Apparatus and method for measuring jugular venous pressure waveform

Abstract

The device for measuring jugular vein pressure waveforms includes a rotation sensor (102) configured to generate a measurement signal when it is in contact with the individual's skin and in a relationship with the individual's jugular vein (104) that detects movement. [Solution] The device includes a processing system (101) configured to receive a measurement signal and generate a waveform of skin movement perpendicular to the skin based on the measurement signal indicating rotation of a rotation sensor, wherein the waveform of skin movement indicates a jugular vein pressure waveform. The rotation sensor that measures rotation does not respond to movements unrelated to fluctuations in jugular vein pressure, for example, an acceleration sensor.

Description

Technical Field

[0001] The present disclosure relates to an apparatus and method for measuring a jugular venous pressure "JVP" waveform. The measured jugular venous pressure waveform can be used, for example, to detect pulmonary arterial hypertension "PAH".

Background Art

[0002] Abnormalities that can occur in the cardiovascular system can gradually deteriorate an individual's health if not diagnosed and appropriately treated and / or cured. For example, pulmonary arterial hypertension "PAH" often represents an early sign of an impending worsening stage of heart failure that occurs, on average, 3 to 4 weeks after the onset of pulmonary arterial hypertension. In many cases, pulmonary arterial hypertension can predict the worsening stage of heart failure at a sufficiently early stage where typical signs of heart failure, such as weight gain and elevated blood pressure, are usually absent. Heart failure diagnosed at an early stage can generally be treated and / or cured, thereby significantly reducing the mortality rate and the need for hospitalization.

[0003] Examination of the behavior of the jugular veins (vena jugularis in Latin) represents a useful tool for diagnosing conditions such as heart failure. Fluctuations in jugular venous pressure are produced by changes in blood flow and blood pressure in the central veins resulting from the filling and contraction of the right atrium and right ventricle of the heart. The jugular veins are directly connected to the right atrium, which opens the door to non-invasive examinations targeting the right side of the heart, i.e., the right ventricle and right atrium. U.S. Patent Application Publication No. 2019254542 describes a venous pressure monitoring system configured to determine central venous pressure (CVP) based on jugular venous pressure (JVP). The venous pressure monitoring system described in U.S. Patent Application Publication No. 2019254542 comprises a signal processor, at least one accelerometer, at least one display, and at least one patch configured to be fixed to the individual's neck in other cases, so as to be held in place. The signal processor communicates with at least one accelerometer to calculate an estimate of central venous pressure. An inherent challenge associated with the aforementioned systems based on one or more accelerometers is that the output signal from each accelerometer includes not only a signal component resulting from fluctuations in jugular venous pressure, but also a signal component resulting from movement unrelated to fluctuations in jugular venous pressure. The latter signal component reduces the accuracy of the central venous pressure estimate.

[0004] The paper "Acquisition of Jugular Venous Pulse Waveforms by Non-Invasive Techniques, Recent advances in mechanical engineering, Lecture notes in mechanical engineering, Springer, Singapore, January 25, 2020" describes a method for measuring jugular venous pressure (JVP) using an accelerometer. The paper "Estimation of Central Venous Pressure by Ultrasound, Resuscitation64(2), 193-199, February 1, 2005" by Baumann, U., Marquis, C., Stoupis, C., Willenberg, T., Takala, J., and Jakob, S. describes a method for estimating central venous pressure (CVP) using ultrasound signals.

[0005] U.S. Patent Application Publication No. 2018184977 describes a method for measuring jugular vein characteristics. The method includes connecting a device including an imaging device to the neck of a patient, imaging the jugular vein at an imaging site using the imaging device, and analyzing at least one image provided by the imaging device to estimate at least one characteristic of the jugular vein. U.S. Patent Application Publication No. 2012136240 describes a system for detecting and measuring global or local elevated intracranial pressure. The system comprises a device for performing controlled occlusion of the jugular vein's cranial blood outflow and generating occlusion data associated with the controlled occlusion, a cranial blood outflow pressure measuring device, and a processor for processing the jugular vein's cranial blood outflow occlusion data and cranial blood outflow data to identify and / or measure a functional relationship between the controlled occlusion of the jugular vein and the jugular vein's cranial blood outflow pressure. International Publication No. 2008098353 describes a device for non-invasively measuring at least one cardiovascular parameter. The device comprises at least one light source emitting light in the wavelength range of 400 nm to 1000 nm, at least one photodetector configured to receive light from patient tissue adjacent to the cardiovascular system and generate an output based on the received light, and at least one probe for delivering light from the light source to the patient tissue. U.S. Patent Application Publication No. 2012197118 describes an ultrasound monitoring device for measuring physiological parameters in mammals. The ultrasound monitoring device comprises a substrate, a plurality of ultrasound transducer elements, computer-readable memory, a microprocessor, and a power supply. The ultrasound transducer elements are connected to the substrate. Each ultrasound transducer element is independently configured to transmit a signal to a target region of a mammal and receive echo signals returning from the target region. International Publication No. 2018161159 describes a device for measuring jugular venous pressure in a patient. The device comprises a main body that defines a longitudinal housing and has windows along the length of the longitudinal housing, allowing light to exit from the longitudinal housing, and a beam generator having a movable part mounted inside the longitudinal housing.The beam generator is configured to generate a sheet of light along a plane perpendicular to the longitudinal direction, at a position adjustable along the longitudinal direction, and to direct the sheet of light outwards through a window. The device further comprises an adjustment mechanism for adjusting the position of a movable part of the beam generator relative to the main body along the longitudinal direction, and a reading device for indicating the position of the sheet of light along the longitudinal direction. U.S. Patent Application Publication No. 2010094141 describes a jugular venous pressure (JVP) ruler and a method for using the ruler to measure a patient's jugular venous pressure. The JVP ruler comprises an oscillator configured to detect the displacement of the patient's skin. [Overview of the Initiative]

[0006] The following provides a simplified overview to offer a basic understanding of several aspects of various embodiments of the invention. This overview is not a comprehensive summary of the invention. It is not intended to identify any major or significant elements of the invention, nor to describe its scope. The following overview simply presents some concepts of the invention in a simplified form, serving as a prelude to a more detailed description of exemplary embodiments of the invention.

[0007] In this specification, the term “geometric,” when used as a prefix, means a geometric concept that is not necessarily part of any physical object. A geometric concept may be, for example, a geometric point, a straight or curved geometric line, a geometric plane, a non-planar geometric surface, a geometric space, or any other geometric entity that is 0-dimensional, 1-dimensional, 2-dimensional, or 3-dimensional.

[0008] According to the present invention, a novel device for measuring jugular venous pressure (JVP) waveforms is provided. The measured jugular venous pressure waveform can be used, for example, to detect pulmonary hypertension (PAH).

[0009] The apparatus according to the present invention is -A rotation sensor, such as a gyroscope, configured to generate a measurement signal indicating the rotation of the rotation sensor when it is in contact with an individual's skin and in a relationship with the individual's jugular vein to detect movement, - A processing system configured to receive a measurement signal and generate a waveform of skin movement perpendicular to the skin based on the measurement signal, wherein the skin movement waveform represents a jugular vein pressure waveform. It is equipped with.

[0010] It is advantageous for a rotation sensor to be positioned such that one end is closer to the jugular vein than the other end. Therefore, fluctuations in jugular vein pressure result in greater movement at the first end of the rotation sensor than at the last end, and this difference manifests as rotational movement of the rotation sensor. Movements that are not related to jugular vein pressure and have substantially the same amplitude and direction across the entire skin area covered by the rotation sensor do not result in significant rotational movement of the rotation sensor, but only translational movement, and thus this movement does not result in a significant signal component in the output signal of the rotation sensor. Therefore, a rotation sensor that measures rotation is less responsive to many movements unrelated to fluctuations in jugular vein pressure than, for example, an accelerometer that measures translational movement.

[0011] The pulsations produced by the jugular vein differ from those produced by the carotid artery. This is due to the difference in structure between the thin-walled, flexible jugular vein and the thick-walled, powerful carotid artery, as well as the different pressures within the jugular and carotid arteries, approximately 10 mmHg in the jugular vein and 100 mmHg in the carotid artery. Experiments have shown that the signal generated by the rotation sensor is a purer signal produced by the jugular vein, while the signal generated by the acceleration sensor is a mixture of signals produced by the jugular and carotid arteries. This can be explained by the difference between the types of motion measured using the rotation sensor and the acceleration sensor, as well as the difference between the types of motion produced by the jugular vein and the carotid artery. The jugular vein produces localized motion in the tissue covering it, while the carotid artery produces sharper pulsations, which result in translational motion over a larger area. As previously stated herein, movements unrelated to jugular venous pressure and having substantially the same amplitude and direction over a larger skin area do not result in significant rotational movement in the rotation sensor, but only translational movement, and thus this movement does not result in a significant signal component in the output signal of the rotation sensor. Therefore, the rotation sensor is less responsive to movement caused by the carotid artery than, for example, an accelerometer that measures translational movement.

[0012] The advantage of rotational sensors over optical sensors is that optical sensors can only measure pulsations originating from the external jugular vein (vena jugularis externa), and therefore must be precisely positioned to cover the external jugular vein, which makes the use of optical sensors difficult. Rotational sensors primarily measure pulsations originating from the internal jugular vein (vena jugularis interna), and therefore the positioning requirements are not as difficult as when using optical sensors.

[0013] According to the present invention, a new method for measuring the jugular venous pressure (JVP) waveform is provided. The method according to the present invention is -Generating a measurement signal using a rotation sensor that is in contact with the individual's skin and has a relationship to detect movement relative to the individual's jugular vein, - Based on the measurement signal indicating the rotation of the rotation sensor, a waveform of skin movement perpendicular to the skin is generated, The waveform of skin movement, including the jugular venous pressure waveform, is shown.

[0014] Exemplary and non-limiting embodiments are described in the attached dependent claims.

[0015] Various exemplary and non-limiting embodiments relating to both the structure and the method of operation, along with their further objectives and advantages, will be best understood by reading the following descriptions of specific exemplary embodiments in conjunction with the accompanying drawings.

[0016] The verbs "to include" and "to have" are used herein as open limitations that do not exclude the existence of features not listed, nor do they require such existence.

[0017] The features enumerated in the attached dependent claims can be freely combined with each other unless otherwise explicitly stated. Furthermore, it should be understood that the use of "a" or "an," i.e., a single form, throughout this specification does not exclude the plural. [Brief explanation of the drawing]

[0018] Exemplary and non-limiting embodiments and their advantages are described below in more detail with reference to the accompanying drawings. [Figure 1] An exemplary and non-limiting embodiment of a device for measuring jugular venous pressure (JVP) waveforms is shown. [Figure 2a] An example waveform generated using an apparatus according to an exemplary and non-limiting embodiment is shown. [Figure 2b] An exemplary waveform of angular displacement generated using an apparatus according to an exemplary and non-limiting embodiment is shown. [Figure 2c] The corresponding waveform of the displacement generated using the accelerometer is shown. [Figure 3] An exemplary and non-limiting embodiment of a device for measuring jugular venous pressure (JVP) waveforms is shown. [Figure 4] A flowchart of a method according to an exemplary and non-limiting embodiment for measuring the jugular venous pressure (JVP) waveform is shown. [Modes for carrying out the invention]

[0019] Description of exemplary and non-limiting embodiments The specific examples provided in the following description should not be construed as limiting the scope and / or applicability of the attached claims. The list and groups of examples provided in the description are not exhaustive unless explicitly stated otherwise.

[0020] FIG. 1 shows an exemplary and non - limiting embodiment of an apparatus for measuring a jugular venous pressure “JVP” waveform. The apparatus comprises a rotation sensor 102, such as a gyroscope, configured to generate a measurement signal indicative of the rotation of the rotation sensor 102 when the rotation sensor 102 is in contact with the skin 103 of an individual 107 and is in a relationship to detect movement with respect to the jugular vein 104 of the individual. The rotation sensor 102 can be, for example, part of a mobile phone disposed in contact with the skin of the individual 107. The apparatus comprises a processing system 101 configured to receive the measurement signal and, based on the measurement signal, generate a waveform of the movement of the skin 103 in a direction perpendicular to the skin. The waveform of the movement of the skin represents the jugular venous pressure “JVP” waveform. In a part 120 of FIG. 1, the direction perpendicular to the skin 103 is substantially parallel to the z - axis line of the coordinate system 199. The processing system 101 can be, for example, part of a mobile phone. Further, both the processing system 101 and the rotation sensor 102 can be, for example, part of the same mobile phone. In this exemplary case, the mobile phone constitutes an apparatus for measuring the jugular venous pressure “JVP” waveform. In the exemplary case shown in FIG. 1, the waveform of the movement of the skin 103 and thereby the jugular venous pressure “JVP” waveform are represented using the temporal variation of the rotation angle φ of the rotation sensor 102. The apparatus can comprise, for example, a display for presenting the measured jugular venous pressure “JVP” waveform. The display is not shown in FIG. 1. It is also possible for the apparatus to comprise a data transfer interface for supplying data representing the jugular venous pressure “JVP” waveform to an external device. The data transfer interface is not shown in FIG. 1.

[0021] In an apparatus according to an exemplary and non - limiting embodiment, the rotation sensor 102 is configured to measure the angular velocity ω of the rotation sensor 102, and the processing system 101 is configured to calculate the time integral of the angular velocity.

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[0022] In an exemplary and non-limiting embodiment of the apparatus, the rotation sensor 102 is configured to measure the angular acceleration α of the rotation sensor 102, and the processing system 101 is configured to calculate a first time integral I1, which is the time integral of the angular acceleration α, and a second time integral I2, which is the time integral of the first time integral.

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[0023] The above embodiment, in which the rotation sensor 102, for example a gyroscope, is configured to measure angular velocity ω, is advantageous in that it requires only one integration with respect to time to obtain the waveform of the angular displacement φ of the skin. Integration with respect to time has a low-pass filter effect, and therefore it is advantageous when only one integration with respect to time is required. For example, if an accelerometer is used, it is possible to obtain the waveform of angular displacement φ using trigonometric functions, but the quality of the measurement is reduced because two integrations with respect to time are required, and furthermore, data processing becomes difficult because trigonometric functions are required.

[0024] In an exemplary and non-limiting embodiment of the apparatus, the processing system 101 is configured to receive electrical signals from electrodes 105 and 106 on the skin of an individual 107, and the processing system 101 is configured to generate an electrocardiogram (ECG) at time intervals of the jugular venous pressure waveform. That is, the jugular venous pressure waveform and the ECG are synchronized with each other.

[0025] Apparatus in exemplary and non-limiting embodiments may also include two or more rotation sensors that measure the same jugular vein to improve accuracy. Furthermore, one or more rotation sensors in apparatus in exemplary and non-limiting embodiments may be one or more implants placed under the skin. The implants may utilize radio frequency identification (RFID) technology to transfer measurement signals from the implants to the processing system of the apparatus.

[0026] Figure 2a shows an exemplary jugular venous pressure waveform 210 and an exemplary electrocardiogram 211 generated using an apparatus according to an exemplary and non-limiting embodiment. The jugular venous pressure waveform 210 and the electrocardiogram 211 are measured simultaneously.

[0027] In an exemplary and non-limiting embodiment of the apparatus, the processing system 101 is configured to generate an indicator signal representing pulmonary hypertension (PAH) in response to a situation in which the a-wave of the jugular venous pressure waveform exceeds a predetermined threshold. The a-wave of the jugular venous pressure waveform 210 is shown in Figure 2a. The increase in the a-wave is characteristic of pulmonary hypertension (PAH), which is caused by an increase in fluid resistance to the pulmonary artery through the pulmonary valve. This is reflected in the jugular vein via the right atrium.

[0028] Figure 2b shows an exemplary waveform of angular displacement generated using an apparatus according to an exemplary and non-limiting embodiment. In this exemplary case, the apparatus includes a gyroscope configured to measure angular velocity, and therefore only one integration with respect to time is required to obtain the angular displacement waveform. As shown in Figure 2b, the angular displacement waveform obtained using the gyroscope can represent a-wave, c-wave, h-wave, and v-wave. Figure 2c shows the displacement waveform obtained with two integrations with respect to time, based on a signal measured perpendicular to the skin using an accelerometer. As shown in Figure 2c, it is not possible to distinguish between a-wave, c-wave, h-wave, and v-wave from the waveform obtained using the accelerometer.

[0029] Figure 3 shows an apparatus for measuring jugular vein pressure (JVP) waveforms according to an exemplary and non-limiting embodiment. The apparatus includes a rotation sensor 302, such as a gyroscope, configured to generate a measurement signal indicating the rotation of the rotation sensor 302 when the rotation sensor 302 is in contact with an individual's skin 303 and is in a relationship to detect movement relative to the individual's jugular vein 304. The apparatus includes a processing system 301 configured to receive the measurement signal and, based on the measurement signal, generate a waveform of the skin 303 motion in a direction perpendicular to the skin. In Figure 3, the direction perpendicular to the skin 303 is substantially parallel to the z-axis of coordinate system 399. The skin motion waveform represents the jugular vein pressure (JVP) waveform. In the exemplary case shown in Figure 3, the skin motion waveform and the resulting jugular vein pressure (JVP) waveform are represented using the temporal variation of the rotation angle φ of the rotation sensor 302.

[0030] The exemplary device shown in Figure 3 comprises a sheet of flexible material 308 with an adhesive for attaching a rotation sensor 302 to an individual's skin 303. Thus, the device can be used in various positions on an individual, for example, when the individual is standing.

[0031] In the exemplary apparatus shown in Figure 3, the processing system 301 and the rotation sensor 302 are configured to maintain a wireless connection to transfer measurement signals from the rotation sensor 302 to the processing system 301. For example, the wireless connection may be a Bluetooth® connection or a Near Field Communication (NFC) connection. The wireless connection may also be an optical connection or an infrared connection.

[0032] Each of the processing systems 101 and 301 shown in Figures 1 and 3 may be implemented by, for example, one or more processor circuits, each of which may be a programmable processor circuit provided with appropriate software, such as a dedicated hardware processor such as an application-specific integrated circuit (ASIC), or a configurable hardware processor such as a field-programmable gate array (FPGA). Each of the processing systems 101 and 301 may further include memory implemented by, for example, one or more memory circuits, each of which may be, for example, a random access memory (RAM) device.

[0033] Figure 4 shows a flowchart of a method according to an exemplary and non-limiting embodiment for measuring the jugular venous pressure (JVP) waveform. This method involves the following steps: - Operation 401: Generate a measurement signal using a rotation sensor that is in contact with the individual's skin and is in a relationship to detect movement relative to the individual's jugular vein, - Operation 402: Based on the measurement signal indicating the rotation of the rotation sensor, generate a waveform of skin movement perpendicular to the skin, The waveform of skin movement, including the jugular venous pressure waveform, is shown.

[0034] In an exemplary and non-limiting embodiment, the method includes measuring the angular velocity of the rotation sensor, and calculating the time integral of the measured angular velocity. The measured angular velocity of the rotation sensor represents the measurement signal described above, and the time integral of the measured angular velocity represents the jugular vein pressure waveform.

[0035] In an exemplary and non-limiting embodiment, the method includes a rotation sensor measuring the angular acceleration of the rotation sensor, and the method calculating a first time integral which is the time integral of the measured angular acceleration, and a second time integral which is the time integral of the first time integral. The measured angular acceleration of the rotation sensor represents the measurement signal described above, and the second time integral represents the jugular vein pressure waveform.

[0036] A method according to an exemplary and non-limiting embodiment includes receiving one or more electrical signals from electrodes on an individual's skin and generating an electrocardiogram at time intervals of jugular venous pressure waveforms.

[0037] In the method according to an exemplary and non-limiting embodiment, the measurement signal is received from a rotation sensor via a wireless connection.

[0038] A method according to an exemplary and non-limiting embodiment includes generating an indicator signal representing pulmonary hypertension "PAH" in response to a situation in which the a-wave of the jugular venous pressure waveform exceeds a predetermined threshold.

[0039] The specific examples provided in the description above should not be construed as limiting the scope and / or applicability of the appended claims. The list and groups of examples provided in the description above are not exhaustive unless explicitly stated otherwise. Accordingly, the exemplary waveforms and other exemplary results presented above and / or in the figures should not be construed as limiting the scope and / or applicability of the appended claims.

Claims

1. A device for measuring jugular venous pressure waveforms, The apparatus includes a processing system (101, 301) configured to receive a measurement signal. The device comprises a rotation sensor (102, 302) configured to generate a measurement signal indicating the rotation of the rotation sensor when it is in contact with the individual's skin and in a relationship to detect movement relative to the individual's jugular vein. The apparatus is characterized in that the processing system is configured to generate a waveform of the movement of the skin in a direction perpendicular to the skin based on the measurement signal, and the waveform of the movement of the skin represents the jugular vein pressure waveform.

2. The rotation sensor is configured to measure the angular velocity of the rotation sensor, The processing system is configured to calculate the time integral of the angular velocity, The angular velocity of the rotation sensor represents the measurement signal, The apparatus according to claim 1, wherein the time integral of the angular velocity represents the jugular venous pressure waveform.

3. The rotation sensor is configured to measure the angular acceleration of the rotation sensor, The processing system is configured to calculate a first time integral, which is the time integral of the angular acceleration, and a second time integral, which is the time integral of the first time integral. The angular acceleration of the rotation sensor represents the measurement signal, The apparatus according to claim 1, wherein the second time integral represents the jugular venous pressure waveform.

4. The processing system is configured to receive one or more electrical signals from electrodes on the individual's skin. The apparatus according to any one of claims 1 to 3, wherein the processing system is configured to generate an electrocardiogram at time intervals of the jugular venous pressure waveform.

5. The apparatus according to any one of claims 1 to 4, wherein the processing system and the rotation sensor are configured to maintain a wireless connection in order to transfer the measurement signal from the rotation sensor to the processing system.

6. The apparatus according to any one of claims 1 to 5, wherein the rotation sensor is part of a mobile phone.

7. The apparatus according to any one of claims 1 to 5, further comprising a sheet of flexible material (308) on which an adhesive is provided for attaching the rotation sensor (302) to the skin of the individual.

8. The apparatus according to any one of claims 1 to 7, wherein the processing system is configured to generate a display signal indicating pulmonary hypertension in response to a situation in which the a-wave of the jugular venous pressure waveform exceeds a predetermined threshold.

9. A method for measuring jugular venous pressure waveform, wherein the method is - Generating a measurement signal using a rotation sensor that is in contact with the individual's skin and is in a relationship to detect movement relative to the individual's jugular vein (401), - Includes generating a waveform of the movement of the skin in a direction perpendicular to the skin based on the measurement signal indicating the rotation of the rotation sensor (402), A method characterized in that the waveform of the movement of the skin shows the jugular vein pressure waveform.

10. The rotation sensor measures the angular velocity of the rotation sensor, The method includes calculating the time integral of the measured angular velocity, The measured angular velocity of the rotation sensor represents the measured signal. The method according to claim 9, wherein the time integral of the measured angular velocity shows the jugular venous pressure waveform.

11. The rotation sensor measures the angular acceleration of the rotation sensor, The method includes calculating a first time integral, which is the time integral of the measured angular acceleration, and a second time integral, which is the time integral of the first time integral. The angular acceleration measured by the rotation sensor represents the measured signal, The method according to claim 9, wherein the second time integral shows the jugular venous pressure waveform.

12. The method involves receiving one or more electrical signals from electrodes on the skin of the individual, The method according to any one of claims 9 to 11, comprising generating an electrocardiogram at the time interval of the jugular venous pressure waveform.

13. The method according to any one of claims 9 to 12, wherein the measurement signal is received from the rotation sensor via a wireless connection.

14. The method according to any one of claims 9 to 13, further comprising generating an indicator signal representing pulmonary hypertension in response to a situation in which the a-wave of the jugular venous pressure waveform exceeds a predetermined threshold.

15. Use of the apparatus according to any one of claims 1 to 8 for measuring jugular venous pressure waveform.

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