Automatic slope adjustment for bi-levelpressure support system

• US 20030127097A1
• Filed: 02/19/2003
• Published: 07/10/2003
• Est. Priority Date: 07/10/2000
• Status: Active Grant

• Current Assignee: RIC INVESTMENTS LLC (Koninklijke Philips N.V.)
• Original Assignee: RIC INVESTMENTS LLC (Koninklijke Philips N.V.)
• Inventors: Yurko, Gregory
• Granted Patent: US 6,640,806 B2
• Time in Patent Office: Days
• US Class Current: 128/204.23
• CPC Class Codes: A61M 16/0066 Blowers or centrifugal pumps
• CPC Class Codes: A61M 16/0069 the speed thereof being controlled by respiratory parameters, e.g. by inhalation
• CPC Class Codes: A61M 16/024 including calculation means, e.g. using a processor
• CPC Class Codes: A61M 16/06 Respiratory or anaesthetic masks
• CPC Class Codes: A61M 2016/0021 with a proportional output signal, e.g. from a thermistor
• CPC Class Codes: A61M 2016/0039 in the inspiratory circuit
• CPC Class Codes: A61M 2230/60 Muscle strain, i.e. measured on the user
• CPC Class Codes: A61M 2230/63 Motion, e.g. physical activity

Abstract

An apparatus and method for a bi-level positive airway pressure support in which the rise time from the expiratory positive airway pressure to the inspiratory positive airway pressure is automatically controlled by the pressure support system. The pressure support system includes a sensor, a control system, and a pressure generating system. The sensor monitors the patient'"'"'s respiration to detect respiratory events, such as an apnea, hyponea or other disturbance, and the control system responds to the sensor information to adjust the rise time from the expiratory positive airway pressure to the inspiratory positive airway pressure gas pressure to maximize patient comfort and pressure support treatment effectiveness.

Claims

1. A pressure support system comprising:

a pressure generating system adapted to produce a flow of breathing gas at an inspiratory positive airway pressure and an expiratory positive airway pressure that is less than the inspiratory positive airway pressure;

a conduit operatively coupled to the pressure generating system to deliver the flow of breathing gas to an airway of a patient;

a sensor adapted to detect a physiological condition of a patient receiving the flow of breathing gas; and

a processor receiving an output of the sensor and providing a control signal to the pressure generating system, wherein the processor executes an algorithm for controlling the pressure generating system so as to automatically adjust a rise time from the inspiratory positive airway pressure to the expiratory positive airway pressure based on the output of the sensor.

2. The pressure support system of claim 1, further comprising:

an input/output device operatively coupled to the processor; and

at least one timer operatively connected to the processor, wherein the processor determines whether to adjust the rise time from the inspiratory positive airway pressure to the expiratory positive airway pressure based on an output of the timer.

3. The pressure support system of claim 2, wherein the input/output device is used to set at least one of (1) a time interval during which the processor checks an output signal from the sensor to determine whether to adjust the rise time, (2) a number of apenic events that can occur in the time interval before the processor will adjust the rise time, and (3) an amount by which the rise time is incremented or decremented by the processor.

4. The pressure support system of claim 1, wherein the processor dynamically determines at least one of (1) a time interval during which the processor checks an output signal from the sensor to determine whether to adjust the rise time, (2) a number of apenic events that can occur in the time interval before the processor will adjust the rise time, and (3) an amount by which the rise time is incremented or decremented by the processor.

5. The pressure support system of claim 1, wherein the sensor is a flow sensor, a pressure sensor associated with the conduit, or both.

6. The pressure support system of claim 1, wherein the processor controls the pressure generating system so as to adjust a fall time from the expiratory positive airway pressure to the inspiratory positive airway pressure.

7. A pressure support system comprising:

pressure generating means for producing a flow of breathing gas at-an inspiratory positive airway pressure and an expiratory positive airway pressure that is less than the inspiratory positive airway pressure;

sensing means for detecting a physiological condition of a patient,receiving the flow of breathing gas; and

controlling means, operatively connected to the sensing means and the pressure generating means, for determining a rise time from the inspiratory positive airway pressure to the expiratory positive airway pressure based on an output of the sensing means and for controlling a change from the inspiratory positive airway pressure to the expiratory positive airway pressure based on the rise time.

8. The pressure support system of claim 7, wherein the controlling means includes a microprocessor.

9. The pressure support system of claim 7, wherein the controlling means includes a memory for storing a value of pressure support system variables.

10. The pressure support system of claim 7, further comprising:

inputting means, operatively coupled to the controlling means, for providing information thereto; and

timing means, operatively connected to the controlling means, wherein the controlling means determines whether to adjust the rise time from the inspiratory positive airway pressure to the expiratory positive airway pressure based on an output of the timing means.

11. The pressure support system of claim 7, wherein the sensing means comprises a flow sensor, a pressure sensor associated with the pressure generating means, or both.

12. The pressure support system of claim 7, wherein the controlling means dynamically determines at least one of (1) a time interval during which the controlling means checks an output signal from the sensing means to determine whether to adjust the rise time, (2) a number of apenic events that can occur in the time interval before the controlling means will adjust the rise time, and (3) an amount by which the rise time is incremented or decremented by the controlling means.

13. The pressure support system of claim 7, wherein the controlling means also controls the pressure generating means so as, to adjust a fall time from the expiratory positive airway pressure to the inspiratory positive airway pressure.

14. A method for automatically adjusting a rise time of a pressure support system, comprising:

producing a flow of breathing gas at an inspiratory positive airway pressure and an expiratory positive airway pressure that is less than the inspiratory positive airway pressure;

detecting a physiological condition of a patient receiving the flow of breathing gas;

determining a rise time from the inspiratory positive airway pressure to the expiratory positive airway pressure based on the physiological condition of such a patient; and

controlling a rate of change from the inspiratory positive airway pressure to the expiratory positive airway pressure based on the rise time.

15. The method according to claim 14, further including setting at least one of (1) a minimum allowed rise time, (2) a maximum allowed rise time, (3) an amount for each incremental change in rise time, and (4) an amount for each decremental change.

16. The method according to claim 14, further including dynamically determining at least one of (1) a time interval during which the physiological condition is checked, (2) a number of apenic events that can occur in the time interval before the rise time is adjusted, and (3) an amount by which the rise time is incremented or decremented.

17. The method according to claim 14, wherein the rise time is decreased responsive to detecting an apenic event of a patient.

18. The method according to claim 14, wherein the rise time is increased after a period of time in which no apenic events are detected.