Systems and methods for monitoring the circulatory system

• US 9,833,151 B2
• Filed: 12/11/2015
• Issued: 12/05/2017
• Est. Priority Date: 01/27/2011
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford Management Co.)
• Inventors: Wiard, Richard M., Giovangrandi, Laurent B., Kovacs, Gregory T.
• Primary Examiner(s): CAREY, MICHAEL JAMES
• Application Number:
  US14/966,527
• Publication Number:
  US 20160095522A1
• Time in Patent Office: 725 Days
• Field of Search: 600526, 600527, 600508
• CPC Class Codes: A61B 5/0002 Remote monitoring of patients using telemetry, e.g. transmission of vital signals via a communication network A61B5/07 takes precedence; transmission systems for measured values G08C; transmission H04B; transmission of digital information H04L; wireless communication networks H04W
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• CPC Class Codes: A61B 5/0205 Simultaneously evaluating both cardiovascular conditions and different types of body conditions, e.g. heart and respiratory condition
• CPC Class Codes: A61B 5/021 Measuring pressure in heart or blood vessels A61B5/0205 takes precedence
• CPC Class Codes: A61B 5/02125 of pulse wave propagation time
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• CPC Class Codes: A61B 5/0265 using electromagnetic means, e.g. electromagnetic flowmeter
• CPC Class Codes: A61B 5/0285 Measuring or recording phase velocity of blood waves
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6829 Foot or ankle
• CPC Class Codes: A61B 5/6887 mounted on external non-worn devices, e.g. non-medical devices
• CPC Class Codes: A61B 5/721 using a separate sensor to detect motion or using motion information derived from signals other than the physiological signal to be measured
• CPC Class Codes: A61B 5/7264 Classification of physiological signals or data, e.g. using neural networks, statistical classifiers, expert systems or fuzzy systems neural networks per se G06N3/00; expert systems per se G06N5/00
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01G 19/50 having additional measuring devices, e.g. for height

Abstract

In accordance with embodiments of the present disclosure, a user-platform apparatus, such as a bodyweight sensing scale, includes a heart/cardiogram sensor which is used to detect heart and vascular characteristics of a user, and provide a cardiogram output indicative of the detected cardiovascular characteristics. The cardiogram output can be used for various purposes, such as detecting arterial stiffness and/or aging.

Claims

1. A bodyweight sensing apparatus comprising:

a bodyweight sensing scale;

a first sensor included in or as part of the bodyweight sensing scale, and configured and arranged to capture a cardiogram signal of a user from at least one foot of the user while the user is in an upright position and with said at least one foot of the user on the bodyweight sensing scale;

a second sensor configured and arranged to capture a pressure pulse from a distal artery location that is at or below a user'"'"'s femoral artery while the user is standing on the bodyweight sensing scale; and

logic circuitry configured and arranged to generate an arterial pulse wave velocity of the user, wherein the logic circuitry is further configured and arranged to respond to the first sensor and to the second sensor by comparing timings corresponding to the cardiogram signal and the pressure pulse, as respectively provided by the first sensor and to the second sensor, whereby the arterial pulse wave velocity is derived from the compared timings and is indicative of arterial stiffness of the user.

2. The apparatus of claim 1, further including another sensor, including circuitry configured to obtain heart-related signals from the user of the bodyweight sensing scale for use by the logic circuity and also configured to wirelessly communicate with the logic circuity.

3. The apparatus of claim 1, wherein the logic circuitry is configured and arranged to generate the arterial pulse wave velocity based on portions of the cardiogram signal that are indicative of a pressure pulse of an ascending portion of an aorta, the pressure pulse of the user at the distal artery location and a distance between the aorta and the distal artery location, wherein the arterial pulse wave velocity is indicative of the biological or physiological aspects relating to the arterial stiffness.

4. The apparatus of claim 1, wherein the logic circuitry is configured and arranged to generate the arterial pulse wave velocity based on portions of the cardiogram signal that are indicative of a pressure pulse of an arch portion of an aorta, the pressure pulse of the user at the distal artery location and a distance between the aorta and the distal artery location, wherein the arterial pulse wave velocity is indicative of the biological or physiological aspects relating to the arterial stiffness.

5. The apparatus of claim 1, further including

a display configured to output a weight of the user while the user is standing on the bodyweight sensing scale, and

a weight-sensing arrangement that includes circuitry and a set of force sensors configured to provide indications of weight distribution across the bodyweight sensing scale to the logic circuit.

6. The apparatus of claim 1, wherein the second sensor is configured to capture photoplethysmography characteristics of the distal artery location that is at or below the user'"'"'s femoral artery.

7. The apparatus of claim 1, further including a tertiary circuit configured and arranged to detect an indication of at least one of noise present in the cardiogram signal and wherein the logic circuitry is configured to process the cardiogram signal by removing the noise present in the cardiogram signal.

8. The apparatus of claim 7, wherein the cardiogram signal is a BCG (ballistocardiogram) signal and wherein

the tertiary circuit includes an electrocardiogram (ECG) sensor configured and arranged to detect an ECG signal from the user and to provide an output characterizing the detected ECG signal, and

the logic circuitry is configured to use the tertiary circuit output to process the captured cardiogram signal by filtering and averaging the cardiogram signal to generate a filtered BCG signal.

9. The apparatus of claim 1, wherein a plurality of pressure sensors are used in conjunction with a T1 signal to derive a central aortic stiffness and a peripheral arterial stiffness from pulse timings.

10. The apparatus of claim 1, wherein the logic circuitry is configured to generate a ballistocardiogram signal by generating an ensemble-average, or triggered moving average, of the cardiogram signal using a detected photoplethysmography signal.

11. The apparatus of claim 1, further including a circuit arrangement integrated with hand-grip electrodes coupled to the bodyweight sensing scale, the electrodes and circuit arrangement being configured to detect at least one of an electrocardiogram (ECG) or photoplethysmography characteristic of the user.

12. The apparatus of claim 1, further including a peripheral blood pressure sensor;

and

the logic circuitry is configured to use an output of the peripheral blood pressure sensor to calculate the central pressures;

to generate ballistocardiogram signals over time; and

to provide an indication of at least one of arterial stiffness and central/peripheral pressure difference.

13. The apparatus of claim 11,

further including a memory circuit that stores baseline data including at least one of root mean square BCG (ballistocardiogram) data and ensemble average BCG amplitude data, and

the logic circuitry is configured to generate output BCG signals based upon the stored baseline data.

14. The apparatus of claim 1, wherein the first sensor is configured and arranged to capture a BCG (ballistocardiogram) signal from pressure exerted by said at least one foot of the user while the user is standing on the bodyweight sensing scale;

and

wherein the logic circuitry is further configured and arranged to generate the arterial pulse wave velocity of the user by comparing timings corresponding to the BCG signal and the pressure pulse.

15. The apparatus of claim 14, wherein the logic circuitry is configured to use changes in the user'"'"'s cardiovascular characteristics and/or bodyweight over a period of time useful for determining a treatment for the user.

16. The apparatus of claim 14, further including:

a circuit arrangement integrated with a detachable component connected to the bodyweight sensing scale and is configured to detect a photoplethysmograph characteristic of the user, and

wherein the logic circuitry is configured to generate BCG signals over time and to provide an indication of at least one of arterial stiffness and central/peripheral pressure difference.

17. The apparatus of claim 14, further including a circuit arrangement including circuitry that is configured to generate an ECG signal using characteristics detected from the user, and wherein the logic circuitry is configured to modify coefficients of a transform function used to generate a BCG signal, based upon the ECG signal.

18. A method comprising:

capturing a cardiogram signal, using a first sensor integrated included in or as part of a bodyweight sensing scale, from at least one foot of a user while the user is standing on the bodyweight sensing scale;

capturing, using a second sensor, a pressure pulse from a distal artery location that is at or below a user'"'"'s femoral artery while the user is standing on the bodyweight sensing scale; and

comparing timings corresponding to the cardiogram signal and the pressure pulse to calculate arterial pulse wave velocity, and using the compared timings to indicate arterial stiffness of the user.

19. The method of claim 18, wherein the cardiogram signal is a BCG (ballistocardiogram) signal, wherein capturing the cardiogram signal includes measuring variations in downward pressure exerted by the user'"'"'s feet and includes capturing a cardiogram T1 signal that is indicative of mechanical movement of blood through a user'"'"'s aorta, and wherein comparing timings includes using a logic circuit to calculate the arterial pulse wave velocity by calculating timings corresponding to the T1 signal and a timing of the pressure pulse.

20. A bodyweight sensing apparatus comprising:

a bodyweight sensing scale;

a first sensor included in or as part of the bodyweight sensing scale, and configured and arranged to capture a cardiogram signal of a user from at least one foot of the user while the user is in an upright position and on the bodyweight sensing scale;

a second sensor configured and arranged to capture a pressure pulse from a distal artery location that is at or below a user'"'"'s femoral artery while the user is standing on the bodyweight sensing scale; and

circuitry, including a programmed logic circuit, configured and arranged to be responsive to the first sensor and the second sensor, by comparing timings corresponding to the cardiogram signal and the pressure pulse, and therefrom, deriving and outputting an indication of arterial stiffness.

21. The bodyweight sensing apparatus of claim 20, wherein the first sensor and the circuitry are configured and arranged to capture the cardiogram signal and derive the indication of arterial stiffness based on calibrated parameters, including a limited frequency response of circuits integrated with the first sensor for capturing the cardiogram signal and limited mechanical bandwidth attributable to stiffness and damping.