VENOUS PRESSURE MEASURING DEVICE, VENOUS PRESSURE MEASURING METHOD, AND VENOUS PRESSURE MEASURING PROGRAM

Abstract

To provide a device, method, and program for measuring a venous pressure capable of calculating a value range of a venous pressure.SOLUTION: A venous pressure measurement device 160 includes: an obtaining unit for obtaining pulse wave information on the pulse wave of a subject measured by a cuff 111; and a processing unit for calculating a value range of the venous pressure of the subject on the basis of the pulse wave information obtained by the obtaining unit when the venous pressure of the subject cannot be estimated from the pulse wave information obtained by the obtaining unit.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a venous pressure measuring device, a venous pressure measuring method, and a venous pressure measuring program. [Background technology]

[0002] In recent years, the number of patients with heart disease, including heart failure, has been increasing, and heart disease is one of the leading causes of death. As the elderly population increases, a significant increase in elderly heart failure patients (the so-called heart failure pandemic) is expected, and the number of heart failure patients is expected to reach 1.3 million by 2030.

[0003] In addition to the increase in the number of patients, the high re-hospitalization rate for heart failure has become a social issue, leading to pressure on medical costs. This problem is occurring not only in Japan, but also in other countries such as the United States.

[0004] One of the reasons for re-admission of patients with heart failure is the worsening of congestion. Since venous pressure can be an indicator of the state of systemic congestion, development of devices and methods for measuring venous pressure is underway (for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2012-205822 A Summary of the Invention [Problem to be solved by the invention]

[0006] In such measurements of venous pressure, even if it is not possible to uniquely determine the value of venous pressure, if information on the range of values ​​that can be estimated as venous pressure, i.e., the range of values ​​of venous pressure, can be obtained, this can be useful information for determining conditions such as systemic congestion.

[0007] Therefore, an object of the present invention is to provide a venous pressure measuring device, a venous pressure measuring method, and a venous pressure measuring program that are capable of calculating the value range of venous pressure. [Means for solving the problem]

[0008] The above-mentioned object of the present invention is achieved by the following means.

[0009] The venous pressure measuring device of the present invention includes an acquisition unit that acquires pulse wave information regarding the subject's pulse wave measured by a sensor, and a processing unit that calculates the range of the subject's venous pressure based on the pulse wave information acquired by the acquisition unit when the subject's venous pressure cannot be estimated from the pulse wave information acquired by the acquisition unit.

[0010] A venous pressure measuring method according to the present invention includes acquiring pulse wave information relating to a subject's pulse wave measured by a sensor, and, when the subject's venous pressure cannot be estimated from the acquired pulse wave information, calculating a value range of the subject's venous pressure based on the acquired pulse wave information.

[0011] A venous pressure measuring program according to the present invention is for causing a computer to execute the venous pressure measuring method according to the present invention. Effect of the Invention

[0012] In the venous pressure measurement device, the venous pressure measurement method, and the venous pressure measurement program according to the present invention, when the venous pressure of the subject cannot be estimated, the range of the venous pressure of the subject is calculated based on the pulse wave information, thereby making it possible to calculate the range of the venous pressure. [Brief description of the drawings]

[0013] [Figure 1] 1 is a diagram illustrating an example of the overall configuration of a venous pressure measurement system according to an embodiment of the present invention. [Diagram 2] 2 is a block diagram illustrating an example of the configuration of the venous pressure measuring device shown in FIG. 1. [Diagram 3]3 is a block diagram illustrating an example of the functions of a CPU illustrated in FIG. 2. [Figure 4] 1. FIG. 4(A) shows an example of pressure information acquired by the venous pressure measuring device 160 shown in FIG. 1, and FIG. 4(B) shows an example of pulse wave information. [Diagram 5] 1. (A) is a diagram showing another example of pressure information acquired by the venous pressure measuring device 160 shown in FIG. 1, and (B) is a diagram showing another example of pulse wave information. [Figure 6] 1. (A) is a diagram showing another example of pressure information acquired by the venous pressure measuring device 160 shown in FIG. 1, and (B) is a diagram showing another example of pulse wave information. [Figure 7] 1. (A) is a diagram showing another example of pressure information acquired by the venous pressure measuring device 160 shown in FIG. 1, and (B) is a diagram showing another example of pulse wave information. [Figure 8] 1. (A) is a diagram showing another example of pressure information acquired by the venous pressure measuring device 160 shown in FIG. 1, and (B) is a diagram showing another example of pulse wave information. [Figure 9] 1. (A) is a diagram showing another example of pressure information acquired by the venous pressure measuring device 160 shown in FIG. 1, and (B) is a diagram showing another example of pulse wave information. [Figure 10] 1. (A) is a diagram showing another example of pressure information acquired by the venous pressure measuring device 160 shown in FIG. 1, and (B) is a diagram showing another example of pulse wave information. [Figure 11] 2 is a flowchart showing an example of a process of the venous pressure measuring device shown in FIG. 1. [Figure 12] 13 is a flowchart showing another example of the process of the venous pressure measuring device shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, a venous pressure measuring device according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the same reference numerals are used for the same components in the drawings. Also, the dimensional ratios in the drawings are exaggerated for the convenience of explanation and may differ from the actual ratios.

[0015] <Embodiment> (Configuration of venous pressure measurement system) Fig. 1 is a block diagram showing a schematic hardware configuration of a venous pressure testing system 100 according to this embodiment. Fig. 2 is a block diagram showing a schematic hardware configuration of a control unit 170.

[0016] The venous pressure testing system 100 is a system for uniquely estimating the venous pressure of a subject or calculating a range of values ​​of the venous pressure. The venous pressure is an index that reflects the pressure measured in the right atrium (right atrial pressure), and reflects the volume of blood returning to the heart and the preload of the right atrium.

[0017] As shown in FIG. 1, the venous pressure inspection system 100 includes a cuff 111 and a venous pressure measuring device 160. The cuff 111 is configured to be connectable to the venous pressure measuring device 160. The venous pressure measuring device 160 includes a pressure pump 112, an exhaust valve 113, a pressure sensor 114, a cuff pressure detection unit 115, an AD converter (ADC) 116, an input device 120, an output device 130, a network interface 140, and a control unit 150. The venous pressure inspection system 100 utilizes the principle of the oscillometric method. Specifically, when the pressure applied to the upper arm or the like of the subject by the cuff 111 is the same as the venous pressure of the subject, the amplitude of the waveform of the pulse wave detected by the pressure sensor 114 becomes maximum.

[0018] The cuff 111, the pressure pump 112, the exhaust valve 113, the pressure sensor 114, the cuff pressure detection unit 115, and the ADC 116 are an example of a configuration for performing sensing processing to measure the venous wave of the subject, and constitute a sensor.

[0019] Cuff 111 is an air bag that is wrapped around the subject's upper arm. Pressurizing pump 112 sends air into cuff 111 in response to instructions from control unit 150, increasing the pressure inside the air bag (hereinafter referred to as "internal cuff pressure"). This can increase the compression pressure (hereinafter referred to as "cuff pressure") applied to the subject's upper arm by cuff 111. Exhaust valve 113 releases the air inside the air bag to the atmosphere, gradually exhausting air from cuff 111 and reducing the internal cuff pressure. This can reduce the cuff pressure.

[0020] The pressure sensor 114 detects the intra-cuff pressure. The subject's pulse wave (hereinafter referred to as "cuff pulse wave") is superimposed on the intra-cuff pressure during the process of increasing and decreasing the cuff pressure. The cuff pulse wave may be a waveform in which the subject's venous wave and arterial wave are superimposed. The cuff pressure detection unit 115 extracts the cuff pulse wave superimposed on the intra-cuff pressure from the detected intra-cuff pressure, and outputs the intra-cuff pressure and the extracted cuff pulse wave as analog signals to the ADC 116. The ADC 116 converts the analog signals of the intra-cuff pressure and the cuff pulse wave into digital signals and transmits them to the control unit 150. Note that the pressure sensor 114, the cuff pressure detection unit 115, and the ADC 116 may be integrated with the cuff 111. Alternatively, the pressure sensor 114 and the cuff pressure detection unit 115 may be integrated with the cuff 111, and the ADC 116 may be in the venous pressure measurement device 160.

[0021] The input device 120 accepts an input operation of a user operating the venous pressure measuring device 160, and generates an input signal corresponding to the input operation. The input device 120 includes, for example, a touch panel arranged overlaid on the display 131 of the output device 130, operation buttons attached to the housing of the venous pressure measuring device 160, a mouse, a keyboard, or the like. The input signal generated by the input device 120 is transmitted to the control unit 150. The control unit 150 executes a predetermined process in response to the input signal.

[0022] The output device 130 outputs the estimation result of the venous pressure of the subject or the calculation result of the range of the venous pressure. The output device 130 includes a display 131 and a speaker 132. The display 131 may be a liquid crystal display, an organic EL display, or the like attached to the housing of the venous pressure measuring device 160. The display 131 may be a display device such as a transmissive or non-transmissive head-mounted display worn on the head of a user.

[0023] The speaker 132 is attached to the housing of the venous pressure measurement device 160 and can output the estimation result of the venous pressure or the calculation result of the range of the venous pressure by voice.

[0024] The output device 130 is not limited to the display 131 and the speaker 132, and may be, for example, a printer for printing and outputting the estimation result of the venous pressure or the calculation result of the range of the venous pressure.

[0025] The network interface 140 is configured to connect the control unit 150 to a communication network. Specifically, the network interface 140 includes processing circuits for various interfaces for communicating with external devices via the communication network, and is configured to conform to communication standards for communicating via the communication network. The communication network may be a local area network (LAN), a wide area network (WAN), the Internet, or the like. The network interface 140 may be a wireless communication interface such as Bluetooth (registered trademark) and near field communication (NFC).

[0026] The control unit 150 estimates the venous pressure of the subject or calculates the range of the venous pressure of the subject. The control unit 150 may be software and hardware that mainly controls the venous pressure measuring device 160, or the control unit 150 may be an independent device. For example, the control unit 150 may be a medical device dedicated to testing the venous pressure, or may be a personal computer, smartphone, tablet terminal, or the like in which a program for testing the venous pressure is installed. Furthermore, the control unit 150 may be a wearable device or the like that is attached to the body (e.g., the upper arm, etc.) of the subject.

[0027] The functions of the control unit 150 will be described in detail later.

[0028] As shown in FIG. 2, the control unit 150 includes a CPU (Central Processing Unit) 151, a memory 152, an auxiliary storage unit 153, and an input / output interface 154.

[0029] The memory 152 may include a ROM (Read Only Memory) and a RAM (Random Access Memory). The ROM stores various programs, various parameters, and the like. The RAM also includes a work area in which the various programs executed by the CPU 151 are stored. The CPU 151 is configured to load a specified program from the various programs stored in the ROM or auxiliary storage unit 153 onto the RAM, and to execute various processes by cooperating with the RAM.

[0030] The auxiliary storage unit 153 may include a storage device (storage) such as a hard disk drive (HDD), a solid state drive (SSD), or a USB flash memory. The auxiliary storage unit 153 stores various programs and various data. The auxiliary storage unit 153 also saves the estimation result of the venous pressure or the calculation result of the range of the venous pressure.

[0031] The input / output interface 154 functions as an interface between the CPU 151 and the input device 120 and output device 130. The input / output interface 154 has various communication modules for communicating with input devices such as a mouse and a keyboard, a drive module for driving the display 131 and the speaker 132, and the like.

[0032] When the CPU 151 executes the program, the control unit 150 controls each unit of the venous pressure testing system 100 and realizes various functions.

[0033] 3 is a block diagram showing functions of the control unit 150. The control unit 150 functions as, for example, an acquisition unit 511, a first determination unit 512, an estimation unit 513, a second determination unit 514, a calculation unit 515, and an output unit 516. Here, the first determination unit 512, the estimation unit 513, the second determination unit 514, and the calculation unit 515 correspond to a specific example of a "processing unit" of the present invention.

[0034] The acquiring unit 511 acquires pulse wave information related to the subject's cuff pulse wave. The pulse wave information is, for example, the waveform of the cuff pulse wave acquired from the cuff pressure detecting unit 115 via the ADC 116. The acquiring unit 511 further acquires pressure information related to the cuff pressure. The pressure information is, for example, the value of the cuff pressure at each time.

[0035] The first determination unit 512 determines whether the venous pressure of the subject can be estimated from the pulse wave information acquired by the acquisition unit 511. For example, the first determination unit 512 determines that the venous pressure of the subject cannot be estimated when it determines that the pulse wave information does not contain a candidate component that can be estimated as the venous wave of the subject (for example, candidate component C in FIG. 4(B) described below). Whether or not the pulse wave information contains a candidate component is determined based on, for example, a change in the amplitude of the waveform of the cuff pulse wave.

[0036] Fig. 4(A) shows an example of pressure information acquired by acquisition unit 511, and Fig. 4(B) shows pulse wave information corresponding to the pressure information shown in Fig. 4(A). Specifically, Fig. 4(A) shows the change in the cuff pressure value over time, and Fig. 4(B) shows the waveform of the cuff pulse wave corresponding to the cuff pressure in Fig. 4(A).

[0037] Here, a method for the venous pressure testing system 100 to uniquely estimate the venous pressure of the subject will be described.

[0038] As the cuff pressure decreases stepwise, the arterial pulse wave component superimposed on the cuff pressure decreases, while the venous pulse wave component gradually increases. As the cuff pressure decreases further, the venous pulse wave component increases further. When the cuff pressure becomes equal to the blood pressure acting on the vascular wall of the vein in the patient's upper arm, the amplitude of the cuff pulse wave waveform becomes maximum. Therefore, the venous pressure testing system 100 estimates the cuff pressure (e.g., Pv in FIG. 4A) at the point when the amplitude of the cuff pulse wave waveform changes in a predetermined way, for example, at the point when the amplitude of the cuff pulse wave waveform becomes maximum, to be the venous pressure of the subject.

[0039] In the examples shown in Figures 4(A) and 4(B), as the cuff pressure is gradually reduced from the subject's diastolic arterial pressure (Figure 4(A)), the amplitude of the cuff pulse wave gradually decreases and then gradually increases again, and the period T V After reaching a maximum at , it gradually decreases (Fig. 4(B)). That is, during the period T V At this time, for example, the first judgment unit 512 detects a period T V Since the candidate component C is included and no noise component affected by external disturbance is included, it is determined that the venous pressure of the subject can be uniquely estimated.

[0040] Fig. 5(A) shows another example of pressure information acquired by the acquisition unit 511, and Fig. 5(B) shows pulse wave information corresponding to the pressure information shown in Fig. 5(A). At this time, as the cuff pressure is gradually reduced from the subject's arterial blood pressure diastolic pressure (Fig. 5(A)), the amplitude of the waveform of the cuff pulse wave continues to decrease. That is, the trend of the amplitude change in this cuff pulse wave waveform has not changed. At this time, for example, the first judgment unit 512 judges that the pulse wave information does not include a candidate component that can be estimated as the subject's venous wave, and the subject's venous pressure cannot be estimated.

[0041] The first determination unit 512 determines that the subject's venous pressure cannot be estimated when the pulse wave information contains noise components influenced by disturbance under a predetermined condition. When the noise components are included, the noise components overlap with components derived from the subject's pulse wave, making it impossible to obtain accurate information on the subject's pulse wave. Even if the pulse wave information contains noise components, the first determination unit 512 may determine that the subject's venous pressure can be estimated when the effect on venous pressure measurement is small. For example, the first determination unit 512 determines that the subject's venous pressure cannot be estimated when the pulse wave information contains noise components of a predetermined magnitude or more, a predetermined number or more, or a predetermined period or more. The first determination unit 512 may determine that the subject's venous pressure can be estimated depending on the position of the noise components included in the pulse wave information (for example, the cuff pressure at which the noise components appear), the length of the period, the number and the magnitude, etc.

[0042] The first determination unit 512 may determine whether the pulse wave information includes a noise component that satisfies a predetermined condition by, for example, performing frequency analysis. Alternatively, the first determination unit 512 may determine whether the pulse wave information includes a noise component that satisfies a predetermined condition based on the rate of change or the magnitude of the amplitude of the waveform of the cuff pulse wave. For example, the first determination unit 512 may determine that the pulse wave information includes a noise component that satisfies a predetermined condition when there is a sudden change in amplitude compared to the waveform of the previous beat, or may determine that the pulse wave information includes a noise component that satisfies a predetermined condition when an amplitude of a predetermined amplitude or greater is included. The first determination unit 512 may determine whether the pulse wave information includes a noise component that satisfies a predetermined condition based on information acquired from an external sensor. For example, an acceleration sensor or the like may be used as the external sensor. The first determination unit 512 may determine whether the pulse wave information includes a noise component that satisfies a predetermined condition using a machine learning model.

[0043] Figures 6(A), 7(A), 8(A), 9(A) and 10(A) show other examples of pressure information acquired by acquisition unit 511, and Figures 6(B), 7(B), 8(B), 9(B) and 10(B) show pulse wave information corresponding to the pressure information shown in Figures 6(A), 7(A), 8(A), 9(A) and 10(A), respectively.

[0044] When the acquisition unit 511 acquires the pressure information and pulse wave information shown in Figures 6(A) and (B), the first judgment unit 512 judges that the subject's venous pressure cannot be estimated, for example, because the pulse wave information contains noise components N1 and N2 as well as candidate component C.

[0045] When the acquisition unit 511 acquires the pressure information and pulse wave information shown in Figures 7(A) and (B), the first judgment unit 512 judges that the subject's venous pressure cannot be estimated because the pulse wave information contains a noise component N for a period Tn.

[0046] When the acquisition unit 511 acquires the pressure information and pulse wave information shown in Figures 8(A) and (B), the first judgment unit 512 judges that the subject's venous pressure cannot be estimated, for example, because the pulse wave information contains a noise component N.

[0047] When the acquisition unit 511 acquires the pressure information and pulse wave information shown in Figures 9(A) and (B), the first judgment unit 512 judges that the subject's venous pressure cannot be estimated, for example, because the pulse wave information contains a noise component N.

[0048] When the acquisition unit 511 acquires the pressure information and pulse wave information shown in Figures 10(A) and (B), the first judgment unit 512 judges that the subject's venous pressure cannot be estimated, for example, because the pulse wave information contains a noise component N as well as a candidate component C.

[0049] When the first determination unit 512 determines that the venous pressure of the subject can be estimated, the estimation unit 513 estimates the venous pressure of the subject based on the pulse wave information acquired by the acquisition unit 511. Specifically, the estimation unit 513 estimates the cuff pressure when the amplitude of the waveform of the cuff pulse wave is maximum as the venous pressure of the subject.

[0050] For example, when the acquisition unit 511 acquires the pressure information and pulse wave information shown in FIGS. 4(A) and 4(B), the estimation unit 513 estimates the cuff pressure Pv during the period Tv as the venous pressure of the subject.

[0051] When the first judgment unit 512 judges that the venous pressure of the subject cannot be estimated, the second judgment unit 514 judges whether the range of the venous pressure of the subject can be calculated based on the pulse wave information acquired by the acquisition unit 511. The second judgment unit 514 judges whether the range of the venous pressure of the subject can be calculated based on at least one of the position of the noise components included in the pulse wave information (for example, the cuff pressure at which the noise components appear), the length of the period, the number, and the size. For example, when the number or the size of the noise components exceeds a predetermined value, the second judgment unit 514 judges that the range of the venous pressure cannot be calculated, and when the number or the size of the noise components is equal to or smaller than the predetermined value, the second judgment unit 514 judges that the range of the venous pressure can be calculated. The second judgment unit 514 may make a judgment based on requirements other than the position, the length of the period, the number, or the size of the noise components, or may make a judgment based on components other than the noise components.

[0052] When the first judgment unit 512 judges that the venous pressure of the subject cannot be estimated and the second judgment unit 514 judges that the range of the venous pressure of the subject can be calculated, the calculation unit 515 calculates the range of the venous pressure of the subject based on the pulse wave information acquired by the acquisition unit 511. When the first judgment unit 512 judges that the venous pressure of the subject cannot be estimated and the second judgment unit 514 judges that the range of the venous pressure of the subject cannot be calculated, the calculation unit 515 does not calculate the range of the venous pressure of the subject.

[0053] For example, when the acquisition unit 511 acquires the pressure information and pulse wave information shown in Fig. 5 (A) (B), as described above, the first judgment unit 512 judges that the pulse wave information does not include candidate components and the subject's venous pressure cannot be estimated. On the other hand, the second judgment unit 514 judges that the pulse wave information does not include noise components of a predetermined condition and therefore the range of the subject's venous pressure can be calculated. At this time, the calculation unit 515 calculates, for example, the outside of the range of the measured cuff pressure as the range of the subject's venous pressure. Specifically, in Fig. 5 (A) (B), the cuff pressure decreases from the arterial blood pressure diastolic pressure to 3 mmHg, and the calculation unit 515 calculates that the range of the subject's venous pressure is 3 mmHg or less.

[0054] For example, when the acquisition unit 511 acquires the pressure information and pulse wave information shown in Fig. 6 (A) (B), as described above, the first judgment unit 512 judges that the subject's venous pressure cannot be estimated because the pulse wave information contains the noise components N1 and N2 as well as the candidate component C. The candidate component C is detected when the cuff pressure is P1, and the noise components N1 and N2 are detected when the cuff pressure is smaller than P1. On the other hand, the second judgment unit 514 judges that the range of the subject's venous pressure can be calculated based on the positions, period lengths, numbers, sizes, etc. of the noise components N1 and N2. At this time, the calculation unit 515 calculates the range of the subject's venous pressure using, for example, the pulse wave information and pressure information in a range including the candidate component C and the noise components N1 and N2. Specifically, the calculation unit 515 calculates that the range of the subject's venous pressure is equal to or less than P1.

[0055] When the acquisition unit 511 acquires the pressure information and pulse wave information shown in Fig. 7(A)(B), as described above, the first judgment unit 512 judges that the subject's venous pressure cannot be estimated because the pulse wave information contains the noise component N for the period Tn. The noise component N is detected when the cuff pressure is P3. On the other hand, the second judgment unit 514 judges that the range of the subject's venous pressure can be calculated based on the position, length, number, and size of the noise component N. In Fig. 7(B), the amplitude of the waveform immediately after the period Tn is larger than the amplitude of the waveform immediately before the period Tn. At this time, the calculation unit 515, for example, infers that the waveform of the cuff pulse wave for the period Tn contains the candidate component C together with the noise component N based on the change in amplitude before and after this period Tn, and calculates the range of the subject's venous pressure. Specifically, the calculation unit 515 calculates that the range of the subject's venous pressure is P3 or more. Alternatively, the calculation unit 515 may calculate that the range of the subject's venous pressure is equal to or higher than P3 and equal to or lower than P2, using the cuff pressure P2 immediately before the period Tn.

[0056] 8(A)(B), the first determination unit 512 determines that the subject's venous pressure cannot be estimated because the pulse wave information contains noise components N, as described above. On the other hand, the second determination unit 514 determines that the range of the subject's venous pressure can be calculated based on the position, period length, number, size, etc. of the noise components N. At this time, the calculation unit 515 calculates, for example, a value outside the range of the measured cuff pressure as the range of the subject's venous pressure.

[0057] When the acquisition unit 511 acquires the pressure information and pulse wave information shown in Fig. 9(A)(B) and Fig. 10(A)(B), as described above, the first judgment unit 512 judges that the subject's venous pressure cannot be estimated because the pulse wave information contains a noise component N. The second judgment unit 514 judges that the range of the subject's venous pressure cannot be calculated based on the position, period length, number, size, etc. of the noise component N (Fig. 9(A)(B)). In Fig. 10(A)(B), the pulse wave information contains the candidate component C along with the noise component N, but the waveform is unstable, so the second judgment unit 514 judges that the range of the subject's venous pressure cannot be calculated.

[0058] The output unit 516 outputs, for example, information on the estimation result by the estimation unit 513, information on the calculation result by the calculation unit 515, or information on an error result indicating that the subject's venous pressure and its range cannot be estimated, by sending it to the output device 60. The output device 60 displays, for example, the subject's venous pressure estimated by the estimation unit 513, or the range of the subject's venous pressure calculated by the calculation unit 515. The output device 60 may display the high or low of the subject's venous pressure relative to a predetermined value. An alarm display or an alarm sound may be output when the estimated subject's venous pressure is higher or lower than the predetermined value. The output device 60 may display an error result indicating that the subject's venous pressure cannot be estimated and its range cannot be calculated, for example, an error display or an error sound may be output.

[0059] (Processing (measurement) method of venous pressure measuring device) FIG. 11 is a flowchart showing an example of the processing by the venous pressure measuring device 160, in other words, a method for measuring venous pressure by the venous pressure measuring device 160.

[0060] First, the venous pressure measuring device 160 acquires pulse wave information and pressure information (step S101). The pulse wave information is acquired, for example, as follows.

[0061] First, cuff 111 is attached to the upper arm of the subject, and cuff pressure is increased by pressure pump 112. Next, cuff pressure is reduced to a pressure equal to or lower than the diastolic blood pressure of the subject (for example, about 40 mmHg to 50 mmHg) by using exhaust valve 113, and then reduced stepwise by a predetermined reduced pressure width (for example, 5 mmHg) every certain time. At this time, information on the cuff pulse wave detected by cuff pressure detection unit 115 is acquired by venous pressure measurement device 160 as pulse wave information.

[0062] After acquiring the pressure information and pulse wave information, the venous pressure measuring device 160 determines whether or not the venous pressure of the subject can be estimated (step S102). Specifically, the determination is made based on the presence or absence of noise components (e.g., noise components N1 and N2 in FIG. 6B) and candidate components (e.g., candidate component C in FIG. 6B) in the pulse wave information.

[0063] When the pulse wave information does not contain a noise component that satisfies a predetermined condition and contains a candidate component, the venous pressure measuring device 160 determines that the venous pressure of the subject can be estimated (step S102: YES). At this time, the venous pressure measuring device 160 estimates the venous pressure of the subject (step S103), outputs information on the estimation result (step S104), and ends the process. Whether or not the pulse wave information contains a noise component that satisfies a predetermined condition is determined by, for example, determining whether the noise component has a large influence on the pulse wave information by determining whether the magnitude of the noise component exceeds a threshold, whether the duration of the noise component exceeds a predetermined number of seconds, or whether the noise component is detected many times within a predetermined time.

[0064] On the other hand, when the venous pressure measuring device 160 determines that the pulse wave information contains noise components that meet a predetermined condition or does not contain a candidate component, it determines that the venous pressure of the subject cannot be estimated (step S102: NO). At this time, the venous pressure measuring device 160 determines whether or not the range of the venous pressure of the subject can be calculated (step S105). The venous pressure measuring device 160 makes this determination based on, for example, the position, period length, number, and size of the noise components.

[0065] The venous pressure measuring device 160 determines that the range of the venous pressure of the subject can be calculated (step S105: YES) when, for example, the pulse wave information does not include noise components and candidate components that satisfy a predetermined condition (for example, FIG. 5(A)(B)). The venous pressure measuring device 160 may determine that the range of the venous pressure of the subject can be calculated when, for example, the pulse wave information includes noise components that satisfy a predetermined condition and does not include the candidate components (for example, FIG. 8(A)(B)). The venous pressure measuring device 160 may also determine that the range of the venous pressure of the subject can be calculated when the pulse wave information includes noise components and candidate components that satisfy a predetermined condition (for example, FIG. 5(A)(B)). Whether or not the pulse wave information includes noise components that satisfy a predetermined condition is determined by determining whether or not the noise components have a large influence on the pulse wave information, similarly to step S102.

[0066] When it is determined in step S105 that the range of the venous pressure can be calculated, the venous pressure measuring device 160 calculates the range of the venous pressure (step S106), outputs information on the calculation result (step S107), and ends the process.

[0067] On the other hand, when it is determined in step S105 that the range of the venous pressure cannot be calculated (step S105: NO), the venous pressure measuring device 160 outputs information about the error result (step S108) and ends the process. The venous pressure measuring device 160 may determine that the range of the venous pressure of the subject cannot be calculated, for example, when the pulse wave information contains a noise component that satisfies a predetermined condition and does not contain the candidate component (for example, FIG. 9(A)(B)). Whether or not the pulse wave information contains a noise component that satisfies a predetermined condition is determined by determining whether or not the noise component has a large influence on the pulse wave information, as in step S102. Furthermore, the venous pressure measuring device 160 may determine that the range of the venous pressure of the subject cannot be calculated, when the pulse wave information contains a noise component and a candidate component that satisfies a predetermined condition but the waveform is not stable (for example, FIG. 10(A)(B)).

[0068] The steps of the venous pressure measurement method shown in Fig. 11 may be performed in a different order, or multiple steps may be performed simultaneously. For example, step S102 and step S105 may be performed simultaneously. In addition, it is also possible to first determine whether or not an error result should be output, taking into account the magnitude of noise, etc.

[0069] 12 is a flowchart showing another example of the venous pressure measuring method by the venous pressure measuring device 160. In this case, the venous pressure measuring device 160 has, for example, a third determination unit that determines the output form, instead of the first determination unit 512 and the second determination unit 514.

[0070] The venous pressure measuring device 160 first acquires pulse wave information and pressure information (step S201) in the same manner as described in step S101 of FIG. 11 above, and then determines the output form (step S202). Specifically, in step S202, the venous pressure measuring device 160 analyzes the noise components and candidate components of the pulse wave information acquired in step S201 to determine whether to output an estimation result that is a unique value, a calculation result of the value range of the venous pressure, or an error result. The venous pressure measuring device 160 determines the output form, for example, in the same manner as described in steps S102 and S105 of FIG. 11 above.

[0071] When it is determined in step S202 that the estimation result is to be output (step S202: estimation result), the venous pressure measuring device 160 estimates a unique value of the venous pressure based on the pulse wave information and pressure information acquired in step 201 (step S203). Thereafter, the venous pressure measuring device 160 outputs information related to the estimation result (step S204) and ends the process.

[0072] On the other hand, when it is determined in step S202 that the calculation result is to be output (step S202: calculation result), the venous pressure measuring device 160 calculates the range of the venous pressure based on the pulse wave information and pressure information acquired in step 201 (step S205). Thereafter, the venous pressure measuring device 160 outputs information related to the estimation result (step S206) and ends the process.

[0073] Moreover, when it is determined in step S202 that an error result is to be output (step S202: error result), the venous pressure measuring device 160 outputs information related to the error result (step S207) and ends the process.

[0074] (Effects of the venous pressure measuring device and venous pressure testing system) In the venous pressure measuring device 160 and the venous pressure testing system 100 of this embodiment, when the venous pressure of the subject cannot be estimated due to the influence of noise or the like, the range of the venous pressure of the subject is calculated based on the pulse wave information. This increases, for example, clinically useful information, which can be useful for medical treatment by doctors. The effect of this will be described below.

[0075] Information on venous pressure such as central venous pressure can be an index of the state of systemic congestion, and can be measured non-invasively and quantitatively by using a cuff or the like. However, when measuring the venous pressure of a patient in a congested state using a cuff or the like, there is a risk that a signal derived from the venous pulse wave cannot be accurately obtained. This is because the respiratory state of a patient in a congested state is easily unstable, and the signal derived from the venous pulse wave is affected by this respiration. In addition, patients with heart failure are likely to suffer from arrhythmia, but when a method using a cuff or the like is used, there is a risk that a signal derived from the venous pulse wave cannot be accurately obtained even when a patient with heart failure develops arrhythmia. Furthermore, it is difficult for a patient who is in a state of difficulty in breathing to keep his or her body still for a certain period of time, and noise due to body movement is likely to occur.

[0076] In this way, the venous pressure measuring device 160 and the venous pressure measuring system 10 calculate the range of venous pressure even when noise, etc. occurs due to the subject's breathing, arrhythmia, etc. For example, when the venous pressure measuring device 160 calculates the venous pressure of the subject to be 10 mmHg or more or 10 mmHg or less based on the pulse wave information and outputs information on the range of the venous pressure, a doctor or the like can effectively use it to diagnose the congestive state of the subject.

[0077] Furthermore, in the venous pressure measurement device 160 and the venous pressure measurement system 10, a determination is made as to whether the range of values ​​of the venous pressure can be calculated, so that the reliability of the range of values ​​of the venous pressure can be maintained.

[0078] As described above, in the venous pressure measurement device 160 and the venous pressure measurement system 10 of the present embodiment, when the venous pressure of the subject cannot be estimated, the range of the venous pressure of the subject is calculated based on the pulse wave information. Therefore, it becomes possible to calculate the range of the venous pressure.

[0079] Furthermore, in the venous pressure measurement system 10, the cuff 111 is used to obtain pulse wave information regarding the subject's pulse wave, so that it is possible to measure the venous pressure of the subject non-invasively.

[0080] As described above, the venous pressure measuring device, the venous pressure measuring method, and the venous pressure measuring program of the present invention have been described in the embodiments. However, it goes without saying that those skilled in the art can appropriately add to, modify, and omit the present invention within the scope of the technical concept thereof.

[0081] For example, in the above embodiment, the pulse wave is measured by reducing the cuff pressure, but the pulse wave may be measured by increasing the cuff pressure.

[0082] In the above embodiment, the example of acquiring pulse wave information using cuff 111 has been described, but the pulse wave information may be acquired using other sensors. For example, the pulse wave information may be acquired using a photoelectric volume pulse wave sensor or the like.

[0083] Alternatively, the venous pressure may be calculated based on pulse wave information measured non-invasively by another system and acquired from a server (computer) on a communication network via a network interface. Alternatively, the venous pressure may be estimated by placing a sensor with a built-in light source and photodetector on the neck of the subject and performing a calculation using NIRS (near-infrared spectroscopy) on the optical signal acquired by the sensor.

[0084] To improve the accuracy of the pulse wave measurement, a plurality of sensors may be used to measure the pulse wave. For example, two cuffs 111 may be used, or the cuff 111 may be used in combination with the photoelectric pulse wave sensor 70. Also, the device may be configured to further include electrodes and an electrocardiogram measuring device to take into account the pulse wave obtained by the electrocardiogram.

[0085] In the above embodiment, an example has been described in which it is determined whether the venous pressure of the subject can be estimated based on the presence or absence of noise components and candidate components, but it may be determined using other methods whether the venous pressure of the subject can be estimated. For example, it may be determined using a machine learning model whether the venous pressure of the subject can be estimated.

[0086] In the above embodiment, the functions of the control unit 150 have been described as being divided into the acquisition unit 511, the first determination unit 512, the estimation unit 513, the second determination unit 514, the calculation unit 515, and the output unit 516, but some or all of these may be integrated. For example, the first determination unit 512, the estimation unit 513, the second determination unit 514, and the calculation unit 515 may be integrated, and the first determination unit 512 and the second determination unit 514 may be integrated.

[0087] In addition, the means and methods for performing various processes in the venous pressure measuring device 160 according to the above-described embodiment can be realized by either a dedicated hardware circuit or a programmed computer. The above-mentioned program may be provided by a computer-readable recording medium such as a CD-ROM (Compact Disc Read Only Memory), or may be provided online via a network such as the Internet. In this case, the program recorded in the computer-readable recording medium is usually transferred to and stored in a storage unit such as a hard disk. In addition, the above-mentioned program may be provided as a standalone application software, or may be incorporated into the software of the venous pressure measuring device 160 as one of its functions.

[0088] Furthermore, the processing units of the flowcharts in the above embodiments are divided according to the main processing contents in order to facilitate understanding of each process. The method of classifying the processing steps does not limit the present invention. Each process can be further divided into more processing steps. Also, one processing step may execute more processes. [Explanation of symbols]

[0089] 100 Venous pressure testing system, 111 Cuff, 112 Pressure pump, 113 Exhaust valve, 114 Pressure sensor, 115 cuff pressure detection unit, 116 A.D.C. 120 Input device, 130 output device, 131 Display, 150 control section, 160 Venous pressure testing device.

Claims

1. an acquisition unit that acquires pulse wave information regarding the pulse wave of the subject measured by a sensor; a processing unit that, when the venous pressure of the subject can be estimated from the pulse wave information acquired by the acquisition unit, estimates a value of the venous pressure of the subject based on candidate components included in the pulse wave information; Equipped with when the processing unit cannot estimate the venous pressure of the subject from the pulse wave information, calculates a range of possible values ​​of the venous pressure of the subject based on the pulse wave information; The candidate component is a component that can be estimated to be a venous wave of the subject among components contained in the pulse wave information.

2. The venous pressure measuring device according to claim 1 , wherein the processing unit further determines whether the venous pressure of the subject can be estimated from the pulse wave information based on a noise component influenced by external disturbance and the candidate component.

3. 3. The venous pressure measuring device according to claim 2, wherein the processing unit determines that the venous pressure of the subject cannot be estimated from the pulse wave information when the pulse wave information contains noise components that meet a predetermined condition or when the pulse wave information does not contain the candidate components.

4. The venous pressure measuring device according to claim 2 , wherein the processing unit estimates a value of the venous pressure of the subject from the pulse wave information when the pulse wave information includes the candidate component and does not include the noise component that meets a predetermined condition.

5. The venous pressure measuring device according to any one of claims 2 to 4, wherein the processing unit further determines whether a range of the venous pressure of the subject can be calculated based on the pulse wave information acquired by the acquisition unit.

6. The venous pressure measuring device according to claim 5 , wherein the processing unit calculates a range of the venous pressure of the subject when the noise component and the candidate component that meet a predetermined condition are not included in the pulse wave information.

7. 6. The venous pressure measuring device according to claim 5, wherein the processing unit calculates a range of the venous pressure of the subject or determines that an error has occurred when the pulse wave information contains the noise component that meets a predetermined condition and does not contain the candidate component.

8. 6. The venous pressure measuring device according to claim 5, wherein the processing unit calculates a value range of the venous pressure of the subject or determines that an error has occurred when the noise component and the candidate component that meet predetermined conditions are included in the pulse wave information.

9. The venous pressure measuring device according to any one of claims 5 to 8, wherein the processing unit determines whether it is possible to calculate a range of the venous pressure of the subject based on at least one of the position, duration, number, and size of the noise components.

10. The sensor is a cuff attached to a predetermined part of the subject, 10. The venous pressure measuring device according to claim 2, wherein the acquisition unit acquires the pulse wave information based on the pressure that the cuff receives from the predetermined site when the cuff pressure of the cuff is changed.

11. A venous pressure measuring device as described in claim 10, wherein when the venous pressure of the subject cannot be estimated from the pulse wave information, the processing unit calculates a value range of the venous pressure of the subject based on the pulse wave information and pressure information related to the cuff pressure.

12. 12. The venous pressure measuring device according to claim 10, wherein the processing unit determines that the pulse wave information includes the candidate component when an amplitude of the pulse wave of the subject changes in a predetermined manner in accordance with a change in the cuff pressure.

13. The venous pressure measuring device according to any one of claims 1 to 12, further comprising an output unit that outputs any one of a calculation result relating to a value range of the subject's venous pressure calculated by the processing unit, an estimation result relating to the value of the subject's venous pressure estimated from the pulse wave information, or an error result indicating that the venous pressure of the subject cannot be estimated and the value range of the subject's venous pressure cannot be calculated.

14. acquiring pulse wave information regarding a pulse wave of a subject measured by a sensor; When the venous pressure of the subject can be estimated from the acquired pulse wave information, estimating a value of the venous pressure of the subject based on a candidate component included in the pulse wave information; calculating a range of possible values ​​of the venous pressure of the subject when the venous pressure of the subject cannot be estimated from the pulse wave information; Including, A venous pressure measuring method, wherein the candidate component is a component that can be estimated to be a venous wave of the subject among components contained in the pulse wave information.

15. A venous pressure measuring program for causing a computer to execute the venous pressure measuring method according to claim 14.

Images