TISSUE PROFILE WELLNESS MONITOR

• US 20150196237A1
• Filed: 01/16/2015
• Published: 07/16/2015
• Est. Priority Date: 04/21/2007
• Status: Active Grant

• Current Assignee: Masimo Corporation
• Original Assignee: Cercacor Laboratories
• Inventors: Lamego, Marcelo M.
• Granted Patent: US 9,848,807 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• 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. (canceled)

2. A patient monitor comprising:

a front-end interface configured to receive, from a sensor comprising a light source that emits a plurality of wavelengths of light into a tissue site of a patient and a detector that detects the emitted light after attenuation by the tissue site, a signal indicative of the detected light at each of the plurality of wavelengths; and

a processor configured to;

normalize the signal, wherein the normalized signal is indicative of a tissue profile; and

analyze the normalized signal that is indicative of the tissue profile at at least some of the plurality of wavelengths to determine a patient wellness.

3. The patient monitor of claim 2, wherein analyzing the normalized signal that is indicative of the tissue profile comprises evaluating a shape of the tissue profile.

4. The patient monitor of claim 3, wherein the processor is further configured to:

output an indication in response to determining the shape of the tissue profile exceeds a predetermined limit.

5. The patient monitor of claim 4, wherein the indication comprises at least one of a display, an alarm, a diagnostic, or a control.

6. The patient monitor of claim 4, wherein the predetermined limit comprises a trend limit.

7. The patient monitor of claim 4, wherein the predetermined limit comprises a boundary.

8. The patient monitor of claim 2, wherein normalizing the signal comprises:

measuring, from the signal, values indicative of an amount of light attenuation for at least some of the plurality wavelengths;

defining, based on characteristics of the tissue site, additional values corresponding to at least a portion of a wavelength spectrum between the respective wavelengths associated with the at least some of the plurality of wavelengths; and

combining the measured values at each of the at least some of the plurality wavelengths with the additional values.

9. The patient monitor of claim 2, wherein the processor is further configured to:

output a first signal indicative of patient normalcy when the normalized signal is within a predefined boundary and a rate of change of the normalized signal is less than a maximum rate of change; and

output a second signal indicative of alert when at least one of the normalized signal is outside of the boundary and the rate of change of normalized signal is greater than the maximum rate of change.

10. The patient monitor of claim 2, wherein the normalized signal is indicative of at least one of oxygen saturation of the patient, carboxyhemoglobin of the patient, or methemoglobin of the patient.

11. The patient monitor of claim 2, wherein the normalized signal comprises a first portion and a second portion, and wherein the first portion is analyzed in comparison to a first portion predetermined limit, and the second portion is analyzed in comparison to a second portion predetermined limit.

12. The patient monitor of claim 11, wherein the processor is further configured to:

provide a first indication in response to the first and second portions not exceeding the respective first and second portion predetermined limits;

provide a second indication in response to one of the first or second portions exceeding the respective first or second portion predetermined limits; and

provide a third indication in response to both of the first and second portions exceeding the respective first and second portion predetermined limits.

13. A patient monitor comprising:

a front-end interface configured to receive, from a sensor comprising a light source that emits a plurality of wavelengths of light into a tissue site of a patient and a detector that detects the emitted light after attenuation by the tissue site, a signal indicative of the detected light at each of the plurality of wavelengths; and

a processor configured to;

determine, based on the signal, a relationship among light attenuation values associated with at least some of the plurality of wavelengths; and

evaluate a shape of the determined relationship in relation to a predetermined limit to determine a patient wellness.

14. The patient monitor of claim 13, wherein the determined relationship exceeding the predetermined limit indicates advance warning of deteriorating patient wellness.

15. The patient monitor of claim 14, wherein the predetermined limit comprises a trend limit.

16. The patient monitor of claim 14, wherein the predetermined limit comprises a boundary.

17. The patient monitor of claim 13, wherein a reference wavelength divides the determined relationship into a first portion and a second portion, and wherein the first portion is evaluated in relation to a first portion predetermined limit, and the second portion is evaluated in relation to a second portion predetermined limit.

18. The patient monitor of claim 17, wherein the processor is further configured to:

provide a first indication in response to the first and second portions not exceeding the respective first and second portion predetermined limits;

provide a second indication in response to one of the first or second portions exceeding the respective first or second portion predetermined limits; and

provide a third indication in response to both of the first and second portions exceeding the respective first and second portion predetermined limits.

19. The patient monitor of claim 13, wherein determining the relationship among light attenuation values associated with at least some of the plurality of wavelengths comprises:

normalizing the signal based on a reference wavelength, wherein the reference wavelength is one of the plurality of wavelengths.

20. The patient monitor of claim 19, wherein normalizing the signal includes:

determining, at each of the at least some of the plurality of wavelengths, a normalized plethysmograph (NP); and

normalizing each of the determined NPs based on the reference wavelength.

21. The patient monitor of claim 20, wherein determining the relationship among light attenuation values associated with at least some of the plurality of wavelengths further comprises:

defining continuous normalized NP values corresponding to at least a portion of a wavelength spectrum between the two or more of the at least some of the plurality of wavelengths based at least in part on characteristics of the tissue site; and

combining the normalized NP values at each of the at least some of the plurality of wavelengths with the defined continuous normalized NP values.

22. The patient monitor of claim 13, wherein the determined relationship is indicative of at least one of oxygen saturation of the patient, carboxyhemoglobin of the patient, or methemoglobin of the patient.