SYSTEMS AND METHODS FOR MONITORING AND DISPLAYING RESPIRATORY INFORMATION

• US 20090301487A1
• Filed: 06/05/2009
• Published: 12/10/2009
• Est. Priority Date: 06/06/2008
• Status: Active Grant

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Masic, Milenko
• Granted Patent: US 8,485,184 B2
• Time in Patent Office: Days
• US Class Current: 128/204.210
• CPC Class Codes: A61B 5/08 Detecting, measuring or recording devices for evaluating the respiratory organs A61B5/0205 takes precedence
• CPC Class Codes: A61M 16/0003 Accessories therefor, e.g. sensors, vibrators, negative pressure
• CPC Class Codes: A61M 16/0051 with alarm devices
• CPC Class Codes: A61M 16/0057 Pumps therefor
• 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 16/12 by mixing different gases
• CPC Class Codes: A61M 2016/0015 inhalation detectors
• CPC Class Codes: A61M 2016/0018 electrical
• CPC Class Codes: A61M 2016/0027 pressure meter
• CPC Class Codes: A61M 2016/0036 in the breathing tube and used in both inspiratory and expiratory phase
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2016/0042 in the expiratory circuit
• CPC Class Codes: A61M 2205/3303 Using a biosensor
• CPC Class Codes: A61M 2205/50 with microprocessors or computers
• CPC Class Codes: G01F 1/00 Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow measuring a proportion of the volume flow G01F5/00
• CPC Class Codes: G01F 1/34 by measuring pressure or differential pressure

Abstract

Various embodiments of the present disclosure provide systems, methods and devices for respiratory support. As one example, a ventilation system is disclosed that includes a graphical display, a processor and a computer readable medium. The computer readable medium is communicably coupled to the processor and includes instructions executable by the processor to receive a measured pressure value, and receive a net flow value. The instructions are further executable to calculate a patient effort value based on a relationship between patient effort, the measured pressure value and the net flow value; and to plot the patient effort value to the graphical display.

Claims

1. A ventilation system, the ventilation system comprising:

a graphical display;

a processor communicably coupled to a computer readable medium, wherein the computer readable medium includes instructions executable by the processor to;

receive a measured pressure value;

receive a net flow value;

calculate a patient effort value based on a relationship between patient effort, the measured pressure value and the net flow value; and

plot the patient effort value to the graphical display.

2. The system of claim 1, wherein the patient effort value is an estimate of actual patient effort.

3. The system of claim 1, wherein the patient effort value is a first derivative of the actual patient effort.

4. The system of claim 1, wherein the patient effort value is a filtered patient effort.

5. The system of claim 1, wherein the instructions are further executable by the processor to:

calculate a mean time between breaths based on the patient effort value; and

display the mean time between breaths to the graphical display.

6. The system of claim 1, wherein the instructions are further executable by the processor to:

identify a peak breathing effort based on the patient effort value; and

display the peak breathing effort to the graphical display.

7. The system of claim 1, wherein the instructions are further executable by the processor to:

identify a peak effort for a particular breath based on one or more patient effort values calculated during the particular breath; and

display the peak effort for the particular breath to the graphical display.

8. The system of claim 1, wherein the instructions are further executable by the processor to:

calculate a duration of last inspiration based on the patient effort value; and

display the duration of last inspiration to the graphical display.

9. The system of claim 1, wherein the instructions are further executable by the processor to:

calculate a duration of last expiration based on the patient effort value; and

display the duration of last expiration to the graphical display.

10. The ventilation system of claim 1, wherein the patient effort value is further based on a combination of one or more intermediate values calculated using the measured pressure value and the net flow value, the one or more intermediate values selected from:

an estimated normalized prediction error (ε

), a filtered pressure value (z), a regression vector (φ

^T), and a current estimated value of a parameter vector (Θ

).

11. The ventilation system of claim 1, wherein the relationship is a parameterized system input to output relationship.

12. The method of claim 11, wherein the parameterized system input to output relationship is the regression form:

z=Θ

^Tφ

+φ

_d.

13. The method of claim 1, wherein the parameterized system input to output relationship is derived from a transfer function.

14. The ventilation system of claim 13, wherein the transfer function is derived from the model:

$\left[\begin{array}{c}{\stackrel{.}{p}}_Y\\ {\stackrel{.}{p}}_L\end{array}\right]=\left[\begin{array}{cc}-\frac{1}{C_T<br><br>R_P}& \frac{1}{C_T<br><br>R_P}\\ \frac{1}{C_L<br><br>R_P}& -\frac{1}{C_L<br><br>R_P}\end{array}\right][<br><br>\begin{array}{c}{p}_Y\\ p_L\end{array}]+\hspace{1em}<br><br>\left[\begin{array}{ccc}\frac{1}{C_T}& \frac{1}{C_T}& -\frac{1}{C_T}\\ 0& 0& 0\end{array}\right]<br><br>\left[\begin{array}{c}{q}_{\mathrm{AIR}}\\ q_{O<br><br><br><br>2}\\ q_E\end{array}\right]+\left[\begin{array}{ccc}0& -\frac{1}{C_T}& 0\\ 1& 0& -\frac{1}{C_T}\end{array}\right]<br><br>\left[\begin{array}{c}{\stackrel{.}{p}}_P\\ q_{\mathrm{Tleak}}\\ q_{\mathrm{Pleak}}\end{array}\right]$

15. A method for providing graphical respiratory feedback, the method comprising:

providing a graphical display;

measuring a pressure and providing a measured pressure;

measuring an inlet flow and an outlet flow, and providing a measured net flow;

using a relationship between a first value related to the measured pressure, a second value related to the measured net flow and a third value related to patient effort to calculate an estimate of patient effort from the measured pressure and measured net flow; and

repeatedly displaying the estimate of patient effort as a function of time via the graphical display.

16. The method of claim 15, wherein the estimate of patient effort is an estimate of actual patient effort for an associated time instant.

17. The method of claim 15, wherein the estimate of patient effort is an estimate of a first derivative of the actual patient effort for an associated time instant.

18. The method of claim 15, wherein the estimate of patient effort is a filtered actual patient effort.

19. The method of claim 15, wherein the method further comprises:

calculating various ventilation characteristics based on the estimate of patient effort, wherein the various ventilation characteristics are selected firom;

a mean time between breaths, a peak breathing effort, a peak effort for a particular breath, a duration of last inspiration, a duration of last expiration, an average duration of inspiration, and an average duration of expiration.

20. The method of claim 15, wherein the method further comprises:

graphically displaying various ventilation characteristics based on the estimate of patient effort, wherein the various ventilation characteristics are selected from;

a mean time between breaths, a peak breathing effort, a peak effort for a particular breath, a duration of last inspiration, a duration of last expiration, an average duration of inspiration, and an average duration of expiration.

21. The method of claim 15, wherein the relationship is defined by a parameterized system input to output relationship in the regression form z=Θ

^Tφ

+φ

_d, and wherein the input to output relationship is derived from a transfer function.

22. The method of claim 21 wherein the transfer function is derived from a model:

$\left[\begin{array}{c}{\stackrel{.}{p}}_Y\\ {\stackrel{.}{p}}_L\end{array}\right]=\left[\begin{array}{cc}-\frac{1}{C_T<br><br>R_P}& \frac{1}{C_T<br><br>R_P}\\ \frac{1}{C_L<br><br>R_P}& -\frac{1}{C_L<br><br>R_P}\end{array}\right][<br><br>\begin{array}{c}{p}_Y\\ p_L\end{array}]+\hspace{1em}<br><br>\left[\begin{array}{ccc}\frac{1}{C_T}& \frac{1}{C_T}& -\frac{1}{C_T}\\ 0& 0& 0\end{array}\right]<br><br>\left[\begin{array}{c}{q}_{\mathrm{AIR}}\\ q_{O<br><br><br><br>2}\\ q_E\end{array}\right]+\left[\begin{array}{ccc}0& -\frac{1}{C_T}& 0\\ 1& 0& -\frac{1}{C_T}\end{array}\right]<br><br>\left[\begin{array}{c}{\stackrel{.}{p}}_P\\ q_{\mathrm{Tleak}}\\ q_{\mathrm{Pleak}}\end{array}\right]$

23. A ventilation system, the ventilation system comprising:

a gas inlet;

a gas outlet;

a tube coupling the gas inlet and the gas outlet;

a pressure sensor, wherein the pressure sensor is operable to provide a measured pressure value indicating a pressure in the tube;

a first flow sensor, wherein the first flow sensor is operable to provide an inlet flow value indicating a flow associated with the gas inlet;

a second flow sensor, wherein the second flow sensor is operable to provide an outlet flow value indicating a flow associated with the gas outlet;

a graphical display; and

a processor communicably coupled to a computer readable medium, wherein the computer readable medium includes instructions executable by the processor to;

receive a measured pressure value;

receive a net flow value;

calculate a patient effort value based on a relationship between patient effort, the measured pressure value and the net flow value;

calculate a gas delivery metric that varies as a first function of the patient effort value;

determine an inhalation phase based on the patient effort value; and

plot the patient effort value to the graphical display.

24. A ventilation system, the ventilation system comprising:

a graphical display;

a processor communicably coupled to a computer readable medium, wherein the computer readable medium includes instructions executable by the processor to;

receive a measured pressure value;

receive a net flow value;

calculate an estimate of at least one respiratory parameter based on a relationship between the at least one respiratory parameter, patient effort, the measured pressure value and the net flow value; and

plot the at least one estimate to the graphical display.

25. The system of claim 24, wherein the at least one respiratory parameter is selected from:

a patient resistance parameter, a lung compliance parameter, a tubing compliance parameter, a patient effort parameter and a leakage parameter.

26. The system of claim 24, wherein the at least one respiratory parameter is a patient resistance parameter.

27. The system of claim 24, wherein the estimate of the at least one respiratory parameter corresponds to a first instance in time.

28. The system of claim 24, wherein the computer readable medium further includes instructions executable by the processor to:

display a numerical representation of the estimate of the at least one respiratory parameter via the graphical display.

29. The system of claim 24, wherein the computer readable medium further includes instructions executable by the processor to:

calculate an average value of the estimate of the at least one respiratory parameter over a predetermined period of time; and

display a numerical representation of the average value via the graphical display.

30. The system of claim 24, wherein the relationship is defined by a parameterized system input to output relationship in the regression form z=Θ

^Tφ

+φ

_d, and wherein the input to output relationship is derived from a transfer function.

31. The system of claim 30, wherein the transfer function is derived from the model:

$\left[\begin{array}{c}{\stackrel{.}{p}}_Y\\ {\stackrel{.}{p}}_L\end{array}\right]=\left[\begin{array}{cc}-\frac{1}{C_T<br><br>R_P}& \frac{1}{C_T<br><br>R_P}\\ \frac{1}{C_L<br><br>R_P}& -\frac{1}{C_L<br><br>R_P}\end{array}\right][<br><br>\begin{array}{c}{p}_Y\\ p_L\end{array}]+\hspace{1em}<br><br>\left[\begin{array}{ccc}\frac{1}{C_T}& \frac{1}{C_T}& -\frac{1}{C_T}\\ 0& 0& 0\end{array}\right]<br><br>\left[\begin{array}{c}{q}_{\mathrm{AIR}}\\ q_{02}\\ q_E\end{array}\right]+\left[\begin{array}{ccc}0& -\frac{1}{C_T}& 0\\ 1& 0& -\frac{1}{C_T}\end{array}\right]<br><br>\left[\begin{array}{c}{\stackrel{.}{p}}_P\\ q_{\mathrm{Tleak}}\\ q_{\mathrm{Pleak}}\end{array}\right].$