats or more, the process advances to step S62, and the DL and DIA of Dr.A.
Compare the DL of 1 beat before s, and if the DL of 1 beat before is larger, the cuff pressure of DIAL is set as the DIA value in step S63, and if the DL of 1 beat before is smaller, step S64
Let the cuff pressure of Dr As be the DIA value.

As explained above, according to the present example, the accuracy of determining blood pressure values based on wave height values is increased and the rate of undeterminable results is reduced. Furthermore, the accuracy of blood pressure determination based on waveform area was increased and the rate of undiagnosed results was reduced. Furthermore, above 2
By selecting a more suitable value from the two determination results, we prevented a decrease in measurement accuracy due to pulse wave noise, etc., and further reduced the rate of undetermined results. [Effects of the Invention] According to the present invention, it is possible to provide an electronic sphygmomanometer that can accurately measure blood pressure values by eliminating the effects of individual fluctuations and pulse wave noise, and that can reduce the rate of unmeasurable blood pressure values.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing the configuration of the electronic blood pressure monitor of this embodiment, Fig. 2A is a diagram explaining the waveform area of the pulse wave, and Fig. 2B is the determination of systolic and diastolic blood pressure based on the waveform area of this embodiment. Figure 3A is a diagram illustrating the waveform area of a pulse wave; Figure 3B is a diagram illustrating the principle of determining systolic blood pressure and diastolic blood pressure based on the waveform area of this embodiment; 4A and 4B are flowcharts showing the operating procedure of the electronic blood pressure monitor of this embodiment, and FIGS. 5 to 7 show in detail each routine showing the procedure for determining the systolic blood pressure of the electronic blood pressure monitor of this embodiment. Flowchart FIGS. 8 to 10 are flowcharts showing in detail each routine showing the procedure for determining the diastolic blood pressure of the electronic blood pressure monitor of this embodiment. In the figure, 1...-CPU, 2...-ROM, 3...-RAM
, 4... Cuff pressure detection section, 5... Cuff pressure control section, 6.
...arm cuff, 7...display section, 8...bath, 3
1-L・D+, value storage section, 32...L, ■ storage section,
33...S・SL value storage unit, 34・-S■. storage section,
35...SYS1DIAL section, 36...-SYS. −
DIA. 4l...Pressure sensor, 42...Amplifier, 43...A/D converter. η7 pressure. ．． ',! Figure 2A Figure 2B Figure 1 Wide 3A factor Smax Figure 3B Haruma Figure 5 Figure 8 Figure 5 Turtle 9 Figure 10 Procedural amendment (self-required 2 Amended by the Commissioner of the License Agency on December 28, 1999) Relationship with the incident

Claims (2)

[Claims] (1) An electronic sphygmomanometer that measures blood pressure based on cuff pressure fluctuations, comprising a range setting means for setting the range of the systolic blood pressure value and the diastolic blood pressure value based on the maximum value of the waveform area of the pulse wave; An electronic sphygmomanometer comprising blood pressure value determining means for determining a systolic blood pressure value and a diastolic blood pressure value within a range set by the range setting means based on a waveform area of a pulse wave. (2) The electronic blood pressure monitor according to claim 1, wherein the blood pressure value determining means further uses a difference in waveform area of adjacent pulse waves as a reference.