Blood pressure measurement system and method

Abstract

Blood pressure measurement system and method, comprising: detecting a first wave signal from a blood vessel during a first pressure application of a wearable pressure application unit by a physiological information measurer, wherein the wearable pressure application unit applies pressure to an upstream blood vessel of the blood vessel; generating a first envelope signal of the first wave signal according to the first wave signal; detecting a second wave signal from the blood vessel during a second pressure application of the wearable pressure application unit by using the physiological information measurer; determining a time point at which a waveform of the second wave signal intersects with a waveform of the envelope signal as a first time point; outputting a pressure value applied by the wearable pressure application unit to the upstream blood vessel at the first time point as a systolic pressure value; determining a time point at which the envelope signal has a preset amplitude as a second time point; and outputting a pressure value applied by the wearable pressure application unit to the upstream blood vessel at the second time point as a diastolic pressure value.

Description

[0001] Cross-reference of relevant applications

[0002] This patent application benefits from U.S. Provisional Application No. 62 / 886,368, filed August 14, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This patent specification pertains to a blood pressure measurement method and apparatus, and more specifically to a blood pressure measurement method and apparatus that reduces measurement errors. Background Technology

[0004] Cardiovascular disease (CVD) accounts for a significant portion of deaths worldwide. CVD includes coronary heart disease, which accounts for the majority of cardiovascular deaths, as well as stroke and heart failure. CVD is closely related to risk factors and lifestyle. In addition to maintaining healthy lifestyle habits, regular monitoring of blood pressure, blood sugar, and cholesterol plays a crucial role in preventing cardiovascular disease. To meet the needs of preventing or controlling cardiovascular disease, many portable physiological information monitoring devices have emerged, allowing users to measure their heart rate, blood pressure, blood sugar, and other vital signs.

[0005] Technical issues

[0006] Arterial blood pressure is most commonly measured using a sphygmomanometer. Traditionally, when monitoring a patient's blood pressure, it varies between systolic and diastolic pressure during each heartbeat. Systolic pressure is the peak pressure in the arteries at the end of the heart cycle or near the end of contraction. Diastolic pressure is the lowest pressure in the arteries that occurs near the beginning of the heart cycle when the heart is pumping blood.

[0007] In traditional portable blood pressure monitoring devices, the mean blood pressure is typically measured first, and then the relationship between the mean blood pressure and systolic and diastolic blood pressure is statistically analyzed to deduce the subject's systolic and diastolic blood pressure. However, the relationship between mean blood pressure and systolic and diastolic blood pressure can vary depending on various variables such as age, physical condition, physical fitness, and living environment, making measurement errors difficult to avoid. These variables include age, individual physiology, or living environment. Therefore, traditional physiological monitoring devices are prone to unavoidable measurement errors. In some variations, portable physiological monitoring devices combine a traditional blood pressure monitor with a finger clip sensor. These devices measure systolic blood pressure in a similar way to traditional methods, applying pressure to the artery to stop flow and then removing the pressure. However, this method still introduces measurement errors due to subject movement noise and respiratory variability. Therefore, there is a need to develop an improved blood pressure measurement reading that reduces errors and improves the accuracy of measuring actual blood pressure. Summary of the Invention

[0008] Accordingly, the present application provides a blood pressure measurement system that implements an improved method for generating improved blood pressure measurements. The objective is to directly measure blood pressure using a portable device configuration and to effectively reduce errors caused by motion noise and respiratory variation-induced blood pressure fluctuations.

[0009] Another aspect of the present application is to provide a blood pressure measurement device that includes a wearable pressure application unit, a physiological information measurement device, and a control unit. The control unit is signal connected to the wearable pressure application unit and the physiological information measurement device to implement the blood pressure measurement method described above.

[0010] Variation embodiments of the system described herein can include a system with only one controller configured to work with a separate physiological information device and / or pressure application unit. For example, such a blood pressure measurement system can include a controller designed to be used with a physiological information measurement device and a pressure application unit, the system including wherein the controller is configured to be in electronic communication with the pressure application unit and the physiological information measurement device to perform the functions discussed herein.

[0011] One variation embodiment of the system includes that the first wave signal has a plurality of periodic waves, and generating the envelope signal further includes: calculating an average value of each of the periodic waves in the first wave signal; obtaining a first wave correction signal by subtracting the average value from an amplitude of each corresponding periodic wave; and connecting each wave peak of the first wave correction signal to each wave valley to obtain the envelope signal.

[0012] In another variation embodiment, the first wave signal has a plurality of periodic waves, and the controller generates the envelope signal by connecting each wave peak of each of the periodic waves to each wave valley of each of the periodic waves.

[0013] Another variation embodiment of the system includes a controller that is further configured to: measure, by the physiological information measurement device, a third wave signal of the blood vessel during a non-pressure application period of the wearable pressure application unit, wherein the third wave signal is a continuous wave; output the systolic pressure value as a starting peak value of a wave peak in the third wave signal; output the diastolic pressure value as a starting valley value of a wave valley in the third wave signal that is adjacent in time to the wave peak; and calculate a plurality of additional peak values of remaining wave peaks and a plurality of additional valley values of remaining wave valleys in the third wave signal based on the systolic pressure value and the diastolic pressure value, respectively.

[0014] A variation embodiment of the controller can determine the first time point by: obtaining an average line of the second wave signal; smoothing the envelope signal to obtain a corrected envelope signal; and determining a time point at which an upper edge of a waveform of the corrected envelope signal intersects the average line as the first time point.

[0015] In another variation, the controller uses a preset amplitude of the envelope signal that is between 50% and 90% of the maximum amplitude.

[0016] The pressure unit disclosed herein is configured to be worn on an arm or a wrist, and the controller is configured to cause the pressure unit to apply pressure during the first pressure application and during the second pressure application, and the physiological information measurer is configured to detect the first wave signal and the second wave signal from a finger.

[0017] The present disclosure also includes a method for measuring blood pressure, comprising: detecting, by a physiological information measurer, a first wave signal from a blood vessel during a first pressure application of a wearable pressure unit to an upstream blood vessel of the blood vessel; generating a first envelope signal of the first wave signal based on the first wave signal; detecting, by using the physiological information measurer, a second wave signal from the blood vessel during a second pressure application of the wearable pressure unit; determining a first time point as a time point at which a waveform of the second wave signal intersects a waveform of the envelope signal; outputting a value of pressure applied by the wearable pressure unit to the upstream blood vessel at the first time point as a systolic pressure value; determining a second time point as a time point at which the envelope signal has a preset amplitude; and outputting a value of pressure applied by the wearable pressure unit to the upstream blood vessel at the second time point as a diastolic pressure value.

[0018] Another variation of the blood pressure measuring device includes: a wearable pressure unit; a physiological information measurer; and a control unit signal connected to the wearable pressure unit and the physiological information measurer, wherein the control unit is capable of performing any of the methods disclosed herein.

[0019] The pressure unit disclosed herein can be any type of sphygmomanometer or other device that performs the function of reducing blood flow in an upstream blood vessel. In addition, the physiological information measurer is a finger clip device that has a pressure sensor for detecting the first wave signal, the second wave signal, and the third wave signal. The finger clip device can include an optical sensor, or any sensor that is capable of detecting wave signals from a downstream blood vessel.

[0020] In one variant, the system and method provide a first wave signal from a blood vessel during a first pressure application of a wearable pressure application unit to the blood vessel by a physiological information measurer, wherein the wearable pressure application unit applies pressure to an upstream blood vessel of the blood vessel; generating a first envelope signal of the first wave signal from the first wave signal; detecting a second wave signal from the blood vessel during a second pressure application of the wearable pressure application unit by using the physiological information measurer; determining a first time point at which a waveform of the second wave signal intersects a waveform of the envelope signal; outputting a pressure value applied by the wearable pressure application unit to the upstream blood vessel at the first time point as a systolic pressure value; determining a second time point at which the envelope signal has a preset amplitude; and outputting a pressure value applied by the wearable pressure application unit to the upstream blood vessel at the second time point as a diastolic pressure value.

[0021] Another suggestion of the present application is to provide a blood pressure measuring device including a wearable pressure application unit, a physiological information measurer, and a control unit. The control unit is signal-connected to the wearable pressure application unit and the physiological information measurer to perform the above-mentioned blood pressure measurement. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Flowchart of the blood pressure measurement method of the first embodiment of the present application.

[0023] Figure 2 Schematic diagram of the blood pressure measurement device of the first embodiment of the present application.

[0024] Figure 3 Pressure-time diagram of the wearable pressure application unit in the first embodiment.

[0025] Figure 4 Schematic diagram of the first wave signal and the second wave signal of the first embodiment.

[0026] Figure 5 Schematic diagram of the envelope signal generated in the variant of the first embodiment.

[0027] Figure 6 Schematic diagram of the envelope signal and the modified envelope signal in the variant of the first embodiment.

[0028] Figure 7 Pressure-time diagram of the wearable pressure application unit in the variant of the first embodiment.

[0029] Figure 8 Flowchart of the envelope signal generated in the second embodiment of the present application.

[0030] Figure 9 Schematic diagram of the envelope signal in the second embodiment.

[0031] Figure 10 This is a schematic diagram of the packet signal and the associated correction packet signal in the second embodiment.

[0032] Figure 11 This is a pressure-time diagram of the wearable pressure application unit in the second embodiment.

[0033] Figure 12 This is a flowchart of a blood pressure measurement method according to the third embodiment of the present invention.

[0034] Figure 13 This is a graph showing the continuous blood pressure results obtained according to the blood pressure measurement method of the third embodiment. Detailed Implementation

[0035] This invention provides a novel and improved method for measuring blood pressure, but there is still a need to produce an improved blood pressure measurement reading to reduce errors and improve the accuracy of measuring actual blood pressure.

[0036] Figure 1 The following are the combinations of the blood pressure measurement method of the first embodiment of the present invention. Figure 1 An example of the process for obtaining a blood pressure measurement method. Figure 2 An exemplary configuration of a blood pressure measuring device for improving the blood pressure measurement process is described. Figure 2 The blood pressure measuring device includes a wearable pressure application unit 1, such as a blood pressure monitor that applies pressure to the arm N1 of an individual N, a physiological information measurement device 2, and a control unit 3. Figure 2 The blood pressure measurement device D includes a wearable pressure application unit 1, such as a blood pressure monitor that applies pressure to the arm N1 of an individual N, a physiological information measuring device 2, and a control unit 3. In this embodiment, the control unit 3 is signal-connected to the wearable pressure application unit 1 and the physiological information measuring device 2 to provide one or more signal implementations. Figure 1 The method for measuring blood pressure. Please refer to [link / reference]. Figure 1 A first variation of the blood pressure measurement method includes step S100: detecting a first wave signal from a blood vessel using a physiological information measuring device 2. This wave signal typically forms a blood pressure waveform as blood flows through blood vessels during a heartbeat. In this embodiment, the physiological information measuring device 2, in conjunction with the wearable pressure application unit 1, detects the first wave signal during a first pressure application period P1, whereby the wearable pressure application unit 1 applies pressure relative to the upstream vessel of the blood vessel measured by the physiological information measuring device 2. Specifically, the wearable pressure application unit 1 can be a blood pressure monitor, capable of inflation and deflation under the control of a control unit 3, while the physiological information measuring device 2 can be a clip-on device including any available pressure sensor (such as a pressure sensor). Therefore, the system measures the pressure of the upstream blood vessel in the arm N1. Furthermore, the first wave signal measured by the measuring device 2 is a blood pressure signal from the blood vessel in the finger N2.

[0037] It is to be noted that the flowcharts shown in Figure 1 , Figure 5 and Figure 8 are intended to provide a detailed description of the behavior associated with the system and / or method. Each item or block shown in the figures is merely for convenience. It can also be considered that the features of the flowcharts can be combined with occurrences in separately identifiable elements, or these elements can be arranged in different orders.

[0038] The method of the present disclosure can include devices other than the blood pressure measuring device described above. In some embodiments, the wearable compression unit 1 can be any compression device other than a sphygmomanometer, as long as it can compress the upstream blood vessel. In other variant embodiments, the compression position of the wearable compression unit 1 is not limited to the arm N1, for example, as long as the physiological information measuring device 2 detects the blood pressure signal from the blood vessel downstream of the blood vessel compressed by the wearable compression unit 1, the compression position can be the wrist N3 of the individual N, and the physiological information measuring device 2 measures the blood pressure signal on the finger N2, so that the blood vessel in the wrist N3 is still the upstream blood vessel of the blood vessel in the finger N2. In other embodiments of the present disclosure, the finger clip physiological information measuring device can not be limited to a pressure sensor, and can be, for example, an optical sensor or other types of sensors for measuring the blood pressure signal of the blood vessel.

[0039] Figure 4 For the waveform signal during the first compression period P1, the control unit 3 controls the wearable compression unit 1 to inflate. During the first compression period P1, the physiological information measuring device 2 measures the first wave signal W1 on the finger N2 during this period. Figure 3 The pressure versus time graph for the wearable compression unit 1 applied to the arm N1. During the first compression period P1, the wearable compression unit 1 applies a linearly increasing pressure to the upstream blood vessel in the arm N1, so that the amount of blood passing through the upstream blood vessel decreases over time. The blood amount received by the blood vessel in the downstream finger N2 also decreases accordingly, so that the blood pressure signal measured by the physiological information measuring device 2 on the finger N2 decreases over time. Figure 4 It can be seen that the amplitude of the first wave signal W1 decreases.

[0040] As shown in Figure 1 , the blood pressure measuring method of the first embodiment of the present disclosure further includes the step S102 of generating an envelope signal E1 from the first wave signal W1 according to the waveform of the first wave signal W1; the step S104 of obtaining a second wave signal W2 of the blood vessel by the physiological information measuring device 2 during the second compression period P2 of the wearable compression unit 1; the step S106 of obtaining a first time point T1a according to the time point at which the waveform of the second wave signal W2 intersects with the waveform of the envelope signal E1; and the step S108 of outputting the pressure value applied by the wearable compression unit to the upstream blood vessel at the first time point T1a as the systolic pressure value. The following is combined with Figures 2 to 4 The steps S102 to S108 are described in detail. AsFigure 4 As shown, the first wave signal W1 of the first embodiment of the present application comprises a plurality of periodic waves (C1, C2,... Cn). In particular, each periodic wave is defined as the wave signal between two adjacent troughs in the first wave signal W1 in the present variant embodiment. Further, the envelope signal E1 is obtained by connecting the peaks and troughs of each periodic wave.

[0041] In step S104 of the first variant embodiment, when the pressure applied by the wearable pressure application unit 1 to the upstream blood vessel is large enough such that the physiological information measurer 2 cannot measure the waveforms, the wearable pressure application unit 2 enters the second pressure application period P2. As shown, the blood pressure signal measured by the physiological information measurer 2 during the second pressure application period P2 is a second wave signal W2. Then in steps S106 and S108, the first time point Tla is obtained according to the time point at which the waveform of the second wave signal W2 intersects with the waveforms of the envelope signal E1. Further, the second time point T2a is obtained according to the time point at which the extension of the envelope signal E1 intersects with the extension of the waveform of the second wave signal W2 in step S108. Figure 4 As shown, the blood pressure signal measured by the physiological information measurer 2 during the second pressure application period P2 is a second wave signal W2. Then in steps S106 and S108, the first time point Tla is obtained according to the time point at which the waveform of the second wave signal W2 intersects with the waveforms of the envelope signal E1. Further, the second time point T2a is obtained according to the time point at which the extension of the envelope signal E1 intersects with the extension of the waveform of the second wave signal W2 in step S108. Figure 3 In step S110, the pressure value Sa applied by the wearable pressure application unit 1 at the first time point Tla is outputted as the systolic pressure. In particular, the envelope signal E1 ends at the end of the first pressure application period P1, and the waveform of the second wave signal W2 starts at the beginning of the second pressure application period P2. In step S106, the second time point T2a is obtained according to the time point at which the extension of the envelope signal E1 intersects with the extension of the waveform of the second wave signal W2. It is noted that in the variant embodiment of the present application, the second pressure application period P2 starts immediately after the first pressure application period P1, and thus the first wave signal W1 and the second wave signal W2 are detected during one continuous inflation of the wearable pressure application unit 1. However, the variant embodiment of the present application is not limited thereto. In other embodiments, the first wave signal W1 and the second wave signal W2 can be obtained separately. In particular, the difference between the first pressure application period P1 and the second pressure application period P2 is mainly that during the first pressure application period P1, the physiological information measurer 2 can measure the diastolic and systolic pressure waveforms of the blood pressure. On the other hand, during the second pressure application period P2, the blood vessels within the finger N2 are poorly circulated due to the compression of the upstream blood vessel by the wearable pressure application unit 1, such that the physiological information measurer 2 cannot measure the blood pressure waveforms. It is not limited whether the wearable pressure application unit 1 of the present application continuously increases, decreases or maintains a constant pressure during the second pressure application period P2. Furthermore, the present embodiment does not limit the execution order of steps S102 and S104. The envelope signal E1 can be generated after both the first wave signal W1 and the second wave signal W2 are measured.

[0042] After step S108, the blood pressure measuring method further comprises step S110: obtaining a second time point T2a according to the time point when the envelope signal E1 has a preset amplitude A2; and step S112: outputting the pressure value applied by the wearable pressure applying unit 1 to the upstream blood vessel at the second time point as the diastolic pressure value. In the present variation, the preset amplitude A2 is 85% of the maximum amplitude A1 of the envelope signal E1. That is, when the amplitude of the envelope signal E1 decreases to 85% of the maximum amplitude A1, the blood pressure measuring method of the present variation determines that the time point is the second time point T2a. In the present embodiment, the maximum amplitude A1 is defined as the largest one among the continuous amplitudes of the envelope signal E1. The present application is not limited to the preset amplitude A2 of the present embodiment. However, in other embodiments, the preset amplitude A2 can be 50% to 90% of the maximum amplitude A1. In other embodiments, the preset amplitude A2 can be determined, for example, according to the sample group to which the subject N belongs. For example, the classification can be based on heart rate, blood pressure waveform, age, gender, height, or weight, etc. Then, the pressure value applied by the wearable pressure applying unit 1 to the subject N at the second time point T2a is outputted as the diastolic pressure value according to the pressure-time graph of the subject N. Figure 3

[0043] In the present variation, the systolic pressure and the diastolic pressure can be displayed on the display screen of the control unit 3. However, other means of displaying the systolic pressure and the diastolic pressure are also within the scope of the present application. In some other variations, the physiological measurer 2 can be integrated with a small display to display on the physiological measurer 2.

[0044] By means of the above technical means, the blood pressure measuring method of the present application can directly obtain the systolic pressure of the subject N from the first wave signal W1. Compared with the blood pressure measuring method in the prior art, which obtains the systolic pressure and the diastolic pressure by averaging the blood pressure, the present application does not need to obtain the systolic pressure from the average blood pressure, thereby improving the accuracy of blood pressure measurement.

[0045] Figure 5 Figure 6 As a variation of the present application, step S102 can further comprise step S200: obtaining an average line W2’ of the second wave average signal; step S202: smoothing the envelope signal E1 to obtain a corrected envelope signal E1’; and step S204: obtaining the first time point T1 b according to the time point when the upper edge of the waveform of the corrected envelope signal E1’ intersects with the average line W2’. In step S200, the average line W2’ is obtained by averaging the second wave average signal. In step S202, the corrected envelope signal E1’ is obtained by smoothing the envelope signal E1. In step S204, the first time point T1 b is obtained according to the time point when the upper edge of the waveform of the corrected envelope signal E1’ intersects with the average line W2’. Figure 6 ​​The average value of the second wave signal W2 is shown as a line segment. The line segment connecting the average value of each preset time segment is the average line W2'. In step S202, the envelope signal E1 can be curve-fitted by regression or interpolation. The envelope signal E1 is shown as a dashed line, and the corrected envelope signal E1' is shown as a solid line. Figure 6 The first wave signal W1 is shown. By steps S202 and S204, the motion noise and respiratory variation caused by the individual N can be reduced. Therefore, when the second wave signal W2 is detected, the upstream blood vessels are in a blocked state, which affects the blood circulation in the blood vessels in the finger, so the second wave signal W2 is less affected by motion noise and respiratory variation. Therefore, in step S204, the first time point T1b obtained from the intersection of the corrected envelope signal E1' and the average line W2' of the second wave signal W2 is the time point at which the systolic pressure occurs after the signal intensity error is corrected.

[0046] In addition, as shown in Figure 6 and Figure 7 When step S108 is performed, the first time point T1b obtained from steps S200 to S204 can obtain a more accurate systolic pressure Sb. In this variant embodiment, the second time point T2b can be obtained from the time point at which the corrected envelope signal E1' has a preset amplitude A2. Since the corrected envelope signal E1' corrects the error caused by motion noise and respiratory variation, the second time point T2b obtained from the corrected envelope signal E1' is also closer to the actual diastolic pressure time point. Therefore, the diastolic pressure Db obtained from the second time point T2b will also be more accurate.

[0047] Figures 8 to 11 Another variant embodiment of the present application is provided. In this variant embodiment, step S102: obtaining the envelope signal E1 of the first wave signal W1 further comprises steps S302: calculating the average value of each periodic wave of the first wave signal W1; step S304: subtracting the amplitude of each periodic wave from the average value corresponding to the periodic wave to obtain the first wave correction signal W1'; and step S306: connecting each peak of the first wave correction signal W1' and connecting each trough to obtain the envelope signal E2 of the first wave correction signal W1'. Figure 4 In this variant embodiment, the average value of each periodic wave (C1, C2... Cn) of the first wave signal W1 is first calculated. Then, by subtracting the calculated average value from the amplitude of each periodic wave (C1, C2... Cn), the first wave correction signal W1' is obtained. For example, the periodic wave C1 is subtracted from the average value of the periodic wave C1, the periodic wave C2 is subtracted from the average value of the periodic wave C2, and so on. Then, the envelope signal E2 of the second embodiment is obtained by connecting each peak of the first wave correction signal W1' and connecting each trough.

[0048] The operation principle of steps S302 and S304 is a high-pass filtering operation to filter out... Figure 4 The offset of the first wave signal W1 from the baseline. To be more specific, such as... Figure 2 and Figure 4 This refers to the situation where, during the first pressure application period, when the wearable pressure unit 1 continuously applies pressure P1, the upstream blood vessels in the arm N1 are compressed to a certain extent. This causes the blood vessels in the downstream finger N2 to stop receiving new arterial blood readings, and the downstream venous blood cannot return to the heart through the upstream blood vessels. Therefore, the relative downstream venous blood causes the baseline of the first wave signal W1 to drift upwards, as... Figure 4 The first wave signal W1 is shown after 20 seconds. After entering the second pressure period P2, water in the downstream venous blood gradually seeps out of the vessels. Therefore, the baseline trend of the second wave signal W2 is a gradual decrease. In addition, variations such as respiratory changes and the movement of blood vessels and tissue fluid can cause low-frequency variations, which may lead to a shift in the baseline of the first wave signal W1. Through steps S302 and S304 in this variation embodiment, the following can be obtained: Figure 9 The first corrected signal W1' is obtained by filtering out the signal baseline offset. Finally, connecting the peaks and troughs in the first corrected signal W1' yields the packet signal E2 of the second embodiment.

[0049] Furthermore, after receiving packet signal E2, actions such as... can be performed. Figure 5 The changes are described in detail in the text. For example... Figure 8 and Figure 10 As shown, the first time point T1c is obtained by curve fitting the first wave correction signal W1'. Specifically, in step S310, the average value of the second wave correction signal W2 is calculated to obtain the average line W2'. Next, in step S312, the packet signal E2 is smoothed to obtain the corrected packet signal E2'. Finally, in step S314, the first time point T1c is obtained based on the time point at which the corrected packet signal E2' intersects the average line W2'.

[0050] In the second variation, the modified envelope signal E2' is used to replace the envelope signal E1 in the first embodiment to determine the first time point T1c and the second time point T2c. In this variation, the first wave modified signal W1' reduces the error caused by the low frequency variation, and the modified envelope signal E2' further reduces the noise of the first wave modified signal W1' caused by the motion noise and the respiration variation. The average line W2' is less affected by the motion noise and the respiration variation. Therefore, the first time point T1c is more close to the actual time point of the systolic pressure by taking the intersection of the modified envelope signal E2' and the average line W2'.

[0051] In addition, in step S318, the second time point T2c is more close to the actual time point of the diastolic pressure by taking the preset amplitude A2 of the modified envelope signal E2' due to the reduced error of the motion noise, the respiration variation noise and the signal drift. As shown in FIG. 6, in the second variation, the pressure values Sc and Dc applied to the upstream blood vessel by the wearable pressure applying unit 1 at the first time point T1c and the second time point T2c are more close to the actual systolic pressure and diastolic pressure of the subject. Therefore, the steps S302 to S306 of the second embodiment improve the accuracy of the blood pressure measurement by reducing the error caused by the first wave signal drift. Figure 11

[0052] Figure 12 And Figure 13 Another variation of the blood pressure measurement method is provided. This variation uses the blood pressure measurement device D described above and can be used after the first embodiment. The blood pressure measurement method of this embodiment uses the blood pressure measurement device D as in the first embodiment and can be implemented after the first embodiment. The blood pressure measurement method of this embodiment includes: step S400: measuring a third wave signal of the blood vessel by the physiological information measurer during the non-pressure applying period of the wearable pressure applying unit, wherein the third wave signal is a continuous wave; step S402: outputting the systolic pressure Sc as a wave peak value in the third wave signal; step S404: outputting the diastolic pressure Dc as a wave trough value in the third wave signal adjacent to the wave peak in time; and step S406: calculating the wave peak values of the remaining wave peaks and the wave trough values of the remaining wave troughs in the third wave signal according to the systolic pressure Sc and the diastolic pressure Dc, respectively.

[0053] Figure 2 And Figure 13 ​It is also shown in detail in step S400 that the third wave signal W3 is obtained by the physiological information measurer 2 from the finger N2 when the wearable pressure applying unit 1 does not apply pressure to the upstream blood vessel. In step S402, the systolic pressure Sc output by the present embodiment is obtained from the second embodiment as the wave peak value of the first wave peak in the third wave signal W3. In step S404, the diastolic pressure Dc output by the present embodiment is obtained from the second embodiment as the wave trough value of the first wave trough in the third wave signal W3. Next, in step S406, the present embodiment linearly scales the vertical axis of the third wave signal W3 according to the systolic pressure Sc and the diastolic pressure Dc. Therefore, the wave peak values of the remaining wave peaks and the wave trough values of the remaining wave troughs in the third wave signal W3 can be directly calculated. Since the systolic pressure Sc and the diastolic pressure Dc are obtained from the directly measured, signal-processed blood pressure waveform, it is more accurate to calculate the remaining systolic pressures and diastolic pressures in the continuous blood pressure waveform according to the systolic pressure Sc and the diastolic pressure Dc. It should be noted that in step S402 of other embodiments, the wave peak value of any wave peak in the third wave signal W3 can be taken as the systolic pressure Sc. In step S404 of other embodiments, the wave trough value of any wave trough in the third wave signal W3 can be taken as the diastolic pressure Dc. The present application is not limited to Figure 13 the embodiments described above.

[0054] Well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of the described apparatuses. The described embodiments can be modified in various ways and all such modifications are, therefore, intended to be within the scope of the application. It should be noted that features from the embodiments and examples described can be combined with each other, as long as there is no contradiction. Therefore, it should be understood that the embodiments described herein are not intended to be exhaustive or to be limited to the precise steps or construction described. It should also be understood that additional embodiments not described can be conceived based on the subject matter disclosed herein.

Claims

1. A system for blood pressure measurement of an individual, comprising: a controller coupled to a pressure applying unit and a physiological information measurer; wherein the controller configured to gradually increase pressure applied by the pressure applying unit to a body part of the individual to compress the body part to affect blood flow of an upstream blood vessel of the body part during a first pressure applying period; wherein the physiological information measurer is configured to generate a first wave signal representing blood activity from a downstream blood vessel during the first pressure applying period and transmit the first wave signal to the controller; wherein the controller generates a packet signal using the first wave signal; wherein the controller is configured to establish a second pressure applying period by determining when the physiological information measurer fails to detect blood activity; wherein the physiological information measurer is configured to generate a second wave signal of the blood vessel using the physiological information measurer during the second pressure applying period; wherein the controller determines a first time point at which a waveform of the second wave signal intersects with a waveform of the packet signal to establish a systolic pressure value using a first pressure value applied by the pressure applying unit to the upstream blood vessel at the first time point; and wherein the controller further determines a second time point at which the packet signal has a predetermined amplitude to establish a diastolic pressure value using a second pressure value applied by the pressure applying unit to the upstream blood vessel at the second time point.

2. The system of claim 1, wherein, the first wave signal comprises a plurality of periodic waves, and generating the packet signal further comprises: calculating an average value of each of the periodic waves in the first wave signal; subtracting the average value from an amplitude of each corresponding periodic wave to obtain a first wave modified signal; and connecting each peak of the first wave modified signal and each valley of the first wave modified signal to obtain the packet signal.

3. The system of claim 1, wherein, the first wave signal comprises a plurality of periodic waves, and the controller generates the packet signal by connecting a peak value of each of the periodic waves and a valley value of each of the periodic waves.

4. The system of claim 1, wherein, the controller is further configured to: measure a third wave signal of the blood vessel by the physiological information measurer during a non-pressure applying period of the pressure applying unit, wherein the third wave signal is a continuous wave; output the systolic pressure value as a starting peak value of a peak of the third wave signal; output the diastolic pressure value as a starting valley value of a valley of the third wave signal adjacent in time to the peak; and calculate additional peak values of remaining peaks and additional valley values of remaining valleys of the third wave signal according to the systolic pressure value and the diastolic pressure value, respectively.

5. The system of claim 1, wherein, the controller is arranged to determine the first time point by: obtaining an average line of the second wave signal; smoothing the packet signal to obtain a modified packet signal; and determining a time point at which an upper edge of a waveform of the modified packet signal intersects with the average line as the first time point.

6. The system of claim 1, wherein, the controller uses a predetermined amplitude of the packet signal between 50% and 90% of a maximum amplitude of the packet signal.

7. The system of claim 1, wherein, the pressure applying unit is configured on an arm or a wrist, and the controller is arranged to cause the pressure applying unit to apply pressure during the first pressure applying period and the second pressure applying period, and the physiological information measurer is arranged to detect the first wave signal and the second wave signal from a finger.

8. A method for measuring blood pressure, comprising: detecting a first wave signal from a blood vessel during a first pressure application period of a wearable pressure application unit by a physiological information measurer, wherein, applying pressure to an upstream blood vessel of the blood vessel by a wearable pressure applying unit; generating a first envelope signal of the first wave signal according to the first wave signal; detecting a second wave signal from the blood vessel by using the physiological information measurer during a second pressure applying period of the wearable pressure applying unit; determining a first time point at which a waveform of the second wave signal intersects with a waveform of the envelope signal as the first time point; outputting a pressure value applied by the wearable pressure applying unit to the upstream blood vessel at the first time point as a systolic pressure value; determining a second time point at which the envelope signal has a preset amplitude as the second time point; and outputting a pressure value applied by the wearable pressure applying unit to the upstream blood vessel at the second time point as a diastolic pressure value.

9. The method of claim 8, wherein, the first wave signal comprises a plurality of periodic waves, and generating the envelope signal further comprises: calculating an average value of each of the periodic waves of the first wave signal; subtracting the average value from an amplitude of each corresponding periodic wave to obtain a first wave correction signal; and connecting all peaks and troughs of the first wave correction signal to obtain the envelope signal.

10. The method of claim 8, wherein, the first wave signal comprises a plurality of periodic waves, and generating the envelope signal further comprises connecting a peak of each of the periodic waves and a trough of each of the periodic waves to obtain the envelope signal.

11. The method of claim 8, wherein, determining the first time point further comprises: obtaining an average line of the second wave signal; smoothing the envelope signal to obtain a corrected envelope signal; and determining a time point at which an upper edge of a waveform of the corrected envelope signal intersects with the average line as the first time point.

12. The method of claim 8, wherein, the preset amplitude is a maximum amplitude of the envelope signal between 50% and 90%.

13. The method of claim 8, wherein, the wearable pressure applying unit applies pressure to an arm or a wrist during the first pressure applying period and the second pressure applying period, and the physiological information measurer detects the first wave signal and the second wave signal from a finger.

14. The method according to claim 8, further comprising: measuring a third wave signal of the blood vessel by the physiological information measurer during a non-pressure applying period of the wearable pressure applying unit, wherein the third wave signal is a continuous wave; outputting the systolic pressure value as a peak value of a peak in the third wave signal; outputting the diastolic pressure value as a trough value of a trough in the third wave signal adjacent in time to the peak; and calculating peak values of remaining peaks and trough values of remaining troughs in the third wave signal according to the systolic pressure value and the diastolic pressure value, respectively.

15. A blood pressure measuring apparatus, comprising: a wearable pressure applying unit; a physiological information measurer; and a control unit signal connected to the wearable pressure applying unit and the physiological information measurer, the control unit being configured to perform the method according to any one of claims 8 to 13. the wearable pressure applying unit is a sphygmomanometer.

16. The apparatus of claim 15, wherein, 17. A blood pressure measuring apparatus, comprising: a wearable pressure applying unit; a physiological information measurer; and a control unit signal connected to the wearable pressure applying unit and the physiological information measurer, the control unit being configured to perform the method according to claim 14. ​ ​ 18. The apparatus of claim 17, wherein, The physiological information measuring device is a finger clip device having a pressure sensor for detecting the first wave signal, the second wave signal and the third wave signal.

19. The apparatus of claim 17, wherein, The physiological information measuring device is a finger clip device having an optical sensor for detecting the first wave signal, the second wave signal and the third wave signal.

20. A system for measuring blood pressure of a person, used with a physiological information measuring device and a pressure applying unit, comprising: a controller in electronic communication with the pressure applying unit and the physiological information measuring device; wherein the controller is configured to gradually increase the pressure applied by the pressure applying unit on a body part of the person during a first pressure applying period to affect blood flow in an upstream blood vessel of the body part; wherein the physiological information measuring device is configured to generate a first wave signal representing blood activity of a downstream blood vessel during the first pressure applying period and transmit the first wave signal to the controller; wherein the controller is configured to generate an envelope signal using the first wave signal; wherein the controller is configured to establish a second pressure applying period by determining when the physiological information measuring device fails to detect blood activity; wherein the physiological information measuring device is configured to detect a second wave signal of the blood vessel using the physiological information measuring device during the second pressure applying period; wherein the controller determines a first time point at which a waveform of the second wave signal intersects with a waveform of the envelope signal to establish a systolic pressure value using a first pressure value applied by the pressure applying unit on the upstream blood vessel at the first time point; wherein the controller further determines a second time point at which the envelope signal has a predetermined amplitude to establish a diastolic pressure value using a second pressure value applied by the pressure applying unit on the upstream blood vessel at the second time point.

Images