Body-worn system for continuous, noninvasive measurement of cardiac output, stroke volume, cardiac power, and blood pressure

• US 10,722,132 B2
• Filed: 12/27/2011
• Issued: 07/28/2020
• Est. Priority Date: 12/28/2010
• Status: Active Grant

• Current Assignee: Sotera Wireless Incorporated
• Original Assignee: Sotera Wireless Incorporated
• Inventors: Banet, Matt, Henry, Isaac, Bernstein, Donald
• Primary Examiner(s): Bloch, Michael R
• Application Number:
  US13/338,238
• Publication Number:
  US 20140249433A1
• Time in Patent Office: 3,136 Days
• 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 electrocardiogram (ECG) module comprising;

i) at least two electrodes configured to be positioned on the patient'"'"'s torso;

ii) an ECG circuit configured to process signals from the at least two 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 configured to be positioned on a digit on a hand of the patient; 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 a TBEV waveform from the patient; and

iii) a second processing system configured to process the TBEV waveform to determine a time dependent derivative of the TBEV waveform (d(TBEV)dZ/dt)), a first zero value in d(TBEV)dZ/dt indicating onset of a pulse in d(TBEV)dZ/dt representing opening of the patient'"'"'s aortic valve, a second zero value in d(TBEV)dZ/dt after onset of the pulse indicating closing of the patient'"'"'s aortic valve, a systolic flow time (SFT) calculated using the first zero value in d(TBEV)dZ/dt and the second zero value in d(TBEV)dZ/dt, a d(TBEV)dZ/dtmax value, and a stroke volume value calculated using the SFT and the d(TBEV)dZ/dtmax 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 TBEV waveform from the impedance module; and

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

a third processing system configured to be worn on the patient'"'"'s body, wherein the third processing system is 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 from the optical module;

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

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

v) receive the heart rate value from ECG module;

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

vii) collectively process the stroke volume value, heart rate value, and blood pressure value to determine a cardiac power value; and

,

wherein the third processing system comprises a wireless system, configured to transmit the stroke volume value, the cardiac output value, and the cardiac power value to a remote location.

2. The system of claim 1, wherein the second processing system is further configured to determine a second stroke volume value based on estimating a pulse pressure value from the TBEV waveform.

3. The system of claim 1, wherein the second processing system is further configured to transmit the d(TBEV)dZ/dtmax value to the third processing system.

4. The system of claim 3, wherein the third processing system is further configured to receive the d(TBEV)dZ/dtmax value from the second processing system.

5. The system of claim 4, wherein the third processing system is further configured to determine a second systolic flow time (SFT) value by processing at least one of:

PPG waveform; and

ECG waveform.

6. The system of claim 1, wherein the third processing system 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.

7. The system of claim 6, wherein the third processing system is further configured to determine a continuous blood pressure value by further processing the pulse transit time value.

8. The system of claim 1, wherein the third processing system is further configured to determine a vascular transit time value by collectively processing the TBEV waveform and the PPG waveform.

9. The system of claim 8, wherein the third processing system is further configured to determine a continuous blood pressure value based on the vascular transit time value.