TISSUE PROFILE WELLNESS MONITOR

• US 20080262325A1
• Filed: 04/21/2008
• Published: 10/23/2008
• Est. Priority Date: 04/21/2007
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Cercacor Laboratories
• Inventors: Lamego, Marcelo
• Granted Patent: US 8,374,665 B2
• Time in Patent Office: Days
• 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:

generating a tissue profile responsive to absorption of a plurality of emitted wavelengths of optical radiation by pulsatile blood flowing within a tissue site,

predetermining a plurality of rules for evaluating at least a portion of the tissue profile; and

applying the predetermined rules to the tissue profile so as to indicate a patient condition.

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 predetermining 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 applying comprises generating at least one of a display, an alarm, diagnostic and a control.

5. The physiological monitoring method according to claim 4 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.

6. The physiological monitoring method according to claim 5 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.

7. The physiological monitoring method according to claim 6 wherein the applying 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.

8. A physiological monitoring method comprising:

measuring a normalized plethysmograph (NP) at each of multiple wavelengths of 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;

testing the tissue profile against predetermined rules; 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 testing 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

applying a first portion of the rules to the tail portion and a second portion of the rules to a head portion.

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

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

generating a tissue profile in response to the physiological parameter;

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

indicating when the tissue profile 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 to claim 15 wherein said normalized wavelength is 700 nm.