Device and method for automatically regulating supplemental oxygen flow-rate

• US 20060225737A1
• Filed: 04/12/2005
• Published: 10/12/2006
• Est. Priority Date: 04/12/2005
• Status: Abandoned Application

• Current Assignee: Mario Iobbi
• Original Assignee: Mario Iobbi
• Inventors: Iobbi, Mario
• Application Number:
  US10/907,693
• Publication Number:
  US 20060225737A1
• Time in Patent Office: Days
• US Class Current: 128/204.210
• 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 16/0677 Gas-saving devices therefor
• CPC Class Codes: A61M 16/101 using an oxygen concentrator
• CPC Class Codes: A61M 16/204 used for inhalation control
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2202/0007 introduced into the body
• CPC Class Codes: A61M 2202/0208 Oxygen
• CPC Class Codes: A61M 2202/03 Gases in liquid phase, e.g. cryogenic liquids
• CPC Class Codes: A61M 2230/06 Heartbeat rate only
• CPC Class Codes: A61M 2230/202 partial carbon oxide pressure, e.g. partial dioxide pressure (P-CO2)
• CPC Class Codes: A61M 2230/205 partial oxygen pressure (P-O2)
• CPC Class Codes: A61M 2230/42 Rate

Abstract

Device and method for limiting adverse events during supplemental oxygen therapy are disclosed. In the present invention, the oxygen flow between a patient and an oxygen source is controlled with a valve such as a proportional solenoid capable of constraining flow-rates within a continuous range. The flow-rate of oxygen is accurately controlled in a closed-loop with flow-rate measurements. Measures of a patient'"'"'s vital physiological statistics are used to automatically determine optimum therapeutic oxygen flow-rate. Controller signal filtering is disclosed to improve the overall response and stability. The control algorithm varies flow-rates to minimize disturbances in the patient feedback measurements.

Claims

1. A device for automatically regulating the flow-rate of supplemental oxygen during respiratory support comprising of:

a valve capable of a variable constraint to the flow-rate between an oxygen source and a patient, the valve is linked to a controller which determines the amount of constraint;

a sensor for measuring the oxygen flow-rate delivered to the patient as governed by said valve and configured to communicate this feedback measurement to the controller;

a sensor measuring at least one of a patient'"'"'s vital physiological statistics and configured to communicate this feedback measurement to the controller;

a signal filter to condition the controller feedback response;

a controller that varies the oxygen flow-rate to the patient based upon the feedback measurement from the patient, the controller determines the change in flow-rate using the differences between said patient feedback measurement and a predetermined target set-point, the oxygen flow-rate is accurately adjusted via a closed-loop control of the valve constraint with said feedback flow-rate measurement.

2. The device according to claim 1, wherein the patient sensor measures one or more of the following vital physiological statistics:

tissue or blood levels of O₂, tissue or blood levels of CO₂, respiratory rate, and heart rate.

3. The device according to claim 1, wherein the patient measurement is supplied via a pulse oximeter device.

4. The device according to claim 1, wherein the valve and flow-rate sensor can be combined into a single flow regulator.

5. The device according to claim 1, wherein the device is used in conjunction with any of the following oxygen sources:

concentrator, gas cylinder, liquid oxygen including continuous and demand delivery systems.

6. The device according to claim 1, wherein the flow-rate determined by the controller is subject to predetermined maximum and minimum limits, including a default value when an error is detected in the patient feedback measurement.

7. The device according to claim 1, further comprising a display unit that interacts with the controller to present and record controller operation.

8. A method for automatically regulating the flow-rate of supplemental oxygen during respiratory support comprising:

adjusting the flow of oxygen between a patient and an oxygen source with a valve capable of a variable flow-rate constraint, the amount of constraint determined by a controller;

measuring the oxygen flow-rate with a sensor between the patient and the oxygen source, and communicating this feedback measurement to the controller;

obtaining a measurement from a sensor regarding the patient'"'"'s vital physiological statistics, and communicating this feedback measurement to the controller;

signal filtering to condition the controller feedback response;

the controller varies the oxygen flow-rate based upon the feedback measurement from the patient, the controller determines the change in flow-rate using the differences between said patient feedback and a predetermined target set-point, the oxygen flow-rate is accurately adjusted via a closed-loop control of the constraint valve with said feedback flow-rate measurement.

9. The method according to claim 8, wherein the method is integrated into the oxygen source and adapted to automatically regulate flow-rate to the patient.

10. The method according to claim 8, wherein the patient sensor measures one or more of the following vital physiological statistics:

tissue or blood levels of O₂, tissue or blood levels of CO₂, respiratory rate, and heart rate.

11. The method according to claim 8, wherein the patient measurement is supplied via a pulse oximeter device.

12. The method according to claim 8, wherein the valve and flow-rate sensor can be combined into a single flow regulator.

13. The method according to claim 8, wherein the method is used in conjunction with any of the following oxygen sources:

concentrator, gas cylinder, liquid oxygen including continuous and demand delivery systems.

14. The method according to claim 8, wherein the flow-rate determined by the controller is subject to predetermined maximum and minimum limits, including a default value when an error is detected in the patient feedback measurement.

15. The method according to claim 8, wherein the signal filtering limits the operational bandwidth to improve controller response or stability.

16. The method according to claim 8, wherein the signal filtering acts on the patient feedback measurement between the sensor and the controller.

17. The method according to claim 8, wherein the signal filtering acts on the controller output signal between the controller and the valve.