COMBINED FLOORMAT AND BODY-WORN PHYSIOLOGICAL SENSORS

• US 20170188961A1
• Filed: 01/05/2016
• Published: 07/06/2017
• Est. Priority Date: 01/05/2016
• Status: Abandoned Application

• Current Assignee: OtoSense, Inc. (Analog Devices, Inc.)
• Original Assignee: OtoSense, Inc. (Analog Devices, Inc.)
• Inventors: COCHRAN, Jonas Dean, BANET, Matthew, DHILLON, Marshal Singh, PEDE, Susan Meeks, DEPTALA, Arthur, HAYWARD, Lauren Nicole Miller
• Application Number:
  US14/988,684
• Publication Number:
  US 20170188961A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 2560/0223 of calibration, e.g. protocols for calibrating sensors
• CPC Class Codes: A61B 5/0022 Monitoring a patient using a global network, e.g. telephone networks, internet
• 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 5/02028 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 5/02141 Details of apparatus construction, e.g. pump units or housings therefor, cuff pressurising systems, arrangements of fluid conduits or circuits A61B5/02233, A61B5/0235 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 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/4872 Body fat
• CPC Class Codes: A61B 5/4875 Hydration status, fluid retention of the body
• CPC Class Codes: A61B 5/6822 Neck
• CPC Class Codes: A61B 5/6892 Mats
• CPC Class Codes: G01G 19/50 having additional measuring devices, e.g. for height

Abstract

The invention provides systems for measuring blood pressure and stroke volume values from a patient. Both systems feature a floormat system and a body-worn sensor working in concert. In aspects, the floormat generates calibrations for both blood pressure and stroke volume measurements. It features a base having a bottom surface configured to rest on or near a substantially horizontal surface, and a top surface configured to receive at least one of the patient'"'"'s feet. Within the floormat are weight and blood pressure-measuring systems that determine, respectively, the calibrations for stroke volume and blood pressure. Its transmits these parameters to the body-worn sensor, which further processes them, along with other signals, to determine real-time values of blood pressure and stroke volume.

Claims

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

a weight-measuring system comprising at least one strain gauge;

a processing system configured to receive a signal from an output of the strain gauge or derived from the output of the strain gauge and process this to determine a stroke volume calibration; and

a first wireless system configured to wirelessly transmit information representing the stroke volume calibration; and

a body-worn sensor comprising;

an electrical impedance system comprising at least four electrodes, at least one of which is configured to inject an electrical current into the patient'"'"'s body, and at least one of which is configured to measure a signal induced by the electrical current and representative of an impedance plethysmogram;

a second wireless system configured to receive information representing the stroke volume calibration;

a heart rate monitoring system comprising at least two electrodes connected to a differential amplifier, the differential amplifier configured to measure a second set of signals representative of a cardiac rhythm from the patient; and

a processing system in electrical contact with the second wireless system, electrical impedance system, and the heart rate monitoring system, and configured to;

     1) receive information representing the stroke volume calibration;

     2) receive the first signals from the electrical impedance system and convert them into a set of impedance values;

     3) analyze the set of impedance values and the stroke volume calibration to determine a stroke volume value;

     4) receive the second set of signals from the heart rate monitoring system and convert them into a set of ECG values;

     5) analyze the set of ECG values to determine a heart rate value; and

     6) collectively process the stroke volume value and the heart rate value to determine the cardiac output value.

2. The system of claim 1, wherein the stroke volume calibration comprises values of the patient'"'"'s weight.

3. The system of claim 1, wherein the stroke volume calibration comprises a value of the patient'"'"'s body composition.

4. The system of claim 1, wherein the stroke volume calibration comprises a value of the patient'"'"'s blood pressure.

5. The system of claim 1, wherein the first wireless system comprises a transmitter based on Bluetooth®

or 802.11.

6. The system of claim 1, wherein the second wireless system comprises a transmitter based on Bluetooth®

or 802.11.

7. The system of claim 1, wherein the electrical impedance system comprises an electrical system that injects a current modulated at a frequency between 25-125 kHz.

8. The system of claim 1, wherein the electrical impedance system comprises an electrical system that comprises two electrodes that inject the electrical current into the patient'"'"'s body.

9. The system of claim 8, wherein the electrical impedance system comprises an electrical system that comprises two electrodes, each configured to measure a signal induced by the electrical current injected into the patient'"'"'s body.

10. The system of claim 1, wherein the processing system comprises computer code configured to analyze the set of impedance values to determine the stroke volume value.

11. The system of claim 10, wherein the computer code is configured to calculate a derivative of the set of impedance values to determine a dΔ

Z(t)/dt waveform.

12. The system of claim 11, wherein the computer code is configured to determine a maximum value of the dΔ

Z(t)/dt waveform.

13. The system of claim 12, wherein the computer code is configured to determine an area of a pulse in the dΔ

Z(t)/dt waveform.

14. The system of claim 11, wherein the computer code is configured to estimate an ejection time from the dΔ

Z(t)/dt waveform.

15. The system of claim 10, wherein the computer code is configured to estimate a baseline impedance (Z₀) from the set of impedance values.

16. The system of claim 15, wherein the computer code is configured to determine:

i) a maximum value of the dΔ

Z(t)/dt waveform ((dΔ

Z(t)/dt)_max); and

ii) a left ventricular ejection time (LVET) from the dΔ

Z(t)/dt waveform.

17. The system of claim 16, wherein the computer code is configured to determine stroke volume (SV) from the equation:

18. The system of claim 16, wherein the computer code is configured to determine stroke volume (SV) from the equation:

19. The system of claim 16, wherein the computer code is configured to determine stroke volume (SV) from the equation:

20. The system of claim 16, wherein the computer code is configured to determine stroke volume (SV) from the equation: