Sensor Model

• US 20110146683A1
• Filed: 02/26/2010
• Published: 06/23/2011
• Est. Priority Date: 12/21/2009
• Status: Abandoned Application

• Current Assignee: Covidien LP (Medtronic Plc)
• Original Assignee: Nellcor Puritan Bennett LLC (Medtronic Plc)
• Inventors: Upham, Gail F., McCoy, Edward R., Jafari, Mehdi M., Jimenez, Rhomere S., Aviano, Jeffrey K., Rush, Russell P.
• Application Number:
  US12/713,483
• Publication Number:
  US 20110146683A1
• Time in Patent Office: Days
• US Class Current: 128/204.21
• CPC Class Codes: A61B 5/085 Measuring impedance of respiratory organs or lung elasticity
• CPC Class Codes: A61M 16/0063 Compressors
• 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 16/0833 T- or Y-type connectors, e.g. Y-piece
• CPC Class Codes: A61M 2016/0015 inhalation detectors
• 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 2205/17 with redundant control systems
• CPC Class Codes: A61M 2205/505 Touch-screens; Virtual keyboard or keypads; Virtual buttons; Soft keys; Mouse touches
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2205/702 automatically during use

Abstract

The disclosure describes a novel approach of utilizing a model-based approach for estimating a parameter at the wye without utilizing a sensor at the wye in the circuit proximal to the patient.

Claims

1. A method for estimating at least one parameter at a patient circuit wye in a medical ventilator providing ventilation to a patient, the method comprising:

monitoring at least one of ventilator settings, internal measurements, available hardware characteristics, and patient characteristics;

extracting respiratory mechanics of the patient from ventilator data by fitting a curve based on at least one of the ventilator settings, the internal measurements, the available hardware characteristics, and the patient characteristics, wherein said fitting relies on one or more fit parameters, and wherein the values of said one or more fit parameters are found by said fitting;

calculating a first estimate of at least one parameter at a patient circuit wye for a time interval with at least one sensor model based on at least one of the ventilator settings, the internal measurements, the available hardware characteristics, the patient characteristics, and the one or more fit parameters; and

displaying the first estimate of the at least one parameter at the patient circuit wye for the time interval.

2. The method of claim 1, wherein displaying further comprising:

displaying the first estimate of the at least one parameter at the patient circuit wye for the time interval when the at least one of the ventilator settings, the internal measurements, the available hardware characteristics, and the patient characteristics have a predetermined value.

3. The method of claim 1 further comprising:

displaying the first estimate of the at least one parameter at the patient circuit wye for the time interval only when the at least one of the ventilator settings, the internal measurements, the available hardware characteristics, and the patient characteristics do not have a predetermined value.

4. The method of claim 1 wherein the first estimate of the at least one parameter at the patient circuit wye estimate is flow rate.

5. The method of claim 1 wherein the first estimate of the at least one parameter at the patient circuit wye estimate is pressure.

6. The method of claim 1 wherein the sensor model utilizes the following equations (in time and frequency domains) for the step of calculating a first estimate of at least one parameter:

7. A pressure support system comprising:

a processor;

a pressure generating system adapted to generate a flow of breathing gas controlled by the processor;

a housing, the housing contains at least one of the processor and the pressure generating system;

at least one sensor, the at least one sensor located in the housing;

a ventilation system comprising a patient circuit controlled by the processor, the patient circuit comprising a wye with an inspiration limb and an expiration limb;

a patient interface, the patient interface connected to the patient circuit; and

a sensor model in communication with the processor, the sensor model is adapted to estimate at least one parameter at the wye based on at least one reading from the at least one sensor in the housing.

8. The pressure support system of claim 7, wherein the sensor model is controlled by the processor.

9. The pressure support system of claim 7, wherein the sensor model is controlled by a processor in the sensor model.

10. The pressure support system of claim 7, wherein the at least one parameter at the wye is flow rate.

11. The pressure support system of claim 7, wherein the at least one parameter at the wye is pressure.

12. The pressure support system of claim 7, wherein the sensor model is adapted to utilize the following model equations to estimate the at least one parameter at the wye:

13. The pressure support system of claim 7, further comprising a display controlled by the processor, the display is adapted to display the estimate of the at least one parameter at the wye.

14. A medical ventilator system, comprising:

a processor;

a patient circuit, the patient circuit comprising a wye with an inspiration limb and an expiration limb;

a patient interface, the patient interface connected to the patient circuit;

a gas regulator controlled by the processor, the gas regulator adapted to regulate a flow of gas from a gas supply to a patient via the patient circuit;

a ventilator housing, the ventilator housing contains at least one of the processor and the gas regulator;

at least one sensor, the at least one sensor located in the ventilator housing; and

a sensor model in communication with the processor, the sensor model is adapted to estimate at least one parameter at the wye based on at least one reading from the at least one sensor during ventilation of a patient by the medical ventilator.

15. The medical ventilator system of claim 14, wherein the sensor model is controlled by a processor in the sensor model.

16. The medical ventilator system of claim 14, wherein the sensor model is controlled by the ventilation system.

17. The medical ventilator system of claim 14, wherein the at least one parameter at the wye is flow rate.

18. The medical ventilator system of claim 14, wherein the at least one parameter at the wye is pressure.

19. The medical ventilator system of claim 14, wherein the sensor model is adapted to utilize the following model equations to estimate the parameter at the wye:

20. The medical ventilator system of claim 14, further comprising a display controlled by the processor, the display is adapted to display the estimate of the at least one parameter at the wye.