Oscillometric blood pressure monitor for wrist wearable

Abstract

The present invention relates to an oscillometric blood pressure monitor for wrist-worn wearables, and more specifically, to a blood pressure monitor that is worn on the wrist to measure a user's blood pressure, comprising: a wrist strap worn on the user's wrist; a sensing unit provided on one side of the wrist strap for measuring a pulse wave signal and a load signal; and a processing unit for calculating systolic blood pressure and diastolic blood pressure using the pulse wave signal and the load signal as input signals.

Description

Technology Field

[0001] The present invention relates to an oscillometric blood pressure monitor for wrist-worn wearables. Background Technology

[0002] Generally, blood pressure is defined as the load that blood exerts on the walls of blood vessels, and the heart contracts and relaxes approximately 60 to 80 times per minute. The load exerted on blood vessels when the heart contracts and pushes blood out is called 'systolic blood pressure,' and because it is the highest, it is also called 'maximum blood pressure.' Additionally, the load on blood vessels when the heart relaxes and receives blood is called 'diastolic blood pressure,' and because it is the lowest, it is also called 'minimum blood pressure.'

[0003] Meanwhile, hypertension can be the cause of other life-threatening complications such as eye disease, kidney disease, arterial disease, brain disease, and heart disease. Therefore, continuous blood pressure measurement and management must be performed for patients with the aforementioned complications. In addition, users without complications must also undergo regular blood pressure measurement and management to check their physical condition.

[0004] The pressurized cuff method is commonly used for blood pressure measurement. The pressurized cuff is a discontinuous measurement method that uses a cuff to constrict the blood vessels to near the peak pressure and then releases them. However, due to components such as the pressurized pump, the pressurized cuff method is not easy to apply to portable devices.

[0005] Recently, a pressurized cuffless blood pressure monitor that measures blood pressure without using a cuff is being researched.

[0006] One example is a capless blood pressure monitor using the Pulse Transit Time (PTT) method. The PTT method estimates blood pressure by utilizing the speed of the pulse wave. Another example is a capless blood pressure monitor using the Pulse Wave Analysis (PWA) method. The PWA method estimates blood pressure by analyzing the shape of the pulse wave.

[0007] However, the PTT method has the disadvantage of requiring individual calibration for accurate measurement, and since biosignals must be measured at two or more locations to measure the speed of the pulse wave, it is difficult to configure it into a compact device.

[0008] In addition, the PWA method has the disadvantage of limiting accurate blood pressure measurement because it estimates blood pressure solely through pulse wave analysis and is susceptible to noise. Prior art literature

[0009] Republic of Korea Registered Patent No. 10-1349767 Republic of Korea Registered Patent No. 10-1798495 Republic of Korea Registered Patent No. 10-2023-0092392 The problem to be solved

[0010] Accordingly, the present invention has been devised to solve the aforementioned conventional problems. According to an embodiment of the present invention, the purpose is to provide an oscillometric blood pressure monitor for wrist-worn wearable devices, such as smartwatches and fitness bands, which measures blood pressure in a wearable device that can be worn on the wrist, and can measure systolic and diastolic blood pressure by using pulse wave signals and load signals simultaneously measured from pulse wave and pressure sensors located on the surface in contact with the wrist as inputs to an artificial intelligence model.

[0011] According to an embodiment of the present invention, the purpose is to provide an oscillometric blood pressure monitor for wrist-worn wearables that can measure blood pressure using an oscillometric method without having a cuff on the strap of a smart watch.

[0012] And according to an embodiment of the present invention, the purpose is to provide a wrist-worn oscillometric blood pressure monitor that can guide the user to the degree of pressure by displaying a pressure signal according to the degree of pressure applied during measurement in real time, and can display the current degree of pressure so that the user can apply pressure corresponding to each step through the display unit.

[0013] In addition, according to an embodiment of the present invention, the purpose is to provide a wrist-worn oscillometric blood pressure monitor capable of measuring systolic and diastolic blood pressure by using pulse wave signals and load signals within a specific time range before and after the point when the pulse wave amplitude is at its maximum as inputs to an artificial intelligence model while changing the pressure applied to the wrist artery.

[0014] And according to an embodiment of the present invention, the purpose is to provide a wrist-worn oscillometric blood pressure monitor that can determine whether the smart watch is measuring at heart level to prevent blood pressure measurement errors caused by hydrostatic pressure, and can determine whether movement is minimized to prevent errors caused by motion noise, and provide notification and guidance.

[0015] In addition, according to an embodiment of the present invention, the purpose is to provide an oscillometric blood pressure monitor for wrist wearables that operates to pressurize and move a sensing unit toward the wrist artery position side through an actuator when measuring blood pressure, and can control the actuator to pressurize in steps set based on the value measured by the pressure sensor.

[0016] And according to an embodiment of the present invention, the purpose is to provide an oscillometric blood pressure monitor for wrist-worn wearables that can automatically proceed with a blood pressure measurement mode when the height of the smartwatch measured by the altitude sensor is maintained for a specific time or longer within a height range set based on the heart height, and when it is determined to be in a correct posture without motion noise for a specific time based on the measurement value of the inertial sensor.

[0017] Meanwhile, the technical problems to be solved by the present invention are not limited to those mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art to which the present invention belongs from the description below. means of solving the problem

[0018] The objective of the present invention can be achieved by a wrist-worn oscillometric blood pressure monitor for measuring a user's blood pressure, characterized by comprising: a wrist strap worn on the user's wrist; a sensing unit provided on one side of the wrist strap for measuring a pulse wave signal and a load signal; and a processing unit that calculates blood pressure during contraction and blood pressure during diastolic using the pulse wave signal and the load signal as input signals.

[0019] And the sensing unit may include a pulse sensor that measures a pulse signal and a pressure sensor that measures a pressure applied load, and the sensing unit may be characterized by being installed on the lower surface of the main body housing of the wrist strap and positioned near the user's wrist artery.

[0020] In addition, the wrist strap may be characterized by including a display unit on one side of the main body housing to display the calculated systolic and diastolic blood pressure, and allowing the user to apply pressure to the sensing unit toward the wrist artery so as to gradually increase the pressure, and then gradually decrease the pressure.

[0021] In addition, guide data for guiding the user's pressure is displayed on the display unit or transmitted through the guide unit, and the display unit may be characterized by displaying the current pressure measured by the pressure sensor and the pressure guide data to guide the user's pressure.

[0022] In addition, the processing unit may be characterized by calculating systolic blood pressure and diastolic blood pressure by using a pulse wave signal of length N+M seconds (N seconds forward and M seconds backward) and a load signal of the same time period as inputs to an artificial intelligence model, based on the point when the amplitude of the measured pulse wave signal is maximum while the pressure is changing.

[0023] And it may further include an operating unit that includes an altitude sensor for measuring the height of the sensing unit, determines whether the height of the sensing unit is within a proximity range set to the user's heart height, and performs blood pressure measurement when it is located within the said proximity range.

[0024] Additionally, the operating unit may further include an inertial sensor for measuring the user's posture, and the operating unit may be characterized by performing blood pressure measurement when, based on the inertial sensor measurement value, the user's movement is less than a set value and the height of the sensing unit is located within the proximity range.

[0025] In addition, it may be characterized by further including an actuator that drives the sensing unit to apply pressure to the vicinity of the user's wrist artery during the blood pressure measurement mode.

[0026] In addition, it may be characterized by including a control unit that controls the actuator in the blood pressure measurement mode to gradually protrude and pressurize the sensing unit near the user's wrist artery, and gradually retracts to reduce the pressure when the set load is exceeded. Effects of the invention

[0027] According to the oscillometric blood pressure monitor for wrist-worn wearable devices according to an embodiment of the present invention, blood pressure can be measured on a wearable device that can be worn on the wrist, such as a smart watch or a fitness band, and the pulse wave signal and load signal simultaneously measured from a pulse wave and pressure sensor located on a surface in contact with the wrist can be used as input to an artificial intelligence model to measure systolic blood pressure and diastolic blood pressure.

[0028] According to the oscillometric blood pressure monitor for wrist-worn wearables according to an embodiment of the present invention, it has the effect of enabling oscillometric blood pressure measurement without providing a cuff on the strap of a smart watch.

[0029] In addition, according to the oscillometric blood pressure monitor for wrist-worn wearables according to an embodiment of the present invention, it is possible to guide the user on the degree of pressure by displaying a pressure signal according to the degree of pressure applied during measurement in real time, and there is an advantage of being able to display the current degree of pressure through the display unit so that the user can apply pressure corresponding to each stage.

[0030] In addition, according to the oscillometric blood pressure monitor for wrist-worn wearables according to an embodiment of the present invention, while changing the pressure applied to the wrist artery, the pulse wave signal and load signal of a specific time range before and after the time when the pulse wave amplitude is at its maximum are used as inputs to an artificial intelligence model to measure systolic blood pressure and diastolic blood pressure.

[0031] And according to the oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention, in order to prevent blood pressure measurement errors caused by hydrostatic pressure, the smart watch can determine whether it is measuring at heart level when measuring blood pressure, and in order to prevent errors caused by motion noise, it can determine whether movement is minimized and provide notification and guidance.

[0032] In addition, according to the oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention, when measuring blood pressure, the sensing part is operated to pressurize and move toward the wrist artery position through an actuator, and the actuator can be controlled to pressurize in steps set based on the value measured by the pressure sensor.

[0033] And according to the oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention, if the height of the smartwatch measured by the altitude sensor is maintained for a specific time or longer within a height range set based on the heart height, and if it is determined to be in the correct posture without motion noise for a specific time based on the measurement value of the inertial sensor, the blood pressure measurement mode can be automatically performed.

[0034] Meanwhile, the effects obtainable from the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art to which the present invention belongs from the description below. Brief explanation of the drawing

[0035] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a diagram showing a wrist-worn oscillometric blood pressure monitor according to an embodiment of the present invention in a worn state. FIG. 2 is a side view of an oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention. FIG. 3 is a bottom view of an oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention, FIG. 4 is a block diagram of an oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention. FIG. 5 is a pulse wave signal graph according to an embodiment of the present invention, FIG. 6 is a load signal graph according to an embodiment of the present invention, FIGS. 7 and 8 are flowcharts for calculating blood pressure by extracting key features from preprocessed data by applying a Multi-Linear Regression (MLR) artificial intelligence model according to an embodiment of the present invention, FIG. 9 is a flowchart for calculating blood pressure by extracting time domain features from an oscillometric waveform by applying a Multi-Linear Regression (MLR) artificial intelligence model according to an embodiment of the present invention, FIG. 10 is a perspective view from the lower side of an oscillometric blood pressure monitor for wrist-worn wearables equipped with an actuator according to an embodiment of the present invention. FIG. 11 shows a side view of an oscillometric blood pressure monitor for wrist-worn wearables equipped with an actuator according to an embodiment of the present invention. Specific details for implementing the invention

[0036] The above objects, other objects, features, and advantages of the present invention will be easily understood through the following preferred embodiments associated with the accompanying drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the spirit of the invention is sufficiently conveyed to a person skilled in the art.

[0037] In this specification, when a component is described as being on another component, it means that it may be formed directly on the other component or that a third component may be interposed between them. Also, in the drawings, the thicknesses of the components are exaggerated for the effective description of the technical content.

[0038] The embodiments described herein will be explained with reference to cross-sectional and / or plan views, which are exemplary illustrations of the invention. In the drawings, the thicknesses of films and regions are exaggerated for effective explanation of the technical content. Accordingly, the shapes of the exemplary drawings may be modified by manufacturing techniques and / or tolerances, etc. Accordingly, the embodiments of the invention are not limited to the specific shapes depicted but include variations in shape produced according to the manufacturing process. For example, a region depicted as a right angle may be rounded or have a certain curvature. Accordingly, the regions illustrated in the drawings have properties, and the shapes of the regions illustrated in the drawings are intended to illustrate specific shapes of the regions of the device and are not intended to limit the scope of the invention. Although terms such as first, second, etc., have been used to describe various components in the various embodiments of this specification, these components should not be limited by such terms. These terms are used merely to distinguish one component from another. The embodiments described and illustrated herein also include their complementary embodiments.

[0039] The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, 'comprises' and / or 'comprising' do not exclude the presence or addition of one or more other components to the mentioned components.

[0040] In describing the specific embodiments below, various specific details have been included to explain the invention more specifically and to aid understanding. However, a reader with sufficient knowledge in the art to understand the invention will recognize that it can be used without these various specific details. In some cases, it is noted in advance that commonly known aspects that are not significantly related to the invention have been omitted to prevent unnecessary confusion in describing the invention.

[0042] Hereinafter, the configuration, function, and operation method of an oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention will be described.

[0043] First, FIG. 1 illustrates a state in which a wrist-worn oscillometric blood pressure monitor according to an embodiment of the present invention is worn. FIG. 2 illustrates a side view of a wrist-worn oscillometric blood pressure monitor according to an embodiment of the present invention. FIG. 3 illustrates a bottom view of a wrist-worn oscillometric blood pressure monitor according to an embodiment of the present invention.

[0044] And FIG. 4 shows a block diagram of an oscillometric blood pressure monitor for wrist-worn wearable according to an embodiment of the present invention.

[0045] An oscillometric blood pressure monitor (100) for wrist-worn wearable according to an embodiment of the present invention is worn on the wrist to measure the user's blood pressure and includes a wrist strap (10) worn on the user's wrist and a main body housing (11) provided on the wrist strap (10). For example, the wrist strap (10) and the main body housing (11) may be configured as a smartwatch.

[0046] And the sensing unit (20) is provided on the lower surface of the main body housing (11) and measures pulse signal and load signal.

[0047] This sensing unit (20) includes a pulse sensor (22) that measures a pulse signal and a pressure sensor (21) that measures a pressure applied load.

[0048] And the sensing unit (20) is installed on the lower surface of the main body housing (11) and is positioned near the user's wrist artery.

[0049] The processing unit (30) is configured to calculate blood pressure during contraction and blood pressure during diastolic using the pulse wave signal and the load signal as input signals.

[0050] And the calculated systolic blood pressure and diastolic blood pressure can be displayed through the display unit (12) installed on the upper surface of the main body housing (11).

[0051] Therefore, the user can calculate the blood pressure during contraction and diastolic blood pressure by applying pressure to the sensing unit (20) towards the wrist artery so that the pressure is gradually increased, and then gradually decreasing the pressure, using the pulse wave signal and the load signal as input signals.

[0052] That is, when a user wears the wrist-worn oscillometric blood pressure monitor (100) according to an embodiment of the present invention on their left wrist and activates the blood pressure measurement function, and then slowly presses the bezel (13) of the main body housing (11) with their right hand, the wrist artery is compressed by the main body housing (11) and ultimately the artery is closed so that blood flow is not allowed.

[0053] At this time, when the user gradually reduces the force applied to the bezel (13), the pressure applied to the wrist artery gradually decreases, causing the blood vessel to gradually open and the pulse wave signal to be measured. The pulse wave signal measured at this time is measured in a form where the amplitude is small and gradually increases depending on the degree to which the blood vessel opens. If the pulse wave signal and the load signal measured during this operation are used as input signals, an oscillogram signal similar to that obtained from a conventional forearm cuff-type oscillometric blood pressure monitor can be obtained.

[0055] FIG. 5 illustrates a pulse signal graph according to an embodiment of the present invention. FIG. 6 illustrates a load signal graph according to an embodiment of the present invention.

[0056] The pulse signal shown in FIG. 5 is measured from the pulse sensor (22) of the sensing unit (20), and the load signal shown in FIG. 6 is measured from the pressure sensor (21) of the sensing unit (20).

[0057] And the guide section (31) can display guide data for guiding the user's pressure on the display section (12) or transmit it through the notification section (32).

[0058] The display unit (12) can display the current pressure measured by the pressure sensor (21) and pressure guide data to guide the user to apply pressure.

[0059] That is, through the guide section (31) and the display section (12), the user can be guided on the degree of pressure to obtain a high-quality oscillogram when pressing the main body housing (11). The user can press the location with the intensity guided by the display section (12) of the main body housing (11). The display section (12) displays the current degree of pressure using numerical values, emoticons, symbols, etc., so that the user can apply pressure corresponding to the time, thereby guiding the arterial occlusion and gradual arterial opening.

[0061] A processing unit (30) according to an embodiment of the present invention calculates blood pressure during contraction and blood pressure during diastolic using a pulse wave signal and a load signal as input signals.

[0062] The processing unit (30) calculates systolic blood pressure and diastolic blood pressure by using a pulse wave signal of length N+M seconds (N seconds forward and M seconds backward) and a load signal of the same time period as inputs to an artificial intelligence model, based on the point when the amplitude of the measured pulse wave signal is at its maximum while the pressure is changing.

[0063] There are two main methods for estimating blood pressure according to an embodiment of the present invention.

[0064] The first method utilizes an oscillometric waveform envelope, which is the form of an oscillometric waveform. This method estimates blood pressure by extracting key features from preprocessed data using techniques such as Multi-Linear Regression (MLR). Figures 7 and 8 illustrate a flowchart for calculating blood pressure by extracting key features from preprocessed data using a Multi-Linear Regression (MLR) artificial intelligence model.

[0065] Secondly, there is a method using an oscillometric waveform pulse. This method estimates blood pressure by extracting time-domain features from an oscillometric waveform using techniques such as Long-Short Term Memory (LSTM). Figure 9 illustrates a flowchart showing the calculation of blood pressure by extracting time-domain features from an oscillometric waveform using a Multi-Linear Regression (MLR) artificial intelligence model.

[0067] And, the oscillometric blood pressure monitor (100) for wrist-worn wearable according to an embodiment of the present invention may include an altitude sensor (41) that measures the current height of the sensing unit. In addition, the operating unit (40) determines whether the height of the sensing unit (20) is within a proximity range set to the user's heart height, and when it is located within the proximity range, it performs blood pressure measurement.

[0068] In addition, the oscillometric blood pressure monitor (100) for wrist-worn wearable according to an embodiment of the present invention may include an inertial sensor (42) for measuring the posture of a user. And the operating unit (40) may control the blood pressure measurement to proceed when the user's movement is less than a set value based on the measurement value of the inertial sensor (42) and the height of the sensing unit (20) is located within the proximity range.

[0069] That is, to prevent blood pressure measurement errors caused by hydrostatic pressure, an altitude sensor (41) embedded in the main body housing (11) is used to determine whether the measurement is being taken at heart level, and to prevent errors caused by motion noise, an inertial sensor (42) embedded in the main body housing (11) is used to determine whether movement is minimized, thereby determining whether the correct measurement posture for blood pressure measurement is being maintained. If the correct measurement posture is not maintained, a change in the incorrect posture can be requested through feedback such as vibration or sound via the display unit (12) and the notification unit (32).

[0071] FIG. 10 is a perspective view of a wrist-worn oscillometric blood pressure monitor equipped with an actuator according to an embodiment of the present invention, viewed from the lower side. FIG. 11 is a side view of a wrist-worn oscillometric blood pressure monitor equipped with an actuator according to an embodiment of the present invention.

[0072] And, the wrist-worn oscillometric blood pressure monitor (100) according to an embodiment of the present invention may be configured to include an actuator (50). The actuator (50) is configured to drive the sensing unit (20) to apply pressure to the vicinity of the user's wrist artery during the blood pressure measurement mode.

[0073] In addition, the control unit can control the actuator (50) in the blood pressure measurement mode so that the sensing unit (20) is gradually protruded and pressurized near the user's wrist artery, and when the set load is exceeded, it is gradually retracted so that the pressure is reduced.

[0074] That is, the sensing unit (20), in which the pulse wave sensor (22) and the pressure sensor (21) are combined, can be operated so that the contact surface on the rear of the main body housing (11) automatically protrudes through the actuator (50) to mechanically compress the wrist artery.

[0075] In such cases, if the aforementioned operating unit (40) determines that the measurement posture is correct, the blood pressure can be automatically measured without the user inputting instructions for blood pressure measurement. For example, when wearing a wrist-worn oscillometric blood pressure monitor (100) equipped with an actuator (50) according to an embodiment of the present invention, and during daily life, if the height of the wrist worn matches the heart height within a limited range and there is no motion noise, and it is determined that the measurement posture is correct, the blood pressure measurement mode can be automatically executed to measure blood pressure. Therefore, the user can measure blood pressure several times a day without any separate will.

[0077] In addition, the apparatus and method described above are not limited to the configurations and methods of the embodiments described above; rather, all or part of each embodiment may be selectively combined to allow for various modifications to be made. Explanation of the symbols

[0078] 10: Wrist strap 11: Main body housing 12: Display section 13: Bezel 20: Sensing unit 21: Pressure sensor 22: Macwave sensor 30: Processing unit 31: Guide Department 32:Notification Department 40: Operations Department 41: Altitude sensor 42: Inertial sensor 50: Actuator 100: Wrist-worn wearable oscillometric blood pressure monitor

Claims

Claim 1 A blood pressure monitor worn on the wrist to measure a user's blood pressure, comprising: a wrist strap worn on the user's wrist; and a sensing unit provided on one side of the wrist strap to measure a pulse wave signal and a load signal. and a processing unit that calculates systolic blood pressure and diastolic blood pressure using the pulse wave signal and load signal as input signals; wherein the sensing unit includes a pulse wave sensor that measures the pulse wave signal and a pressure sensor that measures the applied load; wherein the sensing unit is installed on the lower surface of the main body housing of the wrist strap and is located near the user's wrist artery, and a display unit is included on one side of the main body housing of the wrist strap to display the calculated systolic and diastolic blood pressure; wherein the user applies pressure to the sensing unit toward the wrist artery so that the pressure gradually increases, and then gradually decreases the pressure; wherein guide data for guiding the user's pressure is displayed on the display unit or transmitted through a guide unit; wherein the display unit displays the current pressure measured by the pressure sensor and the pressure guide data to guide the user's pressure; and wherein the processing unit inputs a pulse wave signal of length N+M seconds (N seconds forward and M seconds backward) and a load signal of the same time period, based on the point where the amplitude of the measured pulse wave signal is maximum while the pressure is changing, into an artificial intelligence model An oscillometric blood pressure monitor for wrist-worn wearables, comprising: an altitude sensor that calculates systolic and diastolic blood pressure and measures the current height of a sensing unit; an operating unit that determines whether the height of the sensing unit is within a set proximity range of the user's heart height and performs blood pressure measurement when it is located within the said proximity range; an inertial sensor that measures the user's posture; and the operating unit that performs blood pressure measurement when, based on the inertial sensor measurement value, the user's movement is less than a set value and the height of the sensing unit is located within the said proximity range. Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 delete Claim 7 delete Claim 8 An oscillometric blood pressure monitor for wrist-worn wearables, characterized in that, in claim 1, it further includes an actuator that drives the sensing unit to apply pressure near the user's wrist artery during a blood pressure measurement mode. Claim 9 An oscillometric blood pressure monitor for wrist-worn wearables, characterized in that, in claim 8, the actuator is controlled to gradually protrude and pressurize the sensing part near the user's wrist artery during a blood pressure measurement mode, and when a set load is exceeded, it gradually retracts to reduce the pressure.

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