JPH0326969B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention uses a vibration method (oscillometric method) that extracts and calculates arterial pulse wave components for each heartbeat superimposed on cuff pressure to measure systolic and diastolic blood pressure values. ) is related to electronic blood pressure monitors.

[Background Art] Conventionally, in this type of electronic sphygmomanometer using a vibration method in which the arterial pulse wave component superimposed on the cuff value is extracted and the maximum and diastolic blood pressure values are determined based on the change, the cuff gradually changes. All arterial pulse wave values from the appearance of the arterial pulse wave during exhaustion until the maximum value of the arterial pulse wave value is determined must be stored in the storage means, and a one-chip microcomputer is used as the blood pressure determination means. When using , a disadvantage is that an expensive device with a large memory capacity must be used. In addition, if the subject's pulse is fast (for example, in the case of an infant, the pulse rate is 120 beats/min), or if the difference between the systolic blood pressure and the mean blood pressure is large, the memory capacity may become insufficient. There was a problem that measurement became impossible. Furthermore, it is necessary to perform many comparison calculations to detect the appearance time of the arterial pulse wave value at a predetermined ratio to the maximum value of the arterial pulse wave value, that is, the systolic blood pressure time, which takes a long time to calculate, and the blood pressure measurement There was a problem that the waiting time until the results were displayed was long.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to reduce the memory capacity of the storage means, to reduce the size and cost, Moreover, it is an object of the present invention to provide an electronic blood pressure monitor that can simplify blood pressure determination calculations and quickly display blood pressure measurement results.

[Disclosure of the Invention] (Structure) The present invention provides a cuff that is attached to the main part of a subject to prevent blood flow, a pressurizing means that increases the pressure inside the cuff,
An exhaust means for gradually lowering the pressure inside the cuff, a pressure sensor for converting the pressure inside the cuff into an electrical signal, a pressure information separation means for extracting an arterial pulse wave value and a cuff pressure value from the pressure sensor output, and a pressure information separation means for extracting an arterial pulse wave value and a cuff pressure value from the pressure sensor output. The maximum
It is composed of a blood pressure determining means for determining the diastolic blood pressure value and a display means for displaying both determined blood pressure values, and the arterial pulse wave value is initially set to the judgment boundary value obtained by multiplying the maximum value of the arterial pulse wave value by a predetermined ratio. In an electronic sphygmomanometer comprising a systolic blood pressure determining means of a blood pressure determining means, the cuff pressure value at that period is determined to be the systolic blood pressure value when the time when the blood pressure begins to exceed 100 yen is determined as the systolic blood pressure value. When the cuff pressure value exceeds a predetermined number, the provisional maximum value, which is the maximum value of the previously extracted arterial pulse wave values, is compared with the oldest arterial pulse wave value among the stored arterial pulse wave values. If the difference between the two values does not exceed a predetermined value, the oldest arterial pulse wave value and cuff pressure value are deleted and the newly extracted arterial pulse wave value and cuff pressure value are stored. If the above provisional maximum value is updated, the memory capacity of the storage means is reduced by configuring the storage means so as not to store the arterial pulse wave value and cuff pressure value extracted thereafter. The device is small and inexpensive, and also simplifies blood pressure determination calculations and quickly displays blood pressure measurement results.

Embodiment 1 FIG. 1 shows the basic configuration of an embodiment of the present invention, which includes a cuff 2 that is attached to the main part of the subject (for example, the upper arm) 1 for blood ischemia, and a cuff 2 that increases the pressure inside the cuff 2. a pressurizing means 3 consisting of a pressurized rubber ball, an evacuation means 4 that gradually lowers the pressure inside the cuff 2, and a
a pressure sensor 5 that converts the pressure into an electric signal within the
A low-pass filter 6 that removes noise signals from the output of the pressure sensor 5, an A/D converter 7 that samples the output of the low-pass filter 6 and converts it into a digital value, and an A/D converter 7 that gradually removes the noise signal from the output of the pressure sensor 5 during the exhaust period.
Arterial pulse wave extraction means 8a extracts an arterial pulse wave value V by digital calculation from the pressure value (digital value) output from the pressure value, and cuff pressure extracts by digital calculation the cuff pressure value P obtained by removing the arterial pulse wave from the pressure value. Pressure information separation means 9 equipped with extraction means 8b; storage means 10 for storing arterial pulse wave values V and cuff pressure values P corresponding to the pulse waves extracted by pressure information separation means 9; a blood pressure determining means 13 comprising a calculating means 11 for appropriately reading out the calculated values and performing comparison calculations; and a blood pressure determining means 12 for determining maximum and diastolic blood pressure values from the calculation results calculated by the calculating means 11; Maximum and diastolic blood pressure values determined in 13, exhaust speed, pulse monitor 1
4, and a display means 16 for appropriately displaying the exhaust velocity value and pulse value output from the cuff pressure monitor 15, and the cuff pressure output from the cuff pressure monitor 15. Here,
Pressure information separation means 9, storage means 10, calculation means 1
1. Blood pressure determining means 13 and both monitors 14, 15
is formed by a microcomputer 18 using a CPU, ROM, RAM, etc.

The basic operation of the first embodiment will be explained below.
Now, the cuff 2 is attached to the upper arm 1 of the person to be measured, and by appropriately pressurizing and depressurizing with the pressurizing means 3 and exhausting means 4, arterial ischemia is achieved, and the arterial counter pressure at the time of opening is reduced by cuff 2. It is transferred to the pressure sensor 5 by air conduction through the tube 21, and electrically converted together with the static pressure (cuff pressure).
An intracuff pressure signal consisting of an analog signal as shown in Figure a is obtained. Next, after this cuff internal pressure signal is filtered to the extent that it can be removed by a low-pass filter 6, the pressure value converted into a digital value by an A/D converter 7 is sent to a microcomputer 18. In the microcomputer 18, the information separating means 8 separates and extracts the arterial pulse wave component and the cuff pressure component, which are observed as a phenomenon of arterial counterpressure, from the pressure value output from the A/D converter 7, and also extracts the extracted arterial pulse wave component and cuff pressure component The pulse wave value V and the cuff pressure value P are stored in the storage means 10, and the blood pressure determination means 13
The calculation means 11 performs a comparison calculation, and the blood pressure determination means 12 determines the systolic blood pressure period and the diastolic blood pressure period.At the same time, the cuff pressure value P corresponding to the maximum and diastolic blood pressure period is read from the storage means 10, The pressure value P is displayed on the display means 16 as the maximum and diastolic blood pressure values. Here, the maximum and minimum blood pressure periods are the maximum and minimum judgment boundary values obtained by multiplying the maximum value Vmax of the arterial pulse wave value V by predetermined ratios α and β.
It is judged based on V〓(α×Vmax), V〓(β×Vmax), and as shown in Fig. 4b, the systolic blood pressure period is when the arterial pulse wave value V starts to exceed the maximum judgment boundary value V〓. The diastolic blood pressure period is the arterial pulse wave value V
The lowest judgment boundary value V〓 which is after the maximum value Vmax of
This is the time when the arterial pulse wave value V, which is below, appears.

FIG. 2 shows a specific configuration example of the storage means 10, and the storage area is the storage area 10 for the arterial pulse wave value V.
a, storage area 10b of cuff pressure value P and maximum value
It has a storage area 10c of Vmax, and each of the storage areas 10a and 10b can store 10 pairs of data (data for 10 beats).

Here, in this embodiment, this storage means 1
0 means that every time a new arterial pulse wave value V is extracted, the maximum value Vmax' (storage area 10
The arterial pulse wave value V and cuff pressure value P before the time when they start to exceed the hypothetical boundary value V〓', which is obtained by multiplying the data stored in c) by a predetermined ratio α, are deleted, and unnecessary data is deleted. By storing only erased and valid data in the storage means 10, the small storage capacity of the storage means 10 is effectively utilized.

FIG. 3 is a flowchart showing the operation of one embodiment of the present invention. Now, when the information separating means 9 newly separates and extracts the arterial pulse wave value V and the cuff pressure value P, the arterial pulse wave value V and the cuff pressure value P are sequentially stored in the storage areas 10a and 10b of the storage means 10 in a left-justified manner, and at the same time, the arterial pulse wave value V is set to the provisional maximum value.
It is determined whether it is larger than Vmax', and if it is larger, the provisional maximum value Vmax' stored in the storage area 10c is updated to the newly extracted arterial pulse wave value V. Next, a provisional maximum judgment boundary value V〓' is calculated by multiplying the provisional maximum value Vmax' by a predetermined ratio α, and the arterial pulse wave value V and cuff pressure value before starting to exceed this provisional maximum judgment boundary value V〓'. Delete P and move the remaining data to the left. In this case, the time when the provisional maximum judgment boundary value V〓′ starts to be exceeded is determined, for example, in order from the latest arterial pulse wave value V to the provisional maximum judgment boundary value V〓′.
V〓′ is compared with the provisional highest judgment boundary value twice or more.
When V〓′ becomes larger, the provisional highest judgment boundary value
It is determined that the time when the arterial pulse wave value V exceeding V〓′ appears is the time when the value begins to exceed V〓′. In this way, malfunctions caused by fluctuations due to noise or the like are prevented by not allowing the temporary maximum judgment boundary value V〓' to exceed the point where it becomes larger only once. Next, in the blood pressure determining means 13,
When the true maximum value Vmax of the arterial pulse wave value V is determined, the oldest data stored in the storage means 10 is set as the data of the systolic blood pressure period, and the cuff pressure value P is displayed as the systolic blood pressure on the display means 16. It is designed to be displayed on the display. That is, in FIG. 4b,
After the point when the arterial pulse wave value V reaches point B, it becomes the provisional maximum value.
Vmax' is not updated, and the arterial pulse wave value V at point B
is determined to be the true maximum value Vmax, and the data at point C, which is the oldest data among the data stored in the storage means 10 (storage areas 10a,
10b) is determined to be the systolic blood pressure period, and the cuff pressure value P stored corresponding to the arterial pulse wave value V at point C is determined to be the systolic blood pressure value. Furthermore, at the time when the true maximum value Vmax of the arterial pulse wave value V is determined, the data at point A is deleted because it is data before the arterial pulse wave value V started to exceed the maximum judgment boundary value V〓. Needless to say, there are. In this way, storage means 1
The systolic blood pressure value can be easily determined based on the oldest data stored in
The calculation time from obtaining Vmax to calculating the systolic blood pressure value can be significantly shortened, and blood pressure measurement results can be displayed quickly.

By the way, as shown in Fig. 5 or 6, systolic blood pressure (cuff pressure value P at the time of systolic blood pressure) and mean blood pressure (cuff pressure value P at the time when the maximum value Vmax appears)
The pulse rate increases until the maximum value Vmax is determined, and the pulse rate increases until the maximum value Vmax is determined.
0a and 10b may become full.
Therefore, in the embodiment, the number of stored arterial pulse wave values V and gas pressure values P is set to a predetermined number (10 in the embodiment).
), the provisional maximum value Vmax', which is the maximum value of the previously extracted arterial pulse wave values V, is compared with the oldest arterial pulse wave value V among the stored arterial pulse wave values V. and if the difference between the two values does not exceed the predetermined value γ, that is, the oldest arterial pulse wave value V is
If it is larger than Vmax' - γ, the oldest arterial pulse wave value V and cuff pressure value P are deleted, the newly extracted arterial pulse wave value V and cuff pressure value P are stored, and the predetermined value γ is If the oldest arterial pulse wave value V exceeds the highest judgment boundary value obtained by multiplying the provisional maximum value Vmax' by a predetermined ratio α, only update the provisional maximum value Vmax', and The storage means 10 is formed so as not to store the arterial pulse wave value V and cuff pressure value P that will be extracted later, thereby avoiding inconveniences due to insufficient storage capacity.

Whether or not the oldest arterial pulse wave value V exceeds αVmax' is the difference between the two values (the oldest arterial pulse wave value V
-αVmax') is equal to or greater than the predetermined value γ, it is determined that the systolic blood pressure period exists within the predetermined number of stored data values. In other words, the timing of the systolic blood pressure is determined based on the amount of increase. Furthermore, in the embodiment, data that does not exceed αVmax' is erased.

For example, in FIG. 5, when the arterial pulse wave value V reaches point B, the storage area 10 of the storage means 10
a, 10b are full, and at this time there is no arterial pulse wave value V less than the provisional maximum judgment boundary value V〓′, so
You will no longer be able to erase old data and move data to the left. In this way, storage areas 10a, 1
When 0b is full, the arterial pulse wave value V at point B
In other words, the provisional maximum value Vmax' is compared with the arterial pulse wave value V at point A, which is the oldest data, and if it has increased by more than a predetermined value γ, the provisional maximum value will be used from now on.
Only the updating of Vmax' and the erasure of the arterial pulse wave value V before it begins to exceed the provisional maximum determination boundary value V〓' are performed, and the new arterial pulse wave value V and cuff pressure value P are not stored. Here, at time D when the arterial pulse wave value V reaches the true maximum value Vmax, the data before point C is erased, and the data at point C, which is the oldest data stored in the storage means 10, is The time when the arterial pulse wave value V appears is determined to be the systolic blood pressure time,
The cuff pressure value P corresponding to this arterial pulse wave value V is displayed on the display means 16 as the systolic blood pressure value.

On the other hand, in the case of FIG. 6, the storage areas 10a and 10b of the storage means 10 are full when the point C' is reached, and the arterial pulse wave values V at the points C' and D' are compared and a predetermined value is determined. Since it has not increased by more than the value γ, delete the data at point D', move the remaining data to the left, and newly calculate the arterial pulse wave value V and cuff pressure value P at point E'.
is recorded at the right end of the storage areas 10a and 10b.
After repeating the above operation, the arterial pulse wave value V at point B'
At the point when , the arterial pulse wave value V at point B' and point A' is compared, and since the difference between the two values has reached the predetermined value γ, the subsequent data is not stored and the provisional maximum value is value
Only updating Vmax' and erasing the arterial pulse wave value V before it begins to exceed the provisional maximum judgment boundary value V〓' is performed, and finally the appearance time of the oldest data stored in the storage means 10 is determined as the systolic blood pressure period. The display means 1 determines that the cuff pressure value P of the data is the systolic blood pressure value.
6. However, it does not necessarily have to be the oldest data; for example, it may be the third oldest data.

Embodiment 2 FIG. 7 is a flowchart showing the operation of another embodiment, in which when the true maximum value Vmax of the arterial pulse wave value V is determined, the arterial pulse wave value V stored in the storage means 10 is A predetermined ratio α to the true maximum value Vmax
The blood pressure determining means 13 is configured to determine the cuff pressure value P corresponding to the arterial pulse wave value V which begins to exceed the maximum determination boundary value V obtained by multiplying is exactly the same as Example 1.

Now, in the case of FIG. 7, until the arterial pulse wave value V at point D is obtained and the true maximum value Vmax is determined, the storage means 10 stores data from point A to point D, as in the first embodiment. is memorized and the true maximum value
After Vmax is determined, from the memorized point A to D
The arterial pulse wave value V at the point and the highest judgment boundary value V〓 are sequentially compared, and the point C, which is the time when the arterial pulse wave value V starts to exceed the highest judgment boundary value V〓, is determined to be the systolic blood pressure period. There is.

On the other hand, in the case of Fig. 6, when the arterial pulse wave value V at point B' appears, the data from A' to B' is stored in the storage area 10 until the true maximum value Vmax is obtained.
a, 10b, and when the true maximum value Vmax is determined at point F', the systolic blood pressure timing is determined at point B'.

[Effects of the Invention] As described above, the present invention includes a cuff that is attached to the main part of a person to be measured, a pressurizing means that increases the pressure inside the cuff, and an exhaust system that gradually lowers the pressure inside the cuff. means, a pressure sensor that converts the pressure within the cuff into an electrical signal, and a pressure information separation means that extracts an arterial pulse wave value and a cuff pressure value from the pressure sensor output;
Storage means for storing arterial pulse wave values and cuff pressure values extracted by the pressure information separation means, and blood pressure determination for determining systolic and diastolic blood pressure values by appropriately reading and comparing the pressure values stored in the storage means. and a display means for displaying both determined blood pressure values, and the time when the arterial pulse wave value first begins to exceed the judgment boundary value obtained by multiplying the maximum value of the arterial pulse wave value by a predetermined ratio is defined as the systolic blood pressure time. In an electronic blood pressure monitor, the systolic blood pressure determining means of the blood pressure determining means is configured to determine the cuff pressure value at that time as the systolic blood pressure value,
When the number of stored arterial pulse wave values and cuff pressure values exceeds a predetermined number, the provisional maximum value, which is the maximum value of the previously extracted arterial pulse wave values, and the oldest of the stored arterial pulse wave values Compare with arterial pulse wave value,
If the difference between the two values does not exceed a predetermined value, the oldest arterial pulse wave value and cuff pressure value are deleted and the newly extracted arterial pulse wave value and cuff pressure value are stored; if the difference exceeds a predetermined value, the oldest arterial pulse wave value and cuff pressure value are stored. , the storage means is configured to only update the provisional maximum value and not to store the arterial pulse wave value and cuff pressure value extracted thereafter, and the storage area of the storage means becomes full. If it is before the period when arterial pulse waves show fluctuations above a certain level, the storage means is configured to erase the oldest arterial pulse wave values and cuff pressure values, and unnecessary data is sequentially erased to make it effective. Since only relevant data is stored in the storage means, the memory capacity of the storage means can be reduced, making it possible to provide a small and low-cost electronic blood pressure monitor, which can also be used for blood pressure determination. Since the amount of data is reduced, blood pressure determination calculations can be simplified and blood pressure measurement results can be displayed quickly.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a schematic configuration of the present invention;
2 to 4 are explanatory diagrams of the same operation as above, FIGS. 5 and 6 are explanatory diagrams of operation of another embodiment, and FIG. 7 is an explanatory diagram of operation of still another embodiment. 2 is a cuff, 5 is a pressure sensor, 9 is an information separation means, 10 is a storage means, 13 is a blood pressure determination means, 16
is a display means.

Claims (1)

[Claims] 1. A cuff that is attached to the main part of the person to be measured, and
A pressurizing means for increasing the pressure within the cuff, an evacuation means for gradually decreasing the pressure within the cuff, a pressure sensor for converting the pressure within the cuff into an electrical signal, and an arterial pulse wave value and cuff pressure determined from the pressure sensor output. A pressure information separation means for extracting values, a storage means for storing arterial pulse wave values and cuff pressure values extracted by the pressure information separation means, and pressure values stored in the storage means are read out as appropriate and are compared and calculated. The arterial pulse wave value is a determination boundary value obtained by multiplying the maximum arterial pulse wave value by a predetermined ratio. In an electronic sphygmomanometer comprising a systolic blood pressure determining means of a blood pressure determining means, the cuff pressure value at that period is determined to be the systolic blood pressure value, with the period when the cuff pressure first begins to exceed the systolic blood pressure period. When the wave value and cuff pressure value exceed a predetermined number, the provisional maximum value, which is the maximum value of the previously extracted arterial pulse wave values, and the oldest arterial pulse wave value among the stored arterial pulse wave values are combined. If the difference between the two values does not exceed a predetermined value, the oldest arterial pulse wave value and cuff pressure value are deleted, the newly extracted arterial pulse wave value and cuff pressure value are stored, and the predetermined value is stored. An electronic sphygmomanometer characterized in that a storage means is configured to only update the provisional maximum value and not to store the arterial pulse wave value and cuff pressure value extracted thereafter when the value exceeds the above value. .