Synthetic Aperture Photoplethysmography Sensor

• US 20180092602A1
• Filed: 10/04/2016
• Published: 04/05/2018
• Est. Priority Date: 10/04/2016
• Status: Active Grant

• Current Assignee: Guardian Health Incorporated
• Original Assignee: Hall Labs, LLC
• Inventors: Hall, David R., Allen, Dan, Davis, Andrew, Hendricks, Daniel, Robinson, Justin
• Granted Patent: US 10,383,576 B2
• Time in Patent Office: Days
• CPC Class Codes: A47K 13/24 Parts or details not covered in, or of interest apart from, groups A47K13/02 - A47K13/22, e.g. devices imparting a swinging or vibrating motion to the seats
• CPC Class Codes: A61B 2090/064 for measuring force, pressure or mechanical tension
• CPC Class Codes: A61B 2090/065 for measuring contact or contact pressure
• CPC Class Codes: A61B 2503/08 Elderly
• CPC Class Codes: A61B 2503/12 Healthy persons not otherwise provided for, e.g. subjects of a marketing survey
• CPC Class Codes: A61B 2505/07 Home care
• CPC Class Codes: A61B 2560/0462 Apparatus with built-in sensors
• CPC Class Codes: A61B 2560/0468 Built-in electrodes
• CPC Class Codes: A61B 2562/046 in a matrix array
• 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 5/02427 Details of sensor
• CPC Class Codes: A61B 5/0261 using optical means, e.g. infrared light
• 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 5/1102 Ballistocardiography
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/6891 Furniture

Abstract

A synthetic aperture photoplethysmography (PPG) sensor is disclosed. A group or matrix of contiguous PPG sensors located on a toilet seat are conditionally combined based on sensor measurements. Conditional combinations may be based on timing data and signal-to-noise ratio data of each of the PPG measurements. Measurements associated with the conditional combinations are then used to determine a cardiac function of a toilet user.

Claims

1. A method of conditionally combining photoplethysmography (PPG) measurements comprising:

obtaining PPG measurements from a group of contiguous PPG sensors located on a toilet seat;

combining the PPG measurements into one or more conditional combinations based on timing data or signal-to-noise ratio data corresponding to each of the PPG measurements; and

using the one or more conditional combinations to determine a cardiac function of a toilet user.

2. The method of claim 1, further comprising averaging the one or more conditional combinations to determine the cardiac function of the toilet user.

3. The method of claim 1, wherein one or more of the one or more conditional combinations are determined at least partially based on an intensity level of received light at the PPG sensors.

4. The method of claim 1, wherein one or more of the one or more conditional combinations are determined at least partially based on an intensity level change of received light at the PPG sensors over a predetermined time interval.

5. The method of claim 4, further comprising obtaining ballistocardiography (BCG) measurements from a BCG sensor located in the toilet seat.

6. The method of claim 5, wherein the timing data includes timing data associated with the BCG measurements.

7. The method of claim 5, wherein the predetermined time interval is obtained using the BCG measurements.

8. The method of claim 5, wherein obtaining BCG measurements comprises measuring a changing weight of the toilet user over time with the one or more force sensors.

9. The method of claim 1, wherein the group of contiguous PPG sensors is arranged in a two-dimensional array.

10. The method of claim 1, wherein the contiguous PPG sensors comprise photodiode devices, charge-coupled devices (CCDs), active-pixel sensors, or complementary metal-oxide-semiconductor (CMOS) sensors.

11. The method of claim 1, wherein the contiguous PPG sensors comprise light emitting diodes or laser diodes.

12. The method of claim 1, wherein the contiguous PPG sensors comprise both light transmitters and light receivers.

13. The method of claim 1, wherein combining the PPG measurements comprises selectively averaging two or more of the PPG measurements.

14. The method of claim 13, wherein the two or more of the PPG measurements are selected based on a signal-to-noise threshold ratio threshold and a data timing threshold.

15. The method of claim 1, wherein the one or more conditional combinations is determined by choosing a conditional combination of the one or more conditional combinations which has a first arrival in time.

16. The method of claim 1, wherein the cardiac function comprises blood oxygen level, heart rate, blood pressure, blood flow rate, pulse transit time, or a combination thereof.

17. The method of claim 1, further comprising obtaining bio-impedance measurements from bio-impedance electrodes on the toilet seat.

18. The method of claim 17, wherein the timing data includes timing data associated with the bio-impedance measurements.

19. The method of claim 1, wherein the toilet seat further comprises optical fibers.

20. The method of claim 19, wherein the optical fibers connect to a plurality of light emitting diodes and at least one optical detector.