JPH0362088B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention uses a vibration method (oscillometric method) that extracts and calculates the arterial pulse wave component of each heartbeat superimposed on the cuff pressure to determine the peak and diastolic blood pressure periods. This relates to an electronic blood pressure monitor using the Tsuku method.

[Prior art] A typical electronic blood pressure monitor uses an electronic blood pressure monitor that uses an auscultation method (Rybarotchi-Korotkoff sound method) to determine blood pressure by detecting arterial blood flow sounds (Korotkoff sounds) using a microphone built into the cuff. A blood pressure monitor and an electronic blood pressure monitor (e.g.
Utility Model Publication No. 60-10601, Japanese Patent Application Publication No. 59-95033, etc.).

[Problems to be Solved by the Invention] FIG. 16 shows a blood pressure monitor using the auscultation method, in which a cuff 2' containing a rubber bladder 20 and a Korotkoff sound sensor 26 is wrapped around the upper arm 1, and the rubber bladder 2 is wrapped around the upper arm 1.
Air is supplied to the tube 21 connected to the tube 21 using a pressurizing means 3 formed of a pressurizing rubber bulb 22, etc., and the artery of the upper arm 1 is blood-isolated. Thereafter, the air in the rubber sac 20 is gradually evacuated and depressurized by the constant-speed exhaust function of the exhaust means 4, thereby transitioning from arterial ischemia to bleeding state, and the Korotkoff sound generated from the artery during the arterial compression operation is changed to Korotkoff sound. The sensor 26 detects the blood pressure, and the blood pressure monitor main body 30 determines the maximum and diastolic blood pressure based on the appearance and disappearance of Korotkoff sounds, and displays the display means 1.
The highest and lowest blood pressure values are displayed at 6. In the figure, 17 is an operation switch.

However, since the electronic blood pressure monitor using the auscultation method described above has the Korotkoff sound sensor 26 inside the cuff 2', it feels strange when the cuff 2' is attached to the upper arm 1 and pressure is increased or decreased, and it is difficult to measure blood pressure accurately. In order to do this, the Korotkoff sound sensor 26 had to be placed precisely at the artery position, and there was a problem in that it was troublesome to attach the cuff 2'. Furthermore, since the Korotkoff sound sensor 26 also detects noise emitted from the upper arm 1 and the cuff 2', there is a problem in that malfunctions are likely to occur.

Therefore, in order to solve such problems,
An electronic sphygmomanometer using a vibration method has been proposed, which extracts and calculates arterial pulse wave components to determine blood pressure. Pressure information separation means is formed to separate the pressure and the arterial pulse wave superimposed on the cuff pressure using filter means (low-pass filter, band-pass filter, etc.) consisting of an analog signal processing circuit. The pressure information separated by the pressure information separation means is digitized by the A/D converter, and the CPU
The digital calculation means configured using the above performs noise removal and comparison calculation for blood pressure determination to determine the maximum and diastolic blood pressures, and the determined maximum and diastolic blood pressures are displayed on the display means, and the pressure is Since the information separation means was constructed from an analog signal processing circuit, and the filter means constituting the pressure information separation means was formed from so-called hardware, the circuit configuration became complex, and the overall shape could not be miniaturized, making it difficult to carry. There were problems in that it was difficult to do so, and it was not possible to lower the price.

The present invention has been made in view of the above points, and its purpose is to provide a cuff that can be easily attached without causing discomfort, has a simple structure, and can be easily miniaturized and reduced in price. An object of the present invention is to provide an electronic blood pressure monitor that can reduce the memory capacity of a storage means.

[Means for Solving the Problems] The electronic sphygmomanometer of 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 a cuff that gradually increases the pressure inside the cuff. a pressure sensor that converts the pressure within the cuff into an electrical signal, an A/D converter that samples the pressure sensor output and converts it into a digital value;
Arterial pulse wave extraction means for digitally extracting an arterial pulse wave value from the pressure value output from the A/D converter during the gradual evacuation period, and digitally extracting a cuff pressure value from which the arterial pulse wave is removed from the pressure value. Pressure information separation means equipped with cuff pressure extraction means;
Storage means for storing arterial pulse wave values and cuff pressure values corresponding to the pulse waves extracted by the pressure information separation means; and systolic and diastolic blood pressure values by appropriately reading and comparing the values stored in the storage means. An electronic sphygmomanometer comprising a blood pressure determining means for determining the blood pressure value, and a display means for displaying the determined blood pressure values, includes a memory having a predetermined storage capacity, and a part of the data stored in the memory in the blood pressure determining means. A storage means is formed with a memory effective use means that secures free space by deleting data that is determined to be unnecessary when determining blood pressure, and stores and updates the used and free space to effectively use the memory. Memory effective utilization means is formed to erase data used for determination and unnecessary when determining diastolic blood pressure after determining systolic blood pressure in the blood pressure determining means to secure a free space in the memory for use when determining diastolic blood pressure. It is something.

(Function) The present invention is configured as described above, and because it does not use a cuff with a built-in microphone unlike the conventional auscultation method, the cuff can be easily worn without any discomfort, and the arterial pulse wave value Since the information is extracted by digital calculation, the structure is simpler than the conventional vibration method in which analog signal processing is performed, making it easier to reduce the size and cost.

In addition, a memory having a predetermined storage capacity and data stored in the memory that are determined to be unnecessary at the time of blood pressure determination by the blood pressure determining means are deleted to secure free space, and used and free space are reduced. A memory effective use means is formed with a memory effective use means for storing and updating the memory to effectively utilize the memory, and data used for determining the systolic blood pressure and unnecessary when determining the diastolic blood pressure is deleted after the blood pressure determining means determines the systolic blood pressure. Since a memory effective utilization means is formed to secure free space in the memory for use in determining diastolic blood pressure, it is possible to effectively use memory with a small storage capacity to perform blood pressure determination calculations, reducing costs. can do. In addition, small capacity
A low-cost one-chip CPU with built-in RAM can be used to form the storage means and calculation means, making it possible to provide a lower-priced electronic blood pressure monitor.

(Embodiment) Figs. 1 to 4 show the basic configuration of an embodiment of the present invention. In Figs. , a rubber bladder 20 is built in, and a pressure means 3 consisting of a rubber bulb 22 is connected to this rubber bladder 20 via a tube 21, so that pressure can be applied until blood ischemia is achieved by pressing the rubber bulb 22. There is. The pressure inside the cuff 2 pressurized in this manner is gradually exhausted by the exhaust means 4 having an exhaust valve, and blood pressure is measured by the blood pressure monitor main body 30 during this gradual exhaustion period. A blood pressure monitor main body 30 to which one end is connected to the rubber bladder 20 and the other end of the tube 21 is connected includes a pressure sensor 5 that converts the pressure within the cuff 2 into an electrical signal as shown in FIGS. 2 and 3; A low-pass filter 6 that removes noise contained in the output of the pressure sensor 5, and an A/D converter that samples the noise-removed output of the pressure sensor 5 at a predetermined period (a period sufficiently shorter than the pulse wave) and converts it into a digital value. 7, and A/D converter 7 gradually 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 cuff pressure output from the cuff pressure monitor 15, and an operation switch section 17 for controlling the blood pressure measurement operation, and the display means. 16 is arranged on the front side of the blood pressure monitor main body 30. Here, pressure information separation means 9, storage means 1
0, the calculation means 11, the blood pressure determination means 13, and both monitors 14 and 15 are formed by a microcomputer 18 using a CPU, ROM, RAM, and the like. In addition, as a means for pressurizing and exhausting the cuff 2,
As shown by phantom lines in the figure, cuff pressure control means 19 may be provided to automatically control the pressurizing pump and the electromagnetic exhaust valve according to a predetermined program set in the microcomputer 18.

The basic configuration and operation described above will be explained in detail below. First, the basic configuration and operation for measuring systolic and diastolic blood pressure using the vibration method are as follows. Now, cuff 2 is placed on the upper arm 1 of the subject.
By attaching the cuff 2 and appropriately pressurizing and depressurizing it with the pressurizing means 3 and exhausting means 4, arterial ischemia is achieved, and arterial counter pressure at the time of opening is taken into the cuff 2, and air is conducted through the tube 21. The pressure is transmitted to the pressure sensor 5 and electrically converted together with the static pressure (cuff pressure) to obtain a pressure signal consisting of an analog signal. Next, this pressure signal is filtered to the extent that it can be removed by a low-pass filter 6, and then the pressure value converted into a digital value by an A/D converter 7 is sent to a microcomputer 18. Next, in the microcomputer 18, this A/D converter 7
The arterial pulse wave, which is observed as a phenomenon of arterial counterpressure, is separated, extracted, memorized, and calculated from the pressure value output from the system, and the systolic and diastolic blood pressure periods are determined, and at the same time, the maximum and minimum cuff pressures separated and extracted are calculated. The values corresponding to the blood pressure periods are read and displayed on the display means 16 as the maximum and diastolic blood pressure values.

The cuff 2 shown in FIG.
As experienced, the shape specified by JIS is adopted, keeping in mind that blood pressure values vary depending on the external shape of the cuff 2, especially the width. Note that blood pressure measurement in areas other than the upper arm 1, such as the forearm, wrist, chest,
The location may be selected as appropriate, such as on the thigh or lower leg. Furthermore, the cuff may be wrapped around the tail of an animal other than the human body, such as a rabbit or a mouse. The internal structure of these cuffs 2 needs to be thinner, have higher compliance, and increase responsiveness in order to better detect arterial counterpressure, so the inner fabric 23 of the cuff 2 is lightweight and elastic. Rubber bag 2
It is designed to withstand repeated pressurization of 0 to 300 mmHg or more, and to be as thin as possible. Furthermore, it is obvious that the best way to eliminate the influence of the inner fabric 23 is to eliminate the inner fabric 23 and apply the rubber bladder 20 directly to the body surface.
In this case, since the inner cloth 23 is not required, the structure is simplified. By the way, another function of the cuff 2 is to transfer the detected arterial counterpressure to the tube 2 through air conduction.
1, but in order to convey the level of arterial counterpressure without attenuation, in this example, the winding diameter,
A method is adopted in which the air portion 25 of the rubber bag 20 has a constant volume regardless of the deformation of the pressurized area during pressurization or the pressurizing pressure, and the outer fabric 24 of the cuff 2 is inflated with low compliance. The configuration is such that it does not allow this. Note that although the winding diameter may vary significantly depending on the human body part, this can be easily accommodated by preparing several types of cuffs 2 with different winding diameters.

In addition, the resonance frequency of the acoustic system closed by the tube 21 that transmits pressure from the cuff 2 to the pressure sensor 5 and the pressure control device is set to be sufficiently higher than the frequency of the arterial pulse wave (2 to 10 Hz), and the component parts Even if the resonant frequency changes due to variations in the
In order to transmit the arterial counterpressure without attenuation, in this embodiment, the length of the tube 21 is reduced in order to reduce the capacity.
In addition to making the tube 21 approximately 50 cm thick, the hardness of the tube 21 made of rubber is increased to allow for expansion due to arterial counterpressure.
It is set so that there is no contraction. Furthermore, the pressure sensor 5 can be directly connected to the rubber bladder 2 without going through the tube.
It may be arranged near 0, or it may be arranged in consideration of the responsiveness and frequency characteristics of the diaphragm so that arterial counterpressure can be reliably detected.

In addition, a low-pass filter 6 placed before the A/D converter 7 adjusts the cut-off frequency.
It is set at about 10 to 20Hz, and cuts out noise generated from inside the human body, noise generated by the cuff 2, noise transmitted from the outside, etc., and only detects static pressure (cuff pressure) and arterial counterpressure. It is now allowed to pass.

In addition, the sampling interval of the A/D converter 7 is set to about 10 to 100 samples/second, which can resolve arterial counterpressure, and the conversion speed (sample hold time) is set to 1/2 to 3/4 of the sampling interval. ,
It is made as long as possible so that noise at a level that cannot be removed by the low-pass filter 6 can be smoothed.

Next, the operation of each means constituted by the microcomputer 18 is as follows. First, the pressure information extraction means 9 converts the arterial pulse wave component and cuff pressure component included in the pressure value, which is a digital value converted from A/D by the A/D converter 7, into an arterial pulse wave value V, respectively. It is separated and extracted as a cuff pressure value P. That is, FIG. 7 shows the A/D converter 7
This shows the pressure curve of the pressure value output from
Curve A is a cuff pressure curve during gradual evacuation, and curve B is an arterial pulse wave curve superimposed on curve A. In the electronic blood pressure monitor according to the present invention, the maximum, Diastolic blood pressure values are beginning to be determined. Here, in the arterial pulse wave extraction means 8a, the peak value or area value of the arterial pulse wave is calculated from the curve B by digital calculation to obtain the arterial pulse wave value V of one heartbeat. The extraction means 8b extracts the curve A obtained by removing the arterial pulse wave component from the pressure curve of FIG. It's getting old.

5 and 6 show the arterial pulse wave value V and cuff pressure value P based on the pressure values shown in the pressure curve of FIG.
2 is a flowchart illustrating an example of digital computation that allows easy separation of . That is, in Fig. 8, the pressure value P Base at the start point of pulse wave rise and its time (time from the start of sampling to the start point of pulse wave rise)
tBase is the pressure value P Peak at the pulse wave peak point and its time (from the start of sampling to the peak point Peak
The arterial pulse wave value V and the cuff pressure value P are obtained by reading tPeak (the time required for the measurement) and performing digital calculations using these four values. FIG. 9 is an explanatory diagram of the operation of the pressure information separation means 9, in which a shows a pressure curve, b shows an extracted arterial pulse wave value V, and c shows an extracted cuff pressure value P. There is.

The arterial pulse wave value V and cuff pressure value P extracted as described above are sequentially stored in the storage means 10,
The blood pressure determination means 13 reads out the values stored in the storage means 10 as appropriate, and the calculation means 11 performs comparison calculations.
The blood pressure determination means 12 determines the systolic blood pressure and diastolic blood pressure periods. Here, as a method for determining the systolic blood pressure period and the diastolic blood pressure period, as shown in FIG. Determine the time based on 〓 and calculate the cuff pressure value P ₅ at that time,
Based on the boundary value determination method that takes _P17 as the maximum or diastolic blood pressure value, and the fluctuation parameters of the arterial pulse wave value V (difference between before and after data, ratio between before and after data, difference between provisional maximum value or provisional minimum value, etc.) There is a variable parameter determination method that determines the period based on the method, and the cuff pressure value P at the systolic blood pressure period or the diastolic blood pressure period determined by either method is displayed on the display means 16 as the systolic blood pressure value and the diastolic blood pressure value. It's becoming like that.

FIG. 11 shows that the storage means 10 is formed by a memory 10a in which the arterial pulse wave value V output from the pressure information separation means 9 and the cuff pressure value P are readably stored as set data. Blood pressure determination means 1
3 is a diagram illustrating a configuration in which the systolic and diastolic blood pressures are determined by appropriately reading data from 3 and performing comparison calculations. In addition to the memory 10a, the storage means 10 also includes a memory storage start point pointer 10b and a memory storage end point pointer. 10c and other information storage section 10d are provided. In the embodiment, a time value t indicating the time at which the arterial pulse wave value V and the cuff pressure value P are obtained is also stored in the memory 10a as set data.

Currently, in electronic blood pressure monitors using the vibration method, in order to calculate or compare the arterial pulse wave value V and determine the maximum and diastolic blood pressure, it is necessary to store information about each pulse wave by some means. There is. Therefore, in the embodiment, the arterial pulse wave value V, the cuff pressure value P, and its time value t obtained for each pulse wave are stored in the memory 10a as one pulse wave set data, and the blood pressure is This facilitates data reading during comparison calculations in the determining means 13. Further, the memory contents stored in the memory 10a are numbered, and the memory storage start point and storage end point of the memory contents are stored in the memory storage start point pointer 10b and the memory storage end point pointer 10c, The data storage area and the free area can be clearly understood.

As described above, in the embodiment, the storage means 10 is stored in the memory 10a in which the arterial pulse wave value V output from the pressure information separation means 9 and the cuff pressure value P are readably stored as set data. Therefore, after determining the peak and diastolic blood pressure periods based on the arterial pulse wave value V, the cuff pressure value P for that period is immediately obtained, and the peak and diastolic blood pressure values, pulse value, exhaust speed, etc. Decisions can be made quickly, the reading means is simple, and the response can be quick.

FIG. 12 and FIG. 13 show a memory 10a having a predetermined storage capacity and a free space obtained by erasing data that is determined to be unnecessary at the time of blood pressure determination in the blood pressure determining means 13 among the data stored in the memory 10a. Secure and remember used space and free space,
An example is shown in which the storage means 10 is formed by memory effective utilization means for updating and effectively utilizing the memory 10a. Now, the arterial pulse wave value V output from the pressure information separation means 9 every time the arterial pulse wave is generated for one beat,
The cuff pressure value P and the time value t are sequentially stored in the memory 10a of the storage means 10, but since the storage capacity of the memory 10a cannot be expanded infinitely, the storage capacity of the memory 10a is It is set to a predetermined value. The predetermined value is determined by the exhaust speed, pulse value, maximum and diastolic blood pressure values, etc. from the nature of blood pressure measurement, and it is possible to set the maximum capacity, but if this maximum capacity is adopted, the storage means 10 will become large. In addition, the problem arises that the cost increases. Therefore, it becomes necessary to delete and rearrange unnecessary data. Here, in the embodiment, as shown in FIG. 12a, 6 of the memory 10a
When data is stored in the first, third, and fifth storage areas when determining blood pressure, this unnecessary data is deleted and the remaining data is As shown in b, the data is moved and collected toward the storage area with the smaller number. Note that, as shown in FIG. 3c, the remaining data may be moved to and collected in a storage area with a larger number.

On the other hand, as shown in Fig. 13a, if the nth storage area is full of data and you want to store more data, the data is stored in the first of the free areas 1 to m as shown in Fig. 13b. Then, a method is adopted in which "1" is stored in the memory storage end point pointer 10c. However, the above method can be realized by sufficiently managing the back-and-forth relationship between the storage start point Mstart and the storage end point Mend.

In this embodiment, the memory 10a having a predetermined storage capacity and the data stored in the memory 10a that are determined to be unnecessary at the time of blood pressure determination in the blood pressure determining means 13 are deleted to free up space. Since the memory 10 is formed by a memory effective use means that secures an area and stores and updates the used area and free space to effectively utilize the memory 10a, the memory 10a of the storage means 10 is not needed when blood pressure is determined. To provide a low-cost electronic blood pressure monitor in which the storage means 10 and calculation means 11 can be formed using a one-chip CPU with a built-in RAM that has a small storage capacity and is effectively used without being occupied by data. I'm starting to be able to do it.

FIG. 14 shows that data used for determining the systolic blood pressure and unnecessary for determining the diastolic blood pressure is transferred to the blood pressure determining means 13.
After the systolic blood pressure is determined, it is erased and stored in the memory 10a.
FIG. 4 is a diagram illustrating an operation when memory effective utilization means is formed to secure a free area for use in determining the diastolic blood pressure.

Now, in a state where data is stored in the first to seventh storage areas of the memory 10a as shown in FIG.
When it is determined that only the data in the 6th and 7th storage areas are necessary for determining the diastolic blood pressure value, the data in the 6th and 7th storage areas are combined with the data in the 1st and 2nd storage areas, as shown in Figure b. The information is moved to the storage area and collected, leaving the third to seventh storage areas as empty areas, and the calculations for determining the diastolic blood pressure are performed using these empty areas. In the embodiment shown in FIG. 5B, the data is moved and collected to the storage area with the smaller number, but the method of movement and collection is not limited to the embodiment. FIG. 15 is a schematic flowchart showing the above operation of organizing data after determining the systolic blood pressure value.

As described above, in the embodiment, data used for determining the systolic blood pressure and unnecessary when determining the diastolic blood pressure is deleted after the systolic blood pressure is determined in the blood pressure determining means 13 to create an empty space in the memory 10a for use when determining the diastolic blood pressure. A means for effective memory utilization is formed to secure the area, and in the vibration method, the number of pulse waves required to determine the systolic blood pressure is approximately 2/3 of the pulse waves obtained within the total blood pressure measurement time, and the number of pulse waves required for determining the systolic blood pressure is approximately 2/3. Since the number of pulse waves required for determination is 1/3 of the remaining number, the storage capacity of the memory 10a can be reduced to approximately 2/3 compared to the case where all data corresponding to all pulse waves is stored. The memory means 10 and the arithmetic means 11 can be formed using a low-cost one-chip CPU with built-in less RAM (about 2/3 of that in Embodiment 14),
This will allow us to provide a lower-priced electronic blood pressure monitor.

[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. a pressure sensor that converts the pressure within the cuff into an electrical signal; and an A/D converter that samples the pressure sensor output and converts it into a digital value;
Arterial pulse wave extraction means for digitally extracting an arterial pulse wave value from the pressure value output from the A/D converter during the gradual evacuation period, and digitally extracting a cuff pressure value from which the arterial pulse wave is removed from the pressure value. Pressure information separation means equipped with cuff pressure extraction means;
Storage means for storing arterial pulse wave values and cuff pressure values corresponding to the pulse waves extracted by the pressure information separation means; and systolic and diastolic blood pressure values by appropriately reading and comparing the values stored in the storage means. It is composed of a blood pressure determining means for determining the blood pressure value, and a display means for displaying both determined blood pressure values, and because it does not use a cuff with a built-in microphone unlike the conventional auscultation method, the cuff can be easily inserted without feeling uncomfortable. It can be installed, and
Since the arterial pulse wave value is extracted by digital calculation, the configuration is simpler than the conventional vibration method that performs analog signal processing, making it easier to downsize and lower the price. be.

In addition, a memory having a predetermined storage capacity and data stored in the memory that are determined to be unnecessary at the time of blood pressure determination by the blood pressure determining means are deleted to secure free space, and used and free space are reduced. A memory effective use means is formed with a memory effective use means for storing and updating the memory to effectively utilize the memory, and data used for determining the systolic blood pressure and unnecessary when determining the diastolic blood pressure is deleted after the blood pressure determining means determines the systolic blood pressure. Since a memory effective utilization means is formed to secure free space in the memory for use in determining diastolic blood pressure, it is possible to effectively use memory with a small storage capacity to perform blood pressure determination calculations, reducing costs. Furthermore, the storage means and the calculation means can be formed using a low-cost one-chip CPU with a built-in small capacity RAM, and a lower-priced electronic blood pressure monitor can be provided.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram of an embodiment of the present invention, and FIG.
The figure is a block circuit diagram of the same essential parts as above, FIG. 3 is a block circuit diagram of essential parts same as above, FIG. 4 is a sectional view of essential parts same as above, FIGS. is a schematic configuration diagram of a conventional example. 1 is an upper arm, 2 is a cuff, 3 is a pressurization means, 4 is a pressure reduction means, 5 is a pressure sensor, 7 is an A/D converter, 8a is an arterial pulse wave extraction means, 8b is a cuff pressure extraction means, 9 is pressure information separation means; 10 is storage means;
10a is a memory, 13 is a blood pressure determining means, and 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 that increases the pressure inside the cuff, an exhaust means that gradually lowers the pressure inside the cuff, a pressure sensor that converts the pressure inside the cuff into an electrical signal, and a pressure sensor that samples the pressure sensor output and converts it into a digital value. an A/D converter that gradually extracts an arterial pulse wave value from the pressure value output from the A/D converter during the evacuation period by digital calculation, and a cuff pressure from which the arterial pulse wave is removed from the pressure value. Pressure information separation means equipped with cuff pressure extraction means for extracting values by digital calculation; storage means for storing arterial pulse wave values and cuff pressure values corresponding to the pulse waves extracted by the pressure information separation means; An electronic sphygmomanometer comprising a blood pressure determining means for determining the maximum and diastolic blood pressure values by suitably reading values stored in the means and performing comparison calculations, and a display means for displaying both determined blood pressure values. A memory having a large capacity, and data stored in the memory that is determined to be unnecessary when determining blood pressure by the blood pressure determination means to be deleted to secure free space, and used and free space are stored and updated. Forming a storage means with a memory effective use means for effective use of memory,
The memory effective utilization means is configured to erase data used for determining the systolic blood pressure and unnecessary when determining the diastolic blood pressure after the systolic blood pressure is determined in the blood pressure determining means to secure a free space in the memory for use when determining the diastolic blood pressure. An electronic blood pressure monitor characterized by: