Intracardiac pressure estimation device, intracardiac pressure estimation system, intracardiac pressure estimation method, and program

Abstract

This intracardiac pressure estimation device comprises an acquisition unit, an input unit, and a control unit. The acquisition unit acquires cardiac function-related information, which relates to cardiac function. The input unit receives input of load information, which indicates a load applied to the body of a measurement subject when measuring the cardiac function-related information. The control unit estimates, on the basis of the cardiac function-related information, an intracardiac pressure, which is the pressure applied to a blood vessel in the vicinity of the heart or inside the heart; acquires variation factor information, which indicates a variation factor that may affect the intracardiac pressure and that includes the load information; and calculates an adjusted value of the intracardiac pressure on the basis of the variation factor information.

Description

Intracardiac pressure estimation device, intracardiac pressure estimation system, intracardiac pressure estimation method, and program

[0001] The present disclosure relates to an intracardiac pressure estimation device, an intracardiac pressure estimation system, an intracardiac pressure estimation method, and a program.

[0002] It is known that estimating and monitoring intracardiac pressures such as left ventricular end-diastolic pressure (LVEDP) and pulmonary artery pressure (PAP) through non-invasive measurement at home is effective in reducing the re-hospitalization rate of heart failure patients. Indicators of hemodynamics generally include intracardiac pressures such as atrial pressure, ventricular pressure, and pulmonary artery pressure, as well as blood pressure and cardiac output, and hemodynamics fluctuates due to the influence of stress caused by diet, exercise, etc. Cited Document 1 indicates that it is preferable to consider the patient's activity cycle when analyzing hemodynamics.

[0003] Patent Document 1 describes that left atrial pressure (LAP) increases during daytime activity due to increased load on the cardiorespiratory system, and decreases during inactivity at night due to reduced load, such as sleep. The invention described in Patent Document 1 determines that there is an abnormality in the heart condition when the difference between daytime LAP and nighttime LAP is smaller than a predetermined value.

[0004] U.S. Patent No. 7,946,995

[0005] Ideally, intracardiac pressure in patients with heart failure should always be measured under consistent conditions because the stress on the patient's body affects the intracardiac pressure. However, when estimating intracardiac pressure through non-invasive measurement at home, for example, it is difficult to maintain consistent conditions for all measurements. If the measurement conditions fluctuate, it becomes difficult to accurately evaluate the measured intracardiac pressure. Therefore, it is desirable to be able to determine the risk of heart failure by taking into account information on fluctuation factors that affect intracardiac pressure, including the stress on the patient's body.

[0006] Therefore, the purpose of the present disclosure, which has been made with these points in mind, is to provide an intracardiac pressure estimation device, an intracardiac pressure estimation system, an intracardiac pressure estimation method, and a program that enable intracardiac pressure to be evaluated while taking into account the influence of variable factors including the load on the subject's body.

[0007] An intracardiac pressure estimation device according to one aspect of the present disclosure includes an acquisition unit that acquires cardiac function-related information relating to cardiac function, an input unit that receives input of load information indicating the load on the body of the subject when measuring the cardiac function-related information, and a control unit that estimates intracardiac pressure, which is the pressure on blood vessels inside or near the heart, based on the cardiac function-related information, acquires variable factor information indicating variable factors that may affect the intracardiac pressure and includes the load information, and calculates an adjustment value for the intracardiac pressure based on the variable factor information.

[0008] In one embodiment, the acquisition unit acquires the cardiac function-related information measured by a non-invasive means.

[0009] In one embodiment, the cardiac function-related information includes at least one of an electrocardiogram, a pulse wave, and a heart sound.

[0010] In one embodiment, the intracardiac pressure includes at least one of left ventricular end-diastolic pressure, pulmonary artery pressure, and pulmonary artery wedge pressure.

[0011] In one embodiment, the load information includes biological information of the subject, environmental information, and at least one of whether the subject is performing a daily living activity and the time elapsed since performing the activity.

[0012] In one embodiment, the control unit calculates the adjustment value by using an adjustment amount determined based on at least one of the type and magnitude of the load included in the load information to adjust the estimated value of the intracardiac pressure estimated based on the cardiac function-related information.

[0013] In one embodiment, the fluctuation factor information includes time fluctuation information indicating fluctuations in the intracardiac pressure over time, and the time fluctuation information includes at least one of fluctuation information of intraday fluctuation, interday fluctuation, weekly fluctuation, monthly fluctuation, seasonal fluctuation, and annual fluctuation.

[0014] In one embodiment, the time-varying information is constructed by accumulating the intracardiac pressure of the subject together with time information.

[0015] In one embodiment, the time variation information includes information on variation in diurnal variation, and the control unit determines that the risk of disease is high when the diurnal variation is smaller than a predetermined threshold.

[0016] In one embodiment, the controller determines a risk of disease based on the adjusted value of the intracardiac pressure.

[0017] In one embodiment, the control unit takes into consideration the weight of the subject inputted into the input unit when determining the risk of the disease.

[0018] In one embodiment, the intracardiac pressure estimation device is used by the subject who has been discharged from a hospital after treatment for heart failure, and the control unit takes into account the period of time that has passed since the subject was discharged from the hospital, as input into the input unit, when determining the risk of the disease.

[0019] In one embodiment, the control unit determines a schedule for measuring the cardiac function-related information based on the determined risk of the disease.

[0020] An intracardiac pressure estimation system as one aspect of the present disclosure includes a measuring device that measures cardiac function-related information related to cardiac function, an acquisition unit that acquires the cardiac function-related information, an input unit that receives input of load information indicating the load on the body of the subject when measuring the cardiac function-related information, and an intracardiac pressure estimation device that includes a control unit that estimates intracardiac pressure, which is the pressure on blood vessels inside the heart or near the heart, based on the cardiac function-related information, acquires variable factor information that indicates variable factors that may affect the intracardiac pressure and includes the load information, and calculates an adjustment value for the intracardiac pressure in accordance with the variable factor information.

[0021] An intracardiac pressure estimation method as one aspect of the present disclosure is an intracardiac pressure estimation method executed by a control unit of a computer, which acquires cardiac function-related information relating to cardiac function, guides the input of load information indicating the load on the body of the subject when measuring the cardiac function-related information into an input unit, receives the load information from the input unit, estimates intracardiac pressure, which is the pressure on blood vessels inside the heart or near the heart, based on the cardiac function-related information, and calculates an adjustment value for the intracardiac pressure in accordance with variable factor information indicating variable factors that may affect the intracardiac pressure and including the load information.

[0022] A program as one aspect of the present disclosure causes a processor to perform the following processes: acquiring cardiac function-related information relating to cardiac function; guiding the input of load information indicating the load on the subject's body when measuring the cardiac function-related information into an input unit; receiving the input of the load information from the input unit; estimating intracardiac pressure, which is the pressure on blood vessels inside the heart or near the heart, based on the cardiac function-related information; and calculating an adjustment value for the intracardiac pressure according to variable factor information, which is information indicating variable factors that may affect the intracardiac pressure and includes the load information.

[0023] According to the present disclosure, an adjustment value for intracardiac pressure is calculated according to fluctuation factor information including load information, making it possible to evaluate intracardiac pressure taking into account the influence of load on the subject's body.

[0024] Fig. 1 is a block diagram showing a schematic configuration of an intracardiac pressure estimation system according to one embodiment. Fig. 2 is a diagram showing an example of components included in a storage unit shown in Fig. 1. Fig. 3 is a functional block diagram illustrating processing executed by a control unit shown in Fig. 1. Fig. 4 is a diagram showing an example of fluctuations in intracardiac pressure. Fig. 5 is a flowchart showing an example of processing executed by the control unit shown in Fig. 1.

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0026] <Intracardiac Pressure Estimation System> The intracardiac pressure estimation system 1 of the present disclosure is a system that estimates the intracardiac pressure of a subject using one or more measurement devices and adjusts the estimated intracardiac pressure to an adjusted value under specified conditions, taking into account differences in measurement conditions. The intracardiac pressure estimation system 1 is expected to be used at home by users who do not necessarily have medical expertise, such as the subject themselves after being discharged from a hospital after treatment for heart failure or their close relatives. In this disclosure, the term "adjusted value" refers to a value converted to the value that would have been measured if the measurement had been performed under specified conditions.

[0027] As shown in Fig. 1, the intracardiac pressure estimation system 1 of the present disclosure includes a measurement unit 10 and an intracardiac pressure estimation device 20. The measurement unit 10 and the intracardiac pressure estimation device 20 may be separate devices mounted on separate hardware. In this case, the measurement unit 10 and the intracardiac pressure estimation device 20 are connected by wired and / or wireless communication means. In other embodiments, all or part of the functions of the measurement unit 10 and the intracardiac pressure estimation device 20 may be mounted on the same hardware.

[0028] <Configuration of the Measurement Unit> The measurement unit 10 is one or more measurement devices that measure cardiac function-related information related to the cardiac function of the measurement subject. The cardiac function-related information includes information related to at least one of heart beat and blood pressure. The measurement unit 10 may include non-invasive measurement means. The non-invasive measurement means include, for example, an electrocardiograph 11, a pulse wave meter 12, and a phonocardiograph 13. The measurement unit 10 may include all of the electrocardiograph 11, the pulse wave meter 12, and the phonocardiograph 13, or may include only some of these. The measurement unit 10 may further include other measurement devices such as a sphygmomanometer. The measurement unit 10 may also include an invasive measurement device such as a catheter for invasive arterial pressure measurement. The measurement unit 10 may transmit the measurement results as an electrical signal to the intracardiac pressure estimation device 20.

[0029] The electrocardiograph 11 includes electrodes attached to the wrists, ankles, chest, and other locations to obtain an electrocardiogram of the user. The electrodes are capable of detecting minute electrical currents generated in the heart. In one embodiment, electrical signals detected by the electrodes of the electrocardiograph 11 are processed in a main body of the electrocardiograph 11 that is separate from the intracardiac pressure estimation device 20, and the measurement results are transmitted to the intracardiac pressure estimation device 20. In another embodiment, the electrical signals detected by the electrodes of the electrocardiograph 11 may be transmitted directly to the intracardiac pressure estimation device 20 and processed therein.

[0030] The pulse wave meter 12 measures pulse waves transmitted to the blood vessels by cardiac pulsation by wrapping a cuff around the user's upper arm or the like and pumping air into the cuff. In one embodiment, the cuff is controlled by a main body of the pulse wave meter 12 that is separate from the intracardiac pressure estimation device 20. In another embodiment, the cuff of the pulse wave meter 12 may be directly connected to the intracardiac pressure estimation device 20, and control and measurement may be performed by the intracardiac pressure estimation device 20. The pulse wave meter 12 is not limited to being a cuff, and a tonometer, pressure sensor, or the like may also be used to measure pulse waves.

[0031] The phonocardiograph 13 measures the heartbeat sound of the user using a microphone. The microphone may be a capacitor microphone that detects changes in capacitance between a diaphragm (diaphragm) and a back plate (electrode), a piezoelectric microphone that uses a piezoelectric element, or an electrodynamic microphone that combines a permanent magnet and a coil. In one embodiment, the microphone of the phonocardiograph 13 is controlled and measures by a main body of the phonocardiograph 13 that is separate from the intracardiac pressure estimation device 20. In another embodiment, the microphone of the phonocardiograph 12 may be directly connected to the intracardiac pressure estimation device 20, and may be controlled and measured by the intracardiac pressure estimation device 20. The phonocardiograph 13 is not limited to a microphone, and may also be one that measures acceleration or body-conducted sound or one that uses a piezoelectric element.

[0032] <Configuration of Intracardiac Pressure Estimation Device> The intracardiac pressure estimation device 20 includes an acquisition unit 21, an input unit 22, a control unit 23, a storage unit 24, and an output unit 25. The intracardiac pressure estimation device 20 is a computer equipped with a program for estimating intracardiac pressure. The intracardiac pressure estimation device 20 may be, for example, a dedicated computer device, a general-purpose computer such as a PC (personal computer), or a server device such as a PC server or a workstation.

[0033] In this application, "intracardiac pressure" refers to pressure inside the heart or pressure exerted on blood vessels near the heart. Examples of intracardiac pressure include, but are not limited to, left ventricular end-diastolic pressure (LVEDP), pulmonary artery pressure (PAP), and pulmonary wedge pressure (PWP), as well as left and right atrial pressures, left and right ventricular pressures, and arterial pressures. Pulmonary artery wedge pressure (PAWP), also known as pulmonary artery wedge pressure (PCWP), or pulmonary artery occlusion pressure (PAOP), can be used as a predictor of worsening heart failure.

[0034] The acquiring unit 21 acquires cardiac function-related information measured by the measuring unit 10 from the measuring unit 10. The acquiring unit 21 may acquire each piece of cardiac function-related information in the measuring unit 10 as an electrical signal. The acquiring unit 21 may receive detection signals before signal processing from the measuring unit 10, or may acquire measured values ​​that have been signal processed by the measuring unit 10. In the former case, signal processing may be performed within the intracardiac pressure estimation device 20 to calculate the measured values. The acquiring unit 21 may include an input terminal that receives input from the measuring unit 10 and / or a communication interface with the measuring unit 10.

[0035] The input unit 22 is an input interface that receives various information input to the intracardiac pressure estimation device 20 from outside the intracardiac pressure estimation device 20 .

[0036] The input unit 22 includes one or more input interfaces that detect user input and acquire input information based on the user's operation. For example, the input unit 22 may include physical keys, capacitance keys, a touch screen that is integrated with a display unit 25a of the output unit 25 (described later), a microphone that accepts voice input, etc.

[0037] The input unit 22 may include an input interface configured to receive an input signal from the external device 30. The input unit 22 may include a connector and a wireless communication device for inputting data to the intracardiac pressure estimation device 20. The external device 30 includes, for example, a body movement sensor that measures load information indicating the load on the subject's body, an activity meter, a blood glucose meter, a thermometer, and the like. The external device 30 may further include a device that measures information about the subject, such as a weight scale.

[0038] The input unit 22 may include a communication interface for receiving input from a remotely located information device and / or system via a communication line. The remotely located information device and system may include, for example, an external server 40 and / or a medical institution system 50. The input unit 22 may be compatible with wired and / or wireless communication means.

[0039] The external server 40 is a server device that collects and / or manages information such as measured values ​​of cardiac function-related information, estimated values ​​and adjusted values ​​of intracardiac pressure from the intracardiac pressure estimation device 20, and provides information to the intracardiac pressure estimation device 20. The information provided by the external server 40 includes, for example, estimated values ​​of the subject's past intracardiac pressure and diurnal fluctuation data of intracardiac pressure in a typical person.

[0040] The medical institution system 50 is a system of a medical institution where the subject is receiving medical treatment as a patient. The intracardiac pressure estimation device 20 may be able to receive information related to the patient's medical treatment from the medical institution system 50. The information related to the patient's medical treatment may include electronic medical record information and discharge date information indicating the date the subject was discharged from the hospital after heart failure treatment. The medical institution system 50 may receive measured values ​​of cardiac function-related information and / or estimated intracardiac pressure values ​​of the subject from the intracardiac pressure estimation device 20. This information may be used by doctors at the medical institution to assess the condition of the subject patient and to consider changes in prescriptions, etc.

[0041] The control unit 23 includes at least one processor, at least one dedicated circuit, or a combination thereof. The processor is a general-purpose processor such as a central processing unit (CPU) or a graphics processing unit (GPU), or a dedicated processor specialized for a specific process. The dedicated circuit is, for example, a field-programmable gate array (FPGA) or an application-specific integrated circuit (ASIC).

[0042] The control unit 23 controls each component of the intracardiac pressure estimation device 20 and executes processes related to the operation of the intracardiac pressure estimation device 20. The processes executed by the control unit 23 will be described later.

[0043] The storage unit 24 may be, for example, a semiconductor memory, a magnetic memory, an optical memory, or the like, but is not limited to these. The storage unit 24 may function, for example, as a main storage device, an auxiliary storage device, or a cache memory. The storage unit 24 stores any information used in the operation of the intracardiac pressure estimation device 20. For example, the storage unit 24 may sequentially store system programs, application programs, information acquired by the intracardiac pressure estimation device 20, and the like. A portion of the storage unit 24 may be installed external to the intracardiac pressure estimation device 20. In this case, the externally installed portion of the storage unit 24 may be connected to the intracardiac pressure estimation device 20 via any interface.

[0044] The storage unit 24 may sequentially store the information input from the input unit 22 under the control of the control unit 23. The storage unit 24 may sequentially update the stored information with new information.

[0045] 2, the storage unit 24 may include a load information storage unit 24a, a time-varying information storage unit 24b, a patient information storage unit 24c, and a past data storage unit 24d. Each unit of the storage unit 24 may store information as a database managed by a database management system or as a file describing the data.

[0046] The load information storage unit 24a stores load information related to the load on the subject's body input from the input unit 22. The load information includes the subject's biological information, environmental information, and at least one of whether the subject engaged in daily activities and the time elapsed since engaging in such activities. The subject's biological information includes physical activity, acceleration, blood glucose level, heart rate, blood pressure, body temperature, sleep time, and autonomic nervous activity. The subject's daily activities include bathing, exercise, medication, eating, drinking, smoking, urination, and defecation. The environmental information includes the temperature and humidity around the subject. Autonomic nervous activity includes various parameters calculated by heart rate variability analysis, such as the LF (low frequency) / HF (high frequency) ratio, which represents the balance between the sympathetic and parasympathetic nervous systems, and Total Power, which represents the total amount of autonomic nervous activity of the sympathetic and parasympathetic nervous systems. The storage unit 24 may store some or all of this load information.

[0047] The time variation information storage unit 24b stores time variation information indicating time variations in the estimated value of the subject's intracardiac pressure. The time variation information includes various types of variation information, such as diurnal variation, interday variation, weekly variation, monthly variation, seasonal variation, and annual variation. The storage unit 24 may sequentially store and accumulate the estimated values ​​of intracardiac pressure estimated by the intracardiac pressure estimation device 20 together with time information. The time information includes, for example, the time when cardiac function-related information related to cardiac function was measured or acquired, the time when the intracardiac pressure was estimated, or the time when the adjusted value of intracardiac pressure was calculated. The time variation information can be constructed by the control unit 23 performing statistical processing on the information on the estimated values ​​of intracardiac pressure stored in the storage unit 24. The control unit 23 can also obtain time variations in the intracardiac pressure of an average person from an external server 40 and use this information to construct the time variation information.

[0048] The patient information storage unit 24c stores, as patient information, information about the subject that the input unit 22 acquires from the external device 30, such as a weighing scale, and the medical institution system 50. The patient information may include the subject's measured value, such as weight, electronic medical record information, and discharge date information.

[0049] The past data storage unit 24d sequentially stores, as past data, at least one of the measured values ​​of cardiac function-related information, the estimated intracardiac pressure, and the adjusted intracardiac pressure value obtained from the measurement unit 10. The past data is used by the control unit 23 for data analysis, generation of time-varying information, and disease risk assessment of the subject.

[0050] The output unit 25 includes one or more output interfaces that output information to notify the user. For example, the output unit 25 includes, but is not limited to, a display unit 25a that outputs information as an image and / or a speaker 25b that outputs information as audio. The output unit 25 may be capable of outputting information in various forms. Under the control of the control unit 23, the output unit 25 can display information guiding the input of load information, a measurement schedule, information notifying the time of measurement, and the like. The output unit 25 may further include a communication interface for transmitting information to remote devices such as the external server 40 and the medical institution system 50.

[0051] <Operation of the control unit> The functions of the intracardiac pressure estimation device 20 are realized by executing a program according to this embodiment on a processor serving as the control unit 23. That is, the functions of the intracardiac pressure estimation device 20 are realized by software. The program causes the processor of a computer to execute the operations of the intracardiac pressure estimation device 20, thereby causing the computer to function as the intracardiac pressure estimation device 20.

[0052] The program can be stored in a non-transitory computer-readable medium. Examples of the non-transitory computer-readable medium include a flash memory, a magnetic recording device, an optical disk, a magneto-optical recording medium, and a ROM. The program can be distributed by selling, transferring, or lending a portable medium, such as a secure digital (SD) card, a digital versatile disc (DVD), or a compact disc read-only memory (CD-ROM), on which the program is stored. The program can also be distributed by storing the program in a server's storage and transferring it from the server to another computer. The program can also be provided as a program product.

[0053] Some or all of the functions of the intracardiac pressure estimation device 20 may be implemented by a programmable circuit or a dedicated circuit serving as the control unit 23. In other words, some or all of the functions of the intracardiac pressure estimation device 20 may be implemented by hardware.

[0054] The processing executed by the control unit 23 will be described with reference to Fig. 3. The control unit 23 includes the following components: an intracardiac pressure estimator 23a, a fluctuation factor acquirer 23b, an adjustment value calculator 23c, a determiner 23d, a measurement schedule determiner 23e, and a notifier 23f. Each component of the control unit 23 may be a hardware module or a software module. The processing executed by each component can be rephrased as processing executed by the control unit 23.

[0055] The intracardiac pressure estimating unit 23a acquires at least one of cardiac function-related information, including an electrocardiogram, a pulse wave, and heart sounds, from the measuring unit 10 via the acquiring unit 21. The intracardiac pressure estimating unit 23a estimates intracardiac pressure from the measured values ​​of the acquired cardiac function-related information. The estimated intracardiac pressure may include, for example, one or more of LVEDP, PAP, and PWP. The intracardiac pressure estimating unit 23a may sequentially store the estimated values ​​of intracardiac pressure in the storage unit 24 together with time information, such as the time when the measuring unit 10 measured the cardiac function-related information.

[0056] The intracardiac pressure can be estimated using a trained model generated by performing machine learning using cardiac function-related information as an input parameter and the intracardiac pressure as an output parameter. The intracardiac pressure estimating unit 23 a may be configured to input cardiac function-related information to the trained model and estimate the intracardiac pressure.

[0057] The fluctuation factor acquiring unit 23b acquires information on fluctuation factors that may affect the intracardiac pressure, including load information and time fluctuation information.

[0058] The variation factor acquisition unit 23b can acquire load information, for example, from the load information input unit 22a of the input unit 22. The load information input unit 22a acquires load information, for example, from an external device 30. The external device 30 is, for example, an activity meter and / or an acceleration sensor. The variation factor acquisition unit 23b can determine the subject's body position and / or exercise status from the activity amount and / or acceleration information detected by these devices. Furthermore, the external device 30 is, for example, a blood glucose meter that measures blood glucose levels, and the variation factor acquisition unit 23b can determine whether the subject has eaten within the last one to two hours based on changes in blood glucose levels. The fact that the subject is in a posture that puts strain on the body, is moving, has just eaten, etc. are determined to indicate a high load on the subject's body.

[0059] The load information input unit 22a is virtually provided as an element that receives input of load information. The input unit 22 does not need to have dedicated hardware or software for the load information input unit 22a. After receiving the load information at the input unit 22, the load information may be stored in the load information storage unit 24a of the storage unit 24 and read out by the fluctuation factor acquisition unit 23b as needed.

[0060] The variation factor acquiring unit 23b may use cardiac function-related information acquired from the measuring unit 10 as load information. The variation factor acquiring unit 23b can determine whether or not there is a load based on, for example, an increase in heart rate and / or an increase in blood pressure compared to when at rest. An increase in the heart rate and / or an increase in blood pressure of the person being measured is determined to indicate a high load on the person's body.

[0061] The load information input unit 22 a may acquire load information through manual input by the user. For example, the user may input the time elapsed since eating or the time elapsed since bathing using a keyboard, a pointing device, a touch panel, or the like of the input unit 22.

[0062] To acquire the load information, the variation factor acquisition unit 23b may cause the display unit 25a of the output unit 25 to display a display guiding the user to input the load information. For example, the variation factor acquisition unit 23b may cause the display unit 25a to display a display urging the user to measure the load information using the external device 30. Furthermore, for example, the variation factor acquisition unit 23b may cause the display unit 25a to display an input screen for inputting meal times, bathing times, etc.

[0063] The fluctuation factor acquisition unit 23b can acquire the time fluctuation information, for example, from the time fluctuation information storage unit 24b of the storage unit 24. As described above, the time fluctuation information can be generated by storing the estimated values ​​of intracardiac pressure estimated by the intracardiac pressure estimation unit 23a together with time information in the storage unit 24 and performing statistical processing on them. The time fluctuation information storage unit 24b may acquire and store time fluctuation information of intracardiac pressure of an average person from the external server 40 via the input unit 22.

[0064] The adjustment value calculation unit 23c calculates an adjusted intracardiac pressure value by adjusting the intracardiac pressure estimated by the intracardiac pressure estimation unit 23a based on the fluctuation factor information acquired by the fluctuation factor acquisition unit 23b. The adjusted intracardiac pressure value is a value obtained by adjusting the estimated intracardiac pressure value to the intracardiac pressure measured at a predetermined time without any load on the body. The predetermined time can be, for example, a time between 6:00 and 8:00 in the morning. The adjustment of the intracardiac pressure is performed based on the load on the body of the subject and / or the diurnal fluctuation of the intracardiac pressure.

[0065] The adjustment based on the load on the subject's body can be performed using as a reference the estimated value of intracardiac pressure measured at rest without any load. For example, the adjustment value calculation unit 23c formulates the amount of change in intracardiac pressure depending on the presence or absence of load and its magnitude based on the subject's past data stored in the storage unit 24, and stores this formulated amount of change in the storage unit 24. During measurement, the adjustment value calculation unit 23c adjusts the estimated value of intracardiac pressure using the load on the subject's body at the time of measurement and the amount of change in intracardiac pressure relative to the load stored in the storage unit 24, and calculates an adjustment value that indicates the intracardiac pressure if there was no load.

[0066] For example, suppose a subject who normally takes a measurement before breakfast forgets to take a pre-meal measurement and instead takes a post-meal measurement. When measuring the subject, the user of the intracardiac pressure estimation device 20 manually inputs, for example, using the input unit 22, that the measurement will be taken after a meal. Eating places a strain on the subject's body, causing the intracardiac pressure to rise. Therefore, the adjustment value calculation unit 23c adjusts the estimated intracardiac pressure obtained as a result of the post-meal measurement to the adjusted intracardiac pressure value that would have been obtained if the measurement had been taken while the subject was at rest before a meal.

[0067] The adjustment based on the diurnal variation of the estimated intracardiac pressure can be performed, for example, based on a diurnal variation curve obtained from the time variation information of the intracardiac pressure calculated for the subject himself / herself. The diurnal variation curve of the intracardiac pressure can be generated in advance by the adjustment value calculation unit 23c based on the time information and the data of the estimated intracardiac pressure of the subject stored in the memory unit 24. The adjustment of the estimated intracardiac pressure may also be performed based on the diurnal variation data of the intracardiac pressure of a typical person obtained from the external server 40.

[0068] For example, suppose a subject who normally takes measurements in the morning forgets to take a morning measurement and instead takes the measurement at night. In this case, the adjustment value calculation unit 23c determines the amount of variation in intracardiac pressure between the time of the night measurement and the time of the usual morning measurement based on the circadian variation curve. The adjustment value calculation unit 23c subtracts, adds, multiplies, or divides this amount of variation from the estimated intracardiac pressure measurement to adjust the estimated intracardiac pressure to the value that would have been obtained if the measurement had been taken in the morning.

[0069] The determination unit 23d determines whether or not there is an abnormality in the intracardiac pressure adjustment value calculated by the adjustment value calculation unit 23c based on predetermined determination criteria. The determination unit 23d can determine whether or not there is an abnormality by setting a relative threshold value for the intracardiac pressure adjustment value by comparing it with past intracardiac pressure adjustment values, or an absolute threshold value. For example, the determination unit 23d determines that there is an abnormality when the intracardiac pressure (e.g., PAP) adjustment value is +5 mmHg or +30% compared to the previous week. Furthermore, for example, the determination unit 23d determines that there is an abnormality when the intracardiac pressure adjustment value is 25 mmHg or more.

[0070] The determination unit 23d can set a threshold value used to determine abnormality based on patient information acquired via the patient information input unit 22b of the input unit 22. For example, the patient information input unit 22b can receive input of the subject's discharge date information, medical history, and medical record information from the medical institution system 50. This information can be acquired from the electronic medical record included in the medical institution system 50. In addition, the patient information input unit 22b can acquire, for example, measurement values ​​such as the patient's weight from a weight scale, which is one of the external devices 30.

[0071] The patient information input unit 22b may acquire the threshold information used for abnormality determination by the determination unit 23d through manual input by a doctor. Alternatively, the determination unit 23d may automatically set and change the threshold for abnormality determination based on the patient information input from the patient information input unit 22b. For example, a lower threshold is set for a subject who has been repeatedly hospitalized at a medical institution. Also, for example, the shorter the time since discharge from a medical institution, the lower the threshold is set.

[0072] The patient information input unit 22b, like the load information input unit 22a, is virtually provided as an element for receiving input of patient information. The input unit 22 does not need to have dedicated hardware and software for the patient information input unit 22b.

[0073] Other than when the adjusted intracardiac pressure value increases as described above, a decrease in the diurnal variation of the estimated intracardiac pressure may indicate deterioration of cardiac function. The determination unit 23d may set a threshold for the diurnal variation of the estimated intracardiac pressure and determine that an abnormality has occurred when the diurnal variation is equal to or less than the threshold. For example, the determination unit 23d may determine that an abnormality has occurred when the diurnal variation of the intracardiac pressure is equal to or less than 3 mmHg. Furthermore, for example, the determination unit 23d may determine that an abnormality has occurred when the diurnal variation of the intracardiac pressure is equal to or less than 10% of the maximum value of the estimated intracardiac pressure. When determining an abnormality based on the diurnal variation of the estimated intracardiac pressure, it is necessary to perform measurements multiple times a day using the intracardiac pressure estimation device 20. The user should perform measurements at least twice a day, in the morning and evening.

[0074] When determining that an abnormality has occurred, the determination unit 23d may notify the occurrence of the abnormality to the medical institution system 50 by communication via the output unit 25. A doctor at the medical institution can consider how to deal with the abnormality of the subject that has been notified to the medical institution system 50.

[0075] A specific example of calculation of the intracardiac pressure adjustment value and abnormality determination by the control unit 23 will be described with reference to FIG. 4 . FIG. 4 is a diagram showing fluctuations in the estimated intracardiac pressure value depending on the intracardiac pressure measurement time as normal time information and the subject's stress state. Such a diagram can be calculated based on the subject's past data accumulated in the past data storage unit 24d of the storage unit 24. The solid line in this diagram indicates the circadian variation curve when no stress is applied to the subject's body. The dashed line indicates the estimated intracardiac pressure value when stress is applied. State A indicates that the estimated intracardiac pressure value in the morning without stress is 10 mmHg. State B indicates that the estimated intracardiac pressure value in the evening without stress is 20 mmHg. State C indicates that the estimated intracardiac pressure value in the morning with stress is 15 mmHg. State D indicates that the estimated intracardiac pressure value in the evening with stress is 23 mmHg. When these are tabulated, the intracardiac pressure of the subject under normal conditions, depending on whether or not there is a load and the time of intracardiac pressure measurement, is expressed as follows:

[0076]

[0077] If we use the unstressed morning intracardiac pressure as a reference, we obtain the following table of adjustment amounts for the estimated intracardiac pressure: The adjustment amounts are used to adjust the estimated intracardiac pressure, and are used to calculate the adjustment values ​​by applying arithmetic operations to the estimated intracardiac pressure, namely, addition, subtraction, multiplication, or division (subtraction in this embodiment).

[0078]

[0079] (Example 1) Assume that the estimated intracardiac pressure in the morning under normal stress is 10 mmHg, and the estimated intracardiac pressure measured under normal stress one evening is 25 mmHg. The intracardiac pressure measured under normal stress at night is +10 mmHg compared to the reference value in the table above. Therefore, this estimated intracardiac pressure of 25 mmHg is adjusted to the morning intracardiac pressure under normal stress by subtracting 10 mmHg, resulting in 15 mmHg. This value is 5 mmHg higher than the estimated intracardiac pressure of 10 mmHg under normal stress. If a threshold value is set that determines an abnormality when the intracardiac pressure is 5 mmHg or higher compared to the normal intracardiac pressure, the control unit 23 determines that an abnormality has occurred.

[0080] (Example 2) Assume that the estimated intracardiac pressure in the morning under normal stress is 10 mmHg, and the estimated intracardiac pressure measured after breakfast under stress is 18 mmHg. The intracardiac pressure after breakfast under stress is +5 mmHg compared to the reference value in the table above. Therefore, this estimated intracardiac pressure of 18 mmHg is adjusted to the intracardiac pressure under stress by subtracting 5 mmHg, resulting in 13 mmHg. This value is 30% higher than the estimated intracardiac pressure of 10 mmHg under stress. If a threshold value is set that determines an abnormality when the intracardiac pressure is 30% or more higher than the normal intracardiac pressure, the control unit 23 determines that an abnormality has occurred.

[0081] In the above-described method for calculating the adjustment value of intracardiac pressure, the control unit 23 evaluates the load on the subject's body in two levels: with load or without load. However, the control unit 23 may adjust the intracardiac pressure by dividing the magnitude of the load into two or more levels. For example, the control unit 23 may divide the load into a first level, which is a low load, and a second level, which is a high load, and set different adjustment amounts for each of the no load, first load level, and second load level. The control unit 23 may also change the adjustment amount depending on the type of load. For example, the control unit 23 may divide the load into levels such as a first level for a light meal, a second level for a heavy meal, a first level for a urination load, and a second level for a defecation load. The control unit 23 may determine the adjustment amount depending on the level of the load. When the load is at the second level, the adjustment amount may be larger than when the load is at the first level.

[0082] The measurement schedule determination unit 23e determines the risk of disease of the subject based on various conditions in addition to the abnormality determination by the determination unit 23d. The measurement schedule determination unit 23e determines a measurement schedule for measuring cardiac function-related information and estimating intracardiac pressure according to the determined risk.

[0083] For example, the measurement schedule determination unit 23e may classify the risk of disease into multiple levels based on the adjusted value of intracardiac pressure. For example, the measurement schedule determination unit 23e may evaluate the risk of disease into three levels based on various criteria such as those shown below.

[0084] (Risk classification criterion 1) High risk: The adjusted value of intracardiac pressure is greater than a threshold value (e.g., 30 mmHg) Medium risk: The adjusted value of intracardiac pressure is equal to or less than the threshold value and has been on the rise for the last three days Low risk: The adjusted value of intracardiac pressure is equal to or less than the threshold value and has been stable for the last three days (Risk classification criterion 2) High risk: The adjusted value of intracardiac pressure has increased for seven consecutive days Medium risk: The adjusted value of intracardiac pressure has increased for three consecutive days Low risk: The adjusted value of intracardiac pressure has not increased (Risk classification criterion 3) High risk: The adjusted value of intracardiac pressure is greater than a first threshold value (e.g., 30 mmHg) Medium risk: The adjusted value of intracardiac pressure is greater than a second threshold value (e.g., 20 mmHg) Low risk: The adjusted value of intracardiac pressure is equal to or less than the second threshold

[0085] Furthermore, the measurement schedule determination unit 23e may reflect the period of time since the subject was discharged from the hospital, the subject's weight, etc. in the risk assessment. For example, this information may be combined with any of risk categories 1 to 3 and used as information to reinforce the assessment of the level of risk.

[0086] (Risk classification criterion 4: Classification by time since discharge) High risk: 1 to 2 months have passed since discharge Medium risk: 2 to 6 months have passed since discharge Low risk: 6 months or more have passed since discharge (Risk classification criterion 5: Classification by weight change) High risk: Weight gain of 2 kg or more in 1 week Medium risk: Weight gain of 1 kg or more in 1 week Low risk: No weight gain of 1 kg or more in 1 week

[0087] The measurement schedule determination unit 23e may determine the level of risk based on the risk classification criteria as described above, and determine a measurement schedule according to the determined level of risk. For example, if the measurement schedule determination unit 23e determines that there is a high level of risk based on any of the risk classification criteria, it determines a measurement schedule to perform measurements multiple times a day, including in the morning and evening. Furthermore, if the result of evaluating risk based on multiple risk classification criteria shows that there are two or more medium risks, the measurement schedule determination unit 23e determines a measurement schedule to perform measurements once every day. Furthermore, if the result of evaluating risk based on multiple risk classification criteria shows that there is only a low level of risk, the measurement schedule determination unit 23e sets a measurement schedule to perform measurements once every two days. These methods for determining a measurement schedule are merely examples. The measurement schedule determination unit 23e can evaluate risk using any method and determine a measurement schedule using any method. The measurement schedule determination unit 23e may select, as the time of measurement in the measurement schedule, a time period during which the subject can stably measure intracardiac pressure, based on past data accumulated in the past data storage unit 24d of the storage unit 24.

[0088] The notification unit 23f notifies the user of the measurement schedule determined by the measurement schedule determination unit 23e using the output unit 25. For example, the notification unit 23f displays the determined measurement schedule on the screen of the display unit 25a. Furthermore, for example, when the measurement time determined in the measurement schedule approaches, the notification unit 23f notifies the user by voice using the speaker 25b. The notification unit 23f may further transmit information to the user's mobile phone, wearable device, and / or television to display it. If measurement has not been performed at the time determined in the measurement schedule, the notification unit 23f may generate an alarm such as a warning sound for the user.

[0089] The notification unit 23f may further share information by transmitting information about the measurement schedule to a pre-registered terminal such as the medical institution system 50 or an information terminal of the subject's family, etc. This allows a person related to the subject to contact the subject or the user at the time of measurement and urge them to take the measurement.

[0090] <Flow of processing executed by the control unit> Next, the intracardiac pressure estimation method executed by the control unit 23 will be described with reference to the flowchart in Fig. 5. The processing executed by each component of the control unit 23 will be described as processing executed by the control unit 23. The processing of the flowchart in Fig. 5 can be executed by the processor of the control unit 23 in accordance with a program stored in the storage unit 24.

[0091] First, the control unit 23 acquires, via the acquisition unit 21, the measurement value of cardiac function-related information relating to cardiac function measured by the measurement unit 10 (step S101).

[0092] The control unit 23 estimates the intracardiac pressure based on the measurement value acquired in step S101 (step S102).

[0093] The control unit 23 acquires information on fluctuation factors affecting intracardiac pressure from the input unit 22 and / or the storage unit 24 (step S103). The fluctuation factor information includes load information indicating the load on the subject's body. The control unit 23 may cause the output unit 25 to display a message prompting the user to input the load information, and wait for the load information to be input to the input unit 22. The fluctuation factor information may further include time fluctuation information indicating fluctuations in intracardiac pressure over time.

[0094] The control unit 23 calculates an adjusted value of the intracardiac pressure by adjusting the estimated value of the intracardiac pressure to the intracardiac pressure under predetermined conditions based on the fluctuation factor information (step S104).

[0095] The control unit 23 determines whether or not there is an abnormality in the intracardiac pressure of the subject based on the adjusted intracardiac pressure value (step S105). If the control unit 23 determines that there is an abnormality, it can transmit to the medical institution system 50 or the like information to that effect, as well as information on the measurement value by the measurement unit 10, the estimated value of the intracardiac pressure, and / or the adjusted value.

[0096] The control unit 23 determines the risk of disease of the subject based on the adjusted intracardiac pressure value and the patient information (step S106). The risk may be evaluated in multiple stages or may be scored.

[0097] The control unit 23 determines a measurement schedule for measuring cardiac function-related information and estimating intracardiac pressure based on the risk determined in step S106 (step S107). The schedule is set so that the higher the determined risk, the higher the measurement frequency.

[0098] The control unit 23 notifies the user according to the determined schedule (step S108). The control unit 23 displays the measurement schedule to the user on the display unit 25a and notifies the user when the measurement time of the measurement schedule approaches. Furthermore, if the measurement time has passed without a measurement being performed, the control unit 23 may issue a warning by voice or the like using the speaker 25b or the like (step S108).

[0099] 5, steps S105 and after are not necessarily required. The intracardiac pressure estimation device 20 can also perform processing different from steps S105 to S108 using the adjusted intracardiac pressure value calculated in step S104. Also, it is not necessary to perform both step S105 and steps S106 to S108; either one of them may be performed.

[0100] As described above, the intracardiac pressure estimation device 20 of the present disclosure calculates an adjusted intracardiac pressure value based on variation factor information, including load information indicating the load on the subject's body, making it possible to evaluate intracardiac pressure while taking into account the influence of the load on the subject's body. Furthermore, by including time-varying information on intracardiac pressure in the variation factor information, the intracardiac pressure estimation device 20 of the present disclosure can evaluate intracardiac pressure while taking into account the influence of time-varying intracardiac pressure. As a result, even if a measurement is performed at an unusual time due to, for example, a missed measurement, the intracardiac pressure can be adjusted taking into account the load on the subject's body and the fluctuation due to the measurement time, making it possible to accurately evaluate the presence or absence of abnormalities and / or the risk of disease.

[0101] Furthermore, the intracardiac pressure estimation device 20 can set a threshold value for the amount of variation in the diurnal variation of the estimated value of intracardiac pressure and determine that an abnormality has occurred when the amount of variation falls below the threshold value. This makes it possible to detect a decrease or disappearance of the diurnal variation due to deterioration of cardiac function and to identify abnormalities in the subject.

[0102] Furthermore, the intracardiac pressure estimation device 20 of the present disclosure can automatically determine the presence or absence of abnormalities and the risk of disease based on the measurement results of the subject's intracardiac pressure, and can contact a medical institution, adjust the number of measurements, etc. This makes it easier for doctors and others at medical institutions to appropriately manage the condition of a subject using the intracardiac pressure estimation device 20.

[0103] Furthermore, the intracardiac pressure estimation device 20 can prompt the user to take a measurement at an appropriate time and issue a warning if the measurement is delayed. Therefore, the user can take a measurement according to the notification content of the intracardiac pressure estimation device 20, and can take a measurement without having to remember a complicated measurement time.

[0104] Furthermore, by using the intracardiac pressure estimation device 20 to perform measurements multiple times under different conditions, such as different load conditions and / or different timing, the possibility of detecting a worsening state of heart failure increases.

[0105] Although the embodiments according to the present disclosure have been described based on the drawings and examples, it should be noted that those skilled in the art would easily be able to make various modifications or alterations based on the present disclosure. Therefore, it should be noted that these modifications and alterations are included within the scope of the present disclosure. For example, the functions included in the components of the intracardiac pressure estimation device or the steps executed by the control unit of the intracardiac pressure estimation device can be rearranged so as not to be logically inconsistent, and multiple components or steps can be combined or divided into one.

[0106] Furthermore, the intracardiac pressure estimation device, intracardiac pressure estimation system, and intracardiac pressure estimation method disclosed herein are not limited to those used by users at home, but may also be used by medical professionals such as doctors in medical facilities.

[0107] REFERENCE SIGNS LIST 10 Measurement unit (measurement device) 11 Electrocardiograph 12 Pulse wave meter 13 Phonocardiograph 20 Intracardiac pressure estimation device 21 Acquisition unit 22 Input unit 22a Load information input unit 23b Patient information input unit 23 Control unit (processor) 23a Intracardiac pressure estimation unit 23b Fluctuation factor acquisition unit 23c Adjustment value calculation unit 23d Determination unit 23d Measurement schedule determination unit 23e Notification unit 24 Storage unit 24a Load information storage unit 24b Time fluctuation information storage unit 24c Patient information storage unit 24d Past data storage unit 25 Output unit 25a Display unit 25b Speaker 30 External device 40 External server 50 Medical institution system

Claims

1. An acquisition unit that acquires cardiac function-related information related to cardiac function; an input unit for receiving input of load information indicating a load applied to the body of the subject when the cardiac function-related information is measured; a control unit that estimates an intracardiac pressure, which is a pressure applied inside the heart or to blood vessels in the vicinity of the heart, based on the cardiac function-related information, acquires fluctuation factor information indicating fluctuation factors that may affect the intracardiac pressure and including the load information, and calculates an adjustment value for the intracardiac pressure in accordance with the fluctuation factor information; An intracardiac pressure estimation device comprising:

2. The intracardiac pressure estimation device according to claim 1 , wherein the acquisition unit acquires the cardiac function-related information measured by a non-invasive means.

3. The intracardiac pressure estimation device according to claim 1 , wherein the cardiac function-related information includes at least one of an electrocardiogram, a pulse wave, and a heart sound.

4. 3. The intracardiac pressure estimation device according to claim 1, wherein the intracardiac pressure includes at least one of a left ventricular end-diastolic pressure, a pulmonary artery pressure, and a pulmonary artery wedge pressure.

5. The intracardiac pressure estimation device of claim 1 or 2, wherein the load information includes at least one of the subject's biological information, environmental information, and whether or not the subject is performing daily living activities and the time elapsed since performing the activities.

6. The control unit of the intracardiac pressure estimation device of claim 1 or 2 calculates the adjustment value by using an adjustment amount determined based on at least one of the type and magnitude of the load included in the load information to adjust the estimated value of the intracardiac pressure estimated based on the cardiac function-related information.

7. The intracardiac pressure estimation device of claim 1 or 2, wherein the fluctuation factor information includes time fluctuation information indicating fluctuations in the intracardiac pressure over time, and the time fluctuation information includes at least any one of diurnal fluctuation, interday fluctuation, weekly fluctuation, monthly fluctuation, seasonal fluctuation, and annual fluctuation.

8. 8. The intracardiac pressure estimation device according to claim 7, wherein the time variation information is constructed by accumulating the intracardiac pressure of the subject together with time information.

9. 9. The intracardiac pressure estimation device according to claim 8, wherein the time variation information includes information on daily variation, and the control unit determines that the risk of disease is high when the daily variation is smaller than a predetermined threshold value.

10. The intracardiac pressure estimation device according to claim 1 , wherein the control unit determines a risk of disease based on the adjusted value of the intracardiac pressure.

11. The intracardiac pressure estimation device according to claim 9 , wherein the control unit takes into consideration the weight of the subject inputted into the input unit when determining the risk of the disease.

12. The intracardiac pressure estimation device of claim 9, which is used by the subject who has been discharged from a hospital after treatment for heart failure, and the control unit takes into account the period of time that has elapsed since the subject was discharged from the hospital, as input into the input unit, when determining the risk of the disease.

13. The intracardiac pressure estimation device according to claim 9 , wherein the control unit determines a schedule for measuring the cardiac-function-related information based on the determined risk of the disease.

14. A measuring device for measuring cardiac function-related information related to cardiac function; an intracardiac pressure estimation device including an acquisition unit that acquires the cardiac function-related information, an input unit that receives input of load information indicating the load applied to the body of the subject when the cardiac function-related information is measured, and a control unit that estimates intracardiac pressure, which is the pressure applied to the inside of the heart or blood vessels in the vicinity of the heart, based on the cardiac function-related information, acquires fluctuation factor information indicating fluctuation factors that may affect the intracardiac pressure and including the load information, and calculates an adjustment value for the intracardiac pressure in accordance with the fluctuation factor information; An intracardiac pressure estimation system comprising:

15. A method for estimating intracardiac pressure executed by a control unit of a computer, comprising: Obtaining cardiac function-related information related to cardiac function; a guide for inputting load information, which indicates a load applied to the body of the subject when the cardiac function-related information is measured, into an input unit; receiving the load information from the input unit; estimating an intracardiac pressure, which is a pressure applied to a blood vessel inside the heart or in the vicinity of the heart, based on the cardiac function-related information; Calculating an adjustment value of the intracardiac pressure according to fluctuation factor information including the load information, the fluctuation factor information indicating a fluctuation factor that may affect the intracardiac pressure Methods for estimating intracardiac pressure.

16. obtaining cardiac function-related information related to cardiac function; a process of instructing the subject to input, into an input unit, load information indicating a load placed on the subject's body when the cardiac function-related information is measured; A process of receiving the load information from the input unit; a process of estimating an intracardiac pressure, which is a pressure applied to a blood vessel inside the heart or in the vicinity of the heart, based on the cardiac function-related information; A process of calculating an adjustment value of the intracardiac pressure in accordance with fluctuation factor information, which is information indicating fluctuation factors that may affect the intracardiac pressure and includes the load information; A program that causes a processor to execute the following: