Photoplethysmography for determining ventilation weaning readiness

• US 8,801,619 B2
• Filed: 06/30/2011
• Issued: 08/12/2014
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Covidien LP (Medtronic Plc)
• Inventors: Baker, Clark R. Jr., Campbell, Shannon
• Primary Examiner(s): D'Angelo, Michael
• Assistant Examiner(s): WESTON, TIFFANY C
• Application Number:
  US13/174,421
• Publication Number:
  US 20130006075A1
• Time in Patent Office: 1,139 Days
• Field of Search: 600529-543, 128/204.18, 128/204.23, 128/204.21
• US Class Current: 600/483
• CPC Class Codes: A61B 5/02405 Determining heart rate variability
• 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 5/0816 Measuring devices for examining respiratory frequency measuring frequency of electric signals G01R23/00
• 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: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/026 specially adapted for predicting, e.g. for determining an information representative of a flow limitation during a ventilation cycle by using a root square technique or a regression analysis
• CPC Class Codes: A61M 2205/3313 used specific wavelengths
• CPC Class Codes: A61M 2205/502 User interfaces, e.g. screens or keyboards
• CPC Class Codes: A61M 2205/581 by audible feedback
• CPC Class Codes: A61M 2205/583 by visual feedback
• CPC Class Codes: A61M 2230/04 Heartbeat characteristics, e.g. ECG, blood pressure modulation
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/207 hematocrit
• CPC Class Codes: A61M 2230/42 Rate

Abstract

Embodiments of the present disclosure relate to a system and method for determining a likelihood of successful ventilator weaning for a patient undergoing mechanical or assisted ventilation. Specifically, embodiments provided herein include methods and systems for determining or predicting weaning readiness in a patient based on physiological parameters determined via photoplethysmography.

Claims

1. A monitor, comprising:

an input circuit configured to receive a photoplethysmography signal from a ventilated patient;

a memory storing an algorithm configured to determine one or more characteristics of the photoplethysmography signal indicative of a ventilation weaning readiness and to determine the ventilation weaning readiness of the ventilated patient based on the one or more characteristics, wherein the one or more characteristics comprise pulse amplitude, and wherein the algorithm is configured to determine weaning readiness based at least in part on an increase in pulse amplitude during an inspiration phase relative to an exhalation phase of a breathing cycle of the ventilated patient;

a processor configured to execute the algorithm; and

a display configured to provide an indication of the ventilation weaning readiness of the ventilated patient.

2. The monitor of claim 1, wherein the input circuit is configured to receive information related to the breathing cycle of the ventilated patient.

3. The monitor of claim 1, wherein the one or more characteristics of the photoplethysmography signal indicative of ventilation weaning readiness further comprises a pulse pressure, an intrathoracic pressure, a modulation of local blood volume at the ventilation rate, a stroke volume, a heart rate, a pulse transit time, or a combination thereof.

4. The monitor of claim 1, wherein the algorithm is configured to determine a lack of weaning readiness based at least in part on a decrease in pulse amplitude, pulse pressure, or heart rate during the inspiration phase relative to the exhalation phase.

5. The monitor of claim 1, wherein the one or more characteristics of the photoplethysmography signal indicative of ventilation weaning readiness further comprises a pulse amplitude variability, a pulse pressure variability, a modulation of local blood volume at the ventilation rate, a stroke volume variability, a heart rate variability, a pulse transit time, or combination thereof.

6. The monitor of claim 1, wherein the monitor comprises a weaning mode, wherein the algorithm is executed during the weaning mode and not executed when not in the weaning mode.

7. The monitor of claim 1, wherein the monitor comprises a baseline mode and wherein the algorithm is configured to determine a baseline characteristic of ventilation weaning readiness during the baseline mode.

10. The monitor of claim 1, wherein the algorithm is configured to determine weaning readiness based at least in part on a comparison of the one or more characteristics to a clinically-determined threshold.

11. The monitor of claim 1, wherein providing an indication of weaning readiness comprises providing a graphical representation of weaning readiness.

12. The monitor of claim 7, wherein the monitor is configured to enter the baseline mode in response to a user input.

8. A system for determining ventilation weaning readiness comprising:

a sensor configured to acquire photoplethysmography data from a ventilated patient and to generate a signal relating to the photoplethysmography data; and

a monitor configured to;

receive the signal;

determining a ventilation weaning readiness of the patient based at least in part on the signal; and

provide an indication of ventilation weaning readiness, wherein the indication of ventilation weaning readiness is based at least in part on an increased pulse amplitude during inspiration relative to exhalation.

9. The system of claim 8, wherein the indication of ventilation weaning readiness is based at least in part on an increased heart rate variability during inspiration relative to exhalation.

13. A system for determining ventilation weaning readiness, comprising:

a sensor configured to acquire photoplethysmography data from a ventilated patient and generate a signal relating to the photoplethysmography data; and

a monitor configured to;

receive the signal;

determine a ventilation weaning readiness of the patient based at least in part on the signal; and

provide an indication of the ventilation weaning readiness, wherein the indication of ventilation weaning readiness is based at least in part on a correlation between pulse amplitude modulation and respiration rate.

14. The system of claim 13, wherein the indication of ventilation weaning readiness is based at least in part on an increased pulse amplitude during inspiration relative to exhalation.

15. A system for determining ventilation weaning readiness, comprising:

a sensor configured to acquire photoplethysmography data from a ventilated patient and generate a signal relating to the photoplethysmography data; and

a monitor configured to;

receive the signal;

determine a ventilation weaning readiness of the patient based at least in part on the signal; and

provide an indication of the ventilation weaning readiness, wherein the indication of ventilation weaning readiness is based at least in part on an increased heart rate during inspiration relative to exhalation.

16. A monitor, comprising:

an input circuit configured to receive a photoplethysmography signal from a ventilated patient;

a memory storing an algorithm configured to determine one or more characteristics of the photoplethysmography signal indicative of a ventilation weaning readiness and to determine the ventilation weaning readiness of the ventilated patient based on the one or more characteristics, wherein the one or more characteristics comprise pulse pressure, and wherein the algorithm is configured to determine weaning readiness based at least in part on an increase in pulse pressure during an inspiration phase relative to an exhalation phase of a breathing cycle of the ventilated patient;

a processor configured to execute the algorithm; and

a display configured to provide an indication of the ventilation weaning readiness of the ventilated patient.

17. The monitor of claim 16, wherein the algorithm is configured to determine a lack of weaning readiness based at least in part on a decrease in pulse amplitude, pulse pressure, or heart rate during the inspiration phase relative to the exhalation phase.

18. A monitor, comprising:

an input circuit configured to receive a photoplethysmography signal from a ventilated patient;

a memory storing an algorithm configured to determine one or more characteristics of the photoplethysmography signal indicative of a ventilation weaning readiness and to determine the ventilation weaning readiness of the ventilated patient based on the one or more characteristics, wherein the one or more characteristics comprise heart rate, and wherein the algorithm is configured to determine weaning readiness based at least in part on an increase in heart rate during an inspiration phase relative to an exhalation phase of a breathing cycle of the ventilated patient;

a processor configured to execute the algorithm; and

a display configured to provide an indication of the ventilation weaning readiness of the ventilated patient.

19. A monitor, comprising:

an input circuit configured to receive a photoplethysmography signal from a ventilated patient;

a memory storing an algorithm configured to determine one or more characteristics of the photoplethysmography signal indicative of a ventilation weaning readiness and to determine the ventilation weaning readiness of the ventilated patient based on the one or more characteristics, wherein the one or more characteristics comprise pulse amplitude modulation and respiration rate, and wherein the algorithm is configured to determine weaning readiness based at least in part on a correlation between pulse amplitude modulation and respiration rate;

a processor configured to execute the algorithm; and

a display configured to provide an indication of the ventilation weaning readiness of the ventilated patient.

20. A monitor, comprising:

an input circuit configured to receive a photoplethysmography signal from a ventilated patient;

a memory storing an algorithm configured to determine one or more characteristics of the photoplethysmography signal indicative of a ventilation weaning readiness and to determine the ventilation weaning readiness of the ventilated patient based on the one or more characteristics, wherein the one or more characteristics comprise heart rate variability, and wherein the algorithm is configured to determine weaning readiness based at least in part on an increase in heart rate variability during an inspiration phase relative to an exhalation phase of a breathing cycle of the ventilated patient;

a processor configured to execute the algorithm; and

a display configured to provide an indication of the ventilation weaning readiness of the ventilated patient.