JPH0472538B2 - - 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. ) concerning electronic blood pressure monitors.

[Background Art] Conventionally, in this type of electronic sphygmomanometer using an oscillation method that extracts an arterial pulse wave component superimposed on the cuff pressure and determines the maximum and diastolic blood pressure values based on the change, the blood pressure determination means Now, the maximum value of the arterial pulse wave value obtained by extracting the arterial pulse wave component superimposed on the cuff pressure (hereinafter referred to as the maximum pulse wave value) is calculated, and a predetermined ratio is applied to this maximum pulse wave value. The time point at which an arterial pulse wave value begins to exceed the multiplied judgment boundary value for determining systolic blood pressure is defined as the systolic blood pressure period, and the cuff pressure value at this period is determined to be the systolic blood pressure value. However, in such conventional cases, if temporary vibrations exceeding the determination boundary value occur due to sudden body movements or premature contractions that occur when the cuff pressure value is higher than the systolic blood pressure value. Or, when the cuff pressure value is lower than the systolic blood pressure, if a temporary vibration that breaks the reference value occurs due to an arrhythmia, the time when the vibration occurs is mistakenly determined to be the systolic blood pressure period, and the systolic blood pressure is incorrectly determined. There was a problem that sometimes a value could be obtained.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to reduce the possibility of incorrectly determining systolic blood pressure, and to make it possible to determine blood pressure by simple calculations. An object of the present invention is to provide an electronic blood pressure monitor that can be easily reduced in size, cost, and size.

[Disclosure of the Invention] (Structure) The present invention provides a cuff that is attached to the main part of a subject for blood ischemia, 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 highest value of the arterial pulse wave value by a predetermined ratio. In an electronic sphygmomanometer, the systolic blood pressure determining means of the blood pressure determining means is configured to determine the period when the cuff pressure begins to exceed 100 yen as the systolic blood pressure period, and the cuff pressure value at that period is determined as the systolic blood pressure value. A storage area for storing a finite number of wave values and cuff pressure values as paired data is provided in the storage means, and the arterial pulse wave values stored in the storage area are compared with judgment boundary values in order of decreasing or increasing cuff pressure values. , the systolic blood pressure determining means is configured to determine the period when the arterial pulse wave value becomes smaller or larger than the determination boundary value for a predetermined number of consecutive times as the systolic blood pressure period, thereby erroneously determining the systolic blood pressure; In addition, the blood pressure can be determined by simple calculations, and the cost and size can be easily reduced.

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
Pressure sensor 5 that converts internal pressure into an electrical signal
, an A/D converter 7 that samples the output of the pressure sensor 5 and converts it into a digital value, and digitally calculates an arterial pulse wave value V from the pressure value (digital value) output from the A/D converter 7 during the gradual exhaust period. Pressure information separation means 9 includes arterial pulse wave extraction means 8a for extracting the arterial pulse wave and cuff pressure extraction means 8b for extracting the cuff pressure value P obtained by removing the arterial pulse wave from the pressure value by digital calculation; A finite number of pair data (for example, 10 pairs) of arterial pulse wave value V and cuff pressure value P for the pulse wave extracted by
storage means 10 for storing in a predetermined storage area,
Calculating means 11 for appropriately reading data stored in storage means 10 and performing comparison operations; and this calculating means 1
a blood pressure determining means 13 comprising a blood pressure determining means 12 for determining maximum and diastolic blood pressure values from the calculation results calculated in step 1; and a blood pressure determining means 13 comprising a blood pressure determining means 12 for determining the maximum and diastolic blood pressure values determined by the blood pressure determining means 13; 14, and a display means 16 for displaying the cuff pressure output from the cuff pressure monitor 15 as appropriate. The systolic blood pressure determining means of the blood pressure determining means 13 determines that the time when the arterial pulse wave value V first begins to exceed the determination boundary value V〓, which is obtained by multiplying the maximum value Vmax of the arterial pulse wave value V by a predetermined ratio α, is defined as the systolic blood pressure period. The cuff pressure value P at this time is determined to be the systolic blood pressure value. Further, in this embodiment, the systolic blood pressure determination means compares the arterial pulse wave values V stored in the storage area of the storage means 10 with the determination boundary values in descending order of cuff pressure value P, and determines a predetermined value. It is formed by a time determining means that determines a time when the arterial pulse wave value V increases several times in succession as the systolic blood pressure time. Note that the pressure information separation means 9, the storage means 10, the calculation means 11, the blood pressure determination means 13, and both monitors 14 and 15 are equipped with a CPU, ROM, and
It is formed by a microcomputer 18 using RAM or the like.

The basic operation of the first embodiment is as follows. 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. The cuff pressure signal is transferred to the pressure sensor 5 by air conduction through the tube 21, and electrically converted together with the static pressure (cuff pressure) to obtain an internal cuff pressure signal consisting of an analog signal as shown in FIG. 3a. Next, the pressure value obtained by converting this intracuff pressure signal into a digital value by the A/D converter 7 is sent to the microcomputer 18. In the microcomputer 18, the information separation means 8 separates and extracts the arterial pulse wave component and the cuff pressure component, which are seen as a phenomenon of arterial counterpressure, from the pressure value output from the A/D converter 7, and also extracts the extracted appropriate information. Arterial pulse wave value V and cuff pressure value P
is stored in a predetermined storage area of the storage means 10 as paired data, and the calculation means 11 of the blood pressure determination means 13 performs a comparison calculation, and the blood pressure determination means 12 determines the systolic blood pressure period and the diastolic blood pressure period, and at the same time determines the maximum blood pressure period. , the cuff pressure value P corresponding to the diastolic blood pressure period is read out from the storage means 10, and the cuff 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 obtained by multiplying the maximum value Vmax of the arterial pulse wave value V by a predetermined ratio α, β, and the maximum and minimum judgment boundary values V〓(α×Vmax),
V〓(β×Vmax), and as shown in Figure 3b, the systolic blood pressure period is determined based on the maximum judgment boundary value V〓
This is the time when the arterial pulse wave value V begins to exceed
The diastolic blood pressure period is a period after the maximum value Vmax of the arterial pulse wave value V and when the arterial pulse wave value V, which is equal to or less than the lowest determination boundary value V, appears.

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

Here, in this embodiment, the determination boundary value V〓 is obtained by multiplying the maximum value Vmax (data stored in the storage area 10c) by a predetermined ratio α among the arterial pulse wave values V extracted during measurement. In the timing determination means for determining the time to start exceeding the storage area 10a, 10
The arterial pulse wave values V stored in b are determined in descending order of cuff pressure value P as the judgment boundary value V for determining the systolic blood pressure timing.
The period when the arterial pulse wave value V increases continuously a predetermined number of times (twice in the example) is determined as the systolic blood pressure period, and the first of the two arterial pulse wave values V is compared. The cuff pressure value P corresponding to the arterial pulse wave value V, that is, the higher one, is displayed on the display means 16 as the systolic blood pressure value. FIG. 3b shows the operation for determining the systolic blood pressure value. As a timing determination method,
Judgment boundary value when maximum pulse wave value Vmax is obtained
V〓 is calculated, and the arterial pulse wave values V stored in the storage means 10 are compared with the determination boundary values V〓 in order from point E with the highest cuff pressure value P. In the illustrated example, the arterial pulse wave value V at point D exceeds the judgment boundary value V〓 once, but the next arterial pulse wave value V does not exceed the judgment boundary value V〓, so
The arterial pulse wave value V at point D is ignored as it is affected by noise. Next, since the arterial pulse wave value V at points B and C exceeds the judgment boundary value V〓 twice in a row, point B is determined to be the systolic blood pressure period, and the cuff corresponding to the arterial pulse wave value V at point B is determined. The pressure value P is displayed on the display means 16 as the systolic blood pressure value.

Further, the diastolic blood pressure determining means determines as the diastolic blood pressure period the time when the arterial pulse wave value V after the maximum pulse wave value is obtained divides the determination boundary value V for determining the diastolic blood pressure period,
The cuff pressure value P at that time is displayed on the display means 16 as the diastolic blood pressure value.

[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,
The storage means is provided with a storage area for storing a limited number of arterial pulse wave values and cuff pressure values at the time of arterial pulse wave extraction as paired data, and the arterial pulse wave values stored in the storage area are determined in descending order of cuff pressure values. Compare with the boundary value,
The systolic blood pressure determining means is configured to determine the time when the first arterial pulse wave value occurs when the arterial pulse wave value becomes larger than the determination boundary value a predetermined number of consecutive times as the systolic blood pressure period. Since the timing of systolic blood pressure is determined based on whether or not the arterial pulse wave value exceeds the determination boundary value multiple times in a row, there is less chance of erroneously determining systolic blood pressure due to the influence of noise, and it is easy to judge blood pressure. can be performed by simple calculations, and has the advantage of being easy to reduce cost and size.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing a schematic configuration of the present invention;
FIG. 2 is a block diagram of the main parts of the same as above, and FIGS. 3a and 3b are explanatory views of the same as above. 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, the systolic blood pressure determining means of the blood pressure determining means is configured to determine the cuff pressure value at that period as the systolic blood pressure value when it first begins to exceed the systolic blood pressure period. Providing a storage area in the storage means for storing a limited number of arterial pulse wave values and cuff pressure values as paired data, comparing the arterial pulse wave values stored in the storage area with judgment boundary values in descending order of cuff pressure values, The systolic blood pressure determining means is configured to determine the time when the first arterial pulse wave value occurs when the arterial pulse wave value becomes larger than the determination boundary value a predetermined number of consecutive times as the systolic blood pressure period. Features of electronic blood pressure monitor.