System and Process for Non-Invasive Collection and Analysis of Physiological Signals

• US 20080275314A1
• Filed: 07/07/2008
• Published: 11/06/2008
• Est. Priority Date: 10/27/2003
• Status: Active Grant

• Current Assignee: Best Buy Health Incorporated (Best Buy Co., Inc.)
• Original Assignee: Home Guardian LLC (Best Buy Co., Inc.)
• Inventors: Mack, David C., Felder, Robin, Wood, Sarah, Turner, Beverly, Alwan, Majd, Kell, Steve
• Granted Patent: US 7,785,257 B2
• Time in Patent Office: Days
• US Class Current: 600/301
• CPC Class Codes: A61B 2562/0247 Pressure sensors
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/024 Detecting, measuring or recording pulse rate or heart rate A61B5/0205, A61B5/021 take precedence
• CPC Class Codes: A61B 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• CPC Class Codes: A61B 5/11 Measuring movement of the entire body or parts thereof, e.g. head or hand tremor, mobility of a limb for measuring pulse A61B5/02 ;A61B5/1038 takes precedence; motion detection to correct for motion artifacts in physiological signals A61B5/721
• CPC Class Codes: A61B 5/1126 using a particular sensing technique
• CPC Class Codes: A61B 5/113 occurring during breathing
• CPC Class Codes: A61B 5/447 specially adapted for aiding the prevention of ulcer or pressure sore development, i.e. before the ulcer or sore has developed
• CPC Class Codes: A61B 5/4818 Sleep apnoea
• CPC Class Codes: A61B 5/6892 Mats

Abstract

A system and method for detecting, monitoring and analyzing physiological characteristics. Signals from a subject are acquired from a suite of sensors, such as temperature, carbon dioxide, humidity, light, movement, electromagnetic and vibration sensors, in a passive, non-invasive manner. The signals are processed and physiological characteristics are isolated for analysis. The system and method are to analyze sleep patterns, as well as to prevent bed sores or detect conditions such as illness, restless leg syndrome, periodic leg movement, sleep walking, or sleep apnea. However, numerous other applications of the invention are also disclosed.

Claims

1. A non-invasive system for assessing physiological characteristics of a subject, said system comprising:

a network of sensors configured to provide electronic output signals indicative of at least one sensed condition, said network including at least one passive sensor selected from the group consistently of vibration, temperature, carbon dioxide, humidity, electromagnetic and light sensors, and wherein said network of sensors further comprises a movable support including at least one of said sensors;

data acquisition circuitry for collecting the electronic signals output from said network of sensors;

a processor configured to process the electronic signals, said processor including an amplifier configured to amplify at least one of the electronic signals, and first and second filters configured to receive the amplified electronic signals to produce two processed electronic signals, wherein said first filter includes a band pass filter and said second filter includes a low pass filter and a high pass filter, and wherein said first filter outputs a first signal corresponding to a respiratory rate on a breath-by-breath basis of the subject and said second filter outputs a second signal corresponding to a heart rate on a beat-by-beat basis of the subject; and

an output device for outputting the processed signals into human-readable data indicative of at least one condition of a subject.

2. The system of claim 1 wherein said system is adapted to assess the quality of sleep of a subject and wherein:

said data acquisition circuitry is configured to collect the electronic signals output from said network of sensors indicative of heart rate and/or respiratory rate;

said first filter receives signals indicative of chest movement and said second filter receives signals indicative of heart movement; and

said processor includes an algorithm to generate a heart rate and a respiratory rate based on processed electronic signals output at or below about 50 Hz.

3. The system of claim 2, further comprising an algorithm for determining sleep staging and aspects of sleep quality based on the heart rate, the respiratory rate, a variability of the heart rate, a variability of the respiratory rate and a subject movement percentage.

4. The system of claim 1, further comprising a microcontroller for converting the collected electronic signals into a bit stream to be logged into a data file for immediate analysis or for later review.

5. The system of claim 1, wherein said network of sensors includes at least one detector for sensing motion, the bit stream includes electronic signals from said at least detector and said processor processes the bit stream to provide a positional map of the subject.

6. The system of claim 1, wherein said amplifier comprises an instrumentation amplifier that provides buffering from said network of sensors and an infinite common mode rejection ratio.

7. The system of claim 1, wherein at least some of the sensors are passive sensors requiring no active involvement from the subject and no direct attachment to the subject.

8. The system of claim 1, wherein human-readable data comprises at least one of a heart rate waveform and a respiratory waveform.

9. The system of claim 1, wherein the human-readable data comprises an obstructive sleep apnea count.

10. The system of claim 1, wherein human-readable data comprises a subject movement percentage.

11. The system of claim 1, wherein at least part of the system is incorporated in one of a mattress pad or pillow, a bed or chair at a sleep lab, a bed or chair at an elder care facility, a bed or chair at a hospital for children or adults, a bed or baby support at a prenatal care facility, and a publicly available health monitoring station.

12. The system of claim 1, wherein said data acquisition circuitry further comprises a user activated privacy flag to flag for omission output signals from said network of sensors.

13. The system of claim 1, wherein said network of sensors can saturate when gross movement occurs.

14. The system of claim 13, wherein the saturation of said sensors allows differentiation between gross movement and acute movements.

15. The system of claim 14, wherein gross movement includes physical repositioning and acute movement includes cardiac and respiratory events.

16. The system of claim 15, wherein at least one of the gross movement and acute movement are interpreted to prevent development of pressure ulcers or bed sores in the patient.

17. The system of claim 1, wherein said sensors are from the group including piezoelectric, fiber optic, or load cell.

18. A non-invasive system for assessing physiological characteristics of a subject, said system comprising:

a network of sensors configured to provide electronic output signals indicative of at least one sensed condition, said network including at least one passive sensor selected from the group consistently of vibration, temperature, carbon dioxide, humidity, electromagnetic and light sensors;

data acquisition circuitry for collecting the electronic signals output from said network of sensors, said circuitry including a user activated privacy flag to flag for omission output signals from said network of sensors;

a processor configured to process the electronic signals, said processor including an amplifier configured to amplify at least one of the electronic signals, and first and second filters configured to receive the amplified electronic signals to produce two processed electronic signals, wherein said first filter includes a band pass filter and said second filter includes a low pass filter and a high pass filter, and wherein said first filter outputs a first signal corresponding to a respiratory rate on a breath-by-breath basis of the subject and said second filter outputs a second signal corresponding to a heart rate on a beat-by-beat basis of the subject; and

an output device for outputting the processed signals into human-readable data indicative of at least one condition of a subject.

19. A non-invasive system for assessing physiological characteristics of a subject, said system comprising:

a network of sensors configured to provide electronic output signals indicative of at least one sensed condition, said network including at least one passive sensor selected from the group consistently of vibration, temperature, carbon dioxide, humidity, electromagnetic and light sensors, wherein said network of sensors can saturate when gross movement occurs;

data acquisition circuitry for collecting the electronic signals output from said network of sensors;

a processor configured to process the electronic signals, said processor including an amplifier configured to amplify at least one of the electronic signals, and first and second filters configured to receive the amplified electronic signals to produce two processed electronic signals, wherein said first filter includes a band pass filter and said second filter includes a low pass filter and a high pass filter, and wherein said first filter outputs a first signal corresponding to a respiratory rate on a breath-by-breath basis of the subject and said second filter outputs a second signal corresponding to a heart rate on a beat-by-beat basis of the subject; and

an output device for outputting the processed signals into human-readable data indicative of at least one condition of a subject.

20. The system of claim 19, wherein saturation of said sensors allows differentiation between gross movement and acute movements.