Weighing scale and sensor systems and methods for monitoring heart function

• US 9,055,871 B2
• Filed: 09/26/2014
• Issued: 06/16/2015
• Est. Priority Date: 10/15/2008
• Status: Active Grant

• Current Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Original Assignee: Board of Trustees of the Leland Stanford Junior University (Stanford University)
• Inventors: Inan, Omer T., Etemadi, Mozziyar, Giovangrandi, Laurent B., Kovacs, Gregory T., Wiard, Richard M.
• Primary Examiner(s): Koharski, Christopher D
• Assistant Examiner(s): CAREY, MICHAEL JAMES
• Application Number:
  US14/498,593
• Publication Number:
  US 20150073234A1
• Time in Patent Office: 263 Days
• Field of Search: 600/481, 600/508, 600/526, 600/527
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0006 ECG or EEG signals
• CPC Class Codes: A61B 5/0024 for multiple sensor units attached to the patient, e.g. using a body or personal area network
• CPC Class Codes: A61B 5/0082 adapted for particular medical purposes
• 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 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/029 Measuring or recording blood output from the heart, e.g. minute volume A61B8/065 takes precedence
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/33 specially adapted for cooperation with other devices
• CPC Class Codes: A61B 5/352 Detecting R peaks, e.g. for synchronising diagnostic apparatus; Estimating R-R interval
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4836 Diagnosis combined with treatment in closed-loop systems or methods A61B5/0036 takes precedence
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence
• 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 5/7203 for noise prevention, reduction or removal
• CPC Class Codes: A61B 5/7207 of noise induced by motion artifacts
• 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 5/7253 characterised by using transforms
• CPC Class Codes: A61B 5/7285 : for synchronising or triggering a physiological measurement or image acquisition with a physiological event or waveform, e.g. an ECG signal A61B6/5205, A61B6/541, A61B8/5207, A61B8/543 take precedence
• CPC Class Codes: A61B 5/74 : Details of notification to user or communication with user or patient indicating measured values G01D7/00; user input means input or output arrangements for computers G06F3/00
• CPC Class Codes: G01G 19/50 : having additional measuring devices, e.g. for height

Abstract

Characteristics of a user'"'"'s heart are detected. In accordance with an example embodiment, a ballistocardiogram (BCG) sensor is used to detect heart characteristics of a user, and provide a BCG output indicative of the detected heart characteristics. The BCG output is further processed using data from one or more additional sensors, such as to reduce noise and/or otherwise process the BCG signal to characterize the user'"'"'s heart function.

Claims

1. An apparatus comprising:

a weighing scale;

a first sensor including a heart-characteristic sensor configured and arranged to capture, from a user, a ballistocardiogram (BCG) signal for a plurality of a heartbeats from the user and indicative of physical cardiovascular movement of the user while the user stands at a stationary position on the weighing scale, including mechanical output of the user'"'"'s heart;

a second sensor configured and arranged to detect an indication of a physiologic characteristic of the user, and to provide an output characterizing the detected indication; and

a processor circuit, responsive to the first sensor and the second sensor, the processor circuit being configured to assess changes in the user'"'"'s bodyweight over time, and;

generate an output signal indicative of a condition of the user'"'"'s heart,

access a cardiovascular waveform reference for the BCG signal, and

estimate, using the cardiovascular waveform reference, a signal relative to noise present in the BCG signal and due to movement of the user while the user stands at a stationary position; and

an interface circuit responsive to the output signal and configured and arranged to track changes for a cardiac condition, or indicate an abnormal cardiac condition, relative to the user'"'"'s physiologic characteristic.

2. The apparatus of claim 1, wherein

the second sensor includes an electrocardiogram (ECG) sensor configured and arranged to detect an ECG signal from the user, the detected signal being indicative of a physiologic characteristic of the user, and to provide an output characterizing the physiologic characteristic to the processor circuit.

3. The apparatus of claim 1, wherein

the second sensor includes an electrocardiogram (ECG) sensor configured and arranged to detect an ECG signal from the user, the detected signal being useful for characterizing the physiologic characteristic of the user, and to provide an output characterizing the physiologic characteristic to the processor circuit, and

the processor circuit is configured with an algorithm for processing the captured BCG signal to generate the output BCG signal, using the detected ECG signal as an input to the algorithm.

4. The apparatus of claim 1, wherein

the second sensor 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 processor circuit is configured to use an output of the second sensor to process the captured BCG signal by filtering and averaging the BCG signal to generate the output BCG signal.

5. The apparatus of claim 1, wherein

the second sensor 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 processor circuit is configured to generate the output BCG signal by generating at least one of an ensemble-average and a triggered-moving average of the captured BCG signal using the detected ECG signal, wherein said at least one of the ensemble-average and a triggered-moving average is used by the processor circuit to provide the waveform reference.

6. The apparatus of claim 1, wherein

the second sensor includes a photoplethysmography sensor configured and arranged to detect a photoplethysmography signal from the user and to provide an output characterizing the detected photoplethysmography signal, and

the processor circuit is configured to generate the output BCG signal by generating an ensemble-average, or triggered moving average, of the detected BCG signal using the detected photoplethysmography signal.

7. The apparatus of claim 1, wherein

the second sensor includes a noise sensor configured to detect noise in the user'"'"'s environment, including using a strain gage that is configured to detect noise by detecting user movement along a particular motion axis, and a heart characteristic sensor configured to detect a physiologic characteristic of the user'"'"'s heart, and

the processor circuit is configured to generate the output BCG signal by using the detected noise to mitigate noise in the captured BCG signal and using the detected heart characteristic to modify the captured BCG signal.

8. The apparatus of claim 1, wherein

the processor circuit is configured to process the captured BCG signal, using previously-obtained data including cardiac output data for the user and both RMS power and an ensemble-average amplitude of the BCG signal, to generate an output signal indicative of the cardiac output of the user'"'"'s heart.

9. The apparatus of claim 1, wherein

the processor circuit is configured to

receive cardiac data indicative of at least one of cardiac output and stroke volume obtained from the user, and

process the captured BCG signal by using the received cardiac data and both RMS power and an ensemble-average amplitude, to generate an output BCG signal indicative of the cardiac output of the user'"'"'s heart.

10. The apparatus of claim 1, wherein

the processor circuit is configured to compare the captured BCG signal to a baseline value, which is based upon cardiac output data for the user and both RMS power and an ensemble-average amplitude of the BCG signal, to generate an output BCG signal indicative of the cardiac output and stroke volume of the user.

11. The apparatus of claim 1,

where the second sensor is 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 processor circuit and the interface circuit are configured to use pacing artifacts in the output from the ECG sensor to process the captured BCG signal by triggered averaging, ensemble averaging, or otherwise filtering the BCG signal.

12. The apparatus of claim 1, wherein

the first sensor includes a BCG capture device.

13. The apparatus of claim 12,

wherein the BCG capture device is an accelerometer within an implantable device.

14. The apparatus of claim 1, wherein the processor circuit and the interface circuit are configured to generate an output to set cardiac resynchronization therapy (CRT) pace parameters for the user, using at least one of a maximum amplitude or minimum ECG R-wave to BCG J-wave interval of the output signal.

15. The apparatus of claim 1, wherein the processor circuit and the interface circuit are configured to generate an output BCG signal indicative of BCG signal variations due to changes in cardiac resynchronization therapy (CRT) parameters used by an implantable CRT device to regulate the user'"'"'s heart, to provide an indication of cardiac responsiveness to CRT parameters.

16. The apparatus of claim 1, wherein

the first sensor includes a BCG capture device that is integrated with a bodyweight sensing scale,

the second sensor is integrated with handlebar electrodes coupled to the scale, the electrodes and second sensor being configured to detect at least one of an electrocardiogram (ECG) or photoplethysmography characteristic of the user, and

the processor circuit and the interface circuit are configured to generate output BCG signals over time to provide an indication of at least one of cardiac output and stroke volume for subsequent determination of a treatment need for the user.

17. The apparatus of claim 16, wherein

the scale includes a memory that stores baseline data including at least one of RMS BCG data and ensemble average BCG amplitude data, and

the processor circuit is configured to generate output BCG signals based upon the stored baseline data.

18. The apparatus of claim 17, wherein

the processor circuit and the interface circuit are configured to use recorded changes in the user'"'"'s bodyweight over time.

19. The apparatus of claim 1, wherein

the second sensor is integrated with a component communicatively connected to the scale and is configured to detect a photoplethysmography characteristic of the user.