PHYSIOLOGICAL MONITORING SYSTEM FEATURING FLOORMAT AND HANDHELD SENSOR

• US 20170188944A1
• Filed: 01/05/2016
• Published: 07/06/2017
• Est. Priority Date: 01/05/2016
• Status: Abandoned Application

• Current Assignee: Tosense Inc (Baxter International Inc.)
• Original Assignee: Tosense Inc (Baxter International Inc.)
• Inventors: HAYWARD, Lauren Nicole Miller, COCHRAN, Jonas Dean, BANET, Matthew, DHILLON, Marshal Singh, PEDE, Susan Meeks, DEPTALA, Arthur
• Application Number:
  US14/988,713
• Publication Number:
  US 20170188944A1
• Time in Patent Office: Days
• CPC Class Codes: A61B 2560/0431 Portable apparatus, e.g. comprising a handle or case
• 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 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 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 5/0537 Measuring body composition by impedance, e.g. tissue hydration or fat content
• CPC Class Codes: A61B 5/4842 Monitoring progression or stage of a disease
• 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 5/6892 Mats

Abstract

The invention described herein is a system that features a Floormat and Handheld Sensor that operate in concert with a user'"'"'s mobile device. The Floormat resembles a conventional bathroom scale, but features an enhanced set of measurements that include pulse rate and/or heart rate, SpO2, respiratory rate, weight, body composition, and Fluids. The Handheld Sensor features an integrated form factor that fits in a user'"'"'s hand, which measures parameters such as blood pressure (e.g. systolic, diastolic, mean and pulse pressures), stroke volume, and cardiac output. Measurements of stroke volume and cardiac output require information from the Floormat (e.g., weight and body composition) to be sent to and processed by the Handheld Sensor. The Handheld Sensor can also make redundant measurements of heart rate, SpO2, and respiratory rate. Both systems transmit information through a wireless interface to a web-based system, where a clinician can analyze it to help diagnose a user.

Claims

1. A system for monitoring a patient suffering from heart failure, comprising:

a floormat sensor configured to rest on a substantially horizontal surface, the floormat sensor comprising;

a weight-measuring system comprising at least one load cell and an amplifier system configured to measure a voltage from the at least one load cell and process it to determine a weight value;

an optical system comprising an optical system with at least two light sources and a photodetector configured to measure at least one photoplethysmogram waveform and process it to determine an SpO2 value;

a first impedance system comprising a first electrode configured to inject an electrical current near a foot of the patient, a second electrode configured to measure at least one signal representative of an impedance encountered by the electrical current and process it to determine a fluid value representative of the patient'"'"'s lower extremities; and

a first wireless transmitter;

a handheld sensor comprising;

a second wireless transmitter in communication with the first wireless transmitter comprised by the floormat sensor; and

a second impedance system comprising a first electrode configured to inject an electrical current near a hand of the patient, a second electrode configured to measure at least one signal representative of an impedance encountered by the electrical current and process it and the weight value received from the floormat system to determine a stroke volume value; and

a processing system configured to receive the weight value, fluid value, and SpO2 value from the floormat sensor and the stroke volume value for the handheld sensor, the processing system configured to detect trends in a set of weight values, a set of fluid values, a set of SpO2 values, and a set of stroke volume values to monitor the patient suffering from heart failure.

2. The system of claim 1, wherein the first impedance-measuring system comprises four electrodes, with two electrodes positioned on a left-hand side of a top surface of the floormat sensor, and two electrodes positioned on a right-hand side of a top surface of the floormat sensor.

3. The system of claim 2, wherein the first impedance-measuring system comprises a first electrode on the left-hand side of the top surface of the floormat sensor that injects an electrical current into the patient'"'"'s left foot, and a second electrode on the right-hand side of the top surface of the floormat sensor that injects an electrical current into the patient'"'"'s right foot.

4. The system of claim 3, wherein the impedance-measuring system comprises a third electrode that senses a first bio-electric signal from near the patient'"'"'s left foot, and a fourth electrode that senses a second bio-electric signal from near the patient'"'"'s right foot.

5. The system of claim 4, wherein the impedance-measuring system comprises an electrical system comprising a circuit that receives the first bio-electric signal from near the patient'"'"'s left foot and the second bio-electric signal from near the patient'"'"'s right foot, and collectively processes these to determine the first set of digital impedance signals that include a DC impedance signal that comprises a baseline impedance.

6. The system of claim 5, wherein the processing system processes the DC impedance signal to determine the fluid value.

7. The system of claim 1, wherein the second impedance-measuring system comprises four electrodes, with two electrodes positioned on a wrist-mounted component, and two electrodes positioned on an exposed surface of the handheld sensor that can be brought in contact with another portion of the patient'"'"'s body when the patient holds the handheld sensor.

8. The system of claim 7, wherein the exposed surface is configured to be brought in contact with the patient'"'"'s torso when the patient holds the handheld sensor.

9. The system of claim 8, wherein the exposed surface is configured to be brought in contact with the patient'"'"'s stomach when the patient holds the handheld sensor.

10. The system of claim 8, wherein the second impedance-measuring system comprises a first electrode on the wrist-mounted component that injects an electrical current into the patient'"'"'s wrist, and a second electrode on the exposed surface that injects an electrical current into the patient'"'"'s torso.

11. The system of claim 10, wherein the second impedance-measuring system comprises a third electrode that senses a first bio-electric signal from near the patient'"'"'s wrist, and a fourth electrode that senses a second bio-electric signal from near the patient'"'"'s torso.

12. The system of claim 11, wherein the second impedance-measuring system comprises an electrical system comprising a circuit that receives the first bio-electric signal from near the patient'"'"'s wrist and the second bio-electric signal from near the patient'"'"'s torso, and collectively processes these to determine the set of digital impedance signals that include a DC impedance signal that comprises a baseline impedance, and an AC impedance signal that comprises time-dependent components due to heartbeat-induced blood flow.

13. The system of claim 12, wherein the processing system comprises computer code configured to analyze the DC impedance signal, AC impedance signal, and weight value to determine the stroke volume value.

14. The system of claim 13, wherein the computer code is configured to calculate a derivative of the AC impedance signal to determine a dΔ

Z(t)/dt waveform.

15. The system of claim 14, wherein the computer code is configured to determine a maximum value of the dΔ

Z(t)/dt waveform.

16. The system of claim 14, wherein the computer code is configured to determine an area of a pulse in the dΔ

Z(t)/dt waveform.

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

Z(t)/dt waveform.

18. The system of claim 17, 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.

19. The system of claim 13, wherein the computer code is configured to estimate a baseline impedance (Z₀) from the DC impedance signal.

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

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

22. The system of claim 1, wherein the processing system is further configured to indicate an alarm when a trend in the set of weight values shows an increase in weight that exceeds a first predetermined threshold value, a rend in the set of fluid values shows an increase in fluid that exceeds a second predetermined threshold value, a trend in the set of SpO2 values shows an decrease in SpO2 that exceeds a third predetermined threshold value, and a trend in the set of stroke volume values shows an decrease in stroke volume that exceeds a fourth predetermined threshold value.