JPS59149129A - Korotokov sound gathering device of hemomanometer - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a sound collection device for a blood pressure monitor.

[Background technology]

Currently, the standard clinical method for non-invasive blood pressure measurement is
The basic method is auscultation using the 0, 0 and 0 sounds. This method involves wrapping a cuff around the upper arm of the human body, injecting air into the ischemic cuff (an air bag made by JM) inside the cuff, and pressurizing the blood pressure to a level 20 to 30 Mm above the expected systolic blood pressure. It compresses arteries and stops blood flow. Next, increase the air pressure inside the ischemic cuff to 2-3 rtrm.
Gradually exhaust the air at the speed of Hy/Maro. Eventually, the artery opens slightly and blood flows out, producing a damped vibration sound called a tokoff sound laterally across the blood vessel wall. This sound continues to occur in synchronization with the pulse, but eventually disappears when the artery is sufficiently opened and the blood flow becomes constant.

The cuff pressure in the pulse zone when this lo) click sound occurs is the systolic blood pressure value, and the cuff pressure before it disappears, that is, when the last]0t]f sound occurs, is the diastolic blood pressure value.

Figure 1 shows a configuration diagram when a doctor measures blood pressure using the M examination method, in which a cuff (2) wrapped around the upper arm of the body is passed through a pressure ball (7) and a conduit ( 5). (8) is exhaust control pulp, (3) is stethoscope, (
4) is a doctor, and (6) is a column of mercury. As mentioned above, the cuff (2) is pressurized using the pressure ball (7), the cuff pressure is adjusted using the exhaust adjustment pulp (8), and the stethoscope (
3) is placed near the finger side of the arm cuff (2), the doctor (4) distinguishes the Korotkoff sound by ear, and determines the cuff pressure at the onset and disappearance of the Korotkoff sound by gazing into the mercury column (6). be able to. Measuring blood pressure using such auscultation method requires a considerable level of skill and often involves subjective judgment, resulting in variations in measurement accuracy. Therefore, electronic blood pressure monitors that can be easily and stably measured even by laymen have been developed. However, in conventional electronic blood pressure monitors, the characteristics of a stethoscope and the characteristics of human hearing have not been sufficiently taken into consideration, and therefore, correlation with blood pressure measurements taken by a doctor has become a problem. In other words, with conventional electronic blood pressure monitors, the sound is detected by a sensor such as a microphone built into the wrist cuff, and the doctor's judgment based on auscultation and statistical analysis (a large amount of clinical data) are used to detect the sound. An appropriate frequency band (so as to be relatively optimal) was determined and discriminated using a filter. Therefore, the sound that the doctor hears and the sound that is detected by the sensor and filter have different wood characteristics and cannot be said to match. In addition, in order to determine the optimal sensor, filter frequency band, and comparator level, statistical matching is required, which requires analysis of a large amount of clinical data, resulting in the problem of requiring a huge amount of time and effort for development. there were.

[Object of the Invention] The present invention has been provided in view of the above-mentioned points, and it is possible to distinguish between the sounds "o" and "f" under the same conditions as those used by doctors using the auscultation method. The present invention provides a sound collection device for a blood pressure monitor aimed at performing consistent and accurate blood pressure measurements.

[Disclosure of the invention] Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 2 shows a configuration diagram that is the premise of an embodiment of the present invention. (2) is an arm cuff wrapped around M(1) above the body;
(6) The part that supplies Qi to the cuff (2) using the pressure ball (7) is constructed as follows. In other words, there is no microphone on one earpiece! Attached to the end of the ring is a microphone for detecting sound. A microphone halter (10) and a pseudo microphone (12) are also attached to the other earmuff. Here, the distance from the end of the earmuff of the stethoscope (3) to the microphone (the length of the ear canal is about 30 rin) is equal to the distance from the end of the earmuff to the microphone (the length of the ear canal is about 30 rin). Stethoscope in this state (3
) is shown in curve 1-1' shown in Figure 4.
), and the stethoscope characteristics when a person actually wears the stethoscope in his or her ear are as shown in song #(0) in FIG. So, here are the characteristics of the stethoscope (3) above! The ear-worn corrector f97- is used to achieve the configuration shown in FIG. 44 (2). This ear-worn corrector (9) has an injection needle (9a) (length: 50 mm,
Two microphones with a diameter of 1.2 m were connected to
), and the other end is communicated with a conduit (9b) (length 135 mm, diameter 4 zm'). This gives the same stethoscope characteristics that the Sims are hearing.

The microphone (II) itself has frequency characteristics, and the electret type microphone (1
1) has microphone sensitivity characteristics as shown in FIG. 5(a). Therefore, in order to flatten the microphone sensitivity characteristics, it is necessary to perform correction using a microphone sensitivity correction filter (13) having characteristics opposite to the microphone sensitivity characteristics as shown in FIG. 5(b).

Next, the human sense of hearing has frequency characteristics. 1 Generally, low frequency sensitivity is poor. As the human hearing characteristics, equal loudness curves for pure tones are used. Figure 6(a) n 60
dB (D '45') Dones curve (ISO/R2
26 Uderu. This was obtained by combining the sound pressure levels measured for each frequency of 60 phones at 1ooOHz. Therefore, we find the inverse characteristic of this characteristic and 1oo
The characteristics of the audibility correction filter shown in FIG. 6(b) are OHz expressed as OdB, and the audibility correction filter (141) is configured to be equivalent to the state of hearing with the human ear.In this way, Stethoscope (3), ear-worn corrector (9)
) and the microphone 0 phon attached to the Holter (101). 14), it is possible to obtain the same Korotkoff sound signal that is felt by the doctor's ears.

In addition, Q Xun uses a sound correction filter (14
) is above a predetermined value, it is recognized as a 0-tone sound signal and sent to the next stage control circuit section. tl@
A pressure sensor detects the cuff pressure of the arm cuff (2).The output of this pressure sensor tlf9 is input to the A/D converter Qη, and the output of the A/D converter (+7), which is converted to a digital signal, is controlled. circuit (sent to Ig+).

The control circuit (18) measures the systolic diastolic blood pressure value based on the output of the comparator (15) and the output of the VD converter t17), and displays the measured value digitally on the display (19).

However, when measuring blood pressure, the arm cuff (2
) and place the membrane side of the stethoscope (3) on the artery near the finger side of arm i +21. After that, the pressure ball (7) is applied to the ischemic cuff inside the arm cuff (2). Inject Qi and pressurize to 20 to 30 aawHy higher than the expected systolic blood pressure. Next, adjust the temperature adjusting pulp (8) and heat it for 2 to 3 hours.
Exhaust at a speed of f/see. At the same time, stethoscopes (3), ear-worn correctors (9), microphones (1)
1), the sound is detected, and after passing through the microphone sensitivity correction filter (131 and hearing correction filter (I4)), the cosciparator (15) detects the signal above a certain level. The cuff pressure is recognized and input to the control circuit (18) as ]0 tocoff sound pulse.On the other hand, the cuff pressure is
It is detected by a pressure sensor 6) connected through 6), and inputted to the control circuit after passing through an A/D converter 0η. In the control circuit (18), when the Korotkoff sound pulse is first input, the pressure sensor haze, A
/I)] The cuff pressure obtained from the converter (+7)K is displayed as the systolic blood pressure value on the display μ9) and 10)
] The cuff pressure when the last sound was input is displayed on the display as the diastolic blood pressure value. After this, exhaust adjustment pulp (
8) is fully opened to rapidly exhaust the air in the ischemic cuff in the arm cuff (2) to complete the measurement.

By the way, when blood pressure is actually measured using the method of this embodiment, the conduit (3a) portion of the stethoscope (3) is on the approximately 70 side, which is inconvenient for measurement and also tends to pick up noise.

In addition, since the frequency characteristic of only the stethoscope head (3b) excluding the conduit (3a) is almost flat, the microphone (1) is directly connected to the stethoscope head (3b) excluding the conduit (3a).
An easy-to-use sphygmomanometer can be obtained by arranging 1) and configuring the conduit (convex a) shown at - in FIG. 4 and the characteristic when worn on the ear using an electric filter. This is the gist of the present invention, and its configuration is shown in FIG. In other words, as shown in Figure 5, a microphone (11) is built into the arm cuff (2) instead of a stethoscope, and the frequency characteristics of this microphone (11) and (a) in Figure 4 are The difference from the stethoscope characteristics shown is realized by a stethoscope characteristics correction filter. The hearing correction filter (1141) is the same as the basic example above. This eliminates the need to use a stethoscope, making it easier to use. Since blood pressure can be measured in the same manner as with the conventional auscultation method, it is possible to measure blood pressure in a manner that closely matches the auscultation method used by doctors.

〔Effect of the invention〕

As described above, the present invention flattens the frequency characteristics of the microphone that collects Korotkoff sounds and the microphone itself, and also flattens the frequency characteristics of the stethoscope itself when the stethoscope is actually held against the upper arm and listened to with the ear. It is equipped with a stethoscope characteristic correction filter that matches the stethoscope characteristic, and an auditory sense correction filter that adjusts the output of the stethoscope characteristic filter to the auditory sense characteristic that the body's ear itself has. , the characteristics of the stethoscope and the characteristics of the auditory sensation can be taken into account, so that the doctor can obtain the sound signal that is the same as the sound that the doctor feels with his ears, and thereby perform Korotkoff-Wr m Wit. This has the effect of being able to perform measurements that closely match blood pressure measurements made by a doctor's auscultation method.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing blood pressure measurement by a doctor's auscultation method, Fig. 2 is a basic block diagram of the present invention, Fig. 5 is the W factor of the above embodiment, and Fig. 4 is the characteristic of the stethoscope. Figure 5 (smell is the same microphone sensitivity characteristic diagram as above, Figure 6 (b) is the same microphone sensitivity correction filter characteristic diagram, Figure 6 (a) is the same auditory characteristic diagram as above, Figure 6 (b) is the same diagram as above). This is a characteristic diagram of the hearing correction filter. (3) shows the stethoscope, (!ri shows the microphone 0) on, the ring shows the hearing correction filter, and (e) shows the stethoscope characteristic correction filter. Agent: Patent Attorney Ishi 1) Chapter 7 Procedural Amendment (Voluntary) January 30, 1980 Dear Commissioner of the Japan Patent Office 1, Indication of the case 1988 Patent Application No. 231124+ 2, Name of the invention Korotkoff sound collector device for blood pressure monitor 3, Amendments made Relationship with the patent case Patent applicant Location 1048 Kadoma, Kadoma City, Osaka Name (583) Matsushita Electric Works Co., Ltd. Representative Iku Kobayashi 4 Agent postal code 530 5 Date of amendment order Application number Patent application 5 .8-23112 No. 1, the claims on page 1 of the specification of the present application are amended as follows. A sound collection device for a blood pressure monitor, comprising an auditory correction filter that adjusts the output of the filter to the auditory characteristics of the body's ears themselves. (2) 60dB etc. loud as a hearing correction filter
- A sound collection device for a blood pressure monitor according to claim 1, characterized in that the inverse characteristic of the ness curve is used. ” 2. Correct “compression” in line 8 of page 2 of the above to “compression”. 3. Correct "pulse band" in line 15 of page 2 of the same as "brachial band". 4. Delete "presupposed" on page 4, line 19 of the same page. 5. Same as above, page 9, line 8, change “when worn” to “when worn”
I am corrected. 6. Delete the sentence "This is the gist of the present invention" in lines 9 and 10 of page 9 of the same above.0 7. Delete "(a)" in line 14 of page 9 of the same above. ” r (o)
Correct it with J. 8. Insert the following sentence before "This is K," on page 9, line 17 of the same page. [In this way, instead of a stethoscope, a microphone 07 (11) is built into the arm cuff (2), and this microphone 07 (11) is built in.
This means that the difference between the frequency characteristics of the stethoscope and the stethoscope characteristics when actually worn in the ear can be realized by the stethoscope characteristics correction filter (b), which eliminates malfunctions due to noise and improves usability. 9. Delete the entire sentence from line 3 to line 16 of page 10 fpJ of the same page and insert the following sentence. [As described above, the present invention consists of a stethoscope that collects sound, a microphone halter attached to the earmuff of the stethoscope, and an S diagnosis when the stethoscope is actually attached to the ear. An ear-worn corrector that adjusts the characteristics of the stethoscope, and a microphone holer 1 attached so that the distance from the end of the earmuff of the stethoscope to the detection surface is approximately equal to the length of the external auditory canal of the ear. Equipped with a detection microphone, a microphone sensitivity correction filter that flattens the frequency characteristics of the microphone itself, and a sensitivity correction filter that adjusts the output of the microphone sensitivity correction filter to the high frequency of the body's ear itself. Because it is a standard, it is possible to take into account stethoscope characteristics and auditory characteristics, and therefore it is possible to obtain a Korotkoff sound signal that is the same as the Korotkoff sound that the doctor senses with his ears. This has the effect of being able to perform measurements that closely match the blood pressure measurements performed by the method. 10, ``Basic'' on page 10, line 19 of the above is corrected to ``Example''. 11. Change “Example” in page 10, line 20 of the same to “Second
Here is an example of an improved diagram.'' 12. Delete the entire sentence from line 5 to line 7 on page 11 of the same page and insert the following sentence. r (31/li stethoscope, (9) is an ear-worn corrector, (10)
) is microphone halter-1 (kawa is microphone 0 phone,
H indicates a microphone sensitivity correction filter, and 04) indicates an auditory sensation correction filter. ” Agent Patent Attorney Ishi 1) Choshichi

Claims (2)

[Claims] (1) A microphone that collects sounds,
A stethoscope characteristic correction filter that flattens the frequency characteristic of the microphone itself and matches the frequency characteristic of the stethoscope itself when actually listening with the stethoscope in contact with the upper arm, and the output of the stethoscope characteristic correction filter. A sound collection device for a blood pressure monitor comprising a sensation correction filter that matches the auditory characteristics of the body's ears themselves. (2) A special ffM range characterized by using the inverse characteristics of the 60 dB equal loudness curve as the @sensation correction filter! The sound collection device for the sphygmomanometer according to item 1.