BODY-WORN SYSTEM FOR CONTINUOUS, NONINVASIVE MEASUREMENT OF CARDIAC OUTPUT, STROKE VOLUME, CARDIAC POWER, AND BLOOD PRESSURE

• US 20140249433A1
• Filed: 12/27/2011
• Published: 09/04/2014
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: Sotera Wireless Incorporated (Foxconn Technology Co., Ltd.)
• Original Assignee: Donald Bernstein, Matt Banet
• Inventors: BANET, Matt, HENRY, Isaac, BERNSTEIN, Donald
• Granted Patent: US 10,722,132 B2
• Time in Patent Office: Days
• US Class Current: 600/485
• CPC Class Codes: A61B 2562/04 Arrangements of multiple sensors of the same type
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• CPC Class Codes: A61B 5/01 Measuring temperature of body parts ; Diagnostic temperature sensing, e.g. for malignant or inflamed tissue clinical contact thermometers G01K13/20
• CPC Class Codes: A61B 5/02028 Determining haemodynamic parameters not otherwise provided for, e.g. cardiac contractility or left ventricular ejection fraction
• 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 5/02427 Details of sensor
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• 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 5/0295 using plethysmography, i.e. measuring the variations in the volume of a body part as modified by the circulation of blood therethrough, e.g. impedance plethysmography
• CPC Class Codes: A61B 5/0535 Impedance plethysmography for measuring blood flow A61B5/0295
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/1116 Determining posture transitions
• CPC Class Codes: A61B 5/14542 for measuring blood gases A61B5/14551 takes precedence
• CPC Class Codes: A61B 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/681 Wristwatch-type devices
• CPC Class Codes: A61B 5/6823 Trunk, e.g., chest, back, abdomen, hip
• CPC Class Codes: A61B 5/6824 Arm or wrist
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/6833 : Adhesive patches
• CPC Class Codes: A61B 5/7239 : using differentiation including higher order derivatives
• CPC Class Codes: A61B 5/725 : using specific filters therefor, e.g. Kalman or adaptive filters A61B5/316 take precedence
• CPC Class Codes: A61B 5/746 : Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: G16H 40/67 : for remote operation

Abstract

The invention provides a system for measuring stroke volume (SV), cardiac output (CO), and cardiac power (CP) from a patient that features: 1) impedance sensor connected to at least two body-worn electrodes and including an impedance circuit that processes analog signals from the electrodes to measure an impedance signal (e.g. a TBEV waveform); 2) an ECG sensor connected to at least two chest-worn electrodes and including an ECG circuit that processes analog signals from the electrodes to measure and ECG signal; 3) an optical sensor connected to a body-worn optical probe and including an optical circuit that processes signals from the probe to measure at least one optical signal (e.g. a PPG waveform) from the patient; 4) a processing system, typically worn on the patient'"'"'s wrist and connected through a wired interface to the optical sensor, and through either a wired or wireless interface to the TBEV and ECG sensors.

Claims

1. A system for measuring cardiac power from a patient, comprising:

an ECG module comprising;

i) at least two electrodes;

ii) an ECG circuit configured to process signals from the at least two ECG electrodes to measure at least one ECG waveform from the patient and;

iii) a first processing system configured to process the ECG waveform to determine a heart rate value;

an optical module comprising;

i) an optical probe; and

ii) an optical circuit configured to process signals from the optical probe and to measure at least one photoplesthymograph (PPG) waveform from the patient;

an impedance module comprising;

i) at least two impedance electrodes;

ii) an impedance circuit configured to process signals from the at least two impedance electrodes to measure at least one impedance waveform from the patient; and

iii) a second processing system configured to process the impedance waveform to determine a stroke volume value;

a blood pressure module configured to;

i) receive the ECG waveform from the ECG module;

ii) receive the PPG waveform from the optical module;

iii) receive the impedance waveform from the impedance module; and

iii) collectively process at least two of these waveforms to determine a blood pressure value; and

,

a third processing system configured to;

i) be worn on the patient'"'"'s body;

ii) receive the stroke volume value from the impedance module;

ii) receive the heart rate value from the ECG module;

iii) receive the blood pressure value from the blood pressure module; and

iv) collectively process the stroke volume, heart rate, and blood pressure values to determine a cardiac power value.

15. The system of claim 1, wherein the impedance module further comprises an accelerometer module configured to measure at least one time-dependent motion waveform from the patient.

16. The system of claim 15, wherein the impedance module is further configured to receive at least one time-dependent motion waveform or at least one value derived from the at least one time-dependent motion waveform from the accelerometer module and to process these to determine a motion value.

17. The system of claim 16, wherein the impedance module is further configured to compare the motion value to a pre-determined threshold value.

18. The system of claim 17, wherein the impedance module is further configured to make an impedance measurement only if the motion value is less than the pre-determined threshold value.

19. The system of claim 18, wherein the impedance module is further configured to reject the impedance value if the motion value is more than the pre-determined threshold value.

2. A system for measuring cardiac power from a patient, comprising:

an ECG module comprising;

i) at least two electrodes;

ii) an ECG circuit configured to process signals from the at least two ECG electrodes to measure at least one ECG waveform from the patient and;

iii) a first processing system configured to process the ECG waveform to determine a heart rate value;

an optical module comprising;

i) an optical probe; and

ii) an optical circuit configured to process signals from the optical probe and to measure at least one photoplesthymograph (PPG) waveform from the patient;

a trans-brachial electrovelocimetry (TBEV) module comprising;

i) at least two TBEV electrodes;

ii) a TBEV circuit, configured to process TBEV signals from the at least two TBEV electrodes to measure TBEV waveform from the patient; and

iii) a second processing system configured to process the TBEV waveform to determine a stroke volume value;

a blood pressure module configured to;

i) receive the ECG waveform from the ECG module;

ii) receive the TBEV waveform from the TBEV module;

iii) receive the PPG waveform value from the optical module; and

iii) collectively process at least two of these to determine a transit time value and a blood pressure value;

a third processing system configured to;

i) be worn on the patient'"'"'s body;

ii) receive the stroke volume value from the TBEV module;

ii) receive the heart rate value from ECG module;

iii) receive the blood pressure value from the blood pressure module; and

iv) collectively process these to determine a cardiac power value; and

,

a wireless system, configured to be worn on the body and comprising;

i) the ECG module;

ii) the TBEV module;

iii) the optical module;

iv) the blood pressure module; and

v) the three processing systems collectively configured to receive, process, transmit at least one of a ECG module-derived data, a TBEV-module-derived data, and a optical module-derived data to a remote location.

5. The system of claim 2, wherein the second processing system is further configured to determine the stroke volume value by estimating a pulse pressure value from the TBEV waveform.

6. The system of claim 2, wherein the second processing system is further configured to determine a (dZ/dt)max value by further processing the TBEV waveform.

7. The system of claim 6, wherein the second processing system is further configured to transmit the (dZ/dt)max value to the third processing system.

8. The system of claim 7, wherein the third processing system is further configured to receive the (dZ/dt)max value from the second processing system.

9. The system of claim 8, wherein the third processing system is further configured to determine an SFT value by processing at least one of:

i) PPG waveform;

ii) TBEV waveform; and

iii) ECG waveform.

10. The system of claim 9, wherein the third processing system is further configured to collectively process the (dZ/dt)max value and the SFT value.

11. The system of claim 2, wherein the blood pressure module is further configured to determine a pulse transit time value by collectively processing the ECG waveform and at least one of the TBEV and PPG waveforms.

12. The system of claim 11, wherein the pulse transit time value is further processed to determine a continuous blood pressure value.

13. The system of claim 2, wherein the blood pressure module is further configured to determine a vascular transit time value by collectively processing the TBEV waveform and the PPG waveform.

14. The system of claim 13, wherein the vascular transit time value is further processed to determine a continuous blood pressure value.

3. A system for measuring cardiac power from a patient, comprising:

a first module, comprising an ECG sensor, configured to;

i) be worn proximal to the patient'"'"'s chest;

ii) measure a first ECG waveform;

iii) connect to an impedance sensor, and iv) process the first waveform and to determine at least a heart rate value;

a second module, comprising the impedance sensor, configured to;

i) be worn proximal to the patient'"'"'s brachium;

ii) measure a second waveform;

iii) connect to the first module through a first serial port; and

iii) process the second waveform and to determine a stroke volume;

a third module, comprising an optical sensor, configured to i);

be worn proximal to the patient'"'"'s hand;

ii) measure a third waveform; and

ii) connect to a second serial port;

a blood pressure module configured to;

i) receive the first, the second, and the third waveforms; and

iii) collectively process at least two of these waveforms to determine a blood pressure value; and

a third processing system, configured to;

i) be worn on the patient'"'"'s body;

ii) receive the heart rate, stroke volume, and blood pressure values;

iii) collectively process these to determine a cardiac power value; and

iv) to transmit the cardiac power value.

4. A system for measuring cardiac power from a patient, comprising:

a body-worn harness, configured to be worn on the patient'"'"'s body, and comprising;

i) a blood pressure sensor;

ii) a stroke volume sensor; and

iii) a processing system;

a transceiver comprising;

i) a port that connects to the harness and is configured to receive blood pressure value from the blood pressure sensor, the stroke volume value from the stroke volume sensor, and the heart rate value from at least one of the stroke volume and blood pressure sensors; and

,

a processor configured to collectively process the blood pressure, stroke volume, and heart rate values to determine a cardiac power value.

20. The system of claim 4, wherein the harness is configured to attach to the patient'"'"'s chest and left arm.

21. The system of claim 20, wherein the blood pressure sensor is configured to measure a digital representation of an ECG waveform.

22. The system of claim 21, wherein the blood pressure sensor is configured to measure a digital representation of an impedance waveform.

23. The system of claim 22, wherein the blood pressure sensor is configured to collectively process the impedance and ECG waveforms to determine a digital representation of blood pressure.

24. The system of claim 23, wherein the blood pressure sensor is configured to calculate a heart rate from the ECG waveform.

25. The system of claim 4, wherein the stroke volume sensor is configured to measure a digital representation of an impedance waveform.

26. The system of claim 25, wherein the stroke volume sensor is further configured to process the impedance waveform to measure, to determine an SFT value.

27. The system of claim 26, wherein the stoke volume sensor is further configured to process the impedance waveform to measure, to determine a (dZ/dt)max value.

28. The system of claim 27, wherein the stroke volume sensor is further configured to collectively process the (dZ/dt)max value and the SFT value to determine a stroke volume value.