Tissue profile wellness monitor

• US 8,374,665 B2
• Filed: 04/21/2008
• Issued: 02/12/2013
• Est. Priority Date: 04/21/2007
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Cercacor Laboratories
• Inventors: Lamego, Marcelo
• Primary Examiner(s): WINAKUR, ERIC FRANK
• Application Number:
  US12/106,969
• Publication Number:
  US 20080262325A1
• Time in Patent Office: 1,758 Days
• Field of Search: 600/310, 600/322, 600/323, 600/324
• US Class Current: 600/322
• 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 5/14551 for measuring blood gases
• CPC Class Codes: A61B 5/72 Signal processing specially adapted for physiological signals or for diagnostic purposes character recognition, recognising digital ink, document-oriented image-based pattern recognition G06V30/00; recognition or understanding of postal images G06V30/424
• 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 5/7405 using sound
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 5/746 Alarms related to a physiological condition, e.g. details of setting alarm thresholds or avoiding false alarms alarms per se G08B
• CPC Class Codes: A61B 5/7475 User input or interface means, e.g. keyboard, pointing device, joystick

Abstract

A tissue profile wellness monitor measures a physiological parameter, generates a tissue profile, defines limits and indicates when the tissue profile exceeds the defined limits. The physiological parameter is responsive to multiple wavelengths of optical radiation after attenuation by constituents of pulsatile blood flowing within a tissue site. The tissue profile is responsive to the physiological parameter. The limits are defined for at least a portion of the tissue profile.

Claims

1. A physiological monitoring method comprising:

emitting light of eight or more wavelengths into tissue of a patient, the eight or more wavelengths responsive to pulsatile blood flowing within the tissue of the patient;

detecting the emitted light after attenuation by the tissue of the patient;

continuously generating a tissue profile responsive to absorption of the emitted wavelengths using a processor in real time,

continuously analyzing the tissue profile using the processor to determine if a change in the shape of the tissue profile has occurred;

indicating a wellness condition of the patient based on the analysis of the tissue profile.

2. The physiological monitoring method according to claim 1 wherein generating comprises:

measuring values at each of the emitted wavelengths; and

defining values corresponding to at least a portion of a wavelength spectrum between the emitted wavelengths based upon known characteristics of the tissue site.

3. The physiological monitoring method according to claim 2 wherein analyzing comprises:

setting a limit corresponding to the tissue profile; and

specifying an output corresponding to a comparison of the tissue profile to the set limit.

4. The physiological monitoring method according to claim 3 wherein indicating comprises generating at least one of a display, an alarm, diagnostic and a control.

5. The physiological monitoring method according to claim 3 wherein the setting a limit comprises defining at least one of a boundary and a maximum rate of change for at least a portion of the tissue profile.

6. The physiological monitoring method according to claim 5 wherein the indicating comprises generating at least one of an audible and visual alarm in response to at least a portion of the tissue profile exceeding the set limit.

7. The physiological monitoring method according to claim 2 wherein the measuring comprises calculating a normalized plethysmograph (NP) for each of the emitted wavelengths with respect to the NP at one of the emitted wavelengths.

8. A physiological monitoring method comprising:

emitting optical radiation of three or more wavelengths into the tissue of a patient;

detecting the optical radiation after attenuation of the light by the tissue of the patient;

continuously measuring a normalized plethysmograph (NP) at each of multiple wavelengths of the optical radiation so as to generate a tissue profile, the NP being responsive to attenuation of the optical radiation by constituents of pulsatile blood flowing within a tissue site illuminated by the optical radiation;

analyzing the tissue profile to determine if the shape of the tissue profile indicates an abnormal condition of the patient; and

outputting at least one of a display, alarm, diagnostic and control according to the testing results.

9. The physiological monitoring method according to claim 8 wherein analyzing comprises:

dividing the profile into a head portion at wavelengths less than a normalizing wavelength and a tail portion at wavelengths greater than a normalizing wavelength; and

evaluating the tail portion separately from the head portion.

10. The physiological monitoring method according to claim 9 wherein the evaluating comprises:

comparing the head portion against a head boundary; and

comparing the tail portion against a tail boundary.

11. The physiological monitoring method according to claim 10 wherein the evaluating comprises:

comparing the head portion against a head trend limit; and

comparing the tail portion against a tail trend limit.

12. The physiological monitoring method according to claim 11 wherein outputting comprises:

activating a first signal indicative of normalcy so long as the head portion is within the head boundary and changing less than the head trend limit and the tail portion is within the tail boundary and changing less than the tail trend limit;

activating a second signal indicative of caution when at least one of the head portion is changing faster than the head trend limit and the tail portion is changing faster than the tail trend limit; and

activating a third signal indicative of high alert when at least one of the head portion is outside the head boundary and the tail portion is outside the tail boundary.

13. A physiological monitoring method comprising:

emitting three or more wavelengths of light into a tissue site of a patient including pulsating blood;

detecting the light after attenuation by the tissue site;

measuring a physiological parameter responsive to multiple wavelengths of optical radiation after attenuation by constituents of pulsatile blood flowing within a tissue site;

continuously generating a tissue profile in response to the physiological parameter using a processor;

defining shape change limits for at least a portion of the tissue profile; and

indicating when the tissue profile changes shape and exceeds the defined limits.

14. The physiological monitoring method according to claim 13 wherein the defining limits comprise setting for at least a portion of the tissue profile at least one of a boundary and a trend limit.

15. The physiological monitoring method according to claim 14 further comprising:

determining a normalizing wavelength so as to divide the tissue profile into a first portion at wavelength of less than the normalizing wavelength and a second portion at wavelength of greater than the normalizing wavelength; and

defining limits for each of the first portion and the second portion.

16. The indicator method according the claim 15 wherein said normalized wavelength is 700 nm.