System and method for detecting fluid responsiveness of a patient

• US 9,060,745 B2
• Filed: 08/22/2012
• Issued: 06/23/2015
• Est. Priority Date: 08/22/2012
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Su, Mark, Watson, James Nicholas, Addison, Paul Stanley
• Primary Examiner(s): MENDEZ, MANUEL A
• Application Number:
  US13/591,455
• Publication Number:
  US 20140058229A1
• Time in Patent Office: 1,035 Days
• Field of Search: 600/323, 600/479
• US Class Current: 1/1
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/02007 Evaluating blood vessel condition, e.g. elasticity, compliance
• 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 5/02416 using photoplethysmograph signals, e.g. generated by infrared radiation A61B5/14552 takes precedence
• CPC Class Codes: A61B 5/0245 by using sensing means generating electric signals, i.e. ECG signals
• CPC Class Codes: A61B 5/026 Measuring blood flow A61B3/1233, A61B3/1241 take precedence
• 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 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/14552 Details of sensors specially adapted therefor
• CPC Class Codes: A61B 5/1495 Calibrating or testing of in-vivo probes
• CPC Class Codes: A61B 5/333 Recording apparatus specially adapted therefor
• CPC Class Codes: A61B 5/4839 combined with drug delivery
• CPC Class Codes: A61B 5/486 Bio-feedback A61B5/375 takes precedence
• CPC Class Codes: A61B 5/6826 Finger
• CPC Class Codes: A61B 5/7214 using signal cancellation, e.g. based on input of two identical physiological sensors spaced apart, or based on two signals derived from the same sensor, for different optical wavelengths
• CPC Class Codes: A61B 5/7225 Details of analog processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation A61B5/30, A61B5/316 take precedence; transformers for specific applications H01F38/00; amplifiers H03F
• CPC Class Codes: A61B 5/7278 Artificial waveform generation or derivation, e.g. synthesising signals from measured signals A61B5/327 takes precedence
• CPC Class Codes: A61B 5/742 using visual displays A61B5/339 takes precedence
• CPC Class Codes: A61B 6/507 for determination of haemodynamic parameters, e.g. perfusion CT
• CPC Class Codes: A61B 8/06 : Measuring blood flow measuring volume flow in general G01F, e.g. G01F1/66, G01F1/72; measuring speed of fluids in general G01P5/00

Abstract

A system is configured to determine a fluid responsiveness index of a patient from a physiological signal. The system may include a sensor configured to be secured to an anatomical portion of the patient, and a monitor operatively connected to the sensor. The sensor is configured to sense a physiological characteristic of the patient. The monitor is configured to receive a physiological signal from the sensor. The monitor may include an index-determining module configured to determine the fluid responsiveness index through formation of a ratio of one or both of amplitude or frequency modulation of the physiological signal to baseline modulation of the physiological signal.

Claims

1. A system for determining a fluid responsiveness index of a patient from a physiological signal, the system comprising:

a sensor configured to be secured to an anatomical portion of the patient, wherein the sensor is configured to sense a physiological characteristic of the patient; and

a monitor operatively connected to the sensor, the monitor configured to receive a physiological signal from the sensor, the monitor comprising an index-determining module configured to determine the fluid responsiveness index through formation of a ratio of one or both of amplitude modulation or frequency modulation of the physiological signal with respect to baseline modulation of the physiological signal.

2. The system of claim 1, wherein the monitor further comprises a normalization module configured to normalize the fluid responsiveness index.

3. The system of claim 2, wherein the normalization module is configured to normalize the fluid responsiveness index to correct for changes in one or both of vascular tone or motion artifacts.

4. The system of claim 2, wherein the normalization module is configured to normalize the fluid responsiveness index based on one or more of a relative amplitude ratio of the physiological signal, a width of at least one primary peak of the physiological signal, a time difference between the at least one primary peak and at least one trailing peak, or a pleth modulation ratio of the physiological signal.

5. The system of claim 1, wherein the index-determining module determines the fluid responsiveness index by applying a calibration coefficient or constant to the ratio.

6. The system of claim 1, wherein the physiological signal comprises a photoplethysmogram (PPG) signal, wherein the sensor comprises a PPG sensor, and wherein the monitor comprises a PPG monitor.

7. The system of claim 1, wherein the sensor comprises a pulse oximetry sensor, and wherein the monitor comprises a pulse oximetry monitor.

8. The system of claim 1, further comprising a fluid delivery device operatively connected to the monitor, wherein the monitor determines whether or not to administer fluid to a patient from the fluid delivery device based on the fluid responsiveness index.

9. A method for determining a fluid responsiveness index of a patient from a physiological signal, the method comprising:

securing a sensor to an anatomical portion of the patient;

sensing a physiological characteristic of the patient with the sensor;

receiving a physiological signal from the sensor at a monitor comprising an index-determining module; and

determining the fluid responsiveness index with the index-determining module, wherein the determining the fluid responsiveness index operation comprises forming a ratio of one or both of amplitude modulation or frequency modulation of the physiological signal with respect to baseline modulation of the physiological signal.

10. The method of claim 9, further comprising normalizing the fluid responsiveness index with a normalization module, the normalizing operation comprises correcting for changes in one or both of vascular tone or motion artifacts.

11. The method of claim 10, wherein the normalizing operation comprises normalizing the fluid responsiveness index based on one or more of a relative amplitude ratio of the physiological signal, a width of at least one primary peak of the physiological signal, a time difference between the at least one primary peak and at least one trailing peak, or a pleth modulation ratio of the physiological signal.

12. The method of claim 9, further comprising applying a calibration coefficient or constant to the ratio.

13. The method of claim 9, wherein the physiological signal comprises a photoplethysmogram (PPG) signal, wherein the sensor comprises a PPG sensor, and wherein the monitor comprises a PPG monitor.

14. The method of claim 9, further comprising determining whether or not to administer fluid to a patient from a fluid delivery device based on the fluid responsiveness index.

15. A tangible and non-transitory computer readable medium that includes one or more sets of instructions configured to direct a computer to:

receive a physiological signal from a sensor secured to an anatomical portion of a patient; and

determine a fluid responsiveness index of a patient by forming a ratio of one or both of amplitude modulation or frequency modulation of the physiological signal with respect to baseline modulation of the physiological signal.

16. The tangible and non-transitory computer readable medium of claim 15, further configured to direct the computer to normalize the fluid responsiveness index with a normalization module by correcting for changes in one or both of vascular tone or motion artifacts.

17. The tangible and non-transitory computer readable medium of claim 16, further configured to direct the computer to normalize the fluid responsiveness index based on one or more of a relative amplitude ratio of the physiological signal, a width of at least one primary peak of the physiological signal, a time difference between the at least one primary peak and at least one trailing peak, or a pleth modulation ratio of the physiological signal.

18. The tangible and non-transitory computer readable medium of claim 15, further configured to direct the computer to apply a calibration coefficient or constant to the ratio.

19. The tangible and non-transitory computer readable medium of claim 15, wherein the physiological signal comprises a photoplethysmogram (PPG) signal.

20. The tangible and non-transitory computer readable medium of claim 15, further configured to direct the computer to determine whether or not to administer fluid to a patient from a fluid delivery device based on the fluid responsiveness index.