Blood pressure measurement device and method

Abstract

A blood pressure measurement device and method are disclosed. [Solution] The blood pressure measuring device of the present invention displays signals detected from the subject on a display in real time while the internal pressure of a cuff surrounding a part of the subject's body is varied, and includes a processor that, when a reference signal corresponding to the subject's blood pressure among the signals is displayed on the display in real time, visually displays the reference signal or displays a visual mark indicating the reference signal.

Description

Technical Field

[0001] The present invention relates to a blood pressure measuring device and method.

Background Art

[0002] There are a wet method and a non-wet method as blood pressure measurement methods. Although the wet method is the most accurate method, the non-wet method is mainly used due to reasons such as pain and infection. The non-wet method is classified into the Korotkoff method and the oscillometric method, and both methods use a cuff. The Korotkoff method is a method of listening through a stethoscope for the generation of sound energy due to turbulence generated during the movement of blood flow caused by the opening and closing of blood vessels. The oscillometric method, which is mainly used in sphygmomanometers, has lower accuracy than the Korotkoff method.

Summary of the Invention

Problems to be Solved by the Invention

[0003] The present invention provides a blood pressure measuring device and method in which the advantages of the Korotkoff method and the oscillometric method are combined by using the characteristics of the Korotkoff sound and the oscillometric signal (for example, the correlation between the Korotkoff sound and the oscillometric signal).

[0004] However, the technical problems are not limited to the above-described technical problems, and further technical problems may exist.

Means for Solving the Problems

[0005] A blood pressure measuring device according to an embodiment visually displays a reference signal corresponding to the blood pressure of the subject in a different manner or displays a visual mark indicating the reference signal when the signal detected from the subject is displayed in real time on a display while the internal pressure of a cuff surrounding a part of the subject's body is variable, and includes a processor.

[0006] The processor can display the signal on the display based on the Korotkoff tone contained in the sound signal collected by the microphone while the internal pressure of the cuff is variable.

[0007] The processor can, if it detects a signal that has not been detected from the person being tested while the internal pressure of the cuff is varying, select that signal as a candidate reference signal, and decide whether or not to set the candidate reference signal as the reference signal based on whether or not a new signal is detected from the person being tested after the candidate reference signal.

[0008] The processor can determine the candidate reference signal as the reference signal in response to the detection of n (where n is a natural number) new signals from the person being tested in succession after the candidate reference signal.

[0009] The processor can display the signal on the display based on the Korotkoff tone detected within an interval reference to the peak of the oscillometric signal detected from the person being tested.

[0010] The processor can determine whether a sound signal is a Korotkoff tone based on the ratio of frequency components in a predetermined frequency band among the frequency components of the sound signal collected from the person being tested, and can display the signal on the display based on the sound signal determined to be a Korotkoff tone.

[0011] The processor can determine a sound signal whose ratio is greater than or equal to a predetermined threshold ratio as the Korotkoff tone.

[0012] The processor can determine whether a sound signal collected from the person being tested is a Korotkoff tone based on its amplitude, and can display the signal on the display based on the sound signal determined to be a Korotkoff tone.

[0013] After the process of detecting the signal from the person being tested is completed, the processor can change the reference signal to the peripheral signal if, in an interval based on the oscillometric peak, the amplitude of the peripheral signal continuously detected relative to the reference signal is smaller than a predetermined threshold amplitude, but the ratio of the frequency components of the peripheral signal that are included in a predetermined frequency band is equal to or greater than a predetermined threshold ratio.

[0014] If the reference signal corresponds to the diastolic blood pressure of the person being examined, the peripheral signal may be a signal detected at a cuff internal pressure lower than the reference signal; if the reference signal corresponds to the systolic blood pressure of the person being examined, the peripheral signal may be a signal detected at a cuff internal pressure higher than the reference signal.

[0015] The Korotkoff tones contained in the sound signal collected from the subject can be output via a speaker.

[0016] The blood pressure measurement result is provided to the person being examined, in which the signal detected by the person being examined and the oscillometric signal are synchronized and displayed. From the blood pressure measurement result, a visual mark indicating the reference signal corresponding to the person being examined's blood pressure can be displayed, or the reference signal can be visually displayed as a difference.

[0017] The blood pressure measurement results can be output in the form of a printed document.

[0018] The blood pressure measurement results are transmitted to an electronic device equipped with a display and can be displayed on the display of the electronic device.

[0019] A blood pressure measuring device according to one embodiment includes a processor that, while the internal pressure of a cuff surrounding a part of the body of the person being examined is variable, detects Korotkoff tones contained in a sound signal collected from the person being examined based on an oscillometric signal detected from the person being examined and displays them in real time on a display, and when a reference Korotkoff tones corresponding to the blood pressure of the person being examined are displayed in real time on the display, visually displays the reference Korotkoff tones in a different way or displays a visual mark indicating the reference Korotkoff tones.

[0020] The processor determines whether a candidate reference Korotkoff tone with an amplitude greater than or equal to a predetermined value is detected in the section of the sound signal that is based on the peak of the oscillometric signal. If a candidate reference Korotkoff tone is detected, the processor can determine whether or not the candidate reference Korotkoff tone is a reference Korotkoff tone based on the ratio of the frequency components of the candidate reference Korotkoff tone that are included in a predetermined frequency band.

[0021] A blood pressure measurement method according to one embodiment includes the operation of detecting a signal from a person being examined while the internal pressure of a cuff surrounding a part of the person being examined is variable, and the operation of displaying the signal on a display in real time, wherein the display operation visually displays the reference signal or displays a visual mark indicating the reference signal when a reference signal corresponding to the blood pressure of the person being examined is displayed on the display in real time from the signals detected from the person being examined.

[0022] The display operation allows the Korotkoff tone contained in the sound signal collected by the microphone to be displayed on the display while the internal pressure of the cuff is variable.

[0023] During the operation of detecting, if a signal that has not been detected from the subject is detected while the internal pressure of the cuff is variable, the corresponding signal is selected as a candidate reference signal, and based on whether a new signal is detected from the subject after the candidate reference signal, it can be determined whether to determine the candidate reference signal as the reference signal.

[0024] During the operation of detecting, in response to the case where n (where n is a natural number) new signals are continuously detected from the subject after the candidate reference signal, the candidate reference signal can be determined as the reference signal.

[0025] During the operation of detecting, the signal can be detected based on the Korotkoff sound detected within a section that is based on the peak of the oscillometric signal detected from the subject.

[0026] During the operation of detecting, based on the ratio of the frequency components included in a predetermined frequency band among the frequency components of the sound signal collected from the subject, it is determined whether the sound signal is a Korotkoff sound, and the signal can be detected based on the sound signal determined as the Korotkoff sound.

[0027] During the operation of detecting, a sound signal whose ratio is equal to or greater than a predetermined threshold ratio can be determined as the Korotkoff sound.

[0028] During the operation of detecting, it is determined whether the sound signal is a Korotkoff sound according to the amplitude of the sound signal collected from the subject, and the signal can be detected based on the sound signal determined as the Korotkoff sound.

[0029] A blood pressure measurement device according to an embodiment includes a cuff that detects both a Korotkoff sound and an oscillometric signal from a subject, and a processor that measures the blood pressure of the subject using the Korotkoff sound and the oscillometric signal.

[0030] The processor can detect the Korotkoff sounds using the oscillometric signal and measure the blood pressure of the person being examined based on the detected Korotkoff sounds.

[0031] The Korotkoff sounds collected from the person being tested can be output via a speaker.

[0032] The blood pressure measurement results are provided to the person being examined, in which the Korotkoff sounds detected by the person being examined and the oscillometric signal are synchronized and displayed. From the blood pressure measurement results, a visual mark indicating a reference Korotkoff sound corresponding to the person being examined's blood pressure can be displayed, or the reference Korotkoff sound can be visually displayed as a difference.

[0033] The blood pressure measurement results can be output in the form of a printed document. [Effects of the Invention]

[0034] According to one embodiment, it is possible to improve the accuracy of blood pressure measurement using a Korotkoff tone base by utilizing oscillometric signals, and to provide a blood pressure measurement device and method that is robust against noise and the skill level of the examiner.

[0035] According to one embodiment, a blood pressure measurement device and method can be provided that combines the advantages of the Korotkoff method based on Korotkoff sounds and the oscillometric method based on oscillometric signals.

[0036] According to one embodiment, when the Korotkoff sounds detected while the cuff is being depressurized are displayed on the display in real time, information regarding systolic and diastolic blood pressure is also displayed on the display in real time, thereby efficiently improving the subject's confidence in the measured blood pressure. By visually confirming the Korotkoff sounds detected in real time, and visually confirming the systolic blood pressure corresponding to the start of the Korotkoff sounds and the diastolic blood pressure corresponding to the end of the Korotkoff sounds, the subject's confidence in the measurement results of the blood pressure measuring device can be improved.

[0037] According to one embodiment, by providing the subject with Korotkoff sounds detected during the blood pressure measurement process as visual and / or auditory feedback, the subject's confidence in the blood pressure measurement results can be efficiently improved.

[0038] According to one embodiment, blood pressure measurement results can be provided in the form of a printed document.

[0039] According to one embodiment, by simultaneously detecting an oscillometric signal and Korotkoff sounds with any one of the cuffs, the accuracy and reliability of blood pressure measurement results can be efficiently improved. [Brief explanation of the drawing]

[0040] [Figure 1] This is a diagram illustrating a blood pressure measuring device according to one embodiment. [Figure 2] This figure illustrates the operation of detecting Korotkoff tones around the peak of an oscillometric signal according to one embodiment. [Figure 3] This figure illustrates the operation of detecting Korotkoff tones via frequency analysis of a sound signal according to one embodiment. [Figure 4] This figure illustrates an operation in which the blood pressure information of a subject is determined using n Korotkoff tones according to one embodiment. [Figure 5] This figure illustrates an operation in which the blood pressure information of a subject is determined using n Korotkoff tones according to one embodiment. [Figure 6] This figure illustrates an operation in which the blood pressure information of a subject is determined using n Korotkoff tones according to one embodiment. [Figure 7] This figure illustrates an operation in which the blood pressure information of a subject is determined using n Korotkoff tones according to one embodiment. [Figure 8] This diagram illustrates the operation of correcting the blood pressure information of the person being examined after blood pressure measurement has been completed according to one embodiment. [Figure 9] This figure shows a blood pressure measurement method according to one embodiment. [Figure 10] This figure shows a blood pressure measuring device according to one embodiment. [Figure 11] This is a diagram illustrating a result sheet according to one embodiment. [Modes for carrying out the invention]

[0041] The specific structural or functional descriptions of the embodiments are disclosed for illustrative purposes only and can be modified in various ways. Therefore, the embodiments are not limited to the specific disclosure, and the scope of this specification includes modifications, equivalents, or substitutions that are part of the technical idea.

[0042] Terms such as "first" or "second" may be used to describe multiple components, but such terms should be interpreted solely for the purpose of distinguishing one component from others. For example, the first component may be named the second component, and similarly, the second component may also be named the first component.

[0043] When it is mentioned that one component is “linked” or “connected” to another component, it should be understood that it is directly linked to or connected to the other component, but that other components may be present in between.

[0044] A singular expression includes plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “includes” or “has” indicate the presence of features, figures, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood not to presuppose the existence or addition of one or more other features, figures, steps, actions, components, parts, or combinations thereof.

[0045] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this embodiment belongs. Commonly used, predefined terms should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and not as ideal or overly formal unless expressly defined herein.

[0046] The embodiments will be described in detail below with reference to the attached drawings. When describing with reference to the drawings, the same components will be given the same reference numerals regardless of the reference numerals used in the drawings, and redundant explanations will be omitted.

[0047] Figure 1 is a diagram illustrating a blood pressure measuring device according to one embodiment.

[0048] Blood pressure measurement methods are classified into direct and indirect methods. Direct measurement involves inserting a catheter into an artery to directly measure the pressure within the blood vessel. However, this method requires intubation of the subject's artery, which carries the risk of damaging the vascular system and makes it impractical for universal use.

[0049] Research is being conducted on indirect measurement methods. Among these, the Korotkoff method, which uses a stethoscope, pressure gauge, and cuff to measure blood pressure, is considered the most traditional yet standard method. The Korotkoff method can determine blood pressure based on the Korotkoff sounds produced when the cuff is pressurized and then depressurized. For example, the point at which the Korotkoff sounds begin to be produced when the cuff is depressurized is determined as the systolic blood pressure (SBP), and the point at which the Korotkoff sounds disappear without further production is determined as the diastolic blood pressure (DBP). However, because the Korotkoff method requires the examiner (e.g., medical staff such as doctors and nurses) to directly listen to the Korotkoff sounds produced by pressurizing and then depressurizing the cuff and determine the blood pressure value, the examiner's skill level greatly affects the accuracy of the measurement.

[0050] Another indirect measurement method, the oscillometric method, is relatively easy to use, robust against noise, and is primarily used in automated blood pressure monitors. The oscillometric method involves applying pressure to an airbag inside the cuff, then gradually decreasing the pressure. The arterial pressure generated by the contraction of the heart is transmitted to the upper arm, and the magnitude of the arterial pressure transmitted to the air pocket of the cuff wrapped around the upper arm is detected to correspond to the internal pressure of the airbag inside the cuff. The internal pressure values ​​of the airbag at the point where a certain magnitude of arterial pressure is located are calculated as the systolic and diastolic blood pressure, using the highest arterial pressure as a reference. The oscillometric method is widely used in automated blood pressure monitors due to its convenience, requiring less skilled technique compared to the Korotkoff method, and its stability, being less susceptible to external noise and movement. However, because there is no clear standard for blood pressure measurement, each blood pressure monitor uses a different blood pressure measurement algorithm, which can lead to errors between blood pressure monitors and a decrease in precision.

[0051] To combine the accuracy of the Korotkoff method with the convenience of an oscillometric-based automated blood pressure monitor, a microphone is attached to the automated blood pressure monitor cuff, and the Korotkoff sound detected by the microphone can be collected together with an oscillometric signal detected by a pressure sensor that measures pressure changes within the cuff. By utilizing the oscillometric signal, the start and end points of detection of the Korotkoff sound, which is an audible signal in the form of an impulse that occurs at the moment when blood pressure rises above the internal pressure of the cuff, can be identified, and the blood pressure information of the person being measured can be determined based on these start and end points. This disclosure relates to a blood pressure measurement device and method that utilizes an oscillometric signal to improve the accuracy of Korotkoff sound-based blood pressure measurement and is robust to noise and examiner skill.

[0052] Referring to Figure 1, the blood pressure measuring device 100 includes a processor (not shown), a display 110, and an input unit 120.

[0053] The processor controls the overall operation of the blood pressure measuring device 100 and controls other components included in the blood pressure measuring device 100.

[0054] The display 110 can display the blood pressure measurement process and results. For example, the display 110 can display in real time the signals detected from the subject 150 while the internal pressure of the cuff 130 surrounding a part of the subject's body is changing. Once the blood pressure measurement is complete, the display 110 can display the blood pressure information of the subject 150. In addition, the display 110 may display various other information related to blood pressure measurement without limitation.

[0055] The input unit 120 receives input related to blood pressure measurement from the person being examined 150 and / or the examiner. For example, the input unit 120 can receive the start of operation, emergency stop, measured blood pressure information, or pre-stored blood pressure information output and input of the blood pressure measuring device 100, but is not limited to the examples described above. In Figure 1, the input unit 120 is shown as a physical button for convenience of explanation, but is not limited to the examples described above and may be implemented in various forms (e.g., touch, jog dial, switch, etc.). In another embodiment, the input unit 120 is omitted, and input is received from the person being examined 150 and / or the examiner via a display 110 embodied as a touchscreen.

[0056] The cuff 130 includes an airbag whose internal pressure is regulated by the injection or discharge of a fluid, and the airbag can surround a part of the body of the person being examined 150 during blood pressure measurement. For example, the part of the body of the person being examined 150 may be the upper arm, but is not limited to the examples given above. In this specification, the internal pressure of the airbag in the cuff 130 may be expressed as the internal pressure of the cuff 130 for convenience of explanation.

[0057] The connecting wire 140 includes an electric wire and a fluid tube that connect the blood pressure measuring device 100 and the cuff 130. The electric wire can electrically connect sensors in the cuff 130 (e.g., a microphone, pressure sensor, etc.) to the blood pressure measuring device 100. Depending on the embodiment, all or some of the sensors may be located inside the blood pressure measuring device 100, and signals acquired in the cuff 130 (e.g., oscillometric signals and / or Korotkoff sounds) may be transmitted to the sensors inside the blood pressure measuring device 100 via the connecting wire 140. The fluid tube can transmit fluid that is injected into the airbag inside the cuff 130 or fluid that is discharged from the airbag.

[0058] The blood pressure measuring device 100 can collect a sound signal generated when the cuff 130 is inflated to a level higher than the typical systolic blood pressure and then gradually released while the cuff 130 is wrapped around the upper arm of the person being measured 150, using a microphone, and detect an oscillometric signal with a pressure sensor. The blood pressure measuring device 100 can analyze the sound signal and the oscillometric signal to detect Korotkoff sounds from the sound signal and determine the systolic and diastolic blood pressure of the person being measured 150 in real time based on the detected Korotkoff sounds. The blood pressure measuring device 100 can also display the detected Korotkoff sounds on the display 110 in real time, and when the reference Korotkoff sounds corresponding to systolic blood pressure and the reference Korotkoff sounds corresponding to diastolic blood pressure are displayed on the display 110 in real time, the reference Korotkoff sounds may be visually distinguished (e.g., different color, different line width, different line shape, etc.) or a visual mark (e.g., arrow, triangle, etc.) indicating the reference Korotkoff sound may be displayed.

[0059] After the subject 150 wraps the cuff 130 around their upper arm without any additional equipment and measures their blood pressure, the blood pressure measuring device 100 can detect both the oscillometric signal and Korotkoff sounds from the subject 150 via the cuff 130. A sound-receiving unit (e.g., a microphone) for detecting Korotkoff sounds can be coupled to the cuff 130 and positioned so as to be in close contact with the body of the subject 150 wearing the cuff 130. A pressure sensor for detecting the oscillometric signal may also be located inside the cuff 130, or a device and / or component for transmitting signals to a pressure sensor located inside the blood pressure measuring device 100 may be located inside the cuff 130.

[0060] When the Korotkoff sounds detected while the cuff 130 is depressurized are displayed in real time on the display 110, information regarding systolic and diastolic blood pressure is also displayed in real time on the display 110, which efficiently improves the subject's confidence in the measured blood pressure. The subject 150 can visually confirm the Korotkoff sounds detected in real time, and by visually confirming the systolic blood pressure corresponding to the start of the Korotkoff sounds and the diastolic blood pressure corresponding to the end of the Korotkoff sounds, the subject 150's confidence in the measurement results of the blood pressure measuring device 100 is improved.

[0061] Furthermore, the Korotkoff sounds detected while the cuff 130 is depressurized may be output via a speaker (not shown). The subject 150 can improve their confidence in the blood pressure measurement results by being provided with real-time auditory feedback of the detected Korotkoff sounds. As described above, the subject 150 can also efficiently improve their satisfaction with the blood pressure measurement results by directly verifying the results through hearing and sight, as they are also provided with real-time visual feedback of the Korotkoff sounds detected via the display 110. The speaker that outputs the Korotkoff sounds may be built into the blood pressure measuring device 100, but is not limited to the example described above, and may be a separate device that receives the Korotkoff sounds detected from the blood pressure measuring device 100 via a wired and / or wireless network. For the sake of explanation, the following description will use the case where the detected Korotkoff sounds are displayed on the display 110 as an example, but this explanation can also be applied when the Korotkoff sounds are output via a speaker.

[0062] According to one embodiment, the blood pressure measuring device 100 can combine the advantages of the Korotkoff method and the oscillometric method using the characteristics of the Korotkoff tone and the oscillometric signal (for example, the relationship between the Korotkoff tone and the oscillometric signal). The blood pressure measuring device 100 may detect the oscillometric signal. The blood pressure measuring device 100 determines whether or not a Korotkoff tone is detected in an interval based on the peak of the oscillometric signal, and whether or not the amplitude of the Korotkoff tone is greater than or equal to a predetermined threshold amplitude. If a Korotkoff tone greater than or equal to a predetermined threshold amplitude is detected in an interval based on the peak of the oscillometric signal, the blood pressure measuring device 100 can determine whether or not it is noise through frequency analysis of the Korotkoff tone. If it is determined not to be noise, the blood pressure measuring device 100 can display the Korotkoff tone on the display 110 in real time.

[0063] Figure 2 illustrates the operation of detecting Korotkoff tones around the peak of an oscillometric signal according to one embodiment.

[0064] Referring to Figure 2, an example is shown to illustrate how the Korotkoff tone is detected from a sound signal using the relationship between the Korotkoff tone and the oscillometric signal.

[0065] Blood pressure changes due to heartbeats are shown in pulse form, and this pulse form can be reflected in the oscillometric signal. Furthermore, since Korotkoff sounds occur at the moment when blood pressure rises above the internal pressure of the cuff, Korotkoff sounds are shown corresponding to the peaks in the oscillometric signal. By utilizing these characteristics, Korotkoff sounds can be detected with high accuracy near the peaks of the oscillometric signal. Generally, since the peaks of the oscillometric signal are more robust to noise and easier to detect than Korotkoff sounds, detecting the peaks of the oscillometric signal first and then detecting the Korotkoff sounds near those peaks can improve the detection accuracy of Korotkoff sounds.

[0066] The blood pressure measuring device can detect Korotkoff sounds within a range based on the peak of the oscillometric signal detected from the subject.

[0067] The screen 210 displayed on the blood pressure measuring device's display may include a sound signal collected by the microphone and an oscillometric signal detected by the pressure sensor (shown as OSC in Figure 2).

[0068] Case 1, 220, illustrates an example where the internal pressure of the cuff is higher than the blood pressure and no Korotkoff sounds are produced. The blood pressure measuring device can check whether the sound signal contains Korotkoff sounds within a section 221 based on the peak of the oscillometric signal. Section 221 is set to have a predetermined magnitude based on the peak of the oscillometric signal, but is not limited to the example described above; for example, section 221 may be set to have a dynamic magnitude depending on the magnitude of the peak. Since the sound signal is kept relatively constant in the section 221, the blood pressure measuring device determines that there are no Korotkoff sounds in the section 221.

[0069] Case 230 is an example of Korotkoff sounds being generated because blood pressure is higher than the internal pressure of the cuff. The blood pressure measuring device can check whether the sound signal contains Korotkoff sounds within a section 231 referenced to the peak of the oscillometric signal. The blood pressure measuring device can detect impulse-shaped waves contained in the sound signal within the relevant section 221 as Korotkoff sounds.

[0070] Blood pressure monitoring devices can minimize the resources required to detect Korotkoff sounds and improve the accuracy of Korotkoff sound detection by detecting Korotkoff sounds in a portion of the sound signal rather than the entire signal, based on the peaks of the oscillometric signal.

[0071] Furthermore, the blood pressure measuring device may determine whether a sound signal is a Korotkoff tone based on the amplitude of the sound signal collected from the person being measured. Since Korotkoff tones are audible signals that are actually heard by the human ear, Korotkoff tones have an amplitude above a certain threshold. Therefore, the blood pressure measuring device can determine whether a sound signal is a Korotkoff tone based on the amplitude of the sound signal. For example, the amplitude of the sound signal may be determined as the maximum difference between the baseline and the signal in question, or the maximum and minimum difference between the signal in question. The blood pressure measuring device can determine whether a sound signal is a Korotkoff tone based on whether the amplitude of the sound signal determined in this way is above a predetermined threshold amplitude.

[0072] Furthermore, a blood pressure measuring device can determine whether a sound signal is a Korotkoff tone or not based on whether the sound signal is audible. For example, sounds that humans can hear are expressed in dBSPL values ​​(or decibels), and sounds from 0 decibels onwards are audible to humans, but for the average person, sounds from around 20 decibels onwards are audible. Also, for humans, even at the same volume, low-frequency sounds are not heard well, while higher frequencies are heard more clearly. This relationship between human hearing levels and frequencies may be used to determine the presence or absence of an audible signal.

[0073] Figure 3 illustrates the operation of detecting Korotkoff tones via frequency analysis of a sound signal according to one embodiment.

[0074] Referring to Figure 3, an example is shown illustrating the operation of determining whether a sound signal contains Korotkoff tones and noise via frequency analysis.

[0075] Since Korotkoff tones are audible signals, they generally have the characteristic of existing in a specific frequency band (e.g., 50-200 Hz). Blood pressure measuring devices use the frequency band characteristics of Korotkoff tones to determine whether a given sound signal is a Korotkoff tone or contains noise. Frequency analysis is performed on sound signals within the range in which Korotkoff tones can be generated. For example, frequency analysis may be performed on sound signals that were initially detected from Korotkoff tones, as shown in Figure 2.

[0076] A blood pressure measuring device can determine whether a sound signal collected from a subject is a Korotkoff tone based on the ratio of frequency components within a predetermined frequency band (e.g., 50-200 Hz) of the frequency components of the sound signal.

[0077] For example, in the first case 310, where the ratio between the frequency components included in a predetermined frequency band and the frequency components included in the remaining frequency band is greater than or equal to a predetermined first threshold ratio, the blood pressure measuring device may determine the sound signal to be a Korotkoff tone.

[0078] Alternatively, in the second case 320, where the ratio between the frequency components included in a predetermined frequency band and the frequency components included in the remaining frequency band is less than a predetermined first threshold ratio and greater than or equal to a predetermined second threshold ratio, the blood pressure measuring device may determine the sound signal in question as a Korotkoff tone containing noise. Here, the second threshold ratio may be set lower than the first threshold ratio. Since the Korotkoff tone in question contains noise, the blood pressure measuring device uses the Korotkoff tone in question to estimate blood pressure, but does not use it for Korotkoff's silent tone correction.

[0079] Alternatively, in the third case 330, where the ratio between the frequency components included in a predetermined frequency band and the frequency components included in the remaining frequency band is less than a predetermined second threshold ratio, the blood pressure measuring device can determine the sound signal in question as noise.

[0080] Figures 4 to 7 illustrate the operation of determining a subject's blood pressure information using n Korotkoff tones according to one embodiment.

[0081] Referring to Figure 4, Korotkoff sounds occur when blood pressure is higher than the internal pressure of the cuff. Therefore, Korotkoff sounds have the characteristic of occurring continuously in accordance with the heartbeat cycle from SBP point 410 to DBP point 420. The blood pressure measurement device can use this characteristic of Korotkoff sounds to correct falsely detected Korotkoff sounds in real time.

[0082] Even when the internal pressure of the cuff is greater than blood pressure, a temporary impulse-type sound signal may be collected. Depending on the circumstances, if such an impulse-type sound signal satisfies the criteria described with reference to Figures 2 and 3, the blood pressure measuring device may mistakenly recognize the sound signal as a Korotkoff tone. However, as explained above, a normal Korotkoff tone has the characteristic of occurring continuously in accordance with the heartbeat cycle from SBP point 410 to DBP point 420, whereas no subsequent Korotkoff tone is detected after such a temporary impulse-type sound signal.

[0083] If a blood pressure measuring device detects a Korotkoff sound that has not been detected from the subject while the internal pressure of the cuff is changing, it can select the signal as a candidate reference Korotkoff sound and decide whether to designate the candidate reference Korotkoff sound as the reference Korotkoff sound corresponding to systolic blood pressure based on whether or not new Korotkoff sounds are detected from the subject after the candidate reference Korotkoff sound. In response to the detection of n (where n is a natural number) new Korotkoff sounds consecutively from the subject after the candidate reference Korotkoff sound, the blood pressure measuring device can decide to designate the candidate reference Korotkoff sound as the reference Korotkoff sound.

[0084] Referring to Figure 5, an example is shown in which a Korotkoff tone is temporarily detected and selected as a candidate reference Korotkoff tone 511, but no new Korotkoff tones are detected after the candidate reference Korotkoff tone 511. The screen displayed on the display shows the Korotkoff tone 510 and the oscillometric signal 520. The oscillometric signal 520 displays the value detected from the pressure sensor as is, while the Korotkoff tone 510 displays only the value detected as a Korotkoff tone from the sound signal collected by the microphone. Over time, the oscillometric signal 520 continues to be detected while the internal pressure of the cuff varies, while the candidate reference Korotkoff tone 511 is not ultimately selected as the reference Korotkoff tone unless a subsequent Korotkoff tone is detected after the initial detection.

[0085] Referring to Figure 6, an example is shown in which a Korotkoff sound is temporarily detected and selected as a candidate reference Korotkoff sound 610, and new Korotkoff sounds are detected after the candidate reference Korotkoff sound 610. Since n new Korotkoff sounds are detected consecutively after the candidate reference Korotkoff sound 610, the blood pressure measuring device may determine the candidate reference Korotkoff sound 610 as the reference Korotkoff sound corresponding to systolic blood pressure, and display the relevant reference Korotkoff sound visually distinct from other Korotkoff sounds, or display a visual mark (e.g., a triangle) to indicate the relevant reference Korotkoff sound. In Figure 6, for the sake of explanation, the case where n=4 is used as the reference, but n may also have a natural value.

[0086] Referring to Figure 7, an example is shown in which visual marks (e.g., triangles) indicating the reference Korotkoff sound 710 corresponding to systolic blood pressure and the reference Korotkoff sound 720 corresponding to diastolic blood pressure are displayed using the method described above. In Figure 7, for the sake of explanation, visual marks indicating the reference Korotkoff sounds 710 and 720 are displayed, but the embodiment is not limited to this, and the reference Korotkoff sounds 710 and 720 may be displayed differently from other Korotkoff sounds.

[0087] If a blood pressure measuring device detects Korotkoff sounds continuously and no further sounds are detected, it can determine the last detected Korotkoff sound as the reference Korotkoff sound 720 corresponding to the diastolic blood pressure. Once blood pressure measurement is complete, the display screen may show not only the detected Korotkoff sounds and oscillometric signals, but also various blood pressure-related information (e.g., systolic / diastolic blood pressure, pulse rate, etc.).

[0088] The Korotkoff sounds shown in Figures 5 to 7 were detected using the Korotkoff sound detection method described earlier.

[0089] Figure 8 is a diagram illustrating the operation of correcting the blood pressure information of a subject after blood pressure measurement has been completed, according to one embodiment.

[0090] Referring to Figure 8, an example is shown in which, after blood pressure measurement is complete, the reference Korotkoff sound 810 corresponding to the diastolic blood pressure is corrected to the peripheral Korotkoff sound 820.

[0091] The blood pressure measurement device can analyze the characteristics of the sound signal being measured and variably adjust the reference used to detect Korotkoff sounds. Even if the amplitude of the sound signal collected by the microphone after the reference Korotkoff sound corresponding to diastolic blood pressure is small, if a Korotkoff sound is detected around the peak of the oscillometric signal, and the ratio of the frequency components of the Korotkoff sound that fall within a predetermined frequency band is greater than or equal to a predetermined threshold ratio, the blood pressure measurement device can change the reference Korotkoff sound 810 to an ambient Korotkoff sound 820. For example, the blood pressure measurement device may change from the reference Korotkoff sound 810 to the ambient Korotkoff sound 820 a predetermined number of times.

[0092] Even after blood pressure measurement is complete, the reference Korotkoff sound 810 can be corrected to the surrounding Korotkoff sound 820, allowing for more accurate detection of the reference Korotkoff sound even if the subject's own Korotkoff sound is faint.

[0093] Figure 8 shows an example where, for ease of explanation, the reference Kortkoff sound 810 corresponding to diastolic blood pressure is corrected to a peripheral Kortkoff sound 820 measured afterward. However, the example described above, in which the reference Kortkoff sound corresponding to systolic blood pressure is corrected to a peripheral Kortkoff sound measured beforeward, can be similarly applied.

[0094] Figure 9 shows a blood pressure measurement method according to one embodiment.

[0095] In the embodiments described below, the operations may be performed sequentially, but do not necessarily have to be. For example, the order of the operations may be changed, and at least two operations may be performed in parallel. Operations 1001 to 1010 can be performed by at least one component of the electronic device (e.g., a processor, a sensor, etc.). In the embodiment, the operations may be performed sequentially, but do not necessarily have to be. For example, the order of the operations may be changed, and at least two operations may be performed in parallel. Operations 910 to 620 can be performed by at least one component of the blood pressure measuring device (e.g., a processor).

[0096] In operation 910, the blood pressure measuring device detects a signal from the subject while the internal pressure of the cuff surrounding a part of the subject's body is variable.

[0097] The blood pressure measuring device selects a signal that has not been detected from the subject while the internal pressure of the cuff is changing as a candidate reference signal, and decides whether to designate the candidate reference signal as the reference signal based on whether or not new signals are detected from the subject after the candidate reference signal. The blood pressure measuring device decides to designate the candidate reference signal as the reference signal in response to the detection of n (where n is a natural number) new signals from the subject consecutively after the candidate reference signal.

[0098] A blood pressure measuring device can detect signals based on Korotkoff sounds detected within an interval referenced to the peak of the oscillometric signal detected from the subject.

[0099] A blood pressure measuring device can determine whether a sound signal is a Korotkoff tone based on the ratio of frequency components within a predetermined frequency band among the frequency components of the sound signal collected from the subject, and can detect a signal based on the sound signal determined to be a Korotkoff tone. A blood pressure measuring device can determine a sound signal as a Korotkoff tone if its ratio is equal to or greater than a predetermined threshold ratio.

[0100] The blood pressure measuring device can determine whether a sound signal is a Korotkoff tone based on the amplitude of the sound signal collected from the person being examined, and can detect a signal based on the sound signal determined to be a Korotkoff tone.

[0101] In operation 920, the blood pressure measuring device displays the signal on the display in real time. When the reference signal corresponding to the subject's blood pressure is displayed on the display in real time from the signals detected from the subject, the blood pressure measuring device may visually display the reference signal or display a visual mark indicating the reference signal. The blood pressure measuring device may display the signal on the display based on the Korotkoff tone contained in the sound signal collected by the microphone while the internal pressure of the cuff is changing.

[0102] Since the aforementioned points apply directly to each operation shown in Figure 9 (referencing Figures 1-8), a more detailed explanation is omitted.

[0103] Figure 10 shows a blood pressure measuring device according to one embodiment.

[0104] Referring to Figure 10, the blood pressure measuring device 1000 includes a processor 1010. The blood pressure measuring device 1000 further includes a display 1020 and a memory 1030. The processor 10140, the display 1020, and the memory 1030 can communicate with each other via a bus, PCIe (Peripheral Component Interconnect Express), and / or NoC (Network on a Chip), etc.

[0105] The processor 1010 displays signals detected from the subject on a display in real time while the internal pressure of a cuff surrounding a part of the subject's body is variable. When a reference signal corresponding to the subject's blood pressure is displayed on the display in real time, the processor may visually display the reference signal in a different way or display a visual mark indicating the reference signal.

[0106] The processor 1010 may display a signal on a display based on the Korotkoff tone contained in the sound signal collected by the microphone while the internal pressure of the cuff is variable.

[0107] If the processor 1010 detects a signal that has not been detected from the person being tested while the internal pressure of the cuff is varying, it may select that signal as a candidate reference signal and decide whether or not to set the candidate reference signal as the reference signal based on whether or not new signals are detected from the person being tested after the candidate reference signal. The processor 1010 may set the candidate reference signal as the reference signal in response to the detection of n (where n is a natural number) new signals from the person being tested in succession after the candidate reference signal.

[0108] The processor 1010 may display a signal on a display based on Korotkoff tones detected within an interval reference to the peak of the oscillometric signal detected from the person being tested.

[0109] The processor 1010 determines whether a sound signal is a Korotkoff tone based on the ratio of frequency components within a predetermined frequency band among the frequency components of the sound signal collected from the person being tested, and displays a signal on the display based on the sound signal determined to be a Korotkoff tone. The processor 1010 may determine a sound signal as a Korotkoff tone if its ratio is greater than or equal to a predetermined threshold ratio.

[0110] The processor 1010 can determine whether a sound signal is a Korotkoff tone based on the amplitude of the sound signal collected from the person being tested, and may display the signal on a display based on the sound signal determined to be a Korotkoff tone.

[0111] After the process of detecting a signal from the subject is completed, the processor 1010 may change the reference signal to the peripheral signal if, even if the amplitude of the peripheral signal detected continuously with respect to the reference signal in an interval based on the peak of the oscillometric signal is smaller than a predetermined threshold amplitude, the ratio of frequency components of the peripheral signal that are included in a predetermined frequency band is greater than or equal to a predetermined threshold ratio. If the reference signal corresponds to the subject's diastolic blood pressure, the peripheral signal may be a signal detected at a lower cuff internal pressure than the reference signal, and if the reference signal corresponds to the subject's systolic blood pressure, the peripheral signal may be a signal detected at a higher cuff internal pressure than the reference signal.

[0112] Furthermore, the processor 1010 detects Korotkoff sounds contained in the sound signal collected from the subject based on the oscillometric signal detected from the subject while the internal pressure of the cuff surrounding a part of the subject's body is variable, and displays them on the display in real time. When a reference Korotkoff sound corresponding to the subject's blood pressure is displayed on the display in real time, the processor 1010 visually displays the reference Korotkoff sound in a different way, or displays a visual mark indicating the reference Korotkoff sound. The processor 1010 determines whether a candidate Korotkoff sound with an amplitude greater than or equal to a predetermined value is detected in an interval based on the peak of the oscillometric signal in the sound signal output. If a candidate Korotkoff sound is detected, the processor 1010 can determine whether or not the candidate Korotkoff sound is a Korotkoff sound based on the ratio of frequency components of the candidate Korotkoff sound that are included in a predetermined frequency band.

[0113] The display 1020 can display in real time the signals detected from the subject while the internal pressure of the cuff surrounding a part of the subject's body is variable, based on the control of the processor 1010. When the reference signal corresponding to the subject's blood pressure is displayed on the display in real time, the display 1020 may visually display the reference signal or display a visual mark indicating the reference signal.

[0114] Memory 1030 may contain instruction words that can be read by the computer. The processor 1010 can perform the operations mentioned above by executing the instruction words stored in memory 1030. Memory 1030 may be volatile memory or non-volatile memory.

[0115] In addition, the blood pressure measuring device 1000 can process the operations described above.

[0116] Figure 11 is a diagram illustrating a result sheet according to one embodiment.

[0117] Referring to Figure 11, an example of a results sheet provided after the blood pressure measurement of the subject is completed is shown. The results sheet can be provided to the subject and / or medical staff in the form of a printed document. For example, the printed document may be the size of A4 paper or Letter paper, but is not limited to the examples given above. Although Figure 11 shows an example of blood pressure measurement results being provided in the form of a results sheet for convenience of explanation, the form in which the blood pressure measurement results are provided is not limited to the examples given above, and the blood pressure measurement results may be displayed on a display provided in the blood pressure measuring device or a separate device that receives the blood pressure measurement results from the blood pressure measuring device.

[0118] The first item on the results sheet, 1110, displays the most recent blood pressure measurement. Korotkoff sounds and oscillometric signals may be displayed in sync with each other, along with visual markers indicating the subject's systolic and diastolic blood pressure.

[0119] The second item on the results sheet, 1120, displays specific blood pressure measurement results set by the subject and / or medical staff. For example, if a blood pressure measurement result at an important point or turning point is marked as a "favorite," it will be displayed in the second item 1120 on the results sheet, allowing for easy comparison with the most recent blood pressure measurement result in the first item.

[0120] The third item 1130 on the results sheet may display a history of previous blood pressure measurement results. Depending on the embodiment, the previous history may be provided in table and graph formats.

[0121] The fourth item on the results sheet, item 1140, may display various pieces of information useful to the test subject.

[0122] The results sheet contains a total of four items, numbered 1110-1140, but it is not limited to the examples mentioned above and can be provided in various forms.

[0123] The embodiments described above can be embodied in hardware components, software components, and / or combinations of hardware and software components. For example, the adaptive supersampling apparatus, method, and components described in the embodiments can be embodied using a general-purpose computer or a special-purpose computer, such as a processor, controller, ALU (arithmetic logic unit), digital signal processor, microcomputer, FPGA (Field Programmable Gate Array), PLU (Programmable Logic Unit), microprocessor, or other device capable of executing and responding to commands. The processing apparatus can execute an operating system (OS) and software applications that run on the OS. The processing apparatus may also access, store, manipulate, process, and generate data in response to the execution of the software. For convenience of understanding, it has sometimes been described that one processing apparatus is used, but a person with ordinary skill in the art will see that the processing apparatus may include multiple processing elements and / or multiple types of processing elements. For example, a processing adaptive supersampling apparatus may include multiple processors or one processor and one controller. Furthermore, other processing configurations, such as parallel processors, are also possible.

[0124] Software may include computer programs, code, instructions, or any combination thereof, which can configure or instruct a processing unit independently or collectively as desired. Software and / or data may be interpreted by a processing adaptive supersampling device or permanently embodied in any type of machine, component, physical adaptive supersampling device, virtual adaptive supersampling device, computer storage medium, or adaptive supersampling device, or transmitted signal waves, for the purpose of providing instructions or data to a processing adaptive supersampling device. Software may be distributed across a networked computer system and stored or executed in a distributed manner. Software and data may be stored on computer-readable recording media.

[0125] The method according to this embodiment is embodied in the form of program instructions that are implemented via various computer means and recorded on a computer-readable recording medium. The recording medium includes program instructions, data files, data structures, etc., individually or in combination. The recording medium and program instructions may be specifically designed and configured for the purposes of the present invention, or they may be known and usable by those skilled in the art who have technology in the field of computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical recording media such as CD-ROMs and DVDs, magneto-optical media such as floppy disks, and hardware devices specifically configured to store and execute program instructions, such as ROMs, RAMs, and flash memory. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code executed by a computer using an interpreter or the like.

[0126] The hardware device described above may be configured to operate as one or more software models to perform the operations shown in the present invention, and vice versa.

[0127] As described above, although embodiments have been illustrated with limited drawings, a person with ordinary skill in the art can apply various technical modifications and variations based on the above description. For example, the described technique may be performed in a different order than described, and / or the described system, structure, apparatus, circuit, and other components may be combined or assembled in a different manner than described, or replaced or substituted by other components or equivalents, and still achieve the desired results.

[0128] Therefore, other embodiments, other embodiments, and claims equivalent to those described below also fall within the scope of the claims. [Explanation of Symbols]

[0129] 100: Blood pressure measuring device 110: Display 120: Input section 130: Cuff 140: Connecting line 150: Person being examined

Claims

1. The system includes a processor that, while the internal pressure of a cuff surrounding a part of the body of the person being examined is variable, displays signals detected from the person being examined on a display in real time, and when a reference signal corresponding to the blood pressure of the person being examined is displayed on the display in real time, visually displays the reference signal in a different way or displays a visual mark indicating the reference signal. The blood pressure measurement results, which are displayed in synchronization with the signal detected by the subject and the oscillometric signal, are provided to the subject. A blood pressure measuring device in which, based on the blood pressure measurement results, a visual mark indicating the reference signal corresponding to the blood pressure of the person being examined is displayed, or the reference signal is visually displayed as a difference.

2. The blood pressure measuring device according to claim 1, wherein the processor displays the signal on the display based on the Korotkoff tone contained in the sound signal collected by the microphone while the internal pressure of the cuff is variable.

3. The aforementioned processor, If a signal not detected by the person being tested is detected while the internal pressure of the cuff is varying, that signal is selected as a candidate reference signal. The blood pressure measuring device according to claim 1, wherein it determines whether or not to determine the candidate reference signal as the reference signal based on whether or not a new signal is detected from the person being examined after the candidate reference signal.

4. The blood pressure measuring device according to claim 3, wherein the processor determines the candidate reference signal as the reference signal in response to the detection of n (where n is a natural number) new signals from the person being examined in succession after the candidate reference signal.

5. The blood pressure measuring device according to claim 1, wherein the Korotkoff sounds contained in the sound signal collected from the person being examined are output via a speaker.

6. The blood pressure measurement device according to claim 1, wherein the blood pressure measurement results are output in the form of a printed document.

7. The blood pressure measurement device according to claim 1, wherein the blood pressure measurement result is transmitted to an electronic device equipped with a display and displayed on the display of the electronic device.

8. A blood pressure measuring device that, while the internal pressure of a cuff surrounding a part of the body of the person being examined is variable, detects Korotkoff tones contained in a sound signal collected from the person being examined based on an oscillometric signal detected from the person being examined and displays them in real time on a display, and includes a processor that visually displays the reference Korotkoff tones or displays a visual mark indicating the reference Korotkoff tones when a reference Korotkoff tones corresponding to the blood pressure of the person being examined is displayed in real time on the display.

9. The aforementioned processor, It is determined whether a candidate reference Korotkoff tone with an amplitude greater than or equal to a predetermined amplitude is detected in the section of the sound signal that is based on the peak of the oscillometric signal. The blood pressure measuring device according to claim 8, wherein if the candidate reference Korotkoff tone is detected, it is determined whether the candidate reference Korotkoff tone is a reference Korotkoff tone based on the ratio of frequency components of the candidate reference Korotkoff tone that are included in a predetermined frequency band.

10. The operation involves detecting a signal from the person being examined while the internal pressure of a cuff surrounding a part of the person's body is variable, The operation of displaying the aforementioned signal on a display in real time, Includes, The display operation involves, when a reference signal corresponding to the blood pressure of the person being examined is displayed on the display in real time from among the signals detected from the person being examined, visually displaying the reference signal in a different way or displaying a visual mark indicating the reference signal. An operation to provide the subject with a blood pressure measurement result displayed in which the signal detected from the subject and the oscillometric signal are synchronized with each other, Based on the blood pressure measurement results, the system displays a visual mark indicating the reference signal corresponding to the blood pressure of the person being examined, or displays the reference signal visually in a different way. A blood pressure measurement method, further including the following.

11. The blood pressure measurement method according to claim 10, wherein the display operation displays the signal on the display based on the Korotkoff tone contained in the sound signal collected by the microphone while the internal pressure of the cuff is variable.

12. The aforementioned detection operation is, If a signal not detected by the person being tested is detected while the internal pressure of the cuff is varying, that signal is selected as a candidate reference signal. The blood pressure measurement method according to claim 10, wherein it is determined whether or not to determine the candidate reference signal as the reference signal based on whether or not a new signal is detected from the person being examined after the candidate reference signal.

13. The blood pressure measurement method according to claim 12, wherein the detection operation determines the candidate reference signal as the reference signal in response to the detection of n (where n is a natural number) new signals continuously detected from the person being tested after the candidate reference signal.

14. The blood pressure measurement method according to claim 10, wherein the blood pressure measurement result is output in the form of a printed document.

15. The blood pressure measurement method according to claim 10, wherein the blood pressure measurement result is transmitted to an electronic device equipped with a display and displayed on the display of the electronic device.

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