JPH0331045B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field] The present invention provides a vibration method (oscillometric method) that determines the peak and diastolic blood pressure periods based on the pulse wave component of each heartbeat superimposed on the pressure inside the cuff. This relates to a blood pressure monitor.

[Background Art] Conventionally, general blood pressure monitors have been designed to apply pressure to a cuff wrapped around the upper arm of the person being measured to isolate blood from the artery, causing the state to transition from arterial ischemia to bleeding, thereby producing and eliminating Korotkoff sounds. The Rybarotschi-Korotkoff method was used to measure the maximum and diastolic blood pressure by detecting the Korotkoff sound sensor. There is the problem that it is troublesome to put on the cuff because it has to be placed at the pulse point, and the Korotkoff sound sensor also detects noise emitted from the upper arm or the cuff, making it prone to malfunction. Ta. Therefore, in order to solve these problems, we have developed an oscillometric blood pressure monitor that extracts and calculates the pulse wave component of each heartbeat superimposed on the cuff pressure to determine the peak and diastolic blood pressure periods. is proposed. In other words, the vibration method sphygmomanometer includes a cuff that is attached to the main part of the subject, and a pressurization means that pressurizes the cuff until the arteries in the main parts are blocked and then gradually evacuates the cuff to open the arteries. , the pulse wave component superimposed on the intracuff pressure P ₀ as shown in Figure 10.
V ₀ is sequentially detected by the pulse wave detection means, and the cuff pressure value P at the time of generation of the pulse wave component and the pulse wave value V of the pulse wave component as shown in FIG. 11 are stored as a pair in the storage means. Then, the stored pulse wave value V is appropriately calculated to determine the peak and diastolic blood pressure periods, and the cuff pressure values P at those times are set as the peak and diastolic blood pressures. By the way, as a method for determining the peak and diastolic blood pressure periods of this type of vibration method blood pressure monitor, for example, a pulse wave having a value obtained by multiplying the pulse wave value Vmax at the maximum of the pulse wave component (at the time of mean blood pressure) by a predetermined ratio is used. There is a judgment method that determines the period when the value V appears as the maximum or diastolic blood pressure period, or a judgment method that determines the maximum or diastolic blood pressure period based on the increase/decrease pattern of the pulse wave value V from the arrangement of the pulse wave values V. When determining systolic blood pressure using such a determination method,
It is necessary to store all the pulse wave values V and cuff pressure values P of the pulse wave components generated from the time when the pulse wave components begin to appear until the time of mean blood pressure in the storage means, and assuming that the cuff pumping speed is constant, When the subject's pulse is fast, a large amount of data must be stored, and a memory with a large memory capacity is required as a storage means, making it impossible to reduce the size and price. For example, as shown in FIGS. 12 and 14, if the subject's pulse speed is normal, the pulse wave value obtained from the measurement start time ts until the maximum value of the pulse wave component appears. Although the number of V is 9, if the subject's pulse is fast as shown in Figs. The number of pulse wave values V that can be obtained may be approximately doubled, and a large amount of data (indicated by arrows in FIG. 15) that is not very effective for blood pressure determination will be included. However, in the conventional example, the pulse wave value V obtained in this way and the cuff pressure value P at that time were all stored in the storage means without considering the pulse speed, etc. The memory capacity of the storage means has become larger than necessary, which has become a big problem when trying to downsize and lower the price.
Note that in the figure, te indicates the time point at which the measurement ends.

[Object of the Invention] The present invention has been made in view of the above points, and its purpose is to easily reduce the size and cost without requiring a memory with a large memory capacity as a storage means. Our goal is to provide a vibratory blood pressure monitor that can.

[Disclosure of the Invention] (Structure) The present invention comprises a cuff that is attached to the main part of a subject, and a pressurizer that pressurizes the cuff until the arteries in the main parts are blocked and then gradually evacuates the blood to open the arteries. The pulse wave component superimposed on the pressure inside the cuff is detected by the pulse wave detection means, and the cuff pressure value at the time the pulse wave component is generated is paired with the pulse wave value of the pulse wave component. The highest and lowest blood pressure periods are determined based on the stored pulse wave values, and the cuff pressure values at those times are set to the highest and lowest.
In a vibratory blood pressure monitor that detects diastolic blood pressure, the cuff pressure value and generation time of the pulse wave component previously stored in the storage means and the pulse wave component detected this time for each pulse wave component detected by the pulse wave detection means. The vibration method blood pressure monitor is characterized in that it is provided with a memory control means for storing the pulse wave value and the cuff pressure value as valid data in the memory means when the change in at least one of them is larger than a predetermined value. By storing only valid data in the means, a memory with a large capacity is not required as the storage means, and miniaturization and cost reduction can be easily achieved.

Embodiment 1 FIGS. 1 to 3 show an embodiment of the present invention, in which a cuff 2 that is wrapped around and attached to the upper arm 1 of the subject is pressurized by a rubber ball 22 via a tube 21. Means 3 is connected so that pressure can be applied by pressing the rubber bulb 22 until blood ischemia is achieved. 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. The blood pressure monitor main body 30, to which one end is connected to the cuff 2 and the other end of the tube 21 is connected, includes a pressure sensor 5 that converts the pressure inside the cuff 2 into an electrical signal, and a pressure sensor 5 that converts the pressure inside the cuff 2 into an electrical signal. A low-pass filter 6 that removes the noise, and an A/D converter 7 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.
Pulse wave detection means 8a digitally extracts a pulse wave value V from the pressure value (digital value) output from the A/D converter 7 during the evacuation period, and digitally extracts the cuff pressure value P from which the pulse wave is removed from the pressure value. A pressure information separating means including a cuff pressure detecting means 8b extracting by calculation, and determining whether the pulse wave value V and cuff pressure value P corresponding to the pulse wave extracted by the pressure information separating means are valid data. A determining means 9, a storing means 10 for storing the pulse wave value V and cuff pressure value P determined as valid data by the determining means 9, and reading out the pulse wave value V stored in the storing means 10 as appropriate and performing a comparison calculation. calculation means 11 and this calculation means 11
a blood pressure determining means 13 comprising a blood pressure determining means 12 that determines the maximum and diastolic blood pressure values from the calculation results calculated by the blood pressure determining means 12; and a pulse monitor 14 for determining the maximum and diastolic blood pressure values, exhaust speed, and pulse rate determined by the blood pressure determining means 13. The display means 16 appropriately displays the exhaust velocity value and pulse value outputted from the cuff pressure monitor 15, and the cuff pressure outputted from the cuff pressure monitor 15.
is arranged on the front side of the blood pressure monitor main body 30. In this embodiment, the determining means 9 determines whether or not there is valid data based on the change ΔP in the cuff pressure value P, and the determining means 9 determines whether or not there is valid data based on the change amount ΔP in the cuff pressure value P, and the determining means 9 determines whether or not there is valid data based on the change amount ΔP of the cuff pressure value P, and the determining means 9 determines whether or not there is valid data based on the change amount ΔP of the cuff pressure value P. When the change ΔP between the detected cuff pressure value P and the currently detected cuff pressure value P is larger than a predetermined value C ₁ (set based on the evacuation speed by the evacuation means and the memory capacity of the storage means 10), the pulse wave is detected. The value V and the cuff pressure value P are stored in the storage means 10 as valid data. Note that the pressure information separation means, the determination means 9, the storage means 10, the calculation means 11, the blood pressure determination means 13, and both monitors 14 and 15 are implemented by a CPU,
It is formed by a microcomputer 18 using ROM, RAM, etc. Further, as a means for increasing and decreasing the pressure of the cuff 2, as shown by the imaginary line in the figure, a cuff pressure control means 19 may be provided which automatically controls a pressurizing pump and an electromagnetic exhaust valve according to a predetermined program set in the microcomputer 18. .

The operation of the embodiment will be explained below with reference to the flowchart of FIG. However, n is a positive integer (1,
2, 3...), the pulse wave values V detected during measurement are V ₁ , V ₂ , V ₃ ...Vn in the order of occurrence, and the cuff pressure values at the time of occurrence are P ₁ , P ₂ , P ₃ ...It is supported as Pn. Now, the pulse wave value V and the cuff pressure value P are calculated by the pulse wave detecting means 8a and the cuff pressure detecting means 8b, respectively, and the determining means determines whether the sequentially outputted pulse wave value V and cuff pressure value P are valid data. Judgment is made in step 9. This determination means 9 sets the first cuff pressure value PX stored in the storage means 10 to a sufficiently large value (P
Set a sufficiently large value PM for (n),
Thereafter, the cuff pressure value previously stored in the storage means 10
If the difference between PX and the currently detected cuff pressure value P(n) is larger than the predetermined value _C1 (PX-P(n)≧ _C1 ), the data is considered valid and stored in the storage means 10. If the data is smaller than the predetermined value _C1 , the data is canceled as invalid data, and it is determined whether the next change ΔP in the cuff pressure value P is larger than the predetermined value _C1 , and the same judgment operation is performed. This is repeated until the end of the measurement. Figures 5 and 6 show actual measurement examples, and in the case of a subject with a typical pulse speed as shown in Figure 5,
The change ΔP in the cuff pressure value P from when the previous pulse wave component is obtained until when the next pulse wave component is obtained is always
Since they are larger than C ₁ , the pulse wave value V and the cuff pressure value P are all stored in the storage means 10 as valid data without being canceled. On the other hand, as shown in FIG. 6, in the case of a subject with a fast pulse, for example, the cuff pressure value between the time when the first pulse wave component is obtained and the time when the second pulse wave component is obtained. Since the change in P ΔP ₁ has become smaller than the predetermined value C ₁ , the data corresponding to the second pulse wave component is determined not to be valid data, is canceled, and is not stored in the storage means 10 . Since the change ΔP ₂ in the cuff pressure value P until the third pulse wave component is obtained is larger than the predetermined value C ₁ ,
The pulse wave value V and cuff pressure value P corresponding to this pulse wave component are stored in the storage means 10 as valid data. Similarly, the data corresponding to the fourth pulse wave component whose variation ΔP ₃ is smaller than the predetermined value C ₁ is canceled, and the data corresponding to the fourth pulse wave component whose variation ΔP ₄ is larger than the predetermined value C ₁ is canceled.
The data corresponding to the th pulse wave component is determined to be valid data and stored in the storage means 10, and the same determination operation is repeated until the end of the measurement. In the embodiment, the second and fourth data are canceled as invalid data, but these second and fourth data are stored as temporary data in the temporary storage circuit, and this temporary data and the next valid data are canceled. The average value of the determined third and fifth data may be calculated and stored in the storage means 10 as representative data corresponding to the second, third or fourth and fifth data.

As described above, in this embodiment, the pulse wave value V and the cuff pressure value P are calculated based on the change ΔP between the cuff pressure value P previously stored in the storage means 10 and the cuff pressure value P detected this time. It is determined whether the data is valid for blood pressure determination, and even if the number of valid data obtained in this way is for a subject with a fast pulse, This results in a blood pressure monitor that does not require a large-capacity memory as the storage means 10 and is easily miniaturized and inexpensive.

Embodiment 2 FIG. 7 is a flowchart showing the operation of another embodiment, in which the determining means 9 determines whether or not there is valid data based on the change Δt in the generation time t(n) of the pulse wave component. , and the change amount Δt (=t(n-1)-t (n)) is larger than a predetermined value C ₂ (set based on the evacuation speed by the evacuation means and the memory capacity of the storage means 10), it is determined that the data is valid, and the pulse wave value V(n) and the cuff pressure are determined to be valid data. The value P(n) and the time t(n) are stored in the storage means 10.

Now, in the pressure information separation means, the pulse wave detection means 8
The pulse wave value V(n) is calculated at step a, the cuff pressure value P(n) is calculated at the cuff pressure detection means 8b, and the occurrence time t is also calculated at the same time. The first occurrence time TX stored in the means 10 is set to a large value (a sufficiently large value TM for t(n)), and thereafter, the occurrence time TX previously stored in the storage means 10 and the current occurrence time t are set.
(n) to find the change Δt, and this change Δt is larger than the predetermined value C ₂ (t(n)−TX≧
C ₂ ), the pulse wave value V(n) and cuff pressure value P(n) at that time are determined to be valid data and stored in the storage means 1. On the other hand, the change Δt is the predetermined value C ₂
If it is smaller than , the data corresponding to that pulse wave component is canceled as invalid data, and the judgment operation for the data corresponding to the next pulse wave component is performed in the same way, and the above judgment is continued until the end of the measurement. Repeat the action.

Figures 8 and 9 show actual measurement examples. As shown in Figure 8, in the case of a subject with a typical pulse speed, the Since the change Δt in the generation time t until the next pulse wave component is obtained is always larger than C ₂ ,
The pulse wave value V and the cuff pressure value P are all stored in the storage means 10 as valid data without being canceled. On the other hand, as shown in FIG. 9, in the case of a subject with a fast pulse, for example, the generation time t between when the first pulse wave component is obtained and when the second pulse wave component is obtained. Since the change Δt ₁ is smaller than the predetermined value C ₂ , the data corresponding to the second pulse wave component is determined not to be valid data, is canceled, and is not stored in the storage means 10 . Next, since the change Δt ₂ in the generation time t until the third pulse wave component is obtained is larger than the predetermined value C ₂ , the pulse wave value V and cuff pressure corresponding to this pulse wave component are The value P is stored in the storage means 10 as valid data. Similarly, the change Δt ₃ becomes the predetermined value C ₂
The data corresponding to the fourth pulse wave component smaller than the predetermined value C2 is canceled, and the data corresponding to the fifth pulse wave component whose change amount _Δt4 is larger than the predetermined value _C2 is determined to be valid data and stored in the storage means 10. The information is stored and the same determination operation is repeated until the end of the measurement. In the embodiment, the second and fourth data are canceled as invalid data, but these second and fourth data are stored as temporary data in the temporary storage circuit, and this temporary data is used as the next valid data. Calculate the average value of the 3rd and 5th data determined as 2 and 3.
The data may be stored in the storage means 10 as representative data corresponding to the fourth or fifth data.

[Effects of the Invention] As described above, the present invention includes a cuff that is attached to the main part of the subject and pressurizes the cuff until the arteries in the main parts are blocked, and then gradually evacuates the blood to open the arteries. The pulse wave component superimposed on the pressure inside the cuff is detected by the pulse wave detection means, and the cuff pressure value at the time the pulse wave component is generated is paired with the pulse wave value of the pulse wave component. In a vibratory sphygmomanometer in which the maximum and diastolic blood pressure periods are determined based on the stored pulse wave values and the cuff pressure values at those periods are the maximum and diastolic blood pressures, the pulse wave detection means The pulse wave is detected when at least one of the cuff pressure value and generation time between the previously stored pulse wave component stored in the storage means for each detected pulse wave component and the pulse wave component detected this time is larger than a predetermined value. A storage control means is provided for storing the wave value and cuff pressure value in the storage means as valid data, and among the pulse wave value and cuff pressure value sequentially detected by the pulse wave detection means, the data valid for blood pressure determination is Since it is designed to efficiently determine and store it in the storage means, there is no need for a large capacity memory as the storage means, and there is an effect that miniaturization and cost reduction can be easily achieved.

[Brief explanation of drawings]

Fig. 1 is a schematic configuration diagram of an embodiment of the present invention, Fig. 2 is a block circuit diagram of the same, Fig. 3 is a main block circuit diagram of the same, Fig. 4 is a flowchart showing the operation of the above, and Fig. 5 6 and 6 are explanatory diagrams of the same operation, FIG. 7 is a flowchart showing the operation of another embodiment, and FIGS. 8 and 9 are explanatory diagrams of the same operation,
10 to 15 are explanatory diagrams of the operation of the vibration method blood pressure monitor according to the present invention. 1 is an upper arm, 2 is a cuff, 8a is a pulse wave detection means, 9
1 is a determination means, and 10 is a storage means.

Claims (1)

[Scope of Claims] 1. A cuff that is attached to the main part of the subject, and a pressurizing/depressurizing means that pressurizes the cuff until the artery in the main part is blocked, and then gradually evacuates the cuff to open the artery. , the pulse wave component superimposed on the pressure inside the cuff is detected by the pulse wave detection means, and the cuff pressure value at the time of generation of the pulse wave component and the pulse wave value of the pulse wave component are stored as a pair in the storage means. ,
Each pulse wave component detected by the pulse wave detection means in a vibratory blood pressure monitor that determines the peak and diastolic blood pressure periods based on stored pulse wave values and uses the cuff pressure values at those times as the peak and diastolic blood pressures. The pulse wave value and cuff pressure value are stored when at least one of the cuff pressure value and generation time between the pulse wave component previously stored in the storage means and the pulse wave component detected this time is greater than a predetermined value. A vibratory blood pressure monitor characterized by comprising a memory control means for storing valid data in a memory means. 2 When the change in cuff pressure value between the pulse wave component previously stored in the storage means for each pulse wave component detected by the pulse wave detection means and the pulse wave component detected this time is larger than a predetermined value, the pulse wave is detected. 2. The vibration method blood pressure monitor according to claim 1, further comprising a memory control means for storing the wave value and the cuff pressure value in the memory means. 3 When the change in the generation time between the pulse wave component previously stored in the storage means of each pulse wave component detected by the pulse wave detection means and the pulse wave component detected this time is greater than a predetermined value, the pulse wave is detected. 2. The vibratory blood pressure monitor according to claim 1, further comprising a memory control means for storing the cuff pressure value and the cuff pressure value in the memory means.