Patent Application
20240324969
The present disclosure generally relates to a diagnostic apparatus and a diagnostic program for determining a possibility of a cardiovascular disease such as a stroke.
In modern times, autonomic nerve disorders have been reported to be associated with various diseases. In addition, utilization of a diagnosis of a state of an autonomic nerve for prediction of risks and prognoses of diseases, detection of onsets of diseases, and the like has been studied. A cardiovascular disease such as a stroke is one disease, which is important to find early after onsets and start treatment. For example, the autonomic nerve is impaired in an acute phase of a stroke, and thus, there is a possibility that an onset of a stroke can be detected at a relatively early stage by monitoring an autonomic nerve function.
Japanese Patent Application Publication No. 2013-46662 A discloses an autonomic nerve function diagnostic apparatus for diagnosing an autonomic nerve function. The autonomic nerve function diagnostic apparatus described in Japanese Patent Application Publication No. 2013-46662 A can independently determine whether a function of a sympathetic nerve and a function of a parasympathetic nerve are normal.
Japanese Patent Application Publication No. 2013-46662 A does not disclose a method for determining a possibility of a cardiovascular disease such as a stroke.
A diagnostic apparatus and a diagnostic program are disclosed, which are capable of determining a possibility of a cardiovascular disease of a subject while preventing occurrence of false positive and false negative of a cardiovascular disease such as a stroke.
A diagnostic apparatus according to the present disclosure includes: a sympathetic nerve activity level index calculation unit configured to calculate a sympathetic nerve activity level index indicating a sympathetic nerve activity level; a parasympathetic nerve activity level index calculation unit configured to calculate a parasympathetic nerve activity level index indicating a parasympathetic nerve activity level; and a disease determination unit configured to determine a possibility of a cardiovascular disease of a subject on the basis of change tendency of the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit and change tendency of the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit.
According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index and the change tendency of the parasympathetic nerve activity level index, so that it is possible to prevent occurrence of false positive and false negative of the cardiovascular disease.
In the diagnostic apparatus according to the present disclosure, preferably, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where both the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit and the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit tend to decrease.
The sympathetic nerve activity level index and the parasympathetic nerve activity level index tend to change in a contradictory manner at normal times and at times other than an onset of a cardiovascular disease. According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where both the sympathetic nerve activity level index and the parasympathetic nerve activity level index tend to decrease, so that it is possible to further prevent occurrence of false positive and false negative of the cardiovascular disease and determine the possibility of the cardiovascular disease with higher accuracy.
In the diagnostic apparatus according to the present disclosure, preferably, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit becomes equal to or less than a first ratio with respect to the sympathetic nerve activity level index of the subject when the subject is healthy, and the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit becomes equal to or less than a second ratio with respect to the parasympathetic nerve activity level index of the subject when the subject is healthy.
According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index of the subject becomes equal to or less than the first ratio with respect to the sympathetic nerve activity level index of the subject when the subject is healthy and the parasympathetic nerve activity level index of the subject becomes equal to or less than the second ratio with respect to the parasympathetic nerve activity level index of the subject when the subject is healthy, so that it is possible to determine the possibility of the cardiovascular disease with higher accuracy in comparison with the subject when the subject is healthy.
In the diagnostic apparatus according to the present disclosure, preferably, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit becomes equal to or less than a third ratio with respect to the sympathetic nerve activity level index a predetermined period ago, and the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit becomes equal to or less than a fourth ratio with respect to the parasympathetic nerve activity level index the predetermined period ago.
According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index of the subject becomes equal to or less than the third ratio with respect to the sympathetic nerve activity level index of the subject himself/herself the predetermined period ago and the parasympathetic nerve activity level index of the subject becomes equal to or less than the fourth ratio with respect to the parasympathetic nerve activity level index of the subject himself/herself the predetermined period ago. It is therefore possible to prevent occurrence of false positive and false negative of the cardiovascular disease due to influence of diurnal variability of the sympathetic nerve activity level index and the parasympathetic nerve activity level index and to determine the possibility of the cardiovascular disease with higher accuracy.
In the diagnostic apparatus according to the present disclosure, preferably, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit becomes equal to or less than a first predetermined value smaller than the sympathetic nerve activity level index a predetermined period ago, and the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit becomes equal to or less than a second predetermined value smaller than the parasympathetic nerve activity level index the predetermined period ago.
According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index of the subject becomes equal to or less than the first predetermined value smaller than the sympathetic nerve activity level index of the subject himself/herself the predetermined period ago and the parasympathetic nerve activity level index of the subject becomes equal to or less than the second predetermined value smaller than the parasympathetic nerve activity level index of the subject himself/herself the predetermined period ago. It is therefore possible to prevent occurrence of false positive and false negative of the cardiovascular disease due to influence of diurnal variability of the sympathetic nerve activity level index and the parasympathetic nerve activity level index and to determine the possibility of the cardiovascular disease with higher accuracy.
In the diagnostic apparatus according to the present disclosure, preferably, the first predetermined value is determined on the basis of a change in the sympathetic nerve activity level index the predetermined period ago and a change in the sympathetic nerve activity level index in the same hours on or before the previous day, and/or the second predetermined value is determined on the basis of a change in the parasympathetic nerve activity level index the predetermined period ago and a change in the parasympathetic nerve activity level index in the same hours on or before the previous day.
According to the diagnostic apparatus of the present disclosure, the first predetermined value is determined on the basis of the change in the sympathetic nerve activity level index the predetermined period ago and the change in the sympathetic nerve activity level index in the same hours on or before the previous day. The second predetermined value is determined on the basis of the change in the parasympathetic nerve activity level index the predetermined period ago and the change in the parasympathetic nerve activity level index of the same hours on or before the previous day. This makes it possible to further prevent occurrence of false positive and false negative of the cardiovascular disease due to influence of diurnal variability of the sympathetic nerve activity level index and the parasympathetic nerve activity level index, and to determine the possibility of the cardiovascular disease with higher accuracy.
In the diagnostic apparatus according to the present disclosure, preferably, the cardiovascular disease is a stroke.
According to the diagnostic apparatus of the present disclosure, it is possible to prevent occurrence of false positive and false negative of the stroke among cardiovascular diseases.
In the diagnostic apparatus according to the present disclosure, preferably, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit becomes equal to or less than a fifth ratio with respect to the sympathetic nerve activity level index in the same hours on or before the previous day, and the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit becomes equal to or less than a sixth ratio with respect to the parasympathetic nerve activity level index in the same hours.
According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine that there is a possibility of the cardiovascular disease in a case where the sympathetic nerve activity level index of the subject becomes equal to or less than the fifth ratio with respect to the sympathetic nerve activity level index of the subject himself/herself in the same hours on or before the previous day and the parasympathetic nerve activity level index of the subject becomes equal to or less than the sixth ratio with respect to the parasympathetic nerve activity level index of the subject himself/herself in the same hours on or before the previous day. It is therefore possible to prevent occurrence of false positive and false negative of the cardiovascular disease due to influence of diurnal variability within a predetermined period of the sympathetic nerve activity level index and the parasympathetic nerve activity level index and to determine the possibility of the cardiovascular disease with higher accuracy.
Preferably, the diagnostic apparatus according to the present disclosure further includes a heartbeat interval calculation unit configured to calculate a heartbeat interval of the subject, in which the sympathetic nerve activity level index calculation unit is configured to calculate the sympathetic nerve activity level index on the basis of heart rate variability indicating variability of the heartbeat interval calculated by the heartbeat interval calculation unit, and the parasympathetic nerve activity level index calculation unit is configured to calculate the parasympathetic nerve activity level index on the basis of the heart rate variability.
According to the diagnostic apparatus of the present disclosure, the sympathetic nerve activity level index calculation unit is configured to calculate the sympathetic nerve activity level index on the basis of the heart rate variability to be used as an autonomic nerve index. The parasympathetic nerve activity level index calculation unit is configured to calculate the parasympathetic nerve activity level index on the basis of the heart rate variability to be used as the autonomic nerve index. For example, in a case where the heartbeat interval calculation unit is configured to calculate the heartbeat interval on the basis of an electrocardiogram and invasive blood pressure data, the disease determination unit can determine the possibility of the cardiovascular disease with higher accuracy. For example, in a case where the heartbeat interval calculation unit is configured to calculate the heartbeat interval on the basis of data measured by a wearable terminal, or the like, it is possible to prevent a scale of the diagnostic apparatus from becoming large and to reduce a burden associated with measurement to be felt by the subject, and the disease determination unit can easily determine the possibility of the cardiovascular disease even in a state where the subject is living his/her daily life.
In the diagnostic apparatus according to the present disclosure, preferably, the disease determination unit is configured to determine the possibility of the cardiovascular disease further on the basis of change tendency of the heartbeat interval calculated by the heartbeat interval calculation unit.
According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine the possibility of the cardiovascular disease on the basis of the change tendency (time domain analysis, or the like) of the heartbeat interval calculated by the heartbeat interval calculation unit, so that it is possible to determine the possibility of the cardiovascular disease with higher accuracy.
In the diagnostic apparatus according to the present disclosure, preferably, the sympathetic nerve activity level index calculation unit is configured to calculate the sympathetic nerve activity level index on the basis of frequency component analysis of the heart rate variability, and the parasympathetic nerve activity level index calculation unit is configured to calculate the parasympathetic nerve activity level index on the basis of the frequency component analysis of the heart rate variability.
According to the diagnostic apparatus of the present disclosure, the sympathetic nerve activity level index calculation unit is configured to calculate the sympathetic nerve activity level index by analyzing a frequency component of the heart rate variability using, for example, a frequency component analysis method such as fast Fourier transform. In addition, the parasympathetic nerve activity level index calculation unit is configured to calculate the parasympathetic nerve activity level index by analyzing a frequency component of the heart rate variability using, for example, a frequency component analysis method such as fast Fourier transform. Thus, the disease determination unit can determine the possibility of the cardiovascular disease with higher accuracy.
The diagnostic apparatus according to the present disclosure preferably further includes a biological information measurement unit configured to measure biological information including at least any one of a blood pressure, a body temperature, or a blood gas of the subject, in which the disease determination unit is configured to determine the possibility of the cardiovascular disease further on the basis of change tendency of the biological information measured by the biological information measurement unit.
The blood pressure, the body temperature and the blood gas tend to change immediately after an onset of the cardiovascular disease. According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine the possibility of the cardiovascular disease of the subject on the basis of not only the change tendency of the sympathetic nerve activity level index and the parasympathetic nerve activity level index but also the change tendency of at least any one of the blood pressure, the body temperature, or the blood gas of the subject, so that it is possible to further prevent occurrence of false positive and false negative of the cardiovascular disease and determine the possibility of the cardiovascular disease with higher accuracy.
The diagnostic apparatus according to the present disclosure preferably further includes a subject information input unit to which subject information including at least any one of information regarding daily movement of the subject, information regarding a drug to be used by the subject, or information regarding a basic disease of the subject is input, in which the disease determination unit is configured to determine the possibility of the cardiovascular disease further on the basis of the subject information input to the subject information input unit.
The sympathetic nerve activity level index and the parasympathetic nerve activity level index may also change depending on daily movement such as standing, meal, and sleeping of the subject, administration of a drug to the subject, medication to the subject, or a basic disease of the subject. According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index and the parasympathetic nerve activity level index in consideration of at least any one of the information regarding the daily movement of the subject, the information regarding the drug to be used by the subject, or the information regarding the basic disease of the subject. It is therefore possible to prevent occurrence of false positive and false negative of the cardiovascular disease due to influence of the daily movement, administration of a drug/medication, and the basic disease of the subject and to determine the possibility of the cardiovascular disease with higher accuracy.
Preferably, the diagnostic apparatus according to the present disclosure further includes a body motion measurement unit configured to measure body motion of the subject, and the disease determination unit is configured to determine the possibility of the cardiovascular disease further on the basis of the body motion measured by the body motion measurement unit.
The sympathetic nerve activity level index and the parasympathetic nerve activity level index may also change depending on the body motion of the subject. According to the diagnostic apparatus of the present disclosure, the disease determination unit is configured to determine the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index and the parasympathetic nerve activity level index in consideration of the body motion of the subject, so that it is possible to prevent occurrence of false positive and false negative of the cardiovascular disease due to influence of the body motion of the subject and to determine the possibility of the cardiovascular disease with higher accuracy.
Preferably, the diagnostic apparatus according to the present disclosure further includes a blood glucose measurement unit configured to measure blood glucose of the subject, and the disease determination unit is configured to determine the possibility of the cardiovascular disease further on the basis of change tendency of the blood glucose measured by the blood glucose measurement unit.
The sympathetic nerve activity level index and the parasympathetic nerve activity level index may also change depending on a change in the blood glucose of the subject. According to the diagnostic apparatus of the present disclosure, the disease determination unit determines the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index and the parasympathetic nerve activity level index in consideration of the blood glucose tendency of the subject, so that it is possible to prevent occurrence of false positive and false negative of the cardiovascular disease due to influence of the blood glucose of the subject and to determine the possibility of the cardiovascular disease with higher accuracy.
A non-transitory computer-readable medium storing a diagnostic program according to the present disclosure that causes a computer to execute: a sympathetic nerve activity level index calculation procedure of calculating a sympathetic nerve activity level index indicating a sympathetic nerve activity level; a parasympathetic nerve activity level index calculation procedure of calculating a parasympathetic nerve activity level index indicating a parasympathetic nerve activity level; and a disease determination procedure of determining a possibility of a cardiovascular disease of a subject on the basis of change tendency of the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation procedure and change tendency of the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation procedure.
According to the diagnostic program of the present disclosure, the diagnostic program causes the computer to execute the disease determination procedure for determining the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index and the change tendency of the parasympathetic nerve activity level index, so that it is possible to prevent occurrence of false positive and false negative of the cardiovascular disease.
A method for determining a possibility of a cardiovascular disease of a subject according to the present disclosure includes calculating a sympathetic nerve activity level index indicating a sympathetic nerve activity level; calculating a parasympathetic nerve activity level index indicating a parasympathetic nerve activity level; and determining the possibility of the cardiovascular disease of the subject on a basis of change tendency of the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit and change tendency of the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit.
According to the present disclosure, it is possible to provide a diagnostic apparatus and a diagnostic program capable of determining a possibility of a cardiovascular disease of a subject while preventing occurrence of false positive and false negative of the cardiovascular disease such as a stroke.
Set forth below with reference to the accompanying drawings is a detailed description of embodiments of a diagnostic apparatus and a diagnostic program for determining a possibility of a cardiovascular disease such as a stroke.
Note that the embodiment described below is a preferred specific example of the present disclosure, and thus various technically preferable limitations are given. However, the scope of the present disclosure is not limited to these aspects unless there is a description to limit the present disclosure in the following description. Furthermore, in the drawings, the same components are denoted by the same reference signs, and the detailed description of the same components are omitted.
A diagnostic apparatus 2 according to the present embodiment is an apparatus that determines a possibility of a cardiovascular disease such as a stroke, and can include an arithmetic unit 4, a determination unit 5, a storage unit 8, and a communication unit 9. The diagnostic apparatus 2 may further include a measurement unit 3, a notification unit 6, an input unit 7, and a display unit 10. In accordance with an embodiment, the measurement unit 3, the notification unit 6, the input unit 7, and the display unit 10 may be provided as part of the diagnostic apparatus 2 or may be provided as another apparatus different from the diagnostic apparatus 2.
The cardiovascular disease can include, but are not limited to, a stroke (cerebral infarction, cerebral hemorrhage, subarachnoid hemorrhage, etc.), and a heart disease (ischemic heart disease such as acute myocardial infarction, heart failure, atrial fibrillation, angina pectoris, etc.).
The measurement unit 3 can include a heart rate measurement unit 31, a body motion measurement unit 32, and a biological information measurement unit 33.
The heart rate measurement unit 31 measures heartbeat, that is, a heart rate of the subject. Examples of the heart rate measurement unit 31 can include an electrocardiogram monitor, a pulse wave monitor, and a sphygmomanometer. The heart rate measurement unit 31 is not limited to an apparatus to be used in a hospital, and a wristband-type wearable terminal, or the like, which is used outside the hospital and can measure the heart rate is preferable because it allows monitoring of a cardiovascular disease even in a state where the subject is living his/her daily life.
The body motion measurement unit 32 measures body motion or a body position of the subject. The body motion referred to herein is a change in posture, that is, motion associated with a change in posture such as from standing to sitting, from standing to lying, from sitting to lying, from sitting to standing, from lying to sitting, from lying to standing, from lying to sitting, from lying to standing, and the like, minute motion in association with breathing during sleep, and the like, and does not include motion of the body due to daily movement, sports, or walking. Examples of the body motion measurement unit 32 include a body motion sensor installed under a bed, a camera, an ultrasonic measurement device, a three-axis acceleration sensor attached to a subject, and the like.
Examples of the body motion sensor include a sensor that detects body motion in association with breathing or rolling over by detecting a pressure change by a pressure sensor built in an air mat. In addition, a wearable measurement device including a three-axis acceleration sensor can be applied as the body motion sensor.
The biological information measurement unit 33 measures biological information including a blood pressure, a body temperature, and a blood gas of the subject. In addition, the biological information measurement unit 33 may measure blood glucose of the subject. Thus, a “blood glucose measurement unit” of the present disclosure may be included in the biological information measurement unit 33. Examples of the biological information measurement unit 33 include thermography, a blood glucose meter, and the like.
The arithmetic unit 4 acquires various kinds of information from the measurement unit 3 and the input unit 7, reads a program stored in the storage unit 8 and executes various kinds of calculation and processing. Alternatively, the arithmetic unit 4 acquires various kinds of information from another apparatus via the communication unit 9, reads a program stored in the storage unit 8 and executes various kinds of calculation and processing. Examples of the arithmetic unit 4 can include a central processing unit (CPU) and a field programmable gate array (FPGA).
The arithmetic unit 4 can include a heartbeat interval calculation unit 41, a sympathetic nerve activity level index calculation unit 42, and a parasympathetic nerve activity level index calculation unit 43.
The heartbeat interval calculation unit 41 calculates a heartbeat interval of the subject on the basis of data measured by the heart rate measurement unit 31. For example, the heartbeat interval calculation unit 41 calculates an interval between R waves of an electrocardiogram, that is, an interval (R-R interval) between vertices of R waves adjacent to each other in a waveform of the electrocardiogram as the heartbeat interval on the basis of the electrocardiogram measured by the electrocardiogram monitoring. In addition, the heartbeat interval calculation unit 41 calculates variability of the heartbeat interval (heart rate variability) of the subject. For example, the heartbeat interval calculation unit 41 calculates variability in the interval of the R waves of the electrocardiogram, that is, variability in an instantaneous heart rate as the heart rate variability.
Furthermore, the heartbeat interval calculation unit 41 executes time domain analysis of the heart rate variability, and calculates, as a time domain index of the heart rate variability, a mean value (Mean) of the R-R intervals (RRI), standard deviation (SDNN) of the R-R intervals, standard deviation (SDANN) over 24 hours of the average R-R interval for each of 5 minutes, and a square root of a mean of squares of a difference between the adjacent R-R intervals (rMSSD) (see
The analysis may be performed on the accumulated data at timings for each of a predetermined number of days (for example, for each day) or timings in real time or for each of a short period (for example, five minutes). Furthermore, in addition to the above items, the heartbeat interval calculation unit 41 may calculate other items related to the heart rate variability, such as a coefficient of variation of RRI (CVRR, value obtained by dividing SDNN by a mean value of RRI), an NN50 (total number of RRI differences exceeding 50 ms which are consecutively adjacent), a PNN50 (ratio of heart rates for which difference in the RRI which are consecutively adjacent exceeds 50 ms), and a VLF (ultra-low frequency band).
Note that the heartbeat interval calculation unit 41 may calculate the heartbeat interval and the heart rate variability on the basis of measurement data other than the electrocardiogram. For example, the heartbeat interval calculation unit 41 may calculate the heartbeat interval and the heart rate variability on the basis of a pulse wave and an invasive blood pressure of the subject. Thus, as described above, the heart rate measurement unit 31 is not limited to the electrocardiogram monitoring and may be pulse wave monitoring, a sphygmomanometer, or the like. In the present embodiment, a case where the heart rate measurement unit 31 performs electrocardiogram monitoring will be described as an example.
The sympathetic nerve activity level index calculation unit 42 calculates a sympathetic nerve activity level index indicating a sympathetic nerve activity level on the basis of the heart rate variability calculated by the heartbeat interval calculation unit 41. For example, the sympathetic nerve activity level index calculation unit 42 calculates LF/HF as the sympathetic nerve activity level index on the basis of the low frequency component LF and the high frequency component HF calculated by the heartbeat interval calculation unit 41 (see
The parasympathetic nerve activity level index calculation unit 43 calculates a parasympathetic nerve activity level index indicating a parasympathetic nerve activity level on the basis of the heart rate variability calculated by the heartbeat interval calculation unit 41. For example, the parasympathetic nerve activity level index calculation unit 43 sets the high frequency component HF calculated by the heartbeat interval calculation unit 41 as the parasympathetic nerve activity level index (see
The determination unit 5 includes a disease determination unit 51. Examples of the determination unit 5 include a CPU and an FPGA. The disease determination unit 51 determines a possibility of a cardiovascular disease of the subject on the basis of change tendency (A: rise/decrease) of the sympathetic nerve activity level index (LF/HF) calculated by the sympathetic nerve activity level index calculation unit 42 and change tendency (B: rise/decrease) of the parasympathetic nerve activity level index (HF) calculated by the parasympathetic nerve activity level index calculation unit 43. This will be described later in detail.
In addition, the disease determination unit 51 may determine the possibility of the cardiovascular disease of the subject further on the basis of change tendency of the heartbeat interval calculated by the heartbeat interval calculation unit 41. In other words, the disease determination unit 51 may determine the possibility of the cardiovascular disease of the subject further on the basis of change tendency (C: rise/decrease) of at least any one of Mean, SDNN, SDANN, or rMSSD calculated as a time domain index of the heart rate variability by the heartbeat interval calculation unit 41.
Furthermore, the disease determination unit 51 may determine the possibility of the cardiovascular disease of the subject further on the basis of the body motion or posture (C: body motion associated with change in posture such as standing to sitting, standing to lying, sitting to lying, sitting to standing, lying to sitting, and lying to standing, and minute body motion in association with breathing during sleep) of the subject measured by the body motion measurement unit 32. In addition, the disease determination unit 51 may determine the possibility of the cardiovascular disease of the subject further on the basis of change tendency (C: rise/decrease) in biological information (a blood pressure, a body temperature, a blood gas, blood glucose, etc.) of the subject measured by the biological information measurement unit 33.
The input unit 7 receives input of subject information including at least any one of information regarding daily movement (meal, sleep, etc.) of the subject, information regarding a drug to be used by the subject, or information regarding a basic disease of the subject. The input unit 7 of the present embodiment is an example of a “subject information input unit” of the present disclosure. The subject information may be input using a method in which the subject information is input by the subject himself/herself or a method in which the subject information is automatically input from the biological information measurement device. The input unit 7 transmits the input subject information to the determination unit 5. The input unit 7 may transmit the subject information to the determination unit 5 via the communication unit 9. Examples of the input unit 7 include a portable electronic terminal apparatus such as a tablet computer. As for the meal, a blood glucose level of the subject may be monitored by a blood glucose meter, and it may be determined that the subject has had a meal when the blood glucose level rises.
The disease determination unit 51 may determine the possibility of the cardiovascular disease further on the basis of the subject information (C: daily movement, administration of a drug/medication, a basic disease) input to the input unit 7.
The notification unit 6 gives a notification of an alert in a case where the disease determination unit 51 determines that the subject has a possibility of the cardiovascular disease. For example, the notification unit 6 gives a notification that the subject has a possibility of the cardiovascular disease by sound, light, or the like. Alternatively, the notification unit 6 may display on the display unit 10 that the subject has a possibility of the cardiovascular disease. The notification unit 6 may notify not only the subject but also a family member of the subject or a medical institution near the home of the subject or used by the subject of the alert by communication.
The storage unit 8 stores various programs such as a calculation program for controlling calculation operation of the heartbeat interval calculation unit 41, the sympathetic nerve activity level index calculation unit 42, and the parasympathetic nerve activity level index calculation unit 43, a determination program for controlling determination operation of the disease determination unit 51, a notification program for controlling notification operation of the notification unit 6, and a display program for controlling display operation of the display unit 10. In addition, the storage unit 8 stores various kinds of data such as calculation data of the heartbeat interval calculation unit 41, the sympathetic nerve activity level index calculation unit 42, and the parasympathetic nerve activity level index calculation unit 43, and determination data of the disease determination unit 51. Note that the program is not limited to being stored in the storage unit 8 and the program may be stored in advance in a computer-readable storage medium and distributed, or may be downloaded to the diagnostic apparatus 2 via a network.
Examples of the storage unit 8 include a semiconductor memory built in the diagnostic apparatus 2. Alternatively, examples of the storage unit 8 include various storage media such as a compact disc (CD), a digital versatile disc (DVD), a random access memory (RAM), a read only memory (ROM), a hard disk, and a memory card connectable to the diagnostic apparatus 2, a data server, and the like.
The heartbeat interval calculation unit 41, the sympathetic nerve activity level index calculation unit 42, and the parasympathetic nerve activity level index calculation unit 43 are implemented by the arithmetic unit 4 executing a program stored (stored) in the storage unit 8. The disease determination unit 51 is implemented by the arithmetic unit 4 executing a program stored (stored) in the storage unit 8. Note that the heartbeat interval calculation unit 41, the sympathetic nerve activity level index calculation unit 42, the parasympathetic nerve activity level index calculation unit 43, and the disease determination unit 51 may be implemented by hardware or may be implemented by a combination of hardware and software.
The program to be executed by the computer including the arithmetic unit 4 and the determination unit 5 corresponds to a “diagnostic program” of the present disclosure. The “computer” as used herein is not limited to a personal computer and includes an arithmetic processing apparatus and a microcomputer which are included in an information processing apparatus, and collectively refers to a device and an apparatus which are capable of implementing the functions of the present disclosure with a program.
Here, the autonomic nerve includes a sympathetic nerve that mainly functions in an active state and a parasympathetic nerve that mainly functions in a resting state. When the living body is in a tension/active state, a state of the autonomic nerve becomes a sympathetic nerve dominant state. On the other hand, when the living body is in a resting state, the state of the autonomic nerve becomes a parasympathetic nerve dominant state. As described above, the activity levels of the sympathetic nerve and the parasympathetic nerve are in a contradictory relationship and vary within a day. For example, the sympathetic nerve activity is dominant in the daytime, whereas the parasympathetic nerve is dominant at night. Furthermore, the activity levels of the sympathetic nerve and the parasympathetic nerve may vary in a short period of a day in association with body motion of the subject caused by a change in posture such as from standing to sitting, from standing to lying, from sitting to lying, from sitting to standing, from lying to sitting, from lying to standing. In addition, even in a case where movement of the subject is relatively small, the activity levels of the sympathetic nerve and the parasympathetic nerve may vary depending on daily movement, meal, sleep, administration of a drug, medication, and the like. Furthermore, the activity levels of the sympathetic nerve and the parasympathetic nerve may vary in a case of diseases other than the cardiovascular disease such as a stroke. Thus, if a possibility of the cardiovascular disease such as a stroke is determined only by setting a threshold regarding the activity levels of the sympathetic nerve and the parasympathetic nerve and determining abnormality of the sympathetic nerve and the parasympathetic nerve, false positive and false negative of the cardiovascular disease may occur.
On the other hand, the disease determination unit 51 of the diagnostic apparatus 2 according to the present embodiment determines the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit 42 and the change tendency of the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit 43. More specifically, according to the findings obtained by the present inventors, in a case where there is a possibility of an onset of a stroke, both the sympathetic nerve activity level index and the parasympathetic nerve activity level index tend to decrease. Thus, the disease determination unit 51 of the diagnostic apparatus 2 according to the present embodiment determines that there is a possibility of an onset of a stroke in a case where both the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit 42 and the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit 43 tend to decrease.
According to the diagnostic apparatus 2 of the present embodiment, the disease determination unit 51 determines the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit 42 and the change tendency of the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit 43. It is therefore possible to prevent occurrence of false positive and false negative of the cardiovascular disease. In addition, on the basis of the findings obtained by the present inventors that the sympathetic nerve activity level index and the parasympathetic nerve activity level index tend to change in a contradictory manner at normal times and at times other than an onset of a stroke, the disease determination unit 51 determines that there is a possibility of an onset of a stroke in a case where both the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit 42 and the parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit 43 tend to decrease. Thus, the disease determination unit 51 can further prevent occurrence of false positive and false negative of the cardiovascular disease and determine a possibility of an acute cardiovascular disease with higher accuracy.
Hereinafter, the determination operation of the disease determination unit 51 will be further described with reference to the drawings.
As indicated in
In the following description, the sympathetic nerve activity level index calculated by the sympathetic nerve activity level index calculation unit 42 may be simply referred to as a “sympathetic nerve activity level index 52”. The parasympathetic nerve activity level index calculated by the parasympathetic nerve activity level index calculation unit 43 may be simply referred to as a “parasympathetic nerve activity level index 53”. The subject information including information regarding daily movement (meal, sleep, etc.) of the subject, information regarding a drug to be used by the subject, and information regarding a basic disease of the subject input to the input unit 7, the time domain index of the heart rate variability calculated by the heartbeat interval calculation unit 41, the body motion (a body position, sleep) of the subject measured by the body motion measurement unit 32, and the biological information (a blood pressure, a body temperature, a blood gas, blood glucose, etc.) of the subject measured by the biological information measurement unit 33 may be simply referred to as “additional information 54”.
In the following description, a case will be described as an example where the disease determination unit 51 determines a possibility of a “stroke” as an example of the cardiovascular disease. A case will be described as an example where the sympathetic nerve activity level index calculation unit 42 calculates LF/HF as the sympathetic nerve activity level index 52 on the basis of the low frequency component LF and the high frequency component HF calculated by the heartbeat interval calculation unit 41. A case will be described as an example where the parasympathetic nerve activity level index calculation unit 43 sets the high frequency component HF calculated by the heartbeat interval calculation unit 41 as the parasympathetic nerve activity level index.
As indicated in
In addition, as indicated in
On the other hand, as indicated in
According to this, the disease determination unit 51 can further prevent occurrence of false positive and false negative of the stroke and determine the possibility of the stroke with higher accuracy. In addition, in a case where the possibility of the stroke of the subject is determined further on the basis of the time domain index of the heart rate variability calculated by the heartbeat interval calculation unit 41 as the additional information 54, the disease determination unit 51 can determine the possibility of the stroke with higher accuracy. Furthermore, in a case where the possibility of the stroke of the subject is determined further on the basis of the body motion (change in posture from a supine position to a standing position, minute body motion in association with breathing during sleep, absence of body motion for a certain period of time although not sleeping (disappearance of body motion)) of the subject measured by the body motion measurement unit 32 as the additional information 54, the disease determination unit 51 can prevent occurrence of false positive and false negative of the stroke due to influence of the body motion of the subject and determine the possibility of the stroke with higher accuracy. Furthermore, in a case where the possibility of the stroke of the subject is determined further on the basis of the biological information (a blood pressure, a body temperature, a blood gas, blood glucose, etc.) of the subject measured by the biological information measurement unit 33 as the additional information 54, the disease determination unit 51 can help prevent occurrence of false positive and false negative of the stroke due to influence of the biological information of the subject and determine the possibility of the stroke with higher accuracy. Furthermore, in a case where the possibility of the stroke is determined further on the basis of the subject information (daily movement, administration of a drug/medication, a basic disease) input to the input unit 7 as the additional information 54, the disease determination unit 51 can prevent occurrence of false positive and false negative of the stroke due to influence of the daily movement, administration of a drug/medication, and the basic disease of the subject, and determine the possibility of the stroke with higher accuracy.
As indicated in
As indicated in
In addition, as indicated in
On the other hand, as indicated in
According to this, an effect similar to the effect described above with reference to
As indicated in
As indicated in
On the other hand, as described above with respect to
According to this, an effect similar to the effect described above with reference to
A numerical value of “healthy person” indicate in
In the example indicated in
In the example indicated in
According to this, the disease determination unit 51 determines that there is a possibility of a stroke in a case where the sympathetic nerve activity level index 52 of the subject becomes equal to or less than the first ratio with respect to the sympathetic nerve activity level index 52 of the healthy person (that is, when the subject is healthy) and the parasympathetic nerve activity level index 53 of the subject becomes equal to or less than the second ratio with respect to the parasympathetic nerve activity level index 53 of the healthy person (that is, when the subject is healthy), so that it is possible to determine the possibility of the stroke with higher accuracy in comparison with the healthy person (that is, when the subject is healthy).
In the graphs indicated in
First, with reference to
As indicated in
Here, as indicated by a two-dot (chain curve in
As indicated in
Here, as indicated by a two-dot chain curve in
In the curves indicated by two-dot chain lines in
Next, with reference to
The change tendency and diurnal variability of the sympathetic nerve activity level index 52 (LF/HF) at normal times are as described above with respect to
Here, as indicated by the two-dot chain curve in
In addition, as indicated in
As indicated by the two-dot chain curve in
In addition, as indicated in
As indicated by the two-dot chain curves in
According to this, the disease determination unit 51 determines that there is a possibility of a stroke in a case where the sympathetic nerve activity level index 52 calculated by the sympathetic nerve activity level index calculation unit 42 becomes equal to or less than the fifth ratio with respect to the sympathetic nerve activity level index 52 in the same hours on or before the previous day and the parasympathetic nerve activity level index 53 calculated by the parasympathetic nerve activity level index calculation unit 43 becomes equal to or less than the sixth ratio with respect to the parasympathetic nerve activity level index 53 in the same hours on or before the previous day. It is therefore possible to prevent occurrence of false positive and false negative of the stroke due to influence of the diurnal variability within a predetermined period of the sympathetic nerve activity level index 52 and the parasympathetic nerve activity level index 53 and to determine the possibility of the stroke with higher accuracy.
In addition, as indicated by the two-dot chain curve in
The “predetermined period” as used herein can be, for example, about 30 minutes or more and 1 hour or less (i.e., 30 minutes to one (1) hour). The third ratio can be, for example, about 10% or more and 20% or less (i.e., 10% to 20%). In addition, instead of the ratio, for example, a value obtained by subtracting a predetermined value (for example, 0.1) from the sympathetic nerve activity level index 52 (LF/HF) one hour ago may be used as a threshold (first predetermined value) for abnormality determination. Here, the value to be subtracted from the sympathetic nerve activity level index 52 (LF/HF) one hour ago is preferably determined on the basis of the change tendency in the same hours on or before the previous day.
As indicated by the two-dot chain curve in
The fourth ratio can be, for example, about 10% or more and 20% or less (i.e., 10% to 20%). The fourth ratio may be the same as or different from the third ratio. In addition, instead of the ratio, as a criterion for abnormality determination, a value obtained by subtracting a predetermined value (for example, 0.5) from the value of the parasympathetic nerve activity level index 53 (HF) one hour ago is abnormal, may be used as a threshold (second predetermined value) for abnormality determination. Here, the value to be subtracted from the value of the parasympathetic nerve activity level index 53 (HF) one hour ago is preferably determined on the basis of the change tendency of the parasympathetic nerve activity level index 53 (HF) on or before the previous day.
As indicated by the two-dot chain curves in
According to this, the disease determination unit 51 determines that there is a possibility of a stroke in a case where the sympathetic nerve activity level index 52 calculated by the sympathetic nerve activity level index calculation unit 42 becomes equal to or less than the third ratio with respect to the sympathetic nerve activity level index 52 a predetermined period ago and the parasympathetic nerve activity level index 53 calculated by the parasympathetic nerve activity level index calculation unit 43 becomes equal to or less than the fourth ratio with respect to the parasympathetic nerve activity level index 53 the predetermined period ago. It is therefore possible to prevent occurrence of false positive and false negative of the stroke due to influence of the diurnal variability of the sympathetic nerve activity level index 52 and the parasympathetic nerve activity level index 53 and to determine the possibility of the stroke with higher accuracy.
In addition, the disease determination unit 51 may determine that there is a possibility of a stroke in a case where the sympathetic nerve activity level index 52 calculated by the sympathetic nerve activity level index calculation unit 42 becomes equal to or less than a first predetermined value smaller than the sympathetic nerve activity level index 52 a predetermined period ago and the parasympathetic nerve activity level index 53 calculated by the parasympathetic nerve activity level index calculation unit 43 becomes equal to or less than a second predetermined value smaller than the parasympathetic nerve activity level index 53 the predetermined period ago. The “predetermined period” as used herein can be, for example, about 30 minutes or more and 1 hour or less (i.e., 30 minutes to one (1) hour).
The first predetermined value is determined on the basis of a change in the sympathetic nerve activity level index 52 of a predetermined period ago and a change in the sympathetic nerve activity level index 52 in the same hours on or before the previous day. In addition, the second predetermined value is determined on the basis of a change in the parasympathetic nerve activity level index 53 a predetermined period ago and a change in the parasympathetic nerve activity level index 53 in the same hours on or before the previous day.
According to this, the disease determination unit 51 can prevent occurrence of false positive and false negative of the stroke due to influence of the diurnal variability of the sympathetic nerve activity level index 52 and the parasympathetic nerve activity level index 53, and can determine the possibility of the stroke with higher accuracy.
As indicated in
In the example indicated in
Then, if a stroke occurs, a state in which the blood pressure is higher than the blood pressure at rest continues for a predetermined period T2 or more. The “predetermined period T2” as used here can be, for example, about 30 minutes or more and 60 minutes or less (i.e., 30 minutes to 60 minutes).
The disease determination unit 51 determines the possibility of the stroke of the subject not only on the basis of the change tendency of the sympathetic nerve activity level index 52 and the parasympathetic nerve activity level index 53 but also on the basis of the change tendency of the blood pressure of the subject. This enables the disease determination unit 51 to further prevent occurrence of false positive and false negative of the stroke and determine the possibility of the stroke with higher accuracy.
If a stroke occurs, the blood gas varies at a predetermined ratio or higher within a predetermined period. The “predetermined period” as used here can be, for example, about 5 minutes or more and 10 minutes or less (i.e., 5 minutes to 10 minutes). The “predetermined ratio” as used here can be, for example, about 5%.
Items of the blood gas test available for detecting an onset of cerebral infarction include hydrogen ion concentration (pH), a carbon dioxide partial pressure (pCO2), an oxygen partial pressure (pO2), base excess (BE), bicarbonate ion concentration (HCO3−), sodium ion concentration (Na+), potassium ion concentration (K+), calcium ion concentration (Ca2+), a blood glucose level (Glu), and the like.
The disease determination unit 51 determines the possibility of the stroke of the subject not only on the basis of the change tendency of the sympathetic nerve activity level index 52 and the parasympathetic nerve activity level index 53 but also on the basis of the change tendency of the blood gas of the subject. This enables the disease determination unit 51 to further prevent occurrence of false positive and false negative of the stroke and determine the possibility of the stroke with higher accuracy.
Note that the disease determination unit 51 may determine the possibility of the stroke on the basis of not only the blood pressure described above with reference to
As described above, according to the diagnostic apparatus 2 of the present embodiment, the disease determination unit 51 determines the possibility of the cardiovascular disease of the subject on the basis of the change tendency of the sympathetic nerve activity level index 52 and the change tendency of the parasympathetic nerve activity level index 53, so that it is possible to prevent occurrence of false positive and false negative of the cardiovascular disease and determine the possibility of the stroke with higher accuracy. For example, the disease determination unit 51 determines that there is a possibility of an onset of a stroke in a case where both the sympathetic nerve activity level index 52 calculated by the sympathetic nerve activity level index calculation unit 42 and the parasympathetic nerve activity level index 53 calculated by the parasympathetic nerve activity level index calculation unit 43 tend to decrease. Thus, the disease determination unit 51 can further prevent occurrence of false positive and false negative of the cardiovascular disease and determine the possibility of the cardiovascular disease with higher accuracy.
The sympathetic nerve activity level index calculation unit 42 calculates the sympathetic nerve activity level index 52 on the basis of the heart rate variability to be used as the autonomic nerve index. The parasympathetic nerve activity level index calculation unit 43 calculates the parasympathetic nerve activity level index 53 on the basis of the heart rate variability to be used as the autonomic nerve index. For example, in a case where the heartbeat interval calculation unit 41 calculates the heartbeat interval on the basis of the electrocardiogram and the invasive blood pressure data, the disease determination unit 51 can determine the possibility of the cardiovascular disease with higher accuracy. For example, in a case where the heartbeat interval calculation unit 41 calculates the heartbeat interval on the basis of data measured by a wearable terminal, or the like, it is possible to prevent a scale of the diagnostic apparatus 2 from becoming relatively large and to reduce a burden associated with measurement to be felt by the subject, and the disease determination unit 51 can more easily determine the possibility of the cardiovascular disease even in a state where the subject is living his/her daily life.
In addition, in a case where the disease determination unit 51 determines the possibility of the cardiovascular disease on the basis of the change tendency (time domain analysis, or the like) of the heartbeat interval calculated by the heartbeat interval calculation unit 41, the possibility of the cardiovascular disease can be determined with higher accuracy.
In addition, the sympathetic nerve activity level index calculation unit 42 calculates the sympathetic nerve activity level index 52 by analyzing a frequency component of the heart rate variability using a frequency component analysis method such as fast Fourier transform, for example. In addition, the parasympathetic nerve activity level index calculation unit 43 calculates the parasympathetic nerve activity level index 53 by analyzing a frequency component of the heart rate variability using a frequency component analysis method such as fast Fourier transform, for example. Thus, the disease determination unit 51 can determine the possibility of the cardiovascular disease with higher accuracy.
The detailed description above describes to a diagnostic apparatus and a diagnostic program for determining a possibility of a cardiovascular disease such as a stroke. The invention is not limited, however, to the precise embodiments and variations described. Various changes, modifications and equivalents can be effected by one skilled in the art without departing from the spirit and scope of the invention as defined in the accompanying claims. It is expressly intended that all such changes, modifications and equivalents which fall within the scope of the claims are embraced by the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-001937 | Jan 2022 | JP | national |
This application is a continuation of International Application No. PCT/JP2022/045150 filed on Dec. 7, 2022, which claims priority to Japanese Application No. 2022-001937 filed on Jan. 7, 2022, the entire content of both of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/JP2022/045150 | Dec 2022 | WO |
| Child | 18740727 | US |
