Floormat physiological sensor

• US 10,314,543 B2
• Filed: 01/05/2016
• Issued: 06/11/2019
• Est. Priority Date: 01/05/2016
• Status: Active Grant

• Current Assignee: Baxter Healthcare SA (Baxter International Inc.), Baxter International Inc.
• Original Assignee: OtoSense, Inc. (Analog Devices, Inc.)
• Inventors: Banet, Matthew, Dhillon, Marshal Singh, Pede, Susan Meeks, Hayward, Lauren Nicole Miller, Deptala, Arthur, Cochran, Jonas Dean
• Primary Examiner(s): Winakur, Eric F
• Assistant Examiner(s): Liu, Chu Chuan
• Application Number:
  US14/988,653
• Publication Number:
  US 20170188956A1
• Time in Patent Office: 1,253 Days
• CPC Class Codes: A61B 5/0008 Temperature signals
• CPC Class Codes: A61B 5/002 Monitoring the patient using a local or closed circuit, e.g. in a room or building A61B5/0017 takes precedence
• 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 5/02125 of pulse wave propagation time
• 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 5/02233 Occluders specially adapted therefor tourniquets A61B17/132
• CPC Class Codes: A61B 5/02427 Details of sensor
• 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 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/4872 Body fat
• CPC Class Codes: A61B 5/6892 Mats
• CPC Class Codes: A61B 5/7275 Determining trends in physiological measurement data; Predicting development of a medical condition based on physiological measurements, e.g. determining a risk factor
• CPC Class Codes: A61B 5/7282 Event detection, e.g. detecting unique waveforms indicative of a medical condition A61B5/4094, A61B5/4818, A61B5/349, A61B5/0823 take precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: G01G 19/50 having additional measuring devices, e.g. for height
• CPC Class Codes: G16H 50/20 for computer-aided diagnosis, e.g. based on medical expert systems

Abstract

A stand-on physiological sensor (e.g. floormat) measures vital signs and various hemodynamic parameters, including blood pressure and ECG waveforms. The sensor is similar in configuration to a common bathroom scale and includes electrodes that take electrical measurements from a patient'"'"'s feet to generate bioimpedance waveforms, which are analyzed digitally to extract various other parameters, as well as a cuff-type blood pressure system that takes physical blood pressure measurements at one of the patient'"'"'s feet. Blood pressure can also be calculated/derived from the bioimpedance waveforms. Measured parameters are transmitted wirelessly to facilitate remote monitoring of the patient for heart failure, chronic heart failure, end-stage renal disease, cardiac arrhythmias, and other degenerative diseases.

Claims

1. A system for measuring a pulse oximetry value from a patient, comprising:

a weight-bearing base comprising a bottom surface configured to rest on a substantially horizontal surface and supports the patient when they stand on the weight-bearing base, and a top surface connected to the weight-bearing base and configured to form an opening that receives at least one of the patient'"'"'s feet when the patient stands on the weight-bearing base;

an optical system deployed in the top surface and comprising a first light source oriented to emit infrared radiation that irradiates a top portion of the patient'"'"'s foot when the opening receives at least one of the patient'"'"'s feet, a second light source oriented to emit red radiation that irradiates the top portion of the patient'"'"'s foot when the opening receives at least one of the patient'"'"'s feet, and a photodetector deployed in the top surface, the photodetector configured to receive infrared radiation after the radiation irradiates the top portion of at least one of the patient'"'"'s feet to generate a first set of signals, and to receive red radiation after the radiation irradiates the top portion of at least one of the patient'"'"'s feet to generate a second set of signals; and

a processing system in electrical contact with the optical system, and configured to receive the first set of signals from the optical system and convert them into a first set of values, and to receive the second set of signals from the optical system and convert them into a second set of values, the processing system further configured to analyze the first and second set of values to determine the pulse oximetry value.

2. The system of claim 1, wherein the first light source is configured to emit optical radiation between 880 and 920 nm.

3. The system of claim 2, wherein the first light source is configured to emit optical radiation around 905 nm.

4. The system of claim 1, wherein the second light source is configured to emit optical radiation between 640 and 680 nm.

5. The system of claim 4, wherein the second light source is configured to emit optical radiation around 660 nm.

6. The system of claim 1, wherein the first and second light sources and the photodetector are connected directly to the top surface.

7. The system of claim 6, wherein the photodetector is configured to receive infrared radiation from the first light source after the radiation reflects off at least one of the patient'"'"'s feet.

8. The system of claim 7, wherein the photodetector is configured to receive red radiation from the second light source after the radiation reflects off at least one of the patient'"'"'s feet.

9. The system of claim 1, wherein the first and second light sources are connected to a member that connects directly to the top surface.

10. The system of claim 9, wherein the member is configured to cover at least a portion of at least one of the patient'"'"'s feet.

11. The system of claim 10, wherein the member is a flexible strap connected at the distal ends thereof to the top surface.

12. The system of claim 10, wherein the photodetector is connected directly to the top surface.

13. The system of claim 12, wherein the photodetector is configured to receive infrared radiation from the first light source after the radiation transmits through a portion of at least one of the patient'"'"'s feet.

14. The system of claim 13, wherein the photodetector is configured to receive red radiation from the second light source after the radiation transmits through a portion of at least one of the patient'"'"'s feet.

15. The system of claim 1, wherein the processing system comprises computer code configured to analyze the first set of values to determine an AC component (infrared(AC)) and a DC component (infrared(DC)).

16. The system of claim 15, wherein the processing system comprises computer code configured to analyze the second set of values to determine an AC component (red(AC)) and a DC component (red(DC)).

17. The system of claim 16, wherein the processing system comprises computer code configured to collectively analyze the infrared(AC), infrared(DC), red(AC), and red(DC) components to determine the pulse oximetry value.

18. The system of claim 17, wherein the processing system comprises computer code configured to collectively analyze the infrared(AC), infrared(DC), red(AC), and red(DC) components according to the following equation to determine a ratio of ratios (RoR):

19. The system of claim 18, wherein the processing system comprises computer code configured to process the RoR according to the following equation to determine a pulse oximetry value:

pulse oximetry value=(a+b×

RoR+c×

RoR²)×

100.

20. A system for measuring a pulse oximetry value from a patient, comprising:

a weight-bearing base comprising a bottom surface configured to rest on a substantially horizontal surface and supports the patient when they stand on the weight-bearing base, and a top surface connected to the weight-bearing base and configured to form an opening that receives at least one of the patient'"'"'s feet when the patient stands on the weight-bearing base;

an optical system deployed in the top surface and comprising a first light source oriented to emit infrared radiation that irradiates a top portion of the patient'"'"'s foot when the opening receives at least one of the patient'"'"'s feet, a second light source oriented to emit red radiation that irradiates the top portion of the patient'"'"'s foot when the opening receives at least one of the patient'"'"'s feet, and a photodetector deployed in the top surface, the photodetector configured to receive infrared radiation after the radiation irradiates the top portion of at least one of the patient'"'"'s feet to generate a first set of signals, and to receive red radiation after the radiation irradiates the top portion of at least one of the patient'"'"'s feet to generate a second set of signals;

a weight-measuring system connected to the weight-bearing base, the weight-measuring system comprising an electrical system that measures a set of voltages that correlates with a force applied to the top surface when the patient stands on the weight-bearing base; and

a processing system in electrical contact with the optical system, and configured to receive the first set of signals from the optical system and convert them into a first set of values, and to receive the second set of signals from the optical system and convert them into a second set of values, the processing system further configured to analyze the first and second set of values to determine the pulse oximetry value.

21. The system of claim 20, wherein the electrical system comprises a Wheatstone Bridge.

22. The system of claim 21, wherein the Wheatstone Bridge connects electrically with an amplifier system.

23. The system of claim 22, wherein the processing system is further configured to receive the set of voltages, and analyze the set of voltages to determine a value of weight corresponding to the force applied on the top surface.

24. The system of claim 20, wherein the first light source is configured to emit optical radiation between 880 and 920 nm.

25. The system of claim 24, wherein the first light source is configured to emit optical radiation around 905 nm.

26. The system of claim 20, wherein the second light source is configured to emit optical radiation between 640 and 680 nm.

27. The system of claim 26, wherein the second light source is configured to emit optical radiation around 660 nm.

28. The system of claim 20, wherein the first and second light sources and the photodetector are connected directly to the top surface.

29. The system of claim 28, wherein the photodetector is configured to receive infrared radiation from the first light source after the radiation reflects off a portion of at least one of the patient'"'"'s feet.

30. The system of claim 29, wherein the photodetector is configured to receive red radiation from the second light source after the radiation reflects off a portion of at least one of the patient'"'"'s feet.

31. The system of claim 20, wherein the first and second light sources are connected to a member that connects directly to the top surface.

32. The system of claim 31, wherein the member is configured to cover at least a portion of at least one of the patient'"'"'s feet.

33. The system of claim 32, wherein the member is a flexible strap connected at the distal ends thereof to the top surface.

34. The system of claim 32, wherein the photodetector is connected directly to the top surface.

35. The system of claim 34, wherein the photodetector is configured to receive infrared radiation from the first light source after the radiation transmits through at least one of the patient'"'"'s feet.

36. The system of claim 35, wherein the photodetector is configured to receive red radiation from the second light source after the radiation transmits through at least one of the patient'"'"'s feet.

37. The system of claim 20, wherein the processing system comprises computer code configured to analyze the first set of values to determine an AC component (infrared(AC)) and a DC component (infrared(DC)).

38. The system of claim 37, wherein the processing system comprises computer code configured to analyze the second set of values to determine an AC component (red(AC)) and a DC component (red(DC)).

39. The system of claim 38, wherein the processing system comprises computer code configured to collectively analyze the infrared(AC), infrared(DC), red(AC), and red(DC) components to determine the pulse oximetry value.

40. The system of claim 39, wherein the processing system comprises computer code configured to collectively analyze the infrared(AC), infrared(DC), red(AC), and red(DC) components according to the following equation to determine a ratio of ratios (RoR):

41. The system of claim 40, wherein the processing system comprises computer code configured to process the RoR according to the following equation to determine a pulse oximetry value:

pulse oximetry value=(a+b×

RoR+c×

RoR²)×

100.