Cardiac disease examination device and method of operating the cardiac disease examination device

Abstract

To provide a heart disease examination device and heart disease examination method capable of examining heart diseases such as aortic stenosis without largely depending on determination of a medical professional such as a doctor.SOLUTION: A heart disease examination device includes a systolic murmur area calculation part for calculating an area of a systolic murmur in heart sound, an IUT calculation part for calculating an IUT (Initial Upstroke Time), the index representing a degree of sluggishness in a rise of a pulse wave, and a determination part for determining whether or not there is aortic stenosis based on the area of the systolic murmur and IUT.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a cardiac disease examination apparatus and a cardiac disease examination method for examining cardiac diseases such as aortic valve stenosis. [Background technology]

[0002] Aortic valve stenosis (AS) is a disease in which the aortic valve, one of the four valves in the heart that is located between the left ventricle and the aorta, becomes difficult to open due to inflammation and hardening. The number of AS patients is on the rise due to the aging population.

[0003] When the aortic valve narrows, the heart tries to overcome the narrowing and squeeze blood throughout the body, placing pressure on the left ventricle, which then becomes enlarged as a compensatory mechanism. Eventually, the left ventricle is unable to withstand the strain, leading to irreversible left ventricular dysfunction, heart failure, and sudden death.

[0004] AS can progress unnoticed, and the prognosis is poor once severe symptoms appear, so early detection and appropriate timing of surgery are essential.

[0005] Primary screening for AS is primarily performed by auscultation of the heart (the systolic murmur specific to AS).

[0006] If a doctor is unable to make a diagnosis based on a heart murmur, they will palpate the pulse (delay in the onset of the pulse wave) or perform an electrocardiogram. If these tests reveal any abnormalities, a detailed echocardiogram will be performed to make a definitive diagnosis and determine the severity of the condition.

[0007] However, experience is required for a doctor to perform cardiac auscultation accurately. Patent Document 1 discloses a technique for determining systolic murmurs using an electrocardiogram and a phonocardiogram. It is believed that this technique can automatically detect cardiac murmurs that may indicate diseases such as aortic valve stenosis, even if the doctor has no experience. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-169615 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-168074 Summary of the Invention [Problem to be solved by the invention]

[0009] As mentioned above, doctors determine the possibility of AS by auscultating the heart sounds. However, systolic murmurs may also be heard in addition to AS, and it is particularly important to distinguish between senile systolic murmurs (systolic murmurs often heard in elderly people without valvular disease) and mitral regurgitation.

[0010] When cardiologists are unsure of the diagnosis, they screen for AS by taking a comprehensive assessment, including pulse diagnosis and electrocardiogram findings. For inexperienced doctors and non-cardiologists, auscultation alone is difficult, and the difficulty increases even more when it comes to making a comprehensive assessment. This can lead to AS being overlooked, potentially preventing early detection.

[0011] The present invention has been made in consideration of the above points, and provides a heart disease examination device and a heart disease examination method that can examine heart diseases such as aortic valve stenosis without relying heavily on the judgment of medical professionals such as doctors. [Means for solving the problem]

[0012] One aspect of the cardiac disease examination device of the present invention is a heart sound acquisition unit for acquiring the heart sound of the subject; a determination unit that determines a cardiac disease based on an area of ​​a systolic murmur in the heart sound acquired by the heart sound acquisition unit; Equipped with.

[0013] One embodiment of the cardiac disease examination method of the present invention comprises: acquiring a heart sound of the subject; a determining step of determining a cardiac disease based on an area of ​​a systolic murmur in the acquired heart sounds; Includes: [Effects of the Invention]

[0014] According to the present invention, it becomes possible to examine heart diseases such as aortic valve stenosis without relying heavily on the judgment of medical professionals such as doctors. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram showing the overall configuration of a blood pressure pulse wave inspection device according to an embodiment. [Figure 2] A block diagram showing the main configuration of a cardiac disease examination device according to an embodiment. [Figure 3] Diagram explaining systolic murmur [Figure 4] FIG. 10 is a diagram illustrating the area of ​​a systolic murmur calculated by a systolic murmur area calculation unit. [Figure 5] Diagram for explaining IUT [Figure 6] 10 is a flowchart showing a procedure of a determination process performed by a determination unit. [Figure 7] A diagram showing the relationship between threshold determination by the determination unit and patients with aortic valve stenosis. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

[0017] <1> Overall configuration of blood pressure pulse wave inspection device FIG. 1 is a diagram showing the overall configuration of a blood pressure pulse wave examination device 1 to which the cardiac disease examination device and cardiac disease examination method of the present invention are applied.

[0018] In FIG. 1, the main body 1a of the blood pressure pulse wave inspection device 1 is provided with an arithmetic processing unit 10, an input unit 70, a display unit 80, a printing unit 91, a memory unit 92, an audio output unit 93, a blood pressure pulse wave measuring unit 30, a heart sound measuring unit 40, an electrocardiogram measuring unit 50, and a pulse wave measuring unit 60.

[0019] The blood pressure pulse wave measurement unit 30 has an upper arm measurement control unit 31 and a lower limb measurement control unit 32. A right upper arm cuff 21R and a left upper arm cuff 21L are connected to the upper arm measurement control unit 31 via hoses 21h, and a right ankle cuff 22R and a left ankle cuff 22L are connected to the lower limb measurement control unit 32 via hoses 22h.

[0020] A heart sound microphone 23 is connected to the heart sound measurement unit 40. A four limb electrocardiogram electrode unit 24a and a chest electrocardiogram electrode unit 24b are connected to the electrocardiogram measurement unit 50. Amorphous pulse wave sensors 25a and 25b are connected to the pulse wave measurement unit 60.

[0021] The arithmetic processing unit 10 is a computer having a CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), various interfaces, etc. The arithmetic processing unit 10 performs arithmetic processing for determining heart disease, which will be described below, by executing a control program stored in the ROM with the CPU. In other words, the arithmetic processing unit 10 has the function of determining heart disease.

[0022] In addition, the calculation processing unit 10 controls the upper arm measurement control unit 31, the lower limb measurement control unit 32, the heart sound measurement unit 40, the electrocardiogram measurement unit 50, and the pulse wave measurement unit 60 (hereinafter referred to as "each biological information measurement unit"), which measure various types of biological information.

[0023] The arithmetic processing unit 10 also receives biological information supplied from each biological information measurement unit. When the received biological information needs to be displayed on a screen, it edits or converts it into display data and outputs it to the display unit 80, and when it needs to be printed on a report form, it edits or converts it into print data and outputs it to the printing unit 91. The arithmetic processing unit 10 also stores the received biological information in the storage unit 92 and reads out the stored biological information as appropriate.

[0024] The calculation processing unit 10 also performs waveform analysis of the biological information received from each biological information measurement unit. In the waveform analysis, characteristic parts (dividing points) in the waveform are detected. Examples of characteristic parts include the start of the second heart sound, the rising edge of the pulse wave at the upper arm, the rising edge of the pulse wave at the ankle, and the notch of the pulse wave at the upper arm.

[0025] The arithmetic processing unit 10 calculates the degree of arteriosclerosis based on the analysis result and the value (for example, blood pressure) indicated by the received biological information.

[0026] In addition, the calculation processing unit 10 receives inputs and instructions from the input unit 70 through user operations, and in accordance with the received contents, performs settings related to the functions of each biometric information measurement unit, display unit 80, printing unit 91, memory unit 92 and audio output unit 93, and controls the start and stop of each operation.

[0027] The display unit 80 is a display device having a display screen such as an LCD (Liquid Crystal Display), and displays on the screen the biological information, analysis results, arteriosclerosis degree, etc. input from the arithmetic processing unit 10 as display data.

[0028] The printing unit 91 has as its main components a paper feed mechanism, a printing head, etc., and prints on paper the biological information, analysis results, and arteriosclerosis degree input as printing data from the arithmetic processing unit 10.

[0029] The storage unit 92 is configured with a hard disk drive, a writable optical disk drive, a nonvolatile memory, etc., and is capable of storing information from the processing unit 10.

[0030] The audio output unit 93 has a speaker or the like as a main component, and outputs a guidance voice, an alert sound, or the like in accordance with the guidance data or an alert sound output instruction signal input from the calculation processing unit 10.

[0031] The input unit 70 is composed of a keyboard, a mouse, buttons, a touch panel, etc., and receives inputs and instructions from the user's operations and sends them to the arithmetic processing unit 10.

[0032] Pulse wave measuring unit 60 supplies the subject's pulse wave signals detected by amorphous pulse wave sensors 25a, 25b appropriately attached to the subject to calculation processing unit 10. This allows measurement and analysis of the pulse wave. Note that one of amorphous pulse wave sensors 25a, 25b is attached, for example, to the subject's carotid artery, and the other is attached, for example, to the subject's femoral artery or knee.

[0033] In this embodiment, the blood pressure pulse wave measuring unit 30 is configured by providing an upper limb measurement control unit 31 and a lower limb measurement control unit 32 independently, but the upper limb measurement control unit 31 and the lower limb measurement control unit 32 may be integrated together. For measuring blood pressure pulse waves by the blood pressure pulse wave measuring unit 30 having the upper limb measurement control unit 31 and the lower limb measurement control unit 32, known technology such as that described in Patent Document 2 may be used, and therefore detailed description thereof will be omitted here.

[0034] The electrocardiogram measurement unit 50 supplies electrocardiogram signals detected by the four limb electrocardiogram electrodes 24a and the chest electrocardiogram electrodes 24b attached to the subject to the arithmetic processing unit 10. This allows electrocardiogram measurement and analysis. The four limb electrocardiogram electrodes 24a typically consist of four electrocardiogram electrodes attached to the right wrist, left wrist, right ankle, and left ankle, respectively. The electrocardiogram electrodes for both ankles are preferably configured so that their attachment to both ankles is not obstructed by the right ankle cuff 22R and the left ankle cuff 22L. The chest electrocardiogram electrode unit 25b typically consists of six electrocardiogram electrodes attached to six locations on the chest.

[0035] The heart sound measurement unit 40 supplies a heart sound signal detected by the heart sound microphone 23 attached to the subject to the calculation processing unit 10. In this way, the heart sounds are measured and analyzed.

[0036] <2> Determining heart disease according to this embodiment As described above, the arithmetic processing unit 10 of this embodiment has the function of diagnosing cardiac disease. In practice, it has the configuration shown in Fig. 2, and diagnosing cardiac disease is performed using this configuration. The arithmetic processing unit 10 has a systolic noise area calculation unit 11, an IUT (Initial Upstroke Time) calculation unit 12, and a determination unit 13.

[0037] The systolic noise area calculation unit 11 calculates the area of ​​the systolic noise in the heart sounds measured by the heart sound measurement unit 40. The IUT calculation unit 12 inputs the pulse wave (blood pressure pulse wave) measured by the blood pressure pulse wave measurement unit 30 and calculates the IUT, which is an index that indicates how sluggish the rise of the pulse wave is (which can also be said to be due to sleeping). Specifically, the degree to which the rise is sluggish can be expressed by the slope (gradient). For example, when the angle with the time axis is 0, the slope (gradient) is 0, and it can be said that the slope (gradient) increases as the angle with the time axis increases. Therefore, it can be said that the sluggish rise of the pulse wave is the smaller the slope (gradient), and the larger the IUT.

[0038] The determination unit 13 determines whether or not there is a cardiac disease based on the area of ​​the systolic noise calculated by the systolic noise area calculation unit 11 and the IUT calculated by the IUT calculation unit 12.

[0039] Here, a brief explanation will be given of the systolic murmur, the systolic murmur area, and the IUT.

[0040] FIG. 3 is a diagram used to explain systolic murmurs. FIG. 3 shows an electrocardiogram, heart sounds, and heart murmurs. The peak of the R wave in the electrocardiogram and the start of the first heart sound are approximately the same, and the end of the T wave in the electrocardiogram and the start of the second heart sound are approximately the same. The systole (ventricular systole) can be said to be the period from the peak of the R wave to the end of the T wave, or the period from the end of the first sound to the start of the second sound. The systolic murmur is a noise contained in the heart sounds during the systole (ventricular systole). In other words, the systolic murmur is the heart sounds during the systole (ventricular systole) excluding the first and second sounds.

[0041] FIG. 4 is a diagram illustrating the area of ​​the systolic murmur calculated by the systolic noise area calculation unit 11. As can be seen from the figure, the systolic noise area calculation unit 11 calculates the area enclosed by the envelope of the amplitude of the systolic murmur. Specifically, the systolic noise area calculation unit 11 detects the first and second heart sounds, determines the heart sounds between them as systolic murmurs, and calculates the area enclosed by the envelope of their amplitude. Note that the area calculated by the systolic noise area calculation unit 11 is not limited to this, and for example, the area of ​​the systolic murmur for only a portion of the systole may be calculated. That is, the systolic noise area calculation unit 11 of this embodiment calculates the area of ​​the systolic murmur for the entire systole as shown in the example of FIG. 4. However, it is also possible to calculate the area for only the latter half of the systole, the latter half of the systole, or a portion including the point at which the maximum amplitude of the systolic murmur appears.

[0042] Fig. 5 is a diagram illustrating the IUT calculated by the IUT calculation unit 12. As shown in Fig. 5, the IUT is the time it takes for a tangent drawn to the ascending limb at the beginning of the rise of the pulse wave to reach its wave height. Therefore, it can be said that the larger the IUT, the slower the rise of the pulse wave.

[0043] 6 is a flowchart showing the procedure of the determination process performed by the determination unit 13. When the determination unit 13 starts the process, it determines in step S11 whether the area of ​​the systolic murmur is equal to or greater than a predetermined threshold A1. If the determination unit 13 determines that the area of ​​the systolic murmur is equal to or greater than the predetermined threshold A1, it proceeds to step S12 and determines that AS is present (i.e., the subject has aortic stenosis).

[0044] On the other hand, if the determination unit 13 determines that the area of ​​the systolic murmur is less than the predetermined threshold A1, the process proceeds to step S13. In step S13, the determination unit 13 determines whether the area of ​​the systolic murmur is equal to or greater than a predetermined threshold A2. Here, the relationship between the thresholds A1 and A2 is A1>A2.

[0045] If the determining unit 13 determines that the area of ​​the systolic murmur is less than the predetermined threshold A2, the process proceeds to step S15, where it determines that there is no AS (that is, the subject does not have aortic stenosis).

[0046] On the other hand, if the determination unit 13 determines that the area of ​​the systolic murmur is equal to or greater than the predetermined threshold A2, the process proceeds to step S14. In step S14, the determination unit 13 determines whether the IUT is equal to or greater than the predetermined threshold B1. If the determination unit 13 determines that the IUT is equal to or greater than the predetermined threshold B1, the process proceeds to step S12, where it determines that AS is present (i.e., the subject has aortic stenosis).

[0047] In this way, the judgment unit 13 judges that AS is present when the area of ​​the systolic murmur is very large (i.e., when it is equal to or greater than threshold A1), and judges that AS is not present when the area of ​​the systolic murmur is very small (i.e., when it is less than threshold A2).

[0048] On the other hand, when the area of ​​the systolic murmur is medium, the judgment unit 13 refers to the value of IUT (i.e., refers to the extent to which the rise of the pulse wave is sluggish), and determines that AS is present if the value of IUT is equal to or greater than threshold B1 (i.e., if the rise of the pulse wave is sluggish), and determines that AS is not present if the value of IUT is less than threshold B1 (i.e., if the rise of the pulse wave is steep).

[0049] FIG. 7 is a diagram showing the relationship between the threshold determination by the determination unit 13 and patients with aortic valve stenosis. In the diagram, a black circle indicates an AS patient, and a circle indicates a non-AS patient. If a positive result is obtained in step S11, patients with values ​​equal to or greater than the threshold A1 in the diagram are determined to be AS patients. In other words, patients in the region [1]+[2] in the diagram are determined to be AS patients.

[0050] If a negative result is obtained in step S11 and a negative result is obtained in step S13, patients whose scores are below threshold A1 and below threshold A2 in the figure are determined to be non-AS patients. In other words, patients in area [4] in the figure are determined to be non-AS patients.

[0051] If a negative result is obtained in step S11, a positive result is obtained in step S13, and a positive result is obtained in step S14, patients whose scores are less than threshold A1, equal to or greater than threshold A2, and equal to or greater than threshold B1 in the figure are determined to be AS patients. In other words, patients in area [3] in the figure are determined to be AS patients.

[0052] In this way, by using not only the area of ​​the systolic murmur but also the degree of blunting of the pulse wave rise as an index for determining aortic stenosis, it is possible to more accurately determine whether or not aortic stenosis is present compared to when aortic stenosis is determined based solely on the area of ​​the systolic murmur. In other words, it is possible to reduce erroneous determinations of the presence or absence of aortic stenosis compared to when determination is based solely on the area of ​​the systolic murmur.

[0053] As described above, according to this embodiment, by providing the systolic murmur area calculation unit 11 that calculates the area of ​​the systolic murmur in the heart sounds, the IUT calculation unit 12 that calculates the IUT which is an index showing the degree of slowing of the rising edge of the pulse wave, and the determination unit 13 that determines whether or not there is aortic stenosis based on the systolic murmur area and the IUT, it is possible to realize a heart disease examination apparatus and a heart disease examination method that can examine heart diseases such as aortic stenosis without relying largely on the judgment of medical professionals such as doctors.

[0054] The above-described embodiments are merely examples of specific embodiments of the present invention, and the technical scope of the present invention should not be construed as being limited by these embodiments. In other words, the present invention can be embodied in various forms without departing from the gist or main characteristics thereof.

[0055] In the above-described embodiment, the case where IUT is used as an index representing the degree of slowing of the rising edge of the pulse wave is described, but the present invention is not limited to this, and another index may be used as an index representing the degree of slowing of the rising edge of the pulse wave.

[0056] In the above embodiment, a case has been described in which aortic stenosis is determined based on the area of ​​the systolic murmur and the pulse wave, but aortic stenosis may also be determined based on the area of ​​the systolic murmur without using the pulse wave. However, as described above, using not only the area of ​​the systolic murmur but also the pulse wave makes it possible to more accurately determine whether aortic stenosis is present.

[0057] Furthermore, in addition to the above-described embodiment, aortic stenosis may be determined using an electrocardiogram in addition to the area of ​​the systolic murmur and the degree of slowing of the pulse wave rise. For example, aortic stenosis may be determined using a left ventricular hypertrophy index, such as Cornell voltage, Cornell product, or Sokolow-Lyon voltage, in the electrocardiogram. Here, the larger the value of Cornell voltage, Cornell product, or Sokolow-Lyon voltage in the electrocardiogram, the more advanced the left ventricular hypertrophy, i.e., the more aortic stenosis, which causes left ventricular hypertrophy, is present. In consideration of this, the determination unit 13 may perform a determination that tends to indicate aortic stenosis as the value of Cornell voltage, Cornell product, or Sokolow-Lyon voltage increases, taking into account a left ventricular hypertrophy index, such as Cornell voltage, Cornell product, or Sokolow-Lyon voltage.

[0058] Cornell Voltage, Cornell Product, and Sokolow-Lyon Voltage are well-known indicators and will be explained briefly below. Cornell Voltage is the value of R amplitude (aVL) + S amplitude (V3) on an electrocardiogram. Cornell Product is the value of {R amplitude (aVL) + S amplitude (V3)} × QRS width. Sokolow-Lyon Voltage is the value of S amplitude (V1) + R amplitude (V5 or V6).

[0059] In the above-described embodiment, the cardiac disease examination device and cardiac disease examination method of the present invention are described as being embodied by a blood pressure pulse wave examination device 1, but the cardiac disease examination device and cardiac disease examination method of the present invention are not limited to this, and may also be embodied by a device (such as a personal computer) separate from the blood pressure pulse wave examination device.

[0060] In essence, the cardiac disease examination apparatus of the present invention may include a calculation unit that calculates the area of ​​a systolic murmur in a heart sound acquired by the heart sound acquisition unit, and a determination unit that determines whether a heart disease has occurred based on the area calculated by the calculation unit. The cardiac disease examination apparatus of the present invention may further include a pulse wave acquisition unit that acquires a pulse wave of the subject, and the determination unit may determine whether a heart disease has occurred based on the onset of the pulse wave in addition to the area of ​​the systolic murmur. Here, the heart sound acquisition unit and the pulse wave acquisition unit may be the heart sound measurement unit 40 and the blood pressure pulse wave measurement unit 30 as in the above-described embodiment, or may be an input unit such as an interface that inputs heart sound information and pulse wave information.

[0061] Furthermore, in the above-described embodiment, the case of determining whether or not there is aortic stenosis has been described, but the present invention is not limited to this and can also be applied to determining other heart diseases (cardiac valve diseases) such as MR (Mitral Regurgitation). In this case, the thresholds A1, A2, and B1 in the above-described embodiment may be appropriately changed, or other indices may be introduced. [Industrial Applicability]

[0062] The present invention is widely applicable to a heart disease examination apparatus and a heart disease examination method for examining heart diseases such as aortic valve stenosis. [Explanation of symbols]

[0063] 1. Blood pressure pulse wave testing device 10. Processing unit 11 Systolic noise area calculation section 12 IUT calculation part 13 Judgment section 30 Blood pressure pulse wave measurement unit 40 Heart sound measurement unit 50 Electrocardiogram measurement unit

Claims

1. a heart sound acquisition unit for acquiring the heart sound of the subject; a pulse wave acquiring unit for acquiring a pulse wave of the subject; a calculation unit that calculates an area of ​​a systolic murmur in the heart sound acquired by the heart sound acquisition unit; a determination unit for determining heart disease based on the area calculated by the calculation unit; Equipped with the determination unit determines whether the subject has aortic stenosis based on the rise of the pulse wave in addition to the area of ​​the systolic murmur, and determines that the subject has aortic stenosis when the area of ​​the systolic murmur is equal to or greater than a predetermined threshold, or when the area of ​​the systolic murmur is less than the predetermined threshold and the rise of the pulse wave is slower than the predetermined threshold. Cardiac disease testing equipment.

2. A cardiac disease examination device according to claim 1, Blood pressure pulse wave testing device.

3. A step in which a heart sound acquisition unit acquires the heart sound of a subject; a step in which a pulse wave acquiring unit acquires a pulse wave of the subject; a processor calculating an area of ​​a systolic murmur in the acquired heart sounds; The processor determines whether a heart disease exists based on the calculated area; Including, The processor determines whether the subject has a heart disease based on the upstroke of the pulse wave in addition to the area of ​​the systolic murmur, and determines that the subject has aortic stenosis if the area of ​​the systolic murmur is equal to or greater than a predetermined threshold, or if the area of ​​the systolic murmur is less than the predetermined threshold and the upstroke of the pulse wave is slower than the predetermined threshold. A method for operating a cardiac disease screening device.

Images