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

• US 20140249443A1
• Filed: 12/28/2011
• Published: 09/04/2014
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: Sotera Wireless Incorporated
• Original Assignee: Donald Bernstein, Matt Banet
• Inventors: BANET, Matt, HENRY, Isaac, BERNSTEIN, Donald
• Granted Patent: US 9,380,952 B2
• Time in Patent Office: Days
• US Class Current: 600/526
• 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) an 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. The processing system analyzes the ECG, TBEV and optical signals to determine SV, and further analyzes SV and HR determined from an ECG sensor to determine CO.

Claims

1. A body-worn system for measuring a stroke volume value from a patient, comprising:

a TBEV module worn on the patient'"'"'s body and comprising;

i) an electrical circuit configured to inject a current proximal to the patient'"'"'s brachium;

ii) a pair of electrical connectors located on a bottom portion of the module, the electrical connectors configured to snap into a pair of mated connectors comprised by a first electrode, with a first connector configured to inject the current into a first portion of the electrode, and a second connector configured to measure signals from a second portion of the electrode that relate to a voltage;

iii) an analog circuit configured to process the signals from the second connector to generate a voltage value; and

iv) a processor configured to convert the voltage value, or a value calculated therefrom, into a time-dependent resistance value, and then convert the time-dependent resistance value into a stroke volume value.

6. The system of claim 1, wherein the first portion of the first electrode comprises a first conductive portion.

7. The system of claim 6, wherein the first conductive portion comprises a conductive gel disposed on an Ag/AgCl film.

8. The system of claim 1, wherein the second portion of the first electrode comprises a second conductive portion.

9. The system of claim 8, wherein the second conductive portion comprises a conductive gel disposed on an Ag/AgCl film.

10. The system of claim 1, wherein the pair of mated connectors comprises a first metal post and a second metal post.

11. The system of claim 10, wherein both the first and second metal posts are a metal rivet.

12. The system of claim 10, wherein the electrical connectors located on a bottom portion of the TBEV module are female connectors, each configured to receive a metal post.

13. The system of claim 1, further comprising an ECG module.

14. The system of claim 13, wherein the ECG module is configured to be worn on the patient'"'"'s body.

15. The system of claim 14, wherein the ECG module comprises i) an ECG circuit configured to measure an ECG waveform from the patient;

ii) a second pair of electrical connectors located on a bottom portion of the ECG module, the electrical connectors configured to snap into a pair of mated connectors comprising a second electrode, with a first connector configured to receive current injected by the first electrode, and a second connector configured to measure signals from a second portion of the electrode that relate to the voltage;

iii) a conducting wire configured to transmit signals measured by the second electrode to the analog circuit in the TBEV module; and

iv) a second serial port configured to transmit a heart rate value to the body-worn TBEV module.

16. The system of claim 15, wherein the first portion of the second electrode comprises a first conductive portion.

17. The system of claim 16, wherein the first conductive portion comprises a conductive gel disposed on an Ag/AgCl film.

18. The system of claim 15, wherein the second portion of the second electrode comprises a second conductive portion.

19. The system of claim 18, wherein the second conductive portion comprises a conductive gel disposed on an Ag/AgCl film.

20. The system of claim 15, wherein the pair of mated connectors comprises a first metal post and a second metal post.

21. The system of claim 20, wherein both the first and second metal posts are a metal rivet.

22. The system of claim 20, wherein the electrical connectors located on a bottom portion of the TBEV module are female connectors, each configured to receive a metal post.

23. The system of claim 1, further comprising a harness comprising:

i) the TBEV module;

ii) a collection of conductive wires that receive and transmit digitized versions of the stroke volume value and the time-dependent resistance value; and

iii) a connector configured to detachably connect to a controller worn on the patient'"'"'s body that receives and analyzes the digitized versions of the stroke volume value and the time-dependent resistance value.

2. A body-worn system for measuring a cardiac output value from a patient, comprising:

a TBEV module worn on the patient'"'"'s body and comprising;

i) an electrical circuit configured to inject a current proximal to the patient'"'"'s brachium;

ii) a first pair of electrical connectors located on a bottom portion of the TBEV module, the electrical connectors configured to snap into a pair of mated connectors comprised by a first electrode, with a first connector configured to inject the current into a first portion of the electrode, and a second connector configured to measure signals from a second portion of the electrode that relate to a voltage;

iii) an analog circuit configured to process the signals from the second connector to generate a voltage value;

iv) a first processor configured to convert the voltage value into a time-dependent resistance value, and then convert the time-dependent resistance value into a stroke volume value; and

v) a first serial port configured to receive a heart rate value from a body-worn ECG module; and

,

the body-worn ECG module, comprising i) an ECG circuit configured to measure an ECG waveform from the patient;

ii) a second pair of electrical connectors located on a bottom portion of the ECG module, the electrical connectors configured to snap into a pair of mated connectors comprising (N.B.;

Accepted syntax prefers “

comprising”

, rather than “

comprised by) a second electrode, with a first connector configured to receive current injected by the first electrode, and a second connector configured to measure signals from a second portion of the electrode that relate to the voltage;

iii) a conducting wire configured to transmit signals measured by the second electrode to the analog circuit in the TBEV module; and

iv) a second serial port configured to transmit a heart rate value to the body-worn TBEV module.

3. A body-worn system for measuring a stroke volume value from a patient, comprising:

a TBEV module worn on the patient'"'"'s body and comprising;

i) an electrical circuit configured to inject a current proximal to the patient'"'"'s brachium;

ii) a pair of electrical connectors located on a bottom portion of the module, the electrical connectors configured to snap into a pair of mated connectors comprising a first electrode, with a first connector configured to inject the current into a first portion of the electrode, and a second connector configured to measure signals from a second portion of the electrode that relate to a voltage;

iii) an analog circuit configured to process the signals from the second connector to generate a voltage value; and

iv) a processor configured to convert the voltage value into a time-dependent resistance value, and then convert the time-dependent resistance value into a stroke volume value; and

,

a harness comprising the TBEV module, a collection of conductive wires that receive and transmit digitized versions of the stroke volume value and the time-dependent resistance value, and a connector configured to detachably connect to a controller worn on the patient'"'"'s body that receives and processes the digitized versions of the stroke volume value and the time-dependent resistance value.

4. A body-worn system for measuring a cardiac output value, comprising:

an ECG module attached to a patient'"'"'s body using a first two-part electrode, the ECG module configured to generate a heart rate value;

an impedance module attached to the patient'"'"'s body with a second two-part electrode, the impedance module configured to generate a stroke volume value from signals collected by the first and second two-part electrodes; and

a processor configured to receive the heart rate and stroke volume values, and from these calculate a cardiac output value.

5. A body-worn system for measuring a cardiac power value, comprising:

an ECG module attached to a patient'"'"'s body, using a first two-part electrode, the ECG module configured to generate a heart rate value and an ECG waveform;

an impedance module attached to the patient'"'"'s body with a second two-part electrode, the impedance module configured to generate a stroke volume value and an impedance waveform from signals collected by the first and second two-part electrodes; and

,

a processor configured to receive the heart rate and stroke volume values, and the ECG and impedance waveforms, and from these calculate a cardiac power value.